阅读说明：本技术 车辆控制方法以及车辆控制装置 (Vehicle control method and vehicle control device ) 是由 伊东敦 于 2018-08-06 设计创作，主要内容包括：在车辆控制方法中,在本车辆(20)的预定行驶的路径上检测本车辆(20)行驶的行驶车道(21)汇流至其它车道(22)的汇流区间(23)(S1),判断在汇流区间(23)中是否执行用于辅助本车辆(20)至其它车道(22)的车道变更的汇流辅助控制(S2),在判断为在汇流区间(23)中不执行汇流辅助控制的情况下,在本车辆(20)通过汇流区间(23)的开始地点(24)之前,控制本车辆(20)的速度,使其变为规定速度(v0)以下(S4～S8)。(In a vehicle control method, a junction section (23) where a traveling lane (21) traveled by a vehicle (20) merges into another lane (22) is detected on a route planned to travel by the vehicle (20) (S1), it is determined whether a junction assist control for assisting a lane change from the vehicle (20) to the other lane (22) is executed in the junction section (23) (S2), and if it is determined that the junction assist control is not executed in the junction section (23), the speed of the vehicle (20) is controlled so as to be equal to or lower than a predetermined speed (v0) before the vehicle (20) passes through a start point (24) of the junction section (23) (S4 to S8).)

1. A vehicle control method characterized by comprising, in a vehicle control unit,

detecting a convergence section where a traveling lane traveled by a host vehicle converges to another lane on a predetermined traveling path of the host vehicle,

determining whether or not a confluence assist control for assisting a lane change of the own vehicle to the other lane is performed in the confluence section,

when it is determined that the bus assist control is not executed in the bus section, the speed of the host vehicle is controlled so as to be equal to or lower than a predetermined speed before the host vehicle passes through a start point of the bus section.

2. The vehicle control method according to claim 1,

the predetermined speed is 10 km or more per hour slower than the lowest speed among the speed limit of the traveling lane in which the host vehicle travels, the speed limit of the other lane, and the traveling speed of the preceding vehicle traveling ahead of the host vehicle.

3. The vehicle control method according to claim 1 or 2,

when it is determined that the confluence assist control is not executed in the confluence section, the speed of the host vehicle is reduced to the predetermined speed before the host vehicle passes the start point.

4. The vehicle control method according to claim 3,

determining a deceleration completion point at which the speed of the host vehicle is decelerated to the predetermined speed so that the speed of the host vehicle can reach the speed limit of the other lane before the host vehicle passes the start point when the host vehicle accelerates from the deceleration completion point at the predetermined acceleration.

5. The vehicle control method according to claim 3 or 4,

the own vehicle has an automatic constant speed running function for running the own vehicle at a set speed,

the deceleration that decelerates the speed of the host vehicle to the predetermined speed is set larger than the deceleration that is decelerated by the automatic constant speed running function when the set speed is reduced.

6. The vehicle control method according to claim 3 or 4,

the own vehicle has an automatic constant speed running function for running the own vehicle at a set speed,

accelerating the host vehicle to the set speed when the speed of the host vehicle is equal to or lower than the set speed after completion of the manual merge operation by the driver in the merge section.

7. A vehicle control apparatus characterized by comprising:

an actuator that controls the speed of the vehicle; and

and a controller that detects a junction section where a traveling lane of the host vehicle joins another lane on a route on which the host vehicle is scheduled to travel, determines whether or not a junction assist control for assisting a lane change of the host vehicle to the another lane is executed in the junction section, and controls the actuator so that a speed of the host vehicle becomes a predetermined speed or less before the host vehicle passes a start point of the junction section when it is determined that the junction assist control is not executed in the junction section.

Technical Field

The invention relates to a vehicle control method and a vehicle control device.

Background

Patent document 1 describes a convergence assisting device that assists a vehicle traveling in a 1 st lane to converge to a 2 nd lane. The confluence auxiliary device comprises: an acceleration unit that accelerates the own vehicle in the 1 st lane to a target speed; a lane change unit that changes the host vehicle from a 1 st lane to a 2 nd lane; a distance A acquisition unit that acquires a distance A from the host vehicle to the reference point; a vehicle speed acquisition unit that acquires a speed of a vehicle; a travel distance B calculation means for calculating a travel distance B from a preset deceleration to a stop of the vehicle; and a stopping means for stopping the assist of the confluence on the condition that a value obtained by subtracting the travel distance B from the distance A is smaller than a preset threshold value.

Documents of the prior art

Patent document

Patent document 1 Japanese patent laid-open publication No. 2017-124743

Disclosure of Invention

Problems to be solved by the invention

The bus assist device described in patent document 1 determines the suspension of the bus assist according to the situation around the vehicle after the bus assist is started. If the confluence assistance is stopped in the middle of the confluence section, the remaining section in which the driver can accelerate the vehicle may be shortened in the confluence section. Therefore, it may become difficult to perform speed adjustment for a lane change by an acceleration operation.

