JPH0438212A - Car suspension device - Google Patents

Abstract

PURPOSE:To effectively restrain a transient rolling state by changing a target roll deflection amount from a previously specified standard value to the reversal roll side against the direction on acceleration in the cross direction by a specific amount at the time when a derivative value of acceleration in the cross direction is higher than a specific value. CONSTITUTION:A suspension characteristic controller 90 enumerates a derivative value of cross direction acceleration added in the cross direction of a car detected by a cross acceleration sensor 16 with a unit 91. Additionally, it compares an absolute value of the derivative value of cross direction acceleration with a first specified value and a second specified value by a unit 92. Additionally, it memorizes a standard map of control gain and outputs each control gain to a fluid control amount enumeration device 100. Thereafter, on the basis of the above judgement signal and a cross acceleration detection signal, for example, when a derivative value of cross direction acceleration is higher than the first specified value, it outputs a target roll deflection amount compensating signal to compensate a target roll deflection amount by a specific amount to a reversal roll side against the direction of cross direction acceleration to the above means 93 by a means 94.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a suspension system for a vehicle, and more particularly to an active suspension system capable of changing suspension characteristics as desired. .

Prior Art Suspension devices conventionally called passive suspensions are composed of a hydraulic shock absorber and a damper unit made of a spring such as a coil spring.The suspension characteristics can be adjusted by making the damping force of the hydraulic shock absorber variable. Although it is possible to change it to some extent, the range is small and, in practice, the suspension characteristics of passive suspension devices are set uniformly.

In contrast, in recent years, a fluid cylinder device is provided between the sprung mass and the unsprung mass, and by controlling the supply and discharge amount of working fluid to this fluid cylinder device,
A suspension device called an active suspension that can change the suspension characteristics as desired has been proposed (for example, Japanese Patent Publication No. 5!11-
14365, JP-A-63-130418, etc. ).

Generally, there are three types of vehicle vibration: bounce, pitch, and roll, and such active suspension systems include a fluid cylinder device for each wheel.
In order to improve riding comfort and running stability against these three types of vehicle vibrations, the supply and discharge amount of working fluid to the fluid cylinder device of each wheel is set and controlled according to the vehicle operating condition. The control is performed by controlling the opening degree of the flow control valve of each wheel using a predetermined control gain.

Problems to be Solved by the Invention As described above, the active suspension device adjusts each wheel to improve riding comfort and running stability against three types of vehicle vibrations, depending on the driving condition of the vehicle. In order to control the supply and discharge of working fluid to the fluid cylinder device with a predetermined control gain, the operating state of the vehicle is detected,
Although the system is equipped with a suspension characteristic control device that changes the settings of each control gain, the control in such an active suspension device is essentially feedback control, and the driver operates the steering wheel greatly and suddenly. When a large lateral acceleration is applied to a vehicle, the phenomenon that the vehicle rolls transiently at a roll angle different from the target roll angle inevitably occurs, causing discomfort and discomfort to the driver. There was a problem that it gave a sense of discomfort. Although this transient roll state generally resolves within a short period of time, it is still difficult to avoid giving the driver a feeling of discomfort or discomfort. When setting the control gain to a large value, the active suspension system reacts too sensitively to changes in driving conditions, causing new problems such as deteriorating ride comfort and causing discomfort or discomfort to the driver. Therefore, there was a problem in that such an excessive roll state could not be effectively suppressed.

Purpose of the Invention The present invention has a fluid cylinder device for each wheel between the sprung mass and the unsprung mass of the vehicle, and sets the control gain of the suspension characteristics according to the driving condition of the vehicle. The suspension characteristic control device includes a suspension characteristic control device for controlling the vehicle, and a displacement detection device for detecting the displacement of the vehicle, and the displacement of the vehicle is determined based on the detection result of the displacement detection device with a predetermined control gain set and controlled by the suspension characteristic control device. An object of the present invention is to provide a suspension device for a vehicle that can effectively suppress a transient roll state in an active suspension device that controls the amount of supply and discharge of working fluid to a fluid cylinder device so as to cancel out the It is something.

Structure of the Invention The object of the present invention is to provide a lateral acceleration detection means for detecting lateral acceleration applied to a vehicle, and a lateral acceleration differential value calculation for calculating a differential value of the lateral acceleration detected by the lateral acceleration detection means. means, wherein the suspension characteristic control device sets the target roll displacement amount to a predetermined reference value when the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means is equal to or greater than a predetermined value. This is achieved by changing the direction of the acceleration in the lateral direction by a predetermined amount toward the opposite roll side.

In a preferred embodiment of the present invention, the suspension characteristic control device calculates the amount of working fluid supplied and discharged to the fluid cylinder device according to the displacement speed of the vehicle so as to suppress the displacement speed of the vehicle. A working fluid flow rate calculation means is provided, and the working fluid flow rate calculation means is configured to calculate the supply amount and discharge amount of the working fluid to the fluid cylinder device based on the changed target roll displacement amount. There is.

In another preferred embodiment of the present invention, the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means is equal to or greater than a predetermined value, and the suspension characteristic control device adjusts the target roll displacement amount to: After changing the direction of the lateral acceleration by a predetermined amount to the reverse roll side from the reference value, the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means becomes less than a predetermined value. When this happens, the suspension characteristic control device is configured to gradually return the target roll displacement amount to the reference value.

In another preferred embodiment of the present invention, the vehicle suspension system further includes a lateral acceleration differential value change rate calculation means for calculating a change rate of the lateral acceleration calculated by the lateral acceleration derivative value calculation means; angle detection means, and even if the lateral acceleration calculated by the lateral acceleration differential value calculation means is greater than or equal to a predetermined value, the differential of the acceleration in the Chinese direction calculated by the lateral acceleration differential value change rate calculation means is provided. When the rate of change of the value is greater than or equal to a predetermined value, and it is determined that the steering angle detected by the steering angle detection means is stable, the suspension characteristic control device adjusts the target roll displacement amount to the reference value. It is configured to revert to the value.

Effects of the Invention According to the present invention, in an operating state in which the handlebar is operated greatly and rapidly and transient roll occurs, the suspension characteristic control device changes the target roll displacement amount by a predetermined amount toward the reverse roll side. Because of this, the roll that occurs transiently can be offset and the transient roll can be prevented. Also, the transient roll has a large handle and
This occurs only in transient operating conditions where the active suspension is being operated rapidly. Therefore, after such transient operating conditions are resolved, it is important to return the target roll displacement amount to the fixed reference value in advance. In order to fully utilize the control characteristics of the device, it is desirable, but according to the present invention, the target roll displacement amount is changed from the reference value to the lateral acceleration only in an operating state where the lateral acceleration is equal to or higher than a predetermined value. Since the direction of the active suspension device is changed by a predetermined amount to the opposite roll side, suspension control is performed in accordance with the predetermined target roll displacement amount in driving conditions other than transient driving conditions. It becomes possible to take full advantage of favorable control characteristics.

