JPH0445368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspension control device for a vehicle that controls a suspension device so as to suppress changes in the posture of a vehicle.

[Prior art]

As a conventional vehicle suspension control device, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 116215/1983.

This device includes a running state detecting means consisting of either an idling switch or a throttle position sensor, a vehicle speed sensor, and a stop switch, and the opening/closing of the idling switch or the opening of the throttle valve based on the detection signal from the running state detecting means. and a shock absorber that is controlled based on the control signal from the arithmetic and control means, and a shock absorber that is controlled based on the control signal from the arithmetic and control means. When the switch is open or the throttle valve opening is above a predetermined reference value, and the stop switch is open, or when the calculated vehicle acceleration is above the predetermined reference value, the calculation control means The damping force of the shock absorber is increased by the output signal of the shock absorber, thereby preventing nose-up and pitching during acceleration, and further improving stability, safety and comfortable driving of the vehicle. It is something that realizes sexuality.

[Problem that the invention seeks to solve]

However, in the above-mentioned vehicle suspension control device, the damping force of the shock absorber is only set in two stages, high and low, so changes in the vehicle's attitude can be reliably prevented in various driving conditions. There was a problem that I couldn't do it. For example, when driving at low speeds on a good road with a flat paved road surface, the damping force of the front and rear wheel shock absorbers is set to the minimum to improve ride comfort, and when driving at high speeds, the damping force of the front and rear wheel shock absorbers is set to the minimum to improve ride comfort. In addition to increasing the damping force of the shock absorber, the damping force of the rear wheel side shock absorber is reduced to create an understeer characteristic that improves vehicle ride comfort, maneuverability, and stability.Furthermore, when turning, the front wheel It is necessary to increase the damping force of the shock absorbers on the side and rear wheels. By the way, if the damping force can be controlled only in two stages, high and low, if the value of the high damping force state is set high in order to exhibit the anti-roll effect, the front and rear wheels will be affected when driving at high speed. The difference in damping force becomes too large and understeer becomes strong, resulting in poor steering performance, a sluggish running feeling, and a delay in response to steering, resulting in poor maneuverability. Conversely, if the value of the high damping force state is lowered in order to maintain appropriate understeer during high-speed driving, the anti-roll effect during turns will be reduced.
In any case, there was a problem in that it was not possible to perform optimal suspension control according to the driving conditions.

[Means for solving problems]

In order to solve the above problems, this invention
As shown in the block diagram in the figure, a variable suspension with control characteristics that can change control characteristics in three or more stages;
a plurality of attitude change detection means for detecting different attitude change states of the vehicle; a control characteristic setting means for individually setting the control characteristic according to the attitude change state detected by each attitude change detection means; and the control characteristic setting means. The present invention is characterized by comprising a selection means for selecting a higher control characteristic from among the control characteristics set in the above, and a control means for controlling the variable control characteristic suspension according to the control characteristic selected by the selection means.

[Effect]

This invention provides a plurality of attitude change detection means such as a steering angle detector, an acceleration/deceleration detector, a braking state detector, a road surface condition detector, a vehicle height detector, etc., and detects the attitude change state of these attitude change detection means. Depending on the value,
The control characteristic setting means sets a control characteristic according to each posture change state, the selection means selects a higher control characteristic among the established control characteristics, and the control characteristic of the variable control characteristic suspension is controlled based on this. By doing so, the stability during driving is improved by prioritizing the attitude change suppression control that requires high control characteristics among various attitude change suppression controls.

〔Example〕

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

Fig. 1 is a schematic configuration diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing an embodiment of the invention, and Fig. 3 shows an example of a variable damping force shock absorber applicable to the invention. 4 is an enlarged sectional view on line II and -, and FIG. 5 is a flowchart showing the processing procedure of the control device.

First, the configuration will be explained. In Fig. 1, 1a, 1b are front wheels, 1c, 1b are rear wheels, 2
The variable damping force shock absorbers 2a to 2d serve as suspension devices for the wheels 1a to 2d.
1d and the vehicle body 3 to suppress changes in the posture of the vehicle body 3.

