空间自由曲面的无允差局部离散化

Local Discretization of a Sculptured Surface without Tolerance

根据点涉法原理和曲面的凸凹性，提出了计算非球面刀刀位轨迹的曲面无允差局部离散化方法。该方法仅对曲面上凹的部位作无允差的离散化处理，即可准确地计算出非球面刀在空间自由曲面上的刀位轨迹。

In the NC programming for a sculptured suface,there exists inconsistency between theparametric representation of the surface and the representation with Cartesian coordinates ofthe same surface in a CAM system by which the surface is to be machined.The commonlyused method for dealing with this problem is to perform discretization by recursive segmenta-tion within a spectified tolerance. A new method Of discretization is proposed,for whichsuch a discretization without tolerance will be carried out only for the concave region on thesculptured surface when the cutter path is to be calculated during the programming.