A modeling and calculating method for wire harness terminal resistance of new energy vehicle

Abstract

A kind of modeling calculation method about new energy vehicle harness terminal resistance belongs to new energy vehicle harness terminal resistance dynamic modeling technical field.For improving the accuracy of new energy vehicle harness terminal resistance modeling, the present application includes extracting the surface node space coordinate point set of N wires and terminal after crimping;Determine the contact domain range of N wires and terminal and extract its node space coordinate point set;Interpolation refinement processing is carried out on the node space coordinate point set in the contact domain range;The contact profile point set in each parallel section is calculated along the axial direction of wire;According to the contact profile point set, the actual contact length, contact width and corresponding contact resistance are calculated;According to the spatial distribution of N wires and terminal after crimping, a new energy vehicle harness terminal resistance network model is established.The present application is suitable for resistance modeling calculation of new energy vehicle harness terminal, and the calculation is accurate.

Description

Technical Field

[0001] This invention belongs to the field of dynamic modeling technology for the terminal resistance of wiring harnesses used in new energy vehicles, and specifically relates to a modeling and calculation method for the terminal resistance of wiring harnesses used in new energy vehicles. Background Technology

[0002] With the rapid development of the new energy vehicle industry, high-voltage wiring harnesses, as core transmission components of electrical systems, directly affect the performance and safety of the entire vehicle. Wiring harness terminals, as a crucial link connecting wires to electrical equipment, require accurate calculation of contact resistance for reducing energy consumption, improving system efficiency, and avoiding the risk of localized overheating. Traditional resistance modeling methods are typically based on idealized assumptions (such as perfectly smooth contact surfaces and uniform pressure distribution), estimating contact resistance through empirical formulas or simplified geometric models. However, they neglect the influence of factors such as microscopic deformation of wires and terminals, surface roughness, and uneven distribution of multiple wires during the actual crimping process. Especially in the high-voltage, high-current scenarios of new energy vehicles, the complex morphology of the terminal contact surface can lead to significant deviations between the actual contact area and the theoretical value, thus affecting the accuracy of resistance calculations. Current technologies lack sufficient research on dynamic contour extraction of the contact domain after crimping multiple wires, modeling of local contact resistance distribution, and construction of the overall resistance network. This results in calculations that fail to meet high-precision design requirements, limiting the optimized design and reliability assessment of wiring harness terminals. Summary of the Invention

[0003] The problem this invention aims to solve is to improve the accuracy of resistance modeling for wiring harness terminals used in new energy vehicles, and proposes a modeling and calculation method for the resistance of wiring harness terminals used in new energy vehicles.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A modeling and calculation method for the terminal resistance of wiring harnesses used in new energy vehicles includes the following steps:

[0006] S1. Extract the surface node spatial coordinates of the N crimped wires and terminals, define the N crimped wires and terminals as parts, and construct the surface node spatial coordinate point set of the parts;

[0007] S2. Based on the set of surface node spatial coordinates of the parts obtained in step S1, determine the contact domain range of different parts, and extract the set of surface node spatial coordinates of the parts within the contact domain range for overlapping parts.

[0008] S3. The set of spatial coordinate points of the surface nodes of the parts within the contact domain obtained in step S2 is subjected to interpolation and refinement to obtain the set of spatial coordinate points of the surface nodes of the parts within the contact domain after interpolation and refinement.

[0009] S4. For the set of surface node spatial coordinate points of the part within the contact domain range obtained by interpolation and refinement in step S3, calculate the set of contact profile points in the parallel section of the part within the contact domain range along the axial direction of the conductor.

[0010] S5. For the set of contact profile points within the parallel cross-section of the parts within the contact domain obtained in step S4, calculate the actual contact length, contact width and contact resistance between the contacting parts.

[0011] S6. Based on the contact resistance between the contacting parts obtained in step S5, and according to the spatial distribution relationship of the N wires and terminals after crimping, establish a wiring harness terminal resistance network model for new energy vehicles.

