Underwater Detection Density Index Fish Size Estimation
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Solution Overview
Problem
Conventional fish finders inaccurately estimate the size of fish due to interference from peak waveforms in dense schools, leading to overestimation of fish length.
Innovation Solution
The underwater detection apparatus calculates a density index value based on the number and intensity of peak waveforms, adjusting the target strength value to account for fish school density, thereby categorizing fish into low, medium, or high density categories to accurately estimate fish length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional fish finder detects single fish based on peak waveform intensity and shape, then detection simplicity is maintained, but measurement precision deteriorates due to interference from dense fish schools causing overestimation
Solution Approach 1:
The patent segments the detection process into multiple stages: initial peak detection, density index calculation based on multiple parameters (peak intensity, width, interval), and conditional size estimation. This segmentation allows the system to handle different fish school densities differently, improving accuracy without requiring completely new detection methods for each scenario
Solution Approach 2:
The patent changes the detection parameters dynamically based on the detected density index. When fish school density is high, the system adjusts which parameters are used for size estimation and applies correction factors. This parameter adaptation resolves the contradiction by maintaining simple detection for sparse schools while applying complex correction only when necessary for accuracy
2Measurement precision
If peak waveform analysis is used for all detected targets, then detection speed is maintained, but measurement precision deteriorates in dense fish schools due to waveform interference
Solution Approach 1:
The patent applies partial action by using full peak waveform analysis only when necessary (when density index indicates sparse schools or isolated fish). For dense schools, it uses a simplified approach with density-based correction factors. This selective application of analysis depth maintains speed while ensuring accuracy when it matters most
Solution Approach 2:
The patent substitutes detailed mechanical waveform analysis with a statistical density-based approach for certain scenarios. Instead of analyzing individual peak waveforms in dense schools, it uses the aggregate density index to estimate and correct measurements, replacing complex individual analysis with a more efficient population-based method
3Measurement precision
If TS value transformation is applied to all detected peaks, then consistency in size estimation is maintained, but measurement precision deteriorates when fish are in dense schools due to peak interference
Solution Approach 1:
The patent performs preliminary density index calculation for all detected peaks before applying TS value transformation. This preliminary assessment allows the system to identify which targets require corrected TS transformation and which can use standard transformation, ensuring precision for dense school fish while maintaining efficiency for isolated fish
Solution Approach 2:
The patent introduces the density index as an intermediary parameter that mediates between raw peak detection and final size estimation. This intermediary calculates fish school density based on multiple peak characteristics and uses this information to modulate the TS transformation process, resolving the contradiction by making the transformation adaptive rather than uniform
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 allows for more accurate estimation of fish size and generation of histograms that reflect the actual distribution of fish schools, reducing errors in dense school scenarios.
Implementation Method 1
a transducer (2) to transmit an acoustic wave into water and to receive an acoustic wave reflected on a target object
Data Source
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AI summary
An underwater detection apparatus is provided. The underwater detection apparatus includes a transmitter (2), a receiver (2), a target detector (11), a density index value estimator (12, 15, 16) and a size index value calculator (13). The transmitter (2) transmits a transmission wave. The receiver (2) obtains a receive signal based on a reflection of the transmission wave. The target detector (11) detects an underwater target object based at least in part on the receive signal. The density index value estimator (12, 15, 16) estimates a density index value of objects within a given area in a vicinity of the underwater target object. The size index value calculator (13) calculates a size index value of the underwater target object based at least in part on the density index value and a target object signal intensity representing a maximum intensity of the receive signal corresponding to the underwater target object.