Method for rapidly determining whole vehicle braking force distribution ratio range

Abstract

The invention discloses a method for rapidly determining a whole vehicle braking force distribution ratio range. The method comprises the following steps that (1) parameters of a vehicle are obtained; 2) calculating an upper limit and a lower limit of a braking force distribution coefficient based on the parameters; (3) whether the braking force distribution ratio range meets the requirements of laws and regulations or not is judged; (4) if the range of the braking force distribution ratio meets the requirements of laws and regulations, the range of the braking force distribution coefficient is determined from the lower limit to the upper limit in the step (2); and if the braking force distribution ratio range does not meet the requirements of laws and regulations, a braking system is adjusted. According to the method for rapidly determining the whole vehicle braking force distribution ratio range, an explicit expression mathematical model of the whole vehicle braking force distribution ratio is adopted, the value range of the braking force distribution ratio is calculated in the forward direction, a traditional reverse assignment method close to regulations is replaced, the braking force distribution range can be conveniently and rapidly determined according to whole vehicle parameters, and the whole vehicle braking force distribution ratio range can be rapidly determined. And unnecessary manpower waste is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of commercial vehicle braking systems, and in particular to a method for quickly determining a braking force distribution ratio range of a whole vehicle. Background Art

[0002] The current standards for commercial vehicle and trailer braking systems have clear requirements for the distribution of braking force, but the required value for the distribution of braking force is not given directly, that is, the distribution value of braking force is not an explicit number of the given parameters.

[0003] At present, the main method for determining whether the braking force distribution ratio of the whole vehicle meets the standard requirements is the reverse adaptation drawing method, that is, first a hypothetical distribution ratio is given, and then the braking intensity is taken as 8 values ​​of 0.1, 0.2, ..., 0.8 respectively, and finally 8 result values ​​are calculated for the front axle adhesion coefficient and the rear axle adhesion coefficient respectively, and the 8 result values ​​are formed into a curve using a function to determine whether the curve is within the limit required by the standard. If it is not within the limit, the distribution ratio β needs to be re-optimized until the curve is within the limit, such as Figures 1 to 3 This method has a large amount of calculation and is relatively complicated to operate. It is only used to determine whether the current braking force distribution ratio of the vehicle meets the regulatory requirements, but does not provide a method for determining the appropriate range of the braking force distribution ratio. Summary of the invention

[0004] In order to overcome the deficiencies of the above-mentioned technology, the purpose of the present invention is to provide a method for quickly determining the braking force distribution ratio range of a whole vehicle, so as to make up for the lack of a method for calculating the braking force distribution ratio range.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A method for quickly determining the range of the braking force distribution ratio of a whole vehicle is special in that it includes the following steps:

[0007] 1) Obtain vehicle parameters;

[0008] 2) calculating the upper limit and the lower limit of the braking force distribution coefficient based on the parameters;

[0009] 3) Determine whether the braking force distribution ratio range meets regulatory requirements;

[0010] 4) If the braking force distribution ratio range meets the regulatory requirements, the range of the braking force distribution coefficient is determined to be from the lower limit to the upper limit in step 2); if the braking force distribution ratio range does not meet the regulatory requirements, adjust the braking system.

[0011] As a preferred solution, the vehicle is a two-axle vehicle other than M1 and N1, including a front axle and a rear axle, wherein the front axle is used for steering and the rear axle is used for driving.

[0012] As a preferred solution, in step 1), the parameters include center of mass height, wheelbase, distance from the front axle to the center of mass, distance from the rear axle to the center of mass, and braking strength.

