Abstract:

 A method for designing a switched controller based on a fuzzy logic system is proposed in this paper for a class of the variable-sweepback-angle near space vehicles (NSV) affected by the external disturbances and parameter uncertainties under the tracking performance and angular rate constraints. The nonlinear switching model of the vehicles containing the unknown disturbances and uncertainties is established. By designing a fuzzy logic system, all the unknown nonlinearities can be real-time estimated. Based on the back-stepping method, a switched controller is designed and the “total disturbances” are compensated in the controller. By means of the common Barrier Lyapunov function theory, it is proved that the proposed control strategy can guarantee the stability of the close-loop switching system and the tracking performance and state constraints are not violated. The numerical examples show the effectiveness and advantages of the proposed method

Key words:  Near space vehicle (NSV), Nonlinear switching system, Tracking performance constraint, State constraint, Fuzzy logic system