| Metal rapid prototyping is an important branch of advanced manufacturing.Since the successful application of a layered entity for manufacturing invention patents in 1984,3D forming has been rapidly advancing to various industries.The most remarkable achievement in laser forming in the metal forming direction is laser molding.It is currently possible to print on tiny precision parts,but there is still considerable resistance to advancement in the direction of printing on large parte.In order to reduce the development cast,this paper designs the arc as the heat source and develops a cylindrical coordinate surfacing welding platform,hoping to quickly form a uniform precision blank.The cylindrical coordin.ate rotation structure reduces the interpolation calculation and enables fast arc filling,The movement axis is supported on the rotation axis to reduce the repeated setting of the mechanical zero point and the vertical adjustment of the coordinate axis in the Cartesian coordinate mode,which is convenient for setting up and printing at any place.For this reason,this paper focuses on the need for cylindrical coordinate overlay welding,and focuses on the interpolation algorithm and forming control strategy in cylindrical coordinate mode.The linear interpolation algorithm for cylindrical coordinates was studied and the angle method was used as the end point discriminating condition,and then the error correction coefficient was used to help the welding gun to cross over the interpolation dead point;The general formula of cylindrical coordinate linear interpolation was deduced,and the setting was given through experimental simulation.The optimal number of subdivisions within the range of molding errors enables the interpolation precision of any coordinate point within the space area to be adjusted and highly efficient.The cyluindrical coordinate arc interpolation algorithm was studied.The velocity curve of the micro segment curve was smoothed on the basis of the paint-by-point comparison method,which reduced the interpolated pendulum of the cantilever bearn,and was posit:ioned by the speed servo and discrete coordinate points.The joint drive method further optimizes the above algorithm and redefines the coordinate points of interpolation critical points.The stability and reliability of the algorithm are proved by software simulation and thin-wall part molding experiments.Studied the cylindrical coordinates NURBS fault-tolerant interpolation algorithm,according to the dynamics of molding equipment real-time adjustment of molding speed.Deduced the node-paraneter recursion formula related only to the velocity to avoid the speed fluctuation and the interpolation uncertainty caused by the time.The genetic algorithm was used to filter the interpolation point twice to get the velocity mutation point in the curve and to add and subtract Speed retrieval and re-correction.Aiming at the problems such as the derivation error caused by high-power denominators,the NURBS interpolation accuracy,forming quality,acceleration and fault tolerance were analyzed by combining fuzzy control and RBF neural network.An ideal numerical model of the macroscopic morphology of a single-channel weld pool was established.Through the rotating combination test,the regression equation between the forming parameters and the bead cross-section parameters was found.The significance of each parameter item was evaluated based on the F-test.An optimal set of molding parameters was chosen to perform the plane layer forming test,and the rule between the overlapping distance between the dripping laps and the surface finish of the forming layer was studied.The optimal lap spacing was found,A graphical control software was written to verify the stability of the interpolation algorithm and the accuracy of the optimal molding parameters. |
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