JP2020117216A - Behavior control device for vehicle - Google Patents

Abstract

To provide a behavior control device for vehicle capable of improving comfort of crew of a vehicle while the vehicle is turning.SOLUTION: A control device 100 includes: a vehicle required brake force acquisition part 105 for acquiring a vehicle required brake force which is a request value of a brake force to be imparted to a vehicle 10; and a roll control part 108 which controls a rolling motion of the vehicle 10 by adjusting a distribution ratio of a brake force with respect to a target wheel including at least one out of a rear wheel which is inside while turning and a front wheel which is outside while turning of the vehicle 10, when the brake force is being imparted to the vehicle 10 according to the vehicle required brake force under the situation where the vehicle 10 is turning.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle behavior control device.

Patent Document 1 describes an example of a behavior control device that automatically turns a vehicle along a curved road. In this behavior control device, when the lateral acceleration or the yaw rate of the vehicle exceeds the determination value, the vehicle is decelerated by applying the braking force.

JP, 2018-95112, A

When the vehicle turns, the rolling motion of the vehicle changes the roll angle of the vehicle. In recent years, it has been required to improve the comfort of a vehicle occupant when the vehicle turns.

The vehicle behavior control device for solving the above-mentioned problem generates an anti-dive force that is a force for displacing the front part of the vehicle upward when a braking force is applied to the front wheels, and the braking force is applied to the rear wheels. It is sometimes applied to a vehicle in which an anti-lift force, which is a force for displacing the rear portion of the vehicle, is generated. The behavior control device includes a vehicle required braking force acquisition unit that obtains a vehicle required braking force, which is a required value of a braking force applied to the vehicle, and the vehicle required braking force according to the vehicle required braking force in a situation where the vehicle is turning. When a braking force is applied to the vehicle, by adjusting a distribution ratio of the braking force to target wheels including at least one of a rear wheel inside the vehicle when turning and a front wheel outside the vehicle when turning, And a roll control unit that controls rolling motion of the vehicle.

As a result of various experiments and simulations, the inventor of the present application has found that it is possible to improve comfort of a vehicle occupant during vehicle turning by appropriately controlling rolling motion during vehicle turning. .. According to the above configuration, when the braking force is applied to the vehicle during turning of the vehicle, the distribution ratio of the braking force to at least one of the rear wheel during turning and the front wheel outside during turning is adjusted, thereby The rolling movement is adjusted. For example, when adjusting the braking force for the inner rear wheel during turning, the rolling motion during turning of the vehicle is adjusted by adjusting the anti-lift force generated near the inner rear wheel during turning of the vehicle rear portion. .. Further, for example, in the case of adjusting the braking force applied to the outer front wheel at the time of turning, the rolling motion of the vehicle is adjusted by adjusting the anti-dive force generated near the outer front wheel at the time of turning of the vehicle front portion. Therefore, according to the above configuration, it is possible to improve the comfort of the occupant of the vehicle when the vehicle turns.

1 is a schematic configuration diagram showing a functional configuration of a control device that is a first embodiment of a vehicle behavior control device and a vehicle including the control device. The schematic diagram which shows a mode that roll suppression control is implemented during turning of the same vehicle. The schematic diagram which shows a mode that stability priority control is implemented during the turning of the same vehicle. 3 is a flowchart illustrating a processing routine executed by the control device in the first embodiment. (A)-(g) is a timing chart in case roll control is implemented during turning of a vehicle in a 1st embodiment. 6 is a flowchart illustrating a processing routine executed by a control device in the second embodiment. The figure which shows the function structure of the control apparatus which is 3rd Embodiment of the behavior control apparatus of a vehicle, and a part of structure of the vehicle provided with the same control apparatus. The flowchart explaining the processing routine which a control apparatus performs in 3rd Embodiment. (A)-(g) is a timing chart in case roll control is implemented during a vehicle turning in 3rd Embodiment. (A)-(g) is a timing chart in case roll control is implemented during a vehicle turning in 4th Embodiment. The block diagram which shows the function structure of a roll control part in the control apparatus which is 5th Embodiment of the behavior control apparatus of a vehicle. The flowchart explaining the processing routine which a control apparatus performs in 5th Embodiment. (A)-(g) is a timing chart in case roll acceleration control is implemented during a vehicle turning in 5th Embodiment. FIG. 9 is a schematic diagram showing how roll suppression control is performed while the vehicle is turning in a modified example. FIG. 9 is a schematic diagram showing a manner in which stability priority control is performed during turning of the vehicle in the modification.

(First embodiment)
Hereinafter, a first embodiment of a vehicle behavior control device will be described with reference to FIGS.
FIG. 1 shows a vehicle 10 including a control device 100 which is the behavior control device of the present embodiment. The left front wheel FL and the right front wheel FR of the plurality of wheels provided in the vehicle 10 are drive wheels to which the driving force output from the power source 11 of the vehicle such as an engine is input via the differential 12. The left rear wheel RL and the right rear wheel RR of the plurality of wheels are driven wheels.

The steering device 20 of the vehicle has a steering actuator 22 that adjusts the steering angles of the front wheels FL and FR, which are also steered wheels, according to the operation of the steering wheel 21 by the driver. The operation of the steering actuator 22 can also be controlled by the control device 100. By controlling the steering actuator 22 by the control device 100, the steering angles of the front wheels FL, FR can be controlled even when the driver is not steering, that is, the vehicle 10 can be automatically turned.

A braking force is applied to each of the wheels FL, FR, RL, RR by the operation of the braking mechanism 30. Each braking mechanism 30 is configured such that the higher the WC pressure PWC, which is the hydraulic pressure in the wheel cylinder 31, is, the greater the force that presses the friction material 33 against the rotating body 32 that rotates integrally with the wheels FL, FR, RL, RR. Has been done. Therefore, the braking force applied to the wheels FL, FR, RL, RR increases as the WC pressure PWC increases.

The vehicle braking device 40 is an example of a friction braking device that adjusts a braking force applied to each of the wheels FL, FR, RL, and RR. The braking device 40 includes a hydraulic pressure generating device 41 and a braking actuator 42 to which brake fluid is supplied from the hydraulic pressure generating device 41. A braking operation member 43 such as a brake pedal is connected to the hydraulic pressure generator 41. Then, the hydraulic pressure generation device 41 generates a hydraulic pressure according to a braking operation amount, which is an operation amount of the braking operation member 43 by the driver of the vehicle 10. The braking actuator 42 is connected to each wheel cylinder 31. Therefore, when the braking operation member 43 is operated, an amount of brake fluid corresponding to the braking operation amount is supplied to each wheel cylinder 31. That is, braking force is applied to each wheel FL, FR, RL, RR. The braking force applied to the wheels FL, FR, RL, RR by operating the braking mechanism 30 is also referred to as "friction braking force".

The operation of the braking actuator 42 can be controlled by the control device 100. By controlling the braking actuator 42 by the control device 100, the braking force applied to each wheel FL, FR, RL, RR can be individually controlled.

The vehicle 10 is provided with various sensors such as an operation amount sensor 110, a wheel speed sensor 111, a longitudinal acceleration sensor 112, a lateral acceleration sensor 113, a yaw rate sensor 114, a steering angle sensor 115 and a suspension stroke sensor 116. Signals from these various sensors 110 to 116 are input to the control device 100. Further, signals are also input to the vehicle 10 from the camera 121 and radar that acquire external information around the vehicle 10.

The operation amount sensor 110 detects the braking operation amount INP of the driver and outputs a signal according to the detected braking operation amount INP. Examples of the braking operation amount INP include the stroke amount of the braking operation member 43 and the operation force input to the braking operation member 43.

The wheel speed sensor 111 is provided for each of the wheels FL, FR, RL, RR. The wheel speed sensor 111 detects the wheel speed VW of the corresponding wheels FL, FR, RL, RR and outputs a signal according to the detected wheel speed VW. Then, the vehicle body speed VS of the vehicle 10 is calculated based on the wheel speed VW of each wheel FL, FR, RL, RR. The vehicle body speed VS mentioned here is the rotational speed of the wheels corresponding to the moving speed of the vehicle 10 in the front-rear direction.

The longitudinal acceleration sensor 112 detects longitudinal acceleration GX which is the longitudinal acceleration of the vehicle 10 and outputs a signal according to the detected longitudinal acceleration GX. The lateral acceleration sensor 113 detects a lateral acceleration GY which is the lateral acceleration of the vehicle 10 and outputs a signal corresponding to the detected lateral acceleration GY. The yaw rate sensor 114 detects the yaw rate YR of the vehicle 10 and outputs a signal according to the detected yaw rate YR. The steering angle sensor 115 detects the steering angle STR of the steering wheel 21, and outputs a signal according to the detected STR.

The suspension stroke sensor 116 is provided for each of the wheels FL, FR, RL, RR. The suspension stroke sensor 116 detects the stroke amount SS of the corresponding wheel suspension 15FL, 15FR, 15RL, 15RR, and outputs a signal according to the detected stroke amount SS.

Information on the travel route of the vehicle 10 is input to the control device 100 from the navigation device 131. Examples of the information on the travel route include the radius of curvature of the travel route and the road surface gradient of the travel route. The navigation device 131 may be a vehicle-mounted navigation device or a tablet terminal having a navigation function.

Then, the control device 100 implements various vehicle controls based on the signals from the various sensors 111 to 116, the signals from the camera 121, and the travel route information from the navigation device 131.

When the vehicle 10 is decelerating due to the application of the braking force, the vehicle 10 makes a pitching motion toward the nose dive side. The nose dive is to displace the front portion of the vehicle 10 downward and displace the rear portion of the vehicle 10 upward. On the other hand, displacing the front portion of the vehicle 10 upward and displacing the rear portion of the vehicle 10 downward is referred to as “nose lift”.

When the vehicle 10 pitches to the nose dive side, the sprung load on the front wheel side increases, so that the front wheel springs forming the suspensions 15FL and 15FR for the front wheels contract and the sprung load on the rear wheel side decreases. Therefore, the rear wheel springs constituting the respective rear wheel suspensions 15RL, 15RR expand. The sprung load is a vertical load applied to the suspension from the vehicle body by the vehicle weight and the pitching moment. When the springs of the suspensions 15FL, 15FR, 15RL, and 15RR operate in this way, the vehicle 10 generates the restoring force of the rear wheel spring and the restoring force of the front wheel spring.

When the braking force is applied to the front wheels FL and FR, the anti-dive force FAD is generated in the front part of the vehicle. When the braking force is applied to the rear wheels RL and RR, the anti-lift force FAL is generated at the rear part of the vehicle. The anti-dive force FAD is a force that displaces the front portion of the vehicle upward when the braking forces BPFL and BPFR are applied to the front wheels FL and FR. The anti-dive force FAD increases as the braking forces BPFL and BPFR applied to the front wheels FL and FR increase. The anti-lift force FAL is a force that displaces the rear portion of the vehicle downward when the braking forces BPRL and BPRR are applied to the rear wheels RL and RR. The anti-lift force FAL increases as the braking forces BPRL and BPRR applied to the rear wheels RL and RR increase. In the present embodiment, the geometry of the front wheel suspensions 15FL, 15FR and the rear wheel suspensions 15RL, 15RR is such that the braking forces BPFL, BPFR applied to the front wheels FL, FR and the braking forces BPRL, applied to the rear wheels RL, RR, When the BPRR and the BPRR have the same value, the anti-lift force FAL is set to be larger than the anti-dive force FAD.

When the vehicle 10 turns, a centrifugal force acts on the center of gravity of the vehicle, so that the sprung load on the outer wheel side during turning increases, while the sprung load on the inner wheel during turning decreases. When the vehicle 10 makes a right turn as shown in FIG. 2, the left wheels FL, RL correspond to the outer wheels during a turn, and the right wheels FR, RR correspond to the inner wheels during a turn. When the vehicle 10 is turning, the spring forming the suspension for the outer wheel during turning contracts due to the increase in the sprung load. On the other hand, the spring forming the suspension for the inner wheel during turning extends due to the decrease in the sprung load. As a result, when the vehicle 10 turns, the vehicle 10 makes a rolling motion and the roll angle Φ of the vehicle changes.

