摘要
针对一类大初始状态含有匹配扰动的不确定非线性系统,在传统终端滑模面的终端吸引子前加入可调指数的非线性项,提出一种新型非奇异固定时间滑模控制方法。传统的线性滑模、终端滑模、快速终端滑模均是这种新型滑模的特例;当新型滑模面的幂指数N>1时,新型滑模是固定时间收敛的,并且收敛时间具有与初始状态无关的上界。进一步证明所提方案优于快速终端滑模,并分析了参数选择对收敛特性的影响并总结规律。基于李雅普诺夫稳定理论,构造一种适用于二阶非线性系统的非奇异固定时间滑模控制器,证明了控制误差在固定时间内收敛于一任意小闭球内。进行四旋翼飞行器姿态控制仿真验证了所提方法具有更快的收敛速度、更强的鲁棒性和更小的稳态误差。
For the class of uncertain nonlinear systems with external disturbance in the big initial state a nonlinear term with adjustable index is added into the traditional terminal sliding mode control and a new fixed-time nonsingular terminal sliding mode control method is proposed.The traditional linear sliding mode Terminal Sliding Mode(TSM)and Fast Terminal Sliding Mode(FTSM)are all special cases of the new sliding mode;and it is proved that the new sliding mode converges in fixed time when N>1.An analytic expression of the upper bound of the convergent time is obtained which is independent of the initial state.It is proved that the scheme is superior to FTSM and the influence of parameter selection on convergence speed and convergence time is further analyzed and the rule is summarized.Based on Lyapunov stability theory a nonsingular fixed-time sliding mode controller is constructed for second-order nonlinear system and it is proved that the control error can converge to any small closed ball at fixed time.Simulation results of quad-rotor aircraft attitude control have demonstrated the superiorities such as faster convergent speed stronger robustness and smaller steady error.
作者
王崇
刘宜成
蒲明
WANG Chong;LIU Yicheng;PU Ming(Sichuan University,Chengdu 610065 China;Chengdu University of Information Technology,Chengdu 610225 China)
出处
《电光与控制》
CSCD
北大核心
2020年第1期47-53,59,共8页
Electronics Optics & Control
关键词
非线性系统
终端滑模
非奇异
固定时间收敛
李雅普诺夫稳定
nonlinear systems
terminal sliding mode
nonsingularity
fixed-time convergence
Lyapunov stability