| Publications |

Volume 9, Number 1, Spring 1997

Topic for this issue: AUTOMATION

Wearable computer promises to revolutionize poultry plant communications

Future technologies will enhance poultry operations

Designing robots for the poultry industry: ATRP researchers turn to academic experts for help

Military technology adapted for visual product inspections

Advanced sensors improve efficience

1997 Poultry Show a success!

 

Wearable computer promises to revolutionize poultry plant communications

Georgia Tech researchers have developed a wearable computer system for the poultry industry. The wearable computer is similar to a standard desktop computer, but in miniature size. It allows plant workers to enter and receive information from anywhere in the plant. Georgia Tech researchers are currently field testing the system and planning for future improvements.
A quality assurance worker on a poultry plant floor inserts a probe into a passing chicken breast to measure its internal temperature, but instead of taking the time to pick up a clipboard and write down the information, he simply says the temperature aloud. A tiny microphone on the worker's headset (similar to a telephone operator's) transmits his voice data to voice-recognition software on a small computer that the worker comfortably wears on his hips. This wearable computer records the temperature into a computer database file and instantly transmits the file over a wireless communications link to quality control's computer. The quality assurance manager taps at her computer keyboard and the product temperature data she needs to complete an important quality assurance report instantly appears on her computer screen. Does this sound far-fetched? Georgia Tech researchers don't think so. They have developed a customized wearable computer system for the poultry industry that does just this.
Poultry processing today requires powerful knowledge bases and timely information to maintain efficient operations. Floor managers often need immediate access to information from other areas of the plant to make more-informed decisions, yet that information may not be available when and where they need it. Wearable computer technology allows a worker on the plant floor to enter and receive information in real time (real time means making information available at the time and place it is needed). In doing so, the system also provides plant management with the latest operations data about what is going on in the plant. This technology promises to be a powerful tool in keeping a plant running smoothly in this era of Hazard Analysis Critical Control Point programs and statistical quality control.
Computer design
The Georgia Tech design team includes an industrial engineer, a human factors engineer, and computer specialists who designed the computer system with user comfort, ease of use, and low cost as priorities. Drawing from each of their fields of expertise, the team members integrated existing hardware and software technologies to develop the wearable computer.
The wearable computer consists of all the major components of a standard desktop computer, but in miniature size. A user wears the computer (about the size of a portable cassette player) on a padded adjustable belt. A battery pack to power the computer also fits on the belt and can be bent slightly to fit comfortably on the user's hips. The battery lasts four to six hours and can easily be replaced while the computer is running. A user also wears a headset consisting of a microphone for voice entry, an earphone for audio feedback, and a tiny computer screen for visual interaction. Combined with customized applications and a wireless communication system, the computer allows a user to enter and receive hands-free information from virtually anywhere in the plant.
Voice entry of data was a key feature deemed important to system success. Yet plant noise levels in operations areas presented serious challenges to voice recognition. "We had to evaluate a number of commercial speech recognition systems to find one that worked well in such an environment," says Chris Thompson, Georgia Tech research engineer. The team tried to replicate the particular noises of a poultry plant but found this difficult in a laboratory environment, so they relied more heavily on their tests in the plant.
As user comfort is a big concern for the design team, balancing the tradeoff between battery weight and performance is important to the design process. The team now uses a nickel metal hydride battery that lasts approximately five hours and can be comfortably worn for a length of time by a user. Lithium ion batteries are available that give higher energy per weight and can last five hours longer than the nickel metal hydride battery. A major drawback, however, is that if mishandled, lithium ion batteries can catch on fire. The team is continuing to look for more efficient and safe batteries.
Initial field trials underway
" The wearable computer system could transform how daily operations take place in a poultry plant," says Thompson. "We are currently field testing the prototype at Cagle's plant in Camilla, Georgia to see how it performs on quality control data entry."
" It is very exciting what this type of system could do for our quality department as well as many other areas of the plant," notes Milton Lowry, Quality Manager at Cagle's plant. The design team has generated several of the plant's quality control forms in electronic format. This has required some ingenuity by the designers because the information must be brief and readable on the small computer display screen yet connected just as it is on the printed form.
Thus far, field tests for recording temperature data from products into the wearable computer have gone smoothly, and Thompson anticipates this will be an attractive use of the wearable computer in poultry plants. In the next phase of field testing, Thompson's team will evaluate how easily poultry workers are able to use the computer system. Cagle's employees will use the computer system in their plant operations and provide feedback to the Georgia Tech team.
Future Improvements
As computer hardware continues to get smaller and lighter, Thompson says the wearable computer may one day fit in a shirt pocket. Voice recognition technology also continues to improve, so the wearable computer will be able to more clearly identify what a worker is saying in a noisy environment such as a poultry plant. The tiny monitor is currently black and white, but the wearable computer will incorporate a color headmount display as these decrease in price and improve in performance; color displays currently cost three times as much as monochrome displays and are typically lower in resolution. Batteries also continue to improve and will likely weigh less and last longer in the future.
Thompson and his team are also looking at other potential enhancements to the system that include adding video capability and supporting the maintenance function in plants by providing not only databases at the plant level, but also longdistance real-time linkages with equipment manufacturers and experts anywhere in the world.
Beyond the poultry industry, the National Aeronautics and Space Administration (NASA) has expressed interest in using the wearable computer for technicians who perform maintenance on the space shuttle. The airline industry may also be interested in it for technicians who repair aircrafts.
In the future, wearable computers may routinely be used to provide multimedia information in the form of text, graphics, video, sound, and animation to mobile workers as they actually perform a task. Other applications of the technology will likely develop as poultry processing plants become more automated.

