非匹配不确定高阶非线性系统递阶Terminal滑模控制

摘要

For higher-order nonlinear system, firstly, improved higher-order sliding mode differentiators are used as indirect disturbance observers to approximate the mismatched compound disturbance except the one which exists in the last subsystem. The estimated errors are arbitrarily small. To avoid the algebraic loop, three schemes are proposed to obtain the estimation value of mismatched compound disturbance of the last subsystem, and the error is bounded. Then, nonsingular recursive terminal sliding mode controller is designed and necessary conditions are given. Finally, it is proved that the system is stable and the tracking error is arbitrarily small. Simulation applied to a near space vehicle has proved all conclusions.%对于高阶非线性系统,首先采用改进的高阶滑模微分器作为间接干扰观测器,获得前n-1个子系统中的非匹配复合干扰的估计值,证明了估计误差可任意小.为避免代数环,设计了三种方案获得最后一个子系统中非匹配复合干扰的估计值,并证明了估计误差有界.在此基础上设计递阶Terminal滑模控制器,证明了控制器参数非奇异及结构非奇异,并给出所需条件.最后,证明了系统稳定,跟踪误差可任意小.近空间飞行器姿态控制仿真验证了本文结论.