• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2025, Vol. 61 ›› Issue (22): 36-46.doi: 10.3901/JME.2025.22.036

Previous Articles    

Magnetic Vector Compensation Control for Desired Target Orientation of Permanent Magnet Spherical Motor

ZHANG Yongshun1,2, WANG Li2, WU Zhenhua2, LIU Gaoren2   

  1. 1. College of Intelligent Manufacture Engineering, Guangdong Baiyun University, Guangzhou 510450;
    2. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024
  • Received:2024-12-03 Revised:2025-05-20 Published:2026-01-10

Abstract: For solving the problems of complex electromagnetic structure, redundant control variables and magnetic torque singularity of permanent magnet spherical motor, according to the rotational coaxial effect of the permanent magnet rotor, in which whose axis always tends to rotate toward the rotational axis of the rotating magnetic field, using the three-axis orthogonal combination coil as the stator, a two-degree-of-freedom permanent magnet spherical motor mainly composed of universal follow-up mechanism with built-in permanent magnet rotor is developed. Aiming at the phenomenon in which the payload generates the orientation deviation between the rotating axis of the magnetic field and the axis of the permanent magnet rotor coaxial with the output end of the motor, an accurate drive and control method for approaching the trace of the desired target orientation of the output end of the motor with payload is proposed by magnetic vector orientation compensation. Specifically, the three-phase current formula with the pitch and yaw angle of the rotating axis of the magnetic field as the independent control variables is used to superimpose the rotating magnetic field, the rotational coaxial magnetic moment model and the slip angle model related to the compensation orientation parameter of the field rotation axis and the target orientation parameter of the motor are derived, achieving the decoupling of the yaw and pitch magnetic moment components. In view of the fact that permanent magnet rotor at the balance point has gyro stability, by ignoring the inertial force of the system, the static torque balance equation of the motor is established at each balance control point of the desired target orientation, and compensation orientation trajectory of the magnetic vector is obtained, as a result, the analytic solution of the drive currents correspondence to magnetic moments each to each is achieved, which lays a foundation for accurate drive and control of permanent magnet spherical motor.

Key words: permanent magnet spherical motor, rotational coaxial magnetic moment modeling, slip angle modeling, static torque balance equation, magnetic vector orientation compensation

CLC Number: