15 September 2000

Auto-steer DGPS due 2003

By Andy Moore

A DGPS guidance system developed to automatically steer tractors with an accuracy of  5cm will be marketed by Renault Agriculture in 2003.

The system, Easy Drive, has been designed to work with Renaults larger Ares and Atles tractors after two years development between Renault, research institute Cemagref and the Blaise Pascal University in France.

Renault says the system will "significantly boost" productivity in precision operations such as drilling and inter-row hoeing by its ability to automatically steer tractors very accurately.

Easy Drive employs a dual frequency receiver linked to a computer inside the cab, and a steering sensor with microprocessor outside the tractor. Decoded DGPS signals are sent to the in-cab receiver from a mini DGPS base station in the corner of the field. This comprises a primary receiver and decoder unit.

The decoded DGPS signals are used to identify the exact location of the tractor and implement in the field, allowing two main functions to be carried out – route recording and automatic steering.

Route recording is typically performed during a preliminary soil engaging operation, such as stubble cultivating.

The route of the tractor and implement recorded in the preliminary cultivation operation is then stored in the computers memory and used to create a map, which is displayed on a monitor inside the cab.

As long as the implement widths are identical, Easy Drive is then set to repeat the exact path made in the previous operation, which is carried out with the microprocessor automatically controlling the tractors hydraulic steering system.

Although Easy Drive is designed to provide highly accurate steering for precision operations such as drilling and inter-row hoeing, at this stage the system still requires an operator to be present inside the cab as a safety measure.

The benefits of Easy Drive are said to be reduced overlap during cultivating and drilling, enabling higher work rates while saving valuable inputs, such as seed and fertiliser.

Also, because the system promises hands-free steering, Renault believes driver fatigue will be cut significantly, allowing more attention to be paid to controlling implements.

Easy Drive will cost about £2000. &#42

Increased output? Renaults Easy Drive DGPS guidance system has been developed to automatically steer tractors with an accuracy of  5cm.