Robotic Welding of VCS Interim Products ManTech Project Number: S2459 MTPR/CCB-15-003 NSRP All Panel Meeting Welding Technology Panel Meeting March 10-12, 2015 Derek McKee Engineer General Dynamics, Electric Boat Corporation 860-867-2797 dmckee@gdeb.com 1
Agenda Project Goals Project Execution Project Team Structure Robotic Welding Technology Accomplishments Next Steps Questions 2
Project Goals Issue Description Need to reduce the costs of structural welding Opportunity to improve weld preparation accuracy, component assembly and fit-up, welding processes, equipment and span time for interim products Increased use of fixturing, positioning, automation and mechanization Electric Boat Corporation believes the best method to reduce welding costs is to increase the number of weld joints that are welded with automated equipment Project Objective Create a manufacturing cell at the Electric Boat Quonset Point Facility to robotically weld interim product assemblies that cannot be welded with a mechanized process. 3
Project Goals (Cont.) Previous Development Efforts NJC Project S2199: Electric Boat implemented multiple track-based (linear) mechanized welding systems. Interim products were evaluated, but determined to require robotic welding as joint configurations are too sophisticated for mechanized welding. 4
Project Execution Phase I - Procure Robotic Welding System Identify Assemblies to Weld in the Robotic Cell Develop Functional Specs for Robotic Welding System & On Line Processing (OLP) Procure Robotic Welding System & OLP Develop OLP for Selected Assemblies Develop Welding Processes for Selected Assemblies 5
Project Execution (Cont.) Phase II - Process Development/Transfer System to EB Deliver System to EWI Develop Welding Processes for Selected Assemblies Deliver Robot Welding Cell to the Electric Boat Quonset Point Facility Transfer Welding Process and OLP Knowledge to Electric Boat Electric Boat Robotic Welding Procedure and Personnel Qualifications Develop Higher Productivity Welding Processes Higher Productivity Electric Boat Robotic Welding Procedure and Personnel Qualifications - If Needed Develop Roadmap to Implement Robotic Manufacturing at Electric Boat 6
Project Team Structure 7
Robotic Welding Technology Wolf Robotics completed system build on May 29, 2013, at which time members of the project team participated in a System Runoff 8
Project team interacting with Wolf staff during Runoff 9
Robot home position was reprogrammed to allow more overhead access for crane and moving parts 10
Robot teach pendant 11
Robot system controller sits between stations 1 and 2 The operator pulls up welding programs and turns the system on from this location 12
Example of the light curtain sensors Cleverly recessed inside of posts 13
Subassembly Registration 14
OLP Development Weld Path Fillet Weld From it s home position, the robot first moves down close to the part 15
The robot uses a wire search function to determine the location of the horizontal plate During this operation the robot slowly lowers the torch until the wire makes contact with the top surface of the place 16
The robot then uses a gas cup search function to determine the side location of the horizontal plate The robot slowly moves the torch until the gas cup makes contact with the side of the plate 17
The robot then uses a wire search function to determine the location of the vertical plate During this operation the robot slowly moves the torch towards the vertical plate until the wire makes contact with the vertical surface of the plate 18
The robot moves to the first robtarget along the weld joint When the robot searches an actual part in the shop, the weld path will be adjusted automatically if the robot detects the part is not in the programmed location 19
The robot will travel in a straight line until it reaches the first robtarget along the radius 20
The robot will follow the path along the radius based on the programmed robtargets 21
The robot will reach the end of the radius 22
The robot will travel in a straight line until the end of the weld joint 23
The robot will then return to it s home position 24
OLP Development Weld Path Partial Penetration Root pass on partial penetration joint configuration is located lower along the vertical plate As weld development progresses, nozzle and contact tip to work distance (CTWD) will be modified to accommodate proper dimensions 25
The nozzle inside diameter (ID) is still too large to properly access root joint As weld development progresses, nozzle and CTWD will be modified to accommodate proper dimensions 26
Accomplishments Welded mockup at EWI 27
Accomplishments Fillet T, Partial Penetration T, and Full Penetration T Torch Paths Programmed Need to determine amount of distortion after each pass and offset tool center point for subsequent passes Need to transfer programs to updated virtual cell environment Corner Joints, Butt Joints Torch paths programmed Need to determine amount of distortion after each pass and offset tool center point for subsequent passes Need to transfer programs to updated virtual cell environment 28
Accomplishments Robot cell was installed in Bay 4 at the Electric Boat Quonset Point Facility Initial Design Cell at Wolf Robotics prior to Shipping to EWI 29
Accomplishments EWI developed partial penetration, full penetration and fillet OLP, bead plans, and spray parameters for limited material combination mockups in the horizontal welding position 30
Accomplishments Developing qualification plate OLP, bead plans, and process parameters Gas Metal Arc Welding (GMAW) spray - flat position Adaptive / Non-Adaptive / 65kJ GMAW spray - horizontal position Adaptive / Non-Adaptive 31
Accomplishments Welded Practice Plates Sample Flat and Horizontal plates were welded and sent for Radiographic (RT) inspection for verification Data Collection software was used to monitor all welding parameters Welded 7 Qualification Plates Flat 65 kj Passed All Tests Flat Non-Adaptive, Passed All Tests Flat Adaptive, 2 Plates, awaiting results Horizontal Non-Adaptive, 2 Plates, retest Horizontal Adaptive, awaiting all results 32
Next Steps Robotic Welding Operation Familiarization and Proficiency Obtain any additional materials for qualification plates Obtain materials for the first article assemblies and develop and verify the bead plans Develop OLP for the first article assemblies Continue welding qualification plates Start shipyard evaluations Identify Process Enhancements for System Continue to collect and document lessons learned during the project to increase productivity 33
Next Steps (Cont.) Continue development of roadmap for implementing robotic manufacturing at Electric Boat such as: Part Family Interim Products (PFIP) Cell Expansion Heavy Structures Cell Implementation Developing Weld Sequencing Methodologies Introduction of Robotics into the Automated Frame and Cylinder Manufacturing Facility (AFC) Process Develop Hull Insert and Penetration Process Establish Integrated Product Development Environment (IPDE) Methodology to Deliver Models to OLP Software 34
Questions Derek McKee Engineer General Dynamics, Electric Boat Corporation 860-867-2797 dmckee@gdeb.com 35