| In modern sea-going vessels, there is a vast amount of welding required during the process of creating the bulkhead assemblies. Traditional robotic systems are inadequate in industries such as shipbuilding because of their inherent inability to adhere and maneuver across uneven, vertical, or inverted surfaces while maintaining a weld. Therefore, these jobs are largely performed by skilled laborers, either by hand or with the use of specialized, job-specific equipment, such as a fixed-track welding mechanism. Beyond the costs involved with such manual processes, many of these tasks involve a significant safety risk to the operator.This thesis discussed the capabilities of a semi-autonomous climbing mobile robotic welding system (MRWS) designed to automate several metal-joining processes in unstructured manufacturing environments such as shipbuilding. This mobile robotic platform is lightweight and capable of climbing ferrous surfaces by the use of permanent magnetic tracks while supporting and manipulating commercial welding equipment. The MRWS has the potential to directly enhance productivity, cut labor costs, and add flexibility to the shipbuilding industry.To solve the problems of robot localization and motion control, a kinematic model of the unique system was presented and evaluated experimentally. In order to comment on the stability of the kinematic model, a dynamic model was constructed that utilized an original method for estimating friction forces between the tracks and the climbing surface. Also, a simple kinematic controller was constructed to lend the MRWS the ability to automatically follow a weld groove. After discussing the solutions to a few problems that occurred during the implementation of the MRWS it was concluded that the MRWS provided a suitable solution to the problem of automating specific metal-joining tasks in unstructured environments such as shipyards. |
