JPH05185816A - Car active suspension system - Google Patents

Abstract

PURPOSE:To keep the balance of bearing power by adding a deviation in rolling directional components to be found out of each controlled variable in regard to both symmetrical wheels at the wheel side on one side, to the central value of a deviation between both actual and desired strokes in both symmetrical wheels as to the wheels side on the other at both front and rear wheel sides among controlled variable setting means. CONSTITUTION:Four stroke selecting means 47A-47D detect each stroke of respective wheels, and three desired stroke setting means 90A-90C set each desired stroke of the wheels. As to the wheel side of either front or rear wheel side, a controlled variable setting means seeks a deviation between both actual and desired strokes of each wheel at symmetrical wheels, setting the controlled variable according to this deviation. In addition, as to the wheel side of either front or rear side, the deviation of rolling directional components being found out of each control variable as to both symmetrical wheels at the wheel side on one side is added to the central value of deviation between both actual and desired strokes in these symmetrical wheels, thereby setting the controlled variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active suspension device for a vehicle, which is capable of controlling a stroke of each wheel with respect to a vehicle body in a vehicle having four wheels of a front left wheel and a right rear wheel.

[0002]

2. Description of the Related Art Conventionally, in a vehicle such as an automobile, an active suspension device has been developed which can adjust the stroke of each wheel (hereinafter referred to as the wheel stroke) to adjust the vehicle height. The active suspension device is provided with an actuator that adjusts the stroke of each wheel, and the stroke of each wheel is controlled independently by controlling the operation of each actuator through the controller.

Therefore, in the controller, for example, the target value (target stroke) of the stroke of each wheel is set, and the actuator of each wheel is operated so that the actual stroke (actual stroke) of each wheel becomes this target stroke. It is conceivable that they are independently feedback-controlled.

[0004]

By the way, when a vehicle provided with the above-mentioned active suspension device has four wheels, that is, left and right front wheels and left and right rear wheels, the stroke of each wheel is independent. However, if the control is performed by such a control, there is a problem that the balance of the supporting force of the suspension of each wheel is likely to be extremely disturbed.

That is, although there are four support points of the vehicle body supported by the suspension for each wheel, these four support points are displaced according to the stroke adjustment of each wheel. Then, if these supporting points are on substantially the same plane at the same load, the supporting force balance of the suspension can be appropriately maintained, but since the plane is determined by three points, generally four supporting points are positioned in this way. It is difficult.

In particular, when the strokes of the wheels are controlled independently, it becomes particularly difficult to position the support points on substantially the same plane, and mutual interference occurs between the suspensions of the wheels, resulting in suspension suspensions. It is easy to lose the balance of bearing capacity. The present invention has been made in view of the above problems, and an object of the present invention is to provide an active suspension device for a vehicle in which the balance of the supporting force of the suspension of each wheel is not disturbed during stroke control of each wheel.

[0007]

Therefore, the vehicle active suspension device of the present invention is a vehicle having four wheels, that is, the left and right front wheels and the left and right rear wheels. Actuators that are respectively interposed in the vehicle and can adjust the stroke of each wheel with respect to the vehicle body, stroke detection means for detecting the stroke of each wheel, and target stroke setting means for setting the target stroke of each wheel. A control amount setting means for setting a control amount for the actuator of each wheel based on the actual stroke detected by the stroke detecting means and the target stroke set by the target stroke setting means, and the control amount setting means. The control means for controlling the operation of the actuator of each wheel based on the control amount set in The amount setting means obtains a deviation between the actual stroke and the target stroke of the wheel corresponding to each of the left and right wheels on one of the front wheel side and the rear wheel side, and sets the control amount corresponding to this deviation. With respect to the other wheel side of the front wheel side and the rear wheel side of the control amount setting means, the one wheel side is set to the representative value of the deviation between the actual stroke and the target stroke of the left and right wheels. It is characterized in that the respective control amounts are set in consideration of the deviation of the roll direction component obtained from the respective control amounts for the left and right wheels.

