JP2002211224A - Suspension control method - Google Patents

Abstract

(57) [Summary] [Problem] To provide a suspension control method capable of obtaining a roll rigidity corresponding to a roll angle in response to a rapid change in a rolling direction during zigzag traveling or the like. SOLUTION: In a suspension of a left rear wheel, a vehicle body B moves up and down with respect to a road surface to roll by cornering, and a lower arm 3L and an upper arm 2L connected to a knuckle 6L move up and down from a base end of the vehicle body B as a starting point. . The spring 7L and the shock absorber connected to the lower arm 3L expand and contract in accordance with the vertical movement, so that the vertical movement of the vehicle body B with respect to the road surface is buffered. Driving actuator 1L, drive arm 4L
Is rotated in the same direction as the rolling, and the torque that moves up and down is transmitted to the lower arm 3L connected to the drive arm 4L, thereby complementing the spring rate of the spring 7L. The same applies to the suspension for the right rear wheel.
L, 1R are controlled in relation to each other, and springs 7L, 7 at cornering
It complements the R spring rate and controls the roll stiffness of the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension for a vehicle such as an automobile, and more particularly to a suspension control method for driving the suspension by electronic control.

[0002]

2. Description of the Related Art As a drive of an electronically controlled suspension, a roll rigidity variable system is conventionally known. This roll stiffness variable system utilizes a method of directly controlling the torsion angle of a stabilizer bar that contributes to the rolling moment of rolling in cornering or the like. That is, the roll rigidity variable system is provided with a telescopic actuator on one or both of the stabilizer link connecting the stabilizer bar and the wheel retainer, and by generating a force opposite to the twisting direction on the telescopic actuator, Adjust the twist angle of the stabilizer and reduce the rolling angle. A hydraulic actuator and a linear motor actuator are known as telescopic actuators used here.

As another roll rigidity variable system, a rotary actuator is provided at the center of a stabilizer bar connected to left and right wheel holders to generate a force repelling against a reverse phase operation. There is also a configuration that reduces the angle of rolling. As described above, the conventional roll stiffness variable system uses the repulsion force of the stabilizer to
By applying the force generated by the actuator, the rigidity of the stabilizer bar is complemented, the resilience of the stabilizer is increased, and when rolling occurs, an apparently thick stabilizer bar is provided. Thereby, according to the above-described variable roll rigidity system, the roll rigidity of the suspension against rolling is improved, and it is possible to control the riding comfort and the steering stability.

[0004]

However, the above-described variable roll stiffness system performs only the operation of reducing the steady-state roll angle during cornering, and takes into account control in an unsteady state such as during zigzag travel. Not configured. Therefore, in the above-described variable roll stiffness system, in a rapid change in the rolling direction due to zigzag traveling or the like, the roll angle adjustment processing delays following the actual roll angle change. In other words, in the above-described variable roll system, the roll angle adjustment process in the transition region when rolling occurs due to the response delay of the lateral G (lateral acceleration) sensor input at the beginning of cornering is performed based on the actual roll angle. There is a problem that the following to the change is delayed.

The present invention has been made in view of such a background, and has been developed for a suspension capable of responding to a sudden change in the rolling direction during zigzag running or the like and obtaining appropriate roll rigidity according to the roll angle. The purpose is to provide a control method.

[0006]

According to the suspension control method described in the present invention, an actuator (for example, the embodiment) capable of generating a force for suppressing the rolling of a vehicle body (for example, the vehicle body B in the embodiment). In the control method of the actuators 1L, 1R in the first embodiment, the difference between the movement amounts of the left and right wheels (for example, the wheels WL, WR in the embodiment) in the vertical direction (for example, the stroke difference ΔLR in the embodiment) is detected. Since the angular velocity is also detected and the actuator is controlled based on the difference between the amount of movement of the wheels and the steering angular velocity, a steering wheel turning speed, that is, a torque based on the steering angular velocity, including when the vehicle body is neutral, is generated. The torque of the actuator is controlled in the direction opposite to the rolling direction based on the Therefore, compared to the control based only on the amount of change in stroke, the roll stiffness in cornering is supplemented, the initial response is improved, the response delay due to vehicle compliance can be improved, and the center of the vehicle body from the start of cornering The center of gravity can be placed on the vehicle, and the stability of the vehicle against the centrifugal force generated by cornering is always obtained.

The method of controlling a suspension according to the present invention uses left and right wheels (for example, a wheel W in the embodiment).
L, WR) are mechanically connected to each other, and a stabilizer is provided which is twisted due to a difference in the amount of movement of the left and right wheels with respect to the vehicle body in the vertical direction (for example, a stroke difference ΔLR in the embodiment). In order to make up for the insufficient force for suppressing the rolling of the wheels by the actuator (for example, the actuators 1L and 1R in the embodiment), the steering wheel is rotated by not performing the steering operation during straight running. , The steering angle speed is determined to be “0”, and the difference in the amount of movement of the wheels relative to the vehicle body due to rolling is determined. Therefore, the control circuit does not control the actuator, and the rigidity of the suspension is reduced. Are not complemented, the stabilizer and the spring (for example, the springs 7L and 7R in the embodiment) Since the work suspension by the spring rate of the reference value of years, there is no compromising the original ride that has been set in advance. The spring rate that determines the roll stiffness of the vehicle body is both the spring rate of the suspension spring and the spring rate based on the torsional stiffness of the stabilizer. Hereinafter, for the sake of explanation, the spring rate of the spring includes the spring rate of the stabilizer.

[0008] The suspension control method according to the present invention provides an actuator (for example, the actuators 1L and 1L in the embodiment) capable of generating a force for suppressing the rolling of the vehicle body (for example, the vehicle body B in the embodiment).
1R) In the control method, the lateral acceleration of the vehicle is detected,
Lateral acceleration (for example, lateral acceleration value DG in the embodiment)
To control the actuator based on the steering angle and the steering angle speed, including when the vehicle is neutral,
That is, a torque based on the steering angular velocity is generated, and the torque of the actuator is controlled in the direction opposite to the rolling direction based on the torque, thereby increasing the wheel rate in the opposite phase. In addition, the roll stiffness in cornering is complemented, the initial response is improved, the response delay due to the compliance of the vehicle can be improved, and the center of gravity of the vehicle body can be centered from the start of cornering, which always occurs due to cornering Vehicle stability against centrifugal force is obtained.
In addition, this suspension control method controls the actuator using lateral acceleration instead of the difference in the amount of movement of the wheel with respect to the vehicle body.
Since a lateral acceleration sensor is used, the link and rod from the drive arm to the stroke sensor are not used as compared with the case of using a stroke sensor, so that two expensive stroke sensors provided on the left and right wheels can be reduced. In addition, since the structure of the detection mechanism for detecting the vehicle body state value is simplified, the system can be simplified, and the manufacturing cost can be reduced.

The method of controlling a suspension according to the present invention provides a method of controlling a suspension when a roll direction of a vehicle (for example, a vehicle body B in the embodiment) coincides with a steering speed direction (for example, a steering angular speed direction in the embodiment). Difference in the amount of movement of the wheels (for example, wheels WL and WR in the embodiment) with respect to the vehicle body (for example, stroke difference ΔLR in the embodiment)
If the roll direction and the steering speed direction of the vehicle do not match, the control is performed based on the difference in the amount of movement of the wheels with respect to the vehicle body (for example, the vehicle body B in the embodiment). In the neutral state where the roll of the vehicle is small, control is performed based on the difference between the amount of movement of the wheels with respect to the vehicle body and the steering angular speed, irrespective of whether the roll direction of the vehicle and the steering speed direction match or not, that is, the steering angle amount is differentiated. The torque based on the determined steering angular velocity is forcibly added to the torque determined from the difference in the amount of movement of the wheels with respect to the vehicle body, so that the torque determined from the steering angular velocity compensates for the control delay of the vehicle body during transient cornering. In addition, the response speed during turning at the beginning of cornering has been improved. Brute, without causing a delay in the body of the control, at the time of cornering start, it is possible to improve the response to rolling.

In the suspension control method according to the present invention, when the rolling direction of the vehicle and the steering speed direction coincide, the suspension control method is based on the lateral acceleration (for example, the lateral acceleration value DG in the embodiment) and the steering angular velocity. When the roll direction of the vehicle (for example, the vehicle body B in the embodiment) does not match the steering speed direction, the control is performed based on the lateral acceleration, and in a neutral state where the roll of the vehicle is small, the roll direction of the vehicle is changed. Irrespective of whether or not the steering speed direction matches or does not match, control is performed based on the difference between the amount of movement of the wheel with respect to the vehicle body and the steering angular speed, that is, the torque based on the steering angular speed obtained by differentiating the steering angle amount is calculated from the lateral acceleration. The control delay of the vehicle body B in the transitional state of the cornering is complemented by the torque obtained from the steering angular velocity by the forced addition to Improves the response speed when turning
In the anti-rolling control, the vehicle body B based on the delay of the control system such as the actuator and the vehicle compliance.
At the start of cornering, the response to rolling can be improved.

