American GNC Corporation
Smart Transducer Integrator (STI)
The Smart Transducer Integrator can operate either as a wireless ZigBee or wired smart sensor with advanced and customizable features or as a communication bridge with its optional ultrasound through-wall communication technology. The STI includes a digital core with machine-readable Transducer Electronic Data Sheets (TEDS) that allow users to easily customize data acquisition, calibration, and transducers related information and provides intelligent embedded functions (such as signal processing and classification by neural networks).
“The STI can be readily used for improving sensor networks and communications for a wide variety of applications and has been utilized by several Government agencies such as NASA and the U.S. Navy. The following 2020 NASA Spinoff article https://spinoff.nasa.gov/Spinoff2020/it_8.html describes the benefits of the STI and how it has been used for meeting NASA Stennis Space Center needs.”
Overview. The STI is a reconfigurable general-purpose device consisting of a small 1¾" x 1¾" Main Processor Unit (MPU) Board and a 2⅜" × 3.0" Expansion Board (smaller form factors are possible) with connection to an optional vibration monitoring satellite board (1.1" × 1.1" AISTS satellite board: http://www.americangnc.com /products/AISTS.htm). The STI is available in an optional 3.5"×3.5"×1.77" NEMA, IP 66, and UL listed enclosure (Hammond 1554E2) with ample space for the MPU Board, Expansion Board, an AA battery pack, cabling, and even a third board up to the same size as the Expansion Board if needed for a user’s application. Smaller enclosures can be used for e.g. MPU only or for the MPU and a smaller expansion board. The STI's modular design allows for custom expansion boards to be attached to the MPU board through an expansion bus, which provides interfacing signals to tailor diverse sensing schemes for specific target applications.
The MPU board consists of: (a) an ultra-low power consumption microcontroller with FRAM technology from Texas Instruments; (b) connections to a flexible array of standard UART, SPI, and I2C ports (e.g. for connecting digital sensors); (c) various analog inputs (e.g. for connecting analog voltage sensors); (d) baseline ultrasound communication interfaces and external customized interfaces; (e) standalone temperature event detector (STED); (f) expansion bus; (g) power and carrier signal quality monitoring; and (h) powering circuits. The optional satellite board is a small and compact board with a high performance triaxial analog accelerometer and an ultra-low power digital triaxial accelerometer.
Flexible Powering Options. Powering of the STI is enabled by four flexible options: (1) Rechargeable batteries; (2) wireless energy transfer through solid barriers (ultrasonic technology; (3) Standard batteries; and (4) Capacitor
Reconfigurable. Hardware and software reconfiguration schemes are available for setting the STI either as a: (a) wireless smart sensor (using ZigBee transceivers); (b) ultrasound-based system for operation in confined/inaccessible spaces; and (c) wired smart sensor
Ultrasound Technology. The STI's ultrasound communication capability includes interfaces for transferring low-rate data across solid thin metal walls (such as steel or aluminum) at a maximum of 10 kbit/s. This is beneficial in cases where it is needed to extend a communication network across solid metal barriers that would block RF signals and without making any modifications to the barrier structure (e.g. no wired feedthrough holes are necessary, simply attaching transducers to opposing sides of a wall). In the case of thick walls, higher data rates, or if different types of structural materials are targeted (such as composites), the STI’s ultrasound interfaces can be customized. For example, the Application Example below shows how the STI was customized for ultrasound communication and powering across a thick steel wall.
Real-World Applications. In a joint effort with the Rensselaer Polytechnic Institute (RPI), the STI was successfully applied to transfer data through thick steel walls towards the design of a safe communication bridge for monitoring critical assets. This enables to sample data from sensors on the outside of the hull of a ship using STI based hardware for data acquisition, where a through-wall wireless ultrasound data link is used to both power the external STI and transfer external data to the inside. Data rate transfer through a 2.5" steel wall was demonstrated by: (1) data transmission optimization (from remote external sensors to STI local electronics); and (2) a testbed that enabled to tailor communication methods, characterize transducers and communication medium, and identify computational requirements to increase data-rates. Deployment options for this STI based system are as a: (a) standalone data acquisition system with real-time processing that allows to deploy custom applications and (b) bridge for expanding the reach of existing networks. A demonstration video of the STI-4SH transferring sensor data across a thick steel wall is at https://youtu.be/tusJbsO1uUk where by using this system, data transfer was achieved through 2.5” thick steel.
Application Example: (energy and data transfer through a thick steel wall)