Raster-based contour swathing for guidance and variable-rate chemical application

Abstract

A raster-based system for global navigation satellite system (GNSS) guidance includes a vehicle-mounted GNSS antenna and receiver. A processor provides guidance and/or autosteering commands based on GNSS-defined pixels forming a grid representing an area to be treated, such as a field. Specific guidance and chemical application methods are provided based on the pixel-defined treatment areas and preprogrammed chemical application prescription maps, which can include variable chemical application rates and dynamic control of the individual nozzles of a sprayer.

What is claimed and desired to be secured by Letters Patent is as follows: 
     
       1. A method of using a processor for guiding an agriculture sprayer vehicle including a motive component and a spray working component with a spray boom having opposite ends and multiple spray nozzles mounted in spaced relation between said ends, said components being interconnected by a power hitch adapted for laterally shifting said working component relative to said motive component, which method comprises the steps of, comprising:
 providing an XY pixel grid page corresponding to the an area, the grid page including pixels associated with different portions of the area; 
 providing a raster-based database page comprising said XY pixel grid for said area; 
 providing a processor on the vehicle; 
 providing a GNSS guidance system connected to the processor on the vehicle; 
 receiving GNSS positioning signals with said guidance system; 
 providing said GNSS positioning signals as input to said processor; 
 computing GNSS-based positioning for said vehicle with said processor; 
 defining a GNSS-defined reference point on said area and storing the reference point coordinates with said processor; 
 computing X and Y pixel indices based on said GNSS-defined vehicle position in relation to said reference point with said processor; 
 treating portions of said area with said working component; 
 with said processor marking pixels in said treated area portions as treated; 
 guiding said vehicle over said area utilizing said treated pixel information; 
 defining additional raster-based XY pixel grid pages in said area; 
 expanding said database by tiling said pixel grid pages over said area; 
 generating X and Y scale factors for said database; 
 relating said X and Y scale factors to latitude and longitude respectively; 
 computing X and Y pixel indices based on the difference between current GNSS-defined position coordinates and the reference position coordinates; 
 creating with said processor a linear or multidimensional database comprising said pixel grid pages; 
 accessing with said processor said database; 
 marking pixels in said database as treated; 
 defining a swath coverage area with said working component ends forming opposite edges of said swath; 
 with said GNSS system and said processor seeking pixels in proximity to said swath edges; 
 with said GNSS system and said processor guiding said vehicle along said swath edges; 
 providing an autosteer system on said vehicle; 
 with said processor generating steering commands using the marked pixel information and said XY pixel page database; 
 outputting said steering commands to said autosteer system for automatically steering said vehicle over said area; 
 with said processor and said GNSS system laterally shifting said working component relative to said motive component for maintaining said working component generally within said swath; 
 computing an application map for said area corresponding to treatments of pixels therein with said working component; 
 guiding said vehicle with said application map while treating said pixels; and 
 guiding the agricultural vehicle in an initial pass over the area corresponding to the grid page; 
 during the initial pass of the area marking the pixels in the XY pixel grid page associated with the portions of the area treated by the working component as applied pixels; 
 during another pass of the area, detecting a vehicle direction of travel path with said a GNSS system; 
 walking up the pixels in the XY pixel grid page along the vehicle direction of travel path to a target pixel in the XY pixel grid page; 
 testing the pixels in multiple scans in the XY pixel grid page alongside said the vehicle path for treated conditions the applied pixels based on a swath width of said the working component; and  
 guiding said the vehicle towards said the target pixel using said treated condition pixel information based on the applied pixels identified alongside said the vehicle path; 
 testing multiple distances ahead for treated pixels; 
 detecting a curve condition defined by treated pixels; 
 guiding said vehicle alongside said curve using said treated pixel information; 
 preprogramming said processor with variables corresponding to vehicle performance dynamics; 
 determining altitudes of said pixels with said GNSS system; and 
 adjusting guidance and steering for vehicle slippage, sloping surface chemical spray patterns and crop heights using said vehicle performance dynamics and said pixel altitudes. 
 
     
     
       2. The method of claim 1, including:
 testing, with the processor, multiple distances ahead for the applied pixels;   detecting, with the processor, a curve defined by the applied pixels; and   guiding, with the processor, the vehicle alongside the curve defined by the applied pixels.   
     
     
       3. The method of claim 1, including:
 determining altitudes for the portions of the area;   assigning the altitudes to the pixels associated with the portions of the area; and   adjusting guidance and steering of the vehicle based on the altitudes assigned to the pixels associated with the portions of the area covered by the working component.   
     
     
       4. The method of claim 1, including:
 defining additional XY pixel grid pages; and   combining the additional XY pixel grid pages with the provided XY pixel grid page.   
     
     
       5. The method of claim 1, including:
 identifying a swath coverage area with swath edges corresponding with opposite ends of the working component;   identifying the pixels in proximity to the swath edges; and   steering the vehicle based on the pixels in proximity to the swath edges.   
     
     
       6. The method of claim 1, including:
 assigning chemical prescription rate values to the pixels;   compute amounts of a chemical applied to the portions of the area;   compare the amounts of the chemical applied to the portions of the area with the chemical prescription rate values assigned to the pixels associated with the portions of the area; and   adjusting the amounts of additional chemical output from individual spray nozzles of the working component on the portions of the area based on the comparisons of the amounts of the chemical previously applied to the portions of the area and the chemical prescription rate values assigned to the pixels associated with the portions of the areas.