Contour Control and Analysis for 3PRPS Platfrom Manipulators

• Main Authors: Yung-Chih Chang, 張永志
• Other Authors: Hua-Yi Chaung
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/99913670370571910663

博士 === 國立臺灣科技大學 === 機械工程系 === 89 === The thesis analyzes the topics about the kinematics, workspace, singularity, dynamics and control of 3 PRPS (parameters P,R, and S denote the prismatic, revolute, and spherical joints) Stewart platform. The Newton-Rapson numerical method solves the forward kinematics since the solutions of closed form are difficult to derive. The workspace of the platform described herein is in a three-dimensional Cartesian space that has a given orientation, allowing for easy computation of the workspace. This thesis also presents a novel means of performing singularity analysis of the six-degree-of-freedom of 3 PRPS Stewart platform. The proposed method is based on the analysis of four bar linkage kinematic chains. The singular configuration of the four bar linkages is initially derived and then applies to the platform manipulators. In the dynamic analysis of parallel robot manipulators, we first divide the dynamic system into three subsystems. The dynamic equations are formulated both in Cartesian space and in joint space. These three dynamic equations are combined into a global dynamic equation in joint space. To reduce the Cartesian space contour error, we derive the transform relations of the contours between Cartesian space and joint space. The cross-coupled control in join space is derived to reduce the contour error in Cartesian space. In addition, the adaptive control algorithms are used to tune the weighting values of the cross-coupled controller. The adaptive cross-coupled weighting controller proposed herein results low contour errors at different feedrates.