Shared understanding for collaborative control

This paper presents results from three experiments in which human operators were teamed with a mixed-initiative robot control system to accomplish various indoor search and exploration tasks. By assessing human workload and error together with overall performance, these experiments provide an objective means to contrast different modes of robot autonomy and to evaluate both the usability of the interface and the effectiveness of autonomous robot behavior. The first experiment compares the performance achieved when the robot takes initiative to support human driving with the opposite case when the human takes initiative to support autonomous robot driving. The utility of robot autonomy is shown through achievement of better performance when the robot is in the driver's seat. The second experiment introduces a virtual three-dimensional (3-D) map representation that supports collaborative understanding of the task and environment. When used in place of video, the 3-D map reduced operator workload and navigational error. By lowering bandwidth requirements, use of the virtual 3-D interface enables long-range, nonline-of-sight communication. Results from the third experiment extend the findings of experiment 1 by showing that collaborative control can increase performance and reduce error even when the complexity of the environment is increased and workload is distributed amongst multiple operators.