基于非线性干扰观测器的不确定非线性系统鲁棒轨迹线性化控制

Design of a Robust Trajectory Linearization Controller for Uncertain Nonlinear Systems Based on Nonlinear Disturbance Observer

摘要: 针对一类不确定非线性系统，基于轨迹线性化控制方法（TLC）及非线性干扰观测器技术（NDO）研究了一种新的非线性鲁棒控制策略．TLC是一种有效的非线性跟踪和解耦控制方法，但当系统中存在内部未建模动态和外界干扰时，当前TLC控制器性能将显著下降．本文利用NDO对系统中的不确定项进行估计，其输出与TLC控制律结合来对消不确定性的影响．最后通过一个数值仿真实例验证了本文提出的方法的有效性，仿真结果表明该鲁棒轨迹线性化控制方法具有很好的干扰衰减能力和鲁棒性能．

Abstract: A novel nonlinear robust control strategy for a class of uncertain nonlinear systems is presented,which is based on trajectory linearization control(TLC) method and nonlinear disturbance observer(NDO) technique.TLC is an effective nonlinear tracking and decoupling control method.However,the performance of the current TLC may significantly degrade when internal unmodeled dynamics and external disturbances exist.In this paper,an NDO is used to estimate the uncertainties,and then its output is integrated with the TLC to cancel the unknown term.Finally,a numerical simulation example is presented to prove the effectiveness of the proposed method.Simulation results demonstrate that the robust trajectory linearization control method has significant disturbance attenuation ability and performance robustness.