JPH0495514A - Roll control device for vehicle - Google Patents

Abstract

PURPOSE:To prevent the amount of roll control from becoming excessive to avoid the generation of back roll by reducing-correcting a steady roll angle to small values when the coefficient of friction becomes smaller enough for the wheels to be likely to slip on the road surface. CONSTITUTION:Flow control valves B and opening and closing valves C correspendingly are controlled by an electron control device 102 to control the road clearance and roll of a vehicle body based on signals from road clearance sensors 87-90, a steering torque sensor 92, a yaw-rate sensor 93, a lateral acceleration sensor 94. Motors A and motors D are controlled by the electron control device 102 to reduce nose drive, squat, and roll of the vehicle based on signals from aspeed sensor 95, a steering angle sensor 96, a throttle opening sensor 97, a brake sensor 98. In this case, a steady angle is corrected so that the smaller it becomes, the smaller the ratio of steering torque to the steady steering torque, and the road clearance adjusting means A-D are controlled based on the steady roll angle after the correction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to roll control of vehicles such as automobiles, and more particularly to a vehicle height adjustable roll control device.

[Prior Art] As one type of roll control device for vehicles such as automobiles, for example, as described in Japanese Patent Application Laid-Open No. 62-295714, the roll of the vehicle body is controlled by adjusting the difference in vehicle height between the left and right sides. A vehicle height adjusting means such as an active suspension configured as above, a vehicle speed detecting means, a steering angle detecting means,
and control means for estimating a steady roll angle (lateral acceleration) of the vehicle body from the vehicle speed detected by the vehicle speed detection means and the steering angle detected by the steering angle detection means, and controlling the vehicle height adjustment means based on the steady roll angle. Vehicle roll control devices are already known.

According to such a roll control device, roll control can be performed with better responsiveness than in the case where the actual lateral acceleration of the vehicle body is detected and the roll of the vehicle body is controlled according to the lateral acceleration.

[Problem to be solved by the invention] However, when a vehicle turns while driving on a road surface with a small coefficient of friction, the wheels may slip on the road surface, and when such slippage occurs, the lateral acceleration of the vehicle body that actually occurs is smaller than the lateral acceleration estimated from the vehicle speed and steering angle,
In the roll control device as described above, reverse roll of the vehicle body may occur due to the roll control amount being excessive compared to the lateral acceleration of the vehicle body that actually occurs.

Therefore, a first object of the present invention is to solve the above-mentioned problem in the conventional roll control device configured to control the roll of the vehicle body based on the lateral acceleration estimated from the vehicle speed and the steering angle. To provide an improved roll control device that prevents reverse roll of a vehicle body even if the wheels slip on the road surface due to turning while traveling on a road surface with a small coefficient.

In addition, if countersteering is performed in response to a drift phenomenon when the vehicle is turning, the turning direction of the vehicle and the steering direction will be different, so the steady roll angle φs estimated and corrected from the vehicle speed and steering angle will be When roll control is performed, the roll of the vehicle body is accelerated due to the difference between the actual turning direction of the vehicle and the steering direction.

Accordingly, a second object of the present invention is to provide an improved roll control device that prevents the roll of a vehicle body from being accelerated even when countersteering is performed in response to a drift phenomenon.

Furthermore, when countersteering is performed to cope with the drift phenomenon when the vehicle turns, when the wheels, especially the rear wheels, regain grip on the road surface, the amount of roll control of the vehicle body suddenly becomes insufficient. This may cause the vehicle to roll over.

Therefore, the third object of the present invention is to improve the vehicle body so that it does not roll back even when the wheels regain grip on the road surface when countersteering is performed in response to a drift phenomenon. It is an object of the present invention to provide a roll control device that has been improved.

[Means for Solving the Problems] According to the present invention, the above-mentioned first object includes: (1) a vehicle height adjusting means configured to control the roll of the vehicle body by adjusting the left and right vehicle height difference; A vehicle speed detection means for detecting vehicle speed, a steering angle detection means for detecting a steering angle, a steering torque detection means for detecting a steering torque T, and a vehicle speed detected by the vehicle speed detection means and a steering angle detection means for detecting the steering angle detection means. The steady roll angle φs and steady steering torque Ts of the vehicle body are calculated from the steering angle, and if the ratio of T to Ts is small, φ
A calculation control means for calculating a corrected steady roll angle φse by correcting φs so that s becomes smaller, and controlling the vehicle height adjustment means based on the corrected steady roll angle φsc. achieved by the device.

According to the present invention, in the configuration (1) above, (1) the roll control device includes means for determining whether or not countersteering is being performed; The arithmetic and control unit has a lateral acceleration detecting means for detecting a lateral acceleration, and when it is determined that countersteering is being performed, the arithmetic and control device determines a corrected steady roll angle according to the lateral acceleration detected by the lateral acceleration detecting means. This is achieved by a roll control device configured to calculate φsC.

