Method, system and terminal for calculating equivalent included angle of electric drive transmission shaft of whole vehicle

Abstract

The invention provides a method and a system for calculating an equivalent included angle of an electric drive transmission shaft of a whole vehicle, a terminal and a medium. The method comprises the following steps: acquiring three-dimensional coordinates of three reference points randomly marked on a circular section of a preset position of the transmission shaft; based on the three-dimensional coordinates of the three reference points on the circular section, calculating to obtain a circle center three-dimensional coordinate of the circular section of the preset position of the transmission shaft; checking the circle center three-dimensional coordinates of the circular section of the preset position of the transmission shaft to obtain the calibrated circle center three-dimensional coordinates of the circular section of the preset position; calculating an included angle between an electric drive output shaft and a front transmission shaft, an included angle between the front transmission shaft and a rear transmission shaft and an included angle between the rear transmission shaft and a drive axle input shaft based on the three-dimensional coordinates of the transmission shaft preset position circular section calibration center; based on the included angle between the electric drive output shaft and the front transmission shaft, the included angle between the front transmission shaft and the rear transmission shaft and the included angle between the rear transmission shaft and the drive axle input shaft, the transmission shaft equivalent included angle is calculated. The equivalent included angle can be accurately and efficiently measured and calculated.

Description

Technical Field

[0001] The present invention relates to the field of mechanical engineering and vehicle engineering technology, and in particular to a method, system, terminal and medium for calculating an equivalent angle of an electric drive transmission shaft of a whole vehicle. Background Art

[0002] In modern automotive engineering, the electric drive system is the core component of vehicle power transmission, and its performance and stability are directly related to the power, economy and comfort of the vehicle. The drive shaft is an important part of the electric drive system, and the accuracy of its equivalent angle has a significant impact on the system's operating efficiency, vibration and noise (NVH) control, and service life.

[0003] Traditionally, the measurement and calculation of the transmission shaft equivalent angle mainly adopts the following methods:

[0004] Commercial software measurement based on 3D model: This method uses CAD software (such as CATIA, UG, etc.) to build a virtual 3D model, obtains the geometric parameters of each component of the transmission shaft through virtual measurement tools, and then calculates the equivalent angle. However, this method cannot fully consider the impact of actual load, transmission shaft processing error and vehicle assembly process on the equivalent angle, resulting in differences in the equivalent angle between the design stage and the prototype tuning stage, affecting the performance of the vehicle.

[0005] Drawing method based on two-dimensional model: This method uses geometric drawing to draw a schematic diagram of each component of the transmission shaft on a two-dimensional plane, and obtains the equivalent angle by calculating the coordinates of the center of each component and the angle. Although this method can reflect the geometric relationship of the transmission shaft to a certain extent, it also cannot take into account the errors in the actual processing and assembly process, and the calculation under different loads needs to be repeated, which is labor-intensive and has limited accuracy.

[0006] Angle meter measurement based on real vehicles: This method uses an angle meter directly on the real vehicle to measure the angles between the components of the drive shaft, and then calculates the equivalent angle using a mathematical formula. However, this method has obvious limitations. First, the angle meter can only measure the angle between lines, and cannot directly measure the angle between the connecting lines between the centers of the shaft ends, resulting in limited measurement accuracy. Secondly, human operation factors will cause large errors, which is not conducive to determining the cause of the problem. Finally, this method cannot adapt to measurement requirements under different loads and assembly conditions.

[0007] In view of the limitations of the above methods, there is an urgent need for a new method that can accurately and efficiently measure and calculate the equivalent angle of the vehicle's electric drive shaft. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention proposes a method, system, terminal and medium for calculating the equivalent angle of the electric drive transmission shaft of a whole vehicle, so as to solve the technical problems existing in the prior art.

