Kinematic Analysis of a Spherical Parallel Mechanism with 3-Degree of Redundancy
摘要
Remote Center of Motion mechanisms are known to rotate their end effector around a point. Spherical Parallel Mechanisms, which use spherical linkages in parallel, have a good kinematic performance close to the workspace center. But the large number of links and joints tends to compromise their behavior as their end effector moves away from it and approaches other parts like their base or other links. Reconfiguration features allow a mechanism to change its configuration for the same end effector position. In the present study, pantographic linkages are used to re-orient the SPM base as reconfiguration method. A preliminary analysis of its kinematic and velocity models is conducted. The reconfiguration joint variables are then determined in order to optimize the kinematic performance of the mechanism. After completing the inverse kinematic model, the reconfigurable mechanism is evaluated and compared to its non-reconfigurable counterpart.