Description: NASA's strategic needs include those related to flexible instrumentation capable of monitoring remote or inaccessible measurement locations within Stennis Space Center (SSC) testing facilities. Looking to support the advancement of NASA SSC's infrastructure, American GNC Corporation (AGNC) and the Rensselaer Polytechnic Institute (RPI) are proposing the Through Wall Wireless Intelligent Sensor and Health Monitoring (TWall-ISHM) System. Distinctive TWall-ISHM system core capability is monitoring remote and/or inaccessible measurement locations constrained or completely sealed by barriers (such as metallic walls, composite structures, or even concrete layers) where wiring through the barrier (wall or enclosed structure) is not an option. TWall-ISHM system's key advantages are: (a) non-intrusive sensing scheme, meaning that perforations through the isolating wall are not required; (b) capability of wireless data and power transmission through the wall by robust ultrasound techniques; (c) Lead Zirconate Titanate (PZT) elements self-diagnostics (those used either for ultrasound communication or as sensors); (d) embedded intelligent algorithms within Transducer Interface Modules (TIM, i.e. smart sensors); (e) Network Capable Application Processor (NCAP) with high level analysis, more powerful algorithms, and standard communications; and (f) sensor network operation capability, i.e. several smart sensors on both sides of the wall and in remote locations can communicate to the NCAP.

Benefits: The TWall-ISHM System will directly support NASA's Propulsion test facilities by providing innovative cost-effective sensor & Structural Health Monitoring (SHM) system with minimally intrusive ultrasound communication and intelligent data analysis diagnostic techniques. SHM will be focused to pipelines health monitoring for leakage detection. Distribution system key parameter (such as pressure, flow, heat flux, and temperature) monitoring capability is leveraged by wireless through wall communication. As result applications of the TWall-ISHM are broad. Potential NASA Stennis Space Center (SSC) use specifically involves: (i) distribution systems; (ii) vacuum lines and pressurized systems; (iii) cryogenic test facilities; (iv) propellant delivery systems; (v) cooling water or gas lines; (vi) various facilities and the A, B, and E test complexes; and (vii) other complex systems. Other potential monitoring applications include support to: (a) Glen Research Center, for example, vacuum line monitoring at the zero gravity research facility; (b) International Space Station (ISS) where the sensor nodes can be deployed along the station's structure or in enclosed, difficult to reach spaces for gathering, processing, and disseminating data; (c) Smart Structures Development; (d) Flight Test and Measurement Technologies; (e) Integrated System Health Management for Sustainable Habitats; (f) Vehicle Safety - Internal Situational Awareness and Response; and (g) NDE analysis, among others.

The TWall-ISHM directly or with few modifications can be applied to embedded system health monitoring (by processing of strain, stress, humidity, temperature, etc.) of equipment/machinery/assets in difficult to access locations such as airframe components (wings and enclosed fuselage compartments); remote and inaccessible bridge elements; civil structures; and military infrastructure. Innovative aerospace instrumentation and advanced measurement techniques are enabled when considering data and energy transferal in pressurized aircraft cabin or cockpit, where sensors in both the outside and inside of the cabin can communicate data based on the thru-wall ultrasound technology. Corrosion monitoring within inaccessible locations where; (a) civil structures (buildings, bridges, etc.); (b) vessels; and (c) military infrastructure can be beneficiated by this technology. Military assets life-cycle status monitoring and tracking by vibration base analysis and internal conditions monitoring (such as temperature and humidity) within sealed metallic structures (as stores) can provide information about operational conditions to which the asset has been exposed (such as transportation or in-fly exposure time to events of interest). When infused to AGNC's Health Monitoring Enterprise infrastructure markets include: (1) Computerized Maintenance Management Systems (CMMS) and Enterprise Asset Management; (2) complex system maintenance and repair guidance; (3) and Internet of Things (IOT).