According to a preferred embodiment of the present invention, the working fluid flow rate calculation calculates the supply amount and discharge amount of the working fluid to the fluid cylinder device so as to suppress the displacement speed of the vehicle based on the changed target roll displacement amount. Since the supply amount and discharge amount of the working fluid in the means are calculated, even when the target roll displacement amount changes slightly, the working fluid flow rate calculation means determines that the displacement speed of the vehicle has changed significantly. As a result, the amount of working fluid supplied and discharged that is sufficient to suppress the displacement speed of the vehicle is quickly calculated, making it possible to reliably prevent the occurrence of transient rolls.
By just slightly changing the target roll displacement amount, it is possible to prevent the occurrence of transient rolls, and by changing the target roll displacement amount, it is possible to effectively prevent the running stability of the vehicle from being impaired. It becomes possible.

According to another preferred embodiment of the present invention, the suspension characteristic control device adjusts the target roll displacement amount from a reference value to
When the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means becomes less than a predetermined value after changing the direction of the lateral acceleration by a predetermined amount to the opposite roll side, the suspension Since the characteristic control device gradually returns the target roll displacement amount to the reference value,
In order to immediately return the target roll displacement amount to the reference value, by discharging the working fluid from the fluid cylinder device of a certain wheel, the ground load of that wheel suddenly changes, causing a change in the steering characteristics of the suspension device. This makes it possible to prevent this from occurring and return to normal suspension control.

Further, when the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means is equal to or greater than a predetermined value, the target roll displacement amount is changed from the reference value to the opposite roll side with respect to the direction of the lateral acceleration. Even if the change is made by a predetermined amount, if the rate of change in the lateral acceleration differential value calculated by the lateral acceleration differential value change rate calculation means is larger than the predetermined value, the driver may frequently turn the steering wheel to the left or right. It is thought that the differential value of the lateral acceleration simply exceeded the predetermined value due to the operation.
Therefore, when controlling the amount of working fluid supplied and discharged to the fluid cylinder device based on the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means, the ground load of each wheel is unnecessary. According to another preferred embodiment of the present invention, the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means may change frequently and the pressure accumulated in the accumulator may decrease. When the target roll displacement is above a predetermined value, the target roll displacement amount is changed from the reference value.
Even when the direction of the lateral acceleration is changed by a predetermined amount to the reverse roll side, the rate of change of the differential value of the lateral acceleration calculated by the lateral acceleration differential value change rate calculation means will not change to the predetermined value. If the steering angle is larger than that, the changed target roll displacement amount is returned to the reference value when the steering angle detected by the steering angle detection means is deemed to be stable, so that the ground load of each wheel is It becomes possible to effectively prevent unnecessary frequent changes and decreases in the pressure accumulated in the accumulator.

Embodiments Hereinafter, embodiments of the present invention will be explained in detail based on the accompanying drawings.

FIG. 1 is an overall schematic diagram of a vehicle including a vehicle suspension device according to an embodiment of the present invention.

Although only the left side of the vehicle body 1 is shown in FIG. 1, the right side of the vehicle body 1 is similarly constructed. In FIG. 1, between the vehicle body 1 and the left front wheel 2PL and between the vehicle body 1 and the left rear wheel 2RL, there are fluid cylinder devices 3.
3 is provided. A hydraulic chamber 3c is formed within each fluid cylinder device 3 by a piston 3b fitted into a cylinder body 3a. The upper end of the piston rod 3d connected to the piston 3b of each fluid cylinder 3 is connected to the vehicle body 1, and each cylinder body 3a is connected to the left front wheel 2.
It is connected to the PL or left rear wheel 2RL.

The hydraulic chamber 3c of each fluid cylinder device 3 communicates with the gas spring 5 through a communication passage 4, and each gas spring 5 is divided into a gas chamber 5f and a hydraulic chamber 5g by a diaphragm 5e. The pressure chamber 5g communicates with the hydraulic pressure chamber 3c of the fluid cylinder device 3 through the communication passage 4 and the piston 3b of the fluid cylinder device 3.

A fluid passage 10 connecting the hydraulic pump 8 and each fluid cylinder device 3 so as to be able to supply fluid has a flow rate of fluid supplied to the fluid cylinder device 3 and a flow rate of the fluid supplied to the fluid cylinder device 3.
A proportional flow control valve 9 that controls the flow rate of fluid discharged from the
．． 9 are provided respectively.

The hydraulic pump 8 includes a discharge pressure gauge 1 that detects the discharge pressure of fluid.
2 is provided, and a hydraulic chamber 3 of each fluid cylinder device 3 is provided.
A hydraulic pressure sensor 13.13 is provided to detect the hydraulic pressure in c.

Further, a vehicle height displacement sensor 14.14 is provided which detects the cylinder stroke amount of each fluid cylinder device 3 and detects the vertical displacement of the vehicle body with respect to each wheel 2PL, 2RL, that is, the vehicle height displacement. A vertical acceleration sensor 15.15 detects the vertical acceleration of the wheels 2PL and 2RL, that is, the vertical acceleration of the springs of the wheels 2PL and 2RL.
．． 15 is on a substantially horizontal plane of the vehicle, left and right front wheels 2PL, 2
A total of three sensors are provided, one above the PR and one at the center of the left and right rear wheels in the width direction of the vehicle, and at the center of gravity of the vehicle body 1 to detect acceleration applied in the lateral direction of the vehicle. A lateral acceleration sensor 16 is provided, and further a steering angle sensor 18
and a vehicle speed sensor 19 are provided, respectively.

The discharge pressure gauge 12 and the hydraulic pressure sensor 13 provided in this way.
13, Vehicle height displacement sensor 14.14, Vertical acceleration sensor 1
5.15.15, Lateral acceleration sensor 16, Rudder angle sensor 18
The detection signals of the vehicle speed sensor 19 are input to the control unit 17 which has a CPU etc. inside, and the control unit 17 performs calculations according to a predetermined program based on these detection signals, and the proportional flow control valve 9.9 The suspension characteristics are variably controlled as desired.

FIG. 2 shows a fluid cylinder device 3.3.
FIG. 3.3 is a circuit diagram of a hydraulic circuit for supplying fluid to or discharging fluid from these.

