Let’s face it, we don’t live in the world of the famed 1960s cartoon The Jetsons, where we whisk off in our flying car to our push-button, automated workplace and then return at the end of the day to our self-cleaning home with Rosie the Robot waiting to care for our every whim. But life today really isn’t that bad. After all, the average person can buy one of those little robots that runs around on the floor and vacuums it. Or how about a remote-control robot to mow the lawn—what could be better?
Actually there is something better. How about robots that keep workers from having to enter dangerous environments? Most people would agree that safety is more important than having to actually push the vacuum or lawn mower yourself.
Dangers in the Trenches
While the PipeMan isn’t going to clean your windows or iron your wrinkly shirts, it could more importantly help save lives. To alleviate the need for workers in trenches, researchers in the civil engineering department at North Carolina State University in Raleigh, NC, as part of the Construction Automation and Robotics Laboratory (CARL), developed the PipeMan, a tele-operated, pipe-manipulating system for laying large-diameter concrete pipe. By connecting the hydraulically operated pipe manipulator to the bucket of a backhoe, workers can stand on either side of the trench while the operator directs the pipe into place. Two small video cameras in the manipulator transmit an image to the excavator cab, allowing the operator to see what’s going on in the trench. Alignment of the pipe is done accurately with an integrated beam laser. After the pipe is in place, a worker can release its support cable from a safe distance.
Traditionally, a crane or a backhoe excavator is used to perform the task of laying pipe in the trench, and workers are required to be inside the trench to guide the laying, alignment, and connection. This can prove to be a dangerous situation, especially if rules are not followed and workers enter unprotected trenches. With no support, soil from the trench wall will eventually move downward and inward into the excavation. This creates a serious life-threatening hazard for workers in the trench, especially taking into account the weight of soil. A cubic foot of soil weighs approximately 100 pounds. A cubic yard of soil weighs 2,700 pounds, which is about the same weight as a mid-sized automobile. Therefore, a person buried under only a couple of feet of soil would experience enough pressure on the chest area to prevent his or her lungs from expanding. Suffocation would occur within about three minutes.
In fact, workers in the water and wastewater industry are the group with the highest percentage of trench-related deaths according to statistics from the National Institute for Occupational Safety and Health (NIOSH). A research team at Purdue University analyzed 52 Fatality Assessment and Control Evaluation (FACE) reports associated with trenching and excavation operations that took place between 1985 and 2000. With that analysis, the group found that sewer systems (35%) and water-supply systems (15%) were the areas with the highest trench-related fatalities.
PipeMan, short for “pipe manipulator,” is the brainchild of Leonhard Bernold, Ph.D., director of CARL and associate professor of civil engineering at North Carolina State University. The idea first came to Bernold in 1994, when he was assigned to a committee of researchers put together by the Federal Highway Administration Department of Transportation (DOT) to find potential areas for robotics in highway construction and transportation system. Bernold’s idea for the PipeMan was evaluated by the Civil Engineers Research Foundation and was found to be useful and desirable because of the safety features, but not technically feasible. Still, Bernold trudged on to prove them wrong on the last point.
“I persisted and still put in a proposal for $50,000, which was funded by the DOT. With this we built the first prototype and were able to prove that we could do it,” he says. Then the project received a three-year, $300,000 grant in 1996 from NIOSH, which enabled CARL to build another prototype to field-test.
CARL has also created the PipeMan Jr., a completely new system capable of laying and joining 8- to 21-inch diameter plastic sewer pipes. This manipulator is again attached to the backhoe and uses wireless communication for both hydraulic control and video interface.
Responding to a Need
While the PipeMan helps with laying the pipes, another piece of robotic equipment, called the Responder, actually travels through them. The Responder is a creation of RedZone Robotics Inc., based in Homestead, PA. This robotic device has the ability to inspect and rehabilitate large-diameter pipes and tunnels.
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| Video cameras transmit an image to the excavator cab, allowing the operator to see what's going on in the trench. |
In the United States there are approximately 1.2 million miles of sewer pipe and 880,000 miles of water-distribution pipes. And these pipes are estimated to be 50–100 years old in many cases.
