1142 Copyright © 2014, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 56 A Hierarchically Structured Collective of Coordinating Mobile Robots Supervised by a Single Human ABSTRACT Using a Single-Human Multiple-Robot System (SHMRS) to deploy rescue robots in Urban Search and Rescue (USAR) can induce high levels of cognitive workload and poor situation awareness. Yet, the provision of autonomous coordination between robots to alleviate cognitive workload and promote situation awareness must be made with careful management of limited robot computational and communication resources. Therefore, a technique for autonomous coordination using a hierarchically structured collective of robots has been devised to address these concerns. The technique calls for an Apex robot to perform most of the computation required for coordination, allowing Subordinate robots to be simpler computationally and to communicate with only the Apex robot instead of with many robots. This method has been integrated into a physical implementation of the SHMRS. As such, this chapter also presents practical components of the SHMRS including the robots used, the control station, and the graphical user interface. INTRODUCTION Mobile robots have been found to be useful for a number of applications such as combat (Yamau- chi, 2004; Barnes, Everett, & Rudakevych, 2005), oceanography (Bellingham & Rajan, 2007), space exploration (Bellingham & Rajan, 2007; Halbers- tam, et al., 2006; Schreckenghost, Fong, & Milam, 2008), as well as search and rescue. In particular, attention has been focused to- wards developing technologies for using mobile robots for Urban Search and Rescue (USAR) and research interest into USAR robotics is currently at a high level. This is not surprising given the Choon Yue Wong Nanyang Technological University, Singapore Gerald Seet Nanyang Technological University, Singapore Siang Kok Sim Nanyang Technological University, Singapore Wee Ching Pang Nanyang Technological University, Singapore DOI: 10.4018/978-1-4666-4301-7.ch056