JPS63145115A - Suspension device for vehicle - Google Patents

Abstract

PURPOSE:To aim at improvement in safety, by finding both command values on the basis of acceleration and a stroke between wheels and a car body, judging whether each command value is correct or not, and making it so as to be selected to the normal command value side, in case of an active type suspension device. CONSTITUTION:A command value of acceleration to be outputted by a first attitude control command means consisting of a lateral acceleration detector and a stroke command value between wheels and a car body to be outputted by a second attitude control command means consisting of stroke detectors at all directions are inputted into a command operation judging means. And, this command operation judging means compares each command with the reference value in conformity with the specified procedure, and it judges whether it is normal or not. And, when one side is abnormal, it selects a selector device to a normal part of the attitude control command side, controlling an active type suspension with the command value at the normal side. With this constitution, safety is yet more improvable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a suspension device for a vehicle, and in particular,
The present invention relates to a vehicle suspension device equipped with an active suspension whose operating pressure can be changed according to a predetermined command value.

[Conventional technology]

As a suspension device for a vehicle, for example, Japanese Patent Application No. 61-39944 and Japanese Patent Application No. 6
There is one described in No. 1-137875.

Among these, the former prior application detects the stroke for each wheel and forms a command value for the active suspension based on this stroke signal, so that the stroke always becomes the target value. By controlling the command value, changes in the vehicle's attitude are suppressed. On the other hand, the latter prior application detects the acceleration of the vehicle body in the lateral or longitudinal direction, multiplies this by a predetermined gain constant to obtain a command value, and controls the active suspension using this.

[Problem that the invention seeks to solve]

However, in each of the above-mentioned prior applications, in order to suppress changes in the posture of the vehicle, the acceleration generated in the vehicle is detected and control is performed based on this, or the stroke between each wheel and the vehicle body is detected. Since only one of the configurations that perform control based on this was installed, for example, due to a detector failure, the vehicle suspension system would become activated during driving conditions (particularly when turning, starting, stopping, etc.) If this happens, it becomes impossible to suppress changes in the vehicle's attitude, and
In the worst case scenario, there were unresolved problems, such as overturning and interfering with stable driving.

Therefore, this invention was made by focusing on such conventional unresolved problems, and it is possible to change the control system that forms and outputs command values for controlling the active suspension based on the acceleration acting on the vehicle. The aim is to improve the fail-safe function and solve the above problems by creating a dual structure, one based on the stroke between the wheel and the vehicle body, and the other based on the stroke between the wheel and the vehicle body, and switching between these as necessary. There is.

[Means for solving problems]

In order to achieve the above object, as shown in the basic configuration diagram of FIG. In a vehicle suspension device that includes an active suspension system and suppresses changes in the posture of the vehicle by changing the command value, a suspension device that detects or estimates acceleration acting on the vehicle and outputs the command value in accordance with the detected or estimated acceleration acting on the vehicle. a second attitude control command means that detects a stroke between a wheel and a vehicle body and outputs the command value in accordance with the stroke;
a command operation determining means for determining whether command operations of the first and second attitude control command means are in a normal state; and a command operation determination means that determines whether the command operation of the first or second attitude control command means is determined by the command operation determination means. The present invention is characterized in that it is equipped with a switching means that switches to supply the command value of the other attitude control command means to the active suspension when it is determined that the command operation of the other attitude control command means is in an abnormal state.

[Effect]

In this invention, the acceleration acting on the vehicle is detected or estimated by the first attitude control command means, and a command value for the active suspension is formed in accordance with this. Further, the stroke between the wheel and the vehicle body is detected by the second attitude control command means, and the command value is generated in accordance with this. Command values from these first and second attitude control command means are supplied to the active suspension via a switching means.

