Suspension control device
阅读说明:本技术 悬架控制装置 (Suspension control device ) 是由 糟谷贤太郎 一丸修之 平尾隆介 于 2018-09-21 设计创作,主要内容包括:本发明提供悬架控制装置,通过将基于路面输入的相对位移和基于驾驶员的车辆操作的相对位移分开,能够提高弹簧上速度的推定精度。本发明的悬架控制装置具有控制各个衰减力调整式缓冲器的衰减特性的控制装置。控制装置具有:外力计算部,其由从物理量提取部输出的物理量算出作用于车身的总外力;操作力计算部,其算出伴随着车辆操作引起的负荷移动而施加于各个衰减力调整式缓冲器上的操作起因力;车辆动作提取装置,其从外力计算部算出的总外力分出由操作力计算部算出的操作起因力,求出由路面输入引起的外力。(The invention provides a suspension control device, which can improve estimation accuracy of speed on a spring by separating relative displacement based on road surface input and relative displacement based on vehicle operation of a driver. The suspension control device of the present invention includes a control device for controlling the damping characteristics of each damping force adjustable shock absorber. The control device has: an external force calculation unit that calculates a total external force acting on the vehicle body from the physical quantity output from the physical quantity extraction unit; an operation force calculation unit that calculates operation-induced forces that are applied to the damping force adjustment dampers in accordance with load movement caused by vehicle operation; and a vehicle behavior extraction device for obtaining an external force due to a road surface input by dividing the operation-induced force calculated by the operation force calculation unit from the total external force calculated by the external force calculation unit.)
1. A suspension control device is provided with:
damping force adjusting dampers, each of which is disposed between a vehicle body and each wheel of a vehicle and changes damping characteristics in response to an external command;
a physical quantity extraction unit that detects or estimates a physical quantity based on a relative displacement between the vehicle body and each of the wheels;
a control device that controls damping characteristics of the damping force adjustable shock absorbers;
the control device has:
an external force calculation unit that calculates a total external force acting on the vehicle body from the physical quantity output from the physical quantity extraction unit;
an operation force calculation unit that calculates an operation-induced force applied to each of the damping force adjustable dampers in accordance with a load movement caused by a vehicle operation;
and a vehicle behavior extracting unit that divides the operation-induced force calculated by the operation force calculating unit from the total external force calculated by the external force calculating unit and obtains an external force due to road surface input.
2. The suspension control apparatus according to claim 1,
the operation-causing force includes an inertial force generated by acceleration and deceleration and steering of the vehicle or a force generated by a suspension geometry.
3. The suspension control apparatus according to claim 1,
the physical quantity extraction unit is provided with a vehicle height sensor.
4. The suspension control apparatus according to claim 1,
the control device has:
a vertical force calculation unit that obtains a vertical force of the vehicle body;
an acceleration calculation unit that calculates an acceleration from the vertical force obtained by the vertical force calculation unit;
a sprung velocity estimating unit that estimates a sprung velocity of the vehicle body based on the acceleration calculated by the acceleration calculating unit;
and a damping characteristic determination unit that determines a damping characteristic of each of the damping force adjustable dampers based on the sprung velocity determined by the sprung velocity estimation unit.
5. The suspension control apparatus according to claim 4,
further comprises a mass calculation unit for calculating the mass of the vehicle body from the displacement calculated by the physical quantity extraction unit,
the acceleration calculating unit calculates the acceleration using the vertical force calculated by the vertical force calculating unit and the mass calculated by the mass calculating unit.
Technical Field
The present invention relates to a suspension control device mounted on a vehicle such as an automobile, for example, and controlling vibration of the vehicle.
Background
In general, as a suspension control device mounted on a vehicle such as an automobile, there is known a suspension control device in which a damping force adjusting type damper capable of adjusting a damping force is provided between a vehicle body and each axle, and a damping force characteristic of the damper is variably controlled based on a detection signal from a vehicle height sensor (for example, see patent document 1).
Disclosure of Invention
Technical problem to be solved by the invention
Patent document 1 discloses a configuration for estimating the sprung state quantity from information of a vehicle height sensor and a vehicle CAN signal. However, the sprung state quantity in this case is a value in which sprung displacement (steering, braking) by the operation of the driver and relative displacement by the road surface input are mixed. Therefore, the estimation accuracy of the sprung state quantity may be lowered.
