Abstract: An opening-closing member controller that solves the problem includes a motor, a speed detection unit, an entrapment determination unit, and a control unit. The motor opens and closes an opening-closing member of a vehicle. The speed detection unit outputs a speed signal corresponding to a rotation speed of the motor. The entrapment determination unit determines whether entrapment of foreign material by the opening-closing member has occurred based on the speed signal. The control unit reverses or stops the motor when the entrapment determination unit determines that entrapment has occurred. The entrapment determination unit performs the determination at shorter time intervals when a remote operation switch that is separated from the vehicle is operated to close the opening-closing member than when a vehicle operation switch that is arranged in the vehicle is operated to close the opening-closing member.

Abstract: A power cable monitoring method which can be used to measure the mechanical state of health of subsea power cables. This method uses the magnetic properties of the load-bearing components of the power cable and the current carried by the power cable to apply an alternating force to itself. The only source of force from an alternating current in the cable which is at the fundamental frequency (F0) of the electrical power originates from magnetostriction of the steel armor. This force is predominantly axial. The strength of the F0 signal is used as an indicator of strain in the cable, where changes over time can be used to monitor the mechanical integrity of the cable structure. 2F0 signals are complex sums of axial, radial and tangential forces which are difficult to analyze. The 2F0 signal is therefore predominantly used to normalize the F0 signal.

Abstract: A tactile and proximity sensor includes a light source, a light receiver, an elastic structure, and a reflecting mirror. The light source emits light. The light receiver receives light and generates a signal indicating a result of reception of the light. The elastic structure includes an elastic body deformable in response to an external force and includes a reflecting portion to reflect light and transmitting portions to transmit light. The reflecting mirror faces the light source to guide the light from the light source to the reflecting portion and the transmitting portion.

Abstract: According to examples, a channel checker optical time-domain reflectometer (OTDR) may include a laser source to emit a laser beam. An optical switch may be optically connected to the laser source to receive the laser beam and to selectively transmit the laser beam to a circulator that is optically connected to a device under test (DUT). A first coupler may be optically connected to a first photodiode and to the circulator. A second coupler may be optically connected to the first coupler, the optical switch, and a second photodiode.

Abstract: An object is to provide a joining state detection film, a joining state detection device, and a joining state detection method, capable of detecting a joining state of a joining portion of two members from the outside. [Solution]A film containing a mechanoluminescent substance is formed on a surface, on a side opposite to a joining surface, of at least one member of two members that are joined at joining parts each having the joining surface, and physical stimulation is applied thereto.

Abstract: A method for evaluating a crack in a metal member comprises a first removal step (S10) and a second removal step (S20). In the first removal step (S10), a step for electrolyzing a metal member having an oxide scale formed on a surface thereof, a step for acquiring an image of the oxide scale as a first image, and a step for determining whether or not a scale crack has occurred are repeated until occurrence of a scale crack is determined. In the second removal step (S20), a step for electrolyzing the metal member having the scale crack, a second image acquisition step for acquiring an image of the oxide scale as a second image, and a second determination step for determining whether or not the scale crack has disappeared are repeated until disappearance of the oxide scale is determined.

Abstract: A shape changeable apparatus according to an embodiment of the present technology includes a space forming section, a fluid controller, a signal emitter, a detector, and a generator. The space forming section forms a space, and includes a deformable member that is arranged in contact with the space. The fluid controller is capable of deforming the member by controlling a flow of fluid with respect to the space. The signal emitter emits a signal into the space. The detector is arranged out of contact with the member within the space, and detects the emitted signal. The generator generates information regarding the deformation of the member on the basis of a result of the detection performed by the detector.

Abstract: Methods and apparatuses for processing materials to enhancing the material's surface strength, improving the material's cyclic and thermal stability of microstructures, and extend the material's fatigue performance. Embodiments include laser shock peening at material temperatures that are moderately elevated (from the material's perspective) above room temperature. Alternate embodiments include laser shock peening at very cold (cryogenic) material temperatures. Still further embodiments include laser shock peening while covering the surface of the material being processed with an active agent that interacts with the laser energy and enhances the pressure exerted on the surface.

Abstract: An aeronautical composite structure configured to monitor a physical status of a bonded portion between structural components using a multi-core optical fiber. A method and system for monitoring the physical status of a bonded portion in an aeronautical composite structure also uses a multi-core optical fiber. More particularly, the invention relates to a structure and method for monitoring the physical status of a bonded portion of an aeronautical composite structure from its manufacturing to its use in flight using a multi-core optical fiber.

