CN109997804B

CN109997804B - Trawl net sac mesh opening angle monitoring device

Info

Publication number: CN109997804B
Application number: CN201910378960.4A
Authority: CN
Inventors: 杨炳忠
Original assignee: South China Sea Fisheries Research Institute Chinese Academy Fishery Sciences
Current assignee: South China Sea Fisheries Research Institute Chinese Academy Fishery Sciences
Priority date: 2019-05-08
Filing date: 2019-05-08
Publication date: 2021-09-10
Anticipated expiration: 2039-05-08
Also published as: CN109997804A

Abstract

The invention discloses a trawl sac mesh opening angle monitoring device, which comprises: the monitoring device comprises a trawl and a plurality of monitoring pieces arranged on the trawl; the tail end of the trawl is provided with a contraction port, the contraction port is provided with a pull wire, and the opening or closing of the contraction port can be controlled through the pull wire; the monitoring pieces are arranged at four corners of meshes of the trawl, and the monitoring pieces at diagonal positions of the same mesh form a group; two groups of monitoring components on the same mesh can detect the diagonal length of the mesh.

Description

Trawl net sac mesh opening angle monitoring device

Technical Field

The invention relates to a monitoring device, in particular to a trawl sac mesh opening angle monitoring device.

Background

The trawl is a fishing gear which is dragged by a fishing boat and forces a caught object to enter a net bag. The net bag is a bag-shaped part for collecting the final catch of the trawl. The trawl is the fishing gear with highest fishing efficiency and maximum yield in 12 types of fishing gears. However, due to the continuous decline of offshore fishery resources and the proposal of the concept of responsible fishing, the adverse effect of trawling on fishery resources is more and more highly concerned by all the communities. The bottleneck problem in developing responsible trawl fisheries is the poor selectivity of its cod end. The cause of this problem is many. Among them, the structure of trawl bag is an important cause of its poor selectivity. The mesh size and the opening angle of the mesh sac are the most important factors for selectivity. The mesh size is relatively easy to quantify. The opening angle of the mesh will vary as the catch accumulates. Only by determining the change rule of the mesh opening angle along with the gathering of the fish catches can the selectivity of the net sacs be improved from a deep level. Real-time monitoring and measuring of the mesh opening angle are important means for mastering the change rule of the mesh opening angle. However, there is no related art for monitoring the opening angle of the trawl net in trawl operation. In order to solve the problem, the invention provides a trawl sac mesh opening angle monitoring device.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides a trawl sac mesh opening angle monitoring device.

In order to achieve the purpose, the invention adopts the technical scheme that: a trawl net sac mesh opening angle monitoring device comprises: the monitoring device comprises a trawl and a plurality of monitoring pieces arranged on the trawl; the tail end of the trawl is provided with a contraction port, the contraction port is provided with a pull wire, and the opening or closing of the contraction port can be controlled through the pull wire; the monitoring pieces are arranged at four corners of meshes of the trawl, and the monitoring pieces at diagonal positions of the same mesh form a group; two groups of monitoring components on the same mesh can detect the diagonal length of the mesh.

In a preferred embodiment of the invention, a plurality of monitoring members are spaced along the axis of the trawl.

In a preferred embodiment of the present invention, the monitoring member is a displacement sensor.

In a preferred embodiment of the present invention, a weight sensor is further disposed on the trawl.

In a preferred embodiment of the invention, the variation of the trawl volume can be analyzed by the variation of the mesh diagonal length.

In a preferred embodiment of the invention, the proportion of jellyfishes in the trawl is analyzed according to the volume-to-weight ratio of the trawl.

In a preferred embodiment of the invention, when the proportion of the mother water in the catch in the trawl is more than 50%, the contraction port is opened, the catch in the trawl is abandoned, and then the catch is caught again.

In a preferred embodiment of the present invention, the data detected by the monitoring device is transmitted to the computer by wireless signals.

The invention solves the defects in the background technology, and has the following beneficial effects:

(1) can carry out the subregion through the monitoring piece along trawl axis direction interval distribution and detect the trawl mesh to can open the angle to the mesh in the different regions of trawl and compare and measure and the record, and then can improve the selectivity of net bag.

(2) Because jellyfish volume is great, but weight is lighter, through displacement sensor and weight sensor's cooperation, can analyze out the proportion of jellyfish in the catch, when jellyfish proportion is greater than 50%, open the shrinkage pool, abandon the catch in the trawl, then carry out the fishing of next time.

(3) Displacement sensor can detect the relative displacement of diagonal node on the mesh, detects the mesh size and opens the change of angle through the relative displacement of node, opens the change of angle according to the mesh, judges the volume of trawl catch thing, through the mode that displacement sensor detected for when using the trawl, carry out the mesh in step and open the angle and detect.