An object of the present invention is to facilitate speed adjustment for a lane change by a driver through an acceleration operation when a merge assist control for assisting a lane change of a host vehicle to another lane is not executed in a merge section where a traveling lane on which the host vehicle travels merges to another lane.

Means for solving the problems

In a vehicle control method according to an aspect of the present invention, a convergence section where a traveling lane on which a host vehicle travels converges to another lane is detected on a route on which the host vehicle is scheduled to travel, it is determined whether or not convergence assist control for assisting a lane change of the host vehicle to another lane is executed in the convergence section, and if it is determined that the convergence assist control is not executed in the convergence section, a speed of the host vehicle is controlled to be equal to or lower than a predetermined speed before the host vehicle passes through a start point of the convergence section.

ADVANTAGEOUS EFFECTS OF INVENTION

According to one aspect of the present invention, in a case where the confluence assist control is not executed, it becomes easy for the driver to perform speed adjustment for a lane change by an acceleration operation.

The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

Fig. 1 is a schematic configuration diagram of an example of a vehicle control device according to an embodiment.

Fig. 2 is a diagram showing an example of the bus section.

Fig. 3 is a block diagram showing an example of a functional configuration of the controller shown in fig. 1.

Fig. 4 is an explanatory diagram showing an example 2 of the bus section in which the bus assist control is not executed.

Fig. 5 is an explanatory diagram showing example 3 of the bus section in which the bus assist control is not executed.

Fig. 6 is an explanatory diagram showing an example 4 of the bus section in which the bus assist control is not executed.

Fig. 7 is an explanatory diagram showing an example 5 of the bus section in which the bus assist control is not executed.

Fig. 8 is an explanatory diagram of a condition in which the bus assist control is not executed.

Fig. 9 is a flowchart of an example of a vehicle control method according to the embodiment.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

(Structure)

Refer to fig. 1. The vehicle control device 1 performs automatic driving control in which a driver automatically drives the vehicle (hereinafter, referred to as "own vehicle") without involvement of the driver and driving assistance control for assisting the driver in driving the vehicle, based on a running environment around the vehicle to which the vehicle control device 1 is mounted.

The driving assistance control may include automatic steering, automatic braking, constant speed running control, lane keeping control, merge assistance control, and the like.

The vehicle control device 1 includes: the system comprises an external sensor 2, an internal sensor 3, a positioning device 4, a map database 5, a communication device 6, a navigation system 7, a running control unit 8, an actuator 9 and a controller 10. In addition, the map database in the added drawings is described as "map DB".

The external sensor 2 is a sensor that detects the surroundings of the host vehicle, for example, objects around the host vehicle. The external sensor 2 may also include, for example, a camera 11 and a distance measuring device 12.

The camera 11 and the distance measuring device 12 detect an object (for example, other vehicles, pedestrians, white lines such as lane boundary lines or lane dividing lines, traffic lights provided on or around a road, stop lines, signs, buildings, utility poles, curbs, crosswalks, and other ground objects) existing around the host vehicle, and detect the surrounding environment of the host vehicle such as the relative position of the object with respect to the host vehicle and the relative distance between the host vehicle and the object.

The camera 11 may be a stereo camera, for example. The camera 11 may be a monocular camera, and the distance to the object may be calculated by photographing the same object from a plurality of viewpoints with the monocular camera. Further, the distance to the object may be calculated from the ground contact position of the object detected from the captured image of the monocular camera.

The distance measuring device 12 may be, for example, a Laser Range Finder (LRF), a radar unit, or a Laser scanning unit.

The camera 11 and the distance measuring device 12 output the information of the detected ambient environment, that is, the ambient environment information to the navigation system 7, the travel control unit 8, and the controller 10.

The internal sensor 3 is a sensor that detects the running state of the vehicle. The internal sensor 3 may have, for example, a wheel speed sensor 13. The wheel speed sensor 13 detects the wheel speed of the own vehicle.

The interior sensor 3 may have, for example, an acceleration sensor that detects acceleration occurring in the own vehicle, or a gyro sensor that detects an angular velocity of the own vehicle.

The internal sensor 3 outputs traveling state information, which is information on the detected traveling state, to the navigation system 7, the traveling control unit 8, and the controller 10.

The positioning device 4 receives radio waves from a plurality of navigation satellites to acquire the current position of the vehicle, and outputs the acquired current position of the vehicle to the navigation system 7, the travel control unit 8, and the controller 10. The Positioning device 4 may include, for example, a GPS (Global Positioning System) receiver or a Global Positioning System (GNSS) receiver other than a GPS receiver.

The map database 5 stores road map data.

The road map data includes: the shape (lane property) and coordinate information of a white line such as a lane boundary line or a lane dividing line, the height of a road or a white line, and the coordinate information of a ground object such as a traffic signal, a stop line, a sign, a building, a utility pole, a curb, or a crosswalk provided on or around the road.

The road map data may further include information on the type of road, the gradient of the road, the number of lanes, a limit speed (legal speed), a track width, the presence or absence of a merging point, and the like. The road category may include, for example, a general road and an expressway.

The map database 5 is referred to by the navigation system 7, the travel control unit 8, and the controller 10.