Abstract: The present disclosure describes systems and methods for conducting deformation (e.g., extension and/or strain) measurements based on characteristics of a test specimen using light sourced from a single side of a test specimen. The light source and an imaging device are arranged on a single side of the test specimen relative to a back screen while the light source illuminates both a front surface of the test specimen and the back screen. The back screen reflects light to create a silhouette of the test specimen. The imaging device captures images of one or more markers on a front surface of the test specimen, as well as measuring position of the markers during the testing process. The imaging device also measures relative changes in position of the edges of the test specimen during the testing process, by analyzing the edges of the silhouetted image created by the reflective back screen.

Abstract: An apparatus for estimating bio-information, includes a sensor including a cover having a transmitting area provided at a center of the cover, and non-transmitting areas provided at both edges of the cover, a light source configured to emit light onto an object that is in contact with the cover, and a detector configured to detect a first optical signal of the emitted light that is scattered or reflected from the object after passing through the transmitting area, and a second optical signal of the emitted light that is reflected from the non-transmitting areas. The apparatus further includes a processor configured to estimate bio-information, based on the detected first optical signal and the detected second optical signal.

Abstract: Systems and methods for bacterial load sensing devices are disclosed. An example contamination sensing device may comprise a body, a light emitter disposed on the body and configured to emit an excitation wavelength of light toward a surface, a sensor disposed on the body, configured to detect light, and directed toward the surface, and a filter adjuster configured to determine, based on the excitation wavelength of light, a filter configured to remove light outside of an emission wavelength range, wherein the emission wavelength range corresponds to wavelengths of light emitted by contamination upon exposure to the excitation wavelength of light, and adjustably move the filter in front of the sensor.

Abstract: A load sensing system for sensing a load on a structure can include an optical load sensing element configured to change an optical state based on a force applied thereto, an optical source operatively connected to the optical load sensing element and configured to input an input optical signal to the optical load element, and an optical detector configured to receive a returned optical signal from the optical load sensing element. The optical detector can be configured to detect one or more frequency peaks of the returned optical signal and to use the one or more frequency peaks of the returned optical signal to correlate to a load value of the load and output the load value indicative of the load.

Abstract: The present invention provides a shaft rotational speed measurement device and method based on variable density sinusoidal fringe pattern. The device comprises a variable density sinusoidal fringe pattern sensor, a high speed image acquisition and transmission module, a computer, and an image processing software module.

Abstract: An apparatus, and related method, relates generally to a fiber-optic sensing system. In such a system, fiber-optic sensors are in a rosette or rosette-like pattern. An optical circulator is coupled to receive a light signal from a broadband light source, to provide the light signal to the fiber-optic sensors, and to receive a returned optical signal from the fiber-optic sensors. A spectral engine is coupled to the optical circulator to receive the returned optical signal and configured to provide an output signal.

Abstract: In a handle unit for interventional procedure, a master device for interventional procedure, and a remote control interventional procedure system, the handle unit is gripped by an operator. The handle unit includes a gripper, a mode selection module and a linear motion module. The gripper is gripped by the operator. The mode selection module is equipped to the gripper, and selects one of motion modes including a linear motion mode, a rotational motion mode and a plane motion mode. The needle linearly moves with one degree of freedom in the linear motion mode. The needle rotationally moves with two degrees of freedom in the rotational motion mode. The needle moves in a plane with two degrees of freedom in the plane motion mode. The linear motion module performs the linear motion of the needle based on the selection of the mode selection module, and is equipped to the gripper.

Abstract: A distance measurement device includes a light-emitting-unit that emits irradiation light toward an object; a light-receiving unit that receives reflected light from the object; a distance-calculation unit that calculates a distance to the object based on a transmission time of the reflected light received; a posture-adjustment mechanism that adjusts a posture of at least the light-receiving-unit; and a posture-controller that drives the posture-adjustment mechanism. The light-receiving unit is formed of a two-dimensional sensor in which a plurality of pixels are two-dimensionally arrayed, and the distance-calculation unit calculates two-dimensional distance data from received light data in each of the pixels of the two-dimensional sensor.

Abstract: An aircraft and method of operating an aircraft. The aircraft includes a temperature sensor and a processor. The temperature sensor that obtains an optical signal indicative of a temperature at a selected location of an outer surface of the aircraft. The processor is configured to determine the temperature at the selected location from the optical signal, and operate the aircraft based on the temperature at the selected location.