 

Future technologies will enhance poultry operations

In the poultry processing plant of the future, machines will communicate with each other and automatically adjust their own controls for better performance. Human workers will track quality control automatically using data transmitted from machines and plant floor workers and, with a few keystrokes, control plant operations. Such futuristic plants may be closer to reality than you think. Advances in automation technology promise to drastically change how poultry plants operate in the coming years.
Computers will likely allow control and monitoring of equipment operations automatically, with human workers overseeing these operations and supervising control strategies. The days when human workers have to manually change machine settings on processing equipment may soon be a thing of the past. For example, when a plant cooks a product, different pieces of cooking equipment will be able to communicate with each other about the condition of the product. If sensors indicate a ready-to-eat product needs more salt, a transmitter will send a radio frequency signal to a device that will automatically add more salt to the product. If a temperature-reading device finds that cooking operations are not hot enough, the device will signal an oven or boiler to increase its temperature. These automated interactions between pieces of equipment will increase the productivity of the plant and will also allow more time for the human work force to check quality and maintain operations for optimal performance.
Although maintenance of such equipment will pose greater challenges, it will also become more automated and easier for workers to perform because processing equipment in the future may have a computer screen built right into the piece of equipment itself. This screen will display information about the piece of equipment such as repair manuals, possible causes of maintenance problems, or step-by-step multimedia (text, drawings, animations, video, and sound) instructions for repair tasks that will aid workers in its maintenance. Other smart technologies built into equipment will also help workers in daily operations.
In another use of the latest electronic technologies, plants are already beginning to take advantage of electronic information both with one another and with suppliers and distributors. This activity can be expected to expand greatly. For example, information about a growout flock about to be delivered to a processing plant could be automatically transmitted the day before the flock is picked up so that the processing plant has a profile on average weight, health, potential risk of pathogen contamination, and the like before the flock arrives. This would better prepare the plant to handle that flock.
Much of this technology is either emerging or already available. Poultry plants must focus on finding ways to economically incorporate them into daily operations. As the industry becomes more sophisticated, daily operations should become less labor intensive, with technology improving efficiency, productivity, and competitiveness.

