A multi-constraint automatic layout method for electrical harness template

Abstract

The present application relates to the technical field of graph layout, and particularly relates to a kind of multi-constraint automatic layout methods for electrical harness template graph, constructs harness initial layout model;Extract the constraint information related to layout model;Based on constraint information, the layout model is optimized round by round, and an optimized model is obtained;The quality of the optimized model is evaluated to determine whether the result is satisfactory, a satisfactory result is obtained, and a selection operation is performed based on the satisfactory result, the layout can obtain a dynamic trend result that adapts to each constraint after each round of iteration, and the final result obtained in random order is almost the same, reducing the additional work caused by sorting, which can greatly reduce the workload of workers in actual tooling plate pre-installation harness, by reasonably setting step, effectively avoid the situation of falling into local optimum in layout, while ensuring the final layout stable trend result, solve the problem that existing graph layout needs tedious manual adjustment and does not satisfy rigid harness.

Description

Technical Field

[0001] This invention relates to the field of graph layout technology, and in particular to an automatic layout method for electrical harness templates with multiple constraints. Background Technology

[0002] A wire harness is an assembly that connects connectors and wires / cables by crimping them together and then molding insulation onto the outside, forming a circuit. The wire / cable segments are called harness segments, and they are crucial components in products such as aircraft, automobiles, and home appliances. In aircraft manufacturing, after designers complete a 3D wire harness design, they need to generate a 2D wire harness layout drawing to guide workers in pre-installing the wire harness on the tooling plate. This layout must meet a series of process constraints. However, the layout obtained directly from the 3D model projection often fails to meet these constraints, requiring designers to perform tedious manual adjustments.

[0003] Although there has been extensive research on graph layout both domestically and internationally, most studies focus on the arrangement of graph nodes where the node spacing can be freely changed. However, there is still a lack of mature research on rigid bodies such as wire harnesses (the length of wire harness segments is fixed, and the nodes are rigidly connected, meaning the node spacing cannot be changed), especially in cases with multiple constraints. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic layout method for multiple constraints of electrical wiring harness template drawings, which aims to solve the problem that existing layout methods require cumbersome manual adjustments and do not meet the requirements of rigid wiring harnesses.

[0005] To achieve the above objectives, the present invention provides an automatic layout method for multiple constraints of electrical wiring harness template diagrams, comprising the following steps:

[0006] Construct the initial layout model of the wire harness;

[0007] Extract the relevant constraint information of the layout model based on the requirements document;

[0008] Based on the constraint information, the layout model is optimized round by round to obtain an optimized model;

[0009] The quality of the optimization model is evaluated to determine whether the result is satisfactory. A satisfactory result is obtained, and a selection operation is performed based on the satisfactory result.

[0010] The specific method for constructing the initial layout model of the wire harness is as follows:

[0011] Extract the list of information about the nodes of the wire harness segment and the list of edge information about the connections between the nodes from the wire harness dataset that has been divided into multiple wire harness segments.

[0012] An initial layout model is constructed based on the information list and the edge information list.

[0013] The relevant constraint information includes the relative angle constraint requirements of the wire harness segments themselves, the vertical distance constraint requirements between wire harness segments, the overall layout boundary range constraint requirements, and the intersection constraint requirements between wire harness segments.

[0014] The round-by-round optimization adopts the SGD algorithm strategy.

[0015] The specific method for performing the selection operation based on the satisfactory result is as follows:

[0016] If the desired result is satisfactory, then accept the result; if the desired result is unsatisfactory, then return to continue optimization round by round until the evaluation result is satisfactory.

[0017] This invention provides an automatic layout method for electrical wiring harness templates with multiple constraints. The method involves constructing an initial layout model for the wiring harness; extracting relevant constraint information from the layout model based on a requirements document; performing successive optimizations on the layout model based on the constraint information to obtain an optimized model; evaluating the quality of the optimized model to determine if the result is satisfactory; obtaining a satisfactory result; and performing a selection operation based on the satisfactory result. This method introduces the SGD strategy into the layout algorithm, resulting in a dynamic trend that adapts to each constraint after each iteration. The final results obtained by random ordering are almost identical, reducing the extra work caused by sorting and significantly reducing the workload of workers pre-installing wiring harnesses on actual tooling plates. By reasonably setting the step size, it effectively avoids getting stuck in local optima during layout, while ensuring a stable and trending final layout. It also provides separate adjustment calculation methods and independent weight allocation for specific process constraints, facilitating users to reasonably set parameters for different feature layouts and obtain the desired results. This solves the problem of existing layouts requiring cumbersome manual adjustments and not meeting the requirements for rigid wiring harnesses. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram for calculating the angle adjustment amount under cross constraints.

