Vibration positioning method and device and double-loop correlation type optical fiber vibration interferometer

Abstract

The invention discloses a vibration positioning method and device and a double-loop correlation type optical fiber vibration interferometer, based on the double-loop correlation type optical fiber vibration interferometer, the double-loop correlation type optical fiber vibration interferometer comprises a first system and a second system, and the first system and the second system are independent and symmetrical in structure. The method comprises the steps of obtaining first phase information and second phase information obtained by demodulation of a photoelectric detector in a first system and a photoelectric detector in a second system after a vibration event occurs; respectively translating the first phase information and the second phase information based on a set translation amount to obtain first intermediate phase information and second intermediate phase information; combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information, and performing time delay estimation to obtain time delay information related to the vibration position of the vibration event; and determining the vibration position of the vibration event in the optical fiber link based on the time delay information and the length of the optical fiber link.

Description

Technical Field

[0001] The present application relates to the technical field of forward optical fiber interferometers, and in particular to a vibration positioning method, device, and double-loop counter-radiation optical fiber vibration interferometer. Background Art

[0002] As the backbone of the modern information society, optical fiber networks have been widely laid and used around the world. Not only does it bear the heavy responsibility of data transmission, but also due to its unique physical properties, it has been developed into a variety of sensing applications, among which distributed optical fiber vibration sensing technology is the best. This technology makes full use of the existing optical fiber network to achieve real-time monitoring of vibration events along the optical fiber link, providing strong technical support for traffic monitoring, building health monitoring, earthquake monitoring, marine hydrological monitoring and other fields.

[0003] In the forward interferometer structure, distributed fiber optic vibration sensing technology has been deeply studied and applied. This structure uses forward-transmitted lasers to carry vibration information along the fiber link. When the laser propagates in the fiber, it interacts with the vibration events in the fiber, causing the phase of the laser to change. At the receiving end, by demodulating the phase of these lasers carrying vibration information, the relevant information of the vibration event can be extracted. When using this technology to accurately locate vibration events, it is usually necessary for two oppositely transmitted lasers to sense the same vibration event respectively, and to achieve positioning by comparing the time difference between them sensing the vibration. In the case of a long link or a short vibration duration, this method can compare the time difference between the two vibrations through delay estimation to determine the location of the vibration.

[0004] However, in most cases, the vibration signals sensed by the oppositely transmitted lasers will be mostly superimposed on each other, which makes the method of determining the delay by delay estimation invalid. In order to solve this problem, researchers have proposed a zero-frequency method for positioning. The zero-frequency method attempts to extract positioning information from the frequency characteristics of the vibration signal. However, this method requires that the vibration itself has a wide spectrum characteristic, that is, the frequency components of the vibration signal must be rich enough to be effectively analyzed. In actual applications, many vibration events do not meet this requirement, resulting in limited positioning accuracy of the zero-frequency method. Summary of the invention

[0005] In view of the above problems, the present application provides a vibration positioning method, device and double-loop counter-radiation optical fiber vibration interferometer to achieve the purpose of improving the accuracy of vibration position positioning. The specific scheme is as follows:

[0006] The first aspect of the present application provides a vibration positioning method, based on a double-loop counter-beam fiber vibration interferometer, the double-loop counter-beam fiber vibration interferometer comprising: a first system and a second system, the first system and the second system are independent and symmetrical in structure, the first system and the second system both comprising: an optical signal transmitting device, a light splitting device, a transmission control device, an optical fiber link and a photoelectric detector; the optical fiber links in the first system and the second system are both in a target form, and a vibration event will be felt twice by the optical fiber links in the first system and the second system in the target form respectively; the method comprises:

[0007] Obtaining first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs;

[0008] Based on a set translation amount, the first phase information and the second phase information are respectively translated to obtain first intermediate phase information and second intermediate phase information; the set translation amount is used to change the distribution of phase values ​​in the first phase information and the second phase information on the time axis;

[0009] By combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information, and performing delay estimation, the delay information related to the vibration position of the vibration event is obtained;

[0010] Based on the time delay information and the length of the optical fiber link, a vibration position where the vibration event occurs in the optical fiber link is determined.