The communication device 6 performs wireless communication with a communication device outside the vehicle. The communication method of the communication device 6 may be, for example, wireless communication of a public mobile telephone network, vehicle-to-vehicle communication, road-to-vehicle communication, or satellite communication.

The navigation system 7, the travel control unit 8, and the controller 10 may acquire road map data from an external information processing device via the communication device 6 instead of or in addition to the map database 5.

The navigation system 7 performs route guidance for the occupant of the host vehicle to a destination set on a map by the driver of the host vehicle. The navigation system 7 estimates the current position of the vehicle using various information input from the external sensor 2, the internal sensor 3, and the positioning device 4, generates a route to a destination, and provides route guidance to the occupant. The navigation system 7 outputs the route information to the travel control unit 8 and the controller 10.

The travel control unit 8 performs driving assistance control such as constant speed travel control and merge assistance control of the vehicle, or automatic driving control.

For example, in the constant speed travel control, a set speed is set in accordance with an input operation by the driver or information on the speed limit output from the navigation system 7. The travel control unit 8 drives the actuator 9 to adjust the speed of the vehicle so that the vehicle travels at a set speed. When the driver performs a braking operation (e.g., an operation of a brake pedal), the travel control unit 8 stops the constant speed travel control.

For example, the merge assist control may include an automatic merge control that automatically changes the lane of the host vehicle in the merge section. In the automatic confluence control, the travel control unit 8 detects a confluence section on a predetermined route on which the vehicle has started traveling from the present position of the vehicle, road map data of the map database 5, and route information output from the navigation system 7.

The travel control unit 8 sets a target travel track on which the host vehicle changes lanes in the confluence section, based on the surrounding environment detected by the external sensor 2 and the traveling state of the host vehicle detected by the internal sensor 3. The travel control unit 8 drives the actuator 9 to perform steering control and acceleration/deceleration control of the vehicle so that the vehicle travels on the target travel track.

Further, the merge assist control may assist the merge of the host vehicle in the merge section by performing a turn signal control in addition to or instead of the steering control and the acceleration/deceleration control. The bus assist control may assist the bus of the host vehicle by presenting a display such as a speed and a steering to the driver or indicating a timing.

For example, in the automatic convergence control, a target travel track on which the host vehicle should travel is set based on the current position of the host vehicle, road map data, route information, and surrounding environment, and the travel state of the host vehicle. The travel control unit 8 drives the actuator 9 to perform steering control and acceleration/deceleration control of the vehicle so that the vehicle travels on the target travel track.

The actuator 9 operates a steering wheel, an accelerator opening degree, and a brake device of the vehicle based on a control signal output from the travel control unit 8, and generates a vehicle behavior of the vehicle.

The actuator 9 includes a steering actuator 16, an accelerator opening actuator 17, and a brake control actuator 18.

The steering actuator 16 controls the steering direction and the steering amount of the steering of the vehicle. The accelerator opening actuator 17 controls the accelerator opening of the vehicle. The brake control actuator 18 controls a braking operation of a brake device of the vehicle.

The controller 10 is an Electronic Control Unit (ECU) that performs bus assist of the vehicle. The controller 10 includes a processor 14 and a storage device 15, among other peripheral components. The processor 14 is, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit).

The controller 10 may be an electronic control unit integrated with the travel control unit 8, or may be a separate electronic control unit.

The storage device 15 may include a semiconductor storage device, a magnetic storage device, and an optical storage device. The storage device 15 may include a register, a cache memory, and a memory such as a rom (read Only memory) and a ram (random Access memory) used as a main storage device.

The controller 10 may be implemented by a functional logic circuit provided in a general-purpose semiconductor integrated circuit. For example, the controller 10 may include a Programmable Logic Device (PLD) such as a Field-Programmable Gate Array (FPGA), and the like.

The controller 10 detects a bus section on a predetermined travel path from which the host vehicle detects travel.

Refer to fig. 2. The controller 10 detects a confluence section 23 where the traveling lane 21 traveled by the host vehicle 20 is confluent to the other lane 22 on a predetermined traveling path. For example, the other lane 22 may be a trunk line, or may be a junction lane in which the travel lane 21 joins the trunk line. Hereinafter, the travel lane 21 on which the host vehicle 20 travels is described as a "merging lane", and the other lane 22 on which the travel lanes 21 merge is described as a "merging destination lane".

The confluence section 23 is a section from the start point 24 to the end point 25, and the confluence lane 21 and the confluence destination lane 22 are partitioned by a lane dividing line of a dotted line.

The controller 10 determines whether or not to execute the confluence assist control for assisting the lane change of the host vehicle 20 from the confluence lane 21 to the confluence destination lane 22 in the detected confluence section. For example, the controller 10 determines whether or not to execute automatic merge control for lane changing the host vehicle 20 from the merge lane 21 to the merge destination lane 22 in the detected merge section. For example, the controller 10 may determine whether or not to execute the automatic bus control based on the presence or absence of road map data or a road shape used for the automatic bus control.