In this case, the command operation determination means determines whether or not the command operations related to the first and second attitude control command means are in a normal state, and the switching means is appropriately switched based on the determination result of the command operation determination means, Any command value is supplied to the active suspension. Specifically, if the command operation determining means determines that the command operation of the first attitude control command means is in an abnormal state and the command operation of the second attitude control command means is in a normal state, The control is switched to the attitude control command means No. 2, and the command value from this means is supplied to the active suspension. In the opposite case, the control is switched to the first attitude control command means, and the command value from this means is supplied to the active suspension. As a result, even if either the first or second attitude control command means does not operate normally due to a detector failure or the like, a normal command value will be supplied from the other.
The fail-safe function will be improved.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIGS. 2 to 6 are diagrams showing an embodiment of the present invention.

In Figure 2, 1) FL, 1) FR, 1) RL,
IIRR is the vehicle body side member 12 and each wheel 13F, respectively.
An active suspension is shown interposed between the wheel side member 14 that individually supports L to 13RR. Each of these active suspensions IIFL to IIRR has hydraulic cylinders 15FL, 15FR, and 15R as actuators.
L, 15RR, coil spring 16FL.

Pressure control valves 17FL, 17PR, 17RL, 17R that control the working oil pressure for 16FR, 16RL, 16RR1 and hydraulic cylinders 15FL to 15RR in response only to command values from controller 31, which will be described later.
R and R are provided separately.

Among these, the hydraulic cylinders 15FL to 15RR are used for the front wheel 13FL and the front right wheel 13FR, as shown in FIG.

It is arranged so as to correspond to the rear left wheel 13RL and the rear right wheel 13RR and to be driven independently. This hydraulic cylinder 1
5FL-15RR each has its cylinder tube 15
a is attached to the vehicle body side member 12, and the piston rod 1
5b is attached to the wheel side member 14. and,
The working oil pressure in the upper pressure chamber B closed by the piston 15c is controlled by pressure control valves 17FL to 17RR, respectively. Further, each of the coil springs 16FL to 16RR is connected to each hydraulic cylinder 15FL to 15RR between the vehicle body side member 12 and the wheel side member 14.
This is installed in parallel with the vehicle body, and this supports the static load of the vehicle body. Here, coil spring 16FL~
16RR each only supports the static load of the vehicle body, so it has a relatively low spring constant.

Each of the pressure control valves 17FL-17RR has a cylindrical valve housing 18 and a proportional solenoid 22 integrally formed therein, as shown in FIG. An insertion hole 18a is provided in the center of the spool 18, and a spool 19 with a spring 21 interposed therebetween and a rod 20 are slidably disposed in the insertion hole 18a.

The valve housing 18 also has a hydraulic pipe 25, one end of which communicates with the insertion hole 18a, and the other end of which is connected to the hydraulic oil supply side of the hydraulic power source 24.
and an output port 18c, which similarly has one end communicating with the insertion hole 18a and the other end connected to the drain side of the hydraulic power source 24 via the hydraulic piping 26.
Similarly, one end communicates with the insertion hole 18a and the other end communicates with the hydraulic piping 2.
An input/output port 18d is formed which communicates with the upper hydraulic chamber B of each of the hydraulic cylinders 15FL to 15RR via 7. This and spool 1 are connected to the output port 18c.
A drain passage 18e communicating between the upper end and the lower end of 9;
18f is formed. Further, the spool 19 is formed with a land 19a facing the input port 18b and a land 19b facing the output port 18C, and a land 19c with a smaller diameter than both lands 19a and 19b is formed at the lower end of the spool 19. It is provided. A pressure control chamber C is formed between the land 19a and the land 19c, and this pressure control chamber C is connected to the input/output boat 18d via a pilot passage 18g.

On the other hand, the proportional solenoid 22 controls the pressing force of the spring 21 via the rod 20, and the position of the spool 19 is
It has a function of controlling movement between the offset position and the operating positions on both ends thereof.

For this reason, the proportional solenoid 22 includes an actuator 22a that is slidable in the axial direction and an excitation coil 22b that drives the actuator 22a.
Command value S (S+ −
34).

