CN107330172B - Body-in-white module design method based on modular product family platform - Google Patents
Body-in-white module design method based on modular product family platform Download PDFInfo
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Abstract
The invention belongs to the field of automobile body-in-white structure design, and relates to a body-in-white module design method based on a modular product family platform. In the conceptual design stage of a body-in-white, the invention introduces the modularization idea of improving the sharing degree of parts in a product family on the premise of comprehensively considering the performance and the cost of the body, performs characteristic and optimization on codes in a topological graph corresponding to a structural assembly model, performs multi-level and multi-target optimization by combining a genetic algorithm, realizes the module sharing between the same-level vehicle models and even cross-level vehicle models in the product family, improves the universality of the parts on the premise of ensuring the performance of the body, and greatly reduces the cost in each aspect. The invention provides a car body assembly design idea based on a modularization idea for realizing the sharing of parts in the car body conceptual design stage for designers, realizes the car body assembly optimization design of the whole product family, and has important practical significance in the process of car body reverse improvement and forward design.
Description
Technical Field
The invention relates to a method for dividing and screening cross-class vehicle type body-in-white structure modules based on a modular product family platform, which is used in a concept design stage, belongs to the technical field of vehicle body design, and is mainly used for designing a module division and assembly mode of vehicle body structures of all vehicle types under the same product family in a design initial stage.
Background
With the annual development of science and technology and the increasing maturity of economic environment, world-class automobile manufacturers begin to adopt a modularized research and development mode under the global integrated stream, so that the production, manufacturing, maintenance and even material transportation costs are reduced, the design and research and development period of new automobile models is shortened, meanwhile, the diversified demands of different consumer groups and even different consumer individuals can be met in a customized mode, and great advantages are brought to enterprises. At present, a novel platform developed based on a modular technology even becomes a main selling point of various vehicle models in the market. However, the modular technology of the automobile industry in China starts late, and the low modular design capability becomes a great bottleneck for limiting the development of the automobile industry in China.
The design of the automobile body can be divided into two stages of conceptual design and detailed design. Wherein, the arrangement scheme and the structural performance of the whole vehicle are determined in the concept design stage, and the total cost is determined to be 70%; the advantage of the automotive platform strategy is in achieving a high degree of part versatility and body structure expandability. Therefore, ideas based on modular design, manufacturing and production should be introduced at the conceptual design stage.
Disclosure of Invention
In the concept design stage, multiple vehicle body performance indexes are comprehensively considered, on the basis of an invention method (patent number CN105787221A) proposed by an inventor before, a white vehicle body structure module assembly design method based on a modular production manufacturing mode is provided, on the premise of ensuring various performances of a vehicle body structure, the vehicle body is divided into assembly structures based on module manufacturing, and then modules are classified and screened according to a calculation optimization result, so that the idea of realizing white vehicle body modular design is provided for the designer.
The technical scheme of the invention is as follows:
a body-in-white module design method based on a modular product family platform comprises the following steps:
(1) establishing an optimization model of a single vehicle type: on the basis of the proposed invention method (patent number CN105787221A), a mathematical model is established for each single vehicle model under the same product family. In order not to affect the following description, the following is briefly described:
taking a plurality of points in the X direction and the Y direction (bottom plate) and in the Y direction and the Z direction (side wall) respectively by taking a coordinate system where the white body model is located as a reference, and partitioning the white body into a plurality of sub-plates and sub-beams according to the points; taking the sub-components after being blocked as nodes, and taking the connection relation between the sub-components as edges, establishing a topological relation G ═ V, E, wherein V ═ { V ═ V1，V2，...，Vp，...，VP}，E＝{E1，E2，...，Eq，...，EQ}. Wherein, { V1，V2，...，Vp，...，VPRepresents a group of nodes, P nodes in total, P being the node number, { E1，E2，...，Eq，...，EQRepresents a group of edges, and has Q edges in total, and Q is the number of the edges; defining a set of binary variables gammaqThe division vector γ (γ) for the original G is composed1，γ2，...，γq，...，γQ): when gamma isqAn edge E in the topological relation is represented when the value is 0qWhen removed, a value of 1 indicates that the edge remains, the segmentation vector γ can be used to express an assembly; and (3) optimizing by taking gamma as a design variable and taking the rigidity of the vehicle body, the manufacturing cost and the assembly cost as optimization targets, wherein the objective functions are respectively as follows:
Fvehicle body stiffnessDisplacement (G (V, E (gamma)))
Body stiffness function F in formulaVehicle body stiffnessMeasured by the maximum displacement of the finite element model calculation result of the corresponding structure of the topological graph G (V, E (gamma)): the larger the displacement is, the larger the structural deformation is, the smaller the rigidity is; comp (k, G (V, E (gamma))) represents the kth sub-component in the model divided by G (V, E (gamma)) in the whole vehicle structure; the smaller the die area, the lower the manufacturing cost F of the sub-partManufacturing costThe lower the number of solder jointsFew, representing the assembly cost F of the structureAssembly costThe lower. The optimization model corresponds to:
