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.
If you are looking for more details, kindly visit our website.
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
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.
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.
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.
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.
Welding is one of the first manufacturing applications to have been automated in industry. Its complexity and the fact that it is a hazardous job has made it the perfect application to give to industrial robots. Since this time, a lot of other robotic applications have been robotized. In some previous posts, we have talked to you about how vision systems improve actual robotic applications by giving eyes to robot arms. Well, robotic welding also follows this trend, since through the help of vision, welding applications can be improved for even better results.
This system allows the robot to precisely locate the joint that will be welded using the two parts as references. Different techniques exist to locate the joint.
Yinglai Product Page
The first one needs contact with the part in order to locate the joint; it is called tactile sensing. It uses the welding wire or another wire to touch the part and determine the best position for the weld. For some kinds of welds such as lap welds, it can be used only with material thicker than 3 mm.
The second technique uses a laser point to locate the work surface. This technique is non-contact and significantly faster. This technique can be used with thinner materials than with touch sensing.
The third technique uses laser cameras. They project a laser line which detects both walls at the same time. Moreover, they can reduce cycle time and provide data about joint gap.
This system is meant to track the weld position, in real time, during welding. It provides better quality welds, better path speed, optimal weld path and reduced cycle time. Moreover, it can simplify the programming, since the robot will be guided by the system.
This sensing technology looks like the one used for seam finding. It can use tactical sensing, as well as optical sensing.
Tactical sensing has the advantage of not being sensitive to weld splatter or extraneous light. It is the simplest to use. The system will detect if there is any deviation between the edge it touches and the programmed path. The welding wire or a separate wire can be use as a sensor.
Optical tracking moves over the seam, in advance, to detect any deviation from the programmed path. It often uses lasers or cameras.
When a deviation is detected, the robot has to compensate for this deviation. To do so, there are two kinds of control scheme: robot-controlled seam tracking and adaptive seam tracking.
For the first method (robot-controlled seam tracking), the robot controller will receive the data and send the corrections to the robot. Its advantages are to have a reduced device overhead and a smaller shape for the processing head.
For the second one (adaptive seam tracking), the robot is mounted with an autonomous processing head that can be programmed independently. So, when a deviation is detected, the data will be sent to this autonomous device that will then determine the compensation. This control scheme is independent from the robot controller and can react fast.
These tools can greatly improve your welding application, so that it always produces an optimal weld each time. Ask your robotic welding integrator about which solution would best suit your production parameters.
---
For more Laser Vision Seam Tracking Systeminformation, please contact us. We will provide professional answers.