As shown in FIG. 3, an example of variable damping force shock absorbers 2a to 2d includes a piston 9 attached to the tip of an inner cylinder 8 of a piston rod 5, and extends through the piston 9 in the axial direction. A central opening 10 is formed, and a variable aperture 11 is formed at the upper end of the central opening 10. As shown in FIGS. 4a and 4b, this variable diaphragm 11 has three types of transparent light 12h and 12 with different opening areas at the upper position.
m, 12s are formed in the same horizontal plane with equal angular spacing, and two types of through holes 13h, 13m with similarly different opening areas are formed at the lower position.
A cylindrical body 15 formed in the same horizontal plane facing 12m and having a central opening 14, and through holes 12h to 12s and 13h fitted inside this cylindrical body 15.
One opening 16, 1 at a position opposite to 13m, respectively.
7 and a shielding cylindrical body 18.
The shielding cylinder 18 is connected to the rotating shaft of an electric motor 19 installed in the piston rod 5 via a reduction gear, thereby being rotationally driven and returned to the position between the openings 16 and 17. A check valve 21 biased downward by a spring 20 is provided.

Further, the electric motor 19 is connected to a control device 3 which will be described later.
The rotational position is detected by a rotational position detector 22 such as a potentiometer attached to the rotating shaft, and the detection signal is sent to the control device 37 as a feedback signal. supplied to

Further, the piston 9 is provided with an extension side orifice 23 and a contraction side orifice 24, which are relatively small holes through which the working fluid C in the liquid chambers A and B defined by the piston 9 passes.

Therefore, when the shielding cylinder 18 is in the first rotating position Rs shown in FIGS. Opposing the holes 12h and 13h, when the piston rod 5 moves in the contraction direction, the working fluid C from the fluid chamber B flows into the fluid chamber A through the central opening 10 and through the through holes 12h and 13h. At the same time, it also flows into the fluid chamber A through the contraction side orifice 24, so that the through hole 12
Since the opening areas of h and 13h are large, fluid resistance is relatively small. On the other hand, when the piston rod 5 moves to the extension side, the check valve 21 prevents the working fluid from flowing through the through hole 12h.
The working fluid C flows from the fluid chamber A to the fluid chamber B through the through hole 13h and the extension side orifice 23, and the damping force of the shock absorber as a whole is minimized while causing a difference in damping force in the direction of contraction and extension of the piston rod 5. It is controlled by the damping force S.

Further, when the electric motor 19 is driven from this state to rotate the shielding cylinder 18 to the second rotation position R _M , in this state, the openings 16 and 17 of the shielding cylinder 18 are opened at the through holes 12m and 13m. Since the opening area is medium, the fluid resistance is increased and the damping force of the shock absorber is increased to an intermediate damping force M compared to the above case.

Further, when the electric motor 19 is driven from this state to rotate the shielding cylinder 18 to the third rotation position R _H , in this state, only the opening 16 of the shielding cylinder 18 has the minimum opening area. Since it faces the through hole 12s, the fluid resistance on the contraction side is maximum, and the working fluid C from the through hole 12s is blocked by the check valve 21 on the expansion side, so the fluid chamber A The working fluid from the extension side orifice 23
The damping force of the shock absorber is increased to the maximum damping force H as the fluid resistance on the contraction side and the expansion side becomes maximum.

As shown in FIG. 1, the vehicle also includes a vehicle speed detector 26 that outputs a vehicle speed detection signal DV according to the output side rotation speed of a transmission (not shown) connected to the engine, and a steering wheel 27. a steering angle detector 28 that detects the rotational position of the steering wheel and outputs a steering angle detection signal Dθ according to the steering angle, and an accelerator pedal 2.
an acceleration/deceleration detector 30 that outputs an acceleration/deceleration detection signal DA according to the depression state of the brake pedal 31; a braking detector 32 that detects the depression state of the brake pedal 31 and outputs a control detection signal DB according to the braking state; A road surface condition detector 33 configured as an ultrasonic distance measuring device that outputs a road surface condition detection signal DR according to the road surface condition, and a vehicle body 3.
A high-speed detector 34 configured as an ultrasonic distance measuring device is attached to the front lower surface of the front wheel 1a and rear wheel 1c.
F and 34R, an auto/manual selection switch 35 for selecting whether suspension control is performed automatically or manually, and a manual damping force selection switch 36 are provided.

Here, the steering angle detector 28, acceleration/deceleration detector 3
0, the brake detector 32, the road surface condition detector 33, and the vehicle height detectors 34F and 34R correspond to posture change detection means.

And each detector 26, 28, 30, 32, 3
Detection signals of 3, 34F, 34R, auto/manual selection switch 35, damping force selection switch 3
6 switch signals are supplied to the control device 37.

