MS Thesis Presentation by Eric Anderson
Tuesday, June 22, 2004
(Dr. Harvey Lipkin, Chair )
"Design of a Low Cost, High Speed Robot for Poultry Processing"
In poultry plants in the United States, a water chiller is used to chill WOGs (de-feathered birds without giblets). After exiting the chiller these birds are manually transferred from a conveyor belt to shackles for further processing. The current process is less than ideal. The labor pool for jobs such as these is continuing to shrink and labor turnover is a constant problem. The rates of repetitive motion injury reported are high and are continuing to rise. In addition, many poultry producers see this as a bottleneck in the process. Automation has the potential to alleviate these problems.
The high variability of this task, cost restrictions, and special design considerations associated with meat handling equipment make automation of this task challenging. Industrial robots have traditionally been limited to tasks with low variability. This task has high variability. WOGs are compliant bodies. They come in a wide variety of sizes and shapes. They are presented on the conveyor belt in a wide variety of positions and orientations. Most robotic automation systems consist of a commercially available industrial robot, a specialized end effector and a control scheme. The economics of this task prohibit the use of a commercially available industrial robot, as there are no industrial robots on the market that will offer a short enough payback. Robots have not yet been adapted to meat handling processes, and existing robotic designs are not well suited to the task. A meat processing robot must meet stringent USDA design criteria to prevent the robot from imparting any taste, color, bacteria, or foreign particles on the meat. In addition, a meat processing robot must be able to withstand the relatively hostile environment of a meat-processing plant.
The design of a robotic system for picking up WOGs and hanging them on shackles is broken up into three areas: specialized end effector design, robot design, and machine vision system design. This thesis presents the robot design.
In designing a low cost, high-speed robot for poultry processing the requirements of the robot are defined and a variety of robot architectures, constructions, and materials are explored. Simple modifications to the existing shackle and conveyor setup to make the task easier for a robot are also explored. After the robot requirements are defined a large group of possible designs are developed. The possible designs are systematically evaluated and/or eliminated until a single design is selected. The forward and reverse kinematics for this robot are developed. A singularity analysis is carried out. A proof of concept model is built. A prototype is modeled and a dynamic analysis of that prototype is carried out. The design is finalized based on the results of the dynamic analysis.