JP2014227045A - Vehicle behavior control device and vehicle behavior control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle behavior control device and a vehicle behavior control method which are capable of suppressing occurrence of deceleration unintended by a driver and performing control for generating friction of a target value in a suspension.SOLUTION: When a braking force conversion value obtained by converting target friction being a target value, to be generated in a suspension for suppressing behavior of a vehicle body is a braking force upper limit value or less, a braking force-driving force distribution ratio that is a distribution ratio between braking force of a wheel and driving force of the wheel necessary for generating friction for suppressing the behavior of the vehicle body in the suspension is calculated using only braking force of the wheel. When the braking force conversion value exceeds the braking force upper limit value, a braking force-driving force distribution ratio is calculated by adding driving force of the wheel corresponding to friction equivalent to exceeding portion of the braking force upper limit value to the braking force-driving force distribution ratio calculated using only the braking force of the wheel.

Description

  The present invention relates to a vehicle behavior control apparatus and a vehicle behavior control method for controlling the roof behavior of a vehicle according to the state of a traveling road surface using friction generated in a suspension.

Conventionally, as a technique for controlling the vehicle roof behavior (the behavior of the vehicle body), for example, there is a technique described in Patent Document 1.
In the technique described in Patent Document 1, the friction generated in the suspension is detected based on the lateral force acting on the vehicle. Then, the detected friction is subtracted from the suppression target value for suppressing the behavior of the vehicle body to calculate the target value of the friction generated by the suspension in order to suppress the behavior of the vehicle body.

JP 2010-137796 A

However, in the technique described in Patent Document 1, the control for generating the target friction in the suspension is performed by increasing the damping force of the suspension by increasing the braking force. For this reason, there is a possibility that a driver's unintentional deceleration may occur in the traveling vehicle due to the increased braking force, and the passengers such as the driver may feel uncomfortable, and the magnitude of the braking force to be generated is limited. It will be. This may cause a problem that the size of the friction generated in the suspension is limited.
The present invention has been made paying attention to the above-described problems, and is a vehicle capable of suppressing the occurrence of deceleration not intended by the driver and controlling the suspension to generate a target value of friction. It is an object to provide a behavior control device and a vehicle behavior control method.

In order to solve the above-described problem, the present invention provides that the braking force of the wheel according to the braking force upper limit exceeds the braking force upper limit if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit. The braking / driving force distribution ratio is calculated by adding the driving force of the wheels corresponding to the corresponding friction. Further, braking force and driving force are applied to the wheels according to the calculated braking / driving force distribution ratio.
Here, the braking / driving force distribution ratio is the distribution ratio between the braking force of the wheel and the driving force of the wheel, which is necessary to generate the friction for suppressing the behavior of the vehicle body in the suspension connecting the vehicle body and each wheel. It is. Further, the braking force upper limit value is a value corresponding to the braking force at which the vehicle occupant feels uncomfortable due to deceleration not intended by the driver of the vehicle.

According to the present invention, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the braking force of the wheel according to the braking force upper limit value and the friction corresponding to the braking force upper limit value are exceeded. The braking / driving force distribution ratio can be calculated based on the driving force of the corresponding wheel.
As a result, even if the friction generated in the suspension does not reach the target value only by the braking force, control is performed to generate the target value of friction in the suspension by the driving force, and the driver generates unintended deceleration. It becomes possible to suppress.

It is a block diagram showing a schematic structure of a vehicle provided with a vehicle behavior control device of a first embodiment of the present invention. It is a block diagram which shows the structure of a brake actuator. It is a block diagram which shows schematic structure of a friction detection block. It is a block diagram which shows schematic structure of a braking force calculation part. It is a block diagram which shows schematic structure of a driving force calculation part. It is a block diagram which shows schematic structure of a suspension state calculation part. It is a block diagram which shows schematic structure of a suspension lateral force calculation part. It is a figure which shows a braking force friction calculation map. It is a figure which shows a driving force friction calculation map. It is a figure which shows a stroke position friction calculation map. It is a figure which shows a stroke speed friction calculation map. It is a figure which shows a lateral force friction calculation map. It is a block diagram which shows schematic structure of a riding comfort control block. It is a block diagram which shows schematic structure of a steering stability control block. It is a figure which shows the friction calculation map for braking force side behavior control. It is a figure which shows the friction calculation map for driving force side behavior control. It is a figure which shows a command hydraulic pressure conversion map. It is a figure which shows a drive torque correction value conversion map. It is a flowchart of the operation | movement performed using a vehicle behavior control apparatus. It is a flowchart of the operation | movement performed using a vehicle behavior control apparatus, and is a flowchart which shows the process which calculates braking / driving force distribution ratio. It is a flowchart of the operation | movement performed using a vehicle behavior control apparatus, and is a flowchart which shows the process which calculates a braking force upper limit. It is a flowchart of the operation | movement performed using a vehicle behavior control apparatus, and is a flowchart which shows a driving force distribution process. It is a time chart which shows the process which calculates braking / driving force distribution ratio during driving | running | working of a vehicle. It is a time chart which shows the process which a vehicle behavior control apparatus performs during driving | running | working of a vehicle. It is a flowchart of the operation | movement performed using the vehicle behavior control apparatus of the modification of 1st embodiment of this invention, and is a flowchart which shows a driving force distribution process. 6 is a time chart showing a process for calculating a braking / driving force distribution ratio, which is performed using the vehicle behavior control apparatus according to the modified example of the first embodiment of the present invention while the vehicle is traveling.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
Hereinafter, a first embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the drawings.
(Constitution)
FIG. 1 is a block diagram illustrating a schematic configuration of a vehicle V including the vehicle behavior control device 1 of the present embodiment.
As shown in FIG. 1, the vehicle V including the vehicle behavior control device 1 includes a G sensor 2, a yaw rate sensor 4, a steering angle sensor 6, a driver brake hydraulic pressure sensor 8, and an accelerator opening sensor 10. . In addition, the vehicle V includes a shift position sensor 12, a stroke sensor 14, a mode switch 16, a wheel speed sensor 18, a braking / driving force controller 20, a brake pedal 22, and a master cylinder 24. Further, the vehicle V includes a brake actuator 26, a power control unit 28, a power unit 30, a wheel cylinder 32, wheels W (right front wheel WFR, left front wheel WFL, right rear wheel WRR, left rear wheel WRL), A suspension SP is provided.

The G sensor 2 includes a block having a function of a sprung vertical acceleration sensor, a block having a function of an unsprung vertical acceleration sensor, a block having a function of a lateral acceleration sensor, and a block having a function of a longitudinal acceleration sensor.
The block having the function of the sprung vertical acceleration sensor detects the acceleration in the vertical direction in the sprung portion of the vehicle body with respect to the vehicle V. Then, an information signal including the detected acceleration (in the following description, may be described as a “sprung vertical acceleration signal”) is output to the braking / driving force controller 20.

The block having the function of the unsprung vertical acceleration sensor detects the acceleration in the vertical direction in the unsprung part of the vehicle body with respect to the vehicle V. Then, an information signal including the detected acceleration (in the following description, it may be described as “an unsprung vertical acceleration signal”) is output to the braking / driving force controller 20.
The block having the function of the lateral acceleration sensor detects acceleration in the lateral direction (vehicle width direction) of the vehicle body in the vehicle V (may be described as “actual lateral acceleration” in the following description). Then, an information signal including the detected actual lateral acceleration (in the following description, may be described as “actually measured lateral acceleration signal”) is output to the braking / driving force controller 20.

The block having the function of the longitudinal acceleration sensor detects acceleration in the longitudinal direction of the vehicle body (vehicle longitudinal direction) with respect to the vehicle V. Then, an information signal including the detected acceleration (in the following description, may be described as “longitudinal acceleration signal”) is output to the braking / driving force controller 20.
The yaw rate sensor 4 detects the yaw rate of the vehicle V (change speed of the rotation angle in the direction in which the vehicle body turns), and may be described as an information signal including the detected yaw rate (hereinafter referred to as “yaw rate signal”). ) Is output to the braking / driving force controller 20.

For example, the steering angle sensor 6 is provided in a steering column (not shown) that rotatably supports a steering operator (for example, a steering hole) (not shown).
The steering angle sensor 6 detects the current steering angle, which is the current rotation angle (steering operation amount) of the steering operator with reference to the neutral position. Then, the steering angle sensor 6 outputs an information signal including the detected current steering angle (may be described as a “current steering angle signal” in the following description) to the braking / driving force controller 20.

The driver brake hydraulic pressure sensor 8 detects a hydraulic pressure (driver brake hydraulic pressure) generated by a driver's depression operation of the brake pedal 22 among hydraulic pressures (brake hydraulic pressure) generated in the master cylinder 24. Then, an information signal including the detected driver brake fluid pressure (may be described as “driver brake fluid pressure signal” in the following description) is output to the braking / driving force controller 20.
The accelerator opening sensor 10 detects the opening of an accelerator pedal (not shown), and an information signal including the detected opening (may be referred to as “accelerator opening signal” in the following description) Output to the controller 20.

The shift position sensor 12 detects the position of a member that changes the gear position (for example, “P”, “D”, “R”, etc.) of the vehicle V, such as a shift knob or a shift lever. Then, an information signal including the detected position (may be described as “gear position signal” in the following description) is output to the braking / driving force controller 20.
The stroke sensor 14 detects an actual stroke amount (actual displacement amount) of the suspension SP, and an information signal including the detected actual stroke amount (in the following description, may be described as “actual stroke amount signal”), Output to the braking / driving force controller 20. The stroke sensor 14 individually detects the actual stroke amount of the suspension SP installed for each wheel W, and generates an actual stroke amount signal.

  The mode switch 16 is a switch for individually switching “ON” or “OFF” of VDC control and TCS control by a driver's operation. The mode switch 16 controls an information signal including a state in which the control of the VDC and the control of the TCS are “ON” or “OFF” (which may be described as “mode state signal” in the following description). Output to the driving force controller 20. Note that VDC is an abbreviation for “Vehicle Dynamics Control”, and TCS is an abbreviation for “Traction Control System”.

The wheel speed sensor 18 detects the rotational speed of the wheel W, and outputs an information signal including the detected rotational speed (in the following description, sometimes referred to as “wheel speed signal”) to the braking / driving force controller 20. To do.
In FIG. 1, the wheel speed sensor 18 that detects the rotational speed of the right front wheel WFR is indicated as a wheel speed sensor 18FR, and the wheel speed sensor 18 that detects the rotational speed of the left front wheel WFL is indicated as a wheel speed sensor 18FL. . Similarly, in FIG. 1, the wheel speed sensor 18 that detects the rotational speed of the right rear wheel WRR is shown as a wheel speed sensor 18RR, and the wheel speed sensor 18 that detects the rotational speed of the left rear wheel WRL is the wheel speed sensor. Shown as 18RL. In the following description, each wheel W and each wheel speed sensor 18 may be indicated as described above.

  The braking / driving force controller 20 controls the entire vehicle V and is constituted by a microcomputer. Note that the microcomputer includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like.

Further, the braking / driving force controller 20 performs various processes, which will be described later, on the basis of various input information signals, and instructs signals (braking force command value, driving force command, etc.) for controlling the brake actuator 26 and the power unit 30. Value).
The braking / driving force controller 20 includes a friction detection block 34, a ride comfort control block 36, and a steering stability control block 38. The configurations of the friction detection block 34, the ride comfort control block 36, and the steering stability control block 38 will be described later.

The brake pedal 22 is a pedal that is depressed when the driver of the vehicle V performs a braking operation, and transmits the pedal depression force of the driver to the master cylinder 24.
The master cylinder 24 generates two systems of hydraulic pressure according to the driver's pedal effort (tandem type). In this embodiment, as an example, the master cylinder 24 transmits the primary side to the left front wheel / right rear wheel wheel cylinder 32 and transmits the secondary side to the right front wheel / left rear wheel wheel cylinder 32 ( The case of using the diagonal split method will be described.

The brake actuator 26 is a hydraulic pressure control device interposed between the master cylinder 24 and each wheel cylinder 32. Further, the brake actuator 26 changes the hydraulic pressure of each wheel cylinder 32 in accordance with the braking command signal received from the braking / driving force controller 20 and applies a braking force to each wheel W. A specific configuration of the brake actuator 26 will be described later.
Further, the brake actuator 26 outputs a flag information signal indicating whether or not the ABS control is operating (in the following description, it may be described as “ABS operation flag signal”) to the braking / driving force controller 20. . Note that ABS is an abbreviation for “Antilocked Breaking System”.

Further, the brake actuator 26 generates an information signal including a command value of the brake fluid pressure applied to the wheels W by a system provided in the vehicle V (in the following description, it may be described as “additional function brake fluid pressure signal”). Output to the braking / driving force controller 20.
The system provided in the vehicle V is, for example, a system that performs preceding vehicle follow-up control, and is a system that controls the inter-vehicle distance between the vehicle V and the preceding vehicle to a distance corresponding to the vehicle speed of the vehicle V. .

Further, the brake actuator 26 outputs an information signal (indicated as “VDC hydraulic signal” in the drawing) including the command value of the brake hydraulic pressure applied to the wheel W by the VDC control described above to the braking / driving force controller 20. .
The power control unit 28 controls the driving force generated by the power unit 30 according to the drive command signal received from the braking / driving force controller 20. In the present embodiment, as will be described later, since the power unit 30 is formed using an engine, the power control unit 28 uses values related to the driving force generated by the engine (for example, driving torque, rotational speed, transmission speed). (Gear ratio) is controlled.

In addition, the power control unit 28 uses a braking / driving force controller 20 to generate a flag information signal (which may be referred to as a “TCS operation flag signal” in the following description) indicating whether or not the above-described TCS control is operating. Output to.
Further, the power control unit 28 outputs an information signal including a torque control value (torque control value) for the front wheels (may be described as “torque control signal” in the following description) to the braking / driving force controller 20. To do.

The torque control value for the front wheel is, for example, a ratio of distributing the torque generated by the power unit 30 (engine) to the right front wheel WFR and the left front wheel WFL. The torque control value for the front wheels is, for example, torque applied to the right front wheel WFR and the left front wheel WFL by the above-described VDC control. That is, the vehicle V of the present embodiment is a two-wheel drive (2WD: Two Wheel Drive) vehicle in which the right front wheel WFR and the left front wheel WFL are drive wheels, and the right rear wheel WRR and the left rear wheel WRL are driven wheels.
Further, the power control unit 28 outputs an information signal including the current torque (engine torque) generated by the power unit 30 (engine) (in the following description, it may be referred to as “current torque signal”). Output to the braking / driving force controller 20.

The power unit 30 is configured to generate the driving force of the vehicle V, and applies driving force to the right front wheel WFR and the left front wheel WFL via a drive shaft (not shown) or the like. In the present embodiment, as an example, a case where the power unit 30 is formed using an engine will be described.
The wheel cylinder 32 generates a pressing force for pressing a brake pad (not shown) constituting the disc brake against a disc rotor (not shown) that rotates integrally with each wheel W.

