JP3046103B2 - Vehicle suspension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling suspension characteristics by supplying and discharging fluid to and from a fluid chamber of a fluid cylinder installed between a vehicle body (above a spring) and each wheel (below a spring) of a vehicle. In particular, the present invention relates to improved control during turning.

[0002]

2. Description of the Related Art Conventionally, as a vehicle suspension device, for example, as disclosed in Japanese Patent Application Laid-Open No. 63-130418, a fluid cylinder is disposed between a vehicle body and each wheel. A pressure source such as a pump is connected to the fluid chamber via a fluid passage, and control valves for controlling the supply and discharge of fluid to and from the cylinder fluid chamber are provided in the middle of each fluid passage, and control of these control valves is performed. A so-called active control suspension device (ACS device) that can stabilize the vehicle body posture and improve ride comfort by changing the suspension characteristics by supplying and discharging fluid to and from the fluid chamber of each cylinder. It has been known.

[0003]

In the above-described ACS device, when controlling the operation of the control valve corresponding to each wheel, usually, a pressure sensor for detecting the internal pressure of each fluid cylinder, a cylinder for each fluid cylinder, A stroke sensor that detects a stroke amount, a longitudinal acceleration sensor that detects a longitudinal acceleration acting on the vehicle body, a lateral acceleration sensor that detects a lateral acceleration acting on the vehicle body, and an up-down acting on a lower portion of each wheel. And four unsprung acceleration sensors for detecting the acceleration in the direction of the vehicle, and controls the supply and discharge of the fluid to and from the fluid cylinder based on the load detected by these sensors and acting on the vehicle body when the vehicle is running. Will be

However, according to such operation control,
The value of the lateral acceleration acting on the vehicle body when the driver gives the target steering angle to the turn R by turning the steering wheel during turning is small, and the value of the lateral acceleration is the actual value of the feedback system such as the lateral acceleration sensor, the pressure sensor and the stroke sensor. Since it is detected by a signal based on the lateral acceleration, a delay occurs in the attitude control (roll control) at the beginning of the turn when the driver operates the steering wheel, and the turning performance is deteriorated.

Therefore, the driver turns the steering wheel R by turning the steering wheel based on signals from a steering angle element of a feedforward system such as a vehicle speed sensor and a steering angle sensor.
A virtual lateral acceleration value corresponding to the vehicle speed is calculated when a target steering angle with respect to the vehicle is given, and the posture control at the time of turning is performed based on the virtual lateral acceleration value. It is conceivable to prevent the delay and enhance the turning performance at the beginning of turning.

However, when the attitude control during turning is performed based on the virtual lateral acceleration value by the steering angle element as described above, the attitude control during turning is completed at the end of turning, that is, at the time of turning back of the steering wheel. The lateral acceleration acting on the vehicle body causes the vehicle body to swing back.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to effectively utilize the features of the attitude control using the steering angle element and the features of the attitude control using the actual lateral acceleration. In addition to improving the turning performance at the beginning of turning,
It is intended to surely prevent the swingback at the time of turning back the steering wheel.

It is another object of the present invention to more reliably prevent the swing-back operation when the steering wheel is turned back on the basis of the phase delay of the actual lateral acceleration generated between the front side and the rear side during turning.

It is another object of the present invention to prevent the occurrence of vibrations due to the change of the attitude control while improving the running stability by being restrained by the attitude control capable of improving the running stability during continuous turning. .

[0010] It is another object of the present invention to improve running stability after the steering wheel is turned back.

[0011]

