Three-dimensional time-varying sliding mode guidance law against maneuvering targets with terminal angle constraint

• Published in: Chinese journal of aeronautics Vol. 35; no. 4; pp. 303 - 319
• Main Authors: WANG, Xinxin, LU, Hongqian, HUANG, Xianlin, YANG, Yefeng, ZUO, Zongyu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2022; Center for Control Theory and Guidance Technology,Harbin Institute of Technology,Harbin 150001,China%The Seventh Research Division,Beihang University,Beijing 100191,China
• Subjects: Guidance law; Maneuvering target; Terminal angle constraint; Three-dimensional; Time-varying sliding mode; Time-varying sliding mode; Maneuvering target; Terminal angle constraint; Three-dimensional; Guidance law
• ISSN: 1000-9361
• DOI: 10.1016/j.cja.2021.05.019

•A three-dimensional terminal angle constraint time-varying sliding mode guidance law is proposed when intercepting maneuvering targets.•The main feature of the proposed guidance law is that it ensures the line-of-sight (LOS) angles to converge to small neighborhoods of the desired values at the interception time. Different from the finite-time guidance laws based on the conventional terminal sliding mode, where the initial overloads are large, this time-varying sliding mode-based guidance law significantly reduces the magnitudes of the overloads.•A fractional power extended state observer (FPESO) is employed to estimate the unknown target acceleration, which enjoy the advantage of restraining the measurement noise.•Comparative simulations show that the proposed guidance law has an excellent performance. This paper deals with the problem of intercepting maneuvering targets with terminal angle constraints for missiles subjected to three-dimensional non-decoupling engagement geometry. To achieve the finite-time interception and satisfactory overload characteristics, a time varying sliding mode control methodology is developed based on a time base generator function. The main feature of the proposed guidance law guarantees the Line-of-Sight (LOS) angles to converge to small neighborhoods of the desired values at the interception time. First, a fractional power extended state observer is used to estimate the unknown target acceleration, which can significantly reduce the adaptive switching gain. The fractional power extended state observer enjoys the advantage of better noise tolerance. Then, a newly designed sliding mode surface is constructed by introducing a time base generator function and the time-varying sliding mode guidance law is developed based on this time-varying sliding surface. The proposed guidance law significantly reduces the overload magnitudes. Numerical simulations are carried out to verify the performance of the proposed guidance law.