A method of a non-contact detection of a moving object absolute position by making use of speckle effect and device for implementation of this method

摘要

A method of a non-contact detection of an absolute position of rotating or translating object by making use of a speckle effect when a monitored object (11) is illuminated by the beam of a coherent or quasi-coherent light from a light source (22), which operates in a visible, near-infrared or near-ultraviolet: region of the spectrum, where the essence of the invention is in the fact that, at first, during a calibration phase, a speckle field, which is generated by tested rotating or translating object (11) for each position of its rotation or translation, is recorded on an image sensor (5) together with information about rotation or translation size, when these information are saved into the memory of the sensor (5) or into a controlling and evaluating system (4) which records change of speckle fields, and consequently, during a measurement and evaluation phase of detection of rotation or translation position of the object (11), the recorded speckle field for an unknown position of tested object (11) is compared to images of speckle fields which were saved during the calibration and there are identified calibration and measuring output images with highly correlated recorded images of speckle fields with which corresponds always one particular position of rotation or translation of tested object (11).