A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Advanced Technologies

Thesis (M.Eng.) - Asian Institute of Technology, 1997

In this study, a collision detection algorithm for the verification of setup sequences of bending operations is developed. The sheet metal part is represented by a set of thin flanges and bending axes. The bending relations and reference relation between flanges are represented by a connectivity matrix. The geometric modification of the sheet metal part corresponding to bending operations are calculated. The press brake machine is modeled geometrically by means of a number of convex polygon-extruded polyhedra in three dimensional space. Tools (punch and die) are each represented by a polygon-extruded polyhedra. Verification for possible collisions during bending operation is carried out by detecting any intersections between the polygons representing flanges of the sheet metal part and polyhedra representing components of the machine and tools. Several levels and procedures of the collision detection algorithm attempt to improve the speed of collision checking. A collision detection for bending operation program has been implemented on a PC' platform using Pascal language. The developed algorithm is found to be very fast in detecting the collisions that may be occur during the bending operation. Some case studies illustrate the efficiency of the program.