Adaptive preassigned-time controller design for a hypersonic vehicle with improved performance and uncertainties.

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Robotics and Automation

Background:

• Hypersonic vehicles (HSV) face complex tracking control challenges due to inherent uncertainties and strict performance requirements.
• Existing control strategies often struggle to guarantee convergence within a pre-defined time under constrained tracking errors.
• The 'explosion of complexity' is a common issue in designing controllers for systems with nested nonlinearities.

Purpose of the Study:

• To develop an adaptive control strategy for hypersonic vehicles (HSV) that ensures tracking errors converge within a specified time.
• To address uncertainties and tracking error constraints in HSV velocity and altitude subsystems.
• To mitigate the 'explosion of complexity' problem in control design for the altitude subsystem.

Main Methods:

• Proposal of a performance function to define pre-assigned time convergence for tracking errors.
• Design of an adaptive pre-assigned-time prescribed performance (PTPP) dynamic inversion controller for the velocity subsystem.
• Development of an adaptive PTPP backstepping controller for the altitude subsystem, incorporating a dynamic gain fixed-time filter (DGFTF) to manage complexity.

Main Results:

• The proposed dynamic gain fixed-time filter (DGFTF) ensures filter errors converge to near-zero in a fixed time.
• The adaptive PTPP controllers successfully guarantee predefined performance for both velocity and altitude tracking errors within the specified time.
• Simulation results demonstrate the effectiveness of the proposed control strategy compared to existing methods.

Conclusions:

• The developed adaptive PTPP control strategy effectively manages tracking control for hypersonic vehicles (HSV) under constraints and uncertainties.
• The integration of DGFTF provides a robust solution to the 'explosion of complexity' issue in altitude control.
• The study validates the capability of the proposed controllers to achieve precise tracking performance within a pre-selected time.