In FIG. 1, the wheel cylinder 32 disposed with respect to the right front wheel WFR is denoted as a wheel cylinder 32FR, and the wheel cylinder 32 disposed with respect to the left front wheel WFL is denoted as a wheel cylinder 32FL. Similarly, in FIG. 1, the wheel cylinder 32 disposed with respect to the right rear wheel WRR is denoted as a wheel cylinder 32RR, and the wheel cylinder 32 disposed with respect to the left rear wheel WRL is denoted as a wheel cylinder 32RL. In the following description, each wheel cylinder 32 may be indicated as described above.
The suspension SP (suspension device) is a suspension device installed between each wheel W and the vehicle body of the vehicle V.

Further, the suspension SP specifically includes a link member that connects the vehicle body and members on the wheels W side, a spring that buffers relative motion between the wheels W and the vehicle body, and relative motion between the wheels W and the vehicle body. It has a shock absorber that attenuates.
In FIG. 1, the suspension SP installed on the right front wheel WFR is indicated as a suspension SPFR, and the suspension SP installed on the left front wheel WFL is indicated as a suspension SPFL. Similarly, in FIG. 1, the suspension SP installed on the right rear wheel WRR is indicated as a suspension SPRR, and the suspension SP installed on the left rear wheel WRL is indicated as a suspension SPRL. In the following description, each suspension SP may be indicated as described above.

(Brake actuator configuration)
Next, the configuration of the brake actuator 26 will be described using FIG. 2 with reference to FIG.
FIG. 2 is a block diagram showing a configuration of the brake actuator 26.
The brake actuator 26 is formed using a brake fluid pressure control circuit used for the above-described ABS control, TCS control, VDC control, and the like.
Further, the brake actuator 26 forms the hydraulic pressure of each wheel cylinder 32FR, 32FL, 32RR, 32RL so that the pressure can be increased, held, and reduced regardless of the driver's brake operation.

The brake actuator 26 has two systems, a P (primary) system and an S (secondary) system, and has a so-called piping structure called X piping. In FIG. 2 and the following description, the P system may be described as “primary side” and the S system may be described as “secondary side”.
The primary side includes a first gate valve 122A, an inlet valve 124FL, an inlet valve 124RR, and an accumulator 126A. In addition, the primary side includes an outlet valve 128FL, an outlet valve 128RR, a second gate valve 130A, a pump 132, and a damper chamber 134A.

The first gate valve 122A is a normally open valve that can close the flow path between the master cylinder 24, the wheel cylinder 32FL, and the wheel cylinder 32RR.
The inlet valve 124FL is a normally open valve that can close the flow path between the first gate valve 122A and the wheel cylinder 32FL.
The inlet valve 124RR is a normally open valve that can close the flow path between the first gate valve 122A and the wheel cylinder 32RR.

The accumulator 126A is a spring-type accumulator in which a compression spring faces the piston of the cylinder, and communicates between the wheel cylinder 32FL and the wheel cylinder 32RR and the inlet valve 124FL and the inlet valve 124RR.
The outlet valve 128FL is a normally closed valve that can open a flow path between the wheel cylinder 32FL and the accumulator 126.
The outlet valve 128RR is a normally closed valve that can open a flow path between the wheel cylinder 32RR and the accumulator 126.

The second gate valve 130A is a normally closed type that can open a flow path that communicates between the master cylinder 24 and the first gate valve 122A, and between the accumulator 126 and the outlet valve 128FL and outlet valve 128RR. It is a valve.
The pump 132 is formed by using a positive displacement pump such as a gear pump or a piston pump that can ensure a substantially constant discharge amount regardless of the load pressure.

Further, the pump 132 communicates the suction side between the accumulator 126 and the outlet valve 128FL and outlet valve 128RR. Further, the pump 132 communicates the discharge side between the first gate valve 122A, the inlet valve 124FL, and the inlet valve 124RR.
The damper chamber 134A is disposed on the discharge side of the pump 132, and suppresses the pulsation of the brake fluid discharged from the pump 132 to reduce pedal vibration.

The secondary side includes a first gate valve 122B, an inlet valve 124FR, an inlet valve 124RL, and an accumulator 126B. In addition to this, the secondary side includes an outlet valve 128FR, an outlet valve 128RL, a second gate valve 130B, a pump 132, and a damper chamber 134B. That is, the primary side and the secondary side share the pump 132. Further, various configurations provided on the secondary side correspond to configurations provided on the primary side.
Each first gate valve 122, each inlet valve 124, each outlet valve 128, and each second gate valve 130 are two-port, two-position switching, single solenoid, spring offset type electromagnetically operated valves.

Each first gate valve 122 and each inlet valve 124 open the flow path at the non-excited normal position, and each outlet valve 128 and each second gate valve 130 close the flow path at the non-excited normal position. To be formed.
With the above configuration, the primary side will be described as an example. The hydraulic pressure from the master cylinder 24 is directly transmitted to the wheel cylinders 32FL and 32RR and becomes a normal brake. This occurs when the first gate valve 122A, the inlet valves 124FL and 124RR), the outlet valves 128FL and 128RR, and the second gate valve 130A are all in the non-excited normal position.

  Even when the brake pedal is not operated, the brake fluid in the master cylinder 24 is sucked through the second gate valve 130A. Further, the discharged hydraulic pressure can be transmitted to the wheel cylinders 32FL and 32RR via the inlet valves 124FL and 124RR to increase the pressure. This energizes and closes the first gate valve 122A while keeping the inlet valves 124FL and 124RR and the outlet valves 128FL and 128RR in the non-excited normal position. In addition to this, the second gate valve 130A is excited and opened, and the pump 132 is further driven.

  Further, it is possible to block the respective flow paths from the wheel cylinders 32FL and 32RR to the master cylinder 24 and the accumulator 126 to maintain the hydraulic pressures of the wheel cylinders 32FL and 32RR. This can be achieved by exciting and closing the inlet valves 124FL and 124RR when the first gate valve 122A, the outlet valves 128FL and 128RR, and the second gate valve 130A are in the non-excited normal position.

Furthermore, the hydraulic pressures of the wheel cylinders 32FL and 32RR can be reduced by flowing into the accumulator 126. This is possible when the first gate valve 122A and the second gate valve 130A are in the non-excited normal position, the inlet valves 124FL and 124RR are excited and closed, and the outlet valves 128FL and 128RR are excited and opened. It becomes.
Then, the hydraulic pressure flowing into the accumulator 126 is sucked by the pump 132 and returned to the master cylinder 24.

Note that the operation of normal braking, pressure increase, holding, and pressure reduction on the secondary side is the same as the operation on the primary side described above, and the description thereof is omitted.
Therefore, the braking / driving force controller 20 controls the drive of each first gate valve 122, each inlet valve 124, each outlet valve 128, each second gate valve 130, and the pump 132, and the hydraulic pressure of each wheel cylinder 32 is controlled. Increase, hold and reduce pressure.

(Configuration of the friction detection block 34)
Next, the configuration of the friction detection block 34 will be described using FIGS. 3 to 12 with reference to FIGS.
FIG. 3 is a block diagram showing a schematic configuration of the friction detection block 34.
As shown in FIG. 3, the friction detection block 34 includes a braking force calculation unit 40, a driving force calculation unit 42, a suspension state calculation unit 44, and a suspension lateral force calculation unit 46. In addition, the friction detection block 34 includes a braking force friction calculation unit 48, a driving force friction calculation unit 50, a suspension state friction calculation unit 52, a lateral force friction calculation unit 54, and a total friction calculation unit 56.

FIG. 4 is a block diagram illustrating a schematic configuration of the braking force calculation unit 40.
As shown in FIG. 4, the braking force calculation unit 40 includes a brake fluid pressure summation unit 58, a brake fluid pressure value selection unit 60, and a wheel braking force calculation unit 62.
Here, the processing performed by the brake fluid pressure summing unit 58, the brake fluid pressure value selecting unit 60, and the wheel braking force calculating unit 62 is performed on each wheel W (right front wheel WFR, left front wheel WFL, right rear wheel WRR, left rear wheel WRL). ) Individually.

The brake fluid pressure summing unit 58 receives a driver brake fluid pressure signal (shown as “driver brake fluid pressure” in the drawing) from the driver brake fluid pressure sensor 8. Further, the brake fluid pressure summing unit 58 sends an additional function brake fluid pressure signal (indicated as “additional function brake fluid pressure” in the figure) and a VDC fluid pressure signal (in the figure, “VDC fluid pressure”) from the brake actuator 26. Pressure)).
Then, the brake fluid pressure summing unit 58 sums the fluid pressure included in the received driver brake fluid pressure signal and the fluid pressure corresponding to the command value included in the additional function brake fluid pressure signal and the VDC fluid pressure signal. Then, an information signal including the combined hydraulic pressure (in the following description, may be described as “hydraulic pressure total value signal”) is output to the brake hydraulic pressure value selection unit 60.

In addition, when adding the hydraulic pressure according to the command value included in the VDC hydraulic pressure signal to the other hydraulic pressures, for example, the mode state signal output by the mode switch 16 is referred to. And only when the state in which the control of VDC is “ON” is included in the mode state signal, the process of adding the hydraulic pressure corresponding to the command value included in the VDC hydraulic pressure signal to the other hydraulic pressure is performed. Good.
The brake fluid pressure value selection unit 60 is formed by using, for example, a multiplexer circuit. Further, the brake hydraulic pressure value selection unit 60 receives an ABS operation flag signal (shown as “ABS operation flag” in the drawing) from the brake actuator 26. Further, the brake fluid pressure value selection unit 60 receives an input of the fluid pressure sum value signal from the brake fluid pressure summation unit 58. Further, the brake fluid pressure value selection unit 60 receives an input of an information signal (shown as “no fluid pressure” in the drawing) indicating the fluid pressure value when the brake fluid pressure stored in advance is “0”. receive.

  When the ABS operation flag signal is a flag information signal in which the ABS control is operating (“ON”), an information signal indicating a hydraulic pressure value when the brake hydraulic pressure is “0” is selected. On the other hand, when the ABS operation flag signal is a flag information signal in which the ABS control is not operating (“OFF”), the hydraulic pressure sum value signal is selected. Further, the selected signal is output to the wheel braking force calculation unit 62 as an information signal indicating the current brake fluid pressure (in the following description, it may be referred to as “current fluid pressure signal”).

  The wheel braking force calculation unit 62 adapts the brake hydraulic pressure included in the current hydraulic pressure signal received from the brake hydraulic pressure value selection unit 60 to a braking force calculation map stored in advance, so that the braking force of the wheel W is adjusted. Is calculated. Then, an information signal including the calculated braking force for each wheel W and the individual ID (right front wheel, left front wheel, right rear wheel, left rear wheel) of the wheel W for which the braking force has been calculated (in the following description, “individual” A wheel braking force signal ”may be output to the braking force friction calculation unit 48. Further, the individual wheel braking force signal is output to the steering stability control block 38.

  Here, in the braking force calculation map, as shown in the figure, the horizontal axis indicates the brake hydraulic pressure (in the figure, indicated as “hydraulic pressure”), and the vertical axis indicates the braking force of the wheel W (in the figure, This is a map showing “braking force”. Further, the relationship between the brake fluid pressure and the braking force of the wheel W shown in the braking force calculation map varies depending on the grip ability of the tire forming the wheel W. Specifically, as the brake fluid pressure increases and the braking force of the wheel W approaches the limit of the grip ability of the tire, the degree of increase in the braking force of the wheel W decreases.

As described above, the braking force calculation unit 40 calculates the braking force for each wheel W individually.
Further, the braking force calculation unit 40 calculates the braking force of the wheels W based on the traveling control of the vehicle V. Here, the traveling control of the vehicle V includes control of the braking force request by the driver of the vehicle V, control of the driving force request by the driver, and system control of the vehicle V. Further, the system control of the vehicle V is, for example, the preceding vehicle following traveling control, the lane keeping traveling control (lane keeping control), or the like.

FIG. 5 is a block diagram illustrating a schematic configuration of the driving force calculation unit 42.
As shown in FIG. 5, the driving force calculation unit 42 includes an estimated torque calculation unit 64, a torque value selection unit 66, and a wheel driving force calculation unit 68.
Here, the processing performed by the estimated torque calculation unit 64, the torque value selection unit 66, and the wheel driving force calculation unit 68 is performed for each wheel W individually.
The estimated torque calculation unit 64 receives an accelerator opening signal (indicated as “accelerator opening” in the drawing) from the accelerator opening sensor 10. Further, the estimated torque calculation unit 64 receives a current torque signal (shown as “current engine torque” in the figure) and a torque control signal (shown as “torque control function” in the figure) from the power control unit 28. Receive input.

Then, the estimated torque calculation unit 64 calculates the estimated engine torque based on the accelerator opening included in the input accelerator opening signal, the torque included in the current torque signal, and the torque included in the torque control signal. Then, an information signal including the calculated estimated engine torque (may be described as “estimated engine torque signal” in the following description) is output to torque value selection unit 66.
The torque value selection unit 66 is formed using a multiplexer circuit, for example, similarly to the brake fluid pressure value selection unit 60. Further, the torque value selection unit 66 receives an input of a TCS operation flag signal (shown as “TCS operation flag” in the drawing) from the power control unit 28. In addition, the torque value selection unit 66 receives an estimated engine torque signal from the estimated torque calculation unit 64. Further, the torque value selection unit 66 receives an input of an information signal (shown as “torque zero” in the drawing) indicating that the torque stored in advance is “0”.

  When the TCS operation flag signal is a flag information signal in which the TCS control is operating (“ON”), an information signal having a torque of “0” is selected. On the other hand, when the TCS operation flag signal is a flag information signal in which the TCS control is not operated (“OFF”), the estimated engine torque signal is selected. Further, the selected signal is output to the wheel driving force calculation unit 68 as an information signal indicating the current torque (in the following description, it may be described as “current torque signal”).

  The wheel driving force calculation unit 68 adapts the torque included in the current torque signal received from the torque value selection unit 66 to a driving force calculation map stored in advance to drive the right front wheel WFR and the left front wheel WFL. Is calculated. Then, an information signal including the calculated driving force for each wheel W and the individual ID of the wheel W for which the driving force has been calculated (in the following description, it may be referred to as “individual wheel driving force signal”) is used as the driving force. The result is output to the friction calculation unit 50 and the steering stability control block 38.

Here, as shown in the figure, the driving force calculation map is a map in which the horizontal axis indicates torque, and the vertical axis indicates the driving force of the wheels W (in the figure, indicated as “driving force”). The relationship between the torque shown in the driving force calculation map and the driving force of the wheels W varies depending on the grip ability of the tire forming the wheels W. Specifically, as the torque increases and the driving force of the wheel W approaches the limit of the grip ability of the tire, the degree of increase in the driving force of the wheel W decreases.
As described above, the driving force calculation unit 42 calculates the driving force for each wheel W individually.
Further, the driving force calculation unit 42 calculates the driving force of the wheels W based on the traveling control of the vehicle V. The traveling control of the vehicle V is the same as the description of the braking force calculation unit 40 described above.

FIG. 6 is a block diagram illustrating a schematic configuration of the suspension state calculation unit 44.
As shown in FIG. 6, the suspension state calculation unit 44 includes a spring upper integration processing unit 70, an unsprung integration processing unit 72, and a vertical acceleration addition / subtraction processing unit 74. In addition to this, the suspension state calculation unit 44 includes a stroke speed integration processing unit 76, a stroke speed differentiation processing unit 78, a wheel stroke selection unit 80, and a wheel stroke speed selection unit 82.
Here, the processing performed by the upper spring integration processing unit 70, the lower spring integration processing unit 72, the vertical acceleration addition / subtraction processing unit 74, and the stroke speed integration processing unit 76 is performed individually for each suspension SP. In addition to this, the processing performed by the stroke speed differentiation processing unit 78, the wheel stroke selection unit 80, and the wheel stroke speed selection unit 82 is performed individually for each suspension SP.

