Research On The Non-contact Equipment Interaction Based On The Doppler Shift

With the development of pervasive computing and the intelligent terminal, the interaction between people and equipment becomes more diverse. Based on the widely use of mobile devices and low power sensors, this paper puts forward a device interaction method within the home environment, which uses the acoustic sensors to send and receive high-frequency sound, using the acoustic technology based on doppler effect, combining with pointing gestures, realize the interaction selection between the household equipment.First, analyzing the generation and characteristics of the doppler signal, in order to successfully extract the doppler shift, it need through band-pass audio signal processing technology to realize the robustness. To improve the frequency resolution of system,analyzing the change over time by using the undersampling technique and short time Fourier transform spectrum, measure the doppler shift and find the peak frequency.Second, the new device interaction method is put forward on the basis of the mapping relationship between doppler shift and gestures. Doppler shift of the positive and negative can be used to determine the direction of gestures, using frequency shift changes proposes gesture categories corresponding to different interaction scenarios.According to the extracted features of spectrum, gets the direction of the user gestures, and as the observed values input classification model, so as to realize the real-time user gesture recognition.Third, in view of the hidden markov has a good ability of modeling to timing signal,using the HMM to gesture recognition, realize corresponding classification between frequency shift and gestures. User equipment according to the specific scene and the requirement of different gestures to perform particular gestures, identifying and connecting with the equipment which has specific frequency shift strength.Finally, using the various mobile devices to collect relevant data, and design a simulation experiment to perform the device interaction method for performance analysis.