As shown in FIG. 2, the control device 37 includes a microcomputer 38 and output circuits 39F and 39R connected to its output side.

The microcomputer 38 includes at least an interface circuit 38a, an arithmetic processing device 38b, and a storage device 38c, and executes arithmetic processing according to the processing program shown in FIG.

That is, in step it is determined whether the system is operating normally or not, and if it is normal, the process moves to step and it is determined whether the auto/manual selection switch 35 is switched to the auto side or the manual side. judge. At this time, if it has been switched to the auto side, the process moves to step.

In this step, variable damping force shock absorbers 2a, 2b and 2c on the front wheel side and rear wheel side,
Control command value to control both 2d to the minimum damping force S
After storing CFs and CRs in the initial setting storage area of the storage device 38c, the process moves to step.

In this step, the detection signal DV of the vehicle speed detection off 26 is read, the vehicle speed V is calculated based on this, and it is determined whether or not V≈0, thereby determining whether or not the vehicle is stopped. At this time, if the vehicle is running, the process moves to step and it is determined whether the vehicle speed V is equal to or higher than a predetermined set vehicle speed Vs. At this time, if the vehicle is traveling at a low speed lower than the set vehicle speed Vs, the process moves to step.

In this step, the detection signal Dθ of each steering sensor 28 is read, and the steering wheel 27
It is determined whether or not the vehicle is in the neutral position, and when it is in the neutral position, it is determined that the vehicle is traveling straight without rolling, and the process proceeds to step.

In this step, it is determined whether the vehicle has finished the steering state based on the detection signal Dθ of the steering angle detector 28, and whether or not the vehicle is in a state where rolling back is occurring as a reaction force of the rolling force in the steering state, and the vehicle is in the rolling back state. If not, move to step.

In this step, it is determined whether the vehicle is decelerating or accelerating based on the detection signal DA of the acceleration/deceleration detector 30, and if the vehicle is running at a low speed without decelerating or accelerating, the process moves to step .

In this step, the detection signal DB of the brake detector 31 is read, and it is determined whether or not a braking operation is in progress. If the braking operation is not in progress, the process moves to step.

In this step, vehicle height detectors 34F and 3
The 4R detection signal is read and it is determined whether or not the vehicle is in the bottoming state. If the vehicle is not in the bottoming state, the process moves to step.

In this step, vehicle height detectors 34F and 3
The detection signal of 4R is read and it is determined whether or not the front and rear parts of the vehicle body 3 are in a bouncing state in which they move up and down in the same phase, and if they are not in a bouncing state, the process moves to step.

In this step, the detection signal DR from the road surface condition detector 33 is read, and it is determined whether the vehicle is traveling on a rough road or not. If the vehicle is traveling on a good road with no unevenness, the process moves to step.

In this step, the control command values CFi (i = _{S, M, H} ) and CRi stored in the angular command value storage area are referred to, and the control commands for suppressing changes in the vehicle's attitude are controlled better than the custom-made control of the suspension system based on the vehicle speed. In order to give priority to the control characteristics of the suspension device, the maximum control command values CFmax and CRmax are selected from among the control command values stored in each command value storage area, and these control command values CFmax and CRmax are stored in the storage device 38c. After storing it in the maximum control command value storage area, proceed to step.

In this step, the detection signals DEa to DEd of the rotational position detectors 22 of the variable damping force shock absorbers 2a to 2d are read, and these are compared with the control command values CFmax and CRmax stored in the previous step to ensure that they match. If the two do not match, the process moves to step and the damping force variable shock absorber 2a to which the two do not match is determined.
Command signal for rotationally driving the electric motor 19 of 2d
_CSF and _CSR are output to the output circuits 39F and 39R via the interface circuit 38a, and then the process moves to step. In this step, it is determined whether the electric motor 19 is normal or not, and if it is normal, the process returns to the step. The determination in this case is that the electric motor 19 uses the control command values CFi and CRi and the detection signals DEa, DEb and
When DEc and DEd do not match, electric motor 1
If the maximum control command values CFmax and CRmax do not match the rotational position detection signals DEa, DEd and DEc, DEd within a predetermined time (for example, 3 seconds) after driving When both match, the state is determined to be normal.

Also, the step judgment result is the maximum control command value.
When CFmax and CRmax match the detection signals DEa, DEb and DEc, DEd of the rotational position detector 22, the process moves to step.

