Missile autopilot design via a multi-channel LFT/LPV control method

In this paper, the missile pitch-axis autopilot design is revisited using a new recently available Linear Parameter-Varying (LPV) control technique. The missile plant model is characterized by a Linear Fractional Transformation (LFT) representation. The synthesis task is conducted by exploiting new capabilities of the LPV method : firstly, a set of H2/Hinfinty criteria defined channel-wise is considered ; secondly, different Lyapunov and scaling variables are used for each channel/specification which is known to reduce conservatism ; and finally, the controller gain-scheduling function is contructed as affine matrix-valued function in the polytopic coordinates of the scheduled parameter. All these features are examined and evaluated in turn for the missile control problem. The method is shown to provide additional flexibility to tradeoff conflicting and demanding performance and robustness specifications for the missile while preserving the practical advantage of previous single-objective LPV methods. Finally, the method is shown to perform very satisfactorily for the missile autopilot design over a wide range of operating conditions