WHITE PAPER. Reducing Workload in Production Design Stage by Rule-based Automation of CAD

Transcription

1 WHITE PAPER Reducing Workload in Production Design Stage by Rule-based Automation of CAD

2 Contents 1. Summary Introduction Manufacturing Generate Manufacturing Output Format Manufacturing Output Connection and Assembly Physical Connection Assembly Hierarchy Pre-process Production Routing Bending Machine Stage Code Grinders Generate Manufacturing Annotations Annotations without Connection Post-process Marking Validation Control Bevel Validation Control Testing and Comparison Output Status Annotation Editor Conclusion References Acknowledgements i

3 1. Summary This white paper was originally submitted to The Royal Institution of Naval Architects. For a long time in the shipbuilding industry, assembly and fabrication information was reflected as drawings and reports generated by the design department and handed over to the construction field. Since the 1990s, it has been common practice to print such assembly and fabrication information, called annotations, on the raw steel plate/profile (structural parts) directly, using CNC printing devices. The annotations represent object/assembly names, assembled mounting angles, bending machines, bevel information, work center, and so forth. These annotations have become indispensable for the current deliverables by helping to improve the efficiency of the construction field. Initial versions placed a burden on the designer, who had to manually input annotations into a CAD system. In this paper, the authors describe how a production designer s work can be reduced and automated. By implementing the rule-based automation of CAD to generate annotations, the current workflow can be analyzed to standardize work processes. In particular, field actions need to be determined based on multiple considerations, such as grinder attribution based on compartments; bending machines based on the curve and pre-welding; and work centers that must be assembled. We introduced a steel part pre-process service called production routing. We achieved rule-based automation by using the relationship between structural parts; structural parts and compartments; and structural parts and assembly hierarchies that exist uniquely in the CAD system. The results confirm that rule-based automation results in dramatic improvement for production design work. 1 1

4 2. Introduction In 1987, the first CNC printing devices became available. In the 1990s, several major CNC contractors developed and sold devices, but their usage did not spread due to the devices low processing power. In the later 1990s, CNC contractors and shipyards jointly developed CNC printing devices with high processing power for handling multiple annotations in one process. Following this, shipbuilders recognized the usefulness of annotations due to the following benefits: Paperless nature. Less manual marking. Reduced misconstruction rates. Increase in productivity. Ability to outfit construction in the early assembly stages. It is common understanding that improving accuracy and productivity in the construction field is high priority, even if it increases the designers work load to input information into CNC printing devices. [1], [2], [3] Since 2007, Shin Kurushima Dockyards Co., Ltd. (SKDY) has sought a new solution to replace its existing production CAD systems, which had reached the end of their technological life cycles. SKDY held several benchmarks and chose to standardize with Intergraph Smart 3D due to its rules, proven efficiency, and ability to include further design automation. This leads to reduced labor costs without sacrificing quality. SKDY is also one of the leading shipyards to use the CNC printing information efficiently in the construction field. By 1997, SKDY was using then-current CNC printing devices in its Onishi shipyards. The production efficiency of Smart 3D, released by Intergraph Corporation in 2004, had already been proven in several shipyards. However, SKDY required enhanced quality automation and customization based on its production manufacturing standard. This allowed for more input for the export of information to be printed for use in the construction field. This also enabled production requests for more information to be efficiently handled, while simultaneously lowering engineering man-hours. The result is close to 100 percent automation of the decision process used to annotate parts for production. This paper describes the implementation of the rule-based automated annotation by CAD system. 2 2

