CN1750007A - Method for tolerance design qualitative simulation of sedan body - Google Patents

Abstract

The present invention belongs to the field of computerized simulation technology. The tolerance design and qualitative simulation process for sedan body includes the following steps: A. utilizing the association matrix and prior association matrix and contracting matrix to judge sub-assembly in serial form, to create all the feasible assembling orders, and reducing the assembling orders with the qualitative information to create assembling process index matrix to create the feasible assembling order set; B. configuring initial assembly jointing scheme and the assembling scheme jointing process restriction to generate assembling scheme joint set; and C. determining the size composition rings of key size chain, performing initial scheme setting of the tolerance of key size composition ring to be optimized and trimming the tolerance limit of the composition ring to create the optimized tolerance configuring scheme of the assembly and qualitative analysis and calculation of the assembling deviation of the assembled size.

Description

Coachbuilt body is carried out the method for tolerance design qualitative simulation

Technical field

What the present invention relates to is the method in a kind of computer simulation technique field, particularly a kind of method of coachbuilt body being carried out tolerance design qualitative simulation.

Background technology

The manufacturing of coachbuilt body is welded by hundreds of shapes and thin-slab construction spare not of uniform size, that punching press is good, when design, the designer distributes the tolerance of car load and each thin-slab construction spare according to accessory size and welding procedure difficulty or ease, if it is reasonable that tolerance is distributed, the size of the profile three-dimensional point of the car body after the dress weldering is finished more easily reaches designing requirement, but the designer can not accomplish once success, usually will be through repeatedly revising.If, the designer uses a computer qualitative simulation is carried out in the tolerance distribution of car load and each thin-slab construction spare, further just can in various qualitative simulation schemes, constantly screen, finally draw optimum tolerance allocative decision, also just may once adorn and weld out the car body that reaches designing requirement.Build-up tolerance design in the past (comprising the distribution of TOLERANCE ANALYSIS and tolerance) all is based on detailed quantitative design, just can be optimized analysis under the prerequisite of clear and definite part parameter information.But many problem origins of the production of product, manufacturing, operation and maintenance all are to occur in conceptual phase, at the body structure conceptual phase, the cad model of part and assembly technology do not determine that also conventional numerical evaluation can't be carried out simulation calculation to dimensional discrepancy.The Hyundai Motor design needs a new technology to come in the prediction of body structure conceptual phase and analyzes build-up tolerance, and can handle the unknown undetermined, incomplete technical parameter, set up tight mathematical logic, carry out the qualitative description of system state, simultaneously, thisly utilize finite information to carry out qualitative reasoning also to help detailed The Automation Design of next stage, making provides a large amount of feasible programs at conceptual phase, to weigh the pros and cons, improve the rationality of design.

Find that through literature search China Patent No. is to prior art: 96196485.5, name is called: statistical tolerance is determined method, this patent is to adopt statistical method to determine effective element size tolerance limit.This method is only selected a kind of preferred part assemble sequence and its validity is confirmed.This method is positioned the detailed process design phase, and all kinds of tolerances of vehicle body were carried out qualitative simulation when the method can not be to the coachbuilt body conceptual design.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, a kind of method of coachbuilt body being carried out tolerance design qualitative simulation is proposed, make it utilize the characteristics of qualitative simulation method, be applied to the conceptual phase of vehicle body assembling, at first integrated assemble sequence, configuration joint carry out build-up tolerance on this basis and distribute.

The present invention is achieved by the following technical solutions, the present invention includes following steps:

A. at first, utilize incidence matrix and precedence relationship matrix,, generate all feasible assemble sequences by after shrinking matrix and judging sub-assemblies with series-parallel form, and, generate feasible assemble sequence collection by utilizing qualitative information generation assembly technology exponential matrix to subtract assemble sequence approximately;

B. by the initial joint scheme of man-machine interaction mode configuration assembly and the joint process constraint of assembling scheme, produce joint categories configuration design proposal, immediate shipment prescription case joint collection with heuristic intelligent algorithm then;

C. on the basis of the assembling scheme joint collection that feasible assemble sequence collection that step a obtains and step b obtain, determine each size composition ring of this critical size chain for the critical product size, then the tolerance of the critical size chain makeup ring of desiring to be optimized design is carried out the initial scheme setting, and the tolerance limit of makeup ring carried out small adjustment, thereby generate the optimization tolerance allocation plan of assembly, the assembling scheme joint collection that feasible assemble sequence collection that integrating step a obtains and step b obtain carries out the assembling deviation qualitative analysis of fitted position and calculates.

