Non-Contact Fruit Firmness Measurement Using Fluid Impulse
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Solution Overview
Problem
Current automatic fruit graders face challenges in determining the firmness of fruits non-destructively and efficiently, as existing methods require physical contact, are complex, and struggle with high-speed processing, leading to reduced throughput and accuracy issues.
Innovation Solution
A system that uses a non-contact method to induce a physical vibration in fruits using a short burst of fluid, employing a spool valve to generate an impulse of fluid that impinges the fruit, and a laser Doppler vibrometer to detect the resulting vibrations, allowing for the determination of firmness without physical contact and at high speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If contact-based firmness sensors are used to measure fruit firmness, then measurement accuracy is improved, but system complexity and throughput are reduced
Solution Approach 1:
The patent replaces contact-based mechanical firmness sensors with a non-contact acoustic measurement system. A speaker generates acoustic impulses that vibrate the fruit, and a microphone detects the resulting vibrations to determine firmness. This eliminates complex mechanical assemblies like bellows and synchronized positioning mechanisms while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces acoustic waves as an intermediary between the measurement system and the fruit. Instead of direct mechanical contact, acoustic impulses are used to excite the fruit's natural vibrations, which are then detected and analyzed to infer firmness properties.
2Measurement precision
If contact-based firmness sensors are used to measure fruit firmness, then measurement accuracy is improved, but processing speed is reduced
Solution Approach 1:
The patent replaces slow mechanical contact-based measurement systems with rapid acoustic measurement. The acoustic impulse method can measure multiple fruits per second without the mechanical synchronization and positioning delays inherent in contact-based systems, thereby increasing throughput while maintaining accuracy.
3Measurement precision
If multiple deformation measurements are taken at different fruit locations, then measurement accuracy is improved, but measurement time increases
Solution Approach 1:
The patent uses acoustic vibration to excite the fruit's natural resonant frequencies. By analyzing the vibration spectrum and identifying peak frequencies, the system can determine firmness from a single measurement location. This eliminates the need for multiple measurements at different fruit locations while maintaining or improving accuracy through resonance-based detection.
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
Enables accurate and efficient determination of fruit firmness at rates exceeding ten objects per second, reducing mechanical complexity and avoiding damage to the fruit, while consuming less compressed air compared to existing methods.
Implementation Method 1
employing a spool valve to generate an impulse of fluid that impinges the fruit
Implementation Method 2
a laser Doppler vibrometer to detect the resulting vibrations
Implementation Method 3
a laser Doppler vibrometer to detect the resulting vibrations
Data Source
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AI summary
A system (100) for determining a property of an object (106) comprises an inducing arrangement (102), a detector (104) and a processor. The inducing arrangement (102) is configured to generate an impulse of fluid and for directing the impulse of fluid towards the object to induce a physical vibration of the object (106). The inducing arrangement (102) does not contact the object 106 when inducing the physical vibration of the object (106). The detector (104) is configured to detect the physical vibration of the object (106). The detector (104) does not contact the object 106 when detecting the physical vibration of the object (106). The processor is coupled to the detector (104) for determining the property of the object (106) based on at least the detected physical vibration.