Wirelessly controlled transceiverable acoustic modem

Abstract

A wirelessly controlled transceiver acoustic modem for a distributed fiber optic sensing (DFOS) system, comprising a circuit that receives a wireless signal containing configuration information, configures the modem to operate according to the configuration information, and generates an acoustic signal detected by the DFOS system. The acoustic modem further includes one or more sensors for detecting environmental information encoded in the acoustic signal for reception in the DFOS system. Depending on the received configuration information, the operating time of the modem, the sensors, or other operating modes are changed as needed, and that information is transmitted from a fixed location or a moving vehicle.

Description

Technical Field

[0001] This application generally relates to distributed fiber optic sensing (DFOS) systems, methods, structures, and related technologies. More specifically, it relates to a wirelessly controlled, transceiver-capable acoustic modem used to transmit vibration signals to an optical sensor fiber.

Background Art

[0002] Distributed fiber optic sensing (DFOS) technologies such as distributed acoustic sensing (DAS), distributed vibration sensing (DVS), and distributed temperature sensing (DTS) are well-established as being most useful for sensing acoustic events, vibration events, and temperature in a variety of modern applications. Considering such importance, improvements to DFOS technology or complementary systems would be a welcome plus for this technology.

Summary of the Invention

[0003] Aspects of the present disclosure relate to a wirelessly controlled, transceiver-capable acoustic modem for use in distributed fiber optic sensing (DFOS) systems and methods, which bring progress in this technology.

[0004] In contrast to the prior art, from a first perspective, the wirelessly controlled acoustic modem of the present invention advantageously receives a wireless signal used to change the operating settings of the acoustic modem. This enables remote control of the acoustic modem and adjustment of its operating characteristics. The transceiver-capable acoustic modem may include one or more sensors that generate acoustically encodable environmental information and acoustically excite a nearby sensing fiber for detection / analysis by a DFOS system.

[0005] In contrast to prior art, and from another perspective, the acoustic modem of the present invention employs a novel method of acoustic modem communication over a DFOS / DAS system that advantageously improves the data transfer rate from the field to a central office or other location where a DFOS / DAS interrogator is installed. Operationally, the acoustic modem of the present invention communicates by spatially multiplexing acoustic vibration codes. Instead of using only a single vibrator (or shaker or speaker), the spatially multiplexed acoustic modem of the present invention uses multiple vibrators placed at various locations along a sensing fiber. As long as the spacing between the multiple vibrators is greater than the resolution of the DFOS / DAS system, the DFOS / DAS system can simultaneously detect signals from multiple vibrators. As a result, using n vibrators can increase the data transfer rate by n times.

[0006] Finally, in contrast to the prior art, from another perspective, the acoustic modem of the present invention charges itself by wirelessly tapping onto a high-power line and supplies power to the sensor and vibrator for the transmission of acoustic data. As a result, the acoustic modem of the present invention is self-charging and can transmit integrated sensor data via vibration through an OPGW (optical ground wire) cable. [Brief explanation of the drawing]

[0007] [Figure 1(A)] Figure 1(A) is a schematic diagram showing an example of a conventional non-encoded DFOS system. [Figure 1(B)] Figure 1(B) is a schematic diagram showing an example of a conventional encoding DFOS system.

[0008] [Figure 2] Figure 2 is a schematic diagram illustrating exemplary wireless programming for an acoustic modem according to an aspect of this disclosure.

[0009] [Figure 3] Figure 3 is a schematic block diagram showing exemplary components of an acoustic modem according to an aspect of the present disclosure.

[0010] [Figure 4] Figure 4 is a schematic flowchart illustrating the operational workflow of DFOS / DAS and an exemplary radio acoustic modem according to an aspect of this disclosure.

[0011] [Figure 5] Figure 5 is a schematic diagram illustrating exemplary features of a DFOS / DAS system employing an exemplary wireless acoustic modem according to an embodiment of the present disclosure.

[0012] [Figure 6] Figure 6 is a schematic diagram illustrating the configuration and operation of an exemplary spatial multiplexed acoustic modem according to an aspect of this disclosure.

[0013] [Figure 7] Figure 7 is a schematic diagram illustrating the overall operating principle of a spatial multiplexed acoustic modem according to an aspect of this disclosure.

[0014] [Figure 8] Figure 8 is a schematic flowchart illustrating the operational workflow of DFOS / DAS and an exemplary spatial multiplexed acoustic modem according to an aspect of this disclosure.

