Impact-Time-Control Guidance Law for Hypersonic Missiles in Terminal Phase

Recent researches on hypersonic vehicles adopted in military have gained a lot of interest because of its high flight speed and efficiency. However the guidance laws for hypersonic missiles against the anti-missile system to increase survivability and defense penetration ability are still need to study. One main countermeasure to deal with this issue is to implement simultaneous attack. Therefore in this paper an impact-time-control guidance law for hypersonic missiles to impact a stationary target at the same desired final time is presented. Time-to-go estimation for time-varying velocity is derived by using a method of approximate acceleration form to extend the estimation method for constant velocity. The impact-time-control guidance law is firstly given and applied in vertical plane based on proportional navigation guidance law to control the impact time in terminal phase. Then the conditions that limit the method to apply are discussed. To overcome this issue, the guidance law applied in lateral plane is derived. The simulations are implemented using each method in vertical and lateral planes respectively and show good results for hypersonic missiles to achieve simultaneous attack.