Online monitoring system and method for stress of hydrographic winch drum based on fiber bragg grating

Abstract

The invention provides an on-line monitoring system and method for stress of a hydrological winch drum based on a fiber bragg grating. The system comprises a fiber bragg grating sensor, an optical fiber transmission cable, a conductive slip ring and an optical fiber demodulator, the number of the fiber grating sensors is multiple, the multiple fiber grating sensors are installed on the inner wall of a winch drum in the circumferential direction and connected with a rotating part of the conductive slip ring through an optical fiber transmission cable, and a fixed part of the conductive slip ring is connected with the optical fiber demodulator through a cable. The device is simple in structure and convenient to operate, the fiber grating sensors are circumferentially mounted along the inner wall of the winding drum, dynamic strain signals in the rotating process of the winch can be collected, the fiber transmission cable is connected to the conductive slip ring, it is guaranteed that in the rotating process of the winding drum, the cable is not wound, and the collected signals can be normally output; and the strain stress in the rotation process of the winding drum and the tension in the cable laying process of the winch can be calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrological winches, and in particular to an online monitoring system and method for hydrological winch drum stress based on optical fiber gratings. Background Art

[0002] As a ship-borne hydrographic measuring equipment, the hydrographic winch is generally used on hydrographic measuring ships in rivers. It is a special mechanical transmission lifting device that delivers hydrographic measuring instruments and equipment (lead fish) to designated testing points for hydrographic sampling during hydrographic tests.

[0003] Most traditional hydrological winches monitor the tension of the cable through a force measuring pin installed on the cable-out wheel system. However, since the cable-out wheel system requires a tensioning device, it will slip when the cable is released at high speed, and the complexity of the wheel system is increased. The tension measured by the force measuring pin has low accuracy and cannot monitor the stress changes of the drum in real time. Therefore, there is an urgent need to develop an online monitoring solution with high accuracy and the ability to monitor the stress changes of the drum in real time. Summary of the invention

[0004] In view of the defects in the prior art, the object of the present invention is to provide a hydrographic winch drum stress online monitoring system and method based on fiber grating.

[0005] The hydrographic winch drum stress online monitoring system based on fiber grating provided by the present invention comprises a fiber grating sensor, a fiber transmission cable, a conductive slip ring and a fiber demodulator;

[0006] There are multiple fiber grating sensors, which are circumferentially mounted on the inner wall of the winch drum and connected to the rotating part of the conductive slip ring through an optical fiber transmission cable. The fixed part of the conductive slip ring is connected to the optical fiber demodulator through a cable.

[0007] Preferably, there are four fiber grating sensors, and the four fiber grating sensors are evenly installed on the inner wall of the winch drum along the circumference of the winch drum.

[0008] Preferably, the stretching direction of the fiber grating sensor is parallel to the axial direction of the winch drum, and the fiber grating sensor is fixedly mounted on the middle inner wall of the winch drum by structural adhesive or spot welding at both ends.

[0009] Preferably, it also includes a bearing seat and a bearing, and the rotating shaft of the winch drum is installed in the bearing seat through the bearing;

[0010] The fixed part of the conductive slip ring is installed on the bearing seat, and the optical fiber transmission cable passes through the rotating shaft of the winch drum and is connected to the rotating part of the conductive slip ring.

[0011] Preferably, it also includes a support seat, which is installed on the winch body, and the bearing seat is fixedly installed on the top of the support seat.

[0012] Preferably, the fixing portion of the conductive slip ring is fixedly mounted on the end surface of the bearing seat by means of bolts.

[0013] Preferably, the optical fiber transmission cable is fixed to the inner wall of the winch drum by structural adhesive, and the optical fiber transmission cable is arranged along an S-shaped line.

[0014] According to the present invention, a hydrological winch drum stress online monitoring method based on fiber Bragg grating is provided, which adopts the hydrological winch drum stress online monitoring system based on fiber Bragg grating, and comprises the following steps:

[0015] Step 1: Collect the wavelength of the fiber Bragg grating sensor when the winch drum is not under tension as a calibration value;

[0016] Step 2: During the rotation of the winch drum, the wavelength deviation of the fiber grating sensor is collected by the fiber demodulator to calculate the strain and stress during the rotation of the winch drum.

