A comprehensive method for determining the internal resistance of a rotating drum based on two-dimensional factors of torque and speed

Abstract

The application relates to a comprehensive drum internal resistance determination method based on two-dimensional factors of torque and speed, which is mainly used for solving the problem of how to correct the size of loading force when the loading force calculation is inaccurate due to the existence of errors in the friction force of the drum itself and the torque feedback of the driver under the two dimensions of speed and driving motor torque. The application is mainly realized through a two-dimensional bilinear interpolation mode of speed and torque, the speed is taken as a step length of 10 km / h, and the driving motor torque is taken as a step length of 10% of the rated torque of the motor. The application can more accurately reflect the self resistance of the system under different working conditions and correct the error of the driving torque, and compared with the traditional calculation of the self resistance of the system from the speed dimension, the method is more accurate and the realization is relatively simple.

Description

Technical Field

[0001] This invention relates to a method for determining the internal resistance of a comprehensive drum based on two-dimensional factors of torque and speed, and particularly to a method for correcting the applied force under different speed and torque conditions when measuring a comprehensive drum test bench for automobiles without a force sensor. Background Technology

[0002] The automotive rotary drum test bench is a basic testing device that can be used to test braking force and simulate road loads. The drum provides a certain amount of resistance to the wheels to simulate the resistance and inertial force of the wheels when they are driving on the road.

[0003] In braking performance and road simulation tests on a comprehensive automotive drum test bench, the magnitude of the drum loading force needs to consider the influence of the drum's internal resistance and the driver feedback force error on the test results. The drum loading force must eliminate the influence of its own resistance and correct for the driver feedback error. Currently commonly used correction methods include torque measurement and dynamic measurement methods. However, these methods have some drawbacks, such as low measurement accuracy and complex operation.

[0004] In fact, the internal resistance of the drum not only increases with the increase of drum speed, but also the magnitude of the torque of the driving motor affects the internal resistance of the drum itself. However, current measurement methods can only measure the magnitude of the internal resistance of the drum at different speeds, and do not consider factors such as the error of the driver feedback and the internal resistance of the drum itself under different driving torques. The most commonly used method is the dynamic measurement method, in which the driving motor of the drum first accelerates the drum to a certain speed, for example, the linear velocity of the drum surface reaches 85km / h, then the driving motor is de-energized, and the drum and the driving motor begin to slide freely. Then, in steps of 1km / h, the time t taken for the linear velocity of the drum to decrease by 1 liter is measured. For example, it takes 0.5s from 85km / h to 84km / h and 0.7s from 84km / h to 83km / h. The average acceleration of the drum at this speed range is calculated from the time taken, a = 1 / 3.6 / t (3.6 is the switching ratio between km / h and m / s). Then, the resistance of the drum at this speed is calculated by applying Newton's first law F = Ma (M is the equivalent inertia of the drum on the surface). Similarly, the drag at different speeds is calculated.

[0005] As can be seen from the above measurement method, the motor is in a free-sliding state with the power off, the motor is not working, and the torque is 0. Therefore, the entire measurement method only considers the relationship between the linear velocity of the drum and the internal resistance of the drum itself. When the drum is loaded, the resistance in this state will be reduced, and the error of the driver feedback and the difference in the resistance of the drum itself under different motor forces will not be considered. Summary of the Invention

[0006] This invention primarily addresses the problem of how to correct the magnitude of the loading force when errors in the calculation of the loading force occur due to the frictional force of the drum itself and the torque feedback of the drive motor, affecting both speed and the torque of the drive motor. It provides a comprehensive drum internal resistance measurement method based on two-dimensional factors of torque and speed, with the specific technical solution as follows:

[0007] A method for determining the internal resistance of a drum based on two-dimensional factors of torque and velocity includes the following steps:

[0008] Step S1: Define two two-dimensional arrays in the PLC program to record discrete points. The two two-dimensional arrays are E1

[10]

[10] and E2

[10]

[10] , respectively. The frequency converter driving the roller works in torque mode.

