Abstract As automobile body panels are one kind of sheet metal part with groups of free form surfaces, the process planning is more complicated than common sheet metal stamping to implode effectively and practically. Based on KBE, new frameworks have been presented as intelligent master model at the system level and as procedure model at the activity level. In accordance with these frameworks, an intelligent CAPP system has been specifically developed. Based on feature technology, features have been extracted and represented by the object-oriented method. Stamping features and their parameters have been defined and ex- tracted based on feature technology and stamping process rules. The whole product knowledge has been represented by frames which directly map to objects (or features) in the object-oriented sense. Relevant appropriate operations fea- tures have been assigned to stamping features of a product based on feature-operation criteria, parameters of the stamping feature and their correlativity. This assignment is a decision-making activity using a set of rules with a decision-making tree and model-based reasoning methods. With knowledge between operations, such as operations order constraint (do-after) and operations combination con- straint, process paths have been improved based on relevant intelligent reasoning methods. Based on the relationships (preferred-to) between processes and machines/dies, the structure of die and machine for each process can be iden- tified, since the process route has been determined. In this stamping process planning, the procedure and information have been controlled by a process control structure that is associative and integrated.68741

Keywords Automobile panel . KBE . Process planning . Feature

J. Zheng (*) . Y. Wang . Z. Li

State Key Laboratory of Die and Mold Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, People’s Republic of China e-mail: fengqiaoz00@sohu。com

1 Introduction

Recently, research on the computer-aided process planning (CAPP) system for sheet metal has been widely reported. Park et al. [1] constructed an automated process planning system for axisymmetric deep drawing products. Tisza [2] and Kang and Park [3] presented a group technology and modularity to construct a CAPP system for process se- quence design in an expert system for non-axisymmetric deep drawing products with elliptical shape. Gao et al. [4] developed an advanced software toolset used for the automation of sheet metal fabrication planning for aircraft components. Zussman and Horsch [5] proposed a motion planning approach for robot-assisted multiple-bent parts based on C-space and a potential field. Wang and Bourne [6] proposed an automatic process planning system with the features well investigated and the production plans researched with near-minimum manufacturing costs. De Vin et al. [7, 8] developed a sheet-metal CAPP system called PART-S, which integrates cutting, nesting, bending and welding processes for bending sequences. Streppel et al. [9] showed the ambiguity of conventional tolerances and presented a method which replaces conventional tolerances with geometrical tolerances for process planning in small batch sheet metal part manufacturing. Aomura et al. [10] proposed a method which generated feasible bending sequences of a sheet metal part handled by a robot, and discussed the determination of the best grasping positions and repositions. Aomura and Koguchi [11] pro- posed a method to generate bending sequences of a sheet metal part handled by a robot. Liao and Wang [12] proposed an evolutionary path-planning approach for robot-assisted handling of sheet metal parts in bending. Lutters et al. [13] developed a generic architecture for computer aided process planning based on information management for sheet metal manufacturing in a small batch part environment. Kumar and Rajotia [14] had proposed a method of scheduling and its integration with CAPP, so that on-line process plans can be generated taking into account the availability of machines and alternative routes. The  contents  above  are  mainly  for  process   parameter