[0009] The technical solution adopted by the present invention is:

[0010] A first aspect of the present embodiment provides a method for calculating an equivalent angle of an electric drive transmission shaft of a vehicle, the method comprising:

[0011] Obtain the three-dimensional coordinates of three reference points randomly marked on the circular cross section of the preset position of the transmission shaft;

[0012] Based on the three-dimensional coordinates of three reference points randomly marked on the circular cross-section at the preset position of the transmission shaft, the three-dimensional coordinates of the center of the circular cross-section at the preset position of the transmission shaft are calculated;

[0013] Verifying the three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft to obtain the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft;

[0014] Based on the three-dimensional coordinates of the calibration center of the circular cross section of the preset position of the transmission shaft, the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the input shaft of the drive axle are calculated;

[0015] Based on the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the input shaft of the drive axle, the transmission shaft equivalent angle is calculated.

[0016] Furthermore, the step of obtaining the three-dimensional coordinates of three reference points randomly marked on the circular cross section of the preset position of the transmission shaft includes:

[0017] The three-dimensional coordinates of three reference points randomly marked on the circular cross section at the preset position in the same coordinate system are measured by a mobile articulated arm three-coordinate measuring machine to obtain the three-dimensional coordinates of three points on the circular cross section at the preset position of the transmission shaft.

[0018] Furthermore, the preset position circular cross section includes:

[0019] Circular sections 1 and 2 located on the electric drive output shaft, circular sections 3 and 4 located on the front drive shaft, circular sections 5 and 6 located on the rear drive shaft, and circular sections 7 and 8 located on the drive axle input shaft;

[0020] The circular section one is close to the input end of the electric drive output shaft, the circular sections two and three are close to the front drive shaft input universal joint, the circular sections four and five are close to the front drive shaft output universal joint, the circular sections six and seven are close to the rear drive shaft output universal joint, and the circular section eight is close to the output end of the drive axle input shaft.

[0021] Furthermore, the three-dimensional coordinates of the center of the circular section at the preset position of the transmission shaft are verified to obtain the three-dimensional coordinates of the calibration center of the circular section at the preset position of the transmission shaft, including:

[0022] Based on the three-dimensional coordinates of the center of the circular cross-section at the preset position of the transmission shaft, the radius and circumference of the circular cross-section at the preset position of the transmission shaft are calculated;

[0023] Compare and verify the radius of the circular section at the preset position of the transmission shaft with the actual circular section radius at the corresponding position, or compare and verify the radius of the circular section at the preset position of the transmission shaft with the actual circular section circumference at the corresponding position to obtain a comparison verification error result;

[0024] If there is a circular section whose comparison verification error result is greater than the preset error value, the three-point distribution positions of the error circular section are re-marked through a cylindrical sleeve, and the three-dimensional coordinates of the three re-marked points to be measured on the error circular section are measured by a mobile articulated arm three-coordinate measuring machine;

[0025] Based on the three-dimensional coordinates of the three points to be measured that are re-marked on the error circle section, the three-dimensional coordinates of the center of the circle on the error circle section are calculated, and the three-dimensional coordinates of the center of the circle on the error circle section are verified again until the comparison and verification error result is less than or equal to the preset value, so as to obtain the three-dimensional coordinates of the calibration center of the circular section at the preset position of the transmission shaft.

[0026] Furthermore, based on the angle between the electric drive output shaft and the front drive shaft, the angle between the front drive shaft and the rear drive shaft, and the angle between the rear drive shaft and the drive axle input shaft, the drive shaft equivalent angle is calculated, and the calculation formula is expressed as:

[0027]

[0028] Among them, a 1 is the angle between the electric drive output shaft and the front transmission shaft, a 2 is the angle between the front drive shaft and the rear drive shaft, a 3 is the angle between the rear drive shaft and the input shaft of the drive axle, a e is the calculated equivalent angle of the transmission shaft;

[0029] The phase ± sign determination rule is as follows: when the first universal joint active yoke coincides with the plane where the universal joint angle is located, it is defined as '+', and when it is perpendicular to the universal joint angle plane, it is defined as '-'.

