Mobile manipulator dual-trajectory tracking using control variables introduced to end-effector task vector

This paper presents a novel control system for redundant mobile manipulators to track simultaneously separate mobile platform and end-effector trajectories (dual-trajectory). Control variables D and α are introduced to define the mobile platform trajectory in relation to the end-effector trajectory. This allows direct control of the mobile platform motion relative to the end-effector. Singularity-robust and task-priority inverse kinematics with gradient projection method is used to find best possible least-square solutions for the dual-trajectory tracking while maximizing the whole system manipulability. MATLAB Simulated Wheelchair Mounted Robotic Arm (WMRA) system is used to test and optimize the proposed control system. The results demonstrate the effectiveness of the control system in keeping the order of priority between the two trajectories and optimizing the whole system manipulability measure.