When the braking force is applied to the vehicle 10 when turning, the vehicle 10 performs both rolling motion and pitching motion. As a result, the sprung load on the front wheel on the outside of each of the wheels FL, FR, RL, RR becomes maximum, and the sprung load on the rear wheel on the inner side of each of the wheels FL, FR, RL, RR during turning. Is the smallest.

Therefore, in order to suppress the change of the roll angle Φ during turning of the vehicle 10, the braking force applied to the outside front wheels during turning is increased by increasing the distribution ratio of the braking force to the outside front wheels during turning. It is effective to increase the braking force applied to the inner rear wheel during turning by increasing the distribution ratio of the braking force to the inner rear wheel during turning. In the present embodiment, as described above, the anti-lift force FAL tends to be larger than the anti-dive force FAD. Therefore, in the roll suppression control that suppresses the rolling motion of the vehicle 10 at the time of turning, the braking force applied to the inner rear wheels at the time of turning is suppressed by the roll by increasing the distribution ratio of the braking force to the inner rear wheels at the time of turning. Make it larger than when control is not implemented. That is, when the vehicle 10 makes a right turn as shown in FIG. 2, in the roll suppression control, for example, by increasing the distribution ratio of the braking force to the right rear wheel RR corresponding to the inner rear wheel at the time of turning, the right rear The braking force BPRR applied to the wheel RR is made larger than the braking force BPFL applied to the left front wheel FL, the braking force BPFR applied to the right front wheel FR, and the braking force BPRL applied to the left rear wheel RL.

When the roll suppression control is performed in this manner, a large anti-lift force FAL is generated at the rear inside of the vehicle 10 when the vehicle 10 is turning. As a result, the rolling motion of the vehicle 10 can be suppressed, and thus the change of the roll angle Φ of the vehicle 10 can be suppressed. Furthermore, the generation of the large anti-lift force FAL can suppress the pitching motion of the vehicle 10 during deceleration of the vehicle 10, and thus can suppress the change in the pitch angle of the vehicle 10.

When the roll suppression control is executed, a braking force difference ΔBPR (=BPRR-BPRL) is generated between the left and right rear wheels RL and RR. Therefore, as shown in FIG. 2, a yaw moment YM1 corresponding to the braking force difference ΔBPR generated between the left and right rear wheels RL and RR is generated in the vehicle 10. Therefore, when the turning radius of the vehicle 10 is small or when the vehicle body speed VS of the vehicle 10 is large, when the roll suppression control is performed, the stability of the behavior of the vehicle 10 decreases due to the generation of the yaw moment YM1. There is a risk. In the present embodiment, the yaw moment YM1 acts in the direction of increasing the oversteer tendency of the vehicle 10.

Therefore, in the present embodiment, the roll suppression control is executed when it can be determined that the vehicle 10 turns gently, but the roll suppression control is not executed when it cannot be determined that the vehicle 10 turns gently. That is, when it cannot be determined that the vehicle 10 turns gently, the stability priority control is executed.

The stability priority control implemented in this embodiment is control for suppressing oversteer of the vehicle 10. FIG. 3 illustrates an example in which the stability priority control is performed when the vehicle 10 is turning. In the example shown in FIG. 3, the braking force BPRR applied to the right rear wheel RR which is the inner rear wheel during turning is larger than the braking force BPRL applied to the left rear wheel RL which is the outer rear wheel during turning, and The braking force BPFL applied to the left front wheel FL, which is the outer front wheel, is larger than the braking force BPFR applied to the right front wheel FR, which is the inner front wheel during turning. The braking force difference ΔBPR that occurs between the left and right rear wheels RL and RR when the stability priority control is performed is smaller than the braking force difference ΔBPR that occurs when the roll suppression control is performed. The yaw moment YM1 corresponding to the braking force difference ΔBPR generated between the left and right rear wheels RL and RR acts in a direction to increase the oversteering tendency of the vehicle 10. On the other hand, the yaw moment YM2 corresponding to the braking force difference ΔBPF generated between the left and right front wheels FL and FR acts in the direction of increasing the understeer tendency of the vehicle 10. That is, since the yaw moment YM1 and the yaw moment YM2 are opposite in direction, the yaw moment YM1 is offset by the yaw moment YM2. As a result, the vehicle 10 is unlikely to oversteer when turning.

Next, the control device 100 will be described with reference to FIG.
The control device 100 is a functional unit that controls the behavior of the vehicle 10 during turning, and is a vehicle required braking force acquisition unit 105, a turning state determination unit 101, a roll control unit 108, a stability priority control unit 103, and a deceleration slip determination unit 104. have.

The vehicle required braking force acquisition unit 105 acquires the vehicle required braking force BPRC, which is the required value of the braking force applied to the vehicle 10. When the driver is performing the braking operation, the vehicle request braking force BPRC is larger as the braking operation amount INP is larger. At the time of automatic braking, the vehicle required braking force BPRC increases as the target value XGT of the deceleration of the vehicle 10 increases.

The turning state determination unit 101 determines whether the vehicle 10 turns gently. The "gradual turn" here means that even if the roll suppression control is performed, the stability of the behavior of the vehicle 10 does not decrease due to the generation of the yaw moment YM1 due to the implementation of the roll suppression control, or The turning of the vehicle 10 is such that the degree of decrease in stability falls within an allowable range. When the vehicle 10 travels at a low speed or when the turning radius of the vehicle 10 is large, it is easy to determine that the vehicle 10 turns gently.

The turning state determination unit 101 determines the vehicle 10 based on the steering angle of the steering wheel 21, the turning angles of the front wheels FL and FR that are steered wheels, the lateral acceleration GY, the yaw rate YR, and the vehicle body slip angle ASL when the vehicle 10 turns. Determines whether the vehicle turns gently. Further, when the vehicle 10 turns in a state where the vehicle body speed VS is high, a large yaw moment YM1 is generated and a large yaw moment YM1 is generated even if the braking force difference ΔBPR generated between the left and right rear wheels RL and RR is not so large. Behavior tends to be unstable. Therefore, the turning state determination unit 101 determines whether or not the vehicle 10 turns gently based on the vehicle body speed VS of the vehicle 10. That is, in this embodiment, the steering angle, the turning angles of the front wheels FL and FR, the lateral acceleration GY, the yaw rate YR, the vehicle body slip angle ASL, and the vehicle body speed VS affect the yawing motion of the vehicle 10 during turning, that is, the parameters. It corresponds to a parameter indicating the yawing motion of the vehicle 10.

Further, the turning state determination unit 101 determines whether or not the vehicle 10 turns gently based on the radius of curvature of the traveling route included in the information regarding the traveling route of the vehicle 10 input from the navigation device 131.

The specific content of the determination as to whether the vehicle 10 turns gently will be described later.
The roll control unit 108 includes the roll suppression control unit 102. The roll suppression control unit 102 executes the roll suppression control when the turning state determination unit 101 determines that the vehicle 10 turns gently. The specific content of the roll suppression control will be described later.

The stability priority control unit 103 implements the stability priority control when the turning state determination unit 101 does not determine that the vehicle 10 turns gently when the vehicle 10 turns.

The deceleration slip determination unit 104 determines whether a deceleration slip has occurred at the wheels FL, FR, RL, RR. The specific content of the determination as to whether a deceleration slip has occurred will be described later.

Next, with reference to FIG. 4, a processing routine executed by the control device 100 when the vehicle 10 turns will be described. Note that this processing routine is repeatedly executed even when the vehicle 10 travels by automatic driving or when the vehicle 10 travels by manual driving. The manual driving here refers to driving of the vehicle 10 in which steering is manual.

As shown in FIG. 4, in this processing routine, in step S11, the turning state determination unit 101 determines whether the vehicle 10 turns gently. For example, the turning state determination unit 101 determines that the vehicle 10 turns gently when all of the following conditions are satisfied.
(Condition 1) The absolute value of the lateral acceleration GY is less than the judgment lateral acceleration GYTh.
(Condition 2) The absolute value of the yaw rate YR is less than the determination yaw rate YRTh.
(Condition 3) The absolute value of the vehicle body slip angle ASL of the vehicle is less than the determination slip angle ASLTh.
(Condition 4) The vehicle body speed VS of the vehicle 10 is less than the determined vehicle body speed VSTh.

The determination values such as the determination lateral acceleration GYTh, the determination yaw rate YRTh, and the determination slip angle ASLTh may fall within the allowable range of the degree of stability deterioration of the behavior of the vehicle 10 when the yaw moment YM1 occurs due to the roll suppression control. It is set as a criterion for judging whether or not it is possible. In the present embodiment, each determination value described above corresponds to a “first predetermined value”. Such a determination value may be fixed at a preset specified value or may be variable. When the roll suppression control is executed, the stability of the behavior of the vehicle 10 is likely to decrease as the vehicle body speed VS of the vehicle 10 increases. Therefore, when changing the above-described determination value, the determination value may be decreased as the vehicle body speed VS increases.

The determination vehicle speed VSTh is set as a criterion for determining whether or not the yaw moment YM1 generated due to the execution of the roll suppression control becomes large. That is, when the roll suppression control is performed when the vehicle body speed VS is equal to or higher than the determined vehicle body speed VSTh, the degree of decrease in the stability of the behavior of the vehicle 10 may exceed the allowable range due to the generation of the large yaw moment YM1. That is, the determined vehicle body speed VSTh is also an example of the “first predetermined value”.

In the present embodiment, even when at least one of the above (Condition 1) to (Condition 4) is not satisfied, when the curvature radius of the traveling course of the vehicle 10 is larger than the determination curvature radius, the vehicle 10 It may be determined that the vehicle turns gently. When the radius of curvature is larger than the determination radius of curvature, it can be determined that the stability of the behavior of the vehicle 10 is unlikely to deteriorate even if the roll suppression control is performed. The radius of curvature for determination may be fixed at a preset value or may be variable. When changing the determination radius of curvature, the determination radius of curvature may be increased as the vehicle body speed VS increases.

If it is not determined in step S11 that the vehicle 10 turns gently (NO), the process proceeds to step S14 described below. On the other hand, if it is determined that the vehicle 10 turns gently (S11: YES), the process proceeds to the next step S12. In step S12, the deceleration slip determination unit 104 calculates the slip amount SLP of each wheel FL, FR, RL, RR. That is, the deceleration slip determination unit 104 calculates a value obtained by subtracting the wheel speed VW of the wheels FL, FR, RL, RR from the vehicle body speed VS as the slip amount SLP of the wheels FL, FR, RL, RR. Subsequently, in the next step S13, the deceleration slip determination unit 104 determines whether or not each of the wheels FL, FR, RL, RR has a wheel whose slip amount SLP is equal to or greater than the determined slip amount SLPTh. Be seen. The determination slip amount SLPTh is set as a criterion for determining whether or not a deceleration slip has occurred at the wheels FL, FR, RL, RR. That is, it can be said that, in step S13, it is determined whether or not a deceleration slip has occurred in at least one of the wheels FL, FR, RL, RR. The determined slip amount SLPTh may be the same value as the slip amount threshold value used when the antilock brake control (ABS) is performed, or may be a value smaller than the threshold value.

If any of the wheels FL, FR, RL, RR has a slip amount SLP equal to or greater than the determination slip amount SLPTh (S13: YES), it can be determined that there is a wheel in which a deceleration slip has occurred, and therefore the process is performed next. Then, the process proceeds to step S14.

In step S14, the stability priority control unit 103 executes the stability priority control. Then, in the next step S15, the control flag FLG is set to OFF. The control flag FLG is set to ON while the roll suppression control is being executed, and is set to OFF when the roll suppression control is not executed. Further, the control flag FLG is set to OFF as an initial value. That is, when the vehicle 10 is not turning, the control flag FLG is set to OFF. When the control flag FLG is set to OFF in step S15, this processing routine is once ended.

On the other hand, in step S13, if there is no wheel in which the slip amount SLP is equal to or larger than the determination slip amount SLPTh among the wheels FL, FR, RL, RR (NO), it means that there is no wheel in which deceleration slip has occurred. Therefore, the roll suppression control unit 102 executes the roll suppression control. That is, first, the process of step S16 is executed. In step S16, it is determined whether the control flag FLG is set to OFF. When the control flag FLG is set to OFF (S16: YES), the process proceeds to the next step S17. On the other hand, when the control flag FLG is set to ON (S16: NO), the process proceeds to step S18 without executing the process of step S17.

