Revisiting Direct Kinematic Singularities of 3PPSR Parallel Manipulator

• Main Authors: Ping-Chen Kuo, 郭昺辰
• Other Authors: Chao-hwa Liu
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/28887708411821956702

碩士 === 淡江大學 === 機械與機電工程學系碩士班 === 95 === The purpose of this study is to locate direct singular positions of the 3PPSR 6dof parallel manipulator. The motion of this manipulator can be categorized into the following two types: 1. rigid body displacement without changing its configuration, and 2. rotation of at least one revolute joint-causing a change in configuration. Direct kinematic singularities for these two types of motion are discussed. For the first type of motion, we found that direct kinematic singularity occurs when all three spherical joints lie along a straight line. As for the second type of motion, namely motion with a configuration change, we may obtain the 3×3 Jacobian matrix by kinematic inversion. Direct singular positions for the second type of motion may be determined by solving a quartic polynomial equation. The technique discussed above helps us to determine the distribution of direct singular positions in the manipulators workspace.