In the suspension control method according to the present invention, when it is determined that the vehicle is in the neutral state, the determination is performed with hysteresis. Since the hunting of the vehicle state value that occurs when the difference in the amount of movement with respect to the vehicle body B) in the embodiment changes across the threshold value is prevented, the control of the actuator due to the vibration of the state value can be prevented from becoming unstable. Since the current value supplied to the actuator is supplied stably without causing hunting, the response generated by the actuator to the rolling state is improved, and the response of the control of the roll rigidity of the suspension is improved. Since there is an effect and it is possible to prevent hunting due to a change across the neutral state of the stroke position described above,
In the anti-rolling control of the vehicle body, the vibration of the vehicle body due to sensitively affecting the subtle changes is eliminated, and the behavior of the vehicle body is stabilized.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is to complement the spring rate of a spring (for example, a coil spring) in a suspension by controlling the expansion and contraction of the spring by the torque generated by an actuator. At this time, the torque generated by the actuator is calculated based on the steering angular velocity of the steering wheel 8 in cornering and the magnitude of the roll angle. Accordingly, the invention of the present application substantially increases the roll rigidity of the vehicle body in accordance with the running state of the vehicle, and reduces the inclination of the vehicle body due to rolling, that is, the magnitude of the roll angle, thereby stabilizing the running of the vehicle. It is intended to obtain the nature.

Further, if the spring rate of the spring is set to a large value from the beginning in order to increase the roll rigidity of the vehicle body, the vehicle body is directly subjected to the impact of the road surface condition, for example, the unevenness of the road surface during straight traveling, and the maneuverability is increased. In addition, the ride quality deteriorates. However, according to the present invention, the spring rate of the spring is set to a value that suppresses the impact due to the state of the road surface when traveling straight, and the difference between the spring rate that obtains the required roll rigidity by cornering and the spring rate of the spring is Because the torque generated by the actuator is used to compensate, the wheel rate in the opposite phase to the rolling direction can be increased, and the roll stiffness can be adjusted according to the running condition. It is possible to improve comfort. Here, the wheel rate means how many N (Newton) force is generated at each wheel end according to each stroke amount change (movement amount of the wheel with respect to the vehicle body) in the suspension on the wheel side WL and the wheel WR side. Is shown. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment> FIG. 1 is a perspective view of a rear (rear wheel) side suspension structure according to a first embodiment of the present invention, as viewed from the rear of a vehicle. In the suspension of the left rear wheel in this figure, the knuckle 6L that rotatably supports the wheel WL is an A-type upper arm 2L.
And a lower arm 3L so as to be vertically movable. The upper arm 2L is connected to the upper part of the knuckle 6L via a joint provided at the distal end, and connected to the vehicle body B via a joint provided at the proximal end. Lower arm 3L
Is connected to the lower part of the knuckle 6L via a joint provided at the distal end, and the vehicle body B is connected via a joint provided at the proximal end.
Connected to. The lower part of the spring 7L is supported by the center of the lower arm 3L, the upper part of the spring 7L is supported by the vehicle body B, and the actuator 1L is connected to the base end of the lower arm 3L via the link 5L and the drive arm 4L. Further, a shock absorber (not shown) is provided between the vehicle body B and the lower arm 3.
L. Here, actuator 1L
Is composed of a speed reducer GL and a motor ML. Further, the configuration of the suspension for the right rear wheel is the same as that of the above, except that the suffixes of the reference numerals of the components described above are changed from “L” to “R”. The front portions of the knuckle 6L and the knuckle 6R are connected to each other by a stabilizer (not shown), and the vehicle body B is connected to the rear portions of the knuckle 6L and the knuckle 6R by lateral links (not shown).

With the above configuration, in the suspension of the left rear wheel, the vehicle body B moves up and down and rolls on the road surface by cornering, thereby forming the knuckle 6.
The lower arm 3L and the upper arm 2L connected to L move up and down from the base end connected to the vehicle body B as a starting point. Thus, the spring 7L and the shock absorber connected to the lower arm 3L expand and contract in accordance with the vertical movement, and the vertical movement of the vehicle body B with respect to the road surface is buffered. At this time, the actuator 1L is driven to rotate the drive arm 4L around the rotation axis.
Is rotated in the same direction as the rolling, torque (N · m) that moves up and down is transmitted to the lower arm 3L connected to the drive arm 4L via the link 5L, and complements the spring rate of the spring 7L. Similarly, in the suspension of the right rear wheel, the same operation as that of the suspension of the left rear wheel is performed, except that the suffixes of the reference numerals of the components described above are changed from “L” to “R”. Thereby, the actuators 1L and 1R provided on the wheel WL and the wheel WR are provided.
, The spring rates of the springs 7L and 7R in cornering can be complemented, and the roll stiffness of the vehicle can be positively controlled.

That is, in the suspension of the left rear wheel, the spring 7L moves the vehicle body B up and down by cornering.
The spring 7L connected to expands and contracts according to the vertical movement,
It functions to apply torque to the vehicle body B and correct the inclination of the vehicle body B. However, as described above, since it is necessary to buffer the state of the road surface when the vehicle is traveling straight, the spring 7L does not have a spring rate that provides a torque enough to return the vehicle body B to the parallel position. For this reason, the actuator 1L
Multiplication of the length of the drive arm 4L by the rotational force in the same direction as the rolling direction, which is obtained by reducing the rotation of the motor ML as a DC motor by the gear ratio through the drive arm 4L and the link 5L. Is given to the lower arm 3L. As a result, the actuator 1L
By applying a torque to the lower arm 3L in the same direction as the rolling direction, the spring rate of the spring 7L is complemented as described above. Hereinafter, for the sake of explanation, the control device controls the actuators 1L and 1R to be driven, and the drive arm is rotated by this drive, whereby the lower arm 3 is driven.
The final target torque applied to each of L and 3R is defined as torque TTL and TTR, respectively.

As shown in FIG. 2, stroke sensors SL (left) and SR (right) are provided on each of the rear wheel suspensions. Left and right are detected independently as quantities. FIG. 2 is a perspective view from above of the vehicle body B showing positions where the stroke sensors SL and SR and the steering angle sensor SA are provided. Further, since the vertical movement due to the rolling depends on the direction of the cornering, a steering angle sensor SA is provided to detect the steering direction of the driver. The steering angle sensor SA detects the steering angle and the steering direction of the steering wheel (handle) 8 and outputs a numerical value detected by adding a sign. For example,
When steering to the right, a positive numerical value is output according to the steering angle, and when steering to the left, a negative numerical value is output according to the steering angle. The stroke sensors SL and SR in FIG.
For example, a stroke potentiometer shown in FIG. 3 for measuring a vertical movement distance, a rotary potentiometer for measuring a moving distance of a drive arm as a rotation angle, or a laser displacement type for measuring a distance between a vehicle and a road surface (not shown). In other words, any device can be used as long as it can measure the amount of inclination of the vehicle body B with respect to the road surface in relation to the roll angle of the vehicle body B by rolling. In FIG.
This is an example in which a stroke type potentiometer is used for the suspension of the left rear wheel.
And is connected to the upper arm 2L by a link. In addition, a rotary potentiometer is used as an example of a stroke sensor SR in the suspension for the right rear wheel. Further, the control of the actuators 1L and 1R and the detection of the outputs of the stroke sensors SL and SR are performed by a control circuit (not shown). This control circuit is C
A PU and a storage unit such as a memory.
U controls the direction and amount of torque of the actuators 1L, R based on the values of parameters such as the stroke amount and the steering angle obtained from each sensor according to the program in the storage unit.

Next, an example of the operation of the embodiment will be described with reference to FIGS. FIG. 4 is a timing chart showing changes in parameters for calculating the amount of torque generated by the actuators 1L and 1R according to the direction in which the driver steers. Before describing the actual operation, a flow of processing performed by a control circuit for controlling the actuators 1L and 1R will be described with reference to a flowchart. As a premise of operation,
When the driver gets into the vehicle and turns on the ignition switch, the control circuit determines that the measured values MDL, M output by the stroke sensors SL, SR at this time point.
DR (unit: mm) is stored in the storage unit as reference values DL, DR (unit: mm), respectively. This is because the stroke difference ΔLR used hereinafter is calculated based on the amount of change in the stroke position from the reference value (the amount of movement of the wheels relative to the vehicle body). The measurement is performed at the time of starting the engine to obtain an accurate reference value at each time according to the weight applied to the suspension depending on the situation.

For this reason, the reference value of the stroke position includes:
Depending on the capacity of the vehicle, the weight of luggage, gasoline, etc.
Since it is necessary to use the value measured in the state of the gravitational acceleration of 9.8 (m / s ² ) at the time of stop, the value read from the stroke sensors SL and SR by the control circuit with the ignition switch turned on is used. Used. And
The control circuit starts the processing of each flowchart shown in FIGS. 5, 7, and 8 according to the program. The processing in these flowcharts is performed at regular intervals (for example, 10 m
(every second), the processing is repeated as one set, and the control of the generation of the torques TL, TR to be generated in the actuators 1L, 1R is performed at regular intervals. Prior to the description of the actual control flow shown in FIG. 4, the processing of the flowcharts shown in FIGS. 5, 7, and 8 will be described.

In the flowchart of FIG. 5, a calculation is performed to determine the torques YL and YR generated in the actuators 1L and 1R based on the steering angular speed (rad / sec) indicating the steering speed. This calculation is based on the steering angular velocity and torque Y shown in FIG.
From the relationship between L and YR, the torque YL,
Find YR. In FIG. 6, the horizontal axis represents the steering angular velocity, and the vertical axis represents the values of the torques YL and YR. Here, when the steering angular velocity is, for example, 0.5 (rad / sec) or less, the torque YL,
The value of YR is set to "0". This prevents a small steering angle from occurring due to the movement of the steering wheel 8 during straight running, and prevents the suspension from being excessively responsive to the movement and increasing the rigidity of the suspension. That is, at a very small steering angular velocity, the actuator 1
When running straight, the suspension operates at the basic spring rate without generating torque in the L and 1R, giving priority to ride comfort. Further, the maximum value of the torques YL and YL is, for example, 200
(N · m). The maximum values of the torques YL and YR are determined based on numerical values and the like selected by a plurality of persons who test-ride the ride comfort and maneuverability of the vehicle.

