Fully Actuated Manifold Constraint Based Output Feedback Control for Input-Constrained Uncertain Nonlinear Systems

TL;DR

This paper introduces a low-complexity, model-free output-feedback control method for uncertain nonlinear systems with input constraints, extending constraint control to nonlinear manifolds and ensuring preset accuracy.

Contribution

It develops a novel control approach that handles unknown time-varying nonlinearities and input constraints without requiring a system model, including nonlinear manifold construction and flexible control after saturation.

Findings

Achieves preset control accuracy within finite or fixed time.

Maintains control accuracy after actuator saturation.

Validated with second-order and higher-order system simulations.

Abstract

This paper presents a low-complexity, model-free, output-feedback controller for a class of unknown time-varying nonlinear systems with unknown input constraints. The controller achieves the preset control accuracy when the actuator is not saturated and maintains flexible control accuracy after actuator saturation. This result extends existing constraint control methods for linear manifolds to a more general form, including the construction of nonlinear manifolds and various types of constraints, thereby achieving preset control accuracy within finite or fixed time. Additionally, flexible control under unknown saturation is achieved through the construction of an error-driven flexible constraint. Finally, second-order and higher-order control examples and simulations are provided.