The present invention aims to provide a suspension control device capable of separating a relative displacement based on a road surface input and a relative displacement based on a vehicle operation by a driver, and improving estimation accuracy of a sprung mass velocity having a high contribution rate in ride comfort control.
Means for solving the problems
According to one embodiment of the present invention, a suspension control device is provided. The suspension control device includes: damping force adjusting dampers, each of which is disposed between a vehicle body and each wheel of a vehicle and changes damping characteristics in response to an external command; a physical quantity extraction unit that detects or estimates a physical quantity based on a relative displacement between the vehicle body and each of the wheels; a control device that controls damping characteristics of the damping force adjustable shock absorbers; the control device has: an external force calculation unit that calculates a total external force acting on the vehicle body from the physical quantity output from the physical quantity extraction unit; an operation force calculation unit that calculates an operation-induced force applied to each of the damping force adjustable dampers in accordance with a load movement caused by a vehicle operation; and a vehicle behavior extracting unit that divides the operation-induced force calculated by the operation force calculating unit from the total external force calculated by the external force calculating unit and obtains an external force due to road surface input.
According to one embodiment of the present invention, the operation-induced force calculated by the operation-force calculating unit can be divided from the total external force calculated by the external-force calculating unit, and the external force caused by the road surface input can be obtained. In other words, by subtracting the relative displacement due to the inertial force caused by the operation of the driver from the relative displacement (physical quantity) between the vehicle body and the wheel, which is detected and estimated by the physical quantity extraction unit such as the vehicle height sensor, for example, the relative displacement based on the road surface input and the relative displacement based on the operation of the driver can be separated, and the estimation accuracy of the sprung velocity having a high contribution rate in the ride comfort control can be improved.
Drawings
Fig. 1 is a perspective view showing a motor vehicle to which a suspension control device according to a first embodiment is applied;
fig. 2 is an explanatory diagram showing a vehicle model used for the design of the state estimating unit in the automobile of fig. 1;
FIG. 3 is a control block diagram of a controller for performing ride comfort control of the vehicle shown in FIG. 1;
fig. 4 is a control block diagram specifically showing the state estimating unit in fig. 3;
FIG. 5 is an explanatory view showing a load shift of a motor vehicle based on a lateral acceleration;
FIG. 6 is an explanatory diagram showing the load shifting of the motor vehicle based on the front-rear acceleration;
fig. 7 is a schematic view showing the operation principle of the suspension device;
FIG. 8 is a characteristic diagram showing relative displacements of 4 rounds in time series;
FIG. 9 is a characteristic diagram showing characteristics of a steering angle, sprung displacement, sprung velocity, and command current of a motor vehicle in time series;
FIG. 10 is a characteristic diagram showing the behavior of the vertical acceleration with respect to the vibration frequency of the spring of the vehicle;
fig. 11 is a control block diagram showing a state estimating unit according to the second embodiment;
fig. 12 is a control block diagram showing a part of the state estimating unit according to the third embodiment;
fig. 13 is a control block diagram showing a part of the state estimating unit according to the fourth embodiment;
fig. 14 is a control block diagram showing a damper response delay calculating unit in fig. 13 as a specific example;
fig. 15 is a characteristic diagram showing damping force characteristics in consideration of response delay of the fourth embodiment;
fig. 16 is a control block diagram showing a control command response delay calculation unit according to the fifth embodiment;
fig. 17 is a characteristic diagram showing current value characteristics in consideration of a response delay of a control command according to the fifth embodiment.
Detailed Description
Hereinafter, a suspension control device according to an embodiment of the present invention will be described in detail with reference to the drawings, taking as an example a case of being applied to a 4-wheel motor vehicle.
In order to avoid the complication of the description, the positions of the wheels of the vehicle are indicated by reference numerals with a Front Left (FL), a Front Right (FR), a Rear Left (RL), and a Rear Right (RR) respectively. When the left front, the right front, the left rear, and the right rear are collectively referred to, the reference numerals will be omitted for explanation. Similarly, the reference numerals denote front (F) and rear (R) pins. In the general terms before and after, the reference numerals are omitted from the description.
