Design And Implementation Of Speed Control System For Brushless DC Motor Based On FPGA

Brushless DC motor is widely used in national defense,aerospace,robotics,precision machine tools and other fields due to its high power density,excellent speed regulation performance,reliable operation and easy maintenance.With the development of information technology,the existing control system based on single-chip microcomputer and DSP and the control algorithm based on PID have been unable to meet the requirements of the application of speed and stability.FPGA and intelligent optimization algorithm with good processing ability have become the research focus of the motor speed control system.In this paper,a genetic optimization fuzzy PID control algorithm is proposed to improve the speed control accuracy of brushless DC motor,and the corresponding speed control system is designed based on FPGA,the system test platform is built,and the system performance is comprehensively tested.Specific research contents include:Firstly,the structure of brushless DC motor is introduced,and its working mechanism is analyzed,and the mathematical model is deduced.Based on the model,a genetic optimization fuzzy PID speed control algorithm was proposed,which used fuzzy control to adapt to the traditional PID Ki,Kp,Kd parameters,and based on the actual working conditions,the fuzzy rules and membership function of the fuzzy controller were dynamically modified by genetic algorithm,so as to accurately control the motor speed.Compared with traditional PID and fuzzy PID control algorithms,the performance of the proposed algorithm is verified.Secondly,the brushless DC motor speed control system is designed by FPGA.The genetic optimization fuzzy control module is designed by NIOS-II soft core,and the speed calculation,PID,PWM and alarm module are designed successively by Verilog language under Quartus-II.According to the finite state machine of the main control module,the speed feedback calculation,speed processing decision,control output and other functions are completed.In addition,the function of each module is tested in the Model Sim environment.Then,design and build the brushless DC motor speed test platform.Cyclone IV FPGA EP4CE115F29C7 is used as the main control,and the peripheral circuit of FPGA is designed respectively,including A/D conversion,level conversion,speed detection,rotor position detection,drive,system protection and power supply.The 80BL110S50-445 TKA brushless DC motor is taken as the object,and the system test platform is built.Finally,based on the established brushless DC speed test platform,the system performance was comprehensively tested.Under the conditions of PID and genetic optimization fuzzy PID algorithm,the tracking ability of the algorithm under different speed conditions was tested by oscilloscope and Signal Tap II,respectively,and the performance and practical application effect of the algorithm were verified.In this paper,the brushless DC motor speed control system is designed by FPGA,and the performance of the system is verified by the measured platform built.It provides a reference for the practical application of brushless DC intelligent control algorithm in FPGA,and can promote the wide application of FPGA in the field of motor control.