%0 Journal Article
%T Design of Second-Order Sliding Mode Guidance Law Based on the Nonhomogeneous Disturbance Observer
%A Huibo Zhou
%A Shenmin Song
%A Junhong Song
%A Jing Niu
%J Journal of Control Science and Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/890824
%X Considering the guidance problem of relative motion of missile target without the dynamic characteristics of missile autopilot in the interception planar, non-homogeneous disturbance observer is applied for finite-time estimation with respect to the target maneuvering affecting the guidance performance. Two guidance laws with finite-time convergence are designed by using a fast power rate reaching law and the prescribed sliding variable dynamics. The nonsingular terminal sliding mode surface is selected to improve dynamic characteristics of missile autopilot. Furthermore, the finite-time guidance law with dynamic delay characteristics is designed for the target maneuvering through adopting variable structure dynamic compensation. The simulation results demonstrate that, for different target maneuvering, the proposed guidance laws can restrain the sliding mode chattering problem effectively and make the missile hit the maneuvering target quickly and accurately with condition of corresponding assumptions. 1. Introduction With the development of flight control technology, the maneuverability of targets is getting much stronger, and how to inhibit the influence of the target¡¯s maneuvering on the missile¡¯s guidance performance and improve the robustness of guidance law is always the research hotspot in the field of missile interception. At present, there are several robust guidance laws, including guidance law [1¨C3], gain guidance law [4], neural network guidance law [5], adaptive guidance law [6], and sliding mode variable structure guidance law. The sliding mode guidance law which is robust with respect to uncertainties and disturbances has aroused a wide research interest in recent years [7¨C11]. However, there is a disadvantage for the sliding mode variable structure control, which is the chattering after the system reaches the sliding mode manifold. Currently, the main solutions to this disadvantage are high-order sliding mode control [10¨C12] and nonsingular terminal sliding mode control [13]. The higher order sliding mode is an extension of the conventional sliding mode and it cannot only eliminate the defect of the conventional sliding mode method but also maintain its advantages. Because the second-order sliding mode controller has simple structure and needs less information, it is the most widely used in the higher order sliding mode. Nonsingular terminal sliding mode can remove the chattering and allow the system state to converge to the equilibrium within finite time. However, considering the capability to reach the sliding mode, this speed is too
%U http://www.hindawi.com/journals/jcse/2014/890824/