November 6, 2013
As technology has changed and improved, it became necessary to update robotic safety standards. The new R15.06 standard is designed to move to a more quantitative approach to safety and to improve production efficiency by streamlining interactions between users and robotic systems.
The past two years have been marked by significant changes in industrial safety standards in the U.S., and metal fabricators who aren’t carefully monitoring these developments may find that their machinery and processes no longer comply with the current code or aren’t keeping up with accepted best practices.
According to the Occupational Safety and Health Administration, “machine guarding” that pertains to machines, general requirements, and general industry (29 CFR 1910.212) consistently falls in the top 10 most frequently cited OSHA standards violated in any given year. Combine this fact with new regulatory changes, and it is easy to understand why this perennially misunderstood topic is more confusing than ever before. The numerous and constantly changing designs and specifications associated with industrial robotic applications only worsen the problem.
Fabricators who want to educate themselves on machine guarding and robotic operations have many options. Organizations such as OSHA, the American National Standards Institute (ANSI), and the International Organization for Standardization (ISO) produce a plethora of information to help keep manufacturing companies updated. Trade groups like the Robotic Industries Association (RIA) also provide a wealth of knowledge when it comes to new regulations that should be followed. Webinars, seminars, and industry conferences also can be great resources when it comes to keeping abreast of the latest regulatory changes. Finally, safety supplier websites often call attention to changes in standards, and most will provide detailed information on how their products can be applied.
First and foremost, conducting a thorough risk assessment is the best way to find out if the work environment in your facility is safe and compliant. If you are not familiar with or have not performed a risk assessment recently, you have many approved methodologies to choose from. Several risk assessment programs can be purchased. For example, the revised ANSI/RIA R15.06 standard provides a detailed structure to follow.
Thanks to these new standards, risk assessments are now mandatory.
Developed by RIA and adopted by ANSI in May 2013, the ANSI/RIA R15.06-2012 standard references ISO 10218-1, 2:2011, which addresses robot systems and integration. Although it was originally developed in 1999, a revision process started shortly after and took longer than 10 years to complete.
The new R15.06 standard was written to be compliant with international standards already in place in Europe and to fit in with existing standard CSA Z434 in Canada, making life easier for manufacturers and metal fabricators. Fabricators won’t have to worry that equipment manufactured in one country will fall out of compliance with standards and regulations in their home country. This harmonization can save costly downtime during installations.
This new standard requires better hazard identification and provides for proper training. It also mandates risk assessments requiring validation of the safety solutions, along with designs that incorporate protective measures for the robot cell and the operator.
This revised regulation does not loosen any guidelines previously in place (see Figure 1), but it does provide several new capabilities as a result of improving technology. These new capabilities could not have been anticipated when the former incarnation of R15.06 was created. It allows for many advantages that streamline fabricating processes.
Some of the biggest changes in the new R15.06 industrial robot standard have to do with safety-rated motion and the use of advanced programmable safety devices. What this means is software is now allowed “safety-rated” control of various aspects of the robot’s function, limiting the area in which the robot operates and the speed of robot motion. This is a departure from older standards in that programmable safety controls were not allowed.
Thanks to technological advances in safety controls, these long overdue applications now can be implemented safely. In the past, engineers designing these systems guarded for the maximum space, speed, and load of the robot (see Figure 2). With these changes, the physical footprint of new robot cells should shrink. Coupled with the proper point-of-interaction safety devices, including automated barrier doors, scanners, or light curtains, these cells may realize significant floor space savings.
Saving space is not the only potential benefit realized through R15.06. Advanced robots with “safety-rated” control now can operate in the same areas as their human counterparts. This collaborative operation allows operators to interact during an automatic robot operation, greatly increasing productivity. Workers can now load and unload robots, as well as manually drive the robot in some instances.
It is important to understand that not all robotic processes are safe enough for workers to interact with. Through risk assessments, a company can consider secondary hazards associated with the process and reduce or eliminate exposure. A collaboration between a fabricating or welding robot and a human worker is not suggested by R15.06. Those processes are best contained by automated barrier doors, which also minimize the robotic cell footprint, or some other limiting safeguarding device.
Another key component of R15.06 is the use of risk assessments. Because every robotic system is different and has its own set of guidelines, it’s important to realize what guidelines are before risk assessment is conducted. Specifications such as space and cycles need to be known. Integrators of new robotic systems will be required to perform these risk assessments in an attempt to identify potential dangers and ways to limit and eliminate them.
R15.06 is similar to ISO 10218-2 in that it takes a quantitative approach to hazard identification. These steps follow in line with the changes made to ISO 13849-1 last year.
A performance level “d,” a quantitative level that specifies the ability of the safety-related parts of the control system to perform as designed, is required of all robotic systems, as well as Category 3, dual-channel architecture, unless a risk assessment determines otherwise. Performance level safety and category ratings offer a much more measurably reliable way to gauge safety.
As technology changed and improved, it became necessary to update safety. The ratified R15.06 upholds the safest regulations that are already in place, provides a more quantitative approach, and looks to improve efficiency by streamlining interactions between operators and robotic systems through a collaborative method.
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