[0008]

In the above-described vehicle active suspension device of the present invention, the stroke detection means detects the stroke (actual stroke) of each wheel, and the target stroke setting means sets the target stroke of each wheel. Then, the control amount setting means obtains a deviation between the actual stroke and the target stroke of the wheel corresponding to each of the left and right wheels on one of the front wheel side and the rear wheel side, and controls in accordance with this deviation. Set the amount.

Further, with respect to either the front wheel side or the rear wheel side, the representative value of the deviation between the actual stroke and the target stroke of the left and right wheels is calculated from the respective control amounts for the left and right wheel on the one wheel side. The control amount is set in consideration of the deviation of the required roll direction component. Based on the control amount thus set, the operation of the actuator of each wheel is controlled by the control means, and the stroke of each wheel with respect to the vehicle body is adjusted through the actuator.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle active suspension device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main configuration of a stroke control (vehicle height control) system, and FIG. FIG. 3 is a schematic block diagram showing the mechanism of the device, FIG. 3 is a block diagram showing the overall configuration of the control system, FIG. 4 is a block diagram showing a concrete configuration example of the stroke control system of the control system, and FIG. It is a block diagram which shows the principal part structure of the modified example of a control system.

The vehicle active suspension system of this embodiment is a hydraulic active suspension system in which the actuator is hydraulically operated. FIG. 2 is a configuration diagram of the hydraulic system. In FIG. 2, the oil pump 1 is provided so as to suck the oil stored in the reserve tank 3 via the oil passage 2 and discharge the oil to the supply oil passage 4. In the vicinity of the oil pump 1 of the supply oil passage 4, accumulators 5 and 6 for absorbing the pulsation of the discharge hydraulic pressure by the oil pump 1 are connected in series, and the accumulators 5 and 6 have different set frequencies. Is becoming Furthermore, accumulator 6
Oil filters 7 and 8 are connected on the downstream side of
A relief oil passage 10 and a pilot relief oil passage 9 are connected to the downstream side of the oil filter 8.

The pilot relief oil passage 9 is connected to a solenoid valve 11, and the solenoid valve 11 is
The discharge oil passage 12 communicating with the reserve tank 3 is selectively communicated with a return oil passage 13 of a control valve or a pilot relief oil passage 9 which will be described later. An operation check valve 14, which operates by receiving the pressure in the pilot relief oil passage 9 as pilot pressure, is provided upstream of the solenoid valve 11 in the return oil passage 13. When the discharge oil passage 12 is in communication with the discharge oil passage 12, the vehicle height is maintained by blocking the discharge oil passage to prevent the discharge of oil, while the return oil passage 13 and the discharge oil passage 1 are held.
When the two are communicated with each other, they are opened to allow oil to be discharged, thereby enabling suspension control described later.

The relief oil passage 10 is connected to the discharge oil passage 12 on the downstream side of the solenoid valve 11, and a relief valve 15 is interposed in the middle of the relief oil passage 10. When the upstream hydraulic pressure of the relief valve 15 becomes equal to or higher than a predetermined pressure, the oil discharged from the oil pump 1 is discharged to the reserve tank 3 side.
Furthermore, the relief valve 15 receives the pilot pressure from the pilot relief oil passage 9, and the set pressure changes depending on the state of the solenoid valve 11 that changes the pressure in the pilot relief oil passage 9. When the vehicle height is maintained so that the oil passage 9 and the discharge oil passage 12 are communicated with each other, the set pressure is reduced and the load on the pump 1 is reduced.

An oil cooler 16 is provided in the discharge oil passage 12.
Further, the oil filter 17 is interposed in series, and a relief valve 18 is provided in parallel with the oil filter 17 for compensation when the oil filter 17 is clogged. Further, the supply oil passage 4 is branched to a front wheel side oil passage 4F and a rear wheel side oil passage 4R at a downstream side of a branch portion with the relief oil passage 10, and line pressures are respectively applied to the oil passages 4F and 4R. Accumulators 19F and 19R for holding and check valve 20
F and 20R are interposed, and each check valve prohibits the flow of oil from the downstream side to the upstream side. An oil filter 21 is provided upstream of the accumulator 19R in the rear wheel side oil passage 4R. The oil passages 4F and 4R have check valves 20F and 20F, respectively.
On the downstream side of R, an oil passage is branched for each wheel, and suspension units 22FL, 22FR, 22RL, 22RR provided for each wheel are connected to each oil passage. In addition, each suspension unit 22FL,
22FR, 22RL, 22RR are check valves 23FL, 2 for prohibiting the flow of oil from the downstream side to the upstream side.
Return oil passage 13 through 3FR, 23RL, 23RR
Check valve 23F on the front wheel side
The upstream sides of the L and 23FR are communicated with each other via the throttle 24F,
A throttle 2 is attached to the check valves 23RL and 23RR on the rear wheel side.
4RL and 24RR are provided in parallel. The throttles 24F, 24RL, 24RR are provided to average the internal pressures of the actuators of the wheels when the vehicle height is maintained as described above.