According to the present invention, in the configuration (2) above, (1) the roll control device has a yaw rate detection means for detecting the yaw rate of the vehicle body, and the arithmetic control device has a counter. When it is determined that steering is being performed, if the absolute value of the yaw rate detected by the yaw rate detection means is less than a predetermined value, the steering angle detection means and the lateral acceleration detection means detect the yaw rate, respectively. This is achieved by a roll control device configured to calculate the corrected steady roll angle φse based on the steering angle and lateral acceleration.

The vehicle height adjustment means in the present invention may have any structure as long as it can control the roll of the vehicle body by adjusting the difference in vehicle height between the left and right sides. It may be an active suspension configured to be able to adjust the height of the vehicle individually, an active stabilizer configured to be able to relatively adjust the left and right vehicle heights, or the like.

In addition, the "steady roll angle φs" in this application refers to the roll angle that occurs in the vehicle body when the vehicle makes a steady circular turn on a dry asphalt road surface (friction coefficient μ of 0.8) at a vehicle speed and steering angle. "Steady steering torque" means the steering torque required to maintain the vehicle turning in a steady circle on a dry asphalt road surface at the vehicle speed and steering angle.

[Operation of the Invention] According to the above-mentioned configuration (2), the calculation control means calculates the steady roll angle φs and the steady steering torque Ts of the vehicle body from the vehicle speed and the steering angle.
The corrected steady roll angle φs is calculated by correcting φs so that the smaller the ratio of the actual steering torque T to the steady steering torque Ts, the smaller the steady roll angle φs.
C is calculated, and the vehicle height adjustment means is controlled based on the corrected steady roll angle φsc.

The magnitude of the actual steering torque T corresponds to the magnitude of the friction coefficient of the road surface, and therefore the ratio T / T s corresponds to the magnitude of the friction coefficient of the road surface. The more slippery the wheels are on the road surface, the smaller the value of φsc is corrected, and as a result, when the wheels are slipping on the road surface, the amount of roll control is reduced compared to the lateral acceleration of the vehicle body that actually occurs when the wheels are slipping on the road surface. By controlling the roll control amount to an amount corresponding to the actual lateral acceleration, the occurrence of reverse roll is avoided.

Further, according to the configuration (2) above, the roll control device has means for determining whether or not countersteering is being performed and lateral acceleration detection means for detecting the lateral acceleration of the vehicle body, and the arithmetic control device has a means for determining whether or not countersteering is being performed, and a lateral acceleration detection means for detecting lateral acceleration of the vehicle body, and the arithmetic control device has a means for determining whether or not countersteering is being performed. When it is determined that this has been carried out, the corrected steady roll angle φsc is calculated in accordance with the lateral acceleration detected by the lateral acceleration detection means.

Therefore, when countersteering is performed, roll control is not performed based on the steady roll angle φs estimated and corrected from the vehicle speed and steering angle, but rather the steady roll angle after correction is calculated according to the actual lateral acceleration of the vehicle body. Since roll control is performed based on the angle φsC, promotion of roll due to the difference between the turning direction and the steering direction of the vehicle is avoided.

Furthermore, according to the configuration (2) above, the roll control device has a yaw rate detection means for detecting the yaw rate of the vehicle body, and the arithmetic control device detects the yaw rate when it is determined that countersteering is being performed. When the absolute value of the yaw rate detected by the detection means is less than a predetermined value, the corrected steady roll angle φsc is calculated based on the steering angle and lateral acceleration detected by the steering angle detection means and the lateral acceleration detection means, respectively. ing.

Therefore, when countersteering is performed to cope with drift phenomena when the vehicle turns, just before the wheels, especially the rear wheels, regain grip on the road surface, the steady roll is corrected based on the steering angle and lateral acceleration. Since the angle φse is calculated, the occurrence of rolling back of the vehicle body when the wheels regain grip on the road surface is avoided.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

[Example 1] Fig. 1 is a schematic configuration diagram showing the hydraulic circuit of the vehicle height adjusting means in one embodiment of the roll control device according to the present invention;
This figure is a block diagram showing an electronic control device that controls the vehicle height adjusting means shown in FIG. 1.

In these figures, 1 indicates a reserve tank that stores oil as a working fluid, and is 2fr.

2fl, 2rr, and 2rl indicate actuators provided corresponding to the front right wheel, front left wheel, rear right wheel, and rear left wheel of the vehicle, which are not shown in the figure, respectively. Each actuator has a cylinder 3 and a piston 4 connected to the vehicle body and suspension arm, respectively, which are not shown in the figure.
By supplying and discharging oil to and from the cylinder chamber 5 defined by these as a working fluid chamber, the vehicle height at the corresponding position can be increased or decreased. The actuator is configured so that the vehicle height at the corresponding position is increased or decreased by supplying or discharging a working fluid such as oil to the working fluid chamber, and the pressure within the working fluid chamber is increased or decreased in accordance with the bounce and rebound of the wheel. It may be any device, such as a hydraulic ram device, as long as it is

The reserve tank 1 is connected to a branch point 11 through a conduit 10 having an oil pump 6, a flow control valve 7, an unload valve 8, and a check valve 9 in the middle.

