Header Floatation Control Using Predictive Ground Following
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Solution Overview
Problem
Existing header floatation systems in agricultural vehicles face variability in floatation force due to factors like hydraulic oil temperature, hysteresis, and changing ground conditions, requiring frequent manual adjustments and leading to issues like excessive ground contact and premature wear.
Innovation Solution
A method and system that adjust the lift pressure of hydraulic actuators based on calculated velocity, acceleration, and change in acceleration to maintain a desired ground reaction force, using sensors and a control system to automatically adapt to changing ground contours and conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a pressure reducing valve is used to control accumulator pressure for header floatation, then the spring force can be adjusted, but the actual floatation force varies significantly due to hydraulic oil temperature, hysteresis, and friction changes
Solution Approach 1:
The system uses a position sensor to detect header position and feeds this information back to the controller, which then adjusts the pressure reducing valve to maintain consistent floatation force. This closed-loop feedback mechanism compensates for variations caused by temperature, hysteresis, and friction changes.
Solution Approach 2:
The invention replaces the purely mechanical pressure reducing valve control with an electronically controlled system using a solenoid valve and controller that processes sensor signals. This substitution enables more precise and consistent floatation force control by eliminating mechanical hysteresis and enabling electronic compensation.
2Reliability
If manual adjustment of PRV signal is performed to maintain desired floatation force, then floatation can be maintained under changing conditions, but frequent manual intervention is required
Solution Approach 1:
The system automatically maintains desired floatation force by using the position sensor and controller to adjust the pressure reducing valve without operator intervention. The header effectively serves itself by the system automatically compensating for weight changes, terrain variations, and environmental conditions.
Solution Approach 2:
The closed-loop feedback system continuously monitors header position and automatically adjusts floatation force, eliminating the need for manual PRV signal adjustments. The controller processes position feedback and makes real-time pressure adjustments to maintain optimal floatation.
3Measurement precision
If hydraulic pressure sensing is used to control header height, then pressure can be monitored, but friction and stiction cause inaccurate pressure readings that do not reflect actual header height
Solution Approach 1:
The invention replaces hydraulic pressure sensing with direct position sensing using a position sensor that mechanically or electrically measures the actual header position. This substitution eliminates the indirect and friction-affected pressure measurement method in favor of direct position measurement.
Solution Approach 2:
The position sensor acts as an intermediary that directly measures header position without being affected by hydraulic friction or stiction. This intermediary measurement device provides accurate position information that is not corrupted by hydraulic system losses.
4Adaptability or versatility
If header is allowed to float over undulating terrain, then floatation performance improves, but ground contact force becomes inconsistent leading to premature wear
Solution Approach 1:
The system uses position feedback to continuously monitor header position over terrain and adjusts floatation force to maintain consistent ground contact force. This feedback control prevents both excessive force that causes wear and insufficient force that loses crop contact.
Solution Approach 2:
The system dynamically adjusts floatation force based on real-time position conditions rather than maintaining a fixed floatation setting. The controller modifies pressure dynamically to compensate for terrain variations while maintaining consistent ground contact force, extending component life.
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 approach ensures consistent ground reaction force, reducing manual intervention, minimizing wear, and improving floatation performance over varying terrain, thereby enhancing operational efficiency and reducing maintenance needs.
Implementation Method 1
the gas can expand and contract to provide a spring-like resilience to the hydraulic circuit. Thus, the header is effectively suspended on an air spring.
Implementation Method 2
The hydraulic actuators comprise piston and cylinder assemblies that use hydraulic fluid to move the piston relative to the cylinder.
Data Source
AI summary
A predictive algorithm for ground conditions using header (108) position feedback to support header (108) floatation control. A velocity, an acceleration, and a change in acceleration associated with a change in header (108) position due to ground contour changes are calculated. Using position feedback, the header floatation control system (400) can predict ground contours to increase floatation ground force when cresting hills and decrease floatation ground force when approaching hills.