Nonlinear Position Control of a Magnetic-Geared Servo Drive With Unknown Load

Magnetic gears (MGs) emerged as an attractive alternative to conventional mechanical gears and their application in different fields, including servo drives, is already being considered. However, high-performance control of magnetic-geared drives is not an easy task due to the low stiffness and highly nonlinear characteristics of MGs. This paper presents a nonlinear approach to position control of magnetic-geared servo drives based on exact feedback linearization and load torque estimation. Simulation results show that the proposed nonlinear controller exhibits excellent tracking and disturbance rejection properties, and that it ensures the same high-performance dynamic behaviour in the entire operating region of the drive.