In step S17, the roll angle Φ and the roll rate ΦR of the vehicle 10 are calculated. The roll angle Φ is calculated based on the stroke amount SS of each suspension 15FL, 15FR, 15RL, 15RR. When the vehicle 10 is provided with a roll angle sensor, the roll angle Φ of the vehicle 10 may be calculated based on the detection signal from the roll angle sensor. The roll rate ΦR is calculated by differentiating the roll angle Φ with respect to time. When the roll angle Φ and the roll rate ΦR are calculated, the process proceeds to the next step S18.

In step S18, the rear wheel during turning is selected as the target wheel, and the wheel required braking force BPRTW, which is the required braking force for the rear inside wheel during turning, is calculated as the control amount of the roll suppression control. The wheel required braking force BPRTW is calculated based on the relationship between the roll angle Φ and the target roll angle ΦTh and the roll rate ΦR. The target roll angle ΦTh is a target value of the roll angle Φ during the roll suppression control. Therefore, the wheel required braking force BPRTW is calculated such that it increases as the roll angle deviation ΔΦ, which is a value obtained by subtracting the roll angle Φ from the target roll angle ΦTh. Further, assuming that the roll suppression control is not performed, the roll angle Φ tends to increase as the roll rate ΦR increases. Therefore, the wheel required braking force BPRTW is calculated to increase as the roll rate ΦR increases.

In the present embodiment, the roll suppression control is performed under the situation where the braking force is applied to the vehicle 10 according to the vehicle required braking force BPRC. In the roll suppression control during vehicle braking, the wheel required braking force BPRTW is calculated based on the relationship between the roll angle Φ and the target roll angle ΦTh and the roll rate ΦR within a range that does not exceed the vehicle required braking force BPRC. It The wheel required braking force BPRTW calculated in step S18 is larger than the braking force applied to the inner rear wheel at the time of turning before the start of the roll suppression control. Therefore, when the roll suppression control is executed, the braking force applied to the inner rear wheel during turning becomes larger than that before the roll suppression control is started even if the vehicle required braking force BPRC has not changed. That is, in the roll suppression control, it can be said that the distribution ratio of the braking force to the rear wheel at the time of turning, which is the target wheel, becomes higher than that when the roll suppression control is not performed. More specifically, in the roll restraining control, the larger the roll angle deviation ΔΦ, the higher the distribution ratio of the braking force to the inner rear wheel during turning. Further, in the roll suppression control, the larger the roll rate ΦR, the higher the distribution ratio of the braking force to the inner rear wheel during turning.

Further, in the present embodiment, the roll suppression control may be performed even when the braking force is not applied to the vehicle 10. The roll suppression control that is performed under the condition that the braking force is not applied to the vehicle 10 is referred to as "non-braking roll suppression control". Also in the non-braking roll suppression control, the wheel required braking force BPRTW is calculated based on the relationship between the roll angle Φ and the target roll angle ΦTh and the roll rate ΦR, similarly to the roll suppression control during vehicle braking.

Then, when the calculation of the wheel required braking force BPRTW is completed, the process proceeds to the next step S19. In step S19, it is determined whether or not the automatic operation is being performed. If it is determined that the vehicle is in automatic operation (S19: YES), the process proceeds to step S21 described below. On the other hand, when it is not determined that the vehicle is in the automatic driving (S19: NO), the steering is being performed manually, so the process proceeds to the next step S20.

In step S20, reduction correction of the wheel required braking force BPRTW calculated in step S18 is performed. That is, a value obtained by multiplying the wheel required braking force BPRTW calculated in step S18 by the correction coefficient is derived as the wheel required braking force BPRTW. In this case, the correction coefficient is a value larger than “0” and smaller than “1”. That is, in the roll suppression control in the case where the steering is performed manually, the increase in the distribution ratio of the braking force to the rear wheels on the inner side during turning is suppressed as compared with the roll suppression control in the automatic operation. When the reduction correction is performed, the process proceeds to the next step S21.

In step S21, the suppression control amount Z that cancels the change in the acceleration of the vehicle 10 caused by the application of the braking force to the inner rear wheel during turning or the increase in the braking force applied to the inner rear wheel during turning is calculated. It In the roll suppression control during vehicle braking, the sum of the braking forces applied to the wheels other than the inner rear wheel during turning is calculated as the suppression control amount Z. That is, a value obtained by subtracting the wheel required braking force BPRTW, which is the braking force for the rear wheel on the inside during turning, from the vehicle required braking force BPRC is calculated as the suppression control amount Z. Therefore, the sum of the wheel required braking force BPRTW and the suppression control amount Z becomes a value according to the target value XGT of the deceleration of the vehicle 10. That is, when the total braking force with the deceleration of the vehicle 10 as the target value XGT is distributed to the wheels FL, FR, RL, RR, the braking force applied to the inner rear wheel during turning is greater than that before the roll suppression control is performed. Is also increased. As a result, the ratio of the braking force applied to the rear wheel on the inside of the turn to the total braking force is greater than that when the roll suppression control is not performed. On the other hand, for any of the wheels other than the turning inner rear wheel, or for a plurality of wheels other than the turning inner rear wheel, the applied braking force is suppressed, and the ratio of the braking force for that wheel to the total braking force is , Becomes smaller than when the roll suppression control is not performed.

On the other hand, when the non-braking roll suppression control is performed, the braking force is not applied to the vehicle 10 before the non-braking roll suppression control is started. In this case, the increase amount of the driving force output from the power source 11 of the vehicle 10 is increased so that the driving force input to the front wheels FL and FR, which are the driving wheels, is increased by an amount commensurate with the wheel required braking force BPRTW. It is calculated as the suppression control amount Z.

Then, when the suppression control amount Z is calculated, the process proceeds to the next step S22. In step S22, the braking device 40, that is, the braking actuator 42 is controlled based on the wheel required braking force BPRTW and the suppression control amount Z. When increasing the driving force output from the power source 11, the power source 11 of the vehicle 10 is also controlled in addition to the braking actuator 42. Then, in the next step S23, the control flag FLG is set to ON. Then, this processing routine is once ended.

Next, the operation and effect of this embodiment will be described with reference to FIG. FIG. 5 illustrates an example of the case where the braking force is applied when the vehicle 10 turns in automatic driving. In the example shown in FIG. 5, the braking force is applied to the vehicle 10 at the timing T11 during turning of the vehicle 10, and the vehicle 10 stops at the subsequent timing T13.

In addition, in FIGS. 5D to 5G, the transitions of the braking forces BPFL, BPFR, BPRL, and BPRR applied to the wheels FL, FR, RL, and RR in the present embodiment in which the roll suppression control is performed are indicated by solid lines. It is shown. On the other hand, the transitions of the braking forces BPFL, BPFR, BPRL, and BPRR applied to the wheels FL, FR, RL, and RR in the comparative example in which the roll suppression control is not performed are shown by broken lines.

As shown in FIGS. 5A to 5G, when it is determined that the vehicle 10 gently turns at the timing T11 during turning of the vehicle 10, the roll suppression control is started. Then, the wheel request braking force BPRTW, which is the braking force applied to the rear wheel on the inside when turning, which is the target wheel, is calculated. At this time, the wheel required braking force BPRTW is set to a value larger than the braking force applied to the wheels other than the inner rear wheel during turning.

Here, in the case of the comparative example, as indicated by the broken lines in FIGS. 5D to 5G, the braking force applied to the inner rear wheel during turning does not become larger than the wheel required braking force BPRTW. Therefore, the anti-lift force FAL generated in the vicinity of the inner rear wheel at the time of turning of the vehicle rear portion does not become so large. As a result, the rolling motion of the vehicle 10 cannot be suppressed, and the roll angle Φ of the vehicle 10 becomes large.

In this respect, in the present embodiment, a larger braking force is applied to the inner rear wheel during turning, as compared with the case of the comparative example. As a result, a large anti-lift force FAL can be generated in the vicinity of the rear wheel on the inside of the rear part of the vehicle at the time of turning. As a result, the rolling motion of the vehicle 10 is suppressed. Therefore, when the vehicle 10 turns gently due to automatic driving, the rolling motion of the vehicle 10 is suppressed, so that the comfort of the occupant of the vehicle 10 can be improved.

Further, by suppressing the change of the roll angle Φ of the vehicle 10 by executing the roll suppression control, it is possible to suppress the change of the angle of view of the vehicle-mounted camera 121. As a result, it is possible to prevent the accuracy of the information obtained from the camera 121 from decreasing when the vehicle 10 turns.

In such roll suppression control, the suppression control amount Z, that is, the braking force applied to the wheels other than the inner rear wheel during turning is adjusted so that the longitudinal acceleration GX of the vehicle 10 becomes the target value XGT of deceleration. .. Therefore, the deceleration of the vehicle 10 caused by the increase of the braking force applied to the inner rear wheel during turning can be offset by the acceleration of the vehicle 10 caused by the decrease of the braking force applied to the other wheels. As a result, it is possible to prevent the longitudinal acceleration GX of the vehicle 10 from deviating from the deceleration target value XGT due to the roll suppression control.

FIG. 5 illustrates an example in which the roll suppression control is performed when the vehicle 10 is decelerated by applying the braking force. However, when the vehicle 10 turns while keeping the vehicle body speed VS constant, that is, when the deceleration target value XGT is "0", the roll suppression control may be performed. That is, the roll suppression control during non-braking may be performed. In this case, the driving force output from the power source 11 of the vehicle 10 is increased when the braking force is applied to the inner rear wheel during turning to suppress the rolling motion of the vehicle 10. That is, the deceleration of the vehicle 10 caused by the application of the braking force to the inner rear wheels during turning is offset by the acceleration of the vehicle 10 caused by the increase in the driving force input to the front wheels FL and FR which are the driving wheels. You can Therefore, even in this case, it is possible to prevent the longitudinal acceleration GX of the vehicle 10 from deviating from the deceleration target value XGT due to the execution of the non-braking roll suppression control.

By the way, when the roll suppression control is being performed when the vehicle 10 is turning, a deceleration slip may occur in at least one of the wheels FL, FR, RL, RR. In particular, a relatively large braking force is applied to the inner rear wheel during turning, even though the vertical load applied to the inner rear wheel during turning is smaller than the vertical load applied to other wheels. As a result, a deceleration slip is likely to occur at the inner rear wheel during turning. If deceleration slips occur on the wheels while the vehicle 10 is turning, the stability of the behavior of the vehicle 10 is likely to deteriorate. Therefore, in the present embodiment, when the deceleration slip occurs in at least one wheel during the roll restraining control, the roll restraining control is ended.

Specifically, when the roll suppression control is finished, the stability priority control is started. In the roll suppression control implemented in the present embodiment, the vehicle 10 tends to have a large oversteer tendency. Therefore, when a deceleration slip occurs in at least one of the wheels FL, FR, RL, RR, the vehicle 10 may exhibit an oversteer tendency. Therefore, even if the vehicle 10 exhibits an oversteer tendency during the roll suppression control, the oversteer tendency of the vehicle 10 can be reduced by ending the roll suppression control and executing the stability priority control. This can prevent the stability of the behavior of the vehicle 10 during turning from being reduced.

Further, in the present embodiment, the determination in step S11 shown in FIG. 4 is performed even during the roll suppression control. When it is not determined that the vehicle 10 turns gently, the roll suppression control is ended and the stability priority control is executed. By performing the stability priority control in this way, it is possible to reduce the oversteer tendency that occurred when the roll suppression control was performed. As a result, it is possible to suppress a decrease in the stability of the behavior of the vehicle 10 when turning.

In addition, in this embodiment, the following effects can be further obtained.
(1) When the driver is manually steering the vehicle, it is desirable that the roll angle Φ of the vehicle 10 be changed to some extent according to the driver's feeling. Therefore, in the present embodiment, in the roll suppression control when the vehicle 10 turns by manual steering, the wheel request braking force BPRTW is made smaller than when the roll suppression control is performed when the vehicle 10 turns by automatic driving. Therefore, at the time of manual steering, the effect of suppressing the rolling motion of the vehicle 10 accompanying the execution of the roll suppression control is reduced. Therefore, when the vehicle 10 turns by manual steering, it is possible to cause the vehicle 10 to perform a rolling motion according to the steering amount while suppressing a large change in the roll angle Φ of the vehicle 10.

