Study on detection of lumps in a soft object by using a scanning roller type palpation sensor system

In this study, a palpation sensor system is developed to detect a lump in a soft object. The developed sensor system consists of a contact part using a bearing, two linear sliders and a 3-axis load cell. While the roller type contact part is scanned against a soft object, reaction force applied to the contact part is measured. Lumps are detected by measuring fluctuation of the reaction force. In experiments, the sensor system is scanned against the samples. From the results, it is found that the lump with a small diameter embedded at a deep position.