Indoor positioning method based on PDR and geomagnetism fusion

Abstract

The invention discloses an indoor positioning method based on PDR and geomagnetism fusion. The method includes the following steps: establishing an indoor global geomagnetism reference image by indoor geomagnetism data acquired by a magnetometer; when a carrier moves in an indoor environment, respectively measuring the accelerated speed and the angular speed of the carrier and the absolute force of the position of the carrier through an acceleration sensor, a gyroscope and a magnetometer on the carrier, and calculating the heading and the step length of the carrier by a PDR algorithm; searching a local geomagnetism reference image from an indoor global geomagnetism reference image according to the position of the carrier at the previous time, the heading and the step length; and matching a magnetic vector obtained by real-time measurement of a magnetic field sensor on the carrier with the local geomagnetism reference image through a geomagnetism matching algorithm to obtain the position coordinates of the carrier to implement positioning. By the indoor positioning method based on PDR and geomagnetism fusion, shortcomings of pure geomagnetism positioning and PDR positioning are overcome, and the positioning precision is superior to 1 m; and therefore, the indoor positioning method based on PDR and geomagnetism fusion can be used for high-precision indoor positioning places.

Description

technical field [0001] The invention relates to the technical field of positioning, in particular to an indoor positioning method based on PDR pedestrian dead reckoning and geomagnetic fusion. Background technique [0002] As the "last mile" of navigation and positioning, indoor positioning has always been a worldwide problem. How to effectively solve it has become the core problem of navigation and location services. Currently disclosed indoor positioning technologies mainly include: WIFI positioning, inertial navigation positioning, Bluetooth positioning, RFID positioning, ultra-wideband (UWB) positioning, LED visible light positioning, geomagnetic positioning, ZigBee positioning, infrared positioning, ultrasonic positioning, computer vision positioning, etc. The traditional inertial navigation system needs to convert the measured acceleration into displacement through quadratic integration, and its error increases with the square of time. Even if the target does not move,...

AI Technical Summary

Problems solved by technology

[0003] For the indoor environment, because the magnetometer is affected by the indoor geomagnetic anomaly field, the magnetic field generated by other indoor equipment, and the equivalence of the geomagnetic field, the positioning area may appear fuzzy.

Because pure geomagnetic positioning cannot give a rough position at the current moment, it can only use the position at the previous moment for geomagnetic matching. The space search domain is large, and the algorithm complexity is high. fuzzy solution

Pure PDR positioning has higher accuracy when the walking distance is small. Due to the inaccurate estimation of the pedestrian's step length, as the walking distance increases, the accumulated error will cause the accuracy to drop sharply.

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