(2) In the stability priority control performed in the present embodiment, the braking force applied to the inner rear wheel during turning is smaller than that during the roll suppression control, but is lower than the braking force applied to other wheels. It is considered a large value. Therefore, even when the stability priority control is performed, the rolling motion of the vehicle 10 can be suppressed to some extent.

(3) If the vehicle 10 is turning, and if it is not determined that the vehicle 10 is turning gently, stability priority control is performed instead of roll suppression control. Therefore, when it is not determined that the vehicle 10 turns gently, the stability of the behavior of the vehicle 10 during turning can be improved.

(Second embodiment)
Next, a second embodiment of the vehicle behavior control device will be described with reference to FIG. The second embodiment is different from the first embodiment in that the roll suppression control is not performed during manual steering. Therefore, in the following description, parts different from the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment will be denoted by the same reference numerals and redundant description will be omitted. I shall.

A processing routine executed by the control device 100 as the behavior control device when the vehicle 10 is turning will be described with reference to FIG. 6. Note that this processing routine is repeatedly executed even when the vehicle 10 travels by automatic driving or when the vehicle 10 travels by manual driving.

In this processing routine, if the turning state determination unit 101 does not determine in step S11 that the vehicle 10 turns gently (NO), the process proceeds to step S14. On the other hand, when the turning state determination unit 101 determines that the vehicle 10 turns gently (S11: YES), the process proceeds to the next step S111. In step S111, it is determined whether or not the vehicle is automatically traveling. When the driver is steering, the vehicle is not in automatic driving. Then, if it is not determined that the vehicle is traveling automatically (S111: NO), the process proceeds to step S14. On the other hand, if it is determined that the vehicle is traveling automatically (S111: YES), the process proceeds to step S12.

In step S12, the deceleration slip determination unit 104 calculates the slip amount SLP of each wheel FL, FR, RL, RR. Then, in the next step S13, if there is a wheel in which the slip amount SLP is equal to or larger than the determination slip amount SLPTh among the wheels FL, FR, RL, RR (YES), the process proceeds to the next step S14. It

In step S14, the stability priority control unit 103 executes the stability priority control. Then, in the next step S15, the control flag FLG is set to OFF. Then, this processing routine is once ended.

On the other hand, in step S13, when there is no wheel in which the slip amount SLP is equal to or larger than the determination slip amount SLPTh among the wheels FL, FR, RL, and RR (NO), roll suppression control is performed by the roll suppression control unit 102. To be done. That is, first, the process of step S16 is executed. If the control flag FLG is set to OFF in step S16 (YES), the process proceeds to step S17. On the other hand, if the control flag FLG is set to ON (S16: NO), the process proceeds to step S18.

In step S17, the roll angle Φ and the roll rate ΦR of the vehicle 10 are calculated, and in the next step S18, the wheel required braking force BPRTW for the rear wheel during turning, which is the target wheel, is calculated as the control amount of the roll suppression control. To be done. Then, in the next step S21, the suppression control amount Z is calculated. Subsequently, in step S22, the braking device 40, that is, the braking actuator 42 is controlled based on the wheel required braking force BPRTW and the suppression control amount Z. When increasing the driving force output from the power source 11, the power source 11 of the vehicle 10 is also controlled in addition to the braking actuator 42. Then, in step S23, the control flag FLG is set to ON. Then, this processing routine is once ended.

In the present embodiment, unlike the case of the first embodiment, when the vehicle 10 turns by the steering by the driver, the roll suppression control is not executed even if it is determined that the vehicle 10 turns gently. Accordingly, by causing the vehicle 10 to perform a rolling motion according to the manual steering, it is possible to give the driver a feeling that the vehicle behavior is appropriately changed by the steering.

(Third Embodiment)
Next, a third embodiment of the vehicle behavior control device will be described with reference to FIGS. The third embodiment is different from the first and second embodiments in that the regenerative braking force and the friction braking force are coordinated. Therefore, in the following description, the parts different from the first and second embodiments will be mainly described, and the same or corresponding member configurations as those of the first and second embodiments are the same. A reference numeral is given and duplicate description is omitted.

FIG. 7 shows a vehicle 10A including the control device 100. In addition to the braking device 40, the vehicle 10A includes a front wheel motor generator MG1 and a rear wheel motor generator MG2. Motor generator MG1 can apply a driving force to both front wheels FL, FR when accelerating vehicle 10A, and can apply a regenerative braking force BPR to both front wheels FL, FR when decelerating vehicle 10A. Regenerative braking force BPR corresponding to the amount of power generation of motor generator MG1 is applied to each front wheel FL, FR. At this time, the magnitude of the regenerative braking force BPR applied to the left front wheel FL is equal to the magnitude of the regenerative braking force BPR applied to the right front wheel FR. Similarly, motor generator MG2 applies a driving force to both rear wheels RL and RR when accelerating vehicle 10A, and applies a regenerative braking force BPR to both rear wheels RL and RR when decelerating vehicle 10A. can do. Regenerative braking force BPR according to the amount of power generation of motor generator MG2 is applied to each rear wheel RL, RR. At this time, the magnitude of the regenerative braking force BPR applied to the left rear wheel RL is equal to the magnitude of the regenerative braking force BPR applied to the right rear wheel RR. In the present embodiment, the motor generator MG1 is an example of a “regenerative device” that adjusts the regenerative braking force BPR applied to both front wheels FL, FR. Further, the motor generator MG2 is an example of a “regenerative device” that adjusts the regenerative braking force BPR applied to the rear wheels RL, RR.

Next, with reference to FIG. 8, a processing routine executed by the control device 100 when the vehicle 10A turns will be described. This processing routine is performed regardless of whether the vehicle 10A runs by automatic driving or the vehicle 10A runs by manual driving as long as the braking force is applied to the vehicle 10A while the vehicle is turning. It is executed repeatedly.

As shown in FIG. 8, in this processing routine, in step S31, as in step S11, the turning state determination unit 101 determines whether or not the vehicle 10 turns gently. When it is not determined that the vehicle 10 turns gently (S31: NO), the process proceeds to step S34 described later. On the other hand, when it is determined that the vehicle 10 turns gently (S31: YES), the process proceeds to the next step S32. In step S32, the deceleration slip determination unit 104 calculates the slip amount SLP of each wheel FL, FR, RL, RR. Subsequently, in step S33, the deceleration slip determination unit 104 determines whether or not any of the wheels FL, FR, RL, RR has a slip amount SLP equal to or greater than the determined slip amount SLPTh. If any of the wheels FL, FR, RL, RR has a slip amount SLP equal to or greater than the determination slip amount SLPTh (S33: YES), it can be determined that there is a wheel in which deceleration slip has occurred. Then, the process proceeds to step S34.

In step S34, the stability priority control unit 103 executes the stability priority control. The vehicle 10A can apply the regenerative braking force BPR to the wheels FL, FR, RL, RR. Therefore, in the stability priority control, the regenerative braking force may be applied to at least one of the front wheels FL, FR and the rear wheels RL, RR. When the stability priority control is performed in this manner, this processing routine is once ended.

On the other hand, in step S33, if there is no wheel among the wheels FL, FR, RL, and RR where the slip amount SLP is equal to or greater than the determination slip amount SLPTh (NO), it means that there is no wheel in which deceleration slip has occurred. Therefore, the roll suppression control unit 102 executes the roll suppression control. That is, first, the process of step S36 is executed. In step S36, it is determined whether or not the execution condition of the increasing process described later is satisfied. For example, the execution condition includes that the longitudinal acceleration GX is decreasing. For example, when the decreasing speed of the longitudinal acceleration GX is equal to or higher than the determination decreasing speed, it can be determined that the longitudinal acceleration GX is decreasing. The determination deceleration speed is set as a criterion for determining whether or not the deceleration of the vehicle 10A is large. Therefore, when the decreasing speed of the longitudinal acceleration GX is less than the determination decreasing speed, it cannot be determined that the longitudinal acceleration GX is decreasing. Then, if it is determined that the execution condition of the increasing process is satisfied (S36: YES), the process proceeds to the next step S37.

In step S37, the roll restraint control increasing process is executed. In the increasing process, the roll suppression control unit 102 increases the distribution ratio of the braking force to the target wheel among the wheels FL, FR, RL, and RR, while increasing the distribution ratio of the braking force to the target wheel among the wheels FL, FR, RL, and RR. The distribution ratio of the braking force to the wheels other than the wheels is reduced.

An example of the increasing process will be described with reference to FIG. The period from the timing T21 to the timing T22 in FIG. 9 is the execution period of the increasing process. 9(d), (e), (f), and (g), the broken line shows the transition of the regenerative braking force BPR when the roll suppression control is not performed. The thin solid line shows the transition of the regenerative braking force BPR when the roll suppression control is executed. That is, the vehicle required braking force BPRC is increased during the period from the timing T21 to the timing T22, so that the braking force applied to each wheel FL, FR, RL, RR is increased. However, in the increasing process, the increasing speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR is smaller than that when the roll suppression control is not performed. If the difference between the vehicle required braking force BPRC and the total regenerative braking force BPR applied to the wheels FL, FR, RL, and RR is regarded as the insufficient braking force, the larger the insufficient braking force is, the more The friction braking force BPF applied to the wheels is increased.

In the present embodiment, both the inner rear wheel during turning and the outer front wheel during turning are target wheels. Therefore, only the regenerative braking force BPR of the friction braking force BPF and the regenerative braking force BPR is applied to the rear wheel on the outside of the turn and the front wheel on the inner side of the turn that are not the target wheels, while the rear wheel on the inside of the turn is applied. Both the friction braking force BPF and the regenerative braking force BPR are applied to the wheel and the front wheel on the outer side during turning. That is, in the increasing process, the sum of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR and the sum of the friction braking force BPF applied to the rear wheel during turning and the front wheel outside during turning. The braking actuator 42 and each of the motor generators MG1 and MG2 are controlled so that is equal to the vehicle required braking force BPRC. As a result, the braking force applied to the target wheel is increased, while the braking force applied to the wheel that is not the target wheel is decreased. In this case, the required value of the friction braking force BPF to be applied to the target wheel is an example of the "control amount of roll suppression control".

By the way, due to the geometry of the front wheel suspensions 15FL and 15FR and the rear wheel suspensions 15RL and 15RR, the greater the braking force applied to the inner rear wheel during turning, the higher the effect of suppressing rolling motion of the vehicle 10A. it can. Therefore, in order to suppress the rolling motion of the vehicle 10A, it is preferable that the friction braking force BPF applied to the inner rear wheel during turning is made larger than the friction braking force BPF applied to the outer front wheel during turning. However, if the difference between the braking force BP applied to the inner rear wheel during turning and the braking force BP applied to the outer front wheel during turning is large, the yaw moment generated by the execution of the increasing process becomes large, and the vehicle 10A has a large yaw moment. There is concern that the stability of the behavior may be reduced. Therefore, the frictional braking force BPF applied to the inner rear wheel during turning and the frictional braking force BPF applied to the outer front wheel during turning allow a degree of decrease in the stability of the behavior of the vehicle 10A due to the execution of the increasing process. Each is set so that it can fit in the range.

Returning to FIG. 8, when the increasing processing is executed, this processing routine is once ended. On the other hand, if it is not determined in step S36 that the execution condition is satisfied (NO), the process proceeds to step S38 described later. In step S38, it is determined whether or not the execution condition of the reduction process described below is satisfied. For example, the execution condition includes both that it can be determined that the longitudinal acceleration GX has not decreased and that the friction braking force BPF applied to the target wheel is larger than the switching determination value BPFTh. In this embodiment, "0" is set as the switching determination value BPFTh. For example, when the decreasing speed of the longitudinal acceleration GX is less than the determination decreasing speed, it can be determined that the longitudinal acceleration GX has not decreased. Then, if it is determined that the longitudinal acceleration GX has not decreased and that the frictional braking force BPF applied to the target wheel is greater than the switching determination value BPFTh, the execution condition of the reduction process is determined. It is determined that the condition is satisfied (S38: YES), and the process proceeds to the next step S39.