An accumulator 25 for preventing pulsation of the return oil passage is provided in the return oil passage 13R on the rear wheel side.
Is provided between the return oil passage 4R on the rear wheel side and the supply oil passage 13R on the rear wheel side, and a relief valve 26 for preventing high pressure in the return oil passage and a cock 27 for maintenance. Are provided in parallel. Since each suspension unit has the same structure, the suspension unit 22FL for the left front wheel will be described. A single-acting hydraulic actuator 30 is provided between the vehicle body and the wheels in parallel with a suspension spring (not shown). Oil passage 3 communicating with the hydraulic chamber of the hydraulic actuator 30
1 and the oil supply passage 4F and the oil discharge passage 13F through the control valve 32 interposed between the hydraulic actuator 1
The supply and discharge of hydraulic pressure to and from the hydraulic chamber 4 is controlled. A proportional solenoid valve is used as the control valve 32, and the hydraulic actuator 1 is proportional to the supply current by controlling the valve opening according to the supplied current.
The pressure in 4 can be controlled. An oil passage 32 is also connected to the hydraulic actuator 30, and the oil leaking from the hydraulic chamber is sent to the discharge oil passage 12.

An accumulator 34 is connected to an oil passage 31 communicating with the hydraulic chamber of the hydraulic actuator 30 via a throttle 33. The throttle 33 exerts a vibration damping effect and is enclosed in the accumulator 34. The gas spring exerts a gas spring action. Further, a damping force control valve 35 is provided in parallel with the throttle 33, and the damping force can be set softly by driving the damping force control valve 35 to the open position. Further, the oil passage 31 is provided with a pressure sensor 36 for detecting the internal pressure of the hydraulic actuator 30.

The operation of each control valve 32, each damping force control valve 33, and solenoid valve 11 is controlled by a controller 40 which is composed of a microcomputer.
When it is necessary to control the operating state of the hydraulic actuator 30, the return oil passage 13 and the discharge oil passage 1 are changed from the state shown in FIG.
2 is allowed to discharge oil from the hydraulic actuator 30, and when it is not necessary to control the operating state of the hydraulic actuator 30 such as during parking, the hydraulic actuator 30 is switched to the state shown in FIG.
The vehicle height is maintained by prohibiting the discharge of oil from the vehicle.

The controller 40, as shown in FIG.
In addition to the detection output of the pressure sensor 36 described above, a detection output from a lateral G sensor 41 that detects the lateral acceleration acting on the vehicle body, and a steering angle sensor 42 that detects the steering angle of the steering wheel.
Speed sensor 43 that detects the detection output of the vehicle and the traveling speed of the vehicle
Detection output, a front-rear G sensor 44 detection output for detecting longitudinal acceleration acting on the vehicle body, a brake switch 45 detection output for detecting a brake pedal operation, and a throttle sensor 46 detection for an engine throttle opening. Output, detection output of a stroke sensor 47 that detects the vertical stroke state of each wheel, detection output of a vertical G sensor 48 that is provided for each wheel and that detects vertical acceleration that acts on the vehicle body, and the state of the road surface in front of the vehicle. The detection outputs of the preview sensor 49 are input, and the controller 40 controls the operating states of the control valve 32 and the damping force switching valve 35 for each wheel based on the detection outputs of these sensors. It has become.

