JPH0195927A - Active type suspension - Google Patents

Abstract

PURPOSE:To promote the prevention of a diagonal roll by decreasing a pressure of working fluid in a hydraulic cylinder in another wheel when a pressure of working fluid in a hydraulic cylinder in one wheel corresponding to the turning outer wheel exceeds a controllable predetermined value. CONSTITUTION:A control device 30 has each front and rear wheel side amplifier 31f, 31r respectively amplifying a lateral acceleration detection signal from a detector 29. And each output of each amplifier 31f, 31r as the roll rigidity instruction value is respectively supplied to each pressure control valve 17FL-17RR of each wheel directly or through each code inverter 32f, 32r. While the control device 30 has an amplifier 34 of longitudinal acceleration detection signal from a detector 33, further an output of the amplifier 34 as the pitch rigidity instruction value is supplied to each pressure control valve 17FL-17RR directly or through a code inverter 35. Here inputting each instruction value from the front wheel side amplifier 31f and the amplifier 34 to an arithmetic part 36, a correction instruction value is calculated and output.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides a system in which a fluid pressure cylinder is inserted between the body of a vehicle and each wheel, and the working fluid pressure of the fluid pressure cylinder is controlled by a pressure control valve. In particular, regarding improvements to active suspensions that suppress changes in vehicle body posture,
The present invention relates to an active suspension that prevents the occurrence of so-called diagonal roll during sudden steering or braking during a turn.

[Prior Art] As a conventional active type suspendillan, there is one described, for example, in Japanese Patent Application No. 137875/1982.

This conventional active suspension detects or estimates the lateral acceleration and longitudinal acceleration of the vehicle body using an acceleration detection or estimation means, outputs a command value from a control device according to the acceleration value, and controls pressure according to the command value. The valve controls the working fluid pressure of a fluid pressure cylinder inserted between the vehicle body and each wheel, thereby continuously changing the roll stiffness or pitch stiffness of the vehicle and improving the roll or pinch posture of the vehicle. The aim is to improve responsiveness and controllability to changes.

[Problem that the invention seeks to solve]

However, in such conventional active suspensions, the lateral acceleration or longitudinal acceleration generated in the vehicle body is detected or estimated, and the operating pressure of the fluid pressure cylinder of each wheel is controlled according to this acceleration, thereby adjusting the vehicle body posture. Because of this, when large longitudinal accelerations occur as well as lateral accelerations, such as during sudden steering or braking during a turn, each cylinder pressure must be adjusted according to a signal that is the sum of both independently. If the maximum cylinder pressure exceeds the controllable maximum pressure, a problem arises in that so-called diagonal rolls occur.

In other words, for example, when braking is applied during a left turn, both the lateral acceleration due to the turn and the longitudinal acceleration due to braking act, and first the pressure in the fluid pressure cylinder of the front right wheel, which is one of the wheels on the outside of the turn, reaches the maximum controllable pressure. Over pressure and lack of pressure, while the other front left wheel.

The pressure of the rear right wheel and the rear left wheel is controlled within the control pressure range, so if the pressure of the front right wheel is insufficient, the vehicle body will roll forward and to the right around the diagonal line connecting the front left wheel and the rear right wheel. A diagonal roll will occur.

When diagonal roll occurs in this manner, the ground load of the inner wheel during turning decreases, making it impossible to obtain the necessary tire lateral force and braking force, which poses a problem in that directional stability may be lost.

Furthermore, if the maximum control pressure is set to a sufficiently large value, there is a problem in that the horsepower consumption of the hydraulic pump deteriorates significantly.

This invention was made by focusing on these conventional problems, and prevents the occurrence of diagonal roll when large longitudinal accelerations occur along with lateral accelerations, such as during sudden steering or braking during a turn. The purpose of the present invention is to provide an active suspension that can secure sufficient directional stability by ensuring tire generation force on the inner wheel during turning, and can reduce pump energy consumption by keeping the maximum working fluid pressure low. It is something to do.

[Means for solving problems]

Therefore, the active suspension of the present invention includes a fluid pressure cylinder inserted between the vehicle body and each wheel, a pressure control valve that controls the working fluid pressure of the fluid pressure cylinder according to a command value, and a pressure control valve that controls the working fluid pressure of the fluid pressure cylinder according to a command value. In an active suspension comprising acceleration detection or estimation means for detecting or estimating lateral acceleration and longitudinal acceleration, and a control device for outputting a command value to a pressure control valve according to the acceleration value, the control device controls the turning of the vehicle body. A calculation that calculates and outputs a correction command value that reduces the working fluid pressure of the fluid pressure cylinder of the other wheel when the working fluid pressure of the fluid pressure cylinder of the wheel on one side of the outer wheel exceeds the controllable working fluid pressure. It is characterized in that it includes a section.