[0012] Furthermore, in step S1, a three-dimensional solid model of the terminal, N wires, upper mold, and lower mold is established based on the actual working conditions. Finite element software is used to simulate the crimping process of the terminal and wires, and then the surface node spatial coordinates of the N wires and terminal after crimping are extracted.

[0013] Define the N crimped wires and terminals as parts, and construct the surface node spatial coordinate point set P of the parts. k The expression is:

[0014]

[0015] Where k is the k-th part, k = 1 to N+1, n k Let be the total number of surface node coordinates of the k-th part, and let i be the i-th surface node of the k-th part. Let i be the spatial coordinates of the i-th surface node of the k-th part. Let X be the X-axis coordinate of the i-th surface node of the k-th part. Let be the Y-axis coordinate of the i-th surface node of the k-th part. Let be the Z-axis coordinate of the i-th surface node of the k-th part.

[0016] Furthermore, the specific implementation method of step S2 includes the following steps:

[0017] S2.1. First, calculate the maximum and minimum values ​​of the part on the x, y, and z coordinate axes respectively, and obtain the minimum point B of the spatial coordinate set of the surface nodes of the part. k min and the maximum point B k max The expression is:

[0018] B k min =(minx i k ,miny ik ,minz i k )

[0019] B k max =(maxx i k ,maxy i k ,maxz i k )

[0020] Where min is the minimum value function and max is the maximum value function;

[0021] Then B k min and B k max Construct the spatial coordinate set P of the surface nodes of the cuboid, given two opposite corners. k The surrounding box;

[0022] If parts m and n, 1≤m, n≤N+1 and m≠n, satisfy the following conditions:

[0023]

[0024] The initial assessment is that part m and part n have an overlapping portion; otherwise, there is no overlapping portion.

[0025] Then, the contact area range of different parts is determined, and parts m and n that are initially judged to overlap are obtained.

[0026] S2.2. For parts m and n that are preliminarily determined to overlap in step S2.1, calculate the spatial coordinate set P of the surface nodes of parts m and n respectively. m and P n The convex hull of P, if P m The convex hull vertex of P n Within the convex hull, determine P m P n There is an overlapping area, and parts m and n have a contact region;

[0027] S2.3. Assuming the Y-axis represents the axial direction of each conductor and terminal, the set of points P containing the contact region is... m and P n Projecting onto the Y-axis, we obtain the coordinate point set Proj of part m in the XZ plane. XZ (P m ), the set of coordinate points Proj of part n in the XZ plane XZ (P n The expression is:

[0028]

[0029] Extract Proj XZ (P m ) and Proj XZ (P n The intersection of Q) mn The expression is:

[0030] Q mn =[Proj XZ (P m )]I[Proj XZ (P n )]

[0031] Where I is the intersection operator;

[0032] Q mn The original surface node spatial coordinate set P mapped to parts m and n respectively m P n Obtain the set of spatial coordinates R of the surface nodes within the contact domain of part m. m The set of spatial coordinates of surface nodes R within the contact domain of part n n The expression is:

[0033]

[0034] Furthermore, the specific implementation method of step S3 is to process the set of spatial coordinate points R of the surface nodes within the contact domain of part m. m Calculate the length L of part m along the X-axis. x m and the interval length L on the Z-axis z m The expression is:

[0035]

[0036] If L x m ≥L z m Then, in the XY plane, for R... m Perform interpolation if L x m <L z m Then, in the YZ plane, for R... m Interpolation is performed to obtain the set of spatial coordinates S of the surface nodes of the part within the contact domain range of the part m after interpolation refinement. m The expression is:

[0037]

[0038] Furthermore, the specific implementation method of step S4 includes the following steps:

[0039] S4.1. The set of spatial coordinates of the surface nodes of the parts within the contact domain obtained in step S3, after interpolation and refinement. m S n Extract the corresponding node set S from the cross section corresponding to each Y coordinate. j m and S j n The expression is:

[0040]

[0041] Among them, y j This is a set of parallel sections along the Y-axis;

[0042] For each section y j Calculate S j m and S j n The distance d between all pairs of points j mn The expression is:

[0043]