Next, each step will be described. In step S01, the control circuit inputs a steering angle amount including the steering angle direction from the steering angle sensor SA. In step S02, the control circuit sets the steering angle direction obtained from the steering angle sensor SA in a steering angle direction flag of the storage unit. Step S0
In 3, the control circuit performs an operation to obtain a change in the steering angle amount over the above-mentioned fixed time, that is, a steering angle speed as a differential value of the steering amount. At this time, the differential value is obtained, for example, by storing the previous measured value in the storage unit and subtracting the previous measured value from the sequentially obtained measured values. Step S
At 04, the control circuit sets a steering angular velocity direction indicating the direction of the steering angular velocity in a steering angular velocity direction flag of the storage unit. Here, even when the steering angle direction is constant, when the steering wheel 8 is returned, the direction of the steering angle and the direction of the steering angular velocity may be different. In step S05, the control circuit determines, from the graphs respectively showing the relationship between the steering angular velocity shown in FIG. YL and YR are selected and output as a calculation result. The maximum value of the torques YL and YL in FIG. 6 is, for example, 200 (Nm).
Is set to The maximum values of the torques YL and YR are determined for each vehicle type based on numerical values and the like selected by a plurality of persons who test-ride the ride comfort and maneuverability of the vehicle. In step S06, the control circuit sets the torques YL and YR generated by the actuators 1L and 1R at regular intervals.

In the flowchart of FIG.
An operation for obtaining the torques TL and TR generated by the actuators 1L and 1R is performed based on the stroke amount. In step S11, the control circuit reads the measured values M from the stroke sensors SL and SR in the left and right suspensions, respectively.
Read DL and MDR. In step S12, the control circuit calculates a difference between the measured value and the reference value, that is, a stroke amount. That is, the control circuit calculates the stroke amount ΔDL of the left rear wheel by the equation “MDL−DL”, and similarly calculates the stroke amount ΔDR of the right rear wheel by the equation “MDR−DR”, It is stored in the storage unit.

Next, in step S13, the control circuit calculates a stroke difference ΔLR between the stroke amount ΔDL of the left rear wheel and the stroke amount ΔDR of the right rear wheel obtained in step S12 by an expression of “ΔDL−ΔDR”. Is calculated by In step S14, the control circuit determines the stroke difference ΔLR
= ± α, the body B is determined to be “neutral” with respect to the road surface,
When the stroke amount ΔLR> α, the vehicle body B is determined to be “lower right”, and when the stroke difference ΔLR <−α, “lower left”.
And the storage unit stores the determination result as a vehicle state value together with the stroke difference ΔLR. Here, α is set to, for example, 0.3 (mm), and is a range in which the stroke difference ΔLR is determined as “0”. By setting the range of “neutral”, it is possible to prevent the rigidity of the suspension from increasing in response to the slight distortion of the road surface when traveling straight. That is, in a very slight change in the stroke position, no torque is generated in the actuators 1L and 1R, and when the vehicle is going straight, the suspension is operated with only the basic spring rate without supplementing the roll rigidity, thereby giving priority to ride comfort.

Next, in step S15, the control circuit determines whether the actuator 1
Calculate the torques TL and TR generated by L and 1R, respectively. That is, the target spring rate JT set according to the vehicle type
(Unit: N (Newton) / mm, including a spring rate based on the torsional rigidity of a stabilizer not shown) and a spring 7 actually provided on the suspension.
L basic spring rate JS (unit N (Newton) / mm)
The value obtained by multiplying the spring rate difference ΔJ with the stroke difference ΔLR (mm) is the roll rigid reaction force insufficient force FW. Here, the target spring rate JT is determined according to the type of vehicle, and is, for example, 32 (N / mm). The maximum value of each of the torque YL and the torque TL is added, and the torque TTL resulting from the addition is converted into a spring rate. And a reference spring rate (this value also varies depending on the type of vehicle, for example, 14.6 (N / mm)). Therefore, the control circuit
An operation is performed based on the formula of “(JT−JS) × ΔLR”,
Find the roll stiffness reaction force shortage force FW. Further, the torques TL and TR generated in the actuators 1L and 1R are torques required to supplement the insufficient spring rate difference ΔJ of the basic spring rate JS with respect to the target spring rate JT. Lever ratio DD (substantially the length of the drive arm 4L or 4R, unit c)
m).

For this reason, the control circuit calculates “(FW × DD)
/ 2 "to calculate the torques TL and TR. In the above equation, “FW × DD” is divided by “2” because the torque (apparent increase in spring rate) required for complementing the roll rigidity is complementarily calculated by the actuator 1.
This is because L and 1R perform control to generate torques in the opposite directions each by “ず つ”. And the control circuit is
It is determined in step S15 depending on whether the vehicle state value is “lower right” or “lower left” (FW × DD)
/ 2) with polarity, and calculate the torques TL and TR. For example, in the control circuit, the driver steers to the right, and the vehicle body B rolls to the left, that is, in FIG. 1, the left side of the vehicle body B sinks in the direction and floats in the direction (vehicle state value: “left Drop), actuator 1
L rotates in the direction of and the torque TL that extends the spring 6L
((+ FW) × DD / 2), while the actuator 1R rotates in the direction of, and the torque T for contracting the spring 6R.
Calculate R ((− FW) × DD / 2). (Conversely, body B
Is rolling rightward, that is, in FIG.
When the left side of the vehicle sinks in the direction and rises in the direction, the vehicle state value becomes “downward to the right”. Hereinafter, for the sake of explanation, the torque in the direction in which the spring is extended is (+), and the torque in the direction in which the spring is contracted is (-). The maximum value of the torques TL and TR obtained from the stroke difference is set to, for example, 200 (Nm). The maximum values of the torques TL and TR are determined for each vehicle type based on numerical values and the like selected by a plurality of persons who test-ride the ride comfort and maneuverability of the vehicle.

Next, in step S16, the control circuit determines whether the vehicle state value is "neutral".
Here, when the vehicle state value is not “neutral”, the control circuit stores the values of the torques TL and TR obtained in step 15 in the storage unit, and ends the processing of this flowchart. On the other hand, when the vehicle state value is “neutral”, the control circuit advances the process to step 17. In step S17, the control circuit determines that the stroke difference ΔLR is in the range of “neutral” and the vehicle state value is “neutral”, so the torque TL and the torque TR based on the stroke difference ΔLR are determined.
Are set to “0” and stored in the storage unit, and the processing of this flowchart ends.

Next, in the flowchart of FIG.
Based on the torques TL, TR and the torques TL, TR obtained by the processing in the flowcharts of FIGS. 5 and 7, the torques TTL, TTR actually generated in the actuators 1L, 1R.
Ask for. In step S21, the control circuit determines whether or not the vehicle state value is “neutral”. If the determination result is not “neutral”, the process proceeds to step S22.
If the vehicle state is "neutral", the process proceeds to step S25. Next, in step S22, the control circuit
A comparison between the vehicle state value and the steering angular velocity direction, that is, whether or not the rolling direction corresponds to the steering angular velocity direction (the roll direction and the steering speed direction of the vehicle match), here the vehicle state value is “left”. It is determined whether "down" and the steering speed direction is right. At this time, the control circuit advances the process to step S25 when the vehicle state value is “downward left” and the steering angular velocity direction is right, and advances the process to step S23 when the combination is not this combination.

Next, in step S23, the control circuit compares the vehicle state value with the steering angular velocity direction, that is, the rolling direction corresponding to the steering angular velocity direction (when the rolling direction of the vehicle and the steering speed direction match each other). Here, it is determined whether the vehicle state value is “downward to the right” and the steering speed direction (steering angular speed direction) is left. At this time, if the vehicle state value is “downward to the right” and the steering angular velocity direction is left, the control circuit proceeds to step S25. Otherwise, the control circuit proceeds to step S24.
Proceed to. Next, in step S24, the control circuit determines the torques TL and TR obtained from the stroke difference ΔLR.
Are stored in the storage unit as torques TTL and TTR, respectively. In step S25, the control circuit sets the torque TTL to be generated in the actuator 1L to "YL + TL".
And the torque TTR generated in the actuator 1R is calculated based on the formula of "YR + TR", and the calculated torques TTL and TTR are stored in the storage unit. Next, in step S26, the control circuit calculates the amount of current for causing the actuators 1L, 1R to output the torques TTL, TTR. For example, when the motors ML and MR to be used are DC motors and the motors ML and MR are subjected to PWM (pulse width modulation) control, the control circuit adjusts the amount of current so that "H" is output in a continuous pulse having a constant period. The duty ratio between the level and the width of the “L” level is calculated.

FIG. 9 shows a combination of calculations performed by the control circuit in the flowchart of FIG. 8 based on the state of the vehicle state value and the steering angular velocity direction flag described above. Here, “forced addition” in the item “vehicle state is neutral” is a name defined as a special addition process that does not depend on the vehicle state in the processing of the program. That is, the vehicle body B is usually
Rolling in the direction opposite to the steering angle due to centrifugal force, delayed by the body compliance. Therefore, when the vehicle body B is in the "neutral" state and the actuators 1L and 1R are not controlled, the steering wheel 8 has already been steered, and in the next stage, rolling is performed in the opposite direction to the steering angle of the steering wheel 8. Is started. Therefore, according to the body compliance,
Since the control of the roll stiffness at the time of the initial cornering is delayed, the forced addition is performed in order to forcibly generate the torque opposite to the rolling direction according to the steering angle direction to the actuators 1L and 1R.