 

Designing robots for the poultry industry: ATRP researchers turn to academic experts for help

In their development of a human-level performance robot for the poultry industry, ATRP researcher Gary McMurray and his research team (which includes several graduate students and professional engineers) have called on the expertise of academic professors Kok-Meng Lee and Harvey Lipkin - recognized experts in the fields of robotics and dynamics - to help them develop new ways of designing and controlling robots. This collaboration between ATRP researchers with their practical expertise and academic experts with their more specialized expertise is helping ATRP researchers tackle more effectively the challenges that affect the ability of robotics technology to be used on a processing plant floor.
A specially designed robot for the poultry industry
For the past several years researchers in Georgia Tech's Agricultural Technology Research Program have been working to advance robotic technology for the poultry-processing floor. Some industries have benefited from robots on the manufacturing floor for some time. Industries that have been successful in using robots are those that make parts that are consistently shaped and easily handled - such as automobile parts and electronic printed circuit boards. The poultry industry, however, has parts that come in all shapes and sizes, that are soft and deformable (and hence, not easily handled), and that can be damaged if not handled appropriately.
A robot for the poultry floor, then, must be able to
  • identify what type of part it must pick up;
  • identify where that part is located;
  • grasp products of varying sizes;
  • change its gripping strength so that it doesn't damage the part;
  • withstand the environment of the processing plant, which includes washdowns.
Traditional robots designed for other industries just haven't met these requirements at a price that would make their introduction onto the poultry floor economically justifiable.
According to ATRP researcher Gary McMurray, human-level performance robots are a possible solution. Human-level performance robots are designed to approach tasks with human-like capabilities. For example, humans are smart: they don't have to be programmed (told how to do each task) as a robot does because humans can learn. Furthermore, humans are extraordinarily successful at pick-and-place tasks: humans can see where objects are and can adjust their motions to pick up a moving object, like a poultry part on a conveyor belt. And humans are adaptable: their body designs let them perform many different types of tasks.
The ATRP research teams have set out to design robots that would incorporate many of the features that we humans take for granted in performing varied tasks - intelligence, adaptability, and vision. The research teams are currently working on two prototypes - the IIBM (Intelligent Integrated Belt Manipulator) and a visual servo unit. Developing such robots has recently brought together researchers in GTRI's ATRP program and Georgia Tech academic experts in the fields of robotics and dynamics. Together, they have forged strong collaborations to meet some of the challenges that developing human-level- performance robots presents.
The IIBM
One prototype robot - the IIBM - that McMurray and his ATRP team have developed over the past two years includes many human-level-performance attributes. For example, the IIBM has an end effector - its hand - that has suction cups for picking up tray packs. This end effector can change its shape and the pressure it exerts to compensate for varying sizes of tray packs, much as a human hand would. A tracking system is used to provide "eyes" for the robot, allowing it to identify different types of products and their location on the conveyor. This information is then transferred to the robot to allow it to move to the correct position to manipulate the part.
The robot arm, to which the effector is attached, can move in three directions. It can move along a horizontal beam 60 inches long; it rotates plus or minus 165 degrees, allowing the robot (after the end effector has grasped the pack) to orient the tray pack inside the box; and the end effector can move up or down 5.25 inches. When the IIBM is placed over a conveyor belt, the robot's arm can move along the beam to position itself over a tray pack, rotate to be in the proper position to pick up the tray pack, and lower the end effector to pick up the tray pack. The robot then places the tray pack in its proper position and orientation in the shipping case.
In their previous tests of the system, McMurray and his coworkers had achieved an 0.6-second move along the horizontal beam and a 1.5-second-per-pack cycle time, with 22 inches of movement in the horizontal, 5 inches in the vertical, and 90 degrees of rotation. The researchers felt that the robot had the potential to perform tray-pack operations under plant conditions. McMurray notes, however, "The system vibrated under certain conditions, and we felt we needed higher speeds. We needed to develop some new-and-improved control algorithms, and we needed an expert in this area. Dr. Kok-Meng Lee with Georgia Tech's School of Mechanical Engineering had the expertise we were looking for, and he had ideas on how to solve the issues." (Algorithms are the equations that produce the control signals to move the robot, based on the data received from the robot's sensors.)
Solving problems with the IIBM
McMurray was concerned about the robot's tendency to vibrate if it moved beyond a certain speed. Dr. Lee involved one of his graduate assistants, Chad Rutherford, to do the modeling on the IIBM robot's horizontal motion under Dr. Lee's guidance. This is the most time-critical motion and the most complicated drive system of the robot's movements. Rutherford worked with what is called a frequency-reshaping algorithm, which achieved two important goals, according to McMurray: first, it improved the cycle time of the robot, decreasing the standard horizontal motion to under 0.5 seconds; second, it was able to make the robot less likely to vibrate.
To achieve these goals, Rutherford needed to model the physical parameters of the robot. For example, the robot does not uniformly accelerate and decelerate - it starts off slowly, rapidly accelerates, and then decelerates before picking up the package. The model needed to incorporate the friction of the parts against each other, the motor design, and the way the system itself is built - all of which affect how the robot performs. Rutherford, under Dr. Lee's guidance, was able to create an experimental model over a small range of inputs that took into account all the physical parameters. "This model, which was accurate over a small range, served as a benchmark for the more complete theoretical model that Rutherford developed as part of his master's thesis," McMurray emphasizes.
