针对一类含有未知时变时滞的不确定非线性系统,提出了一种自适应模糊控制方案。系统不确定项通过模糊逻辑系统辨识,未知时变时滞由参考信号代换,估计误差上界和构造Lyapunov—Krasovskii范函的方法相结合处理辨识误差争时滞代换误差。证明了闭环系统所有信号一致半全局有界(SGUUB),通过调节设计参数可以实现任意的跟踪精度。对含有滞后循环蒸汽的化学反应堆的实例仿真结果进一步说明了方案的可行性。
An adaptive fuzzy control approach was proposed for a class of uncertain nonlinear systems with unknown time varying delays. The uncertain items are approximated by fuzzy logic systems, the unknown time delays are replaced by known constants, and the approximation errors and delay replacement errors are dealt with by combining the techniques of upper bound approximation and constructing Lyapunov-Krasovskii functional. The closed-loop system is proven to be semiglobally uniformly ultimately bounded, and the arbitrary output tracking accuracy is guaranteed by tuning the design parameters. The feasibility is investigated by the simulation result of a practical example of two stage chemical reactor with delayed recycles streams.