The schematic structure of the controller 40 is shown in the control block diagram of FIG. As shown in FIG. 3, in the controller 40, a control unit (steering control unit) 40A for adjusting the steering stability of the vehicle and a control unit (attitude control unit) 40B for adjusting the posture of the vehicle. And a control unit (vehicle height control unit) 55 for adjusting the vehicle height of the vehicle,
A control unit (ride comfort control unit) 40C for adjusting the ride comfort of the vehicle is provided.

The steering control section 40A has an anti-roll control section 50 and an OS / US control section (steer control section) 51, the attitude control section 40B has an anti-pitch control section 52, and the riding comfort control section 40C. Has a composite control unit 56 and a preview control unit 59. The detection outputs of the pressure sensor 36, the lateral G sensor 41, the steering angle sensor 42, the vehicle speed sensor 43, and the longitudinal G sensor 44 are input to the anti-roll control unit 50 to support the load movement amount during steering and to support the vehicle body. A control amount for suppressing the posture change in the roll direction is output.

Further, the US / OS control section 51 receives the detection outputs of the steering angle sensor 42 and the vehicle speed sensor 43,
A control amount for controlling the vehicle body steer characteristic is output by increasing or decreasing the roll rigidity ratio between the front and rear wheels based on the steering angular velocity calculated from the output of the steering angle sensor 42 and the vehicle speed. In the anti-pitch control section 52, the detection outputs of the vehicle speed sensor 43, the longitudinal G sensor 44, the brake switch 45, and the throttle sensor 46 are input, and the load movement amount during acceleration / deceleration is supported based on the output of the longitudinal G sensor 44. Then, the control amount for suppressing the posture change of the vehicle body in the pitching direction is output, and the gain with respect to the output of the front-rear G sensor 44 is increased particularly during braking and acceleration.

Further, in the vehicle height control section 55, the detection outputs of the vehicle speed sensor 43 and the stroke sensor 47 are input, and the target vehicle height (that is, the target stroke) corresponding to the vehicle speed is obtained by integral control based on the detection outputs of the stroke sensor 47. ) Is output. The details of the vehicle height control unit 55 will be described later.

Further, the composite control unit 56 includes a skyhook damper control unit and a mass increase control unit (not shown). In the skyhook damper control unit, the steering angle sensor 42, the vehicle speed sensor 43, the brake switch 45, the throttle sensor 46, and the vertical G sensor 4
8 is input, and control is performed to suppress the fluffy feeling of the vehicle body by reducing the sprung mass absolute speed calculated from the detection output of the up and down G sensor 48. Especially, during sudden steering, high speed, and braking. , And during acceleration, the gain for the vertical absolute speed increases.

In the mass increase control section, the vehicle speed sensor 43, the stroke sensor 47 and the vertical G sensor 4
The detection output of 8 is input, and the control amount for suppressing the sprung acceleration and reducing the vibration transmission force is output. In addition to this, the riding comfort control section 40C is adapted to output a control amount for reverse spring control for reducing the spring constant to reduce the vibration transmission force during a minute stroke.

Further, although not shown, a stroke damper control section is also provided, and the steering angle sensor 42, the brake switch 45, the throttle sensor 46, and the stroke sensor 4 are provided.
The detection output of No. 7 is input, and the control for reducing the stroke speed calculated from the detection output of the stroke sensor 47 to attenuate the vehicle body vibration is performed, and the gain with respect to the stroke speed is increased especially during sudden steering, braking and acceleration. It is supposed to do.

The control amounts output from the control units 50 to 56 are input to the adder 57 for each wheel, and the adder 5
The total control amount added in 7 is input to the drive circuit 58. Then, the drive circuit 58 outputs a current corresponding to the input control amount to the control valve 32 to perform active control of the operation of the hydraulic actuator 30, thereby realizing control in which the posture change is small and a good ride comfort is obtained. It Further, the detection output of the pressure sensor 36 is input to the drive circuit 58, and constant pressure control for feedback control is performed so that the internal pressure of the hydraulic actuator 30 becomes a target control pressure (output of the adder 57).

In the preview controller 59,
When the detection outputs of the vehicle speed sensor 43 and the preview sensor 49 are input and it is detected from the outputs of the preview sensor 49 that there is a protrusion or a step ahead of the vehicle, the time when the wheel passes through the protrusion or the step is calculated in relation to the vehicle speed. The damping force switching valve 3 when passing through a protrusion or a step
By outputting a control signal to the drive circuit 60 so as to bring the opening 5 into the open state, the vibration transmission at the time of passing over the protrusion is reduced.