[0030] A second aspect of the present embodiment provides a system for calculating an equivalent angle of an electric drive transmission shaft of a vehicle, the system comprising:

[0031] A module for obtaining the three-point coordinates of a circular cross section is used to obtain the three-dimensional coordinates of three reference points randomly marked on the circular cross section at a preset position of the transmission shaft;

[0032] A circle center coordinate calculation module, which calculates the three-dimensional coordinates of the circle center of the circular section at the preset position of the transmission shaft based on the three-dimensional coordinates of three reference points randomly marked on the circular section at the preset position of the transmission shaft;

[0033] A circle center coordinate verification module verifies the three-dimensional coordinates of the circle center of the circular section at the preset position of the transmission shaft to obtain the three-dimensional coordinates of the calibration circle center of the circular section at the preset position of the transmission shaft;

[0034] A transmission shaft angle calculation module calculates the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft based on the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft;

[0035] The transmission shaft equivalent angle calculation module calculates the transmission shaft equivalent angle based on the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft.

[0036] A third aspect of this embodiment provides a terminal, including a processor, an input device, an output device and a memory, wherein the processor, input device, output device and memory are interconnected, wherein the memory is used to store a computer program, and the computer program includes program instructions, and the processor is configured to call the program instructions to execute any method described in the first aspect of this embodiment.

[0037] A fourth aspect of this embodiment provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the processor executes the method as described in any one of the first aspects of this embodiment.

[0038] It can be seen from the above technical solution that the beneficial technical effects of the present invention are as follows:

[0039] 1. The present invention can measure and calculate the equivalent angle of the vehicle in the actual state through the articulated arm three-dimensional measuring instrument, avoiding the direct measurement through the three-dimensional model without considering the vehicle load, transmission shaft system installation error and manufacturing error. At the same time, compared with the angle meter measurement, it can avoid the large human error caused by measuring only on the surface of the transmission shaft, which is more in line with the actual situation and has a higher accuracy.

[0040] 2. The present invention uses a mobile articulated arm three-coordinate measuring machine to measure and calculate the equivalent angle of the electric drive transmission shaft, which can be quickly applied to direct measurement and calculation under different loads in the actual state of the vehicle, without the need for indirect recalculation after two-dimensional and three-dimensional load application. It has the advantages of being fast, efficient and accurate in diagnosing and analyzing NVH problems caused by excessive equivalent angles of the transmission shaft, and the efficiency can be improved by 50%.

[0041] 3. The present invention can fully consider the influence of actual load, transmission shaft processing error and vehicle assembly process, simplify the measurement and calculation process, improve work efficiency, and provide a scientific basis for troubleshooting, analyzing and diagnosing NVH problems caused by the equivalent angle of the transmission shaft.

[0042] 4. The present invention not only solves the problems of low measurement accuracy and complicated calculation process of traditional methods, but also improves the adaptability and accuracy of measurement and calculation, providing strong support for the design and optimization of the vehicle electric drive transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0044] Figure 1 This is a flow chart of an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of the coordinates of three-dimensional points on the circular cross-section of a transmission shaft measured by a mobile articulated arm three-dimensional coordinate measuring machine according to an embodiment of the present invention;

[0046] Figure 3 It is a schematic diagram of the system of the present invention;

[0047] Figure 4 It is a terminal schematic diagram of the present invention. DETAILED DESCRIPTION

[0048] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0049] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0050] Example

[0051] This embodiment provides a method for calculating the equivalent angle of the electric drive transmission shaft of the whole vehicle;

[0052] The working principle of the embodiment is described in detail below:

[0053] A method for calculating the equivalent angle of the electric drive shaft of the vehicle, such as Figure 1 As shown, the method includes:

[0054] S01: Obtain the three-dimensional coordinates of three reference points randomly marked on the circular cross section of the preset position of the transmission shaft;

[0055] S02: Calculating the three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft based on the three-dimensional coordinates of three reference points randomly marked on the circular cross section at the preset position of the transmission shaft;

[0056] S03: Verify the three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft to obtain the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft;

[0057] S04: Based on the three-dimensional coordinates of the calibration center of the circle section of the preset position of the transmission shaft, calculate the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the input shaft of the drive axle;

[0058] S05: Based on the angle between the electric drive output shaft and the front drive shaft, the angle between the front drive shaft and the rear drive shaft, and the angle between the rear drive shaft and the drive axle input shaft, an equivalent angle of the drive shaft is calculated.