In FIG. 2, the hydraulic pump 8 is a hydraulic pump 21 for a power steering device driven by a drive source 20.
The accumulator 22 is connected to a discharge pipe 8a which is connected in parallel with the hydraulic pump 21 and discharges fluid from the hydraulic pump 21 to the fluid cylinder device 3.3.3.3. On the downstream side,
It branches into a front wheel side pipe 23F and a rear wheel side pipe 23R. The front wheel side piping 23F branches into a left front wheel side piping 23FL and a right front wheel side piping 23PR on the downstream side of the branching part with the rear wheel side piping 23R, and the left front wheel side piping 23FL and the right front wheel side piping 23FR are, respectively, It communicates with the hydraulic chambers 3c and 3C of the fluid cylinder device 3FL for the left front wheel and the fluid cylinder device 3FR for the right front wheel. Similarly, the rear wheel side pipe 23R branches into a left rear wheel side pipe 23RL and a right rear wheel side pipe 23RR on the downstream side of the branching part, and the left rear wheel side pipe 23R branches into a left rear wheel side pipe 23RL and a right rear wheel side pipe 23RR.
RL and the right rear wheel side pipe 23RR communicate with the hydraulic chambers 3c, 3c of the fluid cylinder device 3RL for the left rear wheel and the fluid cylinder device 3RR for the right rear wheel, respectively.

These fluid cylinder devices 3FL, 3FR13RL.

3RR has gas springs 5FL, 5FR, 5, respectively.
RL and 5RR are connected, each gas spring 5P
L.

5FR15RL and 5RR are composed of four gas spring units) 5a, 5b, 5c, and 5d, and these gas spring units 5a, 5b, 5c, and 5d are connected to corresponding fluid cylinder devices 3FL and 3FR, respectively.

A branch communication path 4a% 4b is provided in the communication path 4 communicating with the hydraulic pressure chambers 3c, 3c, 3c, and 3c of 3RL and 3RR.

4c and 4d. In addition, each gas spring 5
FL, 5FR, 5RL, 5RR branch communication path 4a.

4b, 4c and 4d each have an orifice 25
a, 25b, 25c, 25d are provided, and these orifices 25a, 25b, 25c.

Damping action of 25d and gas springs 5 FL, 5 FR,
5RL.

Due to the buffering effect of the gas sealed in the gas chamber 5f of the 5RR, high frequency vibrations applied to the vehicle are reduced.

Of the gas spring units 5a, 5b, 5c, and 5d constituting each gas spring 5FL, 5FR, 5RL, and 5RR, each fluid cylinder device 3FL, 3FR, 3RL, and 3R
In the communication path 4 between the first gas spring unit) 5a provided at the position closest to the hydraulic pressure chambers 3c, 3c, 3c, 3c of R and the second gas spring unit) 5b adjacent thereto, , the passage area of the communication passage 4 is adjusted by taking an open position where the communication passage 4 is opened and a closed position where the passage area is narrowed, and the gas springs 5FL and 5FR15RL.

Switching valve 26 that switches the damping force of 5RR into two stages
is provided. FIG. 2 shows the switching valve 26 in the open position.

Near the upstream side of the connection part of the accumulator 22 of the discharge pipe 8a of the hydraulic pump 8, there is an unload IJ IJ-F valve 2.
8 is connected, and the unload relief valve 28 is switched to the open position when the oil discharge pressure measured by the discharge pressure gauge 12 is higher than a predetermined upper limit, for example, 160 kgf/cnf, and the unload relief valve 28 is switched to the open position, and the unload relief valve 28 is The discharged oil is directly returned to the reserve tank 29, and on the other hand, when the predetermined lower limit M is below 120 kgf/cITf, the oil is switched to the closed position, supplying oil to the accumulator 22, and reducing the hydraulic pressure of the accumulator 22. The pressure accumulation value is controlled to be maintained at a predetermined value. In this way, oil is supplied to each fluid cylinder device 3 by storing oil in the accumulator 22, which is maintained at a predetermined pressure storage value. FIG. 2 shows the unload relief valve 28 in the closed position.

The hydraulic circuits for the left front wheel, right front wheel, left rear wheel, and right rear wheel are configured in the same way, so below we will explain only the hydraulic circuit for the left front wheel, and for the others, we will explain the same. Omitted.

The proportional flow control valve 9 is a three-way valve, with a closed position where all ports are closed, a supply position where the left front wheel side piping 23FL is opened to the hydraulic pressure supply side, and a fluid cylinder device 3 of the left front wheel side piping 23FL connected to the return piping 32. It is designed to be able to take three positions, including a communicating discharge position. FIG. 2 shows the proportional flow control valve 9 in the closed position. Further, the proportional flow rate control valve 9 includes pressure compensation valves 9a, 9a.
The pressure compensating valves 9a, 9a allow the proportional flow control valve 9 to be in the supply position or the discharge position.
The hydraulic pressure within the hydraulic pressure chamber 3C of the fluid cylinder device 3 is maintained at a predetermined value.

On the fluid cylinder device 3 side of the proportional flow rate control valve 9, a pilot pressure-responsive on-off valve 33 that can open and close the left front wheel side piping 23F is provided. When the solenoid valve 34 that guides the hydraulic pressure of the left front wheel side piping 23F on the hydraulic pump 8 side of the proportional flow rate control valve 9 is opened, the hydraulic pressure of the solenoid valve 34 is introduced as pilot pressure to the on-off valve 33. When the pressure is above a predetermined value, the on-off valve 33 opens the left front wheel side pipe 23FL, allowing the proportional flow rate control valve 9 to control the flow rate of fluid to the fluid cylinder device 3.

Furthermore, an IJ valve 35 that opens when the fluid pressure in the fluid pressure chamber 3C of the fluid cylinder device 3 increases abnormally and returns the fluid in the fluid pressure chamber 3C to the return pipe 32, downstream of the accumulator 22 connection part. Discharge pipe 8 of hydraulic pump 8 near the side
a, opens when the ignition is turned off, and stores the oil stored in the accumulator 22 into the reserve tank 29.
ignition key to release the high pressure state in the accumulator 22. When the oil discharge pressure of the hydraulic pump 8 increases abnormally, the oil in the hydraulic pump 8 is returned to the reserve tank 29. Return accumulators 38 and 38 are provided, respectively, which are connected to the hydraulic pump IJ IJ-f valve 37 and the return piping 32 to lower the oil discharge pressure of the hydraulic pump 8, and which perform a pressure accumulation function when fluid is discharged from the fluid cylinder device 3. ing.

3A, 3B, and 3C are block diagrams of the fluid control amount calculation device 100 provided in the control unit 17. FIG.

3A, 3B, and 3C, a fluid control amount calculation device 100 provided in the control unit 17 according to the present embodiment is connected to a vehicle height sensor 14 for each wheel.
14.14 and 14 vehicle height displacement signals XFR, XFL,
X! 111. X [l+, 2 base tweets, control system A that controls the vehicle height to the target vehicle height, and vehicle height displacement signal X FllSX
FLN A control system C that aims to reduce vertical vibration of the vehicle based on acceleration signals GFR%GFL and G□, and a hydraulic pressure sensor 13.1 for each wheel.
3.13.13 Pressure signals PFi, PFL, P□, PR
A control system that calculates and suppresses twisting of the vehicle body based on L, and a lateral acceleration detection signal G of the lateral acceleration sensor 16.
It is comprised of a control system E that aims to reduce lateral vibration of the vehicle based on L.

