2009 年 75 巻 754 号 p. 1639-1646
This paper presents the development of a finger-mounted tactile sensor for surface irregularity detection. The sensor is composed of a thin rubber sheet and a silicone rubber with the void in the center. On the center of the rubber sheet, two strain gauges are attached point-symmetrically. In addition, a silicone oil sheet is attached on the bottom of the sensor as a viscous fluid medium for keeping steady contact with the object surface. For mounting the sensor on the finger, the sensor is embedded in a cotton work glove. The user puts his/her finger on the silicone rubber of the sensor and slides the sensor over the object surface. By obtaining difference between the two strain gauges, the sensor responds to the surface irregularity, not to the uniform surface. Furthermore, real-time signal processing utilizing the wavelet transform is introduced for detecting surface irregularity from sensor output signals. Theoretical analysis of sensor output signals and experiments using the developed sensor on the plane surface and curved surface with a small protrusion are presented. The results show the validity of the proposed tactile sensor.