[0059] Specifically, in step S01, the three-dimensional coordinates of three reference points randomly marked on the circular cross section of the preset position of the transmission shaft are obtained, including:

[0060] like Figure 2 As shown, the preset position circular section is determined by a cylindrical sleeve tool to ensure that the measurement is on the same plane circumference, and the preset position circular section includes:

[0061] Circular sections 1 and 2 located on the electric drive output shaft, circular sections 3 and 4 located on the front drive shaft, circular sections 5 and 6 located on the rear drive shaft, and circular sections 7 and 8 located on the drive axle input shaft;

[0062] The circular section one is close to the input end of the electric drive output shaft, the circular sections two and three are close to the front drive shaft input universal joint, the circular sections four and five are close to the front drive shaft output universal joint, the circular sections six and seven are close to the rear drive shaft output universal joint, and the circular section eight is close to the output end of the drive axle input shaft.

[0063] like Figure 2 As shown, the three-dimensional coordinates of three reference points randomly marked on the circular cross section at the preset position, A, B, C;

[0064] The three-dimensional coordinates of the three points to be measured marked on the circular section at the preset position in the same coordinate system are measured by a mobile articulated arm three-coordinate measuring machine to obtain the three-dimensional coordinates of the three points on the circular section at the preset position of the transmission shaft, and the measurement results are output and recorded as shown in Table 1 for subsequent calculation of the center position of each circular section.

[0065] Table 1 Three-dimensional coordinates of three different points on each circumference of the circular section ① to the circular section ⑧

[0066]

[0067] In step S02, the three-dimensional coordinates of the center of the circular section at the preset position of the transmission shaft are calculated based on the three-dimensional coordinates of three reference points randomly marked on the circular section at the preset position of the transmission shaft;

[0068] Specifically, the calculation of the center coordinates of the circular section is mainly based on the principle of determining a circle by three points, and is determined by the coordinates of the intersection of the perpendicular bisectors between two points. Before calculation, fill the coordinate data of each point in Table 1 into D 24×3 In the matrix (a 24-row, 3-column matrix), each three rows represent the three positions A, B, and C on the same circle, and the columns represent the coordinate values ​​of the three dimensions X, Y, and Z. The calculation code matlab program is as follows:

[0069] yx=zeros(8,5); % Initialize the 8-row 5-column matrix yx to store the center coordinates X, Y, Z, radius r and circumference L of the 8 cross sections;

[0070] for i=1:3:22% Loop to extract the coordinates of the three points A, B, and C of the circular section in every three rows;

[0071] x1=D(i,1); y1=D(i,2); z1=D(i,3); % D matrix extracts the coordinates of point A of the circular section in every three rows;

[0072] x2=D(i+1,1); y2=D(i+1,2); z2=D(i+1,3); % D matrix extracts the coordinates of point B of the circular section in every three rows;

[0073] x3=D(i+2,1); y3=D(i+2,2); z3=D(i+2,3); % D matrix extracts the coordinates of point C of the circular section in every three rows;

[0074] a1=y1*z2-y2*z1-y1*z3+y3*z1+y2*z3-y3*z2;%Calculate the three-point coplanar constraint equation a 1 x+b 1 y+c 1 z+d 1 =0 coefficient a1 ;

[0075] b1=-(x1*z2-x2*z1-x1*z3+x3*z1+x2*z3-x3*z2); % Calculate the three-point coplanar constraint equation a 1 x+b 1 y+c 1 z+d 1 =0 coefficient b 1 ;

