Shen Yanxia

Model Reference Fuzzy Adaptive Control of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motors (PMSM) are widely used in industrial drives due to their simple structure, high efficiency and high factor. Variable speed system of PMSM based on vector has owed an important position where has seriously requirement for celerity and precision. Firstly, the controlling characteristics and working principles of PMSM are analyzed, and the PMSM precision mathematical models are established based on the dq reference coordinates by strict analysis and calculation. The fuzzy model reference adaptive control method uses the fuzzy basis function expansion to represent the unknown parameters and change the identification problem from identifying the original unknown parameters to identifying the coefficients of fuzzy basis function expansion. The stability and convergence properties of the controller are ensured. The results of the simulation based on Matlab and dSPACE experiment show the fuzzy adaptive speed controller has high control and parameter track performance.

Finite-Time Stability Analysis for a Class of Continuous Switched Descriptor Systems

Finite-time stability has more practical application values than the classical Lyapunov asymptotic stability over a fixed finite-time interval. The problems of finite-time stability and finite-time boundedness for a class of continuous switched descriptor systems are considered in this paper. Based on the average dwell time approach and the multiple Lyapunov functions technique, the concepts of finite-time stability and boundedness are extended to continuous switched descriptor systems. In addition, sufficient conditions for the existence of state feedback controllers in terms of linear matrix inequalities (LMIs) are obtained with arbitrary switching rules, which guarantee that the switched descriptor system is finite-time stable and finite-time bounded, respectively. Finally, two numerical examples are presented to illustrate the reasonableness and effectiveness of the proposed results.