A novel orientation and position measuring system for large & medium scale precision assembly

In the field of precision assembly of large & medium scale, the orientation and position measurement system is quite demanding. In this paper a novel measuring system, consisting of four motorized stages, a laser rangefinder, an autocollimator and a camera is proposed to assist precision assembly. Through the design of coaxial optical system, the autocollimator is integrated with a laser rangefinder into a collimation rangefinder, which is used for measuring orientation and position synchronously. The laser spot is adopted to guide autocollimation over a large space and assist the camera in finding collimated measurand. The mathematical models and practical calibration methods for measurement are elaborated. The preliminary experimental results agree with the methods currently being used for orientation and position measurement. The measuring method provides an alternative choice for the metrology in precision assembly. (C) 2014 Elsevier Ltd. All rights reserved.