Global practical tracking by output feedback for nonlinear systems with unknown growth rate and time delay

Area of Science:

• Control Systems Engineering
• Nonlinear Dynamics
• Robotics

Background:

• Addresses limitations in existing control strategies for uncertain nonlinear systems.
• Builds upon prior work by Yan and Liu (2011).
• Focuses on practical tracking problems with complex system dynamics.

Purpose of the Study:

• To develop an adaptive output-feedback tracking controller.
• To handle systems with unmeasured states and time-varying time delays.
• To ensure finite-time convergence of tracking errors and signal boundedness.

Main Methods:

• Employs universal control and dead zone techniques.
• Designs an adaptive output-feedback controller.
• Utilizes a novel Lyapunov-Krasovskii functional for stability analysis.

Main Results:

• Achieves arbitrarily small tracking errors in finite time.
• Guarantees boundedness of all closed-loop signals.
• Demonstrates controller effectiveness via a numerical example.

Conclusions:

• The proposed controller effectively manages uncertain nonlinear systems with unmeasured states and time delays.
• Offers a robust solution for practical tracking applications.
• Validates the theoretical design through simulation.