5 3. Manufacturing Smart 3D offers rule-based decision-making at every step of the design process. Rule-based automations are implemented as the user steps from surface to solid and solid to manufacturing, and so forth. In this section, to understand Smart 3D s rule-based automation and data generation process, we explain the definition of the term as used by Smart 3D, as well as the manufacturing functions that apply when generating annotations. The manufacturing process in Smart 3D is unique when compared with other, existing CAD systems. Other CAD system manufacturing processes for shipbuilding generally transition from 2D to 2D, considering the thick side of the shape. Therefore, definition 2D geometries themselves are used to create output data. However, Smart 3D uses real solid data. So the transition is from 3D to 2D data. We call this transition process the Generate Manufacturing process. [4] 3.1. Generate Manufacturing The Generate Manufacturing plate process is controlled by plate process settings and plate marking settings. The profile process is controlled by different profile process settings and profile marking settings. When we apply settings, we define which automation rule is triggered for application to the structural part. The plate/profile process setting controls certain actions, such as those that create contours (such as the unfolding of a curved object); tab definition; bevel control; and so forth. The plate/profile marking setting controls the actions for creating markings and annotations Output Format To allow easy interface with a nesting solution, Smart 3D uses SMS_SCHEMA files. Steel Manufacturing System (SMS) has been used since 1998 to support Intergraph s previous CAD tool. SMS is an application of extensible Markup Language (XML) and is compatible with XML. SMS makes use of a second XML application, CAD Vector Graphic (CVG), for geometry. A key feature of XML is the flexibility to easily add new elements and attributes as necessary to support new functionality Manufacturing Output Manufacturing output falls into four categories based on four different data groups: SMS_PLATE_CONTOUR Parts shapes, including bevel and margin information, are represented in SMS_PLATE_CONTOUR. SMS_INNER_CONTOUR Inner contour (holes) elements are represented in SMS_INNER_CONTOUR. SMS_MARKINGS Connected structural part locations and their fitting marks are represented in SMS_MARKINGS. Fitting marks specify the location for marking lines that exactly match the connected structural parts. In Japan, fitting marks are generally placed at the structural part end, at the curved end, and at the knuckle location. The seam control mark is also included, though it is not included in the fitting mark conditions. Marking lines must be accurate; therefore, information will generally be sent to the CNC cutting device and not to printing devices. SMS_ANNOTATIONS To transfer annotations used by CNC printing devices, Smart 3D has added SMS_ANNOTATIONS to SMS_SCHEMAS. A wide variety of annotation objects that can be printed on steel is available. Annotations are classified as three types: as text (single or multiple lines); as geometric symbols; and as combinations of text with symbols. 3 3

6 Figure 1, which shows the part label, is an example of the text alone. The part label annotation represents ship direction, ship number, block, part name, shot primer, board information, quantity, production routing information, plate thickness, grade, grinder, and major weld type. Figure 2, which shows the center line mark, is an example of the geometric symbol alone. The center line mark is represented by geometric data. Figure 3, which shows the bevel symbol, is an example of combined text and geometric symbols. Figure 1: Text example. Figure 2: Geometric symbol example. Figure 3: Text and symbol example. The difference between marking and annotation symbol placement is the requirement for accuracy. The marking line should be placed at the exact location supported by the fitting marking. Annotations don t require accuracy in placement; however, each annotation must be unique for reorganization purposes. Marking data will sent to the CNC cutting device, while annotation data will be sent to the CNC annotation device. 4 4

7 4. Connection and Assembly The Generate Manufacturing information derives from the 3D model, with Smart 3D using the physical connection to acquire the connected objects from actual objects. Additionally, the location at which objects to objects first meet is defined in the Assembly Hierarchy tree. Assembly attributions also use manufacturing rule input to specify frame lines to be marked Physical Connection In Smart 3D, there are three connection types defined in the modeling process: logical, assembly, and physical connections. Physical connection is the object type used to represent Solid to Solid parts connections. This connection contains properties and physical attributes for welds. Physical connections are created for each assembly connection when parts are detailed. End-to-end, edge-to-edge, end-toface, edge-to-face and face-to-face relationships map to physical connections for each part. Each physical connection is a child of an assembly connection or a feature Assembly Hierarchy The assembly hierarchy is a grouping of parts for assembly and welding. Small assemblies belong to large assemblies, while large assemblies belong to blocks. From the assembly hierarchy system, we can determine the points at which objects first meet. Three assembly types and two block types are defined for controlling SKDY requirements. Figure 4 shows a block hierarchy example. In this assembly hierarchy example, N1-0G-1 and N1-0G1-A first meet at Ko-gumi 0G1. N1-BW-1 and N1-0G1-A first meet at O-gumi N1. O-gumi: Most large assemblies belong to blocks and include several small assemblies and parts. Chu-gumi: Middle-sized assemblies belong to blocks and include several small assemblies and parts. Chu-gumi does not belong to O-gumi. Ko-gumi: Most small assemblies belong to O-gumi or Chu-gumi. Block: Blocks are still assembled before they are lifted onto the dock. Generally, shell plates and internal plates are assigned to different blocks due to the required bending process that is defined by the stage code, as described in Section T-Block: This block is lifted onto the final dock. Figure 4: Assembly hierarchy. 5 5