[0020] Figure 2 This is a case study illustrating the upward transmission strategy.

[0021] Figure 3 This is a diagram illustrating a strategy for passing information down the chain of command.

[0022] Figure 4This is a flowchart of an automatic layout method for multiple constraints of electrical wiring harness template provided by the present invention.

[0023] Figure 5 This is a flowchart for calculating the adjustment amount of the wire harness segment under the current pairing result in S34.

[0024] Figure 6 This is a flowchart for updating the layout results using the calculated adjustment amount in S35.

[0025] Figure 7 These are before-and-after diagrams showing the results of processing a real-world case using the present invention.

[0026] Figure 8 This is a flowchart illustrating the steps of an automatic layout method for multiple constraints of electrical wiring harness templates provided by the present invention. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] Please see Figures 1 to 8 This invention provides an automatic layout method for multiple constraints in electrical wiring harness template diagrams, comprising the following steps:

[0029] S1 constructs the initial layout model of the wire harness;

[0030] Specific methods:

[0031] S11 extracts a list of information about the nodes of the wire harness segment and a list of edge information about the connections between the nodes from the wire harness dataset that has been divided into multiple wire harness segments.

[0032] Specifically, from the wire harness dataset S, which is divided into multiple wire harness segments to be optimized, extract the position information list {P1, P2, ..., P} of the n+1 nodes corresponding to the n wire harness segments. j ...,P n+1}, and the list of edge information connecting nodes {L1,L2,...,L i ,···,L n}, where P j This represents information about the j-th node, including its two-dimensional coordinates, L. i This represents the information of the line segment corresponding to the i-th edge, including the starting point number x, the ending point number y, and the line segment radius R. i Harness segment length Len i , 1≤j≤n+1, 1≤i≤n.

[0033] S12 constructs an initial layout model based on the information list and the edge information list.

[0034] Specifically, the initial layout model of the wire harness, M0 = {Seg1, Seg2, ..., Seg...}, is constructed using the node information list and the edge information list. i ,···,Seg n}, where Seg i Representing edge L i The corresponding harness segment information includes the harness segment connection relationship (a list of harness segments connected at the starting point and branch harness segments connected at the ending point), and the radius R. i The angle θ relative to the upper-level harness segment i Length Len i Since the connection relationships, radius, and length of the harness segments will not change after the layout model is established, the initial layout model can be simplified and redefined as M0 = {θ1, θ2, ..., θ...} i ,···,θ n}, 1≤i≤n.

[0035] S2 extracts the relevant constraint information of the layout model based on the requirements document;

[0036] Specifically, relevant constraint information is extracted from the requirements document. The constraint requirements mainly include four aspects of information data, namely LayoutConstraints.

[0037] LayoutConstraints={AngleConstraint,DistanceConstraint,BoardlineConstraint,CrossConstraint}

[0038] Among them, AngleConstraint is the relative angle constraint requirement of the wire harness segment itself, DistanceConstraint is the vertical distance constraint requirement between wire harness segments, BoardlineConstraint is the overall layout boundary range constraint requirement, and CrossConstraint is the cross constraint requirement between wire harness segments.