the optimization model is a multi-objective optimization problem, the optimization independent variable is a binary vector consisting of 0 and 1, the genetic algorithm can be directly used for optimization calculation without a special encoding process, and the iterative population and the iterative algebra are determined according to the convergence condition after a plurality of trial calculations. According to related research, for a general engineering optimization problem, the replacement rate of children to parents can be set to be 50%, the cross probability is 90%, the mutation probability is 10%, and the convergence condition is that the change rate of a population average fitness function is not more than 3%. Through trial calculation, for a common vehicle model, the population size is 200, and the convergence requirement can be met when the iteration algebra is 100. Through optimization, the optimal assembly mode of a single vehicle type can be obtained;
(2) the method is characterized by optimizing on the basis of a single vehicle model optimization model, and the assembly design of multiple vehicle models is considered in a product family.
Optimizing the assembly structure of each single vehicle type, comparing the optimization results, enlarging the population scale in the optimization model of each single vehicle type, ensuring that enough individuals with the same assembly structure or only locally different individuals appear in each generation of population (the population scale at least reaches 3-4 times of that in the optimization model of each single vehicle type after a plurality of trial calculations) when different vehicle types are optimized in parallel, selecting the individuals as the initial solution of the next iteration until the optimization converges, and for n vehicle types, dividing the vehicle types into m sections of structures, wherein each section of structure consists of α subcomponents, and each section of assembly mode is determined by (2 α -1) codes, namely
The optimization model is as follows:
in the formula
Representing the comparison of the assembly modes of corresponding positions of two vehicle types, the two are the same in time meter 0 and different in time meter 1, then
Smaller means more similar assembly structure; by selecting the guarantee solutions among the populations of different models, the modular idea-based assembly scheme design of a plurality of models is realized.
(3) The vehicle body structure parts which are finished with the assembly design are taken as modules and classified. In the method, the modules are divided into the following four types and are gradually screened:
a parameter module: a module which needs to be redesigned when a new vehicle type is designed;
a general module: the module can be commonly used among all vehicle types;
a flexible module: but require local adjustment;
a personality module: the module is universal between similar vehicle types and not universal between different vehicle types.
(4) Firstly, selecting a personality module: according to the type of the vehicle and the structural characteristics of the vehicle body, individual modules can be directly selected;
(5) secondly, a parameter selection module: when a new model is designed using a certain model as a prototype, the dimensions of the new model can be changed at a plurality of positions. According to the assembly result, selecting a coordinate point u (u) of each module in the reset directionmin，umax) Wherein u is x, y, z, uminIs the minimum coordinate value in the corresponding direction, umaxIs the maximum coordinate value; for two adjacent modules R and R +1, if there is uR max＞uR+1 minThen in that direction there is a module R that can be changedAnd the size of R +1 to change the location of the overall vehicle size. If u isR max＝uR+1 minThen the entire cart size change can be achieved by changing only one of the modules R or R + 1. If there are three adjacent modules, and there is u at the same timeR max＞uR+1 min，uR+1 max＞uR+2 min，uR max＞uR+2 minWhen the size of the vehicle body structure is changed at the corresponding position, the three modules of R, R +1 and R +2 need to be changed simultaneously; therefore, the position where the size of the vehicle body can be adjusted and the corresponding module needing to be changed can be found out. When a new vehicle model is manufactured, different additional costs can be increased by selecting different adjusting positions, and the manufacturing cost F is mainly considered in the concept design stageManufacturing costAnd FAssembly cost. Since the dimensional change at this time is not too great and may be uncertain, the body performance function F is usedVehicle body stiffnessChecked as constraints, requiring a predefined stiffness to be met
And selecting the position with the minimum additional cost as a main redesign area, wherein the corresponding module needing to be changed is a parameter module. If the location cannot meet the performance requirement, returning to reselection. The optimization model can be expressed as:
(6) finally, selecting a flexible module; all the unscreened modules are constrained to be universal modules, i.e. each design parameter has tVehicle type 1＝tVehicle type 2＝…＝tVehicle type n. Optimizing each vehicle type under the current constraint, wherein the optimization target is the maximum vehicle weight
Module mass (Comp k) and body Properties FVehicle body stiffness. Setting the selection interval and the optimal solution of two optimization targets according to the requirement of a designer and matching the design requirement
And
comparing according to the solution and the delta StValue releases its tVehicle type 1＝tVehicle type 2＝…＝tVehicle type n(ii) (i.e., the design parameters need not be consistent with corresponding parameters in other vehicle models): if the optimization result of a certain vehicle type
If at least one is not true (if two are true, the requirement is met), releasing the delta S in the vehicle modeltThe design parameter constraint corresponding to the lowest module, which becomes the flexible module; on the contrary, if the optimization result of a certain vehicle type
And if at least one fails, releasing Δ StThe highest module becomes the flexible module subject to the design parameter constraints. And after the change is restrained, the next iteration is carried out until all the vehicle types meet the design requirements, the rest unselected modules are universal modules, and finally the screening of all the types of modules is finished.
