Development Of Variable Frequency Speed Controller For Treadmill

With novel coronavirus pneumonia being raised,especially in the outbreak of new crown pneumonia,home exercise has become a trend.Treadmill as an important indoor fitness equipment has been widely used.In the course of running,the load torque changes greatly because of the different weight and speed of each athlete.Therefore,this paper aims to develop a special AC speed controller for treadmill,which can adjust the motor speed smoothly under the action of pulse load to realize comfortable control.In this paper,the mathematical model,vector control,voltage space pulse width vector and pulse load characteristics of treadmill are analyzed in detail,and the structure diagram of vector control system based on pulse load is established.In order to solve the problem of insufficient adaptive ability of PI controller in vector control,a single neuron PI controller is proposed.The proportional gain K of the single neuron PI controller is optimized by using Sgn function and fuzzy control respectively to further improve its adaptive ability.The simulation results show that the control system has better robustness.Based on the simulation and verification,a controller is developed based on DSP TMS320F28335.Firstly,according to the requirements of treadmill parameters,the power supply,digital part and analog circuit of the controller are designed.Then,the main program and interrupt service subprogram of the whole system are written by CCS operating platform.Finally,the speed adjustment performance test is carried out for the controller.The test results show that the variable frequency speed controller of the treadmill developed in this paper can keep the overshoot of motor speed within 3% when facing different types of pulse load,and meet the highest speed accuracy level of national standard GB17498.6-2008.