1. A calibration method of an air suspension is characterized by comprising the following steps:

s1, measuring the distance H1 from the lower wing plate of the frame (100) to the ground or the distance H2 from the upper wing plate of the frame (100) to the ground; measuring a static radius R of the tyre (200);

s2, obtaining the actual height H of the suspension according to the formula (1) or the formula (2);

H＝H1-R (1)

H＝H2-H3-R (2)

wherein H3 is the width of the web of the frame (100);

and S3, calculating the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension, adjusting the actual height H of the suspension according to the difference delta, and calibrating the suspension (300).

2. The method for calibrating an air suspension according to claim 1, wherein in step S3, after the actual height H of the suspension is adjusted, the method returns to step S1 until the absolute value of the difference Δ does not exceed a set threshold.

3. The method for calibrating an air suspension according to claim 2, wherein the set threshold is 0-3 mm.

4. The calibration method of the air suspension according to claim 1, wherein the suspension calibration height is obtained by a vehicle identification number.

5. The calibration method of the air suspension according to claim 1, wherein the distance H1 from the lower wing plate of the vehicle frame (100) to the ground, the distance H2 from the upper wing plate of the vehicle frame (100) to the ground, and the static radius R are obtained by laser ranging in step S1.

6. The calibration method for an air suspension according to claim 4, wherein when the vehicle identification number includes a calibration pressure sensor, the calibration method further comprises step S4, the calibration pressure sensor is specifically:

-deflating the air bag of the suspension (300), -recording the lowest value of the pressure of the air bag and-calibrating the pressure sensor.

7. The calibration method of the air suspension according to claim 6, wherein the air bag deflation is specifically as follows:

and continuously deflating the air bag for multiple times at intervals, reading the numerical value of the pressure sensor after each deflation until the last three deflation pressures are equal, and taking the numerical value as the lowest value of the pressure of the air bag and calibrating the pressure sensor.

8. The method for calibrating an air suspension according to claim 1, wherein the static radius R of the tire (200) comprises the static radius of two rear or front tires, and the distance H1 from the lower wing plate or the distance H2 from the upper wing plate of the frame (100) to the ground comprises the distance from the lower wing plate or the upper wing plate of the two ends of the frame (100) to the ground in the rear or in the front.

9. An air suspension calibration device, characterized in that, the air suspension calibration device is used for realizing the air suspension calibration method of any one of claims 1-8, and the air suspension calibration device comprises:

the data acquisition device is used for measuring the distance H1 from the lower wing plate of the frame (100) to the ground, the distance H2 from the upper wing plate to the ground and the static radius R of the tire (200) and acquiring a vehicle identification number;

the industrial personal computer is electrically connected with the data acquisition device, receives the distance H1 from the lower wing plate of the frame (100) to the ground, the distance H2 from the upper wing plate to the ground, the static radius R of the tire (200) and the calibrated height H0 of the suspension, calculates the actual height H of the suspension, calculates the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension, and then sends out a suspension adjustment command;

and the vehicle controller is connected with the industrial personal computer through an OBD interface, receives the suspension adjusting instruction, and adjusts the actual height H of the suspension to the suspension calibration height H0 by controlling the inflation or deflation of the air bag so as to calibrate the suspension (300).

10. The calibration device for the air suspension as claimed in claim 9, wherein the vehicle controller is used for realizing the adjustment of the actual height of the suspension by controlling the air bag to be inflated or deflated for a plurality of consecutive intervals.

Background

In a vehicle equipped with an air suspension (hereinafter referred to as a suspension), since suspension heights required by different vehicles are different, and the calibration height ranges are different from 120 mm to 230 mm, the suspension heights need to be calibrated in advance.

