Statina – touch interface engine

• Main Author: Huang, Jiesi.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Computer hardware, software and systems
• Online Access: http://hdl.handle.net/10356/49340
• Institution: Nanyang Technological University

Human-computer interface (HCI) technologies have been moving away from buttons and pointing devices towards more intuitive options, most notably the touch screen. Current touch screen technologies are costly, especially for large screens since special screens are used. In the STATINA project, an affordable touch screen option is presented as shock sensors are used to transform ordinary surfaces into touch screens. In this project, an overall understanding of the project is gained, leading to an exploration on the distinction between finger and fingernail tap signals. Eight methods to distinguish between these two signals are explored, including analysis of the time-domain signals, frequency-domain signals (linear and in dB), cross-correlation, signal sparseness measure, Kullback-Leibler distance and counting the number of zero crossings (using the smoothed and non-smoothed time-domain signals). The results show that smoothed zero crossings is the best method to distinguish between the two types of signals, followed by using cross-correlation, the sparseness measure, and finally the KLID. The other methods explored did not give conclusive results. These results can be used to reject signals from finger taps, which would increase the system accuracy but decrease its sensitivity. Further study can also be made from these differences found, to find a way to increase the accuracy of the system towards finger taps.