Research On Brushless DC Motor Based On Advanced Control Algorithm

With the development of modern industrialization, the brushless direct current motor (BLDCM) is widely used to build servo drive system. In order to meet the demands of high control accuracy, the servo control system should not only have fast dynamic response, high dynamic and high static precision, and should have strong robustness to overcome parameter variations and unknown disturbances. Since it is hard to meet these demands by traditional control methods, the high performance control technology, which is based on the advanced control algorithm, is attracting the attention in the industrial field widely.Using human fuzzy language to describe complex systems, fuzzy control does not depend on the mathematical model of the controlled system. So it is especially suitable for the nonlinear, time-varying control system. However, it has the defect of lower accuracy. Compared with the fuzzy control, the sliding mode control (SMC) has better robustness to imprecise system mathematical mode and external interference. But the chattering caused by high-frequency limits the sliding mode control widespread and promotion of the method. Based on the above analysis and integrating fuzzy logic control and sliding mode control, a new design method of fuzzy sliding mode controller is introduced. In order to suppress the high-frequency chattering of SMC, the paper also designs a disturbance observer to compensate for external interferences. Meanwhile, a fuzzy sliding controller is designed to adjust the switching amplitude in real time. On condition that the system have high robustness and fast tracking performance, this method overcomes both the inaccuracy and external interferences by SMC and eliminate the high-frequency chattering by fuzzy control.Based on the analysis of the above theoretical method, the paper designs a fuzzy sliding controller to control the speeding of brushless DC motor. First, the mathematic model of brushless DC motor is analyzed, and the vector control methods of brushless DC motor simulation experiment, and points out the deficiency of traditional control. Based on the deficiency of traditional control, the fuzzy sliding strategy is introduced, which assesses system inaccuracies quantitative boundary value by fuzzy control and adjusts the parameters of fuzzy control by adaptive algorithm on-line. Finally, the experiment results show this method has the advantages of auto optimizing parameters, high control accuracy and high ant-interference ability etc. Therefore, it is a high-performance servo control method with adaptive capacity.