| Patent application number | Description | Published |
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| 20080255774 | 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. | 10-16-2008 |
| 20080255775 | ENVIRONMENTAL CHANGE COMPENSATION IN A STRUCTURAL HEALTH MONITORING SYSTEM - 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. | 10-16-2008 |
| 20080255778 | DETECTING DAMAGE IN METAL STRUCTURES WITH STRUCTURAL HEALTH MONITORING SYSTEMS - A method useful in structural health monitoring (SHM) systems for detecting damages in metal structures includes extracting the zero-order symmetric and anti-symmetric mode signal components from each of a plurality of current sensor signals of an array of transducers mounted on the structure, matching the extracted signal components with corresponding signal components of a plurality of baseline sensor signals previously detected in the structure, computing respective indices I | 10-16-2008 |
| 20080255804 | 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. | 10-16-2008 |
| 20090043516 | 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. | 02-12-2009 |
| 20090071078 | INTEGRATED FASTENER-SENSOR ARRANGEMENT - Characteristics of a multi-layer structure are detected, such as for detecting mechanical and/or corrosive damage of the multi-layer structure. In an example embodiment, an integrated in-situ sensor device senses characteristics of a multi-layer structure during operation thereof. The device includes a mechanical coupler and a sensor circuit. The mechanical coupler couples layers of the multi-layer structure together via an opening traversing the multi-layer structure. The sensor circuit inserts into the opening with the mechanical coupler, and induces an electrical response in a portion of the multi-layer structure adjacent the opening. This induced electrical response is indicative of characteristics of the multi-layer structure, and is sensed to provide a signal characterizing characteristics of the multi-layer structure. | 03-19-2009 |
| 20090276168 | 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. | 11-05-2009 |
| 20100161283 | STRUCTURAL HEALTH MONITORING NETWORK - A networked configuration of structural health monitoring elements. Monitoring elements such as sensors and actuators are configured as a network, with groups of monitoring elements each controlled by a local controller, or cluster controller. A data bus interconnects each cluster controller with a router, forming a networked group of “monitoring clusters” connected to a router. In some embodiments, the router identifies particular clusters, and sends commands to the appropriate cluster controllers, instructing them to carry out the appropriate monitoring operations. In turn, the cluster controllers identify certain ones of their monitoring elements, and direct them to monitor the structure as necessary. Data returned from the monitoring elements is sent to the cluster controllers, which then pass the information to the router. Other embodiments employ multiple sensor groups directly connected to a central controller, perhaps with distributed local control elements. Methods of operation are also disclosed. | 06-24-2010 |
| 20110035167 | 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. | 02-10-2011 |
| 20110040496 | 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. | 02-17-2011 |
| 20110042832 | EXTENDABLE CONNECTOR AND NETWORK - Extendable connectors are facilitated. According to an example embodiment, an integrated electrical circuit uses a connector that has first and second connected ends. The connector is unbundled from an initial state in which the first and second connected ends are separated by a first proximate distance and applied in an extended state in which the first and second connected ends are separated by a second distance that is greater than the first proximate distance. | 02-24-2011 |