Means for Solving the Problems In order to achieve the above object, a solution taken by the invention according to claim 1 is to dispose an extendable fluid cylinder installed between a sprung portion and a unsprung portion of a vehicle. It is assumed that the suspension device is provided and supplies and discharges fluid to and from the fluid chamber of the fluid cylinder to change and adjust the suspension characteristics. Virtual lateral acceleration calculating means for calculating a virtual lateral acceleration value acting on the vehicle body based on a vehicle speed signal from a vehicle speed sensor for detecting the vehicle speed and a signal from a steering angle sensor for detecting the steering angle; Based on the lateral acceleration detecting means for detecting the actual lateral acceleration value of the vehicle, the virtual lateral acceleration value acting on the vehicle body from the virtual lateral acceleration calculating means, and the actual lateral acceleration value from the lateral acceleration detecting means. The control means for performing control with a predetermined gain, and the attitude control gain of the control means based on the virtual lateral acceleration value is corrected to be greater than the gain of the attitude control of the control means based on the actual lateral acceleration value at the beginning of turning, and at the time of turning back. and a correcting means for correcting smaller than the gain of the attitude control of the control means according to the actual lateral acceleration value a gain of attitude control of the control means by the virtual lateral acceleration value, the correction means , Switchback
Control of the attitude of the control means based on the virtual lateral acceleration
The gain of the attitude control of the control means by the actual lateral acceleration value
When the correction is smaller than
Correct the gain to be larger than the front-wheel-side attitude control gain.
The configuration is as follows.

Further, the solution taken by the invention according to claim 2 is, like the invention described in claim 1 , a spring-loaded vehicle.
Telescopic fluid cylinder installed between
To supply and discharge fluid to and from the fluid chamber of the fluid cylinder.
Suspension that changes and adjusts the suspension characteristics
Device. Then, the vehicle speed control for detecting the vehicle speed is performed.
A steering angle sensor that detects the vehicle speed signal and steering angle from the sensor
Based on these signals, the virtual lateral acceleration value acting on the vehicle
Virtual lateral acceleration calculation means for calculating
Lateral acceleration detecting means for detecting an actual lateral acceleration value;
Virtual lateral acceleration acting on the vehicle body from the lateral acceleration calculation means
Value and the actual lateral acceleration value from the lateral acceleration detecting means.
To control the attitude during turning with a predetermined gain.
Control means and control means based on a virtual lateral acceleration value at the beginning of a turn.
The posture control gain is determined by the actual lateral acceleration value.
While the correction is made larger than the control gain,
The gain of the attitude control of the control means based on the virtual lateral acceleration
Less than the gain of the attitude control of the control means by the lateral acceleration value
And a correcting means for fence corrected, the correcting means is smaller than the gain of the attitude control of the control means according to the actual lateral acceleration value a gain of attitude control of the control means by the virtual lateral acceleration value during continuous turning the steering direction is reversed Correct to keep
Configuration .

Further, the solution taken by the invention according to claim 3 is, like the invention according to claim 1 , a spring-loaded vehicle.
Telescopic fluid cylinder installed between
To supply and discharge fluid to and from the fluid chamber of the fluid cylinder.
Suspension that changes and adjusts the suspension characteristics
Device. Then, the vehicle speed control for detecting the vehicle speed is performed.
A steering angle sensor that detects the vehicle speed signal and steering angle from the sensor
Based on these signals, the virtual lateral acceleration value acting on the vehicle
Virtual lateral acceleration calculation means for calculating
Lateral acceleration detecting means for detecting an actual lateral acceleration value;
Virtual lateral acceleration acting on the vehicle body from the lateral acceleration calculation means
Value and the actual lateral acceleration value from the lateral acceleration detecting means.
To control the attitude during turning with a predetermined gain.
Control means and control means based on a virtual lateral acceleration value at the beginning of a turn.
The posture control gain is determined by the actual lateral acceleration value.
While the correction is made larger than the control gain,
The gain of the attitude control of the control means based on the virtual lateral acceleration
Less than the gain of the attitude control of the control means by the lateral acceleration value
And a correcting means for fence corrected, the correction means, and configured to return the gain of the attitude control of the control means after switching back completion to the initial value.

[0014]

According to the first aspect of the present invention,
First, when turning based on the virtual lateral acceleration value from the virtual lateral acceleration calculating means calculated based on both signals from the vehicle speed sensor and the steering angle sensor and the actual lateral acceleration value from the lateral acceleration detecting means. Since the predetermined gain of the attitude control by the control means is corrected by the correction means in the initial stage of the turn so that the gain of the attitude control based on the virtual lateral acceleration value is larger than the gain of the attitude control based on the actual lateral acceleration value, Initially, the attitude control is performed by the control means with the gain of the attitude control based on the virtual lateral acceleration value calculated based on the signal from the steering angle element of the feedforward system such as the vehicle speed sensor and the steering angle sensor. A delay in attitude control in the initial stage of turning in which the target steering angle is given to the turning R by the operation of the steering wheel is prevented, and the turning performance in the initial stage of turning is enhanced.