[0011] In a possible implementation, the optical fiber link is in a folded state, the midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system;

[0012] Obtaining first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs, comprising:

[0013] By the first demodulation formula Φ Obtaining first phase information demodulated by the photodetector in the first system after a vibration event occurs; wherein Φleft(t) represents the first phase information, represents the phase waveform of the return optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, represents the phase waveform of the outbound optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, t represents the moment when the optical fiber link of the first system senses the phase information φ, l 1 represents the distance between the vibration position and the optical signal transmitting device in the first system, l 2 represents the distance between the vibration position and the midpoint of the optical fiber link in the first system, and v represents the propagation speed of the optical signal;

[0014] By the second demodulation formula Φ Obtain the second phase information obtained by demodulating the photodetector in the second system after the vibration event occurs; wherein Φright(t) represents the second phase information, represents the phase waveform of the return optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, represents the phase waveform of the outbound optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, t represents the moment when the optical fiber link in the second system senses the phase information φ, l 1 represents the distance between the vibration position and the midpoint of the optical fiber link in the second system, l 2 represents the distance between the vibration position and the wideband signal transmitting device in the second system, and v represents the propagation speed of the optical signal.

[0015] In a possible implementation, based on a set translation amount, respectively translating the first phase information and the second phase information to obtain first intermediate phase information and second intermediate phase information includes:

[0016] Will Substituting into the first demodulation formula, we get represents the set translation amount, Φ′left(t) represents the first intermediate phase information, Express The phase waveform after translation, Express The phase waveform after translation;

[0017] The Substituting into the second demodulation formula, we get Φ′right(t) represents the second intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

[0018] In a possible implementation, the time delay information related to the vibration position of the vibration event is obtained by combining the first phase information, the second phase information, the first intermediate phase information, and the second intermediate phase information, and performing time delay estimation, including:

[0019] Cross-combining the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) yields The Φ 1 (t) represents the difference between Φ′left(t) and Φright(t), and Φ 2 (t) represents the difference between the Φ′right(t) and the Φleft(t);

[0020] For the Φ 1 (t) and the Φ 2 (t) Perform delay estimation to obtain delay information

[0021] In another aspect of the present application, a vibration positioning device is provided, which is based on a double-loop counter-beam fiber vibration interferometer, and the double-loop counter-beam fiber vibration interferometer includes: a first system and a second system, the first system and the second system are independent and symmetrical in structure, and the first system and the second system both include: an optical signal transmitting device, a light splitting device, a transmission control device, an optical fiber link and a photoelectric detector; the optical fiber links in the first system and the second system are both in a target state, and a vibration event will be felt twice by the optical fiber links in the first system and the second system in the target state respectively; the device includes:

[0022] An obtaining module, used to obtain first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs;

[0023] A translation module, used to translate the first phase information and the second phase information respectively based on a set translation amount to obtain first intermediate phase information and second intermediate phase information; the set translation amount is used to change the distribution of phase values ​​in the first phase information and the second phase information on the time axis;

[0024] A first determining module, configured to obtain delay information related to a vibration position of the vibration event by combining the first phase information, the second phase information, the first intermediate phase information, and the second intermediate phase information;

[0025] The second determination module is used to determine the vibration position where the vibration event occurs in the optical fiber link based on the delay information and the length of the optical fiber link.

[0026] In a possible implementation, the optical fiber link is in a folded state, the midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system;

[0027] The obtaining module is specifically used for:

[0028] By the first demodulation formula Obtaining first phase information demodulated by the photodetector in the first system after a vibration event occurs; wherein Φleft(t) represents the first phase information, represents the phase waveform of the return optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, represents the phase waveform of the outbound optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, t represents the moment when the optical fiber link in the first system senses the phase information φ, l 1 represents the distance between the vibration position and the optical signal transmitting device in the first system, l 2 represents the distance between the vibration position and the midpoint of the optical fiber link in the first system, and v represents the propagation speed of the optical signal;

[0029] Through the second demodulation formula Obtain the second phase information obtained by demodulating the photodetector in the second system after the vibration event occurs; wherein Φright(t) represents the second phase information, represents the phase waveform of the return optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, represents the phase waveform of the outbound optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, t represents the moment when the optical fiber link in the second system senses the phase information φ, l 1 represents the distance between the vibration position and the midpoint of the optical fiber link in the second system, l 2 represents the distance between the vibration position and the wideband signal transmitting device in the second system, and v represents the propagation speed of the optical signal.

