JPH01160716A - Height adjuster - Google Patents

Abstract

PURPOSE:To enhance height adjustment accuracy by counting the number of detection times for high, neutral, and low height within a given time, and by contriving so that when the number of high or low height detection times exceeds a prescribed value, height adjustment is commenced, and that when the number of neutral height detection times exceeds a prescribed value, height adjustment is stopped, and further that the stoppage judging criterion is renewed in accordance with the number of high or low height detection times. CONSTITUTION:Height sensors 7a, 7b are provided at the front and rear respectively, and the detected heights are input into a controller 8 to supply or discharge fluid to or from respective actuators, so that the height can be adjusted. In this case, the controller 6 counts the number of detection times for high, neutral, and low height within a given time. And, when the number of high or low height detection times exceeds a prescribed value, height adjustment is commenced; while, when the number of neutral height detection times exceeds a prescribed value, height adjustment is stopped. Further, the height adjustment stoppage judging criterion times is renewed in accordance with the number of high or low height detection times. By this constitution, height adjustment can be properly carried out.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a vehicle height adjustment device that improves the ride comfort of a vehicle by adjusting the suspension according to the driving conditions of the vehicle. .

"Prior Art" The vehicle height adjustment device described above generally has a method of controlling the vehicle height to a target value based on vehicle height data obtained from a vehicle height detection means such as an optical sensor. As a conventional example of a specific control method, the following method is known.

In other words, when high or low vehicle height data is continuously detected for a certain period of time, the pressure of the suspension's fluid system is adjusted to return the vehicle height to the neutral position, and the suspension stops when neutral is detected for a certain period of time. Met.

``Problems to be Solved by the Invention'' However, in the above method, the vehicle height adjustment is stopped by detecting the neutral vehicle height for a certain period of time, and therefore may lack accuracy depending on road surface conditions.

For example, if you set the above-mentioned "fixed time" according to a good road, it may be difficult to detect a continuous fixed time on a rough road, so the vehicle height adjustment may be overdone, or conversely, the "fixed time" may be adjusted too much depending on the rough road. If you set the “fixed time” to a shorter value,
There is a problem in that the adjustment ends before the vehicle height adjustment is completed on a relatively good road surface. .

The present invention has been proposed in view of the above circumstances, and an object of the present invention is to provide a vehicle height adjustment device that can accurately stop vehicle height adjustment control regardless of whether the road is rough or good.

"Means for solving the problem" In order to achieve the above object, the present invention controls a valve provided in a fluid system connecting an actuator and a pressure source to supply or discharge fluid to the actuator. A vehicle height adjustment device that adjusts a vehicle height by controlling a vehicle height includes a vehicle height sensor that detects at least three levels of vehicle height: high, neutral, and low, and controls the fluid system based on detection data of the vehicle height sensor. The controller includes a counting means for counting the number of times high, neutral, and low vehicle heights are detected within a predetermined time period, and a counting means for counting the number of times the vehicle height of either high or low is greater than or equal to a set value. a start determining means for starting the vehicle height adjustment control when the vehicle height adjustment control is counted; and a start determination means for starting the vehicle height adjustment control when the counting means detects the neutral vehicle height more than a reference number of times within a predetermined time after once detecting the neutral vehicle height during the vehicle height adjustment control. The vehicle height adjustment control system comprises a stop determining means for stopping the vehicle height adjustment control, and a reference number updating means for updating a reference number of times in the stop determining means according to the number of times either high or low vehicle height is detected within a certain period of time. It is.

