The Research And Design Of Brushless Direct Current Motor Speed Regulating System Based On DSP

With the rapid development of power electronics technology and automatic control technology,the application of motor control has been ubiquitous in people's life,and the research and application of motor control has been increasingly concerned by people.The brushless dc motor(BLDCM)along with the development of technology,from the original mechanical reversing into electronic commutation,make it has small volume,wide speed range,safe and reliable operation,simple structure,easy to realize the advantages of digital control,in the modern society has been widely used in various fields,such as national defense,aerospace,robotics,medical equipment,confidential machine,etc.Therefore,the research and analysis of brushless dc motor control system is of great significance.Firstly,the structure,working principle and mathematical model of the brushless dc motor control system are deeply analyzed in this paper.Then,the mathematical model of the motor control system is established,and the velocity and current double closed-loop control scheme is established.The simulation model of brushless dc motor double closed-loop control system was built on Matlab/Simulink simulation platform.Based on the research of control strategy and characteristics of brushless dc motor,the fuzzy controller is optimized by genetic algorithm.In this paper,the inner loop current loop is controlled by traditional PI,and the outer loop velocity loop is controlled by fuzzy PI,fuzzy PI and traditional PI optimized by genetic algorithm.Comparative experiments are carried out on the established simulation system.Simulation results show that the fuzzy PI control strategy optimized by genetic algorithm has better response speed and dynamic steady-state performance.Then,on the basis of theory and simulation,the DSP chip TMS320F2812 controller launched by TI company is taken as the core,and each module is planned to carry out the software and hardware design of the brushless dc motor control system.Hardware includes core processor,drive circuit,detection circuit,inverter circuit and isolation circuit and other peripheral circuit design.Then in DSP integrated development environment CCS using C language to write the system debugger,implements the genetic algorithm to optimize the fuzzy PI control module,the motor commutation,speed calculation,with current PI regulation dead area,serial communication module,using vc + + to develop the function of PC monitor,can realtime observation and control the running state of the machine.Finally,PC software and instrument testing software and hardware of the control system,through the observation to the test results summary analysis,the study found that the genetic algorithm to optimize the fuzzy PI control algorithm is compared with the fuzzy PI control and traditional PI control algorithm has better performance,with fast response,less overshoot and good stability,etc.It is proved that the brushless dc motor control system designed in this paper has good performance.