Experimental study on the estimating plant operators' cognitive behavior at man-machine interface

An experimental study to observe and interpret plant operators' cognitive activities at man-machine interface(MMI) has been performed using a nuclear power plant simulator. The specific feature of the present study is that the state of the operator during the interaction through the MMI is estimated based on the diverse information; 1) Estimated cognitive state, 2) Estimated mental work load(MWL), 3) Operational sequence history, 4) Questionnaire and 5) Video record. These information are integrated and graphically represented as the form of chronological diagram(CD), by which the operators' dynamic cognitive behavior can be analyzed consistently. Results of the simulator experiments demonstrated that the present method can provide the valuable information concerning the operators' cognitive behavior during the task of anomaly diagnosis.