Active Fish Sorting System Using Ultrasound Detection
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Solution Overview
Problem
Current fish-sorting systems in dragged fishing nets are not reliable in distinguishing and releasing fish of sizes smaller than the desired size, leading to unintended catches and potential harm to non-commercial fish.
Innovation Solution
A fish-sorting system equipped with detection devices (such as ultrasound sensors and cameras) that measure fish size and species, a processing unit for comparison, and a sorting device with a flap mechanism to actively retain larger fish and release smaller ones, ensuring only commercial fish are caught and non-target species are given a chance to survive.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive mesh-based sorting is used in the fishing net, then the device complexity is low, but the reliability of size-based fish sorting deteriorates because small fish cannot reliably escape
Solution Approach 1:
The patent replaces the passive mechanical mesh-based sorting system with an active electronic detection and control system. Distance sensors (optical, acoustic, or electromagnetic) detect fish size, and a control unit activates sorting mechanisms (flaps, gates, or water jets) to reliably sort fish by size, overcoming the limitations of passive mesh structures.
Solution Approach 2:
The patent introduces an intermediary control system between fish detection and physical sorting. The control unit processes sensor data and coordinates the activation of multiple sorting components, enabling reliable size-based separation while managing system complexity through centralized control.
2Productivity
If all caught fish are brought on board for sorting, then the measurement precision can be ensured, but the loss of time and productivity increases due to onboard sorting work
Solution Approach 1:
The patent performs fish size detection and sorting decisions while the net is still in the water, before the catch is brought on board. This preliminary action eliminates the need for time-consuming onboard sorting operations, significantly improving productivity and reducing time loss.
Solution Approach 2:
The fishing net system performs its own sorting function autonomously in the water using integrated sensors and control mechanisms. The system sorts fish by size automatically without requiring subsequent manual intervention on board, making the fishing operation more efficient.
3Ease of operation
If mesh width is increased to allow small fish escape, then the ease of operation improves, but the manufacturing precision of the net structure deteriorates
Solution Approach 1:
The patent replaces the mechanical mesh structure's sorting function with an active electronic detection and control system. This substitution allows the use of uniform mesh construction while achieving precise size-based sorting through sensors and controlled mechanisms, eliminating the need for variable mesh widths.
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 system significantly reduces the risk of catching undesired fish by actively sorting fish, optimizing onboard work by preventing the sorting of non-commercial fish and enhancing their survival chances by not bringing them on board.
Implementation Method 1
the detection device may comprise one or more distance sensors... An ultrasound sensor may, for example, be selected as a distance sensor of this kind
Implementation Method 2
an ultrasound sensor with doppler technique
Implementation Method 3
the detection device may comprise one or more light sensors
Data Source
AI summary
A fish-sorting system for sorting fish in a dragged fishing net (1), wherein the fish are actively sorted by means of a detection device (2, 3) which detects at least one size of a fish to be sorted; a processing unit which compares the size detected by the detection means (2, 3) with the desired size; and a sorting device (4) which retains fish in the fishing net (1) of a size greater than the desired size and which releases fish of a size smaller than the desired size from the fishing net (1) on the basis of the comparison between the detected size and the desired size carried out by the processing unit.