JPH0328010A - Car height control device for vehicle - Google Patents

Abstract

PURPOSE:To allow one side of a vehicle to move vertically with respect to the other side by providing car height detecting devices for respective front and rear, and right and left wheels of the vehicle, obtaining an average value or detected ground clearances or peak values and bottom values of the fluctuations for the respective wheels, and controlling the car height so that they become respective target values. CONSTITUTION:Car height detecting means C are provided for respective right and left, front and rear wheels of a vehicle, and respective detected car heights are inputted to an average value calculating means D. The average value calculating means D calculates 1/4 moving average of detected car height for each detecting means C. A drive control means E compares the calculated average values with target car height for each detecting means C to drive respective vertical motion driving drives B so that the average values becomes the target car heights. In this constitution, the vehicle can be maintained in the level position even on any inclined ground by moving one side of the vehicle vertically with respect to the other side.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a vehicle height control device that variably controls the vehicle height of a vehicle. <Prior Art> Conventional examples of vehicle height control devices include the following. In other words, the vehicle height is controlled by moving the vehicle body up and down using a hydraulic device or the like so that it moves in the longitudinal direction of the vehicle while the vehicle is traveling. I am trying to use a forward system.

<Problems to be Solved by the Invention> However, in such conventional vehicle height control devices, the vehicle height is controlled by moving the vehicle body up and down so that it moves tM in the longitudinal direction of the vehicle. When driving or stopping with the sides of the vehicle elevated, there is a problem in that the vehicle body cannot be controlled to be in a horizontal state.

In addition, a vehicle speed sensor is provided to detect the height of the vehicle body relative to the running wheels, and the detected value of the vehicle speed sensor is
+sec) and sampled multiple times (for example, 4
In order to prevent noise, the average value of the sampled values is used as the actual detected vehicle height, and the vehicle height is controlled by feedforward control so that the vehicle body reaches the target vehicle height based on the detected vehicle height. There is something. However, since the vehicle body is always moving up and down while the vehicle is running, the output of the vehicle speed sensor also oscillates as shown in FIG. 6, so that the average value also oscillates. Therefore, when the target vehicle height is changed as shown in Figure 6, the average value becomes the target vehicle height before the actual vehicle height reaches the target vehicle height (position A in Figure 6), and the vehicle height There is a problem that the control is stopped.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a vehicle height control device that can move one side of a vehicle up and down relative to the other side, and can optimally control the vehicle height. do.

<Means for Solving the Problems> Therefore, as shown in FIG.
A plurality of vertical movement devices B are provided at at least two positions in the vehicle width direction at the rear of the vehicle and move the vehicle body up and down with respect to the front and rear running wheels A + and A t, respectively, and a plurality of vertical movement devices B are provided in the vicinity of each of the vertical movement devices B, respectively. A vehicle height detection means C provided as a vehicle height detection means C for detecting the height of the vehicle body, and an average value of a substantially fluctuation peak value and a substantially fluctuation bottom value of the vehicle height detected by these vehicle height detection means C or data corresponding thereto. and a drive control means E for driving and controlling the vertical movement device B so that the calculated average value becomes the target vehicle height. I made it.

<Function> Then, each vertical movement device is independently drive-controlled based on the detection signal of each vehicle height detection means to tilt the vehicle forward and backward as well as to the side. The vehicle height is controlled so that the average value of the approximate peak value of the fluctuation and the bottom value of the fluctuation of the height or the data corresponding thereto becomes the target vehicle height.

<Example> An example of the present invention will be described below based on FIGS. 2 to 5.

In FIG. 2, a piston rod 2A of a hydraulic cylinder 2 is freely attached to the axle housing near each running wheel 1 of the vehicle, and the main body of the hydraulic cylinder 2 is attached to the vehicle body (not shown). . The main body of the hydraulic cylinder 2 has a hydraulic chamber 2C defined by a diaphragm 2B and a gas chamber 2D filled with an inert gas for a damper. An oil supply passage 3 and an oil discharge passage 4 are connected to the hydraulic chamber 2C. The oil supply passage 3
An upper solenoid valve 5 is installed in the oil discharge passage 4, and a lower solenoid valve 6 is installed in the oil discharge passage 4. Here, the hydraulic cylinder 2, the upward movement electromagnetic valve 5, and the downward movement electromagnetic valve 6 constitute a vertical movement device.

Further, the vehicle body is provided with a potentiometer-type vehicle height sensor as a vehicle speed detection means, and a swing lever 7A of the vehicle height sensor 7 is provided.
is attached to the member on the running wheel l side so as to be able to swing freely. In each vehicle height sensor, a swing lever swings in accordance with the vertical movement of the vehicle body, and outputs a signal corresponding to the position of the vehicle body to a control device 8 comprising a microcomputer or the like.

Oil is supplied to the oil supply passage 3 from a high pressure tank 9,
Pressurized oil is supplied to the high pressure tank 9 by a hydraulic bomb 10 . The oil discharged from the oil discharge passage 4 is introduced into a reserve tank 11, and is supplied from the reserve tank 11 to the hydraulic bomb 10. The control device 8 receives a target vehicle height signal from a manual potentiometer (not shown) that continuously indicates the height of the vehicle body for each running wheel 1. Based on the detection signal of the vehicle height sensor, the control device 8 controls the vehicle height so that the vehicle height is as instructed by the indicator.
An upward movement solenoid valve 5 and a downward movement solenoid valve 6 are installed independently for each traveling port.
It is designed to drive and control.

Here, the control device W8 constitutes a drive control means and an average value calculation means. Next, the operation will be explained according to the flowchart in Figure 3.
This routine is executed every 10 msec.

