A Coaxial and Coplanar Wireless Slipring for Multi-Axis Robot Manipulators

Abstract

This manuscript proposed a compact slipring based on inductive power transfer (IPT) technology for multi-axis robot manipulators. Compared with conventional solutions, the minimum axial length of the proposed magnetic coupling assembly in the IPT based slipring makes it possible to integrate in-robot joint actuators (electrical motors) with high power and torque densities. Additionally, the voltage transfer characteristic of the wireless slipring system is investigated to provide stable and reliable output voltage in the presence of arbitrary motor speeds and load conditions. A 100-W slipring prototype is designed for a practical three-axis robot arm. The simulation and experimental results clearly verify the system feasibility and effectiveness. The maximum efficiency of 90.3% at an 800 kHz operating frequency is achieved.