Acellent Technologies, Inc.

Samsung Electronics Co., Ltd.

The Boeing Company

Xinlin Qing

Shawn J Beard

Chang Zhang

Irene Li

Fu-Kuo Chang

Hung Chi Chung

Zengpin Yu

Matthew C Malkin

Lien Ouyang

Tom Chang

Hian Leng Chan

Fuo-Kuo Chang

Sourav Banerjee

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.

Transducer array self-diagnostics and self-healing

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.

Structural health monitoring system having integrated power supply

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.

Method and apparatus for estimating damage in a structure

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.

Integrated circuit system for controlling structural health monitoring processes

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.

Method and apparatus for conducting structural health monitoring in a cryogenic, high vibration environment

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.

Optimal sensor location for damage detection

Integrated circuit system for controlling structural health monitoring processes and applications therefor

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.

Structural health monitoring system having memory on structure

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.

Method and apparatus for reducing crosstalk in a structural health monitoring system

An apparatus for establishing a substantially unitary connecting structure including a generally flat conductor member carrying a first plurality of first electrical conductors and a second conductor member carrying a second plurality of second electrical conductors includes: (a) an electrical connecting structure configured for receiving the second conductor member to establish electrical connection between at least one first electrical conductor of the first plurality of first electrical conductors and at least one second electrical conductor of the second plurality of second electrical conductors; (b) a generally inflexible support structure; and (c) at least one connecting member traversing the flat conductor member and cooperating with the electrical connecting structure and the support structure for capturing the flat conductor member between the connecting structure and the support structure in an installed orientation.

Method and apparatus and method for connecting a first flat conductor with a second conductor

A sensor network is attached to a structure and employed to detect and analyze load changes. The sensor network has transducers, capable of acting as both passive sensors and active actuators, integrated within it. In a passive mode, the transducers detect load changes upon the structure, such as impacts. Upon detection of a load change, the transducers are engaged in an active mode to actively scan the impact area to determine the location and size of any resulting damage region. In this manner, passive and active systems are integrated within a single, convenient layer that possesses the best features of both active systems and passive systems.

Method and apparatus for detecting a load change upon a structure and analyzing characteristics of resulting damage

A method for both detecting and analyzing a change in the loading condition of a structure. A flexible substrate is employed, in which a distributed network of sensors is built. This substrate is either affixed to the surface of the structure, or built within it, so as to be able to detect propagating stress waves. After load change is detected, the resulting sensor signals are analyzed to determine the location, severity, and/or any characteristic frequencies of the load change. This information is then used to determine an appropriate response.

Method of detecting and analyzing changes in the external loading conditions of a structure

Methods of manufacturing a diagnostic layer containing an array of sensing elements. The sensing elements, associated wires, and any accompanying circuit elements, are incorporated various layers of a thin, flexible substrate. This substrate can then be affixed to a structure so that the array of sensing elements can analyze the structure in accordance with structural health monitoring techniques. The substrate can also be designed to be incorporated into the body of the structure itself, such as in the case of composite structures.

Method of manufacturing a structural health monitoring layer

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.

Method and apparatus for switching among elements of a structural health monitoring system

A sensor/actuator network configured with a number of electrically-interconnected elements. More specifically, the sensors/actuators are each placed in electrical communication with the same transmission line. Various embodiments of such networks employ sensors/actuators connected in electrical series and in electrical parallel. Networks having these configurations, when placed upon a structure, are capable of detecting and/or transmitting stress waves within the structure so as to detect the presence of an impact, or actively query the structure. Advantageously, as these networks employ a single transmission line, they utilize fewer wires than current sensor/actuator networks, thus making them easier to install and maintain. They can also be configured as flexible layers, allowing for further ease of installation and maintenance.

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Cupertino, CA, United States of America

Xinlin Qing