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."
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.
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.
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.
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."