A pressure compensation method and load calculation method for a commercial vehicle based on an electronically controlled air suspension

Abstract

The present application relates to the field of vehicle load calculation method, disclose a kind of based on electric control air suspension commercial vehicle pressure compensation method and load calculation method, comprising the following steps: step one, the relationship between the height of the body and pressure is calibrated;Step two, the relationship between the pressure correction coefficient, i.e. the amount of pressure change and the amount of height change is calibrated;Step three, the actual height and actual pressure of the current vehicle are obtained;Step four, the calibrated height under the pressure of the vehicle is obtained according to the relationship between the height of the body and pressure;Step five, the difference between the actual height and the calibrated height is calculated;Step six, the pressure that needs to be compensated is calculated through the pressure correction coefficient of step two and the height difference in step five;Step seven, the compensated pressure is input into the system for pressure compensation.The pressure value and load value calculated by this scheme are more accurate, and the error condition of load output change after the height of the body is adjusted is avoided.

Description

Technical Field

[0001] This invention relates to the field of vehicle load calculation methods, and mainly to a commercial vehicle pressure compensation method and control method based on electronically controlled air suspension, as well as an electronic parking assembly. Background Technology

[0002] Existing air suspension systems only accurately calculate loads when the vehicle height is constant, as illustrated in Chinese patent application CN113320348A, which describes an electronically controlled air suspension system and load identification method for commercial vehicles. However, when the vehicle height changes (e.g., the airbag pressure changes due to variations in the airbag's contact area), the theoretically calculated load changes, while the actual load remains the same. This invention addresses this by using an algorithm that corrects the load based on height changes to ensure the accuracy of load calculations at different vehicle heights. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a pressure compensation method and load calculation method for commercial vehicles based on electronically controlled air suspension.

[0004] A pressure compensation method for commercial vehicles based on electronically controlled air suspension includes the following steps:

[0005] Step 1: Calibrate the relationship between vehicle height and pressure;

[0006] Step 2: Calibrate the pressure correction factor, i.e., the relationship between pressure change and height change;

[0007] Step 3: Obtain the current actual height and actual pressure of the vehicle;

[0008] Step 4: Based on the relationship between the calibrated vehicle height and pressure, obtain the calibrated height of the vehicle under that pressure;

[0009] Step 5: Calculate the difference between the actual height and the calibrated height;

[0010] Step 6: Calculate the pressure that needs to be compensated using the pressure correction factor from Step 2 and the height difference from Step 5;

[0011] Step 7: Input the compensation pressure into the system for pressure compensation.

[0012] As a preferred option, the pressure correction coefficient in step two is obtained through calibration, wherein the calculated pressure is based on the no-load pressure.

[0013]

[0014] Where CF is the compensation coefficient, P x To calibrate the pressure at the current altitude, P0 is the pressure under no-load conditions, hx The calibration height is h0, which is the vehicle height when unloaded.

[0015] Preferably, the compensation pressure calculation method in step six is ​​as follows: by obtaining the calibrated vehicle height h under the current pressure condition through the calibrated relationship between vehicle height and pressure. x Then calculate the actual height h of the vehicle body. 实 With the specified height h x The difference between them: Δh = h x -h 实 ;

[0016] PH_offset = Δh * CF * P0

[0017] In the formula, PH_offset is the compensation pressure, CF is the compensation coefficient, and P0 is the no-load pressure.

[0018] As a preferred option, the calibrated relationship between vehicle body height and pressure is as follows:

[0019] k1 = h x / p x

[0020] In the formula, k1 is the coefficient relating vehicle height and pressure, h x To calibrate the pressure, p x For calibration pressure.

[0021] As a preferred option, the calibration of the pressure correction coefficient is performed in two ways: one coefficient is used to calculate the calibration height and pressure when the pressure is higher than that under no-load conditions, and the other coefficient is used to calibrate the vehicle height and pressure when the pressure is lower than that under no-load conditions.

[0022] Preferably, the vehicle height is obtained through a height sensor, and the vehicle pressure is obtained through a pressure sensor that collects the pressure inside the airbag.

[0023] An axle load identification algorithm for commercial vehicles based on electronically controlled air suspension includes the following steps:

[0024] Step 1: Calibrate the relationship k1 between vehicle height and pressure;

[0025] Step 2: Calibrate the pressure correction factor, i.e., the relationship between pressure change and height change;

[0026] Step 3: Calibrate the relationship coefficient KPW between vehicle pressure and load;

[0027] Step 4: Obtain the current vehicle's actual height and actual pressure;

[0028] Step 5: Obtain the calibrated height of the vehicle under this pressure based on the coefficient k1, which is the relationship between the calibrated vehicle height and the pressure.