[Effect]

A command value is output by the control device according to the acceleration value detected or estimated by the acceleration detection or estimation means, and a fluid pressure cylinder inserted between the vehicle body and each wheel is activated by a pressure control valve according to the command value. The working fluid pressure is controlled so that the vehicle body is kept in a flat position.

When both lateral acceleration and longitudinal acceleration are large, such as during sudden steering or braking during a turn, and the working fluid pressure in the hydraulic cylinder of one wheel on the outer turning wheel exceeds the controllable working fluid pressure. The calculation unit included in the control device calculates and outputs a correction command value for reducing the working fluid pressure of the fluid pressure cylinder of the wheel on the other side of the outer turning wheel.

Therefore, even when suddenly steering or braking while turning,
The roll behavior is centered around the normal front and rear roll axes,
This prevents diagonal roll from occurring, prevents the large ground load of the inner wheel from shifting, provides the necessary tire lateral force and braking force, and ensures directional stability.

〔Example〕

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

First, to explain the configuration, in FIG. 1, 11FL,
11FR, 11RL, and 11RR are the vehicle body side member 12 and each wheel 13FL, 13FR, and 13RL, respectively.
, 131? An active suspension device inserted between the wheel side member 14 that individually supports R,
Hydraulic cylinder 15FL each as an actuator
15RR, coil springs 16FL to 16RR, and pressure control valves 17FL to 17RR that control the working oil pressure for the hydraulic cylinders 15FL to 15RH in response only to command values from a control device 30, which will be described later.

Here, each of the hydraulic cylinders 15FL to 15RH has a cylinder tube 15a attached to the vehicle body side member 12, a piston rod 15b attached to the wheel side member 14, and an operation inside the upper pressure chamber B closed by the piston 15c. Oil pressure is controlled by pressure control valves 17FL to 17RR. In addition, coil springs 16FL to 16
Each of the RRs is installed in parallel with the hydraulic cylinders 15FL to 15RR between the vehicle body side member 12 and the wheel side member 14 to support the static load of the vehicle body. Note that the coil springs 16FL to 16RR may have low spring constants that only support the static load of the vehicle body.

Each of the pressure control valves 17FL to 17RR includes a cylindrical valve housing 18, a spool 19 slidably disposed in an insertion hole 18a provided in the valve housing 18, and a a rod 20; a spring 21 interposed between the spool 19 and the rod 20;
It has a proportional solenoid 22 that controls the pressing force of a spring 21 via a rod 20 to control the movement of the spool 19 between an offset position and an operating position on both ends thereof.

Here, the valve housing 18 has input ports 18b each having one end communicating with the insertion hole 18a and the other end connected to the hydraulic oil supply side of the hydraulic power source 24 via a hydraulic piping 25.
, an output port 18C connected to the drain side of the hydraulic power source 24 via a hydraulic pipe 26, and an input/output port 18 communicating with the upper hydraulic chamber B of the hydraulic cylinders 15FL to 15RR via a hydraulic pipe 27. ing. The output port 18C is connected to drain passages 18e and 18f that communicate between the output port 18C and the upper and lower ends of the spool 19.

The spool 19 also includes a land 19a facing the input port 18b and a land 1 facing the output port 18c.
9b is formed, and both lands 19a, 19
A land 19C having a smaller diameter than b is formed at the lower end, and a pressure control chamber C is formed between the land 19a and the land 19C. This pressure control chamber C has a biloft passage of 18 g.
It is connected to the input/output capo 18d via the input/output capo.

Furthermore, the proportional solenoid 22 is composed of an actuator 22a that is slidable in the axial direction and an excitation coil 22b that drives the actuator 22a, and a command value V (Vf, Vr .

Vx, V. ) is driven and controlled by Here, the relationship between the command value V and the working oil pressure P output from the input/output coupler 18d is as shown in Fig. 3. When the command value V is zero, a predetermined offset pressure P is output. However, when the command value V increases in the positive direction from this state, the working pressure P increases with a predetermined proportional gain of 1, and when it reaches the maximum pressure P six of the hydraulic source 24, it becomes saturated and the command value V increases in the negative direction. As the pressure increases, the operating pressure decreases proportionally. here,
Let the command value corresponding to the maximum pressure Psaw be vl,8.

