| With the deepening of the age of intelligence,information,and networking,location services based on positioning technology have become more and more important and have penetrated into all aspects of people’s lives.According to relevant research surveys,more than 80%of human activities are carried out indoors,and there is a great demand for indoor target location information.Traditional radio frequency wireless communication technology has problems such as high cost and multipath effect,while visible light communication technology has the characteristics of low cost,energy saving and environmental protection.The received signal strength method in the indoor positioning algorithm based on visible light has the advantages of low complexity and no need for synchronization.Therefore,the research of visible light indoor positioning based on the received signal strength has become a relatively popular research field.This paper first studies the research background and significance of visible light positioning and the current research status at home and abroad,and analyzes the current status of visible light positioning based on the received signal strength.Secondly,it conducts detailed research on the relevant theoretical knowledge of visible light communication and received signal strength algorithms.On the above,completed the following research content:(1)Study the relevant characteristics of light-emitting diodes and photodiodes,and analyze the optical channel model.Use MATLAB to simulate optical power distribution,illumination distribution and signal-to-noise ratio distribution,and tests the feasibility of visible light communication with simple experiments.(2)Study the influence of received signal strength algorithm on positioning accuracy.Aiming at the problem of inaccurate distance estimation between the sender and receiver,a solution to correct the estimated distance using a correction factor is proposed.In addition,the algorithm of using mathematical analysis and exhaustive methods to screen the optimal correction factor minimizes the error between the estimated distance and the true distance.The corrected distance is then used to estimate the target position using the trilateral positioning algorithm.The simulation results show that the improved positioning algorithm can greatly improve the positioning accuracy of the system.(3)Research on the visible light positioning system based on the received signal strength.The system uses MiniSTM32 as the central control chip,designs the transmitter and receiver hardware circuits,and test the circuits to ensure the normal operation of the transceiver.Design the transmitter and receiver software programs,use curve fitting to obtain the relationship between output voltage and distance,and finally test the positioning error in the positioning model.The positioning accuracy is within 3cm,which can meet the daily positioning needs. |
