Multi-element sensor for monitoring a composite structure

Abstract

To provide a sensor for monitoring a composite structure, a method for manufacturing the sensor, and a method for attaching the sensor to the composite structure.SOLUTION: The system includes a plurality of sensors coupled to the composite cylinder and configured to detect deformation data about the composite cylinder, a controller communicatively coupled to the plurality of sensors and configured to determine a damage value based on the deformation data when the composite cylinder experiences impact damage and to provide a notification when the damage value exceeds an impact damage threshold, and a fill controller communicatively coupled to the plurality of sensors and configured to control a valve to fill the composite cylinder with a fluid, to detect damage to the composite cylinder based on the deformation data from the plurality of sensors when the composite cylinder is filled with the fluid, and to automatically perform a safety action when damage to the composite cylinder is detected.SELECTED DRAWING: Figure 2A

Description

Related Applications

[0001] This application is a continuation of U.S. patent application Ser. No. 17 / 395,885, filed August 6, 2021, entitled "Multi-Element Sector Sensor for Monitoring Composite Structure and U.S. patent application Ser. No. 17 / 223,628, filed April 6, 2021, entitled "Composite Cylindrical Device." Priority for the "Linder Monitoring System" The entire disclosures of each application are incorporated herein by reference. Let's say. [Technical Field]

[0002] The present disclosure relates to sensors for monitoring composite laminate structures. [Background technology]

[0003] Vehicles may be used for the transport of passengers and / or cargo. Vehicles for the transport of cargo include Some engines use fuel stored in a cylinder as their power source. Summary of the Invention [Problem to be solved by the invention]

[0004] Such cylinders can be damaged during vehicle operation. It is important to repair the cylinder. [Means for solving the problem]

[0005] Described herein is a sensor for monitoring composite structures. a first size of a first network device configured to detect data relating to a monitoring task; The sensor further comprises a sensor element for detecting a second monitoring task. a second sensor element of a second size configured to detect the data;

[0006] Also described herein is a method of manufacturing a sensor, the method including: and forming a first positive electrode having a second size. The method further comprises: The method further comprises fabricating a ground electrode having a size suitable for the first positive electrode and the second positive electrode. and disposing a piezoelectric material between the layer of the second positive electrode and the ground electrode. do.

[0007] Also described herein is a method for monitoring a composite structure, the method comprising: The method includes determining a plurality of monitoring tasks for a sensor having a plurality of sensor elements. The method further comprises: monitoring the plurality of sensors based on each of the plurality of monitoring tasks. The method further comprises determining a plurality of sensor element sizes for each of the elements. and manufacturing the sensor based on the plurality of sensor element sizes determined. The method further comprises coupling the sensor to the composite structure.

[0008] Those skilled in the art will appreciate other aspects of the present invention upon review of the following drawings and detailed description. The system, method, features, and advantages will also be understood. , which are not necessarily to scale, are intended to more clearly illustrate the important features of the present invention. It may be an exaggeration. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a vehicle equipped with a composite cylinder that stores fuel used to power the vehicle in each embodiment. FIG. [Figure 2A] FIG. 1 is a diagram showing a composite cylinder in each embodiment. [Figure 2B] FIG. 10 is another view showing the composite cylinder in each embodiment. [Figure 3A] 1 is a block diagram illustrating each monitoring component of the system in accordance with various embodiments. FIG. [Figure 3B] FIG. 10 is another block diagram illustrating the monitoring components of the system, according to embodiments. [Figure 4] 3A to 3C are diagrams showing models of the cylinder, sensors, and impact points in each embodiment. [Figure 5] FIG. 4 is a diagram showing sensor data of the present system in each embodiment. [Figure 6] FIG. 10 is another diagram showing sensor data of the system in each embodiment. [Figure 7] 10A and 10B are diagrams illustrating models of the cylinder, sensors, and estimated impact locations in each embodiment. [Figure 8] FIG. 2 is a diagram showing data of the present system in each embodiment. [Figure 9] FIG. 2 is a block diagram showing the components that fill the cylinder in each embodiment. [Figure 10] FIG. 1 is a block diagram showing components that monitor and fill cylinders in each embodiment. [Figure 11] 10A to 10C show data detected during the filling of the cylinder in accordance with the embodiments; [Figure 12] 10A-10C are other diagrams illustrating data detected during the filling of the cylinder in accordance with various embodiments. [Figure 13] 10A-10C are further diagrams illustrating data detected during filling of the cylinder in accordance with various embodiments. [Figure 14] FIG. 2 is a block diagram of the system according to each embodiment. [Figure 15A] FIG. 2 is a flow chart of each process executed by the system in each embodiment of the present invention. [Figure 15B] FIG. 10 is another flowchart of each process executed by the system in each embodiment of the present invention. [Figure 16A] FIG. 2 is a plan view of a sensor in each embodiment of the present invention. [Figure 16B] FIG. 2 is a side cross-sectional view of the sensor according to each embodiment of the present invention. [Figure 16C] FIG. 2 is a side view showing the sensor on a flat surface in each embodiment of the present invention. [Figure 16D] FIG. 10 is a side view showing the sensor on a curved surface in each embodiment of the present invention. [Figure 17] 1A to 1C are plan views of sensors having sensor elements of three different sizes in accordance with embodiments of the present invention. [Figure 18] 1A to 1C are plan views of sensors having sensor elements of four different sizes in accordance with embodiments of the present invention. [Figure 19] 1A to 1C are plan views of sensors having sensor elements of five different sizes in accordance with embodiments of the present invention. [Figure 20] 1 is a schematic diagram of an experimental setup for applying the sensor in accordance with embodiments of the present invention. FIG. [Figure 21A] 10A to 10C are diagrams showing detected experimental data in each embodiment of the present invention. [Figure 21B] FIG. 10 is another diagram showing detected experimental data in each embodiment of the present invention. [Figure 22] 10A and 10B are diagrams showing detection data that have been time-shifted to a coherent state and the sum of signals that have been brought into a time-coherent state in each embodiment of the present invention. [Figure 23A] 10A to 10C are diagrams showing detected experimental data in each embodiment of the present invention. [Figure 23B] FIG. 10 is another diagram showing detected experimental data in each embodiment of the present invention. [Figure 24]FIG. 2 is a diagram showing the frequency-wavelength dispersion relationship in each embodiment of the present invention. [Figure 25] 1 is a schematic diagram of an experimental setup for applying the sensor in accordance with embodiments of the present invention. FIG. [Figure 26] 10A-10C are diagrams comparing sensing elements of different diameters in accordance with embodiments of the present invention; [Figure 27] FIG. 2 is a flow diagram illustrating a method for manufacturing a sensor in accordance with embodiments of the present invention. [Figure 28] FIG. 1 is a flow diagram showing a method for manufacturing and using a sensor in each embodiment of the present invention. [Figure 29A] 3A to 3C are diagrams illustrating a manufacturing process of a piezoelectric element used in the sensor in each embodiment of the present invention. [Figure 29B] 6A to 6C are diagrams illustrating other steps for manufacturing a piezoelectric element used in the sensor in each embodiment of the present invention. [Figure 29C] 10A to 10C are diagrams illustrating still another manufacturing process of the piezoelectric element used in the sensor in each embodiment of the present invention. [Figure 29D] 10A to 10C are diagrams illustrating still another manufacturing process of the piezoelectric element used in the sensor in each embodiment of the present invention. [Figure 29E] 10A to 10C are diagrams illustrating still another manufacturing process of the piezoelectric element used in the sensor in each embodiment of the present invention. [Figure 29F] 10A to 10C are diagrams illustrating still another manufacturing process of the piezoelectric element used in the sensor in each embodiment of the present invention. [Figure 30A] 29A to 29F according to the embodiments of the present invention. [Figure 30B] 29A to 29F according to the embodiments of the present invention. [Figure 30C] FIG. 29B is still another diagram showing a sensor having the piezoelectric element of FIGS. 29A to 29F in each embodiment of the present invention. [Figure 30D]FIG. 29B is still another diagram showing a sensor having the piezoelectric element of FIGS. 29A to 29F in each embodiment of the present invention. [Figure 31] 1 is a schematic diagram of an experimental setup for applying the sensor in accordance with embodiments of the present invention. FIG. [Figure 32] 10 is a graph of sources used in an experimental setup applied to the sensor in accordance with embodiments of the present invention. [Figure 33] 10A to 10C are diagrams showing detected experimental data in each embodiment of the present invention. [Figure 34A] FIG. 10 is another diagram showing detected experimental data in each embodiment of the present invention. [Figure 34B] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 35] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 36A] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 36B] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 37] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 38A] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 38B] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 39] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 40A] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 40B] FIG. 10 is yet another diagram showing detected experimental data in accordance with each embodiment of the present invention. [Figure 41]FIG. 2 is a flow diagram illustrating a method for manufacturing a sensor in accordance with embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Described herein is a system, vehicle, and method for monitoring a vehicle's composite cylinder. The systems, vehicles and methods disclosed herein are directed to the composite bonnet. The system and method described herein automatically detects damage to the vehicle and takes appropriate action. The law requires that the integrity of the composite cylinder be maintained from the time of use to the time of filling (or refilling). The composite cylinders are used to continuously monitor the safety of vehicles. Improve your performance.

[0011] Although the description herein is directed to composite cylinders, the system and method may also be used in wind turbines. Any composite structure where impact damage is detrimental, such as a turbine, airframe, or wing leading edge. It can be applied to a variety of situations.

[0012] Additionally, sensors used to monitor the composite structure are also disclosed. The sensors described herein are capable of performing multiple monitoring tasks with a single sensor. The sensors described herein are easily adjustable and reconfigurable. Conventional piezoelectric sensors are cost-effective and can be mass-produced. Not only is it time-consuming, but it does not support multiple monitoring tasks.

[0013] As used herein, "driver" refers to a human driver of a vehicle when the vehicle is a non-autonomous vehicle. and / or as used herein, "driver" may refer to a person who controls a vehicle autonomously or refers to one or more computer processors used to drive a vehicle autonomously or semi-autonomously. "User" refers to the driver or passenger of a vehicle if the vehicle is a non-autonomous vehicle. While the term may be used to refer to an occupant of a vehicle if the vehicle is an autonomous or semi-autonomous vehicle, As used herein, "cylinder" refers to a storage tank, a pressure vessel, or a and other containers that can be used to store gases, but not necessarily For specific shapes, such as right cylinders and / or cylinders with constant or non-varying circular cross-sections As used herein, "fuel" or "gas" refers to any fuel, including gaseous fuels and liquid fuels. It also refers to any fluid used to power a vehicle.

[0014] 1 shows a vehicle 102. Specifically, the vehicle 102 is coupled to a trailer 106. The vehicle 102 is a tractor configured to pull a trailer 106. The fuel stored in a composite pressure cylinder (or "composite cylinder" or "cylinder") is operated. For example, the fuel may be compressed natural gas stored in a composite cylinder. .

[0015] The cylinder may be part of a gas cylinder assembly comprising: The fuel supply is in fluid communication with any power generating system, such as an engine, of the vehicle 102. The vehicle 102 may be a car, a wagon, a van, a bus, a multi-passenger vehicle, a truck, or a trailer. (tractor trailer truck), large vehicles such as garbage trucks, or any other vehicle In some embodiments, the gas cylinder assembly is configured for use on a marine vessel. or those configured for aircraft or for mobile or stationary fuel stations. It is something.

[0016] The fuel bottle may be mounted, for example, in a compartment or housing 104A in the side of the vehicle 102, A section or housing 104B of the trailer 106, or a section behind the cab of the vehicle 102 In some embodiments, the fuel bottle may be housed in a housing 104C. The vehicle may be stored on the rooftop or mounted on the tailgate of the vehicle.

[0017] In-service failures of composite pressure cylinders are primarily due to thermal exposure events, impact damage, and composite laminate failures. The cumulative damage that harms the body comes from three different root causes. While heat exposure can be mitigated, , impact damage (e.g., vehicle collision) or improper operating conditions (e.g., improper installation, Accumulative damage caused by debris caught between the cylinder and the enclosure systems and methods for protecting composite pressure cylinders from ) does not exist. Experience to date has shown that the cylinders have not sustained significant impact damage. or inappropriate environmental conditions (e.g., a bolt stuck between the cylinder and the enclosure) The stress state within the laminate exceeds a critical level due to the accumulation of potential damage. However, it has been found that the cylinder will experience catastrophic failure during subsequent filling cycles.

[0018] FIG. 2A illustrates a cylinder 100 configured to store a fluid such as compressed natural gas or hydrogen. The cylinder 100 may be made of metals such as steel and aluminum, glass fiber, carbon fiber, polymers, Constructed from a composite material such as a carbon fiber reinforced polymer, another suitable material, or a combination of these. For example, the cylinder 100 may have an airtight polyethylene plastic inner liner. In another example, the casing may be a carbon fiber reinforced plastic structure for high pressure applications. Cylinder 100 may have a metal liner encased in a composite or fiber resin.

[0019] 2B is a cross-sectional side view of cylinder 100. Cylinder 100 may be made up of multiple layers. For example, the cylinder 100 may have an inner layer 222 and an outer layer 220. The inner layer 222 may be made of gold. The outer layer 220 may be made of metal, plastic, or any other highly rigid material. The outer layer 220 may be made of a composite material or fiber resin disposed on the inner layer 222 in a process. The wall of the cylinder 100 may form the outer surface 218 of the cylinder 100. FIG. 2B shows two layers (e.g., an inner layer 222 and an outer layer Although multiple layers (220) are depicted, how many layers are used to construct cylinder 100? It may be any number.

[0020] Referring again to Figure 2A, the cylinder 100 has a central portion 216 and two ends 208, 219. 0. The central portion 216 may be cylindrical, but may have any other shape. In some embodiments, the two ends 208, 210 may be the same as those shown in FIG. In some embodiments, the two ends are symmetrical to each other. The dome-shaped structure may be generally hemispherical at least at its end. In this example, the two ends 208, 210 are different shapes, resulting in an asymmetrical shape of the cylinder 100. It is.