[0076] c1=x1*y2-x2*y1-x1*y3+x3*y1+x2*y3-x3*y2; % Calculate the three-point coplanar constraint equation a 1 x+b 1 y+c 1 z+d 1 =0 coefficient c 1 ;

[0077] d1=-(x1*y2*z3-x1*y3*z2-x2*y1*z3+x2*y3*z1+x3*y1*z2-x3*y2*z1); % Calculate the three-point coplanar constraint equation a 1 x+b 1 y+c 1 z+d 1 =0 coefficient d1;

[0078] a2=2*(x2-x1); % Calculate the three-point coplanar constraint equation a 2 x+b 2 y+c 2 z+d 2 =0 coefficient a 2 ;

[0079] b2=2*(y2-y1); % Calculate the three-point coplanar constraint equation a 2 x+b 2 y+c 2 z+d 2 =0 coefficient b 2 ;

[0080] c2=2*(z2-z1); % Calculate the three-point coplanar constraint equation a 2 x+b 2 y+c 2 z+d 2 =0 coefficient c 2 ;

[0081] d2=x1^2+y1^2+z1^2-x2^2-y2^2-z2^2; % Calculate the three-point coplanar constraint equation a 2 x+

[0082] b 2 y+c 2 z+d 2 =0 coefficient d 2 ;

[0083] a3=2*(x3-x1); % Calculate the three-point coplanar constraint equation a 3 x+b 3 y+c 3 z+d 3 =0 coefficient a 3 ;

[0084] b3=2*(y3-y1); % Calculate the three-point coplanar constraint equation a 3 x+b 3 y+c 3 z+d 3 =0 coefficient b 3 ;

[0085] c3=2*(z3-z1); % Calculate the three-point coplanar constraint equation a 3 x+b 3 y+c 3 z+d 3 =0 coefficient c 3 ;

[0086] d3=x1^2+y1^2+z1^2-x3^2-y3^2-z3^2; % Calculate the three-point coplanar constraint equation a 3 x+

[0087] b 3 y+c 3 z+d 3 =0 coefficient d 3 ;

[0088] x=-(b1*c2*d3-b1*c3*d2-b2*c1*d3+b2*c3*d1+b3*c1*d2-b3*c2*d1) / (a1*b2*c3-a1*b3*c2-a2*b1*c3+a2*b3*c1+a3*b1*c2-a3*b2*c1); % Calculate the coordinate x of the center of the circular section;

[0089] y=(a1*c2*d3-a1*c3*d2-a2*c1*d3+a2*c3*d1+a3*c1*d2-a3*c2*d1) / (a1*b2*c3-a1*b3*c2-a2*b1*c3+a2*b3*c1+a3*b1*c2-a3*b2*c1); % Calculate the coordinate y of the center of the circular section;

[0090] z=-(a1*b2*d3-a1*b3*d2-a2*b1*d3+a2*b3*d1+a3*b1*d2-a3*b2*d1) / (a1*b2*c3-a1*b3*c2-a2*b1*c3+a2*b3*c1+a3*b1*c2-a3*b2*c1); % Calculate the coordinate z of the center of the circular section;

[0091] r=sqrt((x1-x)^2+(y1-y)^2+(z1-z)^2); % Calculate the radius r of the circular section to verify the correctness of the calculation;

[0092] yx((i+2) / 3,1)=x; %Store the coordinate x of the center of the circular section;

[0093] yx((i+2) / 3,2)=y; %Store the coordinate y of the center of the circular section;

[0094] yx((i+2) / 3,3)=z; %Store the coordinate z of the center of the circular section;

[0095] yx((i+2) / 3,4)=r; %Store the radius r of the circular cross section;

[0096] L=3.1415926*2*r; %Calculate the circumference L of the circular section to verify the correctness of the calculation;

[0097] yx((i+2) / 3,5)=L;%Store the radius r of the circular cross section;

[0098] end%End.