When the bus assist control is not executed in the detected bus section, the controller 10 controls the speed of the host vehicle 20 to be equal to or lower than the predetermined speed v0 before the host vehicle 20 passes through the starting point 24 of the bus section.

In this case, for example, the controller 10 outputs the predetermined speed v0 to the vehicle speed control unit 19 of the travel control unit 8 shown in fig. 1. For example, when the traveling speed of the host vehicle 20 is higher than the predetermined speed v0, the vehicle speed control unit 19 may decelerate the host vehicle 20 to the predetermined speed v0 before the host vehicle 20 passes through the starting point 24 of the confluence section. For example, when the host vehicle 20 is traveling at or below the predetermined speed v0, the vehicle speed control unit 19 may restrict acceleration so that the speed of the host vehicle 20 does not exceed the predetermined speed v 0.

In this way, by setting the speed of the host vehicle 20 to the predetermined speed v0 or less before the host vehicle 20 passes through the start point 24 of the confluence section 23, the section length in which the driver can accelerate the host vehicle can be secured in the confluence section 23. This makes it easy for the driver to perform speed adjustment for a lane change only by an acceleration operation.

Next, referring to fig. 3, a functional configuration of the controller 10 will be described. The controller 10 has: the merge search unit 31, the merge assist availability determination unit 32, the preceding vehicle recognition unit 33, the following vehicle estimation unit 34, the vehicle speed estimation unit 35, and the deceleration method determination unit 36.

The functions of the confluence searching section 31, the confluence assistance availability judging section 32, the preceding vehicle recognizing section 33, the following vehicle estimating section 34, and the deceleration method determining section 36 can be realized by, for example, the processor 14 of the controller 10 executing a computer program stored in the storage device 15.

The merge search unit 31 estimates the current position of the vehicle 20 from the measurement result of the current position of the vehicle by the positioning device 4, the surrounding environment detected by the external sensor 2, and the road map data in the map database 5.

The merge search unit 31 searches for a merge section that exists on a predetermined travel route to be traveled from the current position of the host vehicle in the future from the road map data, based on the route information output from the navigation system 7. The convergence searching unit 31 acquires information such as the shape of the detected convergence section, the speed limit of the convergence lane, and the speed limit of the convergence destination lane.

The merge search unit 31 may use road map data received from an external information processing device via the communication device 6, in addition to or instead of the road map data of the map database 5.

The bus searching unit 31 outputs the acquired information of the bus section to the bus assist availability determining unit 32 and the deceleration method determining unit 36.

The bus searching unit 31 may output only the information of the bus section closest to the host vehicle among the bus sections on the predetermined travel route, or may output the information of a plurality of bus sections in the order of moving away from the host vehicle.

The bus assist availability determining unit 32 determines whether or not the bus assist control by the travel control unit 8 can be executed based on the information of the bus section output from the bus searching unit 31.

Refer to fig. 2. For example, when the section length Lj of the bus section 23 is shorter than a predetermined length, the bus assist availability determining unit 32 determines that the bus assist control cannot be executed.

For example, when the curvature radius of the merging lane 21 is shorter than the predetermined length or when the curvature radius of the merging destination lane 22 is shorter than the predetermined length, the merging assistance availability determination unit 32 may determine that the merging assistance control cannot be executed.

Refer to fig. 4. When the difference in height between the merging lane 21 and the merging destination lane 22 is equal to or greater than a predetermined value and the merging lane 21 is lower than the merging destination lane 22, the merging destination lane 22 is hidden in a blind spot caused by the road structure.

Therefore, the merge assist availability determination unit 32 may determine that the merge assist control cannot be executed when the difference in height between the merge lane 21 and the merge destination lane 22 is equal to or greater than a predetermined value and the merge lane 21 is lower than the merge destination lane 22.

Refer to fig. 5. When the shade 28 having a predetermined height or more is present between the merging lane 21 and the merging destination lane 22, the merging destination lane 22 is hidden in a blind spot caused by the shade 28.

Therefore, when the shield 28 having a predetermined height or more exists between the merging lane 21 and the merging destination lane 22, the merging assist availability determination unit 32 may determine that the merging assist control cannot be executed.

Further, depending on the road shape of the merging lane 21 and the road shape of the merging destination lane 22, the traffic condition of the merging destination lane 22 may not be determined in front of the merging section 23, and the merging assist control may not be executed. Fig. 6 and 7 show an example of a case where the traffic condition of the merging destination lane 22 cannot be determined from the merging lane 21 according to the road shape.

Refer to fig. 6. If the difference θ between the traveling direction 41 of the merging lane 21 and the traveling direction 42 of the merging destination lane 22 at the point located a predetermined distance D1 before the merging section 23 is large, the length L2 of the range of the merging destination lane 22 that enters the detection range 43 of the external sensor 2 in front of the host vehicle 20 (that is, the range in which the traffic condition can be detected by the external sensor 2) becomes short, and the traffic condition of the merging destination lane 22 may not be determined.