  The spring upper integration processing unit 70 receives an input of a sprung vertical acceleration signal from a block having a function of a sprung vertical acceleration sensor (shown as “sprung vertical G sensor” in the drawing). Then, the upper spring integration processing unit 70 integrates the vertical acceleration in the sprung portion included in the received sprung vertical acceleration signal, and calculates the displacement speed of the suspension SP in the vertical direction in the sprung portion. . Then, an information signal including the calculated displacement speed of the suspension SP in the up-down direction in the sprung portion (in the following description, may be described as “a sprung vertical speed signal”) to the vertical acceleration addition / subtraction processing unit 74. Output.

  The unsprung-side integration processing unit 72 receives an unsprung vertical acceleration signal from a block having a function of an unsprung vertical acceleration sensor (shown as “unsprung vertical G sensor” in the drawing). Then, the unsprung-side integration processing unit 72 integrates the acceleration in the vertical direction in the unsprung part included in the received unsprung vertical acceleration signal, and calculates the displacement speed of the suspension SP in the vertical direction in the unsprung part. To do. Then, the information signal including the calculated displacement speed of the suspension SP in the vertical direction in the unsprung part (in the following description, may be described as “unsprung vertical speed signal”) is sent to the vertical acceleration addition / subtraction processing unit 74. Output.

  The vertical acceleration addition / subtraction processing unit 74 receives the sprung vertical speed signal from the spring upper integration processing unit 70 and receives the unsprung vertical speed signal from the unsprung integration processing unit 72. Then, the estimated stroke speed of the suspension SP is calculated by subtracting the displacement speed included in the received unsprung vertical speed signal from the displacement speed included in the received sprung vertical speed signal. Further, an information signal including the calculated estimated stroke speed (may be described as “estimated stroke speed signal” in the following description) is output to the stroke speed integration processing unit 76 and the wheel stroke speed selection unit 82.

The stroke speed integration processing unit 76 integrates the estimated stroke speed included in the estimated stroke speed signal received from the vertical acceleration addition / subtraction processing unit 74, and calculates the estimated stroke amount (estimated displacement amount) of the suspension SP. Then, an information signal including the calculated estimated stroke amount of the suspension SP (in the following description, may be described as “estimated stroke amount signal”) is output to the wheel stroke selection unit 80.
The stroke speed differentiation processing unit 78 differentiates the measured stroke amount of the suspension SP included in the measured stroke amount signal received from the stroke sensor 14 per unit time, and calculates the measured stroke speed of the suspension SP. Then, an information signal including the calculated actual measured stroke speed of the suspension SP (in the following description, may be described as “actually measured stroke speed signal”) is output to the wheel stroke speed selection unit 82.

  The wheel stroke selection unit 80 selects one of the actual stroke amount included in the actual stroke amount signal and the estimated stroke amount included in the estimated stroke amount signal as the stroke amount of the suspension SP. Then, the stroke position of the suspension SP is calculated based on the selected stroke amount and the neutral position of the suspension SP. Here, the neutral position of the suspension SP is the position of the suspension SP in an unloaded state. The stroke position of the suspension SP is a position displaced by a selected stroke amount with reference to the position of the suspension SP in an unloaded state.

Further, the wheel stroke selection unit 80 outputs an information signal including the calculated stroke position (in the following description, sometimes described as “suspension stroke position signal”) to the suspension state friction calculation unit 52. The suspension stroke position signal includes the individual ID of the wheel W on which the suspension SP with the stroke amount selected is installed.
Here, the wheel stroke selection unit 80 performs a process of selecting the estimated stroke amount as the stroke amount of the suspension SP when, for example, an abnormality such as a failure occurs in the stroke sensor 14.

  The wheel stroke speed selection unit 82 selects one of the estimated stroke speed included in the estimated stroke speed signal and the actually measured stroke speed included in the actually measured stroke speed signal as the stroke speed of the suspension SP. Then, an information signal including the selected stroke speed (may be described as “suspension stroke speed signal” in the following description) is output to the suspension state friction calculation unit 52. The suspension stroke speed signal includes the individual ID of the wheel W on which the suspension SP that has selected the stroke speed is installed.

Here, the wheel stroke speed selection unit 82 performs a process of selecting the estimated stroke speed as the stroke speed of the suspension SP, for example, when an abnormality such as a failure occurs in the stroke sensor 14.
As described above, the suspension state calculation unit 44 calculates the stroke position of each suspension SP (suspension SPFR, suspension SPFL, suspension SPRR, suspension SPRL) individually.
In addition, the suspension state calculation unit 44 calculates the stroke speed of each suspension SP individually.

FIG. 7 is a block diagram showing a schematic configuration of the suspension lateral force calculation unit 46.
As shown in FIG. 7, the suspension lateral force calculation unit 46 includes a vehicle state calculation unit 84, a lateral acceleration selection unit 86, a first wheel suspension lateral force calculation unit 88, and a second wheel suspension lateral force calculation unit 90. And a lateral force determination unit 92.
Here, the processing performed by the vehicle state calculation unit 84, the lateral acceleration selection unit 86, the first wheel suspension lateral force calculation unit 88, the second wheel suspension lateral force calculation unit 90, and the lateral force determination unit 92 is performed for each suspension SP. Individually.

The vehicle state calculation unit 84 receives an input of a wheel speed signal (shown as “vehicle speed” in the drawing) including the rotation speed of the wheel W for detecting the speed (vehicle speed) of the vehicle V from the wheel speed sensor 18. . Further, the vehicle state calculation unit 84 receives an input of a current steering angle signal (shown as “steering angle” in the drawing) from the steering angle sensor 6.
Then, the vehicle state calculation unit 84 calculates the estimated lateral acceleration using the vehicle speed based on the rotation speed of the wheel W included in the wheel speed signal and the current steering angle included in the current steering angle signal. Then, an information signal including the calculated estimated lateral acceleration (may be described as “estimated lateral acceleration signal” in the following description) is output to the lateral acceleration selecting unit 86.

Here, the calculation of the estimated lateral acceleration is performed by substituting the input vehicle speed and steering angle into the motion equation stored in advance. The equation of motion stores, for example, two types of cases where the configuration of the vehicle V is a two-wheel drive vehicle (2WD) and a four-wheel drive vehicle (4WD).
Further, the vehicle state calculation unit 84 uses the vehicle speed based on the rotation speed of the wheel W included in the wheel speed signal and the current steering angle included in the current steering angle signal, for example, for the wheel W per preset load. The slip angle is calculated as the vehicle state. Then, an information signal including the calculated vehicle state (which may be described as “calculated vehicle state signal” in the following description) is output to the second wheel suspension lateral force calculation unit 90.

The lateral acceleration selection unit 86 receives the estimated lateral acceleration signal from the vehicle state calculation unit 84 and inputs the measured lateral acceleration signal from a block having a function of a lateral acceleration sensor (in the figure, indicated as “lateral G sensor”). Receive. Then, one of the estimated lateral acceleration included in the estimated lateral acceleration signal and the measured lateral acceleration included in the measured lateral acceleration signal is selected as the acceleration in the lateral direction of the vehicle body. Further, an information signal including the selected lateral acceleration (in the following description, may be described as “selected lateral acceleration signal”) is output to the first wheel suspension lateral force calculation unit 88.
Here, the lateral acceleration selection unit 86 selects the estimated lateral acceleration as the lateral acceleration of the vehicle body when, for example, an abnormality such as a failure occurs in the G sensor 2 (a block having the function of the lateral acceleration sensor). Perform the process.

  The first wheel suspension lateral force calculation unit 88 adapts the lateral acceleration included in the selected lateral acceleration signal received from the lateral acceleration selection unit 86 to a prestored lateral force calculation map, and performs suspension SP. The lateral force of is calculated. Then, an information signal including the calculated lateral force for each suspension SP (in the following description, may be described as “first individual wheel lateral force signal”) is output to the lateral force determining unit 92. The first individual wheel lateral force signal includes the individual ID of the wheel W on which the suspension SP for which the lateral force is calculated is installed.

  Here, in the lateral force calculation map, as shown in the figure, the horizontal axis indicates the acceleration in the horizontal direction (in the figure, indicated as “lateral G”), and the vertical axis indicates the lateral force of the suspension SP (in the figure, , “Suspension lateral force”). Further, the relationship between the lateral acceleration and the lateral force shown in the lateral force calculation map varies depending on the grip ability of the tire forming the wheel W. Specifically, as the torque increases and the lateral force of the suspension SP approaches the limit of the grip ability of the tire, the degree of increase in the lateral force of the suspension SP decreases.

The second wheel suspension lateral force calculation unit 90 substitutes the vehicle state included in the calculated vehicle state signal received from the vehicle state calculation unit 84 into the specifications (tire model) of the wheel W stored in advance, The lateral force of the suspension SP is calculated. Then, an information signal including the calculated lateral force for each suspension SP (in the following description, may be described as “second individual wheel lateral force signal”) is output to the lateral force determining unit 92. The first individual wheel lateral force signal includes the individual ID of the wheel W on which the suspension SP for which the lateral force is calculated is installed, like the second individual wheel lateral force signal.
The specifications of the wheel W stored in the second wheel suspension lateral force calculation unit 90 may be updated / changed according to the travel distance of the vehicle V or the like.

The lateral force determination unit 92 calculates the lateral force for each suspension SP based on at least one of the lateral force included in the first individual wheel lateral force signal and the lateral force included in the second individual wheel lateral force signal. Then, an information signal including the calculated lateral force for each suspension SP (in the following description, may be described as “each wheel lateral force signal”) is output to the lateral force friction calculation unit 54.
Here, in the processing performed by the lateral force determination unit 92, for example, one of the lateral force included in the first individual wheel lateral force signal and the lateral force included in the second individual wheel lateral force signal is converted into a lateral force for each suspension SP. May be calculated as Further, the average value of the two lateral forces may be calculated as the lateral force for each suspension SP.

As described above, the suspension lateral force calculation unit 46 individually calculates the lateral force for each suspension SP.
The braking force friction calculation unit 48 adapts the braking force included in the individual wheel braking force signal received from the braking force calculation unit 40 to a braking force friction calculation map stored in advance. Thus, the friction generated in each suspension SP is calculated by the braking force. Then, an information signal including the calculated friction for each suspension SP (in the following description, it may be described as “braking force friction signal”) is output to the total friction calculation unit 56. In the following description, the friction generated in the suspension SP by the braking force may be referred to as “braking force friction”.

  Here, as shown in FIG. 8, the braking force friction calculation map is a map showing the braking force of the wheels W (shown as “braking force [N]” in the drawing) on the horizontal axis. Further, the braking force friction calculation map is a map in which the vertical axis indicates the friction generated in the suspension SP by the braking force (indicated as “friction-braking force [N]” in the drawing). FIG. 8 is a diagram showing a braking force friction calculation map. Further, in FIG. 8, the friction generated in the suspension SP (suspension SPFR, suspension SPFL) connecting the front wheel WF and the vehicle body by the braking force is indicated by a solid line (in the figure, “friction-front axle braking force [N]”). Show). Further, in FIG. 8, the friction generated in the suspension SP (suspension SPRR, suspension SPRL) connecting the rear wheel WR and the vehicle body by the braking force is indicated by a broken line (in the figure, “friction-rear axle braking force [N]”). Is shown).

  As described above, the braking force friction calculation unit 48 individually calculates the braking force friction generated based on the braking force calculated by the braking force calculation unit 40 for each suspension SP. The braking force friction is an estimated value of the friction generated in the suspension SP based on the braking force calculated by the braking force calculation unit 40.

  The driving force friction calculation unit 50 adapts the driving force included in the individual wheel driving force signal received from the driving force calculation unit 42 to a driving force friction calculation map stored in advance. Thus, the friction generated in each suspension SP is calculated by the driving force. Then, an information signal including the calculated friction for each suspension SP (in the following description, it may be described as “driving force friction signal”) is output to the total friction calculation unit 56. In the following description, the friction generated in the suspension SP by the driving force may be referred to as “driving force friction”.

  Here, as shown in FIG. 9, the driving force friction calculation map is a map showing the driving force of the wheels W (shown as “driving force [N]” in the drawing) on the horizontal axis. Further, the driving force friction calculation map is a map showing the friction generated in the suspension SP by the driving force (indicated as “friction-driving force [N]” in the drawing) on the vertical axis. FIG. 9 is a diagram showing a driving force friction calculation map. Further, in FIG. 9, the friction generated in the suspension SP (suspension SPFR, suspension SPFL) connecting the front wheel WF and the vehicle body by the driving force is indicated by a solid line (in the drawing, “friction-front shaft driving force [N]”). Show).

The two-wheel drive vehicle may be configured such that the right front wheel WFR and the left front wheel WFL are driven wheels, and the right rear wheel WRR and the left rear wheel WRL are drive wheels. For this reason, in FIG. 9, the friction generated in the suspension SP (suspension SPRR, suspension SPRL) connecting the rear wheel WR and the vehicle body by the driving force is indicated by a broken line (in the drawing, “friction-rear shaft driving force [N] "). Further, in the driving force friction calculation map shown in FIG. 9, the right half of the map is used as the acceleration state region, and the left half of the map is used as the engine brake operation region.
As described above, the driving force friction calculation unit 50 individually calculates the driving force friction generated based on the driving force calculated by the driving force calculation unit 42 for each suspension SP (suspension SPFR, suspension SPFL). The driving force friction is an estimated value of the friction generated in the suspension SP based on the driving force calculated by the driving force calculation unit 42.

  The suspension state friction calculation unit 52 adapts the stroke position included in the suspension stroke position signal received from the suspension state calculation unit 44 to a stroke position friction calculation map stored in advance. Thus, the suspension state friction calculation unit 52 calculates the friction generated in the suspension SP according to the stroke position. Then, an information signal including the calculated friction for each suspension SP (in the following description, it may be described as “stroke position friction signal”) is output to the total friction calculation unit 56. In the following description, the friction generated in the suspension SP according to the stroke position may be referred to as “stroke position friction”.

  Here, as shown in FIG. 10, the stroke position friction calculation map is a map showing the stroke position of the suspension SP (shown as “stroke position [mm]” in the figure) on the horizontal axis. Further, the stroke position friction calculation map is a map showing, on the vertical axis, friction generated in the suspension SP in accordance with the stroke position (indicated as “friction-stroke position [N]” in the drawing). FIG. 10 is a diagram showing a stroke position friction calculation map. In FIG. 10, the friction generated in the suspension SP (suspension SPFR, suspension SPFL) connecting the front wheel WF and the vehicle body according to the stroke position is indicated by a solid line (in the figure, “friction—front shaft stroke position [mm] "). Further, the friction generated in the suspension SP (suspension SPRR, suspension SPRL) connecting the rear wheel WR and the vehicle body according to the stroke position is indicated by a broken line (in the figure, indicated as “friction—rear shaft stroke position [mm]”). It shows with. Furthermore, in the stroke position friction calculation map shown in FIG. 10, the right half of the map is used as an area indicating upward displacement, and the left half of the map is used as an area indicating downward displacement.

