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NEW DEVELOPMENTSIN AGRICULTURAL EQUIPMENT TRACTORS. R. T. Schuler National AgrAbility Project University of Wisconsin - Madison. November 14 , 2006. Tractors. Guidance and Auto-Steer Global Positioning System Guidance Auto-Steer Autonomous Transmissions Number of gears/speeds
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NEW DEVELOPMENTSIN AGRICULTURAL EQUIPMENT TRACTORS R. T. Schuler National AgrAbility Project University of Wisconsin - Madison November 14 , 2006
Tractors • Guidance and Auto-Steer • Global Positioning System • Guidance • Auto-Steer • Autonomous • Transmissions • Number of gears/speeds • CVT - Continuously Variable Transmission • IVT - Infinitely Variable Transmission • Suspension • Tractor Chassis • Cab • Seat
Global Position Systems Basic GPS Satellite System Only (3 of 24) Low cost – automobiles Error – 100 feet Satellite Constellation
Global Position Systems Basic GPS Satellite System Only (3 of 24) Low cost – automobiles Error – 100 feet Satellites plus free beacon Intermediate cost Error – 2 to 3 feet
Global Position Systems Basic GPS Satellite System Only (3 of 24) Low cost – automobiles Error – 100 feet Satellites plus free beacon Intermediate cost Error – 2 to 3 feet Satellites plus geostationary satellite More costly Error – 3 to 5 inches
Global Position Systems Basic GPS Satellite System Only (3 of 24) Low cost – automobiles Error – 100 feet Satellites plus free beacon Intermediate cost Error – 2 to 3 feet Satellites plus geostationary satellite More costly Error – 3 to 5 inches Satellites plus base station nearby Costly ($18,000 in 2006) One inch or less
Guidance and Automatic Steering Adoption • Most systems use GPS • Payback Improve productivity Increased forward speed Reduced crop inputs Reduced operator fatigue Ability to operate longer hours (darkness) • Simple installation – 30 minutes • Lower cost in recent years
Line A – B is base line called Track 0 Guidance provided between points A and B
Example of a Light BarLocated in front of operator All lights on in test mode Green light – acceptable area Yellow light - caution area Red light - unacceptable
Light Bar Middle green light is on- Driving right on target
Light Bar Right most green light is on: Driving to right of center but acceptable (error increment can be adjusted)
Light Bar First yellow light is on: Caution – corrective steering should be taken
Light Bar Red light is on: Operator needs to make steering correction
Another Display System Green rectangle represents front end of tractor and angle of line indicates error (magnitude of error also displayed) Track Error No Error
Another Display System Audio alarm when error occurs Green rectangle represents front end of tractor and angle of line indicates error (magnitude of error also displayed) Track Error Track 2 ft. Small Error No Error
Another Display System Audio alarm when error occurs Green rectangle represents front end of tractor and angle of line indicates error (magnitude of error also displayed) Track Error Track 2 ft. Track 5ft Small Error Large Error No Error
New Special Feature Automatic turn around on headland New Features – automatic headland turn around
Option with GPS • Guidance e.g. lightbar
Option with GPS • Guidance • Autosteer • Steering wheel control
Option with GPS • Guidance • Autosteer • Steering wheel control • Steering control system valve
Transmissions for Mobile Equipment • Gear • Speed changes in steps • Single power transmission path • Efficiency at part loads dependent on the number of gears • Hydrodynamic • Automotive transmission • Infinitely variable • Not adaptable to high torque • Hydrostatic • Infinitely variable • Inefficient • Infinitely/continuously variable • Power split in the transmission • Electronic control of transmission and engine for most efficient operation
Background-Gear Transmissions • Early Tractors had one or two forward speeds, one reverse • More forward speeds were added • Speed change without clutching-torque amplifier • Synchronized transmission • Shifting on the go • Infinitely/continuously variable transmission
Tractor Engine and Driveline for Two Wheel Drive Single path for the flow of power through transmission Transmission Engine Axles Clutch Differential
Infinitely/Continuously Variable Transmission Power is directed into two paths Planetary gear systems facilitates this Power from the two paths are merged
Basic CVT/IVT Transmission Sun Fixed path Planetary Gear Set (power split) Carrier Output Variable Path Ring Input 2 gears
Basic CVT/IVT Transmission Carrier Fixed path Sun Planetary Gear Set (power merge) Output Variable Path Input Ring 2 gears
IVT/CVT Characteristics • Hand control for forward, reverse, speed changes and stopping • Smooth, seamless shifting • Unlimited speeds from 0.03 to 26 mph (Deere) • Improved fuel economy at reduced load • Reduced load-maintain forward speed with changing engine speed • Need for feet only to start the tractor engine • Cost – $9780 (right side), $10,490 (left side)
Suspension System Goals • Improve operator comfort and reduce long term health issues • Reduce vibration from traveling over rough terrain • Reduce vibration due engine and drive train vibration • Improve tractor performance • Reduce the potential for power hop on FWD and FWA • Improve contact between wheels and soil surface
Background on seat suspension • First tractor operators had to stand • Seats rigidly attached to tractor chassis • Spring supported seats-passive • Spring plus shock absorbers -passive • Air suspensions seats-passive • Active suspension seats
John Deere Active Seat- $3641 Source: Dufner and Shick, Deere
John Deere Active Seat Source: Dufner and Shick, Deere
John Deere Active Seat Source: Dufner and Shick, Deere
John Deere Active Seat Source: Dufner and Shick, Deere
Tractor chassis suspension • More beneficial for the higher speeds • Front axle suspension – Deere • Front and rear axle suspension - Fastrac
Tractor chasis suspension • More beneficial for the higher speeds • Front axle suspension – Deere • Front and rear axle suspension - Fastrac • Reduces potential for power hop • Improved performance with FWA tractor
Concluding remarks • Guidance and auto-steer • IVT/CVT • Fuel saving • Automatic shift up-throttle back • Suspension Systems • Seat • Cab • Chassis