"Function" With the above configuration, for example, when driving on a rough road, the actuator is actuated by continuous detection of either high or low vehicle height to control the vehicle height to be neutral.
Not only can vehicle height adjustment be stopped accurately if neutral vehicle height is detected more than a standard number of times within a predetermined period of time, but the vehicle height adjustment can also be accurately stopped based on the number of times neutral vehicle height is detected within a predetermined period of time while driving on a good road. It is possible to accurately determine whether the vehicle is traveling on a rough road or not, and change the criteria for determining whether the vehicle height adjustment is complete.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, the configuration of the suspension pneumatic system to be controlled will be explained with reference to FIG. 3. Reference numeral 1 is interposed between the frame and the body near each wheel (both shown on the road shown), and adjusts the vehicle height by expanding and contracting. Actuator (e.g. pneumatic cylinder, air spring, shock absorber with air spring, etc.). These actuators 1 are connected to air piping via a front solenoid valve 2 and a rear solenoid valve 3 as a pair on the front side and a rear side, respectively, and are connected to an air pressure source (for example, a compressor) 4 or , and is connected to an exhaust solenoid valve 5 that is open to the atmosphere.

Next, the configuration of a control circuit for controlling the pneumatic system will be explained with reference to FIG.

Reference numeral 6 denotes a controller comprised of a CPU, etc. Connected to this controller 6 are front and rear vehicle height sensors 7a and 7b each formed by arranging, for example, a plurality of phototransistors in a line along the detection direction. , multiple bits of data indicating the vehicle height are supplied.

The vehicle height sensors 7a and 7b each include a plurality of switches (for example, photo sensors) in the vehicle height displacement direction (usually in the vertical direction) that are turned ON or OFF when the vehicle height is within a predetermined range. In the case of , 3 pieces) are arranged side by side,
Each of them is connected to the controller 6 via signal lines A to C.

Note that the reference numeral indicates a ground line connected to the vehicle height sensors 7a and 7b, and the reference numeral E indicates a power supply line. When the vehicle height is H (high), 0M (medium), L (low), and at neutral 1 and neutral 2, which are intermediate points between these,
As shown in FIG. 2, 3-bit vehicle height data representing each of these vehicle heights is supplied to the controller 6, and the controller 6 periodically receives the vehicle height data at a predetermined sampling period. . In this embodiment, either Neutral 1 or Neutral 2 is selected as the neutral position, and if it is higher than that, it is determined to be 'high', if it is lower than that, it is determined to be 'low', and the control described below is executed. This allows you to set the vehicle height higher or lower.

The controller 6 also supplies control signals to the front and rear solenoid valves 2 and 3 and the exhaust solenoid valve 5 to operate them according to the control law described below, and also operates the air pressure source 4. A relay l connects and connects the motor 8 that drives the motor 8 and the power source (battery) 9.
It is designed to operate O. Note that the motor 8
A switch it is provided between the power source 9 and the power source 9 to arbitrarily connect and disconnect the power source 9 and the power source 9.

Next, we will explain the operation of the vehicle height adjustment device configured as above.
The control operation of the controller will be explained using chart 70 in FIG. 4. Note that in the following description, Sn indicates the n-th step in the flowchart.

Sl: A neutrality determination counter (built in the controller 6) that measures the neutrality determination time every time it is determined to be neutral.
After detecting the neutral position, it is determined whether the counter (which measures time) has started by counting up at the same cycle as the sampling of vehicle height data, and if YES, the process goes to S2; if NO, the process goes to S2. proceeds to S3.

S2: Neutral judgment counter increments.

S3: Front or rear vehicle height sensor 7a/7b
It is determined whether data indicating the vehicle height "low" has been supplied, and if YES, the process advances to S4; if NO, the process advances to 317.

S4: Determine whether the solenoid valve 2 or 3 is opened and the air pressure source 4 is in the air supply control state, and answer YES.
In the case of , the process advances to S31, which will be described later, and in the case of NO, the process advances to S5.

S5+ Determine whether or not the delay timer counter built into the controller 6 (a timer that measures time by counting up to the full count Np in synchronization with the sampling period, similar to the neutral judgment counter) has started, and select YES. In the case of No, the delay timer counter is incremented (S6), and in the case of No, the delay timer counter is started (S7), and then the process advances to S8.

