Torque Ripple System Design By Mixed Sensitivity And Study On Compensation To Disturbance In Input Of Object

Recently, the modern robust control theory gets more and more attentive and applied. H_∞control theory is a very effective way to solve the robust problem of uncertain system. In fact, H_∞mixed sensitivity theory is a design method in frequency domain. Compared with the other robust controller, the controller designed by this method has lower ranks. That is why this method is popularly used in practicality. Based on the test turntable, the paper does a research on the using of mixed sensitivity design method on the system with disturbance on the input of the object. The paper presents a new system design method, which is to design system using mixed sensitivity method with disturbance observer.The paper first analyzes the models of the uncertain system, then presents the method to build the model of uncertain system and to select the bound of uncertain parameter. The model built for linear uncertain system on frequency domain is strongly studied in the paper. The paper discusses the robust stability of the uncertain system which can not be described by parameter. Based on the discussion, standard H_∞control method and H_∞mixed sensitivity theory are presented. The paper discusses how to select the weighting function. Then the H_∞qualification to ensure the system's robust stability and performance under the disturbance in both input and output of the object is presented. The paper proves that the mixed sensitivity design method is to restrain the disturbance in the output of object.Based on the test turntable system controller designed by H_∞mixed sensitivity theory, the paper presents a method that a disturbance observer is added to the system. The paper discusses how to design the disturbance observer. Then the paper presents the H_∞qualification for the stability of the system with DOB. The simulation proves the system's robust stability. Also, the periodic torque ripples brought by the brushless DC motor is investigated. The whole system is simulated and the results show that the periodic force ripples can be well attenuated under the design using mix-sensitive method and disturbance...