Sensorless Fuzzy Control Of In-wheel Motor

In this paper,based on the operating principle of the in-wheel motor and the control method of the traditional Hall sensor,the sensorless control method uses the method of detecting the back-EMF zero-crossing signal instead of the traditional Hall commutation logic.The commutation method of the hub motor adopts the best time-sharing commutation strategy to guide the commutation.The starting method of the sensorless hub motor uses a three-stage starting method.Since it is difficult to measure the back EMF when the motor speed is low,start the motor in an open loop to extract the back EMF when the motor reaches a higher speed,and then perform the commutation according to the time at which the back EMF crosses the zero point 30 °.This method has The advantages of small overshoot of motor and corresponding high speed.Based on the operating principle of the in-wheel motor and the control principle of the traditional Hall sensor,this paper uses the detection of the back-EMF zero-crossing point instead of the Hall commutation logic.The motor commutation method uses the best time-sharing commutation strategy to guide commutation.The position sensorless hub motor control uses a three-stage start.Due to the back-EMF,it is difficult to measure when the motor speed is low.Start the motor in an open loop first,so that when the motor reaches a relatively high speed,the back electromotive force is extracted,and then the commutation is performed according to the moment of the back electromotive force 30 °.According to the principle of motor control,Simulink in MATLAB software is used to simulate the in-wheel motor.The control system adopts double closed-loop control of current loop and speed loop.The current loop is traditional PI control,and the speed loop is fuzzy PI control.After simulation experiments,the motor control effect is good.The experimental platform control chip is STM32F103 chip,the development language is C language,and the compilation environment is Keil u Vision5.The hardware circuit uses Altium Designer software to design the power module,hardware drive circuit module,back-EMF detection circuit module and key circuit module respectively.The software part is designed under the Keil u Vision5 compilation environment to design the main motor control program,and to encapsulate the interrupt program,motor start program,external synchronous operation program,commutation logic program and fuzzy PI setting function related modules.The motor control chip is powered on,and the experimental results are compared and analyzed.The motor operation effect meets the expectations of the simulation.It has a wide application space in applications such as poor working environments and high precision requirements.