Next, Dr. Lee and the research team, of which Rutherford was now a part, constructed a complete theoretical model for all the elements of the drive system. The model of the elements was based on the manufacturer's data for the motors, gear boxes, and the oil- filled bearings, for example. However, McMurray explains that many of the elements of the design had to be modeled by the team. He sighs, "There was a lot of tedious modeling of the elements, such as the damping effect of the oil-filled bearings." (Damping is the resistance that the part encounters during operation.)
The research team put all this information together using a mathematical package called MATLAB™. McMurray and the team were delighted with the results: "We were able to model the robot system in complete detail and to get the complete mathematical model to agree with our experimental data, which is a major triumph. We can actually model the robot under any circumstances that we want and start changing components in the model. For example, if I want to change out the gear box, I can put a new gear box in the model and see how it would affect the system almost as if I were physically running the system. We can make all kinds of changes to optimize the system without the tedious, time-consuming, and limited experimental trials." What the model also allows the researchers to do is to try out the control algorithms - the various control ideas - in real time and see how the robot would perform. Through modeling, the research team can simulate a wide range of operating conditions, some that could potentially damage the robot or cause excessive wear and tear under real-world test conditions.
Improving performance on the visual servo robot
McMurray and his team not only were interested in solving the issues associated with the IIBM but also had begun another project to improve the sensor inputs of robots (their "eyes") in general. McMurray and his coworkers wanted to mimic the sort of hand-eye coordination that a human uses in performing tasks.
McMurray notes how important this sort of research is to overcoming some of the limitations of placing robots in food processing plants: "Robots are traditionally blind machines that are preprogrammed to move from point 'a' to point 'b' in a very fast, accurate manner. If the part is outside of its preprogrammed position, the robot assumes that the part isn't there, and the robot doesn't know what to do." McMurray cautions that food products can vary in position, orientation, size, and sometimes product type: in a poultry processing plant, for example, product can come down mixed - wings and thighs. To cope with what would be a perplexing situation for a robot, a human just looks down at the part and picks it up in the appropriate manner.
McMurray and his research team are developing a system so that the robot can "see" the way a human does and respond accordingly - it could adjust its movements based on what it "sees." The human looks at his/her hands, looks at the target (the piece of poultry), and moves based on what he/she sees. The person makes small corrections as he/she moves and as the part moves. Unfortunately, current robots can't match this level of flexibility and adaptability .
To try to incorporate these attributes into robots, McMurray turned to Dr. Harvey Lipkin with Georgia Tech's School of Mechanical Engineering for his controls expertise and background in kinematics (the study of the motion of mechanisms). As a graduate student, McMurray had worked with Lipkin, and they had maintained interest in each other's research projects over the years. Lipkin agreed to serve as a mentor to two graduate students, Jenelle Piepmeier and Rob Biro, who were part of the ATRP research team. Their task was to design the control algorithms and to build a small concept robot that would be controlled by these new algorithms.
McMurray stresses the importance of the research: "If we can develop this visual servo robot and control algorithm, we can start building low-cost robots because we don't need the incredibly accurate joint sensors and the rigid construction that drive up the cost of current robot technology." He states, "What we are trying to build is a low-cost, simple, slow robot that will have varying joint lengths and inexpensive, low-accuracy sensors. We will be demonstrating the robustness of the algorithm under the varying kinematic changes in this type of robot."
Biro, under Lipkin's guidance, is currently designing the prototype. His design consists of a horizontal robot with three degrees of freedom (three movements), all rotation axes. It is a very simple mechanism that can actually be adjusted to have various joint lengths. This type of adjustment would be analogous to a human's being able to change the length of the arm from the elbow to the wrist to pick up a pencil, McMurray explains. Biro plans to test the varying lengths of the robot's "arm" to see how the robot manages the changes.
Piepmeier, also under Lipkin's guidance, is working on the algorithms that can control such a visual servo robot. She is investigating simulation work performed by previous researchers, identifying (with Lipkin's assistance) limitations in the previous research and current theory, and making suggestions for improvements.
McMurray compares the theory with which they are dealing to the complexity of downhill skiing: "Imagine that you are at the top of a very difficult ski slope and are trying to get down to the base. You can't map the entire way down the ski slope because you can't see the entire terrain. As you start to move, your algorithm needs to be able to guide you down that path (and keep the base in sight) without misleading you down false paths. The current algorithms we are using are one-dimensional, but our ski problem is a three- dimensional problem. Our one-dimensional algorithms work well in a limited small area; but if we have a big area like our ski slope, then the algorithm begins to fail. For example, imagine the ski slope with a sudden drop that you can't see until you've gone over it - we have a problem like that with our current algorithm: we call it a singularity position. So we have to keep the robot's motions very small and examine very small portions at a time."
McMurray, coordinator of the project, and his academic collaborators hope to begin constructing the prototype this summer and start testing some of the controls in the fall. The visual servo robot could add the versatility of the human to the robot through incorporating a type of human vision. McMurray is enthusiastic about the visual servo design: "This type of robot, with its ability to see and handle products in an unstructured environment, combined with its potential low cost, could have a major impact on the poultry-processing floor."