[0009] Step S2: The frequency converter drives the motor to accelerate to 120 km / h at 15% of the rated torque, then the frequency converter applies 0% of the rated torque to decelerate the drum, with the set force being F. S ;

[0010] Step S3: Calculate the average acceleration within the range of 105-95 km / h, and record the acceleration 'a' at a speed of 100 km / h. Calculate F using the formula F = Ma. a1 ; Calculate the acceleration force F generated a1 ;

[0011] Step S4: Calculate F S and F a1 The difference F E1 F E1 =F S -F a1 ;

[0012] Step S5: Calculate F E1 The value is written into the two-dimensional array E2[0,10];

[0013] Step S6: Repeat steps S3 to S5, except that in step S3, 105-95km / h is replaced with 95-85km / h, and F is in the 95-85km / h speed range. E1 Write to array E2[0,9];

[0014] Repeat steps S3 to S5, except that when 105-95km / h in step S3 is replaced with 85-75km / h, the speed range F at 85-75km / h is... E1 Write to array E2[0,8];

[0015] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 75-65km / h, the speed range F in the 75-65km / h range... E1Write to array E2[0,7];

[0016] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 65-55km / h, the speed range F at 65-55km / h... E1 Write to array E2[0,6];

[0017] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 55-45km / h, the speed range F at 55-45km / h... E1 Write to array E2[0,5];

[0018] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 45-35km / h, the speed range F at 45-35km / h... E1 Write to array E2[0,4];

[0019] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 35-25km / h, the speed range F at 35-25km / h... E1 Write to array E2[0,3];

[0020] Repeat steps S3 to S5, except that when 105-95km / h in step S3 is replaced with 25-15km / h, the speed range F at 25-15km / h is... E1 Write to array E2[0,2];

[0021] Repeat steps S3 to S5, except that when 105-95km / h in step S3 is replaced with 15-5km / h, the speed range F at 15-5km / h is... E1 Write to array E2[0,1];

[0022] Step S7: After the drum stops, the frequency converter drives the motor to accelerate at 10% of the rated torque;

[0023] Step S8: Calculate the average acceleration within the range of 5-15 km / h, and record the acceleration 'a' at a speed of 10 km / h. Calculate F using the formula F = Ma. a2 ; Calculate the acceleration force F generated a2 ;

[0024] Step S9, Calculate F S and F a2 The difference F E2 =F S -F a2 ;

[0025] Step S10: Calculate F E2The value is written into the two-dimensional array E1[1,1];

[0026] Step S11: Repeat steps S8 to S10, except that 5-15km / h in step S8 is replaced with 15-25km / h, and F is the speed range of 15-25km / h. E2 Write to array E1[1,2];

[0027] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 25-35km / h, the F speed in the 25-35km / h range... E2 Write to array E1[1,3];

[0028] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 35-45km / h, the speed range F at 35-45km / h... E2 Write to array E1[1,4];

[0029] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 45-55km / h, the speed range F at 45-55km / h... E2 Write to array E1[1,5];

[0030] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 55-65km / h, the speed range F at 55-65km / h... E2 Write to array E1[1,6];

[0031] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 65-75km / h, the speed range F at 65-75km / h... E2 Write to array E1[1,7];

[0032] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 75-85km / h, the speed range F at 75-85km / h... E2 Write to array E1[1,8];

[0033] Repeat steps S8 to S10, except that when 5-15km / h in step S8 is replaced with 85-95km / h, the speed range F at 85-95km / h is... E2 And write it to array E1[1,9];

[0034] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 95-105km / h, the speed range F at 95-105km / h... E2 Write to array E1[1,10];

[0035] Step S12: When the speed is greater than 120km / h, the drive motor starts to decelerate with 10% of the rated torque in the reverse direction;

[0036] Step 13: Calculate the average acceleration within the range of 105-95 km / h, and record the acceleration 'a' at a speed of 100 km / h. Calculate F using the formula F = Ma. a3 ; Calculate the acceleration force F generated a3 ;

[0037] Step S14: Calculate F S and F a3 The difference F E3 =F S -F a3 ;

[0038] Step S15: Calculate F E3 The value is written into the two-dimensional array E2[1,10];

[0039] Step S16: Repeat steps S13 to S15, except that in step S13, 105-95km / h is replaced with 95-85km / h, and F is in the 95-85km / h speed range. E3 Write to array E2[1,9];

[0040] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 85-75 km / h, and F is in the 85-75 km / h speed range. E3 Write to array E2[1,8];

[0041] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 75-65 km / h, and F is in the 75-65 km / h speed range. E3 Write to array E2[1,7];

[0042] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 65-55 km / h, and F is in the 65-55 km / h speed range. E3 Write to array E2[1,6];

