A Study on the Measurement of Human Mental Work-load in Ship Handling Using SNS Value

As the navigation environment has been changing recently, the methods of evaluation that accomplish to measure the operator's mental workload are desired. We propose the new measuring method using SNS values obtained through RRV procedure which can estimate the human mental workload moment to moment. In this paper, firstly we discuss the methods of data processing which enable to estimate the human mental workload in ship handling. And then, using proposed measurement methods, we estimated the human mental workload in two ship handling situations, namely fairway passing maneuvering and stopping maneuvering in short distance with keeping ship's heading. The obtained results are as follows ; (1) The useful signal can be selected by adapting the proposed filtering procedure. (2) The operator's mental workload under passing narrow fairway is corresponding to E-value which indicates difficulty of maneuvering concerning with the characteristic of ship and fairway conditions. (3) High level of human workload during altering course in fairway is shown in the before and the after altering course rather than the time of changing course. (4) High level of human workload is shown in time with the occurrence of big difference between planed situation and realized one.