For producers who need highly precise implement guidance, the sub one-inch accuracy offered by an RTK guidance signal is essential, but that alone cannot guarantee the openers on a drill will always end up where they’re supposed to.
Even though a tractor can easily follow the same A-B line time after time under the guidance of RTK, a number of factors can cause a trailed implement to move off track. Skewing on steep hillsides or “cheating” on corners are among the causes. But John Deere’s iGuide and brand new iSteer systems are designed to correct for those kinds of problems and keep an implement on course. Both require an RTK signal, but they work in very different ways. Each will appeal to different kinds of producers.
“The major difference is iGuide is a passive implement guidance system and iSteer is an active implement guidance system,” says Holli Brokaw, John Deere’s product manager. “The difference between (them) is how they respond to the correction signal they’re given. With iGuide, the tractor will move away from the A-B line to pull the implement onto it. But iSteer teams up with a steerable mechanism on the implement.”
Both of these systems use an additional GPS receiver mounted directly on the implement, which works in cooperation with the one on the tractor. The two work together to keep tractor and implement on course. “If you can move the receiver back to the implement you’re getting accuracy to where it really becomes useful,” adds Brokaw.
SEPARATE STEERING OF THE IMPLEMENT
The iSteer system relies on having a steerable mechanism on an implement to receive direction input from the GPS receiver mounted on it, just like auto steer on a tractor. But Deere doesn’t supply the actual mechanical steering systems. Some implements, like potato planters will likely already have them, but it may be necessary to look to a third-party supplier to add that feature to another machine.
One advantage of that system is how quickly iSteer can get an implement to respond to course corrections. Brokaw likens the response to that of a rudder on a boat, which quickly snaps an implement into line.
Brokaw says Deere’s iSteer differs from other implement steering systems in how easy it is to disengage for parking. “You can actually control the steering mechanism through the SCVs on your tractor,” notes Brokaw. “You can disengage and engage right at your fingertips. It gives you fingertip control to back up and park.”
According to Brokaw, iSteer was intended to appeal mainly to speciality producers, like potato growers. “The development of iSteer really focused on specialty producers, because beds are already built and the tractor doesn’t have the ability to leave the A-B line without damaging the bed or the crop,” she says. “In more recent years, as strip till becomes more popular, it’s becoming something for row crop customers to consider to get that level of accuracy.”
BROAD ACRE APPLICATIONS
The iGuide system will appeal primarily to broad acre farmers, and it provides one more tool for those who are chasing yield gains from seeding between last year’s stubble rows. This system provides an alternative to the adjustable drill hitches matched with paddle-type stubble detectors offered by some air seeder manufacturers.
With iGuide, the implement rather than the tractor stays on line. If necessary, the tractor will move off it’s path to keep the implement in position. But that means it responds a little slower to course corrections than iSteer does.
Deere’s iGuide was released in June of 2009 and won an AE50 award from the American Society of Agricultural and Biological Engineers (ASABE) this year. The iSteer system was just released in February and will be making its debut in fields this spring.
If a producer is already set up to receive an RTK signal, the additional cost of adopting iGuide is roughly US$10,000, plan on spending about US$13,000 for iSteer. For anyone starting from scratch, that cost jumps to about US$35,000 for a complete iSteer system and US$32,000 for iGuide.
Scott Garvey is machinery editor for Grainews.
Contact him at [email protected]