Research And Design Of Speed Control Of DC Motor Based On FPGA

In recent years,motor has been widely used in various fields of life and production as an electromechanical energy conversion device.In the process of the rapid development of industrial electronics,the traditional single motor control system has been unable to meet the needs of modern industry,and more of the work is done by the cooperation of multiple motors.Compared with brush motor,brushless Direct Current motor(BLDCM)has become the first choice for motor design with its excellent performance.At present,the traditional PID control algorithm of BLDCM has problems such as poor response performance and low control accuracy.Moreover,the controllers with Microcontroller Unit(MCU)and Digital Signal Processors(DSP)as control cores cannot used for the various needs of multi-motor system control due to the limitations of their own structures.In order to solve the above problems,due to the advantages of real-time parallel processing,so uses FPGA as the control chip in this paper.It can not only quickly implement complex control algorithms,but also control multiple motors at the same time,and can reconfigure the motor control system by the actual needs,and improve the system response speed and control accuracy,to achieve the purpose of improving the response speed and control accuracy of the system.The specific work in this paper includes the following aspects:Firstly,this paper describe the background significance of the research and the current status of domestic and foreign research in the field of BLDCM control,and introduce the physical structure and working principle of the BLDCM,and derived the mathematical model.Secondly,the traditional PID control algorithm of the BLDCM is introduced.According to the problems of the PID control algorithm,the three parameters of the PID control are adjusted through fuzzy control to adapt to the changes of the system and achieve the ideal control effect.The single motor speed control system was built in Matlab/Simulink,and the simulation analysis of the two speed control systems was carried out from the aspects of speed mutation and load change respectively.The simulation results showed that the stability time and overshot of the fuzzy PID speed control system were improved by 36% and 1.8% respectively compared with the PID speed control system.Moreover,when the speed changes suddenly and the load is added,the time for the fuzzy PID speed control system to reach the stable state is also about 5% higher than that of the PID speed control system,indicating that the fuzzy PID speed control system has better control effect and performance than the PID speed control system.Thirdly,the BLDCM speed control system with FPGA as the core is designed.In the aspect of hardware circuit,FPGA control chip with Cyclone ? series chips of the Altera company,the design of BLDCM drive circuit,position detection circuit and A/D conversion circuit and other peripheral circuit.The driving circuit is composed of the inverter circuit and the driving chip circuit,which are used to drive the motor.The position detection circuit and the A/D conversion circuit are used to collect the data information in the working process of the motor and feed it back to the FPGA chip.In terms of software,according to the system function division,the PID control module,fuzzy control module,PWM module,speed calculation module and A/D conversion module are designed with Verilog HDL language in Quartus II,and each module is simulated.Finally,the function of the designed speed control system of BLDCM is tested in ModelSim under the sudden change of speed.The test results show that the speed control system by FPGA design is fully digitized,the response time is short,the control precision is high and the reliability is good.