[0044] S4.2. For the pairwise distances between all points obtained in step S4.1 For points less than a given criterion ε, determine the point closest to the upper or lower limit in the X or Z direction, expressed as:

[0045]

[0046] in, Let be the minimum point closest to the X direction in the upper boundary set. Let be the point in the upper bound set that is closest to the maximum value in the X direction. Let be the minimum point closest to the Z direction in the lower boundary set. Let argmin be the point in the lower boundary set closest to the maximum value in the Z direction, where argmin represents the computation of x. j or z j The minimum value of j, where argmax represents the value of x when calculated. j or z j The maximum value of j;

[0047] S4.3. Based on the points closest to the upper and lower limits in the X or Z directions obtained in step S4.2, construct the contact profile point set within the parallel cross-section of the part within the contact domain, and the contact profile upper boundary point set T. mn-sand the lower boundary point set T mn-x The expression is:

[0048] T mn-s ={t is =(x is ,y is ,z is | i = 1, 2, ..., n s}

[0049] T mn-x ={t ix =(x ix ,y ix ,z ix | i = 1, 2, ..., n x}

[0050] Among them, t is For the i-th adjacent point of the upper boundary, t ix Let n be the i-th lower boundary adjacent point. s n is the total number of adjacent points to the upper boundary. x This represents the total number of adjacent points to the lower boundary.

[0051] Furthermore, the specific implementation method of step S5 includes the following steps:

[0052] S5.1. Calculate the adjacent points t of the above boundary. is t (i+1)s Adjacent point t to the lower boundary ix t (i+1)x The contact length l of the spatial quadrilateral formed by the vertices i(i+1) mn and contact width w i(i+1) mn The expression is:

[0053]

[0054] S5.2. Calculate the contact resistance of a single spatial quadrilateral. The expression is:

[0055]

[0056] Where ρ is the resistivity of the material, and r is the radius of the circular cross-section of the conductor;

[0057] S5.3. Considering that the contact resistances of multiple spatial quadrilaterals are in parallel, the contact resistance between the contacting parts is obtained. The expression is:

[0058]

[0059] Furthermore, the specific implementation method of step S6 is to obtain the contact resistance R between the contacting parts. c mn Then, based on the distribution relationship between the crimped wires and terminals, a wire harness terminal resistance network is established. Considering that the contact resistances between the N wires and terminals are in parallel, the wire harness terminal resistance R is obtained. c The expression is:

[0060]

[0061] The beneficial effects of this invention are:

[0062] The present invention provides a modeling and calculation method for the terminal resistance of wiring harnesses for new energy vehicles. By extracting the spatial coordinates of the surface nodes of the wires and terminals after crimping, and combining dynamic division and interpolation refinement of the contact domain, the microscopic contact morphology is accurately restored, overcoming the problem of contact area calculation deviation caused by the simplification of geometric models in traditional methods.

[0063] The present invention discloses a modeling and calculation method for the terminal resistance of wiring harnesses for new energy vehicles. Based on the layer-by-layer calculation of the contact profile point set of axial parallel cross sections, it can quantify the influence of local deformation, material properties and pressure distribution on contact resistance, and provide refined modeling support for multi-wire non-uniform crimping scenarios.

[0064] The present invention discloses a modeling and calculation method for the terminal resistance of wiring harnesses for new energy vehicles. By establishing a spatially distributed resistance network model covering N wires and terminals, it can reflect the complex coupling relationship of the current path and significantly improve the overall resistance prediction accuracy. It is especially suitable for multi-condition calculation of high-voltage wiring harnesses for new energy vehicles.

[0065] The modeling and calculation method for the resistance of wiring harness terminals in new energy vehicles described in this invention can be directly applied to the design optimization of wiring harness terminals, verification of production process parameters, and reliability assessment. It provides a theoretical basis for reducing contact resistance and suppressing temperature rise, and helps improve the energy efficiency and safety of electrical systems in new energy vehicles. Attached Figure Description

[0066] Figure 1 This is a flowchart illustrating a modeling and calculation method for the terminal resistance of a wiring harness used in new energy vehicles, as described in this invention.