In the figure, a vehicle body 1 constitutes a vehicle body of a vehicle (automobile). On the lower side of the vehicle body 1, for example, as shown in fig. 2, a front left wheel 2FL, a front right wheel 2FR, a rear left wheel 2RL, and a rear right wheel 2RR (hereinafter collectively referred to as wheels 2) are provided. The
As shown in fig. 2, a stabilizer 4F is provided between the left front wheel 2FL and the right front wheel 2FR to suppress rolling of the vehicle body 1. A stabilizer 4R is also provided between the left rear wheel 2RL and the right
The front wheel side suspension device 5 is mounted between the vehicle body 1 and the wheels 2 (the left front wheel 2FL, the right
The suspension devices 5 and 8 on the front and rear wheel sides may be configured to use, for example, air springs (not shown) of an air suspension instead of the coil springs 6 and 9 as the suspension springs. In this case, the vehicle height, which is the distance between the
Here, in the suspension devices 5 and 8 on the front and rear wheel sides, each shock absorber 7 is configured using a damping force adjusting type hydraulic shock absorber such as a semi-active shock absorber. In these shock absorbers 7, an
The
The controller 11 is constituted by a microcomputer or the like, and constitutes a control device that controls the damping characteristics of the damper 7. The Controller 11 is connected at its input side to the
As shown in fig. 3, the controller 11 includes a
As shown in fig. 4, the
The
Here, the longitudinal
The vertical
The front wheel lifting
The front wheel forward-lean/aft-lean
The damper damping
[ number 1 ]
The front wheel spring
The vertical relative
[ number 3 ]
[ number 4 ]
The relative
The vehicle motion extracting unit 23 is configured as a vehicle motion extracting unit that obtains the external force due to the road surface input by dividing the operation-induced force calculated by the operation-force calculating unit from the total external force calculated by the external-force calculating unit 15. In other words, the vehicle behavior extraction unit 23 calculates a relative displacement due to road surface disturbance (i.e., a road surface disturbance relative displacement) by subtracting the relative displacement (Δ X21offset) based on the operation by the driver from the sensor value of the
In other words, the
Among them, the vertical force calculation unit 17 (for example, the front wheel lifting
For example, as shown in fig. 5, the load movement and the jack-up-down force generated by the lateral acceleration Ay, and as shown in fig. 6, the load movement and the lift-up/down force generated by the front-rear acceleration Ax calculate the relative positional movement generated by the operation of the driver while the vehicle is running. Fig. 5 and 6 are schematic views of the situation in which these forces are applied.
As shown in fig. 5, when the relative displacement caused by the lateral acceleration Ay between the vehicle body 1 and the
[ number 5 ]
[ number 6 ]
Next, the height of the sprung center of gravity G is hg [ M ], the lateral acceleration is Ay [ M/s2], the roll angle generated by rolling is θ roll [ deg ], the sprung mass as the vehicle weight is M [ kg ], the vehicle width is T [ M ], and the load Δ W applied to each wheel 2 (i.e., the wheel loads Δ WFL, Δ WFR, Δ WRL, Δ WRR) can be calculated by the following equations 7 to 10. The dimension of the half width T/2 of the vehicle width T shown in fig. 2 corresponds to the dimensions of the widths TF1, TFr, TRl, TRr in the equations 7 to 10. In this case, for simplicity, the roll angle θ roll is calculated by setting the angle to zero (θ roll is 0) as in the following equation 11.
[ number 7 ]
[ number 8 ]
[ number 9 ]
[ number 10 ]
[ number 11 ]
Since the change in the load Δ W of each wheel (i.e., the wheel loads Δ WFL, Δ WFR, Δ WRL, Δ WRR) due to the lateral acceleration Ay calculated by the above equations 7 to 10 is equal to the value obtained by multiplying the sprung mass M of each wheel by the relative acceleration Ay as shown by the following
[ number 12 ]
[ number 13 ]
When the lateral acceleration Ay is positive (Ay > 0), the jacking-up and lowering forces JFFL, JFFR, JFRL, and JFRR can be expressed by the following
[ number 14 ]
JFF1=PCF1×Ay
[ number 15 ]
JFFR=-NCFr×Ay
[ number 16 ]
JFRL=PCR1×Ay
[ number 17 ]
JFRR=-NCRr×Ay
When the lateral acceleration Ay is zero or less (Ay is less than or equal to 0), the jacking descent forces JFFL, JFFR, JFRL and JFRR are calculated by the following equations of 18 to 21. Wherein the coefficients NCF1, PCFr, NCRR and PCRR are proportionality coefficients.
