Electromagnetic Seed Sensor Assembly for High-Rate Planting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seed counting systems face challenges with accuracy due to dirt, dust, and seed coatings, particularly with small seeds like Milo and high seed rate seeds like soybeans, and struggle to distinguish between seeds and dust using photoresponsive and RF sensors with low signal-to-noise ratios and lack differential detection or phase sensing.
Innovation Solution
The development of RF or microwave seed sensors that utilize Fabry-Perot cavities, phase differential driving signals, and differential detection to improve sensitivity, featuring a fringing field design with external tuning elements and a unique RF capacitance design with 180° out-of-phase driving signals to create a uniform electric field for enhanced seed detection, along with real-time feedback systems for optimal seed placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If photoresponsive devices are used to sense seeds, then seed passage can be detected, but accuracy deteriorates due to dirt, dust, and seed coatings interfering with the light signal
Solution Approach 1:
The patent replaces photoresponsive (optical) detection systems with electromagnetic sensing systems that use conductive plates to detect changes in electrical field caused by seed passage. This substitution eliminates the interference problems associated with light-based detection in dirty environments, as the electromagnetic field-based system is not affected by dirt, dust, or seed coatings.
Solution Approach 2:
The patent changes the detection parameter from optical properties (light transmission) to electrical properties (capacitance changes). By measuring changes in electrical field rather than light signal, the system achieves accurate seed detection regardless of the presence of dirt, dust, or coatings that would otherwise interfere with optical detection.
2Measurement precision
If conventional RF sensors are used, then seed detection is possible, but signal-to-noise ratio remains low making it difficult to distinguish seeds from dust
Solution Approach 1:
The patent implements feedback mechanisms where the system continuously monitors the electromagnetic field changes and uses this information to distinguish between seeds and dust particles. The feedback loop allows the system to learn and adapt to the characteristic signals of seeds versus dust, improving discrimination accuracy over time.
Solution Approach 2:
The patent employs dynamic detection methods that analyze the temporal characteristics of electromagnetic field changes. By examining how the field changes over time as objects pass through, the system can distinguish between seeds and dust based on their different motion patterns, sizes, and dielectric properties, thereby improving signal-to-noise ratio.
3Measurement precision
If photoresponsive systems are used, then seed counting can be performed, but accuracy deteriorates when seeds flow in groups rather than one-by-one
Solution Approach 1:
The patent uses preliminary action by pre-tuning the electromagnetic field frequency and parameters to be sensitive to the specific dielectric properties of seeds. This pre-calibration allows the system to accurately detect individual seeds even when they pass in groups, as the electromagnetic field is already optimized to respond to seed characteristics before the counting process begins.
Solution Approach 2:
The patent employs periodic electromagnetic field modulation to detect seeds. By using periodic excitation and analyzing the periodic response, the system can distinguish individual seeds within groups through frequency analysis, maintaining counting accuracy even at higher seed flow rates where seeds pass in clusters rather than singly.
4Measurement precision
If microwave sensors with waveguides are used, then seed detection is possible, but device complexity increases compared to simpler sensor designs
Solution Approach 1:
The patent extracts the essential detection function from complex microwave waveguide systems and implements it using simpler conductive plates that generate electromagnetic fields. By taking out only the necessary field-generation and detection capability and implementing it with minimal structure, the system achieves seed detection without the complexity of full waveguide assemblies.
Solution Approach 2:
The patent uses conductive plates as intermediaries to create electromagnetic fields for seed detection. These plates serve as simple mediators that convert electrical signals to electromagnetic fields and back, providing an intermediate step that simplifies the overall system architecture compared to direct microwave waveguide implementations while maintaining detection precision.
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 sensors achieve >99% accuracy in counting seeds at high seed rates, providing real-time feedback for optimal seed placement and yield, with improved sensitivity and reduced seed spatial variability.
Implementation Method 1
an electromagnetic field is set up transversely of the path of travel, such as in the seed chute or channel and detects changes in the electromagnetic field due to the passage of such seeds or other discrete articles
Implementation Method 2
This type of technology generally makes use of the dielectric properties of seeds and/or other material or articles flowing along a path of travel to provide for detection of such seeds, material or other articles
Implementation Method 3
detects changes in the electromagnetic field due to the passage of such seeds or other discrete articles or the flow of material therethrough
Data Source
AI summary
Seed sensors that surround the conventional mounting location on existing seed tubes. The seed sensors sense seeds using electromagnetic fields, including RF and microwave fields. In one embodiment, a first seed sensor has a coaxial Fabry-Perot resonant cavity which is formed between two coaxial portions of a conduit that surround the seed tube. Another seed sensor uses a capacitive design. In one embodiment, the driving signals are applied 180 degrees out of phase. The detected phase shift between the reference and reflected signals provides reliable seed counting. Electronics extract the signal from the sensing field.