Acoustic motion tracking and its application

Video games, Virtual Reality (VR), Augmented Reality (AR), and Smart appliances (e.g., smart TVs) all call for a new way for users to interact and control them. This thesis explores high precision acoustic motion tracking system which aims to replace traditional control devices such as mouse and let the user play games, interact with VR/AR headsets, and control smart appliances. We develop a lightweight system which can achieve mm-level tracking accuracy using inaudible sounds. At the heart of our system lies a distributed Frequency Modulated Continuous Waveform (FMCW) which is able to accurately estimate the absolute distance between a receiver and a transmitter that are separate and unsynchronized. We further develop an optimization framework to combine FMCW estimation with Doppler shifts and Inertial Measurement Unit (IMU) measurements to enhance the accuracy, and efficient algorithm to solve the optimization problem. We develop several interesting applications on top of our motion tracking technology, including audio ruler, drawing in the air, and playing motion-controlled games