Detection and Isolation Method for Operator Failure by Unknown Input Observer

In this paper, a fault detection method for operator failures using the observation technique is proposed The suggested algorithm is extended using the conventional sensor/actuator fault detection method First, it is assumed that operator failure affects human work operations, as it is an external input signal. With this assumption, a human work model with operator failure is suggested Second, an unknown input observer with proportional and integral gains is introduced The characteristic of this observer of estimating an external signal without an exact input is shown, and the conditions for the detection of an operator failure are proposed Finally, by simulating the container crane operations, it is verified that the observer can accurately detect an operator failure and estimate its magnitude from the given internal signal