[21] Appl. No.: 08/840,771 [22] Filed: Apr. 16, 1997
Related U.S. Application Data
[60] Provisional application No. 60/016,236, Apr. 19, 1996.
[51] Int. CI. G06F 15/20
[52] U.S. CI 56/10.2 F; 364/424.07
[58] Field of Search 56/10.2 A, 10.2 F,
56/10.2 R, 10.2 J, 11.9, 16.7, DIG. 15; 172/2, 4, 4.5; 364/413.13, 424.07; 382/10, 11, 12, 13, 14, 15
[56] References Cited
U.S. PATENT DOCUMENTS
4,077,488 3/1978 Bennett, Jr. et al 180/98
4,482,960 11/1984 Pryor 364/424
4,700,301 10/1987 Dyke 364/424
5,442,552 8/1995 Slaughter et al 364/424.07
5,444,965 8/1995 Colens 56/10.2 A
OTHER PUBLICATIONS
The Philadelphia Inquirer, Jul. 11, 1996; (Farm Machines: The Next Step in Field Robotics), (Robo-Cop - A farm tractor that drives itself?).
Primary Examiner—Michael J. Carone
Assistant Examiner—Robert Pezzuto
Attorney, Agent, or Firm—Griffin, Butler, Whisenhunt &
Szipl
A self-propelled harvester is provided with apparatus for tracking a crop line and steering the harvester along the crop line without operator assistance. The apparatus includes a video camera for viewing the landscape in front of the harvester and forming an image which may be electronically scanned pixel-by-pixel and line by line to produce a video signal containing information regarding the spectral characteristics of the image at each pixel. A microprocessor is programmed to act as a discriminator and a segmentor. The discriminator produces discriminant signals D(i,j) where i is the magnitude of a discriminant function and j is the relative position of a pixel on a scan line. The segmentor determines a step function which best fits the magnitudes of the discriminant signals for one scan line. The pixel position j„ corresponding to the step of this step function is taken as a vote on the location of the crop line and thus a vote on the direction the harvester should be steered. The votes are summed for each pixel position j over one full scan of image. The summed votes are then normalized, time-weighted, and averaged with the normalized and time-weighted votes derived from previously scanned images to derive a steering command.
21 Claims, 4 Drawing Sheets
