毕业生知识库

本课题针对航空制造中复杂曲面构件的机器人磨抛技术展开研究。在飞机制造过程中，存在大量复杂曲面的加工处理，而磨抛是复杂曲面构件制造过程中重要但比较薄弱的环节。目前航空制造过程中普遍是人工磨抛，技术工人靠自己的经验进行磨抛，无法保证加工产品质量的稳定性；并且磨抛的劳动强度大，环境差，对工人健康产生危害，实现磨抛自动化是非常必要的。本课题针对机器人磨抛技术开展了机器人磨抛路径规划算法、机器人磨抛离线编程技术及机器人主动柔顺控制理论三个方面研究，主要研究工作概要如下：

（1）实现了一种基于STL（STereoLithography）文件的复杂曲面机器人磨抛路径规划算法。根据STL格式文件获得三角网格的工件模型，构建半边结构对三角网格进行拓扑重建，使用活性表算法提取磨抛面。采用等间距截面法生成了期望的均匀磨抛路径；同时，提出了等轮廓距离的路径规划算法，以解决部分曲面过磨或欠磨的问题。通过法向磨抛的特点计算磨抛路径点的位姿。

（2）设计开发了一种复杂曲面机器人磨抛离线编程软件。在QT Creator集成开发环境下进行离线编程软件设计，使用GUI（Graphical User Interface）设计库QT实现软件界面的设计，使用OpenGL（Open Graphics Library）来进行三维模型的显示。机器人离线编程软件集成文件模块、工艺选择模块、路径规划模块、机器人离线程序生成以及机器人正逆运动学模块，通过算法生成机器人磨抛的路径点。

（3）研究了机器人磨抛的主动柔顺控制理论方法。分析了力信息获取的方式，研究重力补偿算法对磨抛工具进行补偿。研究了阻抗控制和力/位混合控制的主动柔顺控制方法，设计了一种机器人磨抛柔顺控制系统通讯方式，提供了一种机器人磨抛柔顺控制策略。

This research focuses on robotic grinding and polishing technology for complex curved surfaces in aeronautical manufacturing. There are a considerable number of complex curved surfaces to be machined in the process of aircraft manufacturing, and grinding and polishing are essential but relatively weak in the manufacturing process of complex curved surfaces. At present, the work-piece of aeronautical manufacturing is generally grinded and polished manually, which can not ensure the stability of the product quality. Meanwhile, the process of grinding and polishing is harmful to the health of workers because of the bad environment and the high labor intensity. So it is essential to achieve the automation of grinding and polishing. This thesis focuses on the path planning algorithm, the off-line programming technology, and the active compliance control for robotic grinding and polishing complex curved surfaces. The main contributions of this thesis are summarized as follows.

A path planning algorithm based on STL (STereoLithography) format file for robotic grinding and polishing is achieved in this thesis. The work-piece model of the triangular mesh surface is obtained by reading the STL file. The half-edge structure is constructed to reconstruct the triangular mesh topology, and the active edge algorithm is to used to extract the surfaces to be grinded and polished. The expected paths are generated by using the equal spacing section algorithm. Otherwise, this thesis proposes the equal contour distance algorithm, which can solve the problem of overlap or leak between two paths. The pose of the path points can be calculated according to the characteristics of grinding and polishing along the normal direction.

A kind of off-line programming software for robotic grinding and polishing is designed and developed based on the Qt Creator, which is the IDE (integrated development environment) of QT. The GUI (Graphical User Interface) of the system is developed based on the QT, and the OpenGL (Open Graphics Library) is used to display the 3D model. The robotic off-line programming software integrates the modules of the file, the technological selection, path planning, generating the off-line program, and calculating the robot forward and inverse kinematics. The software can generate the path points of robotic grinding and polishing.

The active compliance control of robotic grinding and polishing is studied theoretically. The method of getting force information is analyzed. The gravity compensation algorithm compensates the gravity of the tool for grinding and polishing. The force/position hybrid control strategy based on position is used to control the force for robotic grinding and polishing after studying the control methods of impedance control and force/position hybrid control. Meanwhile, this thesis designs a communication method of the compliance control system for robotic grinding and polishing.