Described step a, the step that comprises is as follows:

(1) by the input of assembly precedence relationship, draw the oriented annexation figure of this assembly, obtain it then and get adjacency matrix;

(2) judge by extraction, the validity of series, parallel and ring connection sub-unit and select, after conversion, generates the contraction matrix by the adjacency matrix of assembly;

(3) select different sub-units to generate assembly tree, obtain all assemble sequences of this assembly by backtracking method;

(4) by calculating the assembly technology matrix of assembly,, subtract the feasible order number that previous step (3) obtains approximately by judging and the substrate of definite assembly and sub-assemblies;

(5) determine the critical product size calculated, by finish all possible dimensions chains of critical product feature based on deep search, according to the final dimension chain of determining the critical product size of technological design rule in the assembling knowledge base.Described technological design rule: tolerance chain is short more good more, if but there is long public chain between many dimension chains, get the long dimension chain that promptly comprises other dimension chains so.

Described step b, the step that comprises is as follows:

(1) determines that at selected assembly the main jointing in the critical size chain carries out the type original definition, form the initial joint collection of assembly;

(2) controlled variable of genetic algorithm is provided with or uses the default setting of genetic algorithm;

(3) heuristic intelligent algorithm adopts genetic algorithm, in advance the joint type of attachment between some part being carried out the design space retrains, the constraint penalty that in genetic algorithm, need be correlated with, abandon in all evolutionary process infeasible solution and the various terminal scheme is carried out Combinatorial Optimization again, and then generate the joint collection of assembling scheme.

Among the described step c, the step that comprises is as follows:

(1) at first determines the critical product size desiring to be optimized, determine the makeup ring of this critical size by deep search automatically;

(2), the assembling deviation of critical part connection features in the assembly critical size chain is carried out the setting of initial tolerances scheme, as the starting point of optimized Algorithm according to experimental design method;

(3) characteristics of utilizing the Tabu neighborhood search are dynamically adjusted the build-up tolerance limit with varying sized chain makeup ring part step by step minutely, generate the tolerance allocative decision collection of critical size;

(4) utilize qualitative simulation that the build-up tolerance of each size ring in the dimension chain is carried out the interval number expression, the assemble sequence collection and (3) the step joint scheme collection that generates that generate in conjunction with (2) step carry out the qualitative simulation analysis of assembly deviation.

Compared with prior art, the present invention is applied to the qualitative simulation theory vehicle body assembling conceptual phase first, provides method for setting up vehicle body conceptual phase assembling deviation analysis software, realizes the qualitative evaluation of the vehicle body conceptual phase vehicle body amount of deflection.The present invention can be at the car body structure conceptual phase, qualitative simulation is carried out in tolerance distribution to car load and each thin-slab construction spare, a large amount of feasible programs is provided, further just can in various qualitative simulation schemes, constantly weigh the pros and cons, finishing screen is selected optimum tolerance allocative decision, like this, just can once adorn and weld out the car body that reaches designing requirement, and need not in trial-manufacturing process, to adjust repeatedly tolerance.

Description of drawings

Fig. 1 is a vehicle body assembly system deviation simulation optimization block diagram of the present invention

The process flow diagram that Fig. 2 obtains for car vehicle body assemble sequence of the present invention

Fig. 3 is car assembling process tolerance stream simulation flow figure of the present invention

Fig. 4 is the integrated order of car of the present invention, the qualitative computation process figure of joint and tolerance

Fig. 5 is car build-up tolerance design software analysis process figure of the present invention

Embodiment

Content provides specific embodiment according to the present invention: a kind of method of the tolerance design qualitative simulation that is used for S6460 type concept car is as follows:

A. at first generate the assemble sequence collection as shown in Figure 1, specifically at first import the assembly part as shown in Figure 5 from model database, each part is with digital 1,2,3 ... be numbered, utilize man-machine interaction to extract incidence matrix and precedence relationship matrix, and by after shrinking matrix and judging sub-assemblies with series-parallel form, generate all feasible assemble sequences, feasible assemble sequence product process concrete steps are seen Fig. 2, the dependency database extracts the qualitative information of assembly, and subtracts assemble sequence approximately as shown in Figure 4 by utilizing qualitative information to generate the assembly technology exponential matrix.

B. then generate the joint assembling scheme as shown in Figure 1, specifically dispose initial joint scheme or extract initial joint scheme with man-machine interaction mode as shown in Figure 4 by case library, and the joint process constraint that extracts this assembling scheme in the dependency database defines the chromosomal constraints module of genetic algorithm joint of this assembly, utilizes heuristic genetic algorithms to produce joint categories configuration design proposal thus.

