Operability Evaluation System and Comparison Experiment of Gesture Operation and Button Operation of Robot Manipulator

Robot manipulators are now widely used in manufacturing industries. When programmed to perform required movements via a process called teaching, they can accomplish a wide variety of complex tasks. In conventional teaching processes, a teaching pendant (TP), which is a tethered controller with which the operator inputs specific movement commands, is used. However, such devices normally have so many buttons that operators often experience difficulty in programming operations intuitively, so the teaching process consumes significant amounts of time and effort. To solve this problem, intuitive operation methods in which human body motions (such as hand gestures) are used as input to the robot have been studied. However, no quantitative comparisons between those new gesture-based and conventional teaching methods have yet been made. With that point in mind, the present paper proposes a virtual space-based evaluation system in which operators control the position and orientation of a six-degree-of-freedom virtual robot hand in order to evaluate and compare TP- and gesture-based operation methods. The experimental results show that when compared to TP-based methods, gesture-based operation methods achieved higher evaluations in terms of time and psychological aspects. In addition, four types of gesture-based operating methods were proposed in order to consider different ways in which position changes and orientation changes could be handled. The operability levels of the four gesture types were also compared quantitatively using the proposed evaluation system, and the obtained experimental results suggest that such differences can affect the cognitive burden imposed on the operator.