The Latest in Robot Safety Standards
How to Ensure a Safe Deployment
By Carole Franklin, A3 Director of Standards Development, Robotics
The wheels of government turn slowly, which means that decades can often pass between updates of safety regulations.
Unlike government regulations, industry standards are updated more frequently to address accelerating technology advances, such as the growing popularity of collaborative and mobile robots. For example, updated standards allow a change from historical guidance that was designed to keep people away from robots to new guidance that is adapted to keep people safe with robots. While adherence to these standards is often not required by law, the standards provide an effective framework for worker safety.
Since 1982, the Association for Advancing Automation (A3) has supported industrial robot safety as a standards-developing organization (SDO) for both American (ANSI) and international (ISO) organizations. Recent updates make this is an ideal time for robot manufacturers, integrators and users to review the current state of these standards to ensure safe deployments.
Safety Standards Address Conventional, Collaborative and Mobile Industrial Robots
A variety of robot standards address safety by establishing the responsibilities of both the robot manufacturer as well as robot integrators and installers. While the goals of these standards are similar – keeping people safe near robot systems – there are important considerations specific to different types of robots.
ANSI R15.06: Conventional and collaborative industrial robots
A3’s flagship standard, ANSI R15.06, is a national adoption of ISO safety standard 10218. The R15.06 standard today has two parts: Part 1 establishes requirements for robot manufacturers (covering the manipulator and controller), while Part 2 defines requirements for the system integrator (including the robot, end-effector (end-of-arm tooling or EOAT), workpiece and any peripheral equipment).
Significant changes for the next revision of R15.06 are expected to be published in the first half of 2024, following updates to the ISO standard 10218. Part 1 revisions add requirements for robot design, functional safety and cybersecurity, and incorporate safety requirements for industrial robots intended for collaborative applications. Part 2 revisions address collaborative applications, clarifying requirements for functional safety and adding relevant requirements for cybersecurity. Because ISO standards are not permitted to address user requirements, a new Part 3 of R15.06 that is specific to industrial robot users will be added to the new edition.
The following definitions in R15.06 are critical for both conventional and collaborative deployments:
- The industrial robot: fixed-in-place manipulators or arms that are reprogrammable on three or more axes, plus robot controller. (Note: The robot arm alone is considered an “incomplete machine” that cannot do any useful work without an end-effector.)
- The industrial robot system: robot arm and end-effector
- The industrial robot application: robot system plus any ancillary equipment
For conventional robot systems, the safety concern has historically been to restrict people’s physical access to potential hazards. The standard defines the maximum space that can be reached by the robot application’s moving parts, including end effector and workpiece. Restricted access is typically achieved by enclosing the maximum space within a safeguarded space, with fencing to keep people out, or safeguards such as a light curtain or pressure-sensitive matting that detects a person in the space and brings the robot system to a safe stop.
While the R15.06 standard permits collaborative and mobile operation for conventional robot systems, it does not explain safety requirements for those types of installations. For now, a separate document (ISO/TS 15066:2016 or the U.S. national adoption, RIA TR R15.606:2016) contain the requirements for collaborative operation. The next edition of R15.06 will include safety requirements for collaborative operation of robots, which the standard defines as a “state in which purposely designed robots work in direct cooperation with a human within a defined workspace.”
The distinction between robot and robot system is crucial for safe collaborative deployments. Integrators and users must consider whether the entire robot system, not just the robot, is “collaborative.” For example, the industrial robots referred to as “collaborative robots” represent only power- and force-limiting (PFL) collaboration. Other types of collaboration, such as speed and separation monitoring (SSM), can be implemented using non-PFL, or conventional, robot arms.
Practical steps for collaborative safety include:
- Understand the relevant standards: R15.06 / ISO 10218 and Technical Report RIA TR 606 / ISO TS 15066.
- Consider the robot system as a whole, not just the robot arm.
- Select equipment such as end-effectors with the goal of avoiding those that pose a safety risk.
- Always conduct a risk assessment (RIA TR R15.306-2016 provides guidance and templates related to task-based risk assessment methodology).
- Watch robot poses and paths to avoid situations where a person could be injured, especially involving contact with face/ head/neck or clamping/pinching.
ANSI R15.08: Industrial mobile robots
In late 2020, A3 published Part 1 of the R15.08 ANSI standard to establish safety requirements for industrial mobile robots (IMRs) as guidance for robot manufacturers. A3’s newest standard, Part 2 of the R15.08 (available September 2023), establishes safety requirements for deploying IMR systems into an industrial environment, including integrating, configuring and customizing the IMR or fleet of IMRs into a site. Work on Part 3 of R15.08, which defines safety requirements for use of IMR systems and applications throughout the robot’s productive life, has begun; publication is targeted for late 2025.
The scope for R15.08 includes ground-based IMRs in an industrial environment with trained personnel. A defining characteristic of an industrial environment is the lack of uncontrolled access by members of the public. Other key concepts for IMRs include “mobile platform” and “attachment.” The mobile platform could be an autonomous mobile robot (AMR), or if the attachment is a manipulator (or industrial robot arm as defined in R15.06), the mobile platform can also be an automated guided vehicle (AGV). (All other configurations of AGVs are covered by other standards such as ANSI/ITSDF B56.5.) Gray areas still exist, however, prompting ongoing discussions in standards committees regarding which standards should cover fixed-path AGVs versus AMRs with free-space navigation.
Key Considerations for Safe Deployment of IMRs
Safety guidance for mobile robots continues to evolve along with new technologies and use cases. The most important step is to consider the entire mapped environment – a different mindset than a fixed robot cell or an AGV. The integrator must assess the entire facility where the IMRs will operate, and manage the deployed operating environment (DOE). Because the IMR system could be deployed in an existing facility, the DOE might not match the specified operating environment (SOE) provided by the IMR manufacturer, so may require plans for mitigating hazards arising from the mismatch. The layout analysis must intentionally design interactions between IMRs and workers as well as between IMRs and docking or charging stations.
As with the R15.06/10218 standards, the risk assessment remains a critical element for safe deployment of mobile robots, particularly when they are not constrained to a defined path. Standards provide important guidance on requirements such as protective and emergency stops, collision avoidance, speed control and stopping distance, as well as cybersecurity concerns.
About the Contributor
Carole Franklin is A3 Director of Standards Development, Robotics. Along with development and management of safety standards, A3 also provides a series of informational Technical Reports, which may contain technical research, tutorials or updates on developments. Access these at: www.automate.org/a3-content/standards-and-certifications.