[0030] In a possible implementation, the translation module is specifically used to:

[0031] Will Substituting into the first demodulation formula, we get represents the set translation amount, Φ′left(t) represents the first intermediate phase information, Express The phase waveform after translation, Express The phase waveform after translation;

[0032] The Substituting into the second demodulation formula, we get Φ′right(t) represents the second intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

[0033] In a possible implementation, the first determining module is specifically configured to:

[0034] Cross-combining the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) yields The Φ 1 (t) represents the difference between Φ′left(t) and Φright(t), and Φ 2 (t) represents the difference between the Φ′right(t) and the Φleft(t);

[0035] For the Φ 1 (t) and the Φ 2 (t) Perform delay estimation to obtain delay information

[0036] In a third aspect of the present application, a double-loop counter-radiation optical fiber vibration interferometer is provided, comprising:

[0037] A first system and a second system, wherein the first system and the second system are independent and symmetrical in structure, and both the first system and the second system include: an optical signal transmitting device, a light splitting device, a transmission control device, an optical fiber link, and a photoelectric detector; the optical fiber link in the first system and the second system is in a target state, and a vibration event will be sensed twice by the optical fiber link in the target state in the first system and the second system respectively;

[0038] The optical signal transmitting device is used to generate an optical signal;

[0039] The optical splitter is used to split the generated optical signal into two beams, one beam is used as a reference optical signal, and the other beam is used as a detection optical signal;

[0040] The transmission control device is used to send the detection optical signal into the optical fiber link and guide the optical signal returned by the vibration event in the optical fiber link to the photoelectric detector;

[0041] The photoelectric detector is used to perform coherent detection on the reference optical signal and the optical signal returned due to the vibration event in the optical fiber link to obtain phase information.

[0042] In a possible implementation, the optical signal transmitting device includes: a laser; and the transmission control device includes: a circulator.

[0043] In the present application, in a double-loop counter-radiation fiber optic vibration interferometer, the first system and the second system are structurally independent and symmetrical, and the fiber optic links in each system are in a target form. The fiber optic links in the first system and the second system are in a target form. A vibration event will be sensed twice by the fiber optic links in the target form in the first system and the second system, respectively, that is, the same vibration event will be sensed four times, and the same vibration event is recorded four times through the first phase information and the second phase information. On this basis, based on the set translation amount, the first phase information and the second phase information are respectively translated to obtain the first intermediate phase information and the second intermediate phase information. By combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information, and performing time delay estimation, the time delay information related to the vibration position of the vibration event is obtained. Based on the time delay information and the length of the fiber optic link, the vibration position of the vibration event in the fiber optic link is determined, which can avoid the problem of inaccurate positioning caused by the frequency resolution limitation of the zero frequency method and improve the accuracy of positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0045] Figure 1 A schematic diagram of the structure of a double-loop counter-radiation optical fiber vibration interferometer provided in the present application;

[0046] Figure 2 A schematic diagram of a flow chart of a vibration positioning method provided in Example 1 of the present application;

[0047] Figure 3 A schematic diagram of an implementation scenario of a vibration positioning method provided in this application;

[0048] Figure 4 A schematic diagram of another implementation scenario of a vibration positioning method provided in the present application;

[0049] Figure 5A schematic diagram of another implementation scenario of a vibration positioning method provided in the present application;

[0050] Figure 6 A schematic structural diagram of a vibration positioning device provided in this application. DETAILED DESCRIPTION

[0051] The following describes the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0052] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0053] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0054] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0055] The vibration positioning method provided in the present application is based on a double-loop counter-radiation fiber optic vibration interferometer, and the double-loop counter-radiation fiber optic vibration interferometer includes: a first system and a second system, the first system and the second system are independent and symmetrical in structure, and the first system and the second system both include: an optical signal transmitting device, a spectrometer, a transmission control device, an optical fiber link and a photodetector; the optical fiber links in the first system and the second system are both in a target form, and a vibration event will be sensed twice by the optical fiber links in the target form in the first system and the second system, respectively.

