28 February 1997

MAFF to finance robot weeder development

PRECISION farming with no operators in sight has taken a step closer to reality.

The Ministry of Agriculture is to foot the bill for developing an automatic inter-row weeder based on the experimental driverless spray vehicle designed by engineers at Silsoe Research Institute.

The robot vehicle was demonstrated for the first time last summer. It can work in crops such as field-scale vegetables which grow in rows with reasonably even spacing between individual plants. Pictures from a camera on the front of the vehicle are constantly analysed by the computer unit which controls the steering system. When the vehicle reaches the end of the rows the steering is programmed to turn it on the headland to begin the next set of rows.

The pictures are also used to identify the crop plants growing at regular intervals within each row and the weeds growing randomly outside the row pattern. The control system can be programmed to spray each crop plant with its own individual nutrient dose or spray the weeds individually with herbicide.

Development has continued since last year. Plot scale tests in specially planted brassica crops showed treating individual weed plants achieved a 90% fall in herbicide use compared with conventional blanket spraying.

Now, new funding from MAFF on Apr 1 will pay for a special research programme to use the control system to operate a down-the-row hoe.

Mechanical weed control is a logical way to use the image analysis and the computer control system, says Nick Tillett, project co-ordinator at SRI.

"The picture analysis guides the hoe blades down the rows between the crop plants, and it should be possible to achieve very accurate control," he says. "Steer-age hoeing with an operator sitting on a tractor-mounted hoe is slow and expensive, and it is also unpopular with the operator.

"We have already had some commercial interest in the idea, and the grant means we can continue the development work."

Mr Tillett believes a steerage hoe with the automatic guidance system will probably be the first commercial result of the research project, and it will be developed as an attachment for a conventional tractor with a driver. "This will help get the control system established and on the market. The spraying system and the automatic vehicle could follow later." &#42

The Silsoe Research robot spray vehicle, which is now being developed for inter-row weeding.


ROBOT WEEDER


&#8226 Camera spots rows for guidance.

&#8226 Steerage hoe removes weeds.

&#8226 Scope for camera to spot weeds between rows and spray accordingly.

&#8226 90% herbicide saving possible.