[ number 18 ]
JFF1=NCF1×Ay
[ number 19 ]
JFFR=-PCFr×Ay
[ number 20 ]
JFRL=NCR1×Ay
[ number 21 ]
JFRR=-PCRr×Ay
On the other hand, as shown in fig. 6, when the relative displacement due to the front-rear acceleration Ax is Δ X21Offset, the height hg of the sprung center of gravity G and the dimension Lwbs of the wheel base are set to Ax [ M/s2], the pitch angle due to the pitch is set to θ pitch [ deg ], and the sprung mass as the vehicle weight is set to M [ kg ], the change in the load Δ WAx on each wheel due to the front-rear acceleration Ax can be calculated by the following
[ number 22 ]
[ number 23 ]
The relative acceleration Ax generated by the front-rear acceleration Ax can be expressed by the following
[ number 24 ]
[ number 25 ]
By the dive squat (ダイブ · スクオット) caused by the forward/backward acceleration Ax, a lifting force (i.e., anti-pitching-tail forces GFFL, GFFR, GFRL, GFRR) based on the suspension geometry is generated in the spring on the vehicle body 1 side. The forces GFFL, GFFR, GFRL and GFRR are proportional to the front-to-rear acceleration Ax. Therefore, when the front-rear acceleration Ax is positive (Ax > 0), the forward-lean-resistant rear-lean forces GFFL, GFFR, GFRL, GFRR can be calculated by the following expressions of numbers 26 to 29. The coefficients ACF1, ACFr, ACR1, and ACRr are proportional coefficients when the vehicle is accelerated.
[ number 26 ]
GFFL=-ACF1×Ax
[ number 27 ]
GFFK=-ACFr×Ax
[ number 28 ]
GFRL=ACR1×Ax
[ number 29 ]
GFRR=ACRr×Ax
When the front-rear acceleration Ax is zero or less (Ax is 0 or less), the forward-lean tail tilt resistance GFFL, GFFR, GFRL, GFRR can be calculated by the following numerical expressions 30 to 33. The coefficients DCF1, DCFr, DCR1, and DCRr are proportional coefficients at the time of deceleration of the vehicle.
[ number 30 ]
GFFL=DCF1×Ax
[ number 31 ]
GFFR=DCFr×Ax
[ number 32 ]
GFRL=-DCR1×Ax
[ number 33 ]
GFRR=-DCRr×Ax
The vertical relative
[ number 34 ]
The suspension control device according to the first embodiment has the above-described configuration, and the control operation thereof will be described next.
The
Therefore, in the first embodiment, in the vertical relative
Next, the relative
In addition, the vehicle behavior extracting unit 23 divides the operation-induced force calculated by the operation force calculating unit from the total external force calculated by the external force calculating unit 15, and obtains the external force due to the road surface input. In other words, the vehicle behavior extraction unit 23 calculates the relative displacement due to the road surface disturbance (i.e., the road surface disturbance relative displacement) by subtracting the relative displacement behavior (Δ X21offset) caused by the operation of the driver from the sensor value of the
Therefore, according to the first embodiment, the relative displacement based on the road surface input (based on the sensor value of the vehicle height sensor 10) and the relative displacement (Δ X21offset) based on the operation by the driver can be separated as the road surface disturbance relative displacement, and the relative displacement based on the road surface disturbance can be calculated. Thus, the accuracy of estimating the sprung velocity with a high contribution rate can be improved by the ride comfort control, and effective ride comfort control corresponding to the road surface input can be performed.
In other words, by removing the relative displacement due to the acceleration/deceleration during the travel of the vehicle, the inertial force due to the driver's operation such as steering, and the force due to the suspension geometry such as the lift-up, the lift-down, and the lift-down from the sensor value measured by each
In addition, the
Therefore, in order to verify the validity of the estimation of the vehicle state of the present embodiment, a running test was performed in which the suspension control device of the present embodiment was mounted on an actual vehicle and run on a winding road. Fig. 8 to 10 show the characteristics of the test results. In this case, the running pattern is a complex effect of the road surface input by the winding road and the sprung motion by the steering, which is obtained by repeating the entering and leaving with the turning on the winding road.
