Study On Indoor Positioning System Based On Ultrasonic Network

With the development of the Internet of Things technology,people's demand for location services is increasing.Outdoor positioning technologies such as GPS and Beidou satellite navigation technology have been developed more mature.Compared with outdoor positioning technology,the development of indoor positioning technology is slower,but the demand for indoor positioning is increasing.Indoor positioning has a wide range of applications in many fields,such as in large shopping malls to guide customers to buy required goods,underground parking lots to find car locations,logistics warehouse robots to sort and move goods,and so on.Among various indoor positioning technologies,ultrasonic positioning technology has the advantages of easy signal processing,low cost,and high positioning accuracy.But at the same time,there are also problems such as layout efficiency of ultrasonic probes used as base stations,inaccurate synchronization timing at the ultrasonic transmitter and receiver,and ultrasonic speed susceptible to temperature.Base on the existing ultrasonic positioning technology,this paper has done relevant research work in the system structure,hardware circuit,and software algorithm to improve the positioning performance and reliability of the positioning system.This article first analyzes and masters the research status of indoor and outdoor positioning related technologies,then introduces the characteristics of ultrasonic,ultrasonic ranging and ultrasonic positioning principles,and elaborates the commonly used ultrasonic positioning algorithms.By designing simulation experiments,analyzing and verifying the performance indicators of these several commonly used positioning algorithms,combining the results of the algorithm simulation experiments,comparing the positioning error data of each algorithm.Judging from the results of positioning errors in each positioning algorithm,the TDOA positioning algorithm has the smallest error and more stable fluctuations.Therefore,this study chooses the TDOA algorithm as the applied algorithm.Then it conducts in-depth research from two aspects of ultrasonic positioning system structure and hardware circuit.Based on the analysis of the principle of the arrangement of the ultrasonic receiving node,the arrangement scheme of the receiving node of the ultrasonic positioning system is proposed.Based on the principle of ultrasonic positioning,the hardware circuit architecture design of the positioning system is proposed.Select the positioning system controller,design the ultrasonic signal transceiver circuit,and complete the PCB design and the welding and debugging of the circuit board.Realize the construction of the experimental platform of the ultrasonic positioning system.Finally,based on the completion of the positioning system structure and hardware experimental platform,the corresponding ultrasonic receiving node arrangement program,positioning system transceiver signal processing program and real-time visualization software are developed.After the construction of the ultrasonic positioning system structure and experiment platform,and the development of the corresponding software.After constructing the structure of the ultrasonic positioning system and the hardware experiment platform and the development of the corresponding software,the functions of the ultrasonic positioning system are tested,and the receiving and sending signal test experiments are carried out.Then measure the direction angle of the ultrasonic sensor and carry out the system positioning experiment.The final experimental results show that the positioning error can be controlled within 3-5cm.After analyzing the positioning result data,it is found that the positioning system still has some shortcomings,and thus put forward the space for further improvement and the direction worthy of further study.