Due to the adoption of the technical scheme, the invention has the following advantages: 1. the invention divides the body-in-white structure based on the body performance, assembly and manufacturing cost, and simultaneously considers the division situation of the assembly structure of the cross-class vehicle type based on module sharing, thereby realizing the product family design based on the modularized platform; 2. module classification and screening are carried out on the division results of the assembly structure, and the sharing condition of the vehicle body parts is further determined and improved; 3. compared with a sensitivity method, the invention is not limited by the design of a telescopic product family of parameters any more, but further realizes the design of a module configuration type product family of standardized interchangeable modules, and is more suitable for the current production and manufacturing mode of each automobile enterprise.
Drawings
FIG. 1 is three example vehicle models of the same product family modularly designed using the method of the present invention, wherein:
FIG. 1(a) is a body-in-white structure of a three-compartment vehicle type;
FIG. 1(b) is a body-in-white structure of a hatchback;
fig. 1(c) shows a body-in-white structure of a certain SUV vehicle.
FIG. 2 is an optimized design of the underbody model of the present invention, wherein:
FIG. 2(a) is a body-in-white floor for smaller three-box and two-box vehicle models;
fig. 2(b) shows a large-sized SUV vehicle body-in-white floor.
FIG. 3 is a diagram of a corresponding topological connection relationship after a pre-segmentation is performed on a backplane by applying the method of the present invention, wherein:
FIG. 3(a) is a floor mapping topology for a sedan model and a two-box model;
fig. 3(b) is a floor mapping topology of an SUV vehicle model.
Fig. 4 is three possible assembly modes based on modular manufacturing.
FIG. 4(a) is a view of lengthening the backplane by adding modules;
FIG. 4(b) is a drawing module to lengthen the base plate;
fig. 4(c) is a view of lengthening the base plate by both stretching the modules and adding the modules.
Fig. 5 shows a partitioning method of a backplane module obtained by applying the method of the present invention, wherein:
FIG. 5(a) is a floor partition of a three-box vehicle type and a two-box vehicle type;
fig. 5(b) shows a floor division method of the SUV vehicle type.
Fig. 6 shows the assembly division result and the size change position at the time of resetting of the body side.
Fig. 7 is a design resulting from the application of the method of the invention to the entire passenger compartment, wherein:
FIG. 7(a) is a modular design of a sedan type;
FIG. 7(b) is a modular design of a hatchback model;
fig. 7(c) is a module design of an SUV vehicle model.
Detailed Description
The invention is further explained in detail below with reference to the drawings and the technical solutions.
As shown in fig. 1, the three cars (fig. 1a), two cars (fig. 1b) and SUV (fig. 1c) in the same product family are respectively the three cars, wherein the wheelbases of the three cars and the two cars are equivalent, the SUV has a larger size than the other two cars, and the axial difference can reach 300 mm. The method is mainly used for assembling and designing the vehicle type with larger size difference in the traditional sense of 'cross-class' in the figure based on modular manufacturing. For the vehicle models with smaller size difference in the same class, the method disclosed by the invention can be simplified and applied according to actual conditions.