In this step, it is determined whether the electric motor 19 is normal or not, and if it is normal, the process returns to the step. The determination in this case is made by determining whether or not the electric motor 19 is rotating when the rotational drive command for the electric motor 19 is not output, and when the electric motor 19 is not rotating, it is determined that it is normal. If it is rotating, it is determined that there is an abnormality.

Further, if the judgment result in the step is that the system is abnormal, the step moves to the step where the variable damping force shock absorber 2a on the front wheel side and the rear wheel side,
2b, 2c, and 2d are all controlled to an intermediate damping force M, and then the process moves to a step where an abnormality warning lamp (not shown) is lit or blinked.

Furthermore, if the judgment result in step is that the auto/manual selection switch 35 has been switched to the manual side, the process moves to step a, where it is judged which selection position the damping force setting switch 36 is set to, and the maximum damping is performed. When the force is set to H, the maximum damping force control command values CF _H and CR _H are stored in the manual command value storage area, and then the process moves to step c to control the electric motor 19.
is driven so that the control command values CF _H and CR _H stored in the manual command value storage area match the detection signals DEa, DEd and DEc, DEd of the rotational position detector 22, and then the process moves to step d. It is determined whether the electric motor 21 is normal or not. If it is normal, the process returns to the step, and if it is in an abnormal state, the process moves to the step described above. Here, when the intermediate damping force M is set in step a, the process moves to step e, where the intermediate damping force control command values C _M and C _M are stored in the manual command value storage area, and then the process proceeds to step c. Transition. If the minimum damping force S has been set in step a, the process proceeds to step f, where the minimum damping force control command values CFs and CRs are stored in the manual command value storage area, and then the process proceeds to step c.

If the judgment result of the step is that the vehicle is stopped, the process moves to step a, and the variable damping force shock absorbers 2a, 2b, 2c, 2d on the front and rear wheels are set to the maximum damping force H in the stop command value storage area. After the control command values CF _H and CR _H to be controlled are stored, the process moves to step.

Here, the step judgment result is the set vehicle speed Vs
When the vehicle speed is above, the process moves to step a, and the front wheel shock absorbers 2a and 2b are set to intermediate damping force M, which is necessary to ensure maneuverability, stability, and ride comfort, in the vehicle speed command storage area. After storing the control command locations CFM and _CRS for controlling the wheel side shock absorbers 2c and 2d to the minimum damping force _S , the process moves to step.

When the determination result of the step is that the vehicle is in a roll state, the step moves to step a, and the damping force on the front and rear wheels necessary to exert an anti-roll effect that suppresses rolling of the vehicle is stored in the roll command value storage area. After storing the control command values CF _H and CR _H for controlling the variable shock absorbers 2a, 2b, 2c, and 2d to the maximum damping force H, the process moves to step.

Furthermore, when the determination result of the step is a swing back state, the process moves to step a,
Vehicle body 3 due to rocking back in the rocking back command value storage area
front wheel side and rear wheel side variable damping force shock absorbers 2a, 2b necessary to suppress changes in attitude of the
After storing control command values CF _H and CR _H for controlling 2c and 2d to the maximum damping force H, the process moves to step.

Further, when the determination result of the step is that the vehicle is in an acceleration or deceleration state, the process moves to step a to suppress the so-called "skirt" in which the rear part of the vehicle body sinks in the acceleration state or the so-called "nose type" in which the front part of the vehicle body sinks in in the deceleration state. Variable damping force shock absorbers 2a and 2b for front and rear wheels necessary for
and 2c and 2d are controlled to the damping force H or M, which is one higher than before the control (that is, when the damping force is S before the control, it is controlled to M, and when it is M before the control, it is controlled to H. However, if the damping force is H before the control (When the signal is set to H), the control command values (CH _H and CR _H ) or (CF _M and CR _H ) are stored, and then the process moves to step.

Furthermore, if the judgment result of the step is that the brakes are being applied, the process moves to step a and the brake control register is set to change the damping force on the front and rear wheels necessary to suppress the nose dive caused by pressing the brake pedal. After storing control command values CF _H and CR _H for controlling the shock absorbers 2a, 2b, 2c, and 2d to the maximum damping force H, the process moves to step.

Furthermore, when the step determination result is a bottoming state, the process moves to step a, and the front and rear wheel variable damping force shock absorbers 2a necessary for suppressing the bottoming state are stored in the bottoming command value storage area. , 2b and 2
After storing the control command values C _M and C _M for controlling the damping force M to the intermediate damping force M, the process moves to step.