[0039] S3 optimizes the layout model round by round based on the constraint information to obtain an optimized model;

[0040] Specifically:

[0041] S31 initializes the iteration round number iter to 0;

[0042] S32 iter increments by one, and the adjustment step size for all harness segments in the iter-th iteration is:

[0043] Stepsize iter =MaxStepsize*e -log(MaxStepSize / MinStepSize)*iter / (MaxIter-1) ,

[0044] Parameters are passed up in the iterth iteration:

[0045] Alpha iter =MaxAlpha*(1-e -log(MaxStepSize / MinStepSize)*iter / (MaxIter-1) ),

[0046] Where MaxStepsize and MinStepsize are the preset maximum and minimum step sizes, MaxIter is the preset maximum allowed number of iterations, and MaxAlpha is the preset maximum value of the upward transmission parameter;

[0047] S33 pairs {Seg1, Seg2, ..., Seg...} i ,···,Seg n Pairing them up in pairs yields n*(n-1) pairs: {(Seg1,Seg2),(Seg1,Seg3),...,(Seg...} i Seg j ),···,(Seg n Seg n-1 (i≠j, 1≤i, j≤n); then rearrange randomly to obtain the pairing results.

[0048]

[0049] Where k1, k2, ..., k i ,···,k j ,···,k n The result is the result of randomly sorting 1, 2, ..., i, ..., j, ..., n*(n-1), (i ≠ j, 1 ≤ i, j ≤ n);

[0050] S34 iterates through all pairing results, and in the current pairing result (Seg... i Seg j Under the constraint Constraint l Lower harness segment Seg i Adjustment vector V l =F l (Constraint l Seg i Seg j Constraint l ∈LayoutConstraints, l∈{Angle,Distance,Boardline,Cross},Fl For Constraint l The adjustment calculation function below; each F l The calculation is as follows:

[0051] I. Under angular constraints: Based on the harness segment Seg i Angle θ i The calculated angle adjustment amount is:

[0052]

[0053] Where θ H θ is the maximum permissible angle value. S k is the desired angle value. H To calculate the hard constraint weights, k S To calculate the soft constraint weights, these parameters are all derived from the AngleConstraint; the corresponding adjustment vector V Angle = (Δx, Δy) is calculated according to equation (1);

[0054]

[0055] In equation (1) θ x Indicates the angle between the harness segment and the X-axis;

[0056] II. Under distance constraints: based on the line harness segment Seg i End point to Seg j reverse vertical distance vector Obtain the corresponding adjustment vector

[0057]

[0058] Where d H d is the minimum allowable distance value. S k is the desired distance value. H To calculate the hard constraint weights, k S These parameters are all derived from DistanceConstraint to calculate the soft constraint weights;

[0059] III. Under boundary constraints: Based on the Seg line harness segment i The adjustment vector is calculated based on the distance d from the endpoint to the nearest boundary (upper boundary / lower boundary).

[0060]

[0061] Where β is a certain distance constraint value to ensure that the wire harness segment does not exceed the template boundary, and k H To calculate the hard constraint weights, k S These parameters are all derived from BoardlineConstraint for calculating the soft constraint weights;

[0062] IV. Under cross constraints: Based on the Seg line harness segment i With Seg j The intersection cases yield Seg i Just peel off Seg j (Non-intersecting) minimum angle adjustment value Δθ=min(θ left ,θ right ),like Figure 1 As shown, its corresponding adjustment vector V cross = (Δx, Δy) is calculated according to equation (1), and the non-crossing constraint requirement comes from CrossConstraint;

[0063] In this pairing, Seg i The weighted cumulative adjustment vector under each constraint is V. sum =∑Stepsize iter *w l *V l , where w l For Constraint l The computational weights corresponding to the constraints are l∈{Angle,Distance,Boardline,Cross};

[0064] Based on the bidirectional transmission strategy, according to the calculated V sum Adjust Seg i The relative angles of the associated harness segments are determined, and for unrelated harness segments, the relative angles remain unchanged; finally, the adjustment result M of the layout model after the iterth round and the kth pairing is obtained. iter,k ={newθ1,newθ2,···,newθ i ,···,newθ n The bidirectional transfer strategy is as follows (1≤k≤n*(n-1)):

[0065] Upward propagation strategy: such as Figure 2 As shown, Seg i ′ for Seg i The expected adjustment position, assuming Seg i The upper-level harness segment is Seg i-1 And so on, then Seg i The actual adjustment vector is (1-Alpha) iter )*V sum Assigned to Seg i-1 The adjustment vector is Alpha iter *V sum Seg i-1 The actual adjustment vector is (1-Alpha) iterAlpha iter *V sum Assigned to Seg i-2 The adjustment vector is (Alpha) iter ) 2 *V sum ...and so on, until it is passed to the highest-level harness segment;

