Design Of Ultrasonic Indoor Positioning System Based On Mobile Domain

In recent years,the demand for indoor positioning has become increasingly urgent,especially in engineering construction,such as: positioning of tunnel personnel and equipment under construction,disaster emergency rescue and daily attendance management.Therefore,the research of fast,low-power,large-capacity indoor positioning systems is particularly important.This paper is based on the ultrasonic ranging system and proposes a mobile domain positioning method for the specific conditions in tunnel construction.The minimum area covered by the ultrasonic waves that can be detected by the position of the moving point to be measured is referred to as a basic positioning domain.According to the actual situation,the measured area is divided into N basic positioning domains.If a basic positioning domain is treated as a window,the window is gradually moved from 1 to N until the basic positioning domain condition is satisfied,that is,the location of the basic positioning domain is determined by the mobile domain.After determining the basic positioning domain,the three optimal values in the domain are found,the theoretical coordinates are solved by the trilateral positioning algorithm,and the actual coordinate values of the moving target are obtained through coordinate transformation,and displayed in the upper computer interface.The design of the ultrasonic positioning system includes hardware design and software design.The hardware system includes an ultrasonic transmitting module,an ultrasonic receiving module,an ultrasonic control module,a wireless transparent transmission module,and a system wireless control module.The software is modularized according to the function of the hardware,and gives the program flow chart,and is written by the upper computer in the eclipse development platform.The experimental results show that the errors of static positioning and dynamic positioning of the system are in line with engineering requirements.Compared with other positioning designs,the positioning capacity is large,the speed is fast,the power consumption is low,and it is more in line with the application of the tunnel construction environment.