On the Development of a Novel Urban Search and Rescue Robot zyx ENS Bryan M. Hudock, USNR Bradley E. Bishop Frederick L. Crabbe United States Naval Academy 105 Maryland Ave (Stop 14a) Annapolis, MD 21402 Keywords: Urban Search and Rescue, robotics Irregular zyxwvut Abstract-- This paper concerns the development of a novel robotic platform for Urban Search and Rescue (USAR) efforts. The main facets of this work involve the design and construction of a new robot morphology and a physical simulation to be used for developing controllers for semi-autonomous (supervisory)operation. I. INTRODUCTION Recovering survivors from a collapsed building has proven to be one of the more daunting challenges that face rescue workers in today’s world. Survivors trapped in a rubble pile generally have 48 hours before they will succumb to dehydration and the elements Cl]. Unfortunately, the environment of urban search and rescue (USAR) does not lend itself to speedy reconnaissance or retrieval. The terrain is extremely unstable and the spaces for exploration are often irregular in nature and very confined. Though these challenges often make human rescue efforts deep within the rubble pile prohibitive, a robot designed for urban search and rescue would be very well suited zyxwvutsrqp to the problem. Robots have already proven their worth in urban search and rescue, most notably in the aftermath of the September 1 l~, 2001 disaster. The combined efforts of Professor Robin Murphy, a computer scientist at the University of South Florida, and Lt. Col (ret) John Blitch, culminated in the creation of the Center for Robot Assisted Search and Rescue (CRASAR), which coordinates and assists robotic search and rescue efforts [2] Though these and other undertakings have shown the potential of a robot in the urban search and rescue environment, there is still room for significant improvement. Most notably, a unique structure and method of mobility could result in a vehicle much improved over existing urban search and rescue robots in terms of range and ability to overcome obstacles. The primary goal of this project was to develop a robot that was highly mobile, lightweight, and easy to control. The robot was to be designed from the ground up with specific features to combat the irregular terrain found in an urban search and rescue environment. Specifically, the robot was designed to overcome three pre-selected obstacles that represent a sample of the types of impediments found in a colIapsed building: irregular terrain, canyon, and ladder (see Fig. 1). zyxwvutsrqp Ladder f!!h z rl) Figure 1: Selected obstacle types The secondary goal of the project was to develop a simulation that modeled the physical prototype and its environment. This simulation could be used to produce pre- programmed controllers to simplify user input under a supervisory control architecture. The remainder of the paper is organized as follows: Section I1 contains the description of the basic robot morphology selected, while Section I11 includes details of the physical prototype. Results of the physical design are discussed in Section IV. The physical simulation is discussed in Section V, and conclusions given in Section VI. 11. ROBOT MORPHOLOGY The preliminary step of physical construction was to determine the robot’s overall design. There were several factors that affected the overall structure. First, the robot needed to be able to move through the confined spaces often found in a collapsed building. Second, the robot needed to be very flexible in structure in order to easily maneuver over and around obstacles. Third, the robot chassis needed to be designed in such a way as to maximize strength while keeping overall weight as low as possible. Ease of transportation was an important factor for the robot, considering how the debris from a collapsed building could often make it difficult to access an area for search efforts. The final requirement was a versatile means of mobility. As the irregular and unpredictable nature of the environment often called for creative ways of dealing with terrain challenges, a robot with a variety of methods of movement had a greater chance of succeeding in such a difficult setting. The brief history of robotic involvement in urban search and rescue has seen designs that have almost exclusively 0-7803-828 zyxwvutsr 1 -1/04/$20.00 02004 IEEE 451