Self-calibration and performance verification of an ultra precision moving stage

Current high quality products may present micro/nano-metrical specifications, which require high accuracy systems in order to be manufactured and inspected. These instruments achieve resolutions below the nanometer level. Unfortunately, the nominal resolution of an instrument does not correspond to its actual performance. The presence of imperfections (form deviations, axes parallelism and orthogonality errors, etc.) in every part of the system generates a volumetric error. Luckily volumetric error tends to show a systematic behavior. It is then possible to evaluate and numerically compensate it. The evaluation is usually based on the measurement of some calibrated artifact, but calibrated artifacts of the required accuracy are not currently available. Therefore, self-calibration methodologies, which do not require calibrated artifacts, should be adopted. In this work, a self-calibration methodology for the Sub-atomic Measuring Machine (SAMM), a nanometer level atomic force microscope, will be proposed. Due to SAMM characteristics, a six degrees-of freedom model will be required. Then, a methodology able to evaluate volumetric error model accuracy will be proposed. This methodology is again a self-calibration one. Methodologies will be validated by means of simulation.