The control system includes vehicle height sensors 14.14.14 for each wheel.
Vehicle height displacement signal X FR%XFL% detected by 14
X11% In order to cut XRL noise, low pass filters 40a, 40b, 4 cut high frequency components.
0c, 40d are provided, and low pass filters 40a, 4
Left and right front wheels 2P with high frequency components cut by 0b
L, 2PR vehicle height sensor 14.14 output X FR%
When XFL is added, the robust filter 40c, 4
Left and right rear wheels 2 with high frequency components cut by 0d
RL, 2RR vehicle height sensor 14.14 output X Rls
The bounce component calculation unit 41 calculates the bounce component of the vehicle, and from the added value of the output X FR% 2 RR) Vehicle height sensor 1
a pitch component calculation unit 42 that calculates the pitch component of the vehicle by subtracting the added value of the output X RRl
Left and right front wheels 2 PL.

2Fft vehicle height sensor 14.14 output XFRSXF,
A roll component calculation R43 is provided which calculates the roll component of the vehicle by adding the difference XFRXFL of the left and right rear wheels 2RL and 2RR to the difference XRR-XRL of the pressure xIlu1xlIL of the vehicle height - t=nt14. ing.

Further, the control system A receives the bounce component of the vehicle and the target average vehicle height TH calculated by the bounce component calculation unit 41, and controls the fluid supply to the fluid cylinder device 3 of each wheel in bounce control based on the gain Kal. The pitch component of the vehicle calculated by the bounce control unit 44 and the pitch component calculation unit 42 is manually input, and the amount of fluid supplied to the fluid cylinder device 3 of each wheel in pitch control is calculated based on the gain KPI. The roll component and the target roll displacement amount T calculated by the pitch control unit 45 and the roll component calculation unit 43 are input, and based on the gain KIFKIl□, the vehicle height is adjusted so that the vehicle height corresponds to the target roll displacement amount Trl. Fluid cylinder device 3 for each wheel in roll control
A roll control section 46 is provided to calculate the amount of fluid supplied to the roller.

In this way, each control amount calculated by the bounce control section 44, the pitch control section 45, and the roll control section 46 has its sign reversed for each wheel, that is, the vehicle height sensor 14.
Vehicle height displacement signal XFR1X detected on 14.14.14
FL% X R11% Control flow signal Q FRI , QFLI , QRRI to flow control valve 9
N QRLI is obtained.

Here, each low-pass filter 40a, 40b, 40c,
40d and the bounce calculation section 41, pitch calculation section 42, and roll calculation section 43, there are insensitive gain devices 47a and 47b.
, 47c, 47d are provided, and the vehicle height sensor 14.
From 14.14.14, low pass filters 40a, 40
b, 40c.

Vehicle height displacement signal x input via 40d, , x
pt, X□, XIL are preset dead zones x
[These vehicle height displacement signals XFRSXFL, xRll, X1lLwo,
It is configured to output to a bounce calculation section 41, a pitch calculation section 42, and a roll calculation section 43.

Control system B receives input from vehicle height sensors 14, 14, 14 and 14, and low-pass filters 40a, 140b, 40c.
, 40d, the high frequency component is cut off. Differentiate the vehicle height displacement signal XF RlX FLsXIl'li,
Differentiator 50a that calculates YFL, YR11, and YRL
150b, 50c, and 50d.

Y-(X,-X,,)/T Here, xo is the amount of vehicle height displacement at time t, X,, -1 is the amount of vehicle height displacement at time t-1, and T is the sampling time.

Furthermore, the control system B generates vehicle height displacement speed signals YuL, Yu++ for the left and right rear wheels 2RL, 2RR from the sum of the vehicle height displacement speed signals ypt, Y for the left and right front wheels 2PL and 2PR.
a pitch component calculating section 51 that calculates the pitch component of the vehicle by subtracting the added value of , and left and right front wheels 2PL, 2PR.
Difference between side vehicle height displacement speed signals YFL and YFR - YFR-
It is provided with a roll component calculating section 52 that calculates a roll component of the vehicle by adding YFL and a difference Y□-YIIL between the vehicle height displacement speed signal YRL% Yllll of the left and right rear wheels 2RL and 2RR side. .

In this way, the pitch component calculated by the pitch component calculation section 51 is input to the pitch control section 53, and the gain KP is input to the pitch control section 53.
2, each proportional flow control valve 9 in pitch control
The flow rate control amount is calculated, and the roll component calculation unit 5
The roll component calculated in step 2 is input to the roll control unit 54, and based on the gain K 1lF2 and KRR2, the vehicle height is adjusted so that the vehicle height corresponds to the target roll displacement amount T.
The flow rate control amount to each proportional flow rate control valve 9' in roll control is calculated.

Each control amount calculated by the pitch control section 53 and the roll control section 54 is further reversed in sign for each wheel, and
That is, the vehicle height displacement speed signal Y Fl1% Y FL calculated by the differentiators 50a, 50b, 50c, and 50d
% Y 19% Y RL is reversed so that its sign is opposite, and then each control amount of pitch and roll for each wheel is added, and the proportional flow control valve 9 of each wheel in the control system is Flow rate signal QFR2-
, QFL25QRR2s QRL2 is obtained.

The control system C includes low-pass filters 60a and 60b.

60c, a bounce component calculating section 61 calculates a bounce component of the vehicle by adding the vertical acceleration detection signals GFR% GFL% GR detected by the vertical acceleration sensors 15a, 15b, and 15c with high frequency components cut, and the left and right The sum of 1/2 of the outputs of the vertical acceleration sensors 15a and 15b installed above the front wheels 2FR and 2PL (G FR
+ G FL) / 2, a pitch component calculating section 62 calculates the pitch component of the vehicle by subtracting the output G of the vertical acceleration sensor 15c provided at the center of the left and right rear wheels in the vehicle width direction; Output G of the vertical acceleration sensor 15a on the front wheel side
Output GF of vertical acceleration sensor 15b on the left front wheel side from FR
The calculated values of the bounce component calculated by the roll component calculation unit 63 and the bounce component calculation unit 61 that calculate the roll component of the vehicle by subtracting L are input, and the gain K 83
Each proportional flow control valve 9 in bounce control based on
The pitch component calculation value calculated by the bounce control unit 64 and the pi-nochi component calculation unit 62, which calculates the amount of fluid to be controlled to The calculated value of the pitch component calculated by the pitch control unit 65 and the roll component calculation unit 63 is inputted, and the proportional flow control valve in pitch control is input based on the gains K RF3 and KR1+3. The roll controller 66 calculates the amount of fluid to be controlled.