  The suspension state friction calculation unit 52 adapts the stroke speed included in the suspension stroke speed signal received from the suspension state calculation unit 44 to a stroke speed friction calculation map stored in advance. Thereby, the suspension state friction calculation unit 52 calculates the friction generated in the suspension SP according to the stroke speed. Then, an information signal including the calculated friction for each suspension SP (in the following description, it may be described as “stroke speed friction signal”) is output to the total friction calculation unit 56. In the following description, the friction generated in the suspension SP in accordance with the stroke speed may be referred to as “stroke speed friction”.

  Here, as shown in FIG. 11, the stroke speed friction calculation map is a map showing the stroke speed of the suspension SP (shown as “stroke speed [m / s]” in the figure) on the horizontal axis. Further, the stroke speed friction calculation map is a map showing the friction generated in the suspension SP in accordance with the stroke speed (indicated as “friction-stroke speed [N]” in the drawing) on the vertical axis. FIG. 11 is a diagram showing a stroke speed friction calculation map. In FIG. 11, the friction generated in the suspension SP (suspension SPFR, suspension SPFL) connecting the front wheel WF and the vehicle body according to the stroke speed is indicated by a solid line (in the figure, “friction-front shaft stroke speed [m / s] ”). Further, the friction generated in the suspension SP (suspension SPRR, suspension SPRL) connecting the rear wheel WR and the vehicle body according to the stroke speed is indicated by a broken line (in the figure, “friction—rear shaft stroke speed [m / s]”). Show). Furthermore, in the stroke speed friction calculation map shown in FIG. 11, the right half of the map is used as an area indicating upward displacement, and the left half of the map is used as an area indicating downward displacement.

As described above, the suspension state friction calculation unit 52 individually calculates the stroke position friction generated based on the stroke position calculated by the suspension state calculation unit 44 for each suspension SP. The stroke position friction is an estimated value of the friction generated in the suspension SP based on the stroke position calculated by the suspension state calculation unit 44.
Further, the suspension state friction calculation unit 52 individually calculates the stroke speed friction generated based on the stroke speed calculated by the suspension state calculation unit 44 for each suspension SP. The stroke speed friction is an estimated value of the friction generated in the suspension SP based on the stroke speed calculated by the suspension state calculation unit 44.

  The lateral force friction calculation unit 54 adapts the lateral force for each suspension SP included in each wheel lateral force signal received from the suspension lateral force calculation unit 46 to a stored lateral force friction calculation map. Thereby, the lateral force friction calculation unit 54 calculates the friction generated in the suspension SP according to the lateral force. Then, an information signal including the calculated friction for each suspension SP (in the following description, may be described as “lateral force friction signal”) is output to the total friction calculation unit 56. In the following description, the friction generated in the suspension SP according to the lateral force may be referred to as “lateral force friction”.

  Here, as shown in FIG. 12, the lateral force friction calculation map is a map showing the lateral force of the suspension SP (shown as “lateral force [N]” in the drawing) on the horizontal axis. Further, the lateral force friction calculation map is a map in which the vertical axis represents the friction generated in the suspension SP according to the lateral force (indicated as “friction-lateral force [N]” in the drawing). FIG. 12 is a diagram showing a lateral force friction calculation map. In FIG. 12, the friction generated in the suspension SP (suspension SPFR, suspension SPFL) connecting the front wheel WF and the vehicle body according to the lateral force is indicated by a solid line (in the figure, “friction—frontal lateral force [N] "). Further, the friction generated in the suspension SP (suspension SPRR, suspension SPRL) that connects the rear wheel WR and the vehicle body in accordance with the lateral force is indicated by a broken line (in the drawing, indicated as “friction—rear shaft lateral force [N]”). It shows with. Further, in the lateral force friction calculation map shown in FIG. 12, the right half of the map is used as an area corresponding to the lateral force to the right when the vehicle V is viewed from the rear in the vehicle front-rear direction, and the left half of the map is used as the vehicle V Is used as a region corresponding to the lateral force to the left as viewed from the rear in the vehicle longitudinal direction.

As described above, the lateral force friction calculation unit 54 individually calculates the lateral force friction generated based on the lateral force calculated by the suspension lateral force calculation unit 46 for each suspension SP. The lateral force friction is an estimated value of the friction generated in the suspension SP based on the lateral force calculated by the suspension lateral force calculation unit 46.
The braking force friction calculation map, the driving force friction calculation map, the stroke position friction calculation map, the stroke speed friction calculation map, and the lateral force friction calculation map described above are formed using data measured on a table run, a road run, or the like. To do. Here, traveling on the table refers to traveling on a chassis dynamometer, for example.

  The total friction calculation unit 56 receives a braking force friction signal from the braking force friction calculation unit 48 and receives a driving force friction signal from the driving force friction calculation unit 50. In addition, a stroke position friction signal and a stroke speed friction signal are received from the suspension state friction calculation unit 52, and a lateral force friction signal is received from the lateral force friction calculation unit 54. Then, the braking force friction, the driving force friction, the stroke position friction, the stroke speed friction, and the lateral force friction are added together.

  Thereby, the total friction of one suspension SP (in the following description, it may be described as “total friction of each wheel”) is calculated. Further, an information signal including the calculated total wheel friction (in the following description, may be described as “total wheel friction signal”) is output to the ride comfort control block 36 and the steering stability control block 38.

(Configuration of ride comfort control block 36)
Next, the configuration of the ride comfort control block 36 will be described with reference to FIGS. 1 to 12 and FIG.
FIG. 13 is a block diagram showing a schematic configuration of the ride comfort control block 36.
As shown in FIG. 13, the ride comfort control block 36 includes a ride comfort control side vehicle behavior calculation unit 94, a behavior suppression friction calculation unit 112, and a ride comfort control side target friction calculation unit 96. In addition, the riding comfort control block 36 includes a riding comfort control side braking / driving force distribution ratio calculation unit 98, a braking force command value calculation unit 100A, and a driving force command value calculation unit 102A.

  The ride comfort control side vehicle behavior calculation unit 94 receives the wheel speed signal (shown as “vehicle speed” in the drawing) and the current steering angle signal (shown as “steering angle” in the drawing). In addition, the ride comfort control side vehicle behavior calculation unit 94 receives an input of an unsprung vertical acceleration signal, an unsprung vertical acceleration signal, and an actually measured stroke amount signal (shown as “suspension” in the drawing). The ride comfort control-side vehicle behavior calculation unit 94 stores in advance specifications of the vehicle V (vehicle weight, balance of vehicle weight, etc., and may be described as “vehicle specifications” in the following description). I'm allowed.

  Also, the ride comfort control-side vehicle behavior calculation unit 94 calculates an estimated vertical behavior, which is an estimated value of the behavior of the vehicle V in the vertical direction, using the sprung vertical acceleration, the unsprung vertical acceleration, and the actually measured stroke amount. . Then, an information signal including the calculated estimated up-down behavior (in the following description, may be described as “estimated up-down behavior signal”) is output to the behavior suppression friction calculation unit 112. Note that the process of calculating the estimated vertical behavior may be performed with reference to vehicle specifications. That is, the ride comfort control-side vehicle behavior calculation unit 94 calculates the vertical behavior of the vehicle body, which is the behavior in the vertical direction generated in the vehicle body.

  The ride comfort control-side vehicle behavior calculation unit 94 calculates an estimated yaw rate, which is an estimated value of the yaw rate of the vehicle V, using the vehicle speed and the current steering angle. Then, an information signal including the calculated estimated yaw rate (in the following description, may be described as “estimated yaw rate signal”) is output to the riding comfort control side braking / driving force distribution ratio calculating unit 98. The process for calculating the estimated yaw rate may be performed with reference to vehicle specifications.

  The behavior suppression friction calculation unit 112 receives the estimated vertical behavior signal from the ride comfort control-side vehicle behavior calculation unit 94, and adapts the estimated vertical behavior included in the estimated vertical behavior signal to a pre-stored target friction calculation map. To calculate the behavior suppression friction. Then, an information signal including the calculated behavior suppression friction (in the following description, may be described as “behavior suppression friction signal”) is output to the ride comfort control side target friction calculation unit 96.

  Here, in the target friction calculation map, as shown in the figure, the horizontal axis indicates the estimated vertical behavior (shown as “vertical behavior” in the figure), and the vertical axis indicates behavior suppression friction (in the figure, “friction”). Is a map). In addition, the relationship between the estimated vertical behavior and the behavior suppression friction shown in the target friction calculation map is formed using data measured in advance on a table run or on a road.

Further, the behavior suppression friction is friction generated in each suspension SP necessary for suppressing the vertical behavior of the vehicle V.
The ride comfort control side target friction calculation unit 96 receives a behavior suppression friction signal from the behavior suppression friction calculation unit 112 and receives an input of each wheel total friction signal from the total friction calculation unit 56. The ride comfort control side target friction calculation unit 96 receives the wheel speed signal described above.

The ride comfort control-side target friction calculation unit 96 calculates the ride comfort control wheel target friction using the behavior suppression friction, the total wheel friction, and the vehicle speed. Specifically, the friction obtained by subtracting the total wheel friction from the behavior suppression friction is calculated as each wheel target friction for ride comfort control.
Here, each wheel target friction for ride comfort control is a target value of the friction generated in each suspension SP in order to suppress the vertical behavior of the vehicle V.

Further, the ride comfort control-side target friction calculation unit 96 calculates a ride comfort control friction difference value that is a difference value between each ride comfort control wheel target friction and each wheel total friction. Then, an information signal including the calculated ride comfort control friction difference value (in the following description, it may be referred to as “ride comfort control friction difference value signal”) is calculated as a ride comfort control side braking / driving force distribution ratio. To the unit 98.
The ride comfort control side braking / driving force distribution ratio calculation unit 98 receives the ride comfort control friction difference value signal from the ride comfort control side target friction calculation unit 96 and receives the total wheel friction signal input from the total friction calculation unit 56. Receive. In addition, the riding comfort control side braking / driving force distribution ratio calculation unit 98 receives the estimated yaw rate signal from the riding comfort control side vehicle behavior calculation unit 94.

Then, the riding comfort control side braking / driving force distribution ratio calculation unit 98 uses the total friction for each wheel and the respective wheel target friction for riding comfort control for all the suspension SPs to calculate the total for each wheel target friction for riding comfort control. Calculate the excess and deficiency of friction individually.
Here, the excess / deficiency is calculated based on the total friction calculated by the total friction calculation unit 56 and the ride comfort control wheel target friction calculated by the ride comfort control side target friction calculation unit 96. Specifically, for example, when the total friction is less than each wheel target friction for ride comfort control, the total friction is subtracted from each wheel target friction for ride comfort control to obtain a total for each wheel target friction for ride comfort control. Calculate the friction deficiency.

The riding comfort control side braking / driving force distribution ratio calculating unit 98 calculates a braking / driving force distribution command value using the estimated yaw rate, each wheel total friction, and each wheel target friction for riding comfort control.
Here, the braking / driving force distribution command value is a command value for causing each suspension SP to generate at least one of friction caused by braking force and friction caused by driving force.

Further, the riding comfort control side braking / driving force distribution ratio calculating unit 98 distributes the friction by the braking force and the friction by the driving force in the suspension SP that generates the friction based on the braking / driving force distribution command value and the excess / deficiency friction. Calculate the ratio. Thus, the ride comfort control side braking / driving force distribution ratio is calculated.
Here, the ride comfort control side braking / driving force distribution ratio is the braking force of the wheel W required to generate in the suspension SP the friction corresponding to the excess or deficiency of the total friction with respect to the ride comfort control wheel target friction. And the driving force of the wheel W.

Accordingly, each wheel target friction for ride comfort control is a target value, and the friction of each wheel W with respect to each wheel target friction for ride comfort control is an actual value. Further, the above-described correction of excess and deficiency is performed by friction generated in the suspension SP by at least one of the braking force of the wheel W and the driving force of the wheel W.
A description will be given later of a process in which the ride comfort control side braking / driving force distribution ratio calculating unit 98 calculates the ride comfort control side braking / driving force distribution ratio.

Furthermore, the ride comfort control side braking / driving force distribution ratio calculating unit 98 includes an information signal including the calculated ride comfort control side braking / driving force distribution ratio (in the following description, “ride comfort control side braking / driving force distribution ratio signal”). Is output to the braking force command value calculation unit 100A. In addition, the riding comfort control side braking / driving force distribution ratio calculating unit 98 outputs a riding comfort control side braking / driving force distribution ratio signal to the driving force command value calculating unit 102A.
The braking force command value calculation unit 100A includes the braking / driving force distribution ratio included in the riding comfort control side braking / driving force distribution ratio signal received from the riding comfort control side braking / driving force distribution ratio calculation unit 98. A riding comfort control side driving force command value is calculated based on the power distribution ratio.

Here, the ride comfort control-side braking force command value is a braking force on the wheel W for causing the suspension SP to generate friction based on the ride comfort control-side braking / driving force distribution ratio included in the ride comfort control-side braking / driving force distribution ratio signal. This is the final command value for power.
The braking force command value calculation unit 100A that has calculated the riding comfort control side braking force command value converts the calculated riding comfort control side braking force command value into a command hydraulic pressure (brake hydraulic pressure). Then, a braking command signal that is an information signal including the converted command hydraulic pressure is output to the brake actuator 26.

The description of the process for converting the ride comfort control side braking force command value into the command hydraulic pressure will be described later.
The driving force command value calculation unit 102A drives the wheels W among the braking / driving force distribution ratios included in the riding comfort control side braking / driving force distribution ratio signal received from the riding comfort control side braking / driving force distribution ratio calculation unit 98. Based on the force distribution ratio, a ride comfort control side driving force command value is calculated. The calculated riding comfort control side driving force command value is converted into a driving torque correction value (driving torque correction value), and a driving command signal, which is an information signal including the converted driving torque correction value, is converted into the power control unit 28. Output to.

The description of the process for converting the ride comfort control side driving force command value into the driving torque correction value will be described later.
Here, the ride comfort control side driving force command value is the wheel W for causing the suspension SP to generate friction based on the distribution ratio of the driving force of the wheel W calculated by the ride comfort control side braking / driving force distribution ratio calculation unit 98. Is the final command value (command value of the driving force of the wheel W). Further, as described later, the ride comfort control side driving force command value is the final command value of the driving force for the wheels W for causing each suspension SP to generate friction for suppressing the vertical behavior of the vehicle V.

(Configuration of Steering Stability Control Block 38)
Next, the configuration of the steering stability control block 38 will be described with reference to FIGS. 1 to 13 and FIG.
FIG. 14 is a block diagram showing a schematic configuration of the steering stability control block 38.
As shown in FIG. 14, the steering stability control block 38 includes an estimated longitudinal force calculation unit 104, a steering stability control side vehicle behavior calculation unit 106, and a steering stability control side target friction calculation unit 108. In addition, the steering stability control block 38 includes a steering stability control side braking / driving force distribution ratio calculation unit 110, a braking force command value calculation unit 100B, and a driving force command value calculation unit 102B.

