Low Voltage Cable Reflectometer Built in Test Module

PM Air Warrior is developing the next generation of body mounted electronics for the aviator. Previous development efforts ran into substantial reliability issues with mounted cables due to their tendency to flex and crimp far more than what is seen on an air or ground vehicle. Cable and connector issues were a big contributor towards an unsuccessful conclusion of that program. The Rapid Innovation Fund topic “Wireless Power” is developing a power and data hub through which all body mounted cables will be connected. While digital BIT is implemented, analog wire testing is not part of the current design approach. A Time Domain Reflectometer (TDR) is used to detect and locate short, open and intermittent faults in a wiring pair. A TDR creates an impedance image along the length of a wiring pair. This impedance image, called a trace, details the impedance variations that are used by the TDR processing algorithms to identify and locate faults. TDR based testing offers a capability to not only identify catastrophic faults but also potential faults. This technology has wide application for production testing resulting in higher quality and more reliable harness assemblies, field testing for installing and maintaining  cable faults and  embedded  for Built-In-Test (BIT) that provides confidence that a piece of equipment or a system is functional and ready to perform. In  Phase I, a TDR prototype was developed, tested and demonstrated. The main objective of Phase II is to adapt the TDR prototype to a TDR module that will be integrated into a Power/Data Hub (Hub). When commanded, the TDR will perform a Built-In-Test (BIT) which can detect and locate various types of faults on connected cables. Size, weight, power and cost are all critical parameters in the design of the TDR Module. The current TDR prototype will be redesigned to use smaller, functionally equivalent parts, and repackaged to use the minimum space possible. Additionally, a new design using an FPGA to reduce the total number of required parts will be developed. Functional testing of both designs will be conducted to compare fault detection accuracy and then a tradeoff analysis will be completed to determine the architecture best suited to be integrated into the Hub. Psiber will work with the Hub vendor to modify the current Hub design to incorporate the TDR module. Hardware interface requirements will be jointly developed to allow the TDR to test the connected cables and communicate test results to the Hub controller. A software requirements document will also be created defining all communications between the TDR module and the Hub controller. Eight TDR/Hub systems with the integrated TDR will be produced by the Hub vendor and delivered to the Government.