The manufacturing unit of the body-in-white bottom plate is pre-divided according to the actual manufacturing and assembling process level, only the left half body can be taken as a research object according to the symmetry of the body structure, the division condition is shown by a red chain line in fig. 2 by taking the bottom plate as an example, proper division points are respectively selected in the X-axis direction and the Y-axis direction of a coordinate system of a body model, the body is respectively divided into X sections and Y sections along two directions, the pre-dividing units share (X × Y) blocks, the number of the pre-dividing blocks of the bottom plate can be controlled by controlling the number of X and Y, and for cross-class vehicle types, the pre-dividing units generally have difference of X blocks to 2X blocks in the Y direction.
The construction diagram of the bottom plate of each vehicle type after being pre-divided is converted into a corresponding topological connection relation diagram, the top point in the topological diagram corresponds to a pre-dividing unit, and the edge in the topological diagram corresponds to the connection relation among all the units. Numbering according to the directions of an X axis and a Y axis in sequence, and sequencing and numbering the unit sets as V1，V2，…,VPThe connection relation set is ordered and numbered as E1,E2,…,EQThe coordinates of four vertexes of the k-number sub-component are
a. b, c, d are daughter board timingThe needle direction is numbered by four nodes, and x, y and z are vertex coordinates. A one-to-one correspondence topology model is established for each vehicle type to be studied in the product family, as shown in fig. 3, where fig. 3a is a floor topology relationship diagram of a hatchback vehicle type and a sedan vehicle type, and fig. 3b is a floor topology relationship diagram of an SUV vehicle type.
For practical structures, there are two possibilities for the connection of one component: the stamping and the separate stamping are performed as a whole and then the welding is performed. In the topological graph, when the edge connecting two nodes exists, the two pre-segmentation units belong to the same part, and no welding seam exists; and when the edge connecting the two nodes does not exist, the welding seam exists after the two pre-segmentation units are disconnected. Therefore, in the topological graph, an array consisting of a group of variables 0 and 1 can be used as a division vector of the structure, wherein when the variable is taken to be 1, the corresponding edge exists, and when the variable is taken to be 0, the edge does not exist. This set of numbers serves simultaneously as the individual code for the genetic algorithm in the optimization calculation.
Structural performance indexes to be considered in the concept design stage of the vehicle body at least include three aspects of vehicle body rigidity (affecting driving feeling, NVH performance, safety performance and the like), assembly performance (affecting manufacturing difficulty, assembly cost, structural reliability and the like), and manufacturability (evaluating manufacturing risk and cost). In the method, the three performance indexes are taken as optimization targets, and the assembly mode of the structure is solved. The evaluation method of each performance index comprises the following steps:
1. vehicle body rigidity: under the same load, the displacement at a predefined node in a finite element model is used for evaluation, and the larger the deformation is, the worse the rigidity is;
2. and (3) manufacturability: the manufacturing cost is estimated approximately in terms of the mold area, which for the kth sub-part is approximately:
3. assembly property: the welding spot number is approximately measured, the welding spot distance in the method is set to be 30mm, and then the welding spot number of the first welding spot in the structure is known as follows:
(y direction) or
(x-direction).
Converting the design into a mathematical multi-objective optimization problem, wherein the optimization variables are positions of segmentation points and connection conditions of all sides in a topological graph, the constraints are contents in aspects of size, rigidity, cost and the like of segmentation units involved in actual manufacturing, and an objective function converts the three performance indexes into:
Fvehicle body stiffnessMin { displacement (G (V, E (γ))) }
And optimizing a plurality of vehicle models involved in the design according to the optimization model. And calculating by combining a genetic evolution algorithm suitable for the multi-objective optimization problem to obtain an optimal Pareto solution set, wherein each individual in the solution set is a segmentation vector and corresponds to a bottom plate segmentation mode. In a set of segmentation vectors, each segment encoded by γ ═ 0 or 1 can correspond to a corresponding position in the assembly. As shown in FIG. 4, E6-E12The three different combinations of the three different assemblies can correspond to three different assembly modes of the section of the bottom plate, and the codes of other parts are unchanged, so that the corresponding parts can be ensured to be universal among the different assembly modes. Since the difference between the cross-class vehicle models is usually one section of bottom plate module, the module sharing degree can be solved in this way. After an optimized solution set is obtained for each vehicle type, individuals with consistent local characteristics are selected from the solution set, and a final result is selected according to design requirements, so that module sharing can be achieved among cross-level vehicle types. FIG. 5 shows the results obtained.