In this way, the bounce control section 64 and the pitch control section 6
5 and the control amount calculated by the roll control unit 66, the positive and negative values are reversed for each wheel, and then the bounce, pitch, and roll control amounts for each wheel are added, and the control amount is output from the control system C. Flow signals Q, l, , QFL3, QRR3 and QRLS to each proportional control valve 9
is obtained.

Note that a low-pass filter 60a cuts high frequency components.
, 60b160c and the bounce component calculation section 61, pitch component calculation section 62, and roll component calculation section 63,
Dead zone devices 67a, 167b and 67c are provided respectively, and vertical acceleration sensors 15a, 15b,
15c, low pass filters 60a, 60b, 6
Vertical acceleration signal GFR input via 0c and 60d
% GFL, GR are in the preset dead zone Xc
, X-, Xc only when these vertical acceleration signals G FR.

GFL% GR is output to the bounce component calculation section 61, pitch component calculation section 862, and roll component calculation section 63.

In the control system, a hydraulic pressure detection signal PFL% PFil detected by the hydraulic pressure sensor 13.13 of the fluid cylinder device 3 of the left and right front wheels 2PL and 2PR is input, and its high frequency component is passed through the low-pass filters 70a and 70b. After being cut by, the difference in the hydraulic pressure of the hydraulic pressure chamber 3C13C of the fluid cylinder device 3 of the left and right front wheels 2PR, 2PL is Pp□-PFL
and the ratio of these added values PFR+PFL = Pr = (
PFl=PFL)/(P□+PFL) is calculated, and if the calculated hydraulic pressure ratio P is -ω, <p, <ω, with respect to the threshold hydraulic pressure ratio ω, then The calculated hydraulic pressure ratio Pf is output as is, and on the other hand, if Pr<-ω or Pr>ω1. If , the threshold hydraulic pressure ratio −ω,
or ω, and the hydraulic pressure detection signal P [11% P RR is input, and after its high frequency components are cut by low-pass filters 70c and 70d, the difference PRRPRL between the hydraulic pressures of the hydraulic pressure chambers 3c and 3c of the fluid cylinder devices 3 of the left and right front wheels 2PR and 2PL, and these Ratio of addition value P□+PRL P R= (P
It has a rear wheel side hydraulic pressure ratio calculating section 71b that calculates Il'RPRL) / (PRR+PRL), and after multiplying the rear wheel side hydraulic pressure ratio P by a predetermined value based on the gain. ,
A warp control section 71 is provided to subtract this from the ratio P of the hydraulic pressure on the front wheel side, and the output of the warp control section 71 is changed to a gain ω8.
Then, on the front wheel side, the gain ω is multiplied by a predetermined value.

is used to multiply the fluid supply control amount by a predetermined value, and then reverse one so that the controlled amount of fluid supplied to each wheel is opposite between the left and right wheels, and the flow rate to each proportional flow control valve 9 in the control system is Signals Q, R,, QFL4, Q 1+14, Q F
L4 is obtained.

Further, the control system E receives a lateral acceleration detection signal applied in the lateral direction of the vehicle detected by the lateral acceleration sensor 16, and after its high frequency component is cut by the low-pass filter 80, the control system E performs control based on the gain Kg. The amount is calculated, and for the left and right front wheels 2FL and 2PR, it is further multiplied by a predetermined value based on the gain AcF, and then,
Reversing the fluid supply control amount for the left front wheel 2PL so that the fluid supply control amount for the left and right wheels is opposite in positive and negative,
On the other hand, for the left and right front wheels 2R17 and 2RR, the fluid supply control amount for the left rear wheel 2PL is reversed so that the positive and negative fluid supply control amounts for the left and right wheels are reversed, and each proportion in the control system is adjusted. Flow rate signal Q FR to flow rate control valve 9
5, QFL5, ΩRR5, and QRLS are obtained.

The flow rate signals to each proportional flow rate control valve 9 in each control system A, B, C1D, and E obtained as described above are added for each wheel, and furthermore, for the left and right front wheels 2PL and 2FR, the gain A, is multiplied by each proportional flow control valve 9
Total flow signal QFIl, QFL-I QRR
lQRL is obtained.

Table 1 shows an example of the control gain reference map used in each of the control systems A, B, C, D, and E stored in the control unit 17. mode is set.

In Table 1, mode 1 is the value of each control gain for 60 seconds after the engine has stopped, and mode 2 is the value of each control gain when the ignition switch is on but the vehicle is stopped and the vehicle speed is zero. The value of the control gain, mode 3, indicates the value of each control gain in a straight-ahead state where the vehicle direction acceleration Gt is 0.1 or less, and mode 4 indicates the reverse roll mode by a roll mode selection switch (not shown). is selected, the selected control gain value is shown instead of mode 5 in a slow turning state where the vehicle's lateral acceleration GL exceeds 0.1 and is 0.3 or less, and the vehicle speed is 120 km/h. When the value exceeds h, even if the reverse roll mode is selected, the mode is automatically switched to mode 5, and mode 5 is the lateral acceleration G of the vehicle.

The value of each control gain in a slow turning state where the vehicle's lateral acceleration G exceeds 0.1 and is 0.3 or less, mode 6 is the value of each control gain in a moderate turning state where the vehicle's lateral acceleration G exceeds 0.3 and is 0.5 or less. The control gain value, mode 7, is when the vehicle's lateral acceleration GL is 0.
．． The value of each control gain in a sharp turning state exceeding 5 is
Each is shown.

In Table 1, Q□8 is the proportional flow control valve 9 of each wheel.
PMAX indicates the maximum pressure in the hydraulic pressure chamber 3c of the fluid cylinder device 3, and the fluid flows back to the accumulator 22 from the hydraulic pressure chamber 3c of the fluid cylinder device 3. It is set so that there is no
Moreover, P x+x is the hydraulic pressure chamber 30 of the fluid cylinder device 3
indicates the minimum pressure within the hydraulic pressure chamber 3c of the fluid cylinder device 3.
The gas spring 5 is designed to prevent the gas spring 5 from being fully extended and damaged due to an excessive drop in internal pressure.

In Table 1, except for mode 4, each control gain is set such that the larger the mode number is, the more the suspension control is performed with emphasis on driving stability.

FIG. 4 is a block diagram of the suspension characteristic control device 90 provided in the control unit 17.

