Research On Indoor Accurate Positioning Based On Rotating Light Fingerprint

Under the demand of information development,the need to know the precise location of people or objects in real time has become more and more prominent,which has attracted a large number of researchers and engineers to study various indoor precise positioning and indoor precision navigation technology,and promoted the development of various positioning technologies.At present,the mainstream indoor positioning technologies include WiFi positioning technology,Bluetooth positioning technology,inertial navigation technology,ultra-bandwidth positioning technology and visible light positioning technology.Although these positioning techniques and methods have been applied in different occasions,the positioning error is large(meter-level accuracy),or the accuracy is high,but the positioning cost is large,and it is easily misdirected by obstacles.In recent years,the academic community has begun to study the technology based on visible light.This positioning method has high precision,but its positioning performance also depends on multi-point deployment,resulting in higher deployment cost.This paper proposes a new positioning scheme based on light,which is a relatively good directivity medium,as an indication signal for positioning.Different from the multi-anchor node/reference point cooperative positioning of the existing positioning system,the positioning scheme proposed in this paper can achieve positioning under a single deployment anchor node,and the positioning accuracy reaches centimeter level.The core positioning idea of the scheme is that a single anchor node realizes light and shadow(invisible to the naked eye)projecting different fast changing laws to different positions in space through a special photoelectric structure design,thereby forming a specific optical fingerprint closely related to the position;The position target is determined by collecting the light intensity signal at the location,extracting the weak light shadow signal hidden therein,and analyzing the change rule,thereby determining the projection position corresponding to the law.The contributions of the thesis include: Proposing a new positioning scheme based on rotating light fingerprints;Designing,fabricating,and implementing a transmitting device(anchor node)capable of generating a rotating optical fingerprint and corresponding detecting device(target);Design and implement(based on STM32 processor)an optical fingerprint signal detection algorithm against ambient light interference.The paper conducted a series of experimental tests on the entire system.The experimental test results show that the positioning scheme of this paper can achieve precise positioning with an average error of less than 5cm.