薄板件多工位装配偏差传递建模与定位基准系统设计评价

发布时间：2018-03-28 08:23

本文选题：多工位装配过程　切入点：偏差传递　出处：《吉林大学》2016年硕士论文

【摘要】：汽车车身装配是典型的薄板件多工位装配过程(MAP),其装配过程极其复杂,且装配尺寸质量直接影响整车的性能和美观。设计阶段是决定产品生命周期成本和质量的最重要因素,该阶段对产品尺寸偏差控制的缺乏是导致设计变更的主要原因。在复杂薄板产品的开发过程中,产品定位基准系统规定了产品设计、制造、装配和检测的统一基准,是产品稳健性的决定性因素。在设计早期实现面向过程的产品尺寸精度控制,可以最大程度上减少设计变更,进而缩短研发周期、节约成本、提高产品质量,以增强产品综合竞争力。建立能够精确描述车身薄板件多工位装配偏差传递的数学模型,是实现早期设计阶段产品装配偏差控制的最重要前提。本文研究了薄板件多工位装配的偏差传递机理,在传统的线性状态空间模型基础上,考虑了产品定位基准偏差对产品尺寸精度的影响,提出了一种离散时间系统的非线性状态空间模型来描述薄板件多工位装配过程中的偏差传递过程。该模型以薄板产品的定位基准系统设计参数为模型参数,以零件局部坐标系的运动矢量为状态变量,对关键控制特性(KCC)偏差与关键产品特性(KPC)偏差之间的关系进行了定量描述。结合某A级车的侧围内板多工位装配的工程实例,利用VSA软件对薄板件进行多工位装配的虚拟装配仿真分析,并分别利用建立的非线性状态空间模型、仿真软件以及现有数学模型对产品的多工位装配偏差进行预测。对比分析结果表明,在考虑定位基准偏差的前提下建立的数学模型对薄板件多工位装配偏差传递模拟具有足够的精度,且模型精度明显高于现有偏差传递模型。基于建立的非线性状态空间模型,采用全局灵敏度分析方法,提出薄板产品定位基准系统面对产品总偏差和面对产品关键特征点偏差的多层级设计评价方法,并将该评价方法应用于工程实例。装配系统层级的设计评价指数可直接用于定位基准系统的稳健优化研究,而工位层级和夹具层级的评价指数则可用来分析多工位装配过程中的关键工位及关键定位元件,进而简化定位基准系统中需要优化的设计参数,使定位基准系统的稳健优化效率得到提高。
[Abstract]:Auto body assembly is a typical thin multi station assembly processes (MAP), the assembly process is extremely complex, and the assembly quality directly affect the vehicle's performance and appearance. The design stage is the most important factor in determining the product life cycle cost and quality, the main causes of stage design change of product size deviation of lack of control yes. In the development process of complex sheet metal products, product positioning reference system provides product design, manufacture, assembly and inspection of the unified datum, is the decisive factor of product robustness. At the early stage of the design product dimension precision control process oriented, can greatly reduce the design change, so as to shorten the development cycle, save the cost. In order to improve product quality, enhance the comprehensive competitiveness of the products. The establishment of accurate description of body metal sheet multi station assembly deviation transfer mathematical model is realized The early stage of product design, assembly deviation control is the most important premise. This paper studies the deviation of thin multi station assembly transfer mechanism, based on the traditional linear state space model, considering the impact of product positioning reference deviation on the dimensional precision of products, put forward the nonlinear state space model for discrete time systems to describe the deviation sheet a multi station assembly during transfer process. The model is based on design parameters of sheet products positioning reference system for the parameters of the model, the motion vector of parts of the local coordinate system as state variable, the key control characteristics (KCC) characteristics of deviation and key products (KPC) the relationship between the deviation between the quantitative description of the combination of a class. The car side wall inner plate assembly of the engineering example, analysis of virtual assembly simulation using VSA software for multi station assembly for sheet metal parts, and used to establish The nonlinear state space model, simulation software and the existing mathematical model to predict the multi station assembly deviation products. The results show that, in considering the premise of establishing positioning deviation under the mathematical model of sheet metal multi station assembly deviation transfer simulation with sufficient accuracy and precision of the model was significantly higher than that of the existing nonlinear deviation transfer model. The state space model is established based on the global sensitivity analysis method, the sheet product positioning reference system with multi level and total deviation product design evaluation facing the product key feature point deviation method, and the evaluation method is applied to an engineering example. The design evaluation index system of assembly level can be directly used for the study of robust optimal positioning reference system while, station level and fixture level evaluation index can be used to analyze the assembly process in turn Key position and key positioning elements are used to simplify the design parameters that need to be optimized in the positioning datum system, so that the robust optimization efficiency of the positioning datum system is improved.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U468.2

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