In FIG. 4, the suspension characteristic control device 90 is
A lateral acceleration differential value calculation means 91 receives the lateral acceleration GL applied to the lateral direction of the vehicle detected by the lateral acceleration sensor 16, differentiates the lateral acceleration GL, and calculates the differential value DGt; The absolute value of the differential value DGL of the lateral acceleration GL manually input from the means 91, the first predetermined value DGLO and the second predetermined value DGLI (DGL.>
DGL+), differential value comparison means 92 for determining the magnitude of
The control gain reference map shown in Table 1 is memorized, and the 3A
The fluid control amount calculation device 100 shown in FIGS. Based on the acceleration detection signal, the differential value DGL of the lateral acceleration G is set to the first predetermined value D.
In the case of GLo or more, the target roll displacement amount T is changed by a predetermined amount Δ to the opposite roll side with respect to the direction of the lateral acceleration GL.
Tll, for example, a target roll displacement amount correction signal that is corrected by 2 mm is output to the control gain output means 93, and after the target roll displacement amount correction signal is output, the differential value DGL of the lateral acceleration GL is set to a second predetermined value. When the value DGL is less than or equal to the value DGL, the target roll displacement amount TR is maintained for a predetermined time t. After passing, a predetermined reference value T,. to return to
A target roll displacement amount correction means 94 is provided that outputs a target roll displacement amount return signal that linearly decreases the correction amount ΔTR to the control gain output means 93.

Suspension characteristic control device 90 configured in this way
In accordance with the flowchart shown in FIG.
The total flow rate signal 018, QFLSQRR, QIl, which is output to the fluid control amount calculation device 100 and supplied to each proportional flow rate control valve 9 by the fluid control amount calculation device 100, is generated to execute suspension control.

As shown in FIG. 5, first, a lateral acceleration detection signal is sent from the lateral acceleration sensor 16 to the lateral acceleration differential value calculation means 91.
is input. The lateral acceleration differential value calculation means 91 calculates a differential value DGL of the lateral acceleration G based on the input lateral acceleration detection signal, and outputs the differential value DGL to the comparison means 92.

The comparison means 92 determines whether the differential value DGt of the lateral acceleration GL inputted from the lateral acceleration differential value calculation means 91 is greater than or equal to a first predetermined value DGLo, and sends the determination signal to the target roll displacement amount correction means 94 Output to.

As a result, the differential value D6L of the lateral acceleration GL is the first predetermined value DG. If the value is less than 1, the amount and speed of operation are small even if the handle is operated, and therefore it can be determined that there is no risk of transient roll occurring. is output to the control gain output means 93, and from the control gain output means 93, based on the reference map shown in Table 1,
Each control gain is output to the fluid control amount calculation device 100, and the fluid control amount calculation device 100 calculates each proportional control valve 9.
Total flow signal Q, RSQP,,Q□ supplied to
, QIIL are generated and suspension control is executed.

On the other hand, when the differential value DGL of the lateral acceleration GL is greater than or equal to the first predetermined value DGLo, the steering wheel is large;
In addition, since it is recognized that the operation is sudden and there is a large risk of causing a transient roll, the target roll displacement amount correcting means 94 changes the target roll displacement amount TR from the reference value T no shown in Table 1. , a predetermined correction amount ΔTR1 is applied to the opposite roll side with respect to the direction of the lateral acceleration GL, for example, 2
A target roll displacement amount correction signal to be corrected by mm is output to the control gain specific force means 93. The control gain output means 93 is
When receiving the target roll displacement amount correction signal from the target roll displacement amount correction means 94, the target roll displacement amount TR is set to the reference value T of the target roll displacement amount in the map shown in Table 1.
From RO, a predetermined correction amount ΔTR1 is applied to the opposite roll side with respect to the direction of the lateral acceleration GL.
The corrected target roll displacement amount TR and other control gains are output to the fluid control amount calculation device 100, and the fluid control amount calculation device 100 performs each proportional control based on the control gain input from the control gain output means 93. Total flow rate signal to be supplied to valve 9 QFR1Q FL% Q 11%
Q RL is generated and suspension control is executed.

Here, as shown in FIG. 3A, the target roll displacement amount T, is the vehicle height displacement speed signal V FR% Y Fl,%
Since YRR and YRL are input to the roll control unit 54 of the control system B that suppresses the vehicle height displacement speed, even if the correction amount ΔTR is set to a small value, the fluid control amount calculation device 100 It is determined that the vehicle height displacement speed has changed extremely significantly, and therefore, the flow rate signal Q to the proportional flow rate control valve 9 of each wheel calculated by the control system
Since FR2, QRL2, Q RR, and QRL2 change greatly immediately, it is possible to reliably prevent the occurrence of transient rolls, and even if the correction amount ΔTR is set to a small value, transient rolls will not occur. can be reliably prevented.

After the target roll displacement amount correction signal is output from the target roll displacement amount correction means 94, the differential value D of the lateral acceleration GL is
When GL becomes less than the second predetermined value DGt+, which is sufficiently smaller than the first predetermined value DGto, it can be determined that the driving state of the vehicle approaches a steady state and there is no longer a risk of transient roll occurring. Therefore, the target roll displacement amount correction means 94 outputs a target roll displacement amount return signal to the control gain output means 93, and returns the target roll displacement amount T to the reference value TRO. However, the corrected target roll displacement amount T, is immediately changed to the reference value T,. When returning to
It became necessary to rapidly discharge the oil in the wheel c, and the ground load of the wheel suddenly changed, resulting in a change in the steering characteristics. When receiving the target roll displacement amount return signal from the amount correction means 94, the predetermined time t is reached. By gradually decreasing the correction amount △T linearly with time so that the correction amount △T becomes zero after the elapse of time, the target roll displacement amount TR is determined.
is calculated and output to the fluid control amount calculation device 100 along with other control gains.

In this way, the target roll displacement amount TR corrected by the correction amount ΔT remains for a predetermined time t. After the elapsed time, the reference value T 9
However, before the predetermined time elapses, when the differential value [IGL of the lateral acceleration GL becomes equal to or greater than the first predetermined value DGLo, the steering wheel is again large and
Since it is determined that the operation has been performed suddenly and there is a high risk of causing a transient roll, the target roll displacement amount correcting means 94 sets the time t to zero and then changes the target roll displacement amount T11 to the first value again. From the reference value TRO shown in the table, to the opposite roll side with respect to the direction of the lateral acceleration G,
A target roll displacement amount correction signal for correcting a predetermined correction amount ΔTR%, for example, 2+nm, is output to the control gain output means 93 to correct the target roll displacement amount TR, and together with other control gains, the fluid control amount calculation device 100 output to perform suspension control.

As described above, according to this embodiment, the handle is large and
A sudden operation is detected based on the differential value DGL of the lateral acceleration GL, and in an operating state in which it is recognized that there is a high risk of transient roll occurring, the target roll displacement amount TR is changed from the reference value TRO. The total flow rate signal QFR to be corrected by a predetermined correction amount T to the reverse roll side with respect to the direction of the lateral acceleration G, and to be supplied to each proportional flow rate control valve 9 by the fluid control amount calculation device 100. ,Q,
Since the L, 011% QRL is generated and suspension control is executed, transient roll can be effectively prevented. Further, the target roll displacement amount T□ is input to the roll control unit 54 of the control system B that suppresses the vehicle height displacement speed based on the vehicle height displacement speed signal Y FR% Y FL% Y, lR, and YRL. From, the correction amount ΔTR
Even if is set to a small value, the fluid control amount calculation device 100 will determine that the vehicle height displacement speed has changed significantly, and therefore the proportional flow rate control valve of each wheel calculated by the control system Flow signal Q4, 2, QFL to 9
Since 2, Q9, 2, and Q RL2 change greatly immediately, it is possible to reliably prevent the occurrence of transient roll. Furthermore, the target roll displacement amount T is set to the reference value T
After correcting the direction of the lateral acceleration G from RO by a predetermined correction amount ΔTR in the opposite roll direction, the driving state of the vehicle approaches a steady state, and there is no longer any risk of transient roll occurring. When is the predetermined time T.

