Abstract
In order to realize a human-directed manufacturing system, it is indispensable to investigate behavior of human operators from the viewpoints of operational efficiency, accuracy, physical safety, fatigue, etc. The present paper deals with difference of the behavior between skilled and unskilled operators in small-hole drilling operations using a milling machine. The experimental result shows that there are strong correlations between operational and physiological measurements, and operator's skill level such as tool breakage, operational error and efficiency. Hence, the skill level can be estimated by using the measurements. In addition, it is confirmed that the skilled operators make their body movement small, and keep their respiration rate low and constant.