The pressure control valves 17PL-17RR operate in a state in which the pressing force by the proportional solenoid 22 is applied to the spool 19 via the spring 21, and the pressing force of the spring 21 and the pressure in the pressure control chamber C are balanced. For example, when a relatively low frequency vibration input corresponding to an upward sprung mass resonance frequency due to passing through a recess on the road surface (or a downward vibration input due to passing through a recess) is transmitted to the wheels, this causes the hydraulic cylinders 15FL to 15RH to Piston rod 1
5b tries to move upward (or downward), and the pressure in the upper hydraulic chamber B increases (or decreases).In this way, when the pressure in the upper hydraulic chamber B increases (or decreases), the pressure chamber The pressure in the pressure control chamber C, which is communicated with B through the hydraulic piping 27, the input/output port 18d, and the pilot passage 18g, increases (or decreases), and the balance with the pressing force of the spring 21 is lost, so the spool 19 moves upward. (or downward), in the direction in which the space between the input port 18b and the input/output port 18d is closed (or opened), and in the direction in which the space between the output port 18C and the input/output port 18d is opened (or (closed direction), so the upper hydraulic chamber B
A part of the pressure from the input/output boat 18d is output from the input/output boat 18d.
c and hydraulic piping 26 to the hydraulic source 24 (or from the hydraulic source 24 to the input port 18b, input/output boat 18
d and hydraulic pressure is supplied to the upper hydraulic chamber B via the hydraulic pipe 27). As a result, hydraulic cylinders 15FL to 15RH
The pressure in the upper hydraulic chamber B is reduced (or increased), and the pressure increase in the upper pressure chamber B due to upward vibration input (or the pressure decrease in upper pressure chamber B due to downward vibration input) is suppressed. Vibration input transmitted to the wheel side member 14 can be reduced.

At this time, since no restriction is provided in the hydraulic piping 26 between the output port 18C of the pressure control valves 17FL to 17RR and the hydraulic power source 24, when controlling the upward vibration input,
No damping force is generated.

In addition, in FIG. 1, 28H is the pressure control valve 17FL~
A high-pressure side accumulator is connected in the middle of the hydraulic piping 25 between 17RR and the hydraulic power source 24, and 28L is the pressure control valve 17.
This is a low-pressure side accumulator connected to the hydraulic piping 27 between the FL-17RR and the hydraulic cylinders 15FL to 15RR via a throttle valve 28V.

On the other hand, there is a lateral acceleration detector 29 on the vehicle body that detects lateral acceleration.
The lateral acceleration detector 29 outputs a lateral acceleration detection signal y, which is a voltage output corresponding to the lateral acceleration of the vehicle, and this lateral acceleration detection signal y is input to the control device 30 . Further, the vehicle body is provided with a longitudinal acceleration detector 33 for detecting longitudinal acceleration, and this longitudinal acceleration detector 33 outputs a longitudinal acceleration detection signal which is a voltage output corresponding to the longitudinal acceleration of the vehicle. A signal is also input to the control device 30.

As shown in FIG. 4, the control device 30 converts the lateral acceleration detection signal y from the lateral acceleration detector 29 into gains Kyf and Ky.
Front wheel side amplifier 31f and rear wheel side amplifier 31 amplified by r
In this embodiment, since the front wheel side load is normally larger than the rear wheel side load, Kyf>Kyr.

Then, the output of the front wheel side amplifier 31f is directly supplied to the front left wheel pressure control valve 17RL as a roll stiffness command value Vf, and the front right wheel pressure control valve 117PR is supplied via a sign inverter 32r that multiplies minus 1. will be supplied.

Similarly, the output of the rear wheel side amplifier 31r is directly supplied to the rear left wheel pressure control valve 17RL as the roll stiffness command value Vr, and the rear right wheel pressure control valve 17RR is supplied with a sign inverter that multiplies by minus 1. 32r.

The control device 30 also includes an amplifier 34 that amplifies the longitudinal acceleration detection signal from the longitudinal acceleration detector 33 with a gain Kx.
The output of the amplifier 34 is used as the pitch stiffness command value Vx for the front left wheel and front right wheel pressure control valves 17RL, 17P.
It is supplied as it is to the pressure control valves 17RL and 17RR of the rear left wheel and the rear right wheel through a sign inverter 35 that multiplies it by minus 1.

