Exploiting Near-Field Antenna Detuning in Collision Avoidance Systems for RFID-Equipped Robots

This paper presents a collision avoidance system for mobile robots equipped with UHF-RFID (Ultra-High Frequency - Radio Frequency IDentification) readers. The proposed system requires the presence of RFID tags with self-tuning chips to recognize the tag antenna mismatch caused by the near-field interaction with the robot-installed antenna. The self-tuning tags are provided with a capacitors network used to re-tune the antenna in presence of mismatches. The network configuration is transmitted to the reader through modulated backscattering. The onboard computing intelligence can use this information to recognize a hazardous situation, stop the robot, and calculate a new safe route. The system is implemented and tested in a real environment where a statistical analysis with a large dataset is conducted to provide an optimized and reliable low-cost system.