[0017] Preferably, in step 2, the calculation of the strain during the rotation of the winch drum includes the following steps:

[0018] The strain during the rotation of the winch drum is:

[0019] ε=C(λ 1 -λ 0 )-B(λ T1 -λ T0 )

[0020] Among them, λ 1 is the wavelength value measured by the fiber Bragg grating sensor during the rotation of the winch drum, λ 0 is the wavelength value measured by the fiber Bragg grating sensor when the winch drum is not under tension, λ T1 is the wavelength value measured by the fiber Bragg grating sensor after temperature compensation during the rotation of the winch drum, λ T0 is the wavelength value measured by the fiber grating sensor after temperature compensation when the winch drum is not subjected to tension, C is the strain coefficient, and B is the temperature compensation correction coefficient.

[0021] Preferably, in step 2, the calculation of stress during the rotation of the winch drum includes the following steps:

[0022] The stress of the measured part of the winch drum is:

[0023] σ=Eε

[0024] Wherein, E is the elastic modulus of the winch drum material.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention has a simple structure and is easy to operate. By installing the fiber optic Bragg grating sensor circumferentially along the inner wall of the drum, the dynamic strain signal of the winch rotation process can be collected. The fiber optic transmission cable is connected to the conductive slip ring to ensure that the cable is not entangled during the rotation of the drum, and the collected signal can be output normally. The signal output through the conductive slip ring is transmitted to the fiber optic demodulator, which can calculate the strain stress during the rotation of the drum. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 It is a cross-sectional schematic diagram of the present invention;

[0030] Figure 3 It is a schematic diagram of the assembly of the present invention and the hydrographic winch from a side view.

[0031] The figure shows:

[0032] Electric slip ring1 Optical fiber transmission cable7

[0033] Support seat 2 Fiber demodulator 8

[0034] Bearing seat 3 First fiber grating sensor 61

[0035] Winch drum 4 Second fiber grating sensor 62

[0036] Bearing 5 Third fiber grating sensor 63

[0037] Fiber Bragg grating sensor group 6 Fourth fiber Bragg grating sensor 64 DETAILED DESCRIPTION

[0038] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0039] The present invention discloses an online monitoring system and method for the stress of a hydrological winch drum based on fiber grating. By installing a fiber grating sensor circumferentially along the inner wall of the drum, the dynamic strain signal of the winch rotation process can be collected. The fiber optic transmission cable is connected to a conductive slip ring to ensure that the cable is not entangled during the rotation of the drum, and the collected signal can be output normally. The signal output through the conductive slip ring is transmitted to a fiber optic demodulator, so that the strain stress during the rotation of the drum can be calculated.

[0040] According to the hydrographic winch drum stress online monitoring system based on fiber grating provided by the present invention, Figure 1-3 As shown, it includes a fiber grating sensor 6, a fiber transmission cable 7, a conductive slip ring 1 and a fiber demodulator 8; the fiber grating sensor 6 is multiple, and the multiple fiber grating sensors 6 are installed on the inner wall of the winch drum 4 along the circumferential direction, and connected to the rotating part of the conductive slip ring 1 through the fiber transmission cable 7, and the fixed part of the conductive slip ring 1 is connected to the fiber demodulator 8 through a cable. The signal of the fiber grating sensor 6 that rotates with the winch drum 4 can be transmitted to the external fiber demodulator 8 through the conductive slip ring 1, and the fiber demodulator 8 is then connected to the host computer signal. The host computer calculates the strain stress during the rotation of the winch drum 4 through the dynamic strain signal output by the fiber grating sensor 6.

[0041] In a preferred embodiment, Figure 3 As shown, there are four fiber grating sensors 6, and the four fiber grating sensors 6 are evenly installed on the inner wall of the winch drum 4 along the circumference of the winch drum 4. Figure 2 As shown, the stretching direction of the fiber grating sensor 6 is parallel to the axial direction of the winch drum 4, and the fiber grating sensor 6 is fixedly mounted on the middle inner wall of the winch drum 4 by structural adhesive or spot welding at both ends.