C. determine the critical size of this assembly, the assemble sequence collection that utilizes step a to generate, determine each size composition ring of critical size chain, makeup ring to the critical size chain that is optimized design, part tolerance is set as shown in Figure 1, promptly carry out the tolerance initial setting up of dimensional chain for assembly makeup ring and the optimization setting of each assembling point tolerance limit, substitution dimensional chain for assembly equation, carrying out the assembling deviation qualitative analysis of assembly critical size at last calculates, calculation process such as Fig. 4, finally obtain at joint prioritization scheme and the Tolerance Optimization allocation plan optimized under the ordered set, with this input as later next detailed design phase by simulation calculating.

Among the described step a, the detailed process that its assemble sequence is obtained is referring to Fig. 2, and the step that comprises is as follows:

(1) by the input of assembly precedence relationship, draw the oriented annexation figure of this assembly, obtain its adjacency matrix then;

Judge by extraction, the validity of series, parallel and ring connection sub-assemblies (2) and select that the adjacency matrix that is calculated by the last step is through shrinking the contraction matrix that matrixing obtains assembly, this shrinks the adjacency matrix of matrix as the next stage sub-assemblies;

With three series connection is that example is analyzed

$R_a=\left[\begin{array}{ccc}0& 1& 0\\ -1& 0& 1\\ 0& -1& 0\end{array}\right],R_b=\left[\begin{array}{ccc}0& 1& 0\\ 1& 0& 1\\ 0& 1& 0\end{array}\right],R_c=\left[\begin{array}{ccc}0& 1& 0\\ 1& 0& 1\\ 0& -1& 0\end{array}\right]$

The mathematical relation that series connection sub-unit adjacency matrix should satisfy is gone into down:

(r _i，j＝1&&|r _j，i|＝-1，j＝i+1)&&(r _i，j＝0，|j-i|＞1)

(3) select the combination of different sub-assemblies to generate assembly tree successively, obtain all assemble sequences of this assembly then by retrogressive method;

(4) by the design basis characteristic of part, the adjacent contact quantity of part, the key dimension of part and the assembly technology matrix that weight calculates assembly, judge thus and the substrate of definite assembly and sub-assemblies, subtract approximately and go up the feasible order number that the step obtains;

The assembly technology indices P of part _DatiCalculate by following formula:

P _dati＝D _dati+x ₁ω _Wi+x ₂ω _degi+x ₃ω _sizei+x ₄ω _stiffnessi

The qualitative attribute value by ${\mathrm{\ω}}_{\mathrm{Wi}}=W_i/\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{W}_j$ Calculate acquisition,

Contact quantity property value by ${\mathrm{\ω}}_{\mathrm{degi}}={\mathrm{Deg}}_i/\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{Deg}}_j$ Calculate and obtain

Design basis property value D _DatiUtilize design specifications to carry out value, size factor ω _SizeiWith stiffness coefficient ω _StiffnessiUtilize fuzzy reasoning (part dimension, the complexity of part, part thickness) to carry out value, wherein x1, and x2, x3, x4} carries out value based on enterprise's design specifications.By the assembly technology indices P _DatiValue determine the substrate of assembly, thereby realize subtracting approximately of feasible assemble sequence.

(5) determine the critical product size calculated, by finish all possible dimensions chains of critical product feature based on deep search, by finally determine the dimension chain of critical product size based on qualitative experimental knowledge.

Among the described step b, the step that comprises is as follows:

(1) determines that at selected assembly main jointing carries out the type original definition in the critical size chain, at conceptual phase, joint categories is represented overlap joint, butt joint and corner connection respectively with alphabetical ABC, form the initial joint collection of assembly as shown in Figure 3, the starting point that initial joint collection calculates as genetic algorithm;

(2) then the controlled variable of genetic algorithm is provided with or directly uses the default setting of genetic algorithm in program;

(3) in advance the joint type of attachment between some part is carried out the design space and retrain, the constraint penalty that in genetic algorithm, need be correlated with.Abandon in all evolutionary process infeasible solution and the various terminal scheme is carried out Combinatorial Optimization again, and then generate the joint collection of assembling scheme.

Among the described step c, the step that comprises is as follows:

(1) determines the critical product size desiring to be optimized and the makeup ring of this critical size thereof;

(2), according to experimental design method the assembling deviation of critical part connection features in the assembly critical size chain is carried out the setting of initial tolerances scheme, as shown in Figure 3 according to designing requirement; The deviation accumulation utilizes interval number to carry out qualitative representation, as table 1.

Table 1, the interval expression of assembling deviation

nlarge，	nmedium	n small	Zero	psmall	pmedium	plarge
							＜-3	[-3，-1]	[-1，-0.5]	[-0.5，0.5]	[0.5，1]	[1，3]	＞3

(3) utilize the characteristics of Tabu neighborhood search dynamically to adjust minutely and the limit that changes the part build-up tolerance step by step;

(4) utilize qualitative simulation to build build-up tolerance as shown in Figure 4 and carry out the interval number expression, merge the assemble sequence collection and the joint scheme collection that generate and carry out the qualitative simulation analysis of assembly deviation.