On the other hand, the predetermined gain of the attitude control by the control means at the end of the turn, that is, the steering wheel return timing, is set so that the gain of the attitude control based on the virtual lateral acceleration value is smaller than the gain of the attitude control based on the actual lateral acceleration value. Since the correction is corrected by the correction means, the attitude control by the control means is detected by detecting the actual lateral acceleration still acting on the vehicle body at the time of the steering wheel return without terminating the attitude control at the time of the steering wheel return. By continuing, the swingback that occurs in the vehicle body at the time of turning back the steering wheel is reliably prevented.

Secondly, the predetermined gain of the attitude control by the control means at the time of turning is determined by changing the gain of the attitude control of the control means by the actual lateral acceleration value at the time of turning back to the attitude of the control means by the virtual lateral acceleration value. When the correction is made smaller than the control gain, the correction means corrects the rear-wheel-side attitude control gain so as to be larger than the front-wheel-side attitude control gain. Even when the actual lateral acceleration on the front side lags between the rear side and the actual lateral acceleration on the front side, the body returns more reliably on the rear side of the steering wheel when the steering wheel is turned back due to the actual lateral acceleration still remaining on the rear side. Is prevented.

Further, in the invention according to claim 2 , the above-mentioned claim is provided.
The first effect of the invention according to item 1 is obtained, and in addition to this,
Te, predetermined gain for attitude control by the control means during turning
However , since the gain of the attitude control based on the virtual lateral acceleration value is maintained to be smaller than the gain of the attitude control based on the actual lateral acceleration value during continuous turning in which the steering direction is reversed, the second correction is performed. It will be restrained by the posture control that reliably prevents the turning back of the steering wheel turning back time while improving the turning performance at the beginning of turning after turning, so that running stability is improved during continuous turning and posture control. The occurrence of vibrations due to the change of is prevented.

Further, in the invention according to claim 3 , the contract
The first operation of the invention according to claim 1 is obtained, and in addition to this,
Ete, predetermined gain for attitude control by the control means during turning
However , since the correction means corrects the attitude control gain to return to the initial value after the turning back is completed, the running stability at the time of the straight line after the turning back of the steering wheel is completed, that is, after the turning back is completed.

[0019]

As described above, according to the vehicle suspension system of the first aspect of the present invention, first, the correction means sets the predetermined gain of the attitude control by the control means during turning to a virtual value at the beginning of turning. While correcting the gain of the attitude control based on the virtual lateral acceleration value from the lateral acceleration calculation means to be larger than the gain of the attitude control based on the actual lateral acceleration value,
At the time of steering wheel turning back, the posture control gain based on the virtual lateral acceleration value was corrected to be smaller than the posture control gain based on the actual lateral acceleration value, so that the delay in the posture control due to the driver's steering operation at the beginning of turning can be prevented. The turning performance can be improved, and the attitude control for the actual lateral acceleration still acting on the vehicle body at the time of turning the steering wheel back can be continued to reliably prevent the swing back.

In addition, second, by the above-mentioned correction means,
The predetermined gain of the attitude control by the control means at the time of turning is corrected so that the gain of the attitude control of the control means by the actual lateral acceleration value is smaller than the gain of the attitude control of the control means by the virtual lateral acceleration value at the time of turning back. Sometimes, the gain of the attitude control on the rear wheel side was corrected to be larger than the gain of the attitude control on the front wheel side, so that even if the actual lateral acceleration on the front side disappeared, the rear side Swing back can be more reliably prevented.

According to the vehicle suspension device of the second aspect of the present invention, the vehicle according to the first aspect of the present invention is provided.
In addition to obtaining the first effect, the correction means sets the predetermined gain of the attitude control by the control means during turning to the gain of the attitude control based on the virtual lateral acceleration value during the continuous turning in which the steering direction is reversed. The value is corrected so as to be kept smaller than the gain of the attitude control by the value, so that it is possible to improve the turning performance at the beginning of turning after the second turning, and to surely prevent the turning back of the steering wheel turning back time. In addition, it is possible to improve the running stability at the time of continuous turning and the like, and to effectively prevent the occurrence of vibration due to the change in the posture control.

