Internal shear strain measurement based on finger dummies

Abstract

Labor shortages and low productivity have a high demand for constructing collaborative operation systems using industrial robots in the current global manufacturing industry. However, it results in that injuries possibly occurring due to contact between the robot system and humans. In the field of skin contact safety, measurement of internal stress or strain distribution inside the skin. Herein, a human dummy consisting of built-in sensors is a solution to obtain the internal physical field. In this study, we focus on the measurement of the internal shear strain of the finger, which is often in contact with human-robot interaction. We propose a design of a finger dummy with a built-in piezoelectric film sensor and aim to reconstruct a detection principle for measuring the internal shear strain based on the elliptical geometry of the finger. To fabricate a finger dummy for the measurement experiment, we also proposed a method for investigating unknown dimensions related to the human body. The internal shear strain was measured and evaluated on the finger dummy with 3 kinds of arrangement angles. These methods are considered to be a reference for constructing other various human body dummies for safety evaluation.