[0043] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 55-45 km / h, and F is in the 55-45 km / h speed range. E3 Write to array E2[1,5];

[0044] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 45-35 km / h, and F is in the 45-35 km / h speed range. E3 Write to array E2[1,4];

[0045] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 35-25 km / h, and F is in the 35-25 km / h speed range. E3 Write to array E2[1,3];

[0046] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 25-15 km / h, and F is in the 25-15 km / h speed range. E3 Write to array E2[1,2];

[0047] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 15-5 km / h, and the speed range F is [not specified]. E3 Write to array E2[1,1];

[0048] Step S17: Repeat steps S7 to S16 with 20%, 30%, 40%... or 100% of the rated torque respectively; thereby obtaining the remaining two-dimensional data in the two-dimensional array;

[0049] Step S18: Using the discrete point data in the two-dimensional array obtained above, the correction value is calculated based on the speed and torque during the drum experiment using the bilinear interpolation method.

[0050] As an improvement to the above technical solution, the method for determining the internal resistance of the drum based on two-dimensional factors of torque and speed is applied in automobile drum testing.

[0051] As an improvement to the above technical solution, no force sensor was installed in the automobile drum test.

[0052] The beneficial effects of this invention are:

[0053] This invention can more accurately reflect the system's own resistance and the error of the corrective drive torque under different operating conditions. Compared with the traditional method of calculating the system's own resistance only from the speed dimension, this method is more accurate and simpler to implement.

[0054] This invention is particularly suitable for methods of correcting applied force under different speeds and torques in the absence of force sensors. Attached Figure Description

[0055] Figure 1 This is a flowchart of the present invention;

[0056] Figure 2 This is a schematic diagram of the two-dimensional bilinear interpolation principle.

[0057] Figure 3 This is a schematic diagram illustrating the principle of two-dimensional bilinear interpolation calculation.

[0058] Figure 4 This is a comparison chart of the errors between the present invention and the traditional method. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0060] Example 1

[0061] This invention primarily utilizes a two-dimensional bilinear interpolation method for speed and torque. The speed step size is 10 km / h, and the drive motor torque step size is 10% of the motor's rated torque. This calculation first requires knowing the sum of the system's internal resistance and the inverter's feedback error at discrete points: 10% torque - 10 km / h, 10% torque - 20 km / h, 10% torque - 30 km / h, ..., 20% torque - 10 km / h, 20% torque - 20 km / h, 20% torque - 30 km / h, ... . The specific range of discrete point values ​​is shown at position X in Table 1 below.

[0062] Table 1

[0063]

[0064]

[0065] The values ​​at discrete points are driven by the motor at 10%, 20%, 30%... of the rated torque F. S The driven roller accelerates and decelerates from -120 to 120 km / h. The speed is measured by an encoder, and the linear acceleration of the roller is calculated. For example, an average accelerometer reading 'a' at 10 km / h is used to measure the acceleration 'a', which is then calculated using F. a =Ma calculates the force F referred to the roller surface, F E =F S -F a Using this method, obtain the F values ​​for all positions D in Table 1. E The specific implementation process is shown in steps S1 to S18 below.

[0066] Using the discrete points in this table, the magnitude of the friction force of the motor at any torque and speed can be obtained through bilinear interpolation. For example, to calculate the friction force at point P at 55% rated torque and 55 km / h, it can be seen that this point falls within the range of four points: 50% torque - 50 km / h Q11, 50% torque - 60 km / h Q21, 60% torque - 50 km / h Q12, and 60% torque - 60 km / h Q22. Interpolation calculations are then performed using these four points.

[0067] For the sake of generality, assume the coordinates of the four points are Q11(x1,y1), Q12(x1,y2), Q21(x2,y1), and Q22(x2,y2).

[0068] First, perform linear difference calculations in the velocity X direction to determine the straight lines defined by Q11 and Q21, and Q12 and Q22; for example... Figure 2 As shown.

[0069] Then, interpolation calculations are performed in the torque Y direction, using the following formula:

[0070]

[0071] Based on this implementation process, the calculation process for the error value that needs to be corrected at 55% torque and 55km / h is as follows: In the formula, x1 is replaced with 50km / h, x2 with 60km / h, y1 with 50% rated torque, y2 with 60% rated torque, and f(Q) 11 Replace ) with the value in the data E[5][5], f(Q 12 Replace ) with the value in the data E[5][6], f(Q 21 Replace ) with the value in the data E[6][5], f(Q 22 Replace ) with the value in the E[6][6] data; therefore,

[0072]

[0073] Substituting the coordinates of point P into the above formula yields F at point P. E Friction value, 3D rendering as follows Figure 3 As shown.

