A relatively simple welding robot production line connects multiple workstations (units) using a workpiece conveyor to form a single production line. This type of line retains the characteristics of a single station; each station can only weld predetermined workpieces using selected workpiece fixtures and the welding robot's program. For a period of time before changing the fixtures and program, the line cannot weld other workpieces.
Another type is the flexible welding production line (FMS-W). Flexible lines also consist of multiple stations, but the difference is that the workpieces to be welded are all clamped on uniform pallets. These pallets can cooperate with the positioners at any station on the line and be automatically clamped. The welding robot system first identifies the pallet number or the workpiece and automatically retrieves the welding program for that workpiece. This allows each station to weld different workpieces without any adjustments. Flexible welding lines typically have a tracked mother-daughter trolley that automatically retrieves the clamped workpieces from the storage station and delivers them to the positioner of an available welding robot workstation. It can also remove welded workpieces from the workstation and deliver them to the finished product output location. The entire flexible welding production line is controlled by a scheduling computer. Therefore, as long as enough workpieces are assembled during the day and placed in storage stations, unmanned or minimally staffed production can be achieved at night.
The choice of which automated welding production method a factory chooses depends on its actual situation and requirements. Dedicated welding machines are suitable for products with large batches and slow modification cycles, and where the workpieces have a small number of long weld seams with regular shapes (straight lines, circles). Welding robot systems are generally suitable for medium to small batch production, where the weld seams on the workpieces can be short and numerous, and have more complex shapes. Flexible welding lines are particularly suitable for situations with many product varieties and small batch sizes. Currently, foreign companies are vigorously promoting zero (or minimal) inventory, just-in-time (JIT) production management methods, in which case flexible welding lines are more appropriate.