The Ergonomics of Automation

As an integrator for FANUC Robotics, North America, ESS has given a good deal of discussion to the advantages of increased productivity achievable when manufacturers automate their manual processes. A number of factors contribute to the increased production, including faster speeds, improved material handling, and reduced downtime associated with changeover. The ergonomics of automation are less widely discussed, but reducing workplace injuries also increases productivity and can save manufacturers thousands of dollars in lost productivity and worker’s compensation.

Ergonomic Injuries by the Numbers

According to the Bureau of Labor Statistics (BLS), “Musculoskeletal disorders (MSDs), often referred to as ergonomic injuries, accounted for 28 percent of all workplace injuries and illnesses requiring time away from work...[i] MSDs include sprains and strains, inflammation, degeneration, tears, pinched nerves or blood vessels, bone splintering and stress fractures. Repetitive motion injuries, such as carpal tunnel syndrome fall into this category as well.

A research paper published earlier this year, “An Ergonomic Investigation of the Case Packing Line at Company XYZ”[ii] provides a succinct analysis of the types of injuries and their impact on a manual case packing operation. The paper concludes that the most common injuries were associated with the wrist and the back.[iii] Back injuries are most commonly the result of improper lifting techniques; wrist injuries are caused by cumulative trauma disorders (CDTs), such as carpal tunnel syndrome and tendonitis. In this particular study, seven OSHA recordable injuries totaled more than $59,000 in workers compensation claims over a four year period.[iv] While the paper did not include data for manual palletizing processes, it is not hard to imagine a similar injury rate for that physically demanding process. Data from the BLS further underscores the lost of productivity due to workplace injuries, for example:

·         3,277,700 total reportable injuries; 965,000 of those injuries resulted in time missed from work

·         379,340 injury reports involved sprains, strains, and tears; 11% of those injuries (43,100) occurred to workers in the manufacturing industry

·         195,150 back injuries were reported; 10% (20,540) occurred to workers in the manufacturing industry [v]

The study of the case packing line concluded that, “The case-packing process should be further investigated in order to implement changes that will reduce the ergonomic risk factors currently present.”[vi]

Automation Solutions

Robotics automation offers a quick and relatively uncomplicated solution to reducing the ergonomic risks of both manual case packing and palletizing processes. Robotic case packers can quickly collate and load cases of product, and often these systems require less floor space than manual case packing stations. While the case packer still requires human intervention to run the machine and re-load the case magazine, the repetitive motions are handled by the robot, which cannot be injured.

Robotic pallet cells also require a human operator, mainly to operate the pallet jack to move pallets into and out of the pallet cell, but the robot handles the case lifting and stacking motions, again reducing the risk of injury to personnel. Even assembly and material handling processes can present an injury risk to employees. Assembly processes very often include repetitive processes that can lead to carpal tunnel syndrome or tendonitis, as can some material handling processes. For example, hand feeding a high speed blister packaging machine can require anywhere from one to six people to repetitively load blisters with product. Robots today have the dexterity needed for many assembly and material handling processes, allowing human personnel to be reassigned to duties that are less likely to cause injury.

Conclusion

Looking at the bottom line only, by reducing the risk of injury to their personnel, manufacturers can realize decreased downtime due to employee absence as well as decreased worker’s compensation costs. This may lead to increased profitability, which may, among other things, allow manufacturers to avoid relocating their factories to countries with lower wages in order to reduce overhead costs. Factor in the human equation and calculate the number of injuries not suffered by employees, and manufacturers can clearly see the ergonomic advantages of automating manual processes.

[i] Bureau of Labor Statistics (11/9/2010) “Nonfatal Occupational Injuries and Illnesses Requiring Days Away From Work, 2009.” Retrieved from http://www.bls.gov 10/14/2011.

[ii] Schmidt, J. (2011) An Ergonomic Investigation of the Case Packing Line at Company XYZ. Retrieved from http://www2.uwstout.edu/content/lib/thesis/2011/2011.schmidtjos.pdf 10/14/2011.

[iii] Ibid, p. 34.

[iv] Ibid, p. 49.

[v] Bureau of Labor Statistics “Latest Numbers.” Retrieved from http://www.bls.gov/IIF/ 10/14/2011.

[vi] Schmidt, p. 38.

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The Eyes Have It: Machine Vision and the Art of Pick & Place

A recent article written by FANUC Robotics about delta-style robots points out, “In an ideal world, parts line up and fit perfectly; however, in the real world work pieces often require a wiggle or visual adjustment.”[i] In pick-and-place applications, this is especially challenging. Hard automation requires relatively precise positioning in order for the system correctly pick and place objects. An offset of even a few millimeters can potentially cause a missed pick or a botched place. In high speed packaging machinery, this will cause a system stop. One solution to avoid this down time requires a pair of eyes and deft handling to quickly and correctly pick and place. Enter the vision-capable delta style robot. The combination a FANUC M-1iA delta-style vision-enabled 6-axis robot with a flexible conveyor system creates a highly reliable and fast pick-and-place system that requires very little floor space.

In picking applications, machine vision systems continuously take a snap shot of the product moving on the conveyor, which is often backlit to increase the machine vision’s accuracy. As the article explains, “When a product is identified by the camera, its location is combined with the current position of the conveyor belt. As the product enters a robot work area the robot is able to accurately move to the product and either pick it or work on it while matching the current conveyor speed.”[ii] This allows even oddly shaped objects to be accurately picked and precisely placed at high speeds. Space-hogging expensive bowl feeders can often be replaced with this type of system. ESS has successfully tested these robotic flexible feeding systems for picking and placing droppers, caps, plugs, wands, filter elements, cosmetic pans, ball bearings and more.

Assembly applications are also taking advantage of vision-enabled robotic systems. A six-axis M-1iA robot offers increased flexibility, allowing parts to be fed from the sides of the work zone, increasing the usable work space.[iii] The use of machine vision and flexible conveyors to handle the assembly components further reduces the floor space required for the system, allowing a wide variety of manual assembly processes to be automated. Manufacturers in a range of industries are beginning to embrace machine vision; in fact, ESS has conceptualized and/or manufactured assembly systems for medical devices, diagnostic test kits, filter assembly, cosmetic compact assembly, cap and wand sub-assemblies, and requests for proposals for these types of systems are on the rise. It’s easy to see how machines with vision offer a clear solution in pick-and-place processes.

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[i] Bruce, David. “How to Automate More Assembly Applications—The Delta Robot Advantage.” Assembly Magazine 18 May 2011. 18 August 2011. <http://www.assemblymag.com/Articles/Howto/BNP_GUID_9-5-2006_A_10000000000001050346>

[ii] Ibid.

[iii] FANUC Robotics America, Inc. M-1iA Genkotsu (fist) Robot. Rochester Hills, MI: FANUC Robotics America, Inc., 07/2009. Print.