[0013] As a preferred embodiment, in step 2), the upper limit is calculated by the following formula:

[0014]

[0015] Where: β is the braking force distribution coefficient; B max The upper limit of the braking force distribution coefficient; ε=h / E, 0<ε<1, h is the height of the center of mass, E is the wheelbase; Z is the braking strength; λ=E1 / E, E2 / E=1-λ, 0<λ<1, E1 and E2 are the horizontal distances from the center of mass of the vehicle to the front axle and the rear axle respectively. The upper limit of the braking force distribution coefficient can be calculated by the height of the center of mass h, the wheelbase E between the front axle and the rear axle, the horizontal distance E1 from the front axle to the center of mass, the horizontal distance E2 from the rear axle to the center of mass, and the braking strength Z. The calculation amount is small and the calculation process is simple. No calculation is required for other cases not specified in the regulations.

[0016] As a preferred embodiment, in step 2), the lower limit is calculated by the following formula:

[0017]

[0018] The lower limit of the braking force distribution coefficient can be calculated through the center of mass height h, the wheelbase E between the front axle and the rear axle, the horizontal distance E1 from the front axle to the center of mass, the horizontal distance E2 from the rear axle to the center of mass, and the braking intensity Z. The calculation amount is small and the calculation process is simple.

[0019] As a preferred solution, in step 3), the determination method includes setting the upper limit B of the braking force distribution coefficient calculated in step 2) to max and lower limit B min For comparison, if B min ≤B max , then the braking force distribution ratio range meets the regulatory requirements, and the braking force distribution coefficient range is [B min , B max ]; if B min >B max , the braking force distribution ratio range does not meet regulatory requirements.

[0020] As a preferred solution, adjusting the braking system in step 4) includes adding a pressure regulating device to the braking system; after adding the pressure regulating device, repeating steps 1) to 4) to recalculate the braking force distribution ratio range that meets regulatory requirements.

[0021] A system for quickly determining the range of the braking force distribution ratio of a whole vehicle is used to implement the above method for quickly determining the range of the braking force distribution ratio of a whole vehicle, and its special features include:

[0022] A data storage module, used for storing parameter data of the vehicle;

[0023] A data processing module, used for calculating the upper limit and the lower limit of the braking force distribution coefficient;

[0024] A judgment module, used to judge whether the braking force distribution ratio range meets regulatory requirements;

[0025] The output module is used to output the upper limit and lower limit of the braking force distribution coefficient calculated by the data processing module and the judgment result of the judgment module.

[0026] An electronic device, which is special in that it includes:

[0027] at least one processor;

[0028] at least one memory for storing at least one program;

[0029] When the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned method for quickly determining the range of the braking force distribution ratio of the entire vehicle.

[0030] A computer-readable storage medium stores a computer program, which is special in that when the computer program is executed by a processor, the method for quickly determining the range of the braking force distribution ratio of the entire vehicle is implemented.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention provides a method for quickly determining the range of the braking force distribution ratio of a whole vehicle. The method adopts an explicit expression mathematical model of the braking force distribution ratio of the whole vehicle, and forwardly calculates the value range of the braking force distribution ratio, replacing the traditional reverse assignment method close to the regulations. The braking force distribution range can be determined conveniently and quickly according to the parameters of the whole vehicle, avoiding unnecessary waste of manpower. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the conditions that need to be met for the braking force distribution ratio of a two-axle vehicle other than M1 and N1 in the prior art;

[0034] Figure 2 A schematic diagram of a drawing in which a braking force distribution ratio determined by a reverse adaptation drawing method in the prior art meets regulatory requirements;

[0035] Figure 3 This is a schematic diagram showing that the braking force distribution ratio determined by the reverse adaptation mapping method in the prior art does not meet the regulatory requirements. DETAILED DESCRIPTION

[0036] In order to better explain the present invention, the main contents of the present invention are further explained below in conjunction with the drawings and specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0037] The present invention provides a method for quickly determining the range of the braking force distribution ratio of a whole vehicle, comprising the following steps:

[0038] 1) Get the parameters of the vehicle.

[0039] The vehicle is a two-axle vehicle other than M1 and N1, including the front and rear axles. The vehicle is a commercial vehicle.

[0040] Parameters include center of mass height, wheelbase, distance from front axle to center of mass, distance from rear axle to center of mass, and braking strength.