S8: A "low" counter that counts the number of times the vehicle height is detected as "low" (built in the controller 6,
A counter is incremented each time ``high'' is detected, and the "high" counter described later is similarly a counter that is incremented each time ``high'' is detected. ).

S9: Determine whether the count of the delay timer counter has expired (full count) or not. If NO, proceed to the next SIO; if YES, proceed to 515, which will be described later.

510: The count value of the “low” counter is the reference value NL
(It is set in the relationship of NL-2/3N). If it exceeds the vehicle height, it is assumed that the vehicle height is low and proceeds to the next Sll. If it is lower, the Sll will be described later.
Proceed to 31.

S II: Exhaust control is stopped by closing the exhaust solenoid valve 5 that was open to the atmosphere.

S122 Start air supply control to raise the vehicle height.

That is, by connecting the 70-ton solenoid valve 2 or the rear solenoid valve 3 to the air pressure source 4, the vehicle height becomes "low" and air is supplied to the suspension on the t; side.

S13: Calculate the ratio between the count number of the "low" counter and the count number of the delay timer, judge whether this ratio exceeds the set value A, and if it does, shift to the "low" side and then ” is detected a large number of times. Therefore, it is assumed that you are driving on a good road, or that there is vibration with a certain amplitude, but it is significantly "low" and has shifted to the side, and goes to 814. If it does not exceed the vibration, it is determined that you are driving on a bad road. The process then proceeds to S17, which will be described later. In this embodiment, the value of A is set to 475.

S14: Assuming that you are driving on a good road, 2/3 N+
Substitute X as N8. (However, N7 is the full count value of the neutral judgment counter, and NN is the count value corresponding to the time that is the criterion for neutral judgment.) In other words, if it is considered that the road is running on a good road, sampling is performed to judge it as neutral. The reliability of judgment is increased by setting a longer time. In the embodiment, N=2/3NT is set, and based on the difference between NH and N1, that is, 173N, half of this 173N is adopted as X, and this 514, 316, which will be described later, and We decided to apply this method to the adjustment of sampling time in 528.

On the other hand, if it is determined in S9 that the delay timer counter has become full, and if the full count value is N, then 515: "Low" counter count number >1/8N#
Also, it is determined whether the count number of the "high"counter>1/8NF holds true.

That is, these count numbers are constant values for the full count (in the example, Nll and N L (!l:
If the vehicle repeatedly exceeds or falls below (1/8 N, selected from the relationship with Np) (YES), the vertical movement of the vehicle body is significant, and it is assumed that the vehicle is traveling on a rough road, and the process proceeds to S16. , otherwise (NO),
It is assumed that the vehicle is traveling on a good road, and the process proceeds to S29, which will be described later.

816: When driving on a rough road, set the NN to 2/3N in order to set a small number of counts that can be considered neutral.
Set ArX. Note that the above-mentioned X is a value set similarly to X in S14.

Furthermore, if it is determined in S3 that the vehicle height is not "low", S17: Determine whether the vehicle height is "high" and select YES.
In the case of , the process proceeds to S18, and in the case of NO, the process proceeds to S34, which will be described later.

818: Determine whether or not exhaust control is in progress. If NO, proceed to 519; if YES, proceed to S31, which will be described later.

519: Determine whether or not the delay timer counter has started, and if YES, increment the delay timer counter (S20), and if No, start the delay timer counter (S20). S21), proceed to S22.

S222 Count the number of times the vehicle height is detected as “high”
increments the "high" counter.

S23: Determine whether or not the count of the delay timer counter has expired (has it counted up to the full count N)? If NO, proceed to the next step 524; if YES, proceed to S15.

S24: The count value of the “high” counter is the reference value N□
It is determined whether or not the value exceeds (N□-2/3N F). If YES, the process proceeds to the next step 525; if NO, the process proceeds to 531, which will be described later.

S25: Front and rear solenoid valve 2
・Stop air supply control by closing 3 (or by cutting off the pressure source as necessary).

S26: Start exhaust control to lower the vehicle height.