Further, according to the vehicle suspension device of the third aspect of the invention, the vehicle according to the first aspect of the invention is provided.
In addition to obtaining the first effect, the correction means corrects the predetermined gain of the attitude control by the control means at the time of turning so that the gain is returned to the initial value after the return is completed. Traveling stability can be improved.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the overall configuration of a suspension device according to one embodiment of the present invention. In the figure, reference numeral 1 denotes a vehicle body constituting a sprung portion of the vehicle, 2F denotes a front wheel, 2R denotes a rear wheel, and these wheels 2F, 2R are supported by wheel support members (not shown) such as axles. And each of these wheels 2
An unsprung portion is constituted by F, 2R and the wheel support member.

The vehicle body 1, ie, a sprung portion, and each wheel 2
An extendable hydraulic cylinder 3 is provided between the unsprung portion including F and 2R. As shown in FIG. 2, each of the cylinders 3 is provided with the wheel support member (wheel 2F, 2R).
And a cylinder body 3a fixedly connected to the cylinder body 3a.
a and a piston 3b for partitioning the inside into upper and lower hydraulic chambers 4 and 5. An upwardly extending piston rod 3c is integrally connected to the piston 3b. An upper end of the piston rod 3c has a pressure sensor 21 for detecting the internal pressure of the cylinder 3 (the upper hydraulic chamber 4 and the lower hydraulic chamber 5).
It is connected and fixed to the vehicle body 1 via (pressure detecting means).

The upper and lower hydraulic chambers 4 and 5 of the cylinders 3 are connected to an oil pump 8 and a reserve tank 9 driven by a vehicle-mounted engine (not shown) through oil passages 6 and 7, respectively. I have. Oil passage 6,
In the middle of 7, there are arranged the same number (four) of control valves 10,... As the wheels 2F, 2R, for controlling the supply and discharge of oil (fluid) to and from the hydraulic chambers 4, 5 of the cylinder 3. Each of the control valves 10 is a proportional control valve having three switching positions, and controls the switching positions (PID control) to control the supply and discharge of oil to and from the hydraulic chambers 4 and 5 of each cylinder 3. .

Each control valve 10 is connected to each wheel 2F, 2R.
The operation is controlled by a controller 22 with a built-in CPU provided correspondingly to. The controller 22 receives the detection signal of the pressure sensor 21 and the wheel 2
A detection signal of a stroke sensor 23 that detects a stroke amount x (spring of the cylinder 3) between the sprung and unsprung portions corresponding to F and 2R is input. Also,
The controller 22 includes a feed-forward signal, that is, a vehicle speed signal output from a vehicle speed sensor 24, a steering angle signal and its speed signal output from a steering angle sensor 25, and a lateral acceleration detection means. An actual actual lateral acceleration signal output from the lateral acceleration sensor 26 is input. The stroke sensor 23 has a sensor main body 23a fixed to the vehicle body 1, and a movable portion 23b slidably fitted in the main body 23a. The movable part 23b is connected to the corresponding body 3a of the cylinder 3 via a rod 23c, and the cylinder 3
The expansion / contraction stroke of is detected. And in this embodiment,
The displacement amount of the unsprung portion of each wheel 2F, 2R is detected by the stroke sensor 23.

Here, a controller 22 for supplying and discharging oil to and from the hydraulic chambers 4 and 5 of each cylinder 3 shown in FIG.
4 will be described with reference to the flowchart of FIG. 4. First, after starting and initializing in step SA, in step SB, the signal from the stroke sensor 23 is measured, and the signal is applied to the vehicle body 1 when the vehicle is running. All the loads to be performed are measured by the pressure sensor 21 as the actual pressure P.

Then, in step SC, based on the actual pressure P measured by the pressure sensor 21, the basic stroke xr
Xr = x0 + (P0-P) / KB {x0: initial stroke} {P0: initial pressure} {KB: spring constant}.

Next, in step SD, the virtual lateral acceleration Dyg acting on the vehicle body 1 based on the vehicle speed signal from the vehicle speed sensor 24 and the steering angle signal from the steering angle sensor 25.
Is calculated, and the actual actual lateral acceleration Yg acting on the vehicle body is measured by the lateral acceleration sensor 26 in step SE.

