Method of three-coordinate machine measuring free-form curve

The invention relates to a method of three-coordinate machine measuring a free-form curve. A normal vector of a middle point between two adjacent points is calculated, and is defined as a normal vector of a to-be-measured point, and therefore a problem of a measuring machine without a digital-analog processing capability or a part without a mathematical model of measuring curve coordinate points is solved The problem of the three-coordinate machine of inability of detecting the free-form curve correctly is effectively solved, even when the part does not have the digital-analog model or the three-coordinate machine does not have a model processing module. 本发明涉及种三坐标机测量自由曲线的方法，通过对相邻两点的中点的法向矢量进行计算，并将其定义为待测量点的法向矢量，从而解决了无数模处理能力的测量机或无数学模型时对曲线坐标点的测量。本发明有效地解决了零件无数模型或三坐标机无模型处理模块时，三坐标机不能正确检测自由曲线的问题。