Robotic Industries Association to adopt ISO functional safety standard
The Robotic Industries Association (RIA) consensus standard for robots (ANSI/ RIA R15.06) has been in the process of being revised over the past 10 years. The 1999 (R2009) edition of ANSI/ RIA R15.06 was used as the basis of the newly adopted international robot safety standards: ISO 10218 part 1 and part 2 – 2011. During the international standards’ development, the R15 working group was actively involved. The hope and plan was that ultimately there would be globally harmonized robot safety standard(s).
The current ANSI/ RIA R15.06 revision was a coordinated activity with Canada, with the intention of developing a standard that would be almost completely harmonized between ISO, the U.S., and Canada. Significant effort had been put into annexes for safeguarding and also risk assessment; however, more work was needed—particularly on the topic of 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. Further information and guidance on ANSI/ RIA R15.06, including functional safety, is offered by RIA, a number of other parties, and at the RIA’s National Robot Safety Conference. This year the conference is being held Sept. 24-26 in Indianapolis.
Until a few weeks ago, it was expected that the new R15.06 would consist of ISO 10218-1, ISO 10218-2, plus U.S. and Canadian additions. These U.S. and Canadian additions included explanations of sections in the ISO text as well as additional requirements addressed specifically to the users of robot systems, robot cells, and robot lines. It is important to note that ISO machine safety standards are written to the suppliers, not users, of equipment. The reason for this is that every country around the world, including the U.S. and each province of Canada, has its own workplace (user) requirements.
Guidance is planned
At the recent R15.06 meeting, it was decided to adopt the ISO robot standards as the new ANSI/ RIA R15.06 standard without the added North American materials. However, the work put into these added materials will continue with the intention of later publishing them to aid in the use of the new ANSI/ RIA R15.06. Canada is moving forward with CSA Z434, which will contain ISO 10218-1, ISO 10218-2, and Canadian additions—including the Canadian user requirements.
What does this mean?
Both the current ANSI/ RIA R15.06 – 1999 and the draft R15.06 comprehensively cover the robot, system, and integration requirements in one standard. The draft ANSI RIA R15.06 breaks these into two parts. Part 1 is specifically directed to the robot manufacturer (no end-effector), which is presently the subject matter of R15.06 – 1999 clause 4. Part 2 covers the robot/ robot system/ robot line integration and instructions for use.
Presuming that the ANSI/ RIA R15.06 ballot is approved, the new ANSI robot safety standard will be identical to ISO 10218 parts 1 and 2. For a two-year period, either the 1999 edition (reaffirmed in 2009) or the new R15.06 – 2012 (if approved) standard can be used. If the new ANSI /RIA R15.06 standard is used, then users will be referred to the information for use in the new standard and to the 1999 (R2009) user requirements—until the new guidance documents are released.
The new standard addresses collaborative robot systems never envisioned in the 1999 standard. This breakthrough in thought and advanced automation allows the robot system and operator to share the same workspace at the same time.
ISO 10218 requires compliance to the new quantitative approach to hazard identification, engineering, and mitigation including performance levels (ISO 13839 or IEC 62061). This approach is required and mandatory as specified by the Machinery Directive in Europe effective Jan. 1, 2012. Alternative methods can be used if their use produces the same results. But this will require a comparison first to determine if the results are the same, so it is likely that instead ISO 13849 or IEC 62061 will slowly start being used in the U.S. This increasing acceptance and use of ISO 13849 requires greater knowledge and competence relative to safety systems design and functional safety.
However, a good safety design by a knowledgeable engineer has long been expected and probably often provided, yet is difficult to quantify. Functional safety provides the means by which to validate a design. Unless a risk assessment requires otherwise, robots and robot systems are expected to meet the functional safety requirement of PL D (performance level “d”) with structure category 3 (dual channel). PL D, category 3 equates to the requirements for control reliability; however, it imposes a structure on the design and validation process.
New robotic terms
There are some changes to definitions as a part of the harmonization:
- “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 robot system(s) and associated equipment to perform the task that is contained within the safeguarded space.
The new standard addresses collaborative robot systems—something never envisioned in the 1999 standard. This is truly a breakthrough in thought and advanced automation. 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. A technical report on safety of collaborative robot systems also is being developed (ISO TS 15066).
We are moving toward a global standard for robots, robot systems, and their integration. For further information about the anticipated ANSI/ RIA R15.06 – 2012, attend the National Robot Safety Conference in Indianapolis from Sept. 24-26.
– Roberta Nelson Shea is director, safety consulting services, Applied Manufacturing Technologies, and chair of the R15.06 Safety Standard Committee and past member of RIA’s Board of Directors. Edited by Mark T. Hoske, content manager CFE Media, Control Engineering and Plant Engineering, firstname.lastname@example.org.
Robotic Industries Association (RIA) safety page: http://bit.ly/uxen4e