That is, when the vehicle body state value is "neutral",
As described above, when the steering angular velocity direction flag and the vehicle state value do not match, the torques TTL and TTR to be controlled become “0”, and in the initial transient state of the cornering (the stroke difference ΔLR is “0”). In the anti-rolling control, a delay in a control system such as an actuator and a delay in control of the vehicle body B based on the vehicle compliance are caused. For this reason, in the first embodiment, when the vehicle body state value is “neutral”, the torques YL and YR based on the steering angular velocity obtained by differentiating the steering angle amount are changed to the torques TL and TR.
Are added forcibly to "0" to compensate for the control delay of the vehicle body B and improve the response speed at the time of turning at the beginning of cornering.

As can be seen from FIG. 9, when the steering angle speed direction flag and the vehicle state value in the rolling direction corresponding to the steering angle speed direction match in the behavior of the vehicle body B, the torque YL obtained from the steering angle speed is obtained. , YR and the torques TL, TR obtained from the stroke difference ΔLR, respectively, and the torque TT output to the final target actuator.
L and TTR are generated. Further, when the control circuit adds the steering angular velocity direction flag and the vehicle state value based on the steering angular velocity direction when they do not match, the stroke difference Δ
Only the torques TL and TR based on the LR are used to output the final target torques TTL and TTR as the calculation results. This is because the directions of the steering angular speeds are opposite to each other, so that the torque directions of the torques YL and YR obtained from the steering angular speeds are opposite to the directions of the torques necessary to suppress the rolling, and the torques TTL and TTR are equal to each other. As an amount, the torque TL, TR is subtracted from the torque YL, YR to obtain the torque TTL,
This is to prevent TTR from decreasing. At this time,
Furthermore, when the steering angle direction is reversed, as can be seen from the steering angular velocity direction, the steering wheel 8 has already been steered in the opposite direction to the direction in which the current rolling direction occurs, and the roll stiffness during initial cornering due to vehicle body compliance. Therefore, it is necessary to forcibly generate a torque opposite to the steering angle direction in the actuators 1L and 1R.

Therefore, if the steering angle speed flag does not match the vehicle state value based on the steering angle speed direction, and the steering angle direction does not correspond to the current rolling direction, the steering angle direction flag is set to At a time point opposite to the direction indicated by the state value, the signs of the torques TTL and TTR are reversed, and the directions of the torques TTL and TTR change in the same direction as the rolling direction. That is, since the steering wheel 8 has already been steered and the steering angle direction has been changed, the control of the roll stiffness at the time of initial cornering is delayed due to the vehicle body compliance. A torque in the same direction as the direction is generated in the actuators 1L and 1R. According to the above-described process, in the anti-rolling control, for example, when the vehicle body state value changes from “downward to the right” to “neutral” and from “neutral” to “downward to the left”, the compliance amount and the control are controlled. In consideration of the delay, the torques TTL and TTR are calculated and calculated while predicting the next rolling direction.
The roll rigidity of the vehicle body B can be smoothly controlled in accordance with the running state such as cornering.

When the control circuit wants to increase the amount of current supplied to the motors ML and MR in order to increase the torque, in the above-described PWM control, the "H" level ("H" pulse in the positive logic) is used in the PWM control. When it is desired to increase the width, reduce the width of the “L” level, and reduce the current in order to reduce the torque, the torques TTL, TL are increased so that the width of the “L” level is increased and the width of the “H” level is reduced. The duty ratio of each TTR is calculated. At this time, the direction in which the torque is generated is controlled by reversing the direction of the current flowing through the motors ML and MR. Hereinafter, for the sake of explanation, the current direction for generating the torque TL in the direction in which the actuator 1L is rotated in the direction (see FIG. 1), that is, the direction (+), that is, when the spring is extended, is referred to as (+). The direction in which the torque TL is generated in the direction in which the spring is contracted by rotating in the direction, that is, in the direction of (-), is defined as (-). Similarly, when the actuator 1R is rotated in the direction of, ie, the direction of (+), the current direction for generating the torque TR in the direction of extending the spring is set to (+), and the actuator 1R is moved in the direction of, ie, the (−) direction. The direction of the current that causes the torque TR to be generated by rotating and contracting the spring is defined as (-).

Next, returning to FIG. 4, the actual control flow will be described. First, each figure in FIG. 4 will be briefly described.
FIG. 4A shows the direction of the steering angle, that is, the steering angle on the right side when the upper side of the reference line is steered to the right, and the left side when the lower side of the reference line is steered to the left. This shows the steering angle. Further, in FIG. 4A, a solid line on a rectangle is shown, which indicates the direction of the steering angular velocity which means the steering direction. For example, even when the steering angle is on the right side, when turning to the left, the direction of the steering angular speed is left, and the directions of the steering angle and the steering angular speed may not match. FIG. 4B shows a vehicle state value that is a rolling state of the vehicle due to steering. That is, the vehicle state value is determined by the stroke difference ΔL.
It is classified into any of "neutral", "downward right", and "downward left" obtained from R.

FIG. 4 (c) shows the state of the steering angle direction flag, and at the same time, the direction in which the actuators 1L and 1R generate torque. For example, as the torque generation direction, the actuator 1R is rotated in the direction of (+) to extend the right spring, and the actuator 1L is moved to (-).
When the steering angle direction flag is set to "left", the actuator L is rotated in the direction of (+) to extend the left spring, and the actuator 1R is set to (-). , The right-side spring is contracted, that is, the steering angle direction flag is “right”. That is, the control circuit controls the polarity of the current applied to the actuators 1L and 1R based on the steering angle direction flag. FIG. 4D shows the absolute values of the torques YL and YR calculated based on the steering angular velocity and the torques TL and TR calculated based on the stroke difference ΔLR. Here, the torque YL and the torque YL have the same value, but the directions of the forces are opposite to each other.
L and the torque TR have the same value, but the directions of the forces are opposite to each other.

FIG. 4E shows a torque TTL, which is a final target value obtained by adding the torque YL and the torque TL of FIG. 4D.
And the absolute value of the torque TTR which is the final target value obtained by adding the torque YR and the torque TR. Here, the torque TTL and the torque TTR have the same value, but the directions of the forces are opposite to each other. Also, this torque TT
The maximum values of L and TTR are obtained by adding the respective maximum values of the torque YL and the torque TL to obtain the torque TTL. When the torque TTL is generated in the actuator 1L, the torque TTL is set in the direction opposite to the direction of the torque TTL. It is determined by the strength of the actuator 1L that can cope with the torque. FIGS. 4D and 4E show absolute values, and the direction of the torque generated in the actuators 1L and 1R is indicated by the steering angle direction flag. At each time described below, the control circuit sets necessary parameters in accordance with the processing of the flowcharts shown in FIGS. Sampling is performed by each sensor, and the final control target torque T
Calculation for obtaining TL and torque TTR is performed.

At time t0, the vehicle body B is not in a rolling state because it has not been steered to the right or left. Therefore, the stroke difference ΔLR is “0”, and the vehicle state value is “neutral”. Therefore, the control target torques YL and YR obtained from the steering angular velocity and the control target torque T obtained from the stroke difference ΔLR
L and TR are both “0”, and the control circuit determines that the current value for generating the torque is “0” because the torques TTL and TTR resulting from the addition are both “0” in the forced addition process. The calculated current is not applied to the actuators 1L and 1R to generate a torque.

Next, at time t1, when the driver starts turning the vehicle to the right in the right cornering, the steering angle gradually increases to the right. However, at the time t1, the control circuit still has
Since the steering wheel 8 is not turned and the steering angular velocity is “0”, both the steering angle direction flag and the steering angular velocity direction flag
Does not change from the left state of the previous state. Therefore, the control circuit obtains all the torques YL, YR, TL, and TR as "0" as the calculation results based on the stroke difference ΔLR and FIG. Output as "0". Therefore, the control circuit includes the actuators 1L, 1R
The current for generating torque is not supplied to each of them, and the torque control of the actuators 1L and 1R is not performed.

Next, at time t2, the steering angle gradually increases to the right due to the driver turning the steering wheel 8, but in the vehicle body B, rolling is delayed due to the delay of the vehicle body compliance. Has not happened,
The vehicle state value is “neutral”. On the other hand, since the steering circuit is steered, a steering angle is generated on the right side, so that "right" is stored in the steering angle direction flag from the steering angle obtained from the steering angle sensor SA at regular intervals, and the control angle is obtained. The steering angle speed is calculated based on the steering angle and the previous steering angle. At this time, at the time of starting the steering, the previous steering angle for calculating the steering angular velocity is:
It is set to "0". Then, the control circuit rewrites the steering angular velocity direction flag to the “right” state because the steering angular velocity direction obtained as the calculation result is “right” because the steering wheel 8 is steered to the right. Then, the control circuit calculates the torques YL and YL as target values from the obtained steering angular velocity from a graph showing the relationship between the torque and the steering angular velocity in FIG. Here, in the case of gentle cornering, in order to make the suspension rigidity that does not affect the ride comfort and steering stability of the driver, the steering angular velocity that affects beforehand is measured for each vehicle type, and based on this measurement result, The lower limit of the steering angular velocity for generating the target values of the torques YL and YL and the gradient of the change in the steering angular velocity up to the maximum value of the target values YL and YL are set. Further, the control circuit obtains the torques TL and TR from the stroke difference ΔLR, but outputs the torques TL and TR as “0” as the calculation result because the vehicle state value is “neutral”. At this time, since the vehicle state is "neutral", the control circuit performs a forcible addition process, and the torque YL and the torque TL, and the torque YR and the torque TR.
And are respectively added. Here, since the torques TL and TR are “0”, the calculated torques TTL and TTR are only the torques YL and YR obtained from the stroke difference ΔLR.
Then, based on the steering angle direction flag set to “right”, the control circuit reduces the torque generation direction of the actuator 1L to “extend the left spring 7L” and reduces the torque generation direction of the actuator 1R to “right spring 7R”. "Direction.

