Method and apparatus for automatically steering a vehicle in an agricultural field using a plurality of fuzzy logic membership functions
First Claim
1. A method of guiding an agricultural vehicle having at least one steerable wheel in an agricultural field having a plurality of rows of crops, the method comprising:
- taking a picture of the rows of crops with an electronic camera;
successively processing a plurality of lines of the picture;
extracting from the plurality of processed lines at least one value indicative of a crop line;
extracting another value from the at least one value that is indicative of the lateral displacement of the crop line with respect to the vehicle;
processing the another value in a fuzzy logic input membership function, then a fuzzy logic inference engine and then a fuzzy logic output membership function to develop a signal indicative of the degree the at least one steerable wheel should be turned;
providing the signal indicative of the degree to which the steerable wheel should be turned to a feedback control circuit configured to steer the at least one steerable wheel in a direction that minimizes a difference between the signal indicative of the degree the at least one steerable wheel should be turned and another signal indicative of the degree to which the at least one steerable wheel is actually turned;
generating a valve control signal calculated to reduce the difference;
applying the valve control signal to an electro-hydraulic control valve configured to steer the at least one steerable wheel; and
steering the wheel accordingly.
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Accused Products
Abstract
A combine having a camera system is disclosed in which pictures of the ground in front of the vehicle are processed to extract the slope and intercept of a characteristic line indicative of the boundary between the cut and uncut portions of the field. A fuzzy logic algorithm compares the slope and intercept using four input membership functions and a single output membership function. If the slope and intercept extracted from the image are deemed acceptable, they are used to navigate the vehicle through the field. If they are not acceptable, the combine continues to use slope and intercept values previously deemed acceptable to guide the vehicle. This process of image data extraction and quality analysis continues repetitively as the combine traverses the field harvesting crops.
56 Citations
17 Claims
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1. A method of guiding an agricultural vehicle having at least one steerable wheel in an agricultural field having a plurality of rows of crops, the method comprising:
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taking a picture of the rows of crops with an electronic camera;
successively processing a plurality of lines of the picture;
extracting from the plurality of processed lines at least one value indicative of a crop line;
extracting another value from the at least one value that is indicative of the lateral displacement of the crop line with respect to the vehicle;
processing the another value in a fuzzy logic input membership function, then a fuzzy logic inference engine and then a fuzzy logic output membership function to develop a signal indicative of the degree the at least one steerable wheel should be turned;
providing the signal indicative of the degree to which the steerable wheel should be turned to a feedback control circuit configured to steer the at least one steerable wheel in a direction that minimizes a difference between the signal indicative of the degree the at least one steerable wheel should be turned and another signal indicative of the degree to which the at least one steerable wheel is actually turned;
generating a valve control signal calculated to reduce the difference;
applying the valve control signal to an electro-hydraulic control valve configured to steer the at least one steerable wheel; and
steering the wheel accordingly. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of guiding an agricultural vehicle having at least one steerable wheel in an agricultural field having a plurality of crop rows, the method comprising:
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taking a picture of the crop rows with an electronic camera;
extracting from the pictures row location values indicative of a location of at least one crop row;
determining, based upon at least one previous row location value, whether the row location values are valid;
and for each such row location values that are determined valid;
deriving therefrom a value indicative of a desired direction of travel;
processing the value indicative of a desired direction of travel in a fuzzy logic inference engine to produce a control signal;
providing the control signal to an automatic control loop that uses feedback control based upon the position of the at least one steerable wheel to generate a valve command signal;
applying the valve command signal to an electro-hydraulic steering control valve;
and for each such row location values that is determined invalid;
not using such invalid row location value in the automatic control loop. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification