Control Contraction Metrics Based Robust Tracking Guidance for Hypersonic Glide Vehicle in Terminal Phase

In this paper, a robust tracking guidance method based on Control Contraction Metrics (CCM) is proposed for Hypersonic Glide Vehicle (HGV) in terminal phase subject to multiple terminal constraints and disturbances. Firstly, we solve the CCM synthesis problem of HGV model, in which the conditions for CCM are transformed into convex constraints, formulating the synthesis problem of CCM as a convex optimization problem. Then, in order to simplify the design of CCM, we choose to linearize HGV's model on the nominal trajectory and design an algorithm to solve the simplified problem using convex optimization. Finally, a feedback tracking guidance law based on CCM is formulated as the solution of an optimization problem minimizing the control effort. Simulation results show that the proposed method is better than LQR in terms of tracking accuracy and robustness, which verifies the feasibility of applying the proposed method to the terminal guidance design of HGV.