Analysis of the effects of time delays on the teleoperation of a mobile robot in various modes of operation

Purpose – The purpose of this paper is to investigate the effect of time delay on the ability of a human operator to complete a task with a teleoperated mobile-robot using two systems, two different ways of interacting with the mobile-robots and several different environments. Design/methodology/approach – Teleoperators are observed completing a series of tasks using a joystick to control a mobile-robot while time delays are introduced to the system. They sit at a computer and view scenes remotely on a screen. Cameras are either mounted on the robot or mounted externally so that they view both the environment and robot. Teleoperators complete the tests both with and without sensors. One robot system uses an umbilical cable and one uses a radio link. Findings – In simple environments, a teleoperator may perform better without a sensor system to assist them but as time delays are introduced then there are more failures. In more complicated environments or when time delays are longer, then teleoperators perform better with a sensor system to assist. Teleoperators may also tend to perform better with a radio link than with an umbilical connection. Research limitations/implications – Teleoperated systems rely heavily on visual feedback and experienced operators. This paper investigates the effect of introducing a delay to the delivery of that visual feedback. Practical implications – The paper suggests that in simple environments with short time delays then the amount of sensor support should be small but in more complicated environments or with longer delays then more sensor support needs to be provided. Originality/value – Results from imposing time delays on a teleoperated mobile-robot are presented. Effects on the task of different ways of viewing activity on a computer display are presented, that is with cameras mounted on the robot or cameras mounted externally to view both the environment and robot. Results from using sensors to assist teleoperators are presented. The paper suggests that the amount of sensor support should be varied depending on circumstances.