Abstract:

For the complicated aerodynamics characteristic and severely parameters uncertainty of nonlinear longitudinal model of a hypersonic vehicle, a novel robust variable gain controller design methodology based on linear parameter varying (LPV) is developed. Firstly, the nonlinear model is transformed into a LPV form by Jacobian linearization of nonlinear plant. And then the polytopic decomposition of the LPV model is obtained by a tensor-product (T-P) model transformation method. So the robust variable gain controller is designed, combined with  H_∞ robust control and gain scheduling, to provide the longitudinal stability for the hypersonic vehicle. The proposed method can not only avoid the complex design process of nonlinear methods, but also restrain the effects of model parameters change in complicated fight conditions. The digital simulation results prove the availability of the proposed method.