The calibrated height refers to the distance from the upper wing plate or the lower wing plate of the vehicle frame to the wheel center, and the height calibration is carried out by an angle sensor arranged on the vehicle frame in the prior art. The angle sensor is connected with the axle by a cross rod and a vertical rod, and when the height of the suspension changes, the angle sensor correspondingly changes the angle, so that after the angle sensor is re-installed each time, the angle sensor is required to record an initial angle value to correspond to the current height, namely calibration. After calibration is completed, the air suspension controller can convert the corresponding actual height value of the suspension according to the actual angle value and the parameters of the cross rod. For example, a nominal normal vehicle suspension height of 200 mm is required. The value of the current angle sensor is calibrated only when the height of the vehicle suspension is adjusted to 200 mm.

Because the suspension height of the truck cannot be directly measured, a traditional manual calibration method cannot simultaneously measure a plurality of points by using tools such as a tape measure and the like, actual parameters of different tires of different vehicle types are different, and the tire parameters are generally calibrated by selecting empirical values, so that the calibration precision is insufficient.

Disclosure of Invention

The invention aims to provide a calibration method and a calibration device for an air suspension so as to solve the problems that the height of the air suspension of a truck cannot be directly measured and the calibration precision of a height sensor is insufficient.

In order to achieve the purpose, the invention adopts the following technical scheme:

a calibration method of an air suspension comprises the following steps:

s1, measuring the distance H1 from the lower wing plate of the frame to the ground or the distance H2 from the upper wing plate of the frame to the ground; measuring the static radius R of the tire;

s2, obtaining the actual height H of the suspension according to the formula (1) or the formula (2);

H＝H1-R (1)

H＝H2-H3-R (2)

wherein H3 is the frame web width;

and S3, calculating the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension, adjusting the actual height of the suspension according to the difference delta, and calibrating the suspension.

Alternatively, in step S3, after the suspension actual height H is adjusted, the process returns to step S1 until the absolute value of the difference Δ does not exceed a set threshold.

Optionally, the set threshold is 0-3 mm.

Optionally, the suspension nominal height is obtained through a vehicle identification number.

Optionally, in step S1, the distance H1 from the lower wing plate of the frame to the ground, the distance H2 from the upper wing plate to the ground, and the static radius R are obtained by laser ranging.

Optionally, when the vehicle identification number includes a calibrated pressure sensor, the method includes step S4, where calibrating the pressure sensor, specifically:

and deflating an air bag of the suspension, recording the lowest value of the pressure of the air bag and calibrating the pressure sensor.

Optionally, the balloon deflation is specifically:

and continuously deflating the air bag for multiple times at intervals, reading the numerical value of the pressure sensor after each deflation until the last three deflation pressures are equal, and taking the numerical value as the lowest value of the pressure of the air bag and calibrating the pressure sensor.

Optionally, the static radius R of the tire comprises the static radius of two rear or front tires, the distance H1 from the lower wing plate or the distance H2 from the upper wing plate to the ground of the frame, the distance H from the lower wing plate or the distance H from the upper wing plate to the ground of the two ends of the frame behind or in front of the frame.

The invention also provides a calibration device of the air suspension for realizing the calibration method of the air suspension, which comprises the following steps:

the data acquisition device is used for measuring the distance H1 from the lower wing plate of the frame to the ground, the distance H2 from the upper wing plate to the ground and the static radius R of the tire and acquiring a vehicle identification number;

the industrial personal computer is electrically connected with the data acquisition device, receives the distance H1 from the lower wing plate of the frame to the ground, the distance H2 from the upper wing plate to the ground, the static radius R of the tire and the calibrated height H0 of the suspension, calculates the actual height H of the suspension, calculates the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension, and then sends out a suspension adjustment instruction;

vehicle controller through OBD interface connection the industrial computer, and receive suspension adjustment command aerifys or deflates through the control gasbag, will suspension actual height H adjusts to suspension demarcation height H0 calibrates the suspension.

Optionally, the vehicle controller effects adjustment of the actual height of the suspension by controlling the air bag to inflate or deflate at successive intervals.

