Method of Measuring Fixture Automatic Design and Assembly for Auto-Body Part

A method of 3-D measuring fixture automatic assembly for auto-body part is presented. Locating constraint mapping technique and assembly rule-based reasoning are applied. Calculating algorithm of the position and pose for the part model, fixture configuration and fixture elements in virtual auto-body assembly space are given. Transforming fixture element from itself coordinate system space to assembly space with homogeneous transformation matrix is realized. Based on the second development technique of unigraphics（UG）, the automated assembly is implemented with application program interface （API） function. Lastly the automated assembly of measuring fixture for rear longeron as a case is implemented.     

基于SPC/SPD的汽车车身装焊质量实时监控与故障诊断

在实现车身装焊质量检验工艺和质量实测数据网络化管理的基础上，采用统计过程控制（SPC）和统计过程诊断（SPD）技术，实现了车身装焊质量的实时与监控和故障原因诊断，提高了质量管理的效率和科学性。     

汽车车身开发产品数据管理系统的研究与应用

为提高车身开发效率,缩短开发周期,将产品数据管理技术应用于车身开发过程。首先构建了面向网络、分布开发环境下的集成于车身开发过程的产品数据管理系统的总体结构和实现环境,在Oracle8i数据库系统的支持下,实现了系统中的主要功能模块,并成功应用于某汽车制造企业轻型卡车车身开发项目的管理。该系统能有效地管理车身开发中的产品数据,提高了车身开发的效率,支持车身开发的并行工程。     

基于检测特征的车身覆盖件检具概念设计

首次提出了车身覆盖件检测特征的概念,在讨论这个概念的基础上,采用人工神经网络进行车身覆盖件检具概念设计,以检测特征的7个分量作为神经网络的输入,以检具类型分量作为输出,对构成的神经网络用生产中的实例作为样本进行训练,达到误差平方和小于0.01的目标,得到检具概念设计神经网络模型,并以具体零件检具概念设计为例验证了该方法的有效可行.     

汽车车身静刚度的试验研究

汽车静刚度是车身变形的重要结构参数。文章通过试验研究了车身在扭转情况下和在不同部位加载弯曲工况的车身变形,分别计算了车身的扭转和弯曲静刚度,得到了车地板变形分布和车身关键部位的变形规律。     

轿车车身结构噪声性能分析与优化研究

随着汽车工业的发展和人们对汽车舒适性的要求越来越高，在轿车车身设计中，运用有限元法来进行结构优化以严格控制噪声性能是一种非常有效的方法。以某型SUV车为例，建立车身及乘坐室声腔的有限元模型，并与刚度实验对比验证模型的正确性，通过频率响应分析得到车内噪声等级以及噪声的频率分布特性。以车内噪声最小化为优化目标函数，车身质量为约束条件，通过车身壁板贡献度分析确定优化设计变量，进行车身关键零件的优化改进，使白车身内两个峰值噪声分别降低了5．1dB和3．6dB，为今后开展轿车车身噪声研究提供可借鉴的方法。     

面向复杂形面匹配的边界特征提取方法

针对车身封闭件装配过程中的匹配优化问题,提出一种面向复杂形面匹配的边界特征提取方法.对匹配边界特点进行分析,确定边界点的提取信息、采样间距大小及其搜索邻域.对采样后的点云数据,建立k-d树进行索引.对采样点在搜索邻域内的邻近点建立最小二乘微切平面,利用投影到微切平面局部坐标系内的邻近点分布特性,判断边界特征点及其匹配特征.案例分析验证了该方法在处理复杂形面匹配边界特征点提取时的有效性,在不影响匹配效果的前提下,本文方法可显著提高复杂形面边界特征的提取效率.     

汽车钢板抗凹性试验研究

汽车零件,尤其是外覆盖件的制造过程中选择钢材等级和规格的重要依据之一是抗凹性.以实验评估为基础介绍抗凹性评估相关参量的物理意义及测量原理,并对数种钢板在不同加工硬化和应变硬化状态下的静态抗凹性行为进行分析.研究表明,本抗凹性评估方法合理,可应用于薄板材料的抗凹性研究.     

Optimisation of assembly sequences for compliant body assemblies

Multi-sequence modelling is proposed to optimise assembly sequences for compliant body assemblies such as automotive and aircraft bodies. Multi-sequence modelling is composed of assembly modelling, assembly sequences, tolerance analysis, and assembly operations. Assembly modelling describes the geometric modelling through the liaison graph, which is based on assembly sequence optimisation. Assembly sequences provide information for assembly sequence optimisation. Three-dimensional tolerance analysis is employed to evaluate assembly operations, which is different from previous conceptual tolerance analysis. A genetic algorithm is presented to optimise assembly operations among components. Results show that different sequences lead to a different tolerance of key product characteristics because assembly operations among components are not identical. This paper provides the flowchart of optimising assembly sequences according to the tolerance of key product characteristics.     

Design and optimisation of assembly technique for auto-body components

The dimensional quality of auto-body relates to the whole external appearance, wind noise, the effect of closing the door and even driving smoothness of vehicles. The assembly dimensional quality can be improved by optimising assembly operations between parts and reasonable allocating tolerances of components. A multi-attribute directed liaison graph is proposed to describe precedence relationships and key control characteristics (KCCs) to eliminate unfeasible assembly sequences. A hybrid particle swarm optimisation and genetic algorithm is presented to optimise assembly operations for selecting the best assembly sequence. Based on the above, tolerances of the optimal KCCs are designed by using NSGA-II algorithm according to assembly tolerances and manufacturing costs. To improve optimisation effectiveness, the initial population uses the orthogonal experimental design and sensitivity coefficients of KCCs to generate chromosomes. Finally, the work applied the method by illustrating the process of assembly sequence optimisation and tolerance allocation, and the results show that this case verified the proposed method.