[0015] [Figure 9] Figure 9 is a schematic diagram illustrating exemplary features of a DFOS / DAS system employing an exemplary spatial multiplexed acoustic modem according to an embodiment of the present disclosure.

[0016] [Figure 10] Figure 10 is a schematic diagram illustrating exemplary operation of an exemplary energy harvesting acoustic modem according to an embodiment of the present disclosure.

[0017] [Figure 11] Figure 11 is a schematic flowchart illustrating the workflow of operation of DFOS / DAS and an exemplary energy harvesting acoustic modem according to an aspect of this disclosure.

[0018] [Figure 12] FIG. 12 is a schematic diagram showing exemplary features of a DFOS / DAS system employing an exemplary ambient power generation acoustic modem according to an aspect of the present disclosure.

Mode for Carrying Out the Invention

[0019] The following merely exemplifies the principles of the present disclosure. Therefore, those skilled in the art should understand that they can conceive of various configurations that embody the principles of the present disclosure, even if not explicitly described or illustrated in this specification, and that are within the spirit and scope of the present disclosure.

[0020] Furthermore, all examples and conditional terms listed in this specification are for the sole purpose of assisting in the understanding of the concepts provided by the inventors to facilitate the principles of the present disclosure and this technology, and should be construed as not being limited to the specifically listed examples and conditions.

[0021] Furthermore, all descriptions in this specification of the principles, aspects, and embodiments of the present disclosure, as well as all specific examples cited therein, are meant to include both their structural and functional equivalents. Furthermore, such equivalents are meant to include both currently known equivalents and equivalents developed in the future, i.e., elements that are developed to achieve the same function regardless of their structure.

[0022] Thus, for example, those skilled in the art will understand that any block diagram in this specification is a conceptual diagram specifically showing a circuit that realizes the principles of the present disclosure.

[0023] In this specification, unless otherwise specified, the drawings, including the figures, are not drawn to an exact scale.

[0024] As additional background, it should be noted that distributed optical fiber sensing systems interconnect optoelectronic integrators to optical fibers (or cables), transforming the optical fibers into an array of sensors dispersed along them. In practice, the fiber becomes the sensor, and the interrogator generates / injects laser light energy into the fiber to sense / detect events along the fiber.

[0025] As those skilled in the art will understand and recognize, DFOS technology can be used to continuously monitor vehicle movement, pedestrian traffic, drilling operations, seismic activity, temperature, structural integrity, fluid and gas leaks, and many other conditions and activities. It is used worldwide to monitor power plants, communication networks, railways, roads, bridges, borders, critical infrastructure, terrestrial and subsea power and pipelines, and downhaul applications in oil, gas, and enhanced geothermal power generation. Distributed fiber optic sensing has the advantage of being unconstrained by line-of-site or remote power access limitations, and can be deployed over continuous lengths exceeding 30 miles, sensing / detecting at any point along its end-to-end depending on the system configuration. Therefore, the cost per sensing point over long distances is far inferior to competing conventional technologies.

[0026] Distributed optical fiber sensing measures changes in the "backscattering" of light that occur within an optical sensing fiber when the sensing fiber encounters environmental changes such as vibration, strain, or temperature changes. As described above, the sensing fiber functions as a sensor along its entire length, providing real-time information about the physical / environmental surroundings and the fiber's preservation / security. Furthermore, distributed optical fiber sensing data pinpoints the precise location of events and conditions occurring on or near the sensing fiber.

[0027] Figure 1(A) illustrates a schematic diagram showing a typical configuration and operation of a distributed optical fiber sensing system that advantageously incorporates artificial intelligence / machine learning (AI / ML) analysis. Referring to Figure 1(A), it can be observed that the optical sensing fiber is connected to an interrogator. Although not shown in detail, the interrogator may include an encoded DFOS system that can employ a coherent receiver configuration known in the art, as shown in Figure 1(B).

[0028] As is well known, modern interrogators are systems that generate an input signal for an optical sensing fiber and detect / analyze the received signal after it has been reflected / backscattered. The received signal is analyzed to generate an output that indicates the environmental conditions that occurred along the fiber. The received backscattered signal is caused by reflections within the fiber, such as Raman backscattering, Rayleigh backscattering, and Brillion backscattering.

[0029] As is understood, modern DFOS systems include an interrogator that periodically generates optical pulses (or any encoded signal) and inputs them into an optical fiber. The input optical pulse signal is then transmitted along the optical fiber.

[0030] Along the fiber, a small portion of the signal is backscattered / reflected and sent back to the interrogator for reception. The backscattered / reflected signal transmits information that the interrogator uses for detection, such as changes in power levels indicating mechanical vibrations.

