Testing a Passive RFID System on Rotorcraft for Tracking Dynamic Components

Continuing TDA's work with passive radio frequency identification (pRFID) systems for tracking dynamic components, tests and assessments were made of commercial off the shelf (COTS) pRFID systems on and off US Navy (USN) rotorcraft. The goal of this testing program was to establish a baseline of functionality for available commercial products, and determine the ability of COTS pRFID systems to meet operational requirements for the end goal of tracking dynamic components in an automated way. Testing took place in two phases. First, tests were conducted in a controlled field environment designed to maintain control over environmental variables such as metallic obstructions and ambient RF interference, and second, in the rotorheads aboard static US Navy rotorcraft, including an MH-53E, CH-53A, and SH-60F, each in different locations. The differing test locations provided an array of varying environments and weather conditions, which helped characterize the performance for the COTS pRFID systems. Due to tightly packed bodies, multiple reflections and large broad-band noise from various sources, optimum placement of a tag and reader system requires numerous trial-and-error measurements involving different positions of reader antenna and tag configurations, indicating a need for the development of a mathematical model and a pRFID system placement algorithm for various rotorcraft configurations. The tests also indicated that tag type/construction is the biggest driver of system performance on rotorcraft, with tag orientation with respect to the antenna being the second most important factor. At close distances it was possible to read high quality, metal-mountable tags but it was difficult to predict performance at read distances greater than 16'. This paper discusses details of the results from these tests and future work on analytical placement models and on-aircraft tests to advance the pRFID system use on rotorcraft.