阅读说明：本技术 车辆的控制装置 (Vehicle control device ) 是由 村松宗太郎 桥本阳介 于 2020-03-30 设计创作，主要内容包括：本发明的作为控制装置的姿态控制装置(40)具备：姿态控制部(42),在因向前轮(11)以及后轮(12)的制动力的施加而车辆停止在坡路的情况下,实施向制动装置(20)指示前轮制动力以及后轮制动力的减少,并向驱动装置(30)指示维持车辆的停止的范围内的车辆的驱动力的增大的姿态控制；以及制动增大指示部(43),在起因于姿态控制的实施的车辆的驱动力的增大结束后,实施向制动装置(20)指示前轮(11)以及后轮(12)中的至少一方的车轮的制动力的增大的制动增大控制。(An attitude control device (40) as a control device according to the present invention includes: an attitude control unit (42) that, when the vehicle stops on a sloping road due to the application of braking forces to the front wheels (11) and the rear wheels (12), performs attitude control that instructs the brake device (20) to reduce the front wheel braking force and the rear wheel braking force, and that instructs the drive device (30) to increase the driving force of the vehicle within a range in which the vehicle is kept stopped; and a brake increase instruction unit (43) that, after the increase in the driving force of the vehicle caused by the implementation of the attitude control has ended, implements brake increase control that instructs the brake device (20) to increase the braking force of at least one of the front wheels (11) and the rear wheels (12).)

1. A vehicle control device that controls a drive device and a brake device of a vehicle, comprising:

an attitude control unit that, when the vehicle is stopped on a slope due to application of braking forces to front wheels and rear wheels of the vehicle, performs attitude control that instructs the braking device to decrease the braking force of the front wheels and the braking force of the rear wheels and instructs the driving device to increase the driving force of the vehicle within a range in which the vehicle is kept stopped;

and a brake increase instruction unit configured to execute brake increase control for instructing the brake device to increase the braking force of at least one of the front wheels and the rear wheels after the increase of the driving force of the vehicle caused by the execution of the attitude control is completed.

2. The control device of the vehicle according to claim 1,

the drive device outputs a drive force to one of the front wheels and the rear wheels, but does not output a drive force to the other wheel,

in the case where the wheel from which the driving force is output from the driving device is the first wheel and the wheel from which the driving force is not output from the driving device is the second wheel,

the attitude control includes a first brake reduction instruction process of instructing the brake device to reduce the braking force of the first wheel, and a second brake reduction instruction process of instructing the brake device to reduce the braking force of the second wheel after the braking force of the first wheel is reduced by the driving of the brake device based on the execution of the first brake reduction instruction process.

3. The control device of the vehicle according to claim 2,

the attitude control includes a drive increase instruction process of instructing the drive device to increase the drive force of the vehicle,

in the above-described attitude control of the vehicle,

the attitude control unit starts the drive increase instruction processing after the start of the decrease in the braking force of the first wheel due to the drive of the brake device by the execution of the first brake decrease instruction processing,

after the first brake reduction instruction processing is ended and the increase in the driving force of the vehicle due to the driving of the driving device based on the execution of the drive increase instruction processing is started, the posture control unit starts the second brake reduction instruction processing.

4. The control device of the vehicle according to claim 3,

in the drive increase instruction processing during execution of the first brake reduction instruction processing, the attitude control unit instructs the drive device to increase the driving force of the vehicle so that a sum of an excess driving force, which is a value obtained by subtracting the braking force of the first wheel from the driving force of the vehicle, and the braking force of the second wheel is equal to or greater than a stop maintaining force, which is a force required to maintain the vehicle in a stop state while opposing the action of the gravity.

5. The control device of the vehicle according to claim 4,

in the drive increase instruction processing after the first brake decrease instruction processing is ended, the attitude control unit instructs the drive device to increase the drive force until the stop maintaining force.

6. The control device for a vehicle according to claim 3 to 5,

the brake increase control includes a first brake increase instruction process of instructing the brake device to increase the braking force of the first wheel and a second brake increase instruction process of instructing the brake device to increase the braking force of the second wheel,

in the above-described brake increase control,

the brake increase instructing unit starts the first brake increase instructing process after the decrease in the braking force of the first wheel by the driving of the brake device based on the execution of the first brake decrease instructing process is completed,

the brake increase instructing unit starts the second brake increase instructing process after the braking force of the second wheel is reduced by the driving of the brake device based on the execution of the second brake decrease instructing process.

7. The control device of the vehicle according to claim 6,

in the above-described brake increase control,

the brake increase instructing unit starts the second brake increase instructing process before the first brake increase instructing process,

the brake increase instructing unit may start the first brake increase instructing process after the decrease in the braking force of the first wheel by the driving of the brake device based on the execution of the first brake decrease instructing process is completed and after the increase in the braking force of the second wheel by the driving of the brake device based on the execution of the second brake increase instructing process is started.

8. The control apparatus of the vehicle according to claim 6 or 7,

a drive reduction instruction unit configured to execute drive reduction control for instructing the drive device to reduce the drive force of the vehicle after the increase in the drive force of the vehicle caused by the execution of the attitude control is completed,

in the drive reduction control, the drive reduction instruction unit instructs the drive device to reduce the drive force of the vehicle at a speed corresponding to an increase speed of the braking force when the braking force of the vehicle is increased by the drive of the brake device based on the execution of the brake increase control.

Technical Field

The present invention relates to a vehicle control device that controls a brake device and a drive device.

Background

Patent document 1 describes an example of a vehicle control device that stops a vehicle on an uphill road. In this control device, the driving force of the vehicle is reduced by controlling the driving device, and the braking force of the vehicle is increased by controlling the braking device, so that the vehicle is stopped on an uphill road.

Patent document 1: japanese patent laid-open publication No. 2018-90064

However, when the vehicle is braked, the vehicle may pitch toward a Nose dive (Nose dive) side. In this case, the front-rear direction position of at least one of the front wheel and the rear wheel may be changed by contraction of the suspension for the front wheel and extension of the suspension for the rear wheel, and the wheel base of the vehicle may be changed. When the application of the braking force to at least one of the wheels is continued, the operation of the suspension, which is to restore the contracted or expanded state of the suspension, is restricted by the frictional force between the wheel and the road surface and the braking force applied to the wheel, in other words, the displacement of the wheel, which is to return the position of the wheel in the front-rear direction to the original position, is restricted. Therefore, when the application of the braking force to each wheel is canceled when the vehicle is started, the restriction of the operation of the suspension is canceled, the state of the suspension is returned to the original state, and the front-rear direction position of the at least one wheel is returned to the original position. Thereby, the state of the change in the wheel base of the vehicle is eliminated. At this time, the posture of the vehicle may change abruptly due to the change in the wheel base. In addition, there are also cases where a sound is generated with a sudden change in the vehicle posture. Such a sudden change in the vehicle posture at the time of starting may cause the vehicle occupant to feel uncomfortable.

Disclosure of Invention

A vehicle control device for solving the above problems is a device for controlling a drive device and a brake device of a vehicle. The control device is provided with: an attitude control unit that, when the vehicle is stopped on a slope due to application of braking forces to front wheels and rear wheels of the vehicle, performs attitude control that instructs the braking device to decrease the braking force of the front wheels and the braking force of the rear wheels and instructs the driving device to increase the driving force of the vehicle within a range in which the vehicle is kept stopped; and a brake increase instruction unit configured to execute brake increase control for instructing the brake device to increase the braking force of at least one of the front wheels and the rear wheels after the increase of the driving force of the vehicle caused by the execution of the attitude control is completed.

According to the above configuration, when the vehicle stops on a slope due to the application of the braking forces to the front wheels and the rear wheels, the attitude control is performed. When an instruction based on the attitude control is input to the brake device and the drive device, the braking forces of the front wheels and the rear wheels are reduced. In addition, even if the braking force of the vehicle is reduced, the driving force of the vehicle is increased so as to maintain the stop of the vehicle. Thus, even if the wheel base of the vehicle changes due to the front-rear direction position displacement of at least one of the front wheels and the rear wheels when the vehicle is stopped, the front-rear direction position of the at least one of the front wheels and the rear wheels can be restored while maintaining the stop of the vehicle by performing the attitude control. That is, the wheel base can be restored while the vehicle is stopped. After the increase in the driving force for maintaining the vehicle at a stop is completed, the braking force of the vehicle is increased by the execution of the brake increasing control. Therefore, when the braking of the vehicle is released at the time of the subsequent vehicle start, a sudden change in the vehicle posture due to a change in the wheel base does not occur. Therefore, it is possible to suppress the discomfort given to the occupant of the vehicle at the time of starting the vehicle.

Drawings

Fig. 1 is a block diagram showing an attitude control device, a drive device, and a brake device as a control device of a vehicle of a first embodiment.

Fig. 2 is a schematic view of a vehicle mounted with the attitude control device.

Fig. 3 is a schematic diagram showing how the vehicle travels on an uphill road.

Fig. 4 is a schematic diagram showing how the vehicle stops on an uphill road.

Fig. 5 is a flowchart illustrating a processing routine executed by the attitude control device.

Fig. 6 is a flowchart illustrating a processing routine executed by the attitude control device.

Fig. 7 is a flowchart illustrating a processing routine for instructing a decrease in the braking force of the first wheel and an increase in the driving force of the vehicle.

Fig. 8 is a flowchart illustrating a processing routine for instructing an increase in the driving force of the vehicle.

Fig. 9 is a flowchart illustrating a processing routine for instructing a reduction in the braking force of the second wheel.

Fig. 10 is a flowchart illustrating a processing procedure for instructing an increase in the braking force of the second wheel and a decrease in the driving force of the vehicle.

Fig. 11 is a flowchart illustrating a processing procedure for instructing an increase in the braking force of the first wheel and a decrease in the driving force of the vehicle.

Fig. 12 (a) to (f) are timing charts in the first embodiment.

Fig. 13 (a) to (f) are timing charts in the first embodiment.

Fig. 14 is a flowchart illustrating a processing procedure for instructing an increase in the driving force of the vehicle in the second embodiment.

Fig. 15 (a) to (f) are timing charts in the second embodiment.

Fig. 16 (a) to (f) are timing charts in the third embodiment.

Fig. 17 (a) to (f) are timing charts in the modification.

Detailed Description

(first embodiment)

A first embodiment of a vehicle control device will be described below with reference to fig. 1 to 13.

Fig. 1 shows an attitude control device 40, a brake device 20, and a drive device 30 as an example of the control device of the present embodiment. The drive device 30 includes a power unit 31 and a drive control unit 32 that controls the power unit 31. The power unit 31 has at least one of an engine and an electric motor as a power source of the vehicle. The drive control unit 32 controls the power unit 31 to adjust the driving force DP of the vehicle. As shown in fig. 1 and 2, the power unit 31 outputs the driving force DP to the front wheels 11, but not to the rear wheels 12, among the plurality of wheels 11, 12 provided in the vehicle. That is, in the present embodiment, the front wheels 11 correspond to "first wheels", and the rear wheels 12 correspond to "second wheels".

As shown in fig. 1, the brake device 20 includes a brake actuator 21 and a brake control unit 22 that controls the brake actuator 21. As shown in fig. 1 and 2, the brake actuator 21 is configured to be able to independently control the braking force of the front wheel 11 and the braking force of the rear wheel 12. The braking force of the front wheels 11 is also referred to as "front wheel braking force BPF", and the braking force of the rear wheels 12 is also referred to as "rear wheel braking force BPR". The brake control unit 22 controls the brake actuator 21 to adjust the braking force BP of the vehicle. The braking force BP of the vehicle is the sum of the braking forces of all the wheels 11 and 12.

Referring to fig. 3 and 4, the change in the vehicle posture when the vehicle 10 decelerates and stops will be described.

