Robust Control Design Of Servo System With Input Delay

Based on the turntable servo system, the mechanism of time delay was studied in this work. Moreover, the synthesis problem of controller in the turntable servo system was investigated with the robust control theory on the basis of the analysis of the effect of the model perturbation to the system.Firstly, the control structure of servo turntable system was analyzed and designed. The mathematic model of permanent magnet synchronous motor was deduced with complete decoupling. The uncertainty and its formation mechanism appeared in the system was analyzed in detail. Two main uncertainties, the input time delay and high frequency no modeling dynamic, were described with the model of unstructured multiplicative uncertainty. The uncertainty of the controlled object modeling was analyzed. As for the time delay and high frequency no modeling considered in design, the uncertainty modeling of non structure was found.Secondly, the concept of the standard H∞problem was introduced based on the relationship between performance index and robust stability in H∞control theory to solve the problem of robust control in the uncertain system. The structured singular value theory was used to reduce the conservation of the standard H∞design in the multi-uncertain system. Meanwhile, the select and adjustment principle of weighted function in design was given out. The sufficient and indispensable condition of the robust stability and robust performance was investigated with the theory ofμ-analysis and synthesis. This condition was described with an inequation of matrix structured singular value. At the same time, the basic framework ofμ-analysis and synthesis was set up. The principle and approach ofμ-analysis and synthesis controller computing was given.Finally, the basic problems of the system design and the performance requirement were described, and the robust controller of the turntable servo system was designed based on theμ-analysis and synthesis framework. The weight function was selected according to its select principle after getting the parameter in the model. Consequently, the controller was designed by use ofμ-analysis and synthesis in the toolbox of Matlab. The results of theory analysis and simulation validation indicate that the robust controller makes turntable system have a good robust performance.