Design And Realization Of Swimming Pool Alarming And Positioning System

In recent years,with the increasing of the number of swimmers,drowning accidents have become an important issue year by year.The traditional lifeguard manpower supervision model is difficult to make a timely response on sudden drowning accidents.So how to quickly find the drowning position and notify lifeguards to rescue becomes a common concern.In order to meet the demand mentioned above,this paper designed a swimming pool alarming and positioning system.The system consists of four parts: underwater acoustic beacon,underwater long baseline array,signal collector and signal processing software.When the drowning accident occurs,the beacon emits the acoustic signal.The signal collector synchronously acquires the acoustic signal received by the long baseline array.Then the collector digitizes the collected signal and transmits it to the host computer via USB.After receiving the digital signal,the computer software makes a series of analysis.Finally,the software calculates the position,displays the drowning information and notifies the lifeguard of rescuing.Firstly,the paper analyzes several methods based on the TDOA long baseline positioning equation.According to the simulation results,the Fang-Chan joint algorithm is used for software implementation.At the same time,the matched filtering and envelope detection techniques are used to estimate the delay signal.Then the paper designed and realized the functions of underwater acoustic beacon and signal processing software.The internal program of the acoustic beacon is developed based on the STM8 L series low-power MCU platform.The use of IIC communication technology can achieve the beacon pressure detection,and the RTC wake-up function makes it possible to reduce the average power consumption of the beacon when the beacon is in the no-signal-transmission state.Signal processing software is designed based on Qt Creator platform,and it consists of a number of independent modules,including signal acquisition,bandpass filter,correlation peak detection,arrival time choosing,position calculation and display interface.The signal acquisition module preprocesses the signal and the position calculation module calculates the position using the correct time delay.Finally,the integrated software platform gives the results of comprehensive processing.In order to verify the system performance,the positioning system designed in the paperhas been tested several times in the reverberation pool and the standard swimming pool.The test results show that the system can achieve real-time signal transmission,signal acquisition,location information display and other functions,so the system can meet the swimming pool alarming and positioning needs.