[0042] like Figure 1 As shown, it also includes a support seat 2, a bearing seat 3 and a bearing 5. The rotating shaft of the winch drum 4 is installed in the bearing seat 3 through the bearing 5; the fixed part of the conductive slip ring 1 is installed on the bearing seat 3, and the optical fiber transmission cable 7 passes through the rotating shaft of the winch drum 4 and connects the rotating part of the conductive slip ring 1. The support seat 2 is installed on the winch body, and the bearing seat 3 is fixedly installed on the top of the support seat 4. The fixed part of the conductive slip ring 1 is fixedly installed on the end face of the bearing seat 3 by bolts. The optical fiber transmission cable 7 is fixed to the inner wall of the winch drum 4 by structural adhesive, and the optical fiber transmission cable 7 is routed along an S-shaped line.

[0043] Example 1

[0044] The present embodiment discloses an online monitoring system for stress of a hydrological winch drum, comprising a conductive slip ring 1, a support seat 2, a bearing seat 3, a winch drum 4, a bearing 5, a fiber grating sensor 6, a fiber optic transmission cable 7, a fiber optic demodulator 8 and a host computer, wherein four fiber optic grating sensors 6 are pasted on the inner wall of the drum along the cross-symmetrical direction of the drum 4, and the fiber optic grating sensor 6 signal is output through the fiber optic transmission cable 7, and the fiber optic transmission cable 7 is connected to the conductive slip ring 1, one end of the conductive slip ring 1 is bolted to the end face of the bearing seat 3, and the other end is connected to the fiber optic demodulator 8 through a cable, and the conductive slip ring is used to ensure that the fiber optic cable is not entangled during the rotation of the drum and the signal is stably output.

[0045] Furthermore, four optical fiber sensors 6 are fixedly installed on the middle inner wall of the drum by structural adhesive or spot welding at both ends. The stretching direction of the optical fiber Bragg grating sensor is parallel to the axial direction of the drum 4. The optical fiber Bragg grating sensor 6 is connected to the conductive slip ring 1 through the optical fiber transmission cable 7. The optical fiber transmission cable 7 is tightly fixed to the inner wall of the drum with structural adhesive, and the cable is routed along the S shape to ensure that it is not tightened during the rapid rotation of the drum. One end of the conductive slip ring 1 is bolted to the end face of the bearing seat 3, the bearing seat 3 is connected through the outer ring of the bearing 5, the inner ring of the bearing 5 is connected to the drum shaft, and the bearing seat 3 is connected to the support seat 2.

[0046] Furthermore, by collecting the wavelength of the optical fiber sensor 6 when the drum 4 is not subjected to tension as a calibration value, during the rotation of the winch drum 4, the wavelength value of each optical fiber grating in each measurement channel is collected and calculated by the optical fiber demodulator 8, and then the actual wavelength deviation of the sensor is calculated, thereby calculating the strain stress during the rotation of the drum.

[0047] According to the method for online monitoring of hydrological winch drum stress based on fiber Bragg grating provided by the present invention, the online monitoring system for hydrological winch drum stress based on fiber Bragg grating is adopted, and the steps are as follows:

[0048] Step 1: collecting the wavelength of the fiber grating sensor 6 when the winch drum 4 is not under tension as a calibration value;

[0049] Step 2: During the rotation of the winch drum 4 , the wavelength deviation of the fiber grating sensor 6 is collected by the fiber demodulator 8 to calculate the strain and stress during the rotation of the winch drum 4 .

[0050] Specifically, in step 2, the calculation of the strain during the rotation of the winch drum 4 includes the following steps:

[0051] The strain during the rotation of the winch drum 4 is:

[0052] ε=C(λ 1 -λ 0 )-B(λ T1 -λ T0 )

[0053] Among them, λ 1 is the wavelength value measured by the fiber grating sensor 6 during the rotation of the winch drum 4, λ 0 is the wavelength value measured by the fiber grating sensor 6 when the winch drum 4 is not under tension, λ R1 is the wavelength value measured by the fiber grating sensor 6 after temperature compensation during the rotation of the winch drum 4, λ T0 is the wavelength value measured by the fiber grating sensor 6 after temperature compensation when the winch drum 4 is not subjected to tension, C is the strain coefficient, and B is the temperature compensation correction coefficient.