By using the method, a vehicle body assembly mode based on modular design can be obtained, however, which parts to be assembled can be shared, and which parts cannot be shared can still not be determined. Therefore, the method of the invention further provides classification of several modules and corresponding screening methods. Taking the side wall as shown in fig. 6 as an example, the assembly method based on the modular design is calculated according to the method. When a new vehicle model is designed by taking the above as a reference, certain modules can be replaced on the premise of keeping the whole structure unchanged. If the wheelbase needs to be lengthened, it is possible to achieve this by replacing the modules 2, 3, and also to replace the modules 4, 5, while leaving the other modules unchanged. Some modules also require thickening and thinning in view of the structural performance requirements of the vehicle body. Thus, modules can be broadly divided into four categories: the individual modules which are obviously different among different vehicle types have greatly changed parameter modules in size, do not need any changed general modules, and only change the flexible modules of the plate thickness. The universal module and the flexible module both belong to a sharing module, and the individual module can be shared among different subdivided vehicle types of the same large vehicle type, such as a three-compartment vehicle type special module.
The parameter module can not be shared between any vehicle types basically, and the extra cost is highest; the individual module can be commonly shared among different subdivided vehicle types under the same large vehicle type, and the additional cost is higher; the flexible module only needs to slightly adjust and modify a female die or a male die of the stamping die, so that the extra cost is low; the universal module can be used by all vehicle types, and the additional cost is lowest.
The results obtained by using the modular design-based method can directly find out the personality module according to observation without researching and screening the method of the personality module.
The parameter module is a module which needs to be redesigned and replaced when a new vehicle model is designed, so that the manufacturing cost and the assembly cost when the module is replaced are taken as optimization targets when the parameterized module is screened, and the vehicle body performance is taken as constraint, namely, the cost is minimized on the premise of ensuring that the vehicle body performance is not damaged. And carrying out priority ranking on the cost corresponding to the replacement module according to the size change position related in vehicle model design, and preferentially considering the position with low cost to replace the module, namely setting the module as a parameter module. As shown in fig. 6, the vehicle body can be moved from four positions I, II, III, and IV when the wheel base direction is changed, and can be moved from two positions I and II when the vehicle body height direction is changed. The axial direction III and the height direction i are the positions with the lowest cost when the modules are replaced in the two directions, respectively, and then the modules 4 and 5 are preferentially considered to be axial parameter modules, and the modules 1,2 and 4 are height parameter modules.
After the module with the lowest cost is selected as the parameterization module, each vehicle type needs to be optimized once respectively to see whether the requirements on performance and vehicle weight can be met. If the optimization result can not be met, a module with the second lowest cost needs to be selected again as a parameter module, single-vehicle type optimization is carried out again, and the like is repeated until the optimization result meets the requirement.
After the personality module and the parameter module are determined, the flexible module needs to be screened out, and the rest are the sharing modules. After the replacement of the parameter module is carried out on the vehicle body structure, the flexible module is mainly used for carrying out partial adjustment on the thickness and the local details so as to meet the requirements of rigidity and light weight for a new vehicle type. Performance criteria in terms of body stiffness, weight, etc. are therefore criteria used primarily to screen flexible modules.
If all the remaining components are considered as generic modules after the selection of the parameter modules, two problems may arise: 1. the vehicle body is heavier due to the fact that a thicker universal module is used in some vehicle types, and the requirement for light weight is not met; 2. after a general module with a small thickness is used in some vehicle types, the performance of the vehicle body is poor, and the requirements on rigidity, strength and the like are not met. Aiming at the two problems which can occur, the method of the invention provides a method for gradually releasing the constraint of a universal module to a flexible module, wherein the method is 'weak constraint and strong target'. In this partial optimization problem, there are two main constraints: platform constraints (constraints that the same design parameters are consistent among different vehicle types) when parallel optimization is performed among different vehicle types and performance constraints in optimization problems of various vehicle types. The "weak constraint" refers to the second type, namely weakening the constraint taking the vehicle body performance as a function in the optimization process, taking the constraint as an objective function to optimize simultaneously with the vehicle body weight, and gradually releasing the platform constraint according to the result.
The problems with this part of the work are mainly: when a plurality of vehicle types are optimized in parallel, optimization under equation constraint is difficult to control the optimization direction when different vehicle types have unknown constraint (the constraint is required to be gradually released when screening of the flexible modules is not finished, namely unreasonable constraint exists in the model), and the convergence difficulty exists. The method for controlling the optimization direction by releasing the constraint after converting the target function into the weakened constraint can obtain a wider solution set space, is more convenient for adjusting the optimized solution set according to the needs of a designer, and can select the next variable of the constraint of the release platform according to the result after each iteration, thereby realizing the screening of the flexible adjusting module while strictly ensuring the performance of the vehicle body.
