Missile guidance with constrained intercept body angle
A linear quadratic based missile guidance law is presented that imposes a predetermined terminal body angle. Solutions are provided for arbitrary order autopilot dynamics, with explicit analytical expressions given for first-order and zero-lag dynamics. Performance is demonstrated through simulation in a planar interception scenario.
Observer-based integrated guidance and control under terminal impact angle constraint
Integrated guidance and control (IGC) design is an active research field in guided weapon system due to ability of utilizing measured information from both guidance loop and control loop. An observer-based composite control framework is proposed to accomplish the engagement of ground-fixed targets with a given impact angle. First of all, a relative motion dynamics in vertical plane of IGC is deducted. Next, an IGC framework is proposed by combining back-stepping method with sliding mode technique to accomplish the engagement while satisfying the terminal angle constraint. Furthermore, first-order low pass filter is utilized to prevent from “explosion of terms”. Lyapunov stability analysis demonstrates that the proposed IGC framework is stable. In addition, a nonlinear disturbance observer is applied to compensate external disturbance, which can improve the robustness of the introduced method. Finally, numerical simulation results prove its effectiveness and robustness.
Recursive time-to-go estimation for homing guidance missiles
This paper addresses the problem of computing accurate time-to-go estimates, which is an important issue in implementing various optimal guidance laws developed for missiles of time-varying velocity. A recursive time-to-go computation method which updates the time-to-go in a noniterative way is presented. The recursive method includes an error compensation feature which explicitly computes the time-to-go error produced by nonzero initial heading errors. The proposed method is simple and straightforward to implement for any missile velocity profiles. Various numerical examples show that the proposed method works effectively for optimal guidance laws as well as proportional navigation and augmented proportional navigation.