Polarized Light Positioning System Design Based On Light Intensity Ratio

The progress of the indoor visible light positioning system has been remarkable in recent years.The indoor visible positioning system has the characteristics of high localization accuracy,low deployment and maintenance costs,abundant spectrum resources,and can work in electromagnetically sensitive places.As a result,it has the ability to integrate indoor and outdoor positioning services seamlessly.Therefore,the indoor visible light positioning system has become a popular research topic.This thesis studies the photodiode-based visible light positioning system in indoor environment and implements a polarized light-based positioning mechanism for movable objects,enriching the positioning technology of visible light positioning system and expanding their application scenarios.Photodiode-based indoor visible light positioning systems are widely investigated and implemented in the indoor environment due to their excellent localization accuracy and low power consumption.However,most of existing researches rely on auxiliary devices or fingerprint databases,such as smartphones or large fingerprint data sets.Many Io T devices do not have enough space to be equipped with additional auxiliary equipments,nor enough capability to support complex computation and high bandwidth communication,thus hindering the promotion and application of indoor visible light positioning system in real life.To address the issues raised above,this thesis presents the design of indoor visible light positioning system P-Light and Polar by considering the elements of localization accuracy,system usability,deployment and maintenance cost.The following are the main contributions of this thesis:(1)This thesis develops a polarized light-based indoor visible light positioning system,P-Light.Based on the polarized light and light propagation model,the Angledifference-based Orientation Method(AOM)and Polarized-light-based Location Algorithm(PLA)are designed to calculate the orientation and coordinate position of the receiver.The results demonstrate that P-Light can achieve the average error of1.24° in orientation estimation using the AOM algorithm.When using the PLA location algorithm for positioning,it can obtain the average Xo Y plane error of 26.09 cm and the average height error of 6.68 cm.(2)Considering the interference of ambient light on the localization performance of indoor visible light positioning system,this thesis designs the Eliminating-ambientlight Location Algorithm(ELA)on the basis of P-Light.The results show that P-Light can achieve the average Xo Y plane error of 27.08 cm and the average height error of6.97 cm using the ELA location algorithm in the presence of ambient light interference,and the localization accuracy of this algorithm is better than that of the PLA algorithm under the same settings.(3)In order to attain improved localization precision,this thesis presents Polar,a light intensity ratio-based indoor polarized light positioning system.In this thesis,Polarized-angle-based Orientation Method(POM)is designed with the help of polarizer.The Light-intensity-ratio-based Location Algorithm(LLA)is designed after researching the Incident Angle Sensing Model(IASM)based on the light intensity ratio.The results demonstrate that Polar can reach the average error of 1.56° in orientation estimate and the average error of 7.87 cm and 2.19 cm in terms of the Xo Y plane and height in localization precision,respectively.