基于齐次变换修正矩阵的刚柔混合模型公差分析
发布时间：2018-12-09 14:54
【摘要】：在零件的加工生产过程中,其尺寸误差以及形状偏差是不可避免的。装配过程中,这些偏差经过累积、叠加后,对装配产品的工作性能、外观质量产生着不容忽视的影响。装配精度是产品质量保障的核心之一,公差分析是尺寸工程的重要环节之一,它可以有效的缩短产品的研发周期,在保证质量的同时降低生产成本。零件公差设计的合理性直接影响着装配偏差和制造成本,所以在设计阶段进行公差分析、装配质量验证有重要的意义。现行的公差分析方法大都是仅针对刚性件或柔性件,以工程领域中大量应用的刚柔混合模型为研究对象的公差分析方法尚处在起步阶段。如何在现有方法的基础上,结合刚柔混合模型的自身特点,建立统一有效的公差分析体系,准确的预测关键尺寸的分布情况,是公差技术中急需深入探索的问题。本文针对现有计算机辅助公差技术应用范围的局限性,研究了刚柔混合模型的公差分析技术,提出了基于齐次变换修正矩阵的公差分析方法;建立了基于蒙特卡洛的敏感度分析方法。本文的主要内容包括以下几个方面:(1)总结了计算机辅助公差技术的发展过程、国内外研究现状。介绍了课题的研究背景和研究意义。(2)介绍了 基于新一代 GPS(Geometrical Product Specifications)的公差技术。分析产品、零件、特征之间的关系,将公差表示为特征的变动,借助SDT(Small Displacement Torsor)理论,实现了公差建模,并将产品内部的装配关系简化为特征间的约束关系。(3)建立了基于齐次变换修正矩阵的刚柔混合模型公差分析方法。将刚柔混合模型的理想位姿、公差域表示为矩阵形式,借助齐次变换进行公差累积。使用有限元模拟装配变形,将仿真结果表示为修正矩阵,对原有的偏差累积路径进行修正,从而实现了对刚柔混合模型关键尺寸的精确预测。(4)建立了基于蒙特卡洛的敏感度分析方法。以敏感度是关键尺寸相对偏差源的变化程度为理论基础,将公差域分为若干个微小量,计算偏差源微小量引起的关键尺寸的变化,敏感度的值等于两者变化的商。多次计算后,用平均值来代表最终的敏感度的值,用MATLAB编程来实现整个计算过程。(5)以汽车底盘装配体为例,用基于齐次变换修正矩阵的刚柔混合模型公差分析方法以及基于蒙特卡洛的敏感度分析方法进行计算,并用3DCS软件验证所提方法的可行性和有效性。
[Abstract]:In the process of machining and production of parts, the error of dimension and shape is inevitable. In the assembly process, these deviations are accumulated and superimposed, which have a great influence on the working performance and appearance quality of the assembly products. Assembly accuracy is one of the core of product quality assurance, tolerance analysis is one of the important links of dimension engineering, it can effectively shorten the product research and development cycle and reduce the production cost while ensuring the quality. The rationality of part tolerance design directly affects the assembly deviation and manufacturing cost, so it is of great significance to carry out tolerance analysis and assembly quality verification in the design stage. Most of the existing tolerance analysis methods are only for rigid or flexible parts. The tolerance analysis method based on the rigid-flexible mixed model which is widely used in engineering field is still in its infancy. How to establish a unified and effective tolerance analysis system and accurately predict the distribution of key dimensions on the basis of existing methods combined with the characteristics of rigid-flexible mixed model is an urgent problem in tolerance technology. In view of the limitation of the existing computer-aided tolerance technology, the tolerance analysis technique of rigid-flexible mixed model is studied, and a tolerance analysis method based on homogeneous transformation correction matrix is proposed. A sensitivity analysis method based on Monte Carlo is established. The main contents of this paper are as follows: (1) the development process of computer aided tolerance technology and the research status at home and abroad are summarized. The research background and significance are introduced. (2) tolerance technology based on new generation GPS (Geometrical Product Specifications) is introduced. By analyzing the relationship among products, parts and features, the tolerance is expressed as the change of feature, and the tolerance modeling is realized with the help of SDT (Small Displacement Torsor) theory. The assembly relationship within the product is simplified as the constraint relationship between the features. (3) A tolerance analysis method for the rigid-flexible mixed model based on the homogeneous transformation correction matrix is established. In this paper, the ideal position and attitude of the rigid-flexible mixed model are expressed as matrix form, and the tolerance accumulation is carried out by means of homogeneous transformation. The assembly deformation is simulated by finite element method, and the simulation result is expressed as a modified matrix, which modifies the original cumulative path of deviation. Thus the key dimensions of the rigid-flexible hybrid model are accurately predicted. (4) sensitivity analysis method based on Monte Carlo is established. Based on the theory that sensitivity is the change degree of relative deviation source of critical size, the tolerance region is divided into several small quantities, and the variation of key dimension caused by small deviation source is calculated. The value of sensitivity is equal to the quotient of both changes. After many calculations, the average value is used to represent the final sensitivity value, and the whole calculation process is realized by MATLAB programming. (5) taking the automobile chassis assembly as an example, The tolerance analysis method of rigid-flexible mixed model based on homogeneous transformation correction matrix and sensitivity analysis method based on Monte Carlo are used to calculate. The feasibility and validity of the proposed method are verified by 3DCS software.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG801
