WO2021112215A1

WO2021112215A1 - Vehicle suspension control device, vehicle control device, and vehicle control method

Info

Publication number: WO2021112215A1
Application number: PCT/JP2020/045214
Authority: WO
Inventors: 山岡　史之
Original assignee: 日立Astemo株式会社
Priority date: 2019-12-06
Filing date: 2020-12-04
Publication date: 2021-06-10

Abstract

A left-front hydraulic cylinder (2) and a right-front hydraulic cylinder (3) are connected in a cross by a first connecting conduit (8) and a second connecting conduit (9), and a left-rear hydraulic cylinder (4) and a right-rear hydraulic cylinder (5) are connected in a cross by a third connecting conduit (14) and a fourth connecting conduit (15). The first and second connecting conduits (8) and (9) are connected by a front-side bridge passage (20), and a front-side bridge valve (21) is provided in the front-side bridge passage (20). The third and fourth connecting conduits (14) and (15) are connected by a rear-side bridge passage (23), and a rear-side bridge valve (24) is provided in the front-side bridge passage (23). Using signals from a steering angle sensor (46) and a torque sensor (47), a controller (33) determines whether steering is performed as a result of a driver's intent or as a result of input from a road surface, and changes a roll stiffness of a vehicle body in accordance with the determination by opening or closing the front and rear bridge valves (21) and (24).

Description

Vehicle suspension control device, vehicle control device and vehicle control method

The present disclosure relates to a vehicle suspension control device, a vehicle control device, and a vehicle control method used in, for example, a four-wheeled vehicle.

Generally, vehicles such as four-wheeled vehicles are equipped with a vehicle control device that controls the roll rigidity of the vehicle body by a suspension device, a stabilizer device, etc. to ensure stability during running. As such a vehicle control device, when the friction coefficient of the road surface with respect to the left and right wheels estimated based on the signals of the steering angle sensor, the vehicle speed sensor, etc. is different, the vehicle behavior is controlled by the active stabilizer and the vehicle behavior of each wheel is controlled. It is known that the steering force by the power steering device is controlled so as to cancel the change amount of the moment around the kingpin axis (see Patent Document 1). Further, the first roll rate calculated based on the steering torque acting on the steering when the frictional force on the road surface changes, and the second roll rate calculated based on the steering angle and the vehicle speed of the vehicle. Among them, those that control the roll rigidity based on the larger roll rate are known (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2009-173169 International Publication No. 2018/003828

According to the prior art, since complicated control is performed to determine the running state of the vehicle, there is a problem that it is difficult to quickly control the roll rigidity according to the running state of the vehicle.

An object of an embodiment of the present invention is to provide a vehicle suspension control device, a vehicle control device, and a vehicle control method capable of quickly controlling roll rigidity according to a running state of a vehicle.

One embodiment of the present invention is a vehicle suspension control device, which includes a force generating mechanism provided on the vehicle and capable of adjusting the force generated by the suspension device, and a control unit for controlling the generated force of the force generating mechanism. The control unit acquires steering torque acting direction information in a steering mechanism directly or indirectly connected to the wheels, and acquires steering direction information based on a physical quantity relating to steering of the steering mechanism. The generated force of the force generating mechanism is controlled so as to change the suspension rigidity according to the steering torque acting direction information and the steering direction information.

Further, one embodiment of the present invention is a vehicle control device provided on the vehicle and having a force generating mechanism capable of adjusting the force generated by the suspension device and a control unit for controlling the generated force in the force generating mechanism. The control unit acquires steering torque action direction information in the steering mechanism directly or indirectly connected to the wheels, acquires steering direction information based on a physical quantity related to steering of the steering mechanism, and obtains steering torque. A command to change the suspension rigidity according to the action direction information and the steering direction information is output to the force generation mechanism.

Further, one embodiment of the present invention is a vehicle control device provided in a vehicle and having a force generating mechanism capable of adjusting the generated force and a control unit for controlling the generated force of the force generating mechanism. The control unit outputs a command to change the suspension rigidity including the roll rigidity to the force generating mechanism according to the difference between the steering command to the steering mechanism provided in the vehicle and the steering state by the steering mechanism.

Further, one embodiment of the present invention is a vehicle control method executed by a control unit provided in a vehicle and for controlling the generated force in a force generating mechanism capable of adjusting the generated force, and is directly or indirectly with the wheels. The steering torque acting direction information in the steering mechanism connected to the steering mechanism is acquired, the steering direction information based on the physical quantity related to the steering of the steering mechanism is acquired, and the acquired steering torque acting direction information and the steering direction information are used. A command to change the suspension rigidity according to the above is output to the force generating mechanism.

According to one embodiment of the present invention, it is possible to determine the running state of the vehicle at an early stage and quickly control the roll rigidity according to the running state.

It is a system block diagram which shows the vehicle suspension control device by one Embodiment of this invention. It is a block diagram which shows the connection state of a controller, various sensors, and various actuators. It is the schematic which shows the steering mechanism, the steering angle sensor, the torque sensor and the like. It is a characteristic diagram which shows the change of the roll angle at the time of danger avoidance running. It is a characteristic diagram which shows the change of the roll angle at the time of traveling straight on a rough road. It is a characteristic diagram which shows the vertical vibration of the driver's seat floor at the time of running. It is a characteristic diagram which shows the output characteristic of a torque sensor. It is a code discrimination table which discriminates the sign of a torque sensor signal and a steering angle sensor signal. It is a flow chart which shows the control process which a controller executes when increasing the roll rigidity. It is a characteristic diagram which shows the relationship between a vehicle speed and a steering angle threshold value. It is a characteristic diagram which shows the relationship between a rudder angle and a roll rate regarding the timing of judgment of switching roll rigidity. It is an enlarged characteristic diagram of the XII part in FIG. It is a characteristic diagram which shows the relationship of a rudder angle, a roll rate, and a cylinder stroke when traveling on a rough road. It is a characteristic diagram which shows the vertical vibration of the driver's seat floor when driving on a rough road. It is a flow chart which shows the control process which a controller executes when the roll rigidity is lowered.

Hereinafter, a case where the vehicle suspension control device, the vehicle control device, and the vehicle control method according to the embodiment of the present invention are applied to a four-wheeled vehicle will be described as an example, and will be described in detail with reference to the attached drawings.

FIG. 1 shows the system configuration of the suspension device according to the embodiment. The suspension device 1 is provided between the vehicle body side and the four wheel sides (left front wheel FL, right front wheel FR, left rear wheel RL, right rear wheel RR), respectively. Each suspension device 1 has a suspension spring (not shown) and four hydraulic cylinders (left front hydraulic cylinder 2, right front hydraulic cylinder 3) provided between the vehicle body side and each wheel side in parallel with the suspension spring. , Left rear hydraulic cylinder 4 and right rear hydraulic cylinder 5) are included. In FIG. 1, each wheel position of the vehicle is shown as a left front wheel (FL), a right front wheel (FR), a left rear wheel (RL), and a right rear wheel (RR).

The left front hydraulic cylinder 2, the right front hydraulic cylinder 3, the left rear hydraulic cylinder 4, and the right rear hydraulic cylinder 5 are interposed between the vehicle body (upper spring) and each wheel (lower spring), and the vehicle body and each wheel. It constitutes a hydraulic damping force adjustment type shock absorber that cushions the vibration of the vehicle by expanding and contracting according to the relative movement of the wheel. That is, each of the hydraulic cylinders 2 to 5 constitutes a force generation mechanism capable of adjusting the force generated by the suspension device 1 between the vehicle body and each wheel. The left front hydraulic cylinder 2 on the left front wheel side has a cylinder (hydraulic cylinder) 6 made of a bottomed tubular tube, a piston 7 slidably inserted in the cylinder 6, and one end side fixed to the piston 7. The other end side is configured to include a piston rod 7A protruding outside the cylinder 6. The inside of the cylinder 6 is defined by a piston 7 into two chambers, an upper chamber A and a lower chamber B, upper and lower.