[0074] like Figure 1 As shown, the method for determining the internal resistance of a drum based on two-dimensional factors of torque and speed includes the following steps:

[0075] Step S1: Define two two-dimensional arrays in the PLC program to record discrete points. The two two-dimensional arrays are E1

[10]

[10] and E2

[10]

[10] , respectively. The frequency converter driving the roller works in torque mode.

[0076] Among them, the E1 array is used to store the error value of the roller during the acceleration process, that is, the positive torque. The element in the first square bracket represents a different torque, and the element in the second square bracket represents a different speed. For example, E1[3][5] represents the difference between the force calculated from the average acceleration of 45 to 55 km / h with 30% positive torque and the set 30% force. The application of the E2 array is similar, representing the error value of the reverse torque during the acceleration process; others are similar.

[0077] Step S2: The frequency converter drives the motor to accelerate to 120 km / h at 15% of the rated torque, then the frequency converter applies 0% of the rated torque to decelerate the drum, with the set force being F. S ;

[0078] Step S3: Calculate the average acceleration within the range of 105-95 km / h, and record the acceleration 'a' at a speed of 100 km / h. Calculate F using the formula F = Ma. a1 ; Calculate the acceleration force F generated a1 ;

[0079] Step S4: Calculate F S and F a1 The difference F E1 F E1 =F S -F a1 ;

[0080] Step S5: Calculate F E1 The value (for speeds between 105-95 km / h) is written into the two-dimensional array E2[0,10].

[0081] Step S6: Repeat steps S3 to S5, except that in step S3, 105-95km / h is replaced with 95-85km / h, and F is in the 95-85km / h speed range. E1 Write to array E2[0,9];

[0082] Repeat steps S3 to S5, except that when 105-95km / h in step S3 is replaced with 85-75km / h, the speed range F at 85-75km / h is... E1 Write to array E2[0,8];

[0083] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 75-65km / h, the speed range F in the 75-65km / h range... E1 Write to array E2[0,7];

[0084] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 65-55km / h, the speed range F at 65-55km / h... E1 Write to array E2[0,6];

[0085] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 55-45km / h, the speed range F at 55-45km / h... E1 Write to array E2[0,5];

[0086] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 45-35km / h, the speed range F at 45-35km / h... E1 Write to array E2[0,4];

[0087] Repeat steps S3 to S5, when replacing 105-95km / h in step S3 with 35-25km / h, the speed range F at 35-25km / h... E1 Write to array E2[0,3];

[0088] Repeat steps S3 to S5, except that when 105-95km / h in step S3 is replaced with 25-15km / h, the speed range F at 25-15km / h is... E1 Write to array E2[0,2];

[0089] Repeat steps S3 to S5, except that when 105-95km / h in step S3 is replaced with 15-5km / h, the speed range F at 15-5km / h is... E1 Write to array E2[0,1];

[0090] Step S7: After the drum stops, the frequency converter drives the motor to accelerate at 10% of the rated torque;

[0091] Step S8: Calculate the average acceleration within the range of 5-15 km / h, and record the acceleration 'a' at a speed of 10 km / h. Calculate F using the formula F = Ma. a2 ; Calculate the acceleration force F generated a2 ;

[0092] Step S9, Calculate F S and F a2 The difference F E2 =F S -F a2 ;

[0093] Step S10: Calculate F E2 The value (for speeds between 5-15 km / h) is written into the two-dimensional array E1[1,1].