The qualitative simulation function of variance analysis is as follows:

R fitted position deviation qualitative description vector; v _i, v _TijThe bias vector of representing parts and technology respectively; ε _i, ε _TijRepresent the influence coefficient of assemble sequence respectively to parts and process deviation; s _i, s _TijThe qualitative influence coefficient of features such as expression joint form and design of part parameter.

Use method of the present invention, after car body parameter (incomplete parameter) substitution with S6460 type concept car, can carry out the qualitative simulation of tolerance design, obtained a large amount of feasible program of the assembly quality the best under the financial cost, filter out optimum tolerance allocative decision, use this scheme, can once adorn and weld out the car body that reaches designing requirement, and need not in trial-manufacturing process, to adjust repeatedly tolerance.

Claims (4)

1, a kind of coachbuilt body is carried out the method for tolerance design qualitative simulation, it is characterized in that, may further comprise the steps:

A. at first, utilize incidence matrix and precedence relationship matrix,, generate all feasible assemble sequences by after shrinking matrix and judging sub-assemblies with series-parallel form, and, generate feasible assemble sequence collection by utilizing qualitative information generation assembly technology exponential matrix to subtract assemble sequence approximately;

B. by the initial joint scheme of man-machine interaction mode configuration assembly and the joint process constraint of assembling scheme, produce joint categories configuration design proposal, immediate shipment prescription case joint collection with heuristic intelligent algorithm then;

C. on the basis of the assembling scheme joint collection that feasible assemble sequence collection that step a obtains and step b obtain, determine each size composition ring of this critical size chain for the critical product size, then the tolerance of the critical size chain makeup ring of desiring to be optimized design is carried out the initial scheme setting, and the tolerance limit of makeup ring carried out small adjustment, thereby generate the optimization tolerance allocation plan of assembly, the assembling scheme joint collection that feasible assemble sequence collection that integrating step a obtains and step b obtain carries out the assembling deviation qualitative analysis of fitted position and calculates.

2, according to claim 1 coachbuilt body is carried out the method for tolerance design qualitative simulation, it is characterized in that, described step a, the step that comprises is as follows:

(1) by the input of assembly precedence relationship, draw the oriented annexation figure of this assembly, obtain it then and get adjacency matrix;

(2) judge by extraction, the validity of series, parallel and ring connection sub-unit and select, after conversion, generates the contraction matrix by the adjacency matrix of assembly;

(3) select different sub-units to generate assembly tree, obtain all assemble sequences of this assembly by backtracking method;

(4) by calculating the assembly technology matrix of assembly,, subtract the feasible order number that previous step (3) obtains approximately by judging and the substrate of definite assembly and sub-assemblies;

(5) determine the critical product size calculated,, finally determine the dimension chain of critical product size based on the design rule in the assembling knowledge base by finish all possible dimensions chains of critical product feature based on deep search.

3, according to claim 1 coachbuilt body is carried out the method for tolerance design qualitative simulation, it is characterized in that, described step b, the step that comprises is as follows:

(1) determines that at selected assembly the main jointing in the critical size chain carries out the type original definition, form the initial joint collection of assembly;

(2) controlled variable of genetic algorithm is provided with or uses the default setting of genetic algorithm;

(3) heuristic intelligent algorithm adopts genetic algorithm, in advance the joint type of attachment between some part being carried out the design space retrains, in genetic algorithm, need carry out corresponding constraint penalty, promptly abandon in all evolutionary process infeasible solution and the various terminal scheme is carried out Combinatorial Optimization again, and then generate the joint collection of assembling scheme.

4, according to claim 1 coachbuilt body is carried out the method for tolerance design qualitative simulation, it is characterized in that among the described step c, the step that comprises is as follows:

(1) at first determines the critical product size desiring to be optimized, determine the makeup ring of this critical size by deep search automatically;

(2), the assembling deviation of critical part connection features in the assembly critical size chain is carried out the setting of initial tolerances scheme, as the starting point of optimized Algorithm according to experimental design method;

(3) characteristics of utilizing the Tabu neighborhood search are dynamically adjusted the build-up tolerance limit with varying sized chain makeup ring part step by step minutely, generate the tolerance allocative decision collection of critical size;

(4) utilize qualitative simulation that the build-up tolerance of each size ring in the dimension chain is carried out the interval number expression, the assemble sequence collection and (3) the step joint scheme collection that generates that generate in conjunction with (2) step carry out the qualitative simulation analysis of assembly deviation.

Images