Here, the relationship between the command value S (S+ - S4) and the working oil pressure P output from the input/output port 18d is as shown in FIG. In other words, when the command value S is zero, a predetermined offset pressure P0 is output, and when the command value S increases in the positive direction from this state, the operating pressure P increases with a predetermined proportional gain. When the output pressure P2 of the hydraulic power source 24 is reached, it becomes saturated. Furthermore, when the command value S increases in the negative direction, the operating pressure P decreases in proportion to this.

Therefore, when the command value S becomes zero, the spool 19 is set to a predetermined neutral position, and the hydraulic cylinders 15FL to 15RR
A predetermined offset hydraulic pressure P0 is supplied to the hydraulic chamber B. In this state, the spool 19 is stopped at a position where the pressing force of the pressure adjustment spring 21 and the pressure in the pressure control chamber C (that is, the pressure in the hydraulic chamber B of the hydraulic cylinders 15FL to 15RR) are balanced.

Further, when the command value S increases in the positive direction, the actuator 22a descends, and the spool 19 descends in response to this, and the input/output boat 18d is communicated with the input boat 18b. Therefore, the pressure in the pressure chambers C of the pressure control valves 17FL to 17RR increases, and the hydraulic cylinders 15FL to 15RR extend. On the other hand, when the command value S increases in the negative direction, the actuator 22a and the spool 19 rise, and the input/output capo) 18d
is communicated with the output port 18c, thereby causing the hydraulic cylinders 15FL to 15RR to contract, contrary to the above.

Furthermore, as shown in FIG. 2, between the predetermined position of the outer cylinder of the cylinder tube 15a and the predetermined position of the vehicle body side member 140,
Stroke detectors 29FL to 29RR consisting of potentiometers to detect the relative distance between these
are arranged corresponding to each of the wheels 13FL to 13RR, respectively. Stroke signals H2 to H4, which are voltage signals, are output from the stroke detectors 29FL to 29RR to a controller 31, which will be described later. The stroke detectors 29FL to 29RR can also be used for vehicle height control, which is not shown in this embodiment.

Here, in FIG. 2, 28H is the pressure control valve 17FL.
- A high pressure side accumulator disposed in the middle of the hydraulic piping 25 between 17RR and the hydraulic power source 24, 28L is the pressure control valve 17FL-17RR and the hydraulic cylinders 15FL to 15RR.
This is a low-pressure side accumulator that is connected to the hydraulic piping 27 between the two through a throttle valve 28V.

On the other hand, a lateral acceleration detector 30 that detects lateral acceleration acting on the vehicle and a controller 31 that controls the entire device are provided at predetermined positions on the vehicle body. The lateral acceleration detector 30 is configured to output a lateral acceleration signal GV, which is a voltage output corresponding to the lateral acceleration, to the controller 31.

As shown in FIG. 5, the controller 31 includes a first attitude control command means 32 formed together with the lateral acceleration detector 30, and a second attitude control command means formed together with the stroke detectors 29FL to 29RR. 33, a switching control section 34, a path switching section 35, stop switches 36A to 36D for forcibly stopping attitude control, amplifiers 37A to 37D, and a warning lamp (LED) 38. ing.

Of these, the first attitude control command means 32 includes a lateral acceleration detector 30, and a front wheel side gain adjustment that multiplies the detection signal GV of the lateral acceleration detector 30 by the gain and K, respectively, to obtain a command value. A sign inverter 41A that multiplies the output of the front right wheel 13PR side by minus 1 among the outputs of the gain adjuster 40f, the rear wheel side gain adjuster 40r, and the front wheel side gain adjuster 40f.
and the rear right wheel 1 of the output of the rear wheel side gain adjuster 40r.
The sign inverter 41B multiplies the output of the 3RR side by minus 1.

Further, the second posture control command means 33 includes the stroke detectors 29FL to 29RR and the stroke detectors 29FL to 29RR.
A predetermined gain K is applied to the detection signals H1 to H of 9FL to 29RR.
It is comprised of gain adjusters 42A to 42D that respectively multiply the values and output the results to the path switching unit 35 as command values.

