Systems Engineering and Electronics ›› 2023, Vol. 45 ›› Issue (5): 1476-1488.doi: 10.12305/j.issn.1001-506X.2023.05.24

• Guidance, Navigation and Control • Previous Articles    

Singularity-free fixed-time adaptive switching control for hypersonic flight vehicle with input constraints

Zehong DONG1,2, Yinghui LI1, Maolong LYU3, Zhe LI1, Binbin PEI1,*   

  1. 1. Aviation Engineering School, Air Force Engineering University, Xi'an 710038, China
    2. Graduate School, Air Force Engineering University, Xi'an 710038, China
    3. Air Traffic Control and Navigation School, Air Force Engineering University, Xi'an 710051, China
  • Received:2022-01-05 Online:2023-04-21 Published:2023-04-28
  • Contact: Binbin PEI

Abstract:

A singularity-free fixed-time adaptive switching control strategy is proposed for hypersonic flight vehicles subject to input saturation, uncertainties of aerodynamic parameters and slow convergence rate of tracking errors. Firstly, the longitudinal dynamics model of hypersonic flight vehicles is decomposed into velocity subsystem and altitude subsystem, then the singularity-free fixed-time tracking controller is designed separately. In order to solve the singular value problem of traditional fixed-time controller, a new differentiable switching function is designed, which switches control laws with tracking error as the decision quantity, ensuring the differentiability of virtual control laws and the feasibility of back-stepping design. Aiming at the input saturation problem of hypersonic flight vehicles, a fixed-time auxiliary error compensation system is designed, which improves the error convergence rate of compensation signals from exponential convergence to fixed-time convergence. Then, with the help of the Lyapunov theorem, it is proved that the velocity tracking error, altitude tracking error and estimation error of approximator converge to arbitrarily small neighborhood of origin within fixed-time. Finally, simulations results validate the effectiveness and superiority of the proposed controller.

Key words: hypersonic flight vehicle (HFV), fixed-time stability, input saturation, singularity-free switching control, neural network

CLC Number: 

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