As shown in fig. 3, when the vehicle 10 decelerates due to the application of braking forces to the front wheels 11 and the rear wheels 12, the vehicle 10 pitches toward the dive side. In this case, the front wheel suspension 13F, which is a suspension provided for the front wheels 11, contracts due to the pitching moment accompanying deceleration, and the rear wheel suspension 13R, which is a suspension provided for the rear wheels 12, extends. At the same time, due to the geometry of each suspension 13F, 13R, an anti-nodding force accompanying the application of braking force to the front wheels 11 is generated at the front portion of the vehicle body 16, and an anti-uplifting force accompanying the application of braking force to the rear wheels 12 is generated at the rear portion of the vehicle body 16. The Anti-nod (Anti-dive) force is a force that displaces the front portion of the vehicle body 16 upward. The Anti-floating (Anti-lift) force is a force that displaces the rear portion of the vehicle body 16 downward. When the vehicle 10 decelerates, frictional forces FF1 and FF2 act on the rear side of the vehicle 10, that is, the lower side of the slope, in the ground contact surfaces with the road surface on the wheels 11 and 12, as indicated by hollow arrows in fig. 3. The frictional force FF1 acting on the front wheel 11 and the ground contact surface with the road surface is referred to as "first ground contact frictional force FF 1", and the frictional force FF2 acting on the rear wheel 12 and the ground contact surface with the road surface is referred to as "second ground contact frictional force FF 2".

In the vehicle 10 shown in fig. 3, the front wheel suspension 13F is provided so that the position in the vehicle longitudinal direction X at the end portion of the front wheel suspension 13F on the front wheel 11 side is different from the position in the vehicle longitudinal direction X at the end portion of the front wheel suspension 13F on the vehicle body 16 side, and the end portion of the front wheel suspension 13F on the vehicle body 16 side serves as a fulcrum. Similarly, the position in the vehicle longitudinal direction X at the end portion of the rear wheel suspension 13R on the rear wheel 12 side is different from the position in the vehicle longitudinal direction X at the end portion of the rear wheel suspension 13R on the vehicle body 16 side, and the rear wheel suspension 13R is provided with the end portion of the rear wheel suspension 13R on the vehicle body 16 side as a fulcrum. Therefore, when the front wheel suspension 13F is displaced in the vertical direction as the front wheel suspension 13F contracts or the like as described above, the position of the front wheel 11 in the vehicle longitudinal direction X is different from the reference position of the front wheel 11. The reference position of the front wheel 11 is a position in the vehicle longitudinal direction X of the front wheel 11 when the front wheel suspension 13F is located at a position in the vertical direction in the stop reference state. As described above, when the rear wheel suspension 13R is displaced in the vertical direction as the rear wheel suspension 13R extends, the position of the rear wheel 12 in the vehicle longitudinal direction X is different from the reference position of the rear wheel 12. The reference position of the rear wheel 12 is a position in the vehicle longitudinal direction X of the rear wheel 12 when the rear wheel suspension 13R is located at a position in the vertical direction in the stop reference state.

The stop reference state is, for example, a state in which, when the vehicle 10 is stopped on a road surface on which the vehicle 10 is located at the present time, no force that is not generated during the stop is applied. That is, the so-called stop reference state when the vehicle 10 is stopped on an uphill road with an inclination α corresponds to, for example, a state in which the vehicle 10 is placed on a horizontal plate, a sufficient braking force is applied to the vehicle 10, and one of the plates in the front-rear direction is lifted from this state, and the inclination of the vehicle 10 in the front-rear direction is made to be the inclination α. The so-called stop reference state when the vehicle 10 is stopped on an uphill road with an inclination α corresponds to a state in which the vehicle 10 is stopped by increasing the braking force instantaneously to a magnitude sufficient to maintain the state in which the vehicle 10 is stopped at a timing at which the vehicle body speed VS becomes "0 (zero)" due to deceleration by gravity while the vehicle 10 is caused to travel on the uphill road with inertia with no application of both the braking force and the driving force.

When the position of at least one of the front wheels 11 and the rear wheels 12 in the vehicle longitudinal direction X is displaced from the reference position of the wheel, the wheelbase WBL of the vehicle is different from the reference wheelbase WBLB. The reference wheel base WBLB is a wheel base when the front wheel 11 is located at a reference position of the front wheel 11 and the rear wheel 12 is located at a reference position of the rear wheel 12. The form of each of the suspensions 13F and 13R shown in fig. 3 is an example, and any other form of suspension may be employed as the suspensions 13F and 13R as long as the position of the wheel in the vehicle longitudinal direction X is changed from the reference position during braking due to displacement of the suspension in the vertical direction or the like by braking.

When the vehicle 10 is stopped on an uphill road due to the application of the braking force to each of the wheels 11, 12, the gravity applied to the vehicle 10 acts on the vehicle 10 as a force to slide it down. Therefore, when the vehicle 10 is stopped on an uphill road, as shown by the hollow arrows in fig. 3, the ground contact surface friction forces FF1 and FF2 act on the front side of the vehicle 10, that is, the upper side of the slope, in the ground contact surfaces with the road surface on the wheels 11 and 12. That is, the orientation of the ground contact surface frictional forces FF1, FF2 changes before and after the vehicle 10 stops.

When the application of the braking force to the front wheels 11 is continued even after the vehicle 10 is stopped, the front wheels 11 are locked in a state in which the rotation is restricted by the front wheel braking force BPF. Thus, the displacement of the front wheel 11, which returns the position of the front wheel 11 in the vehicle longitudinal direction X to the reference position, is restricted by the influence of the first ground contact friction force FF1 between the front wheel 11 and the road surface and the front wheel braking force BPF. That is, the operation of the front wheel suspension 13F is restricted such that the vertical position of the front wheel suspension 13F is returned to the vertical position in the stop reference state. Similarly, when the application of the braking force to the rear wheels 12 is continued even after the vehicle 10 is stopped, the rear wheels 12 are in a locked state in which the rotation is restricted due to the rear wheel braking force BPR. Thus, the displacement of the rear wheel 12, which returns the position of the rear wheel 12 in the vehicle longitudinal direction X to the reference position, is restricted by the influence of the second ground contact friction force FF2 and the rear wheel braking force BPR between the rear wheel 12 and the road surface. That is, the operation of the rear wheel suspension 13R is restricted such that the vertical position of the rear wheel suspension 13R is returned to the vertical position in the stop reference state. The vertical positions of the suspensions 13F and 13R are vertical positions of the wheels 11 and 12 with respect to the vehicle body 16 in association with contraction and expansion of the suspensions 13F and 13R.

As shown in fig. 1, a vehicle 10 is provided with various sensors. Examples of the sensor include a wheel speed sensor 101 and a longitudinal acceleration sensor 102. The wheel speed sensor 101 is provided for each of the wheels 11 and 12. The wheel speed sensor 101 detects a wheel speed VW of the corresponding wheel 11, 12, and outputs a signal corresponding to the detected wheel speed VW as a detection signal. The longitudinal acceleration sensor 102 detects a longitudinal acceleration GX, which is an acceleration in the longitudinal direction X of the vehicle, and outputs a signal corresponding to the detected longitudinal acceleration GX as a detection signal.

The attitude control device 40 inputs a detection signal from the wheel speed sensor 101 and a detection signal from the front-rear acceleration sensor 102. The attitude control device 40 derives the vehicle body speed VS of the vehicle 10 from the wheel speeds VW of the wheels 11 and 12 based on the detection signals from the respective wheel speed sensors 101. Further, in the attitude control device 40, a value obtained by time-differentiating the vehicle body speed VS is derived as the vehicle body acceleration DVS of the vehicle.

The attitude control device 40 includes a slope determining unit 41, an attitude control unit 42, a brake increase instructing unit 43, and a drive decrease instructing unit 44 as functional units for adjusting the vehicle attitude when the vehicle 10 stops on a slope.

The slope determination unit 41 determines whether or not the road surface on which the vehicle 10 is stopped is an uphill road. That is, when the vehicle 10 is stopped, the slope determining unit 41 derives the road surface gradient θ, which is the gradient of the road surface, and performs determination based on the road surface gradient θ. For example, the slope determination unit 41 calculates a value obtained by subtracting the vehicle body acceleration DVS from the front-rear acceleration GX as the road surface slope θ. When the vehicle is stopped on an uphill road, the road surface gradient θ is a positive value because the front-rear acceleration GX is large compared to the vehicle body acceleration DVS. Therefore, when the road surface gradient θ is equal to or greater than the ascending road determination value θ Th1, the slope road determination unit 41 determines that the road surface is an ascending road. On the other hand, when the road surface gradient θ is less than the ascending road determination value θ Th1, the slope road determination unit 41 does not determine that the road surface is an ascending road.

When the vehicle 10 is stopped and the slope determining unit 41 determines that the road surface is an uphill road, the posture control unit 42 performs posture control. The attitude control is control for instructing the brake device 20 to decrease the front wheel braking force BPF and the rear wheel braking force BPR and instructing the drive device 30 to increase the driving force DP of the vehicle within a range in which the vehicle 10 is kept stopped. The attitude control includes a first brake reduction instruction process, a second brake reduction instruction process, a first drive increase instruction process, and a second drive increase instruction process. The start timing of each process and the contents of each process will be described later.

After the increase in the driving force DP of the vehicle caused by the posture control is completed, the brake increase instructing unit 43 performs brake increase control for instructing the brake device 20 to increase at least one of the front wheel braking force BPF and the rear wheel braking force BPR. In the present embodiment, the brake increase instructing unit 43 instructs the brake device 20 to increase both the front wheel braking force BPF and the rear wheel braking force BPR during the brake increase control. The brake increase control is a first brake increase instruction process and a second brake increase instruction process. The start timing of each process and the contents of each process will be described later.

After the increase in the driving force DP of the vehicle caused by the execution of the attitude control by the attitude control unit 42 is completed, the drive reduction instruction unit 44 executes drive reduction control for instructing the drive device 30 to reduce the driving force DP. The drive reduction control includes a first drive reduction instruction process and a second drive reduction instruction process. The start timing of each process and the contents of each process will be described later.

Next, a processing routine executed by the attitude control device 40 will be described with reference to fig. 5 to 11. A series of processing procedures shown in fig. 5 to 11 are repeatedly executed when the vehicle 10 is located on an uphill road.

First, a main processing routine shown in fig. 5 will be described.

In the present processing routine, a determination is made as to whether or not the vehicle 10 is stopped in step S11. For example, when vehicle body speed VS is "0 (zero)", it is determined that vehicle 10 is stopped, and when vehicle body speed VS is not "0 (zero)", it is not determined that vehicle 10 is stopped. If it is not determined that the vehicle 10 is stopped (S11: NO), the process proceeds to the next step S12. In step S12, the second instruction braking force BPTr2 at the current time is set as the second pre-stop braking force BP2 b. The second indication braking force BPTr2 is an indication value of the braking force of the second wheel. When the braking force BP of the vehicle 10 is adjusted by automatic braking, the instruction value of the braking force of the second wheel determined by the control device for automatic braking is set as the second instruction braking force BPTr 2. On the other hand, in the case where the braking force BP of the vehicle 10 is adjusted by the driver's braking operation, the braking force of the second wheel at the present time is set as the second instruction braking force BPTr 2. In the present embodiment, the rear wheel 12 corresponds to the second wheel, and therefore, as the second instruction braking force BPTr2, either one of the instruction value of the braking force of the rear wheel 12 at the current time and the rear wheel braking force BPR at the current time is set. If the second pre-stop braking force BP2b is set, the process moves to the next step S13.

In step S13, the in-control flag FLG1 and the control completion flag FLG2 are set to OFF (OFF), respectively. In addition, the stop counter CNTT and the step counter CNTS are reset to "0 (zero)", respectively. The during-control flag FLG1 is a flag that is set to ON (ON) when at least one of the attitude control, the brake increase control, and the drive decrease control is implemented. The control completion flag FLG2 is a flag that is set to on when all of the attitude control, the brake increase control, and the drive decrease control are completed. The stop counter CNTT is a counter updated to measure the start timing of attitude control. The step counter CNTS is a counter updated when various processes described later are switched. After that, the present processing routine is once ended.

