Design of a Pneumatic-Electric Hybrid Linear End-effector for Robot Polishing

A pneumatic-electric hybrid linear force control end-effector is proposed in this paper. A tubular voice coil motor (VCM) is implemented as the active force actuation unit and the nitrogen spring is implemented as the passive vibration absorb unit. The VCM is designed with Halbach permanent magnet (PM) array to improve force density, the air-gap magnetic field and the thrust of the VCM are analyzed by the magnetic equivalent circuit (MEC) method and the finite element method (FEM). The output force of the nitrogen spring is fitted by experimental data. Because of the fast response characteristic of VCM and the high damping coefficient of the nitrogen spring, the designed end-effector can meet the force tracking required for high-performance robotic polishing.