Further, in step SF, based on the virtual lateral acceleration Dyg in step SD and the actual lateral acceleration Yg in step SE, a steering angle element during vehicle running, that is, a steering angle amount during turning and a roll angle generated by the speed thereof. Roll gain Kg of actual lateral acceleration Yg according to
And the roll control gain Kd of the virtual lateral acceleration Dyg. Thereafter, in step SG, a correction stroke x2 at the time of vehicle body behavior during vehicle running is calculated based on the roll control gains Kg and Kd in step SF as follows: x2 = − (P0−P) / KB + Kg × Yg + Kd × Dy
g.

Thereafter, in step SH, a target stroke x1 is calculated from the basic stroke xr calculated in step SC and the correction stroke x2 calculated in step SG according to x1 = xr + x2. x1
After the PID control is performed so as to converge to the above, returning to step SA is repeated.

Therefore, in the present embodiment, the vehicle body 1 is determined based on the vehicle speed signal from the vehicle speed sensor 24 and the steering angle signal from the steering angle sensor 25 in step SD in the above flow.
A virtual lateral acceleration calculating means 31 for calculating (calculating) the virtual lateral acceleration Dyg acting on. In addition, the actual lateral acceleration Y set according to the roll angle generated by the steering angle amount and the speed at the time of turning in the above-described step SF.
g and the roll control gain Kd of the virtual lateral acceleration Dyg.
B, in addition to the control for changing the steering angle, the actual lateral acceleration Y corresponding to the roll angle generated by the steering angle amount and the speed at the time of turning.
Correction means 32 is configured to correct the roll control gain Kg of the g and the roll control gain Kd of the virtual lateral acceleration Dyg.

Next, the steering angle amount θH and the speed dθH during turning while the vehicle is running in step SF of the above flow.
The correction of the roll control gains Kg and Kd according to the roll angle caused by / dt will be described with reference to a subroutine shown in FIG. 5. First, step SF1 in FIG.
, It is determined whether or not the flag F is F = 1.
In the present embodiment, the flag F is set to F = 1 during continuous turning in which the steering direction is reversed left and right. Therefore, at the start of turning, the flag F is set to F = 0. The result is NO. Then, step S
In F2, the absolute value | dθH / dt | of the steering angular velocity dθH / dt during turning becomes a somewhat sharp steering angular velocity dθH0 /
It is determined whether it is larger than dt, and as a result, in the case of YES, in step SF3,
While the roll control gain Kg of the actual lateral acceleration Yg is set to 1.7 and the roll control gain Kd of the virtual lateral acceleration Dyg is set to 0.3, when NO, the process returns to step SF1 is repeated.

Next, in step SF4, it is determined whether or not the sign of the steering angular velocity dθH / dt has been inverted.
In the case of S, it is determined that the turning back has been completed at the turning end timing, and the process proceeds to Step SF5. In this step SF5, the roll control gain KgF (actual lateral acceleration Yg) on the front wheel 2F side according to the roll angle is set to 0.4, the roll control gain KgR on the rear wheel 2R side is set to 0.3, and the front wheel 2 is set.
F-side roll control gain KdF (virtual lateral acceleration Dyg)
Is set to 1.6 and the roll control gain KdR on the rear wheel 2R side is set to 1.7, respectively. On the other hand, if NO, the process returns to step SF1.

Thereafter, in step SF6, it is determined whether or not both the steering angle amount θH and the steering angle speed dθH / dt during turning are substantially zero. If YES, the steering wheel is returned to the straight-ahead position and the steering angular speed is determined. It is determined that dθH / dt has not been reached and the steering wheel has been returned, and the process proceeds to step SF7. Then, in this step SF7,
After a predetermined time has elapsed, the roll control gain Kg (KgF,
KgR) to 1 and the roll control gain Kd (KdF, Kd
R) is set to 1, that is, returned to the initial value, while NO
In this case, returning to step SF1 is repeated. In this case, the predetermined time from the completion of the steering wheel return for returning the roll control gains Kg and Kd to the initial values is changed depending on the vehicle speed.