Further, the control device 30 controls the command value Vf output from the front wheel side amplifier 31f and the command value Vf output from the amplifier 34.
It includes an arithmetic unit 36 which inputs x and calculates and outputs a correction command value (2) as described later.

Next, the operation of the above embodiment will be explained.

As shown in Fig. 6, the lateral acceleration detection signal y takes a positive value when the lateral acceleration acts in a rightward direction during a right turn, and takes a positive value when the longitudinal acceleration detection signal or longitudinal acceleration acts in a backward direction during braking. It shall take a value.

The lateral acceleration detection signal y from the lateral acceleration detector 29 is amplified by the gain Kyf by the front wheel side amplifier 31f and supplied to the front left wheel pressure control valve 17RL as the roll stiffness command value Vf, and the command value Vf is sent to the sign inverter 32f. The multiplied by minus 1 is supplied to the front left wheel pressure control valve 17FH. Further, the lateral acceleration detection signal y from the lateral acceleration detection -29 is amplified by the gain Kyr by the rear wheel side amplifier 31r and supplied to the rear left wheel pressure control valve 17RL as the roll stiffness command value Vr, and the command value Vr has a sign It is multiplied by minus 1 in the inverter 32r and supplied to the rear right wheel pressure control valve 17RL.

In addition, the longitudinal acceleration detection signal from the longitudinal acceleration detector 33 or the amplifier 34 amplifies it with a gain Kx and outputs it as a pinch stiffness command value Vx to the pressure control valve 17 of the front left wheel and the front right wheel.
At the same time, the command value Vx is multiplied by minus 1 in a sign inverter 35f and is supplied to pressure control valves 17RL and 17RR of the rear left wheel and the rear right wheel.

Furthermore, the command value Vf from the front wheel side amplifier 31f and the command value Vx from the amplifier 34 are input to the calculation section 36, and the fifth
The calculation is performed according to the procedure shown in the figure.

In the figure, first, in the step, the absolute value 1Vf1 of the command value Vf from the front wheel side amplifier 31f and the amplifier 34
Difference between the sum of the absolute value IVx1 of the command value Vx from V and the controllable maximum command value V saw
l + l V x l V m-- is calculated, and then in step (2) it is checked whether this difference value ΔV is positive or not. If Δ■≦0, this means that the hydraulic cylinder 15FL~ It is determined that the pressure of 15RH is within a controllable range, and then, in step (2), the correction command value Vo is set to 0, and further, in step (2), no correction command value is output to any of the hydraulic cylinders 15FL to 15RR.

The command values (Vf+Vx) and (-Vf+Vx) supplied to the pressure control valves 17FL to 17RR in this way.

(Vr-Vx) and (-Vr-Vx), the working pressure PFL*PF of the hydraulic cylinders 15FL to 15RH is determined according to the characteristics shown in FIG. 3 of the pressure control valves 17FL to 17RR.
R+ P RLI P ** is given.

That is, the relationship between the lateral acceleration y and the cylinder oil pressure is as shown in FIG. The relationship with the cylinder oil pressure is as shown in FIG. 7 (bl), and the command value Vx is converted to bP2.

Therefore, the working oil pressure of the hydraulic cylinders 15FL to 15RR of each wheel is P FLI P Flll P RLI
P R11 is PFL=PN+ΔP1 +Δp z
(1) aPFR=PM-ΔP, +ΔP z
(11bP It = P M + ΔPl゛ - bP, (11cP □ = PN - ΔP, °
-bP z (1) d, both of these oil pressures are within controllable ranges, and the vehicle is controlled to maintain a flat attitude even when turning and braking or accelerating.

Returning to FIG. 5, if it is determined in step (■) that Δv>O, this is because the sum of the lateral acceleration y due to turning and the longitudinal acceleration X due to braking or acceleration is large;
It is determined that the controllable range is exceeded, and the process then proceeds to step (3), where a correction command value Vo''K·ΔV (where K is a proportionality constant) is calculated.

The value of the proportionality constant is set differently depending on the vehicle, especially depending on the front and rear weight distribution and the gains Kyf and Kyf of the front wheel amplifier 31f and rear wheel amplifier 31r, but it is generally set to a value of l or less. Take.

