A comparison of smartphone interfaces for teleoperation of robot arms

Abstract

Human-in-the-loop control of remote robot arms and hands, telemanipulation, is commonly done by using a mechanical master device specifically designed to match the robot and its degrees-of-freedom (DOF). For simultaneous arm and hand manipulation, this device might be complex and expensive. In order to introduce telemanipulation into human environments, intuitive and inexpensive interfaces are needed. Most people carry smartphones, and thus smartphone-based interfaces allow people to be “on-call” to intervene with a robot while going about their other daily activities. In this paper, we design and compare three interfaces on an inexpensive smartphone to telemanipulate a Barrett WAM arm and hand, and we use a conventional gamepad interface as a reference. Visual feedback is provided by streaming video of the robot's workspace to the smartphone. We establish the completion time, pose error and energy consumption while picking-and-placing an object in a particular location as objective measurements. We combine these measurements with a Likert-type qualitative evaluation. Results show that smartphone-based interfaces are a good compromise between availability and performance in human-in-the-loop scenarios. Nevertheless, conventional gamepad interfaces are still at least 43% better in regard to completion time and 29% in relation to pose error, but they are 24% less efficient concerning energy consumption.