Mobile 3D vision measurement system for large-scale free form surface

A mobile 3D vision measurement system for large-scale free form surface is introduced. The sensor of the system adopts binocular stereo vision principle combined with coded structured light technology, which simplifies the process of finding correspondence. The sensor is moved around a large-scale object, and each local surface is measured. Using a planar target as intermedium, an optimized object function of the position and orientation transformation matrix of the sensor is established; and the matrix, namely registration matrix is derived from the feature points on the planar target. The 3D data obtained at the local locations are unified in the global coordinate frame using the registration matrix. This measurement system was used to measure a Venus plaster model at two local locations, and the 3D data were registered. The experimental results show that the measurement system features simple operation and wide application fields; the registration RMS errors for x, y and z coordinates are 0.038 mm, 0.022 mm and 0.135 mm respectively.