That is, from time t2 to time t3 when the vehicle state is "neutral", the final target torques TTL and TTR generated by the actuators 1L and 1R are determined by the stroke difference Δ
Since the torques TL and TR based on LR are "0", the torques TL and TR can be obtained only from the torques YL and YL obtained from the steering angular velocity. Then, the control device supplies a corresponding current to each of the actuators 1L and 1R to generate the torques TTL and TTR based on the steering angle direction flag indicating “right”. As a result, the control circuit sets the actuator 1L
Generates a torque TTL in the (+) direction (see FIG. 1), and applies a torque TTR in the (-) direction to the actuator 1R.
Generate. Accordingly, the rolling of the vehicle body B is controlled in a direction in which the roll angle is set to “0” with respect to the road surface, that is, in a direction opposite to the rolling direction falling leftward.

Next, at time t3, the control circuit sets the vehicle body state to "neutral" based on the value of the stroke difference ΔLR.
From "to the left" is detected. Therefore, when the vehicle state is “downward left” and the steering angular velocity direction flag is “right” (the roll direction and the steering speed direction of the vehicle match), the control circuit determines the stroke based on the stroke difference ΔLR. Target torques TR and TL are set to "0
Instead of the torque value as a control value. Thus, the control circuit obtains the torque TTL as an operation result by adding the torque YL and the torque TL, and similarly obtains the torque TTR as an operation result by adding the torque YR and the torque TR. Then, the control circuit generates a (+) direction torque TTL for the actuator 1L and a (-) direction torque TTR for the actuator 1R based on the steering angle direction flag indicating “right”. Therefore, the rolling of the vehicle body B is controlled in the direction of setting the roll angle to “0” with respect to the road surface and in the direction opposite to the rolling direction of setting the stroke difference ΔLW to “0”.

Next, at time t4, the control circuit outputs the torques YL and YR as "0" because the steering angular velocity falls below the lower limit set in the graph of FIG. As a result, the control circuit calculates the torques TTL and TTR as calculation results.
Are output according to the values of the torques TL and TR, respectively. At this time, similarly to the control at the time t3, the control circuit generates a (+) torque TTL for the actuator 1L and a (-) torque TTR for the actuator 1R.
In the direction opposite to the rolling direction,
Control.

Next, at time t5, the driver turns around the corner and starts to return the vehicle to the straight traveling direction. For this reason, the steering angle direction of the vehicle is to the right, but the steering angle speed direction for turning the steering wheel 8 is to the left. At this time, the control circuit sets the steering angular velocity direction flag to “left”, but outputs the torques YL and YR as “0” because the steering angular velocity is lower than the lower limit set in the graph of FIG. That is, the control circuit determines that the time t 5 is a constant steady circular turning region where the steering angle does not change.
In step 5, only the torques TL and TR obtained from the stroke difference ΔLR are output as the torques TTL and TTR with the setting of the torque direction based on the steering angle direction flag.

Next, at time t6, the control circuit outputs the torques YL and YR obtained from this graph as the calculation results because the steering angular velocity exceeds the lower limit set in the graph of FIG. However, the control circuit sets the vehicle state value to “left” and sets the steering angular velocity direction flag to “left” based on the processing of the flowchart of FIG. If they do not match), the torque YL obtained based on the steering angular velocity,
Without using YR, the torques TL, TR obtained based on the stroke difference ΔLR are output as torques TTL, TTR. As a result, the control circuit still determines that the steering angle direction flag is “right”, so that the torque TTL of the actuator 1L in the (+) direction is applied to the actuator 1L, similarly to the control at time t3.
Is generated to generate a torque TTR in the (-) direction on the actuator 1R to control the vehicle body B in the direction opposite to the rolling direction.

Next, at time t7, the control circuit detects from the steering angle obtained from the steering angle sensor SA that the steering direction has turned left, and sets the steering angle direction flag to "left". Further, the control circuit sets the direction of the torque to be generated in the actuator 1L to the direction to “shrink the left spring 7L” based on the “left” data set in the steering angle direction flag, and sets the torque to be generated in the actuator 1R. Is set to the direction of “extend right spring 7R”. Then, the control device determines the torques TTL, TTL based on the direction of the torque generated by each actuator set as described above.
In order to generate TR, a corresponding current flows through each of the actuators 1L and 1R. With this, the control circuit
A (-) direction torque TTL is generated in the actuator 1L, and a (+) direction torque TTR is generated in the actuator 1R. Therefore, the control circuit
Is based on the vehicle body compliance, based on the steering direction of the steering wheel 8 and corresponding to the next rolling, the direction in which the roll angle is set to “0” with respect to the road surface, that is, in the direction of the lower right rolling direction. Start control in the reverse direction. At this time, the control circuit does not change other control parameters.

Next, at time t8, the control circuit detects that the stroke difference ΔLR is within the range of “neutral”, and sets the vehicle body state value to “neutral”. Then, the control circuit sets the torques TL and TR obtained from the stroke difference ΔLR to “0” in the forced addition based on the vehicle body state value and the steering angular velocity direction, and sets only the torques YL and YR obtained from the steering speed. Is the final target torque TTL,
Output as TTR. Next, at time t9, the control circuit sets the vehicle body state flag to “downward right” and sets the steering angular speed direction flag to “left” (the roll direction of the vehicle and the steering speed direction match. No), the vehicle state is “neutral” based on the value of the stroke difference ΔLR.
From "to the right" is detected. Therefore, based on the stroke difference ΔLR, the control circuit obtains the calculated target values of the torques TR and TL by calculation as torque values as control values instead of “0”. Thus, the control circuit obtains the torque TTL as an operation result by adding the torque YL and the torque TL, and similarly obtains the torque TTR as an operation result by adding the torque YR and the torque TR. Then, the control circuit, based on the steering angle direction flag indicating “left”, “shrinks left spring 7L” in the torque generation direction of actuator 1L and actuator 1R
The torque T of the actuator 1L in the (−) direction is set based on the setting of “extend the right spring 7R” in the torque generation direction of
TL is generated, and a torque TTR in the (+) direction for the actuator 1R is generated. Accordingly, the rolling of the vehicle body B is controlled in the direction of setting the roll angle to “0” with respect to the road surface, that is, in the direction opposite to the rolling direction of setting the stroke difference ΔLW to “0”.

Next, at time t10, the control circuit outputs the torques YL and YR as "0" because the steering angular velocity falls below the lower limit set in the graph of FIG. As a result, the control circuit outputs the torques TTL and TTR as calculation results as values of only the torques TL and TR, respectively, because of the state of steady circular turning. At this time, since the steering angle direction flag indicates “left” as before, the control circuit
Similarly to the control in FIG. 9, a (-) direction torque TTL is generated in the actuator 1L, a (+) direction torque TTR is generated in the actuator 1R, and the vehicle body B is controlled in a direction opposite to the rolling direction. I do.

Next, at time t11, the driver starts to return the vehicle to the straight traveling direction by turning the corner. Therefore, the steering angle direction of the vehicle is the left direction, but the steering angle speed direction of turning the steering wheel 8 is the right direction. At this time, the control circuit sets the steering angular velocity direction flag to “right”, but outputs the torques YL and YR as “0” because the steering angular velocity is lower than the lower limit set in the graph of FIG.

Next, at time t12, the control circuit outputs the torques YL and YR obtained from this graph as the calculation results because the steering angular velocity exceeds the lower limit set in the graph of FIG. However, the control circuit sets the vehicle state value to “right” and sets the steering angular velocity direction flag to “right” based on the processing of the flowchart of FIG. If they do not match), the torque YL obtained based on the steering angular velocity,
Without using YR, the torques TL, TR obtained based on the stroke difference ΔLR are output as torques TTL, TTR. As a result, the control circuit still generates the (−) torque TTL in the actuator 1L in the same manner as the control at the time t9 because the rudder angle flag indicates “left”, and the control A torque TTR in the (+) direction is generated to control the vehicle body B in a direction opposite to the rolling direction.

Next, at time t13, the control circuit
The steering direction is shifted to the right by the steering angle obtained from the angle sensor SA.
Is detected, and the steering angle direction flag is set to "right".
You. Also, the control circuit sets the steering angle direction flag to
Based on "right" data, torque of actuator 1L
The direction of occurrence of
Change the torque generation direction of the tutor 1R to "Right spring 7R
Set to And the control circuit is set as above
Direction of torque to be generated for each actuator
Generates each actuator torque TTL, TTR based on
For each actuator 1L, 1R
The electric current that flows. As a result, the control circuit
A torque TTL in the (+) direction is applied to
Generates a negative (-) torque TTR on the actuator 1R
Let it. Therefore, the control circuit determines that the vehicle body B is
Based on the steering direction of steering wheel 8
And, corresponding to the next rolling,
The direction in which the roll angle is set to “0”,
Control in the direction opposite to the rolling direction is started. This and
Control circuit changes the other control parameters.
Do not make any changes. Here, the processing after time t14 is performed at time t14.
Since the description is repeated from 1, the description is omitted.

As described above, according to the suspension control method of the present invention, the respective torques obtained from the steering angular velocity direction and the stroke difference are obtained by performing the addition processing shown for each condition of the table in FIG. A state in which the roll stiffness of the vehicle body is caused to occur during straight running and cornering by generating torque opposite to the rolling direction to the actuators 1L and 1R with the torque as a target value and increasing the wheel rate in the opposite phase. Is controlled in accordance with each of the above. For this reason, the suspension control method generates the torques TL and TR based on the turning speed of the steering wheel 8, that is, the steering angular speed, including the case where the vehicle body is neutral, and the actuators 1L, 1R in the direction opposite to the rolling direction. Torque control to increase the reverse phase wheel rate, so that compared to control based on stroke change, the initial responsiveness of complementing roll stiffness in cornering is improved, and response delay due to vehicle compliance can be improved. In addition, since the center of gravity can be placed at the center of the vehicle body from the start of cornering, the stability of the vehicle can always be obtained against centrifugal force generated by cornering.

At this time, the direction of the torque generated by the actuators 1L and IR is determined by the steering angle direction flag. In the above-described torque control of the actuators 1L and 1R, if the direction of the torque force of the actuators 1L and IR is determined from the vehicle state value based on the stroke difference ΔLR, the torque control in the rolling direction can be performed unless a neutral state is established. However, as described above, torque control cannot be performed in response to a change in the rolling direction due to the compliance of the vehicle and the delay of the control system. Therefore, the suspension control method of the present invention predicts the next rolling direction based on the steering angle direction and performs torque control.
Even if the steering wheel 8 is turned zigzag and the steering angle direction is continuously changed, the torque control reacts to the change in the rolling direction,
The responsiveness of control according to the rolling of the roll rigidity can be improved.

Further, the suspension control method of the present invention is applied to a method of controlling the steering wheel 8 when a tire falls into a rut or the like generated by traveling of a large vehicle or the like during high-speed traveling on an expressway or the like, or when a tire receives a cross wind. Even if it is taken, the torque generated according to the steering angular velocity generated at this time complements the rigidity of the stabilizer in the suspension, so the apparent rigidity of the stabilizer increases, and it is possible to suppress the fluctuation around the rear . Further, in the suspension control method according to the present invention, the steering angle is determined as “0” because the steering operation is not performed during straight running, and the steering angle input by rotating the steering wheel 8 is small. In addition, since the stroke difference ΔLR due to rolling is also required to be “0”, the control circuit does not control the actuators 1L, R, and the rigidity of the suspension is not supplemented, so that the springs 7L,
Since the suspension operates at the original reference spring rate of 7R, the original riding comfort that is set in advance is not impaired.

<Second Embodiment> The configuration of the second embodiment is the same as that of the above-described first embodiment, and a description of the configuration will be omitted. The second embodiment differs from the first embodiment in that step S14 in FIG.
Is replaced by the flow of steps S31 to S39. In the first embodiment, the range α in which the stroke difference ΔLR is “0” is fixed to ± 0.3 (mm). On the other hand, in the second embodiment, as shown in FIG. 11, the range α in which the stroke difference ΔLR is set to “0” is changed from “neutral” to “lower right” or “lower left” when the vehicle state value is “neutral”.
To the range αo (for example, 0.3 (m
m)), and the range when the vehicle state value shifts from “lower right” or “lower left” to “neutral” is defined as a range αi (for example, 0.15 (mm)). That is, in the second embodiment, the vehicle state value changes from “neutral” to another state.
After changing from other states to "neutral", a different value is used for the range determined as "neutral", and the hysteresis width is 0.15.
(Mm) hysteresis.

Next, the operation in the step of FIG. 10 will be described. Since these steps only replace step S14 in FIG. 7, the description of the operation of the other steps in FIG. 7 is omitted. In step S13 in FIG. 7, the control circuit calculates a stroke difference ΔLR between the stroke amount ΔDL of the left rear wheel and the stroke amount ΔDR of the right rear wheel obtained in step S12 by using the equation “ΔDL−ΔDR”. And Returning to FIG. 10, in step S31, the control circuit determines whether or not the stroke difference ΔLR is larger than 0.3 (mm). At this time, the control circuit
If the stroke difference ΔLR is not larger than 0.3 (mm), the process proceeds to step S32, while if the stroke difference ΔLR is larger than 0.3 (mm), the process proceeds to step S35. Next, in step S35, the control circuit sets the vehicle state value to “downward right” because the vehicle state is downward rightward. In step S32, the control circuit determines whether or not the stroke difference ΔLR is smaller than 0.3 (mm). At this time, the control circuit
If the stroke difference ΔLR is not smaller than 0.3 (mm), the process proceeds to step S33, while if the stroke difference ΔLR is smaller than 0.3 (mm), the process proceeds to step S36.

Next, in step S35, the control circuit sets the vehicle state value to "left down" because the vehicle state is down left. In step S33,
The control circuit determines whether or not the current vehicle state value set last time is set to “downward right”. At this time,
The control circuit advances the process to step S34 when the vehicle state value is set to "downward right", and advances the process to step S37 when the vehicle state value is not set to "downward right". Next, in step S37,
Since the control circuit has confirmed that the current vehicle state value is set to "Left-downward", the stroke difference ΔLR becomes-
It is determined whether or not it is larger than 0.15 (mm). At this time, the control circuit determines that the stroke difference ΔLR is −0.15 (m
If it is not larger than m), the process proceeds to the next step S15 (FIG. 7) without changing the current vehicle state value “Left-down”, and if the stroke difference ΔLR is larger than −0.15 (mm), the processing is performed. To step S38.

Next, in step S38, since the stroke difference ΔLR is larger than -0.15 (mm), the control circuit detects that the current vehicle state has transitioned to "neutral", and changes the vehicle state value to "neutral". Change from "Left down" to "Neutral". Further, in step S34, since the control circuit has confirmed that the current vehicle state value is set to "downward right", the control circuit determines whether the stroke difference ΔLR is smaller than 0.15 (mm). At this time, if the stroke difference ΔLR is not smaller than 0.15 (mm), the control circuit proceeds to the next step S15 (FIG. 7) without changing the current vehicle state value “downward to the right”. Difference ΔLR
Is smaller than 0.15 (mm), the process proceeds to step S3.
Proceed to 9. Next, in step S39, since the stroke difference ΔLR is smaller than 0.15 (mm), the control circuit detects that the current vehicle state has transitioned to “neutral”, and changes the vehicle state value from “lower right”. Change to "neutral".

As described above, according to the present invention, the stroke difference ΔL obtained from the change amount of the left and right stroke positions
When the vehicle state is detected based on R, a threshold value for detecting that the vehicle body B has transitioned from a state in which the vehicle body B has dropped to the left or right to “neutral”, and a hysteresis width in which the vehicle body B has shifted from “neutral” to the left or right. As a different value from the threshold value for detecting the transition to the state of
The hysteresis width is set as shown in FIG. In this hysteresis width, the threshold from “neutral” to “downward to right” or “downward to left” for determining the vehicle state value is greater than the threshold from “downward to right” or “downward to left” to “neutral”. The wide one prevents a sensitive response to a slight change in the stroke difference in the "neutral" state, and once changes to the "lower right" or "lower left" state, the slight change in the stroke difference This is to prevent returning to the "neutral" state. The hysteresis width is arbitrarily adjusted and set in accordance with the response speed of the control of the vehicle body B and the response characteristics of the sensor.

By including the above-described processing, the present invention has a hysteresis in the threshold value for the "neutral" state in addition to the effect of the first embodiment. Since the hunting of the vehicle state value that occurs when the stroke difference ΔLR changes across the threshold value is prevented, the target values of the torques TL and TR obtained from the stroke difference ΔLR are set to “0” in step S17 (FIG. 7). Or the output of the torques TTL and TTR, which are the final target values of the torque, can be avoided between the cases where the torques TL and TR have values. As a result, according to the present invention, the control circuit stabilizes the current value supplied to the actuators 1L and 1R without causing hunting,
This has the effect of improving the responsiveness of the control of the current corresponding to the torques TTL and TTR and improving the responsiveness of the control of the roll stiffness of the suspension. In addition, the present invention can prevent hunting due to the above-mentioned change of the stroke position across the “neutral” position.
Since the vibration of the vehicle body B due to sensitively affecting the subtle change is eliminated, the behavior of the vehicle body B is stabilized.

<Third Embodiment> As shown in FIG. 12, the configuration of the third embodiment is similar to that of the stroke sensor SL,
The point is that a lateral acceleration sensor SG for measuring the lateral acceleration of the vehicle body B is provided instead of SR. The lateral acceleration sensor SG is provided at a point on the axis of the roll center in the rolling of the vehicle body B. FIG. 12 is a see-through view from above showing the arrangement of the acceleration sensor SG and the steering angle sensor SA in the vehicle body B. Other configurations of the third embodiment are the same as those of the above-described first embodiment, and a description of the configuration will be omitted. Due to the difference in the configuration described above, in the third embodiment, the control circuit converts the torques TL and TR obtained from the stroke difference ΔLR in the first embodiment into lateral acceleration values DG ( m / s ² ). In the third embodiment, since the flow of the process for obtaining the torques YL, YR from the steering angular velocity is the same as that of the first embodiment, the description of the process for obtaining the torques YL, YR will be omitted.