A
A
The
A characteristic line 39 indicated by a solid line in fig. 9 indicates a characteristic of the steering angle in the present embodiment when the vehicle is running on a curve. A characteristic line 40 shown by a broken line in fig. 9 represents a change in the steering angle of the related art (i.e., in the case where the relative displacement based on the driver's operation and the relative displacement based on the road surface input are not separated). Further, a characteristic line 41 shown by a solid line represents the characteristics of the sprung displacement in the present embodiment (i.e., a case where the relative displacement based on the driver's operation and the relative displacement based on the road surface input are separated). In contrast, the characteristic line 42 indicated by a broken line shows the characteristic of the displacement on the spring of the prior art.
Next, a characteristic line 43 indicated by a solid line in fig. 9 shows a characteristic of the sprung velocity in the present embodiment during the turning travel on the winding road. In contrast, a characteristic line 44 shown by a broken line represents the characteristic of the spring speed of the prior art. The characteristic line 45 shown by the solid line represents the characteristic of the command current in the present embodiment (that is, the case where the relative displacement based on the driver operation and the relative displacement based on the road surface input are separated). A characteristic line 46 shown by a dotted line represents the characteristics of the command current of the prior art.
From the characteristic lines 40 to 46 shown in fig. 9, it is understood that the command current appears as an erroneous command at the time when the steering input and the winding road input are combined (for example, at times t1 to t2 in fig. 9), as indicated by the broken line of the conventional characteristic line 46. Therefore, in the conventional technology, the ride comfort feeling as a whole deteriorates due to the erroneous command. That is, in the conventional technology, the sprung movement caused by the driver input is determined as the displacement due to the road surface input, and the erroneous control is performed.
A
As described above, according to the first embodiment, the control of separating the relative position shift by the driver's operation and the relative position shift by the road surface input can improve the sprung mass estimation accuracy and improve the riding comfort. In other words, since the number of erroneous commands as in the conventional technique is reduced, the riding comfort in the high frequency region can be improved as indicated by the
Therefore, according to the first embodiment, the accuracy of estimation of the sprung velocity for ride comfort control based on the influence of the sprung motion of the acceleration/deceleration and steering of the driver can be improved, and the ride comfort performance of the vehicle (automobile) shown in fig. 1 and 2, for example, can be improved. In addition, by taking into account the jacking-and-landing force and the lifting/lowering force generated by the driver's operation due to the suspension geometry, the accuracy of the estimated value of the relative displacement generated in the suspension form and specification can be improved.
Further, according to the first embodiment, by separating the relative displacement based on the driver's operation and the relative displacement based on the road surface input, it is possible to reduce the erroneous control of the ride comfort control at the time of turning and the time of acceleration and deceleration, and to improve the ride comfort performance. Moreover, the ride comfort performance equivalent to that of a conventional system using sprung acceleration sensors can be achieved only by the
Next, fig. 11 shows a second embodiment. The feature of the present embodiment is that the sprung mass is estimated from the displacement or the like calculated by the physical quantity extracting unit (vehicle height sensor), and even when the number of occupants in the vehicle and the load weight change, the robustness of the estimation accuracy of the relative displacement value due to increase or decrease of the sprung mass is improved. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.
The signal processing unit 51 of the
However, the sprung mass calculating unit 51C of the signal processing unit 51 has a function of estimating and calculating the mass (sprung mass M) of the vehicle body 1 based on a signal from the CAN12 (e.g., a signal including the sensor value of each vehicle height sensor 10). At this time, the sprung mass calculating unit 51C can improve the robustness of the estimation accuracy of the relative displacement value due to increase and decrease of the sprung mass M by using the mass value estimated by the mass estimation logic using the
Therefore, according to the second embodiment configured as described above, when the load
In addition, in the load
The vertical relative acceleration calculating unit 20 (acceleration calculating unit) calculates the relative acceleration a using the vertical force (operation-induced force) obtained by the vertical
Therefore, when the offset amount of the relative displacement is derived from the lateral acceleration and the front-rear acceleration of the driver's steering by the
Therefore, according to the second embodiment, even if the number of occupants and the load weight change, the acceleration can be calculated using the sprung mass estimated from the displacement or the like calculated by the physical quantity extracting unit (for example, the vehicle height sensor 10), and therefore the influence of the change in the sprung mass M can be directly taken into consideration. As a result, the estimation accuracy at the time of the weight change can be improved, and the riding comfort of the vehicle can be improved.