Further, the path switching unit 35 switches between the output path of the first attitude control command means 32 and the output path of the second attitude control command means 33 (switch circuits 43A to 43A which are energized by No. g J and switched). In other words, in this embodiment, when the switch switching signal J is at the logic H level, the contacts of each of the switch circuits 43A to 43D are switched to the terminal rAJ side, thereby issuing the first attitude control command. The means 32 outputs the command values S, J to 84' to the amplifiers 37A to 37D via the stop switches 36A to 36D, respectively.Furthermore, when the switch changeover signal J is at the logic L level, each switch is outputted. Circuits 43A to 43
The contact piece D is switched to the terminal rBJ side, whereby the command values S, J~84 from the second attitude control command means 33
′ is output in the same way. Then, the amplifiers 37A to 37D amplify the power of the input command values SI' to 34' to a predetermined level, respectively, and set them as command values S, ~S4.
This is connected to the excitation coil 22 of the pressure control valves 17FL to 17RR.
Output each to b.

Furthermore, as shown in the figure, the lateral acceleration detector 30 and the stroke detector 29 are connected to the command motion determining means 34.
Detection signals from FL to 29RR are input. That is, the command operation determination means 34 includes a microcomputer 45, a multiplexer 46 that switches the detection signals of the stroke detectors 29FL to 29RR and the lateral acceleration detector 30, and converts the detection signal of the analog quantity selected by the multiplexer 46 into a digital signal. A/D to convert to
A converter 47 is provided.

The microcomputer 45 has an I10 port 50, a central processing unit (hereinafter referred to as rCPUJ) 51, and RAM, R
It is configured to include a memory 52 consisting of an OM etc. and a timer 53. The A/D converter 47 is connected to the input port side of the (10) port 50, and the switch switching signal J is sent to the switch circuits 43A to 43D through the output port, and the control stop signal ST is sent to the stop switch circuits 43A to 43D. The signal is configured to be output to each of the switches 36A to 36D.

The CPU 51 controls the switching of the multiplexer 46 via the I10 port 50, thereby controlling the detection signal Gv of the selected lateral acceleration detector 29 and the stroke detector 29F.
The detection signals H+ to H4 of L to 29RR are read, and based on these, calculations and other processing to be described later are performed. Also,
The memory 52 stores in advance a predetermined program necessary for the execution of processing by the CPU 51.
Processing results etc. can be stored sequentially.

Furthermore, the stop switches 36A to 36D receive a control stop signal S.
When T is at the logic H level, the contact is turned "off" to cut off the circuit, and when T is at the logic L level, the contact is turned "on". Also, alarm lamp 3
8 is adapted to be lit based on a lighting instruction from the CPU 51.

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

When the ignition switch (not shown) of the vehicle is turned on, lateral acceleration detection and stroke detection are started, and after initialization such as clearing the program counter is performed in the microcomputer 45 of the controller 31, Processing is performed based on a predetermined main program.

First, when a roll occurs in a vehicle due to a person getting on or off in a stopped state or a turn in a running state, the lateral acceleration detector 30 and stroke detectors 29FL to 29RR of the first and second attitude control command means 32 are activated. The lateral acceleration and stroke change due to the roll are detected respectively.

First, the individual operations associated with the first attitude control command means 32 will be explained. The lateral acceleration G7 from the lateral acceleration detector 30 is
Front wheel side gain adjuster 40f and rear wheel side gain adjuster 40
At r, the gains Kf and Kr are respectively multiplied, and the command value S% ~
It is output as 84'. Of these, the old pressure control valve 17
Command value SZ' for FR and rear right pressure control valve 17RR
+34' is inverted by the sign inverters 41A and 41B, and reaches the switch circuits 43A to 43D together with the uninverted command values s and '+82'. The contacts of the switch circuits 43A to 43D are connected to the switch switching signal J.
When the control stop signal ST is energized to the logic H level and is switched to the front side of the terminal, and when the contacts of the stop switches 36A to 36D are energized to the logic L level of the control stop signal ST and are in the on state, the command value 815 ~84' is the amplifier 37A~3
Each reaches 7D. The amplifiers 37A to 37D amplify the input command values SI' to 84' to a predetermined level, and output the amplified command values 81 to S4, which are current signals, to the excitation coils 22b of the pressure control valves 17FL to 17RR.

