Resonant Capacitive Crop Sensor for Grain and Straw Differentiation
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Solution Overview
Problem
Existing sensor systems in agricultural machines are unable to distinguish between different elements in a crop flow, such as grains and straw, and cannot accurately detect the type of elements impacting or exerting force on the sensor surface.
Innovation Solution
A sensor system comprising a resonant circuit with a capacitive and inductive component, where the capacitive component is designed as a planar capacitor, allowing for the detection of changes in capacitance and resonance frequency influenced by individual elements, enabling differentiation between grain and straw elements based on permittivity, and counting of elements in a crop flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor measures force or impact to detect crop elements, then the number of elements can be detected, but the sensor cannot identify the type of elements (grain vs. straw)
Solution Approach 1:
The patent applies parameter changes by utilizing the permittivity (dielectric constant) of different crop elements as a distinguishing parameter. Grain elements have significantly higher permittivity than straw elements, causing different changes in the resonant frequency of the capacitive sensor. By measuring and comparing the resonant frequency shifts, the system can identify element types while maintaining accurate counting capability.
2Productivity
If the resonant frequency is measured at high speeds, then productivity is improved, but measurement accuracy may deteriorate
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between permittivity values and resonant frequency changes during system calibration. During high-speed operation, the system only needs to measure the resonant frequency and quickly lookup the corresponding element type from pre-stored data, avoiding complex real-time calculations and maintaining both speed and accuracy.
3Area of stationary object
If the capacitive element is positioned to detect all crop elements, then detection coverage is improved, but the sensor cannot distinguish between grain and straw elements
Solution Approach 1:
The patent resolves this contradiction by utilizing parameter changes - specifically, the difference in permittivity between grain and straw elements. Even though the same capacitive sensor area detects both element types, the varying permittivity values cause distinct resonant frequency shifts, enabling the system to differentiate element types while maintaining comprehensive detection coverage.
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
The sensor system effectively differentiates between grain and non-grain elements, providing accurate counting and movement speed detection of crop flow elements, even at high speeds, ensuring reliable capture of grains in various agricultural machinery operations.
Implementation Method 1
the capacitive element is configured such that the capacitance is influenced by individual elements of the crop flow
Implementation Method 2
the resonant circuit has a resonant frequency, the resonant frequency depending on the capacitance and the inductance
Implementation Method 3
The magnitude of the change in capacitance and resonant frequency depends on the permittivity of the element in the crop flow
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Sensor system for counting elements of a crop flow, particularly in an agricultural machine, wherein the sensor system comprises a resonant circuit and a measuring device, wherein the resonant circuit consists of at least one capacitive element with a capacitance and an inductive element with an inductance, wherein the resonant circuit has a resonant frequency, the resonant frequency depending on the capacitance and the inductance, wherein the measuring device is provided and configured to determine the resonant frequency of the resonant circuit, wherein the capacitive element is arranged in the area of the crop flow, wherein the capacitive element is configured so that the capacitance is influenced by individual elements of the crop flow, and wherein the sensor system is provided and configured to infer at least one property of the respective element of the crop flow from the resonant frequency of the resonant circuit.