Fig. 12 shows a third embodiment. The present embodiment is characterized in that, as the inertial force caused by the operation of the driver and the force generated by the suspension geometry, in addition to the above-described lifting/lowering force (JF) and lifting/lowering force (GF), a gas reaction force (KGas), a trigger (KFriction), an oil pressure (KOil), a damping force response (Tdelay), and the like, which are forces generated by the shock absorber, are considered. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.
The up-down force calculation unit 17 (i.e., the front wheel lift
The stabilizer spring
The damper gas
The damper
The damping force response (Tdelay) of the suspension devices 5 and 8 on the front and rear wheel sides can also be used as an element for improving the estimation accuracy. In the following
The following
[ number 35 ]
[ number 36 ]
[ number 37 ]
Therefore, in the third embodiment configured as described above, the stabilizer spring
Next, fig. 13 to 15 show a fourth embodiment. In the present embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof is omitted. However, the fourth embodiment is characterized in that the damper response delay calculation unit 71 is provided between the damper damping
Here, the damper response delay calculation unit 71 includes, as shown in fig. 14, a rising-side primary delay element 72, a falling-side primary delay element 73, and a minimum value selection unit 74. The minimum value selection unit 74 selects the smaller one of the damper damping force (a characteristic line 75 indicated by a broken line in fig. 15) calculated and output via the ascending-side primary delay element 72 and the damper damping force (a characteristic line 76 indicated by a two-dot chain line in fig. 15) calculated and output via the descending-side primary delay element 73.
Thus, the damping force in consideration of the damper response delay can be output from the minimum value selecting unit 74 of the damper response delay calculating unit 71 to the upper and lower relative
The damping force Fd in the
Therefore, in the fourth embodiment configured as described above, as shown by the characteristic line 77 indicated by the solid line in fig. 15, the damping force in consideration of the response delay is estimated and calculated, and the damping force Fd based on the calculation result is output to the upper and lower relative
Next, fig. 16 and 17 show a fifth embodiment. In the present embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof is omitted. However, the fifth embodiment is characterized in that a control command response delay calculation unit 81 is provided between the FB
Here, as shown in fig. 16, the control command response delay calculation unit 81 includes a rising-side primary delay element 82, a falling-side primary delay element 83, and a minimum value selection unit 84. The minimum value selection unit 84 selects a small current value from the current value of the control command (a characteristic line 85 shown by a broken line in fig. 17) output from the FB
Thus, the current value of the control command in consideration of the response delay as shown by the characteristic line 87 shown by the solid line in fig. 17 can be output from the minimum value selection unit 84 of the control command response delay calculation unit 81 to the damper damping
The command current (current value of the control command) calculated from the target damping force calculated by the controller 11 and the current actually flowing through the circuit affect the rise and fall of the command current due to the rise of the temperature of the solenoid and the temperature of the transistor. As shown in fig. 16, the control command response delay calculation unit 81 combines the primary delay elements 82 and 83, and thus, by considering the increase and decrease of the current in the response characteristic of the command current value as shown in fig. 17, the damping force actually generated can be accurately estimated, and the estimation accuracy of the relative displacement offset due to the driver's operation can be improved.
Therefore, in the fifth embodiment configured as described above, as shown by the characteristic line 87 shown by the solid line in fig. 17, it is possible to estimate and calculate the current value of the control command in consideration of the response delay, and output the current value based on the calculation result to the damper damping
In the above embodiments, a case has been described as an example where the physical quantity extracting unit is configured to detect and estimate the physical quantity (i.e., the vertical force and/or the vertical position) based on the relative displacement between the vehicle body 1 and each
In each of the above embodiments, the
In the above embodiments, the case where the damping force adjusting damper 7 formed of the semi-active damper is formed of the damping force adjusting damper has been described as an example. However, the present invention is not limited to this, and for example, an active damper (any of an electric actuator and a hydraulic actuator) may be used to form the damping force adjusting type shock absorber.