The invention has the beneficial effects that:

according to the calibration method of the air suspension, the actual height of the vehicle air suspension is indirectly obtained through a calculation formula by measuring the distance between the upper wing plate or the lower wing plate of the vehicle frame and the ground and the static radius of the tire, so that the actual height of the suspension can be conveniently adjusted to the calibrated height by a vehicle, the problem that the air suspension of a truck cannot be directly measured is solved, and the high-precision calibration of the height sensor on the vehicle suspension, namely the vehicle frame is realized.

According to the calibration device for the air suspension, the distance from the upper wing plate or the lower wing plate of the frame to the ground and the static radius of the tire are acquired through the data acquisition device, the actual height of the suspension is calculated in the industrial personal computer, a suspension adjustment instruction is sent to the vehicle controller according to the difference value between the actual height of the suspension and the calibrated height of the suspension, the actual height of the suspension is adjusted through controlling the inflation or deflation of the air bag by the vehicle controller, the suspension is calibrated, the problem that the suspension of a truck cannot be directly measured is solved, and the high-precision calibration of the suspension of the vehicle is realized.

Drawings

FIG. 1 is a flow chart of a method of calibrating an air suspension of the present invention;

FIG. 2 is a schematic illustration of the position of the truck rear air suspension in an embodiment of the invention;

FIG. 3 is a schematic illustration of the distance between the upper and lower wing plates of the frame and the ground and the static radius of the tire in an embodiment of the present invention;

FIG. 4 is a flow chart of a method for calibrating an air suspension according to a preferred embodiment of the present invention;

FIG. 5 is a schematic view showing the measured positions of the two side frames and the tires in the calibration method of the air suspension according to the present invention.

In the figure:

100. a frame; 200. a tire; 300. a suspension; 1. a height sensor.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning. The term "plurality" is to be understood as more than two.

The following describes the calibration method of the air suspension provided by the present invention in detail with reference to fig. 1 to 3.

As shown in the flowchart of fig. 1, a calibration method of an air suspension specifically includes the following steps:

s1, measuring the distance H1 from the lower wing plate of the frame 100 to the ground or the distance H2 from the upper wing plate to the ground; measuring the static radius R of the tyre 200;

s2, obtaining the actual height H of the suspension according to the formula (1) or the formula (2);

H＝H1-R (1)

H＝H2-H3-R (2)

wherein H3 is the frame 100 web width;

and S3, calculating the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension, adjusting the actual height H of the suspension according to the difference delta, and calibrating the suspension 300.

As shown in fig. 2 and 3, the calibration method of the air suspension 300 (simply suspension 300) includes the calibration of the height sensor 1 and the calibration of the pressure sensor (if present). Since the actual suspension height H of the truck cannot be directly measured, the present invention obtains the actual suspension height H indirectly. In the above formula (2), H3 is the web width of the frame, and the web width H3 of the frame can be obtained by a system or directly measured in a whole factory, but the static radius R of the tire 200 will be slightly different according to the conditions of tires of different brands, hubs of different brands and materials and actual tire pressures, and different vehicles to be installed, so how to accurately calibrate the suspension 300 of the vehicle needs to accurately measure the distance from the upper wing plate (lower wing plate) of the frame 100 to the ground and the static radius of the actual tire 200.

It can be understood that the calibration method of the air suspension according to the present invention indirectly obtains the actual height of the vehicle suspension through a calculation formula by measuring the distance from the upper wing plate or the lower wing plate of the vehicle frame 100 to the ground and the static radius of the tire 200, so that the vehicle can adjust the actual height H of the suspension to the calibrated height H0 of the suspension, thereby solving the problem that the truck suspension 300 cannot be directly measured and realizing the high-precision calibration of the vehicle suspension 300, i.e., the height sensor 1 on the vehicle frame 100.

Alternatively, in step S3, after the suspension actual height H is adjusted, the process returns to step S1 until the absolute value of the difference Δ does not exceed the set threshold.