Here, the vehicle height control section (vehicle height adjustment line) will be described. The main portion of this vehicle height adjustment line is constructed as shown in FIG. That is, as shown in FIG. 1, target strokes are set by the respective target stroke setting units (target stroke setting means) 90A and 90B for the two left and right front wheels. Then, for each of the right front wheel (FR wheel) and the left front wheel (FL wheel), the subtraction units 93A, 93B calculate the respective stroke sensors (stroke detection means) 47A, 47B from the respective target strokes.
The actual stroke (actual stroke) detected in 1 is subtracted, and the deviation is obtained.

Here, PI is calculated by integrating this deviation.
I feedback control in D control is executed. Therefore, integrators 93F and 93G for integrating the deviations of the right front wheel (FR wheel) and the left front wheel (FL wheel) are provided, respectively. In each of the integrators 93F and 93G, an integration constant of K1 is set, and the integration constant K1 is set according to a parameter such as vehicle speed. For the right front wheel (FR wheel) and the left front wheel (FL wheel), the stroke corresponding amounts thus integrated are the stroke control amount for the right front wheel (vehicle height control amount) and the stroke control amount for the left front wheel, respectively. (Vehicle height control amount) is output.

On the other hand, for the two left and right rear wheels, the target stroke setting unit (target stroke setting means) 90C for the rear wheels does not set the target strokes for the two wheels independently of the left and right wheels. A target stroke is set. Then, the right rear wheel (RR wheel) and the left rear wheel (RL
Each stroke sensor (stroke detection means) 47 of the wheel
After averaging the actual strokes detected by C and 47D, the average value of the actual strokes is subtracted from the target stroke of the rear wheel to obtain the deviation.

For this reason, the stroke sensors 47C, 47
Adder 93 for adding the value of the actual stroke detected in D
D, a calculation unit 93E that calculates the average value of the actual strokes of the left and right wheels by multiplying the value added by the adder 93D by a coefficient 1/2, and the average value of the actual strokes is subtracted from the target stroke of the rear wheels. And a subtractor 93C for determining the deviation. That is, for the rear wheels, an average value is set as a representative value of the deviation between the actual stroke and the target stroke of the left and right wheels. It should be noted that instead of the simple average value of the deviation between the actual stroke and the target stroke of the left and right wheels, other representative values such as a weighted average value in which one of the left and right wheels is weighted according to the running state may be considered.

The subtractor 93 also applies to this rear wheel.
By integrating the deviation obtained at C, I feedback control in PID control is executed. Therefore, the integrator 93 that integrates the signal from the subtractor 93C
H is provided. In this integrator 93H, an integration constant of K2 is set, and this integration constant K2 is also set corresponding to a parameter such as vehicle speed.

For the rear wheels, this integrator 93
The stroke corresponding amount integrated by H is not output as it is as a control amount, but for the right rear wheel, the adder 93K performs an addition process on this stroke corresponding amount and the stroke control amount for the right rear wheel ( The vehicle height control amount) is calculated, and for the left rear wheel, the stroke corresponding amount is subjected to subtraction processing by the subtractor 93L to calculate the stroke control amount for the left rear wheel (vehicle height control amount). Is becoming

The value added by the adder 93K and the value subtracted by the subtractor 93L are both coefficient-added to the deviation obtained by subtracting the stroke control amount for the front left wheel from the stroke control amount for the front right wheel in subtractor 93I. It is multiplied by the auxiliary coefficient K3 in the portion 93J. This is because the left and right wheels have a deviation between the stroke control amounts of the left and right wheels according to the load difference in the roll direction of the vehicle body, but here, the right wheel side is set positive and the load difference in the roll direction is set. The stroke control amount deviation of the left and right front wheels is calculated by the subtractor 93L, and the deviation is also given to the stroke control amounts of the left and right rear wheels according to this deviation.

