ATLANTA — At the 2016 B.&C.M.A. Technical Conference, held May 1-4 in Atlanta, Ben Sagan, business development manager, Mitsubishi Electric Automation, posed the question, “Can new technology advances in collaborative robotics be applied — safely, practically and profitably — to biscuit and cracker manufacturers?”
The first step in answering that question, he noted, was to balance risk versus rewards, asking questions such as how much experience the bakery has with robotics and who will be responsible for the integration. And while it’s important to know what to ask, it’s just as critical to know who should be asking — and answering — those questions.
|Ben Sagan, business development manager for Mitsubishi Electric Automation|
“I guarantee that no one person knows how everything is supposed to be working within a factory,” Mr. Sagan said, noting that oftentimes the engineering staff will have a set procedure, but the operations team will find new — creative, even — ways to adjust processes for unexpected glitches that happen upstream. “You always need to get everyone involved in the process because different people will have information that’s not always in one spot.”
Whether in assembly operations (such as with sandwich cookies), decorating and finishing, quality control, packaging or palletizing, safety is one of the biggest factors to consider with collaborative robotics. In fact, a collaborative robotics operation is only possible when all the required protective measures are active, Mr. Sagan said.
First of all, a bakery must understand what collaborative robotics means, as opposed to traditional robotic operations.
“Collaboration is when a person is working with a robot or sharing the same workspace,” Mr. Sagan said. “In order to have this process, you have to be able to predetermine the tasks. What does the operator do? What does the robot do?” This is critical to consider in terms of safety when collaborating with a robot on a specific task.
Safety comes into play first when replacing a person with a robot because many times, a collaborative robotic workspace may not be contained inside the fencing that a traditional robot would.
A bakery should first make sure a risk assessment is completed; this is often done by the integrator or a Robotic Industries Association (R.I.A.) safety inspector.
“The risk assessment should lay out the robot limits and identify hazards,” Mr. Sagan said. He suggested applying for the R15.306 technical form, which is accessible through the R.I.A.
While a person typically understands the safety considerations of the task at hand, a robot, at the most basic level, understands only the task itself. Robots need programming to ensure those safety considerations.
“You need to control speed, control force, control the area in which the robot operates,” Mr. Sagan explained. “Speed of control,” he said, is a situation where the robot is moving quickly, and it must be able to slow down, or even come to a stop, when a person is nearby.
Working collaboratively with a robot means sharing a workspace, and that means identifying the minimum clearance for trap or pinch points.
“You don’t want to have an operator walking into a work cell and have the robot pin him or her between it and a post,” he cautioned.
Work spaces, or “blocks,” must be established in order to keep operator and robot functioning safely together. A worker should have a clear understanding of his/her domain versus the robot’s domain. Scanner systems and light curtains are useful tools to accomplish this.
“When a worker is in one zone — outside the light curtain — the robot will be running at full speed,” Mr. Sagan said. “But if you enter through the next area, the robot will slow down, and if you enter through the next one, it will stop.”
These zones must be determined based on how quickly a person can, and will, move, as well as the speed, position and torque of the machine. So the programmer must calculate how fast a person can move versus how much time it takes the robot to slow down or stop in order to determine the correct distance before an unsafe condition occurs.
Simulation and testing are important in gauging not only the effectiveness and efficiency of a robotic line but also the safety considerations, and robotic integrators are available to assist in properly implementing a collaborative robotic system that is both effective and safe.
“Don’t just buy a robot and think, ‘I can do this myself,’” Mr. Sagan said. “Allow your first application to be low-risk with a higher reward, and get an integrator to do it. There are many things in the process that are important to understand, especially from a safety standpoint.”Mr. Sagan suggested using resources such as the R.I.A. for guidance before implementing a collaborative robotic system.