[0031] The received backscattered signal is converted to the electrical domain and processed by an interrogator. Based on the pulse input time and the time the signal was detected, the interrogator determines the location of the received signal along the optical sensing fiber, allowing for sensing of activity at each location along the optical sensing fiber. The classification method may be further used to detect and identify events or other environmental conditions, including acoustic and / or vibration and / or heat, along the optical sensing fiber.

[0032] Figure 2 is a schematic diagram illustrating exemplary DFOS operation, including an acoustic modem positioned on a utility pole from which a fiber optic sensor cable, a component of the DFOS system, is suspended. As shown in this figure, the acoustic modem generates an acoustic signal, which excites the fiber optic sensor cable, causing vibrations that are detected / interpreted by the operation of the DFOS / DAS system. As described above, the acoustic modem supports wirelessly controlled transmit and receive communications, receiving and responding to transmitted, compliant wireless signals.

[0033] In the illustrative scenario shown in the diagram, the vehicle is equipped with a radio transmitter that emits radio waves to communicate with an acoustic modem and change the settings of the acoustic modem. For example, depending on the actual distance between the central office and the acoustic modem, the transmitter may be located in the central office (or other fixed location) or in a mobile station such as the vehicle shown in the diagram.

[0034] As will be readily apparent to those skilled in the art, the wirelessly controlled acoustic modem of the present invention provides, for example, a snow depth measurement function that can be disabled in the summer and turned on again in the winter. Alternatively, the transmission cycle of the acoustic modem may be changed according to the operator's requirements.

[0035] As illustrated, the radio signal transmitted to the acoustic modem may originate from a fixed station, a moving or stationary vehicle, or a fixed stationary vehicle. In a preferred embodiment, the radio signal may be in an unlicensed radio frequency band and may use a known protocol.

[0036] In a preferred embodiment, the wirelessly controlled acoustic modem of the present invention employs communication that can be transmitted and received over two different media.

[0037] The first type of communication and medium uses acoustic vibrations that can be excited by a nearby fiber optic cable and detected by a DFOS / DAS system over a distance of at least 50 km. This medium (DFOS / DAS fiber optic sensor cable) is placed from an acoustic modem to an interrogator installed in the central office.

[0038] The second type of communication and medium is one of the ISM (Industrial, Scientific, and Medical) bands, which uses unlicensed radio signals in a frequency band. Although such radio bands are unlicensed, they are not without limitations. The main limitation is that the transmission power level cannot be very high. In other words, the distance between the radio receiver (acoustic modem) and the transmitter (controller) must be approximately 100 meters or less. Depending on the distance between the acoustic modem and the central office, the transmitter can be installed in the central office or in a mobile station such as a vehicle. This type of operation is schematically shown in Figure 2.

[0039] In summary, the wirelessly controlled acoustic modem of the present invention provides two communication functions of the acoustic modem and a mobile transmitter that enables control of the acoustic modem across an entire city. The acoustic modem can be switched on and off, and the measurement settings of the acoustic modem (sensitivity, accuracy, etc.) can be adjusted and changed as needed or requested in response to changes in sensing requirements and environmental conditions.

[0040] Figure 3 is a schematic block diagram showing exemplary components of an acoustic modem according to an aspect of the present disclosure. As shown in this figure, the acoustic modem includes an acoustic / vibration generator, a transceiver capable of advantageously providing the multimode communication described above, and a controller / computer for coordinating the operation of the acoustic modem.

[0041] Figure 4 is a schematic flowchart illustrating the operational workflow of the DFOS / DAS and an exemplary radio acoustic modem according to an aspect of this disclosure. As shown in this figure, the acoustic modem is first mounted in a location that makes physical contact with a nearby fiber optic cable. Next, the acoustic modem measures certain physical parameters and transmits the results via vibration based on its settings. The vibrations are remotely detected by the DFOS / DAS. To change the settings of the acoustic modem, a transmitter transmits radio waves containing configuration / setting data from a fixed or mobile station to the acoustic modem. The acoustic modem's controller receives this data and uses it to reconfigure its operating parameters. Finally, the settings and parameters of the acoustic modem are changed. Such changes may include switching sensors on or off as needed or desired.

