Research On Human-Computer Interaction Via RFID Tag Array

Recently,with the increasing popularity of sensing technology,people desire to have a more natural and continuous way of human-computer interaction which has attracted more and more attention.Therefore,the demand for more convenient human-computer interaction is impending.As an effective tracking scheme for target object,Radio Frequency Identification(RFID)has been widely used in locating,sensing,and tracking with the advantages of battery-less sensor and light-weight.But it has some shortcomings such as the signal of tag is vulnerable to the multi-path effect.So the perception of a single tag is limited.In this paper,we talk about how to use the tag array to overcome the shortcomings.Following by the main work of this paper:(1)This paper proposes RF-Brush,a battery-free and light-weight solution for orientation estimating and trajectory tracking based on RFID,by simply attaching a linear RFID tag array onto the linear shaped object like a brush.Particularly,we build two geometric models to depict the relationship between the RF-signal and the 3D orientation as well as 2D movement,respectively.Then,abnormal result detection and correction algorithm is designed.Finally,we evaluated the performance in real environment.The experiments show that RF-Brush achieves an average error of 5.7 degrees and 8.6 degrees of elevation and azimuthal angle,respectively,and an average error of 3.8cm and 4.2cm in movement tracking along X-axis and Y-axis,respectively.(2)Based on the RF-Brush,this paper proposes the linear tag array-based HCI solution,a device-based art design system.Particularly,in the process of writing letters,there has some invalid operations such as pen-lifting.So a feature extraction algorithm based on Arrival of Angle(AOA)is proposed,we are able to extract the obviously different phase features of invalid operations to effective operations.In addition,we evaluated the robustness,stability and real-time performance of this prototype system.The experimental results show that it has excellent robustness and real-time performance.And it is able to interact with intelligent devices without obvious time delay.(3)This paper explores the absorption effect of liquid on tag signal.Based on the phenomenon that the liquid can reduce the energy of tag,we propose the twodimensional tag array-based HCI solution.Particularly,we design the layout of twodimensional tag array to obtain more stable tag signal.In view of the recognition accuracy and robustness of the system,a experimental evaluation was carried out in real environment.The experimental result shows the system can correctly recognize the user's input of letter and realize device-free HCI experience.