The size measurement of large hot forgings plays an important role during the process of production. In order to realise the size measurement of large forgings in thermal state, an automatic size measurement method for large forgings based on the scattering of rough surface is proposed in this study. In the method, the theory of random facets is applied to research the characteristic of laser scattering on the surface of hot forgings. The model of laser scattering on the random rough surface of cylinder is built. According to the model, the edges of forgings can be detected and the size of forgings can be got. First, the charge coupled device (CCD) camera and the green laser are driven by the motor to move on the guide rail. The real-time images of forgings are captured by CCD camera and the positional information of laser is acquired by pulse coder. Then according to the change of the intensity of the scattered light, whether the laser line is on the edge of forgings is decided. Second, the positional information of two edges is got by pulse coder and the size of forgings is figured out by the positional information. Finally, the feasibility of the method is verified by the experiment of size measurement.

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Automatic measurement method for the size of large forgings based on scattering on rough surface

References

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