Investigation Into Robotized Digital Cutting Of Intersection Line Of Steel Structure Joints

Driven by the exhaustive needs from manufacturers of large span spatial steelstructures for the development of an interface between the structure models androbotized cutting equipment, this dissertation investigates the approach for digitalcutting of intersection line of steel structure joints and develops a software forgeneration verification of cutting path, covering digital cutting process planning, dataextraction of the joints from CAD model of the structure, analytical model and CADmodel formulation of joints, development of motion control algorithm, etc. Theeffectiveness of the approach has been verified by computer simulation andengineering application. The following achievements have been made:(1) An approach for digital manufacturing of steel structure is proposed, coveringextraction and examination of feature data of joints, model formulation of intersectionline, cutting path planning, welding and assembling of joints, providing technicalsupport for manufacturing of large-span spatial steel structure.(2) Feature data of steel structure joint is extracted, analyzed and examined withsecondary development technology of AutoCAD and SolidWorks. Feature data ofjoints is got with defined format, establishing a data interface between digital modeland cutting equipment.(3) Two methods are used to formulate model of intersection line. Firstly, analyticalmodel is formulated for joints with regular section and real-time solving algorithm isdeveloped using the movement of generatrix of branch pipe. Secondly, for joints withirregular section, cutting path of intersection line and axis vector of cutting torch areextracted and calculated using secondary development technology of CAD from3Ddigital model of spatial steel structure, and cutting path in operation space of robot isgenerated.Digital cutting software of intersection line for TriVariant-B hybrid robot isdeveloped. The quality of intersection line and groove cut meet the standard, and theeffectiveness of the approach proposed is verified by many engineering applications.The results researched have important engineering value for digital manufacturing of complex spatial steel structure.