[Abstract]:In the process of machining and production of parts, the error of dimension and shape is inevitable. In the assembly process, these deviations are accumulated and superimposed, which have a great influence on the working performance and appearance quality of the assembly products. Assembly accuracy is one of the core of product quality assurance, tolerance analysis is one of the important links of dimension engineering, it can effectively shorten the product research and development cycle and reduce the production cost while ensuring the quality. The rationality of part tolerance design directly affects the assembly deviation and manufacturing cost, so it is of great significance to carry out tolerance analysis and assembly quality verification in the design stage. Most of the existing tolerance analysis methods are only for rigid or flexible parts. The tolerance analysis method based on the rigid-flexible mixed model which is widely used in engineering field is still in its infancy. How to establish a unified and effective tolerance analysis system and accurately predict the distribution of key dimensions on the basis of existing methods combined with the characteristics of rigid-flexible mixed model is an urgent problem in tolerance technology. In view of the limitation of the existing computer-aided tolerance technology, the tolerance analysis technique of rigid-flexible mixed model is studied, and a tolerance analysis method based on homogeneous transformation correction matrix is proposed. A sensitivity analysis method based on Monte Carlo is established. The main contents of this paper are as follows: (1) the development process of computer aided tolerance technology and the research status at home and abroad are summarized. The research background and significance are introduced. (2) tolerance technology based on new generation GPS (Geometrical Product Specifications) is introduced. By analyzing the relationship among products, parts and features, the tolerance is expressed as the change of feature, and the tolerance modeling is realized with the help of SDT (Small Displacement Torsor) theory. The assembly relationship within the product is simplified as the constraint relationship between the features. (3) A tolerance analysis method for the rigid-flexible mixed model based on the homogeneous transformation correction matrix is established. In this paper, the ideal position and attitude of the rigid-flexible mixed model are expressed as matrix form, and the tolerance accumulation is carried out by means of homogeneous transformation. The assembly deformation is simulated by finite element method, and the simulation result is expressed as a modified matrix, which modifies the original cumulative path of deviation. Thus the key dimensions of the rigid-flexible hybrid model are accurately predicted. (4) sensitivity analysis method based on Monte Carlo is established. Based on the theory that sensitivity is the change degree of relative deviation source of critical size, the tolerance region is divided into several small quantities, and the variation of key dimension caused by small deviation source is calculated. The value of sensitivity is equal to the quotient of both changes. After many calculations, the average value is used to represent the final sensitivity value, and the whole calculation process is realized by MATLAB programming. (5) taking the automobile chassis assembly as an example, The tolerance analysis method of rigid-flexible mixed model based on homogeneous transformation correction matrix and sensitivity analysis method based on Monte Carlo are used to calculate. The feasibility and validity of the proposed method are verified by 3DCS software.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG801
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相关期刊论文 前10条
1 唐健钧;田锡天;耿俊浩;刘海涛;张世炯;;基于多维矢量环的装配偏差源敏感度分析[J];机械工程学报;2015年17期
2 周玲华;余德忠;徐向~，
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