Indoor Positioning Technology Research

With the development of application technology based on location information,LBS(location-based services)has become an indispensable demand in People's daily life and work,especially in the complex indoor environment,such as airports,hospitals,supermarkets,underground mine area and so on.People have a pressing need for location service.Additionally,traditional positioning mainly includes two types of technology:GPS and the positioning based on mobile network base-station.For GPS,radio signal refraction or reflection caused by indoor obstacles and energy decay will lead to inaccurate positioning or even unable to perform positioning.GPS is not available indoors,while mobile network positioning lacks high accuracy.Consequently,special indoor positioning technology must be applied in indoor circumstance.This paper firstly introduces various indoor positioning solutions:LED visible light positioning,Wi-Fi positioning,Bluetooth positioning,etc.and researches their status,prospect,positioning principal and system architecture.Then the paper improves two positioning algorithms:three points positioning algorithm based on ranging and improved centroid positioning algorithm based on non-ranging,and explains their positioning algorithm,compares their positioning accuracy in parking lot circumstance.Further researches on three points positioning algorithm based on ranging,and improves the system model.According to distance measuring in real condition,the relation model between signal strength and distance is seriously affected by circumstance.The comparison of improved model and former model in ideal environment is conducted by simulation.Finally,illustrates the real application of these three positioning solutions in parking lot.Best fusion of positioning solution is given according to field test result and feasibility analysis of above three positioning solutions in parking lot.