As a result, in the pressure control valves 17FL to 17RR, each excitation coil 22b is excited in accordance with the command value S (S, -34), and as if in the vanguard, the output pressure P is increased to the command value S (S, -34).
, ~S4). As a result, the position of the piston 15c of each hydraulic cylinder 15FL-15RR is controlled by the pressure P from each pressure control valve 17FL-17RR.

For example, when the vehicle turns to the right and rolls downward to the left when viewed from the front side of the vehicle body, and the detected value GV of the lateral acceleration detector 30 becomes a positive value, the front pressure control valve 17FL and rear left pressure control valve 17RL Positive command values S1 and S3 are supplied to the pressure control valve 17FL.

The output pressure P of 17RL increases from the offset pressure P0, and the corresponding pressure in the hydraulic chambers B of the hydraulic cylinders 15FL and 15RL increases. In this running state, the hydraulic cylinders 15PL and 15RL are in the direction of being contracted by the rolls, but a cylinder biasing force that resists this contraction force is generated by the pressure increase in the hydraulic chamber B, and an anti-roll effect is exerted. On the other hand, in the above case, the front cloth pressure control valve 1
Negative command values S2 and S4 are supplied to 7FR and the rear right pressure control valve 17RR by the sign inverters 41A and 41B, and the output pressure P of the pressure control valves 17PR and 17RR is lower than the offset pressure P0. Compatible hydraulic cylinder 15FI? , the pressure in hydraulic chamber B of 15RR decreases.

Therefore, the force of the hydraulic cylinders 15FR, 15RH that tends to extend due to the rolls is absorbed by the pressure drop in the hydraulic chamber B, and an anti-roll effect is exerted.

Further, if the vehicle turns to the left and rolls to the right when viewed from the front side of the vehicle body, and the lateral acceleration detector 30 detects a negative lateral acceleration GV, in this case, the control is performed in the opposite manner to that described above.
A similar anti-roll effect is obtained.

Furthermore, for example, when a vehicle is traveling straight on a flat road with no unevenness, no roll occurs in the vehicle body and the lateral acceleration G,
- becomes approximately zero, and in this state, each pressure control valve 17FL
The excitation coil 22b of ~17RR is in a non-excited state, and a predetermined offset pressure P0 is output. In this state, relatively low frequency vibrations input from the road surface through the wheels 13FL to 13RR are responded to by slight movement of the spool 19 due to pressure fluctuations in the pressure control chambers C of the pressure control valves 17FL to 17RR. Relatively high frequency vibration input corresponding to the unsprung resonance frequency due to fine irregularities on the road surface is absorbed by the throttle valve 28V.

Next, individual operations associated with the second attitude control command means 33 will be explained. The stroke signals H5 to H4 detected by the stroke detectors 29FL to 29RR are transmitted to the gain adjuster 4.
2A to 42D, the command value SI' to 3 is multiplied by the gain.
4' to the switch circuits 43A to 43D.

Here, if the contacts of the switches 43A to 43D are switched to the terminal B side, and if the stop switches 36A to 36
When D is off, the outputs of gain regulators 42A-42D are routed to pressure control valve 17 via amplifiers 37A-37D, respectively.
From FL to 17RR. Then, the same control as in the vanguard is performed.

Next, the overall operation of this device will be explained based on FIG. 6.

In the figure, the microcomputer 45, for example,
A processing procedure executed as a timer interrupt processing every msec is shown.

In FIG. 6, first in step (2), the CPU 51
10 ports 50 to switch the multiplexer 46;
Lateral acceleration detector 30 and stroke detector 29FL~2
Lateral acceleration signal G7 and stroke signal H applied to 9RR
I"" Read H4 in sequence and move on to step ■.

