From Farm to Fairground
by Doug Drummond
May 1, 2009
A real-time machine control network helps an Illinois contractor create a new county fairground.
“Building a new county fairground from scratch is not the kind of job you work on every day,” observes Ruben Cuevas, chief surveyor of Lake County Grading Company in Libertyville, Illinois. “That’s one of the things that makes it so interesting.”
The Lake County Fairground’s move to a new 128-acre facility near Grayslake, Illinois, presented Cuevas and his crews with a number of unusual site preparation challenges. It also gave them an opportunity to apply a set of technologies that marries their GPS-based machine control systems to a real-time GNSS network created by their local Topcon dealer, Positioning Solutions Company of Carol Stream, Illinois.
A John Deere 850 dozer outfitted with Topcon 3DMC accesses PSC Net for real-time GNSS guidance at the fairgrounds.
“The new fairground is literally a ‘green field’ site,” Cuevas says. “It was a piece of farmland when we started. We had to do a massive amount of earthwork.” The project, which began in December 2007 and required the contractor to move 467,000 cubic yards of dirt, included multiple ponds, roadways, parking and all of the site preparation for the midway and permanent exhibition buildings.
“To make things even more interesting, our part of the project was done in stages. We did a phase and then left the site while someone else came in. Then we came back and continued our work, then left again while the next phase was completed. It went that way from start to finish,” Cuevas says.
“That kind of job can be a surveyor’s nightmare,” he adds. “It’s almost like starting over every time you come on the site, because you can’t be sure nothing has been disturbed. In the days before GPS you would spend as much time retracing your steps as you would advancing the job. That’s all different now, of course, with today’s technology.”
Lake County Grading first adopted GPS technology in 2005 when it equipped two John Deere 850 dozers with Topcon 3DMC. “We used it and learned, and in the end we really liked it,” Cuevas says. Based on that experience, Lake County Grading now runs nearly a dozen 3DMC-equipped dozers, and has recently equipped a motor grader with the GPS system.
Lake County Grading’s Joe Gore and Ruben Cuevas review the fairground plans.
When they won the fairground project, Lake County Grading’s crews already had a lot of experience linking their own base/rover systems to the machine controls on their equipment. But the unique nature of this project made it a natural for the next step—integrating the machine controls with a real-time GNSS network.
Real-time GNSS networks link a number of base stations together via a computer network, usually through a cellular connection to the Internet. Inside the geographic area covered by the network, a contractor can walk around with a GPS rover or operate a machine-controlled dozer and get centimeter-level accuracy, just as if a mobile GPS base station were operating a few feet away.
“We knew that Positioning Solutions was in the process of building a machine control network, so we made the decision to get onboard,” Cuevas says. He further explains, “Even using our own Topcon base and rover, we would have to send someone out to prep the jobsite every time we went back. You can’t leave that kind of equipment on the site because it tends to ‘grow legs’ if it isn’t watched.”
Positioning Solutions Company has taken an unusual approach to network building. Nearly all of the reference stations are owned by individual customers. Positioning Solutions helps them select the best location and supplies the computer networking technology required to integrate them into PSC Net. Any member of the network can access any of the reference stations as if it were their own.
“We are a very customer driven company,” says Jerry Bickner, president of Positioning Solutions Company, “and our customers wanted something more than a simple GNSS network.” In response, Positioning Solutions Company built its network for the 3D machine control users instead of aiming it at the surveying market. Bickner points out that the Topcon hardware and software used by PSC Net provide several advantages for his contractor clients, including latency reduction and increased vertical accuracy.
“Latency is the time lag built into any network,” he explains. “A surveyor can afford to wait a few seconds while the system processes and communicates a position update. A moving dozer can’t. The Topcon network and machine control software have built-in compensation routines to reduce the impact of the inevitable latency.” Bickner also notes that PSC Net is focused on vertical accuracy because large, inconsistent errors in the vertical plane are unacceptable for a machine control application.
For Lake County Grading’s Cuevas, the benefit of being part of PSC Net was very simple. “Every time we went back to the fairground, all we had to do was send out the equipment and operators,” he says. “As soon as they unloaded, they were ready to go to work because nothing had changed with the network reference stations.”
Cuevas adds, “Because the fairgrounds are relatively close to our offices, we were able to use our own reference station for the whole project. But on other jobs we have used signals from competitor’s reference stations that are also part of the Positioning Solutions’ network.”
This is not a downside because, according to Cuevas, “Everyone benefits. We use their signals and they use ours. It doesn’t matter because we’re all part of the same network.”
Modeled for Success
The fairground project included a number of ponds that served as practical water collection and storage as well as aesthetic landscaping functions. Each pond had to provide a specified storage volume, and none of them were square.
“Nobody builds square ponds today,” Cuevas says. “We were able to model each pond with our Topcon software and then excavate them accurately using the networked 3D machine controls.” The team used Topcon Pocket-3D for the rovers, Topcon 3D-Office for the laptop and Topcon 3DMC software for the machine controls. “That capability saved us a tremendous amount of time that would have been spent staking and re-staking without the network and machine controls,” Cuevas says.
“The machine controls are really quite intuitive,” he continues, “and the operators took to them right away. They simply go into full-auto whenever the machine is within 6 inches of grade. In many ways, running one of these machines is like playing a video game.”
Building the models those controls rely on, however, is a good bit more complicated. So Lake County Grading also has taken advantage of another unique service offered by Positioning Solutions, a comprehensive training program called PSC University. “We’ve sent point men and the people who produce our surface models to PSC University for in-depth training,” Cuevas says. “Everyone realizes this is the future of our business.”
Cuevas adds that the project is on schedule to finish in June, which will be just in time for the 81st annual Lake County fair planned for July. In spite of the project’s required starts, stops and re-starts, the farmland has efficiently become a fairground with the help of modern satellite technology.
SIDEBAR: PSC Net: A Real-Time GNSS Network for the Midwest
Bickner explains how his firm developed its real-time network: “We started in Indianapolis about three years ago because we had both a strong market presence and a strong technical base there. Chicago was the second area to be added, but we have kept the actual network computers and processing centralized in Indianapolis to take maximum advantage of the experience base there.”
According to Bickner, the growth of PSC Net has been tremendous. “We started with half a dozen Topcon reference stations in 2005. Today, PSC Net has grown to more than 40 with an average of four more being added each month. Our goal is to cover all of the major metropolitan areas in the five states seamlessly within the next three years or so.”
Doug Drummond
Doug Drummond is owner and editor for National Editorial Services of Northport, Michigan.
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