Automatic determination of bending sequences for sheet metal parts with parallel bends

A method for solving the problem of bend sequencing in sheet metal manufacturing is presented. The algorithm developed divides the part into basic shapes (channels and spirals) and determines the partial sequences associated with them. The complete bending sequences associated with the complete part were obtained from the combination of these partial sequences. To make this combination possible, several strategies were defined to reduce the number of solutions and, therefore, the searching time. All sequences (partial and complete) were checked considering possible part–tool collisions and tolerance constraints. The last stage was to order the sequences by taking into account the total process time. To attain the required process time accuracy, a robot was used for the handling operations. Finally, the sequence associated with the lower process time was selected as the optimal solution.