Proposal of a SkilMate finger for EVA gloves

Abstract

It has been pointed out that the hard structure of an EVA glove deteriorates e±ciency of tasks in the space environment. We also found a claim that an EVA glove did not allow an astronaut to acquire contact information at the¯ngertips. In the study, we proposed a SkilMate Hand for space EVA gloves which has both a tactile media and a power assist devices. We locate SkilMate in a wider framework of wearable intelligent machines which assist in a®ording such working surroundings that they can exhibit their skills in spite of their necessity for wearing special suits typically in hazardous environments. The paper focuses on the development of a¯nger system of a SkilMate Hand, and begins with determination of the design guidelines through analyses from an interview with an astronaut. To improve the task e±ciency, we manufacture a power assist device which compensates the bending moment exerted at a human¯nger joint utilizing an ultrasonic motor. We show the structure and the control strategy of the motor drives. To overcome the second problem of tactile insensibleness, we produce a tactile media device which is composed of a slip sensor element on the outer side and a vibrotactile display element on the inner side of a SkilMate Hand. Transduction characteristics of both pressure sensitive conductive rubber and piezo-rubber are experimentally examined in the low temperature region. Finally, piezo-rubber is chosen to be used as a slip sensing transducer. Such a proposal of a wearable intelligent machine as that of a SkilMate with its concept has not been o®ered, and moreover, the technical argument about temperature dependence of tactile sensing performance has not been intensively made so far in the¯eld of robotics.

Hand Rehabilitation Robotics on Poststroke Motor Recovery

“…The sensors detecting physical signal such as the force and position (or motion) are the most used sensors in the robot system of hand rehabilitation [ 24 ]. The function of force or position signal is to provide the physical state of the hand such as the exerted force of motion or the bending angle of the finger [ 84 – 88 ]. For example, the sensing and force-feedback exoskeleton (SAFE) robotics was designed by Ben-Tzvi et al, in which an optical position sensor and strain gauges are set to detect the motion and force signal [ 89 ].…”

Power-Assistive Finger Exoskeleton With a Palmar Opening at the Fingerpad

“…The majority of the hand exoskeletons that have been developed so far can be classified into three categories according to the source of intention extraction: fingerpad contact force [7]- [10], finger motion [11]- [13], and surface electromyography (sEMG) [14]- [17]. Although muscle hardness can also be utilized for intention extraction [18], it has neither been proven to be able to identify individual finger force nor been widely adopted.…”

A Finger Grip Force Sensor with an Open-Pad Structure for Glove-Type Assistive Devices

“…To assist reduced grip strength or prevent WMSDs, many assistive hand exoskeletons have been developed [8][9][10][11][12][13][14][15][16] that detect the intention of the wearer's intention via fingerpad contact forces [17][18][19][20], finger motion [20][21][22][23][24], surface electromyography (sEMG) [25][26][27], or multimodal sensing [28]. Although the measurement of fingerpad contact force enables the acquisition of individual finger forces with simple sensors, the tactile sensation of the wearer is inevitably diminished because of the presence of the force sensor between the fingerpad and object being manipulated.…”