Similarly, the right front hydraulic cylinder 3, the left rear hydraulic cylinder 4, and the right rear hydraulic cylinder 5 each include a cylinder 6, a piston 7, and a piston rod 7A. The inside of each cylinder 6 is defined by a piston 7 into an upper chamber A and a lower chamber B.

The left front hydraulic cylinder 2 and the right front hydraulic cylinder 3 are connected by a cross between the first connection line 8 and the second connection line 9. That is, the first connection pipeline 8 extends left and right between the

hydraulic cylinders

2 and 3 so as to communicate between the lower chamber B of the left front hydraulic cylinder 2 and the upper chamber A of the right front hydraulic cylinder 3. Is arranged. The second connecting pipeline 9 is arranged so as to extend between the

hydraulic cylinders

2 and 3 in the left and right directions so as to communicate between the upper chamber A of the left front hydraulic cylinder 2 and the lower chamber B of the right front hydraulic cylinder 3. Has been done. In this way, the left front hydraulic cylinder 2 and the right front hydraulic cylinder 3 form a related suspension device connected via cross pipes (first and second connecting pipes 8 and 9).

A left front compression side damping force control valve 10 is provided at a connection portion between the upper chamber A of the left front hydraulic cylinder 2 and the second connection line 9. The left front compression side damping force control valve 10 variably adjusts the damping force of the oil liquid flowing out from the upper chamber A toward the second connecting pipe line 9 when the left front hydraulic cylinder 2 is compressed by electronic control, and the upper chamber A Attenuate the flow from. Further, the left front compression side damping force control valve 10 has a check valve 10A that allows the oil liquid to flow in from the second connecting pipe line 9 toward the upper chamber A and blocks the reverse flow. ..

On the other hand, a left front extension side damping force control valve 11 is provided at a connection portion between the lower chamber B of the left front hydraulic cylinder 2 and the first connection pipe line 8. The left front extension side damping force control valve 11 variably adjusts the damping force of the oil liquid flowing out from the lower chamber B toward the first connecting pipe line 8 when the left front hydraulic cylinder 2 is extended by electronic control, and the lower chamber B Attenuate the flow from. Further, the left front extension side damping force control valve 11 has a check valve 11A that allows the oil liquid to flow in from the first connecting pipe line 8 toward the lower chamber B and blocks the flow in the opposite direction. ..

A right front compression side damping force control valve 12 is provided at a connection portion between the upper chamber A of the right front hydraulic cylinder 3 and the first connection line 8. The right front compression side damping force control valve 12 variably adjusts the damping force of the oil liquid flowing out from the upper chamber A toward the first connecting pipe line 8 when the right front hydraulic cylinder 3 is compressed by electronic control, and the upper chamber A Attenuate the flow from. Further, the right front compression side damping force control valve 12 has a check valve 12A that allows the oil liquid to flow from the first connecting pipe line 8 toward the upper chamber A and blocks the flow in the opposite direction. ..

On the other hand, a damping force control valve 13 on the right front extension side is provided at a connection portion between the lower chamber B of the right front hydraulic cylinder 3 and the second connection pipe line 9. The right front extension side damping force control valve 13 variably adjusts the damping force of the oil liquid flowing out from the lower chamber B toward the second connecting pipe line 9 when the right front hydraulic cylinder 3 is extended by electronic control, and the lower chamber B Attenuate the flow from. Further, the right front extension side damping force control valve 13 has a check valve 13A that allows the oil liquid to flow in from the second connecting pipe line 9 toward the lower chamber B and blocks the reverse flow. .. These damping

force control valves

10, 11, 12, and 13 are controlled by drive signals from the controller 33, which will be described later, and the damping force during expansion and contraction of the left front hydraulic cylinder 2 and the right front hydraulic cylinder 3 is adjusted according to the traveling state of the vehicle. It will be adjusted.

The left rear hydraulic cylinder 4 and the right rear hydraulic cylinder 5 are connected by a cross by a third connecting pipe 14 and a fourth connecting pipe 15. That is, the third connecting pipeline 14 communicates between the lower chamber B of the left rear hydraulic cylinder 4 and the upper chamber A of the right rear hydraulic cylinder 5 in the left and right directions between the

hydraulic cylinders

4 and 5. It is arranged extending to. The fourth connecting pipeline 15 extends between the

hydraulic cylinders

4 and 5 in the left and right directions so as to communicate between the upper chamber A of the left rear hydraulic cylinder 4 and the lower chamber B of the right rear hydraulic cylinder 5. Is arranged. In this way, the left rear hydraulic cylinder 4 and the right rear hydraulic cylinder 5 form a related suspension device connected via cross pipes (third and fourth connecting pipes 14 and 15).

A left rear compression side damping force control valve 16 is provided at a connection portion between the upper chamber A of the left rear hydraulic cylinder 4 and the fourth connection pipe line 15. The left rear compression side damping force control valve 16 variably adjusts the damping force of the oil liquid flowing out from the upper chamber A toward the fourth connecting pipe line 15 when the left rear hydraulic cylinder 4 is compressed by electronic control, and the upper portion. Attenuates the flow from chamber A. Further, the left rear compression side damping force control valve 16 has a check valve 16A that allows the oil liquid to flow in from the fourth connecting pipe line 15 toward the upper chamber A and blocks the reverse flow. There is.

On the other hand, a damping force control valve 17 on the left rear extension side is provided at a connection portion between the lower chamber B of the left rear hydraulic cylinder 4 and the third connection pipe line 14. The left rear extension side damping force control valve 17 variably adjusts the damping force of the oil liquid flowing out from the lower chamber B toward the third connecting pipe 14 when the left rear hydraulic cylinder 4 is extended by electronic control, and lowers the lower part. Attenuate the flow from chamber B. Further, the left rear extension side damping force control valve 17 has a check valve 17A that allows the oil liquid to flow in from the third connecting pipe line 14 toward the lower chamber B and blocks the reverse flow. There is.

A right rear compression side damping force control valve 18 is provided at a connection portion between the upper chamber A of the right rear hydraulic cylinder 5 and the third connection line 14. The right rear compression side damping force control valve 18 variably adjusts the damping force of the oil liquid flowing out from the upper chamber A toward the third connecting pipe 14 when the right rear hydraulic cylinder 5 is compressed by electronic control, and the upper part. Attenuates the flow from chamber A. Further, the right rear compression side damping force control valve 18 has a check valve 18A that allows the oil liquid to flow in from the third connecting pipe line 14 toward the upper chamber A and blocks the reverse flow. There is.

On the other hand, a damping force control valve 19 on the right rear extension side is provided at a connection portion between the lower chamber B of the right rear hydraulic cylinder 5 and the fourth connection pipe line 15. The right rear extension side damping force control valve 19 variably adjusts the damping force of the oil liquid flowing out from the lower chamber B toward the fourth connecting pipe line 15 by electronic control, and damps the flow from the lower chamber B. .. Further, the right rear extension side damping force control valve 19 has a check valve 19A that allows the oil liquid to flow in from the fourth connecting pipe line 15 toward the lower chamber B and blocks the reverse flow. There is. These damping

force control valves

16, 17, 18, and 19 are controlled by drive signals from the controller 33, and the damping force when the left rear hydraulic cylinder 4 and the right rear hydraulic cylinder 5 expand and contract according to the running state of the vehicle. It will be adjusted.