[0041] 2) Based on the parameters, the upper and lower limits of the braking force distribution coefficient are calculated.

[0042] The upper limit is calculated by the following formula:

[0043]

[0044] Where: β is the braking force distribution coefficient; B max is the upper limit of the braking force distribution coefficient; ε=h / E, 0<ε<1, h is the height of the center of mass, E is the wheelbase; Z is the braking intensity; λ=E1 / E, E2 / E=1-λ, 0<λ<1, E1 and E2 are the horizontal distances from the center of mass of the vehicle to the front axle and the rear axle respectively.

[0045] The lower limit is calculated by:

[0046]

[0047] 3) Determine whether the braking force distribution ratio range meets regulatory requirements.

[0048] The judgment method includes setting the upper limit B of the braking force distribution coefficient calculated in step 2) to max and lower limit B min For comparison, if B min ≤B max , then the braking force distribution ratio range meets the regulatory requirements, and the braking force distribution coefficient range is [B min , B max ]; if B min >B max , the braking force distribution ratio range does not meet regulatory requirements.

[0049] 4) If the braking force distribution ratio range meets the regulatory requirements, the range of the braking force distribution coefficient is determined to be from the lower limit to the upper limit in step 2); if the braking force distribution ratio range does not meet the regulatory requirements, adjust the braking system.

[0050] Adjusting the brake system includes adding a pressure regulating device to the brake system, adjusting the front axle brake pressure or the rear axle brake pressure, and after adding the pressure regulating device, repeating steps 1) to 4) to recalculate the braking force distribution ratio range that meets regulatory requirements.

[0051] The technical ideas of the technical solution in the present invention are as follows:

[0052] For commercial vehicles other than M1 and N1 types, the braking force distribution ratio range must meet the following conditions:

[0053] 1) For vehicles with an adhesion coefficient K between 0.2 and 0.8, the braking intensity Z must meet the following requirements:

[0054] Z≥0.1+0.85(K-0.2).

[0055] 2) When the vehicle is in various load conditions, the front axle adhesion coefficient utilization curve should be above the rear axle adhesion coefficient utilization curve.

[0056] 2.1) For braking intensity Z between 0.15 and 0.30, if the adhesion coefficient utilization curve of each axle is between two straight lines parallel to the ideal adhesion coefficient utilization line determined by the formula K = Z ± 0.08, it is considered to meet the requirements, such as Figure 2 and Figure 3 shown.

[0057] 2.2) For braking intensity Z ≥ 0.3, if the rear axle adhesion coefficient curve can satisfy the formula Z ≥ 0.3 + 0.74 (K - 0.38), it is considered to meet the requirements.

[0058] The following is a further analysis of the above two conditions:

[0059] 1) For vehicles with an adhesion coefficient K between 0.2 and 0.8, the braking intensity Z must meet the following requirements:

[0060] Z≥0.1+0.85(K-0.2).

[0061] That is: when 0.2≤K≤0.8, Z≥0.85K-0.07.

[0062] Assume k is the road adhesion coefficient, k0 is the synchronous adhesion coefficient, and k0 satisfies the following formula:

[0063] or

[0064] Substituting β for k0 can obtain the following formula for the braking strength of the vehicle:

[0065] When k≤k0, the braking strength of the vehicle is:

[0066]

[0067] When k>k0, the braking intensity of the vehicle

[0068]

[0069] Where Z1 and Z2 represent the braking strength of the vehicle under two working conditions respectively.

[0070] Substituting k into condition 1), we can know that when 0.2≤k≤0.8, Z≥0.85k-0.07. That is, we get:

[0071]

[0072] Right now:

[0073]

[0074] When the wheel is in a locked state, the road adhesion coefficient k is the utilized adhesion coefficient K.

