• A Common Solution to Custom Network Applications

      Yin, Jennifer; Dehmelt, Chris; L-3 Communications – Telemetry East (International Foundation for Telemetering, 2007-10)
      The deployment of networks has become ubiquitous in the avionics world, as they have opened the door to a rich suite of common and open hardware and software tools that provide greater functionality and interoperability. Unfortunately, a number of networked avionic and other related applications can be affected by vendor or application specific proprietary implementations. These “closed” implementations may reduce or eliminate the benefits of a standardized network, requiring the customization of the data acquisition system to allow it to properly operate with the other devices. This paper presents the approach that was recently employed for the development of a network interface module that can be quickly reconfigured to address the changing requirements of network applications, including monitoring of industry standard and proprietary networks, or providing the command and data interface to the data acquisition system itself. This reconfigurability of the module is shown in a review of four different specific applications.
    • THE IMPLEMENTATION OF AN IRREGULAR VITERBI TRELLIS DECODER

      Rice, Michael; Lavin, Christopher; Brigham Young University (International Foundation for Telemetering, 2007-10)
      The Viterbi algorithm has uses for both the decoding of convolutional codes and the detection of signals distorted by intersymbol interference (ISI). The operation of these processes is characterized by a trellis. An ARTM Tier-1 space-time coded telemetry receiver required the use of an irregular Viterbi trellis decoder to solve the dual antenna problem. The nature of the solution requires the trellis to deviate from conventional trellis structure and become time-varying. This paper explores the architectural challenges of such a trellis and presents a solution using a modified systolic array allowing the trellis to be realized in hardware.
    • LONG TERM VEHICLE HEALTH MONITORING

      L3 Communications – Telemetry East; Cridland, Doug; Dehmelt, Chris (International Foundation for Telemetering, 2007-10)
      While any vehicle that is typically part of a flight test campaign is heavily instrumented to validate its performance, long term vehicle health monitoring is performed by a significantly reduced number of sensors due to a number of issues including cost, weight and maintainability. The development and deployment of smart sensor buses has reached a time in which they can be integrated into a larger data acquisition system environment. The benefits of these types of buses include a significant reduction in the amount of wiring and overall system complexity by placing the appropriate signal conditioners close to their respective sensors and providing data back over a common bus, that also provides a single power source. The use of a smart-sensor data collection bus, such as IntelliBus™1 or IEEE-1451, along with the continued miniaturization of signal conditioning devices, leads to the interesting possibility of permanently embedding data collection capabilities within a vehicle after the initial flight test effort has completed, providing long-term health-monitoring and diagnostic functionality that is not available today. This paper will discuss the system considerations and the benefits of a smart sensor based system and how pieces can be transitioned from flight qualification to long-term vehicle health monitoring in production vehicles.