  The estimated longitudinal force calculator 104 receives an individual wheel braking force signal from the braking force calculator 40 and receives an individual wheel driving force signal from the driving force calculator 42. Then, using the calculated braking force and individual ID for each wheel W and the calculated driving force and individual ID for each wheel W, the estimated value of the force in the vehicle front-rear direction among the forces acting on the vehicle V Calculate the estimated longitudinal force.

Further, the estimated longitudinal force calculation unit 104 outputs an information signal including the calculated estimated longitudinal force (in the following description, sometimes referred to as “estimated longitudinal force signal”) to the steering stability control side vehicle behavior calculation unit 106. Output to.
The steering stability control-side vehicle behavior calculation unit 106 includes the wheel speed signal (shown as “vehicle speed” in the drawing), the current steering angle signal (shown as “steering angle” in the drawing), and the estimated longitudinal force signal. Receive input. Further, the vehicle specifications are stored in the steering stability control side vehicle behavior calculation unit 106 in advance.

  The steering stability control-side vehicle behavior calculation unit 106 calculates an estimated roll rate that is an estimated value of the roll rate of the vehicle V using the vehicle speed and the current steering angle. Then, an information signal including the calculated estimated roll rate (which may be described as “estimated roll rate signal” in the following description) is output to the steering stability control-side target friction calculation unit 108. Note that the process of calculating the estimated roll rate may be performed with reference to vehicle specifications.

  Further, the steering stability control side vehicle behavior calculation unit 106 calculates an estimated pitch rate that is an estimated value of the pitch rate of the vehicle V using the estimated longitudinal force. Then, an information signal including the calculated estimated pitch rate (which may be described as “estimated pitch rate signal” in the following description) is output to the steering stability control-side target friction calculation unit 108. Note that the process of calculating the estimated pitch rate may be performed with reference to vehicle specifications.

The steering stability control-side target friction calculation unit 108 receives the estimated roll rate signal and the estimated pitch rate signal from the steering stability control-side vehicle behavior calculation unit 106, and receives the total wheel friction signal input from the total friction calculation unit 56. Receive. The steering stability control side target friction calculation unit 108 receives the wheel speed signal described above.
The steering stability control-side target friction calculation unit 108 calculates each wheel target friction for steering stability control using the estimated roll rate, the estimated pitch rate, the total wheel friction, and the vehicle speed.

Here, each wheel target friction for steering stability control refers to each suspension in order to suppress the roof behavior (pitch behavior, roll behavior) generated in the vehicle V by the driving operation of the driver or the above-described TCS control. This is a target value of friction generated in the SP.
Further, the steering stability control-side target friction calculation unit 108 calculates a steering stability control friction difference value, which is a difference value between the steering stability control wheel target friction and each wheel total friction. Then, an information signal including the calculated steering stability control friction difference value (which may be referred to as “steering stability control friction difference value signal” in the following description) is used as the steering stability control side braking / driving force. Output to the distribution ratio calculation unit 110.

The steering stability control side braking / driving force distribution ratio calculation unit 110 receives an input of the steering stability control friction difference value signal from the steering stability control side target friction calculation unit 108, and receives the total friction of each wheel from the total friction calculation unit 56. Receives signal input.
Then, the steering stability control side braking / driving force distribution ratio calculating unit 110 calculates the steering stability control side braking / driving force distribution ratio using each wheel total friction and each wheel target friction for steering stability control.

  Here, the steering stability control side braking / driving force distribution ratio refers to the control of the wheel W for suppressing the behavior (pitch behavior, roll behavior) related to the steering of the vehicle V among the roof behavior generated in the vehicle V. It is a distribution ratio between the power and the driving force of the wheels W. In other words, the steering stability control side braking / driving force distribution ratio is obtained by correcting the excess or deficiency of the friction (actual value) of each wheel W with respect to each wheel target friction (target value) for steering stability control. This is a distribution for controlling the braking force and the driving force.

Further, the steering stability control side braking / driving force distribution ratio calculation unit 110 includes an information signal including the calculated steering stability control side braking / driving force distribution ratio (in the following description, “steering stability control side braking / driving force distribution ratio” Signal ”may be described) to the braking force command value calculation unit 100B. In addition, the steering stability control side braking / driving force distribution ratio calculation unit 110 outputs a steering stability control side braking / driving force distribution ratio signal to the driving force command value calculation unit 102B.
A description will be given later of processing in which the steering stability control side braking / driving force distribution ratio calculation unit 110 calculates the steering stability control side braking / driving force distribution ratio.

The braking force command value calculation unit 100B includes a steering stability control side braking / driving force distribution ratio signal included in the steering stability control side braking / driving force distribution ratio signal received from the steering stability control side braking / driving force distribution ratio calculation unit 110. Among them, the steering stability control side braking force command value is calculated based on the distribution ratio of the braking force of the wheels W.
Here, the steering stability control side braking force command value is a value for the wheel W for causing the suspension SP to generate friction based on the steering stability control side braking force correction value included in the steering stability control side braking force correction value signal. This is the final command value for braking force.

The braking force command value calculation unit 100B that has calculated the steering stability control side braking force command value converts the calculated steering stability control side braking force command value into a command hydraulic pressure (brake hydraulic pressure). Then, a braking command signal that is an information signal including the converted command hydraulic pressure is output to the brake actuator 26. The braking force command value calculation unit 100B included in the steering stability control block 38 may be shared with the braking force command value calculation unit 100A included in the riding comfort control block 36, or may be configured separately.
Note that the processing for converting the steering stability control-side braking force command value into the command hydraulic pressure will be described later.

The driving force command value calculation unit 102B includes a steering stability control side braking / driving force distribution ratio signal included in the steering stability control side braking / driving force distribution ratio signal received from the steering stability control side braking / driving force distribution ratio calculation unit 110. Among them, the steering stability control side driving force command value is calculated based on the distribution ratio of the driving force of the wheels W. Then, the calculated driving stability control side driving force command value is converted into a driving torque correction value (driving torque correction value), and a driving command signal which is an information signal including the converted driving torque correction value is converted into power control. Output to unit 28. The driving force command value calculation unit 102B included in the steering stability control block 38 may be shared with the driving force command value calculation unit 102A included in the riding comfort control block 36, or may be configured separately.
Note that the processing for converting the steering stability control side driving force command value into the driving torque correction value will be described later.

  Here, the steering stability control side driving force command value is a value for causing the suspension SP to generate friction based on the distribution ratio of the driving force of the wheels W calculated by the steering stability control side braking / driving force distribution ratio calculation unit 110. This is the final command value of the driving force for the wheel W (command value of the driving force of the wheel W). Further, as described later, the steering stability control-side driving force command value is applied to the wheels W for causing each suspension SP to generate friction for suppressing the behavior (pitch behavior, roll behavior) related to the steering of the vehicle V. This is the final command value for the driving force.

(Riding comfort control side braking / driving force distribution ratio calculation unit 98 calculates the riding comfort control side braking / driving force distribution ratio, and steering stability control side braking / driving force distribution ratio calculation unit 110 calculates steering stability control side braking / driving force distribution ratio. Processing to calculate distribution ratio)
Hereinafter, a process in which the riding comfort control side braking / driving force distribution ratio calculation unit 98 calculates the riding comfort control side braking / driving force distribution ratio will be described with reference to FIGS. 1 to 14 and FIGS. 15 and 16. . The processing for calculating the steering stability control side braking / driving force distribution ratio by the steering stability control side braking / driving force distribution ratio calculating unit 110 is the same, and therefore, in the following description, the ride comfort control side braking / driving force distribution ratio is calculated. Only the process in which the calculation unit 98 calculates the riding comfort control side braking / driving force distribution ratio will be described.

First, the braking force upper limit value is calculated using the following equation (1). In the present embodiment, a case where the braking force upper limit value is calculated in advance and stored in the riding comfort control side braking / driving force distribution ratio calculating unit 98 and the steering stability control side braking / driving force distribution ratio calculating unit 110 will be described. To do. That is, in this embodiment, a case where the braking force upper limit value is used as a preset value will be described.
Braking force upper limit value = current driving force-deceleration threshold value ... (1)

Here, the current driving force is the driving force generated by the power unit 30 at the time of performing the process of calculating the ride comfort control side braking / driving force distribution ratio, and is obtained from the power control unit 28, for example. Calculate using information.
Further, the deceleration uncomfortable feeling threshold is a braking force that generates a braking force in which the driver of the vehicle V, such as the driver, receives an uncomfortable feeling due to unintended deceleration by the driver due to an increase in braking force different from the braking force increase request by the driver. This is the lower limit of the command value. In addition, the braking force increase request | requirement by a driver | operator is operation which increases the depression amount of a brake pedal, for example.

Further, the uncomfortable feeling of deceleration threshold value is calculated according to traveling conditions such as the specifications of the vehicle V and the vehicle speed, for example, through experiments, and is stored in the riding comfort control side braking / driving force distribution ratio calculating unit 98. Note that the uncomfortable deceleration threshold value stored in the riding comfort control braking / driving force distribution ratio calculation unit 98 may be updated in accordance with, for example, the travel distance of the vehicle V or the change in elasticity of the suspension SP over time. Good.
Further, the reason why the above formula (1) is satisfied is that a value obtained by subtracting the braking force upper limit value from the current driving force becomes a deceleration uncomfortable threshold value.
After calculating the braking force upper limit value, whether or not the friction corresponding to the excess or deficiency of the total friction with respect to each wheel target friction for ride comfort control can be generated in the suspension SP only by the braking force of the wheels W. Determine.

When it is determined that the friction corresponding to the excess / deficiency of the total friction can be generated in the suspension SP only by the braking force of the wheels W, the braking force that generates the friction corresponding to the excess / deficiency is controlled. It is determined whether or not the power upper limit is exceeded.
If it is determined that the braking force that generates the friction corresponding to the excess / deficiency is less than or equal to the upper limit of the braking force, the distribution ratio of the friction caused by the braking force and the friction caused by the driving force is set to the ratio shown in the following equation (2).
Friction caused by braking force: Friction caused by driving force = 100: 0 (2)
The friction due to the braking force is calculated using, for example, a braking force side behavior control friction calculation map, which will be described later.

On the other hand, if it is determined that the braking force that generates the friction corresponding to the excess / deficiency exceeds the braking force upper limit value, the following processing is performed to calculate the distribution ratio of the friction due to the braking force and the friction due to the driving force. .
First, with respect to the suspension SP that generates at least one of friction due to braking force and friction due to driving force, a distribution ratio of friction due to braking force and friction due to driving force is calculated among excess and deficient friction. In the following description, the friction caused by the braking force may be referred to as “braking force friction for riding comfort control”. Similarly, in the following description, the friction caused by the driving force may be referred to as “riding comfort control driving force friction”.

The braking force friction for ride comfort control is calculated by adapting the excess / deficiency friction to, for example, the braking calculation map for braking force side behavior control stored in advance in the ride comfort control braking / driving force distribution ratio calculation unit 98. To do.
Here, as shown in FIG. 15, the braking force side behavior control friction calculation map shows the braking force of the wheel W on the horizontal axis (shown as “braking force” in the figure), and the vertical axis indicates excess or deficiency. FIG. 6 is a map showing minute friction (indicated as “friction” in the figure). Further, the relationship between the braking force and the friction shown in the braking force-side behavior control friction calculation map varies depending on the relationship between the braking force of the wheel W and the behavior of the vehicle V. Specifically, even when the braking force of the wheel W increases, the degree of increase in the braking force of the wheel W decreases as the behavior of the vehicle V approaches a limit value at which rapid braking does not occur. FIG. 15 is a diagram showing a braking force side behavior control friction calculation map.

The braking force friction for riding comfort control is a value obtained by multiplying the braking force of the wheel W by the coefficient Kb shown in the braking force side behavior control friction calculation map. Here, the coefficient Kb is an inclination indicating a relationship between the braking force of the wheel W and the excess / deficiency friction in a region where the braking force of the wheel W is equal to or less than Fb_max which is a preset braking force limit value. Note that Fb_max is set using data measured in advance on a table, on the road, or the like based on a limit value at which the behavior of the vehicle V does not suddenly brake even when the braking force of the wheel W increases.
The driving force friction for riding comfort control is calculated by adapting the excess / deficiency friction to, for example, the driving force side behavior controlling friction calculation map stored in advance in the riding comfort control braking / driving force distribution ratio calculation unit 98. To do.

  Here, in the friction calculation map for driving force side behavior control, as shown in FIG. 16, the horizontal axis indicates the driving force of the wheel W (in the drawing, indicated as “driving force”), and the vertical axis indicates excess or deficiency. FIG. 6 is a map showing minute friction (indicated as “friction” in the figure). Further, the relationship between the driving force and the friction shown in the driving force-side behavior control friction calculation map varies depending on the relationship between the driving force of the wheel W and the behavior of the vehicle V. Specifically, even if the driving force of the wheel W increases, the degree of increase in the driving force of the wheel W decreases as it approaches a limit value at which the behavior of the vehicle V does not rapidly accelerate. FIG. 16 is a diagram showing a driving force side behavior control friction calculation map.

  The driving force friction for riding comfort control is a value obtained by multiplying the driving force of the wheel W by the coefficient Ka shown in the driving force side behavior control friction calculation map. Here, the coefficient Ka is an inclination indicating the relationship between the driving force of the wheel W and the excess / deficiency friction in a region where the driving force of the wheel W is equal to or less than Fa_max which is a preset limit value of the driving force. Note that Fa_max is set using data measured in advance on a table, running on the road, or the like based on a limit value at which the behavior of the vehicle V does not suddenly accelerate even when the driving force of the wheels W increases.

Further, when the riding comfort control side braking / driving force distribution ratio calculating unit 98 calculates the riding comfort control side braking / driving force distribution ratio, for example, the braking force of the wheels W is equal to or greater than the driving force of the wheels W. Then, a process for calculating the ride control side braking / driving force distribution ratio is performed.
As a specific example, in the state where the following formulas (3) to (5) are established, the relationship between excess / deficiency friction, the braking force of the wheel W, and the driving force of the wheel W is expressed by the following formula. The relationship shown in (6) is used.
Fraction excess and shortage <Kb × Fb_max + Ka × Fa_max (3)
Braking force of wheel W <Fb_max (4)
Driving force of wheel W <Fa_max (5)
Wheel W braking force = Wheel W drive force = excess / deficiency friction / Kb + Ka
(6)

Further, in the case of performing processing for bringing the deceleration of the vehicle V close to “± 0”, such as during steady turning, the driving force of the wheel W is expressed as The relationship shown in (8) is assumed. The relationship between the excess / deficiency friction and the braking force of the wheels W is represented by the following equation (9).
Driving force of wheel W> Fa_max (7)
Driving force of wheel W = Fa_max (8)
Braking force of wheel W = excess / deficiency friction-Fa_max / Kb (9)

As described above, the ride comfort control side braking / driving force distribution ratio calculating unit 98 performs the process of bringing the deceleration of the vehicle V close to “± 0”, such as during steady turning, and the ride comfort control side braking / driving force distribution ratio. Is calculated so that the braking force of the wheel W and the driving force of the wheel W are equal.
Here, in this embodiment, if the friction for suppressing the behavior is equal to or less than the braking force upper limit value, the riding comfort control side braking / driving force distribution ratio calculating unit 98 sets the riding comfort control side braking / driving force distribution ratio to the wheel. A case where calculation is performed only with the braking force of W will be described. This processing is the same for the steering stability control side braking / driving force distribution ratio calculation unit 110.