In step S39, the roll restraint control decreasing process is executed. In the reduction processing, the roll suppression control unit 102 reduces the distribution ratio of the braking force applied to the target wheels by reducing the friction braking force BPF applied to the target wheels to the switching determination value BPFTTh. In the reduction process, the roll suppression control unit 102 increases the regenerative braking force BPR applied to each wheel FL, FR, RL, RR, thereby increasing the distribution ratio of the braking force applied to the wheels that are not the target wheels. To do.

An example of the reduction process will be described with reference to FIG. The period from the timing T22 to the timing T23 in FIG. 9 is the execution period of the reduction process. In the example shown in FIG. 9, the vehicle required braking force BPRC is not increased during the period from timing T22 to timing T23. Then, in the reduction processing, the friction braking force BPF applied to the inner rear wheel during turning and the friction braking force BPF applied to the outer front wheel during turning are both reduced. The decreasing speed of the friction braking force BPF at this time is larger than the increasing speed of the friction braking force BPF at the time of executing the increasing process. The decreasing speed of the friction braking force BPF when executing the decreasing process may be the same as the increasing speed of the friction braking force BPF when executing the increasing process, or may be smaller than the increasing speed.

In the reduction processing, the wheels FL, FR, RL, and RR are changed according to the reduction of the friction braking force BPF applied to the inner rear wheel during turning and the friction braking force BPF applied to the outer front wheel during turning. The applied regenerative braking force BPR is increased. This maintains a state in which the total braking force applied to each wheel FL, FR, RL, RR is equal to the vehicle required braking force BPRC.

Returning to FIG. 8, when the reduction processing is executed, this processing routine is once ended. On the other hand, if it is determined in step S38 that at least one of the fact that the longitudinal acceleration GX has not decreased and that the friction braking force BPF applied to the target wheel is greater than the switching determination value BPFTh are not satisfied, the execution condition is satisfied. Is not determined (NO), and the process proceeds to step S40 described below. In step S40, it is determined whether or not the execution condition of the holding process described below is satisfied. For example, the execution condition includes both that it can be determined that the longitudinal acceleration GX has not decreased and that the frictional braking force BPF applied to the target wheel is equal to or less than the switching determination value BPFTh. If both the determination that the longitudinal acceleration GX has not decreased and the friction braking force BPF applied to the target wheel is equal to or less than the switching determination value BPFTh, the execution condition of the holding process is satisfied. Is determined (S40: YES), and the process proceeds to the next step S41. On the other hand, if at least one of the fact that it can be determined that the longitudinal acceleration GX has not decreased and that the frictional braking force BPF applied to the target wheel is equal to or less than the switching determination value BPFTh is not satisfied, the execution condition is satisfied. It is not determined that there is (S40: NO), and this processing routine is temporarily terminated.

In step S41, a roll restraining control holding process is executed. In the holding process, the roll suppression control unit 102 holds the friction braking force BPF applied to the target wheel in a state of not more than the switching determination value BPFTh, while the braking force BP applied to each wheel FL, FR, RL, RR is held. The state where the total is equal to the vehicle required braking force BPRC is maintained. In this embodiment, "0" is set as the switching determination value BPFTh. Therefore, it is possible to replace all of the friction braking force BPF applied to the target wheel by the reduction process with the regenerative braking force BPR. Then, this processing routine is once ended.

When the vehicle speed VS decreases to the switching determination speed VSTh1 when the vehicle 10A is decelerated by applying the regenerative braking force BPR to the wheels FL, FR, RL, and RR, the regenerative braking force BPR is replaced by the friction braking force BPF. Control is implemented. That is, as shown in FIG. 9, when the vehicle body speed VS reaches the switching determination speed VSTh1 at timing T24, it is determined that the switching control start condition is satisfied, the roll suppression control is ended, and the switching control is started. It

Next, the operation and effect of this embodiment will be described with reference to FIG. 9. The example shown in FIG. 9 is a case where the braking force is applied to the vehicle 10A when the vehicle 10A is turning to either the right side or the left side. That is, the turning direction of the vehicle 10A does not change during the deceleration of the vehicle 10A.

As shown in FIGS. 9A to 9G, the braking force is applied to the vehicle 10 from the timing T21 when the vehicle 10A is turning. At this time, if it is determined that the vehicle 10A is gently turning, and if there is no wheel whose slip amount SLP is equal to or greater than the determined slip amount SLPTh, execution of the roll suppression control is started. Then, in the period from the timing T21 to the timing T22, the increase process is executed to increase the braking force BP applied to the rear wheel during turning, which is the target wheel, that is, the total of the friction braking force BPF and the regenerative braking force BPR. It Further, the braking force BP applied to the front wheel on the outer side during turning, which is the target wheel, that is, the total of the friction braking force BPF and the regenerative braking force BPR is increased. By increasing the braking force applied to the inner rear wheel during turning, the anti-lift force generated near the inner rear wheel during turning in the rear part of the vehicle is increased compared to when the roll suppression control is not performed. be able to. Also, by increasing the braking force applied to the outer front wheel during turning, the anti-dive force generated near the outer front wheel during turning of the vehicle front part is increased compared to when the roll suppression control is not performed. Can be made As a result, in the present embodiment, even when the regenerative braking force is applied to the vehicle 10A, the rolling motion at the time of turning the vehicle can be suppressed, and the comfort of the occupant of the vehicle 10A at the time of turning the vehicle can be improved. You can

In the present embodiment, the braking force is increased for the rear wheel on the inside of the turn and the front wheel on the outside for the turn, which are arranged diagonally. Therefore, the yaw moment generated by the increase in the braking force applied to the inner rear wheel during turning can be offset by the yaw moment generated by the increase in the braking force applied to the outer front wheel during turning. As a result, it is possible to suppress a decrease in the stability of the behavior of the vehicle 10A at the time of turning due to the execution of the roll suppression control.

In the increasing process, the regenerative braking force BPR applied to each wheel FL, FR, RL, RR is reduced by the amount that the friction braking force BPF applied to the target wheel is increased. As a result, it is possible to suppress a change in the longitudinal acceleration GX of the vehicle 10A due to the roll suppression control.

In the roll suppression control executed in the present embodiment, during the period from the timing T22 to the timing T23 after the friction braking force BPF applied to the target wheel is increased by executing the increasing process, the decreasing process is performed to the target wheel. The applied friction braking force BPF is reduced. Further, as the friction braking force BPF decreases, the regenerative braking force BPR applied to each wheel FL, FR, RL, RR increases. By executing the reduction process in this way and starting the holding process from timing T23, it is possible to suppress a reduction in the recovery efficiency of the regenerative energy during braking of the vehicle 10A.

(Fourth Embodiment)
Next, a fourth embodiment of the vehicle behavior control device will be described with reference to FIG. In the fourth embodiment, the content of the roll suppression control differs from that of the third embodiment. Therefore, in the following description, the parts different from the third embodiment will be mainly described, and the same or corresponding member configurations as those of the above-mentioned respective embodiments will be designated by the same reference numerals and duplicate description will be omitted. I shall.

The roll suppression control executed in this embodiment includes an increasing process, a decreasing process, and a holding process. Then, as described in the third embodiment, when the vehicle 10A is being turned and the braking force BP is applied to the vehicle 10A, it is determined that the vehicle 10A is gently turning (S31 in FIG. 8: (YES), if there is no wheel in which the slip amount SLP is equal to or larger than the determination slip amount SLPTh among the wheels FL, FR, RL, RR (S32: NO in FIG. 8), the roll suppression control is executed.

When the execution condition of the increasing process is satisfied, the increasing process is executed. When the execution condition for the decrease process is satisfied while the execution condition for the increase process is not satisfied, the decrease process is executed. When neither the execution condition of the increasing process nor the execution condition of the decreasing process is satisfied and the execution condition of the holding process is satisfied, the holding process is executed.

However, the content of the execution condition of the increasing process is different from that of the third embodiment. That is, as shown in FIGS. 10A to 10G, the execution condition of the increasing process includes that the absolute value of the lateral acceleration GY of the vehicle 10A is increasing. For example, when the increasing speed of the absolute value of the lateral acceleration GY is equal to or higher than the first determination speed, it can be determined that the absolute value of the lateral acceleration GY is increasing. The execution condition of the increasing process in the present embodiment does not include that it can be determined that the longitudinal acceleration GX of the vehicle 10A is decreasing.

Further, the content of the execution condition of the reduction processing is also different from that of the third embodiment. That is, the execution condition of the reduction process includes that the absolute value of the lateral acceleration GY of the vehicle 10A is decreasing. For example, when the decreasing speed of the absolute value of the lateral acceleration GY is equal to or higher than the second determination speed, it can be determined that the absolute value of the lateral acceleration GY is decreasing. The execution condition of the reduction process in the present embodiment does not include that it can be determined that the longitudinal acceleration GX has not decreased.

The content of the execution condition of the holding process is also different from that of the third embodiment. That is, the execution condition of the holding process includes that it can be determined that the lateral acceleration GY of the vehicle 10A has not changed. For example, when the increasing speed of the absolute value of the lateral acceleration GY is equal to or higher than the first judgment speed and the decreasing speed of the absolute value of the lateral acceleration GY is equal to or higher than the second judgment speed, the lateral acceleration GY is not changed. Can be determined. The execution condition of the reduction process in the present embodiment does not include that it can be determined that the longitudinal acceleration GX has not decreased.

Next, the operation and effect of the present embodiment will be described with reference to FIG. The example shown in FIG. 10 is a case where the turning direction of the vehicle 10A is changed during vehicle braking, such as when the vehicle 10A changes lanes. 10(d), (e), (f), and (g), the broken line is the transition of the regenerative braking force BPR when the roll suppression control is not executed, and the thin solid line is the case where the roll suppression control is executed. Is a transition of the regenerative braking force BPR of. The thick solid line shows the transition of the friction braking force BPF when the roll suppression control is executed.

As shown in FIGS. 10A to 10G, the braking force is applied to the vehicle 10A from the timing T31. In the example shown in FIG. 10, the regenerative braking force BPR is applied to each wheel FL, FR, RL, RR. Then, from timing T32, a yaw moment that changes the lateral acceleration GY of the vehicle 10A in the positive direction is generated in the vehicle 10A. Then, the lateral acceleration GY increases.

In this embodiment, the roll suppression control is started from timing T32. That is, in the period from the timing T32 to the timing T33, the execution condition for the increase process is satisfied, so the increase process is executed. In the increasing process, the regenerative braking force BPR applied to each wheel FL, FR, RL, RR is reduced, and the friction braking force BPF applied to the target wheel is increased. In the example shown in FIG. 10, since both the inner wheel at the time of turning and the front wheel at the outer side at the time of turning are target wheels, the friction braking force BPF applied to the rear wheel at the time of turning and the front wheel at the outer side at the time of turning are set. The applied friction braking force BPF is increased. As a result, the braking force applied to the outer rear wheel during turning, which is not the target wheel, and the braking force applied to the inner front wheel during turning are respectively reduced, and the braking force applied to the inner rear wheel during turning, Also, the braking force applied to the outer front wheels during turning is increased. Then, by increasing the braking force applied to the inner rear wheel during turning, the anti-lift force generated in the vicinity of the inner rear wheel during turning of the vehicle rear portion is increased as compared to when the roll suppression control is not performed. be able to. Further, by increasing the braking force applied to the outer front wheel at the time of turning, the anti-dive force generated in the vicinity of the outer front wheel at the time of turning of the vehicle front part is increased as compared to when the roll suppression control is not performed. You can As a result, in the present embodiment, even when the regenerative braking force is applied to the vehicle 10A, the rolling motion at the time of turning the vehicle can be suppressed, and the comfort of the occupant of the vehicle 10A at the time of turning the vehicle can be improved. You can

In the example shown in FIG. 10, a yaw moment in the direction in which the lateral acceleration GY decreases from timing T33 is generated in the vehicle 10A. As a result, the absolute value of the lateral acceleration GY becomes small, so that the execution condition for the reduction process is satisfied, the increase process is terminated, and the reduction process is executed. The smaller absolute value of the lateral acceleration GY means that the centrifugal force acting on the vehicle 10A becomes smaller. That is, the force that suppresses the rolling motion of the vehicle 10A may be reduced. By executing the reduction processing, the friction braking force BPF applied to the inner rear wheel during turning and the friction braking force BPF applied to the outer front wheel during turning are both reduced. Further, as the friction braking force BPF decreases, the regenerative braking force BPR applied to each wheel FL, FR, RL, RR increases. In this way, the rolling motion of the vehicle 10A is adjusted by reducing the braking force applied to the target wheel in accordance with the decrease in the absolute value of the lateral acceleration GY.

