Surface measurement using improved crossed-optical-axes geometry

Crossed-optical-axes project grating system is fundamental architecture in 3-D profilometry measurement. Confined by three conditional constraints, it has some limitations in practical application. An improved system relieving the constraints was proposed here. Geometrical deduction based on image ray tracing, optical triagulation and pinhole model was carried out. By projecting another central line fringe as the zero-phase datum, wrapped phase map about reference or measured object could be unwrapped without inducing systematic errors. The simulation was to measure a plate with a height of 80mm when changing geometrical parameters. Compared with the conventional configuration, new system approves more flexibility and maneuverability.