JPH04191109A - Active suspension for vehicle - Google Patents

Abstract

PURPOSE:To improve riding comfort by detecting vibration input from each front wheel caused by the irregularities of the surface of a road, computing the time required for each rear wheel to come to the irregularities of the road based on vehicle speeds when the detected value exceeds a specified one, and thereby controlling each actuator of the rear wheels in such a way that the vibration of the rear wheels is relaxed. CONSTITUTION:A vibration input means is made up of the height sensor 29 and the vertical G sensor 28 of each front wheel, so that the detected signals are thereby inputted to a controller 23. Each stroke and each vertical acceleration of the front wheels are detected by a rear wheel correction control section 42 based on the aforesaid input signals so as to be stored. The maximum stroke and the maximum vertical acceleration are then obtained based on stored data. And when those exceed specified values respectively, the time for each rear wheel to come to the irregularities of the surface of a road, is operated based on the detected vehicle speed by a sensor 24 and the dimension of a wheel base. After the aforesaid time has elapsed, each actuator 14 of the rear wheels is controlled in such a way that vibration input is thereby relaxed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a vehicular active suspension used in a vehicle such as an automobile.

(Prior art) Conventionally, for example, as shown in Japanese Patent Application Laid-Open No. 64-90811, a non-contact road sensor is used to predict the unevenness of the road surface in front of the wheels, and the wheel passes over the unevenness. Active suspensions are known that control the operation of actuators to keep the displacement of the vehicle body constant when the vehicle is moved.

(Problem to be Solved by the Invention) However, when the operation of the actuator is simply controlled according to the unevenness of the road surface detected by the road sensor as in the above conventional example, the front and rear wheels are controlled before passing the unevenness of the road surface. As the amount of vibration is set, there may be cases where a relatively large vibration is generated in the vehicle body when the front wheels pass the unevenness even though the control is performed. There is a problem in that similar vibrations are generated, which tends to cause discomfort to the occupants.

(Means for Solving the Problems) The present invention has been devised in view of the above points, and is provided with a device that is interposed between a vehicle body and a rear wheel and is capable of increasing and decreasing the supporting force of the vehicle body with respect to the rear wheels. a vibration input detection means for detecting vibration input from the front wheels due to uneven road surfaces;
It has a vehicle speed detection means for detecting the traveling speed of the vehicle, and a control means for controlling the operation of the actuator based on the detection output of each of the detection means. When it is detected that the vibration input from the vehicle speed exceeds a predetermined value, the time point at which the rear wheel reaches the uneven road surface that has been subjected to a vibration input equal to or greater than the predetermined value is calculated based on the output of the vehicle speed detection means, and the time point at which the rear wheel reaches the same point is determined. The active suspension for a vehicle is characterized in that the actuator is configured to operate in a direction that alleviates the vibration input.

(Function) According to the present invention, when the vibration input from the front wheels due to the unevenness of the road exceeds a predetermined value, the point in time when the rear wheels reach the unevenness of the road that gave the vibration input equal to or greater than the predetermined value based on the output of the vehicle speed detection means. The control means is configured to operate the actuator in the direction of alleviating the vibration input at the same time by calculating the vibration input, so even if relatively large vibrations are generated in the vehicle body when the front wheels pass over uneven road surfaces, the control means will not be affected by the vibration input on the rear wheels. When the vehicle passes through a bump, control is performed based on the vibration input to the front wheels when passing the bump, so when the rear wheel passes the bump, the vibration input can be reduced compared to when the front wheel passes the bump, providing better ride comfort for the occupants. be able to.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic diagram of the system configuration of this embodiment.