[0021] In some embodiments, the cylinder 100 includes an inlet and / or outlet for the interior space of the cylinder 100. or at least one neck 212, 214 (e.g., a longitudinal protrusion of a boss) that serves as an outlet. In some embodiments, the cylinder 100 has a neck 212 at each end 208, 210. , 214 are formed. In some embodiments, one of the two ends 208, 210 In some embodiments, the necks 212, 214 may be formed only on the cylinder side. The high pressure enclosure (inner liner assembly, or simply liner) inside 100 A metal structure (sometimes called a boss) is formed so as to penetrate one end of the may be part of a

[0022] The necks 212, 214 may be made of any number of materials, such as metal. In this case, the necks 212 and 214 are made of a material not used in the inner high pressure enclosure. In some embodiments, the necks 212, 214 are constructed using the above materials. It is made of the same material as the inner high-pressure enclosure.

[0023] The cylinder 100 may have an exterior surface 218 that spans the body of the cylinder 100. In this embodiment, the necks 212, 214 are included in the outer surface 218. 214 is not included on the outer surface 218. As described herein, the cylinder 100 has a Such damage may occur when the cylinder 100 is struck by an object such as a stone or another vehicle. The damage can occur when an object such as a bolt gets stuck between the cylinder 100 and the cylinder 100. The cylinder 100 may be pinched between the cylinder and a container (e.g., housing or compartment 104) and may lose pressure or temperature. This can occur when the cylinder 100 expands due to changes in temperature, causing damage to the cylinder. In some cases, the damage may result in a visible dent 204, but in most cases, the damage is This damage is often not easily visible to the human eye and is often not visible to the naked eye. As much as possible dents can be harmful to the cylinder 100. The system and method detects damage, such as a cylinder that has damage not readily visible to the human eye. This prevents the reuse of the cylinder.

[0024] Multiple sensors 202 may be attached to the cylinder 100 at various sensor locations 206 . The sensor 202 is configured to detect an impact to the cylinder 100. The out-of-plane deformation of a laminate of a composite pressure cylinder (e.g., cylinder 100) is The sensor 202 may be a wideband piezoelectric sensor that senses the magnitude component of the energy of the impact event. The wideband piezoelectric sensor is a piezoelectric material and a composite laminate. The interaction between the layers causes damage caused by impacts and the accumulation of damage that progresses within the laminate. In some embodiments, the wideband piezoelectric sensors used herein measure stress waves. By measuring the shift in the resonant frequency and anti-resonant frequency caused by the change in the stress state of the piezoelectric material, Therefore, it is not necessarily intended to detect damage to the composite laminate. Therefore, as used herein, a wideband piezoelectric sensor is a sensor that detects the resonances that occur due to changes in the stress state of the piezoelectric material. Detecting damage to said composite laminate without relying on measuring shifts in resonance or anti-resonance frequencies. is.

[0025] The sensor 202 does not actively generate waves to be detected by another sensor. In this respect, the sensor 202 may be considered a passive sensor. Rather, the sensor 202 detects when and where in the tank. This allows the laminate to determine how severe the impact event was as well as to detect if the laminate is responding to an external source. The stack is passively monitored when subjected to a force.

[0026] In some embodiments, the sensor 202 is removably attached to the cylinder 100. In another embodiment, the sensor 202 is integrally formed and embedded within the cylinder 100. The sensor 202 may be located on the exterior surface 218 or may be located on the cylinder 10. 0 layer (or between layers). The sensor 202 may be mounted on an inner surface within the interior space 224 of the cylinder 100 .

[0027] The sensor 202 may be located at a known sensor location 206. The collected data may include the sensor location 206 on the cylinder 100 as well as any dents 204 or other features to be detected. The sensors 202 can be used to determine the location of any damage. However, any number of sensors may be used. In most cases, the number of sensors used is The more 02s there are, the more accurate the determination of the location and extent of damage. .

[0028] FIG. 3A is a block diagram of components that may be connected to cylinder 100. As will be seen, the system 300 includes a cylinder 100 and a sensor 202. As will be explained later, the sensor 202 is physically coupled to the cylinder 100 .

[0029] The sensor 202 is connected to a control unit 302 (also referred to as a "cylinder control unit" or "cylinder side control unit"). or "impact monitoring control"). Detect deformation data relating to the impact received by (or caused to) the cylinder 100. In this specification, the term "deformation data" refers to the deformation of the cylinder 100. In this context, the terms "disturbance data," "shock data," and " "Cylinder integrity data" and other terms are sometimes used synonymously with "transformation data."

[0030] The transformation data can be supplied to the control unit 302. The control unit 302 is a computer program. The processor, microprocessor or controller may be a non-transient memory. It may be any device configured to execute stored instructions. 2 may be provided in a housing that is physically connected to the cylinder 100 (for example, It may be provided directly on the cylinder 100, or in the storage section of the cylinder 100. As shown in FIG. 3A, the control unit 302 controls the cylinder. 100 is configured to be the monitoring target, and the vehicle 102 is configured to monitor multiple cylinders. If a cylinder 100 is being used, each cylinder 100 is associated with a series of sensors 202 and controls 302. You will be forced to respond.

[0031] The sensors 202 and the control unit 302 are connected by wire or by their respective transceiver units (e.g., 302 and the control unit 302) can be connected wirelessly to be able to communicate. Although two sensors 202 are shown in the drawing, the system 300 includes the sensors 202. The number of 2s can be any number, and any of the sensors 202 can communicate with the control unit 302. can be connected to

[0032] The control unit 302 receives the deformation data detected by the sensor 202 and controls the cylinder 10 0, it is possible to detect whether an impact event has occurred and determine the energy level of the impact event. In this embodiment, the control unit 302 converts the deformation data detected by the sensor 202 into digitized to detect whether an impact event has occurred on the cylinder 100 and to determine the energy of the impact event. - Seek level.

[0033] FIG. 3B shows a diagram of a gas supply system connected to each cylinder 100 (for example, cylinder 100A and cylinder 100B). 1 is a block diagram illustrating components that may be included in system 350 as described herein. is a plurality of cylinders 100 and sensors 202 (e.g., sensor 202A and sensor 20 2B). As also described herein, the sensor 202 is Physically linked to 00.

[0034] The sensor 202 may be communicatively connected to a controller 352 similar to the controller 302. The variable 202 is a variable related to the impact that the cylinder 100 received (or that occurred in the cylinder 100). The control unit 352 may be configured to detect the deformation data. The control unit 352 may be a computer processor, a microprocessor, or The controller may be configured to execute instructions stored in a non-transitory memory. The control unit 352 is physically connected to the cylinder 100. It may be mounted in a container (e.g., directly on any cylinder 100, It may be provided in the storage section of the cylinder 100 or in a device connected to the cylinder 100. As shown in FIG. 3B, the control unit 352 controls the cylinder 100A and the cylinder 100B. The cylinder 100A and the cylinder 100B are configured to be monitored. B receives an impact, the control unit 352 can detect the impact. It has become.

[0035] The sensors 202 and the control unit 352 are connected by wire or by respective transceivers (e.g., The transmitter and receiver of the control unit 352 may be connected wirelessly to enable communication. Although two sets of sensors 202 and cylinders 100 are shown in the drawing, the system 35 The number of sets of sensors 202 and cylinders 100 included in the table may be any number. The sensors 202 of the different sets may also be communicatively connected to the controller 302 .

[0036] The control unit 352 receives the deformation data detected by the sensor 202 and controls the cylinder 10 It is possible to detect whether an impact event has occurred in the sensor and determine the energy level of the impact event. The data received from the sensor 202 is stored in the storage unit 100. For example, each sensor 202 may include an identifier. The identifier can be associated with the deformation data by the sensor 202, and the identifier can be transmitted to the control unit 352 together with the deformation data. can be communicated to.

[0037] In some embodiments, the control unit 302, 352 may be a control unit of the vehicle 102 (e.g., It is a separate control unit from the control units of the sub-controllers (sub-controllers) and any other sub-systems of the vehicle 102. In some embodiments, the control unit 302, 352 may also control one or more other systems in the vehicle 102. a control unit of the vehicle configured to control the

[0038] FIG. 4 shows a model 40 of a cylinder and a sensor configured to detect deformation data. 1. The model 401 is communicatively connected to a sensor (e.g., sensor 202, etc.). The model 401 can be configured with a controller (e.g., controllers 302, 352, etc.). In some embodiments, the controller includes a cylinder 400. The identification information corresponding to the base 100 is provided and stored from a local or remote non-transient memory. A size corresponding to the cylinder 100 can be dispensed. The dimensions are provided to the control unit.

[0039] The sensor 402 of the model 401 is equivalent to the real sensor 202. Given the position of the real sensor 202 on the real cylinder 100, Determine the corresponding position of the sensor 402 of the model on the base 400. Although sensors 402 are depicted, any number of sensors may be used. In most cases, the more sensors 402 used, the more accurate the location and magnitude of the damage. The judgment will be more accurate.

[0040] Experiments conducted using the systems and methods described herein used a 353 mm diameter x 353 mm long Wideband piezoelectric sensor on the surface of an 889mm type 4 composite pressure cylinder (250bar) The combination of these is modeled by a cylinder 400 and a sensor 402.

[0041] Next, a hemispherical TUP with a diameter of 50 mm was placed on the instrumented cylinder (a modeled collision As shown in point 404, the particles collide (energy level: 600 J) and propagate in the out-of-plane direction. The stress waves of the displacement components are collected and digitized, and the position and energy are quantitatively analyzed. Ta.

[0042] FIG. 5 shows graphs 500 of waveforms collected from an example impact event. From the graph, we can see the propagation of the guided stress wave caused by the impact event. It can be confirmed.

[0043] Each trace in the graph corresponds to a sensor 202, and the amplitude detected by each sensor (i.e., out-of-plane displacement) over time. The propagation of these waves is The extensional mode E0 is followed by a larger amplitude The flexural mode F0 follows. Each mode has a different velocity and consists of The frequency bandwidth is also wide, so the frequency components of the same mode common to each sensor channel can be detected. A good proposition is to identify the wave and try to determine the arrival time of that wave at each sensor. It is clear that there is no such thing.

[0044] Figure 6 shows the 25-second time-series wave propagation of the fundamental bending vibration in each channel using a threshold-independent arrival time estimation method. Each graph 600 shows the direct arrival time of the kHz component (shown as a vertical line). The direct arrival time at each sensor channel is calculated as the source position for which the geodesic of the surface is to be calculated. Input to a specific algorithm.

[0045] Specifically, a fundamental bending wave model derived from knowledge of the dispersion relations of laminated materials is Knowledge of the group velocity of the 25 kHz component of the cylinder, discretization of the cylinder surface into N points, Calculation of the geodesic propagation distance from the i-th point on the vector to the j-th sensor, and Minimizing the sum of squared errors due to the difference between the calculated and measured arrival times This allows for an optimal calculation of the source location on the cylinder surface.

[0046] Figure 7 shows the location of the source of the impact event identified in Figure 6 after optimal estimation (cylinder). The model shows the geodesic path superimposed on the surface. By identifying the impact location, The direct arrival time of the wave at each sensor can be determined from the above. It is used to obtain a direct waveform energy measurement.

[0047] The systems and methods described herein quantify and calculate waveform energy directly. Direct waveform energy measurement (U WAVE ) can be calculated from the collected waveform using the following formula:

[0048]

number

[0049] The systems and methods described herein use direct energy because The amount of external energy includes reflected waves and waves propagating along other (longer distance) paths from the impact. This may also contain wave energy that may have been amplified by constructive interference with other waves. In this case, the quantitative value of the detected impact may be inaccurate. For example, the quantitative value of energy focused on the evaluation of amplitude is calculated based on the degree of constructive interference between propagating waves or the degree of interference between propagating waves. The wave energy may be estimated inaccurately due to destructive interference. In contrast, the systems and methods described herein are not as accurate. The system and method utilize direct wave energy, thereby suppressing reflected and deflected waves. Energy loss according to the propagation distance due to the wavefront propagating from the source and expanding geometrically Losses are addressed by the normalization process described herein.

[0050] From Figure 8, the measured direct wave energy (generated by the impact event) is It follows the inverse square law and decays as it moves further away. The magnitude of the impact energy can be quantitatively evaluated from the measured value of the Determine impact energy based on distance and compare it to a threshold value for any cylinder configuration. The systems and methods described herein can be used to evaluate the Detects events and normalizes for any wave propagation effects that may occur in practice This normalization reduces the number of false triggers and improves the reliability of the system. As explained in , the amplitude and energy are affected by the geometric spread over the source-sensor distance. Energy losses are also addressed along with other damping effects through normalization.

[0051] A quantitative evaluation of the magnitude of the impact energy is the impact damage threshold (e.g., the impact energy of a given laminate). If the energy threshold is exceeded, the control unit 302, 352 determines that damage has occurred to the cylinder 100. The notification may be sent to the ECU of the vehicle 102, a local non-transient This may be done to any number of devices, such as local memory, remote non-transient memory, etc.

[0052] When the notification is sent to the ECU of the vehicle 102, the ECU of the vehicle 102 lighting or other notifications, such as lights on the dashboard or instrument panel of the vehicle 102 The light or other type of notification may be used to indicate that the cylinder 100 is being refilled. This can serve as a reminder to have the cylinder 100 inspected.

[0053] When the notification is made to a local non-transient memory, the control unit 302, 352 The vehicle 102 is configured to store a non-transient memory for updating the status indicators associated with each cylinder 100. The condition indicator may vary from a first condition corresponding to an undamaged cylinder to a second condition corresponding to an undamaged cylinder. The cylinder 100 may be changed to a second state corresponding to a state in which the cylinder may be damaged. from another device (e.g., a filling device) to determine whether the The local non-transient memory may be accessed. If the automatic memory indicates that the cylinder is in the second state, the filling device The operator may be notified by a separate device or the cylinder 100 may be filled. can be automatically prevented.

[0054] Similarly, when the notification is sent to a remote non-transient memory, the control unit 302, 352 The state indicators corresponding to each cylinder 100 in the vehicle 102 are updated to a non-transient memory of the vehicle 102. The condition indicator may vary from a first condition corresponding to an undamaged cylinder to a second condition corresponding to an undamaged cylinder. The cylinder 100 may be changed to a second state corresponding to a state in which the cylinder may be damaged. from another device (e.g., a filling device) to determine whether the The remote non-transient memory may be accessed. If the cylinder status is indicated as the second status by the The operator may be notified of this or the cylinder 100 may be automatically filled. The control units 302 and 352 may block the transmission of their respective data to the remote non-transient memories. A receiver (e.g., a transceiver connected to the controller 302, 352) and the remote non-transient The access can be performed using a transceiver connected to the memory.

