Hybrid material-handling robot facilitates poultry processing

Scientists at the Georgia Tech Research Institute (Georgia Institute of Technology, EOEML/IMB, MARC Bldg., Rm. 335, Atlanta, GA 30332) are developing a new breed of robot that will help increase efficiency and competitiveness in 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 for this is that robotic systems on the market aren't completely compatible with poultry needs.

Existing robotic systems tend to be too complex, which makes them expensive to purchase and maintain. Compounding the problem, the industry needs robots that can withstand the rigors of the food processing environment, which typically add to their cost. Although poultry plants are using simple forms of fixed automation, these systems have very limited capabilities. The goal of Georgia scientists was to develop a low-cost robot that could perform materials handling tasks with the same speed and dexterity as a human.

Enter the Intelligent Integrated Belt Manipulator (IIBM). 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 and was attractive because of its low cost and ease of use. Its speed was good, but accuracy was not up to expectations. The prototype fluctuated up to an inch in position when picking up items. The robot could 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 the poultry business, products vary considerably in size and shape, making grasping demands another challenge for the IIBM. Physical dimensions of a tray pack remain constant, but the poultry pieces inside vary the contours of the package's top by as much as 2 in. The IIBM's end effector had to be constructed with some flexibility. Suction cups made from bellow material compress up to 0.75 in. 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 facility in Gainesville, GA. Speed and accuracy are the main focus of the field test, and early results have been encouraging. In lab trials, the IIBM's average cycle time was clocked at 2.1 sec, 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 pickups have been almost nonexistent in the plant trial.

Researchers hope to have the technology commercialized within the next two years. Preliminary discussions are already being held with companies. The next step is to enhance the system with a vision system that 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.

Further information. Gary McMurray; phone: [phone]; fax: [phone]; email: [e-mail].