8 5. Pre-process Attributions required by the annotation by part label are automatically defined by a pre-process called Production Routing Production Routing The Production Routing command defines the destination of the part after the CNC cutting. This is based on geometrical aspects of the parts, stage code, and work center. The command also triggers multiple programs that have different purposes in one process. The result is a collection of routing action definitions, supported with action, machine, and code. SKDY implemented the following rules, all of which support the part unfolding process, including the Part Label annotation: Bending machine. Stage code. Shot primer. Grinder. Major weld type. In the current work process at SKDY, all the decisions and definitions resulting from the designers experience of drawing contents and length are checked against the 2D graphic. SKDY has sheets describing 130 patterns of stage code condition; designers choose from among these. This process was time-consuming, and the quality and speed of decision-making all depended on the designers experiences. By building the designers knowledge into a rule-based approach, the production routing decisions are now automatic, reducing time and improving quality. 6 6

9 Bending Machine The bending machine selection is an interesting process because it is selected by the geometric aspects of each part. In SKDY, the bending machine used for fabrication of curved (knuckled) parts is labeled on the part label by annotation. This information becomes part of the stage code. (Assigned assembly types determine the stage code for non-curved parts that are constructed or welded.) The bending machine is selected from seven machines for plates, including line heating, and six machines for profiles. Plate-bending machines with code: BB Flange Bracket Bending Machine. Profile-bending machines with code: FBK Flat Bar Knuckle Bender. RB Bending Roller. FBR Face Plate Bender. 5B 500T Press Bending Machine. ABR Angle Bender. PB 1000T Press Bending Machine. TFB Build Up Profile Bender. SB 1750T Press Bending Machine. TAB Build Up Angle Bender. 3B 3000T Press Bending Machine. OB Invert Bending Line Bending. 7B Line Heating. The rules consider: Plate thickness. Plate curvature type. Plate dimensions. Knuckled location from the parts edge. Knuckle length. Profile type (such as FB, IA, and BP). Build up. Profile curvature type. For example, essential conditions for the 1750T press bending machine (SB) are as follows: A knuckle length must equal more than 1,600 millimeters, but less than 2,200 millimeters. The knuckled location from the edge must equal more than 140 millimeters. The plate curvature type must be a knuckle bend. The plate thickness must equal less than 16 millimeters. It does not require complicated calculations, except in welding the multi part before bending. What is logically important is the sequence of classifying each machine, from the conditions of small bending machines to those of large bending machines. 7 7

10 Stage Code Stage code is defined by a bending machine type, which is defined by the bending machine process, assembly type, welding information, and other factors. Different selection rules are processed by each assembly type described in Section 4.2. Example rules that execute according to assembly types are shown in Table 1. In Table 1, B is replaced based on the Bending Machine information in The program itself is very simple, but embedding this logic in rules results in major time savings for the designer. The program checks each qualification, then answers either YES or NO. It then defines the stage code on the Plate/Profile Parts. Assembly Type Curved Part? Naigyo Itatsugi? Senko Kogumi? Build up Profile? Panel Block? Stage Code Yes Yes Yes No No BIFS Yes Yes No No No BI Yes No Yes No No BFS Kogumi Yes No No No No B No Yes No No No I No No Yes No No FS No No No Yes Yes SLW No No No Yes No SA Assembly Type Curved Part? FCB Weld? IXYY7 Weld? Panel Block? Stage Code Yes Yes No No BJF Yes No Yes No BJ Yes No No Yes BLW Ogumi/ Chugumi Yes No No No B No Yes No No JF No No Yes No J No No No Yes LW No No No No A Table 1: Stage code. 8 8

