Pedestrian inertial positioning system based on indoor magnetic field feature assistance

Abstract

The invention provides a pedestrian inertial positioning system based on indoor magnetic field feature assistance. The system comprises a magnetic field and inertial data obtaining module, a magnetic field positioning module, a pedestrian dead reckoning module, a positioning fusion module and an output module, wherein the magnetic field and inertial data obtaining module is used for acquiring magnetic field, accelerated speed and angular velocity information; the magnetic field positioning module is used for building a magnetic field feature library and carrying out time-frequency analysis on the magnetic field vector sequence in real time to extract the time-frequency feature, and matching with the magnetic field feature library to carry out magnetic field feature positioning; the pedestrian dead reckoning module is used for updating accelerated speed and angular velocity zero offset according to the condition that the step velocity discontinuity is zero during walking, judging the step number and calculating the step length and the direction of each step; the positioning fusion module is used for fusing a magnetic field feature positioning result and a pedestrian dead reckoning inertial positioning result by means of particle filter; and the output module is used for displaying a positioning result on web pages and terminals. The system provided by the invention has the characteristics of being independent from beacon during positioning, low in cost and consumption of positioning terminals, accurate in positioning result and adaptive to environment change.

Description

technical field [0001] The invention relates to the fields of inertial navigation and indoor positioning, in particular to a pedestrian inertial positioning system based on indoor magnetic field feature assistance. Background technique [0002] The geomagnetic field from geomagnetic south to geomagnetic north is distributed in space. Under the indoor environment, the geomagnetic field is jointly affected by the reinforced concrete structure of the building and indoor motors and electrical appliances, forming an anomaly whose size and direction deviate from the original geomagnetic field. This magnetic anomaly is stable even after several months and can be used as a basis for positioning. Current research and patents use magnetic field information for positioning, mostly robot-based applications, matching the magnetic field database point by point during positioning. Existing indoor positioning schemes have the following defects: [0003] 1. The existing indoor positioning...

AI Technical Summary

Problems solved by technology

[0004] 2. Existing indoor positioning systems require high energy consumption to obtain positioning signals

The use of video systems to obtain positioning information in the existing technology means high energy consumption, and long-term positioning work cannot be performed in portable devices

[0005] 3. The cost of existing positioning equipment is relatively high

Some fusion systems use devices such as distance sensors and air pressure sensors. The cost of equipment such as cameras is relatively high.

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