34 results about "Tolerance optimization" patented technology

The invention discloses a tolerance optimization allocation method based on a tolerance grade and a genetic algorithm, comprising the following steps: (1) creating a tolerance optimization mathematical model; (2) creating a standard tolerance database; (3) encoding based on the tolerance grade; (4) determining an adaptability function of the genetic algorithm; (5) setting a genetic operator; (6) performing genetic evolution; and (7) decoding to obtain a corresponding tolerance grade and inquiring a corresponding tolerance value. The method disclosed by the invention realizes the tolerance optimization allocation in the product design by using a computer, thereby replacing the manual distribution, improving the efficiency and saving the time; meanwhile, the method performs the optimization allocation through the genetic algorithm, serves the minimum processing cost as an optimization target and reduces the processing cost of products. Therefore, the method has good practical value and extensive application prospect in the technical field of computer aided tolerance design.

The invention relates to a joint surface error and joint surface tolerance optimization method for a machine tool fixture component. According to the prior art, the quality characteristics of a machine tool fixture component cannot truly reflect the quality distribution condition of the machine tool fixture component, which can influence calculation accuracy and trimming precision and make automation hard to realize, and therefore, the invention provides the method to solve the problems in the prior art. The method of the invention includes the following steps that: 1, surface tolerance is represented by a homogeneous matrix; 2, joint surface error is represented by a homogeneous matrix; 3, a geometric error transfer model of assembly is constructed; 4, the surface tolerance and joint surface error are optimized according to the nature of error terms; 5, sensitivity is analyzed; 6, a part surface error or surface tolerance parameter optimization method is established with the processing cost of the fixture component adopted as an objective and assembly precision reliability and tolerance selection principles adopted as constraints; and 7, the distribution rule and parameter of theimbalance of a fixture component assembly body are obtained through a simulation experiment after the optimization result of the spinor parameter of the assembly body is obtained, and therefore, the dynamic balance optimization design of the assembly body is realized.

The invention relates to an assembly tolerance optimization designing method based on the genetic algorithm. The method comprises the steps that a target function for assembly tolerance optimization is established with the minimum processing cost of an assembly body as the optimization target; the constraint conditions of assembly tolerance are determined; tolerance type information is added to a VGC network to obtain a tolerance network of the assembly body and the value range of dimensional tolerance of various assembly features and the value range of geometric tolerance of the assembly features are selected and determined; genetic coding is conducted by the adoption of a multi-parameter cascade coding method; a fitness function is determined; an operator function is selected and determined; operating parameters of the genetic algorithm are determined. According to the assembly tolerance optimization designing method based on the genetic algorithm, the genetic algorithm shows great application potential through the global searching capacity, the high robustness and the calculation parallelism.

The invention relates to an assembly tolerance optimization method based on quality loss and cost minimization. The method mainly comprises the following steps: establishing a mathematical model of quality loss and processing cost; adding actual processing capability constraints; performing parameter initialization on a multi-objective teaching and learning algorithm; performing iteration in a teaching phase on an initial solution of the algorithm; adopting a hill-climbing search strategy to further develop the solution; performing Pareto ranking on a population; further studying the solution, and further increasing the accuracy of the solution; and completing the iterative process and finding the optimal solution. The assembly tolerance optimization method based on the quality loss and cost minimization provided by the invention is based on the computer technology, and combines the swarm intelligent optimization algorithm in the field of artificial intelligence, which further improves the calculation efficiency and calculation accuracy of assembly tolerance design, and aims to satisfy the design accuracy under precision manufacturing, improve the production efficiency, and improve the parts quality, so as to further reduce the production cost.

The invention discloses a tolerance optimization method of a feed mechanism. The method comprises the following steps: A, establishing a feed mechanism tolerance-processing cost function model: C(t)=a0e<-a1t>, wherein the C(t) expresses processing cost of a corresponding tolerance t and a0 and a1 are weighting coefficients of different processing cost evaluation functions; B, employing a random simulation algorithm to calculate a correlated statistic characteristic of a feed mechanism quality characteristic according to design parameters of all components of the feed mechanism and initial tolerance data; and C, employing a genetic algorithm to output an optimized tolerance of the design parameters according to the correlated statistic characteristic of the feed mechanism quality characteristic. According to the invention, correlated knowledge of tolerance robustness is employed and a quality-cost balance relation is utilized as a quality maxim for a tolerance robustness optimization design; therefore, it can be ensured that the quality of the feed mechanism has good robustness and processing cost of the mechanism can be effectively reduced, thereby reaching an optimum balance between the product quality and the cost and thus further improving product market competitiveness.

The invention relates to an assembly tolerance optimum design method based on cost objective optimization. According to the method, the minimum machining cost of an assembly body is determined as an optimization target, and an objective function of assembly tolerance optimum is established; the function is obtained through the following steps that a part representative function of a mechanical assembly body is set; a total machining cost representative function of the mechanical assembly body is determined; a machining cost function of each part in the assembly body is determined; a machining cost function of assembly features is determined; a total machining cost-tolerance function of the assembly body is obtained; the objective function of assembly tolerance optimum is obtained. According to the assembly tolerance optimum design method, the optimum tolerance is obtained with the minimum machining cost as the target and with the machining capacity, the machining cost or the machining economic accuracy as constraint conditions respectively, so requirements of products for assembly functions can be met, the constraint conditions of machining can be met, and good economic benefits can be obtained.

