Research And Implementation Of Visible Indoor Positioning Based On Single LED Lamp

LED-based VLP has attracted more and more attention due to its high accuracy and low cost.VLP usually uses a photodiode or image sensor as a receiver,which is more resistant to ambient light interference.However,the LEDs need at least three light sources to implement triangulation.More and more researchers pay attention to the positioning of a single LED light.However,a single LED lamp needs additional auxiliary information such as inertial sensor,marker or the shape of the lamp.It is difficult to realize high precision single-LED-based positioning with less auxiliary information as possible.To solve the problem of insufficient accuracy caused by scale factor approximation in single-circular-LED-based positioning,geometric analysis positioning method,and distance constraint positioning methods based on single rectangular-LED are proposed and implemented in this thesis.The formal realizes positioning by using the geometric relationship between four vertices and the diagonal intersection and its projection of rectangular-LED lamp.The latter uses the distance relationship between the projection point and the actual vertex to find the coefficient of the transmission projection,and implements positioning by using the distance from the vertex to the optical center.As system noise and vertex recognition errors have a certain impact on the positioning results,error analysis and simulation verification show that the geometric analysis method is sensitive to vertex errors,achives high positioning accuracy but low algorithm complexity,distance constraint positioning methods can tolerate a level of vertice errors,thus achieves higher accuracy performance.In this thesis,a rectangular lamp with a side length of 16.2cm was installed in the area of 2×2×2.98m~3,and a single-lamp indoor positioning experiment environment was established.Experimental results show that,compared with the geometric analysis method,the positioning accuracy of the distance constraint method is higher,and its three-dimensional positioning error is 10cm?12cm.The average positioning accuracy is improved by 18.3%?26.5%compared to the circular-LED lamp positioning method.