In one embodiment, a sensor network is attached to a structure and employed to detect and analyze load changes such as impacts from projectiles. An analyzer coupled to the sensors can determine where on the structure the projectile impacted. Coupled with information on the origin point of the projectile, i.e. where it was fired from, the analyzer can then estimate the trajectory of the projectile. The analyzer can also determine whether the projectile passed through the structure and, if so, can extrapolate the estimated trajectory to determine an estimation of whether the projectile has also impacted an object behind the structure.
F41H 13/00 - Moyens d'attaque ou de défense non prévus ailleurs
F41J 5/056 - Actionnement des commutateurs ou des contacts par les vibrations mécaniques du corps de la cible, créées par l'impact d'un projectile, p. ex. utilisant des transducteurs de choc ou de vibrations
G01L 5/14 - Appareils ou procédés pour la mesure des forces, du travail, de la puissance mécanique ou du couple, spécialement adaptés à des fins spécifiques pour la mesure de la force des explosionsAppareils ou procédés pour la mesure des forces, du travail, de la puissance mécanique ou du couple, spécialement adaptés à des fins spécifiques pour la mesure de l'énergie des projectiles
G01L 1/14 - Mesure des forces ou des contraintes, en général en mesurant les variations de la capacité ou de l'inductance des éléments électriques, p. ex. en mesurant les variations de fréquence des oscillateurs électriques
G01L 5/00 - Appareils ou procédés pour la mesure des forces, du travail, de la puissance mécanique ou du couple, spécialement adaptés à des fins spécifiques
09 - Appareils et instruments scientifiques et électriques
Produits et services
structural health monitoring products, namely, sensors, detectors, and downloadable computer software for the evaluation of structural integrity for the automotive, aviation, aerospace, naval, and construction industries
4.
System and method for monitoring the structural health of coupled bearings
Placement of structural health monitoring sensors within a coupled bearing assembly. An exemplary structural health monitoring system comprises first and second bearings configured for rotatable positioning along a structure, and a spacer positioned between the first and second bearings. The first and second bearings are placed against opposing sides of the spacer, and have a preload force engaging the respective first and second bearings against the opposing sides of the spacer. A plurality of sensors are coupled to the spacer so as to be positioned between the spacer and at least one of the first and second bearings, the sensors further coupled to at least one of the first and second bearings so as to be configured to monitor a structural health of the at least one of the first and second bearings.
A structural health monitoring system comprises a first set of sensors operable for coupling to a structure positioned under ground, the first set of sensors further configured to detect an impact upon the structure while the first set of sensors is positioned under the ground; a second set of sensors operable to be positioned on or proximate to a surface of the ground, the second set of sensors further configured to detect an audible event occurring at a distance from the second set of sensors and the structure; and a computer readable memory storing one or more audio signatures that may correspond to the audible event.
A structural health monitoring system comprises: a flexible substrate configured for attachment to a structure, the flexible substrate having a plurality of sensors affixed thereon. The flexible substrate comprises a first portion configured for attachment to the structure, a second portion extending in continuous manner from the first portion, and a third portion extending in continuous manner from the second portion and being configured for attachment to the structure. The second portion includes a first section extending in continuous manner from the first portion, a second section connected between the first section and the third portion and having an edge extending in a direction different from an edge of the first section.
A structural health monitoring apparatus is presented. According to an embodiment, the structural health monitoring apparatus comprises: a plurality of transducers configured for coupling to a structure, the structure comprising an outer structure surrounding and coupled to an inner structure, the transducers further configured for coupling to only the outer structure so as to transmit stress waves through the inner structure, and still further configured to receive the transmitted stress waves from the outer structure after they have passed through the inner structure; and an analyzer configured to detect damage within the inner structure according to the received transmitted stress waves from the outer structure.
G01N 29/48 - Traitement du signal de réponse détecté par comparaison d'amplitude
G01N 29/265 - Dispositions pour l'orientation ou le balayage en déplaçant le capteur par rapport à un matériau fixe
G01N 29/22 - Recherche ou analyse des matériaux par l'emploi d'ondes ultrasonores, sonores ou infrasonoresVisualisation de l'intérieur d'objets par transmission d'ondes ultrasonores ou sonores à travers l'objet Détails
Methods and apparatuses for monitoring a first structure at least partially according to properties of a second structure. One such method comprises determining a first relationship between a first variable and a second variable, wherein the first variable represents sizes of actual damage to the second structure, and the second variable represents sizes of simulated damage on the second structure; determining a second relationship between a third variable and a fourth variable, wherein the third variable represents sizes of simulated damage on the first structure, and the fourth variable represents values of a damage index determined for the simulated damage on the first structure; and determining an estimate of damage to the first structure according to the first and second relationships.
