Two-Tone CW Acoustic Ranging Technique for Robotic Control

摘要

A technique for ranging to a target surface from a robot manipulator has been demonstrated using a continuous wave (cw) acoustic signal consisting of two pure tones of equal amplitude. Square-law detection of transmitted and received signals produces two sine waves at the beat frequency with relative phase delay resulting from the transmission time of flight. With control of initial conditions and tracking of phase, it is a simple matter to measure absolute distwlce indefinitely, within the dynamic range of the system. Doppler shift velocity detection should be possible, but results were not satisfactory.