On the other hand, if it is determined in step S11 that the vehicle 10 is stopped (YES), the process proceeds to next step S14. In step S14, a determination is made as to whether the control completion flag FLG2 is set to on. With the control completion flag FLG2 set to on, the attitude control, the brake increase control, and the drive decrease control are all completed. On the other hand, in the case where the control completion flag FLG2 is set to off, none of the attitude control, the brake increase control, and the drive reduction control is implemented, or at least one of the attitude control, the brake increase control, and the drive reduction control is implemented. When the control completion flag FLG2 is set to on (S14: YES), the present processing routine is temporarily ended. On the other hand, in the case where the control completion flag FLG2 is set to off (S14: NO), the process moves to the next step S15.

In step S15, a determination is made as to whether or not the flag FLG1 is set to on in control. In the case where the in-control flag FLG1 is set to on, at least one of the attitude control, the brake increase control, and the drive decrease control is being implemented. On the other hand, in the case where the in-control flag FLG1 is set to off, no attitude control, brake increase control, and drive decrease control are implemented. In the case where the in-control flag FLG1 is set to on (S15: YES), the process moves to the next step S16.

In step S16, it is determined whether or not there is an instruction to start the vehicle 10. When the vehicle 10 is caused to travel by the automated driving, a start instruction is input from the control device for the automated driving to the posture control device 40. Therefore, when a start instruction is input to the posture control device 40, it is determined that the start instruction is present. On the other hand, when the vehicle 10 is caused to travel by a manual operation of the driver, it is determined that there is a start instruction when the start of the accelerator operation is detected. The presence of the start instruction may be determined when a sudden release of the brake operation is detected. If it is not determined that the start instruction is present (NO in S16), the process proceeds to step S23, which will be described later. That is, the control in the implementation is continued.

On the other hand, if it is determined that the start instruction is present (YES at S16), the process proceeds to the next step S17. In step S17, "0 (zero)" is set as the first instructed driving force DPTr1 that is the instruction value of the driving force input to the first wheel. In the present embodiment, the front wheels 11 correspond to the first wheels, and therefore the first instructed driving force DPTr1 is an instructed value of the driving force input to the front wheels 11. Then, the process proceeds to step S13 described above.

On the other hand, in step S15, in the case where the flag FLG1 is set to off in control (NO), the process moves to the next step S18. In step S18, the counter CNTT is stopped from self-adding "1". Next, in step S19, a determination is made as to whether or not the stop counter CNTT updated in step S18 is larger than the control start determination value cntth. The control start determination value cntth is set as a determination criterion whether or not to permit the start of the attitude control based on the magnitude of the stop counter CNTT corresponding to the duration of the state in which the vehicle 10 is stopped. When the stop counter CNTT is equal to or less than the control start determination value cntth (S19: NO), the present processing routine is once ended. That is, the attitude control is not started.

On the other hand, when the stop counter CNTT is larger than the control start determination value cntth (S19: YES), the process proceeds to the next step S20. In step S20, the in-control flag FLG1 is set to on, and the step counter CNTS is self-incremented by "1". Next, in step S21, the stop holding force Fh is derived. The stop holding force Fh is a force required to maintain the vehicle 10 in a stopped state on an uphill road. That is, the stop holding force Fh is a force required to maintain the stop of the vehicle 10 against the action of gravity. The stop holding force Fh is derived based on the road surface gradient θ of the uphill road on which the vehicle 10 is stopped. Specifically, the stop holding force Fh increases as the road surface gradient θ increases. Then, in step S22, the first instruction braking force BPTr1 at the present time is set to the first previous braking force value BP1a, the second instruction braking force BPTr2 at the present time is set to the second previous braking force value BP2a, and the first instruction driving force DPTr1 at the present time is set to the first previous driving force value DP1 a. The first indicated braking force BPTr1 is an indicated value of the braking force of the first wheel. In the present embodiment, the front wheels 11 correspond to the first wheels, and therefore the first command braking force BPTr1 sets either one of the command value for the braking force of the front wheels 11 and the front wheel braking force BPF at the current time. Then, if the processing of step S22 is completed, the processing moves to the next step S23.

In step S23, a process for adjusting the braking/driving force is executed. This processing will be described later. Then, when this processing is executed, the present processing routine is once ended.

Next, the processing of step S23 will be described with reference to fig. 6.

In the present processing routine, in step S31, it is determined whether or not the step counter CNTS is "1". If it is determined that step counter CNTS is "1" (S31: YES), the process proceeds to the next step S32. In step S32, the attitude control unit 42 executes a first braking reduction instruction process and a first driving increase instruction process of the attitude control. The first braking reduction instruction processing is processing for instructing the braking control unit 22 to reduce the braking force of the first wheel. The first drive increase instruction processing is processing for instructing the drive control portion 32 to increase the driving force of the first wheel, that is, the driving force DP of the vehicle 10. This first drive increase instruction processing is one of the drive increase instruction processing that instructs the drive device 30 of an increase in the drive force DP of the vehicle 10 in the range in which the stop of the vehicle 10 is maintained. The first brake reduction instruction processing and the first drive increase instruction processing will be described in detail later. When the first braking reduction instruction processing and the first driving increase instruction processing are executed, the present processing routine is ended.

If it is not determined in step S31 that step counter CNTS is "1" (NO), the process proceeds to next step S33. In step S33, a determination is made as to whether or not the step counter CNTS is "2". If it is determined that the step counter CNTS is "2" (S33: YES), the process proceeds to the next step S34. In step S34, the posture control unit 42 executes a second drive increase instruction process of the posture control. The second drive increase instruction process is a process of instructing the drive control unit 32 to increase the driving force DP of the vehicle 10, which is the driving force of the first wheel. That is, the second drive increase instruction processing is also one of the drive increase instruction processing. The second drive increase instruction processing will be described later in detail. When the second drive increase instruction processing is executed, the present processing routine is ended.

If it is not determined in step S33 that step counter CNTS is "2" (NO), the process proceeds to next step S35. In step S35, a determination is made as to whether or not the step counter CNTS is "3". If it is determined that step counter CNTS is "3" (S35: YES), the process proceeds to next step S36. In step S36, the attitude control unit 42 executes a second braking reduction instruction process of the attitude control. The second braking reduction instruction processing is processing for instructing the braking control unit 22 to reduce the braking force of the second wheel. The second braking reduction instruction processing will be described later in detail. When the second braking reduction instruction processing is executed, the present processing routine is ended.

If it is not determined in step S35 that step counter CNTS is "3" (NO), the process proceeds to next step S37. In step S37, a determination is made as to whether or not the step counter CNTS is "4". If it is determined that the step counter CNTS is "4" (S37: YES), the process proceeds to the next step S38. In step S38, the brake increase instructing unit 43 executes the second brake increase instructing process of the brake increase control, and the drive decrease instructing unit 44 executes the first drive decrease instructing process of the drive decrease control. The second brake increase instruction processing is processing for instructing the brake control unit 22 to increase the braking force of the second wheel. The first drive reduction instruction process is a process of instructing the drive control unit 32 to reduce the drive force of the first wheel. The second brake increase instruction processing and the first drive reduction instruction processing will be described in detail later. When the second brake increase instruction processing and the first drive decrease instruction processing are executed, the present processing routine is ended.

In step S37, if it is not determined that the step counter CNTS is "4" (NO), the step counter CNTS is "5", and therefore the process proceeds to the next step S39. In step S39, the brake increase instructing unit 43 executes a first brake increase instructing process of the brake increase control, and the drive decrease instructing unit 44 executes a second drive decrease instructing process of the drive decrease control. The first brake increase instruction processing is processing for instructing the brake control unit 22 to increase the braking force of the first wheel. The second drive reduction instruction process is a process of instructing the drive control unit 32 to reduce the drive force of the first wheel. The specific contents of the first brake increase instruction processing and the second drive decrease instruction processing will be described later. When the first brake increase instruction processing and the second drive decrease instruction processing are executed, the present processing routine is ended.

Next, the first braking reduction instruction processing and the first driving increase instruction processing in step S32 described above will be described with reference to fig. 7. The present processing program is executed by the posture control unit 42.

In the present processing routine, a first braking reduction instruction process is executed. In the first brake reduction instruction processing, in the first step S51, the value obtained by subtracting the first brake reduction amount Δ BP1 from the previous value BP1a of the above-described first braking force is calculated as the latest first instruction braking force BPTr 1. The first braking reduction amount Δ BP1 is set to a positive value. Next, in step S52, it is determined whether or not the first instruction braking force BPTr1 calculated in step S51 is "0 (zero)" or less. If the first instructed braking force BPTr1 is "0 (zero)" or less (S52: YES), the process proceeds to the next step S53. In step S53, "0 (zero)" is set as the first instruction braking force BPTr1, and the step counter CNTS self-increments "1". That is, the step counter CNTS is "2". Then, the process moves to the next step S54. On the other hand, in step S52, in the case where the first instruction braking force BPTr1 is large compared with "0 (zero)" (NO), the process moves to the next step S54. That is, the step counter CNTS remains "1".

In step S54, an output process of outputting the first and second instruction braking forces BPTr1 and BPTr2 to the brake device 20 is performed. While the present process routine is being repeatedly executed, the first instruction braking force BPTr1 output to the brake device 20 continues to decrease. Therefore, outputting the first instructed braking force BPTr1 to the brake device 20 by executing the present processing routine corresponds to instructing the brake device 20 of a decrease in the braking force of the first wheel. Then, the executed process shifts from the first braking reduction instruction process to the first driving increase instruction process.

When the first and second command braking forces BPTr1 and BPTr2 are input as a result of execution of the output process, the brake control unit 22 controls the brake actuator 21 such that the braking force of the first wheel follows the first command braking force BPTr1 and the braking force of the second wheel follows the second command braking force BPTr 2. In the first brake reduction instruction process, the first instruction braking force BPTr1 is reduced while the second instruction braking force BPTr2 is maintained. Therefore, by inputting an instruction based on the execution of the first brake reduction instruction processing to the brake control unit 22, the braking force of the second wheel can be maintained, and the braking force of the first wheel can be reduced at a speed corresponding to the first brake reduction amount Δ BP 1.

In the first drive increase instruction processing, at the beginning of step S55, it is determined whether or not the sum of the first instruction braking force BPTr1 and the previous value BP2a of the second braking force is equal to or greater than the stop holding force Fh. In the case where the sum is equal to or greater than the stop maintaining force Fh, the stop of the vehicle 10 can be maintained by making the braking force of the first wheel equal to the first instruction braking force BPTr 1. On the other hand, in the case where the sum is insufficient for the stop maintaining force Fh, it may not be possible to maintain the stop of the vehicle 10 even if the braking force of the first wheel is made equal to the first instruction braking force BPTr 1.

If the sum of the first indicated braking force BPTr1 and the previous value BP2a of the second braking force is equal to or greater than the stop maintaining force Fh (S55: YES), the process proceeds to the next step S56. In step S56, "0 (zero)" is set as the first instructed driving force DPTr 1. Then, the process proceeds to step S58 described later. On the other hand, in the case where the sum is less than the stop holding force Fh (S55: NO), the process proceeds to the next step S57. In step S57, the value of the stop holding force Fh subtracted from the sum is calculated as the first indicated driving force DPTr 1. Since the first commanded braking force BPTr1 decreases if the present processing routine is repeatedly executed, the sum of the first commanded braking force BPTr1 and the previous value BP2a of the second braking force gradually decreases. Therefore, in the first drive increase instructing process, the first instructed driving force DPTr1 is increased at a speed corresponding to the reduction speed of the first instructed braking force BPTr 1. Then, the process moves to the next step S58.

In step S58, an output process of outputting the first instructed driving force DPTr1 to the drive device 30 is performed. While the present process routine is repeatedly executed, the first instruction driving force DPTr1 output to the drive device 30 continues to increase. Therefore, outputting the first instructed driving force DPTr1 to the drive device 30 by executing the present processing corresponds to instructing the drive device 30 of an increase in the driving force DP of the vehicle 10.

Further, when the first instructed driving force DPTr1 is input due to the execution of the output process, the drive control section 32 controls the power unit 31 so that the driving force DP follows the first instructed driving force DPTr 1. This can increase the driving force DP of the vehicle 10 within a range in which the stop of the vehicle 10 can be maintained.