 

Military technology adapted for visual product inspections

Georgia Tech researchers are using computer simulations to mimic the way human visual processes determine if a poultry product is defective. The research is based on a model of human visual processes developed by a team of GTRI research scientists to help the U.S. Army and Air Force identify tanks on rural and urban landscapes. This technology has strong potential benefits for the poultry industry, since it provides an opportunity to speed up the inspection process while maintaining a higher degree of consistency and accuracy.
Georgia Tech researchers are adapting computer technology developed to detect helicopters and tanks that are located in the midst of clutter to the quality-control needs of the poultry- and food-processing industries.
The research is still exploratory, but scientists and engineers at the Georgia Tech Research Institute (GTRI) have made progress in getting a computer simulation of a human quality inspector to distinguish between defective and first-quality poultry products and fruit products.
The computer simulation used in this project mimics the way human visual processes pick out targets against cluttered backgrounds. It reviews a series of images of food and poultry products photographed by a camera. With the help of previously stored calculations concerning color, shape, and texture of poultry or fruit, the computer determines if the product is defective.
The simulation is based on a model of human visual processes developed by a team of GTRI research scientists, headed by Dr. Ted Doll, to help the U. S. Army and Air Force identify tanks on rural and urban landscapes. The team has been looking for ways to apply the Georgia Tech Vision Model (GTV) to an industrial processing operation. Product inspection is an ideal use of the technology because this task involves "looking" for defects just as human workers do. Computer automation has strong potential benefits for the poultry- and other food-processing industries, since it provides an opportunity to speed up the inspection process while also maintaining a higher degree of consistency and accuracy.
The Georgia Tech Vision team began adapting their model to the needs of the poultry industry when approached by Wayne Daley, a research leader in Georgia Tech's Agricultural Technology Research Program (ATRP). Since 1988, Daley has been working with computer vision on a variety of applications for the poultry industry, including such tasks as sizing, part sorting and quality control.
The simulation software can pick out defects, such as tears in poultry and scarring in grapefruit. But to be practical in a factory setting, it must make these identifications at a much higher speed than is now possible. Capable human workers can inspect 35 chickens a minute - or, one every two seconds. The computer doesn't come close to meeting these speeds yet, although Daley is presently working to increase the simulation's inspection speed. Doll is confident that the simulation can achieve the required inspection speed if it is implemented on a very fast computer or in special-purpose hardware.
Once the simulation is operating in real time (real time means making information available at the time and place it is needed), it will provide a general-purpose tool that can be adapted to any inspection task that a human can do. Because it imitates human vision, the vision simulation will be much more powerful and flexible than existing automatic inspection tools based on artificial neural networks. Based on the technology's success in the past and the promising results of the system’s adaptation, researchers are optimistic about the future benefits to the poultry- and food-processing industries.

