Design and development of a tactile feedback system, and its application to prosthetics and tele-operated robots

Abstract

After seeing and hearing (vision and audition), tactile sensing (feeling of touch) is the third most utilized sensation. We use our fingertips to examine properties of objects such as weight (heavy or light), shape (spherical/round or shapes with edges and corners etc.), and texture (smooth or rough). In many situations we can identify and discriminate objects by touch only. Furthermore, tactile sensing is needed for controlling the gripping force of objects and object manipulation tasks. An example would be holding an egg without dropping. We apply just enough grip force to hold the egg and careful not to crush the shell. This is possible due to the ability of the tactile sensors in the fingertips to detect micro slips occurring at the common surface of the object and the fingertips. The adjustment of its grip force is controlled by the detection of insipient slip. This tactile sensing capability is required for both tele-operated robot systems and artificial prosthetic hands that has actuated fingers for grasping and manipulation. However, limited research has been conducted to address these issues. Researchers have tried to copy the abilities of human fingertips to robots. However, only few research has emerged with usable technologies due to the complexity of the tactile system and its information processing. Therefore, this project is conducted mainly to develop a biomimetic tactile sensing system and its control strategy for the use in prosthetic hands and a tele operated robot systems. The project proposed a tactile sensing system and an accompanying haptic feedback systems developed using soft materials. The tactile sensors were made using magnets, hall sensors and soft overlays. The tactile arrays were used to measure tactile data while haptic feedback system made from magnets, voice coils and soft material overlays transmitted the tactile information back to the skin. The grant was successful to develop soft tactile sensor array and a soft haptic device. These devices were utilized in a prosthetic arm to transmit tactile data to the wearer of the prosthetic arm. This tactile data was used to manipulate an object from the prosthetic hand..