文件名称：Stable Adaptive Fuzzy Control of Nonlinear Systems
文件大小：1018KB
文件格式：PDF
更新时间：2014-02-03 04:16:41
adaptive fuzzy controller
An adaptive fuzzy controller is synthesized from a collection of fuzzy IF-THEN rules.The parameters of the membership functions characterizingthe linguistic terms in the fuzzy IF-THEN rules change accordingto some adaptivelaw for the purpose of controllinga plant to track a reference trajectory. These fuzzy IF-THEN rulesare eithercollectedfrom experienced human operators or generatedautomaticallyduring the adapta- tion procedure.In this paper,a direct adaptivefuzzy controlleris designedfor a general higher-ordernonlinearcontinuoussystem through the following three steps:first,define some fuzzy sets whose membership functions cover the state space;then,use fuzzy IF-THEN rules from human experts and some arbitrary rules to construct an initial adaptive fuzzy controller in which some parameters are free to change;finally,develop an adaptive law to adjust the free parameters based on a Lyapunov synthesis approach.It is proved that 1)the closed-loop system usiog this adaptive fuzzy controller is globally stable in the sense that all signalsinvolvedare bounded and 2)the tracking error converges to zero asymptotically if the minimum approximation error of the fuzzy controllerto an optimal controlleris squared integrable along the state trajectory.Finally,we apply this direct adaptive fuzzy controller to control an unstable system and a chaotic system.