Home SCIENCE The Spirit Autonomous Tractor Eliminates Need For Driver

The Spirit Autonomous Tractor Eliminates Need For Driver

SHARE

Advertisement

The company’s design goal was to build a low-cost, efficient, reliable tractor with a fail-safe no-driver navigation system. Spirit will have a long, 25,000-hr. service life, a 500-hr. service interval, a maximum 2-hr. repair time and a selling price of $500 per horsepower, Anderson says.That includes a hybrid laser-radio navigation system that eliminates the possibility of the tractor straying outside of field boundaries.

image/text credit: Helenachuva

The Spirit tractor borrows design elements from railroad locomotives, including a tubular steel frame and a diesel-electric power plant that eliminates the need for a transmission and differentials. Power is supplied by twin 202-hp, 5.2-liter Isuzu diesel engines, which drive dual generators that provide power to four oil-cooled electric wheel motors.

image/text credit: Helenachuva

Depending on power needs, the dual-diesel configuration can be run at drawbar horsepower ratings ranging from 100 to 400 hp in 100-hp increments.Power is transferred to rubber tracks via powered truck tires on each corner, which Anderson says provide more surface area than traditional track systems. The weight of the tractor —25,000 lbs.—was kept low to minimize soil compaction.

Advertisement

An additional 5,000 lbs. of weight can be added by ballasting the tubular frame with water.Anderson opted for a laser and radio navigation system instead of a GPS-based system because of reliability concerns. “We decided GPS is not satisfactory for an autonomous tractor because GPS can fade periodically,” he says.

The Spirit navigation system uses two lasers mounted on the tractor, which bounce signals from three or four mobile transponders placed around the field. Lasers are supplemented with 150 MHz radios, which are needed to overcome line-of-sight issues with laser systems.

VIAHelenachuva
SHARE