We propose an accurate acoustic direction finding scheme, Swadloon, according to the arbitrary pattern of phone shaking in rough horizontal plane. Swadloon tracks the displacement of smartphone relative to the acoustic direction with the resolution less than 1 millimeter. The direction is then obtained by combining the velocity from the displacement with the one from the inertial sensors. Major challenges in implementing Swadloon are to measure the displacement precisely and to estimate the shaking velocity accurately when the speed of phone-shaking is low and changes arbitrarily. We propose rigorous methods to address these challenges, and apply Swadloon to several case studies: Phone-to-Phone direction finding, indoor localization and tracking. Our extensive experiments show that the mean error of direction finding is around 2.1o within the range of 32m. For indoor localization, the 90-percentile errors are under 0.92m. For real-time tracking, the errors are within 0.4m for walks of 51m.
展开▼
机译：根据电话在粗糙水平面上的任意摇动模式，我们提出了一种精确的声向测向方案Swadloon。 Swadloon跟踪智能手机相对于声音方向的位移，分辨率小于1毫米。然后通过将来自位移的速度与来自惯性传感器的速度相结合来获得方向。实施Swadloon的主要挑战是精确测量位移并在电话摇动速度较低且任意变化时准确估计摇动速度。我们提出了严格的方法来应对这些挑战，并将Swadloon应用于一些案例研究：电话到电话的定向，室内定位和跟踪。我们广泛的实验表明，测向的平均误差在32m范围内约为2.1 o 。对于室内定位，90％的误差在0.92m以下。对于实时跟踪，对于51m的走步，误差在0.4m以内。
展开▼
