Observer-Based Active Fault/Disturbance Compensation Control for Fully Actuated Systems

Abstract

This paper is concerned with fault/disturbance compensation control for fully actuated systems. In particular, we explore observer-based control, incorporating an active compensation mechanism. First, we propose a novel observer with enhanced design flexibility for the fully actuated system model, enabling simultaneous estimation of system states and exogenous unknown signals, such as faults or disturbances. Then, a nonlinear controller is developed with an active fault or disturbance compensation term, leveraging the fully actuated system approach. The asymptotic stability of both the state estimation error and the closed-loop control system is systematically established. Finally, the feasibility and merits of the proposed method are validated through comparative simulations and experiments.

Figures (5)

• Figure 1: Block diagram of the proposed observer-based fault/disturbance compensation control.
• Figure 2: Comparative state estimation results of the states (a) $q$, (b) $\dot{q}$, (c) $\ddot{q}$, and (d) the fault/disturbance $d$ for FAS model \ref{['eq:sim_FAS model']} when the control input $u\equiv 0$. The black solid line represents the actual signal, the blue dotted line indicates the estimation by the proposed observer \ref{['eq:oberver']}, and the red dash-dot line corresponds to the estimation by the PI observer from JiangDuanHou2024TCSI.
• Figure 3: The comparative control performance of the state response and control input of (a) the proposed method and (b) the method of JiangDuanHou2024TCSI. Note that the 'state' presented in this figure is the original system \ref{['eq:sim_electromechanical system']}'s state, i.e., $[q ~I ~\dot{q}]^{\mathrm{T}}$, instead of the FAS state $[q ~\dot{q} ~\ddot{q}]^{\mathrm{T}}$ that was presented in Figure \ref{['fig:sim_estimation']}.
• Figure 4: Quanser Ball and Beam system, motion data acquisition card, and power amplifier.
• Figure 5: Experimental results. (a) Scenario 1; (b) Scenario 2. Each subfigure contains: state responses for ball position $z$, servo angle $\theta_l$, and control input $V_m$ using the proposed method with active compensation (top left); corresponding results without active compensation (top right); and the estimation of the fault/disturbance signal $d$ (bottom).

Theorems & Definitions (11)

• Remark 1
• Remark 2
• Lemma 1
• Lemma 2
• Lemma 3
• Lemma 4
• Theorem 1
• proof
• Theorem 2
• proof