RFID-Based Rotary Position Sensor

Passive Smart Container system comprises four major components: RFID circuits embedded in or around the container, an antenna and RF distribution system, and an interrogator/reader. The system uses passive RFID circuits placed on a bulk item container to track consumption and quantify items as the items are removed, added or replaced in the container. The antenna is strategically integrated with the lid or elsewhere in or around the container and is constantly coupling RFID signals to/from the RFID circuits. The circuits reply with information regarding the fill level in the container. A processor connected to the reader/interrogator can infer the fill level according to which RFID circuits respond and the magnitude and phase of the returned signals. The technology is compatible with the EPCglobal Class-1 Generation-2 RFID standard. This setup can be modified to track all kinds of items, large and small, making this technology suitable and applicable to an array of commercial fields. RFID is a disruptive technology that has made a large impact on several industries, especially in supply chain and asset management. Passive Smart Container is well positioned to tap into this growing market. Its ability to account for discrete items as well as liquids and bulk goods that were deemed impossible or impractical to tag makes this technology relevant for an array of applications and industries.

The smart enclosure innovation employs traditional RFID cavities, resonators, and filters to provide standing electromagnetic waves within the enclosed volume in order to provide a pervasive field distribution of energy. A high level of read accuracy is achieved by using the contained electromagnetic field levels within the smart enclosure. With this method, more item level tags are successfully identified compared to approaches in which the items are radiated by an incident plane wave. The use of contained electromagnetic fields reduces the cost of the tag antenna; making it cost-effective to tag smaller items. RFID-enabled conductive enclosures have been previously developed, but did not employ specific cavity-design techniques to optimize performance within the enclosure. Also, specific cavity feed approaches provide much better distribution of fields for higher read accuracy. This technology does not restrict the enclosure surface to rectangular or cylindrical shapes; other enclosure forms can also be used. For example, the technology has been demonstrated in textiles such as duffle bags and backpacks. Potential commercial applications include inventory tracking for containers such as waste receptacles, storage containers, and conveyor belts used in grocery checkout stations.

The RFID Tag with Long Range and Wide Coverage Capabilities technology allows a RFID tag to direct a RFID reader beam signal back in the direction of arrival. This technology requires no added power to provide telemetry for long range readers by using multiple beams instead of one narrow beam signal. Each of the predetermined number of beams is typically associated with a unique identification number to derive bearing information. This innovation is suited for IC-based RFID tags as well as Surface Acoustics Wave (SAW) tags, which are useful for extreme environments. The technology improves the ability to obtain telemetry (quantity, location, or sensor information) without GPS over a distant range. When the tag reports its identification, it also provides angular information to the source, which makes this technology useful for navigation and mapping applications. Because the technology provides an estimated angle between the signal antenna and the surface of each tag, the technology is able to triangulate the position of a mobile item identified with a RFID tag. The same innovation can be integrated to a RFID reader in order to enhance its range and distribute power to passive tags. The innovation has commercial applications in construction, oil and gas, seaport/harbor management, Internet of Things (IoT) and many more industries.

In operation, this RFID-enabled patented technology reacts to a pressure change causing the passive tag to generate an electromagnetic field. The RFID pressure sensor/passive tag reacts to the electromagnetic field and responds by sending a signal to an interrogator. The interrogator receives the reflected signal, measures the returned signal strength indications ("RSSI") of the reflected signal and sends the RSSI measurements and identification of the responding RFID sensors to the processor to determine the pressure. Potential applications for this technology include remote patient mobility monitoring, robotic control systems, and pressure sensing gloves. Older devices may also be outfitted with these sensors to add pressure-monitoring functionality while avoiding the cost of a total system replacement.

This technology exploits the inherently passive nature of RFID to approximate the services provided by traditional active Internet of Things (IOT) protocols like ZigBee and Bluetooth. A novel store-and-forward overlay on COTS RFID protocols allows an RFID active tags to transit through an ecosystem of RFID interrogators, exploiting contact opportunities as they arise and quietly transfers sensor readings at nearly no power cost to the RFID active tag. Specific intelligence built into both the interrogator and the tag leverages the RFID tag user memory (UM) as a stand-in IOT interface. The tag operates by sampling data into timestamped packets and loads them into tag memory. When an interrogator in the ecosystem realizes that a tag is in view and that there is unrecovered data on the tag, it takes custody of the sensor data packet and offloads the data into a database. A smart scheduler reads from the population of interrogators and schedules data transfers for specific tags when an interrogator can seed the custody transfer process for the data packets. NASA has produced working prototypes of wearables, worn by the crew aboard the International Space Station, that reports humidity, temperature and CO2 readings. In one estimate, the battery life is on pace to last an estimated nine years. The Low-Power RFID to Collect and Store Data From Many Moving Wearable Sensors is a technology readiness level (TRL) 6 (system/subsystem prototype demonstration in a relevant environment). The innovation is now available for your company to license and develop into a commercial product. Please note that NASA does not manufacture products itself for commercial sale.