Research And Simulation Of Terminal Guidance Law For Hypersonic Vehicle

In recent years, many countries begin to pay attention to the hypersonic vehicle’s features, including high altitude, high speed, and high flexibility. And the hypersonic vehicle’s tremendous economic and military values are gradually revealed from its potential and hypersonic vehicle is increasingly becoming a hotspot of research for countries all around the world. From the prospect of military use, as hypersonic vehicle can reach anywhere in the world within a short time, it greatly expands the radius for combat; meanwhile, its ultra-fast speed makes it gain the ability of superior penetration and high concealment. From the prospect of civilian use, it may be possible for hypersonic vehicle of the next generation to serve as the primary tool for aerospace transportation or interstellar travel. The advert of hypersonic vehicle also poses great challenges to the guidance technique of spacecraft. Such technique is required in the terminal phase of flight trajectory, and whether the hypersonic vehicle can strike the target with high precision is directly determined by the performance of the control technology. This paper concentrated on homing models of hypersonic missiles and a nonlinear terminal guidance law regarding 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 coordinate system were given, the kinematic equations of the centroid of missile and target have be analysed; the relative motion equation of the missile and target in two-dimensional plane and three-dimensional space were built, which provide the basis for the analysis and design of the guidance laws in later chapters.Secondly, theories on stability of finite-time are studied. First, definition and important lemma of finite-time theories are given, and guidance law with finite time convergence for planer guidance models are designed based on these rules, and demonstration for the correctness of the guidance law were given. Then, such guidance law were improved and applied to deal with equations describing relative motion of missile target in the three-dimension space, and it was proved that guidance law with finite time convergence could make the turning rate of the line-of-sight angle go to zero within a given time and remain stable within a certain realm, which could provide some redundant time for the fast reaction of hypersonic vehicle. And then, estimation theory based on extended state observer was proposed in this treatise, which could provide precise observation of the uncertainty caused by combination of non-linear couple and target maneuvering.Finally, several classical guidance laws are simulated through M-file. Simulink is used to build a guidance model of three-dimensions, and simulations were carried out on constant and sinusoidal target maneuvering respectively to verify the effectiveness of time guidance law, and compare was made with the proportional navigation law. Then the estimation performance of the extended state observer estimator was verified and analyzed.