Research On Inertial Navigation Assisted Visible Light Imaging Indoor Positioning System

In recent years,the demand for indoor positioning services has been increasing day by day.In indoor scenarios,Global Positioning System(GPS)is often not available due to the obstruction of buildings.Most of the common indoor positioning systems nowadays utilize mature short-range wireless communication technologies to achieve positioning functions,such as UWB,WIFI and RFID technologies.The positioning accuracy of these positioning systems basically meets the application requirements,but they often fail to locate in complex electromagnetic environments,and besides,the multipath effect during electromagnetic signal propagation may also bring about large positioning errors.To address these problems,an indoor positioning system based on visible light imaging positioning technology is developed in this paper,supplemented by inertial navigation positioning technology,to achieve high accuracy positioning in indoor environments.The research content of this paper mainly includes.(1)System design.Based on the application requirements of the indoor positioning system,the overall scheme design of the system is carried out.The system consists of five parts: signal transmitting module host computer,signal transmitting module,data acquisition module,positioning solution module and positioning visualization platform.The data acquisition module and the positioning solution module are fixed on the carrier equipment that needs to realize the positioning function,and the data acquisition module completes the reception of visible light signals and the collection of inertial information.(2)Visible light communication scheme design.The coding and modulation scheme of the signal transmitting module is designed according to the influencing factors of visible light communication,and the number and the image coordinate information of the light source are resolved by processing the collected light and dark streak images.(3)Indoor positioning algorithm research.The advantages and disadvantages of the traditional visible light imaging positioning algorithm are analyzed,and the optimization idea of establishing an accurate imaging model and using inertial navigation positioning algorithm to assist in positioning is proposed.Based on the light source imaging model,an improved visible imaging positioning algorithm is proposed,supplemented with attitude information to reduce the complexity of the solution.The unscented Kalman filter algorithm is used to solve the carrier attitude,and inertial information is used to solve the positioning data directly when visible light information cannot be used for positioning.At the same time,the carrier coordinates are predicted,thus simplifying the bright and dark streak image processing process.(4)System software and hardware development.The overall hardware selection of the system is carried out,as well as the LED driver circuit design.Complete the software development of the upper computer of the signal transmitting module and the signal transmitting module,and realize the serial communication between the two.Implemented the four functions of data reading,data processing,position solving and result sending in the positioning solution module,using multi-threaded programming to solve the problem of time mismatch of each function.The positioning visualization platform communicates with the positioning solution module via TCP/IP protocol,thus realizing the display of positioning results.(5)System testing.A test environment was set up to make the carrier device move along the prescribed path for positioning tests,and the positioning results and positioning errors of different positioning algorithms were analyzed and compared.The test results show that the average positioning error of the system positioning algorithm proposed in this paper is 2.24 cm,while the positioning errors of the inertial navigation positioning algorithm and the traditional visible light positioning algorithm alone are9.63 cm and 3.16 cm respectively,and the system positioning algorithm has a more stable positioning effect and higher positioning accuracy.The inertial navigation-assisted visible light imaging indoor positioning system built in this paper can achieve stable and reliable indoor positioning with high accuracy,which has certain significance to the development of indoor positioning technology.