The pump 6 is driven by the engine 12 to pump up oil from the reserve tank 1 and discharge high-pressure oil, and the flow control valve 7 controls the flow rate of the oil flowing in the conduit 10 on the downstream side. is designed to be controlled. The unload valve 8 detects the pressure in the conduit 10 downstream of the check valve 9, and when the pressure exceeds a predetermined value, the pressure is passed through the conduit 13 to the conduit 10 upstream of the pump 6.
By returning the oil to zero, the pressure of the oil in the conduit 10 on the downstream side of the check valve 9 is maintained below a predetermined value. The check valve 9 is designed to prevent oil from flowing backward in the conduit 10 from the branch point 11 toward the unload valve 8.

The branching point 11 is connected to the cylinder chambers 5 of the actuators 2fr and 2rl through conduits 20 and 21, which have check valves 14 and 15, electromagnetic on-off valves 16 and 17, and electromagnetic flow control valves 18 and 19, respectively, in the middle. Further, the branch point 11 is connected to the branch point 23 by a conduit 22,
The branch point 23 is connected to the actuator 2 by conduits 30 and 31, which have check valves 24 and 25, electromagnetic shut-off valves 26 and 27, and electromagnetic flow control valves 28 and 29, respectively.
rr and 2' are connected to the cylinder chamber 5 of 1.

Thus actuators 2rr, 2N, 2"", 2"1
The cylinder chamber 5 has conduits 10.20 to 22.30.31.
Oil is selectively supplied from the reserve tank 1 via the on-off valve 16, and the oil supply and flow rate in this case are controlled by the on-off valve 16, as will be explained in detail later.
．． 17.26.27 and flow control valve 18.19.28.
29 is appropriately controlled.

The portions of the conduits 20 and 21 between the flow control valves 18 and 19 and the actuators 2fr and 2f1 are provided with electromagnetic flow control valves 32 and 33 and an electromagnetic shut-off valve 3, respectively, in the middle.
Conduits 36 and 37 with 4 and 35 are connected in communication to a return conduit 38 which communicates with the reserve tank 1. Similarly, the portions of the conduits 30 and 31 between the flow control valves 28 and 29 and the actuators 2 and 2rl are a conduit 43 and a conduit having electromagnetic flow control valves 39 and 40 and electromagnetic on-off valves 41 and 42 in the middle, respectively. 44,
It is communicatively connected to a return conduit 38 .

Thus actuators 2rr, 2rl, 2rr, 2''
The oil in cylinder 5 of 1 is connected to conduits 36 to 38.43.4
The oil is selectively discharged to the reserve tank l through 4, and in that case, the oil discharge and its flow rate are as follows.
As will be explained in detail later, on-off valves 34, 35.
41, 42 and flow rate control valves 32, 33, 39, 40 are controlled as appropriate.

In the illustrated embodiment, the on-off valve 16.17.26.27
．． 34, 35, 41, and 42 are normally closed on-off valves, and when the corresponding solenoids are not energized, they maintain the closed state as shown in the diagram and cut off communication with the corresponding conduit to respond. When the solenoid is energized, the valve opens to allow communication with the corresponding conduit. Also flow control valve 18.19.28.29.32.33
．． 39 and 40 change the degree of throttling by changing the voltage or duty of the drive current applied to the corresponding solenoid, thereby controlling the flow rate of oil flowing in the corresponding conduit. There is.

Each of the conduits 20.21.30.31 has a check valve 14.
Accumulators 45 to 48 are connected in communication at a position upstream of 15.24.25. Each accumulator is composed of an oil chamber 49 and an air chamber 50 that are separated from each other by a diaphragm, and compensates for and responds to pressure changes in the conduit 10 caused by oil pulsation caused by the pump 6 and the action of the unload valve 8. A pressure accumulating effect is exerted on the oil in the conduit 20.21.30.31.

Flow control valves 18 for each of the conduits 20.21.30.31
．． Main springs 59 to 62 are connected to the portion between 19.28.29 and the corresponding actuator by conduits 55 to 58 having variable throttle devices F51 to 54 in the middle, respectively. A secondary spring 7 is connected between each variable throttle device and the main spring by conduits 67 to 70 having normally open on-off valves 63 to 66 in the middle.
1 to 74 are connected. The main springs 59 to 62 each consist of an oil chamber 75 and an air chamber 76 that are separated from each other by a diaphragm, and similarly, the sub springs 71 to 74
each consists of an oil chamber 77 and an air chamber 78 separated from each other by a diaphragm.

Thus, when the volumes of the cylinder chambers 5 of each actuator change due to the bounce and rebound of the wheels (not shown in FIG. 1), the cylinder chambers and oil chambers 75, 77
The oil inside flows through the variable throttling devices 51 to 54, and the vibration damping effect is exerted by the flow resistance at that time. In this case, the degree of throttling of each variable throttling device is controlled by the corresponding motors 79 to 82, so that the damping force C can be switched to three stages of high, medium, and low, and the on-off valves 63 to 66 are selectively opened and closed by the corresponding motors 83 to 86,
The spring constant K can be switched to two levels: high and low.