Further, when the determination result of the step is a bouncing state, the process moves to step a, and the variable damping force shock absorbers 2a, 2b on the front and rear wheels necessary for suppressing bouncing are stored in the bouncing command value storage area. and 2c, 2d
After storing the control command values C _M and C _M for controlling the damping force M to the intermediate damping force M, the process moves to step.

Further, if the judgment result of the step is that the vehicle is traveling on a rough road, the process moves to step a, and the variable damping force shock absorbers 2a for the front wheels and rear wheels, which are optimal for traveling on rough roads, are stored in the rough road command value storage area. 2b
Then, the control command values C _M and C _M for controlling the damping forces 2c and 2d, respectively, to the intermediate damping force M are stored, and then the process moves to step.

Furthermore, if the determination result in step d, step and step is that the motor is abnormal, the process moves to the step described above.

Here, steps ~, a correspond to the control characteristic setting means, the processing of the steps corresponds to the selection means, and the processing of the steps corresponds to the control means.

Next, the effect will be explained. First, in order to selectively control the damping force of the variable damping force shock absorbers 2a to 2d to a desired value, the auto/manual selection switch 35 is switched to the manual side, and the damping force selection switch 36 is used to select the damping force H, M,
Select a desired damping force in S, for example, intermediate damping force M.

In this way, when the arithmetic processing unit 38b of the control device 37 executes the process shown in FIG. is cleared, and then the process moves to step a. Since the damping force selection switch 36 has selected the intermediate damping force M, the process moves to step e, and the intermediate damping force M is stored in the manual command value storage area.
The control command values C _M and C _M for setting are stored, and then the process moves to step c, where the detection signals DEa to DEd of the rotational position detectors 22 provided in each of the variable damping force shock absorbers 2a to 2d are read. If there is a difference between the rotational position of C M and the control command values C _M and C _M , the electric motor 19 is driven to rotate until the two match, and then the process moves to step d to determine whether the electric motor 19 is normal. If it is normal, return to the step and repeat these manual processes.

During this manual process, the damping force selection switch 3
When the damping force is switched to No. 6, steps b and f are selected according to the switching position, and the corresponding control command values CF _H and CR _H or CF _S and CR _S are stored in the manual command value storage area. In step c, the electric motor 19 is rotationally driven to control the damping force of the variable damping force shock absorbers 2a to 2d to a desired value.

Furthermore, when the auto/manual selection switch 35 is switched to the auto side from this manual processing state, the process shifts from step to auto processing after step.

That is, when the vehicle is stopped, the process moves from step to step to step;
In the initial setting command value storage area, front wheel side and rear wheel side variable damping force shock absorbers 2a, 2b and 2 are stored.
The control command values CF _S and CR _S for controlling the damping forces S and 2 d to the minimum damping force S, respectively, are stored. Next, the process moves to step A to determine whether or not the vehicle is stopped. Since the vehicle is stopped, the process moves to step a, and the variable damping force shock absorbers for the front and rear wheels are stored in the stop command value storage area. Control command value CF _H that controls the damping forces of 2a, 2b, 2c, and 2d to the maximum damping force H
and CR _H , and then proceed to step. Thereafter, the process moves to step 1 through step 1, reads the storage contents of each command value storage area, and selects the maximum control command values CFmax and CRmax among the stored control command values. In this case, the contents of the initial setting command value storage area are the control command values CF _S and CR _S that command the minimum damping force S.
The contents of the stop command value storage area are the maximum control command values CF _H and CR _H , and the contents of the other command value storage areas are cleared, so the maximum control command values CF H and CR _{H of both are the maximum control command values CF H} and CR H. CR _H is selected, and then in a step, the control command values CF _H and CR _H and the rotational position detector 2 of each damping force variable shock absorber 2a to 2d are selected.
2 detection signals DEa to DEd are compared, and if there is a difference, the process moves to step to rotationally drive the electric motor 19 of the variable damping force shock absorber 2a to 2d where there is a difference, and when the two match, The drive of the electric motor 19 is stopped. In this way, when the electric motor 19 is rotationally driven, the shielding cylinder 18 of the variable diaphragm 11 installed in the variable damping force shock absorbers 2a to 2d rotates, and the opening 16 of the variable diaphragm 11 is rotated.
is opposed to the through hole 12s of the cylindrical body 15, and the opening 17 is opposed to the peripheral wall of the cylindrical body 15, so that the variable damping force shock absorbers 2a to 2d
The damping force is suppressed to the maximum damping force H. As a result, it is possible to prevent the vehicle body from shaking when an occupant gets on or off the vehicle when the vehicle is stopped, thereby improving ride comfort.
Next, in step it is determined whether the electric motor 19 is normal or not, and then the process returns to step. The above-described stopping process is continued until the vehicle starts traveling.