[0055] When refilling a cylinder 100 that has been subjected to an impact and has weakened in strength, the impact is detected. The sensor 202 used to detect loss of integrity of the cylinder during refilling Modal acoustic emission (MAE) testing can also be performed to assess the effect of the acoustic emission on the vehicle.

[0056] Figure 9 shows a system 900 that includes a cylinder 100 connected to a filling device. The loading device may include a valve 902 and a supply tank 904. The valve 902 is by a control unit to control the filling of the cylinder 100 with the gas stored in the tank 904. The cylinder 100 can be filled while attached to the vehicle 102. In some cases, this may be the case.

[0057] When the cylinder 100 is filled, the contents of the cylinder 100 cause the internal pressure to rise relative to the outer shell of the cylinder. The outward pressure from the cylinder 100 creates mechanical stresses within the composite laminate of the cylinder 100. As explained in the specification, damage to the composite laminate materially deteriorates the composite laminate. There are numerous failure mechanisms associated with pressure cylinders (e.g., fiber fracture, matrix fracture, etc.). The damage mechanism is the loss of material volume at the affected area through cracks, interface fractures, etc. As this occurs, stress waves propagate from the origin of the damage mechanism site to the wall of the cylinder 100 . The sensor (e.g., a wideband piezoelectric sensor) 202 converts the stress wave into a voltage and digitally collects it for analysis. By collecting data, deformation data related to those damage mechanisms can be detected.

[0058] If damage is detected during filling, one step is taken to limit the adverse effects of a damaged cylinder. One or more measures can be taken: a visual warning such as a light or a message display can be activated; An audible warning, such as a siren or alarm, may be activated. It may be dynamically closed to prevent further filling of the cylinder with gas.

[0059] In some embodiments, one of the supply tank 904-cylinder 100-surge tank 906 By selectively opening and closing these ports, the supply tank 904 and / or cylinder 1 For example, valve 902 can be used to redirect gas from supply tank 900 to surge tank 906. a port connected to the tank 904, a port connected to the cylinder 100, and a surge tank The ports connected to 906 can be opened or closed. The ports can be selected in any combination. For example, when filling, the port of the supply tank 904 and the port of the cylinder 100 may be opened and closed automatically. The port of the surge tank 906 can be opened and the port of the surge tank 906 can be closed. If damage to cylinder 100 is detected, the port of cylinder 100 and the port of surge tank 906 The port may be opened and the port of the supply tank 904 may be closed.

[0060] In some embodiments, the surge tank 906 is set at a lower pressure than the cylinder 100. This opens the port between the surge tank 906 and the cylinder 100. In this case, the gas may be forced to move to the surge tank 906. In some embodiments, the gas Suction is applied to force the gas from the cylinder 100 to the surge tank 906. Alternatively, pressure may be applied to the gas. Also, a vent stack may be present to facilitate gas movement. It may be possible.

[0061] Acoustic emission modal analysis algorithm for digitally acquired waveforms : Detection and quantification of fiber tow breakage above a specified threshold; instability within a local material volume Measurement of instability above a specified threshold for damage mechanisms accumulated in a local material volume damage mechanisms exceeding specified thresholds; and specified thresholds depending on the cylinder stack. detection of fretting emissions in excess of 100 Hz;

[0062] When detecting the presence or absence of defects in a cylinder during filling by combining multiple of the above, The factors are weighted based on various characteristics of the fuel system, including the size and construction of the cylinder. For example, a combination of fretting emissions and local damage growth can cause a specific Fretting emissions are weighted when determining whether or not there are defects in the cylinder filling. It may be set higher than the weighting of local damage growth.

[0063] FIG. 10 is a block diagram of a system 1000. As described herein, the system The system 1000 includes a cylinder 100 , a sensor 202 and a control unit 302 .

[0064] The control unit 302 is a filling control unit 1002 (or a "filling device control unit" or "filling side control unit"). The control unit 302 may be communicatively connected to a filling control unit 102 via wire or wirelessly. 1002. The filling control unit 1002 may also be communicatively connected to the cylinder 100. The fuel supply 902 may be communicatively connected to a valve 902 that controls the flow of fuel over time.

[0065] As described herein, the fill control 1002 may be connected to the control 302 and / or the vehicle 102 ECUs and / or local non-transient memory and / or remote non-transient memory The status of the cylinder 100 may be obtained from a memory.

[0066] The filling control unit 1002 can also communicate with a display 1004 and a speaker 1006. The fill control 1002 may be connected to a display 1004 to display a graphical user interface. The graphical user interface may be configured to display a The display may include a notification as to whether the cylinder 100 should be inspected before filling. The ray 1004 may display the notification. The speaker 1006 is configured to notify the user whether the vehicle 100 should be inspected. The speaker 1006 can be configured to emit sounds, alarms, spoken messages (e.g., "Detect cylinder before filling"). The company may issue a notice such as "Please check the product before purchasing."

[0067] In some embodiments, the fill control 1002 may be unaware of the state of the cylinder 100. It performs the functions described herein regardless of the current state of the cylinder 100. It is possible.

[0068] When the cylinder 100 is filled with fuel, the sensor 202 detects deformation data and outputs the detected data. The deformation data may be provided to the filling control unit 1002. 02 is communicably connected to the filling control unit 1002 via the control unit 302. In an embodiment, the sensor 202 and the filling control unit 1002 are connected by wire or by their own transceiver units. are directly communicatively connected using the same.

[0069] The filling control unit 1002 receives the detected deformation data and performs the filling of the cylinder 100. The filling control unit 1002 detects damage to the cylinder 100 by detecting the detected damage. If the threshold is exceeded, the valve 902 is automatically closed to prevent further filling of the cylinder 100. In some embodiments, the fill control 1002 may detect damage to the integrity of the cylinder 100. The cylinder 100 is constantly monitored during filling to detect the presence of a gas. In some embodiments, the filling control unit 1002 may monitor the cylinder 10 using the sensor 202. The control unit 302, 352 monitors the direct energy of the impact while filling the This is only performed if damage exceeding the impact damage threshold is detected.

[0070] The filling control unit 1002 receives the detected deformation data and performs the following operations by filling the cylinder 100. If damage to the cylinder 100 is detected by the surge tank, as described herein, Fuel reception by a tank (e.g., surge tank 906) may be performed.

[0071] The control unit 302, 352 and the filling control unit 1002 use the same sensor 202, but the control The control units 302 and 352 are configured to detect impacts caused by external forces on the cylinder 100. On the other hand, the filling control unit 1002 is configured to detect in advance the expansion of the cylinder 100 during filling. Possible rupture due to weakened or deformed parts (e.g., parts subjected to impact) The cylinder 100 is configured to detect damage to the cylinder 100.

[0072] Experiments conducted using the systems and methods described herein used a 353 mm diameter x 353 mm long A wideband piezoelectric sensor was installed on the surface of a type 4 composite pressure cylinder (250 bar) with a length of 889 mm. The combination of the cylinder 400 and the sensor 402 in Figure 4 is modeled as follows. The sensor also performed a filling simulation to demonstrate MAE testing of an aged cylinder.

[0073] FIG. 11 shows a plot 1100 (vertical) of cumulative event detections by channels above a first threshold. The plot 1100 shows the pressure of the cylinder (axis: pressure, horizontal axis: test time). 1 represents the cumulative number of events from the first detection channel during the filling simulation of The dashed lines in the figure correspond to the pressure inside the cylinder during two filling cycles.

[0074] Figure 12 shows a plot of the local instability of a cylinder during a filling simulation. The solid line represents the pressure inside the cylinder. The dashed line represents the background energy that indicates the instability. (background energy), which represents the local instability within a given volume of the cylinder. If the energy curve experiences a number of oscillations exceeding a specified threshold for a given cylinder configuration, Instability analysis was performed and the The gas exceeds a threshold level determined according to the construction of the cylinder, causing the filling process to stop. It showed local instability such as rubbing.

[0075] As described herein, the instability analysis shown in FIG. 12 is based on the analysis of losses during filling of the cylinder 100. This may be one of several factors used to identify the flaw. Quantitative evaluation of the degree of fiber damage using a number and energy quantification algorithm Alternatively, it may be possible to assess the risk against specified thresholds.

[0076] Figure 13 shows the impact damage detected during the filling simulation of the impacted cylinder. Time-domain and time-frequency analysis of impact fiber tow failure events occurring in the same material volume A plot of the area is shown.

[0077] FIG. 14 shows an example of a system 1400 according to each embodiment of the present invention. 400 includes a cylinder 100, a sensor 202, and a control unit 30, each as described herein. 2. As described herein, the sensor 202 collects deformation data of the cylinder 100. The sensor 202 is configured to detect the deformation and communicate the deformation data to the control unit 302. , piezoelectric sensors (e.g., fiber Bragg gratings, non-contact lasers, etc.) or any other sensor configured to detect deformation of the cylinder 100. As also described herein, the control unit 302 may and detecting damage to the cylinder 100 based on the impact threshold. The damage is based on the direct energy caused by the impact of an object that comes into contact with the cylinder 100. It may be a quantitative value determined based on the above.

[0078] The system 1400 further includes a memory 1402 coupled to the controller 302. The memory 1402 is a computer processor such as a microprocessor or microcontroller. a non-transient memory configured to store instructions to be executed by the controller 302, which may be a The memory 1402 may be a memory for storing, for example, the data detected by the sensor 202. The data may include deformation data, the state of the cylinder 100, etc. is a word (e.g., "normal," "requires examination," "damaged," etc.) or a number (e.g., 1, 2 , 3, 4, etc.) are associated with multiple stages (e.g., 2 stages, 3 stages, 4 stages, etc.) ) can be expressed as

[0079] The system 1400 further comprises a transceiver 1404 coupled to the controller 302 . The control unit 302 transmits and receives data via a local area network (LAN), a wireless network (WAN), or the like using a transmission / reception unit 1404. Wide Area Network (WAN), Cellular Network, Digital Short Range Communications (DS RC), a network such as the Internet, or a combination thereof.

[0080] The transceiver 1404 may comprise a communication port or channel, such as a Wi-Fi i Unit, Bluetooth® Unit, Radio Frequency Identification (RFID) Tag a tag or reader, a DSRC unit, or a cellular network (3G, 4G, 5G, etc.) One or more cellular network units that access the network. The unit 1404 transmits data to and from devices and systems that are not directly connected to the control unit 302. For example, the control unit 302 may receive data from a remote data server 1408 and / or a filling station. The transceiver 1404 may also communicate with a remote data server 1408 or The filling device 1416 may have access to a connected network.

[0081] The control unit 302 also controls one of the vehicles (for example, the vehicle 102) that uses the cylinder 100 as a power source. The present invention may be configured to communicate with one or more computers or electronic control units (ECUs). As explained in the specification, the vehicle's ECU detects damage to the cylinder 100 by the control unit 302. When the vehicle is turned on, one or more of the vehicle's indicator lights, display screens, speakers, or other notification devices may be activated. The above aspects can be controlled to warn the driver, i.e., the user. 2 is connected to its own transceiver unit by wire or via transceiver unit 1404. In this regard, the ECU may store data in memory 14. 02 or similar, connected with its own non-transient memory.

[0082] Cylinder 100, sensor 202, control unit 302, memory 1402 and transceiver unit 1404 These may be collectively referred to as a cylinder monitoring device 1406. The device 1406 may be physically installed in a vehicle (e.g., vehicle 102). In the above, the "cylinder monitoring device" includes a sensor 202 and / or a control unit 302 and and / or memory 1402 and / or transceiver 1404. 14, the control unit 302 may not include each component. The diagram shows how the components of the cylinder monitoring device 1406 are connected. The components may be connected to each other by a communication bus.

[0083] The control unit 302 receives deformation data from the sensor 202 and / or the state of the cylinder 100. The updated information may be communicated to a remote data server 1408. The remote data server 1408 may: The processor 1410 may include a memory 1412 and a transceiver 1414. 410 is any computer configured to execute instructions stored in non-transitory memory. The memory 1412 may be similar to the memory 1402, The instructions executed by the processor 1410 and the sensed signals, for example, by the sensor 202 The storage device may be configured to store the deformation data, the state of the cylinder 100, etc.

[0084] The transceiver 1414 is similar to the transceiver 1404 and is a part of the cylinder monitoring device. 1406, to send and receive data to and from one or more other devices, such as a filling device 1416. It is structured as follows:

[0085] In some embodiments, the controller 302 makes the determination based on the deformation data from the sensor 202. Alternatively, the processor 1410 may receive the transformation data and apply the control described herein. In this embodiment, the control unit 302 may be configured to take on one or more roles of the control unit 302. Rather than performing processing, the deformation data detected by the sensor 202 is transmitted to a remote data server. 1408 (via their respective transceivers 1404, 1414) to It may be computationally more efficient to force it to 0.

[0086] Although only one remote data server 1408 is shown in the figure, it is possible to distribute the computation load. There are multiple remote data servers 1408 configured to combine data to improve computational efficiency. In some embodiments, the remote data server 1408 may 1406 and capable of performing computer processing. It can be any device, for example, a vehicle ECU, a mobile device (e.g., a smartphone), (phone, laptop, tablet, etc.)

[0087] The control unit 302 also receives deformation data from the sensor 202 and / or the deformation data of the cylinder 100. Status updates may be communicated to the fill device 1416. The fill device 1416 may communicate status updates to the fill device 1416. The filling control section 1002 controls a valve for filling the cylinder 100. The filling control section 1002 is configured to control the supply of the liquid (e.g., the valve 902). The control unit 302 transmits the signal via a transmitting / receiving unit 1418 similar to the receiving unit 1404 and the transmitting / receiving unit 1414. The fill control unit 1002 may receive data from a memory 1422 (e.g., a non-transient memory The memory 1422 may be connected to the memory 1402 or the memory 1404. 12, and the instructions executed by the filling control unit 1002, For example, the deformation data detected by the sensor 202, the state of the cylinder 100, etc. are stored. It can be done.

[0088] As used herein, a "unit" refers to a processor configured to execute instructions stored in non-transient memory. configured to, for example, include one or more computer processors, controllers, or computers It can refer to a hardware component such as a computer operating device.

[0089] FIG. 15A is a flow diagram illustrating a method 1500 performed by the system described herein. Figure.

