Guidance Law Design for Hypersonic Missile in Striking Fixed Target Case

This dissertation makes a research on television-guided hypersonic missile that attacks fixed target. The TV homer doesn’t supply the information of relative velocity and the distance of the target, so the guidance law should corresponding adjustments. Hypersonic missile takes supersonic combustion ramjet as its propulsion system and flies for a long time at very high speed, the airflow environment is complex and parameters change rapidly, these all have brought new challenges to the design of guidance law. This thesis establishes differential equations to describe the relative motion between the missile and the target, the differential equations take the relative distance between missile and target as parameters. This approach supplies a new way to design guidance law. According to it, this paper designs three new guidance laws.Firstly, in order to describe the 3D motion of the missile accurately, this thesis defines several frames and the transition matrices among them. Furthermore, the dynamic and kinematic equations in the inertial launch frame are developed. Being different from differential equations that used to describe the relative motion between the missile and the target, the new approach takes the relative distance between the missile and the target as parameter. This new approach simplifies the relative motion equations, and reveals the nature of guidance.Secondly, this dissertation uses the first kind of differential equations to design a guidance law based on stability concept,this guidance law guarantees that the angular speed of LOS converges to zero. For the second kind of differential equations, two guidance laws are proposed. The first one is based on optimal control theory; it can ensure that the missile has expectation of impact angle at the end of guidance. The second one is based on variable structure theory; it can guarantee that the angular speed of LOS converges to zero in finite time and it has the ability of anti-disturbance.Finally, simulations of the three guidance laws are conducted; the results are used to verify that they satisfy requirements proposed.