When the vehicle starts running from this stop processing state, the acceleration state at the time of starting is determined to be an acceleration state in step a.
Then, the control command values CF _H and CR _H that command the maximum damping force are stored in the acceleration/deceleration command value storage area, and then the maximum control command values CF H and CR _H are stored in the acceleration/deceleration command value storage area. Select CR _H , then step to control command values CF _H and CR _H
The detection signals DEa to DEd of the rotational position detector 22 are compared to determine whether they match or not, and each variable damping force shock absorber 2a to
2d is controlled to the maximum damping force H, and the control command values CF _H and CR _H and the detection signal of the rotational position detector 22
Since DEa to DEd match, the process directly proceeds to step ⓓ, determines whether the electric motor 19 is normal, and then returns to step. As a result, variable damping force shock absorbers 2 on the front and rear wheels
a, 2b and 2c, 2d can be maintained at the maximum damping force H, respectively, to suppress the scuffing that occurs when the vehicle starts moving.

After that, when the vehicle shifts to relatively low constant speed running, the control command value CF _S that commands the minimum damping force S and the initial setting command value storage area are stored in the step.
After storing CR _S , the program moves from step to step to step, reads the contents of each command value storage area, and selects the maximum control command value, but in this case, only the initial setting command value storage area is the minimum. Since the damping force values CF _S and CR _S are memorized, select these and proceed to step. In this step, the front wheel side and rear wheel side variable damping force shock absorbers 2 are
Since a, 2b and 2c, 2d are each controlled to the maximum damping force H, their rotational position detector 22
Since the detection signals DEa, DEb, DEc, DEd and the control command values CF _S and CR _S do not match, the electric motor 19 is rotated by repeating step, step, and step until the two match. The process moves to step, determines whether the electric motor 19 is normal or not, and returns to step.

Thereafter, when the vehicle is running at high speed, the process moves from step to step a, and a control command value for controlling the variable damping force shock absorbers 2a, 2b on the front wheel side to the intermediate damping force M is stored in the high speed command value storage area. After storing CF _M and the control command value CR _S for controlling the variable damping force shock absorbers 2c and 2d on the rear wheel side to the minimum damping force S, each variable damping force shock is controlled from step to step. The electric motors 19 of the absorbers 2a and 2d are driven to rotate, and the variable damping force shock absorbers 2a and 2b on the front wheel side are controlled to have an intermediate damping force M.
, variable damping force shock absorber 2 on the rear end side.
After controlling the damping forces c and 2d to the minimum damping force S, the process moves to step, determines whether the electric motor 19 is normal, and returns to step. in this way,
Front wheel side variable damping force shock absorber 2a, 2
When b is controlled to an intermediate damping force M and the variable damping force shock absorbers 2c and 2d on the rear wheel side are controlled to a minimum damping force S, the steering characteristics of the vehicle becomes understeer, improving maneuverability and stability during high-speed driving. be able to.

In this high-speed running state, if the steering wheel 27 is turned to the right or left to enter a turning state, the high-speed running state will not be changed.
The process moves from step a to step a, where the intermediate damping force control command value C _M and the minimum damping force control command value CR _S are stored in the high speed command storage area, and then the process moves to step a, where the roll state is determined. Therefore, the process moves to step a, and the front wheel side and rear wheel side variable damping force shock absorbers 2a, 2b, 2c, 2d are stored in the roll command value storage area.
After storing the control command values CF _H and CR _H for controlling the damping force H to the maximum damping force H, the process moves to step 1 through steps. In this step, the control specified values CF _S and CR _S are stored in the initial setting command value storage area, and the control command values CF _M are stored in the high speed command value storage area.
and CR _S stores the control command value in the roll command value storage area.
Since CF _H and CR _H are memorized,
The maximum control command values CF _H and CF _H of these are selected as control command values, and then the process moves to step. Therefore, in these steps, the electric motor 19 of each variable damping force shock absorber 2a to 2d is rotationally driven to control each variable damping force shock absorber 2a to 2d to the maximum damping force H. After determining whether or not it is normal, the process returns to step. In this way, when the vehicle turns, the variable damping force shock absorbers 2a, 2b, 2c, 2d on the front wheel side and the rear wheel side
By controlling each of the damping forces to the maximum damping force H, it is possible to exert an anti-roll effect that suppresses rolling of the vehicle body 3 that is accompanied by a large change in attitude.

