Combine Harvester Header Height Control via Speed-Weighted Sensor Fusion
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Solution Overview
Problem
Combine harvester header height adjustment systems face sub-optimal harvesting when traveling at slow speeds due to premature detection of ground contours by forward-looking sensors, leading to unnecessary upward or downward movement of the header.
Innovation Solution
A system that includes ground speed, ground height, and forward-looking sensors, with a controller calculating and weighting the sensor inputs based on combine speed to optimize header height adjustments, reducing premature movements at low speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If forward-looking sensors are used to detect ground contours at high speeds, then advanced detection capability is improved, but premature header movement occurs at low speeds
Solution Approach 1:
The system dynamically adjusts the weighting between forward-looking sensor data and ground contact sensor data based on the combine's ground speed. At high speeds, forward-looking sensor input is weighted more heavily to provide advanced detection. At low speeds, the weighting shifts to rely more on ground contact sensor input to prevent premature header movement. This dynamic adaptation resolves the contradiction between advanced detection capability and control accuracy across varying operating conditions.
Solution Approach 2:
The controller changes the parameter of sensor input weighting as a function of ground speed. By adjusting the relative weights assigned to forward-looking sensor data versus ground contact sensor data based on the detected ground speed, the system optimizes header height control for different operating conditions, preventing premature movements at low speeds while maintaining advanced detection at high speeds.
2Loss of information
If forward-looking sensors detect contour changes too far in advance at slow speeds, then detection range is improved, but header movement timing becomes premature
Solution Approach 1:
The system uses feedback from both forward-looking sensors and ground contact sensors to continuously monitor actual header-to-ground distance. By comparing the predicted contour from forward-looking sensors with actual ground contact measurements, the controller can adjust the timing and magnitude of header movements, ensuring they occur at the appropriate moment rather than prematurely. This feedback mechanism resolves the timing issue at low speeds.
3Measurement precision
If ground contact sensors are used alone, then immediate ground contour detection is improved, but advanced detection capability is lost
Solution Approach 1:
The system merges the capabilities of two different sensor types: forward-looking sensors that provide advanced detection of upcoming ground contours, and ground contact sensors that provide precise measurement of actual ground position. By combining these complementary sensing approaches and intelligently weighting their inputs based on operating conditions, the system achieves both advanced detection capability and precise measurement without the limitations of using either sensor type alone.
Data Source
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AI summary
A method and apparatus for controlling a header height of a combine harvester that includes a header, a ground speed sensor, a ground height sensor configured to detect a ground contour directly beneath the header, a forward looking sensor (FLS) configured to detect a ground contour forward of the header, and a controller. The controller receives signals from the ground speed sensor, the ground height sensor and the FLS, and calculates a header height output as a function of (i) an output of the ground speed sensor, which represents a ground speed of the combine, (ii) an output of the ground height sensor, and (iii) an output of the FLS. The controller is further configured to weight the outputs of the ground height sensor and the FLS as a function of the speed of the combine harvester in calculating the header height output.