Header Height Control Gain Adjustment for Combine Harvesters
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Solution Overview
Problem
Existing header height control systems for combine harvesters lack sensitivity and responsiveness when the crop divider snouts are run at or near the ground, leading to potential impacts with the ground surface or loss of crop due to inadequate detection of terrain changes.
Innovation Solution
A header height control system that modifies the signal output from height sensors by applying a gain or multiplier when the header is at or below a critical operating height, ensuring maximum warning time and improved responsiveness by maintaining sensor sensitivity and proportionality, even when snout tips contact the ground.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If height sensors are mounted near the snout tips to enable early ground sensing, then ground detection capability is improved, but sensor sensitivity and responsiveness deteriorate when snouts are run at or near the ground due to limited rotational movement
Solution Approach 1:
The patent applies parameter changes by modifying the electrical output signal from the height sensor through a gain circuit or software multiplication when the header is at or below a critical height. This signal amplification compensates for the reduced rotational movement of the sensing arm, maintaining adequate signal variation and control system responsiveness even when the snout tips are running at or near the ground surface.
2Productivity
If the header is lowered to run snout tips at ground level to pick up downed corn, then harvesting effectiveness is improved, but the likelihood of header impact with ground surface increases due to reduced sensor responsiveness
Solution Approach 1:
The patent implements preliminary anti-action by amplifying the height sensor signal before it reaches the header control system when operating at critical low heights. This enhanced signal provides earlier and more pronounced warning of ground contact, allowing the control system to take preventive action by raising the header before impact occurs, thus counteracting the harmful effect of reduced sensor responsiveness at low operating heights.
3Speed
If proportional header control systems are used to raise header quicker in response to ground elevation changes, then response speed is improved, but responsiveness is still compromised when snouts are run at ground level due to limited sensor rotational movement
Solution Approach 1:
The patent combines proportional header control with signal amplification by multiplying or increasing the gain of the height sensor's electrical output signal when the header is at or below critical height. This ensures that even though the sensor arm has limited rotational movement at low heights, the amplified signal provides sufficient input to the proportional control system to maintain quick and responsive header adjustment capability.
Data Source
AI summary
A header height control system and a method for improving the responsiveness of a header height control system. A height sensor is disposed with respect to the header to generate a signal varying in magnitude with respect to changes in distance between a preestablished point on the header and the ground. The magnitude of the generated signal when the header is at a predefined set point is determined. For generated signal magnitudes indicating the header is below the set point, the signal magnitudes are operably modified by applying a gain value. For generated signal magnitudes indicating the header is above the set point, the signal magnitudes may be modified by applying a different gain value. The application of a gain value or different gain values depending on the height of the header above or below the set point improves the responsiveness of the header height control system to changes in terrain.