[0099] Based on the three-dimensional coordinates of the three reference points randomly marked on the circular cross section at the preset position of the transmission shaft, the three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft are calculated, as shown in Table 2:

[0100] Table 2 Three-dimensional coordinates of the center of the circular section ① to the circular section ⑧

[0101]

[0102] In step S03, the three-dimensional coordinates of the center of the circular section at the preset position of the transmission shaft are verified to obtain the three-dimensional coordinates of the calibration center of the circular section at the preset position of the transmission shaft;

[0103] Specifically, the three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft are verified to obtain the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft, including:

[0104] Based on the three-dimensional coordinates of the center of the circular cross-section at the preset position of the transmission shaft, the radius and circumference of the circular cross-section at the preset position of the transmission shaft are calculated;

[0105] Compare and verify the radius of the circular section at the preset position of the transmission shaft with the actual circular section radius at the corresponding position, or compare and verify the radius of the circular section at the preset position of the transmission shaft with the actual circular section circumference at the corresponding position to obtain a comparison verification error result;

[0106] In this example, the preset error value is 1mm;

[0107] If there is a circular section whose comparison verification error result is greater than the preset error value, the three-dimensional coordinates of the three randomly marked reference points on the error circular section are re-obtained;

[0108] Specifically, if there is a circular section whose comparison verification error result is greater than the preset error value, the three-point distribution positions of the error circular section are re-marked through a cylindrical sleeve, and the three-dimensional coordinates of the three re-marked points to be measured on the error circular section are measured by a mobile articulated arm three-coordinate measuring machine;

[0109] Based on the three-dimensional coordinates of the three reference points randomly marked on the error circle section, the three-dimensional coordinates of the center of the circle on the error circle section are calculated, and the three-dimensional coordinates of the center of the circle on the error circle section are verified again until the comparison and verification error result is less than or equal to the preset value, so as to obtain the three-dimensional coordinates of the calibration center of the circular section at the preset position of the transmission shaft.

[0110] If the comparison verification error result is less than or equal to the preset error value, the three-dimensional coordinates of the center of the circular section at the preset position of the transmission shaft in step S02 are directly used as the three-dimensional coordinates of the calibration center of the circular section at the preset position of the transmission shaft.

[0111] In step S04: based on the three-dimensional coordinates of the calibration center of the circle section of the preset position of the transmission shaft, the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the input shaft of the drive axle are calculated;

[0112] Specifically, the MATLAB program code for calculating the angle of each transmission shaft through the coordinate matrix of the center of each circular section is as follows:

[0113] Angle=zeros(1,3); % Initialize 1 row and 3 column matrix Angle to store the angle α between the electric drive output shaft and the front drive shaft, the front drive shaft and the rear drive shaft, and the rear drive shaft and the drive axle input shaft 1 , α 2 , α 3 ;

[0114] forxh=1:2:5%xh takes circles 1, 3, 5, 7 according to the calculated angle position;

[0115] forj=1:3%j loop to calculate the angle between each axis;

[0116] a=[yx(xh+1,1)-yx(xh,1),yx(xh+1,2)-yx(xh,2),yx(xh+1,3)-yx(xh,3)];%Calculate the spatial direction vector of the first axis;

[0117] b=[yx(xh+3,1)-yx(xh+2,1),yx(xh+3,2)-yx(xh+2,2),yx(xh+3,3)-yx(xh+2,3)];%Calculate the spatial direction vector of the second axis;

[0118] dotProduct = dot(a,b); % Calculate the dot product of the two-axis space direction vectors;

[0119] lengthA = norm(a); % Calculate the modulus of the spatial direction vector of the first axis;

[0120] lengthB = norm(b); % Calculate the modulus of the second axis space direction vector;

[0121] Angle(1,j)=acosd(dotProduct / (lengthA*lengthB)); %Calculate the spatial angle between the two axes;

[0122] end%End the calculation of the angle between the two axes;

[0123] end%End all axis angle calculations.

