Acoustic positioning and orientation prediction

US4964303A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Martin B. Barmatz · La Cañada Flintridge, US
• Glenn Aveni · Burbank, US
• Seth Putterman · Los Angeles, US
• Joseph Rudnick · Los Angeles, US

Key dates

• Filing date: Nov 15, 1988
• Grant date: Oct 23, 1990
• Expiry date: Nov 15, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G10K15/00
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A method for use with an acoustic positioner, which enables a determination of the equilibrium position and orientation which an object assumes in a zero gravity environment, as well as restoring forces and torques on the object, of an object of arbitrary shape in a chamber of arbitrary configuration. An acoustic standing wave field is established in the chamber, and the object is held at several different positions near the expected equilibrium position. While the object is held at each position, the center resonant frequency of the chamber is determined, by noting which frequency results in the greatest pressure of the acoustic field. The object position which results in the lowest center resonant frequency, is the equilibrium position. The orientation of a nonspherical object is similarly determined, by holding the object in a plurality of different orientations at its equilibrium position, and noting the center resonant frequency for each orientation. The orientation which results in the lowest center resonant frequency is the equilibrium orientation. Where the acoustic frequency is constant but the chamber length is variable, the equilibrium position or orientation is that whi…