[0090] A plurality of sensors (e.g., sensor 202) detects the temperature of a composite cylinder (e.g., cylinder 100). The composite cylinder is made of multiple layers and deformation data is detected (step 1502). and the deformation data detected by the plurality of sensors is Each sensor may indicate damage to one or more of several layers on the composite cylinder. The sensor may be a piezoelectric sensor provided at various positions.

[0091] The control unit (e.g., control unit 302) detects and controls the composite cylinder when the composite cylinder is damaged by impact. A damage value is calculated based on the deformation data (step 1504). The damage value may be connected to the controller by wire or wirelessly. This can be determined based on measurements of direct wave energy as detailed in relation to 15B.

[0092] Continuing with method 1500 of FIG. 15A, the controller determines whether the damage value is greater than an impact damage threshold. If the impact damage threshold is exceeded, a notification is made (step 1506). The impact damage threshold may be stored in a memory (e.g., memory 1402). Each composite cylinder model may vary in construction, size, and material composition.

[0093] As described herein, when the damage value exceeds the impact damage threshold, the control unit Providing the notification by means of a signaling device may include providing the notification to at least one of the vehicles (e.g., vehicle 102). and / or Alternatively, the notification may be stored in a non-transient memory (e.g., memory 1402, 1412, 1422). to update a stored state for the composite cylinder. When the damage value exceeds the impact damage threshold, the notification by the control unit 302 is This can be done using a unit (e.g., transceiver units 1404, 1414, 1418).

[0094] The notification may be sent to a user, operator, or other personnel to inspect the composite cylinder before refilling. This is to warn the technician that damage to the composite cylinder caused by the impact of the object is occurring. The composite cylinder can then be removed and / or repaired as appropriate. However, damage from impact with an object or improper operating conditions (e.g., the cylinder and the container) may occur. Although there is undetected damage accumulated due to the bolt getting stuck between the There may be situations where the composite cylinders are refilled.

[0095] A filling control unit (for example, filling control unit 1002) controls a valve (for example, valve 902) The composite cylinder is filled with a fluid (e.g., gas fuel, liquid fuel, etc.) by controlling the (Step 1508). This filling (or refilling) of the composite cylinder with the fluid ) the integrity of the composite cylinder can be monitored using the sensors.

[0096] The filling control unit receives the deformation data from the sensor and supplies the composite cylinder with the deformation data. When the fluid is filled, damage to the composite cylinder is detected based on the deformation data. (Step 1510). Modal testing of emissions can detect damage to the composite cylinder.

[0097] The filling control unit determines at least It is determined whether each of the indicators exceeds its respective predetermined threshold, and if so, It may be determined that the integrity of the wood cylinder has been compromised.

[0098] The at least one indicator may comprise: quantification of detected fiber tow break events and Fiber tow failure index equivalent to comparison with failure threshold; instability within local material volume is the instability threshold Instability index corresponding to exceeding the specified local material volume; accumulated damage within the specified local material volume; The damage mechanism threshold is the damage mechanism accumulated in the material volume. and fretting emissions depending on the laminate composition of the composite cylinder. fretting emissions equivalent to exceeding the fretting emissions threshold based on and / or a function indicator;

[0099] The fiber tow fracture index is determined by measuring the fiber tow fracture index during modal testing of the acoustic emission. Based on the frequency and energy content of the waves detected by the sensors and reflected in the sensor data, The fiber tow breakage index is determined by the plurality of sensors and normalized. The energy may be determined based on the direct energy measured.

[0100] The instability indicator is measured by the sensor during modal testing of the acoustic emission. Based on the detected vibration and background energy values ​​reflected in the sensor data, It can be a local instability indicator determined by the

[0101] The detachment event index is based on the normalized direct energy determined by the plurality of sensors. The delamination event indicator may be determined based on the acoustic emission. The frequency spectrum of the waves detected by the sensor during modal inspection and reflected in the sensor data. The curve may be identified based on the sharpness of the curve.

[0102] The damage mechanism indicator may be related to damage from a local material volume. The location (clustering) of the mechanism is determined by the arrival time of the damage detected by the sensor. and a threshold-independent measurement of the shortest propagation distance of the damage in the curved space detected by the sensor. can be identified based on

[0103] The above indicators may be considered individually or in combination. When considered in combination, each indicator can be assigned a weight. When considering both the fracture index and the instability index, the weight of the fiber tow fracture index is It may be set lower than the weight of the instability index, or vice versa. The indicators to be considered depend on the composition of the composite cylinder, the materials used in the composite cylinder, and the It may vary based on any characteristic of the composite cylinder, such as the size of the composite cylinder. In addition, the threshold values ​​for the indicators also depend on the composition of the composite cylinder and the materials used in the composite cylinder. The composite cylinder may vary based on any characteristic of the composite cylinder, such as the material, dimensions of the composite cylinder, etc. obtain.

[0104] In some embodiments, the filling control unit may, at the time of filling, determine whether or not any of the above indicators is satisfied. If a threshold is exceeded, damage to the composite cylinder may be detected. For example, the fiber tow breakage may occur. When the fracture index and the instability index are considered, the fiber tow fracture index is When the threshold value of the instability indicator is exceeded or the instability indicator is exceeded, the filling control unit Detect damage to wood cylinders.

[0105] In some embodiments, the filling control unit performs a summary based on the number of indicators that exceed each threshold. The total damage index is calculated, and the number (or percentage) of indexes that exceed each threshold during filling is the threshold. If the fiber tow fracture index exceeds the threshold, damage to the composite cylinder is detected. The fretting emission index and the instability index are considered as the targets of investigation. The threshold for the number of indicators that exceed this threshold can be two out of three. Among the fiber tow fracture index, the fretting emission index and the instability index, When two or more of the above exceed their respective thresholds, the filling control unit detects damage to the composite cylinder. do.

[0106] In some embodiments, the filling control unit weights the number of indicators that exceed each threshold. The integrated damage index based on the value is calculated, and if the weighted ratio of the index exceeds the threshold value at the time of filling, In this case, the filling control unit detects damage to the composite cylinder. The target, the fretting emission index and the instability index are considered. The weighting of the fiber tow failure was set to 5, and the weighting of the fretting emission index was set to 1. The value is 1 (the fiber tow failure is five times more important than the fretting emission index). The weighting of the instability index is set to 2. index, the fretting emission index and the instability index are all below their respective threshold values If the threshold is exceeded, there are eight possible total points for the indicator. Therefore, when the fiber tow breakage index is greater than the threshold value, the (5 points), and the fretting emissions indicator exceeds its threshold (1 point). If the instability index does not exceed the threshold, 6 points divided by 8 points is 65%. When the fiber is filled, the filling control unit detects damage to the composite cylinder. If only the tow fracture index exceeds the threshold, 5 points divided by 8 points does not exceed 65%. Therefore, the filling control unit does not detect damage to the composite cylinder.

[0107] Each threshold value described herein is determined based on testing and calibrated for composite cylinders. Each threshold may be stored in a non-transient memory (e.g., memory 1402, 1412, 1422). ) and indexed with an identifier associated with the composite cylinder being monitored. This allows the filling control unit to monitor the composite cylinder to be Based on this, a corresponding threshold value may be referenced.

[0108] Both the control and the fill control are resistant to external noise commonly encountered in normal operation. Digital signal processing reduces noise sources (e.g., electromagnetic interference (EMI), flow noise, mechanical friction, etc.) By implementing a digital signal processing algorithm, false triggers can be avoided. An algorithm may be applied to the deformation data detected by the sensor. The signal processing algorithm is based on: the coincidence of arrival of waves at the sensor; the detected energy before triggering; and the ratio of post-trigger energy to pre-trigger energy; A false trigger determination may be made based on this.

[0109] When the composite cylinder is filled with fluid, the filling control unit After detecting the flaw, a safety action may be automatically taken (step 1512). the filling control closes the valve to prevent further filling of the composite cylinder. The safety action may include issuing a notification of the detection of damage via a speaker or a display screen. allowing an operator to stop filling of the composite cylinder. The safety operation is performed by the filling control adjusting the valve to direct the fluid to the surge tank. This may include:

[0110] The above-mentioned automatic process during filling of the composite cylinder is carried out by the control unit. In another embodiment, the detection of impact damage to the vehicle may be performed at all times. The automated process during filling of the composite cylinder may include the control unit detecting impacts of the composite cylinder. It can only be performed if damage is detected.

[0111] FIG. 15B illustrates the direct wave energy measurement performed by the system described herein. 15A. Method 1520 is a flow diagram illustrating a method 1520. Method 1520 is a step of method 1500 of FIG. A method used by the control unit to determine the impact value related to impact damage in step 1504 It could be.

[0112] The control unit (for example, the control unit 302) receives the signal from the sensor (for example, the sensor 202) in front of the sensor. The modified data is received and digitized (step 1522).

[0113] Next, the control unit calculates a specific wave component from the impact position to each of the plurality of sensors, The direct arrival time of each of the plurality of sensors is calculated (step 1524). The sensors detect the deformation data (for example, the deformation data represented by waves from four sensors). (The data appears in the four channels in Figure 5). The specific wave components common to each wave (e.g., the The vertical lines attached to each wave from the four sensors are identified. The arrival time of the wave is calculated from the impact position of the specific wave component to each sensor. represents the travel time to

[0114] The control unit determines an estimated location of the impact position on the composite cylinder (step 1 526). The estimated position is calculated based on the arrival time and the wave components used to estimate the arrival time. The velocity of the cylinder, the geometry of the cylinder being monitored, and the known values ​​of each sensor on the cylinder. The geometry of the various cylinders, the dispersion relation (as a function of frequency) The wave mode velocity of each sensor and the known position of each sensor are stored in a memory (e.g., memory 1402, 412, 1422) and can be accessed by the control unit. The estimated location of the impact point on the composite cylinder is modeled (e.g., as shown in FIG. 7). It can become.

[0115] The control unit detects the direct arrival time of each specific wave component at each sensor and the time at each sensor. Based on the detected voltage, the direct wave energy is calculated (step 1528). In an embodiment, the controller calculates the direct waveform energy (U WAVE ) can be obtained.

[0116]

number

[0117] The systems and methods described herein utilize a relatively large number of sensors 202 to: Highly reliable coverage and monitoring can be achieved. The relatively high cost of monitoring makes it difficult to implement a robust system. Therefore, it is necessary to have a small number of options (e.g., in terms of sensitivity and bandwidth) at economical cost. Therefore, a new sensor structure that provides at least the same performance is required.

[0118] FIG. 16A illustrates the systems and methods described herein, as well as other systems and methods. 16 is a plan view of a sensor 1600 configured for use in the methods and methods described herein. As such, the sensor 1600 is a sensor that can be used as the sensor 202. When a sensor 202 is described herein as having certain characteristics or capabilities, the sensor 160 0 may have the same characteristics and capabilities. As described herein, sensor 1 The sensor 600 can be mass-produced and is relatively low cost. The sensor 160 is capable of performing sensing for a number of different applications. 0 also allows for economical adjustments and modifications to the design.

[0119] The sensor 1600 may be mounted on a composite structure, such as the composite cylinder 100 or any of the components listed herein. or any other composite structure (e.g., wind turbines, fuselages, wing leading edges, etc.) Multi-element structure configured to detect deformation data of any composite structure where flaws can have adverse effects The sensor 1600 is a piezoelectric sensor. The sensor 1600 is configured to detect the deformation data. Specifically, the sensor 1600 includes a first sensing element 1602. 02A, a second sensing element 1602B, a third sensing element 1602C, a fourth sensing element 160 2D and a fifth sensing element 1602E.

[0120] The sensor 1600 is configured to connect each sensing element 1602 to a connector 1610. Specifically, the first sensing element 1602A has a plurality of leads 1616. 1 is connected to the connector 1610 by lead 1616A, and the second sensing element 16 02B is connected to the connector 1610 by a second lead 1616B, and the third sensor The sensing element 1602C is connected to the connector 1610 by a third lead 1616C. , the fourth sensing element 1602D is connected to the connector 1610 by a fourth lead 1616D. The fifth sensing element 1602E is connected to the connector 16 by a fifth lead 1616D. 10. The sensor 1600 is connected to the system via a connector 1610. connected to other components (for example, the control unit 302, the control unit 352, the filling control unit 1002, etc.) In most embodiments, the sensing element 1602 is connected to the connected to a preamplifier circuit configured to amplify the received signal, the preamplifier circuit , connected to the control unit (for example, the control unit 302, the control unit 352, the filling control unit 1002, etc.) This is what was done.

[0121] As shown in FIG. 16, the sensing elements 1602 have sensing areas (or apertures or A first sensing element 1602A, a second sensing element 1602B, a third sensing element 1602C, and a third sensing element 1602D having a size 1612 are shown. The first sensing element 1602C and the fourth sensing element 1602D form a larger sensing area 1614 The first sensing element 1602E is disposed so as to surround the fifth sensing element 1602E having the first sensing element 1602A. A sensing element 1602A, a second sensing element 1602B, a third sensing element 1602C, and a fourth sensing element 1602B. The sensing elements 1602D may have the same diameter 1604, resulting in sensing areas of the same size. 1612. The fifth sensing element 1602E may have a larger diameter 1606. The result is a larger sensing area 1614.

[0122] Larger diameter elements (e.g., sensing element 1602E) have a larger surface area and therefore a larger sensitivity (for a given low frequency). Although it has excellent sensitivity in the range of several Due to cancellation, performance is poor at high frequencies. Small diameter elements (e.g., sensing element 1602A) ~1602D) the larger the diameter element (assuming all structural details other than the diameter are the same) Although the sensitivity cannot be increased, it is not subject to phase cancellation due to the aperture effect, and therefore is suitable for high frequency applications. The answer will be excellent.

[0123] Although the sensing element 1602 is depicted as a circle in the drawing, the sensing element 1602 in other embodiments may be may have other shapes, such as hexagonal, pentagonal, decagonal, etc. In other embodiments, each element The element is designed to have an elliptical geometry and is aligned on an anisotropic structure that exhibits a quasi-elliptical wave mode. It can be said.

[0124] Also, although FIG. 16A depicts sensing elements 1602 in a particular number and arrangement, No matter how many sensing elements are fabricated and used in any form or arrangement, The number of sensing elements, the size of each sensing area, and the arrangement of each sensing element may all be , the application of the sensor 1600 and / or the location of the sensor 1600 on the structure being monitored. It may be adjusted based on the location and / or composition of the structure being monitored.