Refer to fig. 7. If the difference θ between the traveling direction 41 of the merging lane 21 and the traveling direction 42 of the merging destination lane 22 becomes larger and approaches 180 degrees, the other vehicles 29 traveling in the merging destination lane 22 overlap each other as viewed from a point a predetermined distance D1 before the merging section 23, and the traffic condition of the merging destination lane 22 may not be determined.

Therefore, when the difference θ between the traveling direction 41 of the bus lane 21 and the traveling direction 42 of the bus destination lane 22 at the point located a predetermined distance D1 before the bus section 23 is equal to or greater than a predetermined threshold value, the bus assist availability determination unit 32 determines that the bus assist control cannot be executed.

The threshold value of the difference θ may be set according to the threshold value L3 of the length of the range in which the traffic condition of the merging destination lane 22 should be detected by the external sensor 2.

Refer to fig. 8. For example, the detection range of the external sensor 2 is a range of the azimuth angle width α centered on the traveling direction 41 of the host vehicle 20, and the length of a perpendicular line from a point a predetermined distance D1 before the merging section 23 to an extension line of the traveling direction 42 of the merging destination lane 22 is defined as P.

The length L2 of the detection range of the merge-destination lane 22 of the external sensor 2 can be obtained by the following expression (1).

L2＝P(tan(90°－θ+α/2)－tan(90°－θ－α/2))…(1)

The threshold value of the difference θ can be calculated as the upper limit value of the range of the difference θ longer than the threshold value L3 by the length L2.

Refer to fig. 7. A distance from a point a predetermined distance D1 before the merging section 23 to the merging destination lane 22 is denoted as D2.

If the distance D2 is too long, the detection resolution of another vehicle 29 on the merging destination lane 22 that enters the detection range 43 of the external sensor 2 is lowered, and the traffic condition of the merging destination lane 22 may not be determined.

Therefore, the bus assist availability determining unit 32 may determine that the bus assist control cannot be executed when the distance D2 from the point that is a predetermined distance D1 before the bus section 23 to the bus destination lane 22 is a predetermined value or more. Reference numeral 44 denotes a point at which an extension of the traveling direction 41 of the traveling lane 21 from the point a predetermined distance D1 before the merging section 23 intersects the merging destination lane 22.

The confluence assistance availability determining unit 32 may determine that the confluence assistance control cannot be executed when the road map data of the confluence section 23 cannot be acquired or when the travel control unit 8 does not have the confluence assistance function.

The confluence assist propriety judging section 32 outputs the judgment result to the deceleration method determining section 36.

The preceding vehicle recognition unit 33 acquires the position of the preceding vehicle 26 traveling in the merging lane 21 in front of the host vehicle 20, based on the surrounding environment information output by the external sensor 2 (see fig. 2). The preceding vehicle recognition unit 33 estimates the speed of the preceding vehicle 26 from the position information of the preceding vehicle 26, and estimates the acceleration of the preceding vehicle 26 from the speed information of the preceding vehicle 26. The preceding vehicle recognition unit 33 may directly measure the speed of the preceding vehicle 26 without estimation from the position information. The preceding vehicle recognition unit 33 may acquire the position information, the speed information, and the acceleration information of the preceding vehicle 26 via the communication device 6.

The preceding vehicle recognition unit 33 outputs the position information, the speed information, and the acceleration information of the preceding vehicle 26 to the deceleration method determination unit 36.

The rear vehicle estimation unit 34 acquires position information and speed information of the rear vehicle 27 traveling behind the host vehicle 20 on the merge lane 21, based on the surrounding environment information output by the external sensor 2 (see fig. 2). The rear vehicle estimation unit 34 may estimate the position information and the speed information of the rear vehicle 27 from the position and the speed of the host vehicle 20, without depending on the surrounding environment information output by the external sensor 2. The rear vehicle estimation portion 34 may also acquire the position information and the speed information of the rear vehicle 27 through the communication device 6.

The rear vehicle estimation unit 34 outputs the position information and the speed information of the rear vehicle 27 to the deceleration method determination unit 36.

The vehicle speed estimating section 35 estimates the speed of the own vehicle from the wheel speed of the own vehicle 20 detected by the wheel speed sensor 13. The vehicle speed estimating unit 35 outputs the speed information of the own vehicle to the deceleration method determining unit 36.

When the confluence assist availability determining unit 32 determines that the confluence assist control cannot be executed, the deceleration method determining unit 36 determines the deceleration method for decelerating the speed of the host vehicle 20 to the predetermined speed v0 or less at the latest before the host vehicle 20 passes through the starting point 24 of the confluence section 23.

Specifically, the deceleration method determination unit 36 determines the predetermined speed v0, the deceleration completion point, the deceleration d0, and the deceleration start point.

For example, the deceleration method determining unit 36 may calculate the predetermined speed v0 from the lowest speed among the speed of the preceding vehicle 26, the speed limit of the merging lane 21, and the speed limit of the merging destination lane 22.

For example, the predetermined speed v0 may be 10 km or more per hour slower than the lowest speed among the speed of the front vehicle 26, the speed limit of the merging lane 21, and the speed limit of the merging destination lane 22.

