Observer-Based Fixed-Time Nested Sliding-Mode Control for Tip-Position Regulation of a Single-Link Flexible Manipulator

TL;DR

This paper introduces a fixed-time nested sliding-mode control method for precise tip-position regulation of a single-link flexible manipulator, combining a novel observer and control design validated through simulations and experiments.

Contribution

It proposes a new fixed-time nested sliding-mode control strategy with an observer for accurate, robust, and fast position control of flexible manipulators.

Findings

The control scheme achieves high accuracy and robustness in simulations.

It demonstrates fast convergence within fixed time in numerical tests.

Experimental validation confirms practical effectiveness of the approach.

Abstract

This paper presents a novel position control strategy for a single-link flexible manipulator, tailored for applications where precise position must be achieved within strict time constraints. To accomplish this objective, firstly, a nested non-singular terminal sliding mode controller is designed for the system, enabling precise and robust control. Furthermore, a fixed-time sliding mode observer is designed to estimate unmeasured system states accurately in a fixed time, thereby enabling closed-loop control implementation. A stability analysis is presented to guarantee the robustness and efficacy of the proposed composite control algorithm. The effectiveness of the proposed fixed-time controller is demonstrated through numerical simulation on accuracy, stability, and convergence speed. The proposed controller's performance is also compared with that of other state-of-the-art control schemes. The proposed controller is further validated through experiments conducted on a real hardware setup.