At IMTS this month, Steve Alexander, vice president of Wisconsin operations and standard products at Acieta, dispelled common myths about collaborative robots for industrial applications. He discussed them during his presentation, “Is Now the Time to Get a Cobot?”
The answer increasingly is “Yes” for a broadening array of applications, said Alexander. Cobot arms can increase productivity and throughput, consistency, employee retention, floor space, and lead times. They can also reduce maintenance costs, scrap parts, and repetitive motion injuries. In addition, cobots can mitigate the skills gap and training challenges, he said.
From concerns about costs to their utility for small production runs and potential threats to jobs, Alexander responded by examining several hidden or unquantified factors (see figure above) for calculating cobot returns on investment (ROI).
He listed three robot myths as:
- Robots are expensive and hard to justify during uncertain times: In fact, hiring and retaining talent, especially for repetitive jobs that can be prone to injury, can be difficult and costly. The cost of onboarding can be 30% the first year of salary.
- Automation is only for high-production jobs: Technology has simplified the process of automation, especially with collaborative robots, making small part runs more efficient and setup faster. Using automation is easier.
- Robots steal jobs: “I don’t know why we still hear this,” Alexander said. Companies have found that they need more people to handle the increased product production created by robot use. “Robots create a virtuous circle of investment and growth,” he said, showing an A3 chart showing that industrial robot shipments coincided with decreasing U.S. unemployment.
Cobots can boost flexibility and productivity
Alexander also provided multiple examples of collaborative robots increasing customer productivity, including the use of one cobot for multiple tasks in a manufacturing facility with high-mix, low-volume production.
With low unemployment, Hytrol needed automation to help meet customer demands. In this application, a robot picked a raw sheet of metal, picked components, moved the product to a bending cell, and then to a welding cell before the finished product exited the work area.
By combining six workcells into one, the automated application cut floor space by 80% and reduced human footsteps and forklift traffic, lowering risk. It also added 50% capacity, lowered lead time, and increased marketplace competitiveness, Alexander said.
Is my application good for a collaborative robot?
Collaborative robots are typically more flexible than industrial automation and can effectively handle smaller jobs with higher variability, according to Alexander. He said he is often asked, “Is my application a good fit for a cobot?”
These applications can include pick and place, packaging, palletizing, machine tending, material handling, fabrication and welding.
In load and unload CNC machine tool applications, Alexander cited increases from cobots of 82% to 19.3 parts per hour, 66% to 21.3 parts per hour, and 96% to 72 parts per hour.
Bundles of automation created for specific uses include:
- A flexible cell to help machine shops and fabrication shops can be useful for rework and even small batch runs (see video below). Skilled welders welcome robotic aid for redundant, lower-value work, saving welding time and expertise for more skilled work.
- A standard collaborative machine tool cell can help with gauge, saw. and machine tending and coordinate measuring machine (CMM) tending.
- A standard collaborative expandable cell can assist with polishing, material removal, sanding, and edge breaks.
Collaborative robots are easier to program, often by teaching the robot where it needs to go by physically moving the robot arm as needed, Alexander noted.
He described an application where two robots grab parts and a press joins two parts. Light curtains separate the press from the cobot and human area. Some robots can be taken out of collaborative mode to go faster.
Because force and speed limits the speed to 1,000 mm/sec (2.2. mph) in collaborative mode, a human can be faster. However, a cobot’s efficiency was higher, with no breaks and providing higher throughput, a 36% productivity increase compared to a human.
Cobots can thus lower the risk of repetitive injury and boredom, Alexander said. He showed applications, quantified labor savings, and specific applications, including a cobot welding workcell.
Applications vary, but most collaborative robot installations have return on investment (ROI) of 18 to 24 months, said Acieta‘s Alexander.
Safety measures depend on the application
Collaborative robots may be considered safer than industrial models because they are force- and speed-limited. However, they may still cause harm in certain applications requiring protection for humans, their environment, and themselves.
Always perform a risk assessment when using robots because even with collaborative robots, applications may require additional safety protections, such as those with:
- Extremely short cycle times
- Sharp objects or edges, such as sheet metal
- Hot parts
- Height of motion, to avoid human heads
- Grippers, which may not sense and stop in case of a human finger
- Other clamping devices or pinch points that could harm
- Peripheral equipment in the application or work area, which may not include safety measures designed into collaborative robots
Economy presents more collaborative robot opportunities
Alexander cited two megatrends that justify development and adoption of collaborative robots:
- U.S. gross domestic product is expected to increase 40% in the next 10 years, with an expected 1% labor pool increase during the same period, likely to increase industrial skills-gap challenges.
- China demographics suggest 150 million fewer people in labor the Chinese labor force in the next 10 years, which creates opportunities for reshoring additional industrial production to the U.S.
Editor’s note: This article was syndicated from Cobot Trends sibling site Control Engineering.
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