Furthermore, each actuator 2 fr, 2 f'l, 2
Vehicle height sensors 87 to 90 are provided at positions corresponding to rr and 2 rl, respectively. These vehicle height sensors detect the vehicle height at the corresponding position by measuring the relative displacement between the cylinder 3 and the piston 4 or a suspension arm (not shown), respectively, and calculate the vehicle height at the corresponding position. The electronic control unit 10 shown in FIG.
It is designed to output to 2.

Flow control valve 18.19.28.29.32.33.39
．． 40 and corresponding on-off valves 16.17.26.
27, 34, 35, 41, 42) are electronic sensors based on signals from vehicle height sensors 87 to 90, steering torque sensor 92) yaw rate sensor 93, and lateral acceleration sensor 94 in order to control vehicle height and roll of the vehicle body. It is controlled by a control device 102. Further, the motors 79 to 82 and the motors 83 to 86 are connected to a vehicle speed sensor 95, as will be explained later, in order to reduce nose dive, swipe, and roll of the vehicle.
, a steering angle sensor 96, a throttle opening sensor 97, and a brake sensor 98, and are controlled by an electronic control unit 102.

The electronic control unit 102 includes a microcomputer 103, as shown in FIG.

The microcomputer 103 may have a general configuration as shown in FIG. 2, and includes a central processing unit (CPU) 104 and a read-only memory (ROM) 1.
05, random access memory (RAM) 106,
It has an input port device 107 and an output port device 108, which are connected to each other by a bidirectional common bus 109.

The input port device 107 has information on whether the selected vehicle height is high (H), normal (N), or low (L) from a vehicle height selection switch 110 provided in the vehicle interior and operated by the driver. A switch function signal indicating . The input port device 107 also includes signals indicating the actual vehicle heights Hfr, Hfl, Hrr, and Hrl detected by the vehicle height sensors 87, 88, 89, and 90, respectively, a steering torque sensor 92), a yaw rate sensor 93, and a lateral acceleration sensor. 94, vehicle speed sensor 95, steering angle sensor 96,
Signals indicating steering torque T1 yaw rate Y1 lateral acceleration Gl, vehicle speed V, steering angle δ (right turn is positive), throttle opening θ, and braking state detected by throttle opening sensor 97 and braking sensor 98 respectively correspond to each other. amplifier 8
7a-90a, 92a-98a,? Lutibrexa 1
11, it is inputted via an A/D converter 112.

ROMI 05 is the standard vehicle height Hhf, Hhr, and Hnf as the target vehicle height of the front wheels and rear wheels when the vehicle height selection switch 110 is set to high, normal, and low.
' and Hnr, Hlf and Hlr (Hhr>Hnf>
HIf, Hhr>Hnr>Hlr), and also stores maps and the like corresponding to graphs shown in FIGS. 5 to 11, which will be explained later. Based on the calculation results, the CPU 104 outputs the output port device 108 to the on-off valve and flow control valve provided corresponding to each actuator, and the corresponding D/A converter 117a to 117h.
and 118a to 118h, amplifiers 119a to 119
h and 120a to 120h, and selectively outputs control signals, and also drives motors 79 to 82 that drive variable throttle devices 51 to 54 and motor 83 that drives on-off valves 63 to 66.
~86 to output port device 108, each corresponding D/
A converters 121a to 121d and 123a-1
23d, amplifiers 122a-122d and 124a-12
Control signals are selectively output for 4d in red.

A display 116 connected to the output port device 108 displays whether the reference vehicle height selected by the vehicle height selection switch 110 is high, normal, or low, and also displays damping force (not shown in the figure). The selection of the selection switch is the normal manual mode where the damping force C is fixedly controlled to low (normal), the sports manual mode where the damping force C is fixedly controlled to medium (sport), and the driving state of the vehicle. Normal-based auto mode, in which the damping force is automatically controlled between low and high, and sports-based auto mode, in which the damping force is automatically controlled between medium and high (hard). However, it is now displayed.

Next, the operation of the roll control device shown in FIGS. 1 and 2 will be explained with reference to the flowcharts shown in FIGS. 3 and 4.

Incidentally, FIG. 4 is a flowchart showing the routines executed in steps 14 to 17 of the flowchart shown in FIG. 3, respectively. Furthermore, the flags FUi (f - f'r, fl, rr, r
l) relates to whether drive current is being supplied to the flow control valve 18.19.28.29 and on-off valve 16.17.26.27 on the supply side, and 0 indicates that no drive current is being supplied. 1 indicates that the drive current is being supplied.

Flag FDI indicates discharge side flow control valve 32.33.39.
40 and on/off valves 34, 35, 41, and 42. 0 indicates a state in which the drive current is not supplied, and 1 indicates a state in which the drive current is supplied. It shows. Flag FTi is a flag related to the setting of damping force C and spring constant, and 0 indicates that damping force K is in base mode (low for normal base, medium for sports base) and spring constant K is low. 1 indicates that the damping force and spring constant are high. Furthermore, flag Fi collectively refers to these flags FUi and FDi 5FTj.

