Reflexive collision avoidance for a novel parallel manipulator

This paper presents an approach in analysis and control of a new, 7-DOF closed-chain manipulator. The collision states of the manipulator were analyzed to construct the 7-D C-space, and this space was represented in a compact and efficient form. Fast, real-time interference evaluation was implemented and tested on the manipulator. The workspace analysis suggests how to optimize use of the kinematic redundancy. Based on the derived C-space, online collision avoidance was enabled. For quasi-static conditions, virtual repulsive from C-space obstacles insulate the boundaries of configuration space. For higher-speed dynamics, an on-line look-ahead algorithm is described that takes into account the manipulator dynamics and the actuator saturation limitations.