New parametric affine modeling and control for skid-to-turn missiles

This paper presents a new practical autopilot design approach to acceleration control for tail-controlled skid-to-turn (STT) missiles. The approach is novel in that the proposed parametric affine missile model adopts acceleration as the controlled output and considers the couplings between the forces as well as the moments and control fin deflections. The aerodynamic coefficients in the proposed model are expressed in a closed form with fittable parameters over the whole operating range. The parameters are fitted from aerodynamic coefficient lookup tables by the proposed function approximation technique, which is based on the combination of local parametric models through curve fitting using the corresponding influence functions. In addition, a feedback linearizing controller is designed by using the proposed parametric affine missile model. Stability analysis for the overall closed-loop system is provided, considering the uncertainties arising from approximation errors. The validity of the proposed modeling and control approach is demonstrated through simulations for an STT missile.