Abstract: A parameterization method for point cloud data, and a device includes performing semantic segmentation on a plurality of three-dimensional data points of point cloud data in a spatial coordinate system to obtain at least one semantic object, the at least one semantic object corresponds to a plurality of three-dimensional semantic data points. The parameterization method for point cloud data further includes performing parametric fitting on the plurality of three-dimensional semantic data points to obtain spatial geometric parameters of the at least one semantic object corresponding to the plurality of three-dimensional semantic data points in the spatial coordinate system. In addition, a map construction method is further provided. By adopting the above technical solution, the automation of constructing a semantic map based on the point cloud data can be achieved.

Abstract: A variable-step-distance micro-milling repair cutter path generating method for damage points on a surface of an optical crystal related to a field of optical material and optical element surface repair and includes steps of establishing a mathematical model of a repair profile; determining discrete contact points between a cutter and the repair profile to obtain a cutter contact control point set by a GPR path generating method to control a movement trend of a pseudo-random path; interpolating the cutter position control point set into a spatial curve by a NURBS modeling method; creating a UG curve in a UG software according to the mathematical model, and using the UG curve as the repair path to perform a machining process simulation. The method has good elimination effects on cutter marks with constant period and improves the ability of the KDP crystal to resist strong laser damage.