The difference between seam tracking and seam locating

1. The difference between seam tracking and seam locating

Seam tracking and seam locating are two important functions in welding automation, and they play different roles in the welding process. Weld positioning is used to detect the position and orientation of the weld before welding begins to ensure the accuracy of the welding path and reduce the occurrence of defects such as notching, overfilling and burning. Weld tracking adjusts the welding position in real time during the welding process to ensure welding strength and integrity.

There are three main ways to find weld position: tactile induction, line induction and laser induction:

Tactile sensing: By physically touching the workpiece surface with a line or nozzle to detect the seam, the method is simple but slow.

Line induction: Use a servo motor to quickly move the line up and down as the robot moves along the workpiece. Detects butt welds that are difficult to find with static line or nozzle contact sensing, but requires specific hardware and software.

Laser sensing: Faster than tactile sensing, can detect 1/16 inch thickness of the seam, but the detection of weld clearance has limitations, can not find square butt weld

2. What is Laser tracking?

The laser tracking is detected by the laser vision sensor ahead of the welding gun, and the deviation of the welding point is calculated according to the calibration relationship between the sensor and the welding gun. In the welding process, the deviation is compensated to the current welding trajectory to realize real-time correction of welding trajectory.

Laser welding seam tracking is based on laser triangulation method. The reflected light is generated by laser irradiation on the workpiece surface, and the image is captured by CCD or CMOS sensor to calculate the spatial position and deviation of the weld. This technology not only accurately positions the weld, but also corrects the welding trajectory in real time, improving welding quality and efficiency, making it ideal for complex welding tasks.

3. What is laser locating?

Laser locating is a single measurement of the target point using a laser sensor, which is suitable for short welds or scenarios that avoid tooling interference. Compared with laser tracking, it is easy to operate. However, due to the first detection and welding, it is not suitable for welding workpieces with serious thermal deformation or irregular welds.

4. When do I need laser vision?

Most of the problems in robot welding are the inconsistency of the welded parts and the low accuracy of the fixture installation, which leads to the inaccurate positioning of the welding torch on the workpiece weld each time, resulting in a decline in production efficiency and quality

In arc welding, if the welding accuracy cannot be guaranteed to reach ±0.5mm, it is necessary to consider the use of laser locating or laser tracking. Select a laser vision weld tracking system, first of all need to verify whether it interferes with the fixture, and then consider whether it will affect the time rhythm, if it does not affect, then it can be fully integrated into the robot workstation.

5. Summarize

Seam locating and seam tracking are the key functions in welding automation, and each has its own emphasis. Weld position finding is responsible for pre-welding positioning, and weld tracking adjusts the path of the tracking weld in real time during the welding process. Both guarantee welding accuracy and quality, provide strong support for welding efficiency and integrity, and effectively reduce the probability of welding defects.