JPH0680006A - Suspension control device - Google Patents

Abstract

PURPOSE:To improve deterioration of comfortableness to ride by stopping useless rear wheel control when tire chains are installed in a vehicle provided with a suspension control device having a function to foresee and control hardness of a rear wheel suspension while detecting front wheel vibration. CONSTITUTION:Judgment is made on whether tire chains are installed or not from a difference in vehicle front and rear wheel vibration detected by vehicle height sensors 3FL, 3FR, 3RL and 3RR. In this case, when the tire chains are installed on front wheels, output can be obtained only from the vehicle height sensors 3FL and 3FR. When the judgment is made such that the tire chains are installed, a prohibiting signal to stop the function is supplied to a foreseeing control operation part 9. A control signal to soften a front wheel suspension is also supplied to the suspension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension controller for controlling a suspension that absorbs vertical vibration of a vehicle.

[0002]

2. Description of the Related Art Conventionally, a vehicle generally travels on a frozen road or a snowy road with tire chains attached to driving wheels.

[0003]

By the way, in the vehicle,
It is known that a suspension control device having a function of detecting the vibration of the front wheels and foreseeing (previewing) controlling the hardness of the suspension of the rear wheels is used. There is a problem that the life of mechanical parts such as the suspension of the rear wheels may be shortened because periodic vibrations that occur when a tire chain is attached to a certain front wheel and the vehicle travels at a low speed are also detected.

There is also a problem that the ride comfort is deteriorated by the vibration of the tire chain.

In view of the above, the present invention provides a vehicle equipped with a suspension control device having a function of detecting vibrations of the front wheels and predicting the hardness of the suspension of the rear wheels. It is an object of the present invention to provide a suspension control device that can prevent the wheels from being controlled and can improve the deterioration of riding comfort.

[0006]

In order to achieve the above object, the suspension control device according to the invention of claim 1 detects a vertical movement of front and rear wheels of a vehicle and a vertical movement of the front wheel. When detected, in a suspension control device comprising a preview control means for preview-controlling the suspension of the rear wheel, a determination means for determining the mounting of the tire chain by the difference in vertical movement of the front wheel and the rear wheel, And a prohibiting means for prohibiting the operation of the preview control means when it is determined that the tire chain is mounted.

In addition to the suspension control device according to the first aspect, the suspension control device according to the second aspect of the invention is a control for controlling the suspension of the front wheels to be soft when it is determined that the tire chain is mounted. Means are provided.

[0008]

According to the first aspect of the present invention, the vertical movement (vibration) of the front wheels and the rear wheels is detected when traveling is started after the tire chains are mounted. Then, based on this detection result, it is determined whether or not the tire chain has been mounted based on the difference in vibration between the front wheels and the rear wheels. When the tire chain is attached, only the front wheels vibrate. When it is determined that the tire chain is mounted, the function of the preview control means for preview-controlling the suspension of the rear wheels stops.

Therefore, when the tire chain is mounted on the front wheels and the vehicle travels, the suspension preview control for the rear wheels is not performed. Therefore, compared to the case where the suspension preview control is performed by detecting vibration, Does not shorten the service life of mechanical parts such as wheel suspensions.

According to the second aspect of the present invention, when it is determined that the tire chain has been attached, the suspension of the front wheels is controlled so as to be soft.

Therefore, since the suspension becomes soft, the absorption rate of vibration is increased, and the deterioration of the riding comfort when the tire chain is mounted is improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a suspension control device 1 according to the present invention, and FIG. 2 is a perspective view showing an appearance of a vehicle 2 to which the embodiment is applied.

[0013] In Configuration Figure 1, each of the _{3 FL, 3 FR, 3 RL} , 3 RR is the vehicle height sensor is attached to the front and rear wheels of the vehicle 2. Each of 4 _FL , 4 _FR , 4 _RL , and 4 _RR is a suspension that suppresses vibration applied to the front wheels and rear wheels, and the hardness changes from hard to soft according to the supplied control signal.

A vehicle speed sensor 5 detects the speed of the vehicle 2 and outputs it. Each of 6F and 6R is an FFT calculator, which calculates and outputs the magnitude of the component of the specific frequency band among the signal components of the outputs of the vehicle height sensors 3 _FL , 3 _FR , 3 _RL and 3 _RR . In this case, the FFT calculator 6F calculates the magnitude of the component in the specific frequency band of the output of the front wheel height sensors 3 _FL , 3 _FR , and the FFT calculator 6R calculates the rear wheel height sensors 3 _RL , 3
Calculate the magnitude of the component in the specific frequency band of the output of _RR .