Since the correction amount ΔT is gradually decreased linearly with respect to time so that the correction amount T becomes zero after the elapse of time, the correction amount ΔTR becomes zero immediately, that is, the target The roll displacement amount T is below the reference value. By immediately returning to , it is possible to prevent the steering characteristics from changing due to a large change in the ground load of the wheel on the outer side of rotation, and to prevent the occurrence of transient roll. Further, since the correction amount ΔT can be set to a small value, the target roll displacement amount TR can be set to be below the reference value. The correction amount ΔTR is gradually reduced to zero without immediately returning to zero, and the target roll displacement amount TR is lowered to below the reference value. Even if the vehicle is returned to the normal state, the running safety of the vehicle will not be impaired.

FIG. 6 is a block diagram of a suspension characteristic control device according to another embodiment, and in this embodiment, further changes in the differential value DGL of the lateral acceleration GL calculated by the lateral acceleration differential value calculation means rate DDGL
The differential value of the lateral acceleration Gt is calculated by the lateral acceleration differential value change rate calculation means 95 which calculates the steering angle detection signal detected by the steering angle sensor 18 manually. It is determined whether the absolute value of the change rate DOGL of DGL is greater than or equal to a predetermined value DD6Lo, and the lateral acceleration G
The rate of change DDGL of the differential value DGL of L is a predetermined value DDGt,
If it is determined that the steering angle is equal to or greater than o, a predetermined time t has elapsed since the steering angle reached a constant value based on the steering angle detection signal input from the steering angle sensor 18. . When the target roll displacement amount T has elapsed, a target roll displacement amount correction cancel signal is output to the control gain output means 93, and the target roll displacement amount T has passed.

, the reference value T,. The suspension characteristic control device 90 is provided with a change rate comparing means 96 for returning the suspension characteristic to 1, and has the same structure as the suspension characteristic control device 90 shown in FIG. 4 in other respects.

The suspension characteristic control device 90 shown in FIG.
According to the flowchart shown in FIG. 7, the target roll displacement amount TR is output from the control gain output means 93 to the fluid control amount calculation device 100, and the fluid control amount calculation device 1
00, total flow signals QFRlQFL, QRRlQRL, which are supplied to each proportional control valve 9, are generated and suspension control is executed.

The flowchart of FIG. 7 is the same as the flowchart of FIG. 6 except that the subroutine shown in FIG. 8 is added. As shown in FIGS. 7 and 8, the suspension characteristic control device 90 according to the present embodiment is configured such that the differential value DGL of the lateral acceleration GL is set to a first predetermined value D.
GLO or more, the target roll displacement amount T is determined by the target roll displacement amount correction means 94 to the reference value T shown in Table 1.
,. A target roll displacement correction signal for correcting the lateral acceleration GtO by a predetermined correction amount ΔTi, for example, 2 mm, on the reverse roll side is output to the control gain output means 93. The corrected target roll displacement amount T and other control gains are output to the fluid control amount calculation device 100, and the fluid control amount calculation device 100 calculates the corrected target roll displacement amount T and other control gains based on the control gain manually input from the control gain output means 93. , after the total flow signals Q□, QptSQ□, and QRL to be supplied to each proportional control valve 9 are generated and suspension control is executed, the differential value DGL of the lateral acceleration G is determined from the first predetermined value DGLo. becomes less than the second predetermined value DG, which is sufficiently small, the target roll displacement amount correction means 94 outputs the target roll displacement amount return bone to the control gain output means 93, and the control gain pressure means 93 Time t. After the elapsed time, go to the correction amount
, the correction amount △ linearly with respect to time so that , becomes zero.
By gradually decreasing TR, the target roll displacement amount T is calculated, and along with other control gains, the fluid control amount calculation device 10
0 while suspension control is being executed, that is, for a predetermined time t. Before the time elapses, the differential value DGL of the lateral acceleration GL again becomes the first predetermined value DG. Therefore, in order to prevent the occurrence of transient rolls, the time t is set to zero, and the target roll displacement amount correction means 94
After the target roll displacement amount correction signal is outputted to the control gain pressure means 93 again, the rate of change DDGL of the differential value DG of the lateral acceleration GL calculated by the lateral acceleration differential value change rate calculation means 95 is calculated. If the absolute value is the predetermined value [IDGL
The change rate comparison means 96 is configured to determine whether or not the change rate is equal to or greater than o.

That is, the differential value []G of the lateral acceleration GL calculated by the lateral acceleration differential value change rate calculating means 95.

If the absolute value of the rate of change, DDG, is greater than or equal to the predetermined value, DDGL, the target roll can be achieved as long as the driver is only slightly operating the steering wheel left and right and the steering angle is stable. The displacement amount TR is a reference value T. The change rate comparing means 96 uses the steering angle sensor 18 to determine that the operating state is such that there is no problem in returning to the operating state, and there is no risk of transient roll occurring without correcting the target roll displacement amount T. A predetermined time t elapses after the steering angle reaches a constant value based on the input steering angle detection signal. When 0 has elapsed, the control gain output means 93 outputs an eye [0-ru displacement correction cancel signal].
and output the target roll displacement amount TR to the reference value Tl1o.
The target roll displacement amount T is controlled so as to return to
On the other hand, the absolute value of the rate of change []DG of the differential value DGt of the lateral acceleration GL calculated by the lateral acceleration differential value change rate calculating means 95 is the predetermined value DDG. In the above case, if the target roll displacement amount T is not corrected, there is a risk that transient roll will occur, so the target roll displacement amount T is controlled in the same manner as in the flowchart of FIG. .

According to the present embodiment, even if the differential value DGL of the lateral acceleration GL is greater than or equal to the first predetermined value DGLO, in an operating state in which there is no risk of transient roll occurring, the corrected target roll displacement Since the amount T is controlled to return to the reference value TRO, the target roll displacement amount T
, the discomfort and discomfort caused by being unnecessarily corrected.
This makes it possible to effectively prevent damage to the driver.

The present invention is not limited to the above-mentioned examples, but various modifications can be made within the scope of the invention described in the claims, and these are also included within the scope of the present invention. Needless to say.

