Method and apparatus for prescription application of products to an agricultural field

A control system for use in controlling functional components of a vehicle operable to change its global position, each of the functional components capable of controllable levels of activity, each functional component having device controller which controls the operation of the corresponding component in response to a control signal derived in accordance with a predetermined prescription of operation over a tract of land, the control system comprising:

• means for storing in a digital memory information defining a digital map representative of the prescription over the tract of land, the map being defined by a number of layers, each layer corresponding to one of the functional components, and each layer including a number of zones, each zone corresponding to a level of activity of the corresponding component in accordance with the prescription for the tract of land at a plurality of global positions within the zone;
• means for storing a data table containing control signal values for each of said number of zones in each of said number of layers, said control signal values being indicative of the level of activity of the functional component associated with a corresponding layer at positions of the vehicle within a corresponding zone;
• navigation means for determining the current position of the vehicle on the tract of land in global coordinates as the vehicle moves over the tract;
• and
• means for transmitting, to each device controller, selected ones of said control signal values corresponding to said zone of each layer for which the determined current position of the vehicle corresponds to one of said plurality of global positions within the zone.

A prescription farming control system for use in controlling product delivery mechanisms mounted on an applicator vehicle, the delivery mechanisms operable to deliver product to spreader mechanisms for spreading products over an agricultural field, each of the product delivery mechanisms having a device controller which controls the rate of operation of the corresponding delivery mechanism in response to a control signal derived in accordance with a prescription for the field, the control system comprising:

• means for storing in a digital memory information defining the rate of operation of each of the delivery mechanisms at each of a plurality of global positions within the agricultural field;
• a graphics processor having;
• a graphics memory with an active invisible page and an inactive visible page;
• means for digitally drawing a layer map corresponding to a user-selected one of the delivery mechanisms on said inactive page, and for visually displaying said layer map of said inactive page;
• means for digitally drawing on said active page a layer map sequentially corresponding to the remaining ones of the delivery mechanisms;
• wherein each layer map includes information indicative of the rate of operation of the corresponding mechanism;
• navigation means for determining the current position of the applicator vehicle on the agricultural field in global coordinates as the vehicle moves over the field;
• means for sequentially interrogating each layer map as it is drawn on said active page to read said information at a location on said each layer map corresponding to the determined current position of the applicator vehicle and generating a control signal value in relation to the rate of operation of the delivery mechanism corresponding to said location on each said layer map;
• and
• means for transmitting control signals to each of the device controllers based upon said control signal value obtained from each said layer map.