[0067] Figure 2 This is a schematic diagram of the wire harness terminal after crimping according to the present invention, wherein 1 is the first wire, 2 is the second wire, 3 is the third wire, 4 is the fourth wire, 5 is the fifth wire, 6 is the sixth wire, 7 is the seventh wire, and 8 is the terminal.

[0068] Figure 3 This is a schematic diagram of the partial contact contours of the two parts of the present invention;

[0069] Figure 4 This is a schematic diagram of the wire harness terminal resistor network established for this invention. Detailed Implementation

[0070] 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 specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0071] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0072] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 -Appendix Figure 4 Detailed explanation is as follows:

[0073] Example 1:

[0074] A modeling and calculation method for the terminal resistance of wiring harnesses used in new energy vehicles includes the following steps:

[0075] S1. Extract the surface node spatial coordinates of the N crimped wires and terminals, define the N crimped wires and terminals as parts, and construct the surface node spatial coordinate point set of the parts;

[0076] Furthermore, in step S1, a three-dimensional solid model of the terminal, N wires, upper mold, and lower mold is established based on the actual working conditions. Finite element software is used to simulate the crimping process of the terminal and wires, and then the surface node spatial coordinates of the N wires and terminal after crimping are extracted.

[0077] Define the N crimped wires and terminals as parts, and construct the surface node spatial coordinate point set P of the parts. k The expression is:

[0078]

[0079] Where k is the k-th part, k = 1 to N+1, nk Let be the total number of surface node coordinates of the k-th part, and let i be the i-th surface node of the k-th part. Let i be the spatial coordinates of the i-th surface node of the k-th part. Let X be the X-axis coordinate of the i-th surface node of the k-th part. Let be the Y-axis coordinate of the i-th surface node of the k-th part. Let Z be the Z-axis coordinate of the i-th surface node of the k-th part;

[0080] S2. Based on the set of surface node spatial coordinates of the parts obtained in step S1, determine the contact domain range of different parts, and extract the set of surface node spatial coordinates of the parts within the contact domain range for overlapping parts.

[0081] Furthermore, the specific implementation method of step S2 includes the following steps:

[0082] S2.1. First, calculate the maximum and minimum values ​​of the part on the x, y, and z coordinate axes respectively, and obtain the minimum point B of the spatial coordinate set of the surface nodes of the part. k min and the maximum point B k max The expression is:

[0083] B k min =(minx i k ,miny i k ,minz i k )

[0084] B k max =(maxx i k ,maxy i k ,maxz i k )

[0085] Where min is the minimum value function and max is the maximum value function;

[0086] Then B k min and B k max Construct the spatial coordinate set P of the surface nodes of the cuboid, given two opposite corners. k The surrounding box;

[0087] If parts m and n, 1≤m, n≤N+1 and m≠n, satisfy the following conditions:

[0088]

[0089] The initial assessment is that part m and part n have an overlapping portion; otherwise, there is no overlapping portion.

[0090] Then, the contact area range of different parts is determined, and parts m and n that are initially judged to overlap are obtained.

[0091] S2.2. For parts m and n that are preliminarily determined to overlap in step S2.1, calculate the spatial coordinate set P of the surface nodes of parts m and n respectively. m and P n The convex hull of P, if P m The convex hull vertex of P n Within the convex hull, determine P m P n There is an overlapping area, and parts m and n have a contact region;

[0092] S2.3. Assuming the Y-axis represents the axial direction of each conductor and terminal, the set of points P containing the contact region is... m and P n Projecting onto the Y-axis, we obtain the coordinate point set Proj of part m in the XZ plane. XZ (P m ), the set of coordinate points Proj of part n in the XZ plane XZ (P n The expression is:

[0093]

[0094] Extract Proj XZ (P m ) and Proj XZ (P n The intersection of Q) mn The expression is:

[0095] Q mn =[Proj XZ (P m )]I[Proj XZ (P n )]

[0096] Where I is the intersection operator;

[0097] Q mn The original surface node spatial coordinate set P mapped to parts m and n respectively m P n Obtain the set of spatial coordinates R of the surface nodes within the contact domain of part m. m The set of spatial coordinates of surface nodes R within the contact domain of part nn The expression is:

[0098]

[0099] S3. The set of spatial coordinate points of the surface nodes of the parts within the contact domain obtained in step S2 is subjected to interpolation and refinement to obtain the set of spatial coordinate points of the surface nodes of the parts within the contact domain after interpolation and refinement.

