Online Measurement Of Key Parameters Of Forging Geometry Based On Laser Detection And Intelligent Algorithm

In the ring rolling and upsetting processes of large forgings,the online measurement of key parameters of the billet geometry is very important.It can also serve to guide production targets and accurately adjust production parameters,thus improving productivity.In this paper,laser displacement sensors were used to obtain spatial information between the sensors and the measured workpiece surface for the online measurement of geometric quantities such as workpiece posture and cross-sectional roundness in the ring rolling and upsetting processes of medium and large forgings,and then a series of intelligent algorithms were used to solve for the relevant data.An online roundness measurement method based on the laser ranging principle and an improved particle swarm optimisation(IPSO)algorithm was proposed for the problem of out-of-roundness during the rolling of ring-shaped forgings.Firstly,the distance from the outer surface of the ring to the laser rangefinder was measured with a triangular laser rangefinder with the aid of the ring rotation during the rolling process.Secondly,the distance data was denoised using a modified Kalman filter algorithm to reduce the effect of random noise on the measurement results.Finally,the roundness and geometric centre were evaluated using the IPSO algorithm in conjunction with the minimum area circle(MZC)method and compared with results obtained using the standard particle swarm optimisation(PSO)algorithm,genetic algorithm(GA)and least squares(LS)algorithms.The experimental results show that the roundness measured by the IPSO algorithm is less than 0.06 mm,showing a better performance in roundness evaluation.The roundness measurement method proposed in this paper is suitable for the online inspection of large aluminium alloy ring parts,avoiding the influence of ring size and speed variation on roundness measurement.The tilt was calculated by fitting the centre of the measured multiple cross-sections in the vertical coordinate direction to the central axis,based on a laser rangefinder encircling the measurement method in the case of a cylindrical forging with an inclined longitudinal section that was elliptical,in the case of a piercing process in which the piercing pin was not parallel to the surface of the forging machine blank.A method for measuring the tilt of a forging was proposed,based on an improved optimisation algorithm to fit an ellipse.Specifically,a laser rangefinder was used to measure the distance to the surface of the workpiece.This was converted to section profile coordinates by means of a coordinate transformation.Next,a randomly divided region and filtered data points were used so that the effect of outliers in the measured points can be effectively eliminated.An improved global-local particle swarm optimisation(GLBest-PSO)algorithm was then proposed to solve the parameters of the target ellipse using the point-to-ellipse orthogonal distance as the geometric model.The fitting effect was then compared with four other contemporary advanced methods to verify the superiority of the algorithm,and the accuracy of the algorithm in judging outliers was verified experimentally using foreign objects of different shapes and sizes;to compensate for the systematic error,a continuously varying tilt angle was set in the XY direction,and the compensation formula was established through the measured and theoretical values,and after compensation for the systematic error,the measurement error of the inclination was less than 0.05°.A new method of processing laser scanning data of the outer radial section dimensions of ring forgings was proposed for the detection of the radial section dimensions of ring parts in the forging process.Based on regression analysis and point cloud filtering,a multiple regression filtering algorithm was proposed to process the point cloud data for the measurement of the outer diameter dimensions of ring forgings.Firstly,the laser scanned point cloud data was characterised and isolated points that deviate from the target point cloud were removed using statistical filtering methods,the outlier clusters were removed using regression analysis methods and processed using Gaussian regression filtering algorithms to obtain point cloud data with good circularity characteristics.The LS principle was used to fit a circle to the processed data to obtain information on the external diameter of the ring forgings to be measured.