Research On Advanced Guidance Law Of Air-to-surface Missile

With the development of missile technology and its successful application in modern warfare, modern warfare has also undergone a change. Air-to-ground missile attacking on ground targets becomes the main combat mode and air-to-ground missile has become the focus of aviation weapons development. In the local wars of recent years, the space attacks have evolved from the conventional carpet-bombing mode to a high degree of precision surgical attack mode. Precision-guided puts forward strict requirements to missile guidance systems, especially to guidance law. Advanced guidance law design has been developed with the development of precision-guided weapons.In this paper, it was studied the impact-angle-constrained optimal guidance law and variable structure guidance law based on the study of existing optimal control theory and variable structure control theory with the background of three-dimensional space air-to-ground missile terminal guidance. The design of general simulation platform of kinematics and dynamics as well as the simulation visualization are also studied in this paper. The main contents include:Firstly, it was established a mathematical model of missile and target as well as guidance model, which laid the foundation for the research of optimal guidance law and variable structure guidance law and the design of the simulation platform. 3D space was divided into two 2D planes perpendicular to each other by sight coordinate system. By analyzing the relationship of motion and parameters between 3D space and 2D plane, it was obtained the speed, angle and angular velocity relationship equation. These equations are highly versatile, and guidance law can be extended directly from 2D to 3D space plane through them. Thus it also greatly reduced the difficulty of 3D space guidance law design.Secondly, it was carried out the study and design of the impact-angle-constrained optimal guidance law with optimal control theory. According to the state of target, optimal guidance law was designed respectively against fixed targets and maneuvering targets. Accompanied transform method was applied to solve the problem of non-homogeneous equation in this period. It was found that traditional 3D guidance law is merely a simplified scenario of guidance law in this paper under certain conditions. It proves the correctness of the conclusions of this paper through simulation comparison.Subsequently, it was carried out the study and design of the impact-angle-constrained variable-structure guidance law with variable-structure control theory. Optimal sliding mode guidance law was gotten binding optimal guidance law conclusions. For reduce the chattering problem, this paper introduced the concept of quasi-sliding mode guidance law. It was derived quasi-sliding mode guidance law that has saturation function and relay characteristics of continuous. It was discovered by comparing the simulation, quasi-sliding mode guidance law weaken chattering effectively.Finally, it was designed a 3D kinematic general simulation platform based on a modular and system engineering thought. One need only replace the corresponding module that can emulate the achievement of specific guidance law to the platform-based. Consider autopilot and missile dynamics, etc. it was designed a common dynamics simulation platform based on the kinematics general simulation platform. Finalized the simulation visual design. The model simulation data trans missed through the interface to the visualization software, which can be observed in real time to achieve the purpose of the simulation process, to facilitate the designer more intuitive, more convenient, more quickly identify the problems in the design so that feedback on the design.