How to ensure safety during industrial robot operation
The first law of robotics: a robot may not injure a human being or, through inaction, allow a human being to come to harm. Isaac Asimov’s three laws of robotics are a cornerstone of sci-fi literature, but the unfortunate truth of modern industrial robots is that they are too dumb to obey these laws and are very dangerous for humans to be around. The common saying is, “this machine has no brain, use yours”. Robot safety, especially with an industrial robot, has an excellent record in the US. Robot accidents happen about once a year, but the bad news is that most of those accidents have ended in deaths.
Robot safety has to be taken seriously. Most robot-related injuries occur during non-routine tasks. The particularly dangerous times are during installation, maintenance, and troubleshooting activities. Patrick Davison, the Director of Standards Development for the Robotic Industries Association, recently identified four OSHA provisions that were essential to robot safety during programming, maintenance, testing, setup, and adjustment:
- Control of Hazardous Energy (lockout/tag out)
- Risk Assessment
Let’s review the discussion on these four areas.
Industrial Robot Lockout/Tagout
Lockout/Tagout refers to OSHA Standard 29 CFR 1910.147. This safety standard is designed to prevent injuries due to the unexpected startup of energized equipment or the sudden release of stored energy during robot maintenance. At its heart, this standard requires the removal of any hazardous energy source associated with the machine before maintenance begins. This process can include electrical plugs, pneumatics, hydraulics, tensioned springs, and plant air. Then the machine is placed under a lock so that nobody can power up the energy source without removing the lock. Finally, a tag is placed on the lock that designates who put the lock, so that only that individual can unlock the power source. Unfortunately, dangerous situations are not so easily secured. Many maintenance conditions require that the machine has power, and many of these situations occur during breakdowns where there is no plan and no clear solution. These conditions require extra vigilance on the part of the worker.
Industrial Robot Safeguarding
Poorly designed machinery and cells are significant risk factors for workers, especially those that perform maintenance. Workers need adequate access to perform maintenance, and it’s critical that they don’t have to combat the machine’s safeguarding to do this. If a particular safeguard prevents the user from running the machine the way the want to, they will try to defeat that protection. It is important then to make sure that all operators understand why safeguards are in place. But it is also critical to ensure that any protection does not end up being an obstacle to safe maintenance. All safeguards need to be designed to allow easy access to relevant components with the necessary power. Robot cells must be designed with the human element in mind.
Risk assessment is one of the most important safety principals, one of the key OSHA provisions, and a critical part of the ANSI/RIA robot safety standard. Risk assessment’s importance cannot be stressed enough. Risk assessment can follow several forms. One of these is Task-Based Risk Assessment. OSHA recognizes TaBRa is an a methodology that focuses on the kinds of tasks that are required, routine and irregular, and the risks that are associated with those functions. TaBRA is a fundamentally different form of risk assessment because it involves understanding the tasks of ALL workers and asking the right questions about them. Instead of approaching safeties and hazards from a top-down direction, which would include experts dictating hazards and safeties, TaBRA approaches risk management from the bottom up. By understanding the perspective of the worker, and understanding what work has to be done and the real conditions it is done under, TaBRA can construct a realistic picture of Risk Assessment that shows the risk environment as it really is under day-to-day, real-world conditions.
Industrial Robot Training
Training makes the difference on the floor. Knowing safe operating procedures is of critical importance. A well-trained worker will be able to identify a machine that stops as a regular part of the operation and a machine stopped due to a fault. The knowledge of when it is and isn’t time to intervene, and subsequently how to speak safely is incredibly important for workplace safety. The responsibility of training starts with the integrator, who in turn has to train the end-user of the robot. Clear communication and feedback are absolutely key. The operator has to know what the machine is and isn’t designed to do, what it’s accomplished of doing, or in other words, why it is so important that they follow procedure. This level of training will keep the machine affordable, useful, and safe.
Safety and Responsibility
Everybody has their role to play in ensuring that robots are safe. From the design of the robot to the layout of the cell, to the training of the operators, robot safety is a comprehensive and ongoing multi-level activity.
ICR can help determine the right used robot for your applications. We can provide turnkey systems including all mechanical and electrical engineering, design/build/install EOAT (end of arm tooling), integration to existing machines and processes, robot programming, field service, start-up assistance, spare parts and robot training.
Request a quote or phone us at (866) 9-Robots to speak with a robotic specialist today.