In the process of the invention, the term Δ S is used primarilytIs used to release the constraint. Delta StS × Δ t, where S is the area of the module, Δ t is the thickness of sheet material that the module needs to increase by 1 unit of performance index, and is obtained by optimizing the sensitivity function found at the current pointtI.e. the weight of the material needed to provide a relative stiffness of 1 unit. When the method is used, all the modules to be screened are regarded as universal modules, namely the same parts are kept consistent among all vehicle types, and then parallel optimization is carried out on all vehicle types, and the performance is compared with the performance when modularized design is not considered. If the performance of a certain vehicle type is qualified but the vehicle weight is heavy and can not meet the preset light-weight requirement, determining the delta S in the vehicle typetScreening high parts into flexible modules, carrying out weight reduction on the parts, namely, carrying out maximum weight reduction under the cost of minimum performance sacrifice, and then carrying out optimization again to continuously screen the rest parts; if the vehicle weight of a certain vehicle type is light but the performance is not qualified, determining the delta S in the vehicle typetThe low component parts are screened for flexibility and are reinforced, i.e., structural performance is enhanced with minimal added weight. And repeating the steps until all the vehicle types meet the preset requirement.
The three models in the invention example are optimized and calculated sequentially according to the above method, and a design manner is obtained as shown in fig. 7, wherein fig. 7(a) is a design result of a three-compartment model, fig. 7(b) is a design result of a two-compartment model, and fig. 7(c) is a design result of an SUV model module. In the figure, the blue part is a general module, the red part is a parameter module, the yellow part is a personality module, and the green part is a flexible module. The parts sharing rate and the weight reduction results of the optimized design are shown in table 1. As can be seen from the table, compared with the lightweight result optimized independently for each vehicle model, the lightweight result manufactured based on the modular design has certain loss, but all the weight is controlled below 10%, and the sharing rate is improved to 40% or even 60%, so that the cost of each aspect of an enterprise can be effectively reduced.
Table 1 modular design results
Through the research of the above examples, a body-in-white block assembly mode based on modular concept design is obtained. The blocking mode improves the universality of parts among different product individuals in the same product family on the premise of meeting and optimizing the performance constraint, the manufacturing cost and the assembly cost of the automobile body, and greatly reduces the cost in the aspects of automobile production, manufacturing, part transportation and the like. The result can provide one or more automobile body modularized manufacturing schemes for designers, and meets the requirement of the designers for improving the sharing degree of parts.
Under the trend that the modularization idea is taken as the main research and development direction at present, the design and optimization of the assembly structure must be carried out on the premise of considering the modularization research and development mode in the concept design stage, and the research and development idea necessarily involves the development of a plurality of vehicle models and directly influences the time and the cost of all links from research and development to production and sale in the life cycle of a product family which is quite long in the enterprise. The design scheme in the concept design stage requires a designer to balance factors in multiple aspects such as process requirements, cost control, structural performance and the like, and various costs are reduced to the maximum extent in each link while the product performance is ensured. The method provides a new thought for designers in the conceptual design stage of the vehicle body, realizes the segmentation, classification and screening of various modules in the vehicle body structure, can obtain a module sharing mode based on the whole product family, improves the module sharing degree, reduces the cost, and has important significance in the reverse design and the forward design of the vehicle body.
The above specific examples are presented to illustrate the body design of the present invention based on the modular design concept to realize the modular product family platform, and these examples are only for the purpose of illustrating the principle and the implementation manner of the present invention, but not for limiting the present invention, and those skilled in the art can make further changes and modifications without departing from the spirit and scope of the present invention. It is therefore intended that all such equivalent aspects be within the scope of the present invention and be defined by the claims appended hereto.