[0056] The optical signal transmitting device can be used to generate an optical signal.

[0057] The light splitting device can be used to split the generated light signal into two beams, one beam being used as a reference light signal and the other being used as a detection light signal.

[0058] a transmission control device for sending a detection optical signal into the optical fiber link and guiding an optical signal returned by a vibration event in the optical fiber link to a photodetector;

[0059] The photodetector is used to perform coherent detection on the reference optical signal and the optical signal returned by the vibration event in the optical fiber link to obtain phase information.

[0060] In this application, if Figure 1 As shown, the optical signal transmitting device may include a laser, and the transmission control device may include a circulator. The optical fiber link is in a folded state. The midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system.

[0061] Of course, the transmission control device may also be: a beam splitter and a reflector in a Mach-Zehnder Interferometer; or a semi-transparent and semi-reflective mirror in a Michelson Interferometer; or a ring light path in a Sagnac Interferometer.

[0062] Reference Figure 2 , is a flow chart of a vibration positioning method provided in Example 1 of the present application, such as Figure 2 As shown, the method may include but is not limited to the following steps:

[0063] Step S101, obtaining first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs.

[0064] In the first system, the optical fiber link is in a target state. In the target state, a vibration event will be felt twice by the optical fiber link. Accordingly, the vibration event can be recorded twice through the first phase information.

[0065] In the second system, the optical fiber link is in a target state. In the target state, a vibration event will be felt twice by the optical fiber link. Accordingly, the vibration event can be recorded twice through the second phase information.

[0066] Since the first system records the vibration event twice, and the second system also records the vibration event twice, the vibration event can be recorded four times.

[0067] Step S102: Based on the set translation amount, the first phase information and the second phase information are respectively translated to obtain first intermediate phase information and second intermediate phase information.

[0068] The set shift amount may be used to change the distribution of phase values ​​in the first phase information and the second phase information on the time axis.

[0069] The set translation amount can be set as needed and is not limited in this application.

[0070] In this embodiment, the directions in which the first phase information and the second phase information are shifted may be consistent or inconsistent.

[0071] Step S103: Obtain delay information related to the vibration position of the vibration event by combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information and performing delay estimation.

[0072] In this embodiment, the first intermediate phase information and the second phase information may be combined to obtain first combined phase information, and the first phase information and the second intermediate phase information may be combined to obtain second combined phase information.

[0073] By performing delay estimation on the first combined phase information and the second combined phase information, the delay information related to the vibration position of the vibration event is obtained. For example, assuming that the length of the optical fiber link is 2L, assuming that the vibration event occurs at a distance of l1 from the starting point of the optical fiber link, and the vibration position is l2 from the midpoint of the optical fiber link, the delay information related to the vibration position of the vibration event can be related to l1, l2 and v. v is the propagation speed of the optical signal.

[0074] Step S104: Determine the vibration position where the vibration event occurs in the optical fiber link based on the time delay information and the length of the optical fiber link.

[0075] When the length of the optical fiber link is known, the vibration position of the vibration event in the optical fiber link can be determined based on the delay information and the length of the optical fiber link. For example, as shown in step S103, when 2L is known, l1 can be calculated based on the delay information related to l1, l2 and v, thereby determining the vibration position of the vibration event in the optical fiber link.

[0076] In this embodiment, in a double-loop counter-radiation fiber optic vibration interferometer, the first system and the second system are structurally independent and symmetrical, and the fiber optic links in each system are in a target form. The fiber optic links in the first system and the second system are in a target form. A vibration event will be sensed twice by the fiber optic links in the first system and the second system in the target form, respectively, that is, the same vibration event will be sensed four times, and the same vibration event is recorded four times through the first phase information and the second phase information. On this basis, based on the set translation amount, the first phase information and the second phase information are respectively translated to obtain the first intermediate phase information and the second intermediate phase information. By combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information, and performing time delay estimation, the time delay information related to the vibration position of the vibration event is obtained. Based on the time delay information and the length of the fiber optic link, the vibration position of the vibration event in the fiber optic link is determined, which can avoid the problem of inaccurate positioning caused by the frequency resolution limitation of the zero frequency method and improve the accuracy of positioning.

