| In recent years,with the rapid development of computer technology,society is gradually moving towards the era of Internet of everything.Due to the wide deployment of Wi Fi infrastructure and the continuous maturation of Wi Fi-based sensing technology,the technology has been widely used in many fields and has brought great convenience to people’s lives.When using Wi Fi radio frequency(RF)signals as sensing work in specific scenes to sense people’s activities,it is necessary to determine in advance whether people have entered the sensing area of the sensing device.This not only excludes the influence of errors caused by other people activities outside the scene,but also provides location-related guidance information for people activity identification.Therefore,it is particularly important to determine the sensing boundary of the sensing device to obtain an accurate person activity detection boundary.Ideally,we obtain accurate person activity detection boundary lines by some methods,which need to be determined based on the sensing range of the sensing device.Although much research has been conducted in detecting person activity states or locating person targets,there are still some limitations in applying these methods to determine clear sensing ranges in real-life scenarios.To address these issues,the research focus of this thesis is as follows:First,in order to eliminate video surveillance blind zones with minimal video communication Quality of Service(Qo S)loss and using the existing Wi Fi infrastructure as a sensing device,this thesis analyzes a boundary for detecting human intrusion activity that takes into account both communication quality and blind zone elimination.The specific approach is as follows: first,an intruder interference channel model is derived to accurately describe the intrinsic relationship between the presence of intruders and wireless channel variations.Then,a sensing device sensing boundary model is further derived from the channel model to obtain the human intrusion detection boundary,and this detection boundary is used to guide the deployment location of the sensing device to simultaneously meet the requirements of surveillance blind zone elimination and communication quality maximization.In addition,a practical person intrusion activity detection boundary estimation system is designed in this thesis.The final simulation and experimental results not only verify the correctness of the derived human intrusion activity detection boundary,but also show that the deployment location of sensing devices guided by the human intrusion detection boundary has good performance in terms of both surveillance blind zone elimination and communication Qo S.Second,considering that different intruders have different body sizes,the area that can reflect and obstruct wireless signals varies,which can affect the determination of accurate man-intrusion activity detection boundaries.To solve such problems and make person activity detection more versatile in daily life environments,this thesis extends the sensing device perception boundary model.Specifically,this thesis uses mathematical modeling to determine the area of intruders that obstruct and reflect wireless signals,and adds consideration of intruder body size in the derivation of the perception boundary model.According to the new perceptual boundary model,the determination of the boundary for the detection of human intrusion activities is extended.Ultimately,by conducting experiments in real environments,the results show the correctness and effectiveness of the sensing device deployment locations determined by the new man intrusion activity detection boundary in terms of communication quality and blind zone elimination. |
