本文系统地研究了机器人离线编程系统的设计与实现中需要解决的两个主要问 题：碰撞检测问题和逆运动学问题。 碰撞检测问题是涉及多个研究领域的重要问题。为保证方法的广泛适用性，本 文重点研究了具有任意形状和任意运动轨迹的空间物体之间的碰撞检测问题， 并将机器人离线编程系统中的碰撞检测作为其中的一个应用问题加以处理。在 系统分析碰撞检测问题的基础上，本文首次提出并实现了一种利用顶点拉伸结 合网格简化技术构造物体的近似精度可控的紧密包围体的算法。在该算法中首 次提出了基于最优准则的拉伸方向的确定方法和拉伸后基于直接解析求解的消 除自相交方法。然后构造了将这样生成的简化包围体与物体的八叉球树(Sphere 0ctree)表示相结合的碰撞检测算法。实验结果表明，这样构造的算法在物体十 分接近时可以用比现有的八叉球树算法低一个数量级的计算代价，达到更高的 检测精度与速度。这样生成的简化包围体表示还可以与其他碰撞检测算法相结 合，有效降低碰撞检测的计算代价，在保证合理的检测精度的前提下达到更高 的检测速度。针对大量空问物体的碰撞检测问题，本文提出了一种固定空间划 分结合利用运动连续性特性的组织方法。 对于机器人的逆运动学问题，本文提出了首先针对特定结构机器人进行分类并 采用解析求解，然后对于一般结构的机器人采用数值求解的方案，实现了一种 能处理多数工业机器人的逆运动学问题的解析求解方法。随后对于各种数值求 解算法进行了全面的分析，对于目前实时性最好的一种全局计算方法进行了系 统整理，针对其数值稳定问题独立提出了结合稳定的局部算法的改进方法并完 成了主要部分的实现。; In this thesis，two main problems in the design and implementation of a robot off-line programming(OLP)system，collision detection and inverse kinematics solution，have been systematically studied． The problem of collision detection is of primary importance in a variety of related fields．The collision detection in an OLP system is treated within a framework of collision detection between objects with arbitrary shape and motion trajectory．Based on an analysis of the nature of the collision detection problem，an algorithm constructing a compact simplified envelope of a given object through vertex offsetting and controlled mesh simplification has been presented and implemented In the algorithm，new method for the determination of the offset direction through optimization and new method for the direct computation of the offset distance to avoid self-intersection have been described Experiment results have proved that the algorithm can significantly improve the accuracy of the existing algorithm based solely on sphere octree while preserving real-time performance．The compact simplified envelope may also be used by other collision detection algorithms to improve their detection speed while maintaining satisfactory accuracy．For the collision detection of a large number of spatial objects which move simultaneously， method of object organization using fixed space division and frame coherence has also been described． In the study of the inverse kinematics problem，a paradigm has been suggested regarding the system design of the inverse kinematics solution subsystem First， existing industrial robots shall be catogorized according to their architecture and solved using analytical methods．A general analytical method applicable to most industrial robots has been implemented．If no analytical solution exists for the given robot，numerical method is used．Various numerical method have been evaluated．The method with the best known real-time performance has been analyzed and method to improve its numerical stability near singular positions has been presented．Main part of the algorithm has also been implemented．
修改评论