A structural health monitoring system capable of maintaining electrical contact with sensors affixed to a rotating structure. One such structural health monitoring system comprises a rotatable structure, a plurality of sensors each affixed to the rotatable structure, and an interface. The interface has an inner housing and an outer housing, and maintains a plurality of individual electrical connections, each of the individual electrical connections being an electrical connection between one of the sensors and an electrical contact maintained on the outer housing, the electrical connections configured to be maintained during rotation of the structure. The inner housing is affixed to the structure and the outer housing is rotationally coupled to the inner housing, so that the inner housing is free to rotate with respect to the outer housing during rotation of the structure and the sensors, while maintaining the electrical connections.
G01N 29/22 - Recherche ou analyse des matériaux par l'emploi d'ondes ultrasonores, sonores ou infrasonoresVisualisation de l'intérieur d'objets par transmission d'ondes ultrasonores ou sonores à travers l'objet Détails
G01N 29/27 - Dispositions pour l'orientation ou le balayage en déplaçant le matériau par rapport à un capteur fixe
10.
System and method for monitoring the structural health of coupled bearings
Placement of structural health monitoring sensors within a coupled bearing assembly. An exemplary structural health monitoring system comprises first and second bearings configured for rotatable positioning along a structure, and a spacer positioned between the first and second bearings. The first and second bearings are placed against opposing sides of the spacer, and have a preload force engaging the respective first and second bearings against the opposing sides of the spacer. A plurality of sensors are coupled to the spacer so as to be positioned between the spacer and at least one of the first and second bearings, the sensors further coupled to at least one of the first and second bearings so as to be configured to monitor a structural health of the at least one of the first and second bearings.
A structural health monitoring system using ASICs for signal transmission, reception, and analysis. Incorporating structural health monitoring functionality into one or more ASICs provides a durable yet small, lightweight, low cost, and portable system that can be deployed and operated in field conditions. Such systems provide significant advantages, especially in applications such as armor structures.
A trigger circuit for use with a structural health monitoring system. To save power, a structural health monitoring system is programmed with a sleep mode and a wake, or operational, mode. In its operational mode, the structural health monitoring system can perform its usual tasks, e.g. monitoring a structure and determining its structural health. In sleep mode, many functions are suspended, so that the system requires less power. The trigger circuit wakes the system when the sensors of the structural health monitoring system emit a sufficiently large signal, i.e. when an event occurs. That is, when not in use, the system enters sleep mode, and when some event occurs (e.g., impact, or some other stresses that are of concern), the trigger circuit alerts the system, prompting it to shift from sleep mode to operational mode and to begin taking/analyzing data.
G01B 5/28 - Dispositions pour la mesure caractérisées par l'utilisation de techniques mécaniques pour mesurer la rugosité ou l'irrégularité des surfaces
13.
Input-protected structural health monitoring system
A structural health monitoring (SHM) system that protects its active and passive components with filter circuits, instead of switches. The active module of the SHM system utilizes a high pass filter, and the passive module of the SHM system utilizes a low pass filter. The active module transmits its interrogating, or excitation, signals at relatively high frequencies that are filtered out by the low pass filter of the passive module, preventing the passive module from sustaining any damage due to the high voltage excitation signals. Meanwhile, the high frequency interrogating signals are passed to the active module's circuitry by its high pass filter, where they can be analyzed accordingly.
G01B 3/44 - Calibres à mâchoire ouverte et faces opposées, c.-à-d. compas à calibrer, où la distance interne entre les faces est fixe, mais peut être réglée à l'avance du type calibre à limitation, c.-à-d. calibres à tolérances maxima et minima réglables à l'avance pour l'usure et les tolérances
A self-sufficient structural health monitoring system that can monitor a structure without need for external power input. Embodiments of the invention provide a structural health monitoring system with a power supply integrated within, so that the system relies on itself for operational power. Systems with such an on-board electrical power source, independent of an external power source (and in particular, independent of the power system(s) of the structure being monitored), are much more self-contained and self-sufficient.
G01B 3/44 - Calibres à mâchoire ouverte et faces opposées, c.-à-d. compas à calibrer, où la distance interne entre les faces est fixe, mais peut être réglée à l'avance du type calibre à limitation, c.-à-d. calibres à tolérances maxima et minima réglables à l'avance pour l'usure et les tolérances
15.
