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Observer-based improved Composite Nonlinear Feedback control for output tracking of time-varying references in
1Department of Electrical and Electronic Engineering, Shiraz University of Technology, Shiraz, Iran.
ISA Transactions
|February 12, 2019
Summary
This study introduces an improved Composite Nonlinear Feedback (CNF) controller for descriptor systems, enhancing output tracking performance despite actuator saturation and external disturbances. The controller ensures reliable tracking accuracy through advanced observer-based state reconstruction and mathematical analysis.
Area of Science:
- Control Systems Engineering
- Nonlinear Control Theory
- Descriptor Systems Analysis
Background:
- Descriptor systems present unique challenges in control design due to inherent algebraic constraints.
- Actuator saturation and external disturbances significantly complicate output tracking control.
- Existing control methods often struggle with the combined complexities of descriptor systems and nonlinear constraints.
Purpose of the Study:
- To propose an observer-based improved Composite Nonlinear Feedback (CNF) controller for descriptor systems.
- To address challenges posed by actuator saturation and time-varying reference signals.
- To investigate and ensure robust output tracking performance in the presence of external disturbances.
Main Methods:
- Design of a full-order descriptor observer for state reconstruction.
- Development of an improved CNF control law incorporating observer feedback.
- Mathematical analysis using a theorem to investigate tracking solvability under saturation and disturbances.
- Steady-state analysis to demonstrate uniform ultimate boundedness of tracking error.
Main Results:
- The proposed observer-based CNF controller effectively achieves output tracking for general time-varying signals.
- The controller demonstrates robustness against actuator saturation, including three different saturation function cases.
- Uniform ultimate boundedness of the tracking error is proven in the presence of external disturbances.
- Computer simulations validate the theoretical findings with numerical and practical examples.
Conclusions:
- The developed observer-based improved CNF controller offers a viable solution for complex descriptor systems.
- The controller successfully manages actuator saturation and external disturbances, ensuring reliable tracking.
- The study provides a rigorous mathematical framework for analyzing and verifying control performance in challenging scenarios.
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