Research On Indoor Device-free Perception Model And Localization Algorithm Based On RSSI

Nowadays,the wireless sensor network as an important component of the bottom of the Internet of things has been more and more development and application,at the same time,people's demand for perception of positioning technology is also increasing;therefore,the use of wireless sensor networks device-free perception location has been widely concerned as a new research direction.The device-free sensing location method based on wireless sensor network has many advantages compared with traditional sensing location method.Commonly used by the detection of light,ultrasound,infrared and other physical properties of the perception-of positioning methods will be subject to many environmental factors,such as light,temperature,blind and so on.The device-free sensing method based on wireless sensor network can not be disturbed by the above factors,it can effectively adapt to a variety of changing environments,and does not need to perceive the target with any electronic tags and mobile devices,is a new type of device-free perceived method.So it has a broader development and application prospects.In the wireless sensor network using RF signal for device-free sensing method,in essence,is the use of obstacles to block the impact of wireless signal link,when an object block the wireless link,it will make the link signal reception strength(Received Signal-Strength Indication,RSSI)changes by analyzing the wireless link of this change attributes,summed up the law of change,can be achieved in the experimental area for the purpose of personnel perception,and through the use of elliptical model algorithm,the perception of the existence of the region To locate.Therefore,this paper focuses on indoor device-free sensing model and localization algorithm.In this thesis,the propagation characteristics and fading models of indoor wireless signals are analyzed.The reason of obstacle to signal power is analyzed and the ellipse model localization method is summarized.On this basis,the device-free sensing location experiment model and experimental scheme are designed.This includes the planning of the perceptual positioning process,the design of the experimental platform,the data collection and processing methods used,and the algorithm used to perceive the location.At the same time,the ellipse model localization algorithm is studied on the basis of the experimental model.Based on the experimental results,the localization algorithm is improved,the edge effect in the positioning is solved,and the positioning accuracy of the ellipse model localization algorithm is improved.In the hardware selection of the experimental system,the ZigBee wireless sensor network positioning node hardware module with CC2530 chip as the control core is used in the experiment.In the software programming,the IAR Embedded Workbench compiles the environment using TI's simple protocol Basic RF to write and modify the node program to complete the program design of the sensing node.Through the use of the ring mechanism to achieve the entire sensor network node control and data acquisition,completed the device-free sensing positioning experimental model of hardware and software platform,and The experimental results were analyzed.