Tunnel three-channel difference range finding method based on RSSI

Abstract

A tunnel three-channel difference range finding method based on a RSSI relates to the wifi positioning technical field, and comprises the following steps: 1, deploying a wifi positioning anchor node in a tunnel narrow long space, wherein the wifi anchor node completes three non-disturbance channels switching in certain time period, respectively receives mobile target signal intensity from three channels, thus obtaining three related RSSI values; 2, selecting the middle channel as a reference according to the three related RSSI values, and the other two channels respectively carries out difference calculation with the middle channel, if a difference absolute value is bigger than a certain threshold, the position is considered to be a deep fading zone, thus correcting a distance position; 3, firstly using three-channel difference value to compensate the deep fading zone, then carrying out distance-loss model fitting, thus determining distance information of the target node. The tunnel three-channel difference range finding method can greatly reduce anchor node device number and antenna complexity, and can improve range finding precision.

Description

technical field [0001] The invention relates to the technical field of WiFi positioning, in particular to an RSSI-based three-channel differential ranging method in a roadway. Background technique [0002] In the existing WiFi ranging methods in various narrow and long spaces such as mine tunnels, subways, highway bridges, etc., the distance of the moving target node is calculated according to the RSSI (Received Signal Strength Indication) value combined with the "distance-loss" fitting curve , is still the only simple and practical way. However, in the narrow and long space of the roadway, due to the reflection of the symmetrical roadway wall, that is, multipath, the electromagnetic wave fluctuates greatly at some fixed positions, resulting in deep fading, which affects the smooth decline of the "distance-loss" model and increases the deviation of the fitting curve. , the ranging accuracy is greatly affected, especially in the deep fading area because the signal strength i...

AI Technical Summary

Problems solved by technology

However, in the narrow and long space of the roadway, due to the reflection of the symmetrical roadway wall, that is, multipath, the electromagnetic wave fluctuates greatly at some fixed positions, resulting in deep fading, which affects the smooth decline of the "distance-loss" model and increases the deviation of the fitting curve. , the ranging accuracy is greatly affected, especially in deep fading areas because the signal strength is very small, and the ranging error is extremely large

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