The invention relates to a method for measuring the
diameter and the straightness accuracy parameters of a seamless round steel
pipe. The method includes the steps as follows: accomplishing the calibration of parameters of a multi-linear
structured light vision sensor formed by one
video camera and multi-line
laser projectors; distributing the multi-linear
structured light vision sensors on the periphery of the seamless round steel
pipe to be tested; respectively controlling the
laser projectors to project
structured light plane onto the measured section of the seamless round steel
pipe by a computer, collecting the images of
laser stripes on the surface of the seamless round steel pipe and
processing the images of the laser strip by a
video camera, and calculating the three-dimensional coordinates of different sections according to a measurement model; determining the elliptical center of each section of the space, realizing the measurement of the straightness accuracy of the seamless round steel pipe and establishing the dynamic and virtual central axis of the seamless round steel pipe; establishing the
reference plane of the dynamic and virtual projection of
ellipse of the section of the space; and front projecting the
ellipse of the section of the space onto the
reference plane of the dynamic and virtual projection, and carrying out the operation of
circle fitting on the
reference plane, thereby obtaining the section circle of the steel pipe. The method can realize the on-line, real-time, automatic and noncontact measurement of the
diameter and the straightness accuracy parameters of the seamless round steel pipe.