Design of a dynamic joint impedance measurement system

Abstract

Identifying dynamic human joint impedance provides essential information for designing robotic system. Most of the previous studies developed control algorithm of the measurement system not on the performance of the actuating system itself, which could result in complexity of the system. In this research, joint impedance measurement system with low-nonlinearity and high back-drivability with less cogging torque was developed. This system comprises the frameless brushless motor, encoder with high resolution and adjustable height, and width supporting structures for multiple users. Torque generation from robot perturbs the human joint in counter direction to measure the resistance torque in dynamic motion ranging from 0.9Nm to 1Nm in short period(similar to 20ms).