I. How to implement automated weld seam tracking and positioning
A common method for achieving weld seam tracking and positioning in welding robots is peripheral auxiliary detection, which mainly utilizes laser tracking and photographic imaging. This weld seam tracking and positioning control system can collect weld-related data using optical measurement equipment. The welding robot can then adjust the motion trajectory of its adaptive arm by comparing the data, thereby achieving real-time tracking of the weld seam.
The laser weld seam tracking system of the welding robot checks the seam gap for suitability before welding using the weld seam positioning function and accurately reaches the joint to be welded. It provides real-time weld seam tracking and monitors product deformation during the welding process. By installing sensors before the welding position data collection, data is collected via power supply or welding parameters and then transmitted to the welding robot. Various adaptive fuzzy control algorithms are used to ensure the correct welding robot trajectory or dedicated machine, thereby achieving adaptive control and realizing real-time weld seam tracking.
The trend of industrial intelligence is irreversible. With economic development, robotic welding will gradually replace manual welding. Although it is difficult to completely replace it, it is still possible to replace 90% of repetitive batch welding work in actual welding applications. Welding robots have higher efficiency, guaranteed welding quality, and are easy to manage without emotional issues, which makes them very popular with enterprises. However, for many welding workpieces with high precision requirements, robots themselves are not up to the task. In this case, laser weld seam tracking systems must be used to assist.
II. Application of Welding Robots in Production
A relatively simple welding robot production line connects multiple workstations using a workpiece conveyor line to form a single production line. This type of production line still retains the characteristics of a single station, meaning that each station can only weld predetermined workpieces using selected workpiece fixtures and the welding robot's program. For a period of time before the fixtures and program are changed, this line cannot weld other workpieces.
There are two main types of welding robot applications: spot welding and arc welding. The earliest application of industrial robots in welding was resistance spot welding on automobile assembly lines. This is because resistance spot welding is relatively simple, easy to control, and does not require weld seam tracking, thus placing lower demands on the robot's precision and repeatability.
The most significant characteristic of robotic arc welding is its flexibility; the welding trajectory and sequence can be changed at any time through programming. Therefore, it is best suited for products with a wide variety of workpieces, short and numerous weld seams, and complex shapes. This perfectly aligns with the characteristics of automobile manufacturing. Especially in modern society, where car models are updated very rapidly, automotive production lines equipped with robots can adapt well to this change.
The widespread application of spot welding robots on automobile assembly lines has greatly improved the productivity and quality of automobile assembly welding. At the same time, it has the characteristics of flexible welding, that is, by simply changing the program, different car models can be assembled and welded on the same production line.
Statistics show that in my country, spot welding robots account for approximately 46% of all welding robots, mainly used in the automotive, agricultural machinery, and motorcycle industries. Typically, assembling the body-in-white of a car requires welding 4,000 to 6,000 weld points. Only by using robots as the core to form a flexible welding production line can large-scale production be achieved and the demands of future new product development and diversified production be met.
