时变输出约束非线性系统的量化反馈自适应终端滑模控制

Adaptive terminal sliding mode control for nonlinear systems with quantized input and time-varying output constraints

针对一类复杂非线性系统,提出一种新型自适应快速非奇异终端滑模控制(IAFNTSMC)方法,用以解决其在输出时变约束及量化输入情形下的轨迹跟踪问题;利用鲁棒自适应方法处理扰动不确定性,并结合反演策略和终端滑模策略设计控制器;构造一种新型的时变约束障碍Lyapunov函数,用于实现对系统的输出误差进行随时间变化的幅值约束;为提高闭环系统的误差收敛速度,提出一种新型的滑模面构造方案.所提控制方法能够保证闭环系统的输出跟踪误差快速收敛到约束边界内,并确保闭环系统所有信号有界.数值仿真验证了所提方法的有效性.

This paper addresses an improved adaptive fast nonsingular terminal sliding mode control(IAFNTSMC)method for a class of nonlinear systems with complicated disturbances and uncertainties under the conditions of time-varying output constraints and quantized input signal.The robust adaptive method is jointly used to deal with the disturbances and uncertainties,and the controller is designed by combining the bakcstepping control strategy with the terminal sliding mode strategy.A novel time-varying barrier Lyapunov function is constructed to time-varyingly constrain the output error of the system during operation.Also,a novel sliding mode surface construction scheme is proposed to improve the error convergence rate of the closed-loop system.The proposed method guarantees that all signals in the closed-loop systems are bounded,and the output tracking error can converge to the given boundary constraints.Finally,a numerical example is given to illustrate the effectiveness of the proposed scheme.