Global calibration of multi-sensor vision measurement system based on line structured light

A novel global calibration method for the multi-sensor vision measurement system based on the line structured light is proposed to resolve the problem that the ordinary calibration method depends on the external high-precision equipment. The 3D coordinates of the intersection points formed by light stripe and the 1D target can be obtained in each coordinate frame of the line structured light vision sensor. The coordinates in the 1D target coordinate frame can be got by the invariance of the cross ratio, and then the spatial distance between the intersections can be further calculated. The objective function to be optimized involving the parameters of rotation matrix and translation vector can be established based on the condition of the distance restraint between the intersections at different positions. The optimized parameters of the global calibration can be resolved by combining these equations and using the non-linear optimization algorithm. The experimental results show that the RMS error is less than 0.1 mm.