[0125] For example, the present invention relates to a method for monitoring a composite structure (e.g., a composite cylinder 100). The system and method described in the present application utilizes quantitative impact detection to detect impact damage or cumulative damage. MAE inspections are also being used to detect damage to composite structures, and to test compressed natural gas, hydrogen, and other gases. The purpose of this example is to detect damage to the composite structure when a fluid is filled into the composite structure. In the example, one or more relatively small sensing elements (e.g., sensing elements 1602A-1602D) Included in the sensor 1600 is a composite structure that is damaged when the composite structure is filled with fluid. Alternatively, one or more relatively large sensing elements (e.g., sensing elements 1602E) are included in the sensor 1600 and may be used to detect impact events.

[0126] In quantitative impact detection, events that are not excited at relatively high frequencies (i.e., short wavelengths) Therefore, a large diameter element with high sensitivity is more appropriate. When conducting MAE inspections of composite structures, high frequencies are detected by sensing elements to detect damage. Distinguishing between mechanisms (e.g., fiber fracture vs. matrix crack vs. delamination) Therefore, a small diameter sensing element is more appropriate.

[0127] By integrating both elements into the same sensor 1600, each sized for a particular application, the sensor 1600 specifically addresses each sensing requirement of the system depending on the particular scenario. This allows two different sensing technologies and sensing applications to be applied. The same sensor 1600 can be used in various situations. As an example, the first size may be optimized for a first technology or application, and the second size may be optimized for a second technology or application. The size can be optimized for a second technology or application. 0 is a sensor element that can be used to provide a single sensor element when connected to various systems (via connector 1610). This allows for greater versatility than other sensors that only have one size. The sensor 1600 is much faster than using two separate sensors of two different sizes. It is highly efficient in terms of both efficiency and cost-effectiveness.

[0128] 16B is a side cross-sectional view taken along line AA in FIG. 16A. A cross-sectional side view of element 1602A and fourth sensing element 1602D is shown. Which sensing features are described with respect to the first sensing element 1602A and the fourth sensing element 1602D? It may also be present in the sensing element 1602.

[0129] The sensor 1600 includes a first polyimide film layer 1624 (e.g., DuPont® The first polyimide film layer 1624 may comprise a polyimide film such as Kapton® manufactured by Epson Corporation. When the sensor is integrated with the laminate, a dielectric layer is formed between the ground electrode and the structure. It is configured to be.

[0130] The sensor 1600 may further include a positive electrode 1626 for each sensing element 1602. The electrode 1626 may be made of a conductive material such as copper. A first positive electrode 1626A corresponding to element 1602A, and a fourth positive electrode 1626B corresponding to element 1602D There is a fourth positive electrode 1626D corresponding to the first positive electrode 1626. The top surface of each positive electrode 1626 is made of a polyimide. As shown in FIG. 16B, the positive electrode of each sensing element 1602 The electrodes 1626 may be flush with one another if the sensor is flat. Even if the sensor is not flat but is wrapped around a curved surface, the The positive electrode 1626 is a curved surface parallel to the curved surface on which the sensor is disposed, and they are on the same plane. This will be done.

[0131] The positive electrode 1626 is located above the first tape layer 1628. 1628 connects the positive electrode 1626 to an active sensing element located below the first tape layer 1628. 1630. The top surface of the first tape layer 1628 contacts the bottom surface of the positive electrode 1626, The bottom surface of the first tape layer 1628 contacts the top surface of the active sensor 1630 .

[0132] The first tape layer 1628 is made of one or more layers of z-axis anisotropic tape that is conductive only in the z-axis. That is, the first tape layer 1628 may be made of a thin film that conducts electricity along the x-axis and the y-axis. Furthermore, the active sensor 1603 in contact with the first tape layer 1628 may There is no conductive layer on the top surface, and it does not become an equipotential surface. and a fourth positive electrode 1626D, both electrically connected to the active sensing element 1630. In the drawing, the first positive electrode 16 Although only the fourth positive electrode 1626A and the fourth positive electrode 1626D are shown, each positive electrode is an active The sensor 1630 is electrically connected to the sensor 1630 and is electrically insulated from each other. It is being done.

[0133] The active sensor 1630 is PVDF-TrFE (polyvinyl difluoride trifluoroethylene). It can be a piezoelectric material with an inherently low quality factor suitable for a broadband response, such as ethylene. The active sensor 1630 is configured to generate an electrical current when subjected to mechanical stress. That is, the active sensing element 1630 (for example, impact on the structure or damage to the material of the structure) When mechanical stress occurs (such as due to the propagation of transient stress waves by the positive electrode 1626-ground) A voltage is generated between the electrodes 1634, and the voltage is transmitted by the system (connected to the connector 1610). (e.g., by a control unit having a function of detecting a deformation of a structure) Used for.

[0134] The active sensor 1630 is located above the second tape layer 1632. The bottom surface of the sensing element 1630 contacts the top surface of the second tape layer 1632. In this embodiment, the second tape layer 1632, like the first tape layer 1628, is oriented only in the z-axis. In another embodiment, the second tape comprises one or more layers of z-axis anisotropic tape that are electrically conductive in the The top surface of the active sensor 1630 is conductive in all directions. The active sensing element 1630 has a conductive layer on the lower surface thereof that contacts the second tape layer 1632. In this case, the lower surface becomes an equipotential surface.

[0135] As can be seen in FIG. 16B, the first tape layer 1628, the active sensor 1630, and the second tape layer 1630 are The width (e.g., horizontal width along the y-axis) of the two tape layers 1632 is For example, the width of the first positive electrode 1626A, the width of the fourth positive electrode 1626D, etc. That is, the first tape layer 1628, the active sensor 1630, and the second tape layer 1630 may be The size and shape of 632 do not match the size and shape of the positive electrode 1602. This is due to the fact that the first tape layer 1628 is conductive only in the z-axis. The first tape layer 1628, the active sensor 1630 and the second tape layer 1631 are 632 does not need to be made to match the size and shape of the positive electrode 1602; The electrode 1602 may extend over a portion of the positive electrode 1602 or over the entire positive electrode 1602. The first tape layer 1628, the active sensor 1630, and the second tape layer 1632 are all The fabrication complexity of sensor 1600 is reduced compared to sensors that are matched to the positive electrode. From the outer shell 1608 of FIG. 16A, the first tape layer 1628, the active sensor 1630, and It can be seen that the second tape layer 1632 extends over a wide area across multiple elements. 16A also shows that the positive electrode 1626 has a circular shape.

[0136] Referring again to FIG. 16B, the second tape layer 1632 is positioned above the ground electrode 1634. The ground electrode 1634 may be made of a conductive material such as copper. The top surface of the second tape layer 1632 may contact the bottom surface of the second tape layer 1632.

[0137] The ground electrode 1634 is covered by a second polyimide film layer 1636 (e.g., DuPont® The second polyimide film layer is located above a polyimide film layer (such as Kapton® by Samsung Electronics). 1636 is a dielectric layer between the ground electrode and the structure (when integrated with the laminate). The purpose is to bond structures that are subjected to complex stress conditions (e.g., biaxial tension). This serves the dual purpose of forming a well-suited compliant substrate.

[0138] In some embodiments, the top of the sensor 1600 is connected to one or more other devices for electromagnetic detection. Copper layer 16 is provided to provide an electromagnetic interference (EMI) shield to protect sensor 1600 from interference. 38 may be provided.

[0139] Also shown in Figure 16B is a cross section of lead 1616A. Lead 1616 is made of a material such as copper. 16B shows a first polyimide layer 1624 and a copper layer 1638. Although a configuration is depicted in which the first poly The imide layer 1624 and copper layer 1638 do not extend laterally over the leads 1616 In some embodiments, the area 1640 below the lead 1616 may In some embodiments, the active element is made of a dielectric material only to insulate it from the underlying object. Some components including the sensor 1630 extend laterally so as to be positioned below the lead 1616. However, in this embodiment, between the active sensing body 1630 and the lead 1616, A non-conductive layer is provided to insulate the leads from the active sensor 1630 .

[0140] The ground electrode layer 1634, the positive electrode 1626, and the lead 1616 are all flexible. As shown in the figure, the device is fabricated on a highly durable flexible printed circuit board using a flexible substrate. In addition, the active sensing element 1630 may also exhibit flexibility. tape layer 1628, second tape layer 1632, first polyimide film layer 1624 and second The polyimide film layer 1636 may also be flexible. The element exhibits flexibility, so that the sensor 1600 also exhibits flexibility and can follow the installation surface. This allows for better adhesion to curved and / or rough surfaces compared to rigid sensors. and acoustic coupling is improved.

[0141] The ground electrode layer 1634, the positive electrode 1626 and the lead 1616 are mounted on the flexible substrate. In contrast, it can be produced by any method, including thermal transfer-resist development method, CNC electrode film formation method, etc. These methods can facilitate cost-efficient manufacturing and mass production.

[0142] FIG. 16C is a cross-sectional side view of a sensor 1600 mounted on the exterior surface 1656 of the cylinder 100. The sensor 1600 has an outer surface 1654 and an inner surface 1652. The inner surface 1652 contacts the outer surface 1656 of the cylinder 100. The sensor 1600 is attached by an adhesive. The sealant may be attached to the exterior surface of the cylinder 100 in any manner, such as by means of an adhesive.

[0143] FIG. 16D is a side cross-sectional view of a sensor 1600 that conforms to the curved surface of the cylinder 100. The sensor 1600 may be attached to the cylinder 100 by adhesive or any other method. In some embodiments, the sensor 1600 may be manufactured integrally with the cylinder 100 . For example, the sensor 1600 may be fabricated directly onto the cylinder 100 or may be attached to the cylinder 100. If the cylinder 100 has multiple layers, the insulating layer 100 may be disposed between those layers.

[0144] In some embodiments, during manufacture of the cylinder 100, the outer surface 1656 (or alternatively, the outer surface 165 6, a part of which the sensor 1600 is attached) is attached to the cylinder 100. For example, during the manufacture of the cylinder 100, the cylinder 100 may be smoothed to make it easier to adhere the cylinder 100 to the cylinder. A backing plate with a curvature that matches the outside diameter of the cylinder may be used. The backing plate may be coated with a release agent. The uncured cylinder 100 can be coated with a mold release agent at the sensor mounting position. The cylinder 100 is cured, and after curing, the cauldron is removed. This creates a smooth surface for the sensor to adhere to. Improved thermal performance (i.e., bondline cycle life) and acoustic coupling (superior response) To rise.

[0145] 16C and 16D show the sensor 1600 attached to the cylinder 100. As depicted, the sensor 1600 detects impact damage to wind turbines, fuselages, wing leading edges, and other structures. Any monitoring, such as composite structures where the It may be bound to a structure of interest.

[0146] FIG. 17 shows a sensor element similar to sensor 1600 and sensor 202 but with three different types of sensors. The sensor 1700 is shown as being different in size. The same symbols as the sensor 1600 are assigned, and unless otherwise specified, the same symbols as the sensor 1600 are assigned. In particular, the cross-sectional structure shown in FIG. 16B is taken along line AA of the sensor 1700. The cross-sectional structure is the same as that of the

[0147] The sensor 1700 has a plurality of sensing elements 1702. First sensing element 1702A, second sensing element 1702B, third sensing element 1702C, fourth sensing element The first sensing element 1702D and the fifth sensing element 1702E. 2A, the second sensing element 1702B and the fourth sensing element 1702D are all the same series. diameter 1704, and therefore have a sensing area (or aperture or size) of the same size. )

[0148] Similar to sensor 1600, the fifth sensing element 1702E is connected to the first sensing element 1702A, The fifth sensing element 1702B is larger than the second sensing element 1702B and the fourth sensing element 1702D. The diameter 1706 of the fifth electrode 1702E is larger than the diameter 1704. The sensing area of ​​the sensing element 1702E is the same as that of the first sensing element 1702A, the second sensing element 1702 B and the fourth sensing element 1702D.

[0149] Unlike the sensor 1600, the third sensing element 1702C has a capacitance similar to that of the first sensing element 1702A. , larger than the second sensing element 1702B and the fourth sensing element 1702D, and The diameter 1740 of the third sensing element 1702D is smaller than that of the first sensing element 1702E. The diameter is larger than the diameter 1704 and smaller than the diameter 1706. The sensing area of ​​the third sensing element 1702D is the same as that of the first sensing element 1702A, the second sensing element 1702B, and the third sensing element 1702C. 702B and the fourth sensing element 1702D, and the fifth sensing element 1702 Smaller than E.

[0150] The Sensor 1600 has two sensor element sizes, while the Sensor 1700 has three. This allows for three different sensing technologies and sensing The sensor 1700 can be used even in situations where a monitoring application is applied. The first size of the element is optimized for a first technology or application. The second size may be optimized for a second technology or application, and the third size may be optimized for a second technology or application. The sensor 1700 may be optimized for a third technology or application. , when connected to various systems (via connector 1710), two or less types of sensor element sizes are This allows for greater versatility than other sensors that only have one size. The sensor 1700 is more computationally efficient and cost-effective than multiple separate sensors of different sizes. It has high efficiency in terms of both cost efficiency and energy efficiency.

[0151] FIG. 18 shows sensors 1600, 1700, and 202 similar to the sensors 1600, 1700, and 202, but of four types. Sensor 1800 is shown, which differs in that it is made up of different sensor element sizes. The same symbols as those of the sensors 1600 and 1700 are assigned to the sensor 00, and there is no particular difference. Unless otherwise specified, the sensor has the same configuration as the sensor 1600 and the sensor 1700. The cross-sectional structure shown in FIG. 6B also applies to sensor 1800. If there is a gap, the cross-sectional structure of the side surface will be similar to that shown in FIG. 16B. As will be described in more detail below, the horizontal width of the first positive electrode is greater than that of sensor 1600. 00 is wider.

[0152] The sensor 1800 has a plurality of sensing elements 1802. First sensing element 1802A, second sensing element 1802B, third sensing element 1802C, fourth sensing element The second sensing element 180 has a first sensing element 1802D and a fifth sensing element 1802E. 2B and the fourth sensing element 1802D both have the same diameter 1804, and Therefore, the sensing areas (or apertures or sizes) are of the same scale.

[0153] Similar to sensors 1600 and 1700, the fifth sensing element 1802E is a second sensing element. The fifth sensing element 1802 is larger than the fourth sensing element 1802B and the fourth sensing element 1802D. The diameter 1806 of the fifth sensing element 180 is larger than the diameter 1804. The sensing area of ​​the second sensing element 1802E is larger than that of the second sensing element 1802B and the fourth sensing element 1802D. Hey.

