Specialized Sensing Technologies

Image: Fusion of data from multiple sensors provides node position, orientation and environment characterization.

Fusion of data from multiple sensors provides node position, orientation and environment characterization.


Image: Features of the wireless sensor network include radar-like distance measurement technique with accuracy to one millimeter.

Features of the wireless sensor network include a radar-like distance measurement technique with accuracy to one millimeter.

Embedded and communication systems and their applications in the research, design, and development of wireless sensor networks are areas in which Southwest Research Institute (SwRI) engineers have extensive experience. SwRI engineers have integrated commercially available, wireless-enabled microcontrollers with custom sensing hardware and embedded software to realize a variety of real-world applications. These wireless sensor nodes are deployed by SwRI engineers in challenging conditions to provide unparalleled characterization of environments once deemed inaccessible.

Development of Wireless Sensor Nodes

SwRI engineers apply wireless sensor systems to a variety of custom applications. Some features and capabilities include:

  • Low-cost, battery-powered, expendable sensor nodes
  • Small onboard processors for data acquisition and telemetry
  • Autonomous and cooperative mesh and mobile ad hoc networking
  • Fusion of data from multiple sensors to provide node position, orientation and environment characterization

Application of Wireless Sensor Systems to Difficult Environments

SwRI engineers have developed wireless sensor systems for measurement of earth processes in hazardous environments. Challenges include:

  • Inaccessible locations
  • Dangerous environments
  • Long-term deployment
  • Lack of power and communications infrastructure
  • Loss of individual nodes

Precise Distance Measurement Using Wireless Sensor Systems

A wireless sensor network for characterizing high-precision movement has been developed by SwRI engineers and the system has been deployed at an active landslide in remote Idaho.

Features of the wireless sensor network include:

  • A radar-like distance measurement technique with accuracy to one millimeter
  • Interrogator and responder nodes using phase difference to provide change in distance
  • Delay lines to avoid pulse overlap and clock drift
  • Distributed coordination and data acquisition using an IEEE 802.15-based wireless network

Waterborne Sensor Node for Underwater Sensing

SwRI engineers have developed a neutrally buoyant waterborne sensor node for the mapping and characterization of karst aquifers. Features include:

  • Ultrasonic ranging to provide distance to conduit geometry
  • Real-time node velocity calculation using feature detection
  • Magnetometer to provide vehicle compass heading
  • Multiple additional sensors (e.g., thermometer, accelerometer) to provide further characterization of travel path
  • Deployment in area water caves to autonomously map conduit characteristics

Cooperative Sensing Using Prototype Unmanned Aerial Vehicles

SwRI participated in a government-funded project to build prototype unmanned aerial vehicles to cooperatively locate targets of interest. Some features of the sensor system developed by SwRI engineers include:

  • Localization of hand-held communication devices using radio frequency (RF) signatures
  • Digital signal and software radio processing
  • Multi-constraint optimization (e.g., power, stealth, accuracy, RF)
  • Demodulation technique to enhance time difference of arrival ranging
  • Propagation modeling using existing city models
  • Distributed coordination and sensor data fusion
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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 10 technical divisions.
07/13/16