Then, at timing T34, the sign of the lateral acceleration GY is reversed. That is, the absolute value of the lateral acceleration GY increases from timing T34. Then, since the execution condition of the increasing process is satisfied, the decreasing process is ended and the increasing process is started. The turning direction of vehicle 10A after timing T34 is opposite to the turning direction of vehicle 10A before timing T34. Therefore, in the increasing process started from the timing T34, a wheel different from that at the time of executing the increasing process started from the timing T32 is selected as the target wheel. For example, when the right front wheel FR and the left rear wheel RL are selected as the target wheels at the time of executing the increasing process started at the timing T32, the left front wheel FL and the right rear wheel RR are set at the increasing process started at the timing T34. It is selected as the target wheel.

In the increasing process started from timing T34, the friction braking force BPF applied to the inner rear wheel during turning and the friction braking force BPF applied to the outer front wheel during turning are increased. As a result, the braking force applied to the outside rear wheel during turning, which is not the target wheel, and the braking force applied to the inside front wheel during turning are both reduced, and the braking force applied to the inside rear wheel during turning, Also, the braking force applied to the outer front wheels during turning is increased. As a result, rolling motion during vehicle turning can be suppressed.

From timing T35, a yaw moment in the direction in which the lateral acceleration GY increases is generated in the vehicle 10A. As a result, the absolute value of the lateral acceleration GY becomes small, so that the execution condition for the reduction process is satisfied, the increase process is terminated, and the reduction process is executed. Then, the reduction processing is executed to reduce the friction braking force BPF applied to the inner rear wheel during turning and the friction braking force BPF applied to the outer front wheel during turning. Further, as the friction braking force BPF decreases, the regenerative braking force BPR applied to each wheel FL, FR, RL, RR increases. In this way, the rolling motion of the vehicle 10A is adjusted by reducing the braking force applied to the target wheel in accordance with the decrease in the absolute value of the lateral acceleration GY.

Then, from timing T36, the lateral acceleration GY hardly changes. That is, since the state in which the changing speed of the lateral acceleration GY is equal to or lower than the threshold value is maintained, it is determined that the absolute value of the lateral acceleration GY has not changed. Then, since the holding condition is satisfied, the reduction processing is ended and the holding processing is started. In the holding process, the friction braking force BPF to be applied to the target wheel is maintained at a state equal to or less than the switching determination value BPFTh, while the total of the regenerative braking force BPR to be applied to each wheel FL, FR, RL, RR is the vehicle request control. The state equal to the power BPRC is maintained.

The execution condition of the switching control is satisfied at timing T37. Therefore, the roll suppression control is ended and the replacement control is started.
(Fifth Embodiment)
Next, a fifth embodiment of the vehicle behavior control device will be described with reference to FIGS. 11 to 13. In the fifth embodiment, the method of adjusting the rolling motion during turning of the vehicle is different from the above-mentioned embodiments. Therefore, in the following description, the parts that are different from the above-described embodiments will be mainly described, and the same or corresponding member configurations as those of the above-described embodiments will be denoted by the same reference numerals and redundant description will be omitted. I shall.

As shown in FIG. 11, the roll control unit 108 includes a roll promotion control unit 106 in addition to the roll suppression control unit 102. The roll promotion control unit 106 executes the roll promotion control when the turning state determination unit 101 determines that the vehicle 10 turns gently. Unlike the roll suppression control, the roll promotion control is control for promoting the rolling motion of the vehicle 10A. The roll promotion control is a control that is executed when the vehicle required braking force BPRC is reduced due to a reduction in the amount of braking operation by the driver.

Here, as a result of various experiments and simulations, the inventor of the present invention improves the comfort of the occupant of the vehicle 10A when the vehicle braking force is reduced during turning of the vehicle 10A to which the braking force is applied. Then, it was found that it is better to promote the rolling motion rather than suppressing the rolling motion. Therefore, in the present embodiment, when the vehicle required braking force BPRC is reduced when the vehicle 10A to which the braking force is applied turns, the roll promotion control is executed.

Next, with reference to FIG. 12, a processing routine executed by the control device 100 when executing the roll promotion control when the vehicle 10A is turning will be described. It should be noted that this processing routine is repeatedly executed even when the vehicle 10A travels by automatic driving or when the vehicle 10A travels by manual driving.

As shown in FIG. 12, in this processing routine, in step S51, similarly to step S11, the turning state determination unit 101 determines whether or not the vehicle 10A turns gently. When it is determined that the vehicle 10A turns gently (S51: YES), the process proceeds to the next step S52. In step S52, it is determined whether the braking force is applied to vehicle 10A. When the vehicle required braking force BPRC is larger than "0", it is determined that the braking force is applied to the vehicle 10A. On the other hand, when the vehicle required braking force BPRC is equal to "0", it is not determined that the braking force is applied to the vehicle 10A. Then, when it is determined that the braking force is applied to the vehicle 10A (S52: YES), the process proceeds to the next step S53. In step S53, it is determined whether the vehicle required braking force BPRC has decreased. For example, when the decreasing speed of the vehicle request braking force BPRC is equal to or higher than the determination speed, it is determined that the vehicle request braking force BPRC is decreasing. On the other hand, when the decreasing speed of the vehicle request braking force BPRC is less than the determination speed, it is not determined that the vehicle request braking force BPRC is decreasing. When it is determined that the vehicle required braking force BPRC has decreased (S53: YES), the roll promotion control unit 106 performs roll promotion control.

The roll promotion control executed in the present embodiment includes a first process and a second process executed after the first process. Therefore, in the roll promotion control, it is determined in step S54 whether a predetermined switching condition is satisfied. The switching condition is a condition for determining whether to switch the processing to be executed from the first processing to the second processing. In the present embodiment, the switching condition includes that the regenerative braking force BPR applied to the wheels FL, FR, RL, RR becomes equal to or less than the switching determination value BPRTh. In this embodiment, “0” is set as the switching determination value BPRTh.

If it is not determined that the switching condition is satisfied (S54: NO), the process proceeds to the next step S55. Then, in step S55, the first process is executed. In the first process, the braking force applied to each wheel FL, FR, RL, RR is set so that the decreasing speed of the braking force applied to the target wheel is higher than the decreasing speed of the braking force applied to the wheel that is not the target wheel. BP is adjusted. Then, this processing routine is once ended.

On the other hand, if it is determined that the switching condition is satisfied (S54: YES), the process proceeds to the next step S56. In step S56, the second process is executed. When the wheel to which the braking force is still applied at the time of shifting from the first process to the second process is the reduction wheel, the braking force applied to the reduced wheel is decreased in the second process. In the present embodiment, the wheel that is not the target wheel corresponds to the reduction wheel. Then, this processing routine is once ended.

In addition, when any of the determination result of step S51, the determination result of step S52, and the determination result of step S53 is a negative determination (NO), this processing routine is once ended. Therefore, when the determination in step S52 or step S53 is negative during the roll promotion control, the roll promotion control is ended.

Next, with reference to FIG. 13, the first process and the second process of the roll promotion control will be described in detail. 13(d), (e), (f), and (g), the broken line indicates the transition of the regenerative braking force BPR when the roll promotion control is not performed, and the thin solid line indicates when the roll promotion control is performed. Is a transition of the regenerative braking force BPR of. The thick solid line shows the transition of the friction braking force BPF when the roll acceleration control is executed.

In the example shown in FIG. 13, the vehicle 10A starts to turn and the vehicle request braking force BPRC starts to decrease from timing T42 during vehicle braking. Therefore, the roll promotion control is executed from timing T42. That is, the period from timing T42 to timing T43 is the execution period of the first process. In the present embodiment, both the rear wheel on the inside of the turn and the front wheel on the outside of the turn are target wheels. Therefore, in the first process, each wheel FL, FR, RL, RR is set so that the speed of decrease of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR becomes larger than that when the roll promotion control is not performed. The regenerative braking force BPR applied to is reduced. As a result, in the first process, the rate of decrease of the regenerative braking force BPR applied to the inner rear wheel during turning can be made larger than that when the roll acceleration control is not performed, and the regenerative braking force BPR applied to the outer front wheel during turning can be increased. The decreasing speed can be made larger than that when the roll promotion control is not performed.

By thus reducing the braking force applied to the target wheel early, the force suppressing the rolling motion of the vehicle 10A can be reduced early. That is, by reducing the braking force applied to the inner rear wheel during turning early, the anti-lift force generated near the inner rear wheel during turning in the rear part of the vehicle is compared with that when the roll promotion control is not performed. And can be made smaller early. In addition, by reducing the braking force applied to the outside front wheels during turning early, the anti-dive force generated near the outside front wheels during turning in the front part of the vehicle is compared with that when no roll acceleration control is performed. Can be made smaller early. As a result, rolling motion is promoted when the vehicle turns.

In the first process, the friction braking force applied to a wheel that is not the target wheel is based on the difference between the vehicle required braking force BPRC and the total regenerative braking force BPR applied to each wheel FL, FR, RL, RR. BPF is adjusted. That is, the total of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR, the friction braking force BPF applied to the outer rear wheel during turning, and the friction braking force BPF applied to the inner front wheel during turning. The friction braking force BPF applied to the outer rear wheel at the time of turning and the friction braking force BPF applied to the inner front wheel at the time of turning are adjusted such that the sum of the two becomes equal to the vehicle required braking force BPRC. That is, the friction braking force BPF applied to the outer rear wheel during turning and the friction braking force BPF applied to the inner front wheel during turning are increased. As a result, the speed of decrease of the braking force applied to the rear wheel during turning, which is the target wheel, is greater than the speed of decrease of the braking force applied to the rear outer wheel during turning, which is not the target wheel. Further, the speed of decrease of the braking force applied to the front wheel on the outside of the turning, which is the target wheel, is higher than the speed of decrease of the braking force applied to the front wheel on the inner side of the turning, which is not the target wheel.

In the example shown in FIG. 13, the regenerative braking force BPR applied to the target wheel at the timing T43 becomes the switching determination value BPRTh or less, and the switching condition is satisfied. Therefore, the first process is ended and the second process is started. In the present embodiment, at the start of the second process, the braking force is not applied to the target wheel, while the braking force is applied to the wheels that are not the target wheel. Therefore, in the second process, the braking force applied to the wheel that is not the target wheel, that is, the rear wheel on the outside during turning and the braking force applied to the front wheel on the inside during turning are both reduced. In the example shown in FIG. 13, the frictional braking force BPF is applied to the rear wheel when turning and the front wheel inside when turning, but the regenerative braking force BPR is not applied. Therefore, the frictional braking force BPF applied to the outer rear wheel during turning and the frictional braking force BPF applied to the inner front wheel during turning are reduced in accordance with the decrease in the vehicle required braking force BPRC. Therefore, even during the execution of the second process, the state where the total braking force BP applied to each wheel FL, FR, RL, RR and the vehicle required braking force BPRC are maintained is maintained.

Then, at the timing T44 when the vehicle required braking force BPRC becomes "0", the second process is executed to perform the friction braking force BPF applied to the outer rear wheel during turning and the friction braking force applied to the inner front wheel during turning. The power BPF becomes “0”, respectively. Therefore, the roll promotion control ends at timing T44.

Next, the operation and effect of this embodiment will be described with reference to FIG. The example shown in FIG. 13 is a case where the vehicle 10A starts to turn while the braking force is applied, and the application of the braking force to the vehicle 10A is started during the turn.

As shown in FIGS. 13A to 13G, the braking force starts to be applied to the vehicle 10A at timing T41. In the example shown in FIG. 13, the regenerative braking force BPR is applied to each wheel FL, FR, RL, RR. The vehicle 10A starts to turn from timing T42 while the vehicle 10A is decelerating due to the application of the braking force to the wheels FL, FR, RL, RR. Further, the vehicle request braking force BPRC starts to decrease. At this time, if it is determined that the vehicle 10A is turning gently, the roll promotion control is started.