Similarly, when braking is performed by depressing the brake pedal 31, the process moves from step to step a, and the variable damping force shock absorbers 2a, 2b, and 2c for the front and rear wheels are stored in the braking command value storage area.
Control command value to control each of 2d to the maximum damping force H
CF _H and CR _H are memorized, and in the bottoming state, bouncing state, and rough road driving state, the steps proceed to step a, step a, and step a, respectively, and the front wheel side and rear wheel side variable damping force shock absorbers 2a, 2b, and 2c and 2d are respectively intermediate damping force M
The control command values C _M and CR _M to be controlled are stored in each command value storage area, and the maximum control command value is selected from the stored contents of each command value storage area in step, and the control command values are stored in the steps from step to step according to this. The damping force of each of the variable damping force shock absorbers 2a to 2d is changed, and it is determined in step whether the electric motor 19 is normal or not, and then the process returns to step.

In this way, when a plurality of different control modes occur simultaneously based on the detection signals from each detector, the highest damping force control command value among the control modes is selected preferentially to control the change in vehicle attitude. It is possible to suppress conditions that are likely to occur, improve maneuverability and stability, and perform optimal suspension control.

In the above embodiment, variable damping force shock absorbers 2a to 2a are used as suspension devices.
2d has been described, but the invention is not limited to this, and a variable spring constant spring device 41 shown in FIG. 6 can also be applied.

That is, the spring constant variable spring device 41
is a shock absorber 42 and an air chamber 43 that is integrally formed in the upper part of the shock absorber 42 and is expandable and retractable in the vertical direction.
Reservoir tanks 45 and 46 communicate with this air chamber 43 via a three-way electromagnetic switching valve 44 that is closed in one direction and have different volumes, and intake and exhaust valves 47 and 48 are connected to these reservoir tanks 45 and 46. and an air supply device 49 communicating with each other via.

This spring constant variable spring device 41
However, the piston rod 4 of the shock absorber 42
The upper end of the air chamber 2a and the upper end of the air chamber 43 are respectively attached to the vehicle body side member, and the shock absorber 42
By attaching the lower end of the to the wheel side member,
installed on the vehicle.

Here, when the electromagnetic switching valve 44 is switched to the closed port side, the spring constant of the variable spring constant spring device 41 is
determined solely by the volume of Furthermore, when the electromagnetic switching valve 44 is switched to the switching position that communicates the air chamber 43 and the reservoir tank 45, the spring of the variable spring constant spring device 41 is A constant is determined. Furthermore, when the electromagnetic switching valve 44 is switched to the switching position that communicates the air chamber 43 and the reservoir tank 46, the spring of the variable spring constant spring device 41 is A constant is determined. Therefore, by controlling the electromagnetic switching valve 44, the air spring constant of the variable spring constant spring device 41 can be controlled to be switched to three levels: large, medium, and small. The switching control of this spring constant variable spring device 41 is performed by the control device 37.
This is done by switching the electromagnetic switching valve 44 using an excitation current from. In addition, in FIG. 6, 37 is a control device, 50 is an elastic body such as rubber, 51 is an air passage, and 52 is another spring constant variable spring device 41.
It is an air passageway that communicates with the In addition, as a suspension device, it is also possible to apply a roll rigidity variable stabilizer that can change the roll rigidity in three or more stages by supplying an excitation current.
It is also possible to use a variable damping force shock absorber, a variable spring constant spring device, and a variable roll stiffness stabilizer in combination.