[0154] Unlike sensor 1600 (but similar to sensor 1700), the third sensing element 180 2C is larger than the second sensing element 1802B and the fourth sensing element 1802D, and , smaller than the fifth sensing element 1802E. The diameter 1840 of the third sensing element 1802D is , which is larger than the diameter 1804 and smaller than the diameter 1806. Therefore, the sensing area of ​​the third sensing element 1802D is larger than that of the second sensing element 1802B and the fourth sensing element 1802C. It is larger than the fifth sensing element 1802D and smaller than the fifth sensing element 1802E.

[0155] Unlike sensors 1600 and 1700, first sensing element 1802A is a second sensing element. sensing element 1802B, the third sensing element 1802C, and the fourth sensing element 1802D. The diameter of the first sensing element 1802A is larger than that of the fifth sensing element 1802E. 1842 is larger than the diameter 1804 and the diameter 1840, and is smaller than the diameter 1806. Therefore, the sensing area of ​​the first sensing element 1802A is smaller than that of the second sensing element 1802A. 802B, the third sensing element 1802C and the fourth sensing element 1802D, and is smaller than the fifth sensing element 1802E.

[0156] The Sensor 1700 has three different sensor element sizes, while the Sensor 1800 has four. This allows for four different sensing technologies and sensing The sensor 1800 can be used even in situations where a monitoring application is applied. The first size of the element is optimized for a first technology or application. The second size may be optimized for a second technology or application, and the third size may be optimized for a second technology or application. The size may be optimized for a third technology or application, and the fourth size may be optimized for a fourth technology or application. For this reason, the sensor 1800 (connector 18 10) When connected to various systems, other sensors with less than three sensor element sizes The sensor 180 may be made up of multiple sensor element sizes, providing greater versatility than conventional sensors. 0 is both computationally and cost-effective than using multiple separate sensors of different sizes. It has high efficiency in terms of surface area.

[0157] 19, similar to the sensor 1600, the sensor 1700, the sensor 1800, and the sensor 202. However, the sensor 1900 differs in that it consists of five different sensor element sizes. The sensor 1900 has the same functions as the sensors 1600, 1700, and 1800. Unless otherwise specified, the sensors 1600, 1700, and and sensor 1800. In particular, the cross-sectional structure shown in FIG. 16B is the same as that of sensor 1 The same applies to the 900.

[0158] The sensor 1900 has a plurality of sensing elements 1902. First sensing element 1902A, second sensing element 1902B, third sensing element 1902C, fourth sensing element The second sensing element 1902D and the fifth sensing element 1902E. 2B has a diameter 1904 and a sensing area (or aperture or size) corresponding to it. It is.

[0159] Unlike sensors 1600, 1700, and 1800, the fourth sensing element 190 The diameter of the fourth sensing element 1902D is 19. 44 is larger than the diameter 1904. Therefore, the sensing element 1902D of the fourth sensing element The sensing area is larger than the second sensing element 1902B.

[0160] Unlike sensor 1600 (but like sensors 1700 and 1800), the third The first sensing element 1902C is more sensitive than the second sensing element 1902B and the fourth sensing element 1902D. The third sensing element 1902D is larger than the fifth sensing element 1902E and smaller than the fifth sensing element 1902E. Diameter 1940 is larger than diameter 1904 and diameter 1944, and diameter 190 6. Therefore, the sensing area of ​​the third sensing element 1902D is smaller than that of the second sensing element 1902B and the fourth sensing element 1902D, and the fifth sensing element 190 Smaller than 2E.

[0161] Unlike sensors 1600 and 1700 (but similar to sensor 1800), the first The first sensing element 1902A is connected to a second sensing element 1902B, a third sensing element 1902C, and Larger than the fourth sensing element 1902D and smaller than the fifth sensing element 1902E The diameter 1942 of the first sensing element 1902A is equal to the diameter 1904, the diameter 1940, and the diameter The diameter is larger than the diameter 1944 and smaller than the diameter 1906. The sensing area of ​​element 1902A is divided into a second sensing element 1902B, a third sensing element 1902C, and a and the fourth sensing element 1902D and smaller than the fifth sensing element 1902E. Sai.

[0162] Similar to the sensors 1600, 1700, and 1800, the fifth sensing element 19 The fifth sensing element 1902E is larger than any of the other sensing elements. diameter 1904, diameter 1940, diameter 1942 and diameter 1944 are larger than Therefore, the sensing area of ​​the fifth sensing element 1902E is larger than that of the other sensing elements. stomach.

[0163] The Sensor 1800 has four different sensor element sizes, while the Sensor 1900 has five. This allows for five different sensing technologies and sensing The sensor 1900 can be used even in situations where a monitoring application is applied. The first size of the element is optimized for a first technology or application. The second size may be optimized for a second technology or application, and the third size may be optimized for a second technology or application. The size may be optimized for a third technology or application, and the fourth size may be optimized for a fourth technology or application. a fifth size may be optimized for a fifth technology or application; Therefore, the sensor 1900 can be connected (at the connector 1910) to various systems. When connected to a stem, it outperforms other sensors with four or fewer sensor element sizes. The sensor 1900, which is made up of multiple sensor element sizes, can be used to measure different sizes. This is more efficient in terms of both computational efficiency and cost efficiency than using multiple separate sensors of the same size. do.

[0164] 16A, 17, 18 and 19 are made up of various numbers of sensor elements of various sizes. Although a sensor with multiple sensor elements is depicted, the sensors described herein may include any number of sensor elements. may be included, and any number of different sizes may be employed. The use of three, four or five different sensor elements and / or sensor element sizes is not permitted. These are merely examples and are not intended to limit the invention.

[0165] As described herein, the sensors (e.g., sensor 1600, sensor 1700, Sensors 1800, 1900, etc.) actively generate waves to be detected by other sensors. They may be considered passive sensors in that they are not designed to detect and respond to a variety of , determine where and how severe an impact event occurred in the composite structure, and The composite structure is passively monitored when the laminate is subjected to stress from an external source.

[0166] Described herein is a multi-purpose multi-element grated array (OMEGA) sensor. To demonstrate the performance of the various aspects of the sensor that can be used, an OMEG similar to sensor 1600 was used. We will introduce the data collected from the A sensor examples and the configuration of each example. Also touches upon.

[0167] To quantify the sensitivity of the OMEGA sensor relative to conventional broadband piezoelectric sensors, To achieve this, we developed an OMEGA sensor as shown in Figures 16A and 16B, and a conventional single-element sensor. Both the B1025 and B1025 sensors are mounted on a 70-inch panel measuring 1200mm x 1800mm in width and 3.1mm in thickness. The left side of Figure 20 shows the relevant dimensions of the experimental setup used. The right side of Figure 20 shows the actual experimental setup.

[0168] Source 2 (0.5mm 6H pencil lead fracture) for B1025 sensor (transducer) The time waveform and time-frequency distribution from the OMEGA (damage source) are shown in Figure 21A. Time waveform from source 2 for element 1 (e.g., first element 1602A) of the sensor The time-frequency distribution is shown in Figure 21B. From Figures 21A and 21B, important information can be seen. First, the OMEGA sensor detects in-plane deformation (S0 mode). While the sensitivity of the B1025 sensor is superior to that of the B1025 sensor, the sensitivity of the A0 mode is Second, the sensitivity of element 1 of the OMEGA sensor (e.g., For example, the peak response of the first element (1602A) was 10 dB below that of the B1025 sensor. .

[0169] If you want to obtain a sensitivity response that exceeds that of a conventional single-element piezoelectric ceramic sensor, The technique of time-shifting and combining these two signals into a coherent state is utilized in the OMEGA sensor. As an example, as shown in FIG. 22, each element (diameter 5 mm) of FIG. 21A and FIG. 21B can be The data of element 1 is time-shifted to a coherent state based on the time base of element 1, and the time coherence The signals in the heritable states were summed together.

[0170] Source 2 (breakage source caused by 0.5 mm 6H pencil lead) for B1025 sensor The time waveform and time-frequency distribution from the OMEGA sensor are shown in Figure 23A. The time waveform from source 2 and the sum of the signals time-shifted to the original state are shown. The time-frequency distribution is shown in FIG. 23B.

[0171] The diameter of the sensing element of the sensor has a large effect on the sensitivity of the sensor due to the so-called aperture effect. It is known that the wavelength of the propagating wave influences the diameter (or , or an integer multiple thereof), half of the piezoelectric element is in tension while the other half is in compression. The sensor then enters a state of contraction, and the response of the sensor to that wavelength (frequency) becomes net zero. In mechanical structures, the thickness of the components is much thinner than the wavelength of the propagating waves, so the types of propagating waves are Figure 24 shows the frequency of a 3.1 mm thick 7075 Al plate. -The dispersion relation of wavelength (λ) is shown. The hatched area of ​​each diameter aperture (φ) is the aperture distortion. From Figure 24, it can be seen that the frequency (wavelength) where the aperture effect occurs is It can be seen that the wavenumber depends on the mode. The larger the diameter of the aperture, the more It can be seen that the sensitivity in the high frequency range decreases with increasing frequency.

[0172] To illustrate the effect of aperture size on the acquired signal, a generation of OMEGA sensors was The example in the table is attached to a 7075T6Al plate with a width of 1200mm x 1800mm and a thickness of 3.1mm. The OMEGA sensor was designed as shown in FIG. 16A, and elements 1 to 4 (e.g., , sensor elements 1602A to 1602D) have a diameter of 5 mm, element 5 (for example, sensor element 1 The diameter of the 602E was 13 mm. Figure 25 shows a schematic diagram of the experimental setup. As an example, in FIG. 25, the source 1 (0.5 mm 6H pencil lead break (PLB)) In Figure 26, element 1 (e.g., sensor element 1602A) (diameter 5 mm) and for element 5 (e.g., sensor element 1602E) (diameter 13 mm), the time response The normalized frequency response (top) and normalized frequency response (bottom) are shown in Figure 26. While the amplitude response is much larger due to the larger area, the 5mm diameter active element It can be seen that the frequency response is relatively excellent above kHz.

[0173] In the data in Figure 26, the damage source is oriented out of plane relative to the plate, so the fundamental bending vibration As can be seen from Figure 26, the 13 mm diameter element In the F0 mode, the first aperture effect occurs at 150 kHz, while in the 5 m diameter For m elements, the first aperture effect of F0 mode does not occur until 550 kHz. Therefore, the smaller diameter element has a better high frequency response.

[0174] Depending on the measurement situation, the desired sensitivity response or high frequency response may differ. For example, the duration should be in the millisecond range and should not excite frequencies above approximately 100 kHz. When monitoring such impact events with passive sensors, it is important to select a large diameter element with high sensitivity. Conversely, material damage (in the nanosecond to microsecond range) can cause up to 1 MHz When monitoring frequency content of 1000 Hz or higher with a passive sensor, A small diameter element without distortion due to the choke effect would be an advantageous solution.

[0175] Composite pressure cylinder inspections provide better quantitative assessment and reduce false alarms From this perspective, it is necessary to distinguish between various damage mechanisms and quantify the damage mechanisms that have adverse effects. For example, modal analysis of acoustic emission from composite pressure vessels is useful. MAE inspection detects fiber breakdown due to frequency components up to 600 kHz (or higher). and various other damage mechanisms (e.g., matrix cracks, fiber / matrix cracks) Distinguish between the adhesive and the material (such as separation and peeling of the material). To detect minute particles, small diameter active sensing elements are necessary.

[0176] FIG. 27 illustrates a sensor described herein (e.g., sensor 1600, sensor 1700, sensor 2 is a flow diagram illustrating a method 2700 for manufacturing a sensor (e.g., sensor 1800, sensor 1900).

[0177] A ground electrode (e.g., ground electrode 1634) is fabricated (step 2702). The ground electrode may be made of a conductive material such as copper and may be flexible as described herein. The substrate may be flexible.

[0178] A plurality of positive electrodes (e.g., positive electrode 1626) and respective leads (e.g., lead 1 616) is fabricated (step 2704). The positive electrode and the lead are made of copper or the like. and a flexible substrate, as described herein, to exhibit flexibility. It can be made using:

[0179] A conductive tape (e.g., second tape layer 1632) is used to connect a piezoelectric material (e.g., a sensing element The bottom surface of the terminal 1630 is connected to the top surface of the ground electrode (step 2706).

[0180] Using z-axis anisotropic tape (e.g., first tape layer 1628), the top surface of the piezoelectric material is The positive electrode is connected to the underside (step 2708). the piezoelectric material, the conductive tape connecting the piezoelectric material to the ground electrode, and the z-axis The anisotropic tape can be shaped and sized independently of the shape and size of the positive electrode. This allows the shape and size of each layer to match the shape and size of the positive electrode. This leads to improved manufacturing efficiency and reduced manufacturing costs compared to conventional sensors.

[0181] In some embodiments, the positive electrode is a polyimide film layer (e.g., a first polyimide The ground electrode is also covered with a polyimide film layer (e.g., a second polyimide film layer 1624). In some embodiments, the sensor is connected to a membrane layer 1636. It is coated with a copper layer (eg, copper layer 1638) configured to provide EMI shielding.

[0182] FIG. 28 illustrates a sensor described herein (e.g., sensor 1600, sensor 1700, sensor 18. A flow diagram illustrating a method 2800 for making and using a sensor (e.g., sensor 1800, sensor 1900). .

[0183] A plurality of monitoring tasks for the sensor are determined (step 2802). The monitoring task consists of the monitored structure and / or the monitored configuration. This may be determined based on the environment in which the structure is installed or has been installed. For example, In the case of a composite cylinder configured to store oxygen, the monitoring task is As will be described, monitoring for impact events that affect the integrity of the composite cylinder, and the loss of structural integrity of the composite cylinder when it is refilled. This may include monitoring.

[0184] A plurality of sensor element sizes are determined based on the plurality of monitoring tasks. In some embodiments, the computing device process a sensor for determining the sensor element size and the sensor based on the monitoring task; The arrangement and layout of sensor elements of various sizes within the computer can be automatically determined. The computing device is configured to store instructions for execution by the processor. The computer has a non-transitory computer-readable memory configured therein. In addition to the multiple monitoring tasks, the device was also used to fabricate composite structures. Depending on the material, the position of the sensor element on the composite structure and / or the sensor element The size and / or arrangement and layout of sensor elements of various sizes within said sensor The size of the sensor element may be determined automatically for each of the plurality of monitoring tasks. For example, if the sensor is configured to monitor three different When configured for monitoring on a task, three sensor element sizes are determined. will be done.