[0042] Figure 5 is a schematic diagram illustrating exemplary features of a DFOS / DAS system employing an exemplary wireless acoustic modem according to an aspect of the present disclosure. As schematically shown in this figure, the acoustic modem enables both optical fiber communication (by acoustic / vibration operation) and wireless communication. The acoustic communication provides a communication medium (an optical fiber sensor cable, which is part of the DFOS / DAS) that does not require cutting / splicing / termination. Wireless communication enables remote control of the acoustic modem and allows for wireless reconfiguration of the acoustic modem. Finally, since the wireless communication containing the reconfiguration information can be provided from a movable or fixed location, the versatility of reconfiguration is greatly improved.

[0043] According to this disclosure and other embodiments of the acoustic modem of the present invention, the acoustic modem is further improved by providing the ability to spatially multiplex and transmit acoustic vibration codes. Instead of using a single vibrator (or shaker or speaker), the operation of the spatially multiplexed acoustic modem of the present invention uses multiple vibrator sources located at different locations along the optical fiber sensor cable. As long as the multiple vibrators are spaced further apart than the resolution of the DFOS / DAS system, the DFOS / DAS operation can simultaneously detect / collect signals from those vibrators. That is, using n vibrators can increase the data transfer rate by n times.

[0044] As those skilled in the art will understand and recognize, the spatial multiplexing operation of the present invention is made possible by the detection function of the DFOS / DAS system, as it can collect data from multiple points along a fiber optic cable. As a result, the spatial multiplexing acoustic modem of the present invention can transmit data from multiple points via multiple vibration sources.

[0045] As will be readily apparent to those skilled in the art, the spatial multiplexing acoustic modem of the present invention provides unique operation in DFOS / DAS data transmission and data reception operations. Regarding data transmission, it employs spatial multiplexing in the acoustic domain (i.e., different parts of the data are transmitted simultaneously at different points along the fiber via different vibrators). Regarding data reception, the DFOS / DAS system simultaneously receives / detects / decodes DFOS / DAS data from multiple points along the path of the optical fiber sensor cable. That is, signals detected at different points are combined and analyzed as a single transmission.

[0046] Figure 6 is a schematic diagram illustrating the configuration and operation of an exemplary spatial multiplexed acoustic modem according to an aspect of the present disclosure. As shown in this figure, a series of n vibrators are mounted at n different locations along the path of an optical fiber cable sensor. The n vibrators are controlled by a single acoustic modem. The n vibrators operate simultaneously at different frequencies and are simultaneously received / detected / analyzed by a single DFOS / DAS interrogator.

[0047] Figure 7 is a schematic diagram illustrating the overall operating principle of a spatial multiplexed acoustic modem according to an aspect of this disclosure.

[0048] First, an acoustic modem and n vibrators are placed in the field. The n vibrators must be placed at n different locations so as to be coupled to a single point along the fiber, and these vibrators must be spaced at least by the spatial resolution of the DFOS / DAS system. The data to be transmitted is sensor data, time values, or other data. Before the data is transmitted, the acoustic modem divides the data into n bits for each of the n vibrators. Next, the acoustic modem maps the bits to frequencies (i.e., 101 is f c (corresponding to...). Next, the acoustic modem determines n vibration patterns of different frequencies, and the vibrator realizes these vibrations. When the vibrations are coupled to the fiber, they are detected by the DAS system, demultiplexed, and decoded. Thus, the complete data stream is recovered.

[0049] Figure 8 is a schematic flowchart illustrating the operational workflow of a DFOS / DAS and an exemplary spatial multiplexed acoustic modem according to an aspect of the present disclosure. As shown in the figure, a spatial multiplexed acoustic modem with n vibrators according to an aspect of the present disclosure is installed in the field, with the n vibrators positioned at different locations along an optical fiber sensor cable. The acoustic modem's mainboard / processor divides the data and transmits it to each of the n vibrators. The n vibrators simultaneously transmit portions of the data from their respective different locations. The DFOS / DAS detects all DFOS / DAS signals from the n vibrators, demultiplexes them to obtain a single data stream, and analyzes that single stream to decode the data. Finally, the entire operation is repeated.

[0050] First, an acoustic modem and n vibrators need to be placed in the field, with the n vibrators positioned at n different locations along the fiber to couple to a single point. They are spaced at least according to the spatial resolution of the DAS system. The data will be sensor data, time values, or other data. Before the data is transmitted, the acoustic modem divides the data into n bits for the n vibrators. Next, the acoustic modem maps the bits to frequencies (i.e., 101 is f c (corresponding to...). Next, the acoustic modem determines n vibration patterns of different frequencies, and the vibrator realizes these vibrations. When the vibrations are coupled to the fiber, they are detected by the DAS system, demultiplexed, and decoded. Thus, the complete data stream is recovered.