As the suspension control device according to the embodiment described above, for example, the following type of device can be considered.
As a first aspect, a suspension control device includes: damping force adjusting dampers, each of which is disposed between a vehicle body and each wheel of a vehicle and changes damping characteristics in response to an external command; a physical quantity extraction unit that detects or estimates a physical quantity based on a relative displacement between the vehicle body and each of the wheels; a control device that controls damping characteristics of the damping force adjustable shock absorbers; the control device has: an external force calculation unit that calculates a total external force acting on the vehicle body from the physical quantity output from the physical quantity extraction unit; an operation force calculation unit that calculates an operation-induced force applied to each of the damping force adjustable dampers in accordance with a load movement caused by a vehicle operation; and a vehicle behavior extracting unit that divides the operation-induced force calculated by the operation force calculating unit from the total external force calculated by the external force calculating unit and obtains an external force due to road surface input.
As a second aspect, in the first aspect described above, the operation-causing force includes an inertial force generated by acceleration/deceleration and steering of the vehicle or a force generated by a suspension geometry. As a third aspect, in the first aspect, the physical quantity extracting unit includes a vehicle height sensor.
As a fourth aspect, in the first aspect described above, the control device includes: a vertical force calculation unit that obtains a vertical force of the vehicle body; an acceleration calculation unit that calculates an acceleration from the vertical force obtained by the vertical force calculation unit; a sprung velocity estimating unit that estimates a sprung velocity of the vehicle body based on the acceleration calculated by the acceleration calculating unit; and a damping characteristic determination unit that determines a damping characteristic of each of the damping force adjustable dampers based on the sprung velocity determined by the sprung velocity estimation unit. As a fifth aspect, in the fourth aspect, the vehicle further includes a mass calculation unit that obtains a mass of the vehicle body from the displacement calculated by the physical quantity extraction unit, and the acceleration calculation unit calculates the acceleration using the vertical force obtained by the vertical force calculation unit and the mass obtained by the mass calculation unit.
According to the fifth aspect, the acceleration can be calculated by dividing the vertical force calculated by the vertical force calculating unit by the mass calculated by the mass calculating unit. Therefore, even if the number of occupants and the load weight change, the acceleration can be calculated using the sprung mass estimated by the displacement or the like calculated by the physical quantity extracting unit (vehicle height sensor), and therefore the influence of the change in the sprung mass can be directly taken into consideration. As a result, the estimation accuracy at the time of the weight change can be improved, and the riding comfort of the vehicle can be improved.
The embodiments of the present invention have been described above, and the embodiments of the present invention are for facilitating understanding of the present invention and do not limit the present invention. The present invention may be modified and improved without departing from the gist thereof, and the present invention includes equivalents thereof. In addition, the respective components described in the claims and the description may be arbitrarily combined or omitted within a range in which at least a part of the above-described problems can be solved or within a range in which at least a part of the effects can be obtained.
The present application claims priority based on japanese patent application No. 2018-060017 applied on 27/3/2018. The entire disclosure including the specification, claims, drawings and abstract of japanese patent application No. 2018-060017 applied on 27/3/2018 is incorporated in the present application by reference in its entirety.
Description of the reference numerals
1: vehicle body
2: wheel of vehicle
4: stabilizer (stabilizer mechanism)
5. 8: suspension device
7: damping force adjusting type shock absorber (damping force adjusting type shock absorber)
10: vehicle height sensor (physical quantity extraction part)
11: controller (control device)
13: state estimation unit
14: arithmetic unit
15: external force calculating part (external force calculating part)
16: signal processing unit
17: up-down force calculating part (Up-down force calculating part, operation force calculating part)
18: damper damping force estimation section (damping characteristic determination section, operation force calculation section)
19: front wheel spring force estimating part (operation force calculating part)
20: upper and lower relative acceleration calculating part (acceleration calculating part)
21: relative speed calculating part (spring speed estimating part)
22: relative displacement calculating part
23: vehicle action extraction part (vehicle action extraction part)
51C: sprung mass calculating section (mass calculating section)
- 上一篇:一种医用注射器针头装配设备
- 下一篇:加热器装置