Research On Indoor Navigation Based On Visible Light Communication Of Automated Guided Vehicles

With the development of the unmanned and smart factory warehouse,the indoor positioning and path planning of Automated Guided Vehicle(AGV)become the central issues which are studied by both domestic and foreign scholars.White Light Emitting Diode(LED)has a lot of merits,such as no electromagnetic noise,low production cost and integration of communication and lighting.Therefore,indoor navigation technology based on visible light communication(VLC)gets more and more attention.In this paper,the improved fingerprint matching scheme based on light intensity is used to position the AGV in the room.The sending module and the receiving module of the LED are designed and simulated to realize the coordinate information reception of the LED.In addition,single-AGV global path planning method based on the A*algorithm is improved in order to implement AGV collision-free path in the indoor map with large nodes.The research contents of this paper are as follows.(1)The optical parameters of LED are introduced in this dissertation.The Lambert radiation model of LED is studied in order to simulate the indoor illumination distribution.The simulation shows that the LED lights meet the requirement of indoor illumination.(2)By analyzing and comparing the existing indoor positioning methods,an improved fingerprint matching scheme based on light intensity is designed in this dissertation.The scheme adopts the grid method to divide the indoor map,and combines grid coordinates with the light intensity of LED at this grid to effectively improve the location accuracy.(3)By comparing with the current indoor map modeling method,the traditional binary grid method is improved.The safety values of the barrier neighborhood grid are increased,and the multiple safety factor model is established according to the size of AGV and grid length.The simulation shows that the model effectively reduces the number of dangerous points and greatly improves the security of the path.(4)The LED positioning module based on VLC technology is designed in this dissertation,including the LED driver module,the photoelectric conversion module,the signal amplifier module and the AD converter module.The process of indoor light positioning program based on FPGA is described,including the time-division multiplexing sending program,the AD converter program,and the digital tube display program.In view of the alternation of Os and 1s in LED coding,the human eye can feel the scintillation.Therefore,the transmission frame structure is designed based on Manchester encoding.The simulation shows that the information transmission of LED coordinates can be realized.(5)The open list,the search strategy,the grid model and the treatment methods of the inflection points are improved to solve the problems of traditional A*algorithm.The simulation in the large map shows that AGV path planning based on the improved A*algorithm achieves higher safety quotiety,smoother path and faster search speed.