[0066] For Seg i and all its superior harness segments Seg i-1 Seg1, calculated sequentially from top to bottom, yields Seg. k The relative angle of ′

[0067]

[0068] Where θ x Seg of wire harness k-1 The angle between Seg and the X-axis, x1 is the angle between Seg and the X-axis. k The starting x-coordinate of Seg k-1 The x-coordinate of the endpoint of Seg (x1 = 0 when k = 1), y1 is the x-coordinate of Seg. k The starting ordinate of Seg k-1 The endpoint y-coordinate of Seg (y1 = 0 when k = 1), k The expected endpoint x2 = oldx + Vx, Seg k The expected endpoint y-coordinate of Seg is y2 = oldy + Vy, where oldx is the ordinate of Seg. k The x-coordinate of the endpoint, oldy, is Seg. k The endpoint ordinate, Vx is Seg k The actual adjustment in the x-direction for this pairing, Vy, is Seg. k The actual adjustment amount in the y-direction for this pairing is 1≤k≤i;

[0069] Downward propagation strategy: such as Figure 3 As shown, assuming Seg i The lower-level harness segment is Seg i+1 And so on, when Seg i Adjust to the expected position Seg i At ′, Seg i+1 The relative angle of ′ is

[0070]

[0071] Where θ x Seg of wire harness i The angle between Seg and the X-axis, x1 is the angle between Seg and the X-axis. i The x-coordinate of the endpoint of Seg is y1. iThe endpoint ordinate of Seg is x2. i+1 The x-coordinate of the endpoint, y2 is Seg i+1 The endpoint ordinate, for Seg i+1 The same principle applies to the lower-level harness segments, and so on, until the last level harness segment is reached;

[0072] If all the pairing results in this round have been traversed, i.e., when k = n*(n-1), then the final layout result M of the iterth round is obtained. iter =M iter,n*(n-1) If the condition is met, proceed to step S4; otherwise, return to step S34.

[0073] S4 evaluates the quality of the optimization model to determine whether the result is satisfactory, obtains a satisfactory result, and performs a selection operation based on the satisfactory result.

[0074] Specifically, when the layout result fully meets the predetermined constraints, or when the iter reaches the preset maximum number of iterations, or when the average adjustment amount (averageAdjust) is not fully met but the layout begins from a certain round... iter When the value is less than the threshold, the algorithm considers the result satisfactory and accepts it; otherwise, it returns to S32 to continue iterating. The average adjustment amount in the iterth round is...

[0075]

[0076] Where ||V iter,k || represents the adjustment vector value under the k-th pairing in the iter round, and threshold is the average adjustment threshold used to exit the iteration early.

[0077] The above description is merely a preferred embodiment of the automatic layout method for multiple constraints of electrical wiring harness template diagrams according to the present invention. Of course, it should not be construed as limiting the scope of the present invention. Those skilled in the art can understand that all or part of the process of implementing the above embodiments and equivalent changes made in accordance with the claims of the present invention still fall within the scope of the invention.