[0054] In step 2, the calculation of the stress during the rotation of the winch drum 4 includes the following steps:

[0055] The stress of the measured part of the winch drum 4 is:

[0056] σ=Eε

[0057] Wherein, E is the elastic modulus of the winch drum 4 material.

[0058] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A hydrographic winch drum stress online monitoring system based on fiber Bragg grating, characterized in that: It comprises a fiber grating sensor (6), an optical fiber transmission cable (7), a conductive slip ring (1) and an optical fiber demodulator (8); There are a plurality of fiber grating sensors (6), which are circumferentially mounted on the inner wall of a winch drum (4) and connected to the rotating part of a conductive slip ring (1) via an optical fiber transmission cable (7), and the fixed part of the conductive slip ring (1) is connected to an optical fiber demodulator (8) via a cable.

2. The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to claim 1 is characterized in that: There are four fiber grating sensors (6), and the four fiber grating sensors (6) are evenly installed on the inner wall of the winch drum (4) along the circumference of the winch drum (4).

3. The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to claim 1 is characterized in that: The stretching direction of the fiber optic Bragg grating sensor (6) is parallel to the axial direction of the winch drum (4), and the fiber optic Bragg grating sensor (6) is fixedly mounted on the middle inner wall of the winch drum (4) by means of structural adhesive or spot welding at both ends.

4. The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to claim 1 is characterized in that: It also includes a bearing seat (3) and a bearing (5), wherein the rotating shaft of the winch drum (4) is installed in the bearing seat (3) via the bearing (5); The fixed part of the conductive slip ring (1) is mounted on the bearing seat (3), and the optical fiber transmission cable (7) passes through the rotating shaft of the winch drum (4) and is connected to the rotating part of the conductive slip ring (1).

5. The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to claim 4 is characterized in that: It also includes a support seat (2), wherein the support seat (2) is mounted on the winch body, and the bearing seat (3) is fixedly mounted on the top of the support seat (4).

6. The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to claim 4 is characterized in that: The fixing portion of the conductive slip ring (1) is fixedly mounted on the end surface of the bearing seat (3) by means of bolts.

7. The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to claim 1 is characterized in that: The optical fiber transmission cable (7) is fixed to the inner wall of the winch drum (4) by means of structural adhesive, and the optical fiber transmission cable (7) is arranged along an S-shaped line.

8. A method for online monitoring of hydrological winch drum stress based on fiber Bragg grating, characterized in that: The hydrographic winch drum stress online monitoring system based on fiber Bragg grating according to any one of claims 1 to 7 comprises the following steps: Step 1: collecting the wavelength of the fiber grating sensor (6) when the winch drum (4) is not subjected to tension as a calibration value; Step 2: During the rotation of the winch drum (4), the wavelength deviation of the fiber optic grating sensor (6) is collected by the fiber optic demodulator (8) to calculate the strain and stress during the rotation of the winch drum (4).

9. The method for online monitoring of hydrological winch drum stress based on fiber Bragg grating according to claim 8, characterized in that: In step 2, the calculation of the strain during the rotation of the winch drum (4) includes the following steps: The strain during the rotation of the winch drum (4) is: ε=C(λ1-λ0)-B(λ T1 -l T0 ) Wherein, λ1 is the wavelength value measured by the fiber Bragg grating sensor (6) during the rotation of the winch drum (4), λ0 is the wavelength value measured by the fiber Bragg grating sensor (6) when the winch drum (4) is not subjected to tension, and λ T1 is the wavelength value measured by the fiber grating sensor (6) after temperature compensation during the rotation of the winch drum (4), λ T0 is the wavelength value measured by the fiber optic grating sensor (6) after temperature compensation when the winch drum (4) is not subjected to tension, C is the strain coefficient, and B is the temperature compensation correction coefficient.

10. The method for online monitoring of hydrological winch drum stress based on fiber Bragg grating according to claim 9, characterized in that: In step 2, the calculation of the stress during the rotation of the winch drum (4) includes the following steps: The stress at the measured part of the winch drum (4) is: σ=Eε Wherein, E is the elastic modulus of the winch drum (4) material.

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