 

Advanced sensors improve efficiency

Georgia Tech researchers are developing smart sensors to assist the poultry industry with the issues of parts tracking and quality inspection. The parts-tracking system records the parameters of a product and tracks it in time on a conveyor belt. The integrated color machine-vision system examines a product for visual defects to determine quality. Both machines are designed to perform functions that currently require human vision.
Just as humans use their eyesight to locate an object when moving it from one place to another, a machine also requires sensors to be as accurate as possible when moving products on a conveyor belt or when checking products for irregularities. For the food processing industry, these sensory machines can be useful when determining meat quality and when handling materials. Today, these tasks frequently must be performed by humans, but the job is often tedious and boring. In an effort to assist the food processing industry in this area, researchers with Georgia Tech's Agricultural Technology Research Program have developed a parts-tracking system and are currently developing an integrated color machine-vision system. These smart sensor systems will assist companies by tracking the position of products on an assembly line and by examining the appearance of a product to determine product quality.
" We are interested in helping the industry improve its overall efficiency in a cost-effective manner," says Wayne Daley, Georgia Tech senior research engineer. "These devices are designed to help machinery function in intelligent ways at reasonable costs."
The two systems operate by using devices such as photodiodes and CCD (Charge-Coupled Devices) arrays, which detect shape and quality details much as the human eye does. The equipment has an advantage over the naked eye however, in that it also employs computers that do not tire after hours of performing repetitive tasks such as inspecting meat for irregularities or checking the position of products on a line. Also, in the poultry industry's factory environment, which can often be harsh due to water and cleaning agents, the size and durability of these compact devices can be important.
The parts-tracking system is a low-cost alternative to computer vision systems for locating and identifying products on a conveyor belt. It uses an array of photosensors to determine the position in time of a product and also records the shape and orientation of the product. It can then supply this information to a handling machine, which can use the data to properly and safely move the product from one location to another. The parts-tracking system can also identify a problem on a conveyer line. For instance, the system can recognize if a product is missing or not properly positioned.
The integrated color machine-vision system is designed to be a cost-effective, self-contained imaging system. Prior to its development, the technology used three separate and bulky systems. First, a camera took a black and white picture of the product. A frame grabber then digitized the picture to put it into the memory of a computer, which analyzed the picture. With the integrated color machine-vision system, the process can now be done in one step and has the added benefit of being in color. Because of this new technology, if any features of the product are unsatisfactory, such as miscolored or bruised skin on a piece of meat, the machine is quickly able to identify the product quality as undesirable.
Georgia Tech is developing these systems in collaboration with local industries. The parts-tracking system, which the researchers are in the process of patenting, is now being evaluated by a northeastern robot company for commercial release. The integrated color machine-vision system is being produced in association with an Atlanta-based computer vision company and a Georgia-based food equipment manufacturer.
Currently, the parts-tracking system is in use in Georgia Tech's own robotics research for the Georgia Poultry Industry. Daley predicts that the integrated machine-vision system will be ready for commercial use in another year or two. He anticipates that both of these devices will prove to be extremely beneficial to the food processing industry because they can increase the accuracy of process control and product quality in the factory.
Back to Topics
1997 Poultry Show a success!
Georgia Tech Agricultural Technology Research Program scientists and engineers met with visitors to the 1997 International Trade Show and Exposition in Atlanta on January 22-24, 1997.
ATRP displayed several of its research projects including the wearable computer. Visitors to Georgia Tech's booth were able to try on the wearable computer and imagine themselves using it in a poultry plant.
We hope to see you at next year's show!

 

Credits
Dara O'Neil, Editor
Rae Adams, Contributing Editor and Photographer
Margie Brown, Contributing Editor
Nancy Davis, Contributing Editor
Jim Demmers, Contributing Photographer
Caroline Fitzpatrick, Contributing Editor
Mark Hodges, Contributing Editor