Roberta Nelson Shea is director of safety consulting services for Applied Manufacturing Technologies (AMT) in Orion, Mich. She heads the Safety Services Business Unit's team of consultants offering hazard assessment and solution validation services.
The consensus standard for robots (RIA 15.06) is being revised — a culmination of about 10 years of work. The 1999 version of the standard was the basis of the international standards ISO 10218-1 Robots and ISO 10218-2 Implementation of Robot Systems. Both ISO standards have been adopted.
During the ISO 10218 drafting process, the R15 working group actively participated in the ISO standards development with the plan of taking the ISO standards as portions of the R15.06 revision.
Draft RIA R15.06 comprehensively covers the robot, system, integration and user requirements in one standard. The draft breaks these into two parts. Part 1 is specifically directed to the robot manufacturer, and Part 2 covers the integration and use of these robots. It consists of ISO 10218-1, ISO 10218-2, and U.S. and Canadian additions. These additions include explanations of sections in the ISO text, as well as additional requirements addressed to the users of robot systems, robot cells and robot lines. User requirements are necessary because ISO machine safety standards are written for the suppliers — not users — of equipment.
The ANSI/RIA R15.06 draft and the CSA Z434 draft include both U.S. and Canadian comments and requirements, so one document will provide the ISO, Canadian (CSA Z434) and U.S. (ANSI/RIA R15.06) robot/integration/use requirements.
Although the next R15.06 standard is based on the 1999 version, there are some significant changes. Compliance will require greater knowledge and competence relating to safety systems design and specifically functional safety. Many people know of the functional safety standard ISO 13849-1:2006, which is now valid for the presumption of conformity to the Machinery Directive in Europe. Unless a risk assessment requires otherwise, robots and robot systems are expected to meet the functional safety requirement of PLd (performance level "d") with structure category 3 (dual channel). This functional safety equates to the requirements for control reliability. ISO 10218 standards require compliance to the new quantitative approach to hazard identification, engineering, and mitigation including performance levels (ISO 13849 or IEC 62061).
There are a few changes in terminology:
• "Safety stop" has been changed to "protective stop," since the purpose is to provide protection to personnel.
• "Robot" now means the robot without the end-effector.
• "Robot system" now means the robot with the end-effector.
• "Robot cell" now means all the robotic equipment within the safeguarded space.
There are new requirements for collaborative robot systems. This is the new frontier with robotic applications. Collaborative operation is when the robot is in automatic operation and the robot system and operator share the same workspace at the same time. There are a number of ways to accomplish cooperative operation, but put simply, it requires newer-generation (and newer-technology) robot systems. There is even work in progress for an added technical report on collaborative robot systems.
Draft R15.06 might be the first safety standard for industrial equipment that is globally harmonized. This is a tremendous advantage to suppliers and users as the same robot, robot system and robot cell design can be used around the globe with only minimal local changes.
Draft ANSI/RIA R15.06 still needs to determine how to present the requirements for functional safety. The R15.06 working group still is grappling with the issue to determine what is best to improve safety, increase safety competence, and yet be reasonably achievable. CSA Z434 has embraced the concept and use of functional safety (ISO 13849 and IEC 62061).
RIA R15.06 is on the path toward a truly global standard for robots, robot systems, and their integration.