The front bridge passage 20 connects between the first connecting line 8 and the second connecting line 9. A front bridge valve 21 is provided in the middle of the front bridge passage 20, and the front bridge passage 20 is communicated (opened) and blocked by the front bridge valve 21. The front bridge valve 21 is, for example, a two-port, two-position switching valve, and is a normally closed type (normally closed type) solenoid valve that holds a closed valve position when no power is applied. While the front bridge valve 21 holds the valve closed position, the connection between the first connecting line 8 and the second connecting line 9 is cut off. The front bridge valve 21 is switched from the valve closing position to the valve opening position by a drive signal from the controller 33, and communicates between the first and second connecting

pipelines

8 and 9 via the front bridge passage 20. As a result, the left front hydraulic cylinder 2 and the right front hydraulic cylinder 3 are in a state in which the upper chamber A and the lower chamber B communicate with each other.

Further, the front bridge passage 20 is provided with a bypass passage 22 that bypasses the front bridge valve 21, and the bypass passage 22 is provided with an orifice 22A. The orifice 22A has a minute size that does not affect the roll rigidity of the vehicle body by the suspension device 1, and is provided in parallel with the front bridge valve 21. The orifice 22A gradually reduces the pressure difference when a pressure difference occurs in front of and behind the front bridge valve 21 (between the left side passage 25 and the right side passage 26, which will be described later) due to a temperature change or the like.

The rear bridge passage 23 connects between the third connecting pipe 14 and the fourth connecting pipe 15. A rear bridge valve 24 is provided in the middle of the rear bridge passage 23, and the rear bridge valve 24 communicates with and shuts off the rear bridge passage 23. The rear bridge valve 24 is, for example, a two-port, two-position switching valve, and is a normally closed type (normally closed type) solenoid valve that holds a closed valve position when no power is applied. While the rear bridge valve 24 holds the valve closed position, the connection between the third connecting line 14 and the fourth connecting line 15 is cut off. The rear bridge valve 24 is switched from the valve closing position to the valve opening position by a drive signal from the controller 33, and communicates between the third and fourth connecting pipelines 14 and 15 via the rear bridge passage 23. As a result, the left rear hydraulic cylinder 4 and the right rear hydraulic cylinder 5 are in a state in which the upper chamber A and the lower chamber B communicate with each other.

The left side communication passage 25 is connected to the first connection line 8 and the third connection line 14, and is always in communication between the first connection line 8 and the third connection line 14. .. The right communication passage 26 is connected to the second connecting pipe 9 and the fourth connecting pipe 15, and is always in communication between the second connecting pipe 9 and the fourth connecting pipe 15 on the rear side. I'm letting you.

A left accumulator device 27 is provided in the middle of the left side passage 25. The left accumulator device 27 is provided at the tip of the oil guide pipe 28 branched from the middle of the left side passage 25, and is connected to the first connection line 8 and the third connection line 14 via the left side passage 25. Has been done. When the front and

rear bridge valves

21 and 24 are closed, the left accumulator device 27 has a lower chamber B of the left front hydraulic cylinder 2, an upper chamber A of the right front hydraulic cylinder 3, and a lower portion of the left rear hydraulic cylinder 4. Compensate for volume changes in the four oil chambers of the chamber B and the upper chamber A of the right rear hydraulic cylinder 5.

A damping valve 29 is provided in the middle of the oil guide line 28. The damping valve 29 is configured as a valve device in which the inflow control valve 29A, the outflow control valve 29B, and the orifice 29C are connected in parallel. When the oil liquid flows from the left side passage 25 toward the left accumulator device 27, the damping valve 29 gives a throttle resistance to the oil liquid by the orifice 29C and the inflow control valve 29A to apply a predetermined damping force. Generate and suppress vibration. On the other hand, when the oil liquid flows out from the left accumulator device 27 toward the left side passage 25, the orifice 29C and the outflow control valve 29B give a throttle resistance to the oil liquid to generate a predetermined damping force to suppress vibration. ..

A right accumulator device 30 is provided in the middle of the right side passage 26. The right accumulator device 30 is provided at the tip of the oil guide pipe 31 branched from the middle of the right side passage 26, and is connected to the second connection pipe 9 and the fourth connection pipe 15 via the right side passage 26. Has been done. In the right accumulator device 30, when the front and

rear bridge valves

21 and 24 are closed, the upper chamber A of the left front hydraulic cylinder 2, the lower chamber B of the right front hydraulic cylinder 3, and the upper part of the left rear hydraulic cylinder 4 Compensate for volume changes in the four oil chambers of the chamber A and the lower chamber B of the right rear hydraulic cylinder 5.

A damping valve 32 in which the inflow control valve 32A, the outflow control valve 32B, and the orifice 32C are connected in parallel is provided in the middle of the oil guide line 31. When the oil liquid flows from the right side passage 26 toward the right accumulator device 30, the damping valve 32 gives a throttle resistance to the oil liquid by the orifice 32C and the inflow control valve 32A to apply a predetermined damping force. Generate and suppress vibration. On the other hand, when the oil liquid flows out from the right accumulator device 30 toward the right side passage 26, the orifice 32C and the outflow control valve 32B give a throttle resistance to the oil liquid to generate a predetermined damping force to suppress vibration. ..

Therefore, when the front and

rear bridge valves

21 and 24 are closed, the oil liquid does not flow between the left side passage 25 and the right side passage 26, and when the vehicle turns in this state, the left side passage is connected. A pressure difference is generated between the passage 25 and the right side passage 26. For example, when the vehicle body tries to roll to the right when the vehicle turns to the left, the lower chamber B of the left front hydraulic cylinder 2, the upper chamber A of the right front hydraulic cylinder 3, the lower chamber B of the left rear hydraulic cylinder 4, and the right rear hydraulic cylinder. The upper chamber A of No. 5 is compressed, an oil liquid flows into the left accumulator device 27, and the pressure in the left side communication passage 25 rises.

At this time, the volume of the oil liquid flowing into the left accumulator device 27 is (cross-sectional area of cylinder 6-cross-sectional area of piston rod 7A) × (cylinder stroke) in the left front hydraulic cylinder 2 and the left rear hydraulic cylinder 4, and the right front hydraulic cylinder. The total volume is (cross-sectional area of cylinder 6) × (cylinder stroke) of the cylinder 3 and the right rear hydraulic cylinder 5. Therefore, in the left accumulator device 27, the gas volume decreases and the gas spring constant increases. Further, since the lower chamber B of the left front hydraulic cylinder 2 and the left rear hydraulic cylinder 4 becomes high pressure and the upper chamber A of the right front hydraulic cylinder 3 and the right rear hydraulic cylinder 5 becomes high pressure, rolling to the right side of the vehicle body is suppressed. Cylinder reaction force acts.

