1 Abstract— As mobile robots have increasingly improved onboard intelligence, they are being used in more flexible manufacturing, warehouse and/or military environments where humans may intervene and interact with these robots frequently causing increased hazards. The US ASME B56.5 - 2004 Safety Standard for industrial trucks was recently changed and now more closely meets the existing British EN 1525 - 1998 Safety Standard for driverless industrial trucks by allowing the use of non-contact safety sensors. Standard-size, material-covered objects, resembling human limb (arm and leg) lengths and diameters positioned in vertical and horizontal orientations, respectively and located within the vehicle path, must be detected and allow the vehicle to react before the vehicle frame contacts these objects. The National Institute of Standards and Technology (NIST) supports the automated guided vehicle industry to not only promote advancement of the ASME standard to use non-contact safety sensors but, to also provide performance evaluation of new 3D real-time range sensor technology toward implementing and further advancing these standards. This paper will provide details of: the US and British safety standards, a new 3D range camera, sensor experiments with ground truth comparison, and obstacle detection and segmentation algorithms and results, and provide further safety standard advancement recommendations to protect humans as they work near mobile robots. Index Terms—ASME B56.5 safety standard, British EN1525 safety standard, 3D range camera, human-robot interaction, obstacle segmentation, intelligent vehicles. I. INTRODUCTION N Isaac Asimov’s 1942 [23] short story called, “Runaround,” he stated three laws that robots must obey. The first of the three laws states that “a robot may not harm a human being …” Although this was a science fiction story, it has relevance to the real world of robotics and automation today. Robots can now be found in even the consumer market with uses in entertainment, home health care, vacuum cleaning, and lawn mowing. Robotic assistants already act as guards, help fight fires, deliver materials on construction sites and in mines, and distribute goods or help consumers in retail stores. Robots might even provide high-interaction services such as taking blood and coloring hair [15]. Manuscript received August 23, 2005. R.V. Bostelman, T.H. Hong, R. Madhavan, T. Chang are with the National Institute of Standards and Technology, Gaithersburg, MD 20899 USA (phone: 301-975-3426; fax: 301-921-6165; e-mail: roger.bostelman@nist.gov). Robots are ever more likely to be fully mobile, bringing them into physical proximity with other robots, people, and objects. Mobile robots will have to negotiate their interactions in a dynamic and sometimes physically challenging environment. Toward military applications, Project Alpha, a U.S. Joint Forces Command rapid idea analysis group, is in the midst of a study focusing on the concept of developing and employing robots that would be capable of replacing humans to perform many, if not most combat functions on the battlefield [21]. In the service industry, for example health care, robots are still delivering pharmaceuticals to patients rooms using the Helpmate [4] robot developed in the early 1990’s by Transitions Research Corporation (now Pyxis Corporation) with funding from the National Institute of Standards and Technology (NIST). This was the first service robot to be widely deployed in American hospitals. NIST researchers were able to advance the original sonar guidance technology on the HelpMate with a LADAR (laser detection and ranging)-based navigation system. The NIST project review suggested that a HelpMate robot made its deliveries faster and more reliably than its human counterparts and produced cost savings (above the rental costs of the robot) of between $5,000 and $10,000 per year per robot in the 1990’s. Approximately one hundred HelpMates were in use in American hospitals by the end of the decade in clinical laboratories, pharmacies, medical records departments, and central supply rooms. For manufacturing, Automated Guided Vehicles (AGVs) are the vehicles of choice and are equipped with automatic guidance systems and are capable of following prescribed paths. In automated factories and facilities AGV's move pallets and containers. In offices they may be used to deliver and pick up the mail. They are even used to transport patrons around in airports. The main benefit of AGVs is that they reduce labor costs. But in material handling facilities there is another benefit. Material handling has always been dangerous. Injuries occur due to a driver’s lack of attention, drivers driving too fast, or other personnel not paying attention. Obstacle detection is therefore a key to allowing AGV’s to interact with personnel safely while optimizing vehicle speeds [17]. Emergency controls are then required which would stop the vehicle if an object is detected in the direction of travel. Although workers are trained to mark AGV travel paths clearly, to watch out for AGV’s keeping clear when vehicles approach, equipping AGV’s with virtual bumpers such as LADAR systems can be beneficial. LADAR systems must be Safety Standard Advancement Toward Mobile Robot Use Near Humans R.V. Bostelman, T.H. Hong, R. Madhavan, T. Y. Chang I