An experimental study on the estimation of plant operators' cognitive behavior at man-machine interface

An experimental study to observe and interpret plant operators' cognitive activities at a 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 in the form of a 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 valuable information concerning the operators' cognitive behavior during the task of anomaly diagnosis.