DEVELOPMENT AND APPLICATION OF VEHICLE GUIDANCE SYSTEMS FOR PRECISION AGRICULTURE

Manual guidance means  Disk markers  Foam spray  Flags – aerial spraying  Tissue markers – aerial spraying

Vehicle Automated Guidance  Furrow followers  Cable tether  Buried Cable Followers  Machine Vision  Positioning Systems

Purpose  Increase efficiency  Reduce fatigue and boredom  Save money  Fewer operators

Resistance  Initial cost  Reliability  Elaborate set-up  Ag machines are “iron tough”

Vehicle Navigation Requirements  Parallel swathing  Crop-edge tracking  Precision path tracking  Turning assists function  Remote guidance  Multi-vehicle cooperation

First guidance attempt First furrow follower patented in 1924  U.S. Patent 1,506,706  Suggested use of guide wheel as a mechanical feeler tethered to the steering wheel so that the tractor could follow a furrow for cultivation

Low Cost Auto Steer - Australia

Furrow Guide  Developed by University of Southern Queensland Nat’l Center for Engineeering  Speeds to 15 km/hr  Furrow following skids or chain  Accuracy of +/- 25 mm  U.S $6,250

Machine Vision Research  Carnegie-Mellon Robotics Institute (1996) NH Speedrower at 7.2 km/hr Vision based perception of cut and uncut crop  Stanford University Carrier phase GPS on JD 7800 tractor Accuracy of 2.5 cm, 0.1 degree heading at 3.25 km/hr  Michigan State University Straight row guidance of Case 7190 MFW tractor Error of 6 cm at 4.8 km/hr, 12 cm at 12.9 km/hr  University of Illinois Joint study with Hokkaido University, Japan Used GPS, vision, inertial, and geomagnetic sensors

Other attempts  Tethered wire for circular operation, Univ. of Illinois, 1941  Mechanical feelers  Buried cables  John Deere orchard sprayer

US DOD Global Positioning System  24 satellites, 6 orbital planes  Orbit height of 11,000 miles  Four satellites needed for accurate positioning  Differential correction required for field navigation

Hardware requirements  GPS Receiver  Differential correction signal receiver  Differential correction antenna  Computer/monitor interface

GPS Light Bar  WAAS or L Band correction  Define first pass  Bright color LEDs define on or off track  Parallel, contour, or standard field tracking  Cost $4,000 - $5,000  Operable day or night  Tracking accuracy, 15 cm

GPS Autoguidance  Parallel, contour, or standard field tracking  WAAS or L Band corection  Increased field efficiency  Increased equipment utilization  Operable day or night  14 cm (6 inch) accuracy sysyem, $9500  One cm (one inch) accuracy, $40,000+

Manufacturers  Trimble Navigation  Outback Guidance  Novatel  Beeline Technologies  Greenstar (John Deere)  Fieldstar (AGCO)

Outback System claims  Install in two hours or less  Operate in 15 minutes or less  Exclusive “Contour” driving  Huge payback (dependent on crop)

Future of Vehicle Guidance  Lightbar systems will be commonplace  Automated systems will increase in higher value crops  Multiple vehicle operation will be feasible  Remote vehicle operation will be feasible

References  New Frontiers in the 21 st Century: A Status Report on Autonomous Guidance of Agricultural Vehicles in the U.S., Dr. John Reid, University of Illinois    “Driverless Tractors”; American Society of Agricultural Engineers, 2001, J. F. Reid & D.G. Niehubr  The Precision Farming Guide for Agriculturalists, Deere & Company, 1997