Reseach On On-line Measuring Method Of The Section Line In Ring Forging Process

Ring forging is a forged part.The casting blank is rolled repeatly to form the ring forging.The columnar dendrites of the cast billet were broken during the rolling process.Shrinkage cavity is eliminated and the uniformity of mechanical properties is eliminated.Therefore,the ring forgings have excellent mechanical properties.Ring forgings are widely used in many industrial categories by virtue of their excellent mechanical properties,For example,ships,trains,aeronautics and Astronautics,petrochemicals,cars,etc.The section line of the ring forgings is the key parameter to check that whether the process of the ring forging meet the process requirements and to ensure the shape of the forgings.And the discrete process parameters for the modification and improvement of the rolling process are provided by the online measurement of the axial section line.Therefore,the measurement of section line of ring forging is an important step in the rolling process of the ring forgings.In view of the problem that the section line can't be measured accurately in the process of ring forging,the online measurement of section line during the process of ring forging is studied in this paper.The specific research contents are as follows:Firstly,according to the forging process of the ring forging,the online measurement system of the section line of the ring forging based on the laser scanning is constructed.By studying the measuring principle of section line of ring forging,the factors affecting the measurement error of section line in the measurement system are analyzed.Secondly,in order to solve the problem that the interference factors such as rotation,vibration,self luminescence and ambient temperature change of the ring forging influence the measurement of section line,in order to achieve the purpose reducing random noise and smoothing section line,the structural feature between the section line and the line gray image is analyzed.The mapping rule between the section line and the line gray image is derived.And the bilateral filtering based on information entropy selection factor is researched.The de-noising algorithm of section line data is proposed.Thirdly,in order to reduce effectively the dislocation of section line caused by the increase of the diameter of the ring forgings,the spatial and temporal characteristics of the section line data were analyzed.The formula for calculating the diameter growth rate of the discrete radial section is derived.And particle filter with time-shared Calman and three order spline curve constructed by three order Hermite interpolation are studied.A position compensation algorithm for section line of ring forging is proposed.Finally,the online measurement system of the section line of the ring forging is built in the laboratory.The second-order ring forging and the third-order ring forging are taken as the experimental object,whose section lines are measured online.Through analyzing the experimental results,we verify that the online measurement system of the section line based on the proposed de-noising algorithm and proposed position compensation algorithm can realize the online measurement of section line.