According to incomplete statistics, nearly half of the industrial robots in service worldwide are used in various forms of welding processing. The two most common applications of welding robots are spot welding and arc welding. Some of these welding robots are specifically designed for a particular welding method, while most welding robots are actually general-purpose industrial robots equipped with certain welding tools.
The application of industrial robots in the welding field began with resistance spot welding on automobile assembly lines. This is because the resistance spot welding process is relatively simple, easy to control, and does not require weld seam trajectory tracking, thus placing lower demands on the robot's precision and repeatability control.
Below, we will review the four key technologies of welding robots in the automotive field.
Weld seam tracking technology
In the application of robots, weld seam tracking technology is commonly used. During the welding operation, the welding process may be affected by factors such as strong arc radiation, smoke, spatter, machining errors, fixture accuracy, and workpiece thermal deformation. Special attention must be paid to controlling these factors to avoid the welding torch deviating from the weld seam, which would lead to welding quality problems. The existence of weld seam tracking technology can, to a certain extent, monitor the deviation of the weld seam in real time in conjunction with changes in welding conditions, and adjust the welding path and welding parameters in a timely manner, effectively avoiding quality problems that occur during the welding process.
Offline programming and path planning technology
In welding operations, offline programming and path planning technology mainly refers to the further expansion of robot programming languages. It primarily utilizes computer graphics research to create models of the robot and its working environment, and through specialized algorithms, controls and manipulates the graphics of the welding components. This enables the robot to perform welding operations based on pre-defined trajectories. Another practical basis for offline programming is the application of automatic programming technology. Automatic programming assists programmers in their programming tasks while simultaneously defining welding tasks, parameters, paths, and trajectories.
Multi-robot coordinated control technology
In practical work, multi-robot coordinated control technology mainly refers to the integrated system formed by selecting and organizing a number of robots through cooperation and coordination to complete a certain task. In its application, before assigning a task to multiple systems, it is necessary to consider how to organize the equipment to work effectively according to the actual operational task. Once the working mechanism is determined, it is necessary to consider how to maintain the consistency of robot motion coordination in conjunction with the actual work.
Dedicated arc welding power supply
Continuous practical experience has shown that a dedicated arc welding power supply with good electrical performance is one of the keys to ensuring the normal operation of the equipment. Most dedicated arc welding inverters used in robots are single-chip microcomputer-controlled transistor-type arc welding inverters. Welding power supplies with precise waveform control methods can, to a certain extent, ensure the consistency of weld width and depth, resulting in a more aesthetically pleasing weld surface. Therefore, in-depth research on dedicated arc welding power supplies is crucial in application.
