PHOTOELECTRIC AUTOCOLLIMATION METHOD AND APPARATUS BASED ON BEAM DRIFT COMPENSATION

摘要

Photoelectric autocollimation methods and apparatuses based on beam drift compensation are provided. The methods and apparatuses can be used to achieve a high autocollimation angle measurement accuracy. The apparatuses includes an autocollimator, a measurement mirror (12a), a beam drift monitoring and separating unit, a beam steering device (8), and a data processing controller (7). The beam drift monitoring and separating unit generate a reference beam with the same drift as the measurement beam. The measurement beam carries both angular deflection information of the measurement mirror and the angular beam drift information, while the reference beam carries only the angular beam drift information. The data processing controller gives out a signal to the beam steering device in real-time according to the magnitude of drift of the reference beam, to compensate the drift of the measurement beam.