Proposal of Tactile Inspection Conditions for Valid Defects Detection Focusing on Haptic Perception with Active Touch

Tactile inspection is a task for detecting minute irregularities of several tens of micrometers and is one of the tasks performed by human senses. However, the detection of defects in tactile inspection has not been evaluated quantitatively. Therefore, this study aims to examine the factors that affect the detection of defects in tactile inspection by focusing on the haptic perception with active touch and to propose inspection conditions for the valid detection of defects based on the experimental results. Specifically, defect height, defect size, and the control force applied by the subject are used as the experimental factors, and their effects on the detection of defects are examined. Moreover, it was found that the detection rate increases with the increase of the defect features and that the strengths of the effect on the detection rate are in the order of defect height, defect size and control force of the subject. Based on the above, we proposed that tactile inspection is effective in detecting defects with heights greater than 15 μm and that the control force of approximately 7.0 N is suitable for defect detection.