Further, the riding comfort control side braking / driving force distribution ratio calculating unit 98 calculates the riding comfort control side braking / driving force calculated only by the braking force of the wheel W if the friction for suppressing the behavior exceeds the braking force upper limit value. The driving force of the wheels W corresponding to the friction exceeding the braking force upper limit value is added to the distribution ratio. Thus, the ride comfort control side braking / driving force distribution ratio is calculated. This processing is the same for the steering stability control side braking / driving force distribution ratio calculation unit 110.
Further, in the present embodiment, the ride comfort control side braking / driving force distribution ratio calculating unit 98 corresponds to the braking / driving force distribution ratio calculated only by the braking force of the wheels W according to the friction that exceeds the braking force upper limit value. When the driving force of the wheels W is added, the following processing is further performed.

That is, the braking force upper limit value is increased according to the driving force added according to the friction exceeding the braking force upper limit value, and the braking force of the wheel W is within a range equal to or less than the increased braking force upper limit value. The braking / driving force distribution ratio with the increased is calculated.
The above processing is the same for the steering stability control side braking / driving force distribution ratio calculation unit 110.
As described above, in this embodiment, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the braking force of the wheel W corresponding to the braking force upper limit value is equivalent to the amount exceeding the braking force upper limit value. The braking / driving force distribution ratio is calculated by adding the driving forces of the wheels W according to the friction.

(Process to convert braking force command value into command hydraulic pressure)
Hereinafter, the process of converting the braking force command value into the command hydraulic pressure will be described with reference to FIGS. 1 to 16 and FIG.
When converting the braking force command value into the command hydraulic pressure, the braking force command value is adapted to, for example, a command hydraulic pressure conversion map stored in advance in the braking force command value calculation unit 100A included in the riding comfort control block 36. Let

Here, as shown in FIG. 17, the command hydraulic pressure conversion map is a map in which the horizontal axis indicates the braking force command value and the vertical axis indicates the command hydraulic pressure. FIG. 17 is a diagram showing a command hydraulic pressure conversion map.
Further, the command hydraulic pressure may be calculated by the following formula (10).
Command hydraulic pressure = (braking force command value [N] x tire dynamic radius [m])
/ (4 × pad μ × pad area × effective diameter) (10)

Here, when the distribution ratio of the friction due to the braking force and the friction due to the driving force is changed from the ratio shown in the above formula (2) and the ratio of the friction due to the driving force is increased with respect to the friction due to the braking force, The “current driving force” in equation (1) increases. As a result, when the ratio of the friction caused by the driving force to the friction caused by the braking force is increased, the braking force upper limit value is increased.
Accordingly, in the present embodiment, as an example, a case will be described in which a process of increasing the braking force command value while maintaining the magnitude below the increased braking force upper limit value in accordance with the increase of the braking force upper limit value will be described. .

(Process to convert the driving force command value to the driving torque correction value)
Hereinafter, the process of converting the driving force command value into the driving torque correction value will be described with reference to FIGS. 1 to 17 and FIG.
When the driving force command value is converted into the driving torque correction value, the driving force command value is converted into a driving torque correction value conversion map stored in advance in, for example, the driving force command value calculation unit 102A included in the riding comfort control block 36. To fit.

Here, as shown in FIG. 18, the drive torque correction value conversion map is a map in which the horizontal axis indicates the drive force command value and the vertical axis indicates the drive torque correction value. FIG. 18 is a diagram showing a drive torque correction value conversion map.
Further, the drive torque correction value may be calculated by the following equation (11).
Driving torque correction value = (driving force command value [N] × tire dynamic radius [m]) (11)

(Operation)
Next, an example of an operation performed using the vehicle behavior control device 1 of the present embodiment will be described using FIGS. 19 to 24 with reference to FIGS.
FIG. 19 is a flowchart of operations performed using the vehicle behavior control device 1. In addition, the vehicle behavior control apparatus 1 performs the process demonstrated below for every preset sampling time (for example, 50 [msec]).
As shown in FIG. 19, when the vehicle behavior control device 1 starts processing (START), first, in step S100, the friction detection block 34 calculates total friction ("estimated friction calculation" shown in the figure). I do. If the process which calculates total friction is performed in step S100, the process which the vehicle behavior control apparatus 1 will transfer to step S102.

  In step S100, for example, a process for calculating the braking force friction by the braking force friction calculation unit 48 and a process for calculating the driving force friction by the driving force friction calculation unit 50 are performed. In addition, in step S100, for example, the suspension state friction calculation unit 52 performs a process of calculating the stroke position friction and the stroke speed friction. Further, in step S100, for example, a process for calculating the lateral force friction by each wheel friction suspension lateral force calculation unit 46 and a process for determining whether or not to allow an operation for adding the calculated various frictions to the total friction. I do.

In addition, the process of step S100 includes a process of acquiring information indicating the state of the vehicle V (information such as each acceleration, yaw rate, and current steering angle) and a behavior of the vehicle V (braking force and driving force of each wheel W). Or the like) may be performed in a state in which the processing for calculating the behavior is performed.
In step S102, the ride comfort control-side target friction calculation unit 96 calculates the ride comfort control wheel target friction, and the steering stability control-side target friction calculation unit 108 calculates the steering stability control wheel target friction. Thereby, in step S102, processing for calculating the target friction ("target friction calculation" shown in the figure) is performed. If the process which calculates target friction is performed in step S102, the process which the vehicle behavior control apparatus 1 will transfer to step S104.

In step S104, the riding comfort control side braking / driving force distribution ratio calculation unit 98 calculates the riding comfort control side braking / driving force distribution ratio, and the steering stability control side braking / driving force distribution ratio calculation unit 110 calculates steering stability control. The side braking / driving force distribution ratio is calculated. In addition, in step S104, the riding comfort control side braking / driving force distribution ratio signal is output to the braking force command value calculation unit 100A and the driving force command value calculation unit 102A, and the steering stability control side braking / driving force distribution ratio signal is output. Is output to the braking force command value calculation unit 100B and the driving force command value calculation unit 102B. Thereby, in step S104, a process of calculating the braking / driving force distribution ratio ("braking / driving force distribution ratio calculation" shown in the figure) is performed. If the process which calculates braking / driving force distribution ratio is performed in step S104, the process which the vehicle behavior control apparatus 1 will transfer to step S106.
The specific process performed in step S104 will be described later.

  In step S106, the driving force command value calculation unit 102A and the driving force command value calculation unit 102B calculate a driving force command value (riding comfort control side driving force command value, steering stability control side driving force command value) ( “Driving force command value calculation”) shown in FIG. Further, in step S106, a process for outputting the driving force command value to the power control unit 28 is performed. When the driving force command value is calculated and output in step S106, the process performed by the vehicle behavior control device 1 proceeds to step S108.

  In step S108, the braking force command value (riding comfort control side braking force command value, steering stability control side braking force command value) is calculated by the braking force command value calculation unit 100A and the braking force command value calculation unit 100B ( "Brake force command value calculation") shown in the figure is performed. Further, in step S108, processing for outputting a braking force command value to the brake actuator 26 is performed. When the braking force command value is calculated and output in step S108, the processing performed by the vehicle behavior control device 1 is ended (END).

Next, specific processing performed in step S104 will be described with reference to FIGS. 1 to 19 and FIGS. 20 to 23. FIG.
FIG. 20 is a flowchart of an operation performed using the vehicle behavior control apparatus 1, and is a flowchart illustrating a process of calculating a braking / driving force distribution ratio.
As shown in FIG. 20, when the process of calculating the braking / driving force distribution ratio is started (START), first, the process of step S200 is performed.

In step S200, it is determined whether or not the target friction (each wheel target friction for ride comfort control and each wheel target friction for steering stability control) is “0” for all wheels W (in the figure). “Four wheel target friction = 0?”) Is performed.
If it is determined in step S200 that the target friction of all the wheels W is “0” (“Yes” shown in the figure), the process of calculating the braking / driving force distribution ratio is ended (END).

On the other hand, if it is determined in step S200 that the target friction of at least one of the wheels W is not "0"("No" shown in the figure), the process of calculating the braking / driving force distribution ratio is as follows. The process proceeds to step S202.
In step S202, processing for calculating the braking force upper limit value ("braking force upper limit value calculation" shown in the figure) is performed using the above-described equation (1). If the process which calculates braking force upper limit is performed in step S202, the process which calculates braking / driving force distribution ratio will transfer to step S204.

Here, with reference to FIG. 1 to FIG. 20, the specific processing performed in step S202 will be described with reference to FIG.
FIG. 21 is a flowchart of an operation performed using the vehicle behavior control device 1, and is a flowchart illustrating a process of calculating a braking force upper limit value.
As shown in FIG. 21, when the process of calculating the braking force upper limit value is started (START), first, the process of step S300 is performed.

In step S300, for example, using the information acquired from the power control unit 28, processing for calculating the current driving force ("driving force calculation" shown in the figure) is performed. When the process for calculating the current driving force is performed in step S300, the process for calculating the braking force upper limit value proceeds to step S302.
In step S302, the current driving force calculated in step S300 is input to the above equation (1), and processing for calculating the braking force upper limit value ("braking force upper limit calculation" shown in the figure) is performed. When the process for calculating the braking force upper limit value is performed in step S302, the process for calculating the braking force upper limit value is ended (END).

Hereinafter, the description returns to FIG.
In step S204, processing for converting the target friction into the braking force of the wheel W ("target friction-braking force conversion processing" shown in the figure) is performed. If the process which converts target friction into the braking force of the wheel W is performed in step S204, the process which calculates braking / driving force distribution ratio will transfer to step S206.
In step S206, a process for determining whether or not the target friction (braking force converted value) converted into the braking force in step S204 exceeds the braking force upper limit value calculated in step S202 ("braking force conversion shown in the figure"). Value> braking force upper limit value? ").

If it is determined in step S206 that the braking force converted value exceeds the braking force upper limit value ("Yes" shown in the figure), the processing for calculating the braking / driving force distribution ratio proceeds to step S208.
On the other hand, if it is determined in step S206 that the braking force conversion value is equal to or less than the braking force upper limit value ("No" shown in the figure), the processing for calculating the braking / driving force distribution ratio proceeds to step S210.
In step S208, a process of allocating a portion exceeding the braking force upper limit value to the driving force out of the braking force converted value ("driving force distribution process" shown in the drawing) is performed. In step S208, when the process of allocating the braking force converted value exceeding the braking force upper limit value to the driving force is performed, the process of calculating the braking / driving force distribution ratio is ended (END).

Here, with reference to FIG. 1 to FIG. 21, the specific processing performed in step S208 will be described using FIG.
FIG. 22 is a flowchart of an operation performed using the vehicle behavior control apparatus 1, and is a flowchart showing a driving force distribution process.
As shown in FIG. 22, when the driving force distribution process is started (START), first, the process of step S400 is performed.

In step S400, a process of calculating the target friction deficiency (“target friction deficit = braking force converted value−braking force upper limit value” shown in the figure) is performed using the following equation (12). In step S400, when the process of calculating the target friction deficiency is performed, the driving force distribution process proceeds to step S402.
Target friction shortage = braking force converted value−braking force upper limit value (12)
That is, in step S400, a process of calculating the deficiency of the target friction by subtracting the braking force upper limit value calculated in step S202 from the target friction (braking force converted value) converted into the braking force in step S204 above. Do.

In step S402, a process for calculating a driving force correction value that is a correction value for increasing the current driving force in order to compensate for the shortage of the target friction calculated in step S400 ("driving force correction shown in the figure"). Value calculation)). If the process which calculates a driving force correction value is performed in step S402, a driving force distribution process will transfer to step S404.
In step S404, a braking force upper limit correction value, which is a correction value for increasing the braking force upper limit value calculated in step S202, is calculated according to the braking force upper limit value increased by the driving force correction value calculated in step S402. Processing ("calculation of braking force upper limit correction value" shown in the figure) is performed. If the process which calculates a braking force upper limit correction value is performed in step S404, a driving force distribution process will transfer to step S406.

In step S406, processing for calculating an increase in the target friction due to the braking force is performed according to the increase in the braking force upper limit increased by the braking force upper limit correction value calculated in step S404.
Here, in step S406, a process of calculating an increase in the target friction due to the braking force for the right front wheel WFR and the left front wheel WFL (drive wheel side braking force target friction calculation shown in the figure) is performed. Do. In step S406, when the process for calculating the increase in the target friction due to the braking force is performed on the right front wheel WFR and the left front wheel WFL, the driving force distribution process proceeds to step S408.

In step S408, processing for calculating an increase in the target friction due to the braking force is performed in accordance with the increase in the braking force upper limit increased by the braking force upper limit correction value calculated in step S404.
Here, in step S408, for the right rear wheel WRR and the left rear wheel WRL, which are the driven wheels, a process of calculating an increase in target friction due to the braking force ("driven wheel side braking force target friction calculation" shown in the figure). )I do. In step S408, when the process for calculating the increase in the target friction due to the braking force is performed on the right rear wheel WRR and the left rear wheel WRL, the driving force distribution process proceeds to step S410.
In step S410, processing for calculating the target value of the braking force of the wheel W according to the increase in the target friction due to the braking force calculated in step S406 and step S408 ("calculation of each wheel target braking force" shown in the figure). I do. If the process which calculates the target value of the braking force of the wheel W is performed in step S410, a driving force distribution process will be complete | finished (END).

Hereinafter, the description returns to FIG.
In step S210, the braking force converted value calculated in step S204 is set to the friction based only on the braking force, and is set as the target value (target braking force) of the braking force of the wheel W ("target" shown in the figure). Braking force = braking force conversion value ”). In step S210, when the process using the braking force converted value as the target braking force is performed, the process of calculating the braking / driving force distribution ratio is ended (END).

  Next, a specific example of a process for calculating the braking / driving force distribution ratio will be described using a time chart with reference to FIGS. 1 to 22 and FIG. FIG. 23 is a time chart showing processing for calculating the braking / driving force distribution ratio while the vehicle V is traveling. FIG. 23A is a diagram showing a change in target friction. FIG. 23B is a diagram showing changes in the braking force conversion value and the driving force correction value in the driving wheels (the right front wheel WFR and the left front wheel WFL). FIG. 23C is a diagram showing a change in the braking force conversion value in the driven wheels (the right rear wheel WRR and the left rear wheel WRL).

In the time chart shown in FIG. 23A, the change in the target friction is indicated by a solid line “TF”. In the time chart shown in FIG. 23B, the change in the braking force conversion value is indicated by a dotted line “BR_RE”, and the change in the driving force correction value is indicated by a broken line “DR_CO”. In the time chart shown in FIG. 23C, the change in the braking force conversion value is indicated by a dotted line “BR_RE”.
As shown in FIG. 23, in a state where the braking force conversion value is equal to or less than the braking force upper limit value (a state before the time point “ta” and a state after the time point “tb” in the drawing), the braking force conversion value is Then, a process of setting to a value corresponding to the friction caused only by the braking force is performed (see step S210).