In step ■, for the lateral acceleration signal Gv, E= l
(d/d t) - Calculate GV 1, thereby finding the absolute value of the rate of change of Gv with respect to time t,
Next, proceed to step (2). In step ■,
For stroke signals H1 to H4, FII= l (d/d t) ・H,1 (n=1
．． . . , 4> are calculated, thereby obtaining the absolute value of the rate of change over time from H1 to H4. Next, the process moves to step ■, and F MA is selected from among the calculated values F7 in step ■.
Calculate X.

Next, in step (2), the value of E calculated in step (2) is set to the reference value 2. which is stored in the memory 52 in advance. will be compared and judged. This determination is to check whether the lateral acceleration signal Gv is in an abnormal state where it has suddenly changed (for example, a step-like upward or downward change) due to some reason (for example, a failure of the lateral acceleration detector 30, etc.). here,
The reference value ZI is set to a value corresponding to the sudden change in the signal.

In the judgment of step (2), if E<Z, it is assumed that the lateral acceleration signal ay is normal, and the process proceeds to step (2), where the CPU 51 sends the switch switching signal J of logic H level to the switch circuit 43A via the I10 port 50. ~Output to 43D. As a result, each contact piece of the switch circuits 43A to 43D is switched to the terminal A side. Next, in step (2), the control stop signal ST becomes the logic L level,
This turns on the stop switches 36A to 36D,
In this state, the vehicle body control performed by the first attitude control command means 32 described above becomes effective.

On the contrary, if E≧21, the lateral acceleration signal Gv
is in an abnormal state, and it is determined that control based on the lateral acceleration signal Gy cannot be performed, and the process moves to step (2), where the trend of the detected stroke value is checked.

Specifically, in step (2), the values of F and Ax calculated in step (2) are compared with a predetermined reference value Z2. This judgment is based on stroke detection! 29FL~2
This is to check whether or not the stroke signal can be adopted when at least one of the 9RI'l is in an abnormal state due to a failure or the like.
This is checked based on the size of X. Similarly to Z, the reference value Z2 is set in advance to a predetermined value that allows it to be determined that there is a sudden change in the signal. Therefore, in step ■, FMAX
If <72, it is assumed that the stroke signals H1 to H4 are in a normal state, and the process proceeds to step (2), where the CPU 51 sets the switch changeover signal J to the logic L level, and proceeds to step (2). energized by this, each of the switch circuits 43A to 43D switches its contact piece position from the A side to the B side. In this state, the control applied to the first attitude control command means 32 is changed to the second attitude control command means 33.
The control is immediately switched to the above control, and the attitude control described above is continued.

On the other hand, if F MAX ≧ Z2 in step ■, the lateral acceleration signal GY and the stroke signal F l4A
Since both of X are abnormal and undesirable, a control stop signal ST of logic H level is output to the stop switches 36A to 36D in step [phase]. As a result, the stop switches 36A to 36D are turned off, the path for outputting the command value is forcibly cut off, and the pressure control valves 17FL to
The excitation coil 22b of 17RR is in a non-excited state. Therefore, the attitude control of the vehicle is stopped, and the hydraulic cylinders 15F to 15RR are offset pressures P of the pressure control valves 17FL to 17RR. Piston position based only on CPU5
1 then lights up the alarm lamp 38 in step (2) to notify the operator of this, and returns.

The above operations are executed at every preset sampling time along with the processing of the main program.

If the above-mentioned abnormal state is not canceled, the attitude control continues to be stopped, and if at least one of the lateral acceleration signal and the stroke signal is corrected to a normal state, the attitude control is stopped based on the one signal. Repeated.

・Here, in the process shown in Figure 6, steps ■～■
, ■ corresponds to the command operation determination means, and step ■ corresponds to the command operation determination means.

(2) and the route switching section 35 form a switching means.