Abstract: The present invention is directed to a system for measuring surface flatness, deformation and/or coefficient of thermal expansion (CTE) of a specimen comprising an image capture and analysis processing calibration means for performing image capture and analysis processing calibration of said system, a measuring means for measuring surface flatness of a specimen in a specimen holder, a heating means for heating said sample holder with a predetermined profile, and a control means for providing the predetermined heating profile onto the surface of said specimen and controlling operations of said image capture and analysis processing calibration means, said measuring means, and said heating means.

Abstract: A measuring apparatus for measuring a flexural strength of a test piece includes a support unit having a first support member and a second support member that are spaced from each other, for supporting a lower surface of the test piece, a presser for pressing the test piece, a moving mechanism for relatively moving the presser toward and away from the test piece supported by the support unit, a load measuring unit for measuring a load applied to the presser when the presser presses the test piece supported by the support unit, and a controller having a calculating section for calculating the flexural strength of the test piece on the basis of a thickness and a width of the test piece, a spacing between the first support member and the second support member, and a maximum value of the load measured by the load measuring unit.

Abstract: An optical force sensor along with an optical processing apparatus and method are disclosed. The optical force sensor includes an optical fiber, a core included in the optical fiber, an instrument including the optical fiber, the instrument having a distal region, and a tubular structure encasing an end of the optical fiber and secured to the first conduit at the distal region of the instrument. When an optical interferometric system is coupled to the optical fiber, it processes reflected light from a portion of the core included within the tubular structure that does not include Bragg gratings to produce a measurement of a force present at the distal region of the instrument.

Abstract: A downhole tubing string and an umbilical harness are combined in a wellbore. The umbilical harness, which is formed remote from the wellbore, includes an umbilical, and umbilical connectors connected to lines in the umbilical. Connectors attach to well components and make up part of the downhole tubing string. The well components include valves, sensors, and actuators. The umbilical connectors attach to the umbilical at strategic locations so the umbilical connectors can reach and be mated to corresponding component connectors when the umbilical harness and downhole string are combined. Electricity, communication signals, or both, are transmitted along the lines in the umbilical, which are selectively conveyed to each component via the mated connectors. As the umbilical connectors are installed on the umbilical prior to wellsite delivery, the umbilical harness and downhole string are combined by engaging plugs on respective ends of umbilical connectors and corresponding ends of component connectors.

Abstract: Management of fatigue life includes partitioning a drilling interval into sections, and calculating a stress value for each section. From the stress value, an equivalent alternative stress amplitude is calculated for each location, and a fatigue life consumption value in each section is computed. The fatigue life consumption value across the sections is aggregated to obtain an aggregated fatigue life consumption value, which is presented.

Abstract: A system for detecting needle dislodgement includes a first sensor element and a second sensor element. The first sensor element is attached to a first associated dialysis tubing having a needle connected at one end offset from the needle and a sterile field, which is an area on a leg or arm adjacent to where the needle is inserted, such that movement of the first associated dialysis tubing results in movement of the first sensor element. The second sensor element attaches to a second associated dialysis tubing having a needle connected at one end and detects movement of the first sensor element with respect to the second sensor element. An alarm is in communication with the first or second sensor element and generates a signal when the movement of the first sensor element with respect to the second sensor element is outside a predetermined threshold.

Abstract: Provided is a screening apparatus or the like of an optical fiber that can suppress or prevent occurrence of a fiber-strike on the side of a feeding bobbin regardless of the weight of the feeding bobbin. An embodiment has a feeding bobbin 12 that feeds out an optical fiber 10; a screening unit 16 that applies a tension to the optical fiber 10 fed out from the feeding bobbin 12; a first capstan 14 that feeds the optical fiber 10 into the screening unit 16; a winding bobbin 20 that winds the optical fiber 10 to which the tension is applied by the screening unit 16; and a control unit 70 that, when disconnection of the optical fiber 10 occurs due to the tension applied by the screening unit 16, controls the feeding bobbin 12 and the first capstan 14 so as to stop rotation of the feeding bobbin 12 and rotation of the first capstan 14 and sets a deceleration rate of the first capstan 14 in accordance with a deceleration rate of the feeding bobbin 12.