If the output processing is executed, the processing moves to the next step S59. In step S59, similarly to step S22 described above, the first instruction braking force BPTr1 at the current time is set to the previous value BP1a of the first braking force, the second instruction braking force BPTr2 at the current time is set to the previous value BP2a of the second braking force, and the first instruction driving force DPTr1 at the current time is set to the previous value DP1a of the first driving force. After that, the present processing routine is ended.

When the present process routine is ended in a state where the step counter CNTS is "1", the first brake reduction instruction process and the first drive increase instruction process are respectively continued. On the other hand, when the present process routine is ended in a state where the step counter CNTS is "2", the first braking reduction instruction process and the first driving increase instruction process are ended, respectively.

Next, the second drive increase instruction processing of step S34 described above will be described with reference to fig. 8. The present processing program is executed by the posture control unit 42.

In the present processing procedure, in step S71, the sum of the above-described first driving force previous value DP1a and the first drive increase amount Δ DP1 is calculated as the latest first instructed driving force DPTr 1. As the first drive increase amount Δ DP1, a positive value derived from the design specification of the power unit 31 is set. Next, in step S72, it is determined whether or not the first instruction driving force DPTr1 calculated in step S71 is equal to or greater than the stop holding force Fh. When the first instructed driving force DPTr1 is equal to or greater than the stop holding force Fh, the vehicle 10 may start when the braking force BP of the vehicle 10 is "0 (zero)". Therefore, when the first instruction driving force DPTr1 is equal to or greater than the stop holding force Fh (S72: YES), the process proceeds to the next step S73. In step S73, the stop holding force Fh is set as the first instruction driving force DPTr1, and the step counter CNTS self-increments by "1". That is, the step counter CNTS is "3". Then, the process moves to the next step S74.

On the other hand, in step S72, in the case where the first instructed driving force DPTr1 is insufficient for the stop maintaining force Fh (NO), the process moves to the next step S74. That is, the step counter CNTS remains "2".

In step S74, an output process of outputting the first instructed driving force DPTr1 to the drive device 30 is performed. While the present process routine is repeatedly executed, the first instruction driving force DPTr1 output to the drive device 30 continues to increase. Therefore, outputting the first instructed driving force DPTr1 to the drive device 30 by executing the present processing corresponds to instructing the drive device 30 of an increase in the driving force DP of the vehicle 10.

When the first instructed driving force DPTr1 is input due to the execution of the output process, the drive control unit 32 controls the power unit 31 so that the driving force DP follows the first instructed driving force DPTr 1. This allows the driving force DP of the vehicle to be increased at a speed corresponding to the first drive increase amount Δ DP 1.

If the output processing is executed, the processing moves to the next step S75. In step S75, similarly to step S22 described above, the first instruction braking force BPTr1 at the current time is set to the previous value BP1a of the first braking force, the second instruction braking force BPTr2 at the current time is set to the previous value BP2a of the second braking force, and the first instruction driving force DPTr1 at the current time is set to the previous value DP1a of the first driving force. After that, the present processing routine is ended.

When the present processing routine is ended in a state where the step counter CNTS is "2", the second drive increase instruction processing is continued. On the other hand, when the present processing routine is ended in a state where the step counter CNTS is "3", the second drive increase instruction processing is ended.

Next, the second braking reduction instruction processing of step S36 described above will be described with reference to fig. 9. The present processing program is executed by the posture control unit 42.

In the present processing routine, in step S91, the value obtained by subtracting the second braking reduction amount Δ BP2 from the second braking force previous value BP2a described above is calculated as the latest second indication braking force BPTr 2. The second braking reduction amount Δ BP2 is set to a positive value. The second braking reduction amount Δ BP2 may be the same as the first braking reduction amount Δ BP1, may be smaller than the first braking reduction amount Δ BP1, or may be larger than the first braking reduction amount Δ BP 1. Next, in step S92, it is determined whether or not the second instruction braking force BPTr2 calculated in step S91 is equal to or less than "0 (zero)". If the second indication braking force BPTr2 is equal to or less than "0 (zero)" (S92: YES), the process proceeds to the next step S93. In step S93, "0 (zero)" is set as the second instruction braking force BPTr2, and the step counter CNTS self-increments "1". That is, the step counter CNTS is "4". Then, the process moves to the next step S94. On the other hand, in step S92, in the case where the second instruction braking force BPTr2 is large compared with "0 (zero)" (NO), the process moves to the next step S94. That is, the step counter CNTS remains "3".

In step S94, an output process of outputting the first and second instruction braking forces BPTr1 and BPTr2 to the brake device 20 and the first instruction driving force DPTr1 to the drive device 30 is performed. While the present process routine is repeatedly executed, the second instruction braking force BPTr2 output to the brake device 20 continues to decrease. Therefore, outputting the second instruction braking force BPTr2 to the brake device 20 by executing the present processing routine corresponds to instructing the brake device 20 of a decrease in the braking force of the second wheel.

When the first and second command braking forces BPTr1 and BPTr2 are input as a result of execution of the output process, the brake control unit 22 controls the brake actuator 21 such that the braking force of the first wheel follows the first command braking force BPTr1 and the braking force of the second wheel follows the second command braking force BPTr 2. In the second brake-reduction instructing process, the first instruction braking force BPTr1 is maintained, and the second instruction braking force BPTr2 is reduced. Therefore, by inputting an instruction based on the execution of the second brake reduction instruction process to the brake control unit 22, the braking force of the second wheel can be reduced at a speed corresponding to the second brake reduction amount Δ BP2 while maintaining the braking force of the first wheel. In addition, the first instructed driving force DPTr1 is not changed during execution of the second braking reduction instruction processing. Therefore, the driving force DP of the vehicle 10 is maintained by inputting the instruction based on the execution of the second braking reduction instruction process to the drive control portion 32.

If the output processing is executed, the processing moves to the next step S95. In step S95, similarly to step S22 described above, the first instruction braking force BPTr1 at the current time is set to the previous value BP1a of the first braking force, the second instruction braking force BPTr2 at the current time is set to the previous value BP2a of the second braking force, and the first instruction driving force DPTr1 at the current time is set to the previous value DP1a of the first driving force. After that, the present processing routine is ended.

When the present processing routine is ended in a state where step counter CNTS is "3", the second brake reduction instruction processing is continued. On the other hand, when the present processing routine is ended in a state where the step counter CNTS is "4", the second brake reduction instruction processing is ended.

Next, the second brake increase instruction processing and the first drive decrease instruction processing in step S38 will be described with reference to fig. 10.

In the present processing routine, the second brake increase instruction processing is executed by the brake increase instruction unit 43. In the second brake increase instruction processing, in the first step S111, the sum of the above-described second previous braking force value BP2a and the second brake increase amount Δ BP21 is calculated as the latest second instruction braking force BPTr 2. The second brake increase amount Δ BP21 is set to a positive value. Next, in step S112, it is determined whether or not the second instruction braking force BPTr2 calculated in step S111 is equal to or greater than the second target braking force BPS 2. As the second target braking force BPS2, for example, the braking force of the second wheel at the start time of the attitude control is set or a value slightly larger than the braking force. Alternatively, as the second target braking force BPS2, a braking force corresponding to the brake operation by the driver at the present time, a braking force set by the control device for automatic braking, or the like may be set. If the second instruction braking force BPTr2 is equal to or greater than the second target braking force BPS2 (S112: YES), the process proceeds to the next step S113. In step S113, the second target braking force BPS2 is set as the second instruction braking force BPTr2, and the step counter CNTS self-increments by "1". That is, the step counter CNTS is "5". Then, the process moves to the next step S114.

On the other hand, in step S112, in the case where the second instruction braking force BPTr2 is insufficient for the second target braking force BPS2 (NO), the process moves to the next step S114. That is, the step counter CNTS remains "4".

In step S114, an output process of outputting the first and second instruction braking forces BPTr1 and BPTr2 to the brake device 20 is performed. While the present process routine is repeatedly executed, the second instruction braking force BPTr2 output to the brake device 20 continues to increase. Therefore, outputting the second instruction braking force BPTr2 to the brake device 20 by executing the present processing routine corresponds to instructing the brake device 20 of an increase in the braking force of the second wheel. Then, the executed process shifts from the second brake increase instruction process to the first drive decrease instruction process.

When the first and second command braking forces BPTr1 and BPTr2 are input by execution of the output process, the brake control unit 22 controls the brake actuator 21 such that the braking force of the first wheel follows the first command braking force BPTr1 and the braking force of the second wheel follows the second command braking force BPTr 2. In the second brake increase instruction process, the first instruction braking force BPTr1 is held, and the second instruction braking force BPTr2 is increased. Therefore, by inputting an instruction based on the execution of the second brake increase instruction processing to the brake control unit 22, the braking force of the first wheel can be increased at a speed corresponding to the second brake increase amount Δ BP21 while maintaining the braking force of the first wheel.

The first drive reduction instruction processing is executed by the drive reduction instruction section 44. In the first drive reduction instruction processing, in step S115, it is determined whether or not the sum of the previous value BP1a of the first braking force and the second instruction braking force BPTr2 is equal to or greater than the stop holding force Fh. If the sum of the stop maintaining force Fh and the shortage of the stop maintaining force Fh is not reduced, the vehicle 10 may start without reducing the driving force DP of the vehicle 10. In the case where the sum is less than the stop holding force Fh (S115: NO), the process proceeds to the next step S116. In step S116, the value obtained by subtracting the sum from the stop holding force Fh is calculated as the first instructed driving force DPTr 1. If the present processing routine is repeatedly executed, the second indication braking force BPTr2 increases, and therefore the sum of the previous value BP1a of the first braking force and the second indication braking force BPTr2 becomes large. As a result, the first instruction driving force DPTr1 decreases at a speed corresponding to the increase speed of the second instruction braking force BPTr 2. Then, the process proceeds to step S118 described later.

On the other hand, in step S115, if the sum of the previous first braking force value BP1a and the second instruction braking force BPTr2 is equal to or greater than the stop holding force Fh (YES), the process proceeds to next step S117. In step S117, "0 (zero)" is set as the first instructed driving force DPTr 1. Then, the process moves to the next step S118.

In step S118, an output process of outputting the first instructed driving force DPTr1 to the drive device 30 is performed. While the present process routine is repeatedly executed, the first instruction driving force DPTr1 output to the drive device 30 continues to decrease. Therefore, outputting the first instructed driving force DPTr1 to the drive device 30 by executing the present processing corresponds to instructing the drive device 30 of a decrease in the driving force DP of the vehicle 10.

When the first instructed driving force DPTr1 is input by the execution of the output process, the drive control unit 32 controls the power unit 31 so that the driving force DP of the vehicle 10 follows the first instructed driving force DPTr 1. In the first drive reduction instruction processing, the first instruction driving force DPTr1 is reduced. Therefore, by inputting an instruction based on the execution of the first drive reduction instruction process to the drive control portion 32, the driving force DP of the vehicle 10 can be reduced.

If the output processing is executed, the processing moves to the next step S119. In step S119, as in step S22, the first instruction braking force BPTr1 at the current time is set to the first previous braking force value BP1a, the second instruction braking force BPTr2 at the current time is set to the second previous braking force value BP2a, and the first instruction driving force DPTr1 at the current time is set to the first previous driving force value DP1 a. After that, the present processing routine is ended.

When the present process routine is ended in the state where the step counter CNTS is "4", the second brake increase instruction process and the first drive decrease instruction process are respectively continued. On the other hand, when the present process routine is ended in a state where the step counter CNTS is "5", the second brake increase instruction process and the first drive decrease instruction process are ended, respectively.

Next, the first brake increase instruction processing and the second drive decrease instruction processing in step S39 will be described with reference to fig. 11.

