Lightweight SLAM Technology For PDR Enhancement

In recent years,there has been an increasing demand for location based services.Although the global satellite navigation system can locate things on the surface of the earth,it cannot be used indoors and in some extreme environments.Both Strap-Down Inertial Navigation System and SLAM technology can solve the problem of indoor positioning.The Foot Strapped PDR Indoor Positioning System used in this paper is a low-cost Strap-Down Inertial Navigation System,which can achieve pedestrian positioning by wearing an inertial measurement unit.But the accumulated error will make the positioning result shift.Therefore,this paper intends to design a new system that combines lightweight SLAM system and the Foot Strapped PDR Indoor Positioning System,which can integrate SLAM data and PDR data,and obtain better PDR indoor positioning results with SLAM system.Firstly,this paper researches and establishes the SLAM system model and probabilistic solution method,compares the external sensors used by the SLAM and selects the LIDAR sensor,then establishes model of LIDAR data;compares several popular map models to select the grid map,updating map by using probability update method,which can be used to assist the positioning function of the system;compares several state estimation algorithms and selects Kalman filtering method.Then based on the above selection,the first version cartographer which is Google's new open source library is selected as the prototype of the lightweight SLAM system of this paper.After analyzing and studying the main modules of the cartographer system,the cutting scheme of the library is proposed,the feasibility and positioning ability of which are verified through simulation comparison.After briefly introducing the Foot Strapped PDR Indoor Positioning System used in this paper,a new system combining a lightweight SLAM system and the Foot Strapped PDR Indoor Positioning System was designed to integrate the laser data of the lightweight SLAM system and PDR data.Experiments show that the combination system designed in this paper can improve the positioning accuracy of Foot Strapped PDR Indoor Positioning System.The combination system designed in this paper can be applied in many aspects and has positive effects and important values in many applications,such as cave exploration,VR games,disaster rescue and relief operation and other scenes that require location based services.