In FIG. 1, an oil pump 1 is provided to suck oil stored in a reserve tank 3 through an oil passage 2 and discharge the oil to a supply oil passage 4. As shown in FIG. Supply oil path 4
An oil filter 9 and a check valve 10 are interposed therein, and the check valve 10 prohibits oil from flowing from the downstream side to the upstream side. An accumulator 11 for maintaining line pressure is located downstream of the check valve 10 in the supply oil line 4.
is connected to the downstream side of the accumulator 11,
A suspension unit 12 is connected. Although one suspension unit 12 is shown as a representative in FIG. 1, the suspension unit 12 is provided for each wheel, and each suspension unit 12
A return oil passage 6 that communicates with the reservoir tank 3 is also connected thereto.

Each suspension unit 12 has the same structure, and between the vehicle body 7 and the wheels 8 is a suspension spring 13 and a single-acting hydraulic actuator 14.
A control valve 17 interposed between an oil passage 16 communicating with the oil pressure chamber 15 of the hydraulic actuator 14 and the supply oil passage 4 and the return oil passage 6 controls the oil pressure to the oil pressure chamber 15 of the hydraulic actuator 14. The supply and discharge of the fuel is controlled. The control valve 17 controls the pressure acting on the hydraulic actuator 14 by controlling the flow rate of oil flowing from the supply oil path 4 side to the discharge oil path 6 side, and controls the valve opening according to the supplied current value. It has become something that will be done. Therefore, this control valve 17 can control the pressure within the hydraulic actuator 14 in proportion to the supplied current value, and the larger the supplied current value, the greater the supporting force generated by the hydraulic actuator 14. It has become something to do.

Further, an oil passage 15 communicating with the hydraulic chamber of the hydraulic actuator I4 is connected to an accumulator 2 via a first orifice 19.
0 is connected, and the first orifice 19 exhibits a vibration damping effect, and the accumulator 20 is filled with gas to exhibit a gas spring action. Further, a second orifice 2I is provided between the accumulator 20 and the oil passage 16 in parallel with the first orifice 19, and a switching valve 22 is provided between the second orifice 21 and the accumulator 20. , which switches communication and cutoff between the second orifice 21 and the accumulator 20. And the second orifice 2
1 has an orifice diameter larger than that of the first orifice 19.

Further, the switching valve 22 is normally turned off and is in the cutoff state shown in the figure.

The operation of the control valve 17 and the switching valve 22 is controlled by a controller 23 composed of a microcomputer. This controller 23 includes a vehicle speed sensor 24 that detects the running speed of the vehicle, a steering angle sensor 25 that detects the steering angle of the steering wheel, a lateral G sensor 26 that detects the left-right acceleration acting on the vehicle body, and a lateral G sensor 26 that detects the acceleration acting on the vehicle body in the longitudinal direction. a longitudinal G sensor 27 that detects the acceleration of the vehicle, a vertical G sensor 28 that detects the vertical acceleration acting on the springs of the vehicle body corresponding to each wheel, and a vehicle height sensor that is provided for each wheel and detects the stroke amount of the wheel. Detection output of sensor 29, hydraulic actuator 14 and first orifice 1
9, a JEE engine sensor 30 for each wheel detects the internal pressure of the hydraulic chamber 15, a throttle sensor 31 detects the opening of the engine throttle valve, and detects the operating state of the brake pedal. Brake switch 32
, and a pair of left and right preview sensors 33 provided at the front of the vehicle body for right and left wheels are connected to detect the presence of a protrusion on the road surface in front of the vehicle. The controller 23 controls the operating states of each control valve 17 and each switching valve 22 for each wheel based on the detection outputs of these sensors 24 to 33. As the preview sensor 43, an ultrasonic sensor is used which is arranged in front of the vehicle body and tilted downward. Further, the vehicle height sensor 29 and the vertical G sensor of the front wheels constitute vibration input detection means of the present invention.

