Intelligent Wireless Sensor Networks for Spacecraft Health Monitoring

Wireless sensor networks (WSN) based on the IEEE 802.15.4 Personal Area Network (PAN) Standard and the ZigBee 2007 Standard provide a framework for component-based software that supports interoperable solutions from multiple vendors. Mesh-enabled WSNs provide inherent fault tolerance and provide low-power, low-cost ancillary sensing systems for Integrated System Health Management for aerospace particularly across pressure interfaces and in areas where it is difficult to run wires. Intelligence for sensor networks could be defined as the capability of forming self-managing dynamic sensor networks, allowing high-level application software to identify a module and interpret sensor values without using a pre-defined configuration database. Self-configuring system architectures for wireless sensor networks can support a large number of sensors in a dynamic configuration, providing intelligent response for fault tolerant networks. The IEEE 1451 Smart Transducer Interface Standard defines Transducer Electronic Datasheets (TEDS) containing key information regarding sensor characteristics such as name, description, serial number and calibration information. By locating this TEDS meta-information on the wireless sensor itself and enabling access to this information from the application software directly, the application can identify the sensor unambiguously and present the sensor data stream through network and module discovery. An interesting method for implementing the IEEE 1451 standard, based on the Air Force Research Lab’s Space Plug-and-Play Avionics (SPA) approach may simplify application software development compatible with modern software standards. The emerging AIAA SPA Standards can simplify adoption by standardizing application software interfaces and development by the use of the xTEDS based on Extensible Markup Language to provide sensor and actuator object virtualization within a standard framework. The authors propose an integration of ZigBee, IEEE 1451 and SPA to further define a facile software framework and the paper outlines the general architecture and approach for implementation of a prototype. The technical feasibility of creating fault-tolerant WSNs for Structural Health Monitoring is presented as a relevant example applied to composite structures for wind tunnel and flight tests to facilitate understanding key aspects of the aerospace vehicle design, test and operations life cycle.