[0100] Furthermore, the specific implementation method of step S3 is to process the set of spatial coordinate points R of the surface nodes within the contact domain of part m. m Calculate the length L of part m along the X-axis. x m and the interval length L on the Z-axis z m The expression is:

[0101]

[0102] If L x m ≥L z m Then, in the XY plane, for R... m Perform interpolation if L x m <L z m Then, in the YZ plane, for R... m Interpolation is performed to obtain the set of spatial coordinates S of the surface nodes of the part within the contact domain range of the part m after interpolation refinement. m The expression is:

[0103]

[0104] S4. For the set of surface node spatial coordinate points of the part within the contact domain range obtained by interpolation and refinement in step S3, calculate the set of contact profile points in the parallel section of the part within the contact domain range along the axial direction of the conductor.

[0105] Furthermore, the specific implementation method of step S4 includes the following steps:

[0106] S4.1. The set of spatial coordinates of the surface nodes of the parts within the contact domain obtained in step S3, after interpolation and refinement. m S n Extract the corresponding node set S from the cross section corresponding to each Y coordinate. j m and S j n The expression is:

[0107]

[0108] Among them, y j This is a set of parallel sections along the Y-axis;

[0109] For each section y j Calculate S j m and S j n The distance between all pairs of points The expression is:

[0110]

[0111] S4.2. For the pairwise distances between all points obtained in step S4.1 For points less than a given criterion ε, determine the point closest to the upper or lower limit in the X or Z direction, expressed as:

[0112]

[0113] in, Let be the minimum point closest to the X direction in the upper boundary set. Let be the point in the upper bound set that is closest to the maximum value in the X direction. Let be the minimum point closest to the Z direction in the lower boundary set. Let argmin be the point in the lower boundary set closest to the maximum value in the Z direction, where argmin represents the computation of x. j or z j The minimum value of j, where argmax represents the value of x when calculated. j or z j The maximum value of j;

[0114] S4.3. Based on the points closest to the upper and lower limits in the X or Z directions obtained in step S4.2, construct the contact profile point set within the parallel cross-section of the part within the contact domain, and the contact profile upper boundary point set T. mn-s and the lower boundary point set T mn-x The expression is:

[0115] T mn-s ={t is =(x is ,y is ,z is | i = 1, 2, ..., n s}

[0116] T mn-x ={t ix =(x ix ,y ix ,z ix| i = 1, 2, ..., n x}

[0117] Among them, t is For the i-th adjacent point of the upper boundary, t ix Let n be the i-th lower boundary adjacent point. s n is the total number of adjacent points to the upper boundary. x This represents the total number of adjacent points to the lower boundary.

[0118] S5. For the set of contact profile points within the parallel cross-section of the parts within the contact domain obtained in step S4, calculate the actual contact length, contact width and contact resistance between the contacting parts.

[0119] Furthermore, the specific implementation method of step S5 includes the following steps:

[0120] S5.1. Calculate the adjacent points t of the above boundary. is t (i+1)s Adjacent point t to the lower boundary ix t (i+1)x The contact length l of the spatial quadrilateral formed by the vertices i(i+1) mn and contact width w i(i+1) mn The expression is:

[0121]

[0122] S5.2. Calculate the contact resistance of a single spatial quadrilateral. The expression is:

[0123]

[0124] Where ρ is the resistivity of the material, and r is the radius of the circular cross-section of the conductor;

[0125] S5.3. Considering that the contact resistances of multiple spatial quadrilaterals are in parallel, the contact resistance between the contacting parts is obtained. The expression is:

[0126]

[0127] S6. Based on the contact resistance between the contacting parts obtained in step S5, and according to the spatial distribution relationship of the N wires and terminals after crimping, establish a network model of the terminal resistance of the wiring harness for new energy vehicles.

