A New High Speed Mass Properties Instrument

摘要

In certain industries, the amount of time required to make a measurement ofrnmoment of inertia and center of gravity can have a dramatic effect on manufacturing cost.rnFor example, thousands of projectiles are measured every year at some proving grounds.rnThis necessitates operating three shifts and using more than one mass properties instrumentrnat the facility. In an effort to reduce measurement cost, Space Electronics has developed arnnew mass properties instrument that is at least three times faster than our traditional KSRrnseries instrument that has been used throughout the industry for over thirty years. This newrninstrument employs a different concept. The old instrument rotated to each of the fourrnquadrants, stopped precisely at the correct angle, and then measured the CG offset moment.rnThis required a variable speed motor drive that slowed down as it approached the correctrnangle, executed motions to damp out any vibration, and then edged slowly to its finalrndestination. The new instrument coasts to a stop at three approximately equally spacedrnlocations. An extremely precise optical encoder then measures the actual angle while arnforce-restoration transducer determines the moment to better than 0.01% accuracy. The onlinerncomputer then uses this data to determine X and Y CG of the object being measured.