Next, the process moves to step ■, and it is checked whether the roll stiffness command value Vf is positive or not. If 'Vf>0, this is a right turn, so the process moves to step ■, and the pitch stiffness command value is determined. It is checked whether the value Vx is positive or not, and if Vx>Q, it is determined that this is a braking state. 'In other words, the brake is applied during a right turn, and the lateral acceleration y and longitudinal acceleration are large, and the sum of the command values of the pressure control valve 17FL for the front left wheel exceeds the maximum controllable value. , as shown in FIG. 8, the maximum oil pressure P that can be controlled by the oil pressure PFL of the front left wheel. 1X
As a result, the oil pressure of the front left wheel becomes insufficient by (PFL p□X), and the vehicle body rolls forward and left about the diagonal line connecting the front right wheel and the rear left wheel, causing a diagonal roll. Therefore, in this case, in step (2), the rear left wheel pressure control valve 171? Correction command value ■ to L. =-K・
Outputs Δ■, and this correction command value■. is converted to the corrected oil pressure P0, PIL=PM-ΔP+″-ΔPg + Po
As (2), the rear left wheel hydraulic cylinder 15RL
hydraulic pressure is reduced to allow normal leftward roll behavior and prevent diagonal roll.

In step (2), if Vx<0, it is determined that this is an acceleration state. That is, the vehicle is in a state of acceleration during a right turn, and the lateral acceleration y and longitudinal acceleration are large, and the sum of the command values of the rear left wheel pressure control valve l7RL exceeds the maximum controllable value. The rear left wheel oil pressure PRL becomes controllable maximum oil pressure P, □ or more, and the rear left wheel oil pressure becomes (
Pi+t-P, , X) is insufficient, and the vehicle body rolls toward the rear left about the diagonal line connecting the front left wheel and the rear right wheel, resulting in a diagonal roll. Therefore, in this case, in step (2), a correction command value V,=-K・Δ■ is output to the pressure control valve 17pt of the front left wheel, and this is converted to Po, PFL=PM-ΔP1 +ΔPz+Po (3)
As a result, the hydraulic pressure of the hydraulic cylinder 15FL of the front left wheel is reduced to achieve normal leftward roll behavior and prevent diagonal roll.

In step ■, if v r<o, this is a left turn, so proceed to step 0, check whether the pitch stiffness command value Vx is positive, and if Vx>0, this is a left turn. is determined to be in a braking state.

That is, the vehicle is in a braking state during a left turn, and the lateral acceleration y and longitudinal acceleration X are large, and the sum of the command values of the front right wheel pressure control valve 17PR exceeds the maximum controllable value. The maximum oil pressure P that can be controlled by the front right wheel oil pressure PFII.

, X or more, the hydraulic pressure of the front right wheel becomes insufficient by (PFRP□X), and the vehicle rolls forward and to the right around the diagonal line connecting the front left wheel and the rear right wheel, causing a diagonal roll. do. Therefore, in this case, in step (3), the correction command value V,=-K・Δ
■ is output, and this is converted to Po, PR1=PN+ΔP1゛-ΔP! +P(+ (4
), the hydraulic pressure of the hydraulic cylinder 15RR of the rear right wheel is reduced to achieve normal rightward roll behavior and prevent diagonal roll.

In step [phase], if Vx<0, this is determined to be an acceleration state. That is, the vehicle is in a state of acceleration during a left turn, and the lateral acceleration y and the longitudinal acceleration are large, and the sum of the command values of the rear right wheel pressure control valve 17RR exceeds the maximum controllable value. Rear right wheel oil pressure pHl
l is the maximum controllable oil pressure P 111111 or more,
The hydraulic pressure of the rear right wheel becomes insufficient by (PRI P,, occurs. Therefore, in this case, in step @, the correction command value V,=-K・ΔV is output to the pressure control valve 17FH of the front right wheel, and this is converted to P, PFl=PM+ΔP1′ +ΔPz+P+ (5
), the hydraulic pressure of the hydraulic cylinder 15FR of the front right wheel is reduced to achieve normal rightward roll behavior and prevent diagonal roll.

In this way, if braking or acceleration is performed during a turn and the oil pressure of the hydraulic cylinder of one of the wheels on the outer wheel of the turn exceeds the controllable range, and a diagonal roll is about to occur, the pressure on the other wheel of the outer wheel of the turn will be reduced. By reducing the hydraulic pressure of the hydraulic cylinders of the wheels and achieving normal roll behavior, sufficient lateral force and braking force are obtained from the tires on the inner wheels of the turn, and the directional stability of the vehicle is ensured.

