Operation

Capacitive Moments Sensing

The Radio Drum is a capacitive moments sensor. Capacitive moments sensing determines the position of an object moving in a contained three-dimensional space above a surface. The Radio Drum uses the "Backgammon" form of capacitive sensing (Fig 2) to interpret the gestures of a performer. The first moments and zero moments of are measured with a linear current division sensing method. The sensor plane is divided into sets of wedge shaped resistive sheets. The position of a current injected into the resistive sheets of the Backgammon pattern is determined by the currents that flow to equal potential corners through a chain of discreet resistors of equal value. Operational amplifiers are placed at the four corners of the sheet to define the terminal potentials and change alternating current signals to voltage signals referenced to ground. The four corners are driven and each corner acts as an antenna or receiver.

back next
The Radio Drum is a three dimensional motion sensing device. It uses capacitive moments sensing to determine the position of an object moving in a three-dimensional space above a surface. The goal of this project is to redesign the Radio Drum control box for UVATT with the purpose of minimizing cost and size.
                                         Copyright 2005 Current Designs. All Rights Reserved.