11 In Table 1, Senko Kogumi, Naigyo Itatsugi, and panel block qualifications are carried out by the keyword in the part name of the present condition. For example, a part name included in a panel block always starts with the prefix PW-. This process could also be used to convey the work center information for the part in the future if doing so benefits the production designer. FCB WELD and IXYY7 WELD qualifications are carried out by the weld type defined on the physical connection Grinders According to IMO (Resolution) A.789 (19) Annex, Performance standard for protective coatings for dedicated seawater ballast tanks on all new ships and double-sided skin spaces of bulk carriers, parts located inside of ballast tanks require edge grinding before they can be painted. For the convenience of field workers, SKDY places grinder and grinding time on the part label, indicated by G1, G2, G3, and so forth. To reduce the manual work of the production designer, Intergraph and SKDY assign grinder attribution on the compartments and automatically transfer the information from compartments to parts based on their location. (Initially, there is another process to define grinder attribution at each edge of the part to start the manufacturing process. However, we realize that a smarter step involves production routing defining grinder information on the part as one of attribution.) 9 9

12 6. Generate Manufacturing SKDY s current in-house system requires that annotation operations placement be managed by user input. The task of the operator is to execute the appropriate commands based on the required annotations. As described in Section 3.1., the Generate Manufacturing process creates the manufacturing output data. In the implementation of Smart 3D in SKDY, we plan to replace all the user input in the current SKDY in-house system with rule-based automation using physical connection and assembly information, as well as the results of production routing in Generate Manufacturing processes. Marking a line automatically generates the location of physical connection where objects first meet. Also, the following annotations are automatically generated by the Generate Manufacturing process: Plate Parts Part label. Ship direction label. Seam marking to be cut at Tab location and annotation. Pad-type Knuckle Tab location label. Center line annotation. Bevel annotation (approximately 47 symbol combinations). Bevel change marking and annotation. Butt-weld connection annotation when thickness is different: Align Center and Align Surface. Seam marking and annotation: Cut After Bend. Grinder edge-specified, or area marking, annotation. Face Plate off edge information label. Special marking and bevel label for common cutting. Declivity, or mounting angle, marking and label for Plate and Profile. Declivity, or mounting angle, marking and label for Edge Reinforcement. Marking line and object name label. Reference Plane name label (frame name, waterline name, buttock line name). Margin marking for cutting off and cutting stage annotation. Seam Control marking and annotation. Plate/Profile lapped annotation. Plate/Plate lapped annotation. Radius End (RE) fitting mark and annotation. KL Fitting Marking. Edge Reinforcement (Face Plate) End-Fitting marking and annotation. Clip/Collar marking and clip name label. Small hole-size label. KL marking and knuckle direction and radius label

13 Flange Bracket FL information label. Sight line annotation. Pre-assembly Plate annotation. Member (Pillar) annotation. Profile Parts Part label. Marking line and object name label. Bevel symbols. Off-edge marking and label. RE Line marking and Bending Radius label. KL marking and Knuckle Angle label. All of the above items are applied on the parts in a default process. We will give several examples and show the resulting annotations Annotations Generally, annotation is associated with geometrical lines. Part names identified in Figure 5 are N1-F12-1, N1-F12-2, and N1-F12-3. The physical connection s marking lines are generated, and the last section of the connected object names (1, 2, and 3) is labeled on the actual plate, N1-F12-V. The Reference Plane (frame and water line) markings and their locations, 1W and 1B, are marked and labeled. Bevel annotations are associated with outer contours. Additionally, bevel change marks are associated with changed locations of bevel marking lines. The exception is the part label, which is not associated with any particular geometry, as shown in Figure 5. Figure 5: Annotation example

