Latest Advances in GPS Technology Randy Taylor Extension Engineer, Machinery Systems Biosystems and Agricultural Engineering
GPS Technology • Precision Ag Technology allows management at a small scale without sacrificing efficiency gained from owning large equipment.
Precision Ag Technologies • Yield Monitors • Guidance Systems • Control Systems • Sensor Technology • Remote Sensing • GIS Advancements
Yield Monitors • Yield monitors are a commercially accepted commodity • They will become standard equipment on new combines by default • Key uses are: • Diagnosing Crop Production Problems • On-Farm Research • Determining Spatial Yield Potential
Guidance Systems • Lightbars are becoming almost a standard item for most farmers and applicators. • Autosteer is experiencing rapid acceptance and new or improved products are flooding the marketplace.
Light Based Interface • Uses lights to indicate what the operator should do to maintain the desired path
Uses an image of the vehicle and an indication of where the vehicle should be Some models have a “moving road” type of display Combination systems Image Based Interface
Automatic Steering Technology • We need a precise (and maybe accurate) and stable GPS navigation signal (pass to pass). • We add a computer controlled electro-hydraulic steering box. • An inertial measurement device to compensate for yaw is nearly essential. • Pitch and roll should be considered.
Inertial Sensors • Combining DGPS with Inertial Measurements • Inertial sensors measure pitch, roll, and yaw • Updates 10-20 times faster than DGPS • Steering is driven by a combination of the two signals • Benefits • Higher travel speed • Maintains straight line on side hills and terraces • Continues to steer through short signal interruptions .
Operator Tasks • Auto steering systems frees the operator to do a better job of monitoring equipment functions • Sprayers • Planter operation • Harvesting • Or maybe just talking on the phone or reading a book • Auto steer makes an inexperienced driver (not operator), experienced
GPS Static Accuracy • Dual frequency signals (Deere SF2 and OMNISTAR HP) easily provide static horizontal precision less than 1 foot. • This typically translates to pass-to-pass accuracies less than 4 inches. • GPS accuracy is not all that matters – vehicle dynamics is important
Sub meter Decimeter Centimeter GPS Signals and Applications • WAAS • Beacon • Single Frequency • Dual Frequency • RTK
Selection Criteria • Operator Steered • Auto Steer • Expansion/Upgrades • Coverage Maps • Boom Section Control
Control Systems • Rate controllers are accepted items on sprayers and fertilizer applicators • These are being integrated into ag vehicles • Recent Advances • Combine feedrate control • Automatic boom section control • Boom height control
Real Time Coverage Maps Are you sure you didn’t miss a spot? Having a coverage map, while you are still at the field is a great asset.
Automatic Boom Section Control For a lot of fields in Oklahoma, more sprayer overlap is due to point rows and irregular fields than steering errors. Can the system integrate with a sprayer rate controller to turn off boom sections that are overlapping previously sprayed areas?
Combine Feedrate Control Project • Soft white wheat was harvested on July 27-29, 2004 near Murtaugh, Idaho • Five experienced operators
Combine • John Deere 9860 STS combine • 36 foot wide draper header
Operating Characteristics • 130 bu/ac irrigated wheat • Baling straw • Straw chopper disconnected • Low cutting height
Conclusions • Automatic feedrate control increased • Material capacity 5.5% across all operators. • Speed by 0.5 km/h (0.3 mph) or 16% • Assuming yield of adjacent passes were similar, speed is a better indicator of potential improvement.
Sensor Technology • Greenseeker • N-management • Veris Technologies • Soil EC Sensor • Mobile Sensor Platform • w/ pH Manager
Remote Sensing • It will be the savior of precision ag technologies • There have been some niche applications, but widespread adoption has not occurred
GIS Advancements • Integration of production and financial records • Data dictionaries • Standardized naming
Precision Agriculture • Mechanization of agriculture was considered one of the top ten engineering achievements of the previous century • The incorporation of electronics and control systems will be one the next great achievement in ag equipment
Remember, its Evolution not Revolution Randy.Taylor@okstate.edu