The present invention provides a dynamic reliability-based gear system tolerance optimization calculation method. The method comprises a first step of modeling for gear system tolerance degradation, analyzing a design requirement of the gear system and processing routing, and determining a processing characteristic, a distribution characteristic and a cost characteristic of each sensitive tolerance parameter and a time-based degradation rule; a second step of determining a general stress model of the gear system; a third step of determining a strength degradation model of the gear system; a fourth step of calculating dynamic reliability; a fifth step of building a tolerance optimization model; and a sixth step of determining an optimal tolerance. Dynamic reliability is introduced to the field of gear system tolerance optimization, so that the traditional optimization model with total mass loss as the target is changed, and the working capability of the gear system can be evaluated more scientifically and objectively.

The invention belongs to the field of aviation machinery, and particularly relates to a tolerance optimization method for a die forging. The tolerance optimization method comprises the following steps of: determining the type of tolerance of a die forging of a part to be optimized according to a drawing of the part, dividing into interior tolerance and exterior tolerance, and then obtaining tolerance data. According to the tolerance optimization method, dimensional tolerance optimization is performed on the die forging of a certain series of a certain airplane, and the requirements of numerical control machining and the technical requirements of part design and manufacturing can be met by rationally adjusting the tolerance of the part and the die forging, so that the machining accuracy, the production efficiency and the yield of products are improved, the machining technical difficulty is reduced, and the method has wide applicability and is convenient to implement. For example, the yield is 80 percent, the production efficiency is 3 pieces per day and the machining accuracy out-of-tolerance use is less than 20 percent before optimization, but the yield reaches over 95 percent, the production efficiency is 5 pieces per day and the machining accuracy out-of-tolerance use can be controlled within 5 percent after optimization; and the equipment and personnel investment is reduced.

The invention discloses a tolerance optimization method for all-welded assemblies, relates to welding deformation accumulated error prediction and tolerance optimization of multiple assemblies, and solves the problem of tolerance design optimization requirements of all-welded assemblies. The method comprises the steps that original design information of all-welded assemblies is collected, and various kinds of tolerance information are summarized; a three-dimensional tolerance analysis model is established, simulation analysis is conducted through virtual assembly, and the deviation of the total deflection amount of the all-welded assembly is predicted; and a weighted calculation value is established based on the contribution degree factor and the sensitivity factor of each deviation and the control difficulty factor of welding deformation, and iteration is continuously performed according to a simulation analysis result until a tolerance optimization scheme meeting an optimization target is obtained and output. According to the method, the welding deformation accumulative error can be effectively predicted, tolerance optimization is achieved, and the efficiency of tolerance secondary design is improved.

The invention discloses an assembly error analysis and tolerance optimization method for a parallel lifting mechanism. The assembly error analysis and tolerance optimization method is characterized byestablishing a part assembly characteristic tolerance model and an assembly error transfer model based on the three-dimensional tolerance model; and establishing a part assembly characteristic tolerance optimization model by taking the minimum machining cost as a target and taking the assembly precision reliability, the parallel matching surface assemblability and the machining capacity as constraint conditions according to the known assembly precision requirement of a certain key size in a mechanism, constructing a fitness function, and solving the part assembly characteristic tolerance optimization model by adopting a genetic algorithm. Based on three-dimensional tolerance model analysis, a tolerance coupling relationship which cannot be expressed by a two-dimensional dimension chain can be introduced into an assembly error transfer model of the mechanism, so that an analysis result of an assembly error is more intuitive and accurate.

The invention discloses an electromagnetic relay step tolerance optimization method based on varying contribution rates. The method comprises the steps of S1, determining a tolerance optimization standard; according to the relations between key elements and output characteristics and an actual processing capacity, determining a tolerance range of the key elements; S2, determining a number of levels of the key elements; design an orthogonal test, and calculating an output result of each group of orthogonal test; solving the contribution rates of all the key elements; S3, according to a certain tolerance step length, subtracting the contribution rates with the tolerance to obtain a new tolerance range of the key elements; calculating the concentration rates of all the key elements again; S4, in the new tolerance range determined in the step S3, solving an output characteristic fluctuation range of the corresponding new tolerance range; S5, repeating work in the step S3 and S4 till the output characteristic fluctuation range meets the tolerance optimization standard, or the new tolerance range reaches a processing precision lower limit, wherein the new tolerance range is a final result of step tolerance optimization.

The invention discloses a connector dimension optimization system and a connector dimension optimization method, which are used for manufacturing a connector dimension and tolerance optimization analysis report. The connector dimension optimization system comprises an operation interface, an engineering module, an orthogonal table generating module and a digital model, wherein the operation interface is used for inputting analysis conditions and calling the engineering module and the orthogonal table generating module to execute the analysis conditions; and the analysis conditions include an input target analysis assembly, quality features, a terminal thickness tolerance, a connection dimension tolerance, an orthogonal table format, a key dimension and a tolerance. The connector dimension optimization system and the connector dimension optimization method have the advantages that a Taguchi analysis report can be automatically output after a user inputs the analysis conditions, so that the basis for optimizing the connector dimension and tolerance is obtained; and the goals of reducing the production cost and reducing the development time are achieved.

The invention discloses an automobile transmission shaft high-antitorque-reliability tolerance optimization design method. The method includes following steps: according to structure and material characteristic of an automobile transmission shaft, determining parameters having impact on reliability of the automobile transmission shaft; building a multi-target function of automobile transmission shaft high-antitorque-reliability tolerance optimization design; building optimization design multimode constraint conditions; solving an automobile transmission shaft high-antitorque-reliability tolerance optimization design model to acquire optimal design parameters. Antitorque strength reliability, antitorque rigidity reliability and weight of the transmission shaft are taken as a target function, the antitorque reliability and section area sensitivity information are embedded in the target function, and constraint conditions of parameters are taken into comprehensive consideration, so that high reliability of the transmission shaft can still be maintained while design parameter perturbation is ensured, and size and weight of a transmission device are reduced; the problem of key technology in automobile transmission device reliability design is solved.