Simulation And Measurement For Torque Of Permanent Magnet Spherical Motor

A spherical motor is a multi-degree-of-freedom motor with a unique stator-rotor structure.Compared with the control system of the traditional motor,the dynamic performance of the system incorporated with the spherical motor is greatly improved:the response becomes faster,the failure rate of the system is reduced,the system stability is significantly enhanced,and the reliability is improved.However,torque measurement technology has become one of the key technologies for the development of spherical motors and the requirements for real industrial applications in the future.The current development of the research on the output torque measurement method of spherical motor is analyzed,and then the electromagnetic torque of a multi-degree-of-freedom permanent magnet spherical motor is simulated in this thesis.Based on the rotor dynamics equation,the no-load output torque was measured by using a MEMS(Microelectromechanical system)gyro sensor.The feasibility of the method is verified by measurement experiments.The main research work of this thesis is as follows:(1)Based on a permanent magnet spherical motor and its specific structure,the basic stator-rotor structure is introduced,the magnetic field and electromagnetic torque are theoretically analyzed.(2)Based on the electromagnetic theory analysis of the motor,the torque simulation model is established.Under different excitation current conditions,the electromagnetic torque is simulated,and the simulation results of magnetic field and electromagnetic torque are obtained.(3)A method for measuring the no-load output torque based on the measurement acceleration at the starting moment is proposed.According to this method,a torque measurement experiment based on MEMS gyroscope sensor detection system is designed.(4)After comparing the torque simulation results with the experimental measurement results,the trend of torque changing with the current,the error source of the experimental results,and the error compensation of the experimental results is analyzed.The final experimental results show that the measurement study is consistent with the simulation study,and the practicability of the no-load output torque detection method is verified.