In the flowchart of FIG. 13, an operation is performed to determine the torques YL and YR generated by the subsequent actuators 1L and 1R based on the lateral acceleration value DG. This calculation is based on the lateral acceleration value DG and the torques YL and Y shown in FIG.
From the relationship with R, the torques YL and YR are obtained corresponding to the steering angular velocity. In FIG. 14, the horizontal axis represents the lateral acceleration value DG, and the vertical axis represents the values of the torques YL and YL. Here, when the absolute value of the lateral acceleration value DG is, for example, not more than 1.5 (m / s ² ), the values of the torques YL and YR are set to “0”. this is,
A slight lateral acceleration may occur due to the movement of the steering wheel 8 during straight traveling, and the rigidity of the suspension is prevented from being excessively increased in response to the movement. That is, at a very small lateral acceleration, no torque is generated in the actuators 1L and 1R.
Operate the suspension at the basic spring rate to prioritize ride comfort. The maximum values of the torques YL and YR are, for example, when the lateral acceleration value DG is 5 (m / s ² ) to 130 (Nm)
Is set to The maximum values of the torques YL and YR and the inclination of the change in the torques YL and YL with respect to the lateral acceleration value DG are determined for each type of vehicle by a plurality of persons who test-ride the riding comfort and maneuverability of the vehicle. It is determined based on the selected numerical value and the like.

Next, the processing in the flowchart of FIG. 13 will be described. In this flowchart,
Based on the lateral acceleration value DG, an operation for obtaining the torques TL and TR generated by the actuators 1L and 1R is performed. Here, the lateral acceleration sensor SG outputs the lateral acceleration value DG applied to the right direction as a numerical value of (+), and outputs the lateral acceleration value DG applied to the left direction as a numerical value of (-). In step S41, the control circuit reads the detected lateral acceleration value DG from the lateral acceleration sensor SG. Step S
At 42, the control circuit determines the input lateral acceleration value DG
Is a preset reference acceleration value, for example, 1.5 (m /
s ² ) It is determined whether it is greater than. At this time, if the lateral acceleration value DG is not larger than 1.5 (m / s ² ), the control circuit advances the processing to step S43, where the lateral acceleration value DG is 1.
If it is larger than 5 (m / s ² ), the process proceeds to step S44. Next, in step S44, since the lateral acceleration value DG is larger than 1.5 (m / s ² ), the control circuit detects that the lateral acceleration is applied in the right direction and performs cornering on the left side. Judgment and the vehicle state value is "sloping down"
Set as

In step S42, the control circuit determines whether or not the input lateral acceleration value DG is smaller than a preset reference acceleration value, for example, -1.5 (m / s ² ). . At this time, control circuit, when the lateral acceleration value DG is not smaller than -1.5 (m / s ^2), processing advances to step S46, lateral acceleration value DG is than -1.5 (m / s ²⁾ If smaller, the process proceeds to step S45. Next, in step S45, the control circuit determines that the lateral acceleration value DG is-
Since it is smaller than 1.5 (m / s ² ), it is detected that the lateral acceleration is applied to the left direction, it is determined that the vehicle is cornering to the right, and the vehicle state value is set to “downward left”.
Further, in step S46, the control circuit determines that the input lateral acceleration value DG is from -1.5 (m / s ² ) to 1.5 (m / s ² ).
s ² ), the vehicle state value is set to “neutral”.

Here, from -1.5 (m / s ² ) to 1.5 (m / s ² )
The range of s ² ) prevents the suspension from increasing its rigidity in response to a slight change in the steering angle when traveling straight or on a gentle curve. In other words, when the lateral acceleration value DG changes very little, no torque is generated in the actuators 1L and 1R, and when the vehicle is going straight, the suspension is operated at the basic spring rate to give priority to ride comfort. Also, the torque Y obtained based on the lateral acceleration FG
The maximum values of L and YR are determined, for example, based on numerical values and the like selected by a plurality of persons who test-ride the ride comfort and maneuverability of the vehicle for each vehicle type. Next, in step S47, the control circuit calculates the torques TL and TR generated by the actuators 1L and 1R based on the lateral acceleration value DG. That is, the control circuit is stored in the storage unit,
From the graphs respectively showing the relationship between the lateral acceleration value DG shown in FIG. 14 and the torque generated in the actuators 1L and 1R, each of the torques YL and YR corresponding to the lateral acceleration value DG is selected and output as a calculation result. .

In step S48, the control circuit determines the torque Y generated by each of the actuators 1L and 1R at regular intervals.
Set L and YR. For example, based on the fact that the driver steers to the right and the steering angle direction flag is set to “right”, the control circuit sets the torque generation direction of the actuator 1L to “extend the left spring 6L”, and sets the actuator 1R The direction in which the torque is generated is set to the direction of “extending the right spring 6R”, and the vehicle body B rolls leftward, that is, in FIG. When the actuator 1L rotates in the direction of “downward”, the torque T that extends the spring 6L is
L is calculated, and on the other hand, the torque TR for compressing the spring 6R is calculated by rotating the actuator 1R in the direction.

Next, in the flowchart of FIG. 15, based on the torques YL and YR and the torques TL and TR obtained by the processing of the flowcharts of FIGS.
Find L, TTR. In step S51, the control circuit determines whether or not the vehicle state value is "neutral".
If the determination is not "neutral", the process proceeds to step S52.
If the vehicle state is "neutral", the process proceeds to step S55. Next, in step S52, the control circuit compares the vehicle state value with the steering angular velocity direction, that is, determines whether or not the rolling direction corresponds to the steering angular velocity direction.
Here, it is determined whether or not the vehicle state value is “downward left” and the steering speed direction is right. At this time, the control circuit advances the process to step S55 when the vehicle state value is “downward left” and the steering angular velocity direction is right, and advances the process to step S53 when the combination is not this combination.

Next, in step S53, the control circuit compares the vehicle state value with the steering angular velocity direction, that is, determines whether or not the vehicle is in a rolling direction corresponding to the steering angular velocity direction. And whether the steering speed direction is left. At this time, if the vehicle state value is “downward to the right” and the steering angular velocity direction is to the left, the control circuit proceeds to step S55. Otherwise, the control circuit proceeds to step S54. Next, in step S54, the control circuit causes the storage unit to store the torques TL and TR obtained from the lateral acceleration value DG as the torques TTL and TTR, respectively. In step S55, the control circuit calculates the torque TTL generated in the actuator 1L based on the equation "YL + TL", calculates the torque TTR generated in the actuator 1R based on the equation "YR + TR", and calculates the calculated torque. TTL and TTR are stored in the storage unit. Next, in step S56, the control circuit applies the torques TTL, TTR to the actuators 1L, 1R.
Calculates the amount of current for outputting. For example, in the case of PWM (pulse width modulation) control, the control circuit calculates the duty ratio of the width between the “H” level and the “L” level in a continuous pulse having a constant period in order to adjust the amount of current.

FIG. 16 is a table showing combinations of calculations performed by the control circuit in the above-described flowchart based on the state of the vehicle state value and the steering angular velocity direction flag in FIG. In this table, “forced addition” in the item “vehicle state is neutral” is a name defined as a special addition process that does not depend on the vehicle state in the processing of the program. Also, as can be seen from the table of FIG.
In the behavior of the vehicle body B, when the steering angular velocity direction flag matches the vehicle state value, the torque Y calculated from the steering angular velocity
L, YR and the torques TL, TR obtained from the lateral acceleration value DG are respectively added to generate torques TTL, TTR to be output to the final target actuator. Here, if the steering angular velocity direction flag and the vehicle state value do not match, if the values are added, the values of the torques TTL and TTR abruptly change because the polarities of the torques YL and YR and the torques TL and TR are opposite. .

Therefore, when the steering angular velocity direction flag does not match the vehicle state value, only the torques TL and TR obtained from the lateral acceleration value DG, which clearly indicate the rolling direction, are used for controlling the actuator. ing. On the other hand, when the vehicle body state value is "neutral" and the steering angular velocity direction flag and the vehicle state value do not match, as described above, the torques TTL and TTR to be controlled become "0", and the initial value of the cornering is reduced. In the transient state (lateral acceleration DG is "-1.5 <DG <1.
5 (m / s ² ) ”), the control cannot be performed, and in the anti-rolling control, a delay in a control system such as an actuator and a delay in control of the vehicle body B based on the vehicle compliance are caused.

Therefore, in the third embodiment, similarly to the first embodiment, when the vehicle body state value is “neutral”, the torques YL and YR based on the steering angular velocities obtained by differentiating the steering angle amount are used as the torques. The TL and TR are each forcibly added to "0" to compensate for the control delay of the vehicle body B and improve the response speed at the time of turning at the beginning of cornering. Therefore, for this reason, when it is desired to increase the current in order to increase the torque, the control circuit increases the duty ratio to increase the width of the “H” level, decrease the width of the “L” level, and reduce the torque. To reduce the current, the torque TT is adjusted so that the width of the “L” level is widened and the width of the “H” level is narrowed.
The duty ratio of each of L and TTR is calculated. At this time, the direction in which the torque is generated is controlled by reversing the direction of the current flowing through the motors ML and MR, as already described in the first embodiment.

Next, FIG. 17 shows an actual control flow. The processing performed at each time is the same as that of the first embodiment, and the torques TL and TR based on the stroke difference ΔLR are calculated as
Since only the torques TL and TR based on the lateral acceleration value DG are replaced with the detection of the vehicle state value, the description of the timing chart is omitted. In addition, in each of the drawings in FIG. 17, FIGS. 17D and 17E different from the first embodiment will be described. FIG. 17D shows the absolute values of the torques YL and YR calculated based on the steering angular velocity and the torques TL and TR calculated based on the lateral acceleration DG. Here, the torque YL and the torque YR are
The values are the same, but the directions in which the torque is applied are opposite to each other. Similarly, the values of the torque TL and the torque TR are the same, but the directions in which the torque is applied are opposite to each other. .