Reference numeral 7 denotes an FFT calculator, which outputs the output of the vehicle speed sensor 5 to vehicle height sensors 3 _FL , 3 _FR , 3 _RL , 3 _RR when the vehicle is traveling at low speed with the tire chain TC (see FIG. 1) attached. Then, the frequency band that is generated is calculated. In addition, the calculated generation frequency band is used as the above-described specific frequency band and the FFT calculator 6
Supply to each of F and 6R. In addition, tire chain TC
When the vehicle is mounted, the vibration becomes the largest especially at low speed running, so the FFT calculator 7 calculates the frequency band generated by the vehicle height sensors 3 _FL , 3 _FR , 3 _RL , 3 _RR during low speed running.

Reference numeral 8 denotes a tire chain mounting determination unit, which is a signal in a specific frequency band output from the FFT calculators 6F and 6R when the tire chain is mounted (ie, vehicle height sensor 3 _FL ,
After inputting a signal of a specific frequency among the signals generated from 3 _FR , 3 _RL , 3 _RR ), the respective signals are compared, and the hardness of the suspensions 4 _FL , 4 _FR is controlled based on the comparison result. That is, the input signals of the respective specific frequency bands are compared with each other, and when only the signals corresponding to the vehicle height sensors 3 _FL and 3 _FR of the front wheels are output, the suspensions 4 _FL and 4 _FL for the front wheels are compared.
Outputs a control signal to soften _FR .

Further, the tire chain attachment judging section 8 causes the preview control computing section 9 to stop its function immediately after outputting the control signal for softening the front wheel suspensions 4 _FL and 4 _FR . Outputs a prohibition signal. In this case, the prohibition signal is output when a plurality of signals in the characteristic frequency band output from the FFT calculator 6F are output within a predetermined period (hereinafter referred to as period T ₀ ).

That is, a plurality of signals (2) corresponding to the vehicle height sensors 3 _FL and 3 _FR are received within a period T ₁ (T ₁ > T ₀ ) after the front wheels have passed over the projection on the road surface and the rear wheels have passed over it.
If more than one) is output, it can be regarded as vibration due to the tire chain TC, and in this case, a prohibition signal is output.

The preview control calculation unit 9 detects the vibration from the front wheels by the vehicle height sensors 3 _FL and 3 _FR when riding over a projection on the road surface, and then detects the vibration of the rear wheel before the rear wheel gets over the projection. It controls the hardness of the suspensions 4 _RL and 4 _RR . In this case, the function is stopped when the prohibition signal is supplied from the tire chain attachment determination unit 8 as described above. That is, the hardness of the variable suspensions 4 _RL and 4 _RR is not controlled.

Each of the vehicle height sensors 3 _FL , 3 _FR , 3 _RL , 3 _RR corresponds to a detecting means. Further, the tire chain attachment determination unit 8 functions as a determination unit, a prohibition unit, and a control unit. The preview control calculation unit 9 corresponds to suspension preview control means.

[0021] Operation Next, the operation of the suspension control apparatus 1 of the above construction will be described with reference to the flowchart shown in FIG.

First, when the vehicle 1 starts running, the outputs of the vehicle height sensors 3 _FL , 3 _FR , 3 _RL and 3 _RR are detected in step S1. And out of each detected output
The outputs of the vehicle height sensors 3 _FL and 3 _FR are supplied to the FFT calculator 6F and also to the preview control calculator 9. Further, the outputs of the vehicle height sensors 3 _RL and 3 _RR are the FFT calculator 6R.
Is supplied to.

Next, in step S2, the output of the vehicle speed sensor 5 is detected. The detected value is supplied to the FFT calculator 7.

Next, in step S3, the magnitudes of the components of the outputs of the vehicle height sensors 3 _FL , 3 _FR , 3 _RL and 3 _RR in the specific frequency band are calculated. That is, the FFT calculator 6F calculates the magnitudes of the outputs of the vehicle height sensors 3 _FL and 3 _FR in the specific frequency band determined by the FFT calculator 7, and the FFT calculator 6R determines the magnitudes of the outputs. The magnitudes of the outputs of the vehicle height sensors 3 _RL and 3 _RR in the specific frequency band are calculated. The calculated results are supplied to the tire chain mounting determination unit 8.