Claims

1. A multi-constraint automatic layout method for electrical wiring harness template drawings, characterized in that, Includes the following steps: Construct the initial layout model of the wire harness; Specific methods: Extract the list of information about the nodes of the wire harness segment and the list of edge information about the connections between the nodes from the wire harness dataset that has been divided into multiple wire harness segments. An initial layout model is constructed based on the information list and the edge information list; Based on the requirements document, extract the relevant constraint information of the layout model, wherein the relevant constraint information includes the relative angle constraint requirements of the wire harness segments themselves, the vertical distance constraint requirements between wire harness segments, the overall layout boundary range constraint requirements, and the intersection constraint requirements between wire harness segments; The layout model is optimized round by round based on the constraint information to obtain an optimized model, wherein the round by round optimization adopts the SGD algorithm strategy; Specifically: Initialize the iteration round number iter to 0; Increment iter by one, and the adjustment step size for all harness segments in the iter-th iteration is: ， Parameters are passed up in the iterth iteration: ， in and For the preset maximum and minimum step sizes, The maximum allowed number of iterations is preset. The maximum value of the parameter to be passed upwards is preset; right By pairing them up, we can obtain... Group matching results Then, the pairs are randomly rearranged to obtain the matching results. , in for The result after random sorting ; Iterate through all pairing results, and in the current pairing result... Below, constraints Lower harness segment Adjustment vector ,in , , for The adjustment calculation function below; each The calculation is as follows: I. Under angular constraints: based on the wire harness segment angle The calculated angle adjustment amount is: ， in This is the maximum permissible angle value. The desired angle value. To calculate the hard constraint weights, These parameters are all derived from the calculation of soft constraint weights. ; Corresponding adjustment vector Calculate according to formula (1); ，(1) In formula (1) Indicates the angle between the harness segment and the X-axis; II. Under distance constraints: based on the wire harness segment End point reverse vertical distance vector Obtain the corresponding adjustment vector ， in This is the minimum allowable distance value. The desired distance value. To calculate the hard constraint weights, These parameters are all derived from the calculation of soft constraint weights. ; III. Under boundary constraints: Based on the wire harness segment Distance from the endpoint to the nearest boundary (upper boundary / lower boundary) Calculate the corresponding adjustment vector ， in To ensure that the wire harness segment does not exceed a certain distance constraint value of the template boundary, To calculate the hard constraint weights, These parameters are all derived from the calculation of soft constraint weights. ; IV. Under cross constraints: Based on the wire harness segment and The intersection cases yielded Just peel Minimum angle adjustment value Its corresponding adjustment vector According to equation (1), the non-intersecting constraint requirement comes from... ; In this pairing, The weighted cumulative adjustment vector under each constraint is: ,in for The corresponding calculation weights of the constraints ; Based on the bidirectional transmission strategy, according to the calculated... Adjustment The relative angles of the associated harness segments are determined, and for unrelated harness segments, the relative angles remain unchanged; finally, the adjustment results of the layout model after the iterth round and the kth pairing are obtained. The bidirectional transmission strategy is as follows: Upward propagation strategy: for The expected adjustment position, assuming The upper-level harness segment is And so on, The actual adjustment vector is Assigned to The adjustment vector is , The actual adjustment vector is Assigned to The adjustment vector is ... and so on, until it is passed to the highest-level harness segment; for and all its superior harness segments Calculated sequentially from top to bottom relative angle ， in For wire harness segment The angle with the X-axis, for The starting x-coordinate (i.e.) The x-coordinate of the endpoint, hour ), for The starting point ordinate (i.e.) The endpoint ordinate, hour ), The expected endpoint x-coordinate , Expected endpoint ordinate ,in for The x-coordinate of the endpoint, for The endpoint ordinate, for The actual adjustment amount in the x-direction for this pairing. for The actual adjustment amount in the y-direction for this pairing. ; Downward propagation strategy: Assumption The lower-level harness segment is And so on, when Adjust to the expected position hour, The relative angle is ， in For wire harness segment The angle with the X-axis, for The x-coordinate of the endpoint, for The endpoint ordinate, for The x-coordinate of the endpoint, for The endpoint ordinate, for The same principle applies to the lower-level harness segments, and so on, until the last level harness segment is reached; If all the pairing results in this round have been traversed, that is... At that time, the final layout result of the iterth round is obtained. The process then proceeds to evaluate the quality of the optimization model to determine if the result is satisfactory. If a satisfactory result is obtained, a selection operation is performed based on the satisfactory result; otherwise, the process returns to iterating through all pairing results and selecting the current pairing result. Below, constraints Lower harness segment Adjustment vector ; The quality of the optimization model is evaluated to determine whether the result is satisfactory. A satisfactory result is obtained, and a selection operation is performed based on the satisfactory result.

2. The automatic layout method for multiple constraints of electrical wiring harness templates as described in claim 1, characterized in that, The specific method for performing the selection operation based on the satisfactory result is as follows: If the desired result is satisfactory, then accept the result; if the desired result is unsatisfactory, then return to continue optimization round by round until the evaluation result is satisfactory.

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