FIG. 17E shows the torque Y in FIG.
Torque TT which is the final target value obtained by adding L and torque TL
L and the absolute value of the torque TTR which is the final target value obtained by adding the torque YR and the torque TR. Here, the torque TTL and the torque TTR have the same value, but the directions of the forces are opposite to each other. Also, this torque T
The maximum values of TL and TTR are determined by adding the respective maximum values of the torque YL and the torque TL to obtain a torque TTL. It is determined by the strength of the actuator 1L that can cope with the torque. FIG. 17 (d)
17 (e) shows the absolute value, and the direction in which the torque of the actuators 1L and 1R is generated is indicated by the steering angle direction flag.

In the third embodiment, in addition to the effects of the first embodiment, since the lateral acceleration sensor SG is used instead of the stroke sensors SL and SR, the third embodiment uses the stroke sensors SL and SR. As compared with the first embodiment, since links and rods from the drive arms 4L and 4R to the stroke sensors SL and SR are not used, two expensive stroke sensors can be reduced, and the structure of the detection mechanism for detecting the vehicle body state value is simplified. This simplifies the system and reduces manufacturing costs. In the third embodiment, without using a stroke sensor, a rolling direction and a required torque value are obtained based on the lateral acceleration value DG, and control is performed to improve the vehicle body state by an actuator. It is possible to prevent a problem in control when a stroke sensor is used, which causes excessive control by picking up.

Further, in the relationship between the lateral acceleration value DG and the torques TL and TR in FIG. 14 used in the flowchart of FIG. 15, the vehicle speed, the steering angle, and the vehicle speed and the steering angle are used instead of the lateral acceleration value DG obtained by the lateral acceleration sensor SG. From the estimated lateral acceleration value DG '. As a result, the third
Since the embodiment of the present invention does not require the lateral acceleration sensor SG, the configuration and system can be further simplified,
Manufacturing costs can be reduced. The estimated lateral acceleration DG ′ used here has a different slope with respect to the change in the actual lateral acceleration depending on the actual size of the vehicle and the like. It has been confirmed that the linear approximation can be performed up to). Therefore, the estimated lateral acceleration D
G 'can be obtained from the test data of the actual vehicle as a graph showing the relationship between the steering angle speed and the vehicle speed.

In addition, in the third embodiment, similarly to the second embodiment, when the vehicle state is detected based on the value of the lateral acceleration value DG, the vehicle body B is moved from the state in which the vehicle body B is lowered to the left or right. A threshold value that detects that the vehicle body B has transitioned to “neutral” and a threshold value that detects that the vehicle body B has transitioned from “neutral” to a state in which the hysteresis width has decreased to the left or right are different numerical values. A hysteresis width as shown in FIG. 11 may be set. As a result, the third
This embodiment also has the effect of the second embodiment. As in the second embodiment, the hysteresis width is arbitrarily adjusted and set according to the response speed of the control of the vehicle body B and the response characteristics of the sensor.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and a design change or the like may be made without departing from the gist of the present invention. The present invention is also included in the present invention. For example, in the above-described first and second embodiments, the actuator is arranged on the rear suspension, but may be arranged on the front suspension and the suspension of all wheels.

[0077]

According to the present invention, the difference between the amount of movement of the left and right wheels in the vertical direction and the steering angular velocity are also detected, and the actuator is controlled based on the difference between the amount of movement of the wheels and the steering angular velocity. In order to do so, including when the body is neutral,
A torque based on the speed at which the steering wheel 8 is turned, that is, a steering angular speed is generated, and based on this torque, the torque of the actuator is controlled in the direction opposite to the rolling direction to increase the wheel rate in the opposite phase. Compared with the control based on, the roll stiffness in cornering is complemented, the initial response is improved, the response delay due to vehicle compliance can be improved, and the center of gravity of the vehicle body can be set from the start of cornering, The stability of the vehicle is always obtained against the centrifugal force generated by cornering. Also, according to the present invention, the steering operation is not performed during straight running, so that the steering wheel
Since the steering angle input by rotating is small,
Since the steering angular velocity is obtained as "0" and the difference in the amount of movement of the wheels with respect to the vehicle body due to rolling is obtained, the control circuit does not control the actuator, and the rigidity of the suspension is not supplemented. Since the suspension operates at the original reference value of the spring rate, the original riding comfort set in advance is not impaired.

[Brief description of the drawings]

FIG. 1 shows a first embodiment (or a second embodiment,
FIG. 11 is a perspective view from the rear of the vehicle, showing a configuration of a suspension on a rear (rear wheel) side according to a third embodiment).

FIG. 2 shows stroke sensors SL and SR in a vehicle body B.
FIG. 4 is a perspective view from above the vehicle, showing a position where a steering angle sensor SA is provided.

FIG. 3 is a conceptual diagram showing the type and configuration of the stroke sensor shown in FIG.

FIG. 4 is a timing chart showing changes in parameters for calculating the amount of torque generated by the actuators 1L and 1R according to the direction in which the driver steers.

FIG. 5 is a flowchart showing a flow of a calculation for obtaining torques YL and YR generated in actuators 1L and 1R based on a steering angular velocity (rad / sec).

FIG. 6 is a diagram showing a relationship between a steering angular velocity and torques YL and YL.

FIG. 7 shows an actuator 1 based on a stroke amount.
5 is a flowchart showing a flow of calculation for obtaining torques TL and TR generated by L and 1R.

8 is a flowchart showing a flow of an operation for calculating torques TTL and TTR actually generated in the actuators 1L and 1R based on the torques TL and TR and the torques TL and TR obtained by the processes in the flowcharts of FIGS. 5 and 7; It is.

FIG. 9 is a graph showing a combination of operations performed by the control circuit in the flowchart of FIG. 8;

FIG. 10 is a flowchart illustrating a determination process when a threshold value used for determination of a vehicle body state value has hysteresis.

FIG. 11 is a conceptual diagram showing a hysteresis width of a threshold value used in determining a vehicle body state value.

FIG. 12 is a see-through view from above showing an arrangement of the acceleration sensor SG and the steering angle sensor SA in the vehicle body B;

FIG. 13 is a flowchart showing a flow of a calculation for obtaining torques YL and YR generated on the actuators 1L and 1R based on a lateral acceleration value DG.

FIG. 14 is a diagram showing a relationship between a lateral acceleration value DG and torques YL and YL.

FIG. 15 is a flowchart showing a calculation flow for calculating torques TTL and TTR to be actually generated in the actuators 1L and 1R based on the torques YL and YR and the torques TL and TR obtained by the processes in the flowcharts of FIGS. It is.

FIG. 16 is a graph showing a combination of calculations performed by the control circuit in the flowchart of FIG.

FIG. 17 is a timing chart showing changes in parameters for calculating the amount of torque generated by the actuators 1L and 1R according to the direction in which the driver steers.

[Explanation of symbols]

 1L, 1R Actuator 2L, 2R Upper arm 3L, 3R Lower arm 4L, 4R Drive arm 5L, 5R Link 6L, 6R Knuckle 7L, 7R Coil spring 8 Handle GL, GR Reducer ML, MR Motor SA Steering angle sensor SG Lateral acceleration sensor SL , SR Stroke sensor WL, WR Wheel

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Koichi Kitazawa 1-4-1, Chuo, Wako-shi, Saitama Pref. Inside of Honda R & D Co., Ltd. (72) Inventor Kazuhisa Watanabe 143, Hagadai, Haga-cho, Haga-gun, Tochigi 3D001 AA03 BA03 CA01 DA17 EA01 EA08 EA22 EA36 EB00 EC03 EC05 EC07 EC08 EC09 ED02 ED09

Claims (6)

[Claims] 1. A method for controlling an actuator capable of generating a force for suppressing a roll of a vehicle body, comprising detecting a difference in the amount of movement of the right and left wheels in a vertical direction and also detecting a steering angular velocity, A method of controlling a suspension, wherein an actuator is controlled based on a difference between a moving amount and a steering angular velocity. 2. A stabilizer which mechanically connects the left and right wheels and generates a twist due to a difference in the amount of movement of the left and right wheels with respect to the vehicle body in the vertical direction, thereby suppressing a required wheel from rolling. 2. The suspension control method according to claim 1, wherein said actuator compensates for a shortage of force to be applied. 3. A method for controlling an actuator capable of generating a force for suppressing rolling of a vehicle body, wherein the lateral acceleration of the vehicle is detected, and the actuator is controlled based on the lateral acceleration and the steering angular velocity. Suspension control method. 4. When the roll direction of the vehicle and the steering speed direction coincide with each other, control is performed based on the difference in the amount of movement of the wheels with respect to the vehicle body and the steering angular speed, and the roll direction of the vehicle and the steering speed direction are determined. In the case of disagreement, control is performed based on the difference in the amount of movement of the wheels with respect to the vehicle body.In the neutral state where the vehicle roll is small, regardless of whether the roll direction of the vehicle and the steering speed direction match or not,
2. The suspension control method according to claim 1, wherein the control is performed based on a difference between a moving amount of the wheel with respect to the vehicle body and a steering angular velocity. 5. When the roll direction of the vehicle and the steering speed direction match, control is performed based on the lateral acceleration and the steering angular speed. When the roll direction of the vehicle does not match the steering speed direction,
Control based on lateral acceleration, in the neutral state where the roll of the vehicle is small, the roll direction of the vehicle matches the steering direction,
The suspension control method according to claim 3, wherein the control is performed based on the lateral acceleration of the wheel with respect to the vehicle body and the steering angular velocity regardless of the mismatch. 6. The suspension control method according to claim 4, wherein when determining that the vehicle is in the neutral state, the determination is performed with hysteresis.