Research On Design And Simulation Of Terminal Guidance Law For Hypersonic Vehicle

Due to the fact that hypersonic vehicle has features of high altitude, high speed,and high flexibility, tremendous economic and military values are graduallyrevealed from its potential and hypersonic vehicle is increasingly becoming ahotspot of research for countries all around the world. From the prospect of militaryuse, as hypersonic vehicle can reach anywhere in the world within a short time, itgreatly expands the radius for combat; meanwhile, its ultra-fast speed makes it gainthe ability of superior penetration and high concealment. From the prospect ofcivilian use, it may be possible for hypersonic vehicle of the next generation to serveas the primary tool for aerospace transportation or interstellar travel. The advert ofhypersonic vehicle also poses great challenges to the guidance technique ofspacecraft. Such technique is required in the terminal phase of flight trajectory, andwhether the hypersonic vehicle can strike the target with high precision is directlydetermined by the performance of the control technology. This paper concentratedon homing models of hypersonic missiles and a nonlinear terminal guidance lawregarding of the strong real time feature for hypersonic missiles are proposed.Specially, the following aspects are included：Firstly, definitions and ways of conversion for commonly used coordinatesystem were given, the kinematic equations of the centroid of missile and targetwere analisysed; the relative motion equation of the missile and target intwo-dimensional plane and three-dimensional space were built, which provide thebasis for the analysis and design of the guidance laws in later chapters.Secondly, theories on stability of finite-time are studied. First, definition andimportant lemma of finite-time theories are given, and guidance law with finite timeconvergence for planer guidance models is designed based on lemma, anddemonstration for the correctness of the guidance law were given. Then, suchguidance law were improved and applied to deal with equations discribing relativemotion of missile target in the three-dimension space, and it was proved thatguidance law with finite time convergence could make the turning rate of theline-of-sight angle go to zero within a given time and remain stable within a cetainrealm, which could provide some redundant time for the fast reaction of hypersonicvehicle. And then, estimation theory based on extended state observer was proposedin this treatise, which could provide precise obbservation of the uncertainty causedby combination of non-linear couple and target manervering.Finally, several calssical guidance laws are simulated through M-file, and GUIinterfaces of each guidance law are created for direct visual display. Simulink was used to build a guidance model of three-dimensions, and simulations were carriedout on constant and sinusoidal target maneuvering respectively to verify theeffectiveness of time guidance law, and compare was made with the proportionalnavigation law. Then the estimation performance of the extended state observerestimator was verified and analyzed.