Abstract: Abstract: This paper investigates the asymptotic tracking control problem of hypersonic flight vehicle with unknown model. In the absence of model prior knowledge, although the traditional intelligent control algorithm based on neural network/fuzzy system can achieve stable tracking of the expected instructions by reconstructing and compensating the unknown dynamics in the model, it cannot obtain accurate tracking results due to the existence of reconstruction errors. To solve the problem of as-ymptotic tracking control of hypersonic flight vehicle under unknown model, a modified Lyapunov function (MLF) is construct-ed by introducing the concept of error accumulation factor, and a new fuzzy adaptive control algorithm is designed based on the MLF. By ensuring the boundedness of modified Lyapunov function, the algorithm can achieve the asymptotic tracking performance without extra processing of the fuzzy reconstruction error. The stability of the closed-loop system is proved by means of Lyapunov stability theory, and the effectiveness of the control algorithm is verified by comparative simulation.

Key words: hypersonic flight vehicle, error accumulation factor, asymptotic control, reconstruction error, adaptive control