[0077] As another optional embodiment of the present application, a vibration positioning method is provided in embodiment 2 of the present application. This embodiment is mainly an implementation of step S101 in the above embodiment 1. In this embodiment, the optical fiber link is in a folded state, the midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system. Step S101 may include but is not limited to the following steps:

[0078] Step S1011: using the first demodulation formula The first phase information obtained by demodulating the photodetector in the first system after the vibration event occurs is obtained.

[0079] Wherein, Φleft(t) represents the first phase information.

[0080] t may represent the time when the optical fiber link in the first system senses the phase information φ. 1 represents the distance between the vibration position and the optical signal transmitting device in the first system, l 2 represents the distance between the vibration position and the midpoint of the optical fiber link in the first system, and v represents the propagation speed of the optical signal.

[0081] like Figure 3 As shown in the first system, the outbound optical signal will first pass through the vibration point (assuming that the vibration event occurs at the l point of the optical fiber link). 1This phase change will propagate to the photodetector along with the propagation of the outbound optical signal.

[0082] Subsequently, the return light needs to reach the midpoint of the optical fiber link before returning. The return light signal will also pass through the same vibration point (on the return path) and produce a phase change again.

[0083] Therefore, when the photodetector in the first system receives the optical signal, it will first receive the phase change of the outbound optical signal (i.e., the time traceback is ), and then the phase change of the return optical signal is received (i.e., the time is traced back to part). Therefore, It can represent the phase waveform of the return optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system. It represents the phase waveform of the outbound optical signal in the first system when it propagates to the photodetector in the first system after sensing the vibration event.

[0084] Step S1012: using the second demodulation formula The second phase information obtained by demodulating the photodetector in the second system after the vibration event occurs is obtained.

[0085] Wherein, Φright(t) represents the second phase information.

[0086] t represents the time when the photodetector in the second system receives the light signal, l 1 represents the distance between the vibration position and the midpoint of the optical fiber link in the second system, l 2 represents the distance between the vibration position and the wideband signal transmitting device in the second system, and v represents the propagation speed of the optical signal.

[0087] like Figure 3 As shown in the second system, the outbound optical signal will first pass through the vibration point (assuming that the vibration event occurs at the l point of the optical fiber link). 1 This phase change will propagate to the photodetector along with the propagation of the outbound optical signal.

[0088] Subsequently, the return light needs to reach the midpoint of the optical fiber link before returning. The return light signal will also pass through the same vibration point (on the return path) and produce a phase change again.

[0089] Therefore, when the photodetector in the second system receives the optical signal, it will first receive the phase change of the outbound optical signal (i.e., the time traceback is ), and then the phase change of the return optical signal is received (i.e., the time is traced back to part). Therefore, represents the phase waveform of the return optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, It represents the phase waveform of the outbound optical signal in the second system when it propagates to the photodetector in the second system after sensing the vibration event.

[0090] As another optional embodiment of the present application, a vibration positioning method is provided in Embodiment 3 of the present application. This embodiment is mainly an implementation of step S102 in the above embodiment 2. Step S102 may include but is not limited to the following steps:

[0091] Step S1021: Substituting into the first demodulation formula, we get

[0092] It can represent the set translation amount, Φ′left(t) represents the first intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

[0093] Step S1022: Substituting into the second demodulation formula, we get

[0094] Φ′right(t) represents the second intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

[0095] After translation, the relationship between the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) can be seen in Figure 4 ,like Figure 4 As shown, Φ′left (t) and Φright (t) Can cancel each other and Φ′right(t) and Φleft(t) Can cancel each other out.

[0096] As another optional embodiment of the present application, a vibration positioning method is provided in Embodiment 4 of the present application. This embodiment is mainly an implementation of step S103 in the above embodiment 3. Step S103 may include but is not limited to the following steps:

[0097] Step S1031: Cross-combine the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) to obtain

[0098] The Φ 1 (t) represents the difference between Φ′left(t) and Φright(t), and Φ 2 (t) represents the difference between the Φ′right(t) and the Φleft(t).