In this case, when one wheel is increased and corrected, the other wheel is decreased and corrected by the same amount as this increase correction so that the required deviation can be obtained. Therefore, the rear wheel is made to share the load difference in the roll direction without changing the average value of the stroke control amounts of the left and right rear wheels. The auxiliary coefficient K3 is set so that the load sharing state of the front and rear wheels is not largely deviated in accordance with the front and rear weight distribution of the vehicle, for example.

The right rear wheel (RR wheel) and the left rear wheel (R
For the L wheel), the adder 93K and the subtractor 9
The stroke corresponding amount calculated in 3L is output as the stroke control amount for the right rear wheel (vehicle height control amount) and the stroke control amount for the left rear wheel (vehicle height control amount), respectively. .. Further, a more specific configuration example of this vehicle height adjustment line is configured as shown in FIG. 4, for example.

In FIG. 4, reference numeral 200 denotes an input unit for A / D (analog / digital) converting the information from the vehicle speed sensor 43 and the stroke sensor 47 and fetching the information.
Reference numeral 1 is a data conversion unit that converts the signal captured by the input unit 200 into each physical quantity (for example, a unit amount of Km / h for vehicle speed and a unit amount of mm for stroke). Reference numeral 90 denotes a target stroke setting unit (target stroke setting means) that sets the target stroke of the suspension of each wheel from the vehicle speed data converted by the data conversion unit 201.
And the target stroke setting units 90A, 90B,
90C corresponds.

This target stroke is set to be a large stroke in the low speed range and a small stroke in the high speed range. Particularly, in the high speed range, the front wheel has a smaller stroke than the rear wheel. Is set to. In addition, the target strokes of the left and right wheels are set so as to compensate for the load difference in the roll direction due to the roll of the vehicle body.

However, as described above, on the front wheel side, the target strokes for the left and right wheels are set separately in consideration of the load difference in the roll direction, but on the rear wheel side, the target stroke for the entire rear wheel is set. Is set to one. That is, three target strokes, that is, the target stroke of the right front wheel (FR wheel), the target stroke of the left front wheel (FL wheel), and the target stroke of the rear wheel are set.

Reference numeral 91 is a subtraction unit for performing steady posture correction on the target stroke of each wheel set by the target stroke setting unit 90. In this steady posture correction, a correction amount for steady posture correction is obtained based on the calculated lateral acceleration (lateral acceleration that should occur in the vehicle) G _YB , and this correction amount is subtracted from the target stroke. The above-described calculated lateral acceleration G _YB is calculated from the steering angle δ _H and the vehicle speed V by the following equation.

G _YB = V ² · δ _H / [(1 + AV ² ) · L · ρ · G] where A: Stability factor L; Wheel base ρ; Steering gear ratio G; Gravity acceleration (= 9.8 m / s ²⁾ Moreover, the constant attitude correction is calculated by the lateral acceleration G _YB large area, a correction to apply so they can maintain a constant attitude by suppressing the floating or the like of the vehicle body of the turning outer, calculated lateral acceleration G _YB
It is conceivable to use a map or the like in which the correction amount can be set according to

Further, reference numeral 92 denotes the stroke sensor 4 from the target stroke after the steady posture correction from the subtraction unit 91.
Detection stroke (actual stroke) based on the detection information of 7
Is a subtraction unit that obtains the deviation between the target stroke and the actual stroke by subtracting. The subtraction unit 92 is the subtraction unit 93 described above.
A, 93B, and 93C correspond. Reference numeral 94 is a correction unit that corrects each stroke deviation calculated by the subtraction unit 92 according to the stroke, and 95 is an integration constant for integrating each stroke deviation corresponding amount corrected by the correction unit 94. (Integral gain) An integral gain setting unit that sets K1 and K2.

Further, the stroke control amount by the I feedback control is calculated from the 96 adders and the 97 integrator based on the integral gains K1 and K2, and is output to the adder 57 as a control gain, for example. There is. The adder 96 and the integrator 97 are the same as the integrator 93 described above.
Equivalent to F, 93G, 93H. The control gain added by the adder 57 is pressure-corrected and D / A (digital / analog) converted before being output.

