Performance Comparative of Impedance Controllers for a Two Degrees of Freedom Robot

Abstract

This thesis details a new design of a physical Human-Robot Interaction platform for the flexion/extension and pronation/supination rotations of the wrist. It was intended for it to be a compact, easy to manufacture system that is comfortable for each user regardless of whether they are right or left-handed. The robot has been programmed for it to function under three different modes of operations, each employing a specific compliance based controller: impedance, admittance and impedance Maxwell-based models. In order for the three of them to be correctly compared, a study was conducted with a total of 120 people where each individual performed a series of predefined movements, displayed on a screen, using the robot. During the experiments, the torque and trajectory error were sensed and computed in order to find the average error and maximum torque for each controller. Afterwards, in order to describe the human perception of each controller, a survey was carried out and the data collected was analyzed via the Kruskal-Wallis test and a factor analysis. Finally a correlation was found between the quantitative measurements, errors and torque, and the human perception results of the survey.