[0124] In step S05: based on the angle between the electric drive output shaft and the front drive shaft, the angle between the front drive shaft and the rear drive shaft, and the angle between the rear drive shaft and the input shaft of the drive axle, the drive shaft equivalent angle is calculated;

[0125] Specifically, by calculating the angle α between the transmission shafts i , calculate the equivalent angle α of the transmission shaft based on the following formula and principle e

[0126]

[0127] Among them, a 1 is the angle between the electric drive output shaft and the front transmission shaft, a 2 is the angle between the front drive shaft and the rear drive shaft, a 3 is the angle between the rear drive shaft and the input shaft of the drive axle, a e is the calculated equivalent angle of the transmission shaft;

[0128] The phase ± sign determination rule is as follows: when the first universal joint active yoke coincides with the plane where the universal joint angle is located, it is defined as '+', and when it is perpendicular to the universal joint angle plane, it is defined as '-'.

[0129] like Figure 3 As shown, this embodiment provides a system for calculating the equivalent angle of the electric drive transmission shaft of the whole vehicle, and the system includes:

[0130] A module 401 for obtaining the coordinates of three points on a circular cross section is used to obtain the three-dimensional coordinates of three reference points randomly marked on a circular cross section at a preset position of the transmission shaft;

[0131] A circle center coordinate calculation module 402 is configured to calculate the three-dimensional coordinates of the circle center of the circular section at the preset position of the transmission shaft based on the three-dimensional coordinates of three reference points randomly marked on the circular section at the preset position of the transmission shaft;

[0132] The circle center coordinate verification module 403 verifies the three-dimensional coordinates of the circle center of the circular section at the preset position of the transmission shaft to obtain the three-dimensional coordinates of the calibration circle center of the circular section at the preset position of the transmission shaft;

[0133] The transmission shaft angle calculation module 404 calculates the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft based on the three-dimensional coordinates of the calibration center of the circle section of the preset position of the transmission shaft;

[0134] The transmission shaft equivalent angle calculation module 405 calculates the transmission shaft equivalent angle based on the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft.

[0135] like Figure 4 As shown, an embodiment of the present application also provides a terminal, including a processor, an input device, an output device and a memory, wherein the processor, the input device, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute part or all of the steps described in a method for calculating the equivalent angle of the electric drive transmission shaft of a whole vehicle in an embodiment of the present application.

[0136] An embodiment of the present application also provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and the computer program includes program instructions. When the program instructions are executed by a processor, the processor executes part or all of the steps described in a method for calculating the equivalent angle of the electric drive transmission shaft of a whole vehicle in an embodiment of the present application.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for calculating the equivalent angle of the electric drive shaft of a vehicle, characterized in that: The method comprises: Obtain the three-dimensional coordinates of three reference points randomly marked on the circular cross section of the preset position of the transmission shaft; Based on the three-dimensional coordinates of three reference points randomly marked on the circular cross-section at the preset position of the transmission shaft, the three-dimensional coordinates of the center of the circular cross-section at the preset position of the transmission shaft are calculated; Verifying the three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft to obtain the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft; Based on the three-dimensional coordinates of the calibration center of the circular cross section of the preset position of the transmission shaft, the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the input shaft of the drive axle are calculated; Based on the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the input shaft of the drive axle, the transmission shaft equivalent angle is calculated.

2. The method for calculating the equivalent angle of the electric drive shaft of a vehicle according to claim 1, characterized in that: The step of obtaining the three-dimensional coordinates of three reference points randomly marked on the circular cross section of the preset position of the transmission shaft includes: The three-dimensional coordinates of three reference points randomly marked on the circular cross section at the preset position in the same coordinate system are measured by a mobile articulated arm three-coordinate measuring machine to obtain the three-dimensional coordinates of three points on the circular cross section at the preset position of the transmission shaft.