On the other hand, the volumes of the upper chamber A of the left front hydraulic cylinder 2, the lower chamber B of the right front hydraulic cylinder 3, the upper chamber A of the left rear hydraulic cylinder 4, and the lower chamber B of the right rear hydraulic cylinder 5 increase, and the volume increases from the right accumulator device 30. The oil liquid flows out and the pressure in the right side passage 26 decreases. At this time, the volumes of the oil liquid flowing out from the right accumulator device 30 are (cross-sectional area of cylinder 6) × (cylinder stroke) in the left front hydraulic cylinder 2 and the left rear hydraulic cylinder 4, and the right front hydraulic cylinder 3 and the right rear hydraulic cylinder. The total volume is (cross-sectional area of cylinder 6-cross-sectional area of piston rod 7A) x (cylinder stroke) in No. 5. Therefore, in the right accumulator device 30, the gas volume increases and the gas spring constant decreases. Further, since the upper chamber A of the left front hydraulic cylinder 2 and the left rear hydraulic cylinder 4 has a low pressure and the lower chamber B of the right front hydraulic cylinder 3 and the right rear hydraulic cylinder 5 has a low pressure, rolling to the right side of the vehicle body is suppressed. Cylinder reaction force acts. As a result, the roll rigidity (suspension rigidity) of the vehicle body by the suspension device 1 can be increased, and the turning performance during turning running can be improved.

Here, when the vehicle is traveling straight with the front and

rear bridge valves

21 and 24 closed, input (kickback) from the road surface may act on the left and right wheels. .. In this case, the roll rigidity of the vehicle body is increased by the action of the left and

right accumulator devices

27, 30 and the like as in the case of turning. As a result, the vehicle body vibrates in response to changes in the unevenness of the road surface, and the riding comfort is greatly impaired.

On the other hand, when the front and

rear bridge valves

21 and 24 are open, the left side passage 25 and the right side passage 26 communicate with each other via the front and

rear bridge passages

20 and 23. As a result, the upper chamber A and the lower chamber B of the hydraulic cylinders 2 to 5 are in communication with each other, and the hydraulic cylinders 2 to 5 smoothly expand and contract with a small resistance in an independent state with respect to the input from the road surface. can do. As a result, the vibration of the vehicle body due to the change of the road surface is suppressed, the riding comfort is improved, and the followability of each wheel to the change of the road surface is also improved. On the other hand, when the front and

rear bridge valves

21 and 24 are open, the inflow and outflow of oil liquid to the left and

right accumulator devices

27 and 30 is very small, which is the sum of the inflow and outflow of the piston rod 7A to each cylinder 6. It becomes a value. Therefore, the roll rigidity of the vehicle body by the suspension device 1 is lowered, and the turning performance is lowered.

Next, the operations of the compression side damping

force control valves

10, 12, 16, 18, the extension side damping

force control valves

11, 13, 17, 19, and the front and

rear bridge valves

21, 24, etc. are controlled. The controller 33 as a control unit that controls the damping force (generated force) of each of the hydraulic cylinders 2 to 5 will be described.

The controller 33 shown in FIG. 2 constitutes a control unit that controls the damping force (generated force) of each of the hydraulic cylinders 2 to 5. The controller 33 includes compression side damping

force control valves

10, 12, 16, 18, left front, right front, left rear, and right rear extension side damping

force control valves

11, 13, 17, right rear, right front, left rear, and right rear. An ECU (Electronic Control Unit) for a suspension device 1 that electronically controls the operations of 19, the front bridge valve 21, the rear bridge valve 24, and the like.

The controller 33 includes, for example, a microcomputer 34 (hereinafter referred to as a microcomputer 34) and a plurality of

drive circuits

35, 36, 37, 38, 39, 40, 41, 42, 43, 44 and the like. The drive circuit 35 outputs a drive signal to the front bridge valve 21, and the drive circuit 36 outputs a drive signal to the rear bridge valve 24. The drive circuit 37 outputs a drive signal to the left front compression side damping force control valve 10, and the drive circuit 38 outputs a drive signal to the left front extension side damping force control valve 11. The drive circuit 39 outputs a drive signal to the right front compression side damping force control valve 12, and the drive circuit 40 outputs a drive signal to the right front extension side damping force control valve 13. The drive circuit 41 outputs a drive signal to the left rear compression side damping force control valve 16, and the drive circuit 42 outputs a drive signal to the left rear extension side damping force control valve 17. The drive circuit 43 outputs a drive signal to the right rear compression side damping force control valve 18, and the drive circuit 44 outputs a drive signal to the right rear extension side damping force control valve 19.

For example, CAN (Controller Area Network) 45, steering angle sensor 46, torque sensor 47, vehicle speed sensor 48, etc. are connected to the input side of the microcomputer 34. A plurality of drive circuits 35 to 44 and the like are connected to the output side of the microcomputer 34. The microcomputer 34 has a memory 34A including, for example, a ROM, a RAM, a non-volatile memory, or the like. The memory 34A stores a processing program or the like for controlling the operation of the drive circuits 35 to 44 according to the traveling state of the vehicle.

CAN45 is a network necessary for data communication, and outputs various vehicle information including, for example, outside air temperature (ambient temperature), date and time information, load information such as load weight, and vehicle speed information. The steering angle sensor 46 is provided on the steering wheel 49A or the like of the steering mechanism 49 shown in FIG. The steering mechanism 49 has a steering wheel 49A, a steering shaft 49B, a steering gear, a tie rod (none of which are shown), and the like, and is directly (mechanically) connected to the left and right front wheels. The steering angle sensor 46 detects the steering angle of the steering wheel 49A, which is a physical quantity related to the steering of the steering mechanism, and outputs a signal corresponding to the steering angle. The torque sensor 47 is provided in the middle of the steering shaft 49B, detects the torque of the steering shaft 49B that is twisted when the steering wheel 49A is steered, and outputs a signal corresponding to the torque. The vehicle speed sensor 48 detects the traveling speed of the vehicle as the vehicle speed and outputs a signal corresponding to the vehicle speed. The output signal according to the steering angle of the steering wheel 49A, the output signal according to the torque of the steering shaft 49B, and the output signal according to the vehicle speed may be included in the vehicle information output from the CAN 45.

Based on the output signals from the CAN 45, the steering angle sensor 46, the torque sensor 47, the vehicle speed sensor 48, etc., the microcomputer 34 is a vehicle such as whether the vehicle is in a straight running state or in a turning running state including a lane change operation. Detects or estimates the running state (vehicle behavior) of. Then, the microcomputer 34 selectively drives the drive circuits 35 to 44 according to the vehicle behavior to control the roll rigidity of the vehicle body by the suspension device 1 and control the damping force of each of the hydraulic cylinders 2 to 5.

The drive circuits 35 to 44 are configured by, for example, a PWM (Pulse Width Modulation) circuit, and output a drive current according to a control signal from the microcomputer 34. The

drive circuits

35 and 36 supply the front and

rear bridge valves

21 and 24 with a drive current for opening the valve from the closed state and a holding current for holding the valve in the opened state. The drive circuits 37 to 44 include compression side damping

force control valves

10, 12, 16, 18 on the left front, right front, left rear, and right rear, and extension side damping force control valves 11, left front, right front, left rear, and right rear. The damping force during expansion and contraction of the left front, right front, left rear, and right rear

hydraulic cylinders

2, 3, 4, and 5 is arbitrarily adjusted according to the magnitude of the current values supplied to 13, 17, and 19. As a result, the ride quality, steering stability, and running stability of the vehicle are ensured according to the running state of the vehicle.

Here, when the front and

rear bridge valves

21 and 24 are closed to increase the roll rigidity of the vehicle body, for example, when traveling at high speed on a highway or the like, the lane shift is performed twice in succession to avoid danger. Even when the traveling (double lane change) is performed, the roll angle of the vehicle body can be kept small as shown by the characteristic line 50 in FIG. As a result, the behavior of the vehicle at the time of double lane change is stable, and safety can be ensured. On the other hand, when the double lane change is performed with the front and

rear bridge valves

21 and 24 open, the roll rigidity of the vehicle body becomes low, so that the vehicle body is shown as the characteristic line 51 in FIG. The roll angle of is large. As a result, the behavior of the vehicle at the time of double lane change becomes unstable.