[0029] Step 6: Calculate the difference between the actual height and the calibrated height;

[0030] Step 7: Calculate the pressure that needs to be compensated using the pressure correction factor from Step 2 and the height difference from Step 6;

[0031] Step 8: Compensate for the actual pressure to obtain the compensated pressure;

[0032] Step 9: Calculate the current vehicle load based on the calibrated relationship between vehicle pressure and load, and the compensated pressure.

[0033] As a preferred method, the calibration method for the relationship between vehicle pressure and load in step three is as follows:

[0034] Obtain the vehicle's unloaded load G0 and unloaded pressure P0; obtain the vehicle's load G when it is half-loaded. 半 Half-load pressure P 半 ; Obtain the load G of the vehicle under full load conditions 满 Full load pressure P 满 The relationship coefficient between load and pressure, KPW, is:

[0035]

[0036] As a preferred option, the pressure correction coefficient in step two is obtained through calibration, wherein the calculated pressure is based on the no-load pressure.

[0037]

[0038] Where CF is the compensation coefficient, Px is the pressure at the current calibrated height, P0 is the pressure when unloaded, hx is the calibrated height, and h0 is the vehicle height when unloaded.

[0039] Preferably, the compensation pressure calculation method in step seven is as follows: by obtaining the calibrated vehicle height h under the current pressure condition through the calibrated relationship between vehicle height and pressure. x Then calculate the actual height h of the vehicle body. 实 With the specified height h x The difference between them: Δh = h x -h 实 ;

[0040] PH_offset = Δh * CF * P0

[0041] In the formula, PH_offset is the compensation pressure, CF is the compensation coefficient, and P0 is the no-load pressure;

[0042] The formula for calculating the load on the vehicle body is as follows:

[0043] G = (P 实 +PH_offset)×KPW

[0044] Where G is the calculated output load, P 实 The current actual pressure is PH_offset, the compensation pressure is PH_offset, and KPW is the coefficient between pressure and load. The vehicle pressure is obtained through a pressure sensor, and the vehicle height is obtained through a vehicle height sensor.

[0045] Compared with existing technologies, this solution has the following advantages: the algorithm for correcting pressure and load based on height changes ensures the accuracy of theoretically calculated loads at different vehicle heights. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to embodiments.

[0047] Example 1

[0048] A pressure compensation method for commercial vehicles based on electronically controlled air suspension includes the following steps:

[0049] Step 1: Calibrate the relationship between vehicle height and pressure;

[0050] Step 2: Calibrate the pressure correction factor, i.e., the relationship between pressure change and height change;

[0051] Step 3: Obtain the current actual height and actual pressure of the vehicle;

[0052] Step 4: Based on the relationship between the calibrated vehicle height and pressure, obtain the calibrated height of the vehicle under that pressure;

[0053] Step 5: Calculate the difference between the actual height and the calibrated height;

[0054] Step 6: Calculate the pressure that needs to be compensated using the pressure correction factor from Step 2 and the height difference from Step 5;

[0055] Step 7: Input the compensation pressure into the system for pressure compensation.

[0056] During the calibration process, the vehicle body pressure is obtained through pressure sensors installed inside the airbags. Since the airbag sensors obtain the pressure of a single airbag, the total vehicle pressure is obtained by multiplying the value obtained by the pressure sensors by the number of airbags. This will not be elaborated further here, as those skilled in the art will understand. Therefore, it can still be understood that the pressure is obtained through pressure sensors.

[0057] The pressure correction factor is calibrated based on the pressure under no-load conditions. The vehicle pressure is adjusted under no-load conditions, and the adjusted height is obtained to establish the relationship between pressure changes and height changes under different calibration conditions. The correction factor is a percentage relative to the initial pressure value, so the denominator is divided by the no-load pressure during calculation.

[0058] In this embodiment, the pressure correction coefficient in step two is obtained through calibration, wherein the calculated pressure is based on the no-load pressure.

[0059]

[0060] Where CF is the compensation coefficient, P x To calibrate the pressure at the current altitude, P0 is the pressure under no-load conditions, h x The calibration height is h0, which is the vehicle height when unloaded.