Abstract: Some embodiments of the disclosure provide an optical fiber Fabry-Perot sensor (1), and a manufacturing method thereof. According to an embodiment, the optical fiber Fabry-Perot sensor (1) includes a hollow tube body (10), a first optical fiber (20), and a second optical fiber (30). The hollow tube body (10) has a first tube body (11), a cavity portion (12), and a second tube body (13) sequentially arranged in an axial direction. The first optical fiber (20) is provided within the first tube body (11) in the axial direction and has a first light guide end face (21) provided within the cavity portion (12). The second optical fiber (30) is provided in the second tube body (13) in the axial direction and has a second light guide end face (31) provided within the cavity portion (12).

Abstract: A guidewire having a fiber optic force sensor with a mirror having encoded reflectance is described. The guidewire has a distal housing supported by a core wire. A distal hypotube connected to the distal housing supports a spring intermediate hypotube proximal and distal portions. An atraumatic head is connected to the distal hypotube portion. An optical fiber having at least one fiber core extends through lumens in the core wire and housing to a distal end of the housing. A mirror supported by the atraumatic head faces proximally but is spaced distally from the fiber core at a distal face of the optical fiber. The mirror is provided with a pattern of reflectance that varies along a radius from a central area of reflectance. Light of a defined power shines from the fiber core to the mirror with a reflected percentage of the defined light power being reflected back to the fiber core.

Abstract: A high throughput rheology machine measures transient response to a material subject to the decaying oscillation to determine nonlinear characteristics of the material with a single test cycle.

Abstract: In the methods for monitoring a bearing clearance of a roller bearing (4), in particular the bearing clearance of a main bearing of a wind turbine, within the scope of a first measuring series using at least one distance sensor (18), a distance (a, a1, a2) between a rotating part (12) and a stationary part (14) is respectively sensed in at least two different recurring load states (L1, L2), and a difference (?a) between the measured distances (a1, a2) is determined. At a later time the distance measurements are repeated in the same at least two recurring load states (L1, L2) within the scope of a second measuring series. A change in the bearing clearance is inferred on the basis of the changes in the distance difference (?a) within the scope of condition monitoring.

Abstract: A method for non-contact measurement of stress in a thin-film deposited on a substrate is disclosed. The method may include measuring first topography data of a substrate having a thin-film deposited thereupon. The method may also include comparing the first topography data with second topography data of the substrate that is measured prior to thin-film deposition. The method may further include obtaining a vertical displacement of the substrate based on the comparison between the first topography data and the second topography data. The method may also include detecting a stress value in the thin-film deposited on the substrate based on a fourth-order polynomial equation and the vertical displacement.

Abstract: A system includes a computer having a processor and a memory storing instructions executable by the processor to acquire a first image of a tire of a vehicle upon shutdown of the vehicle. The instructions include instruction to then, upon startup of the vehicle, and in response to determining that the tire is unmoved since the shutdown and, in response, acquire a second image of the tire. The instructions include instruction to actuate a component of the vehicle in response to determining that the first image is different that the second image.

Abstract: A pressure sensor, a method for manufacturing the pressure sensor, and an electronic device are provided. The pressure sensor includes an electroluminescent device and a resistor layer. The resistor layer and one electrode of the electroluminescent device are connected to two electrodes of a power source respectively to form a loop. The pressure sensor is capable of converting a deformation amount caused by a pressure into a brightness change of the electroluminescent device, and determining a size of the pressure in accordance with the brightness change.

Abstract: A debonding detecting method detects debonding of an adhering portion at which an adhering object adheres to an adherend. An optical fiber sensor is provided on the adherend adjacent to the adhering object. A longitudinal direction of the optical fiber sensor is along a direction in which the adhering object extends. Reference strain data of a strain measured by the optical fiber sensor is prepared in advance when a load is applied to the adherend in a reference state in which debonding of the adhering portion does not occur. The debonding detecting method includes: applying a load to the adherend; measuring a strain of the adherend by the optical fiber sensor; and the determining presence or absence of debonding based on comparison result obtained by comparing measured strain data measured in the measuring and the reference strain data.

Abstract: The invention relates to a load measuring device including a deformable component configured to be deformed under a load to be measured and a sensor assembly attached to a first portion of the deformable component and to a method for determining load using such a sensor assembly. It is proposed that the sensor assembly includes at least one acceleration sensor configured to detect a change in an orientation of the first portion with regard to the direction of gravity and that the deformable component is formed as a seal configured to be in sliding contact with a component configured to rotate in relation to the seal.

Abstract: A lighting system is described for a treadmill, the treadmill including a tread that rotates around a front axle and a rear axle, wherein the tread comprises slats each having a tread surface and an underside. The lighting system includes a light positioned on at least one slat, wherein the light is configured to emit light between the adjacent slats and a controller in communication with the light and configured to control the light.