[0094] Step S11: Repeat steps S8 to S10, except that 5-15km / h in step S8 is replaced with 15-25km / h, and F is the speed range of 15-25km / h. E2 Write to array E1[1,2];

[0095] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 25-35km / h, the F speed in the 25-35km / h range... E2 Write to array E1[1,3];

[0096] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 35-45km / h, the speed range F at 35-45km / h... E2 Write to array E1[1,4];

[0097] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 45-55km / h, the speed range F at 45-55km / h... E2 Write to array E1[1,5];

[0098] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 55-65km / h, the speed range F at 55-65km / h... E2 Write to array E1[1,6];

[0099] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 65-75km / h, the speed range F at 65-75km / h... E2 Write to array E1[1,7];

[0100] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 75-85km / h, the speed range F at 75-85km / h... E2 Write to array E1[1,8];

[0101] Repeat steps S8 to S10, except that when 5-15km / h in step S8 is replaced with 85-95km / h, the speed range F at 85-95km / h is... E2 And write it to array E1[1,9];

[0102] Repeat steps S8 to S10, when replacing 5-15km / h in step S8 with 95-105km / h, the speed range F at 95-105km / h... E2 Write to array E1[1,10];

[0103] Step S12: When the speed is greater than 120km / h, the drive motor starts to decelerate with 10% of the rated torque in the reverse direction;

[0104] Step 13: Calculate the average acceleration within the range of 105-95 km / h, and record the acceleration 'a' at a speed of 100 km / h. Calculate F using the formula F = Ma. a3 ; Calculate the acceleration force F generated a3 ;

[0105] Step S14: Calculate F S and F a3 The difference F E3 =F S -F a3 ;

[0106] Step S15: Calculate F E3 The value (for speeds between 105-95 km / h) is written into the two-dimensional array E2[1,10].

[0107] Step S16: Repeat steps S13 to S15, except that in step S13, 105-95km / h is replaced with 95-85km / h, and F is in the 95-85km / h speed range. E3 Write to array E2[1,9];

[0108] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 85-75 km / h, and F is in the 85-75 km / h speed range. E3 Write to array E2[1,8];

[0109] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 75-65 km / h, and F is in the 75-65 km / h speed range. E3 Write to array E2[1,7];

[0110] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 65-55 km / h, and F is in the 65-55 km / h speed range. E3 Write to array E2[1,6];

[0111] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 55-45 km / h, and F is in the 55-45 km / h speed range. E3 Write to array E2[1,5];

[0112] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 45-35 km / h, and F is in the 45-35 km / h speed range. E3 Write to array E2[1,4];

[0113] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 35-25 km / h, and F is in the 35-25 km / h speed range. E3 Write to array E2[1,3];

[0114] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 25-15 km / h, and F is in the 25-15 km / h speed range. E3 Write to array E2[1,2];

[0115] Repeat steps S13 to S15, except that in step S13, 105-95 km / h is replaced with 15-5 km / h, and the speed range F is [not specified]. E3 Write to array E2[1,1];

[0116] Step S17: Repeat steps S7 to S16 at 20%, 30%, 40%... or 100% of the rated torque respectively;

[0117] Step S18: Using the discrete point data in the two-dimensional array obtained above, the correction value is calculated based on the speed and torque during the drum experiment using the bilinear interpolation method in Formula 1.

[0118] In the above embodiments, to verify the accuracy of the calibration, we designed the following experimental method: the drive motor accelerates the roller from 0 to 70 km / h with 30% torque, and from 10 km / h to 70 km / h, the inertia is calculated every 5 km / h, and then the total average value is calculated. The inertia is calculated using both the force value obtained by the conventional calibration method and the force value obtained by the present invention. The accuracy of the equipment inertia is assessed from five calculations (see Table 2 and...). Figure 4 This method has obvious advantages.

[0119] Table 2

[0120]