The basic control operations for control valve 17 performed within controller 40 are represented by the control block diagram shown in FIG. That is, the output of the vertical G sensor 28 is integrated by an integrator 35 and then multiplied by K1 by an amplifier 36, and the output of the vehicle height sensor 29 is differentiated by a differentiator 37 and then multiplied by KP by an amplifier 38. Ru. and amplifier 36.3
The output of 8 is input to an adder 39 and added to the control amount for vehicle height maintenance stored or calculated in the controller 23. The output of the adder 39 is input to the valve drive unit 40, and the valve drive unit 40 controls the pressure sensor 3 so that the hydraulic actuator 14 generates a control amount corresponding to the output of the adder 39.
Control valve 17 while feeding back the detection output of 0.
Outputs a drive signal to. In this way, the control valve 17
The operation of the hydraulic actuator 14 is controlled, and the hydraulic actuator 14 expands and contracts to effectively absorb input vibrations, thereby providing a soft ride.

Although not shown in the figure as control for the control valve 17, it goes without saying that known active suspension control, such as control to suppress vehicle body posture such as rolling or pitching, is also performed in response to acceleration acting on the vehicle body.

On the other hand, a preview sensor 33 is provided in the controller 23.
a preview control unit 41 that detects unevenness on the road surface in front of the vehicle based on the detection output of the preview control unit 41 and controls the operation of the switching valve 22;
, and a rear wheel correction control section 42 that corrects and controls the operation of the control valve 17 for the rear wheels based on road surface passing information for the front wheels. Note that the rear wheel correction control B42 constitutes a control means of the present invention.

First, the preview control section 41 will be described. The control operation of the switching valve 22 performed by the preview control section 41 is represented by the control flowchart shown in FIG.

To explain the flowchart shown in Figure 3,
First, in step AI, the fluctuation frequency of the output of the vehicle height sensor 29 is calculated, and in the subsequent step A2, it is determined whether the calculated fluctuation frequency is greater than or equal to a predetermined value, thereby determining whether the fluctuation frequency corresponds to a high-frequency road surface. If it is determined that it corresponds to a high-frequency road surface, the process proceeds to step A3, where the switching valve 22 is turned on and opened to set the suspension characteristics softly, and then the process is returned. The processing from step S1 onwards is repeated.

Further, when it is determined in step A2 that the fluctuating frequency does not correspond to a high-frequency road surface, the process proceeds to step A4, and it is determined whether or not there is a protrusion or step on the road surface in front of the vehicle based on the output of the preview sensor 33. Step A4
If it is determined that there is no protrusion or step, there is no need to soften the suspension characteristics, so proceed to step A.
5, the switching valve 22 is turned off to be in the closed state, and then the process returns.

On the other hand, if it is determined in step A4 that there is a protrusion or step, the process proceeds to step A6, where the time required for the wheel to reach the protrusion or step is calculated. This time is
As shown in Figure 4, the distance between the protrusion or step on the road in front of the vehicle and the wheel (in the case of the front wheels, L in the case of the rear wheels).
+1) and the vehicle speed V detected by the vehicle speed sensor 24. In this case, preview sensor 3
If 3 detects the presence or absence of a protrusion or step at a predetermined distance in front of the vehicle body, the above L value will be a fixed value, and if the distance to the protrusion or step can be detected, the above L value will be This is the measured value.

After the time required for the wheel to reach the protrusion or step is calculated in step A6, the process proceeds to step A7, where it is determined whether or not the time calculated in step A6 has elapsed; if the time has not elapsed, then This determination is repeated, and when the time comes for the wheel to reach a protrusion or step, the process proceeds to step A8.

Then, in step A8, the switching valve 22 is turned on for a predetermined time t for the wheel on the same side as the preview sensor that detected the protrusion, and the second orifice 21 and the accumulator 20 are communicated via the switching valve 22. The suspension characteristics are set to be soft, and after the predetermined time t has elapsed, the switching valve 22 returns to the OFF state, after which the process returns and the processing from step S1 onwards is repeated.

