QP-based smoother self-motion planning and control of redundant manipulators using ZD variant with effective verifications

As an important issue of inverse kinematics, the self-motion planning and control (SMPC) of redundant manipulators has been widely investigated to perform various subtasks. But there are still some weaknesses in SMPC researches [e.g., physical limits are usually not taken into consideration, and joint-velocity profiles are mutational (or say rigorously, nondifferentiable) at some time instants], which may jeopardize its future in practical applications. Aiming at remedying these weaknesses mentioned above, a smoother self-motion planning and control (S-SMPC) scheme is proposed and investigated in this paper, which is based on a novel variant of the Zhang dynamics (ZD) design formula. This S-SMPC scheme is then reformulated as a quadratic program (QP) solved in real time. A comparison between the pseudoinverse-based scheme (the conventional scheme used to solve the SMPC issue) and the proposed QP-based scheme is presented, and the differences are revealed. For illustrating the efficacy and superiority of the QP-based S-SMPC scheme, computer-simulation results are presented as well.