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Runs Like a By Jill Brimeyer John Deere engineers apply high technology such as GPS to farming, improving efficiency and reducing costs and environmental impact
"When we whittled our ideas down, precision agriculture kept bubbling up," recalls Pickett, who bills himself as an electrical engineer who likes to play with agriculture. "We ended up convincing Hans Becherer (then Deere’s chairman and CEO) that pursuing this market was a good idea." Precision agriculture, which uses signals from the constellation of Global Positioning System (GPS) satellites for farming applications, showed promise. But at the time, there were far more questions than answers. Competitors had already developed yield mapping systems for combines that measured the mass flow of grain by using an impact plate at the top of a grain elevator. Data was collected instantly and paired statistically to the plot of field that produced it. With this information, a farmer could determine if his 130 bushels per acre is due to some areas yielding 180 an acre and others only 80 and treat those fields accordingly. Despite the idea’s promise, most companies that offered the technology floundered. It was difficult to attain the necessary level of GPS accuracy needed for these farming applications without driving up cost. And it was even harder to convince farmers of the systems’ payback potential.
Solving the GPS Puzzle It became clear the linchpin of a successful guidance system would be a simple GPS system supported by the John Deere dealer network. So while Mayfield continued to work with Stanford engineers to refine the overall product concept, Nelson, Pickett, and their Advanced Engineering peers went back to the drawing board. Teamed with talented engineers from NavCom Technology, now a wholly owned subsidiary of John Deere, and NASA’s Jet Propulsion Laboratory, the group spent weeks deconstructing problems and looking at new ways to put the pieces back together. One of these challenges was differential correction, the ability to fine-tune GPS signals by using a ground receiver to adjust for error. Without accurate correction, readings could be off by half the length of a football field. In 1998, GPS accuracy of mere centimeters was pie in the sky. But for this group of engineers, their fresh eyes worked to their advantage. "People who develop GPS have a paradigm," explains Nelson. "Those of us who didn’t grow up in the GPS world don’t have those paradigms. You can more easily shift into a different direction and make a dramatic difference."
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Accuracy To reach its accuracy goals, Deere created its own means for differential correction. "We came up with the idea to create a set of corrections for each satellite, rather than a correction for each base station," says Nelson. "There’s one for each satellite, orbiting anywhere in the world, and then one for each region. It’s a cheaper system to run, and it improves accuracy." The result of their efforts can pinpoint location within an inch and is billed as the first truly global DGPS network as well as the most accurate and reliable system available. "Our collaborations allowed us to extend DGPS to the entire globe, with a signal valid anywhere you go in the world," states Nelson. Pickett shakes his head at the memory. "We really turned around precision ag to a level that no one had even dreamed about."
Many in the industry questioned John Deere’s approach as it set out to reinvent everything right down to their own set of application-specific integrated circuits, chipsets, and controls. "People may have asked, ‘why would John Deere build their own GPS when they could acquire the technology so easily?’" remarks Nelson with a chuckle. "Well, if it’s something we build ourselves, it’s repeatable year after year. We couldn’t guarantee that if we used another manufacturer, particularly when we were only a small part of the growing commercial GPS industry." Farming the High-tech Way
"If a farmer’s machinery typically has 10 percent overlap in the field, that’s three feet of overlap using a 30-foot implement," explains Nelson. "If you give accurate guidance, that’s 10 percent less time in the field, chemicals, and wages. When you calculate that, it’s very easy to justify the steering system. And that’s not even counting being able to farm in conditions when you couldn’t have worked before, like in darkness. Some years, that makes the difference between having a crop and not having one." John Deere also took yield mapping and cranked it up a notch, extending its Combine Yield Mapping System to cotton pickers. This variation of the system used for grain leverages Doppler radar technology to measure the mass flow rate of the problematic fluffy stuff. It beams microwaves, which illuminate the stream of cotton and then reflect to a sensor. The ability to accurately measure yield is changing the face of farming. "In the early stages of precision farming, the variable rate information never could be conclusive," says Pickett. "You’d have to base your current year’s yield on last year, which doesn’t do much good. It all relies on nitrogen availability, which varies greatly. Now it can be a real time, in-season activity that puts on nitrogen when the crop can use it, improving the environment while going easier on the producer’s wallet." John Deere AMS has come a long way from 1997 and that seed of an idea planted in an Illinois conference room. Even so, the process, and progress, continues. The precision ag concept will be implemented on a wider range of vehicles in the future, and studies are continuing on fully autonomous vehicles. Right now, the latter is looking like another one of those "impossible problems." But don’t write off the idea just yet -- the engineers at John Deere seem to specialize in impossibilities. "The best meetings we’ve had were like a thundercloud -- utter chaos," muses Pickett with a smile. "You start by saying, ‘how are you going to get around this?’ Then discussion builds up and builds up, and at the end of the day you come up with a solution that was so unique, you are just amazed with it." For more information on John Deere Ag Management Solutions, visit www.deere.com/en_US/ag/servicesupport/ams/index.html Jill Brimeyer is a freelance writer in Ankeny, Iowa |
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