Research Of Brushless DC Motor Control Based On The Improved Active Disturbance Rejection Controller

Brushless DC motor(BLDCM) has been widely used in daily life and industrial production for its many advantages. Along with the spread of application field and the development of control theory, the BLDCM with higher performance is demanded. Therefore, the research on advanced strategies becomes more and more important in nowadays. While the technology of Active disturbance rejection control(ADRC) is applied into the control system of BLDCM, the better control effect can be achieved. The technology of ADRC integrates modern control theory with classical PID control, which can effectively process the uncertainty and nonlinearity of control systems without much dependence on accurate mathematical model of controlled objects. Thus, it has been widely applied and obtained some research results. However, the conventional ADRC has some disadvantages, such as large workload of parameter tuning, low control accuracy when the interference occurs in system. So, the improved algorithm of ADRC has been proposed and the control system of Brushless DC motor has been further researched in the dissertation. The main research contents are as follows:(1) The feedback channel tracking differentiator(TD) has been introduced to enhance the interference-free ability. TD can quickly track the input signal, and effectively provide the corresponding differential signal. When the control system encounters interference, the extended state observer(ESO) is difficult to get better state variables, which results in the low precision of the control system, incapable of accurate implementing the estimation and compensation of practice disturbance. However, the feedback channel TD can easily deal with the problems. The simulation results show that this improvement can effectively wipe off the negative effect caused by the disturbance signal, and the system also has better robustness.(2) The problem of large workload of parameters tuning is resolved by fuzzy control technology. Fuzzy control technology has good robustness and dynamic properties, which is independent of the accurate mathematics model of the controlled objects. Within a certain range, parameters can be optimally estimated to adjust the system's parameters automatically. After the simulation, the results show that the method is feasible and effective.(3) The double closed-loop speed regulating system of BLDCM is designed and the improved ADRC is applied into the system. Through the establishment of the simulation models in the system, the improved ADRC device proposed in the dissertation has been simulated for verification. The experiment results show that the proposed device is prior to others and the control system has better robustness and self-adaptability.