Since the active suspension device for a vehicle as one embodiment of the present invention is configured as described above, the stroke control is performed as follows. That is, first, the vehicle speed data signal of the detection signals taken in the controller is the target stroke setting unit 90 (9
0A, 90B, 90C), and the target stroke of the suspension of each wheel is set based on the vehicle speed.

Then, with respect to the front wheel side, the subtracting section 93A
Is calculated by a integrator 93F to calculate the stroke control amount (vehicle height control amount) for the right front wheel, and the deviation relating to the left front wheel from the subtraction unit 93B is calculated by the integrator 9F.
The stroke control amount (vehicle height control amount) for the left front wheel is calculated by performing integration processing in 3G. Further, the subtractor 93I subtracts the stroke control amount for the left front wheel from the stroke control amount for the right front wheel to obtain the deviation, and the coefficient integrating section 93J integrates the auxiliary coefficient K3 with the deviation.

Then, for the rear wheel side, the subtracting section 93C
The deviation relating to the rear wheel is integrated by an integrator 93H to obtain a control amount, and the adder 93K adds a coefficient-corrected deviation output from the coefficient integrating section 93J to the control amount (stroke control for the right front wheel). The difference obtained by subtracting the stroke control amount for the left front wheel) is added to calculate the stroke control amount for the right rear wheel (vehicle height control amount). Further, the subtractor 93L subtracts the above deviation from the control amount obtained by the integrator 93H to calculate the stroke control amount (vehicle height control amount) for the left rear wheel.

As described above, the stroke control amount set for each wheel is sent to the adder 57 as a stroke control gain, and the stroke control is reflected in the control of each actuator. As a result, the stroke control is performed for a total of three points, that is, two points on the left and right front wheels and one point on the rear wheels, and the four vehicle body support points supported by the suspension for each wheel. However, since they can always be located on substantially the same plane, the supporting force balance can be properly maintained. In addition, the stroke control can be appropriately performed while the four wheels are responsible for the load difference in the roll direction of the vehicle body.

Therefore, the performance of the active suspension device is improved, and there is an effect that it can contribute to the improvement of the running performance and the riding comfort of the vehicle. The stroke control system may be configured as shown in FIG. That is, the target stroke is set for the left and right wheels on the rear wheel side, and is set on the front wheel side as the target stroke for the front wheel regardless of the left and right wheels. Then, for the rear wheel side, the stroke control amount (vehicle height control amount) for each of the left and right wheels is calculated, and for the front wheel side, the deviation relating to the front wheel from the subtraction unit 93C is calculated by the integrator 93.
Integral processing is performed at H to obtain a control amount, and a coefficient-corrected deviation output from the coefficient integrating unit 93J is added to this control amount by the adder 93K (from the right rear wheel stroke control amount to the left rear wheel stroke control amount. It is configured to calculate the stroke control amount (vehicle height control amount) for the right front wheel by adding the deviation obtained by subtracting the amount).

With such a structure, the same operation and effect as those of the above-described embodiment can be obtained. It should be noted that the device itself relating to the stroke control of the present invention is not limited to the above-mentioned embodiment, the characteristics of the map in the embodiment are not limited to this, and the active suspension device for vehicles of other mechanisms may be used. It is needless to say that the present invention can be widely applied and various modifications can be made without departing from the gist of the present invention.

[0050]

As described above in detail, according to the vehicle active suspension device of the present invention, in a vehicle having four wheels of left and right front wheels and left and right rear wheels, each of the above wheels and the vehicle body is Actuators which are respectively interposed between the wheels to adjust the stroke of each wheel with respect to the vehicle body, stroke detection means for detecting the stroke of each wheel, and target stroke setting for setting the target stroke of each wheel. Means, control amount setting means for setting the control amount of the actuator of each wheel based on the actual stroke detected by the stroke detecting means and the target stroke set by the target stroke setting means, and the control amount. The control means for controlling the operation of the actuator of each wheel based on the control amount set by the setting means, The control amount setting means obtains a deviation between the actual stroke and the target stroke of the wheel corresponding to each of the left and right wheels on one of the front wheel side and the rear wheel side, and sets the control amount corresponding to this deviation. With respect to the other wheel side of the front wheel side and the rear wheel side of the control amount setting means, the one wheel is set to the representative value of the deviation between the actual stroke and the target stroke of the left and right wheels. By configuring the respective control amounts in consideration of the deviation of the roll direction component obtained from the respective control amounts for the left and right wheels on the side, while maintaining the balance of the supporting force of the suspension of each wheel, Stroke control of each wheel can be performed sufficiently, the performance as an active suspension device is improved, and it contributes to the improvement of running performance and riding comfort of the vehicle. Ur.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of a stroke control (vehicle height control) system of a vehicle active suspension device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a mechanism of a vehicle active suspension device as one embodiment of the present invention.