For example, in the embodiment described above, the vehicle suspension system is equipped with the gas spring 5, but the present invention is also applicable to a fully active suspension system that does not include the gas spring 5. be able to.

In addition, in the present invention, each means does not necessarily mean a physical means, and even if the function of each means is realized by software, the present invention also includes the case where two or more means are implemented. The present invention encompasses cases where a function is realized by one physical means, and cases where a function of one means is realized by two or more physical means.

Effects of the Invention According to the present invention, it is possible to provide a suspension device for a vehicle that can effectively suppress transient roll.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic diagram of a vehicle including a vehicle suspension device according to an embodiment of the present invention. FIG. 2 is a circuit diagram of a hydraulic circuit that supplies fluid from a hydraulic pump to a fluid cylinder device or discharges fluid therefrom. 3A, 3B, and 3C are block diagrams of a fluid supply amount calculation device provided in the control unit. FIG. 4 is a block diagram of a suspension characteristic control device for a suspension device according to an embodiment of the present invention, and FIG. 5 is a flowchart thereof. FIG. 6 is a block diagram of a suspension characteristic control device for a suspension device according to another embodiment of the present invention, and FIG. 7 is a flowchart thereof. FIG. 8 is a diagram showing a subroutine. 1...Vehicle body, 2PL...Left front wheel, 2PR...Left rear wheel,
2RL...right front wheel, 2RR...right front wheel,
3...Fluid cylinder device, 3FL...Fluid cylinder device for left front wheel, 3FR...
-Fluid cylinder device for right front wheel, 3RL...Fluid cylinder device for left rear wheel, 3RR...Fluid cylinder device for right rear wheel, 3a...Cylinder body, 3b...Piston, 3c... ... Hydraulic pressure chamber, 3d... Piston rod, 4... Communication path, 4a, 4 b, 4 c, 4 d... Branch communication path,
5...Gas spring, 5FL...Gas spring for left front wheel, 5FR...Gas spring for right front wheel, 5RL...Gas spring for left rear wheel, 5RR...Gas spring for right rear wheel, 5a, 5b, 5c, 5d --- Gas spring unit 5e...
・Diaphragm, 5f... Gas chamber of gas spring, 5g... Hydraulic pressure chamber of gas spring, 8... Hydraulic pump, 8a... Discharge pipe, 9.
...Proportional flow control valve, G, 9a...Pressure compensation valve, 10...Fluid passage, 12...Discharge pressure needle, 1
3... Hydraulic pressure sensor, 14... Vehicle height displacement sensor, 15... Vertical acceleration sensor, 16... Lateral acceleration sensor, 17... Control unit, 18... Rudder angle sensor, 19.・Vehicle speed sensor,
20... Drive source, 21... Hydraulic pump for power steering device, 22
...accumulator, 23F...front wheel side piping, 23R...rear wheel side piping,
23FL...Left front wheel side piping, 23FIl...Right front wheel side piping, 23RL...Left rear wheel side piping, 23RR...Right rear wheel side piping, 25a, 25b, 25c, 25d...orifice, 2
6... Switching valve, 28... Unload relief valve, 29... Reserve tank, 33... Opening/closing valve, 34... Solenoid valve, 35
...Relief valve, 36...Ignition key chain valve, 37...Hydraulic pump relief valve, 38...Return accumulator, 41...Bounce component calculation section, 42...Pitch component calculation section, 43... Roll line segment calculation unit, 44... Bounce control unit, 45... Pitch control unit, 46... Roll control unit, 50 a, 50 b, 50 c, 50 d-... Differentiator, 51... Pitch component calculation section, 52... Roll component calculation section, 53... Pitch control section, 54... Roll control section, 61... Bounce component calculation section, 62... Pitch component calculation section 63...Roll line segment calculation unit, 64...Bounce control unit, 25...Pitch control unit,...Roll control unit,...Warp control unit, a...Front wheel side hydraulic pressure ratio Calculation unit, b... Rear wheel side hydraulic pressure ratio calculation unit. ... Suspension characteristic control device, ... Lateral acceleration differential value calculation means, ... Differential value comparison means, ... Control gain output means, ... Target roll displacement amount correction means, ... Lateral acceleration derivative Value change rate calculation means, . . . change rate comparison means, 0 . . . fluid control amount calculation device.

Claims (4)

[Claims] (1) Suspension characteristics that each wheel has a fluid cylinder device between the sprung weight and unsprung weight of the vehicle, and controls the control gain of the suspension characteristics according to the driving condition of the vehicle. The vehicle includes a control device and a displacement detection means for detecting displacement of the vehicle, and is configured to cancel the displacement of the vehicle with a predetermined control gain set and controlled by a suspension characteristic control device based on the detection result of the displacement detection means. , the amount of working fluid supplied to the fluid cylinder device,
In an active suspension device that controls emissions, a lateral acceleration detection means for detecting lateral acceleration applied to a vehicle, and a lateral acceleration differential value calculation for calculating a differential value of the lateral acceleration detected by the lateral acceleration detection means means, wherein the suspension characteristic control device adjusts the target roll displacement amount from a predetermined reference value when the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means is equal to or greater than a predetermined value. . A suspension device for a vehicle, characterized in that the direction of the lateral acceleration is changed by a predetermined amount toward a reverse roll side. (2) the suspension characteristic control device suppresses the displacement speed of the vehicle according to the displacement speed of the vehicle;
The working fluid flow rate calculation means calculates the supply amount and discharge amount of the working fluid to the fluid cylinder device, and the working fluid flow rate calculation device calculates the supply amount and the discharge amount of the working fluid to the fluid cylinder device based on the changed target roll displacement amount. The suspension device for a vehicle according to claim 1, wherein the vehicle suspension device is configured to calculate the supply amount and discharge amount of the working fluid. (3) When the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means exceeds a predetermined value, the suspension characteristic control device changes the target roll displacement amount from the reference value to the lateral acceleration. When the differential value of the lateral acceleration calculated by the lateral acceleration differential value calculation means becomes less than a predetermined value after changing the direction by a predetermined amount to the reverse roll side, the suspension characteristic control is performed. Claim (1) characterized in that the device is configured to gradually return the target roll displacement amount to the reference value.
Or the vehicle suspension device according to (2). (4) The lateral acceleration differential value calculation means further includes a lateral acceleration differential value change rate calculation means and a steering angle detection means for calculating a change rate of the lateral acceleration calculated by the lateral acceleration derivative value calculation means. Even when the lateral acceleration calculated by is equal to or higher than a predetermined value, the rate of change of the differential value of the lateral acceleration calculated by the lateral acceleration differential value change rate calculating means is
The suspension characteristic control device is configured to return the target roll displacement amount to the reference value when it is recognized that the steering angle detected by the steering angle detection means is stable when the steering angle is equal to or greater than a predetermined value. The suspension device for a vehicle according to any one of claims (1) to (3), characterized in that: