Multi-Source Indoor Localization For Smart Phone With Fusion Of Inertial Measurement Unit And Near-Ultrasound

With the rapid development of network communication technology and the popularity of smart mobile terminals,location-based service provides convenience for people in outdoor scenarios and has been perfectly integrated into ordinary daily life.However,due to the poor development of indoor localization technology,the location-based service in the indoor scenarios such as the searching for cars in underground parking lots,the rapid localization of trapped people by firefighters,and the searching for people in large traffic hubs,cannot be carried out for a long time.In order to solve the dilemma of indoor localization,a high-precision indoor localization system which can be used in the smart mobile terminal is needed.This paper analyzes the indoor localization that can be used in smart mobile terminals from the perspectives of positioning accuracy,range,cost,etc,Finally,it decides to use the acoustic signal to build an indoor localization system with high accuracy.After that,this paper optimizes the system and puts forward a new way of single base station localization.The main research contents and innovations of this paper are as follows:Firstly,for a better IMU attitude estimation,this paper proposes a Mahony-OAMS algorithm on the basis of the Mahony algorithm.The Mahony-OAMS algorithm is to make up for the unsatisfactory effect of the Mahony method in dynamic scenarios.After that,this paper uses the given sensor movement rate and the attitude given by the Mahony-OAMS algorithm to estimate the position of the sensor,which provides evidence for the fourth section.Secondly,a near-ultrasonic localization system based on the "Base station-Terminal" mode is proposed.This paper gives the system design including the system architecture,hardware composition,and acoustic signal design.In the part of acoustic signal design,this paper analyzes the characteristics of acoustic channels in two common indoor environments,signal processing and signal arrival detection.After obtaining the TDOA values,this paper researches and simulates the TDOA localization algorithms.Finally,the localization performance of the near-ultrasonic localization system is analyzed experimentally.Thirdly,this paper proposes a performance-improvement method integrating IMU and Doppler based on the near-ultrasonic localization system.This paper analyzes the Doppler effect and uses the Doppler effect to detect the velocity of the smart phone and provide the velocity for INS.Then,a tripartite data fusion method based on KF is proposed,and the experiment and analysis of this method are carried out.Finally,because of the deployment of speakers in large indoor scenarios,this paper creatively proposes a localization method based on the fusion of independent near-ultrasonic base station and AHRS.The biggest advantage of this method is that only one speaker is needed in the stage of base station deployment.So when it needs to deploy the localization system,such as airport,station,and other scenarios where a large number of speakers have been deployed,there is no need to change the equipment,and the cost is effectively reduced.