Design And Dynamic Characteristics Study On Metamorphic Mechanisms Of Cutting Machines For Complex Surface

There is a very big gap between China and developed countries in the field of advancedshipbuilding technology and equipment manufacturing especially the key shipbuildingtechnologies of complex-surface cutting, which affects, even restricts the improvement anddevelopment of shipbuilding technology. So how to solute the cutting problem of bigopenings, variable posture and changing track in large complex-surface cutting has importantacademic significance and application value in improving the technical level of shipbuilding.Through the research and analysis on the cutting equipment at home and abroad, theprinciple structure of cutting machine for complex-surface was designed and theconfiguration of key parts such as rotation mechanism, lifter mechanism and adjustingmechanism were selected and designed as well. To realize the objective of variable postureand changing track, the configuration of swinging mechanism was chosen and analyzed andthe principle structure of metamorphic mechanism was designed as well.Based on the screw representation of spatial rigid motion the complete kinematic productof exponentials formula of serial-parallel mechanism was established in the paper, and thenumerical calculation of cutting machine for complex-surface have been done usingMATLAB. To verify the result of numerical calculation, the motion simulation ofcomplex-surface cutting machine in ADAMS was researched and the result of simulationshows the practicality of screw method’s application in the analysis of serial-parallelmechanism.The errors of4D-H parameters were equivalent to error screw and the practical screwcoordinate containing error screw of every joint axis was established. After the practicalkinematic product of exponentials formula of serial-parallel mechanism being derived, thepose error model of tool coordinate system was established. According to the above screwmethod, numerical calculation of cutting machine about kinematic error analysis wasperformed with MATLAB and the calculation results were compared with the simulationresults of ADAMS. The comparison results show the correctness of screw method’sapplication in the kinematic error analysis of serial-parallel mechanism.Taking the metamorphic kinematic pair as cut-off joint of closed-chain mechanism, the configuration-complete kane dynamics equations of metamorphic mechanism in cuttingmachine for complex-surface was established by introducing the constraint equation of cut-offjoint. After analyzing the Shock Problem during the configuration switching of theMetamorphic Mechanism, the method of decreasing the shock was studied from the view ofcontrolling the motion law. Through the motion simulation in ADAMS, the validity of themethod was verified and a basis for studying the Metamorphic Mechanism of cutting machinefurther was provided.