The preview control unit 41 that performs the above-described control controls the switching valve 2 when the fluctuation frequency of the vehicle height sensor output is equal to or higher than a predetermined value (when high-frequency vibrations are continuously input).
2 is turned on, while the switching valve 22 is turned on for a predetermined time t when passing over a protrusion (when high frequency vibration is inputted singly). Then, by turning on the switching valve 22, the second orifice is opened, and since the orifice diameter of the second orifice 21 is larger than the first orifice 19, the substantial The orifice diameter increases greatly. This reduces the damping force and the vibration transmission force to the vehicle body, making it possible to efficiently attenuate high-frequency vibration input, and in particular, significantly reducing the feeling of pushing up when going over a bump. Further, after the predetermined time t has elapsed, the switching valve 22 is turned off again and the damping force increases, so that vibrations after riding over the protrusion can be efficiently contained.

Further, the correction control for each rear wheel hydraulic actuator 14 performed by the rear wheel correction control section 42 is represented by the control flowchart shown in FIG.

To explain the flowchart of FIG. 5, first, in step S1, timers 1 and 2, which will be described later, are initialized.
is turned off and the memories Smax and Gmax are cleared, and in the following step S2, the detection outputs of each sensor necessary for control are read. After step S2, the process proceeds to step S3, where it is determined whether the vehicle speed V detected by the vehicle speed sensor 24 is within a predetermined range of 30 to 120 km/h, and if it is within the predetermined range, step S4 Then, it is determined whether the steering angle θ detected by the steering angle sensor 25 is 10° or less, that is, whether the vehicle is traveling substantially straight.

If it is determined in step S4 that the vehicle is traveling substantially straight, the process proceeds to step S5, where it is determined whether or not the opening speed U of the throttle valve detected based on the detection output of the throttle sensor 31 is 20 deg/s or less, that is, if the It is determined whether or not it is a time of sudden start and acceleration, and if it is not a time of sudden start and sudden acceleration, the process advances to step S6.

Then, in step S6, the brake switch 32
It is determined whether or not the is off, that is, whether or not braking is in progress. If braking is not in progress, that is, if the vehicle speed is within a predetermined range, the vehicle is traveling approximately straight, and the vehicle is not suddenly starting, accelerating, or braking, the following Proceed to step S7.

By the way, if it is determined in step S3 that the vehicle speed V is not within the predetermined range, it is determined that the effect of the control described later is small, and the process returns to step S1 described above.
If it is determined in Step 4 that the vehicle is not traveling substantially straight, if it is determined in Step S5 that the vehicle is suddenly starting or rapidly accelerating, and if it is determined that the vehicle is braking in Step S6, the control described below will have an adverse effect on the attitude control of the vehicle body. In order to avoid this, the process returns to step S1 described above and the subsequent processes are repeated.

When the process proceeds to step S7 described above, it is determined whether or not timer 1 is on, and since it is initially in the off state, step S7 is performed.
Proceeding to step 8, it is determined whether the absolute value of the stroke S of the corresponding front wheel (front wheels on the same side in left and right positions) determined based on the detection output of the vehicle height sensor 29 is 5n+m or more. If it is less than 5+mm, step S2 described above.
Return to and repeat the following process, but the stroke S of the front wheel
If the absolute value of is 5 mm or more, the process advances to step S9 and timer 1 is turned on. Step S1 following step S9
0, the current front wheel stroke S is stored in the front wheel maximum stroke memo jlsmax, and the process advances to step Sll.

In step Sll, it is determined whether or not the timer 2 is on, and since it is initially in the off state, the process proceeds to step 512, where detection is performed from the vertical G sensor 28 on the corresponding front wheel (the front wheel with the same left and right positions). The absolute value of the vertical G of the vehicle body is 0
．． It is determined whether the weight is 15g or more. If it is less than 0.15 g, the process returns to step S2 and the subsequent processes are repeated, but if the absolute value of the vertical G on the front wheel side is 0.15 g or more, the process proceeds to step S13 and timer 2 is turned on.

Continuing to step 313 (in step 514, the current upper and lower G is stored in the maximum upper and lower G memo 'JGmax, and step S
The process returns to step 2 and the subsequent processes are repeated.