For example, the predetermined speed v0 may be 20% or more lower than the lowest speed among the speed of the front vehicle 26, the speed limit of the merging lane 21, and the speed limit of the merging destination lane 22.

The predetermined speed v0 may be an average value of the lowest speed among the speed of the preceding vehicle 26, the speed limit of the merging lane 21, and the speed limit of the merging destination lane 22, and the legal creep speed (10 km/h).

However, when the predetermined speed v0 calculated through the above-described processing is lower than the legal creep speed, the deceleration method determining unit 36 may reset the slower of the legal creep speed and the speed of the preceding vehicle 26 to the predetermined speed v 0.

Next, the deceleration method determination unit 36 calculates a deceleration completion point at which the deceleration of the speed of the host vehicle 20 is completed to the predetermined speed v 0.

For example, the deceleration method determining unit 36 may use the start point 24 of the confluence section 23 as the deceleration completion point. In this case, the host vehicle is decelerated from a deceleration start point immediately before the start point 24 to a predetermined speed v0 at a constant deceleration d 0.

For example, the deceleration method determining unit 36 may determine a point a predetermined distance before the start point 24 of the confluence section 23 as the deceleration completion point. In this case, the speed of the vehicle from the deceleration completion point to the start point 24 may be maintained at the predetermined speed v 0.

For example, the deceleration-method determining unit 36 may determine the deceleration completion point so that the speed of the host vehicle reaches the speed limit v1 of the merging-destination lane 22 before the host vehicle passes through the start point 24 when the host vehicle accelerates from the deceleration completion point at the predetermined acceleration a.

Specifically, a point located by the distance D determined by the following expression (2) and located before the start point 24 may be determined as the deceleration completion point.

D＝(v1²－v0²)/2a…(2)

The acceleration a may be set within a range of an acceleration used by a standard driver when accelerating, and may be, for example, 0.8m/s 2. Further, the acceleration pattern of the driver of the vehicle may be recorded, and a value obtained by subtracting a certain ratio from the highest acceleration in the recorded acceleration range may be used as the acceleration a.

Next, the deceleration method determination unit 36 calculates a deceleration d0 that decelerates the speed of the host vehicle to a predetermined speed v 0.

When there is no preceding vehicle 26 ahead of the host vehicle, the deceleration-method determining unit 36 may determine the deceleration d0 to be greater than the deceleration used when the travel control unit 8 decelerates the host vehicle in the constant-speed travel control.

For example, in the constant speed running control performed by the running control unit 8, when the host vehicle is decelerated to a set speed in a case where there is no other vehicle that is an obstacle in front of the host vehicle, the host vehicle is decelerated at a constant deceleration da. For example, when the set speed is changed so as to be further reduced, the host vehicle is decelerated at a constant deceleration da in the constant speed travel control.

For example, the deceleration method determining unit 36 may set the deceleration d0 to a value larger than the deceleration da. By decelerating at the deceleration d0 that is larger than the deceleration da used in the constant speed running control, the driver can be notified that the confluence assist control is not performed.

When the rear vehicle 27 is present, the deceleration method determining unit 36 may calculate the deceleration d0 in consideration of the inter-vehicle time between the rear vehicle 27 and the host vehicle so that the inter-vehicle time between the rear vehicle 27 and the host vehicle is not too short.

For example, the deceleration method determining unit 36 may calculate the deceleration db that is equal to or greater than 1 second after 1 second and is ensured in the inter-vehicle time with the rear vehicle 27 according to the following equation (3).

db＝2d－4vr+2vs…(3)

In equation (3), d is the inter-vehicle distance between the host vehicle and the rear vehicle 27 before deceleration, vr is the speed of the rear vehicle 27, and vs is the speed of the host vehicle before deceleration.

The deceleration method determination unit 36 may determine the deceleration d0 to be equal to or greater than a smaller deceleration of the deceleration da used for the constant speed travel control and the deceleration db corresponding to the time between the rear vehicle 27 and the host vehicle.

However, when deceleration dr at which the brake lamp can be turned on during regenerative braking is set as the lower limit of deceleration and deceleration da or deceleration db is smaller than deceleration dr, deceleration d0 may be set as deceleration dr. For example, deceleration dr may be 0.7m/s 2.

The upper limit du of the allowable deceleration may be determined in advance, and the deceleration d0 may be set as the upper limit du when the deceleration da or the deceleration db is larger than the upper limit du. For example, the upper limit du of deceleration may be 1.3m/s 2.

The above-described upper limit du, lower limit dr, and relationship with the rear vehicle 27 are merely examples. The upper limit du of the deceleration may be determined in a range where the occupant is not disturbed by sudden deceleration, and the lower limit dr of the deceleration may be determined in a range where the driver can perceive deceleration. The relationship with the rear vehicle 27 may be determined so as not to significantly increase the risk of collision by the rear vehicle 27.

On the other hand, when the front vehicle 26 is present ahead of the host vehicle, the deceleration method determining unit 36 may calculate the deceleration d0 based on the deceleration db based on the inter-vehicle time between the rear vehicle 27 and the host vehicle, and the deceleration df of the front vehicle.