In the first step 10, the vehicle height sensors 87 to 9 are
0 detected vehicle height Hi (i - fr.

rl, rrSrl), steering torque sensor 92
) Yaw rate sensor 93, lateral acceleration sensor 94, vehicle speed sensor 95, steering angle sensor 96, throttle opening sensor 9
7. Steering torque T, yaw rate Y, lateral acceleration Gl, vehicle speed V1 and steering angle δ detected by the brake sensor 98, respectively
, the throttle opening θ, a signal indicating the braking state, a signal of the switch function S input from the vehicle height selection switch 110, and a signal of the switch function input manually from the damping force selection switch (not shown in the figure). is carried out, and the process then proceeds to step 20.

In step 20, based on the vehicle speed V and steering angle δ read in step 10, the map in the ROM 105 corresponding to the graph shown in FIG. The steady roll angle φs is calculated with the direction as positive, and then the process proceeds to step 21.

In step 12, it is determined whether or not countersteering is being performed, and when it is determined that countersteering is being performed, the process proceeds to step 24, and if countersteering is not being performed. If it is determined that there is no such person, the process advances to step 22.

Note that the determination as to whether or not countersteering is being performed may be performed, for example, by determining whether the product of the steering angle δ and yaw rate Y read in step 10 is positive or negative, and when this product is positive, countersteering is being performed. What has not been done and
Further, when this product is negative, it may be determined that countersteering is being performed.

In step 22, based on the vehicle speed V and steering angle δ read in step 10, the steady steering torque Ts is calculated from a map corresponding to the graph shown in FIG. 6, and then the process proceeds to step 23. move on.

In step 23, based on the steering torque T1 read in step 10, the steady roll angle φs and the steady steering torque Ts calculated in steps 20 and 22, the graph shown in FIG. The corrected steady roll angle φse is calculated from the corresponding map, and then the process proceeds to step 30.

In step 24, it is determined whether the absolute value of the yaw rate Y read in step 10 is less than the reference value yo, and if it is determined that IYI<Yo, the step Proceed to 26, IYIkuY. If it is determined that this is not the case, the process advances to step 25.

In step 25, based on the lateral acceleration Gl read in step 1o, a corrected steady roll angle φse is calculated from a map corresponding to the graph shown in FIG.
After that, proceed to step 3o.

In step 26, based on the steering angle δ and lateral acceleration Gl read in step 1o, the corrected steady roll angle φsc is calculated from a map corresponding to the graph shown in FIG.
is calculated, and then the process proceeds to step 30.

In step 30, based on the vehicle speed V read in step 1o, a time constant T(
V) is calculated, and then the process proceeds to step 40.

In step 40, step 23, 25, or 26
and φse and T(V) calculated in step 3o.
Based on the formula (1) below, the roll angle compensation value Φ
sc is calculated, and then the process proceeds to step 50. Naotake (
S in 1) is a Laplace operator, and k is a constant.

In step 50, a target roll angle φa (0 in the illustrated embodiment, but when the absolute value is less than φ0 (described later) and Φsc is positive and negative) is determined according to the following equation (2). The deviation φd between the roll angle compensation value ΦSe and the roll angle compensation value ΦSe is calculated, and the process then proceeds to step 60.

φd-φa-φsc (2) In step 60, the absolute value of the roll angle deviation φd exceeds the control threshold φo (a positive constant close to 0). When it is determined that 1φdl>φ0, the process advances to step 70, and 1φdl>φ
When it is determined that the value is not 0, the process advances to step 120.

In step 70, based on the roll angle deviation φd calculated in step 5o, the drive duty of the drive current supplied to each flow control valve is determined from a map corresponding to the graph shown in FIG. D11 is calculated, and then the process proceeds to step 80.

In step 80, it is determined whether the roll angle deviation φd is negative or not. When it is determined that φd<0, the process proceeds to step 90, and it is determined that φd<0. When the determination has been made, the process advances to step 100.

At step 90, flags FUrl, FUrl.

F D frSF D rrSF T i is set to 1, and the process then proceeds to step 110.

In step 100, the flag FUfrSFUrr,
F D fL F D rL F T i is set to 1, and the process then proceeds to step 110.

In step 110, if step 90 has been passed, the flow control valve 1 on the supply side for the left front wheel and the left rear wheel is
Drive duties Dr+ and Drl to 9 and 29, respectively.
A drive current is supplied to the discharge side flow control valves 32 and 39 for the right front wheel and the right rear wheel, respectively, through a drive duty D.
A drive current is supplied to f'r and I)rr, and at the same time a drive current is supplied to the corresponding on-off valve, thereby increasing the vehicle height on the left side and decreasing the vehicle height on the right side. Conversely, if step 100 is passed, the drive current is supplied to the supply side flow control valves 18 and 28 for the right front wheel and the right rear wheel at the drive duties Drr and Drr, respectively, and Flow control valve 3 on the discharge side for rings
Drive duties Dr+ and Drl to 3 and 40, respectively.
At the same time, a drive current is supplied to the corresponding opening/closing valve, thereby increasing the vehicle height on the right side and decreasing the vehicle height on the left side. In addition, in this step, the damping force C and the spring constant K are set to high values by controlling the energization of the motors 79 to 82 and 83 to 86, regardless of whether steps 90 or 100 are passed. be done. When step 110 is completed, step 1
Return to 0.

