Elbow Angle Guidance System Based on Surface Haptic Sensations Elicited by Lightweight Wearable Fabric Actuator

The demand for wearable haptic devices has rapidly increased for various applications. However, many haptic devices interfere with the wearer’s activities and movements. In addition, several haptic devices fail to elicit intuitive haptic sensations by adjusting to the natural posture of the wearer. To address these issues, we propose an elbow angle guidance system using a lightweight wearable fabric actuator. The proposed actuator is made of fabric and has two McKibben-type artificial muscles attached to it, rendering it extremely lightweight and facilitating the delivery of surface haptic sensations to intuitively induce elbow extension and flexion. The surface haptic sensation elicited by the fabric actuator is adjusted to natural body movements without interfering with the wearer’s movements. Moreover, the proposed system measures and guides the elbow angle by changing the intensity of the surface haptic sensation delivered to users in real time. The accuracy of the proposed system is demonstrated through experiments involving human participants.

I. Introduction

The demand for haptic devices for rehabilitation and teleoperation based on virtual reality has notably increased [1], [2], [3]. In particular, many wearable haptic devices for parts of the upper limbs, such as the elbow, have been developed [4]. Several requirements must be satisfied for such haptic devices. For instance, the haptic devices should not fatigue the wearer. In addition, the elicited haptic sensations should not interfere with the user’s motion, and the sensations should be intuitive for the user to interpret. However, few haptic devices satisfy such requirements [5], [6].