[0185] The computing device may be configured to determine the number of monitoring tasks and / or the number of monitoring resources. Any variation in the type of sensing task and / or sensor location and / or material of the composite structure The layout of each sensing element of the sensor can be quickly adjusted to accommodate changes in the Since the layers above and below the positive electrode may remain the same across different sensor designs, The layout of the sensing element may refer to the layout of the positive electrode. The sensors described herein are not like conventional sensors where all layers of the sensor can be redesigned and adjusted. The redesign cost is lower and the redesign time is faster than that of a conventional sensor.

[0186] Sensors having a plurality of element sizes according to the plurality of monitoring tasks are manufactured. The manufacturing process of step 2806 is performed in accordance with method 2 described herein. 700. The manufacturing process may be similar to that of 700. The manufacturing process may be similar to that of 700. , positive electrode layer and lead layer) and / or grasping each layer of the sensor. One or more machines configured to perform each of the manufacturing steps described herein by the arrangement The design of each sensor element can be automated by dedicated computer-assisted methods. Computer-aided design data that can be understood by computers and is compatible with computer-aided design software The machine that prints the printed circuit board can do this using the computer-understandable Using such computer-aided design data, each layer of the sensor can be automatically fabricated.

[0187] The fabricated sensor is coupled to the composite structure (step 2808). As will be explained, the outer surface of the composite structure facilitates intimate contact of the sensor with the composite structure. This improves the acoustic coupling and mechanical reliability of the bond line. The manufactured sensor is attached to the composite structure by any method such as applying an adhesive or The method can be automatically linked.

[0188] Advantageously, the piezoelectric elements used in the sensors described herein are manufactured using a die and fill process. The polymers prepared by the DFC process described herein can be prepared by the DFC process. The piezoelectric element may also be referred to as a DFC piezoelectric element.

[0189] 29A to 29F are diagrams illustrating a method for fabricating a DFC piezoelectric element 2900. In FIG. 29A, a piezoelectric material 2902 is provided. In FIG. 29B, a second Dicing is performed in one direction 2906 (e.g., along the x-axis) (i.e., the cuts are 29C, the piezoelectric material 2902 is placed in a rectangular array 2904. Dicing occurs in a second direction 2910 (e.g., along the y-axis) relative to 902. 2902) to create pillars 2908 of piezoelectric material 2902.

[0190] In FIG. 29D, epoxy 2912 is applied over the diced piezoelectric material 2902. In FIG. 29E, grooves 291 between pillars 2908 of diced piezoelectric material 2902 are 4. Apply epoxy 2912 to the diced board. The resulting piezoelectric material 2902 may be heated and / or exposed to a vacuum. It may be liquid at the initial stage, and heating reduces its viscosity and promotes flow. In FIG. 29F, the piezoelectric material 2902 is covered with a conductor 291. 6 is coated onto the piezoelectric material 2902. For example, a sputtered film of gold is applied to the piezoelectric material 2902.

[0191] The DFC piezoelectric element 2900 is a piezoelectric element that is continuously solid along its length and / or width. Compared to the element, the groove is filled with epoxy, so it easily conforms to the mounting surface. The finished DFC Piezoelectric / DFC Sensor 2900 is made of epoxy 29 12 is heated to a temperature sufficient to soften it and bend it, It can be made to have a specific profile according to the surface of the composite structure of the elephant.

[0192] Although the first direction 2906 is depicted as being perpendicular to the second direction 2910 in the drawing, In some embodiments, the first direction 2906 and the second direction 2910 may not be orthogonal. For example, if the surface of a composite structure consists of multiple contours in various directions, the DF The dicing of the piezoelectric elements 2900 is performed in a pattern specific to the surface of the composite structure. The closer the shape of the DFC piezoelectric element 2900 is to the surface of the composite structure, the The contact area between the sensor using the piezoelectric element 2900 and the composite structure can be increased. The increased contact area between the sensor and the composite structure improves acoustic coupling (i.e., sensor response). ) and bond line integrity. As shown in Figures 29A-29F, the resulting The piezoelectric element 2900 is a 1-3 piezoelectric composite, which suggests that it is conductive in only one direction. There are.

[0193] FIG. 30A shows a piezoelectric element manufactured using a DFC piezoelectric element (e.g., DFC piezoelectric element 2900). A plan view of a sensor 3000. The sensor 3000 includes a sensing element 3002 and leads 3003. In most embodiments, the sensing element 3002 has a and a preamplifier circuit configured to amplify the detected signal. The loop circuit includes the control unit (for example, the control unit 302, the control unit 352, the filling control unit 1002, etc.) It is connected to.

[0194] Figure 30B is a side cross-sectional view taken along line AA in Figure 30A. Except for this point, the layer structure of sensor 3000 is the same as that of sensor 1600. Similar components / layers are numbered similarly.

[0195] The sensor 3000 includes a first polyimide film layer 3024 (e.g., Dupont® The first polyimide film layer 3024 may comprise a polyimide film such as Kapton® manufactured by Epson Corporation. When the sensor is integrated with the laminate, a dielectric layer is formed between the ground electrode and the structure. It is configured to be.

[0196] The sensor 3000 may further include a positive electrode 3026. The positive electrode 3026 may be made of a material such as copper. The upper surface of the positive electrode 3026 is made of a conductive material. contact with the surface.

[0197] The positive electrode 3026 is located above the first conductive layer 3028. 28 connects the positive electrode 3026 to the active sensing element 303 located below the first conductive layer 3028. The first conductive layer 3028 is electrically connected to the adjacent components. The conductive tape may be made of any conductive material, such as conductive tape, Z-axis conductive tape, or solder. The upper surface of the first conductive layer 3028 contacts the lower surface of the positive electrode 3026, and the first conductive layer The bottom surface of 3028 contacts the top surface of active sensing element 3030 .

[0198] The active sensor 3030 may be a piezoelectric element, such as the piezoelectric element 2900. 30 is configured to generate an electric current when subjected to mechanical stress. The sensor 3030 (for example, due to a transient stress caused by an impact on the structure or damage to the material of the structure) When mechanical stress occurs due to wave propagation, etc., a voltage is generated between the positive electrode 3026 and the ground electrode 3034. This voltage is generated by the system (at the control unit connected to lead 3016) Deformations of the structure are identified by detection as described herein.

[0199] The active sensing element 3030 is located above the second conductive layer 3032. The lower surface of the sensor 3030 is in contact with the upper surface of the second conductive layer 3032. 32 is a conductive tape, z-axis conductive material, etc., configured to connect adjacent components. The second conductive layer 3032 may be made of any conductive material such as conductive tape, solder, etc. 3034. The ground electrode 3034 may be made of a conductive material such as copper. The top surface of the ground electrode 3034 may contact the bottom surface of the second conductive layer 3032.

[0200] In embodiments where the first conductive layer 3028 and the second conductive layer 3032 are solder, adjacent Solid solder is placed between the corresponding layers and the sensor is placed in a reflow oven. In the reflow oven, the solder melts and bonds the adjacent corresponding layers together. are conductively connected.

[0201] The ground electrode 3034 is covered by a second polyimide film layer 3036 (e.g., DuPont® The second polyimide film layer is located above a polyimide film layer (such as Kapton® by Samsung Electronics). 3036 is a dielectric layer between the ground electrode and the structure (when integrated with the laminate). The purpose is to bond structures that are subjected to complex stress conditions (e.g., biaxial tension). This serves the dual purpose of forming a well-suited compliant substrate.

[0202] In some embodiments, the top of the sensor 3000 is connected to one or more other devices for electromagnetic detection. The copper layer 30 acts as an electromagnetic interference (EMI) shield to protect the sensor 3000 from interference. 38 may be provided.

[0203] The leads 3016 may be made of a conductive material such as copper. A polymer layer 3024 and a copper layer 3038 cover the leads 3016. The first polyimide layer 3024 and the copper layer 3038 are laterally arranged to cover the leads 3016. In some embodiments, the area below the lead 3016 does not extend in the direction of the lead. In some embodiments, the board consists solely of a dielectric material to insulate it from the object underneath. Some components including the active sensor 3030 are laterally positioned below the lead 3016. However, in this embodiment, the active sensing element 3030 and the lead 3016 extend in the opposite direction. In between, a non-conductive layer is provided to insulate the leads from the active sensor 3030.

[0204] The ground electrode layer 3034, the positive electrode 3026, and the lead 3016 are all flexible. As shown in the figure, the device is fabricated on a highly durable flexible printed circuit board using a flexible substrate. In addition, the active sensing element 3030 may also exhibit flexibility. The conductive layer 3028, the second conductive layer 3032, the first polyimide film layer 3024 and the second polyimide film layer 3036 are The imide film layer 3036 may also be flexible. exhibits flexibility, the sensor 3000 also exhibits flexibility and can follow the installation surface. This allows for better adhesion and sound quality on curved and / or rough surfaces compared to rigid sensors. This improves acoustic coupling.

[0205] The ground electrode layer 3034, the positive electrode 3026 and the lead 3016 are mounted on the flexible substrate. In contrast, it can be produced by any method, including thermal transfer-resist development method, CNC electrode film formation method, etc. These methods can facilitate cost-efficient manufacturing and mass production.

[0206] FIG. 30C is a cross-sectional side view of a sensor 3000 mounted on the exterior surface 3056 of the cylinder 100. The sensor 3000 has an outer surface 3054 and an inner surface 3052. The inner surface 3052 contacts the outer surface 3056 of the cylinder 100. The sensor 3000 is attached by an adhesive. The sealant may be attached to the exterior surface of the cylinder 100 in any manner, such as by means of an adhesive.

[0207] FIG. 30D is a side cross-sectional view of the sensor 3000 that follows the curved surface of the cylinder 100. The sensor 3000 may be attached to the cylinder 100 by adhesive or any other method. In some embodiments, the sensor 3000 may be manufactured integrally with the cylinder 100 . For example, the sensor 3000 may be fabricated directly onto the cylinder 100 or may be attached to the cylinder 100. If the cylinder 100 has multiple layers, it may be disposed between the layers of the cylinder 100.

[0208] In some embodiments, during manufacture of the cylinder 100, the outer surface 3056 (or alternatively, the outer surface 305 6, a part of which the sensor 3000 is attached) is attached to the cylinder 100. For example, during the manufacture of the cylinder 100, the cylinder 100 may be smoothed to make it easier to adhere the cylinder 100 to the cylinder. A backing plate with a curvature that matches the outside diameter of the cylinder may be used. The backing plate may be coated with a release agent. The uncured cylinder 100 can be coated with a mold release agent at the sensor mounting position. The cylinder 100 is cured, and after curing, the cauldron is removed. This creates a smooth surface for the sensor to adhere to. Improved thermal performance (i.e., bondline cycle life) and acoustic coupling (superior response) To rise.

[0209] In some embodiments, the sensor 3000 is made of resin 2912 of the DFC piezoelectric element 2900. The transition temperature at which a material changes from a solid to a malleable state (e.g., the glass transition temperature T g ) or higher. When heated upward, the DFC piezoelectric element 2900 bends and curves to change the shape of the composite being monitored. The resin (or resins) is selected based on a number of factors, including the desired transition temperature. In other words, in order to achieve a desired transition temperature, One or more resins may be used.

[0210] In contrast to the sensor 1600, which is a multi-element sensor, the sensor 3000 is a single-element sensor. Therefore, the sensor 3000 may be used multiple times in the composite structure monitoring system described herein. Although multiple sensors 3000 are used, the DFC piezoelectric element 2900 This reduces the cost of electronic components compared to other similar sensors such as the multi-element sensor 1600. Therefore, the system cost can be significantly reduced. The 900 conforms to composite surfaces better than other similar sensors It could be.

[0211] 30C and 30D show the sensor 3000 attached to the cylinder 100. As depicted, Sensor 3000 detects impact damage to wind turbines, fuselages, wing leading edges, and other structures. Any monitoring, such as composite structures where the It may be bound to a structure of interest.

[0212] To demonstrate the performance of the various embodiments of the DFC sensor described herein, sensor 300 We will introduce the data collected from the same sensor examples as in Example 0, and the configuration of each example. We will also touch on this.

[0213] To quantify the sensitivity of the DFC sensor relative to conventional wideband piezoelectric sensors, Both the FC sensor and the conventional single-element B1025 sensor were installed in a 1200mm wide area. The specimen was bonded to a 7075 aluminum plate measuring 1800 mm x 1800 mm and 3.1 mm thick. FIG. 1 is a schematic diagram of the experimental setup with relevant dimensions.

[0214] Figure 32 shows the source of the damage (the source of the damage caused by the breakage of a 0.5 mm 6H pencil lead). The source model is a cosine bell forcing function (magnitude : 1N, rise time: 1μs).

[0215] Source 1 (0.5 mm 6H pencil lead) for B1025 sensor and DFC sensor The time and frequency waveforms from the fracture (damage source) are shown in Figure 33.

[0216] Regarding the DFC sensor, from source 1 (damage source due to 0.5 mm 6H pencil lead breakage) The time-frequency distribution of the signal from source 1 for the B1025 sensor is shown in Figure 34A. The frequency distribution between the DF and the DF is shown in Figure 34B. As can be seen from a comparison of Figures 34A and 34B, The C sensor is an order of magnitude more sensitive than the B1025 sensor.

[0217] Time waveforms and frequency from source 2 for the B1025 sensor and DFC sensor The waveforms are shown in FIG.

[0218] The time-frequency distribution from source 2 for the DFC sensor is shown in Figure 36A. The time-frequency distribution from source 2 for 25 sensors is shown in Figure 36B. As can be seen from the comparison with Figure 36B, the DFC sensor is more sensitive than the B1025 sensor. It's a huge number.

[0219] Time waveforms and frequency from source 3 for the B1025 sensor and DFC sensor The waveforms are shown in FIG.

[0220] The time-frequency distribution from source 3 for the DFC sensor is shown in Figure 38A. The time-frequency distribution from source 3 for 25 sensors is shown in Figure 38B. As can be seen from the comparison with Figure 38B, the DFC sensor is more sensitive than the B1025 sensor. It's a huge number.