In step 120, when the switch function S is H, the reference vehicle heights Hbfr and Hbf of the front wheels are Hhf'.
and the reference vehicle height Hbrr and Hbrl of the rear wheels are H.
hr and the switch function S is N, then
If the reference vehicle heights Hbfr and Hbf'1 of the front wheels are set to Hnf and the reference vehicle heights Hbrr and Hbrl of the rear wheels are set to nnr, and the switch function S is , the reference vehicle heights Hbf'r and Hbf'1 of the front wheels are set to Hbrl is set to Hlr, and the reference vehicle height Hbrr and Hbrl of the rear wheels are set to Hlr, and then the process proceeds to step 130.

In step 130, the actual vehicle height H for each wheel is determined.
The deviation Hi between i and the reference vehicle height Hbi is calculated according to the following formula, and then the process proceeds to step 140.

ΔOld=Old-Hbj In step 140, the control flow shown in FIG. 4 is executed as i-rr to adjust the vehicle height of the right front wheel, and then the process proceeds to step 150.

In step 150, the control flow shown in FIG. 4 is executed as 1-fl to adjust the vehicle height of the left front wheel, and then the process proceeds to step 160.

In step 160, the control flow shown in FIG. 4 is executed as 1-r'' to adjust the vehicle height for the right rear wheel, and then the process proceeds to step 170.

In step 170, the control flow shown in FIG. 4 is executed as i-rl, thereby adjusting the vehicle height of the left rear wheel. After step 170 is performed, the process returns to step 1.

Although not shown in the plan view, in this embodiment, when a condition that causes a nose dive or a short auto is detected, the degree of aperture of the variable aperture devices 51 to 54 is increased to control these conditions. The damping force C is switched to high, and the on-off valve 6 is
A control routine for closing valves 3 to 66 and switching the spring constant K to high is executed by an interrupt.

Next, the flowchart shown in FIG. 4, which is executed in steps 140 to 170, will be explained.

In the first step 201, the vehicle height deviation △H1
It is determined whether or not ΔHi exceeds the control threshold H, and when it is determined that ΔHi > ΔHo, the process proceeds to step 202, and it is determined that ΔHi > ΔH. When the determination is made, the process advances to step 205.

In step 202, it is determined whether the vehicle height deviation △H1 is less than △H, and when it is determined that it is not △H1 - △H, the process proceeds to step 203. ,
When it is determined that ΔHi<-ΔHo, the process advances to step 208.

In step 203, all flags F1 are reset to 0, and the process then proceeds to step 204.

In step 204, the flow control valve 18.19.28
．． 29.32.33.39.40 and on-off valve 16.17
．． 26.27.34.35.41.42 is de-energized, vehicle height adjustment is thereby stopped, and motor 79 is de-energized.
By controlling the energization to 82 and 83 to 86, the damping force C is set to the best mode and the spring constant K is set to low.

In step 205, the drive duty DO of the drive current supplied to the flow control valve on the discharge side is determined from the map corresponding to the graph shown in FIG. 11 based on the vehicle height deviation ΔH1.
i is calculated, and then the process proceeds to step 206.

In step 206, the flag FDj is set to 1, the flag FTi is reset to 0, and then the process proceeds to step 207.

In step 207, a drive current is supplied to the corresponding discharge side flow control valve at the drive duty DO+, and at the same time, a drive current is supplied to the corresponding opening/closing valve, thereby executing the vehicle height reduction adjustment. The damping force C is set to base mode, and the spring constant K is set to low.

In step 208, the drive duty DO of the drive current supplied to the flow control valve on the supply side is determined from the map corresponding to the graph shown in FIG. 11 based on the vehicle height deviation ΔHj.
i is calculated, and then the process proceeds to step 209.

In step 209, the flag FUi is set to 1, the flag FTj is reset to 0, and the process then proceeds to step 210.

In step 210, a drive current is supplied to the corresponding flow control valve on the supply side at the drive duty DO+, and at the same time, a drive current is supplied to the corresponding opening/closing valve, thereby executing an increase adjustment of the vehicle height. and the damping force C and spring constant K are set high.

Thus, in steps 201 to 210, when the vehicle is not under conditions that cause the vehicle body to roll more than a predetermined amount, the vehicle height at the position corresponding to each wheel is determined to be within the target vehicle height region Hb.
It is adjusted to i±△Ho. Vehicle height control threshold △H
o is preferably a value substantially equal to or smaller than the absolute value 1ΔHi l of the vehicle height deviation of each wheel when the absolute value φd of the roll angle deviation is φ0.

Therefore, ΔHo may be set for each wheel or individually for the front wheel and the rear wheel.

The operation of the illustrated embodiment will now be described with reference to the flowcharts shown in FIGS. 3 and 4.

