Command Filter-Based Adaptive Fuzzy Finite-Time Output Feedback Control of Nonlinear Electrohydraulic Servo System

TLDR

The paper investigates a command filter‑based adaptive fuzzy finite‑time output‑feedback controller for electro‑hydraulic servo systems. The authors employ fuzzy logic systems to estimate nonlinear uncertainties, design a fuzzy state observer for unmeasurable hydraulic cylinder speed and force, and implement a command‑filter‑based finite‑time output‑feedback controller that achieves high tracking precision while reducing backstepping complexity and compensating for filter errors via Lyapunov stability analysis. Simulation results confirm the effectiveness of the proposed controller.

Abstract

In this paper, the command filter-based adaptive fuzzy finite-time output feedback control (FOFC) is investigated for the Electro-hydraulic servo system. For the uncertainties in the system, we utilize the fuzzy logic systems (FLSs) to estimate these uncertain nonlinearities and fuzzy state observer is established to approximate the unmeasurable hydraulic cylinder stem speed and the internal cylinder force. Then, a command filter-based finite time output feedback control is proposed to achieve high tracking precision, where the tracking errors can be regulated into a small neighborhood around the equilibrium proved by the Lyapunov finite-time stability theory. Moreover, a command filter is introduced to avoid the explosion of complexity in the backstepping procedure, where a compensation mechanism is developed to compensate for filter errors. Finally, simulation results are provided to demonstrate the effectiveness of the proposed control.