Therefore, the maximum control pressure of the hydraulic pump can be kept low, and energy consumption can be reduced.

In the embodiments described above, the case where braking is performed during a left turn is exemplified, but the present invention can be similarly applied to cases where braking is performed during a right turn, or when acceleration is performed during a turn.

Further, the calculation unit 36 calculates the lateral acceleration detection signal y and the longitudinal acceleration detection signal Although shown as an example, it may be calculated based on the lateral acceleration detection signal y and the longitudinal acceleration detection signal k, or the hydraulic cylinder 1
It may be calculated based on the operating pressure value of 5FL-15RH.

In addition, although the case where the distribution of the gains Kyr and Kyr between the front wheel side amplifier 31f and the rear wheel side amplifier 31r is set to be Kyf>Kyr and constant, the distribution and the total value of both can be set arbitrarily at the driver's seat. It may be possible, or the distribution and total value may be automatically set depending on the steering angle, for example.

In addition, although the lateral acceleration value is actually measured by a lateral acceleration detector, the vehicle roll It is also possible to remove the influence of the lateral acceleration caused by the lateral acceleration and estimate only the true lateral acceleration by calculation.

Further, the longitudinal acceleration may also be estimated from the brake depression force or the brake operating oil pressure instead of the actual measured value.

〔Effect of the invention〕

As explained above, the active suspension of the present invention includes a fluid pressure cylinder inserted between the vehicle body and each wheel, and a pressure control valve that controls the working fluid pressure of the fluid pressure cylinder according to a command value. In an active suspension comprising an acceleration detection or estimation means for detecting or estimating the lateral acceleration and longitudinal acceleration of the vehicle body, and a control device for outputting a command value to a pressure control valve according to the acceleration value, the control device comprises: , when the working fluid pressure of the hydraulic cylinder of the wheel on one side of the rotating outer wheel of the vehicle body exceeds the controllable working fluid pressure,
Since the configuration includes a calculation unit that calculates and outputs a correction command value that reduces the working fluid pressure of the fluid pressure cylinder of the other wheel, the lateral acceleration can be reduced during sudden steering or braking during a turn. This also prevents the occurrence of diagonal rolls when large longitudinal accelerations occur, ensuring sufficient directional stability by ensuring the tire generated force on the inner wheel of the turn, and reducing pump energy consumption by keeping the maximum working fluid pressure low. This has the effect of reducing the

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of an active suspension according to the present invention, FIG. 2 is a sectional view showing an example of a pressure control valve applicable to the present invention, and FIG. 3 is a pressure control valve shown in FIG. FIG. 4 is a block diagram showing an example of a control device that can be applied to the present invention, and FIG.
The figure is a flowchart showing the procedure of processing executed in the arithmetic unit included in the control device, FIG. 6 is a plan view of the vehicle for explaining the operation of the above embodiment, and FIGS. 7(a) and (
b) is a graph showing the relationship between lateral acceleration and longitudinal acceleration and cylinder pressure, respectively, and Fig. 8 is a graph showing the relationship between lateral acceleration and longitudinal acceleration, respectively, and cylinder pressure.
) is a graph that combines the characteristics shown in 11FL~IIRR-...Suspension device, 12.
・・Vehicle side member, 13FL~13RR・・Wheel, 15
FL~15RR...Hydraulic cylinder, 16FL~16R
R...Coil spring, 17FL~17RR...
Pressure control valve, 22... Proportional solenoid, 29... Lateral acceleration detector, 30... Control device, 33... Longitudinal acceleration detector, 36... Arithmetic unit.

Claims (1)

[Claims] A fluid pressure cylinder inserted between the vehicle body and each wheel, a pressure control valve that controls the working fluid pressure of the fluid pressure cylinder according to a command value, and a pressure control valve that controls the lateral acceleration of the vehicle body and An active suspension comprising an acceleration detection or estimation means for detecting or estimating longitudinal acceleration, and a control device for outputting a command value to the pressure control valve according to the acceleration value, wherein the control device is configured to control a turning outer wheel of a vehicle body. a calculation unit that calculates and outputs a correction command value to reduce the working fluid pressure of the fluid pressure cylinder of the other wheel when the working fluid pressure of the fluid pressure cylinder of the wheel on one side exceeds the controllable working fluid pressure; An active suspension characterized by including.