Research On Indoor Location Of Intelligent Mobile Terminals Based On GIS And BIM

Global navigation satellite system(GNSS)has many advantages,such as high location accuracy,high speed,time saving and high efficiency.It is widely applied in outdoor location.However,due to the satellite signals are easily blocked,it is difficult to receive GNSS signals indoors,so it is very important to find the indoor location methods.Now,the indoor positioning has become a hot topic,and the relevant methods and technical achievements are also emerging.Most of the existing indoor positioning techniques are carried out around the two-dimensional plane,focusing on the location process of the target point,often ignoring the positioning influence caused by the spatial geometric information of the building,and the positioning results are rarely visualized in real time.In view of the above problems,this paper based on the new and low power iBeacon technical device,combined with 3D map visualization of building information model(BIM)and the multi sensor of the mobile terminal(mobile phone,Pad,etc.),an intelligent mobile terminal location method based on GIS cooperative BIM is proposed.The main research contents include:(1)The research on BIM model lightweight preprocessing method for Indoor location and 3D map scene construction.Including the modeling process of building CAD drawings to BIM and the information structure contained in the BIM model.Then exporting the attribute information data,geometric information data and texture information data of BIM model information,and according to the data structure GIS management and realize lightweight data processing.Finally,through WebGL programming,finished the research for mobile location display of indoor location BIM lightweight model,and developed a lightweight BIM display platform for indoor positioning.(2)The research on the indoor location of intelligent mobile terminals based on BIM coordinated iBeacon under spatial geometric constraints.In the scene of 3D map visualization of BIM,using the weighted path loss model to ensure the relational model of iBeacon signal transmission intensity and distance,and utilizing the signal intensity received by intelligent mobile terminal to compute the distance between smart mobile terminal and the effective iBeacon label,then through the weighted three edge positioning algorithm by the BIM geometric constraints to get the indoor coordinates of the intelligent mobile terminal.(3)The research and demonstration of intelligent mobile terminal indoor location system of GIS cooperate with BIM.Through the fusion of BIM model lightweight preprocessing method for indoor location and the indoor location method of BIM cooperate with iBeacon to instantiatly construct the intelligent mobile terminal indoor location system of GIS cooperate with BIM.The system includes the two functions of iBeacon label configuration,indoor location calculation and 3D map visualization.It effectively completes the demonstration of the indoor location method and technological process of the intelligent mobile terminal of GIS cooperative BIM,and provides data and system support for the follow-up research work based on this system.In this paper,a feasible indoor location scheme for smart mobile terminals based on GIS and BIM is proposed.This paper focuses on the research and demonstration of the indoor location oriented BIM model lightweight preprocessing method and 3D map scene construction,as well as the intelligent mobile terminal indoor location method of BIM cooperative iBeacon under the condition of spatial geometric constraints.The statistical analysis of indoor space positioning error of the intelligent mobile terminal of GIS with BIM shows that the error of X direction is 0.297 ~2.071 meters,the error of Y direction is located at 0.368~1.569 meters,the error of Z direction is 1.370~1.91 m,and the point mean square error of the location point is 1.905~3.178 meters.The positioning accuracy can basically meet the needs of indoor space positioning application in daily life,and can be applied to the indoor space of large public buildings,such as shopping malls,hospitals,parking lots and so on.