[0061] The compensation pressure calculation method in step six is ​​as follows: by obtaining the calibrated vehicle height h under the current pressure condition through the calibrated relationship between vehicle height and pressure. x The calibration height here refers to the theoretical height of the system. Then, the actual height h of the actual vehicle body is calculated. 实 With the specified height h x The difference between them: Δh = h x -h 实 ;

[0062] PH_offset = Δh * CF * P0

[0063] In the formula, PH_offset is the compensation pressure, CF is the compensation coefficient, and P0 is the no-load pressure. As can be seen from the formula, the height change value can be positive or negative, so the compensation pressure can be either a decrease or an increase. Specifically, when the actual height is greater than the rated height, the compensation pressure is negative, which is to offset the increase in air pressure caused by the vehicle height increase; conversely, when the actual vehicle height is lower than the rated vehicle height, compensation is needed to offset the decrease in air pressure caused by the vehicle height decrease.

[0064] The relationship between the calibrated vehicle body height and pressure is as follows:

[0065] k1 = h x / p x

[0066] In the formula, k1 is the coefficient relating vehicle height and pressure, h x To calibrate the pressure, p x This is used to calibrate the pressure; the formula can be used to obtain the value of the calibration height under the current pressure, thus providing parameters for compensating the pressure.

[0067] The vehicle height is obtained through a height sensor, and the vehicle pressure is obtained through a pressure sensor that collects the pressure inside the airbag.

[0068] Example 2

[0069] Based on Example 1, this example provides a commercial vehicle axle load identification algorithm based on electronically controlled air suspension, including the following steps:

[0070] Step 1: Calibrate the relationship k1 between vehicle height and pressure;

[0071] Step 2: Calibrate the pressure correction factor, i.e., the relationship between pressure change and height change;

[0072] Step 3: Calibrate the relationship coefficient KPW between vehicle pressure and load;

[0073] Step 4: Obtain the current vehicle's actual height and actual pressure;

[0074] Step 5: Obtain the calibrated height of the vehicle under this pressure based on the coefficient k1, which is the relationship between the calibrated vehicle height and the pressure.

[0075] Step 6: Calculate the difference between the actual height and the calibrated height;

[0076] Step 7: Calculate the pressure that needs to be compensated using the pressure correction factor from Step 2 and the height difference from Step 6;

[0077] Step 8: Compensate for the actual pressure to obtain the compensated pressure;

[0078] Step 9: Calculate the current vehicle load based on the calibrated relationship between vehicle pressure and load, and the compensated pressure.

[0079] As a preferred method, the calibration method for the relationship between vehicle pressure and load in step three is as follows:

[0080] Obtain the vehicle's unloaded load G0 and unloaded pressure P0; obtain the vehicle's load G when it is half-loaded. 半 Half-load pressure P 半 ; Obtain the load G of the vehicle under full load conditions 满 Full load pressure P 满 The relationship coefficient between load and pressure, KPW, is:

[0081] Of course, other methods can also be used to calibrate the relationship between load and pressure. The half-load, no-load, and full-load conditions can also be calibrated using other working conditions.

[0082] The pressure correction coefficient in step two is obtained through calibration, with the calculated pressure based on the no-load pressure.

[0083]

[0084] Where CF is the compensation coefficient, Px is the pressure at the current calibrated height, P0 is the pressure when unloaded, hx is the calibrated height, and h0 is the vehicle height when unloaded.

[0085] The compensation pressure calculation method in step seven is as follows: by obtaining the calibrated vehicle height h under the current pressure condition through the relationship between the calibrated vehicle height and the pressure. x Then calculate the actual height h of the vehicle body. 实 With the specified height h x The difference between them: Δh = h x -h 实 ;

[0086] PH_offset = Δh * CF * P0

[0087] In the formula, PH_offset is the compensation pressure, CF is the compensation coefficient, and P0 is the no-load pressure;

[0088] The formula for calculating the load on the vehicle body is as follows:

[0089] G = (P 实 +PH_offset)×KPW

[0090] Where G is the calculated output load, P 实 The current actual pressure is PH_offset, the compensation pressure is PH_offset, and KPW is the coefficient between pressure and load. The vehicle pressure is obtained through a pressure sensor, and the vehicle height is obtained through a vehicle height sensor.

[0091] This solution uses algorithms to correct pressure and load based on height changes, ensuring the accuracy of theoretically calculated loads at different vehicle heights.

