State and Disturbance Estimations of Typical Nonlinear Systems in Electromechanical Engineering

Taking a single-link flexible system driven by a DC motor as an example, the Takagi-Sugeno (T-S) fuzzy model is used to study the state and disturbance estimation methods for nonlinear systems, which are commonly present in the field of electromechanical engineering. By analyzing the working mechanism of the system, a nonlinear model of the system is established and then expressed as a T-S fuzzy model. By utilizing system state extension, the original system is transformed into a formal generalized system to achieve both system state estimation and estimation of system output disturbances. A robust proportional-integral observer is designed to achieve system state and disturbance estimation. The solution for the observer gain matrix is obtained by solving linear matrix inequalities. The system is studied separately with and without disturbance, and the correctness and effectiveness of the proposed method are verified through simulation results.