Claims (1)
1. A body-in-white module design method based on a modular product family platform is characterized by comprising the following steps:
(1) establishing an optimization model of a single vehicle type:
taking a plurality of points in the X direction, the Y direction and the Z direction respectively by taking a coordinate system where the white body model is located as a reference, and partitioning the white body into blocks according to the points, namely, a plurality of sub-plates and sub-beams; taking the sub-components after being blocked as nodes, and taking the connection relation between the sub-components as edges, establishing a topological relation G ═ V, E, wherein V ═ { V ═ V1，V2，...，Vp，...，VP}，E＝{E1，E2，...，Eq，...，EQ}; wherein, { V1，V2，...，Vp，...，VPRepresents a group of nodes, P nodes in total, P being the node number, { E1，E2，...，Eq，...，EQRepresents a group of edges, and has Q edges in total, and Q is the number of the edges; defining a set of binary variables gammaqThe division vector γ (γ) for the original G is composed1，γ2，…，γq，…，γQ): when gamma isqAn edge E in the topological relation is represented when the value is 0qRemoved, 1 indicates that the edge remains, and the split vector γ is used to express an assembly; and (3) optimizing by taking gamma as a design variable and taking the rigidity of the vehicle body, the manufacturing cost and the assembly cost as optimization targets, wherein the objective functions are respectively as follows:
Fvehicle body stiffnessDisplacement (G (V, E (gamma)))
Body stiffness function F in formulaVehicle body stiffnessMeasured by the maximum displacement of the finite element model calculation result of the corresponding structure of the topological graph G (V, E (gamma)): the larger the displacement is, the larger the structural deformation is, the smaller the rigidity is; comp (k, G (V, E (gamma))) represents the kth sub-component in the model divided by G (V, E (gamma)) in the whole vehicle structure; the smaller the die area, the lower the manufacturing cost F of the sub-partManufacturing costThe lower the number of solder joints, the lower the assembly cost F of the structureAssembly costThe lower; the optimization model corresponds to:
the optimization model is a multi-objective optimization problem, the optimization independent variable is a binary vector consisting of 0 and 1, the optimization calculation is carried out by using a genetic algorithm, and the iterative population and the iterative algebra are determined according to the convergence condition after being tried out for several times; setting the replacement rate of filial generations to parent generations to be 50%, the cross probability to be 90% and the mutation probability to be 10%, and taking the change rate of the population average fitness function not more than 3% as a convergence condition; obtaining the optimal assembly mode of a single vehicle type through optimization;
(2) the method is characterized by optimizing on the basis of a single vehicle model optimization model, and realizes the assembly design of multiple vehicle models simultaneously considered in a product family:
optimizing the assembly structure of each single vehicle type, comparing the optimization results, expanding the population scale in the optimization model of the single vehicle type so as to ensure that enough individuals with the same assembly structure or only locally different assemblies appear in each generation of population when different vehicle types are optimized in parallel, selecting the individuals as the initial solution of the next iteration until the optimization converges, and for n vehicle types, dividing the vehicle types into m sections of structures, wherein each section of structure is composed of α subcomponents, and each section of assembly mode is determined by (2 α -1) codes,
namely, it is
The optimization model is as follows:
in the formula
Representing the comparison of the assembly modes of corresponding positions of two vehicle types, the two are the same in time meter 0 and different in time meter 1, then
Smaller means more similar assembly structure; the method comprises the steps of selecting a guarantee solution among populations of different models to realize the modular thought-based assembly scheme design of a plurality of models;
(3) the vehicle body structure parts which are assembled and designed are taken as modules and classified, and the modules are classified into the following four classes and are screened step by step:
a parameter module: a module which needs to be redesigned when a new vehicle type is designed;
a general module: the module can be commonly used among all vehicle types;
a flexible module: a module requiring local adjustment;
a personality module: modules which are universal among similar vehicle types and not universal among different vehicle types;
(4) firstly, selecting a personality module: according to the type of the vehicle and the structural characteristics of the vehicle body, directly selecting individual modules;
