A sprayer that steers itself would have amazed farm show goers in the past. Now it seems such things are expected. Tech-savvy farmers who saw Midwest Technologies' FieldPilot demonstration at this summer's MAGIE trade show in Danville, IL, figured an autosteer sprayer was just the next logical progression in rapidly evolving guidance technology. GPS-guided autosteer systems have already proven themselves by running perfectly parallel to the previous pass at higher speeds than human operators can manage.

What surprised many who participated in the “ride and drive” demonstration was that the same console that controls the self-steering capabilities also regulates a map-based variable-rate application system. One GPS-guided system eliminates wasteful overlap on passes and puts down just the right amount of weed control product. Company reps explained the system would work for precision variable-rate control of chemicals, fertilizer and seed.

AGCO agreement

The FieldPilot's debut marks an end to a patent dispute between Midwest Technologies and AGCO Corporation. A new agreement between the companies gives Midwest Technologies nonexclusive rights to manufacture and distribute multiple-product variable-rate application systems.

Two decades ago, a company called Soilteq patented the technology to apply fertilizer at variable rates. By 1996, Ag-Chem Company had acquired full interest in Soilteq. Then AGCO acquired Ag-Chem in 2001, effectively locking up the Soilteq patent for itself.

Until now, the patent represented a significant barrier for Midwest Technologies, which specializes in control systems that precisely vary application rates of liquid and granular products. It was the first company to offer control systems capable of map-based variable-rate applications. Multiple-product application also has been conducted for many years and is a key capability of many Midwest Technologies control products.

The agreement paves the way for Midwest Technologies to capitalize on the full capabilities of its Legacy 6000 controller. The unit regulates liquid, granular and anhydrous application as well as seed population. For the FieldPilot system, Trimble provides the automated steering components, and Midwest Technologies adds the steering system interface to its Legacy 6000 console.

Trimble autosteer

“Our field-testers really appreciate the fact that we aren't adding more cables, control consoles and clutter to their cabs,” says Dugan Petersen, national accounts manager for Midwest Technologies. “Automatic steering functions are integrated into the Legacy 6000 console, so the user almost doesn't realize it's there. All the operator sees is one extra button to engage the automatic steering function.”

Although autosteer systems are relatively easy to install on sprayers and tractors, they aren't quite as easy for companies to develop. Because the system must be integrated with each particular machine's steering and drive systems, each machine requires careful study, engineering and testing prior to its release as an approved vehicle. The resulting vehicle-specific installation means better performance, improved safety and a more transparent system to the operator.

Midwest Technologies and Trimble are working together to expand the list of vehicles to which the FieldPilot system can be adapted. Several self-propelled sprayers and more than 15 tractor models are currently supported. The system is capable of submeter accuracy using Trimble GPS receivers using the Wide Area Augmentation System (WAAS), Beacon or satellite differential corrections or centimeter-level accuracy from RTK receivers.

Mid-Tech rate control

The FieldPilot system expands the scope of traditional rate control by also managing as-applied data collection, manual lightbar guidance or automatic steering from a single console. The Legacy 6000 interface and controller ties it all together. It is the only unit an operator needs to set up and monitor, clearing the cab of multiple systems and simplifying complex operations.

The Legacy 6000 console mounts in the cab as the user interface and data storage device, putting all FieldPilot functions at the operator's fingertips. A Swath XL lightbar provides steering cues in manual mode when turning corners. It also helps the operator confirm that the vehicle is on track during autosteer.

The navigation controller mounts to the vehicle chassis. It is a self-contained unit that houses the advanced steering processor and solid-state inertial components that measure pitch and roll.

A steering interface is made up of two parts. Vehicles with hydraulic steering require a hydraulic valve to be plumbed into the system. A steering angle sensor gives the navigation controller information about the steering angle. Steer-by-wire systems such as those found on John Deere T tractors do not require a hydraulic valve; the automatic steering system interfaces directly with the machine's steering electronics.

A Trimble DGPS or RTK receiver provides position information. The DGPS receiver is good for submeter accuracy, whereas RTK, which requires a base station, provides centimeter-level accuracy. For less demanding applications, receiver systems for Beacon, L-band and WAAS correction sources also are available.

Company spokesperson Rich Gould points out that for its price tag of $23,000 to $25,000, the FieldPilot has a lot of flexibility. “A farmer can move components between machines, making this a system that can be useful over the entire production season,” Gould says. “Use it on tractor for variable-rate seeding. Later use it on a self-propelled sprayer or fertilizer spreader. And not too far in the future, we hope to have it ready so farmers can move components to a harvesting machine as well.”

Omnistar guidance

To make the system work best for variable-rate planting, Gould also points to new GPS subscription services on the horizon. “Right now we have submeter accuracy with DGPS and the subscription-free WAAS system. That's great for spraying,” he says. “For planting, you'd probably want more precision. But paying an extra $23,000 for RTK and a base station might be overkill for some growers. That's where we think a new version of Omnistar called Omnistar HP will be a good alternative. A yearly subscription will give a corrected signal with 4- to 6- in. accuracy per pass.”

For more information about Omnistar, contact Omnistar Inc., Dept. FIN, 8200 Westglen Dr., Houston, TX 77063, 800/338-9178, visit www.omnistar.com or www.freeproductinfo.net/fin, or circle 203.

Evaluating the investment

Overall, the FieldPilot appears to address several concerns farmers have had about investing in precision ag. The system is capable of doing just about any site-specific guidance or application function, so an owner isn't forced to buy a lot of additional equipment later on.

Because it fits on many machines, it doesn't lock a farmer into buying just one particular brand of machinery. And for the privacy-minded, it doesn't necessarily require that a farmer share field data with a company that may sell that data or use it to sell something later. The biggest carrots that could compel farmers to buy are that a guidance-equipped machine can accomplish more work in a day, and variable-rate application technology can save money on inputs. If one tractor or sprayer can do the work of two and save money, it starts to justify the price tag of the technology.

For more information about FieldPilot, contact Midwest Technologies Inc., Dept. FIN, 2864 Old Rochester Rd., Springfield, IL 62703, 217/753-8424, visit www.MidwestTechnologies.com or www.freeproductinfo.net/fin.