Abstract: A method for condition monitoring of distributed drive-trains using Bayesian data fusion approach for measured data includes measurement of physical signals obtained from sensors attached to the components being chosen from the drive-train which are delivered to the computer means for processing the measured data and performing data fusion processes, using a data from information database containing at least one information system. The method is characterized by comprising two stages for data fusion processes performed by using Bayesian Inference, the first one for local data fusion process and the second one for global data fusion process, and on the basis of the second stage the assessment process of the condition of the drive-train is performed by choosing the maximum value of the received data, which maximum value serves as an indicator for the most likely fault present in the drive-train.

Abstract: The educational system for teaching mechanical failure includes first and second specimen pieces. The first and second specimen pieces are adapted to be magnetically joined to one another at a selected magnitude of magnetic force. A linear force measuring device, such as a load cell, is secured to the first specimen piece and a support frame. A linear actuator is secured to the support frame and the second specimen piece to selectively apply a separation force to the first and second specimen pieces. In use, a user may increase a magnitude of the separation force until the first and second specimen pieces separate from one another. The measured separation force when the first and second specimen pieces separate from one another is representative of a required force to cause mechanical failure.

Abstract: A compression test fixture including a first specimen engagement member having a first channel, the first channel having a first depth; a second specimen engagement member having a second channel having a second depth that is different than the first depth; and at least one coupling member engaged to both the first specimen engagement member and the second specimen engagement member such that a gap is defined between the first specimen engagement member and the second specimen engagement member, where the first channel and the second channel support the test specimen within the gap such that at least one opposing major surface of the test specimen is visible within the gap.

Abstract: The invention relates to an ultrasonic flow measurement system comprising a flow tube for the fluid whose flow rate is to be determined and at least two ultrasound transducer circuitry. At least one of the at least two ultrasound transducer circuitry comprises an ultrasound transmitter that is arranged for transmitting ultrasound signals through said fluid in a transmitting phase, and at least another one of the at least two ultrasound transducer circuitry comprises an ultrasound receiver that is arranged for receiving transmitted ultrasound signals in a receiving phase. The system further comprises at least one receiving circuit that is arranged for reading out the ultrasound receiver in the receiving phase; and control means connected to the at least two ultrasound transducer circuitry and to the at least one receiving circuit.

Abstract: Provided are a material in-situ test device and method under multi-load and multi-physical field coupled service conditions. The device is composed of a precise six-degree-of-freedom composite load applying module, a precise torsion module, a precise indentation module, a clamp module and a control module which work together to complete a composite-load and multi-physical field coupled experiment, and is integrated with a digital speckle strain measurement and infrared thermal imaging module and a microscope observation module, so as to carry out in-situ observation and quantitative characterization on material deformation behaviors and damage mechanism phenomena in a composite-load and multi-physical field loading process. For example, loading methods of “cantilever type pure bending, cantilever type tension/compression-torsion, and cantilever type bending-torsion”, etc. can realize the loading of composite load.

Abstract: A pressure three-dimensional non-uniform loading/unloading and steady pressure model test system has a pressure three-dimensional non-uniform loading/unloading device. The pressure three-dimensional non-uniform loading/unloading device is controlled via an input instruction of the hydraulic loading/unloading and steady pressure automatic control system to carry out pressure three-dimensional gradient non-uniform loading/unloading and steady pressure control. An automatic model displacement test system automatically acquires the displacement of any part inside a test model. A multi-probe peeping system observes a cavern excavation deformation and failure process dynamically in real time.

Abstract: A vibration measurement system and relative method to monitor multiphase flows in extraction wells or conduits, by analysis of backscattered multimode fiber light comprising: • a sensing multimode optical fiber; • an optical source, containing a high coherence laser that emits optical pulses to be sent in said sensing fiber; • a photonic lantern with 3 or more single-mode optical fiber ports and one multimode fiber port that is connected to the sensing multimode fiber; • an optical receiver, comprising a number of photodetectors equal to the number of the single-mode optical fiber ports of said photonic lantern minus 1, wherein each photodetector is connected to each of said single-mode ports; • a system for processing output signals from the optical receiver, the optical source being connected to one of the single-mode optical fiber ports and the other single-mode fibers being connected to the optical receiver.