For example, the deceleration method determining unit 36 may determine which of the deceleration db and the deceleration df is larger. When deceleration df is equal to or greater than deceleration db, deceleration d0 may be determined so as to be equal to or greater than deceleration df. When deceleration df is smaller than deceleration db, deceleration d0 may be determined so as to be equal to or larger than deceleration df and equal to or smaller than deceleration db.

Next, the deceleration method determination unit 36 calculates a deceleration start point satisfying the predetermined speed v0, the deceleration completion point, and the deceleration d 0.

The deceleration method determining unit 36 outputs the calculated deceleration start point, deceleration d0, and predetermined speed v0 to the vehicle speed control unit 19 of the travel control unit 8.

The vehicle speed control unit 19 decelerates the own vehicle to the predetermined speed v0 at a constant deceleration d0 from the deceleration start point output from the deceleration method determination unit 36.

For example, when the start point 24 of the confluence section 23 is a deceleration completion point, the vehicle speed control unit 19 may set the speed of the host vehicle at the start point 24 to the predetermined speed v0 by decelerating the host vehicle at the constant deceleration d0 from the deceleration start point immediately before the start point 24.

For example, when the point located a predetermined distance D from the start point 24 of the junction section 23 is the deceleration completion point, the vehicle speed control unit 19 decelerates the host vehicle from the deceleration start point at a constant deceleration D0, sets the speed of the host vehicle at the predetermined speed v0 at the deceleration completion point, and maintains the speed of the host vehicle at the predetermined speed v0 from the deceleration completion point to the start point 24.

The vehicle speed control unit 19 determines whether or not the deceleration of the host vehicle is completed. After the deceleration of the host vehicle is completed, the vehicle speed control unit 19 determines whether or not the manual merge operation by the driver in the merge section 23 is completed.

When the speed of the host vehicle is equal to or lower than the set speed of the constant-speed travel control by the travel control unit 8 (for example, the speed limit of the merging destination lane 22) after the manual merge operation by the driver is completed, the vehicle speed control unit 19 accelerates the host vehicle up to the set speed.

In addition, when the bus assist control is not performed according to the determination result of the bus assist availability determining portion 32, the controller 10 may broadcast to the driver that the bus assist control is not performed by means other than the deceleration of the host vehicle at the deceleration d0 (for example, an output of a voice signal or a signal display).

Further, when the driver performs an acceleration operation (for example, an accelerator pedal operation), the driver may receive the acceleration operation in priority to deceleration of the host vehicle.

(action)

Next, an example of a vehicle control method according to the embodiment will be described with reference to fig. 9.

In step S1, the bus searching unit 31 detects the bus section 23 existing on the predetermined travel route from the current position of the host vehicle to travel in the future.

In step S2, the bus assist availability determination unit 32 determines whether or not the bus assist control by the travel control unit 8 is executed in the bus section 23 detected by the bus search unit 31. In the case where the bus assist control is executed (step S2: yes), the processing proceeds to step S3. In the case where the bus assist control is not executed (step S2: no), the processing proceeds to step S4.

In step S3, the travel control unit 8 executes the merge assist control for assisting the lane change of the host vehicle from the merge lane 21 to the merge destination lane 22 in the merge section 23. After which the process ends.

On the other hand, in step S4, the deceleration method determining unit 36 calculates the predetermined speed v 0.

In step S5, the deceleration method determination unit 36 calculates the deceleration completion point.

In step S6, the deceleration method determining unit 36 calculates the deceleration d 0.

In step S7, the deceleration method determination unit 36 calculates the deceleration start point.

The vehicle speed control unit 19 decelerates the own vehicle to the predetermined speed v0 at a constant deceleration d0 from the deceleration start point output from the deceleration method determination unit 36.

In step S8, the vehicle speed control unit 19 determines whether or not the deceleration of the host vehicle is completed. When the deceleration of the own vehicle has been completed (step S8: yes), the processing proceeds to step S9. If the deceleration of the own vehicle has not been completed (step S8: no), the processing proceeds to step S8.

In step S9, the vehicle speed control unit 19 determines whether or not the manual merge operation by the driver in the merge section 23 is completed. In the case where the manual bus operation has been completed (step S9: YES), the processing proceeds to step S10. In the case where the manual bus operation has not been completed (step S9: NO), the processing returns to step S9.

In step S10, the vehicle speed control unit 19 accelerates the own vehicle up to the set speed. After which the process ends.

(effects of the embodiment)

(1) The convergence searching part 31 detects a convergence section 23 where the convergence lane 21 on which the host vehicle 20 travels converges to the convergence destination lane 22 on a route on which the host vehicle 20 is scheduled to travel. The confluence assistance availability determining portion 32 determines whether or not the confluence section 23 performs the confluence assistance control for assisting the lane change of the host vehicle 20 to the confluence destination lane 22. When determining that the confluence assist control is not executed in the confluence section 23, the deceleration method determining section 36 and the vehicle speed control section 19 control the speed of the vehicle 20 to be equal to or lower than the predetermined speed v0 before the vehicle 20 passes through the start point 24 of the confluence section 23.

