Research On Indoor Integrated Navigation And Location Method

With the development of mobile Internet,location-based services(LBS)has received more and more attention,positioning and navigation is one of the key technologies.The GNSS(Global Navigation Satellite System),such as GPS,Glonass,Galileo,has been able to provide location service in outdoor environment.However in indoor environment,signals are blocked by buildings,which result in weak or loss of satellite signal.With the complex indoor environment,severe fading,reflection,diffraction of signals,result to non-line of sight and multipath error.So there still exist some problems in current positioning world.As leap forward of our science research and Internet technology,a mature method is still waiting to be found.So there has important theoretical significance and application value in indoor positioning research.Firstly,this article proposes a new ranging method,then the deficiency of traditional ranging method“Large scale attenuation model”get analyzed.After that,a new method of ranging processing—generalized extension interpolation method is proposed.The ranging accuracy of the new method was verified by simulation and experiment.This article also makes a comparison with the new ranging method and large scale attenuation model.At last,through the experiment verify the superiority of the method described in this article.In the third part,another indoor positioning method is introduced.It mainly use dead reckoning(DR)algorithm to update current location point.The magnetic compass and accelerometer provide angle and speed information.This article proposes a differential correction method to correct the directional angle error through an error database.Steels in the buildings and power supplies are strong magnetic interferences in indoor environment.It affects the magnetic compass and gives inconsistent results.The error is hard to correct because of the uncertainty of the interference.In this article we get measurement samples of the location to get the error distribution,and then build an error database based on generalized extended approximation method.The magnetic compass error was adjusted thanks to the error database and the tracking precision was greatly improved.In the fourth part,a research has been done on a combination of owe star positioning method with IMU(Inertial Measurement Unit).Algorithm makes full use of carrier's prior tracking data,current movement information,location nodes' pseudo range and electronic map information.Meanwhile,a weighted fusion algorithm is proposed too in this paper,which makes up the problem of lacking sufficient equations,and makes a reasonable analysis on choosing the weights.The last part of this paper we use micro base station with car OBD for indoor positioning.CAN-BUS is a broadcast serial bus system.It can connect to the equipment inner buses and able to realize the data communication of the vehicle's inner sensors,controllers,actuators with outside computer.The internal sensors can provide more stable and high accuracy steering angles and current speed data than external inertial components,and the dead reckoning accuracy will be greatly improved using these data.The ranging principle of micro base station is based on TOA(Time of Arrival).This paper gives a ranging test and analysis on its ranging accuracy.The relationship between the positioning accuracy of the micro base station and HDOP(Horizontal Dilution of Precision)is derived from theory.The selection criterion of micro base station is presented.Then,a weighted filter is designed and a combined positioning method of micro base station/OBD is presented.In order to verify the feasibility of the method,indoor vehicle positioning application and demonstration are carried out in many demonstration bases.