1、外文原文：http:/ 中文2648字出处： International Journal of Production Economics, 1999, 60: 203-209. An automated welding operation planning system for block assembly in shipbuilding Kyu-Kab Cho*, Jung-Guy Sun, Jung-Soo Oh Abstract The block assembly process is one of the most important manufacturin
2、g processes for shipbuilding. Since block is composed of several steel plates and steel sections with predetermined shapes according to ship design, the welding operation planning to construct a block is a critical activity for shipbuilding, but this activity has traditionally been experience based.
3、 Thus, it is required to develop an automated welding operation planning system to assemble blocks. This paper describes the development of an automated welding operation planning system for block assembly in shipbuilding. Based on the information about parts, topological relationship between parts
4、and assembly sequences for block, the developed system performs the determination of welding postures, welding methods, welding equipment and welding materials. The developed system implemented successfully for real blocks constructed in shipyard. Keywords: Block assembly； Expert system； Opera
5、tion planning； Welding process 1. Introduction Shipbuilding is traditionally a labor-intensive assembly industry that employs the welding process as a basic production technology. In shipbuilding, there are several types of manufacturing process planning for cutting and bending, assembly, out-
6、 fitting, and erection. Among these process planning activities, the assembly process planning is by far the most important, since the construction process for a hull block comprises approximately 4850% of the total shipbuilding process 1,2. The main operation for block assembly is the welding opera
7、tion. The welding operation planning problems in block assembly are very difficult to solve because all blocks are different in size, type, and constituting sub-assemblies that depend on the types of ships. Also, since this activity has traditionally been experienced-based, welding operation plannin
8、g in shipbuilding has been performed manually. Thus, it is very important to develop an automated welding operation planning system for shipbuilding. There is relatively very little literature available on automated welding operation planning systems for shipbuilding 3,4. This paper deals with
9、 the development of an automated welding operation planning system for block assembly in shipbuilding. The rule-based expert system for welding operations has been developed using Smart Elements as an expert system tool. The developed system is demonstrated and verified by using actual blocks in the
10、 shipyard. 2. Development of an automated welding operation planning system 2.1. System framework The automated welding operation planning system developed in this paper consists of four modules: welding postures module, welding methods module, welding equipment module, and welding materials m
11、odule. The framework of this system is shown in Fig. 1. 2.2. Determination of welding postures This module determines the posture of the welding operator. Welding posture is reasoned by considering connection types and positional direction between two connected parts, direction information of
12、assembly base part, existence of turnover, and assembly level. Connection types are classified into butt type (B) and fillet type (T), as shown in Fig. 2. The four types of welding postures, down posture (D), overhead posture (O), horizontal posture (H), and vertical posture (V), are considered in t
13、his paper, as shown in Fig. 2 5,6. The most stable and easiest welding posture is the down welding posture, and the most difficult one is the overhead welding posture. The welding operator determines an efficient welding posture according to the working conditions. For relationship of connection bet
14、ween two parts that are welded, one part is considered as the base and the other is connected to the base. The part that is considered as a base is represented as PartFrom and the other that is connected to the base is represented as PartTo. The levels of block assembly to assemble steel plate
15、s and sections into the final block are classified into subassembly (SA) level, unit block assembly (UBA) level, and final block assembly (FBA) level.Subassembly levels may be divided into small subassembly (SSA) levels and intermediate subassembly (ISA) levels according to the size and weight of th
16、e subassembly as shown in Fig. 3. For determining welding postures, the block assembly levels are classified into two groups. The first group is the small subassembly level； the second group consists of the intermediate subassembly, the unit block assembly, and the final block assembly levels. The reason for this grouping is that there is no turnover process in the small subassembly level, but the assembly levels belonging to the second group may have turnover processes. Turnover processes cause the change of welding postures that are determined before the turnover process.
