Shipbuilding CAR-W (Computer Aided Robotic-Welding)

Of significant importance to the U.S. Shipbuilding industry is a widening gap in the use of robotic welding automation versus foreign shipbuilders.  Used heavily on higher volume commercial ship production in other regions globally, automated robotic welding solutions are used sparsely by comparison in the US Defense Shipbuilding Industry.  The result is incrementally higher costs and longer lead times in production.

The lack of robotic automation in the US shipbuilding industry has often been attributed to the “programming barrier” where the high cost of staffing for robotic programming creates a cost barrier with weak investment returns on low volume – high mix shipbuilding volumes.  In this integration effort, the foreign technology gap described above closes that process by taking a major step towards solving “the” critical bottleneck to the application of robotic welding technologies in lower volume applications; automated robotic path and process solution generation (i.e., the shift from “manual off-line” to “computer automated robotics” (CAR) programming).

Shipbuilding is different from many other industries, such as the automobile industry, in that ships are not mass produced like automobiles. The cost of man programmed robot welding for automobiles can be absorbed more easily because of the number of same robot welds made over and over, and the number of welds are few compared to a ship. In shipbuilding, man programming of the many different welds of a ship get very costly and these costs are hard to absorb when considering the number of welds in a ship and the low volume of the number of ships that will be built of that same design.

Additionally, the urgency of this integration in relation to the aging U.S. shipbuilding welder workforce nearing retirement makes this effort critical. These welder's expertise and process knowledge must be captured and documented within the next five to ten years or the risk of losing knowledge and increasing production cost.

The general objectives of this integration effort included:

• Development of a general - executable Business Process Flow (organizational and technical) for implementing Computer Aided Robotic Welding that provides the industry a guideline roadmap for success.
• Standardization of the ShipConstructor / AutoCAD for processes required to drive CAR-W applications
• Development of a CAR-W process database that captures critical welding process data and leverages it for future use in the design and manufacturing planning processes.  
• Development of a methodology to allow flexibility / changes to the Sequence of Welds from within the 3D ShipConstructor / AutoCAD Model for part and assembly build-up without the requirement for manually re-programming the robot.
• The development of Computer Aided Robotics Path Planning algorithms for typical high-use weld types in the shipbuilding industry, to help breakdown the programming barrier for shipyards and expand robotic welding technology applications throughout the industry.
• Conduct technical demonstrations, virtual and live, highlighting each CAR-W milestone achievements so that both knowledge and technology transfer can occur rapidly among shipyards.

The automated path planning algorithm development was a major undertaking and it was at the heart of the success of the project, an equally critical component is the adaptation and alignment of the industry’s current design and manufacturing planning processes to support Computer Aided Robotics (CAR).  Designing and building the organizational and technical infrastructure as well as the information flow to support Computer Aided Robotic Welding was a large scale challenge.  Identifying key personnel who supply pertinent information, what form it is in (electronic or manual), what platforms or tools they currently work in etcetera, allowed proper integration of the designer, planner, manufacturer user work flows. In short, getting the right information, to the right people, in the right form - to the right place helped to ensure a successful adoption of Computer Aided Robotic Welding.

In this effort a “process map” and workflow was developed to allow successful Computer Aided Robotic Welding applications to occur within a shipbuilder’s organization. An outline of the general technical approach used to build the “organizational and technical” process for Computer Aided Robotic Welding solutions (CAR-W) is outlined below in the following development and service tasks:

1. Project Organization and Participant Alignment: Professional Consulting services were provided to map organizational and technical alignment.
2. CAR-W Application Assessment of Individual Participating Yards
3. CAD Ingredient Standardization: ShipConstructor / AutoCAD / Navisworks / Inventor
4. Process Ingredient Standardization: ShipConstructor / AutoCAD data exports to Robot Studio
5. Database Development & Data Strategy: ShipConstructor / AutoCAD database alignment to Robot Studio
6. Sequence of Welds Flexibility & Deformation Software Strategies: ShipConstructor / AutoCAD / Navisworks data exports to Robot Studio
7. Path Planning Development: Robot Studio
8. Equipment Translation
9. Technical Demonstration / Training / Workshop

Completion of this integration provides a major steppingstone towards the wider-spread application of automated robotic welding in the US shipbuilding industry.  Much like the way that Computer Aided Manufacturing (CAM) software development led to the wider spread use of CNC machinery, Computer Aided Robotics (CAR) for Welding applications (CAR-W) will lead to the wider-spread use of robotic automation in the US shipbuilding industry helping to meet the cost, quality, and lead time objectives of the industry stakeholders.

This effort provided a way to capture and compartmentalize that knowledge in such a way so that it can be drawn upon and potentially applied automatically to Computer Aided Robotics applications based on the types of welds, materials, etc. selected by designer, process planners, and engineers.  Another concern is the effect that a retiring welding workforce will have on the overall capacity of the industry, which could be offset trough robotic welding systems.

The project results helped those adopted shipyards in overall process improvement and integration efforts.  The project provided general costs and savings through use of CAR-W applications based upon well-known guidelines and data for robotic versus manual welding applications.   

The cost and savings are simple:  

1. Robotic welding lays more wire faster than manual welding.  
2. Robotic welding has more “arc on” time per day than manual welding.  
3. Robotic welding is more efficient and uses less wire than manual welding for the same application.  
4. Robotic welding produced better quality consistently… scrap, rework, and over-welding associated with Robotic Welding are less than Manual welding.  
5. Automated programming is faster than manual programming.  
6. Automated or computer assisted process planning is faster than manual process planning.  
7. Shipyard implementation costs, (equipment, labor, materials, training, etc.) will vary based on the Robotic Investment per shipyard and the number and type of system purchased.