Parking system and its vehicle positioning method based on uwb and geomagnetic parking space detection

Abstract

The invention relates to a parking system based on UWB and terrestrial magnetism parking space detection, and a vehicle positioning method for the parking system. The technical characteristics are that the system comprises a vehicle-mounted tag with a UWB radio frequency tag and an acceleration sensor, a terrestrial magnetism parking space detector with a UWB radio frequency tag, a wireless gateway, and a server; the vehicle-mounted tag transmits a UWB positioning signal and vehicle identity recognition information to the terrestrial magnetism parking space detector; the terrestrial magnetism parking space detector detects the current parking space state, receives the UWB positioning signal, carries out the UWB positioning calculation, locates a vehicle at a current parking space and transmits the vehicle identity recognition information and parking space state change time to the server through the wireless gateway after the locating of the vehicle. According to the invention, the system employs flight time range-finding between two points for replacing a conventional UWB positioning method, thereby solving a problem of clock synchronization between base stations, greatly simplifying the construction difficulty and complexity of UWB positioning, greatly reducing the cost, and completely meeting the precision requirements of the positioning of a to-be-parked vehicle.

Description

technical field [0001] The invention belongs to the technical field of intelligent parking, and in particular relates to a parking system based on UWB and geomagnetic parking space detection and a vehicle positioning method thereof. Background technique [0002] For a long time, the on-board tag + geomagnetic parking space detector roadside parking charging system based on the RSSI signal receiving strength has the problem of inaccurate positioning accuracy. However, since the signal is easily disturbed by the environment during propagation, such as obstacles such as pedestrians, the signal cannot propagate in a straight line, but reaches the receiver through diffraction, transmission and reflection. Therefore, it will bring a large measurement error to the positioning method based on the received signal strength and reduce the positioning accuracy. [0003] In order to solve the problem of inaccurate RSSI positioning, an improvement method is to use UWB positioning instead...

AI Technical Summary

Problems solved by technology

[0004] The existing UWB positioning methods generally adopt two methods: TOA and TDOA. Although the time-of-arrival (TOA) method is simple, it requires strict time synchronization between the tag and the base station. The circles cannot intersect at one point, resulting in a large positioning error

The TDOA-based UWB positioning method is similar to the TOA positioning method. It does not require synchronization between base stations and tags, but only requires time synchronization between base stations. However, if the selected reference base station has serious clock drift, it will affect the positioning accuracy of the entire system.

[0005] In short, the above two methods require clock synchronization between the tag and the base station, between the base station and the base station, but clock synchronization is very difficult to achieve, and requires very high synchronization accuracy: even a few nanoseconds of clock error between the base stations It will cause a few meters of error in the parking space

Since each parking space is generally only 2 meters wide and 4 meters long, if there is an error of a few meters, parking positioning cannot be realized at all.

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