非线性系统的有限时间扩张状态观测器的设计

摘要

To investigate a class of nonlinear systems with uncertainties and external disturbances,a finite time extended state observer is designed to estimate the uncertainties and external disturbances in finite time.Compared to standard extended state observer,based on the idea of terminal sliding mode,the observer makes use of fractional powers to reduce extended state error to zero in finite time,and then strengthen the robustness.A sufficient condition on the issue of finite time stability is established through the theory of Lyapunov,and finally,an illustrative numerical simulation is given to demonstrate the effectiveness of the strategy proposed.%针对非线性系统的不确定项和外部干扰问题,提出了一种有限时间扩张状态观测器的设计方案,实现了非线性系统不确定项和外部干扰的有限时间估计.与传统的线性扩张状态观测器相比,有限时间扩张状态观测器基于终端滑模的思想而设计,其非线性项的引入保障了扩张状态的有限时间估计,进而辅助设计控制器,可以提高系统的鲁棒性能.利用Lyapunov有限时间稳定性理论得到该观测误差系统收敛的充分条件.最后,实例仿真进一步验证了该策略的有效性.