As shown in the flow chart of fig. 4, the actual height H of the suspension of the vehicle may be higher or lower than the nominal height H0 of the suspension, so that the difference Δ has a positive or negative value, and needs to be treated differently to avoid an adjustment direction error. In the actual operation process, since the process of adjusting the actual height H of the suspension is realized by inflating and deflating the airbag, after the adjustment, the actual height H of the suspension needs to be measured again and calculated to perform calibration or readjustment, so as to further improve the calibration accuracy of the suspension 300. As shown in fig. 4, after the actual suspension height H is adjusted, if the absolute value of the difference Δ is greater than the set threshold, the actual suspension height H is continuously adjusted, otherwise, the suspension is calibrated directly according to the actual suspension height H or the calibrated suspension height H0.

Optionally, the threshold is set to 0-3 mm.

In the embodiment, for the height calibration of the truck suspension 300, the high-precision requirement can be met by selecting the set threshold value to be 0-3 mm. In practice, the setting threshold may be set according to actual needs. Generally, the accuracy is best when the difference Δ is 0.

Optionally, the suspension nominal height is obtained by a vehicle identification number.

The vehicle identification number, also called frame number and VIN number, includes serial codes of a vehicle body and a chassis, etc., and can obtain calibration parameters of the vehicle, such as height calibration and pressure calibration, etc. in this embodiment, the calibration of the height sensor 1 on the frame 100 and the calibration of the pressure sensor are involved, and the pressure sensor is not provided on all vehicles, so that the height calibration is used as the suspension 300, and the pressure sensor calibration is an optional calibration. Specifically, the suspension calibration height H0 and whether the pressure sensor needs to be calibrated or not can be obtained from the system in a mode that the VIN code is scanned by the scanning gun, and the calibration height and the calibration requirement can also be manually input.

Optionally, in step S1, the distance H1 from the lower wing plate of the frame 100 to the ground, the distance H2 from the upper wing plate to the ground, and the static radius R are obtained by laser ranging.

The laser ranging method includes measuring the distance by using a laser ranging sensor, and optionally, measuring by using a special measuring tool. The static radius R of the tire 200 is the distance between the wheel core of the tire 200 and the ground, and is affected by factors such as tire pressure and vehicle body weight, and the measured value will be different from the standard value, so that the measured value needs to be measured during calibration to obtain an accurate value, which is convenient for improving the calibration precision.

Optionally, when the vehicle identification number includes a calibrated pressure sensor, the calibration method of the air suspension further includes step S4 of calibrating the pressure sensor.

In this embodiment, the calibration of the air suspension 300 includes the calibration of the height sensor 1 and the calibration of the pressure sensor, and the calibration of the pressure sensor is continued after the height sensor 1 is calibrated according to whether the pressure sensor is configured for the vehicle.

Optionally, step S4 specifically includes:

the air bag of the suspension 300 is deflated, the lowest value of the air bag pressure is recorded and the pressure sensor is calibrated.

In this embodiment, after the suspension 300 is installed, the actual height H of the suspension is adjusted through the inflation or deflation process of the air bag, in this embodiment, when calibrating the pressure sensor, the air bag needs to be completely deflated, and the pressure lowest value after the air bag is completely deflated is recorded to calibrate the pressure sensor.

Optionally, the balloon deflation is specifically:

the air bag is deflated continuously for a plurality of times at intervals, the numerical value of the pressure sensor is read after each deflation until the last three deflation pressures are equal, and the numerical value is used as the lowest value of the air bag pressure and the pressure sensor is calibrated.

In the embodiment, the air bag is continuously deflated for multiple times, pressure reading is carried out at fixed time intervals twice, if pressure values are acquired at intervals of 500s, after deflation for multiple times, continuous three times of pressure are not reduced, namely, when the pressure values of the readings of the three times are equal, any air bag is completely deflated, and the pressure value at the moment is used as the lowest pressure value to calibrate the pressure sensor.

Alternatively, the static radius R of tire 200 includes the static radius of two rear or front tires, the lower wing-to-ground distance H1 or the upper wing-to-ground distance H2 of frame 100, including the lower wing or upper wing-to-ground distance at both ends of frame 100 rearward or forward.

