摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A sensor array embedded within a flexible layer. The sensors, which can be transducers, are controlled by local electronics also embedded within the flexible layer. The invention includes numerous different arrangements of these electronic controllers and their associated transducers. For example, each transducer can have its own controller embedded nearby. Alternatively, one controller can control a number of transducers, and can therefore be embedded in various configurations proximate to one or more of the transducers it controls. The controllers can include various components that impart other advantages, such as wireless transceivers for reducing the number of wires needed within the flexible layer, and local processors for reducing or eliminating the need for a remote data processor.
摘要:
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.
摘要:
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.
摘要:
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 IS0 and IA0 for each of the matched extracted current and baseline signal components based on respective signal energies thereof, and determining the presence of a damage in the structure if either of the indices IS0 and IA0 of a plurality of neighboring sensor paths of the structure is greater than a selected threshold value.
摘要:
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.
摘要:
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 IS0 and IA0 for each of the matched extracted current and baseline signal components based on respective signal energies thereof, and determining the presence of a damage in the structure if either of the indices IS0 and IA0 of a plurality of neighboring sensor paths of the structure is greater than a selected threshold value.