GOALI: Enabling Friction Stir Welding in Unstructured Environments Through Process Identification and Shared Control

这个项目的目标是确定熟练的人类操作员在机器人搅拌摩擦焊接系统的控制中能发挥多大的作用。搅拌摩擦焊被称为近20年来连接技术最重大的进步。与传统的连接方法相比，它在焊接质量、一致性、能耗和成本方面具有优势，但由于需要在开发用于机器控制的零件专用程序方面进行大量的前期工作，因此它的引入受到了阻碍。为了证明这些前期投资是合理的，生产量必须足以以合理的每件成本摊销投资，避免在小批量和维修应用中使用搅拌摩擦焊。此外，在许多制造应用中会出现很大的工艺不确定性，如焊接路径偏差和板之间的间隙条件变化很大，但使用传统控制技术无法解决这些问题。最后，搅拌摩擦焊接过程中所需的大作用力防止了它成为手动过程。为了实现搅拌摩擦焊在小批量和修复应用中的优势，我们相信，采用共享人机控制的远程操作机器人系统提供了克服这些限制的最佳机会。为了实现这一目标并评估其有效性，我们设计了一个三阶段研究方法。阶段1将试图了解特定的搅拌摩擦焊接工艺参数，如进给速度、行程角度和工作角度，如何影响搅拌摩擦焊接的质量。阶段2将确定控制这些参数的最佳方法？通过直接计算机控制或通过共享的人类控制方法。在第三阶段，我们将评估共享控制架构在制造大型铝组件的实验室和生产环境中的性能。为社会带来的好处包括开发了一种现场搅拌摩擦焊接技术--使这种新兴的固态焊接工艺具有与当前熔化工艺相同的灵活性。此外，对维修、一次性和小批量生产中使用的各种制造工艺应用共享控制还会产生社会效益。将技术和成果整合到工程课程中，并在这种跨学科研究中培训学生，将产生进一步的社会影响。密切的产业合作将加强技术转让，为学生提供获得不同研究经验的机会，并成功地将基础科学与重要的技术需求联系起来。

The objective of this project is to determine how well a skilled human operator can share in the control of a robotic friction stir weld system. Friction stir welding has been called the most significant advance in joining technology in the last 20 years. It offers advantages in weld quality, consistency, energy consumption, and cost over traditional joining methods, yet its introduction has been hampered by a need for significant up-front effort in developing part-specific programs for machine control. To justify these up-front investments, production volumes must be sufficient to amortize the investment at a reasonable cost per part, precluding use of friction stir welding in low-volume and repair applications. In addition, large process uncertainties such as weld path deviation and widely varying gap conditions between plates arise in many manufacturing applications but cannot be addressed using traditional control techniques. Finally, the large forces required during friction stir welding prevent it from becoming a manual process. To realize the benefits of friction stir welding for low-volume and repair applications, it is our belief, that a tele-operated robotic system, employing shared human-computer control, offers the best chance to overcome the limitations. To accomplish this and evaluate its effectiveness, we have devised a three phase research approach. Phase1 will seek to understand how specific friction stir welding process parameters, such as feed rate, travel angle, and working angle, affect the quality of a friction stir weld. Phase 2 will determine the optimal method of controlling these parameters ? through direct computer control or through a shared-human control approach. In Phase 3, we will evaluate the performance of the shared-control architecture in a lab and production environment where large aluminum assemblies are fabricated. The benefits to society include the development of an enabling technology for on-site friction stir welding - giving this emerging solid-state welding process the same flexibility that current fusion processes enjoy. In addition, societal benefits arise from the application of shared control to a variety of manufacturing processes used in repair, one-off, and low-volume production. Further societal impact will result from integrating techniques and results into the engineering curriculum and training students in this interdisciplinary research. Close industrial collaboration will enhance technology transfer and the opportunity for students to receive diverse research experience, and to successfully make connections from basic science to important technological needs.