21 March 1997

Robot technology steers a fine line

FARMING by robot is on the way. A driverless self-propelled windrower is the first in a series of projects by an American research team aiming to bring robot technology into a wide range of farm equipment.

They plan to adapt the control system for the windrower, other types of harvesting machinery and, next year, they begin work on a robot tractor.

Based at Carnegie Mellon University, Pennsylvania, the research team has a long history of developing driverless vehicles, including the Lunar Rover which travelled on the moon.

The harvester project was financed with $2m of the National Aeronautics and Space Administration funds, with New Holland providing a model 2550 windrower plus technical assistance from their engineers.

Two cameras are used by the guidance system – placed at roof level on the front of the windrower – with pictures analysed by a computer which looks for the edge of the standing crop.

This is the line the machine follows, the computer controlling the steering to keep the outside of the table just beyond the line.

The computer also scans the picture for obstructions and, if it detects a potential hazard, takes evasive action. At the end of each row the control system makes a headland turn and seeks another cut line to follow.

The control system is also linked to GPS but only as a back-up to check the windrowers position and keep it within the field boundary.

Walter Pype, New Hollands chief engineer, says the windrower was chosen to start the project because of its relative simplicity. The same system could also be used in a combine harvester but would require additional control sensors.

Advantages offered by robot control include a large reduction in labour costs plus the ability to work long hours without tiring.

"We would also expect faster working speeds from a robot," says Mr Pype. "Speed for most field machines is limited by the driver – and the comfortable speed for windrowing appears to be 3.5-4mph. This can be increased up to 8mph without a driver on board."

A robotic control system would add about 15% to the cost of the windrower, but there would also be cost savings. If the operator only takes the machine to the field and does the headlands a less expensive cab could be fitted.

My Pype believes a robot controlled windrower could be available within about four years.n

Robotic control for New Hollands 2550 windrower. Inset: Note the two cameras which the computer uses to "see" the row edge.