Development of soft sensor exterior embedded with multi-axis deformable tactile sensor system

Abstract

In some important robotic human daily life support applications, such as housework or nursing care, soft sensor exterior is needed for allowing close contacts against humans or environments. Although there are many studies on tactile sensing elements themselves and some of them realize the mechanical softness of the element, most of their studies just propose their detection theory with their sensor element prototypes and it is difficult to use them for developing soft tactile exterior. Therefore a soft sensor exterior embedded with multi-axis deformation sensor is developed in this paper. The most important feature for this sensor is that it can detect multi-axis deformation, and the sensor element itself has enough softness to deform with the outer exterior. The developed sensor is constructed by molding a soft urethane foam with infrared LEDs and corresponding phototransistors. It detects 3D deformation of the sensor as voltage changes at each phototransistors. Furthermore, a prototype of soft sensor exterior embedded with the developed sensing elements is realized and we confirmed that the 3D deformation, such as stroking, pinching, and pushing, can be detected using the developed sensor exterior prototype.

Designing for a Wearable Affective Interface for the NAO Robot: A Study of Emotion Conveyance by Touch

“…Different types of transduction methods have been used such as optical transduction and piezoelectric for dynamic tactile sensing on deformable surfaces (e.g., [25]) as well as capacitive, piezoresistive and magnetic, among others (cf. [24]).…”

Humanoid Multimodal Tactile-Sensing Modules

“…2) A combination of light emitter and detector can sense light reflected on an approaching object [27], in a cavity [32] or within foam material [8] compressed by force. A method to measure the effect of shear and lateral force on cross coupling between multiple pairs is proposed in [33]. In most cases optical reflective couples are suitable, as nearly all materials, independent of conductivity but dependent on the reflective coefficient, can be detected.…”

Detecting shape deformation of soft objects using directional photoreflectivity measurement

“…There have also been several sensors proposed for sensing the touch interaction on the robot's skin [7,11]. Kadowaki et al have developed a method that uses a sensor attached to a soft body to sense and differentiate between interactions (such as push, pinch, and rub) with the object [9]. The soft object used was a piece of urethane foam, with five phototransistors attached at the top and three infrared light-emitting diodes (IR LEDs) attached at the bottom.…”