坐标测量机测量点通用可达性分析方法

A Generic Method of Measuring Points Accessibility Analysis for Coordinate Measuring Machines

坐标测量机接触式点位测量必须事先分析测量点的可达性以免测量时发生碰撞,并给出测量点的可达方向,为测量方向选择提供基础。对于目前常见的各种类型探针,论文提出了一种通用的测量点可达性分析方法。由用户交互建立任意类型的探针和测头等测量机部件的简化模型,可达性分析首先根据探针类型快速排除不可达方向,然后通过计算测量机部件与工件、夹具等障碍物的最小距离精确判断测量点在各个测量方向下的静态可达性和动态可达性,由此可得到测量点的全部可达方向。在可达性分析中对障碍物进行了离散化处理,因此,该方法适用于任意复杂程度的零件。

The accessibility of measuring points has to be analyzed before contact probing with coordinate measuring machines（CMMs） to avoid collision and provide accessible orientations for the determination of measurement orientations.This paper proposes a generic accessibility analysis algorithm for common styluses.Users construct interactively the models of styluses,probes and other CMMs components.Inaccessible orientations of measuring points are excluded fast according to the kind of stylus tip.Then,the static and dynamic accessibility of measuring points in each measurement orientation is analyzed through computing the minimum distance between CMMs components and barriers such as workpiece and fixture.All accessible orientations of measuring points are obtained accordingly.Because barriers are discretized for accessibility analysis,this method is suitable for any complicated workpiece.