基于关键特性控制点的飞机产品公差设计理论与关键技术研究

As the manufacture variation is increasingly prominent, it is difficutlt to ensure the quality of airplane. This project takes airplane key characteristics and quality control points' tolerance distribution as research object. This project will investigate such botttlenecks and key technical problems of digital coordination which is based on key characteristic control points. (1) Quantitatively recognize and decouple key characteristics. Information entropy theory is introduced to recognize key characteristics, Rough sets theory is applied for the attribute reduction, then the index system of evaluating the importance of characteristics is built. On this basis, the evaluation results of two methods above are combined by fuzzy Borda method. (2) Quantitatively decompose and propagate key characteristics. Low-dimensional incidence matrix is solved by means of regression analysis. High-dimensional incidence matrix is solved by means of Information entropy theory. (3) Control method of key characteristic variation based on key characteristic points and digitally coordinate of key characteristic points. The variations of key characteristics are mapped by the coordinates of key characteristic points. The traditional dimension chain is replaced by point coordinate chain for key characteristic points. Error ellipse and relative error ellipse is introduced to calculate absolute error and relative error for two-dimensional tolerance distribution. Error ellipsoid and relative error ellipsoid is introduced to calculate absolute error and relative error for three-dimensional tolerance distribution. A new tolerance distribution method is put forward for points’ tolerance distribution which is based on point coordinate chain. . The project expected outcomes would overcome the problem of complex structure quality stability control, and realize the digital coordinate of key characteristic points. Moreover, the project will extend the traditional tolerance distribution theory which is based on dimension chain and promote lean manufacturing of complex structure products.

为解决飞机产品日益突出的生产波动带来的质量问题，以飞机产品关键特性及其控制点的公差设计为研究对象，研究基于关键特性控制点的数字化协调的瓶颈问题和关键技术：①关键特性量化识别与解耦。引入信息熵理论，建立基于信息熵的特性量化评价模型；利用粗糙集，通过抽取分类规则，求解特性的重要程度指标；用模糊Borda法对两组量化指标进行组合评价。引入相对熵，建立关键特性耦合度计算模型。②关键特性量化传递与分解。采用回归分析法求解低维关联矩阵，用装配特性熵求解高维关联矩阵。③基于控制点的关键特性波动控制方法及其公差设计。用控制点坐标变动映射关键特性波动，用点坐标链方程替代尺寸链方程，用误差椭圆/误差椭球的描述控制点绝对误差，用相对误差椭圆/相对误差椭球的描述控制点相对误差，提出基于点坐标链方程的点公差设计理论。研究成果有望解决复杂结构产品的质量稳定性控制难题，给出控制点的数字化协调方法，拓展传统公差设计理论。

零部件生产波动不仅严重影响到飞机产品质量，而且关系到飞机制造周期和生产成本，需全面采用基于关键特性的飞机质量控制方法，解决基于关键特性的飞机协调难题。关键特性通常以公差、轮廓度、位置度等形式的信息出现，其基本的定量分析工具是公差分析方法。为此，本项目以飞机产品关键特性及其控制点的公差设计为研究对象，建立基于关键特性的数字化协调理论和方法，从根本上解决飞机等复杂结构产品的质量稳定性控制难题，实现飞机等复杂结构产品的精益制造。该理论和方法适应了现代飞机产品数字化研制及其高质量控制的发展，对提高我国飞机等复杂结构产品的制造水平具有非常重要的理论意义和工程应用价值。. 针对目前飞机结构件的关键特性识别与传递过程中缺乏定性定量结合分析的具体识别方法、在飞机研制阶段信息储备贫瘠以及不确定性大等的现状，提出了一种新的飞机结构件关键特性量化识别方法；提出了一种基于传递熵的各装配单元装配特征偏差之间量化描述方法，利用传递熵来确定装配偏差变量间的拓扑关系和衡量因果性的指标。针对工装制造安装误差对装配精度的影响，提出了基于SDT和间接平差的装配工装偏差传递累计方法，实现了提出多定位器球铰中心点动态误差计算。为适应数字化协调和坐标点数字化测量设备在飞机装配中的广泛应用，提出了基于公差图的飞机部件交点装配数字化协调方法，将装配特征几何要素映射为欧氏空间中的点，利用闵可夫斯基和对统一后的T-Maps进行累积，得到协调要素的累积T-Map。并依据累积T-Map和交点轴线T-Maps的几何关系进行公差累积与分配。针对装配过程基准变换导致几何公差变化的问题，并使装配方案满足点测量模式，提出了一种基于公差图的公差转化方法。