In the present processing routine, the first brake increase instruction processing is executed by the brake increase instruction unit 43. In the first brake increase instructing process, in the first step S131, the sum of the first braking force previous value BP1a and the first brake increase amount Δ BP11 is calculated as the first instructed braking force BPTr 1. The first brake increase amount Δ BP11 is set to a positive value. Next, in step S132, it is determined whether or not the first command braking force BPTr1 calculated in step S131 is equal to or greater than the first target braking force BPS 1. As the first target braking force BPS1, for example, the braking force of the first wheel at the start time of the attitude control is set or a value slightly larger than the braking force. Alternatively, as the first target braking force BPS1, a braking force corresponding to a brake operation by the driver at the present time, a braking force set by a control device for automatic braking, or the like may be set. If the first instructed braking force BPTr1 is equal to or greater than the first target braking force BPS1 (S132: YES), the process proceeds to the next step S133. On the other hand, when the first command braking force BPTr1 is less than the first target braking force BPS1 (S132: NO), the process proceeds to step S134, which will be described later.

In step S133, the first target braking force BPS1 is set as the first instruction braking force BPTr1, and the step counter CNTS is reset to "0 (zero)". In addition, the control completion flag FLG2 is set to on. That is, both flags FLG1 and FLG2 are turned on. Then, the process moves to the next step S134.

In step S134, an output process of outputting the first and second instruction braking forces BPTr1 and BPTr2 to the brake device 20 is performed. While the present process routine is being repeatedly executed, the first instruction braking force BPTr1 output to the brake device 20 continues to increase. Therefore, outputting the first instructed braking force BPTr1 to the brake device 20 by executing the present processing routine corresponds to instructing the brake device 20 of an increase in the braking force of the first wheel. Then, the executed process shifts from the first brake increase instruction process to the second drive decrease instruction process.

When the first and second command braking forces BPTr1 and BPTr2 are input by execution of the output process, the brake control unit 22 controls the brake actuator 21 such that the braking force of the first wheel follows the first command braking force BPTr1 and the braking force of the second wheel follows the second command braking force BPTr 2. In the first brake increase instruction process, the second instruction braking force BPTr2 is held, and the first instruction braking force BPTr1 is increased. Therefore, by inputting an instruction based on the execution of the first brake increase instruction processing to the brake control unit 22, the braking force of the second wheel can be maintained, and the braking force of the first wheel can be increased at a speed corresponding to the first brake increase amount Δ BP 11.

The second drive reduction instruction processing is executed by the drive reduction instruction section 44. In the second drive reduction instruction processing, at the beginning of step S135, it is determined whether or not the sum of the second previous braking force value BP2a and the first instruction braking force BPTr1 is equal to or greater than the stop holding force Fh. If the sum of the stop maintaining force Fh and the shortage of the stop maintaining force Fh is not reduced, the vehicle 10 may start without reducing the driving force DP of the vehicle 10. In the case where the sum is less than the stop holding force Fh (S135: NO), the process proceeds to the next step S136. In step S136, the value obtained by subtracting the sum from the stop holding force Fh is calculated as the first instructed driving force DPTr 1. When the present process routine is repeatedly executed, the first indicated braking force BPTr1 increases, and therefore the sum of the second previous braking force value BP2a and the first indicated braking force BPTr1 becomes large. As a result, the first indicated driving force DPTr1 decreases at a speed corresponding to the increasing speed of the first indicated braking force BPTr 1. Then, the process proceeds to step S138 described later.

On the other hand, in step S135, if the sum of the second previous braking force value BP2a and the first instructed braking force BPTr1 is equal to or greater than the stop holding force Fh (YES), the process proceeds to next step S137. In step S137, "0 (zero)" is set as the first instructed driving force DPTr 1. Then, the process moves to the next step S138.

In step S138, an output process of outputting the first instructed driving force DPTr1 to the drive device 30 is performed. While the present process routine is repeatedly executed, the first instruction driving force DPTr1 output to the drive device 30 continues to decrease. Therefore, outputting the first instructed driving force DPTr1 to the drive device 30 by executing the present processing corresponds to instructing the drive device 30 of a decrease in the driving force DP of the vehicle 10.

When the first instructed driving force DPTr1 is input by the execution of the output process, the drive control unit 32 controls the power unit 31 so that the driving force DP of the vehicle 10 follows the first instructed driving force DPTr 1. In the second drive reduction instruction processing, the first instruction driving force DPTr1 is reduced. Therefore, by inputting an instruction based on the execution of the second drive reduction instruction process to the drive control portion 32, the driving force DP of the vehicle 10 can be reduced.

If the output process is executed, the process proceeds to the next step S139. In step S139, similarly to step S22 described above, the first instruction braking force BPTr1 at the current time is set to the first previous braking force value BP1a, the second instruction braking force BPTr2 at the current time is set to the second previous braking force value BP2a, and the first instruction driving force DPTr1 at the current time is set to the first previous driving force value DP1 a. After that, the present processing routine is ended.

When the present processing routine is ended with the control completion flag FLG2 set to off, the first brake increase instruction processing and the second drive decrease instruction processing are respectively continued. On the other hand, when the present processing routine is ended with the flags FLG1 and FLG2 turned on, the first brake increase instruction processing and the second drive decrease instruction processing are ended, respectively.

Next, the operation and effect of the present embodiment will be described with reference to fig. 12. As a premise, it is assumed that the vehicle 10 is located on an uphill road.

As shown in (a), (b), (c), (d), (e), and (f) of fig. 12, the braking force BP is applied to the vehicle 10 at a timing T11 when the vehicle is traveling on an uphill road. At this time, during the period from the timing T11 to the timing T12, the front wheel braking force BPF, which is the braking force of the first wheel, increases, and the rear wheel braking force BPR, which is the braking force of the second wheel, increases. Then, at and after the timing T12, the front wheel braking force BPF and the rear wheel braking force BPR are respectively held.

When a braking force is applied to the front wheel 11 as the first wheel in this way, a first contact surface friction force FF1 acts on the rear side of the vehicle 10, that is, the lower side of the slope, in the contact surface with the road surface on the front wheel 11. The larger the front wheel braking force BPF, the larger the first ground contact surface friction force FF 1. Similarly, when a braking force is applied to the rear wheel 12 as the second wheel, a second ground contact surface friction force FF2 acts on the ground contact surface with the road surface on the rear wheel 12, i.e., on the lower side of the slope, behind the vehicle 10. The larger the rear wheel braking force BPR, the larger the second ground contact surface friction force FF 2. When the vehicle 10 stops at the timing T13 due to the application of the braking force BP, the positive and negative of the first ground contact surface friction force FF1 and the second ground contact surface friction force FF2 are reversed. That is, the first ground contact surface friction force FF1 acts on the front side of the vehicle 10, i.e., the upper side of the slope, in the ground contact surface with the road surface on the front wheel 11, and the second ground contact surface friction force FF2 acts on the front side of the vehicle 10, i.e., the upper side of the slope, in the ground contact surface with the road surface on the rear wheel 12.

When the vehicle 10 decelerates due to the application of the braking force BP, the vehicle 10 performs pitching toward the dive side. Then, the front wheel suspension 13F contracts, and the rear wheel suspension 13R extends. At the same time, due to the geometry of the suspensions 13F and 13R, an anti-nodding force corresponding to the front wheel braking force BPF is generated at the front portion of the vehicle body 16, and an anti-uplifting force corresponding to the rear wheel braking force BPR is generated at the rear portion of the vehicle body 16. Thereby, the position in the vehicle front-rear direction X of the front wheels 11 is changed from the reference position of the front wheels 11, and the position in the vehicle front-rear direction X of the rear wheels 12 is changed from the reference position of the rear wheels 12. As a result, the wheelbase WBL of the vehicle 10 is changed from the reference wheelbase WBLB.

In the example shown in fig. 12, even if the vehicle 10 is stopped at the timing T13, the front wheel braking force BPF and the rear wheel braking force BPR are respectively maintained. As a result, the wheels 11 and 12 are locked in a locked state in which rotation is restricted, and the vertical displacement of the suspensions 13F and 13R is maintained. Thus, the state continues in which the position in the vehicle longitudinal direction X of the front wheel 11 is different from the reference position of the front wheel 11 and the position in the vehicle longitudinal direction X of the rear wheel 12 is different from the reference position of the rear wheel 12. That is, the state in which the wheelbase WBL of the vehicle 10 is different from the reference wheelbase WBLB continues.

In the present embodiment, the attitude control is started from the timing T14 while the vehicle 10 is stopped. When the attitude control is performed, the front wheel braking force BPF and the rear wheel braking force BPR decrease. In addition, even if the braking force BP of the vehicle is reduced like this, the driving force DP of the vehicle is increased so as to maintain the stop of the vehicle 10. When the front wheel braking force BPF is reduced by the implementation of the attitude control, the rotation of the front wheel 11 is permitted, so that the position of the front wheel 11 in the vehicle longitudinal direction X can be returned to the reference position of the front wheel 11, that is, the state of the front wheel suspension 13F can be restored. Further, when the rear wheel braking force BPR is reduced by the implementation of the attitude control, the rotation of the rear wheel 12 is permitted, so that the position of the rear wheel 12 in the vehicle longitudinal direction X can be returned to the reference position of the rear wheel 12, that is, the state of the rear wheel suspension 13R can be restored. That is, while the vehicle 10 is stopped, the wheelbase WBL of the vehicle 10 can be returned to the reference wheelbase WBLB. Therefore, when the brake of the vehicle 10 is released to start the vehicle 10 thereafter, the posture of the vehicle 10 can be prevented from changing abruptly due to the change of the wheelbase WBL. Therefore, it is possible to suppress the discomfort given to the occupant of the vehicle 10 at the time of vehicle startup.

Specifically, from the timing T14, the first braking reduction instruction processing of the attitude control is started. When the first brake reduction instruction processing is executed, the first instruction braking force BPTr1 is reduced, and therefore the front wheel braking force BPF is reduced by driving the brake actuator 21. At the timing T16, the first indicated braking force BPTr1 is "0", and thus the first brake reduction indication process ends. In the present embodiment, when the front wheel braking force BPF decreases from the timing T14 to the timing T16, the rotation of the front wheel 11 is permitted, and the position of the front wheel 11 in the vehicle longitudinal direction X is returned to the reference position of the front wheel 11.

In the execution of the first braking reduction instruction process, the braking force BP of the vehicle is reduced. Then, at the timing T15 in the execution of the first brake reduction instructing process, since the sum of the first instructed braking force BPTr1 and the previous value BP2a of the second braking force is insufficient to stop the holding force Fh, the increase of the first instructed driving force DPTr1 is started by the execution of the first drive increase instructing process of the posture control. Then, as the first instructed driving force DPTr1 increases, the driving force DP of the vehicle 10 increases due to the driving of the power unit 31. That is, by executing the first drive increase instruction processing also during execution of the first brake decrease instruction processing, replacement from the front wheel braking force BPF to the driving force DP of the vehicle 10 is performed. Thus, even if the braking force BP of the vehicle 10 decreases due to the execution of the first brake reduction instruction processing, the stopped state of the vehicle 10 can be maintained.

When the first braking reduction instruction processing ends at the timing T16, the first driving increase instruction processing ends, and the second driving increase instruction processing starts as the driving increase instruction processing. Therefore, the first instructed driving force DPTr1 also increases at the timing T16 and later, and thus the driving force DP of the vehicle 10 increases. Then, the first instructed driving force DPTr1 reaches the stop holding force Fh at the timing T17, and thus the second drive increase instructing process is ended. That is, the increase in the driving force DP of the vehicle 10 is ended. At this time, even if the braking of the vehicle 10 is released, the stop of the vehicle 10 can be maintained by the driving force DP.

Then, from the timing T17, the second brake reduction instruction process of the attitude control is started with the first instructed driving force DPTr1, that is, the driving force DP of the vehicle 10, being maintained. When the second brake reduction instruction processing is executed, the rear wheel braking force BPR is reduced by the driving of the brake actuator 21 because the second instruction braking force BPTr2 is reduced. The second indication braking force BPTr2 is "0" at the timing T18, and therefore the second brake reduction indication process is ended. In the present embodiment, when the rear wheel braking force BPR decreases from the timing T17 to the timing T18, the rotation of the rear wheel 12 is permitted, and the position of the rear wheel 12 in the vehicle longitudinal direction X is returned to the reference position of the rear wheel 12. As a result, the wheelbase WBL of the vehicle returns to the reference wheelbase WBLB during the period from the timing T17 to the timing T18.

