Nonlinearity compensation based robust tracking control of nonlinear nonminimum phase hypersonic flight vehicles.

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Nonlinear Dynamics

Background:

• Hypersonic flight vehicles present complex control challenges due to nonminimum phase characteristics and system uncertainties.
• Robust control is essential for maintaining stability and performance in the presence of these challenges.
• Existing control methods may struggle with nonlinearity compensation and robustness.

Purpose of the Study:

• To develop a nonlinearity compensation based robust tracking controller for hypersonic flight vehicles.
• To address the nonminimum phase feature and system uncertainties inherent in these vehicles.
• To enhance tracking accuracy and robustness compared to existing methods.

Main Methods:

• Decomposition of the complex robust tracking problem into two simpler sub-problems: a linear tracking problem with disturbances and a nonlinear stabilization problem.
• Design of a proportional-integral (PI) controller for the linear subsystem.
• Design of a feedback linearization controller for the nonlinear subsystem.
• Integration of the PI and feedback linearization controllers to form the final robust tracking controller.

Main Results:

• The proposed controller effectively compensates for system nonlinearities.
• Simulation results demonstrate superior tracking accuracy compared to feedback linearization and composite neural learning control.
• The controller exhibits enhanced robustness against system uncertainties and external disturbances.

Conclusions:

• The nonlinearity compensation based robust tracking controller successfully meets the control requirements for nonlinear, nonminimum phase hypersonic flight vehicles.
• The proposed method offers a significant improvement in tracking performance and robustness.
• This approach provides a viable solution for advanced hypersonic vehicle control.