Scalability of Robotic Controllers: An Evaluation of Controller Options

Report No. ARL-TR-4457
Authors: Rodger A. Pettitt, Elizabeth S. Redden, and Christian B. Carstens
Date/Pages: May 2008; 85 pages
Abstract: This study, conducted at Fort Benning, Georgia, was an operational investigation of tele-operation control performance with the use of three different robotic control devices. Twelve Soldiers from the Officers' Candidate School and three Soldiers from Headquarters Company, 1st Battalion, 11th Infantry Regiment served as participants. Before any training, Soldiers provided an initial evaluation of the intuitiveness of controller features. After training in the operation of the IRobot PackBot Robot system, each Soldier completed a driving course using three different controller types. Controller A was the largest of the three controllers and each control manipulation had a single function. Both controller A and controller B had a similar number of single-function controls; however, controller B's controls were laid in a different configuration and were smaller than controller A's. Controller C had the fewest controls and the controls were multi-functional. Soldiers were tasked to drive the robot and to perform operations such as surveillance using the robotic arm. We measured workload for each controller was measured by having the Soldiers complete the NASA (National Aeronautics and Space Administration) Task Load Index survey after they used each controller type. Controller type and usability were evaluated, based on objective performance data, data collector observations, and Soldier questionnaires. The multifunctional controller was reported to be more difficult to learn and use than the controller with reduced control sizes because switching between functions was time consuming and confusing. This difficulty increased perceived workload. Soldiers also found that several robotic control functions (e.g., raising the control arm while turning the sensor head) could not be performed simultaneously with the multifunction controller. This necessitated sequential operation which was time consuming and difficult. Findings indicate that reducing the size of the individual controls shows promise as a valid approach for reducing overall controller size.
Distribution: Approved for public release
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Last Update / Reviewed: May 1, 2008