14 6.2. Annotations without Connection The items listed in Section 5, Pre-Assembly Plate Annotation and Member (Pillar) Annotation, are unique. They do not have a direct physical connection between labeled objects and active plates. Pre-assembly plate annotations generally reference indirectly connected objects, such as brackets that are pre-assembled with the face plate prior to welding the face plate to the active plate. Therefore, face plates are placed between the labeled plate and the active plate. The Member (Pillar) Annotation modeling condition is very similar to the previous example. It is very rare to connect an active plate and pillar in shipbuilding design. In general, there are girder plates, gusset plates, or face plates defined between the two objects. Recognition of the modeling case is one of the keys to supporting the annotation rule-based solution. To resolve this, we make use of the assembly definitions. Within one assembly, we expect limited cases of the same assembly containing a pre-assembled assembly of the bracket part. Figure 6 shows that N1-0G1-A and N1-0G1-2 don t have a connection because N1-0G-1 is between them. However N1-0G1-2 s object name is still labeled on N1-0G1-A by annotation with arrow. Figure 6 shows further annotation labels. The seam control line is annotated; the butt-weld connection is annotated Align or Center; the Face Plate off edge information is annotated; and the Plate/Plate lap is annotated. Figure 6: Annotation without connection

15 7. Post-process When markings and annotations are executed, situations will arise in which there may be an overlap of marking lines, or there may be a condition in which a bevel angle has minor bevel changes. These cannot be applied (marked or cut) by the CNC devices. To resolve the overlapping marking and bevel cases for the CNC cutting devices, the system applies a validation as a post- process at the end of the Generate Manufacturing process Marking Validation Control Duplicate marking lines generally occur when connected objects and reference lines are defined at the same reference or when marking lines are generated from a condition when an object is attached to both the marking and the anti-marking side (see Figure 7). If the objective is to initially create the marking and annotation on actual objects as much as possible, post-processing can be applied at the final stage of the unfolding. Marking lines are ranked by priority. Based on cases of overlap, the proper markings are removed or trimmed. Additionally, the profile end fitting mark and labeled name provide the information for field workers as to which object is connected to the marking side and which to the anti-marking side. Figure 7: Duplicated marking condition. The large bracket in Figure 7 is connected on the marking side marked with annotation 5, which is labeled in the direction of the counter-thickness. The small bracket is connected on the anti-marking side marked with the annotation $4, which is labeled in the thickness direction. The $ sign denotes objects on the anti-marking side. Additionally, the arrow head annotations representing bracket areas are automatically generated in the marking validation

16 7.2 Bevel Validation Control When we try to define the outer contour shape at the bend knuckle location, the attached angles change excessively before and after the knuckle line. Following the SKDY beveling logic, the bevel changes every five degrees. The rules automatically calculate the required bevels along the length of the connection. However, when the angle changes by 30 degrees at the before and end marks, it s possible that at least six different bevel symbols and bevel transition marks are placed in very narrow locations. Not only are annotations unrecognizable in such a situation, but the CNC cutting devices cannot correctly cut the steel. (In this situation, the torch stays longer in small areas. Therefore, the outer contour shape may be excessively cut off, as well as becoming jagged.) Figure 8: Knuckle result before and after validation. SKDY requires simplified output, in which we take the middle angle between, before, and after the knuckle line, and apply the middle angle between bended lengths. New geometric functions are needed to implement the requirements. However, Smart 3D handles this difficult issue by applying logic (that is, standardization of the manual operation). Therefore, this is the key to implementing experienced designers know-how on computer programs. Future versions will supply automated geometry services. Figure 8 shows the result before and after applying bevel validation control. The bevel changes from 0 to 45 degrees before and after the bend knuckle. Therefore, the middle value is 22.5 degrees. In the bevel logic, if the bevel is between 20 to 25 degrees, choose 25 degrees, and then apply the 25-degree measurement on the unfolded bending area. After applying bevel validation, segments 3 millimeters in length are placed between different bevels and apply small side bevel value before and after. This derives from SKDY s basic bevel handling rule

