The enhanced compact QP method for redundant manipulators using practical inequality constraints

For resolving the manipulator redundancy under inequality constraints, the compact QP method (including the improved Compact QP method) is very effective and efficient. From a viewpoint of practical applications, however, it turns out, we found, to have some performance limitations such as unrealistically high torque due to joint angle limit constraints and tracking errors due to joint torque limit constraints under parameter variation and disturbance. Remedying the limitations, the enhanced compact QP method is developed by using the practical inequality constraints with p-step-ahead predictor and time delay estimation. Through dynamic simulation results, it is verified that the enhanced compact QP method significantly improves the compact QP method in terms of efficiency and effectiveness for the real-time control of redundant manipulators under physical limits.