Further, at the timing T16 and after when the braking of the front wheels 11 is released, the driving force DP of the vehicle 10 increases, and therefore a propulsive force tending to advance the vehicle 10 is applied to the vehicle 10. Then, the sum of the driving force DP and the rear wheel braking force BPR becomes larger than the stop maintaining force Fh. When the front wheel braking force BPF is larger than "0 (zero)", it can be said that the driving force DP is cancelled by the front wheel braking force BPF. Therefore, the sum of the extra driving force, which is the value obtained by subtracting the front wheel braking force BPF from the driving force DP, and the rear wheel braking force BPR can be said to be larger than the stop maintaining force Fh. In this case, since the front wheel braking force BPF is "0 (zero)", the extra driving force is equal to the driving force DP. Then, as the driving force DP, i.e., the excessive driving force, increases, the propelling force increases, and the second ground contact friction force FF2 acting on the rear wheel 12 gradually decreases. This is because the gravity for moving the vehicle 10 to the lower side of the slope is balanced by the above-described propulsive force. Then, when the first instructed driving force DPTr1 is equal to the stopping holding force Fh, that is, the excessive driving force is equal to the stopping holding force Fh, the second ground contact surface frictional force FF2 is almost "0 (zero)".

Here, when the second contact surface friction force FF2 before the vehicle 10 stops is set to the second contact surface force reference value FF2B, the rear wheel suspension 13R moves more rapidly when the vehicle front-rear direction X position of the rear wheel 12 returns to the reference position of the rear wheel 12 and the deviation Δ FF2 between the second contact surface friction force FF2 and the second contact surface force reference value FF2B increases from the state in which the rear wheel 12 is locked to the state in which the rear wheel 12 rotates. That is, the displacement speed of the rear wheel 12 when the position of the rear wheel 12 in the vehicle longitudinal direction X is returned to the reference position of the rear wheel 12 is high. At this time, there is a possibility that vibration or sound is generated due to rapid movement of the rear wheel suspension 13R.

In this regard, in the present embodiment, after the second ground contact friction force FF2 becomes substantially "0 (zero)" due to the increase in the driving force DP, the position of the rear wheel 12 in the vehicle longitudinal direction X can be returned to the reference position of the rear wheel 12. When the rear wheel 12 is rotated in this manner, the frictional force corresponding to the rear wheel braking force BPR changes from static friction to dynamic friction when the state is shifted from the state in which the rear wheel 12 is locked to the state in which the rear wheel 12 is rotated. For example, when the brake mechanism provided in the rear wheel 12 is a disc brake mechanism, the friction between the disc and the friction material changes from static friction to dynamic friction. Therefore, even if the pressing force, which is the force pressing the friction material against the disk, is reduced smoothly, the braking force is rapidly reduced at the moment when the static friction is changed to the dynamic friction. At this time, the smaller the deviation Δ FF2, the smaller the force for displacing the rear wheel 12 to the reference position of the rear wheel 12 at the time of shifting to the state where the rear wheel 12 is rotated. As a result, as compared with the case where the deviation Δ FF2 is large, it is possible to suppress a sudden movement of the rear wheel suspension 13R when the friction force corresponding to the rear wheel braking force BPR changes from static friction to dynamic friction while the state where the rear wheel 12 is locked is shifted to the state where the rear wheel 12 rotates.

During braking, the rear wheel suspension 13R is extended compared to the stop reference state, and therefore the position of the rear wheel 12 in the vehicle longitudinal direction X during braking is located on the side where the wheelbase WBL is shortened with respect to the reference position of the rear wheel 12. Therefore, after braking, the position of the rear wheel 12 in the vehicle longitudinal direction X is halfway returned from the position where the wheelbase WBL is shortened with respect to the reference position during braking to the reference position of the rear wheel 12. Therefore, a force that moves the rear wheel 12 rearward of the vehicle acts on the rear wheel 12. When the vehicle 10 is stopped on an uphill road, the second ground contact friction force FF2 acts on the ground contact surface with the road surface on the rear wheel 12, i.e., on the lower side of the slope, behind the vehicle. In this case, the second ground contact surface friction force FF2 acts on the rear wheel 12 as a force that moves the rear wheel 12 toward the rear of the vehicle. That is, the force for moving the rear wheels 12 rearward of the vehicle is further increased. Therefore, by reducing the second ground contact friction force FF2 with an increase in the driving force DP, the force for rotating the rear wheel 12 can be reduced in the direction for moving the rear wheel 12 rearward of the vehicle at the time of shifting to the state where the rear wheel 12 is rotated. As a result, as compared with the case where the second ground contact surface friction force FF2 is large toward the rear of the vehicle 10, that is, toward the lower side of the slope, it is possible to suppress a shift from the state where the rear wheel 12 is locked to the state where the rear wheel 12 rotates, and to suppress a sudden shift of the rear wheel suspension 13R when the friction force corresponding to the rear wheel braking force BPR changes from static friction to dynamic friction with respect to the rear wheel suspension 13R.

As described above, the second ground contact surface friction force FF2 is appropriately changed by the driving force DP, so that the change in the posture of the vehicle 10 caused by the change in the wheelbase WBL can be made gentle. Further, the generation of vibration and sound due to the movement of the rear wheel suspension 13R can be suppressed.

In the present embodiment, the timing of returning the position of the rear wheel 12 in the vehicle longitudinal direction X to the reference position of the rear wheel 12 and the timing of returning the position of the front wheel 11 in the vehicle longitudinal direction X to the reference position of the front wheel 11 are shifted from each other. This can suppress the change speed of the wheel base WBL from becoming high, as compared with the case where the front wheels 11 and the rear wheels 12 are returned to the reference positions at substantially the same time. Thus, the change in the posture of the vehicle 10 caused by the change in the wheelbase WBL while the vehicle 10 is stopped can be made less noticeable to the passengers of the vehicle 10.

When the second brake reduction instruction processing, that is, the attitude control is ended in this way, the front wheel braking force BPF and the rear wheel braking force BPR are increased by the driving of the brake actuator 21 by the execution of the brake increase control. Further, the driving force DP of the vehicle 10 is reduced by the driving of the power unit 31 by the implementation of the drive increase control. This can suppress continuation of the application of the driving force DP to the vehicle 10 while the vehicle 10 is stopped, and accordingly can suppress a decrease in energy efficiency of the vehicle.

In the present embodiment, the second brake increase instruction processing and the first drive reduction instruction processing are started from the timing T18. When the second brake increase instruction processing is executed, the second instruction braking force BPTr2 increases, and therefore the rear wheel braking force BPR increases due to the driving of the brake actuator 21. The second indication braking force BPTr2 reaches the second target braking force BPS2 at the timing T19, thus ending the second brake increase indication process. That is, at the timing T19 and thereafter, the rear wheel braking force BPR is maintained.

Further, when the first drive reduction instruction processing is executed, the first instruction driving force DPTr1 is reduced, and therefore the driving force DP of the vehicle 10 is reduced by driving the power unit 31. The speed of decrease of the driving force DP at this time corresponds to the speed of increase of the rear wheel braking force BPR. That is, the replacement from the driving force DP to the rear wheel braking force BPR is performed during the period from the timing T18 to the timing T19. Then, the first drive reduction instruction processing ends at timing T19.

Then, the first brake increase instruction processing and the second drive reduction instruction processing are started from the timing T19. When the first brake increase instruction processing is executed, the first instruction braking force BPTr1 increases, and therefore the front wheel braking force BPF increases due to the driving of the brake actuator 21. At the timing T111, the first indicated braking force BPTr1 reaches the first target braking force BPS1, thus ending the first brake increase indication process. That is, at the timing T111 and later, the front wheel braking force BPF is maintained.

Further, when the second drive reduction instruction processing is executed, the first instruction driving force DPTr1 is reduced, and therefore the driving force DP of the vehicle 10 is reduced by driving the power unit 31. Then, at the timing T110, the first instructed driving force DPTr1 is "0 (zero)". The speed of decrease of the driving force DP at this time corresponds to the speed of increase of the front wheel braking force BPF. That is, during the period from the timing T19 to the timing T110, the replacement from the driving force DP to the front wheel braking force BPF is performed.

Here, a comparative example in which the front wheel braking force BPF and the rear wheel braking force BPR are simultaneously increased is considered. In this comparative example, in the case where the driving force DP of the vehicle 10 is replaced with the braking force BP of the vehicle 10, the reduction speed of the driving force DP is high. In this case, the passenger of the vehicle 10 can easily perceive the sound and vibration generated from the power unit 31 due to the reduction of the driving force DP.

In this regard, in the present embodiment, the increase in the rear wheel braking force BPR is offset in time from the increase in the front wheel braking force BPF. Therefore, the reduction rate of the driving force DP can be made lower than in the case of the above comparative example. This makes it difficult for the occupant of vehicle 10 to perceive the sound and vibration generated from power unit 31 due to the decrease in driving force DP.

In addition, in the present embodiment, the driving force DP of the vehicle 10 is reduced while the braking force BP of the vehicle 10 is increased. Thus, as compared with the case where the reduction of the driving force DP is started after the increase of the braking force BP caused by the execution of the brake increasing control is completed, the reduction of the driving force DP can be started early, and accordingly, the energy efficiency of the vehicle can be improved.

The example shown in fig. 12 is an example of a case where the rear wheel braking force BPR before the start of the attitude control is smaller than the stop maintaining force Fh. Depending on the road surface gradient θ, the rear wheel braking force BPR before the start of the attitude control may be larger than the stop maintaining force Fh. Fig. 13 is a timing chart showing a case where the rear wheel braking force BPR before the start of the attitude control is larger than the stop maintaining force Fh.

As shown in (a), (b), (c), (d), (e), and (f) of fig. 13, when the vehicle 10 stops due to the application of the braking forces to the front wheels 11 and the rear wheels 12, the first braking reduction instruction process of the attitude control starts from the timing T41. The first braking reduction instruction processing is executed until the timing T42. Therefore, when the front wheel braking force BPF decreases during the period from the timing T41 to the timing T42, the rotation of the front wheel 11 is permitted, and the position of the front wheel 11 in the vehicle longitudinal direction X is returned to the reference position of the front wheel 11. Further, the state of the front wheel suspension 13F is restored.

In the example shown in fig. 13, the stop holding force Fh is small as compared with the rear wheel braking force BPR. Therefore, during execution of the first brake reduction instruction process, the increase of the first instruction braking force BPTr1 is not started by execution of the first drive increase instruction process. Therefore, the first indicated driving force DPTr1 is increased by the execution of the second drive increase instruction processing that starts from the timing T42 at which the first brake reduction instruction processing ends. When the first instructed driving force DPTr1 reaches the stop holding force Fh at the timing T43, the second drive increase instructing process is ended and the second brake decrease instructing process is started. The flow of the processing at the timing T43 and thereafter is the same as that in the example shown in fig. 12, and therefore, the description thereof is omitted.

(second embodiment)

Next, a second embodiment of the vehicle control device will be described with reference to fig. 14 and 15. In the second embodiment, the contents of a part of the various processes executed are different from those of the first embodiment. Therefore, in the following description, the description will be given mainly of portions different from the first embodiment, and the same reference numerals are given to the same or equivalent components as those in the first embodiment, and redundant description thereof will be omitted.

The second drive increase instruction processing executed in the present embodiment will be described with reference to fig. 14. The present processing program is executed by the posture control unit 42.

In the present processing routine, in step S151, it is determined whether or not the second instruction braking force BPTr2 at the present time is smaller than the second pre-stop braking force BP2 b. In step S12 of the processing routine explained using fig. 5, the second pre-stop braking force BP2b is set. In the case where the second instruction braking force BPTr2 is smaller than the above-described second pre-stop braking force BP2b (S151: YES), the process proceeds to the next step S152. In step S152, the second instruction braking force BPTr2 is set as the lift target force BP2 t. Then, the process proceeds to step S154 described later.

On the other hand, in step S151, when the second instruction braking force BPTr2 is equal to or greater than the second pre-stop braking force BP2b (NO), the process proceeds to next step S153. In step S153, the second pre-stop braking force BP2b is set as the lift target force BP2 t. Then, the process moves to the next step S154.

