Development Of DSP Control System For Brushless DC Motor By Model-based Design

The brushless DC motor is based on electronic commutation, replacing the traditional brush and mechanical commutation, effectively eliminating the traditional motor problems. It greatly improves the work efficiency and is widely used in household appliances, medical equipment, aerospace and other fields. Brushless DC motor control system algorithm is complex and need large amount of computation, usually using DSP as the controller. Traditional brushless DC motor embedded system development uses C language to write code, in the target DSP to achieve. The shortcomings are complicated programming, long development cycle. According to above issues, the rapid development of the embedded control system of Brushless DC motor has practical significance.In this paper, the DSP control system of Brushless DC motor based on model design is developed in the Real Time Workshop environment in order to improve the development efficiency of Brushless DC motor control system. The main researches are as follows:(1) The hardware design of the control system is carried out. Firstly, the selection of DSP chip is carried out and the design of DSP external expansion circuit is carried out on this basis. According to the motor power, the power device is selected and the power driving circuit is designed. The power driving circuit is composed of a driving inverter circuit, a power supply circuit, a hall signal circuit and an over current protection circuit. At last, the hardware system is tested, and the test results show that the system can work normally.(2) In the RTW environment, the DSP control system code of Brushless DC motor is developed by the model based design method. Firstly, taking the PWM signal generation as an example, the development of DSP code in RTW environment is realized by setting up the Simulink model and configuring the environment parameters. On this basis, use C2833 x module, Simulink standard module, Stateflow module provided by Simulink to set up an open loop control system Simulink model. On the basis of open loop model, the Simulink modulewhich uses hall signal to measure speed is added and a closed loop control system model using PID algorithm is built. The open loop and closed loop control system model is compiled and downloaded to the DSP to operate separately. The experimental results show that adjusting the PWM duty cycle can control speed under the open loop control and adjusting the given speed can control the actual speed of the motor under closed loop control.(3) DSP code of the brushless DC motor vector control system was developed. According to the structure diagram of vector control system, the Simulink model of Brushless DC motor vector control system is built by using the C2833 x module library and C28 x DMClib in the embedded code tool box.The model is used to realize the vector control of motor. However, due to the limited hardware conditions, the experiment can not be verified. Therefore, this paper uses the embedded code tool box to simulate and analyze the speed regulation performance of the control system, which lays the foundation for the hardware implementation of the motor complex control algorithm.To a certain extent, this paper's research results can provide a reference for future research in the field of motion control.