Method and apparatus for estimating damage in a structure
Detecting damage in a structure without comparing sensor signals to a baseline signal. Once a structure is interrogated, a process based on a Gaussian Mixture Model is applied to the resulting data set, resulting in quantities for which Mahalanobis distances and Euclidian distances can be determined. A damage index is then determined based on the calculated Euclidian distance. A high value of this damage index coupled with an abrupt change in Mahalanobis distance has been found to be a reliable indicator of damage. Other embodiments may employ a baseline, but determine damage according to ratios of energy values between current and baseline signals.
G01B 3/44 - Calibres à mâchoire ouverte et faces opposées, c.-à-d. compas à calibrer, où la distance interne entre les faces est fixe, mais peut être réglée à l'avance du type calibre à limitation, c.-à-d. calibres à tolérances maxima et minima réglables à l'avance pour l'usure et les tolérances
16.
Integrated circuit system for controlling structural health monitoring processes and applications therefor
A structural health monitoring system using ASICs for signal transmission, reception, and analysis. Incorporating structural health monitoring functionality into one or more ASICs provides a durable yet small, lightweight, low cost, and portable system that can be deployed and operated in field conditions. Such systems provide significant advantages, especially in applications such as armor structures.
Storage of information, such as baseline information and structure ID, in a memory that is mounted on the structure, rather than inside the diagnosis hardware. This allows for faster and more convenient information retrieval. In particular, this approach allows for a more modular system in which different diagnosis hardware or other analyzers can be simply plugged into a structure's sensor network, whereupon they can quickly download any desired structure-specific information (e.g., baseline information, structure ID, and other useful information) from the on-structure memory.
G06F 19/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des applications spécifiques (spécialement adaptés à des fonctions spécifiques G06F 17/00;systèmes ou méthodes de traitement de données spécialement adaptés à des fins administratives, commerciales, financières, de gestion, de surveillance ou de prévision G06Q;informatique médicale G16H)
18.
Method and apparatus for loosening of fasteners on structures
Methods and apparatuses for detecting fastener loosening. Sensors query a structure at a baseline value of an environment variable, such as temperature, and this baseline signal is stored for later use. Subsequently, users can query the structure remotely and at any time, and the signals from these queries are compared to the stored baseline signal. In some embodiments, an index is calculated, and the system determines that one or more fasteners have come loose if the calculated index exceeds a predetermined threshold value. It is desirable to select a time window within which the query signal is most sensitive to fastener loosening but least sensitive to variations in the environment variable. Accordingly, embodiments of the invention include methods and apparatuses for determining an optimal time window for use in calculating the above described index.
G01N 29/14 - Recherche ou analyse des matériaux par l'emploi d'ondes ultrasonores, sonores ou infrasonoresVisualisation de l'intérieur d'objets par transmission d'ondes ultrasonores ou sonores à travers l'objet utilisant des techniques d'émission acoustique
19.
Method and apparatus for conducting structural health monitoring in a cryogenic, high vibration environment
Sensors affixed to various such structures, where the sensors can withstand, remain affixed, and operate while undergoing both cryogenic temperatures and high vibrations. In particular, piezoelectric single crystal transducers are utilized, and these sensors are coupled to the structure via a low temperature, heat cured epoxy. This allows the transducers to monitor the structure while the engine is operating, even despite the harsh operating conditions. Aspects of the invention thus allow for real time monitoring and analysis of structures that operate in conditions that previously did not permit such analysis. A further aspect of the invention relates to use of piezoelectric single crystal transducers. In particular, use of such transducers allows the same elements to be used as both sensors and actuators.
G01N 29/14 - Recherche ou analyse des matériaux par l'emploi d'ondes ultrasonores, sonores ou infrasonoresVisualisation de l'intérieur d'objets par transmission d'ondes ultrasonores ou sonores à travers l'objet utilisant des techniques d'émission acoustique
20.
Method and apparatus for detecting damage in armor structures
Detection of damage in armor structures, using networks of piezoelectric transducers. In particular, piezoelectric transducers can be placed at various points on the armor structure, effectively creating a number of paths between pairs of transducers. Each of these paths can be queried by transmitting an ultrasonic stress wave from one transducer to the other, and analyzing changes in the stress wave. The signal from the received stress wave can be time gated to remove crosstalk, and the resulting time gated signal can be analyzed for characteristics of damage. For instance, if the time gated signal is sufficiently attenuated, it can be determined that the armor structure has sustained damage to at least that region traversed by this particular path.
G01B 5/28 - Dispositions pour la mesure caractérisées par l'utilisation de techniques mécaniques pour mesurer la rugosité ou l'irrégularité des surfaces
G01M 3/00 - Examen de l'étanchéité des structures ou ouvrages vis-à-vis d'un fluide
21.