In step S154, the sum of the above-described first driving force previous value DP1a and the first drive increase amount Δ DP1 is calculated as the latest first instructed driving force DPTr1, similarly to the above-described step S71. Next, in step S155, it is determined whether or not the first instruction driving force DPTr1 calculated in step S154 is equal to or greater than the sum of the stop holding force Fh and the lift target force BP2 t. When the first instructed driving force DPTr1 is equal to or greater than the sum, the vehicle 10 is started if the driving force DP of the vehicle 10 is continuously increased. Therefore, in the case where the first instructed driving force DPTr1 is the sum or more (S155: YES), the process moves to the next step S156. In step S156, as the first instructed driving force DPTr1, the sum of the stop holding force Fh and the lift target force BP2t is set, and the step counter CNTS self-increments "1". That is, the step counter CNTS is "3". Then, the process moves to the next step S157.

On the other hand, in step S155, in the case where the first instructed driving force DPTr1 is small compared to the sum of the stop holding force Fh and the lift target force BP2t (NO), the process moves to the next step S157. That is, the step counter CNTS remains "2".

In step S157, the output process of outputting the first instructed driving force DPTr1 to the drive device 30 is performed as in step S74 described above. While the present process routine is repeatedly executed, the first instruction driving force DPTr1 output to the drive device 30 continues to increase. Therefore, outputting the first instructed driving force DPTr1 to the drive device 30 by executing the present processing corresponds to instructing the drive device 30 of an increase in the driving force DP of the vehicle 10. Then, in the next step S158, as in the above step S22, the first instruction braking force BPTr1 at the present time is set to the first previous braking force value BP1a, the second instruction braking force BPTr2 at the present time is set to the second previous braking force value BP2a, and the first instruction driving force DPTr1 at the present time is set to the first previous driving force value DP1 a. After that, the present processing routine is ended.

Next, the first drive reduction instruction processing executed in the present embodiment will be described. In the first embodiment, the first drive reduction instruction process is started simultaneously with the second brake increase instruction process, while in the present embodiment, the first drive reduction instruction process is started before the second brake reduction instruction process is started after the increase in the driving force DP of the vehicle 10 is completed due to the execution of the second drive increase instruction process. Specifically, the first drive reduction instructing process is started when the increase in the driving force DP of the vehicle 10 due to the execution of the second drive increase instructing process is completed.

In the first drive reduction instruction processing executed in the present embodiment, the first instructed driving force DPTr1 is updated such that the first instructed driving force DPTr1 is reduced at a speed set in advance. The first drive reduction instruction processing is also continued after the second brake increase instruction processing is started. Then, when the second brake increase instruction processing is ended, the first drive decrease instruction processing is also ended.

Next, with reference to fig. 15, the operation and effect of the present embodiment will be mainly described as different from those of the first embodiment.

As shown in (a), (b), (c), (d), (e), and (f) of fig. 15, the vehicle 10 is stopped at a timing T21 due to the application of the braking forces to the front wheels 11 and the rear wheels 12. The front wheel braking force BPF and the rear wheel braking force BPR are held during the period from the timing T21 to the timing T22 at which the attitude control is started. Therefore, a state continues in which the vehicle longitudinal direction X position of the front wheel 11 is different from the reference position of the front wheel 11 and the vehicle longitudinal direction X position of the rear wheel 12 is different from the reference position of the rear wheel 12. That is, the state in which the wheelbase WBL of the vehicle 10 is different from the reference wheelbase WBLB continues.

Then, the first braking reduction instruction processing of the attitude control is started from the timing T22. The first braking reduction instruction processing is executed until the timing T24. Therefore, when the front wheel braking force BPF decreases from the timing T22 to the timing T24, the rotation of the front wheel 11 is permitted, and the position of the front wheel 11 in the vehicle longitudinal direction X is returned to the reference position of the front wheel 11. Further, the state of the front wheel suspension 13F is restored.

At the timing T23 in the execution of the first brake-reduction instructing process, since the sum of the first instructed braking force BPTr1 and the previous value BP2a of the second braking force is smaller than the stop holding force Fh, the increase of the first instructed braking force BPTr1 is started by the execution of the first drive-increase instructing process of the attitude control. Then, the first braking reduction instruction processing is ended at the timing T24, and thus the drive increase instruction processing is switched from the first drive increase instruction processing to the second drive increase instruction processing.

The second drive increase instructing process is also continued at the timing T25 and thereafter when the first instructed driving force DPTr1 reaches the stop holding force Fh. Then, at the timing T26, the first indication driving force DPTr1 reaches the sum of the stop holding force Fh and the lift target force BP2T, thus ending the second drive increase indication process. Therefore, in the present embodiment, by execution of the second drive increase instruction process, the driving force DP of the vehicle 10 can be increased to the sum of the stop holding force Fh and the lift target force BP2t, or the vicinity of the sum. The sum of the stop holding force Fh and the lift target force BP2t is an upper limit or a value near the upper limit of the driving force DP that can maintain the stop of the vehicle 10 while maintaining the braking force BP at the present time.

Further, by making the driving force DP of the vehicle 10 larger than the stop maintaining force Fh, the second ground contact surface friction force FF2 acts on the ground contact surface of the rear wheel 12 with the road surface toward the lower side of the slope. Then, at a timing T26 at which the driving force DP is equal to the sum of the stop maintaining force Fh and the lift target force BP2T, the second ground contact surface friction force FF2 is almost equal to the second ground contact surface friction force FF2, that is, the second ground contact surface force reference value FF2B, before the timing T21 at which the vehicle 10 stops.

In the present embodiment, after the second ground contact surface friction force FF2 and the second ground contact surface force reference value FF2B are made almost equal, the second indication braking force BPTr2, that is, the rear wheel braking force BPR, is reduced by the execution of the second brake reduction indication process. That is, when the deviation Δ FF2 is a value close to "0 (zero)", the position of the rear wheel 12 in the vehicle longitudinal direction X is returned to the reference position, and the state of the rear wheel suspension 13R is restored. At this time, since the position of the rear wheel 12 in the vehicle longitudinal direction X can be displaced more gradually, the change in the posture of the vehicle 10 due to the change in the wheelbase WBL can be made more gradually. Further, since the effect of suppressing sudden movement of the rear wheel suspension 13R can be improved, the effect of suppressing generation of vibration and sound due to movement of the rear wheel suspension 13R can be improved.

Since the rear wheel braking force BPR decreases due to the execution of the second brake reduction instruction process from the timing T26, the first instruction driving force DPTr1, that is, the driving force DP of the vehicle 10 decreases in accordance with the decrease in the rear wheel braking force BPR at the timing T26 and later. Then, at the timing T27 at which the second brake reduction instruction processing is ended, the first instruction driving force DPTr1 reaches the stop holding force Fh. Therefore, the stop of the vehicle 10 can be maintained even during execution of the second braking reduction instruction process.

(third embodiment)

Next, a third embodiment of the vehicle control device will be described with reference to fig. 16. In the third embodiment, the start timings and the like of various processes are different from those in the second embodiment. Therefore, in the following description, the portions different from the first embodiment and the second embodiment will be mainly described, and the same reference numerals are given to the same or equivalent components as those in the first embodiment and the second embodiment, and redundant description thereof will be omitted.

The following description will focus on differences between the first drive increase instruction processing executed in the present embodiment and the first drive increase instruction processing executed in the second embodiment.

In the first drive increase instruction processing executed in the present embodiment, in step S55 shown in fig. 7, a determination is made as to whether or not the sum of the first instruction braking force BPTr1 and the previous value BP2a of the second braking force is equal to or greater than the sum of the stop holding force Fh and the first correction amount F α. A value corresponding to the road surface gradient θ is set as the stop holding force Fh, but there is a possibility that a derived error is included in the road surface gradient θ. When the road surface gradient θ is smaller than the actual road surface gradient, if the sum of the first instruction braking force BPTr1 and the previous value BP2a of the second braking force is smaller than the stop maintaining force Fh and then the increase in the driving force DP of the vehicle 10 is started, there is a possibility that the vehicle 10 slips due to the decrease in the braking force of the first wheel resulting from the execution of the first brake reduction instruction process. Therefore, as the first correction amount F α, a value corresponding to the error in deriving the road surface gradient θ or a value larger than this value is set.

Then, when the sum of the first commanded braking force BPTr1 and the previous value BP2a of the second braking force is equal to or greater than the sum of the stop holding force Fh and the first correction amount F α (S55: YES), the process proceeds to step S56, where "0 (zero)" is set as the first commanded driving force DPTr 1. That is, the increase in the driving force DP is not started. On the other hand, in the case where the sum of the first instructed braking force BPTr1 and the previous value BP2a of the second braking force is smaller than the sum of the stop maintaining force Fh and the first correction amount F α (S55: NO), the process proceeds to step S57. In step S57, a value obtained by subtracting the sum of the stop maintaining force Fh and the first correction amount F α from the sum of the first indicated braking force BPTr1 and the previous value BP2a of the second braking force is calculated as the first indicated driving force DPTr 1.

The contents of the processing in step S58 and subsequent steps are the same as those in the first and second embodiments, and therefore the description thereof is omitted.

Next, a description will be given centering on a difference between the second drive increase instruction processing executed in the present embodiment and the second drive increase instruction processing executed in the second embodiment.

In the second drive increase instruction processing executed in the present embodiment, in step S151 shown in fig. 14, it is determined whether or not the second instruction braking force BPTr2 at the present time is smaller than the second pre-stop braking force BP2 b. In the case where the second instruction braking force BPTr2 is smaller than the above-described second pre-stop braking force BP2b (S151: YES), the process proceeds to the next step S152. In step S152, a value obtained by subtracting the second correction amount F β from the second instruction braking force BPTr2 is set as the lift target force BP2 t. Then, the process proceeds to step S154 described later. On the other hand, in step S151, when the second instruction braking force BPTr2 is equal to or greater than the second pre-stop braking force BP2b (NO), the process proceeds to next step S153. In step S153, a value obtained by subtracting the second correction amount F β from the second pre-stop braking force BP2b is set as the lift target force BP2 t. Then, the process moves to the next step S154.

As described above, the stop holding force Fh may contain an error component derived from the road surface gradient θ. In addition, there is also a possibility that a deviation may occur between the second indication braking force BPTr2 and the actual rear wheel braking force BPR. If the lift target force BP2t is set without taking such an error component into consideration, the vehicle 10 may not be able to be maintained at a stop when the first instruction driving force DPTr1 is increased to the sum of the stop maintaining force Fh and the lift target force BP2 t. Therefore, the second correction amount F β is set in consideration of the error in deriving the stop holding force Fh and the deviation between the second instruction braking force BPTr2 and the actual rear wheel braking force BPR.

The contents of the processing in step S154 and subsequent steps are the same as those in the second embodiment, and therefore, the description thereof is omitted.

Next, the first brake increase instruction processing executed in the present embodiment will be described.

The first brake increase instruction processing executed in the present embodiment is started when the second drive increase instruction processing is ended. That is, the first brake increase instruction processing is started simultaneously with the second brake decrease instruction processing and the first drive decrease instruction processing.

The first brake increase instruction processing includes first increase instruction period processing, holding period processing executed after the first increase instruction period processing ends, and second increase instruction period processing executed after the holding period processing ends. In the first increase instruction period process, the first instruction braking force BPTr1 is increased at a speed lower than the speed corresponding to the above-described first brake increase amount Δ BP 11. When the second brake reduction instruction processing and the first drive reduction instruction processing are ended and the second brake increase instruction processing is started, the first increase instruction period processing is also ended.

The hold period processing is executed in the execution of the second brake increase instruction processing. In the holding period process, the first instruction braking force BPTr1 is held. That is, in the present embodiment, when the braking force of the second wheel increases due to the execution of the second brake increase instruction processing, the braking force of the first wheel is maintained. Then, when the second brake increase instruction processing is ended, the holding period processing is also ended.