On the other hand, if the determination in step SF1 is YES that the flag F is F = 1, in step SF8, the steering angle θH and the steering angular velocity dθH / dt during turning are determined.
Are substantially zero or not, and if YES,
After resetting the flag F to F = 0 in step SF9,
In step SF10, the roll control gains Kg and Kd are each set to 1 (initial value) after a predetermined time has elapsed, and when NO, the process returns to step SF1.

Next, the setting of the flag F in step SF1 of the above flow will be described with reference to a subroutine shown in FIG. 6. First, in step SFF in FIG.
1, the absolute value of the steering angular velocity dθH / dt during turning |
The steering angular velocity dθH0 / d where dθH / dt |
It is determined whether or not it is greater than t. If the result is YES, a timer is started in step SFF2. Next, in step SFF3, the steering angular velocity dθH / dt
In step SFF4, the number of reversals of the negative sign, that is, the number of times the vehicle has passed the straight-ahead position of the steering wheel in accordance with the left and right turns is integrated until the time is up. Then, in step SFF5, it is determined whether or not it is a continuous turning in which the number of reversals of the sign of the steering angular velocity dθH / dt within this predetermined time (the number of times of passing the steering straight position) is large. It is determined that the vehicle is in continuous turning, and the flag F is set to F = 1 in step SFF6. On the other hand, when NO, it is determined that the vehicle is not in continuous turning, and when the determination in step SFF1 is NO. Similarly, in step SFF7, the flag F is set to F = 0.

Therefore, in the above embodiment, the virtual lateral acceleration Dyg acting on the vehicle body 1 from the virtual lateral acceleration calculating means 31 calculated based on the vehicle speed signal from the vehicle speed sensor 24 and the steering angle signal from the steering angle sensor 25. , And the roll control gains Kd, Kg by the controller 22 at the time of turning performed based on the actual actual lateral acceleration Yg acting on the vehicle body measured by the lateral acceleration sensor 26 are the continuous turning in which the steering direction is reversed left and right. In the initial turn when the vehicle is not turning, the absolute value | dθH / dt | of the steering angular velocity dθH / dt at the time of turning is larger than the steering angular velocity dθH0 / dt, which is somewhat steep, at the beginning of turning, and the roll control gain K based on the virtual lateral acceleration Dyg is obtained.
The correction means 32 corrects d so that d becomes larger than the roll control gain Kg based on the actual lateral acceleration Yg, that is, the roll control gain Kd of the virtual lateral acceleration Dyg becomes 1.7, and the roll of the actual lateral acceleration Yg is obtained. The control gain Kg is set to 0.3. As a result, in the initial stage of turning, the virtual lateral acceleration D calculated on the basis of the signal from the feedforward steering angle element such as the vehicle speed sensor 24 and the steering angle sensor 25 is calculated.
The roll control is performed with a roll control gain Kd based on yg, thereby preventing a delay in the posture control at the beginning of turning when the driver gives the target steering angle to the turning R by operating the steering wheel at the time of turning, and turning at the beginning of turning. Performance can be improved.

On the other hand, the roll control gains Kd and Kg by the controller 22 at the steering wheel turning back time when the sign of the steering angular velocity dθH / dt is reversed, that is, when the turning back is completed at the turning end time, are the virtual lateral The roll control gain Kd by the acceleration Dyg is smaller than the roll control gain Kg by the actual lateral acceleration Yg, and the roll control gain Kg on the rear wheel side.
R is corrected by the correction means 32 so that R becomes larger than the roll control gain KgF on the front wheel side, that is, the roll control gain KdF (virtual lateral acceleration Dyg) on the front wheel 2F side becomes 0.4,
The roll control gain KdR on the rear wheel 2R side is 0.3, and the roll control gain KgF on the front wheel 2F side (virtual lateral acceleration Yg).
Is set to 1.6, and the roll control gain KgR on the rear wheel 2R side is set to 1.7. As a result, the actual lateral acceleration Yg still acting on the vehicle body at the steering wheel return time is detected without ending the roll control during turning at the steering wheel return completion time, and the control by the controller 22 is performed.
The phase delay of the actual lateral acceleration Yg between the front side and the rear side at the time of turning, that is, due to the actual lateral acceleration Yg still remaining on the rear side even if the actual lateral acceleration Yg on the front side disappears, while continuing the control of the vehicle. It is possible to reliably prevent the vehicle from swinging back on the rear side when the steering wheel is turned back.

