Abstract
Focusing on the non-concave trajectory constraint,a sliding-mode-based nonsingular feedback fast fixed-time three-dimensional terminal guidance of rotor unmanned aerial vehicle land-ing,planetary landing and spacecraft rendezvous and docking terminal phase with external distur-bance is investigated in this paper.Firstly,a fixed-time observer based on real-time differentiator is developed to compensate for the external disturbance,whose estimation error can converge to zero after a time independent of the initial state.Then,a sliding surface ensuring fixed-time convergence is presented.This sliding surface can guarantee that the vehicle achieves a non-concave trajectory,which is better for avoiding collision and maintaining the visibility of the landing site or docking port.Next,the nonsingular guidance ensuring the fixed-time convergence of the sliding surface is proposed,which is continuous and chatter free.At last,three numerical simulations of Mars land-ing are performed to validate the effectiveness and correctness of the designed scheme.
基金项目
National Defense Basic Scientific Research Project,China(JCKY2020903B002)
国家自然科学基金(61973100)
国家自然科学基金(62273118)
国家自然科学基金(12150008)
国家科技期刊平台
NSTL
万方数据