Sensor Fault Masking of a Ship Propulsion System

This paper presents the results of a study on fault-tolerant control of a ship propulsion benchmark (Izadi-Zamanabadi and Blanke, 999), which uses estimated or virtual measurements as feedback variables. The estimator operates on a self-adjustable design model so that its outputs can be made immune to the e®ects of a peci¯c set of component and sensor faults.

The adequacy of sensor redundancy is measured using the control recon¯gurability (Wu, Zhou, and Salomon, 2000), and the number of sensor based measurements are increased when this level is found inadequate. As a result, sensor faults that are captured in the estimator's design model can be tolerated without the need for any recon¯guration actions.

Simulations for the ship propulsion benchmark show that, with additional sensors added as described, satisfactory fault-tolerance is achieved under two additive sensor faults, an incipient fault, and a parametric fault, without having to alter the original controller in the benchmark.