The initial robustness analysis of designed U-pole placement control systems

In this study, an initial robust stability analysis procedure is proposed to test the performance of the designed U-pole placement control systems. Unlike the classical design procedures for non-linear control systems, the control-oriented U-model based non-linear control systems cancel the non-linearity of the non-linear models. Therefore, the closed loop transfer function of U-pole placement control system can be regarded as a linear block. Once the internal parameter changes, the parameter variation of the closed loop characteristic equation can be detected by the least squares method to fit measured input and output. The stability margin of the closed loop system can be determined by using LMI (Linear Matrix Inequality) based robust stability analysis procedure. In this study a Hammerstein model is selected to test the robust stability of the U-pole placement control systems. The simulation results demonstrate the proposed procedure effective.