AWS WHC-10.1.11 pdf free download

AWS WHC-10.1.11 pdf free download.MONITORING AND CONTROL 0F WELDING AND JOINING PROCESSES.
In summary, welding processes are complex and becoming more so. The variables that can adversely affect the properties of the completed weidments are also difficult to sense and/or control. 1-lowever, the industry is continuing to advance the performance and capabilities of sensing equipment; the sophistication and robustness of control models and algorithms; and the speed and modularity of computer processing. These evolving sensing and control building blocks become the platform for the ultimate monitoring and control objective, to successfully achieve autonomous automated welding.
Most welding automation techniques did not evolve from traditional manual methods. Instead control engineers have applied conventional quantitative techniques of system analysis through the use of difference, differential, and integral equations to model and control the mechanized aspects of welding. Applications involving through-the-arc sensing, such as arc voltage control and joint tracking, have met with a great amount of success and they have found their way into commercial use and have been successfully used in industry. The sensing technique is low cost, reliable, and nonmtrusive. Both of these automated solutions are mechanistic, governed by electromagnetic laws, and employ a single-input, single-output controller. These laws are well understood and are therefore strategically and efficiently applied to both the sensor feedback information and to the control laws within the closed-loop feedback path. In short, their success is directly correlated to their relative simplicity, inherent robustness, and adequate performance in a production environment.
More complex variables, such as bead geometry or penetration control, are well-understood phenomena that can he reasonably accurately modeled from a theoretical standpoint, but the computational complexity of the numerical models and the multiple-input, multiple- output nature of the required control laws are factors that account for the significant variability associated with real world applications, and have precluded their integration into mainstream commercial weld process controllers. Yet, the ability of a skilled human welder to assess and control head geometry, for example, is not due to a fundamental understanding of the laws of physics. Instead of applying a mechanistic approach to the control of the weld pool, a seasoned welder applies a more humanistic approach in which the feedback information is not based on precision and formal truths, hut rather on imprecision and partial truths. Fully automated welding systems will require a marriage between mechanistic approaches for phenomena that are physically well understood and mathematically feasible for both sensors and control algorithms and heuristic approaches for phenomena that are otherwise difficult to account for, or impractical to implement using conventional control techniques due to the required complexity resulting in a diminished accuracy.
The aim of this chapter is to provide the reader with a background in basic monitoring and control concepts and what general monitoring and control capabilities are commercially available across a broad spectrum of welding and joining processes. Unfortunately, to proide a broad coverage with sufficient depth, it was necessary to make some difficult choices with regard to the processes and capabilities covered. Therefore, the choice of processes and capabilities was based Ofl covering as broad a cross section of welding and joining processes as reasonably possible, to give an appreciation of what monitoring and control capabilities arc commercially available and provide the starting point for addressing the monitoring and control needs for a specific process. Also, a reasonably comprehensive supplemental reading list has been prepared containing many recent and relevant articles to aid in obtaining more specific information and to provide insight into technologies that will be implemented in the near future. This supplementary reading list follows the bibliography at the conclusion of the chapter.AWS WHC-10.1.11 pdf download.