| With the development of China’s information society,the Internet of Things technology has received widespread attention from industry and academia.The Internet of Things technology realizes the ubiquitous connection of things and things,things and human.It provides technical support for the realization of the underlying perception in wireless sensor networks.As an architectural foundation of the Internet of Things Radio frequency identification technology(RFID)has played an important role in the field of human perception.Human perception technology is usually realized by video or image at present,but these traditional perception methods are more limited and easily affected by conditions such as lighting and obstructions.Using RFID technology to measure human body characteristics not only overcome the traditional problems but also greatly reduce the risk of privacy leakage.In unmanned stores,in order to better serve customers,it is necessary to collect user information.height as one of the signs of customers can help merchants provide customers with exclusive services.In this paper,we modeled,analyzed and tested the body height of the human body signs in the passive environment.The specific content will be studied around the following points:First of all,we carry out theoretical modeling for signal occlusion in shopping environment.According to the propagation characteristics of the signal in indoor environment,we analyzed the relationship between the decline of indoor wireless signal and the distance.Through the simulation of the shopping environment,a linear label array is designed to detect the height of the human body.and the design verification experiment fully demonstrates the feasibility of the current signal arrangement.In addition,in a static environment,this paper summarizes the signal change pattern corresponding to the dynamic human body,and uses the signal strength information change based on the human occlusion signal to infer several situations of human motion.Secondly,we explored the establishment of a theoretical system of height recognition to solve the problem of passive perception of height recognition,and then we preprocessed the signal and innovatively proposed an automatic threshold method to segment the signal.In this paper,the influence degree of human body parts on the signal is classified according to the way of image transformation.After the signal classification is completed,the height recognition and classification algorithm is proposed to judge the height of human body.Finally,we test the height recognition system from many angles and analyze the accuracy of the proposed method.The experimental results show that our method has strong applicability and high recognition accuracy in the field of RFID human body recognition,and can be applied to the experimental scene. |
