带有时变时滞和未知死区的纯反馈系统的自适应跟踪控制

Adaptive Tracking Control of Pure-feedback Systems with Time-varying Delay and Unknown Dead-zone

针对一类带有时变时滞和未知死区的纯反馈非线性系统,提出一种新的自适应模糊跟踪控制方案。采用自适应反步法设计了一个虚拟控制输入信号;利用模糊逻辑近似解决了系统中的未知函数所带来的困扰;为了处理未知死区干扰,设计了一个自适应模糊控制器,使用中值定理解决纯反馈结构中设计控制器的复杂问题。该控制方案保证闭环系统所有信号半全局一致有界,与此同时,系统的跟踪误差收敛到原点的一个小邻域内。最后,仿真例子证明了方案的有效性。

For a class of pure-feedback nonlinear systems with time-varying delay and unknown dead-zone, this paper proposed a new adaptive fuzzy tracking control scheme. A virtual control input signal was first designed by using back-stepping technique. Based on a fuzzy logic system approximation, the trouble brought about by the unknown function system was settled. In order to solve the interference by the unknown dead zone, an adaptive fuzzy controller was designed. Mean-value theorem was introduced to deal with the difficulty arising from the pure-feedback structure in designing controller. This control scheme can ensure that all the semi-global signals in the closed-loop systems are uniformly bounded and the tracking error of the system can converge to a small neighborhood of the origin. The effectiveness of the proposed scheme was finally verified with simulated examples.