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UBC Theses and Dissertations

Definition of a distributed machine health monitoring system : application to the design of a hydraulic marine steer-by-wire system Cullingham, Nicholas Eoghan


The objective of this thesis is to define a general tool set for monitoring the health of the physical part of a system that is operated by an embedded computer system. Embedded computer systems are commonly found in industrial, military, transportation and consumer products. Health monitoring is usually required to track the health of actuators, sensors, communication, and computational resources. The novel tool set presented in this thesis provides three measures of component health, all of which indicate errors based on the performance of a system state relative to a base model. A set of software classes is defined, which interacts with an object-oriented model of the physical system that supports distributed processing, fault tolerance and redundancy management. The model based health monitor also integrates into the redundancy management. When a redundant physical sensor fails, the health monitor provides analytical redundancy for that system state, by predicting it and generating adaptive thresholds on the accuracy of the analytical sensor. The health monitoring system has been implemented on an experimental apparatus built to approximate the functionality of a hydraulic, steer-by-wire system for marine applications.

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