After that, if the timer 1 is on when the process reaches step S7 again, the process proceeds from step S7 to step 515, and if the time T1 in the timer 1 exceeds the predetermined time T[1 (front wheel stroke sampling time) If the predetermined time is within the TCI, the process advances to step 516. In step 816, it is determined whether or not the absolute value of the current front wheel stroke S is greater than the absolute value of the front wheel maximum stroke memory Smax, and if it is, the memo! After JSmax is rewritten, proceed to step 311, and note the absolute value of the front wheel stroke S! If it is less than the absolute value of JSmax, the process directly goes to step 311.

In this way, if the timer 2 is on when step S11 is reached again, the process proceeds from step S11 to step 317, where the time T2 in the timer 2 is a predetermined time TC2 (front wheel side vehicle body It is determined whether or not the time exceeds the predetermined time Te3 (up/down G sampling time), and if it is within the predetermined time Te3, the process proceeds to step 518. In step 318, the absolute value of the current vehicle body vertical G detected by the vertical G sensor 28 on the front wheel side is the maximum vertical G memo! It is determined whether or not it is larger than the absolute value of IGmax, and if it is larger, the memory IJGmax is rewritten in step 514 described above, and then the process returns to step S2, and the current absolute value of the upper and lower G is less than or equal to the absolute value of the memory Gmax. If the time TI in timer 1 is
exceeds the TCI for a predetermined time, step S1
The process proceeds from step 5 to step 519, where it is determined whether or not timer 2 is on. If it is determined in step S19 that timer 2 is not on, this is a situation in which a certain amount of front wheel stroke occurred but not a large vertical G force was generated on the vehicle body. It is determined that the correction control of
x is cleared.

If it is confirmed in step 519 that the timer 2 is on, the process proceeds to step S17 described above, where it is determined whether or not the time T2 in the timer 2 exceeds the predetermined time TC2. When this happens, the process advances from step S17 to step 520.

In step 320, maximum upper and lower G memo! It is determined whether the absolute value of JGmax is 0.5 g or more, and if it is less than 0.5 g, it is determined that the vertical G generated on the vehicle body is not so large and that correction control of the rear wheels is not necessary, and the process proceeds to step Sl. return. Maximum upper and lower G memo in step S20! IGm
If it is determined that the absolute value of ax is 0.5 g or more, the process advances to step 321 and the front wheel maximum stroke memory S
max and maximum upper and lower G memo') Gtnax is positive or not, that is, memory S max and memory Gmax
It is determined whether the direction of the Since it cannot be determined, the process returns to step S1 without performing rear wheel correction control. In this case, the stroke S is detected with the compression stroke side as positive, and the vertical direction G is detected with the upward side as positive. Also, in step S21, the memory S
max and memo! If it is determined that the direction is the same as JGmax, proceed to step S22 and record the front wheel maximum stroke memo! It is determined whether ISmax is positive, that is, whether memory Smax is in the compression stroke direction.

In step S22, front wheel maximum stroke memory 3
If it is determined that max corresponds to the compression stroke direction of the suspension, it is determined that the front wheels have passed the 6th road, and the process proceeds to step S23, where it is determined whether the absolute value of the memo jlsmax is greater than the threshold value 30 mm for the 5th road. If it is determined that the distance is 30 mm or less, it is determined that correction control for the rear wheels is not necessary, and the process returns to step S1. And step S2
If it is determined in step S3 that the absolute value of the memory 5ITlax is larger than the threshold value for the 5th road, the process proceeds to step S24, where program control for the 5th road is executed for the rear wheels.

The control performed in step S24 will be explained with reference to FIG. 6.7. First, the memory Sma
The corrected pressure P max corresponding to the value of x is read, and control is performed over time as shown in FIG. That is, the time tR shown in FIG. 7 is the elapsed time from when the front wheels approach road 6 to when correction control for the rear wheels is started.
It is calculated using the following formula.

tR = (3,61/V) - Δ, where l is the wheelbase ■ is the vehicle speed Δt is the calculation and response delay time tR, and the unit is sec. Here, the starting point of time tR is when timer 1 starts operating. If the time in the timer l exceeds the calculated time tR, correction control of the rear wheels is started.