[0221] In another experiment, the DFC sensor and the B1025 sensor were placed in a Type 3 self-contained breathing apparatus (SCB) A) They were joined so that they were close to each other on the cylinder. Source 1 was an out-of-plane fracture, and the source Source 2 was an in-plane fracture. The following table shows the locations of each source and each sensor:

[0222] [Table 1]

[0223] Time from source 1 (out-of-plane fracture) for B1025 sensor and DFC sensor The time and frequency waveforms are shown in Figure 39.

[0224] The time-frequency distribution from source 1 (out-of-plane fracture) for the DFC sensor is shown in Figure 40. The time-frequency distribution from source 1 for the B1025 sensor is shown in Figure 40B. As can be seen from a comparison of Figures 40A and 40B, the DFC sensor is Its sensitivity is an order of magnitude greater than that of the .

[0225] FIG. 41 illustrates a method for making and using a sensor described herein (e.g., sensor 3000). FIG. 4 is a flow diagram illustrating method 4300.

[0226] A ground electrode (e.g., ground electrode 3034) is fabricated (step 4302). The ground electrode may be made of a conductive material such as copper and may be flexible as described herein. The substrate may be flexible.

[0227] A positive electrode (e.g., positive electrode 3026) and each lead (e.g., lead 3016 The positive electrode and the lead are made of a conductive material such as copper (step 4304). The substrate may be made of a flexible material and may be made of a flexible substrate to provide flexibility as described herein. It can be made by

[0228] Fabrication of a DFC piezoelectric element (e.g., DFC piezoelectric element 2900) is performed (step 43 06). As described herein, the DFC piezoelectric element is shown in FIGS. 29A-29F. As shown, the piezoelectric material is diced in multiple directions, and the grooves formed by the dicing It can be made by filling with resin.

[0229] The bottom surface of the DFC piezoelectric element (e.g., sensing element 3030) is in contact with the top surface of the ground electrode ( For example, they are connected (step 4308) using the second conductive layer 3032.

[0230] The top surface of the DFC piezoelectric element is connected to the bottom surface of the positive electrode (e.g., first conductive layer 3028 ) (step 4310).

[0231] In some embodiments, the positive electrode is a polyimide film layer (e.g., a first polyimide The ground electrode is also covered with a polyimide film layer (e.g., a second polyimide film layer 3024). In some embodiments, the sensor is connected to a membrane layer 3036. It is coated with a copper layer (eg, copper layer 3038) configured to provide EMI shielding.

[0232] The fabricated sensor is coupled to a composite structure (step 4312). The outer surface of the composite structure facilitates intimate contact of the sensor with the composite structure. This can be smoothed to improve acoustic coupling and mechanical reliability of the bond line. As also described herein, the sensor may be configured to: The transition temperature (e.g., glass transition temperature T) at which a material changes from a solid to a plastic state. g ) or above. When heated, the DFC piezoelectric elements flex and bend to move the composite structure being monitored. The manufactured sensor is attached to the composite structure by applying an adhesive. The fabric may be automatically connected by any method or technique.

[0233] Although exemplary embodiments of the present method / system have been disclosed, they are for illustrative purposes only. Therefore, the terms used throughout should be read as limiting the present invention. Minor modifications to the teachings of this specification would be apparent to those skilled in the art. Although the scope of the present application will likely be determined by a patent if one is granted, Within the scope of the above, it is reasonable to consider that the invention falls within the category of innovation that the patent contributes to the technical field. All conceivable embodiments are encompassed within the scope of the appended claims and their equivalents. It should be understood that the present invention is not limited to the above-described configurations and combinations of two or more. Such combinations of features are not mutually exclusive. Unless otherwise specified, all of them are included within the scope of the present invention.

Claims

1. a composite cylinder coupled to said composite cylinder for detecting deformation data relating to said composite cylinder; a plurality of sensors configured as follows: a control unit communicatively connected to the plurality of sensors, When the composite cylinder is impact damaged, based on the detected deformation data, To calculate the damage value, and providing a notification if the damage value exceeds an impact damage threshold; A control unit configured as A filling control unit communicatively connected to the plurality of sensors, controlling a valve to fill the composite cylinder with fluid; and The deformations from the plurality of sensors are detected as the composite cylinder is filled with the fluid. detecting damage to the composite cylinder based on the data; and and automatically performing a safety action if damage to said composite cylinder is detected. 、 A filling control unit configured as follows: A monitoring system comprising:

2. 10. The system of claim 1, wherein the composite cylinder is a laminated structure made of multiple layers. the deformation data detected by the plurality of sensors is , which indicates damage to one or more layers of the system.

3. 3. The system according to claim 1, wherein the control unit further controls the composite material bolt. and determining direct wave energy from the object when the vessel sustains the impact damage. The control unit calculates the damage value based on the calculated direct wave energy. ,system.

4. 4. The system according to claim 3, wherein the control unit: digitizing the deformation data from the plurality of sensors; The direct arrival of the lowest velocity wave component from the impact position to each of the plurality of sensors In search of time, determining an estimated location of the impact location on the composite cylinder; The respective direct arrival times of the lowest velocity wave components at each sensor and The direct wave energy is calculated based on the detected voltage. The system determines the direct wave energy by:

5. 5. The system according to claim 1, wherein the filling control unit further comprises: When the composite cylinder is filled with the fluid, an acoustic emission monitor is a system configured to perform a radiological inspection to detect damage to the composite cylinder. Tem.

6. 6. The system according to claim 1, wherein the control unit transmits the notification. to the vehicle's ECU to illuminate a light indicating an inspection of the composite cylinder; and / or Alternatively, the notification may be made to a non-transient memory to store information about the composite cylinder. The system is configured to update the status of the

7. 7. The system according to claim 1, wherein the safety operation is performed by the valve closing the door to prevent filling of the composite cylinder, and / or or notifying the user on a display screen, and / or adjusting the valve to allow the fluid to flow. system, including leading to a surge tank.

8. 8. The system according to claim 1, wherein the filling control unit is When the fluid is filled into the cylinder, at least one indicator exceeds a respective predetermined threshold. and detecting damage to the composite cylinder based on the detected damage. Tem.

9. 10. The system of claim 8, wherein the at least one indicator comprises: a detected fiber trace; Fiber tow failure index, corresponding to the quantification of failure events and comparison with the fiber tow failure threshold; an instability index corresponding to an instability within a volume of material exceeding an instability threshold; a delamination event indicator corresponding to the delamination of one or more layers of a cylinder exceeding a delamination threshold; Damage corresponding to the damage mechanism accumulated in a given material volume exceeding the damage mechanism threshold and a mechanism index; and a laminate composition of the composite cylinder in which fretting emissions are measured. fretting emissions equivalent to exceeding the fretting emissions threshold based on a system comprising one or more of:

10. 10. The system according to claim 1, The sensors are formed by dicing the piezoelectric material in multiple directions. and a piezoelectric element having grooves formed therein, each of which is configured to follow the shape of the composite cylinder. a sensor, The grooves in the piezoelectric material are configured to change to a plastic state when heated above a threshold temperature. It is filled with resin that has been formed. The system wherein the piezoelectric material is located between a positive electrode and a ground electrode.

11. 11. The system of claim 10, wherein each piezoelectric sensor further comprises: a first polyimide film positioned below the ground electrode; and a second polyimide film positioned below the ground electrode. The system includes a membrane.

12. A plurality of sensors coupled to the composite cylinder collect deformation data about the composite cylinder. detecting the data; When the composite cylinder is impact damaged, the plurality of sensors are communicatively connected to the cylinder. determining a damage value based on the detected deformation data by the control unit; a step of notifying the controller when the damage value exceeds an impact damage threshold; A filling control unit communicably connected to the plurality of sensors controls a valve to filling the composite cylinder with a fluid; When the composite cylinder is filled with the fluid, the filling control unit detecting damage to the composite cylinder based on the deformation data from the sensor; 、 automatically performing a safety action if damage to the composite cylinder is detected; A method comprising:

13. 13. The method of claim 12, wherein the composite cylinder is a laminated structure made of multiple layers. the deformation data detected by the plurality of sensors is A method for indicating damage to one or more layers.

14. The method of claim 12 or 13, further comprising: The control unit determines whether the composite cylinder is directly damaged by an object when the composite cylinder is damaged by the impact. In the step of determining the indirect wave energy, the control unit determining the damage value based on A method comprising:

15. 15. The method of claim 14, wherein the step of determining the direct wave energy comprises: the substep of digitizing the deformation data from the plurality of sensors; The direct arrival of the lowest velocity wave component from the impact position to each of the plurality of sensors Sub-process to find the arrival time, a substep of determining an estimated location of the impact location on the composite cylinder; and The respective direct arrival times of the lowest velocity wave components at each sensor and A sub-step of determining the direct wave energy based on the detected voltage. A method comprising:

16. 16. The method of any one of claims 12 to 15, wherein the composite cylinder is The process of detecting damage to the composite cylinder when the fluid is being filled is performed by the filling control unit. and performing modal inspection of acoustic emissions using the plurality of sensors. A method including a sub-process.

17. 17. The method of any one of claims 12 to 16, wherein the damage value is the impact damage The step of notifying the user by the control unit when the threshold value is exceeded includes notifying the user by the control unit by transmitting the notification to an ECU of the vehicle. and / or The notification is performed in a non-transient memory to store the stored state of the composite cylinder. The method includes the substep of updating.

18. 18. The method of any one of claims 12 to 17, wherein the safety operation is performed by closing the cap to prevent further filling of the composite cylinder; and / or , by a speaker or a display screen, and / or by adjusting the valve. directing the fluid to a surge tank.

19. 19. The method of any one of claims 12 to 18, wherein the composite cylinder is The process of detecting damage to the composite cylinder as it is filled with fluid includes at least one finger. The method includes the substep of determining whether the targets exceed their respective predetermined thresholds.

20. 20. The method of claim 19, wherein the at least one indicator comprises: a detected fiber tow. Fiber tow failure index, which corresponds to the quantification of failure events and comparison with the fiber tow failure threshold; local material an instability index corresponding to an instability within the material volume exceeding an instability threshold; a delamination event indicator corresponding to the delamination of one or more layers of the cylinder exceeding a delamination threshold; The damage mechanism corresponding to the damage mechanism accumulated in the material volume exceeding the damage mechanism threshold is called the damage mechanism. and fretting emissions depending on the laminate composition of the composite cylinder. fretting emissions equivalent to exceeding the fretting emissions threshold based on and an index of the activity.

21. 1. A sensor for monitoring a composite structure, comprising: a first size configured to detect data related to a first monitoring task; a first sensor element; a second size configured to detect data related to a second monitoring task; a second sensor element; wherein the first sensor element includes a first positive electrode and the second sensor element includes a second positive electrode. wherein the first positive electrode is coplanar with the second positive electrode. 。

22. 22. The sensor of claim 21, wherein the first positive electrode has the first size; The second positive electrode has the second size, and the first positive electrode and the second positive electrode The polar electrodes have a first conductive layer on their lower surface configured to conduct electricity only along a vertical axis. configured to generate an electric current when placed under mechanical stress through the tape layer; connected to an active sensor having a size larger than the sum of the first size and the second size. The sensor.

23. 23. The sensor of claim 22, wherein the size of the first conductive tape layer is the sensor being larger than the sum of the first size and the second size.

24. 24. The sensor according to claim 22 or 23, wherein the lower surface of the active sensing element is a second conductive a tape layer, the tape layer being larger than the sum of the first size and the second size; The size of the ground electrode is connected to the top surface of the sensor.

25. 25. The sensor of claim 24, wherein the size of the second conductive tape layer is greater than the size of the first conductive tape layer. the sensor being larger than the sum of the first size and the second size.

26. 26. The sensor of claim 24 or 25, further comprising: a first polyimide film layer positioned above the first positive electrode and the second positive electrode; and a second polyimide film layer located below the ground electrode. A sensor comprising:

27. 27. The sensor of claim 26, further comprising: a first polyimide film layer positioned above the first polyimide film layer to block electromagnetic interference from the sensor; a copper layer configured to A sensor comprising:

28. 28. The sensor of claim 26 or 27, wherein the first polyimide film layer, the first the positive electrode, the second positive electrode, the first conductive tape layer, the active sensor, The second conductive tape layer, the ground electrode, and the second polyimide film layer are each made of flexible material. and configured to follow a surface to which the sensor is coupled.

29. 29. The sensor of any one of claims 21 to 28, wherein the composite structure is and the first monitoring task comprises: Direct wave energy from an object when the composite cylinder is impact damaged by the object and the second monitoring task is to detect whether the fluid is in the composite structure. A sensor for detecting damage to the composite cylinder as it is being filled.

30. 30. The sensor of claim 29, wherein the first sensor element detects the direct wave. and electrically connected to a controller configured to determine a damage value based on the energy. The second sensor element detects an acoustic signal when the composite cylinder is filled with the fluid. Modal testing of electrical emissions was performed to detect damage to the composite cylinder. The sensor is electrically connected to a control unit configured in the

31. 1. A method of manufacturing a sensor, comprising: A first positive electrode having a first size and a second positive electrode having a second size are fabricated. a manufacturing process; A ground electrode having a size larger than the sum of the first size and the second size. A process of making A piezoelectric material is disposed between the layer consisting of the first positive electrode and the second positive electrode and the ground electrode. placing the material; A method comprising:

32. 32. The method of claim 31 further comprising: connecting a bottom surface of the piezoelectric material to a top surface of the ground electrode using conductive tape; Using z-axis anisotropic tape, the top surface of the piezoelectric material is connected to both bottom surfaces of the positive electrodes. and A method comprising:

33. 33. The method of claim 31 or 32, further comprising: a first polyimide film layer is connected above the first positive electrode and the second positive electrode; The process and connecting a second polyimide film layer below the ground electrode; A method comprising:

34. 34. The method of any one of claims 31 to 33, The step of fabricating the first positive electrode includes forming the first positive electrode using a flexible substrate material. A sub-assembly that makes the electrode flexible so that it can follow the surface to which the sensor is connected. Including the process, The step of fabricating the second positive electrode includes forming the second positive electrode using a flexible substrate material. A sub-assembly that makes the electrode flexible so that it can follow the surface to which the sensor is connected. Including the process, The step of fabricating the ground electrode includes using a flexible substrate material to make the ground electrode flexible. and a sub-step of forming the sensor so as to conform to the surface to which the sensor is connected. Law.

Images