一类不确定非线性系统自适应输出反馈跟踪控制的新结果

研究了一类不确定非线性系统的自适应输出反馈实际跟踪控制问题. 解决该控制问题的困难主要源于此类系统控制系数不确定, 并具有依赖于不可测状态的增长且其增速是关于输出的多项式函数. 首先, 通过推广现有的K–滤波器, 引入了新的动态高增益K–滤波器, 并基于此构造了状态观测器. 然后, 应用反推技术, 成功的设计了系统的自适应输出反馈跟踪控制器. 主要结果表明, 通过设计参数的适当选择, 所构造的控制器能保证闭环系统的所有状态全局有界, 并且当时间足够大时, 跟踪误差收敛到零点的既定小邻域内.

New results on adaptive tracking by output feedback for a class of uncertain nonlinear systems

We consider the adaptive practical tracking control by output feedback for a class of uncertain nonlinear systems. This class of systems has an uncertain control coefficient and unmeasured states dependent growth with growth rate of polynomial-of-output. To deal with the difficulty caused by this control coefficient, we extend the existing K-filters to new dynamic K-filters with high gains; based on which we construct a state observer. Then, the adaptive tracking controller by output feedback is successfully designed using the backstepping technique. It is shown that if the design parameters are suitably chosen, the designed controller guarantees the closed-loop system states to be globally bounded, and the tracking error to converge to the prescribed small neighborhood of the origin after the elapse of a long time.