Study on Vision Inspecting Method of Through or Blind State of Film Cooling Holes
In an aero engine,film cooling hole has become one of the key geometrical features that determine the serv-ice performance of turbine blades.To inspect the through or blind state of those film cooling holes in an accurate and rapid manner,a non-contact 5-axis vision inspecting system based on the principle of machine vision and multi-axis motion control is established in the paper.The panoramic image of the measured hole is derived through its focused image sequence by the focus stacking technology.And then,according to the differences in imaging effect due to the different diffuse reflection states of the bottom of hole under the illumination of light source,the average pixel grayscale of a circular sub region in the panoramic image is selected as the criterion to be compared with the threshold,in which the result could be used to recog-nize and determine the through or blind state of film cooling hole.A test piece of high pressure turbine blade is selected to be tested,which verified the inspecting method proposed in the paper.
film cooling holemachine visionfocus stackingthrough or blind state
万方数据
维普
