Self-localization method of sensor network node based on smartphone

Abstract

The invention discloses a self-localization method of a sensor network node based on a smartphone. The method uses a general smartphone to replace a custom hardware module to be used as a network node, a plurality of mobile phone nodes orderly transmit linear frequency modulation (LFM) sound signals of 2k-6kHz by means of a loudspeaker and a microphone, and meanwhile, different mobile phone nodes sample the linear frequency modulation sound signals at a fixed frequency (44.1 kHz). Detection is performed on a sampling waveform by means of a generalized correlation method, and in view of a multipath effect, the self-localization method of the sensor network node based on the smartphone provided by the invention adopts a method of combining a threshold value method and time-frequency analysis to effectively inhibit the multipath effect, so that the arrival time of the linear frequency modulation sound signals can be obtained, then distance information between different nodes can be obtained, and finally, the unknown nodes can be located by adopting a multidimensional scaling (MDS) algorithm. The method of the invention does not need clock synchronization between the mobile phone nodes, and since the frequency is fixed, the arrival time of the sound signals can be accurately estimated through a sampling number; besides, the location accuracy is high, the cost is low, the networking is convenient and the prospect is wide.

Description

technical field [0001] The invention relates to a node self-positioning method, in particular to a smart phone-based sensor network node self-positioning method. Background technique [0002] In the application of sensor networks, the location information of nodes plays a very important role in many fields of sensor network applications, especially in indoor and outdoor environments where GPS applications are limited. By obtaining the location information of nodes, not only can the topology of the network be established, and then the cooperation of nodes can be realized, but it is also crucial for data fusion and network management. At present, there are many methods and researches on self-location of nodes. The present invention is a kind of node self-location method that uses a general-purpose smart phone instead of a customized hardware module as a sensor node, only uses acoustic signals, and uses the MDS algorithm to realize node self-location. It is suitable for limited...

AI Technical Summary

Problems solved by technology

In these methods, ultrasonic, wireless and other signals are mostly used as measurement signals, and sensor nodes are often customized hardware modules, which are costly and poor in portability.

The disadvantages mainly include the following aspects: (1) The application of ultrasonic and wireless signals requires additional hardware support, which reduces its convenience; (2) The propagation speed of wireless signals is fast, and the accuracy of time-of-arrival measurement is required to be high; ( 3) Clock synchronization between different hardware modules is required, and there is uncertainty in the time delay between wireless signal synchronization and acoustic signal acquisition

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