  On the other hand, in a state where the braking force conversion value is less than the braking force upper limit value (a state between “ta” and “tb” shown in the figure), the portion of the braking force conversion value that exceeds the braking force upper limit value. Is distributed to the driving force (see step S208). In addition, in the suspension SPFR and the suspension SPFL installed for the driving wheel, in addition to the braking force friction, the driving force friction corresponding to the amount exceeding the braking force upper limit value is generated. In FIG. 23 (b), an area indicating the portion of the braking force converted value that is allocated to the driving force exceeding the braking force upper limit value is indicated by reference numeral “EDR”.

Further, in a state between “ta” and “tb”, the braking force upper limit correction value is calculated, and the target friction due to the braking force is calculated according to the increment of the braking force upper limit value by the calculated braking force upper limit correction value. Is calculated (see steps S400 to S408). Then, in the suspension SPRR and the suspension SPRL installed on the driven wheel, braking force friction corresponding to the increase in the target friction is generated. In FIG. 23 (c), an area indicating an increase in the braking force upper limit value increased by the braking force upper limit correction value is indicated by a reference sign “EBR”.
Therefore, in a state where the braking force conversion value is equal to or less than the braking force upper limit value, braking force friction is generated in each suspension SP installed on the driving wheel and the driven wheel.

  On the other hand, in a state where the braking force conversion value exceeds the braking force upper limit value, in addition to the braking force friction, the driving force friction is generated in the suspension SPFR and the suspension SPFL installed on the driving wheel. In addition, in the suspension SPRR and suspension SPRL installed on the driven wheel, the braking force friction is increased according to the magnitude of the driving force friction.

Here, the increase in the braking force friction generated by the suspension SPRR and the suspension SPRL installed on the driven wheel is a value corresponding to the driving force friction generated by the suspension SPFR and the suspension SPFL installed on the driving wheel. . For this reason, it is possible to suppress an increase in the deceleration of the vehicle V in both the state where the braking force conversion value is equal to or less than the braking force upper limit value and the state where the braking force conversion value exceeds the braking force upper limit value. .
That is, in the present embodiment, the braking force command value calculation unit 100A and the braking force command value calculation unit 100B apply the braking force of the wheel W increased within the range of the braking force upper limit value or less only to the driven wheel. The braking force command value is calculated.

  Next, a specific example of processing performed by the vehicle behavior control device 1 will be described using a time chart with reference to FIGS. 1 to 23 and FIG. 24. FIG. 24 is a time chart showing processing performed by the vehicle behavior control device 1 while the vehicle V is traveling. FIG. 24A is a diagram showing a change in the target friction, a change in the braking force upper limit value, and a change in the target friction shortage amount. FIG. 24B is a diagram showing a change in the braking force upper limit correction value, a change in the target friction shortage amount, and a change in the driving force correction value. FIG. 24C shows a change in driving force friction, a change in braking force friction generated in the suspension SP installed on the driving wheel, and a braking force friction generated in the suspension SP installed on the driven wheel. It is a figure which shows the change of. Further, FIG. 24C shows a change in the braking force command value for the driving wheel and a change in the braking force command value for the driven wheel.

Note that the time chart shown in FIG. 24 shows a case where the target friction of the driving wheel and the target friction of the driven wheel are always the same. Therefore, in the time chart shown in FIG. 24A, the change in the target friction of the driving wheel is indicated by a solid line “TF_F” and the symbol “◇”, and the change in the target friction of the driven wheel is indicated by a solid line “TF_R” and the symbol “◇”. ". In the time chart shown in FIG. 24A, the change in the braking force upper limit value is indicated by a solid line “BR_LIM” and a symbol “Δ”. In the time charts shown in FIGS. 24A and 24B, the change in the target friction deficiency is indicated by a solid line “TF_DEF” and a symbol “x”.
In the time chart shown in FIG. 24B, the change in the braking force upper limit correction value is indicated by a solid line “BR_CO” and the symbol “□”, and the change in the driving force correction value is indicated by a solid line “DR_CO” and the symbol “◯”. It shows with.

  Further, the time chart shown in FIG. 24 shows a case where the braking force friction generated in the suspension SP installed on the driving wheel is always the same as the braking force command value on the driving wheel. Similarly, the time chart shown in FIG. 24 shows a case where the braking force friction generated in the suspension SP installed for the driven wheel and the braking force command value for the driven wheel are always the same. Therefore, in the time chart shown in FIG. 24C, the change in the braking force friction generated in the suspension SP installed on the driving wheel is indicated by the solid line “BRF_F” and the symbol “▽”, and the braking force command for the driving wheel is shown. The change in value is indicated by a solid line “BRCO_F” and a symbol “「 ”. Similarly, in the time chart shown in FIG. 24C, the change in the braking force friction generated in the suspension SP installed on the driven wheel is indicated by a solid line “BRF_R” and the symbol “☆”, and the braking force applied to the driven wheel. The change in the command value is indicated by a solid line “BRCO_R” and a symbol “☆”.

Furthermore, in the time chart shown in FIG. 24C, the change in driving force friction is indicated by a solid line “COF_F” and a symbol “+”.
As shown in FIG. 24, in the process performed by the vehicle behavior control device 1, from the time when the target friction of the wheel W exceeds “0” (time “t1” in the figure) while the vehicle V is traveling. The brake command signal is output to the brake actuator 26. Thereby, the braking force friction corresponding to the target friction is generated in the suspension SP installed on the wheel W.

Then, after the time point t1, the drive command signal is output to the power control unit 28 from the time point when the increased target friction of the wheel W exceeds the braking force upper limit (time point “t2” in the figure). Thus, in addition to the braking force friction corresponding to the target friction, the driving force friction corresponding to the target friction is generated in the suspension SPFR and the suspension SPFL installed on the driving wheel.
Further, in a state where the target friction of the wheels W exceeds the braking force upper limit value, the braking force command value for the driving wheel is held at a magnitude corresponding to the braking force upper limit value.

In addition, if the driving force friction corresponding to the target friction is generated in the suspension SPFR and the suspension SPFL installed on the driving wheel, the braking force upper limit correction value becomes larger than the braking force upper limit value, and the driving force friction is changed. Increase.
Therefore, in the state where the driving force friction is generated after the time point t2, the braking force friction generated in the suspension SP installed on the driven wheel is set according to the braking force upper limit value according to the change in the driving force friction. It is possible to increase the value above the specified value.

  For this reason, even if the braking force friction is increased, it is possible to reduce the possibility that an occupant such as the driver will feel uncomfortable by suppressing the deceleration that the driver does not intend in the traveling vehicle V. It becomes. As a result, it is possible to suppress the occurrence of deceleration unintended by the driver and control the suspension SP to generate a target value of friction. Therefore, the passenger of the vehicle V feels uncomfortable during the control of generating the friction. The possibility of receiving can be reduced.

Then, after the time point t2, the output of the drive command signal to the power control unit 28 is stopped from the time point when the target friction of the wheel W decreases and becomes equal to or less than the braking force upper limit value (time point "t3" in the figure). To do. As a result, only the braking force friction corresponding to the target friction is generated in the suspension SPFR and the suspension SPFL installed on the drive wheels.
Furthermore, the output of the brake command signal to the brake actuator 26 is stopped from the time when the target friction of the wheel W decreases to “0” (time “t4” in the figure).
In addition, the brake actuator 26, the master cylinder 24, and each wheel cylinder 32 mentioned above respond | correspond to a braking force provision part.

Here, as described above, the braking force application unit of the present embodiment is based on the braking force command value based on the braking force according to the control of the braking force request by the driver and the braking force according to the system control of the vehicle V. The braking force is added to the wheel W to add the braking force.
The braking force according to the control of the braking force request by the driver is a braking force that is controlled according to the operation of the brake pedal 22 by the driver. The braking force according to the system control of the vehicle V is a braking force that is controlled according to, for example, the preceding vehicle following traveling control or the lane keeping traveling control described above.

Further, the power control unit 28 and the power unit 30 described above correspond to a driving force application unit.
Here, as described above, the driving force application unit of the present embodiment is based on the driving force command value based on the driving force according to the control of the driving force request by the driver and the driving force according to the system control of the vehicle V. The braking force is applied to the wheels W by adding the driving forces.
In addition, the driving force according to control of the driving force request | requirement by a driver | operator is a driving force controlled according to operation of the accelerator pedal by a driver | operator. The driving force according to the system control of the vehicle V is a driving force that is controlled according to the preceding vehicle following traveling control, the lane keeping traveling control, or the like described above, for example.

The suspension state calculation unit 44 described above corresponds to a stroke position calculation unit and a stroke speed calculation unit.
The suspension state friction calculation unit 52 described above corresponds to a stroke position friction calculation unit and a stroke speed friction calculation unit.
Further, as described above, in the vehicle behavior control method implemented by the operation of the vehicle behavior control device 1 of the present embodiment, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the following processing is performed. To calculate the braking / driving force distribution ratio. Furthermore, braking force and driving force are applied to the wheels W according to the calculated braking / driving force distribution ratio.
That is, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the wheel corresponding to the friction exceeding the braking force upper limit value is added to the braking force of the wheel W corresponding to the braking force upper limit value. The braking / driving force distribution ratio is calculated by adding the driving force of W.

(Effects of the first embodiment)
If it is the vehicle behavior control apparatus 1 of this embodiment, it will become possible to show the effect described below.
(1) The ride comfort control side braking / driving force distribution ratio calculation unit 98 and the steering stability control side braking / driving force distribution ratio calculation unit 110 exceed the braking force upper limit value in the braking force of the wheel W according to the braking force upper limit value. The braking / driving force distribution ratio is calculated by adding the driving forces of the wheels W according to the corresponding friction. This calculation is performed when the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value.

Therefore, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the braking force of the wheel W corresponding to the braking force upper limit value and the friction corresponding to the amount exceeding the braking force upper limit value are determined. Based on the driving force of the wheel W, the braking / driving force distribution ratio can be calculated.
As a result, even when the friction generated in the suspension SP does not reach the target value only by the braking force, it is possible to perform control for generating the target value of friction in the suspension SP by the driving force. In addition, it is possible to suppress the occurrence of deceleration that is not intended by the driver.

(2) When the friction for suppressing the behavior of the vehicle body is less than or equal to the braking force upper limit value, the ride comfort control side braking / driving force distribution ratio calculating unit 98 and the steering stability control side braking / driving force distribution ratio calculating unit 110 The braking / driving force distribution ratio is calculated only by the braking force of the wheels W. In addition, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the braking / driving force distribution ratio calculated only by the braking force of the wheel W corresponds to the friction that exceeds the braking force upper limit value. The braking / driving force distribution ratio is calculated by adding the driving forces of the wheels W.

For this reason, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the driving force of the wheel W corresponding to the friction exceeding the braking force upper limit value and the friction below the braking force upper limit value The braking / driving force distribution ratio is calculated as the distribution ratio between the braking force of the wheels W according to the above.
As a result, when the friction generated in the suspension SP does not reach the target value only by the braking force, control is performed to generate the friction of the target value in the suspension SP by the driving force, and the occurrence of deceleration not intended by the driver is suppressed. It becomes possible to do. As a result, friction for suppressing the behavior of the vehicle body can be generated in the suspension SP, and the uncomfortable feeling experienced by the vehicle occupant can be reduced.

(3) The ride comfort control side braking / driving force distribution ratio calculating unit 98 and the steering stability control side braking / driving force distribution ratio calculating unit 110 increase the braking force upper limit value, and further reduce the braking force upper limit value below the increased braking force upper limit value. Within the range, a braking / driving force distribution ratio obtained by increasing the braking force of the wheel W is calculated. Here, the process of increasing the braking force upper limit value is performed on the driving force of the wheel W added to the braking / driving force distribution ratio calculated only by the braking force of the wheel W in accordance with the friction exceeding the braking force upper limit value. Do it accordingly.
For this reason, it becomes possible to increase the braking force of the wheel W according to the braking force upper limit value according to the driving force of the wheel W added to the braking / driving force distribution ratio calculated only by the braking force of the wheel W.
As a result, it is possible to increase the braking force of the wheels W for causing the suspension SP to generate friction for suppressing the behavior of the vehicle body, and to suppress the occurrence of deceleration unintended by the driver. Become.

(4) Only the driven wheel (the right front wheel WFR and the left front wheel WFL) increases the braking force of the wheel W that the braking force command value calculation unit 100A and the braking force command value calculation unit 100B have increased within the range of the braking force upper limit value or less. The braking force command value is calculated so as to be applied to
As a result, it is possible to reduce the calculation load related to the control for applying the braking force compared to the case where the braking force of the wheel W increased within the range of the braking force upper limit value or less is applied to all the wheels W. Become.

(5) The total friction calculation unit 56 adds the braking force friction calculated by the braking force friction calculation unit 48 and the driving force friction calculated by the driving force friction calculation unit 50. Then, the total friction generated in the suspension SP is individually calculated for each suspension SP.
For this reason, the friction generated in the suspension SP is appropriately calculated based on the longitudinal force received by the suspension SP by the braking force and driving force of the wheels W even during straight traveling where the lateral force is difficult to act. Is possible.
As a result, it is possible to calculate the braking force command value and the driving force command value using the friction generated in the suspension SP, which is appropriately calculated according to the traveling state of the vehicle V, and according to the traveling state of the vehicle V. It is possible to perform the behavior control more appropriately.

(6) The total friction calculation unit 56 adds the stroke position friction calculated by the stroke position friction calculation unit to the braking force friction and the driving force friction, and calculates the total friction for each suspension SP individually.
For this reason, it is possible to appropriately calculate the total friction on the basis of the stroke position of the suspension SP that changes when the vehicle V travels, in addition to the longitudinal force that the suspension SP receives.
As a result, it is possible to calculate the braking force command value and the driving force command value by using the total friction whose calculation accuracy is improved according to the traveling state of the vehicle V based on the stroke position of the suspension SP.

(7) The total friction calculation unit 56 adds the stroke speed friction calculated by the stroke speed friction calculation unit to the braking force friction and the driving force friction, and calculates the total friction individually for each suspension SP.
Therefore, it is possible to appropriately calculate the total friction based on the stroke speed of the suspension SP that changes when the vehicle V travels in addition to the longitudinal force that the suspension SP receives.
As a result, it is possible to calculate the braking force command value and the driving force command value by using the total friction whose calculation accuracy is improved according to the traveling state of the vehicle V based on the stroke speed of the suspension SP.

(8) The total friction calculation unit 56 adds the lateral force friction calculated by the suspension lateral force friction calculation unit 54 to the braking force friction and the driving force friction, and calculates the total friction for each suspension SP individually. .
Therefore, it is possible to appropriately calculate the total friction based on the lateral force acting on the suspension SP when the vehicle V is turning, in addition to the longitudinal force that the suspension SP receives input.
As a result, it is possible to calculate the braking force command value and the driving force command value by using the total friction whose calculation accuracy is improved according to the traveling state of the vehicle V based on the lateral force acting on the suspension SP. .

(9) The braking force calculation unit 40 calculates the braking force of the wheel W based on the traveling control of the vehicle V, and the driving force calculation unit 42 calculates the driving force of the wheel W based on the traveling control of the vehicle V.
As a result, it is possible to calculate the braking force and driving force of the wheels W that do not reflect the control for suppressing the roll behavior of the vehicle body, and it is possible to appropriately calculate the total friction.