3. A method for calculating the equivalent angle of the electric drive shaft of a vehicle according to any one of claims 1-2, characterized in that: The preset position circular cross section comprises: Circular sections 1 and 2 located on the electric drive output shaft, circular sections 3 and 4 located on the front drive shaft, circular sections 5 and 6 located on the rear drive shaft, and circular sections 7 and 8 located on the drive axle input shaft; The circular section one is close to the input end of the electric drive output shaft, the circular sections two and three are close to the front drive shaft input universal joint, the circular sections four and five are close to the front drive shaft output universal joint, the circular sections six and seven are close to the rear drive shaft output universal joint, and the circular section eight is close to the output end of the drive axle input shaft.

4. The method for calculating the equivalent angle of the electric drive shaft of a vehicle according to claim 2, characterized in that: The three-dimensional coordinates of the center of the circular cross section at the preset position of the transmission shaft are verified to obtain the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft, including: Based on the three-dimensional coordinates of the center of the circular cross-section at the preset position of the transmission shaft, the radius and circumference of the circular cross-section at the preset position of the transmission shaft are calculated; Compare and verify the radius of the circular section at the preset position of the transmission shaft with the actual circular section radius at the corresponding position, or compare and verify the radius of the circular section at the preset position of the transmission shaft with the actual circular section circumference at the corresponding position to obtain a comparison verification error result; If there is a circular section whose comparison verification error result is greater than the preset error value, the three-dimensional coordinates of three randomly marked reference points on the error circular section are re-obtained; Based on the three-dimensional coordinates of the three reference points randomly marked on the error circle section, the three-dimensional coordinates of the center of the circle on the error circle section are calculated, and the three-dimensional coordinates of the center of the circle on the error circle section are verified again until the comparison and verification error result is less than or equal to the preset value, so as to obtain the three-dimensional coordinates of the calibration center of the circular section at the preset position of the transmission shaft.

5. The method for calculating the equivalent angle of the electric drive shaft of a vehicle according to claim 1, characterized in that: The transmission shaft equivalent angle is calculated based on the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft. The calculation formula is expressed as: Among them, a1 is the angle between the electric drive output shaft and the front drive shaft, a2 is the angle between the front drive shaft and the rear drive shaft, a3 is the angle between the rear drive shaft and the drive axle input shaft, and a e is the calculated equivalent angle of the transmission shaft; The phase ± sign determination rule is expressed as follows: when the first universal joint active yoke coincides with the plane where the universal joint angle is located, it is defined as '+', and when it is perpendicular to the universal joint angle plane, it is defined as "-".

6. A system for calculating the equivalent angle of the electric drive shaft of a vehicle, characterized in that: The system comprises: A module for obtaining the three-point coordinates of a circular cross section is used to obtain the three-dimensional coordinates of three reference points randomly marked on the circular cross section at a preset position of the transmission shaft; A circle center coordinate calculation module, which calculates the three-dimensional coordinates of the circle center of the circular section at the preset position of the transmission shaft based on the three-dimensional coordinates of three reference points randomly marked on the circular section at the preset position of the transmission shaft; A circle center coordinate verification module verifies the three-dimensional coordinates of the circle center of the circular section at the preset position of the transmission shaft to obtain the three-dimensional coordinates of the calibration circle center of the circular section at the preset position of the transmission shaft; A transmission shaft angle calculation module calculates the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft based on the three-dimensional coordinates of the calibration center of the circular cross section at the preset position of the transmission shaft; The transmission shaft equivalent angle calculation module calculates the transmission shaft equivalent angle based on the angle between the electric drive output shaft and the front transmission shaft, the angle between the front transmission shaft and the rear transmission shaft, and the angle between the rear transmission shaft and the drive axle input shaft.

7. A terminal, characterized in that: The method comprises a processor, an input device, an output device and a memory, wherein the processor, the input device, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program comprises program instructions, and the processor is configured to call the program instructions to execute the method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the processor is caused to perform the method according to any one of claims 1 to 5.

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