On the other hand, when the front and

rear bridge valves

21 and 24 are closed to increase the roll rigidity of the vehicle body while traveling straight on a rough road with a large change in the road surface, the roll angle of the vehicle body is characteristic in FIG. It changes like line 52. On the other hand, when the front and

rear bridge valves

21 and 24 are opened to reduce the roll rigidity of the vehicle body, the roll angle of the vehicle body changes as shown in the characteristic line 53 in FIG. In this case, focusing on the vertical vibration of the driver's seat floor of the vehicle, as shown in FIG. 6, when the front and

rear bridge valves

21 and 24 are closed (characteristic line 54), the front and

rear bridge valves

21 , 24, the vertical vibration of the driver's seat floor becomes larger than when the valve is opened (characteristic line 55). In particular, when the front and

rear bridge valves

21 and 24 are closed, vibration in the frequency band of 2 (Hz) to 8 (Hz), which is highly sensitive to human vibration, increases. Therefore, when the front and

rear bridge valves

21 and 24 are closed while traveling straight on a rough road, the riding comfort is deteriorated and the followability of the wheels (tires) to the road surface is also lowered.

Here, the state in which the steering wheel 49A is steered by the driver's will is a case where the vehicle makes a turning run, a lane change, a double lane change for avoiding danger, etc., and the roll rigidity of the vehicle body is increased by the suspension device 1. As a result, we want to ensure steering stability and stable turning performance. The state in which the steering wheel 49A is steered by the driver's will is defined as a positive input to the steering mechanism 49.

On the other hand, when driving straight on a rough road, the steering mechanism 49 may be steered regardless of the driver's intention due to input (kickback) from the road surface due to unevenness or the like. When there is such an input from the road surface, the suspension device 1 lowers the roll rigidity of the vehicle body to reduce the transmission of vibration to the vehicle body, improve the riding comfort, and improve the road surface of the wheels (tires). It is a situation where we want to improve the followability to. In this way, the state in which the steering wheel 49A is steered by the road surface input regardless of the driver's intention is defined as the reverse input to the steering mechanism 49.

Therefore, whether the roll rigidity of the vehicle body by the suspension device 1 is set to a high state or a low state by determining whether the forward input or the reverse input is performed on the steering mechanism 49 when the vehicle is running. Can be controlled quickly. In the present embodiment, as a method of determining whether a forward input or a reverse input is performed on the steering mechanism 49, a signal corresponding to the steering angle of the steering wheel 49A output from the steering angle sensor 46 and a torque sensor 47 are used. A signal corresponding to the torque of the steering shaft 49B output from is used.

When the steering wheel 49A is steered by the driver's will, the steering direction information included in the output signal from the steering angle sensor 46 and the steering torque acting direction information included in the output signal from the torque sensor 47 are the same. As for the direction, when the steering mechanism 49 is steered by the input from the road surface (torque acts on the steering shaft 49B), the steering direction information included in the output signal from the steering angle sensor 46 and the torque sensor The steering torque action direction information included in the output signal from 47 is in the opposite direction. Then, the controller 33 acquires the steering torque action direction information in the steering mechanism 49 from the torque sensor 47, and also acquires the steering angle direction information based on the physical quantity (steering angle) related to the steering of the steering mechanism 49 from the steering angle sensor 46. , The roll rigidity (suspension rigidity) of the vehicle body is changed according to the steering torque action direction information and the steering angle direction information. That is, the controller 33 outputs a command to change the suspension rigidity including the roll rigidity of the vehicle body according to the difference between the steering command to the steering mechanism 49 and the steering state by the steering mechanism 49.

Here, as shown by the characteristic line 56 in FIG. 7, the sign of the signal of the output signal from the torque sensor 47 differs depending on the twisting direction of the torque sensor 47, for example, the twisting direction is the clockwise direction (CW). ) Is positive (+), and counterclockwise (CCW) is negative (-). As a result, as shown in the code discrimination table of FIG. 8, the code of the output signal from the steering angle sensor 46 (steering direction information) and the code of the output signal from the torque sensor 47 (steering torque acting direction information) are changed. By discriminating, it is possible to determine whether the steering mechanism 49 is in the normal input state or the reverse input state.

For example, the output signal from the steering angle sensor 46 when the steering wheel 49A is steered in the right turning direction is positive (+), and the output signal when the steering wheel 49A is steered in the left turning direction is negative (-). .. Further, the signal output when the torque sensor 47 is twisted in the right turning direction is set to positive (+), and the signal output when the torque sensor 47 is twisted in the left turning direction is set to negative (−). As a result, the determination of whether the steering mechanism 49 is in the normal input state or the reverse input state can be divided into four modes.

The first aspect in FIG. 8 is a case where the steering wheel 49A is steered in the right turning direction by the driver's will, and the sign (+) of the output signal from the torque sensor 47 and the output from the steering angle sensor 46. The sign (+) of the signal matches. In this case, since it is determined that the steering mechanism 49 is in a positive input state, control is performed to increase the roll rigidity of the vehicle body. The second aspect is a case where the driver does not steer the steering wheel 49A (straight running state) and a torque is applied to the steering shaft 49B in the right turning direction by an input from the road surface, and the torque sensor The sign (+) of the output signal from 47 and the sign (−) of the output signal from the steering angle sensor 46 do not match. In this case, since it is determined that the steering mechanism 49 is in the reverse input state, the roll rigidity of the vehicle body is controlled to be lowered.

The third aspect is a case where the driver has not steered the steering wheel 49A (straight running state), and a torque in the left turning direction is applied to the steering shaft 49B by an input from the road surface, and the torque sensor 47 The sign (−) of the output signal from the steering angle sensor 46 and the sign (+) of the output signal from the steering angle sensor 46 do not match. In this case, since it is determined that the steering mechanism 49 is in the reverse input state, the roll rigidity of the vehicle body is controlled to be lowered. The fourth aspect is the case where the steering wheel 49A is steered in the left turning direction by the driver's will, and the sign (-) of the output signal from the torque sensor 47 and the sign (-) of the output signal from the steering angle sensor 46. ) Matches. In this case, since it is determined that the steering mechanism 49 is in a positive input state, control is performed to increase the roll rigidity of the vehicle body.

As described above, in the present embodiment, the direction of the steering torque action direction information included in the output signal from the torque sensor 47 and the direction of the steering direction information included in the output signal from the steering angle sensor 46 are the same. When in the same direction, the controller 33 determines that a positive input has been made to the steering mechanism 49, and closes the front and

rear bridge valves

21 and 24 so that the roll rigidity (suspension rigidity) of the vehicle body becomes high. Let me. As a result, the oil liquid flows in and out of the left and

right accumulator devices

27 and 30, and the roll rigidity of the vehicle body is increased, so that stable turning performance can be obtained.

On the other hand, when the direction of the steering torque acting direction information included in the output signal from the torque sensor 47 and the direction of the steering direction information included in the output signal from the steering angle sensor 46 are different, the controller 33 determines the steering mechanism 49. It is determined that the reverse input has been performed with respect to the above, and the front and

rear bridge valves

21 and 24 are opened so that the roll rigidity (suspension rigidity) of the vehicle body becomes low. As a result, the inflow and outflow of the oil liquid to the left and

right accumulator devices

27 and 30 becomes a very small value only the sum of the inflow and outflow of the piston rod 7A to each cylinder 6, and the roll rigidity of the vehicle body becomes low. As a result, the vibration of the vehicle body due to the change of the road surface is suppressed, the riding comfort is improved, and the followability of each wheel to the change of the road surface is also improved.

