T-S Model Robust Control And Its Applications To Speed Control Of PMLSM System

Permanent magnet linear synchronous motor (PMLSM) system overcomes a series ofunfavorable effects caused by driving chains and become one of the most importantadvanced techniques of modern numerical control tools. On the other hand, many factorschallenge the control strategies of PMLSM, such as the nonlinear coupling of systemvariables, uncertainties of system parameters, load perturbation and end-effect, etc.T-S fuzzy model is adopted in this dissertation to deal with the nonlinear coupling ofthe variables in PMLSM system. Robust speed control algorithms of PMLSM system areobtained based on the improved robust stabilization condition of T-S fuzzy model.Aiming at the parametic uncertainties of PMLSM system, structural decomposition ofuncertain parameter matrices of PMLSM model is obtained based on the parameters'quantitative analysis. Based on piece-wise linear method, uncertain T-S fuzzy model ofPMLSM system is founded by selecting fuzzy rules, local linear models and membershipgrade function. Load perturbation is considered simultaneously. So a foundation isobtained for further theoretical analysis and applied research.Aiming at the robust stabilization conditions published in the literature is moreconservative, the improved robust stabilization condition of T-S fuzzy model withparametric uncertainties is proposed. This condition enlarges the solution set because ofincluding more free variables, and is shown to be less conservative than existed results.The guaranteed cost controller exist condition and H_∞robust controller exist condition areobtained based on the improved robust stabilization condition.In order to make the PMLSM system have optimal performances for variation ofsome parameters, algorithm of guaranteed cost control law for T-S fuzzy model withparametric uncertainties is proposed. This algorithm is applied to the velocity control ofPMLSM system. The better system's speed performance is gained by modifying theweight coefficient matrices. Simulation comparison research is given aiming at differentvelocity objectives, load and weight coefficients. Based on the background of unknown load perturbation in some energy bound inPMLSM system, the H_∞robust control law algorithm for T-S fuzzy model with parametricuncertainties is obtained. This algorithm is applied into the perturbation restraint of thevelocity control. The velocity performance and current components are both optimized bymodifying the controlled output matrix. Simulation comparison research is given aiming atdifferent velocity objectives, load and parameters.Experimental research of PMLSM system is conducted based on TMS320 LF2812,which illustrates the validity of the theoretical research and the simulation results of theproposed control strategies.