[0128] Furthermore, the specific implementation method of step S6 is to obtain the contact resistance R between the contacting parts. c mnThen, based on the distribution relationship between the crimped wires and terminals, a wire harness terminal resistance network is established. Considering that the contact resistances between the N wires and terminals are in parallel, the wire harness terminal resistance R is obtained. c The expression is:

[0129]

[0130] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A modeling calculation method for a wire harness terminal resistance for a new energy vehicle, characterized by, Comprise the following steps: S1. Extract the surface node spatial coordinates of the N wires and terminals after crimping, define the N wires and terminals after crimping as parts, and construct the surface node spatial coordinate point set of the parts; S2. Determine the contact domain range of different parts based on the surface node spatial coordinate point set of the parts obtained in step S1, and extract the surface node spatial coordinate point set of the parts in the contact domain range for overlapping parts; S3. Perform interpolation refinement processing on the surface node spatial coordinate point set of the parts in the contact domain range obtained in step S2 to obtain the surface node spatial coordinate point set of the parts in the contact domain range after interpolation refinement processing; S4. Calculate the contact contour point set in the parallel cross section of the parts in the contact domain range along the axial direction of the wire based on the surface node spatial coordinate point set of the parts in the contact domain range after interpolation refinement processing obtained in step S3; S5. Calculate the actual contact length, contact width and contact resistance between the contact parts based on the contact contour point set in the parallel cross section of the parts in the contact domain range obtained in step S4; S6. Based on the contact resistance between the contact parts obtained in step S5, establish a wire harness terminal resistance network model for new energy vehicles according to the spatial distribution relationship of the N wires and terminals after crimping.

2. The method for modeling and calculating the resistance of a wire harness terminal for a new energy vehicle according to claim 1, characterized in that, Step S1 establishes a three-dimensional entity model of the terminal, N wires, upper die and lower die according to the actual working condition, applies finite element software to simulate the crimping process of the terminal and wire, and then extracts the surface node spatial coordinates of the N wires and terminals after crimping; The N crimped wires and the terminal are defined as a part, and a surface node space coordinate point set P of the part is constructed k The expression is: wherein k is the kth part, k = 1 ~ N+1, n k is the total number of surface node coordinates of the kth part, i is the ith surface node of the kth part, is the spatial coordinate point of the ith surface node of the kth part, is the X-axis coordinate point of the ith surface node of the kth part, is the Y-axis coordinate point of the ith surface node of the kth part, is the Z-axis coordinate point of the ith surface node of the kth part.

3. The method according to claim 2, wherein, The specific implementation method of step S2 comprises the following steps: S2.

1. First, the maximum and minimum values of the part on the x, y and z coordinate axes are calculated respectively to obtain the minimum point B of the surface node space coordinate point set of the part k min and the maximum point B k max , the expression is: B k min = (minx i k ,miny i k ,minz i k ) B k max = (maxx i k ,maxy i k ,maxz i k ) Wherein, min is the minimum function, max is the maximum function; Then take B k min and B k max Two opposite corners of the cuboid, build the bounding box of the surface node space coordinate point set P k of the part; If parts m and parts n, 1≤m,n≤N+1 and m≠n, satisfy the following conditions: Preliminary judgment that parts m and parts n have overlapping parts, otherwise there is no overlapping part; Then determine the contact domain range of different parts, and obtain the parts m and parts n which are preliminarily judged to have overlap; S2.

2. For the preliminary judgment obtained in step S2.1, if there are overlapping parts m and n, calculate the surface node space coordinate point set P of part m and part n respectively m and the convex hull of P n , if the convex hull vertex of P m is in the convex hull of P n , determine that P m , P n have overlapping parts, and part m and part n have a contact domain; S2.