[0051] Figure 9 is a schematic diagram illustrating exemplary features of a DFOS / DAS system employing an exemplary spatial multiplexed acoustic modem according to an embodiment of the present disclosure.

[0052] It should be noted that the power requirements of acoustic modems may limit their practical and widespread use, as they need to be installed in a location with available power for long-term operation without technical intervention.

[0053] Therefore, in this invention, the acoustic modem is equipped with a wireless power tapping function from high-voltage lines to supply power to the acoustic modem. Since such power supply requires proximity to high-power lines, applications related to monitoring high-power lines are optimized.

[0054] In operation, the acoustic modem of the present invention is an upgraded acoustic modem that wirelessly taps into a high-power line to charge itself and power sensors and vibrators for long-term or continuous operation. Our approach uses a wireless energy harvester similar to wireless charging technology. As a result, the acoustic modem of the present invention self-charges and transmits integrated sensor data via vibration through an OPGW (optical ground wire) cable.

[0055] Advantageously, the acoustic modem of the present invention is practical for operation near high-voltage lines because it is powered by power tapping from high-voltage lines. Since the acoustic modem utilizes the detection capabilities of the DFOS / DAS system, it can be detected by a DFOS / DAS interrogator system located several kilometers away simply by generating mechanical vibrations near an OPGW (optical ground wire) cable.

[0056] Figure 10 is a schematic diagram illustrating exemplary operation of an exemplary energy harvesting acoustic modem according to an aspect of the present disclosure. As can be seen from this figure, the acoustic modem of the present invention, which acquires electrical energy, includes at least three main operating components. The first component is a main control unit, which includes sensors and a rechargeable battery. The second component is a wireless power tapping antenna, which is located near the high-voltage cable but does not make physical contact with it. This component is responsible for wirelessly acquiring electrical energy and supplying it to the main control unit. The third component is the acoustic modem, which includes a shaker / vibrator and is mounted on or near the OPGW cable. Furthermore, there is also a DFOS / DAS system which includes an interrogator that interrogates the OPGW cable and detects vibrations generated by the shaker / vibrator of the device.

[0057] One of the advantageous features of the acoustic modem of the present invention, which is equipped with an energy harvesting function, is that it is a system that is completely isolated in terms of power. The modem of the present invention does not require an optical connection or a "hard" physical electrical connection. It does not need to receive any communication or control signals from the outside. It is a completely self-contained device that is self-charging, capable of performing pre-programmed missions (such as measuring specific physical parameters (temperature, humidity, pressure, snow depth, etc.) and transmitting those values ​​by vibration at predetermined time intervals), and is plug-and-play.

[0058] Figure 11 is a schematic flowchart illustrating the operational workflow of a DFOS / DAS and an exemplary energy harvesting acoustic modem according to an aspect of this disclosure.

[0059] Figure 12 is a schematic diagram illustrating exemplary features of a DFOS / DAS system employing an exemplary energy harvesting acoustic modem according to an embodiment of the present disclosure.

[0060] While several specific examples have been used to illustrate this disclosure, those skilled in the art will recognize that this teaching is not limited thereto. Therefore, this disclosure should be limited only by the claims appended herein.

Claims

1. A distributed optical fiber sensing (DFOS) system having an interrogator and a wirelessly controlled transceiverable acoustic modem, The aforementioned acoustic modem is Receiving a wireless signal containing the configuration information of the aforementioned acoustic modem, The configuration information is processed, and the operating parameters of the acoustic modem are established according to the processed configuration information. The circuit is configured to cause n vibrators, each mounted at n different positions along the optical sensor fiber of the DFOS system (where n is an integer greater than or equal to 2), to generate physical vibrations according to the operating parameters. The n vibrators simultaneously generate the physical vibrations at different frequencies. A distributed optical fiber sensing system in which the physical vibrations generated by the n vibrators are detected by the interrogator.

2. The distributed optical fiber sensing system according to claim 1, wherein the acoustic modem further comprises one or more sensors for measuring physical environmental parameters, and the circuit is further configured to process the measured environmental parameters and cause the n vibrators to generate the physical vibrations according to the measured environmental parameters.

3. The distributed optical fiber sensing system according to claim 2, comprising enabling or disabling the sensor based on the received configuration information.

4. The distributed optical fiber sensing system according to claim 3, wherein the received wireless signal is transmitted from a fixed position.

5. The distributed optical fiber sensing system according to claim 3, wherein the received wireless signal is transmitted from a mobile vehicle.

Images