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Physics Based Wire Fault Detection

This software package provides a toolbox of MATLAB functions for detecting precursor wiring faults, such as chafing, in shielded impedance controlled cable using measurements from off-the-shelf time domain reflectometry or vector network analyzer hardware. It accomplishes this by combining high fidelity analytical physics-models for signal propagation on faulty cable with Bayesian inference algorithms for intrinsic cable and fault parameter retrieval. The toolbox is intended as a proof-of-concept and baseline platform for external researchers and industry partners to easily build on and further advance the state-of-the art in electronic wiring diagnostics technology.

The core component parts of the software toolbox are:

(i) High fidelity physics-based models for signal propagation in impedance controlled shielded twisted pair cable expressed in symbolic mathematical form.

(ii) Automatic conversion of mathematical models, through use of the MATLAB symbolic math toolbox, into efficient functions for the simulation of time or frequency domain measurements given input parameters capturing the intrinsic cable, fault, and physical setup of the measurement system.

(iii) Efficient methods for setting up and solving a Bayesian maximum a-posteriori (MAP) formulation of the fault detection problem, with uncertainty quantification.

The toolbox functions enable a user to specify parameters of a particular supported wire type, measurement data file, and various system settings including prior information regarding the measurement system. Using this information, the optimal fault detection algorithm is executed to locate potential faults along the length of the cable. Additional support functions are provided to perform statistical analysis and display estimation results.

Documentation covering background information and theory is available in our technical report,

S. Schuet, D. Timucin, and K. Wheeler. Shielded twisted pair cable model for chafe fault detection via time-domain reflectometry. NASA Technical Report NASA/TM-2012-216001, National Aeronautics and Space Administration, March 2012.

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This software is released under the terms and conditions of the NASA Open Source Agreement (NOSA) Version 1.3 or later.

Wiring Fault Detection Toolbox NOSA Software Agreement

Wiring Fault Detection Toolbox NOSA Software Agreement (PDF Version)

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