Design and Validation of Cable-Driven Robots for Human Rehabilitation and Assistance

Abstract

Human and robot interaction is the key to improving the lives of many people around the world through rehabilitation, simulation, and performance enhancement. To improve rehabilitation initiatives and provide patients and doctors with the means for episodic future thinking (EFT), implementation of virtual reality (VR) simulations and the rendering of internal impedances in those simulations is key. While previous research has explored external effects in these simulations (such as haptic interaction with a virtual object), internal avatar changes remain an open question. Given that current devices only generate external effects, it is extremely valuable to understand if those effects could be interpreted as internal ones. To assess this, Ideveloped a novel robotic system (Stiffness Emulation Robot, SER) and a new controller for an existing haptics glove (HaptX G1) and conducted a binary discretion experiment which reveals that most people can differentiate the two impedance types. Alternatively, instead of providing simulation effects, robots can be used to increase human performance by manipulating how one interacts with the world. An example of this is in search-and-rescue litter carry groups, where long-distance carry of high-loads can impose significant stress on human fingertips, leading to grip fatigue and eventual failure. While there exists off-the-shelf means of alleviating this stress, a robotic device could provide additional advantages such as enabling/disabling to remain unobtrusive when not in use – a critical requirement in high-stakes environments. To achieve such performance, the Curling Artificial Soft ExoskeleTon (CASET) was developed. An experiment where participants held high loads to failure both with and without CASET revealed drastic performance increases, both in carry time and grip fatigue reduction.