Pulse-Modulated Valve Calibration for Agricultural Fluid Application
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Solution Overview
Problem
Current agricultural application devices face challenges in controlling the discharge of fluids accurately, leading to inefficiencies and environmental issues due to manufacturing deviations and the need for tight tolerances, which increase costs and reduce accuracy.
Innovation Solution
The use of pulse-modulated valves with a calibration unit to determine and adjust pulse modulation parameters based on manufacturing deviations, allowing for more flexible tolerance ranges and improved accuracy in fluid application, incorporating a control unit and storage device to manage these parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tight tolerances are applied to manufacturing deviations, then accuracy of fluid application is improved, but costs increase and device complexity increases
Solution Approach 1:
The patent applies parameter changes by using pulse modulation parameters (duty cycle, frequency, pulse width) to compensate for manufacturing deviations in valve characteristics. Instead of requiring tight manufacturing tolerances, the system changes the temporal parameters of valve actuation to achieve accurate fluid application rates, thereby reducing manufacturing costs while maintaining precision.
Solution Approach 2:
The patent replaces mechanical precision requirements with electronic control. Instead of relying on mechanically precise valve components, the system uses electronic pulse modulation to control valve opening times and durations, substituting mechanical tolerance requirements with electronically adjustable parameters that can be calibrated after manufacturing.
2Measurement precision
If tight tolerances are applied to manufacturing deviations, then accuracy of fluid application is improved, but device complexity increases
Solution Approach 1:
The patent introduces a calibration unit as an intermediary between the valve and the control system. This calibration unit stores characteristic values determined during calibration and provides them to the control unit, which uses them to adjust pulse modulation parameters. This intermediary layer enables accurate fluid application without requiring complex manufacturing tolerances by mediating between manufacturing variations and control requirements.
Solution Approach 2:
The patent applies preliminary action by performing calibration before actual operation. The calibration unit determines characteristic values for each valve during a calibration phase, storing these values for subsequent use. This preliminary calibration action eliminates the need for tight manufacturing tolerances by pre-characterizing each valve's actual behavior and compensating for deviations in normal operation.
3Measurement precision
If pulse modulation parameters are adjusted to compensate for manufacturing deviations, then accuracy of fluid application is improved, but control complexity increases
Solution Approach 1:
The patent applies self-service by enabling the control unit to automatically calculate and adjust pulse modulation parameters based on stored characteristic values from the calibration unit. The system performs self-calibration and self-adjustment without requiring manual intervention or complex operator input, thereby improving accuracy while keeping operation simple through automated compensation for manufacturing deviations.
Solution Approach 2:
The patent implements feedback by using the characteristic values determined during calibration to continuously adjust pulse modulation parameters. The control unit reads the actual valve characteristics from the calibration unit and uses this feedback information to calculate the appropriate pulse modulation parameters that will achieve the desired fluid application rate, compensating for manufacturing deviations automatically.
Data Source
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AI summary
The invention relates to an agricultural application device for the application of fluids such as pesticides or fertilizers in agriculture. According to the invention, the use of a pulse-width modulated valve (18) is proposed for controlling the application rate of the fluid, wherein the pulse-width modulated valve is calibrated and, during operation, is controlled according to the result of the calibration.