Further, the roll control gains Kd and Kg by the controller 22 at the time of turning are determined when the turning is continuous during which the number of reversals of the negative sign of the steering angular velocity dθH / dt within a predetermined time becomes large. The roll control gain Kd based on the virtual lateral acceleration Dyg is changed to the roll control gain K based on the actual lateral acceleration Yg.
Since the correction is made by the correction means 32 so as to keep it smaller than g, the turning back of the steering wheel turning back time is surely prevented while improving the turning performance at the beginning of turning after the second turning. As a result of being constrained by the roll control gain Kg of the actual lateral acceleration Yg, it is possible to improve running stability during continuous turning, etc., and to effectively prevent the occurrence of vibrations due to changes in attitude control. can do.

Further, the roll control gains Kd and Kg by the controller 22 at the time of turning are the gains of the attitude control after turning back when the steering angle amount θH and the steering angular velocity dθH / dt are both substantially zero at the time of turning. Is corrected by the correction means so as to return to the initial value, that is, each is set to 1 (initial value), so that the running stability at the time of the straight line after the turning back of the steering wheel is completed, that is, the turning is completed can be improved.

It should be noted that the present invention is not limited to the above-described embodiment, but includes various other modifications.
For example, in the above-described embodiment, the controller 22 performs a turning operation based on the virtual lateral acceleration Dyg acting on the vehicle body 1 from the virtual lateral acceleration calculating means 31 and the actual lateral acceleration Yg from the lateral acceleration sensor 26. Control gain Kd,
Kg is the steering angular velocity dθH at which the absolute value | dθH / dt | of the steering angular velocity dθH / dt at the time of the first turn is not a continuous turn in which the steering direction is reversed to the left and right.
At the beginning of a turn larger than 0 / dt, the virtual lateral acceleration Dyg
Correction means 3 so that the roll control gain Kd based on the actual lateral acceleration Yg becomes larger than the roll control gain Kg based on the actual lateral acceleration Yg.
However, at the beginning of a turn in which the absolute value of the steering angular velocity is larger than the steering angular velocity to some extent during continuous turning, the roll control gain based on the virtual lateral acceleration is reduced by the actual lateral acceleration. The gain may be corrected by the correction means so as to be larger than the control gain.

Further, in the above embodiment, the roll control gains Kd and K by the controller 22 at the time of turning back the steering wheel.
g is the roll control gain Kd based on the virtual lateral acceleration Dyg.
Is corrected by the correction means 32 such that the roll control gain KgR on the rear wheel side is larger than the roll control gain KgF on the front wheel side and smaller than the roll control gain Kg based on the actual lateral acceleration Yg. The correction means may make correction so that the roll control gain based on the virtual lateral acceleration is simply smaller than the roll control gain based on the actual lateral acceleration.

Further, in the above embodiment, the roll control gains Kg and Kd are set to 1 after a predetermined time has elapsed when both the steering angle amount θH and the steering angular velocity dθH / dt during turning are substantially zero. However, each of the roll control gains may be set to 1 after a predetermined time has elapsed when the steering angular velocity is equal to or less than a predetermined value and the actual lateral acceleration is equal to or less than a predetermined value. In this case, the predetermined time and the predetermined steering angular speed are changed according to the vehicle speed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of a suspension device.

FIG. 2 is a system diagram showing a configuration of a control system.

FIG. 3 is a block diagram showing a configuration of a control system by blocks.

FIG. 4 is a flowchart showing a signal processing procedure in a controller.

FIG. 5 is a subroutine showing correction of a roll control gain during turning.