(10) The braking force applying unit adds the braking force based on the braking force command value to the braking force according to the control of the braking force request by the driver and the braking force according to the system control of the vehicle V, and the wheel W A braking force is applied to.
As a result, in addition to the braking force that does not reflect the control for suppressing the behavior of the vehicle body, the braking force that reflects the control for suppressing the behavior of the vehicle body can be applied to the wheels W.

(11) The driving force application unit adds the driving force based on the driving force command value to the driving force according to the control of the driving force request by the driver and the driving force according to the system control of the vehicle V, and the wheel W A driving force is applied to.
As a result, in addition to the driving force that does not reflect the control for suppressing the behavior of the vehicle body, the driving force that reflects the control for suppressing the behavior of the vehicle body can be applied to the wheels W.

(12) In the vehicle behavior control method implemented by the operation of the vehicle behavior control device 1 of the present embodiment, the braking force of the wheel W according to the braking force upper limit value corresponds to the friction that exceeds the braking force upper limit value. The braking / driving force distribution ratio is calculated by adding the driving forces of the wheels W. Further, the braking force command value and the driving force command value are calculated according to the calculated braking / driving force distribution ratio, and the braking force and the driving force are applied to the wheels W based on the calculated braking force command value and the driving force command value. Give.
Here, the process of calculating the braking / driving force distribution ratio by adding the driving force of the wheel W corresponding to the friction exceeding the braking force upper limit value to the braking force of the wheel W corresponding to the braking force upper limit value is as follows. This is performed when the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value.

Therefore, if the friction for suppressing the behavior of the vehicle body exceeds the braking force upper limit value, the braking force of the wheel W corresponding to the braking force upper limit value and the friction corresponding to the amount exceeding the braking force upper limit value are determined. Based on the driving force of the wheel W, the braking / driving force distribution ratio can be calculated.
As a result, even when the friction generated in the suspension SP does not reach the target value only by the braking force, it is possible to perform control for generating the target value of friction in the suspension SP by the driving force. In addition, it is possible to suppress the occurrence of deceleration that is not intended by the driver.

(Modification)
(1) In the present embodiment, the configuration of the vehicle V is a two-wheel drive vehicle in which the front wheels are drive wheels, but the configuration of the vehicle V is not limited to this. That is, the configuration of the vehicle V may be an all-wheel drive vehicle in which all wheels (right front wheel WFR, left front wheel WFL, right rear wheel WRR, left rear wheel WRL) are drive wheels.
In this case, in step S208 described above, the driving force distribution process shown in FIG. 25 is performed. FIG. 25 is a flowchart of an operation performed using the vehicle behavior control device 1 according to the modification of the present embodiment, and is a flowchart showing a driving force distribution process.

As shown in FIG. 25, when the driving force distribution process is started (START), first, the process of step S500 is performed, and the process proceeds to step S502. In addition, since the process of step S500 is the same as the process of step S400 mentioned above, the description is omitted.
Since the process of step S502 is the same as the process of step S402 described above, the description thereof is omitted. When the process of step S502 is performed, the driving force distribution process proceeds to step S504.

Since the process of step S504 is the same as the process of step S404 described above, the description thereof is omitted. When the process of step S504 is performed, the driving force distribution process proceeds to step S506.
In step S506, a process of calculating an increase in the target friction due to the braking force is performed on all the wheels W according to the increase in the braking force upper limit value increased by the braking force upper limit correction value calculated in step S504. . In step S506, when processing for calculating an increase in target friction due to braking force is performed for all wheels W, the driving force distribution processing proceeds to step S508.

  In step S508, processing for calculating the target value of the braking force of the wheel W ("calculation of each wheel target braking force" shown in the figure) is performed according to the increase in the target friction due to the braking force calculated in step S506. If the process which calculates the target value of the braking force of the wheel W is performed in step S508, the driving force distribution process of a modification will be complete | finished (END).

  Here, a specific example of the process of calculating the braking / driving force distribution ratio when the configuration of the vehicle V is an all-wheel drive vehicle will be described with reference to the time chart shown in FIG. FIG. 26 is a time chart showing processing for calculating the braking / driving force distribution ratio, which is performed using the vehicle behavior control device 1 according to the modification of the present embodiment while the vehicle V is traveling. FIG. 26A is a diagram showing a change in the target friction. FIG. 26B is a diagram illustrating changes in the braking force conversion value and the driving force correction value in all the wheels W.

In the time chart shown in FIG. 26A, the change in the target friction is indicated by a solid line “TF”. In the time chart shown in FIG. 26B, the change in the braking force conversion value is indicated by a dotted line “BR_RE”, and the change in the driving force correction value is indicated by a broken line “DR_CO”.
As shown in FIG. 26, in a state where the braking force conversion value is equal to or less than the braking force upper limit value (a state before the time point “ta” and a state after the time point “tb” in the drawing), the braking force conversion value is Then, a process of setting to a value corresponding to the friction caused only by the braking force is performed (see step S210).

  On the other hand, in a state where the braking force conversion value is less than the braking force upper limit value (a state between “ta” and “tb” shown in the figure), the portion of the braking force conversion value that exceeds the braking force upper limit value. Is distributed to the driving force (see step S208). In each suspension SP, in addition to braking force friction, driving force friction corresponding to the amount exceeding the braking force upper limit value is generated. In FIG. 26 (b), the region indicating the portion of the braking force converted value that is allocated to the driving force exceeding the braking force upper limit value is indicated by reference numeral “EDR”.

Further, in a state between “ta” and “tb”, the braking force upper limit correction value is calculated, and the target friction due to the braking force is calculated according to the increment of the braking force upper limit value by the calculated braking force upper limit correction value. Is calculated (see steps S500 to S506). In each suspension SP, braking force friction corresponding to the increase in target friction is generated. In FIG. 26 (b), a region indicating an increase in the braking force upper limit value increased by the braking force upper limit correction value is indicated by a reference numeral “EBR”.
Therefore, when the braking force conversion value is equal to or less than the braking force upper limit value, braking force friction is generated in each suspension SP.

On the other hand, in a state where the braking force conversion value exceeds the braking force upper limit value, driving force friction is generated in each suspension SP in addition to the braking force friction. In addition, in each suspension SP, the braking force friction is increased according to the magnitude of the driving force friction.
Here, the increment of the braking force friction generated in each suspension SP is a value corresponding to the driving force friction generated in each suspension SP. For this reason, it is possible to suppress an increase in the deceleration of the vehicle V in both the state where the braking force conversion value is equal to or less than the braking force upper limit value and the state where the braking force conversion value exceeds the braking force upper limit value. .

(2) In the present embodiment, the total friction is calculated by adding the braking force friction, the driving force friction, the stroke position friction, the stroke speed friction, and the lateral force friction. However, the present invention is not limited to this. That is, the total friction may be calculated based on at least the braking force friction and the driving force friction.
(3) Although the braking force upper limit value is used as a preset value in the present embodiment, the present invention is not limited to this. That is, the braking force upper limit value may be calculated / updated for each cycle in which the ride comfort control side braking / driving force distribution ratio calculating unit 98 and the steering stability control side braking / driving force distribution ratio calculating unit 110 perform processing.

DESCRIPTION OF SYMBOLS 1 Vehicle behavior control apparatus 20 Braking / driving force controller 24 Master cylinder 26 Brake actuator 28 Power control unit 30 Power unit 32 Wheel cylinder 34 Friction detection block 36 Riding comfort control block 38 Steering stability control block 40 Braking force calculation part 42 Driving force calculation Unit 44 Suspension state calculation unit 46 Suspension lateral force calculation unit 48 Braking force friction calculation unit 50 Driving force friction calculation unit 52 Suspension state friction calculation unit 54 Lateral force friction calculation unit 56 Total friction calculation unit 94 Ride comfort control side vehicle behavior calculation unit 96 Ride comfort control side target friction calculation unit 98 Ride comfort control side braking / driving force distribution ratio calculation unit 100A Braking force command value calculation unit 100 provided in the ride comfort control block 36 B Driving force command value calculation unit 102A included in the steering stability control block 38A Driving force command value calculation unit 102B included in the riding comfort control block 36B Driving force command value calculation unit 106 included in the steering stability control block 38 Vehicle behavior calculation unit 108 Steering stability control side target friction calculation unit 110 Steering stability control side braking / driving force distribution ratio calculation unit 112 Behavior suppression friction calculation unit V Vehicle W Wheel SP Suspension

Claims (12)

A vehicle behavior control device that controls the behavior of the vehicle body with respect to a vehicle including a vehicle body, a plurality of wheels, and a suspension that connects the vehicle body and each wheel.
A braking / driving force distribution ratio calculating unit for calculating a braking / driving force distribution ratio between the braking force of the wheel and the driving force of the wheel, which is necessary for generating the friction for suppressing the behavior in the suspension;
A braking force command value calculating unit for calculating a braking force command value as a final command value for the wheel for causing the suspension to generate friction based on the braking force distribution ratio of the wheel calculated by the braking / driving force distribution ratio calculating unit; ,
A driving force command value calculating unit that calculates a driving force command value as a final command value for the wheel for causing the suspension to generate friction based on the wheel driving force distribution ratio calculated by the braking / driving force distribution ratio calculating unit; ,
A braking force applying unit that applies a braking force to the wheel based on the braking force command value calculated by the braking force command value calculating unit;
A driving force applying unit that applies driving force to the wheel based on the driving force command value calculated by the driving force command value calculating unit;
The braking / driving force distribution ratio calculating unit is configured such that the friction for suppressing the behavior exceeds a braking force upper limit value according to a braking force in which a vehicle occupant feels uncomfortable due to deceleration not intended by the driver of the vehicle. For example, the braking / driving force distribution ratio is calculated by adding the driving force of the wheel corresponding to the friction that exceeds the braking force upper limit value to the braking force of the wheel corresponding to the braking force upper limit value. A vehicle behavior control device.   The braking / driving force distribution ratio calculation unit calculates the braking / driving force distribution ratio only by the braking force of the wheel and suppresses the behavior if the friction for suppressing the behavior is equal to or less than the braking force upper limit value. If the friction for driving exceeds the braking force upper limit value, the driving of the wheel according to the friction corresponding to the braking force upper limit value calculated by the braking / driving force distribution ratio calculated only by the braking force of the wheel. The vehicle behavior control device according to claim 1, wherein a force is added to calculate the braking / driving force distribution ratio.   The braking / driving force distribution ratio calculating unit sets the braking force upper limit value to the braking / driving force distribution ratio calculated only by the braking force of the wheel, with the friction for suppressing the behavior exceeding the braking force upper limit value. When the driving force of the wheel according to the excess friction is added, the braking force upper limit value is increased according to the added driving force, and further within the range of the increased braking force upper limit value or less. The vehicle behavior control device according to claim 2, wherein a braking / driving force distribution ratio obtained by increasing a braking force of a wheel is calculated. The vehicle includes a driving wheel that is a wheel that applies the driving force and the braking force, and a driven wheel that is a wheel that applies only the braking force.
The braking force command value calculation unit calculates the braking force command value so that the braking force of the wheel increased within a range equal to or less than the braking force upper limit value is applied only to the driven wheel. The vehicle behavior control device according to claim 3. A braking force calculator for calculating the braking force of the wheel;
A braking force friction calculation unit that calculates braking force friction that is friction generated in the suspension based on the braking force calculated by the braking force calculation unit;
A driving force calculator for calculating the driving force of the wheels;
A driving force friction calculating unit that calculates driving force friction that is friction generated in the suspension based on the driving force calculated by the driving force calculating unit;
The braking force friction calculated by the braking force friction calculation unit and the driving force friction calculated by the driving force friction calculation unit are added together, and the total friction, which is the friction generated in the suspension, is applied to each suspension. The vehicle behavior control device according to any one of claims 1 to 4, further comprising: a total friction calculation unit that calculates individually. A stroke position calculator for calculating a stroke position of the suspension;
A stroke position friction calculation unit that calculates a stroke position friction that is a friction generated in the suspension based on the stroke position calculated by the stroke position calculation unit;
The total friction calculation unit adds the stroke position friction calculated by the stroke position friction calculation unit to the braking force friction calculated by the braking force friction calculation unit and the driving force friction calculated by the driving force friction calculation unit. 6. The vehicle behavior control device according to claim 5, wherein the total friction is individually calculated for each suspension. A stroke speed calculation unit for calculating the stroke speed of the suspension;
A stroke speed friction calculation unit that calculates a stroke speed friction that is a friction generated in the suspension based on the stroke speed calculated by the stroke speed calculation unit;
The total friction calculation unit adds the stroke speed friction calculated by the stroke speed friction calculation unit to the braking force friction calculated by the braking force friction calculation unit and the driving force friction calculated by the driving force friction calculation unit. 7. The vehicle behavior control device according to claim 5, wherein the total friction is calculated individually for each suspension. A suspension lateral force calculation unit for calculating the lateral force of the suspension;
A suspension lateral force friction calculating unit that calculates a lateral force friction that is a friction generated in the suspension based on the lateral force calculated by the suspension lateral force calculating unit,
The total friction calculation unit adds the lateral force friction calculated by the suspension lateral force friction calculation unit to the braking force friction calculated by the braking force friction calculation unit and the driving force friction calculated by the driving force friction calculation unit. The vehicle behavior control device according to any one of claims 5 to 7, wherein the total friction is calculated individually for each suspension. The braking force calculation unit calculates the braking force of the wheel based on the travel control of the vehicle,
The vehicle behavior control device according to any one of claims 5 to 8, wherein the driving force calculation unit calculates a driving force of the wheel based on traveling control of the vehicle.   The braking force applying unit is configured to set the braking force command value calculated by the braking force command value calculating unit to the braking force according to the control of the braking force request by the driver of the vehicle and the braking force according to the system control of the vehicle. The vehicle behavior control device according to any one of claims 1 to 9, wherein a braking force is applied to the wheels by adding together the braking forces based on the braking force.   The driving force imparting unit sets the driving force command value calculated by the driving force command value calculating unit to the driving force according to the driving force request control by the vehicle driver and the driving force according to the vehicle system control. The vehicle behavior control device according to any one of claims 1 to 10, wherein a driving force is applied to the wheels by adding together the driving forces based on the driving force. A vehicle behavior control method for controlling the behavior of the vehicle body with respect to a vehicle comprising a vehicle body, a plurality of wheels, and a suspension that connects the vehicle body and each wheel.
If the friction for suppressing the behavior exceeds a braking force upper limit value that is a value corresponding to a braking force that causes a vehicle occupant to feel uncomfortable due to deceleration not intended by the driver of the vehicle, the braking force upper limit value Necessary for generating the friction for suppressing the behavior in the suspension by adding the wheel driving force corresponding to the friction exceeding the braking force upper limit value to the braking force of the wheel corresponding to Calculating a braking / driving force distribution ratio between the braking force of the wheel and the driving force of the wheel,
A braking force command value is calculated as a final command value for the wheel for causing the suspension to generate friction based on the calculated braking force distribution ratio of the wheel, and the wheel is controlled based on the calculated braking force command value. Power,
A driving force command value is calculated as a final command value for the wheel for causing the suspension to generate friction based on the calculated driving force distribution ratio of the wheel, and the wheel is driven based on the calculated driving force command value. A vehicle behavior control method characterized by applying force.

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