Automatic Unloading Control of Dump Train Based on Passive RFID Positioning Technology
Abstract
The current status and development of dump trains suggest that the unloading system of
trains is developing towards automation and intelligence. The positioning system of
vehicles has become the key to the unloading system. Passive RFID is characterized by
general non-line of sight (NLOS), contactless communication, etc. Passive RFID also
has a low cost, excellent reliability, and adaptability to the harsh environment at the
unloading site. Hence, the passive RFID system is applicable for the automatic
unloading positioning system of hopper dump trains. In this paper, based on the
unloading logic requirements of unloading trains, the unloading algorithm in the control
system is designed. The composition and basic working mechanism of RFID are
analyzed, focusing on the design of the positioning system based on the passive RFID
(mainly readers with the RSSI value reading function according to the RSSI acquisition
method). The positioning algorithms based on the ranging and non-ranging are analyzed,
and the positioning of passive RFID based on RSSI is introduced. For the issue of
passive RFID without field strength detection, the field strength detection circuit is
designed and analyzed for the tag. Finally, the experimental data are analyzed and
simulated, and the factors affecting the accuracy of train positioning are analyzed.