FIG. 6 is a subroutine showing setting of a flag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2F, 2R Wheel 3 Hydraulic cylinder (fluid cylinder) 4, 5 Hydraulic chamber (fluid chamber) 21 Pressure sensor (pressure detecting means) 22 Controller (control means) 24 Vehicle speed sensor 25 Steering angle sensor 26 Lateral acceleration sensor (lateral) Acceleration detecting means) 31 virtual lateral acceleration calculating means 32 correction means Yg actual lateral acceleration Dyg virtual lateral acceleration Kd, Kg Roll control gain (gain of attitude control)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60G 17/01 B60G 17/015

Claims (3)

(57) [Claims] An extendable fluid cylinder is provided between a sprung portion and a unsprung portion of a vehicle, and fluid is supplied to and discharged from a fluid chamber of the fluid cylinder to change and adjust a suspension characteristic. In the suspension device as described above, virtual lateral acceleration calculating means for calculating a virtual lateral acceleration value acting on the vehicle body based on a vehicle speed signal from a vehicle speed sensor for detecting a vehicle speed and a signal from a steering angle sensor for detecting a steering angle, A lateral acceleration detecting means for detecting an actual actual lateral acceleration value acting on the vehicle body, a virtual lateral acceleration value acting on the vehicle body from the virtual lateral acceleration calculating means, and an actual lateral acceleration value from the lateral acceleration detecting means. A control means for controlling the attitude during the turning with a predetermined gain, and a gain for controlling the attitude of the control means based on the virtual lateral acceleration value at the beginning of the turning. On one correcting larger than the gain, and a correcting means for correcting smaller than the gain of the attitude control of the control means according to the actual lateral acceleration value a gain of attitude control of the control means by the virtual lateral acceleration value to failback time, the The correction means controls at the time of switchback based on the virtual lateral acceleration value.
The gain of the attitude control of the control means is controlled by the actual lateral acceleration value.
When the correction is smaller than the gain of the attitude control of the step
The gain of the attitude control on the rear wheel side is
A suspension device for a vehicle, wherein the suspension device is configured to perform correction larger than in . 2. A vehicle which is provided between a sprung portion and an unsprung portion of a vehicle.
Telescopic cylinder is provided,
Suspension characteristics are changed by supplying and discharging fluid to and from the fluid chamber.
In a suspension device that adjusts the vehicle speed, a vehicle speed signal and a steering angle from a vehicle speed sensor that detects the vehicle speed are obtained.
Acts on the vehicle body based on the signal from the detected steering angle sensor
Virtual lateral acceleration calculating means for calculating a virtual lateral acceleration value, and lateral acceleration for detecting an actual actual lateral acceleration value acting on the vehicle body
Detecting means and a virtual lateral force acting on the vehicle body from the virtual lateral acceleration calculating means;
Acceleration values, and the actual lateral acceleration value from YokoKa speed detecting means
Based on the above, the posture control at the time of turning with a predetermined gain
Control means for controlling the attitude of the control means based on the virtual lateral acceleration value at the beginning of the turn.
Gain of attitude control of control means by actual lateral acceleration value
Virtual acceleration during switchback
The gain of the attitude control of the control means by the degree value is the actual lateral acceleration value
To be smaller than the gain of the attitude control of the control means by
Correction means, wherein the correction means performs virtual rotation during continuous turning in which the steering direction is reversed.
The actual lateral gain of the attitude control gain of the control means based on the lateral acceleration value
Less than the gain of the attitude control of the control means by the speed value
That it is configured to compensate for
A suspension device for a vehicle. 3. A vehicle which is provided between a sprung portion and an unsprung portion of a vehicle.
Telescopic cylinder is provided,
Suspension characteristics are changed by supplying and discharging fluid to and from the fluid chamber.
In a suspension device that adjusts the vehicle speed, a vehicle speed signal and a steering angle from a vehicle speed sensor that detects the vehicle speed are obtained.
Acts on the vehicle body based on the signal from the detected steering angle sensor
Virtual lateral acceleration calculating means for calculating a virtual lateral acceleration value, and lateral acceleration for detecting an actual actual lateral acceleration value acting on the vehicle body
Detecting means and a virtual lateral force acting on the vehicle body from the virtual lateral acceleration calculating means;
Acceleration value and actual lateral acceleration value from lateral acceleration detection means
Based on the above, the posture control at the time of turning with a predetermined gain
Control means for controlling the attitude of the control means based on the virtual lateral acceleration value at the beginning of the turn.
Gain of attitude control of control means by actual lateral acceleration value
Virtual acceleration during switchback
The gain of the attitude control of the control means by the degree value is the actual lateral acceleration value
To be smaller than the gain of the attitude control of the control means by
Correction means, and the correction means controls the posture of the control means after the completion of the switchback.
A vehicle for returning a gain to an initial value.
Suspension equipment.