The consistent implementation of Industry 4.0 has a decisive influence on the factory of the future, which will develop into a ‘smart factory’. For a ‘smart factory’ to work more or less autonomously without human interaction, some criteria must be met for welding applications. The welding know-how has to be digitized and prepared in such a way that a computer can make similarly correct decisions as an experienced welding technologist. The welding equipment must be equipped with high-performance information and communication technology and customized sensors so that all production-relevant information can be digitized and given the necessary real-time behaviour of the system. The need to transfer and store large amounts of data requires powerful network infrastructures and sufficient storage capacity. Concepts for data and communication security must be created and implemented. This will change the core business of a welding power source manufacturer.
In the early stages of welding technology the development was focused on the intensive examination of the direct conversion of electrical energy from the grid into suitable welding currents and voltages. In the 1990s, the full digitization of the welding process and its digital control became the main topic of innovations. Current welding systems have ultra-fast machine-internal and external data communication channels, high-resolution real-time control, the ability to store large amounts of data, IT security and intelligent human machine or machine to machine communication. In future fully automatic welding systems will independently and without human intervention organize the production of new parts and access the wide experience in the central storage systems. However, as long as the digitization process in welding technology is not completely completed, humans will continue to play a central role in determining welding solutions. Accordingly, the communication channel between human welding machines will continue to be one of the most important success factors.
Digitalized Welding Knowledge
A networked, modular welding cell must be equipped with the right welding parameters and welding consumables, depending on the task assigned by the production control. Nowadays the welding technologist holds responsibility for the right choice of welding parameters. If these tasks are to be supported by intelligent software systems in the future, it is necessary to digitize existing knowledge and make it automatically retrievable. This is probably the most difficult challenge of Industry 4.0 in welding technology, as all the existing knowledge very difficult to quantify and therefore hardly comprehensible to digitization. For autonomous cells, however, digitized knowledge is a prerequisite.
Modern Welding Power Sources
Modern ‘Industry 4.0 ready’ welding systems consist of several microprocessors networked by means of bus systems and thus already form a network internally. This architecture allows flexible implementation of a variety of system configurations with relatively few different base devices.
One of the key words in Industry 4.0 is communication, but what does communication mean when it comes to welding? In the case of modern MIG/MAG power sources, the necessary in-machine communication can be estimated by a simplified calculation: Modern short arc processes, operate at a droplet stripping frequency of up to 150 Hz, which means that one drop is removed approximately every 7 msec. In order to optimally control the drop, the right control action must take place; finally all the derived control signals are sent back to the systems actuator. All these real-time demands concerning the data transfer and signal processing represent an enormous technical challenge.
Welding Parameter Selection and Data Storage
One of the most challenging goals of Industry 4.0 is the flexible, autonomously working manufacturing cell, which consist of different, but closely networked individual subsystems. In order to work autonomously, the manufacturing cell must be able to identify the blanks of the product to be manufactured and the product order. With reference to this component, the individual systems are then instructed and, in the case of the welding system, the welding parameters are transmitted. During the ongoing welding process, these are checked and, if necessary, corrected. For this purpose, as already discussed, a modern robot welding power source with powerful microprocessors, real-time data communication and appropriate control algorithms is necessary.
The article is written by Mr Vishwanath Kamath, Chairman, CII Task Force on Welding Technology 2021-22 and Managing Director, Fronius India Ltd.