As described above, according to this embodiment, the command system for controlling the active suspension IIFL-1) RR is duplicated and used by switching as appropriate, so that the fail-safe function is improved accordingly. In addition, the stroke detector 29F
Since the L~29RR can also be used as a detector for vehicle height control, there is no need to add a new stroke detector exclusively for this device, which is rarely used in terms of -C, resulting in lower parts costs and smaller size. Effects such as reduction can be obtained. Furthermore, in the normal case where both the lateral acceleration signal and the stroke signal are normal, this embodiment is configured to take the lateral acceleration signal first and perform roll control based on this lateral acceleration signal, so that the turning movement of the vehicle is controlled. Control such as reverse roll, zero roll, and normal roll can also be easily performed depending on the situation.

In the above embodiment, the lateral acceleration signal is used as the acceleration signal, but the present invention is not limited to this, and can be applied, for example, when controlling pitching of the vehicle using the longitudinal acceleration signal. can also be applied. In this case, the configuration is as shown in FIG.
The aforementioned front wheel side and rear wheel side gain adjusters 40 are installed on the output side of the
Equipped with f, 40r, of which the rear wheel side gain adjuster 40
It is equipped with sign inverters 41A and 41B for the output of r, and the other parts are the same as those in FIG. It has been replaced with .

Further, in the above embodiment, the configuration uses a lateral acceleration detector, but the present invention is not necessarily limited to this.
For example, the vehicle may be equipped with a vehicle speed sensor and a steering angle (or actual steering angle) sensor, and may be equipped with means for estimating lateral acceleration based on data output from these sensors, and control may be performed based on these.

Further, in the above embodiments, a case has been described in which a hydraulic cylinder is used as the fluid pressure cylinder, but the present invention is not limited to this, and other cylinders such as a pneumatic cylinder may be used.

Furthermore, the switching control section 34 in FIG. 5 is not necessarily limited to a configuration using a microcomputer;
Other electronic circuit elements may also be used.

Additionally, the stop switches 36A-36D may have other configurations and locations.

〔Effect of the invention〕

As explained above, according to the present invention, the attitude control command means for the active suspension has a dual structure including a system that detects acceleration and is based on this, and a system that detects stroke and is based on this, and each command is The configuration is such that the operation is determined at predetermined timings and the above two command systems are switched as appropriate based on the results of this determination, so if one of the attitude control command means is in an abnormal state, for example, if the acceleration detector or stroke detector fails, etc. Even if the vehicle attitude control command means is in a normal state, this can be avoided and the control can be continued immediately by the other attitude control command means in the normal state. Therefore, the fail-safe function for vehicle attitude control is dramatically improved, and the reliability of the entire system is improved. An excellent effect of improvement can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram showing an overview of the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of the invention, FIG. 3 is a schematic configuration diagram of a pressure control valve in the embodiment of FIG. Figure 4 is the third
A graph showing the relationship between the command value S for the pressure control valve shown in the figure and its output pressure P, Fig. 5 is a block diagram of the controller of the embodiment shown in Fig. 2, and Fig. 6 is the processing procedure of the microcomputer shown in Fig. 5. FIG. 7 is a block diagram showing another configuration example of the present invention. In the figure, IIFL to IIRR are active suspensions, 1
2 is a vehicle body side member, 14 is a wheel side member, 15FL to 15R
R is a hydraulic cylinder, 17FL to 17RR are pressure control valves,
32 is a first attitude control command means, 33 is a second attitude control command means, and 35 is a path switching section forming a part of the switching means. Figure 1 Figure 3 b Kaya Haubunfu Figure 6

Claims (1)

[Claims] (1) An active suspension is provided between the vehicle body side member and the wheel side member and the operating pressure is controlled according to a predetermined command value, and the command value is changed to suppress changes in the posture of the vehicle. In the vehicle suspension device, the first attitude control command means detects or estimates the acceleration acting on the vehicle and outputs the command value in accordance with the detected acceleration; a second attitude control command means for outputting the command value according to the command value; a command operation determination means for determining whether the command operations of the first and second attitude control command means are in a normal state; and the command operation. If the determination means determines that the command operation of either the first or second attitude control command means is in an abnormal state, the command value of the other attitude control command means is supplied to the active suspension. A suspension device for a vehicle, characterized in that it is equipped with a switching means for switching.