Now, consider a comparative example in which the roll acceleration control is not performed when the application of the braking force to the vehicle 10A is canceled while the vehicle 10A is turning and the vehicle 10A accelerates. In such a comparative example, as shown in FIG. 13C, the absolute value of the lateral acceleration GY increases and the braking force BP applied to the wheels FL, FR, RL, RR decreases during turning of the vehicle. Due to changes in the anti-dive force and the anti-lift force, the roll angle Φ of the vehicle 10A may fluctuate during turning of the vehicle. That is, the roll angle Φ will continue to change during the period in which the braking force decreases, and this may cause the occupant of the vehicle 10A to feel uncomfortable.

On the other hand, in the present embodiment, the roll promotion control is executed when the vehicle required braking force BPRC is reduced during turning of the vehicle. In the first process of the roll promotion control, the braking force applied to the rear wheel at the time of turning and the front wheel on the outer side at the time of turning, which are the target wheels, is reduced at an early stage, while The braking force applied to the outer front wheel during turning is less likely to be reduced. Therefore, the anti-lift force generated in the vicinity of the outer rear wheel at the time of turning of the rear part of the vehicle is controlled by the roll acceleration control by suppressing the decrease of the braking force applied to the outer rear wheel at the time of turning or by increasing the braking force. It can be increased compared to the non-implementation. In addition, the anti-dive force generated in the vicinity of the inner front wheel at the time of turning of the vehicle front portion is controlled by the roll acceleration control by suppressing the decrease of the braking force applied to the inner front wheel at the time of turning or increasing the braking force. It can be increased compared to the time of implementation. As a result, the roll angle Φ of the vehicle 10A can be maintained in a large state in the initial stage of the reduction of the vehicle required braking force BPRC. As a result, the fluctuation of the roll angle Φ of the vehicle 10A during the decrease of the vehicle required braking force BPRC is suppressed, and the comfort of the occupant of the vehicle 10A can be improved. In particular, for example, by performing roll acceleration control during turning of the vehicle 10A in which a decrease in braking force and an increase in roll angle Φ overlap, vertical movement of the front part on the outside of the vehicle during turning and the rear part of the vehicle on the inside during turning is performed. It is suppressed, and as a result, passenger comfort can be improved. When the vehicle 10A turns so that the braking force decreases and the roll angle Φ increase, the vehicle 10A turns, for example, from a state in which the vehicle 10A is straightened while applying the braking force to the vehicle 10A. There may be mentioned a case of shifting to the state, and a case of increasing the degree of turning while reducing the braking force while turning the vehicle 10A while applying the braking force. Increasing the degree of turning means that the absolute values of the yaw rate YR and lateral acceleration GY of the vehicle 10A increase due to an increase in the steering angle of the steering wheel.

However, in the present embodiment, when the braking force BP applied to the target wheel becomes “0”, the first process is transferred to the second process, so that the braking force applied to the front wheel on the outer side during turning and the inner force on the inner side during turning. The braking force applied to the rear wheels is reduced.

(Example of change)
Each of the above embodiments can be modified and implemented as follows. The above-described embodiments and the following modifications can be implemented in combination with each other within a technically consistent range.

In the second embodiment, the stability priority control may not be performed during manual steering.
In the roll restraint control executed in the first embodiment, the reduction of the wheel required braking force BPRTW may not be corrected during manual steering.

The lower the μ value of the road surface on which the vehicle 10 travels, the easier the wheels FL, FR, RL, RR are to decelerate and slip when the braking force is applied to the wheels FL, FR, RL, RR. Therefore, if the μ value of the road surface can be estimated or the μ value can be acquired, when the μ value of the road surface is less than or equal to the judgment μ value, a large braking force is applied to the rear wheel during turning by the roll suppression control. If it is given, it is determined that deceleration slip may occur at the wheel, and the roll suppression control may not be performed. Even if the roll suppression control is performed, the wheel required braking force BPRTW for the target wheel may be reduced and corrected according to the low μ value of the road surface.

When the braking force is applied to the target wheel or the braking force to be applied to the target wheel is increased by executing the roll suppression control, the deceleration of the vehicle 10 by the execution of the roll suppression control is allowed to some extent. Good. That is, when the braking force applied to the target wheel is increased or the braking force is applied to the target wheel, the driving force output from the power source 11 of the vehicle 10 may not be adjusted. In particular, when the braking force is applied to the target wheel by performing the non-braking roll suppression control, it is not necessary to adjust the driving force output from the power source 11 of the vehicle 10.

In each of the above-described embodiments, the wheel required braking force BPRTW for the rear wheel on the inside during turning is calculated based on the roll angle deviation ΔΦ and the roll rate ΦR at the start of the roll suppression control. However, if the wheel required braking force BPRTW is calculated in consideration of the roll angle deviation ΔΦ, the roll rate ΦR does not have to be used to calculate the wheel required braking force BPRTW. On the contrary, if the wheel required braking force BPRTW is calculated in consideration of the roll rate ΦR, the roll angle deviation ΔΦ does not have to be used for the calculation of the wheel required braking force BPRTW.

In each of the above embodiments, the wheel required braking force BPRTW may be calculated based on the roll angular acceleration that is the change speed of the roll rate ΦR of the vehicle. For example, the wheel request braking force BPRTW may be calculated such that the wheel request braking force BPRTW increases as the roll angular acceleration increases.

In the above-described first and second embodiments, the wheel required braking force BPRTW is calculated by the feedforward control that inputs the roll angle deviation ΔΦ at the start of the roll suppression control. However, in the roll suppression control, the roll angle deviation ΔΦ may be sequentially monitored, and the wheel required braking force BPRTW may be varied according to the roll angle deviation ΔΦ. For example, the wheel required braking force BPRTW may be varied so that the roll angle deviation ΔΦ approaches “0”. In this case, when the roll angle deviation ΔΦ becomes “0”, the wheel required braking force BPRTW is held.

In the first and second embodiments described above, the wheel required braking force BPRTW is calculated by the feedforward control in which the roll rate ΦR at the start of the roll suppression control is input. However, in the roll suppression control, the deviation between the roll rate ΦR and the target value of the roll rate may be sequentially monitored, and the wheel required braking force BPRTW may be varied according to the deviation. For example, the wheel required braking force BPRTW may be varied so that the deviation approaches "0". In this case, when the deviation becomes "0", the wheel required braking force BPRTW is held.

In the first embodiment and the second embodiment, the wheel required braking force BPRTW for the rear wheel at the time of turning may be the sum of the braking force before the start of the roll suppression control and the preset specified value. ..

In the third and fourth embodiments described above, the friction braking force BPF applied to the target wheel during the increasing process is increased based on the roll angle deviation ΔΦ and the roll rate ΦR at the start of the increasing process of the roll suppression control. The speed and the decreasing speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR may be determined. In this case, the increasing speed of the friction braking force BPF applied to the target wheel during the increasing process is held at a constant value. On the other hand, during the increasing process, the roll angle deviation ΔΦ and the roll rate ΦR are sequentially monitored, and based on the changes in the roll angle deviation ΔΦ and the roll rate ΦR, the increasing speed of the friction braking force BPF applied to the target wheel, Also, the reduction speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR may be varied. For example, the increase speed of the friction braking force BPF applied to the target wheel and the decrease speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR are set so that the roll angle deviation ΔΦ approaches “0”. It may be variable. In this case, the increasing speed of the friction braking force BPF applied to the target wheel may change during the increasing process.

In the fifth embodiment, based on the roll angle deviation ΔΦ and the roll rate ΦR at the start of the first process of the roll promotion control, the increasing speed of the friction braking force BPF applied to the target wheel during the first process, and , The reduction speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR may be determined. In this case, the increasing speed of the friction braking force BPF applied to the target wheel during the first processing is maintained at a constant value. On the other hand, during the first process, the roll angle deviation ΔΦ and the roll rate ΦR are sequentially monitored, and the increase speed of the friction braking force BPF applied to the target wheel is based on the changes in the roll angle deviation ΔΦ and the roll rate ΦR. , And the reduction speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR may be varied. For example, the increase speed of the friction braking force BPF applied to the target wheel and the decrease speed of the regenerative braking force BPR applied to each wheel FL, FR, RL, RR are set so that the roll angle deviation ΔΦ approaches “0”. It may be variable. In this case, the increasing speed of the friction braking force BPF applied to the target wheel may change during the first process.

-In the said 3rd Embodiment and 4th Embodiment, you may set the value larger than "0" as switching determination value BPFTh. As a result, for example, when the longitudinal acceleration GX is not reduced and the friction braking force BFP applied to the target wheel is reduced to the switching determination value BPFTh or less by the reduction process, the process to be executed is reduced. Then, the process proceeds to the holding process, and the friction braking force BFP applied to the target wheel is held. As a result, the roll suppressing effect according to the friction braking force BFP applied to the target wheel is maintained even during the holding process.

-In the said 5th Embodiment, you may set the value larger than "0" as switching determination value BPRTh.
-In the said 5th Embodiment, you may add that the degree of turning of the vehicle 10A becomes strong and roll angle (PHI) increases as an implementation condition of roll promotion control. For example, the increase amount of the absolute value of the yaw rate YR during the predetermined period is equal to or larger than the determination value, the increase amount of the absolute value of the lateral acceleration GY during the predetermined period is equal to or larger than the determination value, and the steering angle STR during the predetermined period. It may be determined that the degree of turning has become stronger when any one of the increase amounts of 1 and 2 is greater than or equal to the determination value. Further, when any of these is established, it may be determined that the degree of turning has become stronger.

In the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment, the stability priority control is performed when it is not determined that the vehicles 10 and 10A turn gently. Has become. However, if the determination is not made, the stability priority control may not be executed if the roll suppression control is not executed.

In the turning area near the boundary where it is determined that the vehicle 10, 10A turns gently, the increase in the wheel request braking force BPRTW for the target wheel may be suppressed as compared with the turning area that is gentler than that. For example, when the absolute value of the yaw rate YR is greater than or equal to the determination yaw rate YRTh2 (second predetermined value) that is smaller than the determination yaw rate YRTh (first predetermined value), the absolute value of the yaw rate YR is compared with the case where the absolute value of the yaw rate YR is less than the determination yaw rate YRTh2. The wheel required braking force BPRTW for the roll angle deviation ΔΦ may be calculated to be small.

When the geometry of the front wheel suspensions 15FL and 15FR and the rear wheel suspensions 15RL and 15RR has the same braking force applied to the front wheels FL and FR and the rear wheel RL and RR, The anti-dive force FAD may be set to be larger than the anti-lift force FAL. In the roll suppression control executed in this case, it is preferable that the front wheel on the outer side during turning is selected as the target wheel and the rolling motion of the vehicle is suppressed by adjusting the braking force applied to the front wheel on the outer side during turning.

For example, when the vehicle 10B makes a right turn as shown in FIG. 14, in the roll suppression control, the braking force BPFL applied to the left front wheel FL corresponding to the outer front wheel at the time of turning is the braking force BPFR applied to the right front wheel FR, The braking force BPRL to be applied to the left rear wheel RL and the braking force BPRR to be applied to the right rear wheel RR are made larger. When such roll restraining control is executed, a large anti-dive force FAD is generated at the outer front portion when the vehicle 10B is turning. As a result, the rolling motion of the vehicle 10B can be suppressed, and thus the change of the roll angle Φ of the vehicle 10B can be suppressed. Furthermore, the generation of the large anti-dive force FAD can suppress the pitching motion of the vehicle 10B during deceleration of the vehicle 10B, and thus suppress the change in the pitch angle of the vehicle 10B.

