气膜孔轴线方向的视觉测量技术研究

针对高压涡轮叶片气膜孔的轴线方向测量难题，将非接触式的视觉测量技术与常规的多轴坐标测量技术相结合，搭建了气膜孔五轴视觉坐标测量系统，以在气膜孔的测量方法和设备方面开展探索与研究。为了获取被测气膜孔的轴线矢量参数，提出了采用景深合成技术来实现气膜孔形貌的三维重建，并将工业相机获取到的图像序列转化为三维物理数据的测量方法，而后通过空间直线拟合获取到了被测气膜孔的轴线矢量，以表征气膜孔的轴线方向。为了验证该方法的有效性和可行性，选取某型高压涡轮导向叶片作为被测物体，应用该测量系统对其前缘部位上的目标气膜孔进行了轴线矢量参数的10次等精度重复测量试验，轴线角度的重复性测量误差不大于0.30°，从而提供了一种气膜孔轴线方向的测量技术解决方案。

Study on Vision Measuring Technology of Axis Direction of Film Cooling Holes

With regard to the measuring difficulty of the axis direction of those film cooling holes on the high-pressure turbine blades,a 5-axis vision coordinate measuring system was established to explore and study the inspecting method and equipment for film cooling holes,which combined non-contact vision measurement with traditional multi-axis coordinate measurement together.In order to derive the axis vector parameter of the measured hole,the measuring method to realize the 3D morphology reconstruction of film cooling hole by depth from focus technology and transform the image sequence captured by the industrial camera to the 3D physical data was proposed.And then,the axis vector of the target hole could be derived by spatial line fitting.Finally,to verify the effectiveness and feasibility of the vision measuring method proposed in the paper,a high-pressure turbine blade was selected and the axis vector of the target hole on its leading edge was inspected by the system ten times,in which the repeatability accuracy of the axis angles was smaller than 0.30°.Therefore,a measurement technology solution of the axis direction of film cooling holes was provided.