The second increase instruction period processing is executed in the execution of the second drive decrease instruction processing. In the second increase instruction period process, the first instruction braking force BPTr1 is increased at a speed corresponding to the above-described first brake increase amount Δ BP11 until the first instruction braking force BPTr1 reaches the first target braking force BPs 1.

Next, the operation and effect of the present embodiment, which are different from those of the first and second embodiments, will be mainly described with reference to fig. 16.

As shown in (a), (b), (c), (d), (e), and (f) of fig. 16, when the vehicle 10 stops due to the application of the braking forces to the front wheels 11 and the rear wheels 12, the first braking reduction instruction process of the attitude control starts from the timing T31. The first braking reduction instruction processing is executed until the timing T33. Therefore, when the front wheel braking force BPF decreases during the period from the timing T31 to the timing T33, the rotation of the front wheel 11 is permitted, and the position of the front wheel 11 in the vehicle longitudinal direction X is returned to the reference position of the front wheel 11. Further, the state of the front wheel suspension 13F is restored.

At the timing T32 in the execution of the first brake reduction instruction process, since the sum of the first instruction braking force BPTr1 and the previous value BP2a of the second braking force is smaller than the sum of the stop maintaining force Fh and the first correction amount F α, the increase of the first instruction driving force DPTr1 is started by the execution of the first drive increase instruction process of the attitude control. By thus starting the increase in the driving force DP of the vehicle 10 before the timing at which the sum of the first instruction braking force BPTr1 and the previous value BP2a of the second braking force is smaller than the stop maintaining force Fh, the effect of suppressing the slip of the vehicle 10 due to the reduction in the front wheel braking force BPF can be enhanced. Then, since the first braking reduction instruction processing ends at the timing T33, the drive increase instruction processing is switched from the first drive increase instruction processing to the second drive increase instruction processing.

At the timing T34 at which the first indication driving force DPTr1 reaches the sum of the stop holding force Fh and the lift target force BP2T by the execution of the second drive increase indication process, the second drive increase indication process is ended. In the present embodiment, the lift target force BP2t is set in consideration of the second correction amount F β. Therefore, even if the driving force DP is increased until the driving force DP of the vehicle 10 becomes equal to the sum of the stop maintaining force Fh and the lift target force BP2t, the effect of suppressing the unintended start of the vehicle 10 can be improved.

In the present embodiment, from the timing T34, the first increase instruction period process in the first brake increase instruction process is started in addition to the second brake decrease instruction process and the first drive decrease instruction process. Thus, the rear wheel braking force BPR and the reduction in the driving force DP of the vehicle 10 are reduced, but the front wheel braking force BPF is increased. As a result, the effect of suppressing the slip of the vehicle 10 when the decrease in the rear wheel braking force BPR and the decrease in the driving force DP of the vehicle 10 are reduced can be improved.

Then, at a timing T35 at which the second instruction braking force BPTr2 becomes "0 (zero)" due to the execution of the second brake reduction instruction processing, the second brake reduction instruction processing is ended, and the second brake increase instruction processing is started. At the timing T35, although the rear wheel braking force BPR is almost "0 (zero)", a braking force is applied to the front wheels 11. Therefore, even if there is a certain deviation between the driving force DP and the stop holding force Fh, it is possible to suppress the slip-off of the vehicle 10 or suppress the undesired start of the vehicle 10. In the first brake increase instruction processing, the first increase instruction period processing is ended and the holding period processing is started. Therefore, the front wheel braking force BPF is maintained while the rear wheel braking force BPR is increased. Then, when the second indication braking force BPTr2 reaches the second target braking force BPS2 at the timing T36, the second brake increase indication process is ended. Further, the first drive reduction instruction processing is ended, and the second drive reduction instruction processing is started. Then, in the first brake increase instruction processing, the holding period processing is ended and the second increase instruction period processing is started.

(modification example)

The above embodiments can be modified and implemented as follows. The above embodiments and the following modifications can be combined and implemented within a range not technically contradictory to each other.

In each of the above embodiments, the reduction of the driving force DP of the vehicle 10 caused by the execution of the drive reduction control is completed before the increase of the braking force BP of the vehicle 10 caused by the execution of the brake increase control is completed. However, the reduction of the driving force DP of the vehicle 10 due to the implementation of the drive reduction control may be completed after the increase of the braking force BP of the vehicle 10 due to the implementation of the brake increase control is completed.

In the first and second embodiments, the drive reduction control may be started after the brake increase control is finished.

In the first and second embodiments, the brake increase control may not be executed when it can be predicted that the vehicle 10 starts relatively early after the stop of the vehicle 10.

In the brake increase control according to the first and second embodiments, the first brake increase instruction process is started after the second brake increase instruction process is ended. However, if the braking force BP of the vehicle 10 can be increased by the execution of the brake increase control, the first brake increase instruction process may be started from the execution of the second brake increase instruction process.

In the brake increase control performed in the first and second embodiments, the second brake increase instruction process is started before the first brake increase instruction process. However, if the braking force BP of the vehicle 10 can be increased by the execution of the brake increase control, the first brake increase instruction process may be started simultaneously with the second brake increase instruction process. The first brake increase instruction processing may be started earlier than the second brake increase instruction processing.

In the first and second embodiments, if the braking force BP of the vehicle 10 can be increased by the execution of the brake increasing control and the stop of the vehicle 10 is maintained by the braking force BP, both the front wheel braking force BPF and the rear wheel braking force BPR may be increased without the execution of the brake increasing control. For example, the brake increasing control may be a control that instructs the brake device 20 to increase the braking force of only one of the front wheel braking force BPF and the rear wheel braking force BPR.

In the first embodiment, as shown in fig. 12, the second brake reduction instruction process is started in a state where the second drive increase instruction process is ended and the first instruction driving force DPTr1 is held at the stop holding force Fh. However, if the stop of the vehicle 10 can be maintained during the attitude control, the second braking reduction instruction process may be started before the second driving increase instruction process is ended. For example, as shown in (a), (b), (c), (d), (e), and (f) of fig. 17, the second brake reduction instruction processing may be started from a timing T51 at which the second drive increase instruction processing is started after the first brake reduction instruction processing is ended. In the example shown in fig. 17, at the timing T52 at which the first instruction driving force DPTr1 reaches the stop holding force Fh due to the second drive increase instruction processing, the second brake reduction instruction processing is executed such that the second instruction braking force BPTr2 is "0 (zero)". However, without being limited thereto, the second brake reduction instruction processing may be executed after the timing T52 such that the second instruction braking force BPTr2 is "0 (zero)".

In the first embodiment, when the second braking reduction instruction process is executed, the braking force may be applied to the front wheels 11 as in the third embodiment.

The vehicle provided with the attitude control device 40 may be a vehicle provided with a drive device that outputs drive force to the rear wheels 12 but does not output drive force to the front wheels 11. In the case of controlling the drive apparatus in attitude control, the rear wheels 12 correspond to first wheels, and the front wheels 11 correspond to second wheels.

The attitude control may be performed when the vehicle is stopped on a downhill. In this case, in the attitude control, an instruction driving force such as a driving force for retreating the vehicle is output from the power unit 31 to the first wheel is output to the drive control unit 32. This can reduce the front wheel braking force BPF and the rear wheel braking force BPR while suppressing the vehicle 10 from moving downward on an incline due to the driving force DP of the vehicle.

The attitude control device 40 may have any one of the following configurations (a) to (c).

(a) The computer program includes one or more processors that execute various processes according to the computer program. The processor includes a CPU, and memories such as RAM and ROM. The memory stores program codes or instructions configured to cause the CPU to execute processing. Memory, i.e., computer-readable media, includes a variety of available media that can be accessed by a general purpose or special purpose computer.

(b) The apparatus includes one or more dedicated hardware circuits for executing various processes. The dedicated hardware circuit may be an application specific integrated circuit, i.e., an ASIC or an FPGA. ASIC is an abbreviation for "Application Specific Integrated Circuit" and FPGA is an abbreviation for "Field Programmable Gate Array".

(c) The computer system includes a processor for executing a part of various processes in accordance with a computer program, and a dedicated hardware circuit for executing the rest of the various processes.

The brake control unit 22 of the brake device 20 may have any one of the above-described configurations (a) to (c).

The drive control unit 32 of the drive device 30 may have any one of the above-described configurations (a) to (c).

The claims (modification according to treaty clause 19)

1. A vehicle control device that controls a drive device and a brake device of a vehicle, comprising:

an attitude control unit that, when the vehicle is stopped on a slope due to application of braking forces to front wheels and rear wheels of the vehicle, performs attitude control that instructs the braking device to decrease the braking force of the front wheels and the braking force of the rear wheels and instructs the driving device to increase the driving force of the vehicle within a range in which the vehicle is kept stopped;

a brake increase instruction unit configured to execute brake increase control for instructing the brake device to increase the braking force of at least one of the front wheels and the rear wheels after an increase in the driving force of the vehicle caused by the execution of the attitude control is completed,

the drive device outputs a drive force to one of the front wheels and the rear wheels, but does not output a drive force to the other wheel,

in the case where the wheel from which the driving force is output from the driving device is the first wheel and the wheel from which the driving force is not output from the driving device is the second wheel,

the attitude control includes a first brake reduction instruction process of instructing the brake device to reduce the braking force of the first wheel, and a second brake reduction instruction process of instructing the brake device to reduce the braking force of the second wheel after the braking force of the first wheel is reduced by the driving of the brake device based on the execution of the first brake reduction instruction process.

[ deletion ]

[ modified ] the control device of a vehicle according to claim 1, wherein,

the attitude control includes a drive increase instruction process of instructing the drive device to increase the drive force of the vehicle,

in the above-described attitude control of the vehicle,

the attitude control unit starts the drive increase instruction processing after the start of the decrease in the braking force of the first wheel due to the drive of the brake device by the execution of the first brake decrease instruction processing,

after the first brake reduction instruction processing is ended and the increase in the driving force of the vehicle due to the driving of the driving device based on the execution of the drive increase instruction processing is started, the posture control unit starts the second brake reduction instruction processing.

4. The control device of the vehicle according to claim 3,

in the drive increase instruction processing during execution of the first brake reduction instruction processing, the attitude control unit instructs the drive device to increase the driving force of the vehicle so that a sum of an excess driving force, which is a value obtained by subtracting the braking force of the first wheel from the driving force of the vehicle, and the braking force of the second wheel is equal to or greater than a stop maintaining force, which is a force required to maintain the vehicle in a stop state while opposing the action of the gravity.

5. The control device of the vehicle according to claim 4,

in the drive increase instruction processing after the first brake decrease instruction processing is ended, the attitude control unit instructs the drive device to increase the drive force until the stop maintaining force.

6. The control device for a vehicle according to claim 3 to 5,

the brake increase control includes a first brake increase instruction process of instructing the brake device to increase the braking force of the first wheel and a second brake increase instruction process of instructing the brake device to increase the braking force of the second wheel,

in the above-described brake increase control,

the brake increase instructing unit starts the first brake increase instructing process after the decrease in the braking force of the first wheel by the driving of the brake device based on the execution of the first brake decrease instructing process is completed,

the brake increase instructing unit starts the second brake increase instructing process after the braking force of the second wheel is reduced by the driving of the brake device based on the execution of the second brake decrease instructing process.

7. The control device of the vehicle according to claim 6,

in the above-described brake increase control,

the brake increase instructing unit starts the second brake increase instructing process before the first brake increase instructing process,

the brake increase instructing unit may start the first brake increase instructing process after the decrease in the braking force of the first wheel by the driving of the brake device based on the execution of the first brake decrease instructing process is completed and after the increase in the braking force of the second wheel by the driving of the brake device based on the execution of the second brake increase instructing process is started.

8. The control apparatus of the vehicle according to claim 6 or 7,

a drive reduction instruction unit configured to execute drive reduction control for instructing the drive device to reduce the drive force of the vehicle after the increase in the drive force of the vehicle caused by the execution of the attitude control is completed,

in the drive reduction control, the drive reduction instruction unit instructs the drive device to reduce the drive force of the vehicle at a speed corresponding to an increase speed of the braking force when the braking force of the vehicle is increased by the drive of the brake device based on the execution of the brake increase control.