Collaborative operation of robots and humans comes to the forefront
More than a last taste of winter came to the Detroit area this past week. Around 900 robotics users and more than 100 system integrators made their way to Auburn Hills, Michigan, for ABB Robotics Technology Days.
From its new dual-arm concept robot to the TiP TiG welding robotic system, ABB Robotics is on the laser-cutting edge of robotic applications. But with increased robotic use comes the need for safer practices.
The new ANSI/RIA R15.06-2012 standard was put in place in April 2013, making ISO 10218-1 and 10218-2 a globally harmonized standard. Pat Davison, director of standards development, Robotic Industries Association (RIA), part of the Association for Advancing Automation, explained the safety standard update at ABB Robotics Technology Days.
“This is the first new update to the ANSI standard since 1999,” said Davison. The standard is available through RIA or ANSI. If you've got a system that's in compliance with the ’99 standard, by and large you're in compliance with the 2012 standard.”
Standards level the playing field and give a common language to robot manufacturers, explained Davison. “They provide risk management assistance by helping to limit liability for products meeting standards,” he said. “Standards help to meet market demands, and they lower costs by standardizing designs and manufacturing. And globally harmonized standards allow products to be global, rather than regional designs. Equipment can be shipped between facilities of global companies. A cell you put in the United States will meet the performance for any other location.”
In the event of a mishap or an inspection, OSHA will look at the most relevant standard, which is the ANSI standard in this case, offered Davison. Several obvious differences exist between American National Standards Institute (ANSI) and the International Organization for Standardization (ISO). ANSI is the accrediting body for standards organizations in North America, primarily the United States. ANSI accredits an organization to be a standards development organization (SDO) for a specific market or scope. Oversight of ANSI standards development is to its processes and the development procedures. Under ANSI, for example, you find RIA, AWS, and NFPA.
ISO is much more rigid. Standardization is highly structured and organized to minimize overlapping scopes; overlap between organizations’ standards is common under ANSI. ISO standards are supposed to use the work of other standards and not reinvent the wheel. For harmonized standards, technical experts (CEN consultants) review the content to judge whether the standard complies with the various EU directives.
ANSI standards also are voluntary. This means an end user can opt to comply with an ANSI standard or opt to comply with another standard. It's the user’s choice. “However if you have an OSHA inspection, OSHA will look at the most relevant standard,” explained Davison. “R15.06 would be the most relevant. The 1999 standard applies to the manufacturer, the integrator, and the user. OSHA regulatory standards are required by law. They are not comprehensive. There are very few OSHA machine safety standards.”
Published in 2011, ISO 10218-1 & -2 are based on 1999 R15.06. The United States provided input to the ISO 10218 standards development. In addition, TS 15066, the technical specification probably coming out in 2015, addresses collaborative robot requirements and the issues surrounding robots on AGVs.
ISO 10218-1 covers the robot arm and its controller only, but no end-effector, while ISO 10218-2 addresses the entire industrial robot system and integration for the integrator, installer, and end user.
Users have a bit of a grace period before the new standard is enforced. During the transition, there's a choice of using either the 1999 R15.06 or new 2012 R15.06 until the end of 2014.
“The big changes in the 2012 standard are changes in terminology, risk assessment requirements, changes to fixed guard dimensions, and collaborative robot operations,” said Davison.
For terminology, a robot now means no end-effector and no programming, just the robot and controller. The robot system includes the robot with end-effector and any task equipment. The robot cell is the robot system and all within the safeguarded space.
Robot risk assessments were optional in the 1999 standard, but they’re now required. “Integrators shall provide the risk assessment results to the end user,” said Davison. “Risk assessment allows tailoring the system to the safety needs.”
Fixed guard dimensions have changed slightly but can be effected simply by dropping the old panel by 5 in. As for fixed guard clearance, the robot cell may utilize a smaller footprint for 2012 compliance as compared to 1999. “Clearance is only required if personnel will be exposed to pinching or crushing or trapping hazards when performing tasks, including teach and minor servicing,” explained Davison. “A collaborative robot is defined as a robot designed for direct interaction with a human within a defined collaborative workspace. This doesn't mean it’s a robot that doesn't require safeguards. The collaborative definition is designed so the person and robot are interfacing on specific tasks, such as a human loading a part onto a robot fixture. There have been some misunderstandings on the definition. Collaborative workspaces are the workspaces within the safeguarded spaces where the robot and human can perform tasks simultaneously.”
Four types of collaborative operation are explained. “First, during a safety-rated monitored stop, the operator may interact with robot and automation operation may resume when the human leaves the collaborative workspace,” explained Davison. “This requires safeguarding.”
Second, hand-guiding operation is allowed with various requirements to ensure safety. “The operator is in direct contact with the robot and is using hand controls to direct the robot where to go and what to do,” explained Davison.
“With speed and separation monitoring, as I move into an area, the robot will sense me and slow down based on predetermined distances,” he said.
The fourth type of collaborative operation, power and force limiting, covers when incidental contact may or is expected to occur, but not enough to incur injury, and it’s addressed in the forthcoming TS 15066.
“The big benefit of the new standard is global harmonization,” said Davison. “We no longer have a situation where you have to create one cell for the U.S. market and a different one for European or Asian market. We've got a lot more safety embedded into the robots now. We've shown savings in space and cost through some case studies. The functional safety concept provides a mechanism for validating safety circuitry. As the area of collaborative robot operation continues to grow, the standard will do its best to keep up. There is a provision for wireless teach pendants. We've identified the technology before the technology is ready.”
For a further update this fall, plan to attend the National Robot Safety Conference, Oct. 14-16 in Ann Arbor, Michigan. Find more information at www.robotics.org.