[0099] right After sorting, we can get

[0100]

[0101] pass It can be determined that Figure 5 As shown, the Φ 1 (t) and the Φ 2 (t) Phase delay only

[0102] Step S1032: 1 (t) and the Φ 2 (t) Perform delay estimation to obtain delay information

[0103] In this embodiment, a delay estimation algorithm can be used to estimate the Φ 1 (t) and the Φ 2 (t) performing delay estimation. The delay estimation algorithm can be selected as needed and is not limited in this application. For example, the delay estimation algorithm may include a cross-correlation method, and the Φ is calculated based on the cross-correlation method. 1 (t) and the Φ 2 (t), the time delay corresponding to the peak value is

[0104] Accordingly, step S104 may include but is not limited to:

[0105] Step S1041: Known and the light signal propagation speed v, the distance difference l can be calculated 1 -l 2 .

[0106] Step S1042: Known 1 +l 2 =L, based on the distance difference l 1 -l 2 and l 1 +l 2 =L, we can calculate l 1 .

[0107] Next, the vibration positioning device provided in the present application is introduced. The vibration positioning device introduced below and the vibration positioning method introduced above can be referred to each other.

[0108] like Figure 6 As shown, the vibration positioning device includes: an acquisition module 100 , a translation module 200 , a first determination module 300 and a second determination module 400 .

[0109] A vibration positioning device is based on a double-loop counter-beam fiber vibration interferometer, the double-loop counter-beam fiber vibration interferometer comprising: a first system and a second system, the first system and the second system are independent and symmetrical in structure, the first system and the second system both comprise: an optical signal transmitting device, a spectrometer, a transmission control device, an optical fiber link and a photodetector; the optical fiber links in the first system and the second system are both in a target form, and a vibration event will be sensed twice by the optical fiber links in the first system and the second system in the target form, respectively.

[0110] The obtaining module 100 is used to obtain first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs.

[0111] The translation module 200 is used to translate the first phase information and the second phase information respectively based on a set translation amount to obtain first intermediate phase information and second intermediate phase information; the set translation amount is used to change the distribution of the phase values ​​in the first phase information and the second phase information on the time axis.

[0112] The first determination module 300 is configured to obtain delay information related to the vibration position of the vibration event by combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information.

[0113] The second determination module 400 is used to determine the vibration position where the vibration event occurs in the optical fiber link based on the delay information and the length of the optical fiber link.

[0114] The optical fiber link is in a folded state, the midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system;

[0115] The obtaining module 100 is specifically used for:

[0116] By the first demodulation formula Obtaining first phase information demodulated by the photodetector in the first system after a vibration event occurs; wherein Φleft(t) represents the first phase information, represents the phase waveform of the return optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, represents the phase waveform of the outbound optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, t represents the moment when the optical fiber link in the first system senses the phase information φ, l 1 represents the distance between the vibration position and the optical signal transmitting device in the first system, l 2 represents the distance between the vibration position and the midpoint of the optical fiber link in the first system, and v represents the propagation speed of the optical signal;

[0117] Through the second demodulation formula Obtain the second phase information obtained by demodulating the photodetector in the second system after the vibration event occurs; wherein Φright(t) represents the second phase information, represents the phase waveform of the return optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, represents the phase waveform of the outbound optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, t represents the moment when the optical fiber link in the second system senses the phase information φ, l 1 represents the distance between the vibration position and the midpoint of the optical fiber link in the second system, l 2 represents the distance between the vibration position and the wideband signal transmitting device in the second system, and v represents the propagation speed of the optical signal.

[0118] The translation module 200 can be specifically used for:

[0119] Will Substituting into the first demodulation formula, we get represents the set translation amount, Φ′left(t) represents the first intermediate phase information, Express The phase waveform after translation, Express The phase waveform after translation;

[0120] The Substituting into the second demodulation formula, we get Φ′right(t) represents the second intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

[0121] The first determining module 300 is specifically configured to:

[0122] Cross-combining the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) yields The Φ 1 (t) represents the difference between Φ′left(t) and Φright(t), and Φ 2 (t) represents the difference between the Φ′right(t) and the Φleft(t);

[0123] For the Φ 1 (t) and the Φ 2 (t) Perform delay estimation to obtain delay information

[0124] It should also be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the device embodiments provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines.