3. Assuming that the Y axis is the axial direction of each wire and terminal, there will be a point set P of the contact domain m and P n Projecting to the Y axis, respectively, the coordinate point set Proj XZ (P m ) of part m in the XZ plane and the coordinate point set Proj XZ (P n ) of part n in the XZ plane are obtained, and the expressions are as follows: Extract Proj XZ (P m ) and Proj XZ (P n ) of the intersection Q mn , the expression is: Q mn = [Proj XZ (P m )] I [Proj XZ (P n )] Wherein, I is the intersection operator; Q mn The original surface node space coordinate point set P m , P n of the parts m and n are respectively mapped to obtain the surface node space coordinate point set R m in the contact domain range of the part m and the surface node space coordinate point set R n in the contact domain range of the part n, and the expression is:

4. The method according to claim 3, wherein, The specific implementation method of step S3 is to calculate the surface node spatial coordinate point set R in the contact domain range of the part m m Calculate the interval length L of the part m in the X axis x m And the interval length L of the part m in the Z axis z m The expression is: If L x m ≥ L z m , interpolation is performed on R m in the XY plane, if L x m < L z m , interpolation is performed on R m in the YZ plane, to obtain a set of surface node space coordinate points S m of the part in the contact domain range of the interpolation refinement processing of the part m, expressed as:

5. The method for modeling and calculating the resistance of a wire harness terminal for a new energy vehicle according to claim 4, characterized in that, The specific implementation method of step S4 comprises the following steps: S4.

1. The surface node space coordinate point set S of the part in the contact domain range of the part m, part n interpolation refinement processing obtained in step S3 m , S n , extract the corresponding node set S in each Y coordinate corresponding section j m and S j n , the expression is: wherein y j is a set of parallel sections along the Y axis; For each cross section y j , calculate S j m and S j n the distance between all pairs of points in S The expression is: S4.

2. For all pairs of points obtained based on step S4.1, the distance between the two points is calculated The point closest to the upper or lower limit in the X or Z direction is determined for points less than a given decision criterion ε, expressed as: wherein, is a minimum point in the upper boundary set closest to the X direction, is a maximum point in the upper boundary set closest to the X direction, is a minimum point in the lower boundary set closest to the Z direction, is a maximum point in the lower boundary set closest to the Z direction, arg min denotes the value of j for which x j or z j is minimum, arg max denotes the value of j for which x j or z j is maximum. S4.

3. Based on the points closest to the upper and lower limits in the X or Z direction obtained in step S4.2, a set of contact profile points in the parallel section of the part within the contact domain range is constructed, the set of upper boundary points T on the contact profile mn-s and the set of lower boundary points T mn-x The expression is: T mn-s = {t is = (x is , y is , z is ) | i = 1, 2,..., n s} T mn-x = {t ix = (x ix ,y ix ,z ix ) | i = 1, 2,..., n x} where t is is the i-th upper boundary adjacent point, t ix is the i-th lower boundary adjacent point, n s is the total number of upper boundary adjacent points, and n x is the total number of lower boundary adjacent points.

6. The method for modeling and calculating the resistance of a wire harness terminal for a new energy vehicle according to claim 5, characterized in that, The specific implementation method of step S5 comprises the following steps: S5.

1. Calculate the above boundary adjacent point t is , t (i+1)s and the lower boundary adjacent point t ix , t (i+1)x The contact length l i(i+1) mn and the contact width w i(i+1) mn of the space quadrilateral composed of the vertices are expressed as: S5.

2. Calculate the contact resistance of a single spatial quadrilateral The expression is: Wherein, ρ is the resistivity of the material, and r is the radius of the circular cross section of the wire; S5.

3. Considering the contact resistance of multiple spatial quadrilaterals as a parallel relationship, the contact resistance between the contact parts is obtained The expression is:

7. The method according to claim 6, wherein, The specific implementation method of step S6 is to obtain the contact resistance R between the contact parts c mn After that, according to the distribution relationship between the contact parts of the completed crimping and the terminals, the terminal resistance network of the wire harness is established, the contact resistance between the N wires and the terminals is considered as a parallel relationship, and the terminal resistance R of the wire harness is obtained c The expression is:

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