An Unknown Input Observer–EFIR Combined Estimator for Electrohydraulic Actuator in Sensor Fault-Tolerant Control Application
Year: 2020
Type: article
Abstract: This article presents a novel unknown input observer (UIO)-integrated extended finite impulse response (EFIR) estimator and its application for an effective sensor fault-tolerant control (FTC) of an electrohydraulic actuator (EHA). The proposed estimator exploits the UIO structure in the EFIR filter. Thus, it requires only a small amount of historical data (N) while ensuring the following: 1) sensor fault and system state estimation accuracy under time-correlated noise; 2) the number of estimator design parameters is significantly minimized; and 3) robust residual generation. A Lyapunov-stability-based theory is carried out to study its convergence condition. Next, an EHA-based test rig has been set up, and sensor FTC is performed by carrying this estimator as part of a fault diagnosis algorithm to evaluate its performance by both simulation and real-time experiments. Results highlight that under optimal setting (N = Nopt), the estimator performance is near accurate to the very well developed extended-Kalman-filter-based UIO in undisturbed conditions but significantly outperforms when dealing with time-correlated noise under the same control environment. The estimator also shows its robustness under below-optimal setting (downgrading Noptby 50%) while performing sensor FTC in real time.
Institutions: University of Warwick, University of Ulsan
Language: English
Subfield: Control and Systems Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W3047138371