In the embodiment shown in fig. 5, taking the rear two tires 200 as an example, the web width of the vehicle frame 100 is H3, the static radii R1 and R2 of the two tires 200 are measured, the distances H21 and H22 between the upper wing plates at the two ends of the rear vehicle frame 100 and the ground are measured, and the actual suspension height H' and the actual suspension height H ″ are calculated as follows by using the formula (1):

H’＝H21-H3-R1 (3)

H”＝H22-H3-R2 (4)

the fact that the actual heights of the suspensions at the two ends of the suspension 300 are adjusted respectively means that the calibrated height H0 is reached, and the heights of the two sides are not consistent, so that the heights of the air suspensions 300 at the two sides can be independently adjusted, and the air suspensions 300 at the two sides are kept horizontal at the same height. It can be understood that the calibration of the front suspension 300 can also adopt a mode of simultaneous measurement and adjustment on two sides, and the static radii of the four tires 200 and the distance between the upper wing plate or the lower wing plate of the frame 100 and the ground are measured simultaneously, so that the four suspensions 300 can be adjusted respectively, and the accurate calibration of the suspensions 300 is realized.

The invention also provides a calibration device of the air suspension for realizing the calibration method of the air suspension, which comprises the following steps:

the data acquisition device is used for measuring the distance H1 from the lower wing plate of the frame 100 to the ground, the distance H2 from the upper wing plate to the ground and the static radius R of the tire 200 and acquiring a vehicle identification number;

the industrial personal computer is electrically connected with the data acquisition device, receives the distance H1 from the lower wing plate of the frame 100 to the ground, the distance H2 from the upper wing plate to the ground, the static radius R of the tire 200 and the suspension calibrated height H0, calculates the actual height H of the suspension, calculates the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension, and then sends a suspension adjustment instruction;

and the vehicle controller is connected with the industrial personal computer through an OBD interface, receives a suspension adjusting instruction, and adjusts the actual height H of the suspension to the suspension calibration height H0 by controlling the inflation or deflation of the air bag so as to calibrate the height sensor.

The data acquisition device generally selects a laser ranging sensor to improve measurement accuracy, the static radius of the tire 200 can be manually measured, but in order to avoid considering errors, a special measurement tool can be generally selected for measurement, and the sensor can directly acquire data and transmit the data, so that the most preferable measurement mode is still provided. The vehicle identification number is scanned by an electronic gun, and electronic data is directly obtained and transmitted.

The industrial personal computer is electrically connected with the data acquisition device, can directly acquire data information acquired and transmitted by the data acquisition device, and processes the data, including preprocessing, and according to a prestored calculation formula (1) and a prestored calculation formula (2), calculates the data to obtain the actual height H of the suspension, the difference value delta and other parameters. It should be noted that, when the difference Δ is not zero or exceeds a set threshold, the industrial personal computer sends a suspension adjustment command. When the actual suspension height H is the same as the suspension nominal height H0, the suspension 300 can be calibrated directly according to the actual suspension height H or the suspension nominal height H0.

The calibration device of the air suspension solves the problem that the truck suspension 300 cannot be directly measured, and realizes high-precision calibration of the vehicle suspension 300.

Optionally, the vehicle controller effects suspension 00 height adjustment by controlling the air bag to inflate or deflate at successive intervals.

When the difference delta between the actual height H of the suspension and the calibrated height H0 of the suspension is larger than 40mm, the industrial control machine continuously sends suspension adjusting instructions for multiple times to a vehicle controller to adjust the actual height H of the suspension; when the difference value delta is smaller than 30mm, every time the air bag is deflated or inflated, the actual height of the suspension and the calibrated height H0 of the suspension need to be compared again, the difference value delta between the actual height of the suspension and the calibrated height H0 of the suspension is compared with a set threshold value, and the suspension adjustment command is stopped sending until the difference value delta is within the range allowed by the set threshold value.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.