The Research On Visible Light Vehicle Positioning Technology In Intelligent Transportation

With the rapid development of light-emitting diodes,LED light sources with high luminous efficiency,low power consumption,long life,and low cost are widely used in the fields of home lighting,traffic signs,and advertising displays.In the field of intelligent transportation,LED-based visible light positioning technology can use existing road signal lights,street lights and other road infrastructure to achieve accurate positioning of driving vehicles,and has the advantages of environmental protection,convenience and speed.It has great development potential and research value in the field of intelligent transportation.This paper studies the visible light positioning technology in outdoor intelligent transportation from the following aspects:1.Introduced the characteristics,luminescence principle and selection of photoelectric detectors of LED traffic lights in the intelligent transportation system.Combined with the outdoor environment,an outdoor visible light signal transmission model was established,and the optical power distribution and signal-to-noise ratio performance of outdoor LED traffic lights were simulated and analyzed.2.In view of the outdoor complex channel environment,the signal transmission model of LED traffic lights was established.The influence of the reception angle and the road width of the vehicle on the signal transmission characteristics of LED traffic lights was discussed.The signal transmission of LED traffic lights under different weather was simulated and analyzed.Attenuation quantitatively gives the working interval when positioning vehicles based on outdoor LED traffic lights.3.Researched positioning algorithms based on received signal strength(RSS),time difference of arrival(TDOA),time of arrival(TOA)and received signal angle(AOA);established a motor vehicle positioning model for urban road traffic system,combining Relevant detection algorithm,the parameter estimation of the arrival time difference of TDOA algorithm is studied;for the nonlinear equations in TDOA algorithm,Chan algorithm is selected as the auxiliary algorithm to solve,and the performance of the visible light vehicle positioning system of Chan-TDOA algorithm is simulated.The research results show that:(1)Different receiving angles have a certain influence on the transmission distance of LED traffic lights,and the best receiving angle is when the receiving angle is 25°.(2)Under the same weather conditions,the working signal of the motor vehicle signal and the crosswalk signal are different due to the different positions.(3)When using visible light to locate the vehicle,weather conditions such as rain,fog,and snow have a great influence on the working area.The worse the weather conditions,the shorter the working interval.(4)The positioning algorithm of Chan-TDOA can be used to effectively locate the moving vehicles,and the average root mean square error is 15.53cm.