Here, focusing on the order of the output signals from various sensors connected to the controller 33 and the phase of the vehicle behavior, when a positive input is made to the steering mechanism 49, the torque signal from the torque sensor 47 is first generated. It is output, the steering angle speed signal from another steering angle sensor (not shown) is output second, the steering angle signal from the steering angle sensor 46 is output third, and the lateral acceleration sensor (not shown) is output fourth. The lateral acceleration signal from (not shown) is output, the roll rate signal from the spring vertical acceleration sensor (not shown) is output fifth, and the roll angle signal from the spring vertical acceleration sensor (not shown) is output sixth. It is output.

On the other hand, when the reverse input to the steering mechanism 49 is performed, the torque signal from the torque sensor 47 is output first, the rudder angle speed signal from the other rudder angle sensor is output second, and the rudder is steered third. The steering angle signal from the angle sensor 46 is output. Therefore, based on the sign discrimination between the output signal from the torque sensor 47 and the output signal from the steering angle sensor 46, it is possible to quickly and accurately determine whether the steering mechanism 49 is in the normal input state or the reverse input state. It is possible to quickly control the roll rigidity of the vehicle body according to the traveling state of the vehicle.

Next, when the vehicle is running, the controller 33 (microcomputer 34) executes the suspension device 1 from a state in which the roll rigidity is low (a state in which the front and

rear bridge valves

21 and 24 are opened) in order to increase the roll rigidity. The control process will be described with reference to FIG. The steps in the flow chart shown in FIG. 9 use the notation "S", and for example, step 1 is shown as "S1".

When the control process shown in FIG. 9 starts, the front and

rear bridge valves

21 and 24 are in the open state in S1. In S2, the torque sensor signal T, which is an output signal from the torque sensor 47, is read, and in S3, it is determined whether or not the absolute value of the read torque sensor signal T is equal to or greater than a preset torque threshold value. When it is determined as "NO" in S3, the counter n is reset (n = 0) in S4 and the process returns to S2.

When it is determined as "YES" in S3, the steering angle sensor signal θ, which is an output signal from the steering angle sensor 46, is read in S5, and the process proceeds to S6. In S6, it is determined whether or not the absolute value of the read steering angle sensor signal θ is equal to or greater than a preset steering angle threshold value. In this case, as shown by the characteristic line 57 in FIG. 10, the steering angle threshold value becomes smaller as the vehicle speed increases, and the steering angle threshold value becomes zero (0) at a predetermined vehicle speed or higher. Then, when it is determined as "NO" in S6, the counter n is reset (n = 0) in S7 and the process returns to S2.

When it is determined as "YES" in S6, it is determined in S8 whether or not the sign of the torque sensor signal T and the sign of the steering angle sensor signal θ have the same sign. When it is determined as "NO" in S8, it is the second or third aspect shown in the code discrimination table of FIG. 8, so it is determined in S9 that it is an input from the road surface (reverse input), and the counter n is set in S10. Reset (n = 0) and return to S2. On the other hand, when it is determined as "YES" in S8, it is the first or fourth aspect shown in the code discrimination table of FIG. The counter n is advanced in S12 (n = n + 1).

Next, in S13, the cycle time Δt is integrated with the counter n to calculate the time t during which the positive input state continues, and then in S14, the calculated time t is a predetermined determination time set in advance. It is determined whether or not it is t0 or more. If "NO" is determined in S14, the system returns to S2, and if "YES" is determined, the front and

rear bridge valves

21 and 24 are closed in S15. As a result, the roll rigidity of the vehicle body is increased, and the steering stability and running stability of the vehicle during turning can be ensured.

In this way, in a transient running state in which the vehicle shifts from straight running to turning running, the roll rigidity of the vehicle body is changed from a low roll rigidity to a high roll rigidity according to the damping force control for each of the hydraulic cylinders 2 to 5. Can be switched to. That is, the suspension rigidity including the roll rigidity includes the transient rigidity when the vehicle is running. In this case, as shown by the characteristic line 57 in FIG. 10, the steering angle threshold value becomes smaller as the vehicle speed increases, and the steering angle threshold value becomes zero (0) at a predetermined vehicle speed or higher. As a result, it is considered that the higher the vehicle speed, the easier it is to control to increase the roll rigidity.

Here, FIG. 11 shows changes over time in the steering angle of the steering wheel 49A and the roll rate of the vehicle body when the vehicle performs a double lane change assuming danger avoidance, and FIG. 12 shows the XII portion in FIG. Is an enlargement of. The characteristic line 58 in FIGS. 11 and 12 indicates the phase of the steering angle of the handle 49A, and the characteristic line 59 is the roll rate (roll behavior of the vehicle body) when the front and

rear bridge valves

21 and 24 are closed. The characteristic line 60 shows the phase of the roll rate (roll behavior of the vehicle body) when the front and

rear bridge valves

21 and 24 are opened. As shown in FIGS. 11 and 12, the phase of the steering angle (characteristic line 58) of the steering wheel 49A is ahead of the phase of the roll behavior of the vehicle body (characteristic lines 59 and 60).

Therefore, in the present embodiment, it is possible to quickly and accurately determine whether the steering mechanism 49 is in the normal input state or the reverse input state based on the torque sensor signal T and the steering angle sensor signal θ. Moreover, as shown in FIG. 12, the front and

rear bridge valves

21 and 24 have the front and

rear bridge valves

21 and 24 with respect to the determination time t for closing the front and

rear bridge valves

21 and 24 from the valve open state (increasing the roll rigidity). The switching time t'from the valve open state to the valve closed state is sufficiently short. Therefore, the roll rigidity of the vehicle body can be quickly switched according to the traveling state of the vehicle.

Moreover, the steering angle sensor 46 and the torque sensor 47 are standard equipment on vehicles equipped with an electric power steering system (Electric Power Steering). Therefore, the signals from the steering angle sensor 46 and the torque sensor 47 already mounted on the vehicle can be used, and there is no need to add new sensors. Therefore, it is possible to simplify the system for controlling the roll rigidity according to whether the steering mechanism 49 has a forward input or a reverse input, and it is possible to contribute to cost reduction.

Note that the control process of FIG. 9 exemplifies a control for increasing the roll rigidity of the vehicle body when it is determined that the steering mechanism 49 is in a positive input state. However, when it is determined that the steering mechanism 49 is in the reverse input state, the controller 33 determines the road surface state based on, for example, the magnitudes of the torque sensor signal T and the steering angle sensor signal θ, and controls each compression side damping force. The

valves

10, 12, 16, 18 and the extension side damping

force control valves

11, 13, 17, 19 can be controlled. As a result, it is possible to suppress the fluttering of each wheel (unsprung mass) and improve the riding comfort when traveling on rough roads.