[0075] When k≤k0, k in the inequality is equal to the front axle adhesion coefficient K1, and the front axle adhesion coefficient K1 is substituted into the above inequality; when k>k0, k in the inequality is equal to the rear axle adhesion coefficient K2, and the rear axle adhesion coefficient K2 is substituted into the above inequality.

[0076] When k = 0.2, Z = 0.1, which is determined by Z = 0.85k - 0.07, and when k = 0.8, Z = 0.61. Therefore, replacing k in the above inequality with Z, the above formula can be transformed into:

[0077]

[0078] The calculation formulas for the front axle adhesion coefficient and the rear axle adhesion coefficient are as follows:

[0079]

[0080]

[0081] Where K1 and K2 are the front axle adhesion coefficient and the rear axle adhesion coefficient respectively; T, T1 and T2 are the braking forces of the whole vehicle, the front axle and the rear axle respectively; N1 and N2 are the vertical forces of the front axle and the rear axle respectively; P is the vehicle mass; Z is the braking strength of the whole vehicle; β is the braking force distribution coefficient β = T1 / T; E1 and E2 are the horizontal distances from the center of mass of the vehicle to the front axle and the rear axle respectively; E is the wheelbase from the front axle to the rear axle; and h is the height of the center of mass.

[0082] 2) When the vehicle is in various load conditions, the front axle adhesion coefficient utilization curve should be above the rear axle adhesion coefficient utilization curve.

[0083] 2.1) For braking intensity Z between 0.15 and 0.30, if the adhesion coefficient utilization curve of each axle is between two straight lines parallel to the ideal adhesion coefficient utilization line determined by the formula K = Z ± 0.08, it is considered to meet the requirements, such as Figure 3 shown.

[0084] That is: when 0.15≤Z≤0.30, Z-0.08≤K1≤Z+0.08, Z-0.08≤K2≤Z+0.08.

[0085] 2.2) For braking intensity Z ≥ 0.3, if the rear axle adhesion coefficient curve can satisfy the formula Z ≥ 0.3 + 0.74 (K - 0.38), it is considered to meet the requirements.

[0086] That is: when Z ≥ 0.3, Z ≥ 0.3 + 0.74 (K2 - 0.38), that is, when Z ≥ 0.3,

[0087] Substituting the calculation formula of the front axle adhesion coefficient K1 and the rear axle adhesion coefficient K2 into the above conditions, the following inequality is obtained:

[0088]

[0089] The inequality is converted into a function expression of β:

[0090]

[0091] The inequalities finally obtained in conditions 1) and 2) are combined to obtain the mathematical model for expressing the braking force distribution requirements:

[0092]

[0093] Assume h / E=ε, E1 / E=λ, then E2 / E=1-λ, where 0<ε<1, 0<λ<1, the above formula can be simplified to:

[0094]

[0095] In actual situations, the range of the braking force distribution coefficient β can be calculated by solving the above equation. If the inequality has no solution, it means that the vehicle model cannot meet the standard requirements with a fixed braking force distribution coefficient.

[0096] In order to analyze and calculate, the above formula is divided into two types of inequality groups, namely:

[0097]

[0098]

[0099] Among them, Bmin and B max are the lower and upper limits of the braking force distribution coefficient respectively.

[0100] It can be seen from the above formula that as long as the vehicle parameters are substituted, B can be obtained min and B max If B min ≤β≤B max , which means that this inequality has a solution and the range of β is [B min , B max ]; if B min >B max , indicating that this inequality has no solution and the brake system needs to be equipped with a pressure regulating device to meet the standard requirements.

[0101] This specific embodiment also provides a system for quickly determining the range of the braking force distribution ratio of the whole vehicle, which is used to implement the above-mentioned method for quickly determining the range of the braking force distribution ratio of the whole vehicle, including:

[0102] A data storage module, used for storing parameter data of the vehicle;

[0103] A data processing module, used for calculating the upper limit and the lower limit of the braking force distribution coefficient;

[0104] A judgment module, used to judge whether the braking force distribution ratio range meets regulatory requirements;

[0105] The output module is used to output the upper limit and lower limit of the braking force distribution coefficient calculated by the data processing module and the judgment result of the judgment module.