First, when the vehicle is traveling in a straight line, a negative determination is made in step 60 of the flowchart of FIG. If the vehicle height deviation △H1 is within the target vehicle height range Hbi±△HO,
In steps 201 and 202 of FIG. 4, a negative determination is made, and therefore the vehicle height is not adjusted to increase or decrease, but the damping force or base mode is set, and the spring constant is set to low, thereby improving the ride of the vehicle. It is intended to improve comfort. If the vehicle height deviation exceeds △Hi or △H, step 201
In step 205, the drive duty DOi is calculated, and this drive duty supplies the drive current to the discharge side flow control valve, and at the same time, the drive current is supplied to the corresponding opening/closing valve. As a result, the vehicle height is adjusted to be reduced to the target vehicle height range Hbi±ΔH.

Also, if the vehicle height deviation △Hi is less than 1H,
A YES determination is made in step 202, a drive duty DOi is calculated in step 208, a drive current is supplied to the flow control valve on the supply side by this drive duty, and at the same time, a drive current is supplied to the corresponding opening/closing valve. A drive current is supplied, thereby increasing the vehicle height to the target vehicle height range Hbi±ΔH.

Furthermore, when the vehicle is turning, if the absolute value of φd is less than or equal to φ0, a negative determination is made in step 60, and as a result, steps 120 to
By executing step 170, the vehicle height Hi is controlled to the target vehicle height region Hbi±ΔHo. Also, the absolute value of φd is φ
If the value exceeds 0, a YES determination is made in step 60, a drive duty Dli is calculated in step 70, the sign of φd is determined in step 80, and if φd is 0, step 90 is performed. If φd is not zero, the process moves from step 100 to step 110, where the vehicle height is adjusted to prevent the vehicle body from rolling, and the damping force and spring constant are switched to high.

Furthermore, by unwinding the handle, 1φd 1
If ≦φ0, a negative determination is made in step 60, and the process returns to normal vehicle height adjustment in steps 120 to 1700.

In this case, during a normal turn without countersteering, a negative determination is made in step 21, a steady steering torque Ts is calculated based on the steering angle δ and the vehicle speed V in step 22, and the process proceeds to step 23. At ratio T/Ts
The corrected steady roll angle φsC is calculated by increasing or decreasing φs depending on the magnitude of φs. As mentioned above, the ratio T/
Since Ts corresponds to the magnitude of the friction coefficient μ of the road surface, the smaller the friction coefficient, that is, the more easily the wheels slip on the road surface, the smaller the value of φse is corrected, thereby making it easier for the wheels to slip on the road surface. If this occurs, the occurrence of reverse roll due to an excessive roll control amount is avoided.

If countersteering is being performed in response to vehicle drift, a YES determination is made in step 21, a NO determination is made in step 24, and lateral steering is performed in step 25. φse is calculated based on the acceleration.

Therefore, the acceleration of roll caused by the difference between the turning direction and the steering direction of the vehicle is avoided.

Furthermore, when countersteer is being performed, the absolute value of the yaw rate Y becomes a small value immediately before the rear wheels regain their grip on the road surface, so a YES determination is made in step 24. , in step 26, φsc is calculated based on the lateral acceleration G1 and the steering angle δ. Therefore, the occurrence of rolling of the vehicle body when the rear wheels regain grip on the road surface is avoided.

In the above-mentioned embodiment, the means for supplying and discharging oil to and from the cylinder chamber of each actuator is a flow control valve.
This means may be a pressure control valve. Also step 4
The calculation of the compensation value ΦSC at 0 is omitted, and step 5
0, the steady roll angle φd after compensation may be calculated according to φd=φa−φsC.

Although the roll direction determination in step 80 is performed by determining the sign of the roll angle deviation φd, it may also be determined by determining the sign of the roll angle compensation value φSC. Further, in step 110, only the damping force and spring constant on the outer turning wheel side may be set to high, and the damping force and spring constant on the turning inner wheel side may be set to base mode and low, respectively. Further, φ0 may be variably set in stages or continuously according to the preferences of the driver or occupant of the vehicle, in which case φ0 is set in the electronic control device shown in FIG. Means are provided.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Effects of the Invention] According to the above-mentioned configuration (2), the ratio T/TS corresponds to the magnitude of the friction coefficient of the road surface, and the smaller the friction coefficient, that is, the more easily the wheels slip on the road surface, the more φsC is corrected to a small value, thus preventing the amount of roll control from becoming excessive compared to the lateral acceleration of the vehicle body that actually occurs when the wheels are slipping on the road surface, and reducing the amount of roll control. Since the amount is controlled to correspond to the actual lateral acceleration, it is possible to avoid the occurrence of reverse roll when the vehicle runs on a road surface with a small coefficient of friction.

Furthermore, according to the above configuration (■), when countersteering is performed, roll control is not performed based on the steady roll angle φs estimated and corrected from the vehicle speed and steering angle, but according to the actual lateral acceleration of the vehicle body. Since roll control is performed based on the corrected steady roll angle φsC calculated by .

