Research And Implementation On Geomagnetic Indoor Positioning And Navigation System

Nowadays,wireless communication technology is developing rapidly,the demand for location-based services is increasing and people are paying more attention on wireless positioning technology.GPS can provide high-precision positioning information in open-air environments where satellite signals are reachable.However,in the indoor environment,because the reinforced concrete structure in the building completely obscures the microwave signal from GPS,it can not provide real-time and effective positioning information.The smartphone's high-precision geomagnetic sensor can receive the geomagnetic information in real time.With the advantage of eliminating the need for additional equipment and high positioning accuracy,geomagnetic positioning technology becomes the most popular new technology in this field.Based on the study of geomagnetic positioning technology,we design and implement a geomagnetic indoor positioning and navigation system deployed on iOS platform,which mainly includes the following aspects.Firstly,geomagnetic information storage model for indoor positioning is proposed.When we collect geomagnetic information,it will make coordinate transform and other process to reduces the workload of data collection.It also makes the geomagnetic information easy to store and express the current point geomagnetic characteristic.Secondly,we come up with a method of making the geomagnetic information map and design a client to collect the geomagnetic information.For the collected information,the cubic spline interpolation algorithm is used to fit the surrounding information to generate a full geomagnetic map.Thirdly,we use the data from geomagnetic sensor and acceleration sensor to deduce user behavior.The accurate deduced data can help in positioning and navigation calculation.Fourth,the use of improved particle filter algorithm for indoor positioning calculation can generate real-time user location information.The ant colony algorithm is used to calculate the indoor navigation path and the optimization algorithm is proposed to optimize the navigation results.Finally,through the experimental analysis and verification,it reflects the stability and rationality of the system.Through the field test,the average positioning accuracy is about 1.5-2.5 meters,the average time to complete the navigation path is about 3 seconds.