S27: Find the ratio between the “neutral” count and the delay timer count, and this ratio becomes the set value A (the S
13) is exceeded, and if it is exceeded, the process proceeds to 328, and if it is not, the process proceeds to S15.

S28: Substitute 2/3NT+X to N.

When the control for each of the vehicle heights "high" and "low" is completed as described above, steps 829 and subsequent steps are executed as described below.

S29: Clear the delay timer counter.

53 (1: Clear the counters for "it high" and "low".

S31: Determine whether the neutral determination counter has reached a full count, and if YES, proceed to the next step 832.
If NO, the process returns to S1.

S32: Clear the neutrality determination counter.

S33: Clear the "neutral" counter.

On the other hand, if the determination result in S17 is NO, that is,
If the vehicle height is neither high nor low, S34: Determine whether or not the neutral judgment counter has started. If YES, proceed to the next step 335; if NO, proceed to 536, which will be described later. Proceed to.

S35: Start the neutral judgment counter.

536: Increment the "neutral" counter.

S37: Determine whether or not the neutral determination counter is at full count. If YES, proceed to the next step 538; if NO, proceed to S42, which will be described later.

338: 'Determine whether the count value of the "neutral" counter exceeds the reference value N. If YES, proceed to the next step 339; if NO, proceed to S40, which will be described later.

S39: Stop air supply and exhaust control.

S40: Clear the neutrality determination counter.

S41: Clear the "neutral" counter.

S42: Determine whether the delay timer counter has reached the full count, and if YES, proceed to the next step 541.
In the case of NO, the process returns to Sl through the processes of S45 and S846, which will be described later, and the same control is repeated.

S432 Clear the delay timer counter.

S44: After clearing both the "high" and "low" counters, return to the aforementioned Sl and repeat the control.

On the other hand, if the determination in S42 is NO, it is determined whether the delay timer counter has started or not.
5) If YES, the delay timer counter is incremented and then the process returns to Sl, and if NO, the process returns to Sl.
Return to step 1 and repeat the control.

Furthermore, based on the judgment results of good roads and bad roads, if data indicating neutral 1 or neutral 2 is input in Fig. 2, it is regarded as "neutral", so that, for example, when driving on a rough road, the vehicle height may be raised. By setting the vehicle height lower when driving on good roads, even better ride comfort can be achieved.

"Effects of the Invention" As is clear from the above description, according to the present invention, the number of neutral judgments as a condition for stopping vehicle height adjustment can be changed depending on whether the vehicle is traveling on a rough road or on a good road. This has the effect that a proper vehicle height can be maintained by adjusting the vehicle height just the right amount.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a block diagram showing the configuration of a control mechanism, Fig. 2 is a chart showing an example of vehicle height data from a vehicle height sensor, and Fig. 3 is a hydraulic system. Figure, 4th
The figure is a flowchart showing the control contents of the controller. l...Actuator, 2...Front solenoid valve, 3...Rear solenoid valve, 4...Air pressure source, 5...Exhaust solenoid valve, 6...controller, 7a.
7b...Vehicle height sensor.

Claims (1)

[Claims] A vehicle height adjustment device that adjusts a vehicle height by controlling a valve provided in a fluid system connecting an actuator and a pressure source to supply or discharge fluid to the actuator, at least high, neutral, low 3
It consists of a vehicle height sensor that detects the vehicle height in stages, and a controller that controls the fluid system based on the detection data of the vehicle height sensor.
a counting means for counting the number of times a low vehicle height is detected; a start determining means for starting vehicle height adjustment control when the counting means counts the number of times either high or low vehicle height is equal to or greater than a set value; stop determination means for stopping the vehicle height adjustment control when the counting means detects the neutral vehicle height more than a reference number of times within a predetermined time after once detecting the neutral vehicle height during the high adjustment control; A vehicle height adjustment device comprising: a reference number updating means for updating a reference number of times in the stop determination means according to the number of times a high or low vehicle height is detected.