Furthermore, according to configuration (2) above, when countersteering is performed in response to a drift phenomenon when the vehicle turns, the steering angle and the Since the corrected steady roll angle φsC is calculated based on the lateral acceleration, it is possible to avoid rolling back of the vehicle body when the wheels regain grip on the road surface.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the hydraulic circuit of the vehicle height adjusting means in one embodiment of the roll control device according to the present invention, and FIG.
3 is a block diagram showing an electronic control device that controls the vehicle height adjustment means shown in FIG. 1; FIG. 3 is a flowchart showing the control flow of the embodiment shown in FIGS. 1 and 2; Figure 4 shows step 14 of the flowchart shown in Figure 3.
5 is a graph showing the relationship between vehicle speed V and steering angle δ and steady roll angle φs, and FIG. 6 is a graph showing the relationship between vehicle speed V and steering angle δ and steady steering torque. 7 is a graph showing the relationship between the ratio T / T s and the ratio φsc/φs. FIG. 8 is a graph showing the relationship between the lateral acceleration G1 and the steady roll angle φsC. The figure shows steering angle δ and lateral acceleration G1
Figure 10 shows the relationship between the roll angle deviation φd and the drive duty Dlj of the drive current supplied to the flow control valve of each actuator for roll control by adjusting the vehicle height. FIG. 11 is a graph showing the relationship between the vehicle height deviation ΔHj and the drive duty DO+ of the drive current supplied to the flow control valve of each actuator for vehicle height adjustment. ]... Reserve tank, 2f", 2rl, 2rr, 2
r...Actuator, 3...Cylinder, 4...
piston. 5... Cylinder chamber, 6... Oil pump, 713.
Flow control valve, 8...Unload valve, 9-mount check valve, 10.
...Conduit, 11... Branch point, 12... Engine, 1
3... Conduit. 14.15...Check valve, 16.17...Solenoid on-off valve. 18.19...Electromagnetic flow control valve, 20-22...Conduit. 23... Branch point, 24.25... Check valve, 26.2
7... Solenoid on/off valve, 28.29... Solenoid flow control valve, 30.31... Conduit, 32.33... Solenoid flow control valve. 34.35... Solenoid on-off valve, 36.37... Conduit,
38...Return conduit, 39.40...Solenoid flow control valve, 41.42...Solenoid on-off valve, 43.44...Conduit, 45-48...Accumulator, 4...Oil Chamber, 50...Air chamber, 51-54...Variable throttle device, 55-58...Conduit, 59-62...Main spring, 63-66...Opening/closing valve, 67-70...・Conduit, 7
1-74... Sub-spring. 75...Oil chamber, 76...Air chamber, 77...Oil chamber. 78...Air chamber, 79-86...Motor 87-9
0...Vehicle height sensor, 87a-91a...Amplifier, 92
...Steering torque sensor, 93...Yaw rate sensor, 9499. Lateral acceleration sensor, 95...vehicle speed sensor,
96... Steering angle sensor 197... Throttle opening sensor 98... Braking sensor, 92a to 98a... Amplifier, 102... Electronic control device, 103... Microcomputer, 104... Central processing unit (CPU)
, 105... Read only memory (ROM), 106
... Random access memory (RAM), 107.
...Input port device, 108...Output port device, 1
09...Common bus, 110...Vehicle height selection switch,
111...Multiplexer, 116...Display device 1
17a-117h, 118a-118h ・D/
A converter, 119a ~ 119h, 120a ~ 1
20h--Amplifier, 121a to 121d-D
/A converter. 122a to 122d - amplifiers, 123a to 123d
・D/A converter, 124a to 124d -・
・Representative of amplifier patent applicant Toyota Motor Corporation

Claims (3)

[Claims] (1) A vehicle height adjusting means configured to control vehicle body roll by adjusting the left and right vehicle height difference, a vehicle speed detecting means for detecting vehicle speed, a steering angle detecting means for detecting a steering angle, and a steering wheel. A steering torque detection means for detecting torque T, and a steady roll angle φs of the vehicle body and a steady steering torque Ts are calculated from the vehicle speed detected by the vehicle speed detection means and the steering angle detected by the steering angle detection means, and T
calculation control means for calculating a corrected steady roll angle φsc by correcting φs such that φs becomes smaller as the ratio of Vehicle roll control device with (2) In the roll control device for a vehicle according to claim 1, the roll control device includes means for determining whether or not countersteering is being performed, and a lateral acceleration detector for detecting lateral acceleration of the vehicle body. and the arithmetic and control unit is configured to calculate a corrected steady roll angle φsc in accordance with the lateral acceleration detected by the lateral acceleration detection unit when it is determined that countersteering is being performed. A vehicle roll control device comprising: (3) In the roll control device for a vehicle according to claim 2, the roll control device has a yaw rate detection means for detecting a yaw rate of the vehicle body, and the arithmetic control device is configured to perform countersteering. If the absolute value of the yaw rate detected by the yaw rate detection means is less than a predetermined value, the steering angle and lateral acceleration detected by the steering angle detection means and the lateral acceleration detection means are Steady roll angle φsc after correction based on acceleration
A vehicle roll control device, characterized in that it is configured to calculate.