Title :
Design and Evaluation of Identifiable Key-Click Signals for Mobile Devices
Author :
Chen, Hsiang-Yu ; Park, Jaeyoung ; Dai, Steve ; Tan, Hong Z.
Author_Institution :
Motorola Corp., Libertyville, IL, USA
Abstract :
As touch based input becomes more popular in mobile devices, there is an increasing need for haptic feedback on key-less input surface. Four experiments were conducted to design and evaluate identifiable emulated key-click signals using a piezoelectric actuator. Experiments I and II assessed the information transmission capacity for the amplitude, frequency, and number of cycles of raised cosine waveforms used to drive the piezo actuators under fixed- and roving-background conditions, respectively. Experiment III estimated the total information transfer for all three parameters. The results were used to reduce the number of stimulus alternatives in the key-click signal set with the goal to achieve perfect identification performance. Experiment IV verified that up to 5 to 6 identifiable key-click signals could be achieved with the experimental setup. The present study outlines an information theoretic approach to conducting identification experiments to guide the design of and to evaluate a perfectly identifiable stimulus set. The methodology can be applied to other applications in need of perceptually identifiable stimulation patterns.
Keywords :
haptic interfaces; mobile handsets; piezoelectric actuators; cosine waveform; fixed-background condition; haptic feedback; identifiable key-click signal; information theoretic approach; information transmission capacity; key-less input surface; mobile device; piezoelectric actuator; roving-background condition; touch based input; Feedback control; Haptic interfaces; Information processing; Mobile communication; Mobile handsets; Object recognition; Piezoelectric actuators; Mobile applications; haptic feedback; human information processing.; key click;
Journal_Title :
Haptics, IEEE Transactions on
DOI :
10.1109/TOH.2011.21