In the course of developing the autom ation programming module software o f GT CNC cutting edge,the method of arc offline
interpolation with the AcDbpolyline object of AutoCAD is discussed in this paper.The characteristi ces of tradition
arc interpolation method are analyzed f irst of all,and the method of increme nt with function directly and offlin e arc
interpolation is put forward in software,and the idea of smooth interpolation is realized.Moreover,error analysis is also su mmarized.The transforming model of arc function l inked with the interpolation method in this paper has come out through com bining with the arc of AcDbPolyline object.The recursion relational expression is derived from model of arc interpolation designing and building.On the basis of end point judgment method summarizing and using for reference and combining the programming design idea,a simple circle interpolation method is derived.In this way,this paper has solved the problem of arc offline in terpolation in software design.