Here, FIG. 13 shows the steering angle (characteristic line 61) of the steering wheel 49A and the roll rate (characteristic line 62) of the vehicle body when the vehicle is traveling straight on a rough road having a road surface shape with opposite phases. The change with time of the cylinder stroke (characteristic line 63) of the hydraulic cylinder on the front wheel side (left front hydraulic cylinder 2 or right front hydraulic cylinder 3) is shown. Here, when there is a reverse input from the road surface to the steering mechanism 49 due to a change in the road surface, the value of the steering angle sensor signal θ intermittently exceeds the threshold value (dead zone). This situation corresponds to the second or third aspect of the code discrimination table of FIG. 8, and the code of the torque sensor signal T and the code of the steering angle sensor signal θ are different. Therefore, the control for increasing the roll rigidity of the vehicle body is not performed, and the front and

rear bridge valves

21 and 24 are opened and the roll rigidity is kept low. As a result, it is possible to prevent an unnecessary increase in roll rigidity that does not match the traveling state, and it is possible to improve the riding comfort when traveling on a rough road.

In this case, focusing on the vertical vibration of the driver's seat floor of the vehicle, as shown in FIG. 14, when the front and

rear bridge valves

21 and 24 are opened (characteristic line 64), the front and

rear bridge valves

21 , 24 is closed (characteristic line 65), and the vertical vibration of the driver's seat floor is smaller. In particular, vibration in the frequency band of 2 (Hz) to 8 (Hz), which is highly sensitive to humans, can be suppressed to a small value. Therefore, when traveling straight on a rough road, by keeping the front and

rear bridge valves

21 and 24 in the open state, the riding comfort can be improved and the followability of the wheels (tires) to the road surface can be improved. ..

As described above, according to the present embodiment, it is possible to quickly determine whether the steering mechanism 49 is subjected to the forward input or the reverse input based on the signals from the steering angle sensor 46 and the torque sensor 47. Can be done. When the steering mechanism 49 is positively input, the front and

rear bridge valves

21 and 24 are closed to control the roll rigidity by the left and

right accumulator devices

27 and 30, and the damping force control valves 10, respectively. By controlling the damping force by 11, 12, 13, 16, 17, 18, and 19, it is possible to improve the steering stability and running stability of the vehicle. Further, at the time of reverse input to the steering mechanism 49, the front and

rear bridge valves

21 and 24 are opened to lower the roll rigidity, improve the riding comfort, and follow the wheel to the road surface (rough road running performance). Can be enhanced.

Next, when the vehicle is running, the controller 33 (microcomputer 34) executes control to reduce the roll rigidity from the state where the roll rigidity of the vehicle body is high (the front and

rear bridge valves

21 and 24 are closed). The process will be described with reference to FIG.

When the control process shown in FIG. 15 starts, the front and

rear bridge valves

21 and 24 are in the closed state in S21. In S22, the torque sensor signal T, which is an output signal from the torque sensor 47, and the rudder angle sensor signal θ, which is an output signal from the rudder angle sensor 46, are read. In S23, LPF (Low Pass Filter) processing is performed on the torque sensor signal T and the steering angle sensor signal θ. In this LPF processing, a high frequency component having a frequency (intermediate frequency) or higher that is an intermediate value between the on-spring resonance frequency and the under-spring resonance frequency, that is, a high frequency component having a frequency higher than the frequency that the driver can steer is removed. In the following S24, it is determined whether or not the vehicle speed is equal to or less than the preset first set speed V1, and if it is determined as "YES", the process proceeds to S25.

In S25, it is determined whether or not the absolute value of the torque sensor signal T1 when the vehicle speed is equal to or less than the first set speed V1 is less than the preset torque threshold value. If "NO" is determined in S25, the counter n is reset (n = 0) in S26 and the process returns to S22. If "YES" is determined in S25, the process proceeds to S27, and whether or not the absolute value of the steering angle sensor signal θ1 when the vehicle speed is equal to or less than the first set speed V1 is less than the preset steering angle threshold value. Is determined. If "NO" is determined in S27, the counter n is reset (n = 0) in S28 to return to S22, and if "YES" is determined, the counter n is advanced in S29 (n = n + 1). ..

In the following S30, by integrating the cycle time Δt on the counter n, the vehicle speed is equal to or less than the first set speed V1, the absolute value of the torque sensor signal T1 is less than the torque threshold, and the absolute value of the steering angle sensor signal θ1 is steering. The time t in which the state of being less than the angle threshold continues is calculated. Then, in S31, it is determined whether or not the calculated time t is equal to or longer than a preset predetermined determination time t0. If "NO" is determined in S31, the system returns to S22, and if "YES" is determined, the front and

rear bridge valves

21 and 24 are opened in S32. As a result, the roll rigidity of the vehicle body is lowered, and the riding comfort when traveling on a rough road can be improved.

On the other hand, when it is determined as "NO" in S24, that is, when the vehicle speed is larger than the preset first set speed V1, the speed shifts to S33 and the vehicle speed is set to the preset second set speed V2. It is determined whether or not it is as follows. In this case, the second set speed V2 is set to be equal to or higher than the first set speed V1 (V1 ≦ V2). If it is determined as "NO" in S33, it returns to S22, and if it is determined as "YES", it proceeds to S34.

In S34, it is determined whether or not the absolute value of the torque sensor signal T2 when the vehicle speed is the second set speed V2 or less is less than the preset torque threshold value. In this case, the torque sensor signal T2 is set to the torque sensor signal T1 or less when the vehicle speed is the first set speed V1 or less (T1 ≧ T2). Then, when it is determined as "NO" in S34, the counter n is reset (n = 0) in S35 and the process returns to S22. If "YES" is determined in S34, the process proceeds to S36, and whether or not the absolute value of the steering angle sensor signal θ2 when the vehicle speed is the second set speed V2 or less is less than the preset steering angle threshold value. Is determined. In this case, the steering angle sensor signal θ2 is set to the steering angle sensor signal θ1 or less when the vehicle speed is the first set speed V1 or less (θ1 ≧ θ2). Then, when "NO" is determined in S36, the counter n is reset (n = 0) in S37 to return to S22, and when "YES" is determined in S36, the process proceeds to S29, and thereafter. Executes the control process of.

In this way, the operation of shifting the roll rigidity of the vehicle body from a high state to a low state is prohibited when the vehicle speed is higher than a predetermined speed (second set speed V2), and the vehicle steering stability and running stability are prohibited. Sex can be ensured. Further, when the roll rigidity of the vehicle body is changed from a high state to a low state, the degree of urgency related to safety is low. Therefore, in the control process described above, in order to reduce the control frequency, the sign discrimination between the steering angle sensor signal θ and the torque sensor signal T is performed even when the direction of the steering torque acting direction information and the direction of the steering direction information are different. Instead, the damping force control is switched according to the magnitude of the absolute value of the torque sensor signal T and the absolute value of the rudder angle sensor signal θ.

Specifically, when the absolute value of the torque sensor signal T and the absolute value of the steering angle sensor signal θ are less than the respective threshold values for a predetermined time or longer, the front and

rear bridge valves

21, 24 By opening the valve, the roll rigidity of the vehicle body can be lowered and the riding comfort can be improved. In this case, the torque threshold value and the rudder angle threshold value are set according to the vehicle speed. For example, when the vehicle speed is larger than the first set speed V1 and is equal to or less than the second set speed V2, the torque threshold value and the rudder angle threshold are set. The angle threshold is set small. As a result, even when the vehicle speed is relatively high, when the torque sensor signal T2 and the steering angle sensor signal θ2 are small, the front and

rear bridge valves

21 and 24 can be opened to improve the riding comfort.