First, to explain normal vehicle height control, when the vehicle is stopped on a slope or the like with one side raised high, the driver uses an indicator to control the control device 8 in order to control the vehicle to a horizontal state. For example, a target vehicle height signal is output so that the vehicle height on the one side is lowered. As a result, the control device 8 outputs an ON signal to the lowering solenoid valves 6 at the front and rear portions of the vehicle to open the valves and reserve oil in the hydraulic chamber 2C of the hydraulic cylinder 2 via the oil discharge passage 6. Drain into 1 liter tank. Therefore, one side of the vehicle moves downward together with the main body of the hydraulic cylinder 2, and the vehicle body is controlled to be horizontal. At this time, the control device 8 performs feedforward control based on the detection signal from the vehicle height sensor 7 so that the actual vehicle height becomes the target vehicle height. Additionally, while driving, feedforward control is performed so that the vehicle height becomes lower as the vehicle speed increases.

In addition, the other side of the vehicle body may be moved upward to control the vehicle body to be horizontal. Next, the routine shown in the flowchart of FIG. 3 will be explained.

si reads the detection signals of each vehicle height sensor 7. In S2, 3Qa+sec before, 20g+sec before, and 10msec
The vehicle height read before and this time is displayed for each vehicle height sensor.
, averaged to 1/4 moving average vehicle height H. (hereinafter referred to as moving average vehicle height H1). This moving average vehicle height H. is calculated in order to prevent the influence of noise even if noise enters the signal from the vehicle speed sensor 7.

? In step 3, the current target vehicle height H, ■ is set.

This target vehicle height H. (2) is set by the signal from the indicator. Further, the target vehicle height H sat is set by a signal from the indicator. In addition, the target vehicle height H
s+et may be set based on the detection signal of the vehicle speed sensor so that the vehicle speed decreases as the vehicle speed increases. In S4, it is determined whether or not the vehicle height is currently being controlled. If YES, the process proceeds to S5; if NO, the process proceeds to S10. In S5, the maximum value (fluctuation peak value) H1, and the maximum value (fluctuation bottom value) H1. Detect. Here, since the vehicle body vibrates up and down while driving, the moving average vehicle height H also changes in substantially the same way as the output change of the vehicle height sensor 7, as shown in FIGS. 4 and 5. In S6, the detected maximum value HIP and minimum value H. The peak average vehicle height HIA■ (=(HIP+Hth)/2) is calculated by averaging. In S7, what is the calculated peak average vehicle height HIAV■?
It is determined whether or not the target vehicle height H1■ has been reached. If YES, the process proceeds to S8; if NO, the process proceeds to S9.

In S8, the normal vehicle height control is performed using the upward movement solenoid valve 5.
and the lowering solenoid valve 6 are closed to complete the process.

In S9, the normal vehicle height control is continued.

In SIO, it is determined whether or not the target vehicle height H sat has been changed. If YES, the routine proceeds to Sll, and if NO, the routine ends.

At Sll, the normal vehicle height control is started. As explained above, the maximum value HIF and the minimum value H. of the moving average vehicle height H+. The peak average vehicle height HIAVt is calculated from the above, and the vehicle height is controlled so that the peak average vehicle height {+avt} becomes 16% of the target vehicle height H, resulting in the following effects.

That is, since the moving average vehicle height H1 changes approximately in the same manner as the output of the vehicle height sensor 7, the peak average vehicle height HIAVf becomes approximately the same as the actual vibration center value of the vehicle body even if the vehicle body vibrates up and down. ．． Therefore, said P? Average vehicle height} 1 tavt
is the target vehicle height H. If the vehicle height is controlled so that (2) is achieved, the actual vehicle height can be set to the target vehicle height when the target vehicle height H sat is changed as shown in FIG.

Note that the average value of the fluctuation peak value and the fluctuation bottom value of the detected value of the vehicle speed sensor 7 may be calculated, and the vehicle height control may be performed so that this average value becomes the target vehicle height.

<Effects of the Invention> As explained above, the present invention allows the front and rear running wheels to move up and down independently using a plurality of vertical movement devices, so that the vehicle can be moved even on slopes, etc. The vehicle body can be held horizontally by moving one side up or down. In addition, since the vehicle height is controlled so that the average value of the approximate fluctuation peak value and the approximate fluctuation bottom value of the vehicle height detected by the vehicle height detection means or the data corresponding thereto becomes the target vehicle height, Even if the target vehicle height is changed during the process, the actual vehicle height can be accurately controlled to match the target vehicle height.

[Brief explanation of drawings]

Fig. 1 is a claim correspondence diagram of the present invention, Fig. 2 is a composition diagram showing an embodiment of the present invention, Fig. 3 is a flowchart of the same as above,
4 and 5 are diagrams for explaining the same effect as above, and FIG. 6 is a diagram for explaining the drawbacks of the conventional method. 1... Travel transport 2... Hydraulic cylinder 5...
Upward movement solenoid valve 6...Downward movement solenoid valve 7...High speed sensor 8...Control device

Claims (1)

[Claims] A plurality of vertical movement devices provided in at least two positions in the vehicle width direction at the front and rear of the vehicle to move the vehicle body up and down relative to the front and rear running wheels, and each vertical movement device provided correspondingly in the vicinity of each vertical movement device. vehicle height detection means for detecting the height of the vehicle body; and the average value of the approximate fluctuation peak value and approximate fluctuation bottom value of the vehicle height detected by these vehicle height detection means or the data corresponding thereto. Vehicle height control for a vehicle, comprising an average value calculation means for calculating each means, and a drive control means for driving and controlling the vertical movement device so that the calculated average value becomes a target vehicle height. Device.