Tuesday, May 26, 2009
Arc Width Measurement Demonstration
As part of the last Friday's project meeting, we demonstrated the latest arc width measurement software application. This application analyzes raw acceleration data from a Wii Remote to compute timing, velocity, and distance for each arc. The resulting distance measurements, together with user set thresholds, are used to generate spoken audio feedback.
On-screen slider controls are used to set thresholds for determining whether an arc is too wide, too narrow, or in the correct range. Other controls are used to set feedback options allowing the user to specify whether feedback should or should not be given when an arc is correct or is too wide or narrow.
Ellen Rubin, Gene Bourquin, and Steven Landau tested the system at the Touch Graphics offices and results were generally positive though the methods used to compute arc width need additional work. Currently, the biggest shortcoming is in the math used to double-integrate instantaneous acceleration to produce distance. Any "roll" in the cane which moves the Wii Remote's Y-Z plane off of alignment with gravity affect the calculated distance traveled along the Remote's X axis.
Future work will concentrate on better using static acceleration readings and an external reference to the light strip to improve arc width distance calculations.