Design and Optimization of Permanent Magnet Synchronous Motors with Segmented Stator for Robotic Actuators

Abstract

Robotic systems require high performance robot joints to achieve advanced mobility capabilities. Recently, innovations in permanent magnet technology, material science, gearbox topologies, and control techniques have facilitated the emergence of unique design and manufacturing approaches, specifically for the electric motors used in the drive mechanism of these structures, known as servo actuators. This study focuses on the design of an inner rotor, surface mounted permanent magnet, frameless synchronous motor with specifications of 48 VDC, 100 W, and 3000 rpm, intended for use in robot joints with gripper. Optimization studies, integrating the segmented stator design, are conducted to enhance the operational performance, environmental interaction, and production efficiency ofthe joints. The advantages and disadvantages of integrated and segmented stator structures are compared. Cogging torque is analyzed, and techniques to reduce this effect is explored. Preliminary sizing is performed using analytical methods, and optimization studies are completed using the finite element method. © 2024 IEEE.