Generating damage probability-of-detection curves in structural health monitoring transducer networks
A method for automatically creating a probability of detection (POD) curve of an entire network of transducers monitoring and detecting damage in a structure is based on the POD of each of the individual actuator-sensor paths. These individual path PODs may be generated in different ways, such as by experimentation or simulation. This technique makes it possible to create the POD curve of a structural health monitoring (SHM) system for the detection of damages in structures.
A method and system of compensating for environmental effect when detecting signals using a structural health monitoring system includes collecting baseline data signals for one or more values of the environmental effect variable from signals transmitted along selected paths between transducers in an array attached to the structure. A threshold is selected based on the baseline data for determining if the signal is detected. Current data signals are collected and matched to the best fit baseline data. The value of the environmental effect variable is determined on the basis of the matching. A signal is detected according to the selected threshold.
G01H 17/00 - Mesure des vibrations mécaniques ou des ondes ultrasonores, sonores ou infrasonores non prévue dans les autres groupes de la présente sous-classe
G06F 19/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des applications spécifiques (spécialement adaptés à des fonctions spécifiques G06F 17/00;systèmes ou méthodes de traitement de données spécialement adaptés à des fins administratives, commerciales, financières, de gestion, de surveillance ou de prévision G06Q;informatique médicale G16H)
G06F 17/40 - Acquisition et consignation de données
A method of improving damage detection in a structural health monitoring system includes obtaining a baseline set of signals corresponding to a range of values of an environmental effect variable for a plurality of first selected paths between pairs of a plurality of transducers configured in an array attached to a structure. Threshold levels are established for each of the selected paths for determining detection of damage in the structure based on differences in the baseline set of signals for the selected path. A current signal is acquired for each of the selected paths. The plurality of current signals are analyzed based on the threshold levels to detect damage in the structure.
G01R 31/00 - Dispositions pour tester les propriétés électriquesDispositions pour la localisation des pannes électriquesDispositions pour tests électriques caractérisées par ce qui est testé, non prévues ailleurs
24.
Transducer array self-diagnostics and self-healing
A method of performing transducer self-diagnostics and self-healing on an array of sensor transducers bonded to a structure for health monitoring includes measuring impedance to detect whether a transducer is missing, or a connection is damaged. Pitch-catch signals generated between one or more pairs of transducers are analyzed for detecting defects according to selected criteria of defect size and location to determine whether the sensors are damaged or partially/fully disbonded. Based on the resulting map of operational transducers, signal transmission paths are added/extended between additional pairs of transducers to maintain inspection coverage of the structure according to the selected criteria.
G01C 25/00 - Fabrication, étalonnage, nettoyage ou réparation des instruments ou des dispositifs mentionnés dans les autres groupes de la présente sous-classe
G01R 15/00 - Détails des dispositions pour procéder aux mesures des types prévus dans les groupes , ou
G01R 31/00 - Dispositions pour tester les propriétés électriquesDispositions pour la localisation des pannes électriquesDispositions pour tests électriques caractérisées par ce qui est testé, non prévues ailleurs
G01N 29/00 - Recherche ou analyse des matériaux par l'emploi d'ondes ultrasonores, sonores ou infrasonoresVisualisation de l'intérieur d'objets par transmission d'ondes ultrasonores ou sonores à travers l'objet
Methods and apparatus for extracting the first arrival wave packet of an acoustic signal in a structural health monitoring (SHM) system include receiving an acoustic signal transmitted between two transducers thereof. Electromagnetic cross-talk is removed from the signal. Signal amplitude threshold values used for picking out the first arrival wave packet are chosen based on signal characteristics or chosen adaptively as the value that leads to the minimum variance of the group velocity estimates of all the actuation-sensing transducer pairs. The group velocity is estimated as the known actuator-sensor distance divided by the propagation time of the first wave packet of which the envelope exceeds a candidate threshold value. The first arrival wave packet is determined as the signal segment where the signal envelope first exceeds the chosen amplitude threshold and the segment length exceeds a specified threshold of time width.
A method for determining optimal locations of a plurality of sensors for damage detection in a structural health monitoring system includes providing a one or more signal performance characteristics, spatial parameters describing a layout of a structure, and generating a layout for the plurality of sensors according to the signal performance characteristics and the spatial parameters. An estimated largest critical damage size that may not be detected by sensors arranged according to the first layout is determined. The layout is edited so as to reduce the estimated largest critical damage size to be less than or equal to a selected maximum size requirement.