Next, in step S4, the calculated values are compared. That is, the tire chain attachment determining unit 8 compares the outputs of the FFT calculators 6F and 6R, and if they are determined to have substantially the same value, it is determined that the tire chain TC is not attached. Is not processed. That is, the hardness of the front wheel suspensions 4 _FL and 4 _FR is not controlled. In this case, the process returns to step S1.

On the other hand, when only the output of the FFT calculator 6F is obtained in the comparison in step S4, it is determined that the tire chain TC is mounted. After this determination, the process proceeds to step S5.

In step S5, it is determined whether a plurality of outputs of the FFT calculator 6F can be obtained within the period T ₀ . In this determination, the tire chain attachment determination unit 8
When determines that the output of the FFT processor 6F is obtained plurality within the period T _0, in step S6, and supplies a control signal the suspension 4 _FL, 4 _FR to soften the front wheel suspension 4 _FL, 4 _FR . Immediately after that, the prohibition signal is supplied to the preview control calculation unit 9 in step S7.

As a result, the function of the preview control calculation unit 9 is stopped.
Stop, rear wheel suspension 4_RL, 4_RRThe hardness of
Not done In contrast, the front wheel suspension
Four_FL, 4 F_RIs controlled to be soft.

On the other hand, in the determination of step S5, FF
If only one output of the T calculator 6F is obtained within the period T ₀ , nothing is done and the process returns to step S1.

As described above, when the tire chain TC is mounted, the hardness of the rear wheel suspensions 4 _RL , 4 _RR is not controlled, and the front wheel suspensions 4 _FL , 4 _FR are not controlled.
Only controlled to be soft.

In the above embodiment, the preview control of the rear wheel suspensions 4 _RL and 4 _RR is prohibited during low speed running, but the reason for limiting it only during low speed running is that it depends on the tire chain TC during high speed running. This is because the vibration will be low. However, this does not apply if the vibration is large even during high-speed traveling.

Further, in the above embodiment, the tire chain T
When C is mounted, the function of the preview control calculation unit 9 is stopped and the suspensions 4 _FL , 4 _{FR of the} front wheels are made soft, but only the function of the preview control calculation unit 9 may be stopped. .

Further, in the above-mentioned embodiment, although each section is constituted by an independent circuit, a microcomputer (CP
(U, RAM, ROM, etc.) can be used to form a single circuit.

Further, although the present invention is directed to the front-wheel drive vehicle, the rear-wheel drive vehicle can also be applied if only the function of the preview control calculation unit 9 is stopped. That is, when the tire chain TC is attached to the rear wheels,
The function of the preview control calculation unit 9 is stopped.

[0035]

According to the present invention, the operation of the suspension preview control means for preview controlling the suspension of the rear wheels is prohibited due to the difference in vibration between the front wheels and the rear wheels when the tire chains are attached to the front wheels. Therefore, compared with the case where the prediction of the suspension is controlled by vibration, the life of the mechanical parts such as the suspension of the rear wheels is not shortened.

Further, when the tire chains are attached to the front wheels, the suspension of the front wheels is controlled so as to be soft, so that the deterioration of the riding comfort when the tire chains are attached can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a suspension control device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an appearance of a vehicle to which the embodiment is applied.

FIG. 3 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

3 _FL , 3 _FR , 3 _RL , 3 _RR vehicle height sensor (detection means) 4 _FL , 4 _FR , 4 _RL , 4 _RR suspension 5 vehicle speed sensor 6F, 6R, 7 FFT calculator 8 Chain installation determination section (determination means, Prohibition means, control means) 9 Preview control calculation unit (preview control means) TC Tire chain

Claims (2)

[Claims] 1. A detection means for detecting vertical movement of front and rear wheels of a vehicle, and a preview control means for predicting and controlling the suspension of the rear wheel when the vertical movement of the front wheel is detected. In the suspension control device, a determination unit that determines whether the tire chain is mounted based on a difference in vertical movement between the front wheel and the rear wheel, and a prohibition that prohibits the operation of the preview control unit when it is determined that the tire chain is mounted. And a suspension control device. 2. The suspension control device according to claim 1, further comprising control means for controlling the suspension of the front wheels to be soft when it is determined that the tire chain is mounted.