[0106] This specific embodiment also provides an electronic device, including:

[0107] at least one processor;

[0108] at least one memory for storing at least one program;

[0109] When the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned method for quickly determining the range of the braking force distribution ratio of the entire vehicle.

[0110] This specific embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the method for quickly determining the range of the braking force distribution ratio of the entire vehicle is implemented.

[0111] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims. Other parts not described belong to the prior art.

Claims

1. A method for quickly determining the range of the braking force distribution ratio of a vehicle, characterized in that: The following steps are involved: 1) Obtain vehicle parameters; 2) calculating the upper limit and the lower limit of the braking force distribution coefficient based on the parameters; 3) Determine whether the braking force distribution ratio range meets regulatory requirements; 4) If the braking force distribution ratio range meets the regulatory requirements, the range of the braking force distribution coefficient is determined to be from the lower limit to the upper limit in step 2); If the braking force distribution ratio range does not meet regulatory requirements, adjust the braking system.

2. The method for quickly determining the range of the braking force distribution ratio of a whole vehicle according to claim 1, characterized in that: The vehicle is a two-axle vehicle other than M1 and N1 categories, including a front axle and a rear axle.

3. The method for quickly determining the range of the braking force distribution ratio of a whole vehicle according to claim 2, characterized in that: In step 1), the parameters include center of mass height, wheelbase, distance from the front axle to the center of mass, distance from the rear axle to the center of mass, and braking strength.

4. The method for quickly determining the range of the braking force distribution ratio of a whole vehicle according to claim 3, characterized in that: In step 2), the upper limit is calculated by the following formula: Where: β is the braking force distribution coefficient; B max is the upper limit of the braking force distribution coefficient; ε=h / E, 0<ε<1, h is the height of the center of mass, E is the wheelbase; Z is the braking strength; λ=E1 / E, E2 / E=1-λ, 0<λ<1, E1 and E2 are the horizontal distances from the center of mass of the vehicle to the front axle and rear axle respectively.

5. The method for quickly determining the range of the braking force distribution ratio of a whole vehicle according to claim 4, characterized in that: In step 2), the lower limit is calculated by the following formula:

6. The method for quickly determining the range of the braking force distribution ratio of a whole vehicle according to claim 5, characterized in that: In step 3), the determination method includes setting the upper limit B of the braking force distribution coefficient calculated in step 2) to max and lower limit B min For comparison, if B min ≤B max , then the braking force distribution ratio range meets the regulatory requirements, and the braking force distribution coefficient range is [B min , B max ]; if B min >B max , the braking force distribution ratio range does not meet regulatory requirements.

7. The method for quickly determining the range of the braking force distribution ratio of a whole vehicle according to any one of claims 1 to 6, characterized in that: Adjusting the braking system in step 4) includes adding a pressure regulating device to the braking system; after adding the pressure regulating device, repeating steps 1) to 4) to recalculate the braking force distribution ratio range that meets regulatory requirements.

8. A system for quickly determining the range of the braking force distribution ratio of a whole vehicle, used to implement the method for quickly determining the range of the braking force distribution ratio of a whole vehicle as claimed in any one of claims 1 to 7, characterized in that: include: A data storage module, used for storing parameter data of the vehicle; A data processing module, used for calculating the upper limit and the lower limit of the braking force distribution coefficient; A judgment module, used to judge whether the braking force distribution ratio range meets regulatory requirements; The output module is used to output the upper limit and lower limit of the braking force distribution coefficient calculated by the data processing module and the judgment result of the judgment module.

9. An electronic device, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method for quickly determining the range of the braking force distribution ratio of the entire vehicle as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for quickly determining the range of the braking force distribution ratio of the entire vehicle as described in any one of claims 1 to 7 is implemented.

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