In the embodiment, the controller 33 executes the control process shown in FIG. 15 when the roll rigidity of the vehicle body is lowered from a high state, and the absolute values of the torque sensor signal and the steering angle sensor signal are each set to a predetermined threshold value. The configuration in which the front and

rear bridge valves

21 and 24 are opened when the state of less than or equal to is continued for a predetermined time or longer is illustrated. However, the present invention is not limited to this, and for example, the steering angular velocity is detected in addition to the torque sensor signal and the steering angle sensor signal, and the absolute values of the torque sensor signal, the steering angle sensor signal, and the steering angular velocity are each less than a predetermined threshold value. The front and

rear bridge valves

21 and 24 may be opened when a certain state continues for a predetermined time or longer.

Further, in the embodiment, a vehicle provided with a steering mechanism 49 directly (mechanically) connected to the left and right front wheels is illustrated. However, the present invention is not limited to this, and can be applied to a vehicle provided with a steering mechanism such as a steering wheel in which the steering wheel and the left and right front wheels are not indirectly connected.

Further, in the embodiment, as a force generating mechanism capable of adjusting the force generated by the suspension device 1, a related suspension suspension in which the left and right sides of the damping force adjusting type hydraulic cylinders 2 to 5 are cross-piped will be described as an example. There is. However, the present invention is not limited to this, and the force generation mechanism may be configured by using, for example, a hydraulic active suspension, an active stabilizer, an air suspension, an electromagnetic suspension, or the like.

Further, the specific numerical values described in the embodiment are shown as an example, and are not limited to the illustrated numerical values.

Next, as the vehicle suspension control device included in the above embodiment, for example, the one described below can be considered.

The first aspect is a vehicle suspension control device, which includes a force generating mechanism provided on the vehicle and capable of adjusting the force generated by the suspension device, and a control unit for controlling the generated force of the force generating mechanism. The control unit acquires steering torque action direction information in a steering mechanism directly or indirectly connected to the wheels, acquires steering direction information based on a physical quantity related to steering of the steering mechanism, and obtains the steering direction information. It is characterized in that the generated force of the force generating mechanism is controlled so as to change the suspension rigidity according to the steering torque acting direction information and the steering direction information.

In the second aspect, in the first aspect, when the control unit is in the same direction state in which the directions of the steering torque action direction information and the steering direction information are the same, the force is increased so that the suspension rigidity is increased. When the generated force of the generating mechanism is increased and the directions of the steering torque acting direction information and the steering direction information are different, the generated force of the force generating mechanism is set to be the same as that in the same direction state so that the suspension rigidity is lowered. It is characterized by controlling it so that it is weaker than that.

The third aspect is a vehicle control device provided in the vehicle and having a force generating mechanism capable of adjusting the force generated by the suspension device and a control unit for controlling the generated force in the force generating mechanism. The control unit acquires steering torque acting direction information in the steering mechanism directly or indirectly connected to the wheels, acquires steering direction information based on a physical quantity related to steering of the steering mechanism, and obtains the steering torque acting direction information. It is characterized in that a command for changing the suspension rigidity according to the steering direction information is output to the force generating mechanism.

A fourth aspect is a vehicle control method executed by a control unit for controlling the generated force in a force generating mechanism provided in the vehicle and capable of adjusting the generated force, which is directly or indirectly connected to the wheels. The steering torque acting direction information in the steering mechanism is acquired, the steering direction information based on the physical quantity related to the steering of the steering mechanism is acquired, and according to the acquired steering torque acting direction information and the steering direction information. It is characterized in that a command for changing the suspension rigidity is output to the force generating mechanism.

A fifth aspect is a vehicle control device provided in the vehicle and having a force generating mechanism capable of adjusting the generated force and a control unit for controlling the generated force of the force generating mechanism. Is characterized in that a command for changing the suspension rigidity including the roll rigidity is output to the force generating mechanism according to the difference between the steering command to the steering mechanism provided in the vehicle and the steering state by the steering mechanism. ..

As a sixth aspect, in the second aspect, the suspension rigidity includes a transient rigidity due to damping force control.

As the seventh aspect, in the third and fifth aspects, the suspension rigidity includes a transient rigidity due to damping force control.

As an eighth aspect, in the first aspect, when the directions of the steering torque acting direction information and the steering direction information are different, the damping force is applied according to the magnitude of the absolute value of the steering torque and / or the steering angle. Switch control.

As a ninth aspect, in the third aspect, when the directions of the steering torque acting direction information and the steering direction information are different, the damping force is applied according to the magnitude of the absolute value of the steering torque and / or the steering angle. It is characterized by switching the control.

1 Suspension device 2 Left front hydraulic cylinder (force generation mechanism)
3 Right front hydraulic cylinder (force generation mechanism)
4 Left rear hydraulic cylinder (force generation mechanism)
5 Right rear hydraulic cylinder (force generation mechanism)
33 Controller (control unit)
46 Steering angle sensor 47 Torque sensor 49 Steering mechanism

Claims

It is a vehicle suspension control device
A force generation mechanism that is installed in the vehicle and can adjust the force generated by the suspension device,
It has a control unit that controls the generated force of the force generating mechanism.
The control unit
Acquires steering torque action direction information in the steering mechanism that is directly or indirectly connected to the wheels,
Obtaining steering direction information based on physical quantities related to steering of the steering mechanism,
A vehicle suspension control device characterized in that the generated force of the force generating mechanism is controlled so as to change the suspension rigidity according to the steering torque acting direction information and the steering direction information.
When the steering torque acting direction information and the steering direction information are in the same direction in the same direction, the control unit increases the generated force of the force generating mechanism so as to increase the suspension rigidity.
When the directions of the steering torque acting direction information and the steering direction information are different, the force generated by the force generating mechanism is controlled to be weaker than that in the same direction state so that the suspension rigidity is lowered. The vehicle suspension control device according to claim 1.
A force generation mechanism that is installed in the vehicle and can adjust the force generated by the suspension device,
A vehicle control device having a control unit for controlling the generated force in the force generating mechanism.
The control unit
Acquires steering torque action direction information in the steering mechanism that is directly or indirectly connected to the wheels,
The steering direction information based on the physical quantity related to the steering of the steering mechanism is acquired, and the steering direction information is acquired.
A vehicle control device characterized in that a command for changing the suspension rigidity according to the steering torque acting direction information and the steering direction information is output to the force generating mechanism.
It is a vehicle control method executed by a control unit for controlling a generated force in a force generating mechanism provided in a vehicle and capable of adjusting the generated force.
Acquires steering torque action direction information in the steering mechanism that is directly or indirectly connected to the wheels,
Obtaining steering direction information based on physical quantities related to steering of the steering mechanism,
A vehicle control method characterized in that a command for changing the suspension rigidity according to the acquired steering torque acting direction information and the steering direction information is output to the force generating mechanism.
A force generation mechanism that is installed in the vehicle and can adjust the generated force,
A vehicle control device including a control unit that controls the generated force of the force generating mechanism.
The control unit
Vehicle control characterized in that a command for changing suspension rigidity including roll rigidity is output to the force generating mechanism according to a difference between a steering command to the steering mechanism provided in the vehicle and a steering state by the steering mechanism. apparatus.
The vehicle suspension control device according to claim 2, wherein the suspension rigidity includes a transient rigidity due to damping force control.
The vehicle control device according to claim 3 or 5, wherein the suspension rigidity includes a transient rigidity due to damping force control.
The first aspect of claim 1, wherein when the directions of the steering torque acting direction information and the steering direction information are different, the damping force control is switched according to the magnitude of the absolute value of the steering torque and / or the steering angle. Vehicle suspension control device.
The third aspect of claim 3, wherein the damping force control is switched according to the magnitude of the absolute value of the steering torque and / or the steering angle when the directions of the steering torque acting direction information and the steering direction information are different. Vehicle control device.