Optical Header Height Control for Agricultural Harvesters
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Solution Overview
Problem
Conventional automatic header height control systems for agricultural harvesters are complex and prone to inaccuracies due to electromechanical sensor mechanisms that require frequent recalibration and have a delay in responding to ground topography changes, leading to potential damage to the crop cutter and reduced crop yield.
Innovation Solution
A light beam emitter and receiver system with apertured sensor guides that communicate with controllers to adjust the header's height and tilt in real-time, allowing for precise adaptation to ground surface changes without the need for extensive user adjustments and minimizing the distance between the skid plate and the crop cutter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electromechanical sensor mechanisms are used for header height control, then header height adjustment capability is provided, but system complexity increases and measurement precision decreases due to calibration requirements
Solution Approach 1:
The patent replaces complex electromechanical sensor mechanisms with a simple optical system consisting of a light source, light sensor, and apertured guide. This substitution eliminates mechanical linkages, tie rods, springs and associated calibration requirements while achieving accurate header height measurement through optical detection of the aperture's vertical position
Solution Approach 2:
The patent uses an optical copy (light beam) to detect the position of the apertured guide rather than direct mechanical contact. The light beam serves as an information carrier that transfers position data from the sensor guide to the receiver without physical connection, eliminating the need for complex mechanical sensing mechanisms
2Reliability
If feeler arms are positioned far behind the crop cutter, then sensor mechanism complexity is reduced, but response time to ground topography changes increases causing cutter damage
Solution Approach 1:
The patent positions the apertured sensor guide directly on the skid plate at the forwardmost position of the header, allowing the sensor to detect ground topography changes before the crop cutter encounters them. This preliminary detection enables the control system to adjust header height in advance, preventing cutter damage from sudden ground variations
3Adaptability or versatility
If multiple movable sensor components are used for height control, then header height adjustment capability is improved, but ease of operation decreases due to frequent recalibration requirements
Solution Approach 1:
The patent eliminates the need for manual calibration by using a fixed apertured guide with predetermined aperture positions that automatically correspond to specific header height settings. The system self-regulates through the mechanical constraint of the aperture geometry, removing dependence on operator skill and experience for calibration
Solution Approach 2:
Instead of using movable sensor components that require calibration, the patent inverts the approach by using a fixed apertured guide where the aperture itself defines the measurement reference. The sensor detects the position of the fixed aperture rather than tracking a movable target, eliminating calibration requirements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution simplifies the header height control system, enhances accuracy, and reduces the likelihood of crop cutter damage by quickly responding to ground topography changes, thereby optimizing crop recovery and reducing manual calibration needs.
Implementation Method 1
a light beam emitter and a light beam receiver or sensor which detects light transmitted by the emitter
Implementation Method 2
the sensor guide either allows or blocks passage of the light beam from the emitter to the receiver
Data Source
AI summary
An improved automatic height adjustment system for use with a header of an agricultural harvester is provided. The system includes apparatus and methods utilizing detection of a light beam at or near the skid plate of a header to adjust the height of the header relative to the ground surface. The apparatus includes an emitter for emitting a beam of light to a receiver. An apertured sensor guide is positioned between the emitter and the receiver. The sensor guide is in communication with a controller. If the body of the sensor guide is detected as blocking passage of light to the receiver then the controller operates an extensible actuator to raise or lower the header relative to the ground surface. The system provides rapid header height adjustment in response to detected changes in elevation of the skid plate as the harvester traverses a crop field.