Study On Multilayer And Multichannel Welding Path Planning And Fitting Method For Pipe Intersecting Line With Medium Thickness Wall

In the field of petrochemical industry,pressure vessel was an important medium for heat transfer,mass transfer and storage.When these pressure vessels were connected with pipelines,there was a great deal of demand for weld welding of the intersecting line of medium and thick wall pipe fittings.Statistics show that 60% ? 65% of the serious damage accidents of pressure vessels in petrochemical industry are caused by welding defects.It was of great engineering application value to develop and study the method to realize such complex curve welding robot welding.Therefore,aiming at the problems existing in the automatic welding process of the intersecting line of medium thick wall pipe fittings,this paper had carried out a series of studies on the welding path planning and fitting method of the intersecting line:(1)For the problem of controller interpolation cycle length,first of all,the intersecting line trajectory was obtained through the simultaneous double-pipe parameter equation;Then,the point point division was set up to obtain the interpolation points,and the Lagrangian,Newton and cubic spline interpolation fitting model with the introduced polar diameter was constructed.Then,using the fitting error and operating efficiency as performance indexes,it was verified that the interpolation fitting model can guarantee high accuracy and improve the real-time performance of interpolation significantly.Finally,by comparing the influence of point position degree on the error,the Lagrangian interpolation fitting model at degree 20 was selected as the optimal interpolation model,and the selected interpolation model was used to interpolate the intersecting line trajectory with equal angles and step lengths.(2)According to the curve of thick wall tube groove area change,firstly analysis the curve of thick wall tube groove area of the influencing factors,and then according to the change of cross-section of groove was put forward based on the cross-sectional area method and the interpolation fitting method combined with such as the exhaust algorithm,this method in the cross-sectional area,such as method of weld bead filling strategy,on the basis of any branch pipe rotation Angle downhill mouth plane by adjusting various weld arc starting point,combined with interpolation fitting method to form densely curves of each pass without changing welding process and parameters can be varied cases,the groove area to realize the curve of thick wall tube multilayer multichannel welding path planning.Then the slope and error of the top line are discussed,the feasibility of the algorithm was analyzed,and the motion stability was analyzed from the Angle of velocity and acceleration of each axis.(3)In view of the existing 3d simulation software model simple problems,in the Microsoft Visual Studio 2017 software platform,combined with c# and Sharp GL graphics library,developed a set of suitable for cantilever interfingering lines of automatic welding machine movement simulation software,and the Lagrange interpolation fitting and multilayer welding path planning was blended in among them,multichannel effectively the curve to verify the mathematical model,the correctness of the Lagrange interpolation fitting method,and made a three-dimensional dynamic simulation of welding path,the curve of the thick wall welding has a certain guiding significance.