Furthermore, in the above embodiment, a case has been described in which the control characteristics such as the damping force, spring constant, and roll rigidity of the suspension device can be switched in three stages, but the control characteristics are not limited to this. It is also possible to configure the damping force variable shock absorbers 2a to 2d to be switchable in four or more stages, and furthermore, to configure the variable damping force shock absorbers 2a to 2d as shown in FIG. By controlling the energization using a controlled excitation current, the control characteristics can be controlled steplessly. In this case, in the variable damping force shock absorbers 2a to 2d shown in FIG. 7, corresponding parts to those in FIG. Extension side and contraction side orifices 61 and 62 are formed, and a fluid passage 63 communicating with the fluid chamber A is bored. On the other hand, within the center opening of the piston 9 is a fluid passage 6 that communicates with the fluid chamber B.
A sleeve 65 having a hole 4 is fitted into the sleeve 65, and a spool 66 is slidably fitted into the sleeve 65. The spool 66 has a recess 67 formed on its outer peripheral surface to communicate the fluid passages 63 and 64. Further, a cylindrical case 68 is integrally fixed to the lower end of the sleeve 65, an electromagnetic solenoid 69 is attached to the inner circumferential surface of the case 68, and a cylindrical magnetic yoke 7 is attached to the inner circumferential surface of the electromagnetic solenoid 69.
0 is fitted inside, and a return spring 71 is accommodated therein, and its upper end is seated on the spool 66.

Therefore, when the electromagnetic solenoid 69 is in a non-energized state, the spool 66 is in a position where it is urged upward by the return spring 71, as shown in FIG. Since the position is in conflict with the opening end, the fluid passages 63 and 64 are cut off, and the fluid chambers A and B are communicated only through the orifices 61 and 62, so that the damping force is maintained at its maximum. Then, when the electromagnetic solenoid 69 is energized by supplying a pulsed excitation current from the control device 37 from this state, the spool 66 moves to the return spring 7 in accordance with the pulse width of the excitation current.
1, the opposing area of the fluid passage 64 and the recess 67 is continuously changed, the fluid resistance between the fluid passages 63 and 64 is continuously changed, and the damping force is changed to the pulse width of the exciting current. It can be changed steplessly as required.

Further, in the above embodiment, a suspension device capable of changing control characteristics is provided on both the front wheel side and the rear wheel side. However, the present invention is not limited to this. The present invention can also be applied to a case where a suspension device is attached only to the vehicle.

Furthermore, in the above embodiment, a case has been described in which the microcomputer 38 is applied as the control device, but instead of this, it may be configured by combining electronic circuits such as a comparison circuit, a logic circuit, a command value setting circuit, a selection circuit, etc. You can also do that.

〔Effect of the invention〕

As explained above, according to the vehicle suspension control device according to the present invention, different attitude change states of the vehicle are detected by the plurality of attitude change detection means, and each attitude change state detected by the control characteristic setting means is The control characteristics are individually set according to the selected control characteristics, the selection means selects the higher control characteristic among the set control characteristics, and the control means controls the variable control characteristics suspension to the selected control characteristics. It is possible to give priority to attitude change suppression control that requires high control characteristics among the attitude change suppression controls of , and it is possible to obtain an effect that stability during driving can be improved.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing an embodiment of the invention, and Fig. 3 shows an example of a variable damping force shock absorber applicable to the invention. Cross-sectional view, Figure 4a
and b are enlarged sectional views on the - line and - line of Fig. 3, respectively, Fig. 5 is a flowchart showing the processing procedure of the control device applicable to this invention, and Figs. 6 and 7 are respectively applicable to this invention. FIG. 8 is a sectional view showing another embodiment of a possible suspension device, and is a diagram showing the relationship between the constituent elements necessary for the present invention. 1a, 1b...Front wheel, 1c, 1d...Rear wheel, 2
a to 2d... variable damping force shock absorber (suspension device), 11... variable aperture, 19...
...Electric motor, 22...Rotational position detector, 26...
...Vehicle speed detector, 28...Steering angle detector, 30...
Acceleration/deceleration detector, 32...braking detector, 33...road surface condition detector, 34F, 34R...vehicle height detector,
35...Auto/manual selection switch, 36
... Damping force selection switch, 37 ... Control device, 3
8...Microcomputer, 39F, 39R...
... Output circuit, 41 ... Spring constant variable spring device (suspension device), 42 ... Shock absorber, 43 ... Air chamber, 44 ... Solenoid switching valve, 45, 46 ... Reservoir tank, 63, 64
...fluid passage, 66 ... spool, 67 ... recess, 69 ... electromagnetic solenoid.

Claims (1)

[Claims] 1. A variable control characteristic suspension capable of changing control characteristics in three or more steps; a plurality of attitude change detection means for detecting different attitude change states of the vehicle; control characteristic setting means for individually setting control characteristics; selection means for selecting a higher control characteristic among the control characteristics set by the control characteristic setting means; and control characteristic variable suspension for the control characteristics selected by the selection means. A suspension control device for a vehicle, comprising a control means for controlling a suspension.