“Because it is a robot, not just an electric cart, it can travel great distances,” says Brian Bannon director of operations for RedZone Robotics Inc. “The Responder can inspect 1–2 miles of pipe a day.”
Ongoing pipe maintenance is necessary to protect against corrosion, root intrusion, structural failure, and other problems. Traditionally, contractors have had to dig trenches down to the pipes to replace them. However, RedZone can send its robots down into the pipes to inspect and clean them.
“Digging up pipes is very invasive, tough on the environment, and tough on traffic control,” Bannon says. Another benefit to using the Responder, Bannon notes, is that the pipes can be inspected while the system remains in service.
RedZone works with municipalities across the country and currently has customers in more than 20 cities.
Putting The Robots To The Test
The PipeMan was put to the test by ABE Utilities of Raleigh. ABE Utilities has been in business since 1979 and specializes in the construction of water lines, sewer lines, and storm-drainage lines. The goal of the field test was to prove not only that PipeMan is a safe, feasible alternative, but also that using the device would provide economic savings.
During the test, eight 8-foot-long, 36-inch-diameter concrete pipes were laid in an open trench, first with manual methods and then with the new device. Justus Everett, owner of ABE Utilities, found the device easy to use and was pleased with the results. Bernold, likewise, was happy with the results. “It worked great. Not only that, but we showed that with small modifications, which you will always have in a prototype, we could actually go below the cost of traditional methods,” he says.
Estimates for installing the pipe in a traditional manner were around $15 per foot, but with an improved version of PipeMan, a crew will be able to install it for under $11 per foot. Obviously, the greater the depth, the greater the savings, which can be attributed to a smaller work crew and the elimination of the OSHA requirements to build a protective system (i.e., smaller volume to excavate and compact when sloping would otherwise be necessary).
Not only is RedZone Robotics providing services to several cities, but in August 2005 it teamed up with the city of Fort Worth, TX, to conduct a sewer assessment to determine the feasibility of using advanced inspection techniques to determine the extent of corrosion in the city’s sewer pipes.
The Fort Worth Water Department collects and treats wastewater for 880,000 customers throughout Fort Worth and 26 customer cities. The sanitary sewer collection system has approximately 2,725 miles of pipe. During the project, RedZone performed six different deployments from which data was collected using a laser scanning system. This assessment provided valuable information as to the extent of pipe corrosion so that the city can now make an informed decision on where it needs to focus its rehabilitation efforts.
The Future of Robotics And The Industry
As the Responder trudges ahead, the PipeMan seems to be stuck motionless in time. Bernold wants to work with a fabricator to get the PipeMan commercialized, but barriers keep getting in the way. Even though the PipeMan has been field-tested, most contractors are reluctant to try something new. “Everybody is kind of sitting on the fence to see if somebody else will use it,” Bernold says. “We are interested in working with the industry to move forward. I would personally come with the system and work with the contractor.”
Another of Bernold’s projects that could prove to be useful in the wastewater industry is an underground-utility detection system, which can be integrated with equipment, such as a backhoe, a trencher, or even a drill. This electronic system warns of utility lines buried immediately ahead of the digging tool and provides a computer readout of the depth, location, and size of buried metallic objects and even nonmetallic objects, such as plastic or terra cotta. However, Bernold can’t find a market for this invention either. “There is no real incentive for a contractor to use this because if he does he is not going to be the lowest bidder because he has to slow down a bit to scan the ground,” Bernold says.
So even though the CARL team has come up with innovative technology that could contribute to worker’s safety, low bid still seems to win in the end. “This industry is very conservative because we have something called the low bid. The low bid really inhibits innovation because the contractor is going to use what he knows and doesn’t want to try something new,” Bernold says. “If you want the lowest bid, you’ll play it safe. You’re not going to use something that you’ve never personally used before. It is too risky unless there’s a huge advantage and you have a backup plan.”
But when you go by the philosophy of the three Ds, there just might be hope yet for CARL’s innovative technology.
“Robots are good when the three D’s are in place: dirty, dangerous, and dull,” Bannon says. “And that tends to be where robotics really help the market.”
NIKKI STILES is a freelance writer based in the city of Fairmont, West Virgina.
OW - July/August 2006 |
