Absolute and high precision 3 degrees of freedom position sensor

AbstractWe present a compact 3 degrees of freedom (dof) (X-Y-θz) absolute position sensor offering a sub-micrometric resolution. The travelling range is 15x15mm2 (translations) and ±180° (rotation), with an absolute precision better than 10μm over the whole travelling range and of less than 1μm of resolution (0.02° for rotation). The position acquisition frequency is 10Hz. The sensor is composed of a CCD camera chip, a silicon target with a pattern of holes constituting a digital code and a luminescent polymer sheet to light the holes. The reading of the pattern code is performed by image processing