17 8. Testing and Comparison Generated data were compared piece by piece with the manufacturing output from a previous sister ship to check data accuracy. Additionally, the data for plates and profiles is required to pass the installation of CNC devices. 8.1 Output Status SKDY used the Smart 3D output on the actual project. Several blocks data are marked and cut off with printed annotations by the CNC devices. Figure 9: Current result. SKDY plans to extend its use of output data and plans to fully replace the new ship plan starting in Bending Machine and Stage Code results were confirmed to be 98-percent accurate in the bulk carrier engine room. The remaining two percent are the parts that do not logically classify, for example, the part requests to be temporarily placed in the base plate and welded in the final dock or T-Block, or in production purposes, the request to replace the process weld first and then bend. Based on placement experience, we tried to re-adjust the default placement position and annotation size automatically. Figure 9 shows the CNC data with annotations automatically generated from Smart 3D, as well as a labeled steel plate Annotation Editor Increasing the number of annotations has its disadvantages. If the part area is large, then few disadvantages exist, but if the part area is small, then many annotations overlap. Smart 3D has the functionality to find white space in the drawing. However, usage inside the unfolding is more complicated, because it has to remain within the plate area, and annotations cannot overlap. We currently are postponing spending additional time on this, as the results depend on the user s preferences. We provide an annotation editor function to allow the user to change the location of the annotation. If necessary, text lines can be split into multiple groups. Additional symbols can be placed manually

18 9. Conclusion SKDY design standards and workflows through manual annotation are well-defined. Generally, the time spent to develop a system to organize and standardize workflow processes is considerable, but in the case of SKDY, we can smoothly start developing work. The SKDY project is defined as a collection of modular processes for which operations give the expected result for a production output with internal control of sequences. Even though each process may be correctly executed, additional improvements are required to achieve the same results as with the manual output. A very thorough output check must be carried out, because the manufacturing output requires a perfect result. Otherwise, misconstruction or fabrication errors occur in the construction field. From the status of SKDY s use of the output in a real project, the project has achieved success. Based on standardization of manual work processes, about 400 documents provided from SKDY must be implemented into automation rules. However, we still must continually provide documents to improve the result with more automation rules. The construction field recognizes the benefits of automated output and requires additional enhancements. What follows is the majority of items we believe require future improvement: Annotation arrangement (white space control). Annotation symbol size control (Several text sizes already automatically adjust by profile/plate size. Expand this logic to other types of symbols). Location marking from outfitting objects, such as hangers, traffic equipment, and equipment foundation. Assembly process automation. Intergraph and SKDY will continue to partner to improve the ship design process and to take better advantage of automation until the construction field is satisfied with the information, without any additional work by the production designer

19 10. References 1. T. YAMAMOTO; Increase in the Precision of Ship Production Process, Mitsubishi Heavy Industries Technical Review Vol. 47, Y. SAITHO; CAD/CAM System, Universal Shipbuilding Corporation Technical Review No. 5, S. IDEUCHI; Establish of Construction Method for Ultra Large Hull Blocks, Mitsubishi Heavy Industries Technical Review Vol. 50, K. COCHRAN; Rule-Based Ship Design, ICCAS,

20 11. Acknowledgements Special thanks to SKDY production and system development teams. Yoshitaka Kosaka holds the current position of Production Design Department Engineering Division at Shin Kurushima Dockyard Co., Ltd., since He is responsible for the production division of the 3D-CAD operation team. He received a master s degree in 3D-CAD operation in shipbuilding from the University of East Asia in

21 For more information about Intergraph, visit our website at Intergraph Corporation. All Rights Reserved. Intergraph is part of Hexagon. Intergraph and the Intergraph logo are registered trademarks and Intergraph Smart is a trademark of Intergraph Corporation or its subsidiaries in the United States and in other countries. Other brands and product names are trademarks of their respective owners. Intergraph believes that the information in this publication is accurate as of its publication date. Such information is subject to change without notice. Intergraph is not responsible for inadvertent errors. 10/13 PPM- US-0256A-ENG