Source localization on solids for touch interfaces

Abstract

Research into human computer interface (HCI) has been very active in recent years due to the advances in software applications. Such devices are aimed at providing a more natural interface for which humans to interact with machines. In this research, we propose a new approach to the development of a touch interface through the use of a surface-mounted sensor which allows one to convert hard surfaces into touch pads. We first develop, using mechanical vibration theories, a mathematical model that simulates the output signals derived from sensors mounted on a physical surface. Utilizing this model, we determine the hardware required for this research. We then develop a source localization algorithm based on an all-pole filter model for location template matching that extracts the dominant frequencies of the tap. The performance of the proposed algorithm is compared with existing approaches and verified both in a synthetic as well as a real environment for the localization of a finger tap on a touch interface. In addition, we explore the time-difference-of-arrival based methods for source localization and implement a real-time wireless source localization prototype. 4 ACKNOWLEDGEMENT I would like to acknowledge and extend my heartfelt gratitude to the persons who have made assisted and guided me thus far in this research, in particular, the members of the Speech, Touch and Acoustic Tangible Interfaces for Nextgeneration Applications (STATINA), for their continual support, guidance and encouragement, (in alphabetical order) Amir bin Sulaiman,