PiLoT: A Precise IMU Based Localization Technique for Smart Phone Users

Pedestrian dead reckoning (PDR) schemes typically rely on inertial measurement unit (IMU) of smart- phones to estimate position of the user. However, the performance of IMU based schemes depends on the placement of the IMU on the user and is affected by error accumulation over time. In this paper, we propose and implement PILoT, a Precise IMU based Localization Technique to overcome these shortcomings without compromising the accuracy of the system. It employs a novel wavelet based filtering technique to i) remove noise from the accelerometer readings and ii) deal with the positional changes of the device on the user. Heading is estimated using magnetometer and gyroscope. These techniques are then used in conjunction with a novel map awareness algorithm which eliminates the accumulated error based on the turn events. The proposed scheme achieves sub meter accuracy with a mean error of $0.52$ meters.