When a large braking force is applied to the outer front wheel during turning by the roll suppression control, the vehicle tends to exhibit an understeer tendency. Therefore, the stability priority control executed in the modified example is control for suppressing understeer of the vehicle. For example, in stability priority control that suppresses understeer of the vehicle, the braking force applied to the outer front wheel during turning is made greater than the braking force applied to the inner front wheel during turning and is applied to the inner rear wheel during turning. The braking force is made larger than the braking force applied to the outer rear wheel during turning. For example, when the vehicle 10B makes a right turn as shown in FIG. 15, in the stability priority control, the braking force BPFL applied to the left front wheel FL which is the outer front wheel at the time of turning is applied to the right front wheel FR which is the inner front wheel at the time of turning. The braking force BPFR is greater than the braking force BPFR to be applied, and the braking force BPRR to be applied to the right rear wheel RR which is the inner rear wheel during turning is greater than the braking force BPRL to be applied to the left rear wheel RL which is the outer rear wheel during turning. The braking force difference ΔBPF that occurs between the left and right front wheels FL and FR when the stability priority control is performed is smaller than the braking force difference ΔBPF that occurs when the roll suppression control is performed. The yaw moment YM2 corresponding to the braking force difference ΔBPF generated between the left and right front wheels FL, FR acts in the direction of increasing the understeer tendency of the vehicle 10B. On the other hand, the yaw moment YM1 corresponding to the braking force difference ΔBPR generated between the left and right rear wheels RL, RR acts to increase the oversteer tendency of the vehicle 10B. That is, since the yaw moment YM2 and the yaw moment YM1 are opposite in direction, the yaw moment YM2 is offset by the yaw moment YM1. As a result, the vehicle 10B is less likely to understeer when turning.

In each of the above-described embodiments, the greater the braking force applied to the vehicle at the time of turning, that is, the greater the deceleration of the vehicle, the more likely the stability of the behavior of the vehicle is reduced when the roll suppression control is performed. Therefore, when the braking force of the vehicle is equal to or larger than the determination braking force, which is an example of the first predetermined value, it is not determined that the vehicle gently turns, and when the braking force of the vehicle is less than the determination braking force, the vehicle is It may be possible to determine that the vehicle gently turns.

・In the roll suppression control, the distribution ratio of the braking force to the inner rear wheel during turning is made higher than that when the roll suppression control is not executed, and the distribution ratio of the braking force to the front front wheel during turning is not executed to the roll suppression control. You may make it higher than time.

In each of the above-described embodiments, when the vehicle is turning, the roll suppression control is performed even when the braking force is not applied to the vehicle. However, the roll suppression control may not be executed when the braking force is not applied to the vehicle even when the vehicle is turning.

In each of the above-described embodiments in which the roll suppression control is performed, when the slip amount SLP of at least one wheel becomes equal to or more than the determination slip amount SLPTh during the execution of the roll suppression control, the roll suppression control is ended and the stability priority control is performed. Be started. In such a case, the transition control may be performed between the end of the roll suppression control and the start of the stability priority control. For example, the transition control is control in which the control amount of each actuator is gradually changed from the control amount of the roll suppression control to the control amount of the stability priority control.

In the above-described third and fourth embodiments, when the roll suppression control is performed, only one of the rear wheel during turning and the front wheel outside during turning may be the target wheel.
In the third embodiment described above, the roll suppression control need not include the decrease process as long as the increase process and the hold process are included. In this case, when the increase of the frictional braking force BPF to be applied to the target wheel is completed by the increasing process and the execution condition of the increasing process is not satisfied, the holding process is executed and the friction braking force BPF is applied to each wheel FL, FR, RL, RR. The braking force may be retained.

-In the said 3rd Embodiment and 4th Embodiment, you may make it not carry out roll suppression control at the time of manual steering. Further, during manual steering, the increase amount of the friction braking force BPF applied to the target wheel due to the execution of the increasing process may be smaller than that during automatic driving.

In the third and fourth embodiments described above, the control device 100 is provided with the motor generator MG1 that applies the regenerative braking force BPR to both front wheels FL and FR, while the regenerative braking force BPR is applied to both rear wheels RL and RR. It may be applied to a vehicle that does not include the motor generator MG2 to be provided. Further, control device 100 may be applied to a vehicle that does not include motor generator MG1 but includes motor generator MG2.

-In the said 5th Embodiment, you may apply the control apparatus 100 to the vehicle which is provided with the motor generator MG1 but not the motor generator MG2. Further, control device 100 may be applied to a vehicle that does not include motor generator MG1 but includes motor generator MG2.

In the fifth embodiment, when the roll promotion control is performed, only one of the rear wheel during turning and the front wheel outside during turning may be the target wheel.
In each of the above-described embodiments, when at least one of the above (Condition 1) to (Condition 4) is not satisfied, it may not be determined that the vehicle turns gently.

Further, when at least a part of the above (condition 1) to (condition 4) is satisfied, it may be determined that the vehicle turns gently.
The conditions other than the above (Condition 1) to (Condition 4) may be included as a condition for determining whether or not the vehicle 10 turns gently. Other conditions include, for example, that the absolute value of the change speed ΔGY of the lateral acceleration GY is less than the judgment lateral acceleration change speed ΔGYTh, and that the absolute value of the change speed ΔYR of the yaw rate YR is less than the judgment yaw rate change speed ΔYRTh. There is one thing. When such a condition is used, at least one of (Condition 1) to (Condition 4) may be deleted from the conditions for determining whether or not the vehicle 10 turns gently.

The braking device may have any configuration as long as it can individually control the braking force applied to each wheel FL, FR, RL, RR. For example, the braking device may be an electric braking device that can apply the friction braking force to the wheels FL, FR, RL, RR without using the brake fluid. Further, in a vehicle in which a motor, that is, an in-wheel motor is provided for each wheel FL, FR, RL, RR, regenerative braking force can be generated by each motor during vehicle braking. That is, in the vehicle, the regenerative braking force applied to each wheel FL, FR, RL, RR can be adjusted individually. Therefore, in the first and second embodiments described above, when a vehicle in which a motor is individually provided for each wheel FL, FR, RL, RR is applied as the vehicle, in the roll suppression control, each wheel FL, The regenerative braking force applied to FR, RL, and RR may be adjusted individually.

The vehicle drive system to which the control device is applied may be a rear wheel drive system or a front wheel drive system.
The control device 100 may have any one of the following configurations (a) to (c).
(A) The control device 100 includes one or more processors that execute various processes according to a 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 perform processing. Memory, computer readable media, includes any available media that can be accessed by a general purpose or special purpose computer.
(B) The control device 100 includes one or more dedicated hardware circuits that execute various processes. Dedicated hardware circuits may include, for example, application specific integrated circuits, ie ASICs or FPGAs. ASIC is an abbreviation for “Application Specific Integrated Circuit”, and FPGA is an abbreviation for “Field Programmable Gate Array”.
(C) The control device 100 includes a processor that executes a part of various processes according to a computer program, and a dedicated hardware circuit that executes the rest of the various processes.

Next, technical ideas that can be understood from the above-described embodiments and modifications will be described.
(A) The parameter is preferably at least one of the steering angle of the steering wheel 21, the turning angle of the steered wheels, the lateral acceleration of the vehicle, the yaw rate of the vehicle, and the vehicle body slip angle of the vehicle. In this case, when the absolute value of the parameter is less than the determination value, it can be determined that the vehicle turns gently.

(B) The parameter is at least one of the vehicle body speed of the vehicle and the braking force of the vehicle. In this case, when the absolute value of the parameter is less than the determination value, it can be determined that the vehicle turns gently.

10, 10A, 10B... Vehicle 11... Power source 40... Braking device 100... Control device as behavior control device 101... Turning state determination unit 103... Stability priority control unit 105... Vehicle required braking force acquisition unit 108... Roll control unit FL, FR... Front wheels RL, RR... Rear wheels MG1, MG2... Motor generator as regenerative device

Claims (14)

When the braking force is applied to the front wheels, an anti-dive force that is a force that displaces the front part of the vehicle upward is generated, and when the braking force is applied to the rear wheels, an anti-lift force that is a force that displaces the rear part of the vehicle downward. Is applied to vehicles where
A vehicle required braking force acquisition unit that acquires a vehicle required braking force that is a required value of the braking force applied to the vehicle,
At least one of a rear wheel when the vehicle is turning and an outer front wheel when the vehicle is turning when a braking force is applied to the vehicle according to the vehicle required braking force in a situation where the vehicle is turning. A behavior control device for a vehicle, comprising: a roll control unit that controls a rolling motion of the vehicle by adjusting a distribution ratio of a braking force to target wheels including the. The roll control unit is configured to perform roll suppression control that suppresses rolling motion of the vehicle by adjusting the distribution ratio of the braking force to the target wheels.
The roll control unit, in the roll suppression control, a distribution ratio of a braking force to at least one of a rear wheel on the inside of the vehicle when turning and a front wheel on the outside of the vehicle when turning, as compared to when the roll suppression control is not performed. The vehicle behavior control device according to claim 1, wherein the vehicle behavior control device is also increased. The vehicle behavior control device according to claim 2, wherein the roll control unit performs the roll suppression control when a parameter indicating a yawing motion of the vehicle is less than a first predetermined value. In the roll suppression control, the roll control unit increases a distribution ratio of a braking force to at least one of a rear wheel inside the vehicle when turning and a front wheel outside when the vehicle is turning, in the roll restraining control. The vehicle behavior control device described in 1. In the roll suppression control, the roll control unit controls, when the parameter is greater than or equal to a second predetermined value that is less than the first predetermined value, for a rear wheel when the vehicle is turning and an outer front wheel when the vehicle is turning. The vehicle behavior control device according to claim 4, wherein an increase in a distribution ratio of the braking force to at least one is suppressed. The roll control unit, in the roll suppression control, a braking force applied to at least one of a rear wheel on the inside of the vehicle when turning and a front wheel on the outside of the vehicle when turning, more than when not performing the roll suppression control. Enlarge the vehicle behavior control device according to any one of claims 2 to 5. In the roll suppression control, the roll control unit, as the value obtained by subtracting the target roll angle from the roll angle of the vehicle at the start of the roll suppression control is larger, the inner rear wheel of the vehicle and the vehicle The vehicle behavior control device according to any one of claims 2 to 6, wherein the braking force applied to at least one of the outer front wheels during turning is increased. In the roll suppression control, the roll control unit, as the roll rate of the vehicle at the start of the roll suppression control is larger, at least one of a rear wheel inside the vehicle when turning and a front outside wheel when the vehicle is turning. The behavior control device for a vehicle according to any one of claims 2 to 7, wherein the braking force applied to the vehicle is increased. The roll control unit permits execution of the roll suppression control when the vehicle turns by automatic driving, but does not allow execution of the roll suppression control when the vehicle turns by manual steering. The vehicle behavior control device according to any one of claims 2 to 8. The roll control unit sets the control amount of the roll suppression control when the vehicle turns by manual steering to be smaller than the control amount of the roll suppression control when the vehicle turns by automatic driving. The vehicle behavior control device according to claim 8. The roll control unit ends the roll suppression control when a deceleration slip occurs in at least one of the wheels of the vehicle during execution of the roll suppression control. 2. A vehicle behavior control device according to claim 1. The vehicle includes a friction braking device that adjusts a friction braking force applied to each wheel, and a regenerative device that adjusts a regenerative braking force applied to two front wheels of each wheel,
In the roll suppression control, the roll control unit applies only the regenerative braking force of the friction braking force and the regenerative braking force to the front inside wheel of the vehicle when turning, and the outer side when turning of the vehicle. The vehicle according to any one of claims 2 to 11, wherein the friction braking device and the regenerative device are controlled so that both the friction braking force and the regenerative braking force are applied to the front wheels of the vehicle. Behavior control device. The vehicle includes a friction braking device that adjusts a friction braking force applied to each wheel, and a regenerative device that adjusts a regenerative braking force applied to two rear wheels of each wheel,
In the roll suppression control, the roll control unit applies only the regenerative braking force of the friction braking force and the regenerative braking force to the rear wheel on the outer side when the vehicle turns, and when the vehicle turns. The friction braking device and the regenerative device are controlled so that both the friction braking force and the regenerative braking force are applied to the inner rear wheel. Vehicle behavior control device. The roll control unit is configured to perform roll promotion control that promotes rolling motion of the vehicle when the braking force of the vehicle is reduced when the vehicle turns.
In the roll promotion control, the roll control unit determines a distribution ratio of a braking force to at least one of a rear wheel on the inside of the vehicle when turning and a front wheel on the outside of the vehicle when turning, as compared to when the roll promoting control is not performed. The vehicle behavior control device according to claim 1, wherein the vehicle behavior control device is also lowered.