[0092] Example 3

[0093] The vehicle integrates the aforementioned pressure compensation algorithm and load calculation algorithm.

Claims

1. A pressure compensation method for commercial vehicles based on electronically controlled air suspension, characterized in that: Includes the following steps: Step 1: Calibrate the relationship between vehicle height and pressure; Step 2: Calibrate the pressure correction factor, i.e., the relationship between pressure change and height change; Step 3: Obtain the current actual height and actual pressure of the vehicle; Step 4: Based on the relationship between the calibrated vehicle height and pressure, obtain the calibrated height of the vehicle under that pressure; Step 5: Calculate the difference between the actual height and the calibrated height; Step 6: Calculate the pressure that needs to be compensated using the pressure correction factor from Step 2 and the height difference from Step 5; Step 7: Input the compensation pressure into the system for pressure compensation; The pressure correction factor in step two is obtained through calibration, where the calculated pressure is based on the no-load pressure. Where CF is the compensation coefficient, P x To calibrate the pressure at the current altitude, P0 is the pressure under no-load conditions, h x The calibration height is h0, which is the vehicle height when unloaded. The compensation pressure calculation method in step six is ​​as follows: Based on the calibrated relationship between vehicle height and pressure, obtain the calibrated vehicle height h corresponding to the current pressure condition. x Then calculate the actual height of the vehicle body. With the specified height h x The difference between them: ; In the formula, To compensate for the pressure, CF is the compensation coefficient, and P0 is the no-load pressure; The calibrated relationship between vehicle body height and pressure is as follows: In the formula, k1 is the coefficient relating vehicle height and pressure, h x To calibrate the height, p x For calibration pressure.

2. The commercial vehicle pressure compensation method based on electronically controlled air suspension according to claim 1, characterized in that: The pressure sensor obtains the pressure value of a single airbag. The pressure value of the vehicle body is equal to the product of the pressure value of a single airbag and the number of airbags.

3. The commercial vehicle pressure compensation method based on electronically controlled air suspension according to claim 1, characterized in that: Vehicle height is obtained through a height sensor, and vehicle pressure is obtained through a pressure sensor that collects the pressure inside the airbag.

4. A commercial vehicle axle load identification algorithm based on electronically controlled air suspension, characterized in that: Includes the following steps: Step 1: Calibrate the relationship k1 between vehicle height and pressure; Step 2: Calibrate the pressure correction factor, i.e., the relationship between pressure change and height change; Step 3: Calibrate the relationship coefficient KPW between vehicle pressure and load; Step 4: Obtain the current vehicle's actual height and actual pressure; Step 5: Obtain the calibrated height of the vehicle under this pressure based on the coefficient k1, which is the relationship between the calibrated vehicle height and the pressure. Step 6: Calculate the difference between the actual height and the calibrated height; Step 7: Calculate the pressure that needs to be compensated using the pressure correction factor from Step 2 and the height difference from Step 6; Step 8: Compensate for the actual pressure to obtain the compensated pressure; Step 9: Calculate the current vehicle load based on the calibrated relationship between vehicle pressure and load, and the compensated pressure. The calibration method for the relationship between vehicle pressure and load in step three is as follows: Obtain the vehicle's unloaded load G0 and unloaded pressure P0; obtain the vehicle's load G when it is half-loaded. 半 Half-load pressure P 半 ; Obtain the load G of the vehicle under full load conditions 满 Full load pressure P 满 The relationship coefficient between load and pressure, KPW, is: ； The pressure correction factor in step two is obtained through calibration, where the calculated pressure is based on the no-load pressure. Where CF is the compensation coefficient, Px is the pressure at the current calibrated height, P0 is the pressure under no-load conditions, hx is the calibrated height, and h0 is the vehicle height under no-load conditions; the compensation pressure calculation method in step seven is as follows: by obtaining the calibrated vehicle height h corresponding to the current pressure condition through the relationship between the calibrated vehicle height and pressure. x Then calculate the actual height of the vehicle body. With the specified height h x The difference between them: ; In the formula, To compensate for the pressure, CF is the compensation coefficient, and P0 is the no-load pressure; The formula for calculating the load on the vehicle body is as follows: Where G is the calculated output load, P 实 For the actual pressure currently being acquired, To compensate for pressure, KPW is the coefficient between pressure and load. The vehicle's pressure is obtained through a pressure sensor, and the vehicle's height is obtained through a vehicle height sensor.

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