The Sensitivity Adjustment Technique within the Exoskeleton Control System

Abstract

An exoskeleton system contains a human operator in the control loop, which imposes restrictions on the applied control algorithms and movement speed. Robotics is the central topic of the latest physical artificial intelligence that links computing, biology, chemistry, material science, and mechanical engineering. This study explores the robotic exoskeleton system that contains a human operator in the control loop, which imposes restrictions on the applied control algorithms and movement speed. At the moment, there are several tasks in research projects toward exoskeleton control algorithms. These tasks include consideration of fatigue of a person arising from the control of the exoskeleton over a long period of time. Operator’s fatigue, as a result of the monotonous operations, leads to the fact that the control efficiency decreases and the positioning error will increase over time. Another task when controlling using human biopotentials is a compensation of the influence of the operator’s tremor on the control signal. In addition, a very important factor is the adaptation of actuators to a change in the transient characteristics of external and internal forces. This paper describes the results of tests of an arm exoskeleton device with DC drive located in the elbow joint and a control algorithm based on an electromyogram of the biceps brachii and triceps brachii of the operator. The structure and features of the experimental stand developed in the Laboratory of Robotics and Mechatronics of IPMech RAS are shown. The sensitivity adjustment technique within the exoskeleton control system is proposed.