Georgia Tech Research News - April 1998
Hatching a Robotics Revolution
Hybrid material-handling robot helps poultry processing industry
 Georgia Tech researchers are developing a new breed of robot that will
help increase efficiency and competitiveness for the poultry industry.
Robots have been a boon in the automotive and electronics industries
for many years, but the food industry ¯ particularly poultry processing ¯ has
not embraced this type of flexible automation.
"One reason is that robotic systems on the market aren't completely
compatible with poultry needs," said J. Craig Wyvill, director of Georgia
Tech's Agricultural Technology Research Program. "Existing robotic
systems tend to be overkill. They're too complex, which makes them expensive
to purchase and expensive to maintain. Compounding the problem, the industry
needs robots that can withstand the rigors of the food processing environment
which typically adds to their cost."
Food Industry Has Unique Robotics Needs
Many jobs in poultry processing consist of materials handling tasks,
such as moving product from a conveyor belt to a box or another conveyor
belt ¯ areas where robots are ideal substitutes for human hands. Although
poultry plants are using simple forms of fixed automation, these machines
have very limited capabilities.
"
Our goal was to develop a low-cost robot that could perform materials
handling with the same speed and dexterity as a human," explained Gary
McMurray, a senior researcher in the ATRP and a project director for the
robotics initiative.
Enter the Intelligent Integrated Belt Manipulator. This robot tackles
a common food industry task by removing items from a conveyor belt and transferring
them into a packing carton for shipping.
The Intelligent Integrated Belt Manipulator (IIBM)
Conceived in 1992, IIBM has gone through several redesigns and refinements
over the years. The first-generation robot was powered exclusively by pneumatics,
attractive because of its low costs and ease of use.
"
Speed was good but the accuracy was not up to expectations," said McMurray,
noting that the prototype fluctuated up to an inch in position when picking
up items. Although poultry processing requires less accuracy than, say,
chip insertion in an electronics plant, "an inch was still too much," noted
McMurray. The robot could still pick up product, but might misplace it in
the shipping carton.
The new IIBM is a hybrid of pneumatics and electro-servo drives. Two
pneumatic axes and two electro-servo axes allow motion in four different
directions: up and down, parallel with the conveyor belt, perpendicular
across the conveyor belt, and a 90-degree rotational pivot.
In automotive and electronics industries, parts are consistently shaped
and easy for robots to handle. Yet in the poultry business, products vary
considerably in size and shape, making grasping demands another challenge
for the IIBM. Physical dimensions of the tray pack remain constant, but
the poultry pieces inside vary the contours of the package's top by as much
as two inches, causing weight and center of gravity to shift.
"
Therefore, the IIBM's end effector had to be constructed with some flexibility," added
McMurray. Suction cups made from bellow material compress up to three-quarters
of an inch; a spring mechanism attached to the suction cups provides another
inch of compliance, allowing the grippers to conform to different contours
of product.
Factory Testing Shows Good Results
After four months of lab testing, the current IIBM prototype has been
sent to the factory floor in a ConAgra (producers of Butterball and Country
Pride products) plant in Gainesville, Ga. Speed and accuracy will be the
main focus of the field test.
Early field test results have been encouraging. In lab trials, the IIBM's
average cycle time was clocked at 2.1 seconds ¯ comparable with a human
worker ¯ and the research team has been able to sustain this time in
the plant. More importantly, the pick-up rate of the robot has improved
significantly. During lab testing, the robot occasionally would drop a tray
pack, but missed pickup has been almost non-existent in the plant.
Besides cutting costs, the IIBM is attractive because it is simple both
to install and maintain. To get the IIBM up and running, only a few physical
dimensions must be programmed such as the size of tray packs, the location
of packing cartons, and the height of the conveyor belt. In contrast, traditional
robotic systems require as many as 300 positions to be programmed individually. "Most
food processing companies don't have the technical base to support that
type of machine," said McMurray.
Wyvill hopes to have the technology commercialized within the next two
years. Preliminary discussions are already being held with private companies.
And this prototype is merely the beginning, stressed McMurray. "The
IIBM wasn't created to perform just one materials handling task, but rather
to demonstrate the cost-effectiveness and flexibility of automation for
the poultry industry."
His next step is to enhance the system with a vision system. This vision
system would help develop hand/eye coordination for the robot and allow
it to operate by merely seeing a picture of the product, eliminating the
need for task-specific software and programming.
IIBM Creates a Better Work Environment for People
Does this mean a triumph of machine over man? Hardly, says Wyvill, adding
that robotics is not about making humans obsolete. Indeed, flexible automation
creates a better workplace for humans by upgrading job skill requirements
to a higher level.
"
The nice thing about this type of automation is that it can eliminate
low-skill labor activities which the industry has the greatest difficulty
filling on a day-to-day basis," observed McMurray.
There's also the issue of safety concerns. Many of these jobs are highly
repetitive, putting workers at risk for cumulative trauma disorders such
as carpal tunnel syndrome. Automation can reduce injuries. The job that
the IIBM performs is a very repetitive motion, observes Wayne Painter, plant
maintenance engineer at ConAgra in Gainesville.
"
The IIBM shows a lot of potential," said Painter. "This machine
would address a lot of ergonomics issues ¯ and we're interested in
anything that can reduce the amount of stressor jobs." |