In this way, by setting the speed of the host vehicle 20 to the predetermined speed v0 or less before the host vehicle 20 passes through the start point 24 of the confluence section 23, the section length in which the driver can accelerate the host vehicle in the confluence section 23 can be secured. This makes it easy for the driver to perform speed adjustment for a lane change only by an acceleration operation.

If speed adjustment for a lane change is performed in both of an acceleration operation (e.g., an accelerator pedal operation) and a braking operation (e.g., a braking operation), the pedal alternate-depression operation between the accelerator pedal and the brake pedal is complicated. By performing the speed adjustment only with the acceleration operation, a complicated alternate pedal depression operation can be avoided.

In particular, when the pedals from the brake pedal to the accelerator pedal are alternately depressed, it is difficult to predict the acceleration with respect to the depression amount of the accelerator pedal. Further, when the pedal is alternately depressed from the brake pedal to the accelerator pedal, the engine rotation speed is low, and therefore a desired acceleration may not be obtained.

By performing the speed adjustment only by the acceleration operation, the acceleration of the vehicle can be easily predicted by continuously increasing or decreasing the depression amount of the accelerator pedal.

Further, when the driver performs a braking operation (for example, an operation of a brake pedal), the running control unit 8 stops the constant speed running control. Therefore, if the brake operation is performed for the confluence, not only the confluence assist control is not performed, but also the constant speed running control is stopped.

By performing the speed adjustment only with the acceleration operation, the constant-speed running control can be continued even if the confluence assist control is not performed.

(2) The predetermined speed v0 may be 10 km or more per hour slower than the lowest speed among the speed limit of the merging lane 21 in which the host vehicle 20 travels, the speed limit of the merging destination lane 22, and the traveling speed of the preceding vehicle 26 traveling ahead of the host vehicle 20.

By limiting the speed of the host vehicle 20 to such a predetermined speed v0, it is possible to promptly notify the driver that the merge assist control is not being executed.

(3) When determining that the confluence assisting control is not executed in the confluence section 23, the deceleration method determining section 36 and the vehicle speed control section 19 reduce the speed of the host vehicle 20 to the predetermined speed v0 before the host vehicle 20 passes through the start point 24.

By decelerating the host vehicle 20 to such a predetermined speed v0, it is possible to promptly notify the driver that the convergence assist control is not being executed.

(4) The deceleration-method determining unit 36 determines a deceleration completion point at which the speed of the host vehicle 20 is decelerated to a predetermined speed so that the speed of the host vehicle 20 can reach the speed limit of the merging-destination lane 22 before the host vehicle 20 passes the start point 24 when the host vehicle 20 is accelerated at a predetermined acceleration a from the deceleration completion point.

Thus, since deceleration can be completed so that the predetermined acceleration a is accelerated to a speed necessary for the confluence before the start point 24 of the confluence section 23, the confluence operation is performed by an acceleration operation that does not give a sense of discomfort to the driver.

(5) The travel control unit 8 may have an automatic constant speed travel function of causing the host vehicle 20 to travel at a set speed. The deceleration method determining unit 36 may set the deceleration d0 that decelerates the speed of the host vehicle 20 to the predetermined speed v0 to be larger than the deceleration da that is decelerated by the automatic constant speed running function when the set speed is reduced.

By decelerating the host vehicle 20 at the large deceleration d0 in this way, it is possible to promptly notify the driver that the merge assist control is not being executed.

(6) The travel control unit 8 has an automatic constant speed travel function of causing the host vehicle 20 to travel at a set speed. The vehicle speed control unit 19 accelerates the host vehicle 20 up to the set speed when the speed of the host vehicle 20 is equal to or lower than the set speed after the manual merge operation by the driver in the merge section 23 is completed.

Thus, after the manual merge operation by the driver is completed, the travel at the set speed by the automatic constant speed travel is resumed.

The terms of all examples and conditions described herein are intended for educational purposes so that the reader may help to understand the present invention and the concept provided by the inventor for the development of technology, and should not be construed as being limited to the specifically described examples and conditions described above and the configuration of the examples of the present specification that show the superiority and inferiority of the present invention. Embodiments of the present invention have been described in detail, but it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and scope of the invention.

Description of the reference symbols

1 … vehicle control device, 2 … external sensor, 3 … internal sensor, 4 … positioning device, 5 … map database, 6 … communication device, 7 … navigation system, 8 … travel control unit, 9 … actuator, 10 … controller, 11 … camera, 12 … distance measuring device, 13 … wheel speed sensor, 14 … processor, 15 … storage device, 16 … steering actuator, 17 … accelerator opening actuator, 18 … brake control actuator, 19 … vehicle speed control unit, 20 … own vehicle, 21 … confluence lane, 22 … confluence destination, 23 … confluence section, 24 … start point, 25 … end point, 26 … front vehicle, 27 … rear vehicle, 31 … search unit, 32 … confluence assist possibility determination unit, 33 … front vehicle recognition unit, 34 … rear vehicle estimation unit, 8235 vehicle speed estimation unit, and 36 … speed reduction method.