[0125] Through the description of the above implementation mode, the technicians in the field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, it can also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components, etc. In general, all functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be various, such as analog circuits, digital circuits or special circuits. However, for the present application, software program implementation is a better implementation mode in more cases. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, a U disk, a mobile hard disk, a ROM, a RAM, a disk or an optical disk, etc., including a number of instructions to enable a computer device (which can be a personal computer, a training device, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0126] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0127] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a training device, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, training device, or data center. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

Claims

1. A vibration positioning method, characterized in that: Based on a double-loop counter-beam optical fiber vibration interferometer, the double-loop counter-beam optical fiber vibration interferometer includes: a first system and a second system, the first system and the second system are independent and symmetrical in structure, the first system and the second system both include: an optical signal transmitting device, a light splitting device, a transmission control device, an optical fiber link and a photoelectric detector; the optical fiber links in the first system and the second system are both in a target state, and a vibration event will be felt twice by the optical fiber links in the first system and the second system in the target state respectively; the method includes: Obtaining first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs; Based on a set translation amount, the first phase information and the second phase information are respectively translated to obtain first intermediate phase information and second intermediate phase information; the set translation amount is used to change the distribution of phase values ​​in the first phase information and the second phase information on the time axis; By combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information, and performing delay estimation, the delay information related to the vibration position of the vibration event is obtained; Based on the time delay information and the length of the optical fiber link, a vibration position where the vibration event occurs in the optical fiber link is determined.

2. The vibration positioning method according to claim 1, characterized in that: The optical fiber link is in a folded state, the midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system; Obtaining first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs, comprising: By the first demodulation formula Φ Obtaining first phase information demodulated by the photodetector in the first system after a vibration event occurs; wherein Φleft(t) represents the first phase information, represents the phase waveform of the return optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, represents the phase waveform of the outbound optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, t represents the moment when the optical fiber link senses the phase information φ, l1 represents the distance between the vibration position and the optical signal transmitting device in the first system, l2 represents the distance between the vibration position and the midpoint of the optical fiber link in the first system, and v represents the propagation speed of the optical signal; By the second demodulation formula Φ Obtain the second phase information obtained by demodulating the photodetector in the second system after the vibration event occurs; wherein Φright(t) represents the second phase information, represents the phase waveform of the return optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, It represents the phase waveform of the outbound optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, t represents the moment when the optical fiber link in the second system senses the phase information φ, i1 represents the distance between the vibration position and the midpoint of the optical fiber link in the second system, i2 represents the distance between the vibration position and the wideband signal transmitting device in the second system, and v represents the propagation speed of the optical signal.

3. The vibration positioning method according to claim 2, characterized in that: Based on the set translation amount, the first phase information and the second phase information are respectively translated to obtain first intermediate phase information and second intermediate phase information, including: Will Substituting into the first demodulation formula, we get Φ′ left represents the set translation amount, Φ′left(t) represents the first intermediate phase information, Express The phase waveform after translation, Express The phase waveform after translation; The Substituting into the second demodulation formula, we get Φ′right(t) represents the second intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

4. The vibration positioning method according to claim 3, characterized in that: The time delay information related to the vibration position of the vibration event is obtained by combining the first phase information, the second phase information, the first intermediate phase information and the second intermediate phase information and performing time delay estimation, including: Cross-combining the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) yields The Φ1(t) represents the difference between the Φ′left(t) and the Φright(t), and the Φ2(t) represents the difference between the Φ′right(t) and the Φleft(t); Perform delay estimation on the Φ1(t) and the Φ2(t) to obtain delay information 5. A vibration positioning device, characterized in that: Based on a double-loop counter-beam type optical fiber vibration interferometer, the double-loop counter-beam type optical fiber vibration interferometer comprises: a first system and a second system, the first system and the second system are independent and symmetrical in structure, the first system and the second system both comprise: an optical signal transmitting device, a light splitting device, a transmission control device, an optical fiber link and a photoelectric detector; the optical fiber links in the first system and the second system are both in a target state, and a vibration event will be felt twice by the optical fiber links in the first system and the second system in the target state respectively; the device comprises: An obtaining module, used for obtaining first phase information and second phase information demodulated by the photodetector in the first system and the photodetector in the second system after a vibration event occurs; A translation module, used to translate the first phase information and the second phase information respectively based on a set translation amount to obtain first intermediate phase information and second intermediate phase information; the set translation amount is used to change the distribution of phase values ​​in the first phase information and the second phase information on the time axis; A first determining module, configured to obtain delay information related to a vibration position of the vibration event by combining the first phase information, the second phase information, the first intermediate phase information, and the second intermediate phase information; The second determination module is used to determine the vibration position where the vibration event occurs in the optical fiber link based on the delay information and the length of the optical fiber link.

