Analysis of singularityfree work space for 6DOF ship swaying platform
1.College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016, China; 2.School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003, China; 3.College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016, China
Abstract： For the 6 degree of freedom parallel mechanism of ship swaying platform, the singular phenomenon is inevitable during kinematic and dynamic analyses. Mechanism in singular state can change the original design of motion trajectory, and greatly affect the control performance. Based on the method of RPY describe rotation matrix, the swaying platform kinematic singularity problem was investigated to obtain a Jacobian matrix. The determinants were solved to obtain the singularity which was directly relative to analytical expression with six position and attitude variables. By Mathematica software,the swaying platform position singularity and posture singularity were simulated to draw the locus of singular position and singular attitude. The singular phenomenon during the control trajectory design was effectively avoided. By Matlab software, the singular value constraint was introduced to solve mechanism work space and program search algorithm. The mechanism in a fixed posture with singularityfree position work space was achieved to provide theoretical basis for general parallel mechanism control.
2012, Vol. 33 