When rear wheel correction control is started, first, after a certain period of time tA, the internal pressure of the rear wheel hydraulic actuator is adjusted to the correction pressure P max
The control amount is decreased by P max, and during the subsequent fixed time tp, control is continued to reduce the control amount by P max. Thereafter, control is performed such that the correction amount of the control amount is set to 0 after a certain period of time tB from the end of the certain period of time tP. In this case, the control amount may be reduced by, for example, adding a correction to the output of the adder 39 shown in FIG. 2, or correcting the vehicle height maintenance control amount in a decreasing direction.

Moreover, the above-mentioned fixed times tA, tP, and tB are determined experimentally.

Then, after the predetermined time tB has elapsed and the five-road rear wheel correction control is completed, the process returns from step S24 to step S1 and the subsequent processes are repeated.

On the other hand, if it is determined in step S22 that the front wheel maximum stroke memory S max corresponds to the extension stroke direction of the suspension, it is determined that the front wheel has passed through the circuit, and the process advances to step S25 to record the memo! ISma
It is determined whether the absolute value of x is greater than a circuit threshold value of 20 mm, and if it is less than 20 mm, it is determined that correction control of the rear wheels is not necessary and the process returns to step S1. If it is determined in step S25 that the absolute value of the memo JSmax is greater than the circuit threshold, the process proceeds to step S26, where circuit program control for the rear wheels is executed.

The control performed in step S26 is performed based on the characteristics as shown in FIG. Since correction control is performed using substantially the same method as in step 324, detailed explanation will be omitted.

After the rear wheel correction control for the circuit in step 326 is completed, the process returns to step S1 and the subsequent processes are repeated.

The rear wheel correction control unit 42, which performs the above-described control, is configured to detect a situation in which, during normal straight-ahead travel in a predetermined vehicle speed range, the front wheels pass through unevenness on the road surface, a stroke of a predetermined amount or more occurs in the front wheels, and the front wheels are sprung. If a vertical G of more than a predetermined value occurs, the unevenness of the road surface is determined based on the direction of the maximum vertical acceleration and the direction of the maximum vertical G of the front wheels. Correction control is performed accordingly. That is,
If the road surface passed by the front wheels is 5-road, the control amount to the rear wheels on the same side as the front wheels decreases, the hydraulic actuator contracts, and the suspension automatically strokes in the direction of compression. It is possible to reduce the impact of vibration input caused by passing the road, and if the road surface that the front wheels pass is a circuit, the suspension can automatically stroke in the direction of extension to alleviate the vibration input. .

Furthermore, since the amount of correction of the control amount for the rear wheels corresponds to the maximum stroke S max of the front wheels when passing through uneven road surfaces, it is possible to perform corrections suitable for the state of uneven road surfaces.

According to the above embodiment, the preview control section 41 performs damping force control based on the preview sensor output, and the rear wheel correction control section 42 performs correction control for the rear wheels based on road surface passing information of the front wheels. Therefore, when the preview sensor 33 detects a protrusion or step on the road surface, the damping force can be lowered to reduce the vibration input when passing the protrusion or step. 33, even when a protrusion or step on the road surface cannot be detected, the vibration input when the rear wheel passes through an uneven surface can be reduced compared to when the front wheel passes through an uneven surface.
The riding comfort of a vehicle can be efficiently improved.