6. The vibration positioning device according to claim 5, characterized in that: The optical fiber link is in a folded state, the midpoint of the optical fiber link in the first system coincides with the starting point of the optical fiber link in the second system, and the midpoint of the optical fiber link in the second system coincides with the starting point of the optical fiber link in the first system; The obtaining module is specifically used for: By the first demodulation formula Φ Obtaining first phase information demodulated by the photodetector in the first system after a vibration event occurs; wherein Φleft(t) represents the first phase information, represents the phase waveform of the return optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, represents the phase waveform of the outbound optical signal in the first system when it senses the vibration event and propagates to the photodetector in the first system, t represents the moment when the optical fiber link in the first system senses the phase information φ, l1 represents the distance between the vibration position and the optical signal transmitting device in the first system, l2 represents the distance between the vibration position and the midpoint of the optical fiber link in the first system, and v represents the propagation speed of the optical signal; By the second demodulation formula Φ Obtain the second phase information obtained by demodulating the photodetector in the second system after the vibration event occurs; wherein Φright(t) represents the second phase information, represents the phase waveform of the return optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, It represents the phase waveform of the outbound optical signal in the second system when it senses the vibration event and propagates to the photodetector in the second system, t represents the moment when the optical fiber link in the second system senses the phase information φ, l1 represents the distance between the vibration position and the midpoint of the optical fiber link in the second system, l2 represents the distance between the vibration position and the wideband signal transmitting device in the second system, and v represents the propagation speed of the optical signal.

7. The vibration positioning device according to claim 6, characterized in that: The translation module is specifically used for: Will Substituting into the first demodulation formula, we get represents the set translation amount, Φ′left(t) represents the first intermediate phase information, Express The phase waveform after translation, Express The phase waveform after translation; The Substituting into the second demodulation formula, we get Φ′right(t) represents the second intermediate phase information, Express The phase waveform after translation, Express Phase waveform after translation.

8. The vibration positioning device according to claim 7, characterized in that: The first determining module is specifically configured to: Cross-combining the Φleft(t), the Φright(t), the Φ′left(t) and the Φ′right(t) yields The Φ1(t) represents the difference between the Φ′left(t) and the Φright(t), and the Φ2(t) represents the difference between the Φ′right(t) and the Φleft(t); Perform delay estimation on the Φ1(t) and the Φ2(t) to obtain delay information 9. A double-loop counter-radiation optical fiber vibration interferometer, characterized in that: include: A first system and a second system, wherein the first system and the second system are independent and symmetrical in structure, and each of the first system and the second system comprises: an optical signal transmitting device, a light splitting device, a transmission control device, an optical fiber link and a photoelectric detector; The optical fiber links in the first system and the second system are both in a target state, and a vibration event will be felt twice by the optical fiber links in the first system and the second system in the target state respectively; The optical signal transmitting device is used to generate an optical signal; The optical splitter is used to split the generated optical signal into two beams, one beam is used as a reference optical signal, and the other beam is used as a detection optical signal; The transmission control device is used to send the detection optical signal into the optical fiber link and guide the optical signal returned by the vibration event in the optical fiber link to the photoelectric detector; The photoelectric detector is used to perform coherent detection on the reference optical signal and the optical signal returned due to the vibration event in the optical fiber link to obtain phase information.

10. The double-loop counter-beam optical fiber vibration interferometer according to claim 9, characterized in that: The optical signal transmitting device includes: a laser; the transmission control device includes: a circulator.

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