FIG. 3 is a block diagram showing an overall configuration of a control system of a vehicle active suspension device as one embodiment of the present invention.

FIG. 4 is a block diagram showing a specific configuration example of a stroke control (vehicle height control) system of the vehicle active suspension device as one embodiment of the present invention.

FIG. 5 is a block diagram showing a main part configuration of a modified example of the stroke control (vehicle height control) system of the vehicle active suspension device as one embodiment of the present invention.

[Explanation of symbols]

1 oil pump 2 oil passage 3 reserve tank 4, 4F, 4R supply oil passage 4F front wheel side oil passage 4R rear wheel side oil passage 5, 6 accumulator 7, 8 oil filter 9 pilot relief oil passage 10 relief oil passage 11 solenoid valve 12 Discharge oil passage 13, 13F, 13R Return oil passage 14 Operate check valve 15 Relief valve 16 Oil cooler 17 Oil filter 18 Relief valve 19F, 19R Accumulator 20F, 20R Check valve 22FL, 22FR, 22RL, 22RR Suspension unit 23FL, 23FR, 23RL , 23RR Check valve 24F, 24RL, 24RR Throttle 25 Accumulator 26 Relief valve 27 Cock 30 Hydraulic actuator 31 Oil passage 32 Control valve 33 Throttle 34 Accumulator 35 Damping force control valve 36 Pressure sensor 40 Controller 40A Steering control part 40B Attitude control part 40C Ride comfort control part 41 Lateral G sensor 42 Steering angle sensor 43 Vehicle speed sensor 44 Front / rear G sensor 45 Brake switch 46 Throttle sensor 47, 47A -47D Stroke sensor 48 Vertical G sensor 49 Preview sensor 50 Anti-roll control unit 51 OS / US control unit (steer control unit) 52 Anti-pitch control unit 55 Vehicle height control unit 56 Combined control unit 57 Adder 58 Drive circuit 59 Preview control unit 60 Drive circuit 90, 90A, 90B, 90C Target stroke setting unit (target stroke setting means) 91, 92, 93A, 93B, 93C, 93I, 93L
Subtraction unit 93F, 93G, 93H, 97 Integrator 93D, 93K, 96 Adder 93E Calculation unit 93J Coefficient integration unit 200 Input unit 201 Data conversion unit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasutaka Taniguchi 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Akihiko Togashi 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Automobile Industry Co., Ltd. (72) Inventor Tadao Tanaka 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Industry Co., Ltd.

Claims (1)

[Claims] 1. A vehicle having four wheels of left and right front wheels and left and right rear wheels, each of which is interposed between each of the above wheels and a vehicle body to increase or decrease a stroke of each wheel with respect to the vehicle body. Actuator, stroke detecting means for detecting a stroke of each wheel, target stroke setting means for setting a target stroke of each wheel, actual stroke detected by the stroke detecting means and target stroke setting means. Control amount setting means for setting the control amount of the actuator of each wheel on the basis of the target stroke set by, and the operation of the actuator of each wheel based on the control amount set by the control amount setting means. The control amount setting means is provided for each of the left and right wheels with respect to either the front wheel side or the rear wheel side. It is configured to obtain a deviation between the actual stroke and the target stroke of the corresponding wheel and set the control amount corresponding to this deviation, and the other one of the front wheel side and the rear wheel side of the control amount setting means. For each wheel side, the respective control amounts are calculated by adding the deviation of the roll direction component obtained from each control amount for the left and right wheels on one wheel side to the representative value of the deviation between the actual stroke and the target stroke on the left and right wheels. An active suspension device for a vehicle, which is configured to be set.