Design of Robotic Measuring System for Large Diameter Pipe Fittings Based on Line Laser

At present, the manual inspection efficiency of large-diameter pipe fittings is low. A high-efficiency automatic measurement system for industrial robots using line laser sensors was proposed. This system has realized the accurate measurement of the inner diameter of the pipe fittings. According to the geometric relationship among pipe fittings, line laser sensors, and industrial robots, a measurement mathematical model was constructed. Among them, a posture analysis method based on projection of three-dimensional contour data was proposed to solve the installation angle of the line laser sensor; the least square method was used to solve the exact solution of the six-axis rotation axis; the Levenberg-Marquardt algorithm was used to fit the ellipse to avoid the singular value problem in the solution process. The system error of the measurement principle was analyzed, and the incremental compensation method was used to construct the system error compensation model to solve the influence of the position and attitude error of the laser sensor on the measurement accuracy. A rigorous calibration and acquisition methods were used to ensure that the engineering system accurately implements the measurement design principle. The experimental results show that the measurement error of the line laser large-diameter pipe robot measurement system designed in this paper was less than 0.025%.