Described in this thesis is a CL-data generation method for Cartesian Machining of 3-D sculpture surface. Cartesian Machining is a way of obtaining a sequence of tool contact points(= CL-data) on the intersection curve between the given surface and a plane. A numerical searching method is employed to obtain intersection curves. Also presented is the Cartesian Machining of compound surfaces. Compound surface is a collection of topologically unrelated composite surfaces.
The main steps of searching a digital intersection curve from a given patch are as follows: 1) obtain the head and the tail point of the curve, 2) starting from the head point, forecast the next point expected to be located near the cutting plane within the required machining tolerance, 3) move the forecasted point to the cutting plane, 4) adjust the step length to meet the tolerance requirements
The above intersection method is used in generating CL-data for the Cartesian Machining of parametric compound surface. The overall procedure consists of the following steps : 1) determine the intersecting interval, 2) determine the current cutting plane position satisfying the required cups height or path interval, 3) search the intersection curve(s) corresponding to current path(cutting plane), 4) link the curves in order to obtain the desired CL-data.
The entire procedure has been implemented in FORTRAN IV on an IBM 8083 computer.