A rfid localization method for mobile robots based on phase features

Abstract

The invention belongs to the field of wireless positioning, and particularly discloses a mobile robot RFID positioning method based on a phase characteristic. The method comprises the following stepsof S1, when an RFID reader-and-writer moves on a mobile robot, forming an RF loop with an RFID label which is mounted on an object, measuring phase information and signal wavelength information of theRFID RF loop by the RFID reader-and-writer; S2, converting periodical non-continuous phase information to continuous non-periodical phase information, and acquiring position information of an RFID reader-and-writer antenna; and S3, constructing an unwrapping phase-position model, introducing signal wavelength information, the continuous non-periodical phase information and position information ofthe antenna into an unwrapping phase-position model, calculating the position information of the RFID label relative to a mobile robot, thereby realizing positioning of the object. The mobile robot RFID positioning method based on the phase characteristic has advantages of high positioning accuracy, high interference resistance, low calculation amount, simple system, etc.

Description

technical field [0001] The invention belongs to the field of wireless positioning, and more particularly relates to an RFID positioning method for a mobile robot based on phase characteristics. Background technique [0002] RFID (Radio Frequency Identification), that is, radio frequency identification technology, is a wireless communication technology for building the Internet of Things. Passive UHF RFID has been widely used due to its unique ID, low cost, long distance, and no need for batteries. warehouse management, etc. RFID-based positioning technology can greatly improve the efficiency of item management. In the past ten years, RFID-based indoor positioning systems and methods have been continuously proposed. Among them, signal strength (RSSI) and phase are the two most important radio frequency information in RFID positioning. [0003] Due to the existence of environmental interference such as multipath effects, the attenuation of signal strength and the mapping rel...

AI Technical Summary

Problems solved by technology

Angle of Arrival (AOA) and Synthetic Aperture (SAR) are the two main phase-based positioning methods. Among them, the AOA method uses the phase difference information between the antenna arrays to calculate the angle between the tag and the antenna. Multiple antenna arrays The position of the tag can be obtained by calculating the intersection point of each direction angle. The AOA method requires the distance between the antennas to be less than half a wavelength, but the size of the directional antenna itself is large, and this requirement is often difficult to meet; while the SAR method uses a moving antenna to form a target for the tag. Synthetic aperture observation, this method can observe tags from all directions, the influence of environmental interference on positioning can be reduced, and the positioning accuracy is high. Has a large computational load, and real-time performance is limited

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