Safety of Human-Robot Systems in Fixed Workcell Environments

Safe human-robot collaboration in manufacturing work cells is widely seen as key to the future of robotics. When humans and robots share the same workspace, a whole class of tasks becomes amenable to automation, especially for small and medium-sized manufacturers who can’t afford the space and implementation cost of current safety requirements.  Work on this project will focus on two ways of ensuring safety: keeping humans and robots separate while they share the work space, and ensuring that any contact that does occur does not involve forces or pressures that are high enough to injure people. The results will be used to develop the next generation of safety standards for manufacturing applications.

To develop and deploy the measurement science needed by industry (manufacturers, integrators and end-users) and robot safety standards organizations to enable humans and robots to safely share workspaces by limiting contact and minimizing the dangers of impact between robots and humans by 2014.

The new idea is to enable collaborative robots to use advanced sensors to detect and track people, to adjust their speed based on the separation distance between the human and the robot, and to moderate the forces and pressures they apply to ensure they stay below biomechanical limits when working in proximity to people. Ensuring that these robots operate in a safe manner will require new guidelines, performance measurement methods and validation procedures that this project will address. The project will also work on a new version of the RIA/ANSI R15.06 standard that incorporates the  ISO 10218 standard to ensure adoption by U.S. industry.

A technical specification (ISO TS 15066) providing the guidelines for the safe operation of collaborative robots is being developed under this project (NIST is taking the lead, with the German ISO members, in this task).    Part of this technical specification requires development of speed and separation monitoring and power and force limiting, the two focus areas of the project. The project will address speed and separation monitoring by developing algorithms for a robot to enable it to use information about where people are in the workspace to modify its planned actions to ensure that contact does not occur while the robot is moving.  The project will also develop performance measures that let users know how well a robot conforms to the speed and separation monitoring requirements. In the area of power and force limiting, instruments  and performances tests will be developed to measure the forces exerted by a robot to ensure they conform to the requirements in the standard. Current robots do not support either of these safety modes and there are no performance measures to assist manufacturers in achieving these capabilities. Guidelines developed as part of the technical specification will be implemented as vendor-neutral prototypes on a robot testbed at NIST.  Results of this research will provide measurement methods for determining the level of safety achieved by a particular application of safeguards.

• Outcome: Adoption of new international safety standard for robots (ISO 10218 parts 1 and 2), which provides the basis for greater human-robot collaboration, and the foundation for the ANSI standard.
• Outcome (September 2012): Adoption of draft U.S. (ANSI/RIA R15.06) and Canadian (Z434) safety standard.    U.S. manufacturers (and OSHA) will use the standard as the basis to keep workers safe while increasing productivity through human-robot collaboration.
• Output: Draft of a NIST-led ISO technical specification 15066 that provides information on and guidance for achieving safety for collaborative robots conforming to the ISO 10218 standards.

The work supports ISO TC 184/SC 2/WG 3 Industrial Safety and ANSI/Robotic Industries Association (RIA) 15.06.  RIA's current  goal is to adopt the ISO standards with additions for the U.S. markets.

• ISO/RIA 10218-1 Safety Requirements – Part 1: Robot
• ISO/RIA 10218-2 Safety Requirements – Part 2: Industrial robot systems and integration
• ISO/RIA TS 15066 Robots and robotic devices – Collaborative Robots
• ANSI/RIA R15.06 Industrial Robots and Robot Systems - Safety Requirements