Towards Mobile Manipulator Safety Standards Jeremy Marvel, Member, IEEE, Roger Bostelman U.S. National Institute of Standards and Technology Gaithersburg, MD, 20899 USA jeremy.marvel@nist.gov, roger.bostelman@nist.gov Abstract — We present an overview of the current (as of Spring, 2013) safety standards for industrial robots and automated guided vehicles (AGVs). We also describe how they relate to the safety concerns of mobile manipulators (robot arms mounted on mobile bases) in modern manufacturing. Provisions for the capabilities of mobile manipulators are provided in relationship to the current standards. Several scenarios are presented for which the behavior of a mobile manipulator may be unpredictable or otherwise contrary to the current safety requirements. We also discuss the needs for a new class of test artifacts for verifying and validating the functionality of mobile manipulator safety systems in collaborative working environ- ments. Keywords—mobile manipulators; AGV safety; robot safety; safety standards; human-robot collaboration I. INTRODUCTION The utilization of robot technologies is rapidly growing globally and across a myriad of industrial domains to accom- modate the need for increasingly flexible automation in modern manufacturing [1]. Such technologies include advan- ces in dexterous robot grippers [2], safe collaborative robot design [3], and pervasive use of robot sensing [4]. A consequence of this rapid growth is that the development and integration of technologies in manufacturing environments is outpacing the evolution of standards and test methods that are used to ensure the safety of humans in these environments. As an example of this rapid growth, mobile manipulators (robot arms mounted on mobile bases) are becoming more common as a means of expanding the utility of manufacturing automation. Safety standards for industrial robot arms and automated guided vehicles (AGVs) are written to reduce the risk to humans in industrial environments, but only with regard to their respective platforms. The marriage of mobility and dexterity enables truly flexible factory environments for lean manufacturing. However, it also presents an increase in capabilities for which the existing robot and AGV standards do not provide sufficient provisions for safeguarding. The U.S. National Institute of Standards and Technology (NIST) helps promote the economic viability of U.S. manufac- turing by developing test methods and metrics for system developers and users to evaluate the performance of new tech- nologies. NIST is also aiding the development and validation of safety standards for both AGVs and industrial robots [5]. Adherence to such standards is voluntary, but compliance may be required by national safety organizations or for global distribution of robot technologies. This paper describes these standards and how they relate to mobile manipulators. This paper also illustrates the safety challenges with the integration of mobile manipulators into human-occupied settings. Section II outlines the mobile manipulator concept, and introduces the need for new safety standards for agile manufacturing. Section III describes the current standards for AGV safety, while Section IV discusses the standards for industrial robot safety. Section V presents the standards for human presence detection. Section VI highlights some conditions under which mobile manipulators are not properly covered by the AGV and industrial robot standards. Section VII details the need for new test piece designs for verifying and validating AGV, industrial robot, and mobile manipulator safety. II. MOBILE MANIPULATORS The arm-on-mobile-base paradigm has been around since the 1970s (e.g., [6]). It is commonplace for teleoperated and semi-autonomous platforms to be used for purposes such as bomb disposal [7], search-and-rescue [8], medical assistance [9], and residential service [10]. Such solutions are single- purpose with targeted applications. General-purpose mobile manipulators are less common, and tend toward proof-of- concept platforms that focus more on the aesthetic (e.g., [11]) and academic (e.g., [12]) functions of robotics, and less on the utilitarian. Following the 2011 disaster at the Fukushima Daiichi nuclear facility in Japan, there has been renewed efforts in researching, developing, and repurposing tele- operated mobile manipulators (e.g., [13]) to address practical needs in environments too dangerous for humans. Few autonomous mobile manipulators are available as commercial, off-the-shelf solutions. Those systems that do exist (e.g., [14]) are intended for research rather than industrial purposes. Mobile manipulators for manufacturing tend toward one-off solutions with little exposure to research publication venues. Due to the requirements for reliability, manufacturing mobile manipulators are not as technologically innovative as their research counterparts. Early mobile manipulators, like AGVs, were separated from human traffic, had primitive sensing and control functions, and were limited to constrained tasks. Frequently, the mobile base and the robot arm are treated as separate components, with the base being used to cart and park the robot arm to task-relevant locations. III. AGV STANDARDS The American National Standards Institute/Industrial Truck Standards Development Foundation (ANSI/ITSDF) B56.5