(5) secondly, a parameter selection module: when a new model is designed by using a certain model as a prototype model, the size of the new model is changed at a plurality of positions; according to the assembly result, selecting a coordinate point u (u) of each module in the reset directionmin，umax) Wherein u is x, y, z, uminIs the minimum coordinate value in the corresponding direction, umaxIs the maximum coordinate value; for two adjacent modules R and R +1, if there is uR max＞uR+1 minThen, in this direction, there is a position where the size of the entire vehicle can be changed by changing the sizes of the modules R and R + 1; if u isR max＝uR+1 minThen the change of the size of the whole vehicle can be realized by changing only one of the modules R or R + 1; if there are three adjacent modules, and there is u at the same timeR max＞uR+1 min，uR+1 max＞uR+2 min，uR max＞uR+2 minWhen the size of the vehicle body structure is changed at the corresponding position, the three modules of R, R +1 and R +2 need to be changed simultaneously; therefore, the position for adjusting the size of the vehicle body and the corresponding module needing to be changed are found out; when a new vehicle model is manufactured, different additional costs can be increased by selecting different adjusting positions, and the manufacturing cost F is mainly considered in the concept design stageManufacturing costAnd FAssembly cost(ii) a Since the dimensional change at this time is not too great and may be uncertain, the body performance function F is usedVehicle body stiffnessChecked as constraints, requiring a predefined stiffness to be met
Selecting a position with the minimum additional cost as a main redesign area, wherein a corresponding module needing to be changed is a parameter module; if the position can not meet the performance requirement, returning to reselect; the optimization model is then expressed as:
(6) finally, selecting a flexible module; all the unscreened modules are constrained to be universal modules, i.e. each design parameter has tVehicle type 1＝tVehicle type 2＝…＝tVehicle type n(ii) a Optimizing each vehicle type under the current constraint, wherein the optimization target is the maximum vehicle weight
And body properties FVehicle body stiffness(ii) a Setting the selection interval and the optimal solution of two optimization targets according to the requirement of a designer and matching the design requirement
And
comparing according to the solution and the delta StValue releases its tVehicle type 1＝tVehicle type 2＝…＝tVehicle type nThe design parameters do not need to be consistent with corresponding parameters in other vehicle models any more: if the optimization result of a certain vehicle type
And
if at least one of the delta S values is not satisfied, the delta S in the vehicle model is releasedtThe design parameter constraint corresponding to the lowest module, which becomes the flexible module; on the contrary, if the optimization result of a certain vehicle type
And
and if at least one fails, releasing Δ StThe design parameter constraint corresponding to the highest module, which becomes the flexible module; and after the change is restrained, the next iteration is carried out until all the vehicle types meet the design requirements, the rest unselected modules are universal modules, and finally the screening of all the types of modules is finished.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5794059A (en) * | 1990-11-13 | 1998-08-11 | International Business Machines Corporation | N-dimensional modified hypercube |
| CN102012958A (en) * | 2010-12-29 | 2011-04-13 | 奇瑞汽车股份有限公司 | Method for designing automobile body structure layout |
| CN103870623A (en) * | 2012-12-18 | 2014-06-18 | 南车青岛四方机车车辆股份有限公司 | Preprocessing template for vehicle model |
| CN104318012A (en) * | 2014-10-21 | 2015-01-28 | 北京汽车股份有限公司 | Body-in-white weight reduction design method and device |
| CN104392031A (en) * | 2014-11-13 | 2015-03-04 | 大连理工大学 | Design method of variable cross-section beam of automobile body in white |
| CN105787221A (en) * | 2016-04-26 | 2016-07-20 | 大连理工大学 | Design and optimization method for baseplate of automobile body |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7530403B2 (en) * | 2004-04-05 | 2009-05-12 | City Of Hialeah | Transport pumper |
| US20150203215A1 (en) * | 2014-01-17 | 2015-07-23 | Eric T. Falangas | Early performance evaluation of conceptual flight and space vehicles |
-
2017
- 2017-06-20 CN CN201710467593.6A patent/CN107330172B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5794059A (en) * | 1990-11-13 | 1998-08-11 | International Business Machines Corporation | N-dimensional modified hypercube |
| CN102012958A (en) * | 2010-12-29 | 2011-04-13 | 奇瑞汽车股份有限公司 | Method for designing automobile body structure layout |
| CN103870623A (en) * | 2012-12-18 | 2014-06-18 | 南车青岛四方机车车辆股份有限公司 | Preprocessing template for vehicle model |
| CN104318012A (en) * | 2014-10-21 | 2015-01-28 | 北京汽车股份有限公司 | Body-in-white weight reduction design method and device |
| CN104392031A (en) * | 2014-11-13 | 2015-03-04 | 大连理工大学 | Design method of variable cross-section beam of automobile body in white |
| CN105787221A (en) * | 2016-04-26 | 2016-07-20 | 大连理工大学 | Design and optimization method for baseplate of automobile body |
Non-Patent Citations (3)
| Title |
|---|
| Modular platform optimization in conceptual vehicle body design;侯文彬等;《Structural and Multidisciplinary Optimization》;20161209;第55卷(第6期);全文 * |
| 模块化产品族的共享模块筛选方法;侯文彬等;《湖南大学学报(自然科学版)》;20170228;全文 * |
| 模块化平台的模块划分及共享模块筛选方法;侯文彬等;《机械工程学报》;20170217;全文 * |
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