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A comprehensive method for measuring the internal resistance of a rotating drum based on two-dimensional factors of torque and speed, characterized by Comprising the following steps: Step S1, defining two two-dimensional arrays for recording discrete points in the PLC program, two two-dimensional arrays are E1[10][10] and E2[10][10] respectively, and the frequency converter driving the roller works in torque mode; Step S2, the frequency converter drives the motor to start accelerating to 120 km / h at 15% of the rated torque, and then the frequency converter is given 0% of the rated torque to decelerate the drum, and the setting force is F S ; Step S3, calculate the average acceleration within 105-95 km / h, calculate the acceleration a at 100 km / h speed, calculate the acceleration force F a1 ; Step S4, calculating F S and F a1 the difference F E1 , F E1 = F S - F a1 ; Step S5, write the calculated F E1 value into the two-dimensional array E2[0,10]. Step S6, repeat steps S3-S5, when the 105-95 km / h in step S3 is replaced by 95-85 km / h, F E1 Write to array E2[0,9]; Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 85-75 km / h, and F E1 Write to array E2 [0, 8]; Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 75-65 km / h, and F E1 Write to array E2[0,7] Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 65-55 km / h, and F E1 Write to array E2[0,6]; Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 55-45 km / h, and F E1 Write to array E2[0,5]; Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 45-35 km / h, and F E1 Write to array E2 [0, 4]; Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 35-25 km / h, and F E1 Write to array E2[0,3]; Steps S3-S5 are repeated, with 105-95 km / h in step S3 replaced by 25-15 km / h, and F E1 Write to array E2[0,2]; Steps S3-S5 are repeated, with the replacement of 105-95 km / h in step S3 by 15-5 km / h, and F E1 Write to array E2 [0, 1]; Step S7, after the roller stops, the frequency converter drives the motor to start accelerating at 10% of the rated torque; Step S8, calculate the average acceleration within 5-15 km / h, calculate the acceleration a at 10 km / h speed, calculate the acceleration force F a2 ; Step S9, calculating F S and F a2 the difference F E2 = F S - F a2 ; Step S10, write the calculated F E2 value into E1[1,1] of the two-dimensional array; Step Sll, repeat steps S8-S10, when the 5-15 km / h in step S8 is replaced by 15-25 km / h, F E2 Write to array E1 [1,2]; Steps S8-S10 are repeated, with 5-15 km / h in step S8 replaced by 25-35 km / h, and F E2 Write to array E1 [1,3] ; Steps S8-S10 are repeated, with 5-15 km / h in step S8 replaced by 35-45 km / h, and F E2 Write to array E1 [1, 4]; Steps S8-S10 are repeated, with the replacement of 5-15 km / h in step S8 by 45-55 km / h, and the F E2 Write to array E1 [1, 5] ; Steps S8-S10 are repeated, with 5-15 km / h in step S8 replaced by 55-65 km / h, and F E2 Write to array E1 [1, 6]; Steps S8-S10 are repeated, with 5-15 km / h in step S8 replaced by 65-75 km / h, and F E2 Write to array E1 [1, 7]; Steps S8-S10 are repeated, with the replacement of 5-15 km / h in step S8 by 75-85 km / h, and the F E2 Write to array E1 [1, 8]; Steps S8-S10 are repeated, with 5-15 km / h in step S8 replaced by 85-95 km / h, and the F E2 and written to array E1 [1, 9]; Steps S8-S10 are repeated, with the replacement of 5-15 km / h in step S8 by 95-105 km / h, and F E2 Write to array E1 [1, 10]; Step S12, when the speed is greater than 120km / h, the driving motor starts to decelerate at 10% of the rated torque in reverse; Step 13, calculate the average acceleration within 105-95 km / h, count as the acceleration a at 100 km / h speed, calculate the acceleration force F a3 ; Step S14, calculating F S and F a3 the difference F E3 = F S - F a3 ; Step S15, write the calculated F E3 value into E2[1, 10] of the two-dimensional array; Step S16, repeat steps S13-S15, when the 105-95 km / h in step S13 is replaced by 95-85 km / h, F E3 Write to array E2 [1, 9]; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 85-75 km / h, and F E3 Write to array E2 [1, 8]; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 75-65 km / h, and F E3 Write to array E2 [1, 7] ; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 65-55 km / h, and F E3 Write to array E2 [1, 6]; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 55-45 km / h, and F E3 Write to array E2 [1, 5] ; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 45-35 km / h, and F E3 Write to array E2 [1,4] ; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 35-25 km / h, and F E3 Write to array E2 [1,3] ; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 25-15 km / h, and F E3 Write to array E2 [1,2]; Steps S13-S15 are repeated, with 105-95 km / h in step S13 replaced by 15-5 km / h, and the F value for the 15-5 km / h speed segment is 0.

5. E3 Write to array E2 [1, 1]; Step S17, repeat steps S7-S16 at 20%, 30%, 40%... or 100% of the rated torque respectively; Step S18, use the discrete point data in the two-dimensional array obtained above to calculate the correction value size according to the speed and torque during the roller experiment by the bilinear difference method.

2. The application of a comprehensive drum internal resistance determination method based on torque and speed two-dimensional factors in the application of automobile drum test.

3. The use of a method for determining the overall resistance in a rotating drum according to claim 2 based on two-dimensional factors of torque and speed in a car test on a rotating drum, characterized in that: In the automobile drum test, no force sensor is set.

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