Drawings

The invention is further explained below with reference to the figures and examples;

FIG. 1 is a partial perspective block diagram of a preferred embodiment of the present invention;

FIG. 2 is a schematic view of the relative displacement of the monitoring member of the preferred embodiment of the present invention;

in the figure: 1. a pull wire; 2. a monitoring member; 3. mesh openings; 4. a constriction; 5. hauling a net; 6. and (6) pulling the rope.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings and examples, which are simplified schematic drawings and illustrate only the basic structure of the invention in a schematic manner, and thus show only the constituents relevant to the invention.

As shown in fig. 1-2, a trawl sac mesh opening angle monitoring device comprises: the monitoring device comprises a trawl 5 and a plurality of monitoring pieces 2 arranged on the trawl 5;

specifically, the tail end of the trawl 5 is provided with the contraction port 4, the contraction port 4 is provided with the stay wire 1, the contraction port 4 can be controlled to be opened or closed through the stay wire 1, the stay wire 1 is fixed on the outer side of the trawl 5 through the fixing ring, the stay wire 1 cannot be far away from the trawl 5, the stay wire 1 is wound by sundries in water, and the safety is high; one end of the trawl 5 is also provided with a traction rope 6, the trawl 5 is fixed at the tail part of the fishing boat through a hanging ring at the end part of the traction rope 6, the monitoring parts 2 are arranged at four corners of meshes 3 of the trawl 5, and the monitoring parts 2 at the diagonal positions of the meshes 3 are in a group; two sets of monitoring members 2 on the same mesh 3 are capable of detecting the diagonal length of the mesh 3.

A plurality of monitoring 2 along 5 axis direction interval distributions of trawl, can carry out the subregion through 5 axis direction interval distributions's of trawl monitoring 2 and detect 5 meshes 3 to can open the angle to trawl 5 not regional 3 and compare and measure and the record, and then can improve the selectivity of net bag.

Monitoring piece 2 is displacement sensor, and displacement sensor can detect the relative displacement of diagonal node department on the mesh 3, detects the change of mesh 3 size and opening the angle through the relative displacement of node, opens the change of angle according to mesh 3, judges the volume of the thing of catching of trawl 5, through the mode that displacement sensor detected for when using trawl 5, carry out mesh 3 in step and open the angle and detect.

The trawl 5 is also provided with a weight sensor, the change of the volume of the trawl 5 can be analyzed through the change of the diagonal length of the meshes 3, the proportion of jellyfish in the trawl 5 is analyzed through the volume-to-weight ratio of the trawl 5, when the proportion of jellyfish in the catch in the trawl 5 is more than 50%, the contraction port 4 is opened, the catch in the trawl 5 is abandoned, and then the catch is fished again.

Because jellyfish volume is great, but weight is lighter, through displacement sensor and weight sensor's cooperation, can analyze out the proportion of jellyfish in the catch, when jellyfish proportion is greater than 50%, open shrink mouth 4, abandon the catch in trawl 5, then carry out the fishing of next time.

Data that monitoring piece 2 detected are through radio signal transmission to computer, can remote monitoring 5 meshs of trawl 3 open angle through the computer to and the volume of catch in 5 is compared with the weight, analyzes out the proportion of jellyfish in 5 trawls, then selects whether to abandon the catch.

In light of the foregoing description of the preferred embodiment of the present invention, it is to be understood that various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A trawl net sac mesh opening angle monitoring device comprises: the monitoring device comprises a trawl and a plurality of monitoring pieces arranged on the trawl; the trawl is characterized in that a contraction port is arranged at the tail end of the trawl, a pull wire is arranged on the contraction port, and the contraction port can be controlled to be opened or closed through the pull wire;

the monitoring pieces are arranged at four corners of meshes of the trawl, and the monitoring pieces at diagonal positions of the same mesh form a group;

two groups of monitoring components on the same mesh can detect the diagonal length of the mesh;

the monitoring pieces are distributed at intervals along the axis direction of the trawl;

the trawl net is also provided with a weight sensor;

the change of the trawl volume can be analyzed through the change of the diagonal length of the mesh;

analyzing the proportion of jellyfishes in the trawl according to the volume-to-weight ratio of the trawl;

when the proportion of the mother water in the catch in the trawl is more than 50%, the contraction port is opened, the catch in the trawl is abandoned, and then the catch is caught again.

2. The trawl sac mesh opening angle monitoring device according to claim 1, wherein: the monitoring piece is a displacement sensor.

3. The trawl sac mesh opening angle monitoring device according to claim 1, wherein: and the data detected by the monitoring piece is transmitted to a computer through a wireless signal.