Haptic human-robot collaboration system based on delta robot with gravity compensation

Abstract

Human-robot collaboration systems have attracted more and more researchers' attention. Many experiments in a new design of robot system illustrated that it can be used to help and support human operator. In the past few decades, delta robots have popular usage in industrial applications, especially in picking and packaging for their relative advantages such as high speed, high accuracy, and light weight devices. Delta robot is a parallel manipulator that consists of three arms connected to universal joints at the base. This paper presents work on a new force sensor less haptic human-robot collaboration system based on 3D parallel mechanism delta robot. The controller of delta robot was designed by using force sensorless bilateral control approach with considering of gravity compensation. Each joint of the AC servo motor can be programmed to estimate the external force from unknown environment by using the disuturbance observer (DOB). It was shown that delta robot can not only be applied for industrial applications, it can also be conveniently used for human-robot interaction. Experimental results are presented which demonstrate that the gravity effect can be compensated. Therefore, our proposed robot system is suitable for human-robot collaboration system.