G01B 5/28 - Dispositions pour la mesure caractérisées par l'utilisation de techniques mécaniques pour mesurer la rugosité ou l'irrégularité des surfaces
G06F 19/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des applications spécifiques (spécialement adaptés à des fonctions spécifiques G06F 17/00;systèmes ou méthodes de traitement de données spécialement adaptés à des fins administratives, commerciales, financières, de gestion, de surveillance ou de prévision G06Q;informatique médicale G16H)
27.
Detectable defect size and probability-of-detection
Predicting the probability of detection of major and minor defects in a structure includes simulating a plurality of N defects at random locations in a region specified by an array of transducers. Defect size is incremented until it intersects one path between two transducers. The defect size is again incremented until it intersects two or more adjacent paths between pairs of transducers. The number of major defects up to a selected size is determined by the total number of single path intersections by defects up to the selected size. The number of minor defects up to a selected size is determined on the basis of the total number of defects intersecting two or more paths up to the selected size. The probability of detection up to a selected size is the cumulative number of major or minor defects up to the selected size normalizing by N.
A method for calculating the probable damage size in a structure includes defining a configuration of an array of transducers mounted on the structure. Any pair of the transducers includes an actuator and a sensor, and each pair defines a propagation path in the structure. All propagation paths that are affected by being touched by a damage of the structure, and all adjacent paths that are untouched and thereby unaffected by the damage, are identified. A range of sizes of the damage is determined, and a probability density of the damage versus damage size is calculated on the basis of the transducer array configuration and the affected and unaffected propagation paths identified. On the basis of the probability density, a most probable damage size is determined, and the probability of the damage being greater or less than the most probable damage size is also determined.
G06F 19/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des applications spécifiques (spécialement adaptés à des fonctions spécifiques G06F 17/00;systèmes ou méthodes de traitement de données spécialement adaptés à des fins administratives, commerciales, financières, de gestion, de surveillance ou de prévision G06Q;informatique médicale G16H)
30.
Functional actuator-sensor path optimization in structural health monitoring system
A method for optimizing transducer performance in an array of transducers in a structural health monitoring system includes specifying a plurality of paths between pairs of the transducers on a monitored structure and evaluating the quality of signal transmissions along the paths so as to optimize the gain and frequency operating condition of the transducers.
G01N 9/24 - Recherche du poids spécifique ou de la densité des matériauxAnalyse des matériaux en déterminant le poids spécifique ou la densité en observant la propagation de l'onde ou de la radiation des particules à travers le matériau
31.
Dynamic environmental change compensation of sensor data in structural health monitoring systems
A method for adjusting signal data detected in a structural health monitoring (SHM) system to compensate for the effects of environmental variables acting thereon includes constructing a baseline data space comprised of sets of signal data. Current signal data sets are collected for comparison to the baseline data space. The collected current signal data sets are amended to best match baseline signal data sets in the baseline data space. A set of indices are computed for comparing the amended current signal data set to the baseline signal data sets. A threshold for detection is determined by outlier detection for the computed indices. A signal in the collected signal data set is determined to be detected on the basis of the threshold. A representation of the detected signal strength is provided on the basis of the computed indices.
09 - Appareils et instruments scientifiques et électriques
Produits et services
Electronic inspection device consisting of thin dielectric film with embedded actuators and sensors, for monitoring structural health of metal, concrete or composite structures
33.
Method and apparatus for reducing crosstalk in a structural health monitoring system
Methods and apparatus for reducing crosstalk in a structural health monitoring system. A pair of actuator input signals are sent to an actuator, each resulting in the transmission of stress waves to a corresponding sensor. The sensor then converts these stress waves to a pair of output signals, each having a crosstalk portion due to electromagnetic interference from the input signals to the actuator, and a stress wave portion corresponding to the stress waves. Various methods of varying the actuator input signals, the input to the actuator, and the output of the sensor result in two output signals that can be combined so as to reduce the crosstalk portions and isolate the stress wave portions. This allows actuators and sensors to be placed sufficiently close together that the stress wave portions of sensor output signals can overlap their crosstalk, without corrupting or otherwise compromising the data contained therein.
Use of a single line for switching multiple monitoring elements on/off, and a single line for sending signals to, or receiving signals from, those elements that are switched on. Monitoring elements each have an associated switching element, and each switching element is connected to a common switching line, or control line. A signal from the control line turns each switch on or off. Each monitoring element is also connected to a single signal line, and only those monitoring elements that are turned on can transmit/receive data signals along this signal line.
09 - Appareils et instruments scientifiques et électriques
Produits et services
Structural Health Monitoring Hardware, namely, scanner for the evaluation of structural integrity applicable in the automotive, aviation, aerospace, naval, energy, and construction industries
