The Software Design Of Active And Real-time Acoustic Localization System

To measure the technical parameter of explosive power during explosion experiment on land and military drill,we usually set a large number of blast wave sensors at a certain distance from explosion point.To measure the location of many sensors fast and accurately,the thesis proposes a scheme of active and real-time acoustic localization and pay attention to researching realization and promotion of the software design of active and real-time acoustic localization system.The thesis builds a system model of active and real-time acoustic localization base on the localization principle of time difference of arrival.Active and real-time acoustic localization system consists of wireless monitoring terminal,acoustic emission system and acoustic signal processing and positioning system.We set the frequency and code of acoustic signal and write programs of the previous two subsystems.Considering the real time of processing and positioning system and superiority of software architecture,the system implements programming base on ?C/OS-II real-time operating system of ARM9.We briefly design the algorithms of 4 process in acoustic signal processing and identification and research the promoted strategy to improve the performance of robustness,real time and accuracy carefully and deep.In the aspect of real-time processing,the thesis presents the algorithm of fast frequency estimation and promoted strategies of several computing methods in detail section.In the aspect of software robustness,we segment effective signal range into short and exact effective signal,save all position point whose segment correlate with characteristic signal to become alternatives during ascertaining characteristic signal's starting point.Besides,we don't estimate the identified frequency any more every time during fast estimating signal's frequency and save the first round result of frequency estimation to estimate this frequency for the second round when some frequency doesn't estimate successfully in the first round.In the aspect of localization accuracy,we use the wayof phase rectification to rectify the deviation of acoustic signal starting point and compute acoustic speed precisely according to environmental temperature to improve the precision of distance difference.Substituting experimental data and Comparing the performance after promoting with before,indeed the performance of all aspects after promoting is improved greatly.Multiple and repeated experiments prove that the scheme of using active and real-time acoustic localization system to locate a great number of sensors is feasible.After the thorough promotion of software program structure and partial algorithm,the robustness,real time and accuracy of system is improved substantially.At present,the precision of locating reaches 40 centimeters and the duration of processing reaches 5 seconds.