| Natural disasters always happen,how to rescue victims effectively in disaster area has become a serious problem.Research on rescue technology has been a hotspot of universities and industry.The traditional rescue techniques such as infrared detection and radar detection have small application range and low search efficiency.With the development of science and technology,more and more people have mobile phones.In this research,a disaster rescue system based on mobile phone signal is developed,which uses the pseudo base station and hand-held detection equipment to accurately locate the victim's mobile phone and rescue the victim.First,we establish a connection with the phone by triggering cell reselection.Then,we can get the approximate position of the mobile phone from the pseudo base station.Finally,we use handheld detection equipment to locate the victim's mobile phone accurately.This research introduces the hardware structure of the hand-held detection equipment and realizes the function of power receiving.Due to the strong noise in disaster environment,high-precision localization algorithms need to be designed.1)For the localization algorithm of pseudo base station,this paper studies three classical algorithms based on TDOA(Time Difference of Arrival)--Fang algorithm,Taylor algorithm and Chan algorithm.The simulation results show that Chan algorithm has the best positioning accuracy and can be used for coarse positioning of mobile phones.2)For the localization algorithm of handheld detection equipment,a ratio approach combined with Gauss-Newton algorithm is proposed in this paper.Simulation results show that the algorithm proposed in this paper has great precision when compared with Cramer-Rao lower bound.In order to verify the effectiveness of this algorithm,we carried a positioning experiment in the space of 10 m×6 m.Experiment results show that the proposed algorithm has great performance because the localization error is only 0.51m when the mobile phone is buried. |
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