Measuring dynamic motion in three axes using multiple cameras

A system for measuring vibratory motion along three spatial axes of an object undergoing movement, from video recordings comprising a plurality of video images of the object as it undergoes movement, the video images being divisible into individual video image frames with each individual video image frame being divisible into a plurality of pixels, said system comprising:

• two or more video acquisition devices operably connected to a processor, that have a fixed spatial relationship and matching lens that are calibrated to determine a depth or series of position measurements in a direction parallel to the optical axis of one of the video acquisition devices serving as a reference camera to a point on the object undergoing motion;
• a computer program operating in said processor to:
• adjust a frame rate of the two or more video acquisition devices to provide for a sampling rate to capture a plurality of frequencies present in the vibratory motion and acquire the individual frames on all video acquisition devices simultaneously;
• calculate a displacement of the object along two axes of the vibratory motion representing the focal plane of each camera pair, wherein the two axes are a first axis referred to as an x-axis and a second axis referred to as a y-axis, respectively;
• and
• determine the vibratory motion in a third axis, referred to as a z-axis, wherein the third axis is parallel to the optical axis of the reference camera.