Abstract: Embodiments of this disclosure provide an optical resonance device, a force measuring device and method, a modulus measuring method and a display panel. The optical resonance device includes: a light emitting layer, a reflecting layer, and a transflective layer. The light emitting layer is configured to generate light. The reflecting layer is arranged at one side of the light emitting layer and is configured to reflect the light generated by the light emitting layer. The transflective layer is arranged at the other side of the light emitting layer and is configured to transmit a portion of the light generated by the light emitting layer and reflect a portion of the light generated by the light emitting layer. The force measuring device includes: an optical resonance device, at least one optical sensor, a bearing unit and a calculation unit.

Abstract: A molded article has an exterior surface, a non-exterior surface, and a projecting or recessed portion provided on at least one of the exterior surface and the non-exterior surface. A repeated pattern of projections and/or recesses or a texture face, which serves to disturb the flow of resin, is provided on the non-exterior surface.

Abstract: A temperature interference-free sensing fiber monitoring apparatus and application method therefor including a vacuum cavity module, a composite material flat groove module and a port fiber-fixing module, wherein the vacuum cavity module is connected with the composite material flat groove module via an glue-injection square groove, and the port fiber-fixing module is connected with the vacuum cavity module via a foursquare plug body; a sensing fiber orderly passes through the composite material flat groove module, the vacuum cavity module and the port fiber-fixing module; the vacuum cavity module, the composite material flat groove module and the port fiber-fixing module are all fixed on a temperature interference-free base platform.

Abstract: Optical connector assemblies for device-to-device optical connections are disclosed. In one embodiment, an optical connector assembly includes a housing having a mating surface, an optical coupling body, a first contact pin, and a second contact pin. The optical coupling body includes an optical coupling face such that the optical coupling face is exposed at the mating surface of the housing. The optical connector assembly further includes a plurality of GRIN lenses disposed within the optical coupling body, wherein each GRIN lens has a coupling surface positioned at the optical coupling face of the optical coupling body. The first and second contact pins extend from the mating surface of the housing such that they are positioned on opposite sides of the optical coupling body. Optical connector assemblies incorporating a total-internal-reflection surface are also disclosed.

Abstract: An accessory is attachable to a portable device equipped with a camera. The accessory includes a camera lens opening and a retainer that retains the portable device such that a lens of the camera of the portable device is aligned with the camera lens opening. At least one source of electromagnetic radiation in the range of ultraviolet and/or blue wavelengths is disposed on the accessory so as to illuminate an object to be authenticated when the object is disposed in front of the camera lens opening of the accessory. A spacer on the accessory positions the accessory with respect to the object to be authenticated so that the camera lens opening has a predetermined positional relationship with a to-be-examined region of the object.

Abstract: The present invention relates to an FBG sensor for measuring a maximum strain of an object being measured, a method for manufacturing the sensor, and a method of using the sensor. To this end, provided is the FBG sensor for measuring a maximum strain, comprising: an optical fiber (130) having an FBG sensor (150) therein; a first metallic foil (120) contacting the optical fiber (130) on one surface thereof; a second metallic foil (120) which comes into surface-contact with the one surface; an adhesive layer (140) provided between the first and second metallic foils (100, 120); a means for measuring a residual strain of the first and second metallic foils (100, 120) through the FBG sensor (150); and a means for calculating a maximum strain on the basis of the measured residual strain and a sensitivity coefficient (Csen) obtained through experimentation.

Abstract: Systems and methods for automatically identifying and classifying distress of an aircraft component are provided. In one embodiment, a method includes accessing one or more digital images captured of the aircraft component and providing the one or more digital images as an input to a multi-layer network image classification model. The method further includes generating a classification output for the one or more images from the multi-layer network image classification model and automatically classifying the distress of the aircraft component based at least in part on the classification output.

Abstract: A method of distributed acoustic sensing includes providing a fiber optic distributed acoustic sensing system having a cable. A straight optical fiber extends parallel to a longitudinal axis of the cable along the cable length. A helically wrapped optical fiber extends along the cable length. The method includes transmitting optical signals into and receiving backscattered signals out of the optical fibers consisting of a component of said optical signals which component has been backscattered from impurities or inhomogeneities in the optical fibers, observing changes in the backscattered signals caused by axial stretching and compressing of the optical fibers caused by an incident wave, comparing the backscattered signals of the straight optical fiber and the helically wrapped fiber, and determining, based on the comparing of the backscattered signals, a direction of wave propagation of the incident wave with respect to the fiber axis for detecting broadside waves and axial waves distinguishably.