Date of Award


Document Type

Open Access Thesis


Computer Science and Engineering

First Advisor

Srihari Nelakuditi


Determining moving direction with smartphone's inertial sensors is a well known problem in the field of location service. Compass alone cannot solve this problem because smartphone's compass cannot achieve high accuracy. Moreover GPS is not suitable in indoor scenario. Another well known approach is dead-reckoning but dead-reckoning needs to know phones initial orientation and over time it keeps accumulating errors and after some time the estimation becomes to noisy to use. To overcome these limitations, we propose a solution called WalkCompass which is specially designed for pedestrians keeping in mind the variation of force during normal human walk. Therefore the algorithm is inherently free from any error generated by the orientation of the phone. However, the performance of the system does not depend on the holding style or location of the phone in the body. The algorithm can work very fast to determine the direction of movement in real time and because of its low complexity the complete system can be implemented on a smartphone. WalkCompass does not need any bootstrapping and can produce results with the granularity of each step of a walk.