In addition, since the correction control for the rear wheels determines the unevenness of the road surface based on the maximum stroke direction and the direction of the maximum vertical G of the front wheels, it is possible to judge the unevenness of the road surface relatively accurately, resulting in excellent reliability and control amount. Since the correction amount corresponds to the maximum stroke S max of the front wheels when passing through uneven road surfaces, it is possible to perform corrections according to the unevenness of the road surface and obtain a stable ride comfort improvement effect. Furthermore, since the correction control for the rear wheels is controlled over time, it is possible to realize stable control that is resistant to noise and the like.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, the damping force control by the preview control section 41 may be abolished, or regarding the correction control for the rear wheels,
Either the vertical G or stroke discrimination can be abolished, or the detection output of the pressure sensor 30 can be set alone or vertically 0.
In combination with one stroke, vibration input information from the road surface passed by the front wheel may be detected.

Furthermore, it goes without saying that various other modifications can be made without departing from the gist of the present invention.

(Effects of the Invention) As described above in detail with the embodiments, according to the present invention, even if a relatively large vibration occurs in the vehicle body when the front wheels pass through the unevenness of the road surface, when the rear wheels pass the unevenness, the front wheels Control is performed with reference to the vibration input when the rear wheels pass through the bumps, so when the rear wheels pass the bumps, the vibration input can be reduced compared to when the front wheels pass the bumps, and the vehicle can provide a better ride comfort for the occupants. This has the effect of providing an active suspension for the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a schematic system configuration diagram showing an embodiment of the present invention;
FIG. 2 is a control block diagram schematically showing the basic control contents for the control valve 17, FIG. 3 is a flow chart diagram showing the control contents in the preview control section 41, and FIG. 4 is a control block diagram showing the basic control contents for the control valve 17. Detection principle diagram; Figure 5 is a flowchart showing the control content in the rear wheel correction control unit 42; Figure 6 is a map diagram for determining the correction control amount when passing 8 roads; Figure 7 is when passing 8 roads. Timing chart diagram showing control details, No. 8゜9! ! 1 are diagrams corresponding to FIGS. 6 and 7 when passing through the circuit, respectively. Engineering...Oil pump, 14...Hydraulic actuator 17...Control valve, 22...Switching valve 23...
・Controller, 24...Vehicle speed sensor 28...Vertical G sensor, 29...Vehicle height sensor 42...Rear wheel correction control unit Applicant: Mitsubishi Motors Corporation Figure 3, Figure 6, Figure 7 Smax (growth side) Figure 8 Figure 9 Procedural amendment (voluntary) Display of September 3, 1990 and 1990 Patent No. 321954 of 1990 Amendment person 1, page 19 of the specification 5-6 In line ``Less than... ・
``...Not necessary'' should be corrected to ``In the above case, the vertical G generated on the vehicle body will be very large, and if correction control is performed on the rear wheels, there is a risk that the suspension will go to full stroke.'' 2. Correct "more than" to "less than" in line 8 of the same page. 3. On page 20, lines 10-11, “The following...
・Correct "Not necessary" to "If it is larger than that, there is a risk that the suspension will go to full stroke if the rear wheel is corrected." 4. On the 133rd line of the same page, correct "greater than" to "less than or equal to". 5. On the same page box 22, lines 12-13, "The following...
・Correct "Not necessary" to "If it is larger than that, there is a risk that the suspension will go to full stroke if rear wheel correction control is performed." 6. In lines 15 and 16 of the same page, "greater than" is corrected to "is more than". 7. Correct Figure 5 as shown in the attached sheet.

Claims (1)

[Claims] an actuator that is interposed between the vehicle body and the rear wheels and capable of increasing or decreasing the supporting force of the vehicle body with respect to the rear wheels; a vibration input detection means that detects vibration input from the front wheels due to road surface irregularities; and a vehicle running speed. and a control means that controls the operation of the actuator based on the detection output of each of the detection means, and the control means is configured to detect vibration input from the front wheels detected by the vibration input detection means. When it is detected that the rear wheel has exceeded a predetermined value, based on the output of the vehicle speed detection means, the time point at which the rear wheel reaches the uneven road surface that has been given a vibration input of the predetermined value or more is calculated, and the vibration input is detected at the same time. An active suspension for a vehicle, characterized in that the actuator is configured to operate in a direction that alleviates the