In Situ Wire Damage Detection and Rerouting System
electrical and electronics
In Situ Wire Damage Detection and Rerouting System (KSC-TOPS-6)
A miniaturized and highly efficient wire damage detection system
Overview
NASA Kennedy Space Center seeks partners interested in the commercial application of the In Situ Wire Damage Detection and Rerouting System. NASA is soliciting licensees for this innovative technology. The In Situ Wire Damage Detection and Rerouting System consists of a miniaturized inline connector containing self-monitoring electronics that use time domain reflectometry (TDR) to detect wire faults and determine fault type and fault location on powered electrical wiring. When a damaged or defective wire is identified, the system is capable of autonomously transferring electrical power and data connectivity to an alternate wire path. When used in conjunction with NASAs wire constructions that use a conductive detection layer, the system is capable of detecting and limiting damage not only to the core conductor, but also to the insulation layer before the core conductor becomes compromised.
The Technology
The tester was designed to monitor electrical faults in either online or offline modes of operation. In the online mode, wires are monitored without disturbing their normal operation. A cable can be monitored several times per second in the offline mode, and once per second in the online mode. The online cable fault locator not only detects the occurrence of a fault, but also determines the type of fault (short/open/intermittent) and the location of the fault. This enables the detection of intermittent faults that can be repaired before they become serious problems. Since intermittent faults occur mainly during operations, a built-in memory device stores all relevant fault data. This data can be displayed in real time or retrieved later so maintenance and repairs can be completed without spending countless hours attempting to pinpoint the source of the problem.
Hardware and algorithms have also been developed to safely, efficiently, and autonomously transfer electrical power and data connectivity from an identified damaged/defective wire in a cable to an alternate wire path. This portion of the system consists of master and slave units that provide the diagnostic and rerouting capabilities. A test pulse generated by the master unit is sent down an active wire being monitored by the slave unit. When the slave unit detects the test pulse, it routes the pulse back to the master unit through a communication wire. When the master unit determines that a test pulse is not being returned, it designates that wire as faulty and reroutes the circuit to a spare wire.
Benefits
- Online operation - system can be used while wires are powered and operational, making it possible to locate intermittent faults that occur only while wires are in use
- Nonintrusive - faults are monitored in the background, using very low power signals that do not disrupt normal circuit operation
- Intelligent - pattern recognition algorithms autonomously identify the type and location of a fault without operator intervention
- Intuitive - an easy-to-understand graphical user interface displays the reflected waveforms and provides information on the type of fault and its distance fromthe test signal injection point
- Flexible - system is capable of monitoring up to 64 individual wires on a cable
- Simultaneously in online or offline mode
Applications
- Aerospace wiring
- Marine wiring
- Automotive wiring
- Industrial wiring
- Smart grid wiring
Similar Results
Multidimensional Damage Detection System
The Damage Detection System consists of layered composite material made up of two-dimensional thin film damage detection layers separated by thicker, nondetection layers, coupled with a detection system. The damage detection layers within the composite material are thin films with a conductive grid or striped pattern. The conductive pattern can be applied on a variety of substrates using several different application methods. The number of detection layers in the composite material can be tailored depending on the level of damage detection detail needed for a particular application. When damage occurs to any detection layer, a change in the electrical properties of that layer is detected and reported. Multiple damages can be detected simultaneously, providing real-time detail on the depth and location of the damage.
The truly unique feature of the System is its flexibility. It can be designed to gather as much (or as little) information as needed for a particular application using wireless communication. Individual detection layers can be turned on or off as necessary, and algorithms can be modified to optimize performance. The damage detection system can be used to generate both diagnostic and prognostic information related to the health of layered composite structures, which will be essential if such systems are utilized to protect human life and/or critical equipment and material.
Polyimide Wire Insulation Repair System
A major limitation of current aerospace wire insulation is that it tends to crack and fray as it ages and is easily damaged. Generally, it is more cost-effective to repair wire insulation than to replace a section of the wire (or bundle) itself. Current repair methods include a tape wrap repair and a heat shrink repair. These methods have a number of drawbacks: susceptibility to vibration, fluid intrusion, and other mechanical stresses. The repair patch/material can loosen or separate, exposing the bare metal conductor or opening the polyimide insulation to more damage at the interface.
The technology developed by KSC is a flexible polyimide film patch (either wrap or sleeve) that is heated with a custom heating tool to melt, flow, and cure the film. The new technology results in hermetically sealed, permanent repairs that are much more flexible and less intrusive than repairs made using current practices. The repair remains flexible after application, has no limit in length or bend radius, and retains the high-temperature exposure of the original polyimide insulation. Extensive testing by NASA and NAVAIR has demonstrated that these repairs comply with industry standards for tensile strength, electrical resistivity, voltage breakdown, solvent resistance, and flammability. This system is adaptable and may also be used on larger-gauge wiring, as well as flat-ribbon wire harnesses and twisted shielded wires.
Directional UAV Localization of Power Line Ultraviolet Corona
This technology comprises a novel system of detecting, inspecting and analyzing a corona discharge using an ultra-violet camera. It is useful for a number of potential applications, most notably, power line fault detection. The most novel feature is that it uses UV instead of IR which has been problematical for corona discharge detection because there is too much interference from other sources. UV detection offers images that isolate the location of the corona discharge with far greater precision.
Damage and Tamper Detection Sensor System
The SansEC sensor system consists of multiple pairs of inductor-capacitor sensors with no electrical connections, which are placed throughout the material being monitored for damage. The sensors are embedded in or placed directly onto the surface of the material. Strains and breaks are detected by changes in resonant frequency read by the accompanying magnetic field data acquisition system. When pulsed by a sequence of magnetic field harmonics from the acquisition system, the sensors become electrically active and emit a wireless response. The magnetic field response attributes of frequency, amplitude, and bandwidth of the inductor correspond to the physical property states measured by the sensor. The received response is correlated to calibration data to determine the physical property measurement. Because each sensor pair has its own frequency response, when damage occurs to that circuit the frequency response changes. This change identifies the damage location within the material.
A unique feature achieved by eliminating electrical connections is that damage to a single point will not prevent the sensor from being powered or interrogated. If a sensor is broken, two concentric inductively coupled sensors are created, thus identifying tamper or damage location.
Rapid and Verified Crimping for Critical Wiring Needs
The crimping innovations are based on traditional ultrasonic nondestructive evaluation methods. The quality of the contact between the connector and wire is determined by sending an acoustic wave through the crimp assembly. As the applied pressure increases and the crimp terminal deforms around the wire, the ultrasonic signature passing through the crimp is altered. The system analyzes the changes in the signal, including the amplitude and frequency content, as an indication of the quality of both the electrical and mechanical connection between the wire and terminal. Various crimp quality issues such as undercrimping, missing wire strands, incomplete wire insertion, partial insulation removal, and incorrect wire gauge have been tested using this technique, and results show that the instrumented crimp tool consistently discriminates between good and poor crimps for all of these potential quality issues. This information can be used to provide a pass or fail indication for instant verification of the crimp quality and to give a better prediction for the service life of the crimp.
