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What is Seam Tracking and How Welding Cobots Don't Require It

28, Jul. 2025

What is Seam Tracking and How Welding Cobots Don't Require It

Perfectly welding a joint is a skill that takes years of training by professional welders to perfect. Automating this function is possible, but you’ll need to evaluate the different approaches, methodologies, and associated technologies before committing to a solution. To help you grapple with the latest capabilities, here’s everything you need to know about welding seam tracking.

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What is Welding Seam Tracking?

Seam tracking or weld joint tracking uses an automated system that provides real-time sensing and adaptive control while executing a robotic welding operation. Different solutions are available on the market that enable automated welding operations to track the welding seam in real-time and control the process using 3D lasers, cameras, slides, controllers, and teach pendants.

Choosing the right technology depends on your current welding workflow requirements, as these systems can control the voltage, travel speed, wire feed, and weld bead formation.

Different Types of Welding Seam Tracking Solutions

Seam tracking systems vary between suppliers and integrators but use the same base technologies to achieve the required control function. Vision and sensing solutions provide high-quality, industrially proven seam tracking, welding inspection, and precise process control in a single operation.

(source: Binzel Abicor)

The different welding seam tracking technologies are:

Touch Sensing
Through Arc Seam Tracking
Tactile Seam Tracking
2D Vision Systems
3D Laser Seam Tracking

Weld Seam Tracking is a Complex Process!

Automating the tracking of weld seam in a robotic process isn’t easy. Each workpiece, fixture, and welding system needs to operate in conjunction to maintain the integrity of every joint. In addition, adopting these solutions adds complexity to the operation, requiring extensive engineering to perfect.

Implementing these solutions will require:

Extensive programming of the system that will require skilled employees
Increased lead times when taking on new jobs to ensure the automation works according to the specification
Welding programmers who aren’t easy to find, meaning the job will often cost more, especially in high-mix, low volume runs.

For those reasons, you should look at automating your welding operations without weld seam tracking systems. With a good fixture design or repeatable jigs, you can remove the need for adding complex technologies to your weld cells.

What is a Welding Cobot?

Welding cobots are redefining the capabilities available to SMEs that deal with high-mix, low-volume orders. It provides consistent, repeatable results by combining easy programming, accurate execution, and proven reliability.

Welding cobots let you set up the weld operation, oversee the process, and interact with the work cell. Cobot welding systems do not need weld seam tracking to weld your part repeatably and provide great ROI. In fact, not needing through arc seam tracking with your cobot helps to reduce complexity and decrease the cost of ownership of the welding cell.

Welding cobots are generally easier to program than traditional welding robots, allowing you to get into production quickly without relying on complex programming skills. These welding cobot tools will enable you to empower your welders to operate them without previous robotics knowledge. They are great solutions to fill your need for welders.

So deciding to add complexity to the system would then defeat the goal of automating with simple-to-use solutions.

How Welding Cobots Do Not Need Seam Tracking

When looking to add automation to welding operations, collaborative welding robots do not need expensive, complex weld seam tracking solutions to produce quality welds.

Here are a few reasons why welding cobots don’t need seam tracking technologies:

The complexity and need for high programming skilled workers defeat the goal of a welding cobot in the first place, which is to leverage the welders you already have to teach the new robot.
The time to implement and program these technologies is long and costly. They keep the manufacturer from starting the production sooner and get faster ROI. Moreover, automated sensing and weld seam tracking systems increase cycle times by three to five seconds for each sensing operation.
Simplifying the welding cell with repeatable jigs removes the need for advanced technologies. With precise fixture designs and experienced welding staff, you can maximize your throughput and reduce cycle times for each welding workflow.
Moreover, some welding cobots come with cloud-connected notifications if the robot encounters an issue. This will help you monitor if the repeatability of your parts is a cause.
Lastly, suppose your parts have so much variability that the robot cannot follow the joints. In that case, you should evaluate your upstream production to fix the issue at the source instead of welding potentially scrap parts.

A welding cobot is already providing a simple solution to automate your welding operations and solve your need for extra welders. They only require the operator, which can be your welder, to set up the weld workflow once and only intervene if something goes wrong. To conclude, you don’t need to add complex seam tracking technologies to get productivity and ROI from those cobots.

Why Welding Cobots Perform Better Without Welding Seam Tracking Systems

Welding seam tracking systems require complex technology and diligent maintenance. On the contrary, a welding cobot reduces the complexity of automation and keeps operators in control of each weld workflow. So, you won’t need expensive programmers. Instead, you’ll be able to start production quickly and empower your current welders to operate the robots. Then, with automated and repeatable results, you can increase your throughput, reduce your cycle times, and ensure consistent quality welds for each high-mix, low-volume job you accept.

Goto Yinglai to know more.

Seam Tracking for Laser Welding and Brazing - ABIBLOG

One of the biggest hurdles in any automated joining system is the ability to find and track the joint in a consistent nature. Joint quality can be poor due to a number of variables including the standard variance in upstream parts supply or simply poor joint design from either a process or product perspective. Firstly, there is the variation that is inherent in single parts and the overall stack up.

As material lots change from one production run to the next along with minor variation resulting from set up, each production run is going to have its own set of idiosyncrasies and variances from part to part which will impact the stability of the joining process. There are numerous ways to combat this sometimes maddening phenomena to stabilize production quality through either high dollar investment in tooling (e.g. stamping or assembly), cycle time increase (e.g. robotic touch sense in arc welding), or using vision packages to help offset robot path to match that of the parts. In the case of the last, this can be very complex to implement and maintain for a multitude of reasons.

Seam Tracking and Laser Welding Solutions

Imagine now you are dealing with a laser process to join components and the process beam size can be anywhere from 0.6 mm to 3.2 mm, which is much smaller than any arc welding process. Applying vision based solutions to laser processes complicate an already complicated process.

The objective in any joining process, whether it be arc or laser, is to ensure the energy provided by the process goes exactly where it needs to be, which is in the joint. When filler wire is added, this adds another complex variable to the process. In the case of laser processing, this is even more critical due in part to the high energy density associated with the beam and the necessity of ensuring the beam is lined up properly to the wire as well.

A solution for this dilemma with laser based processes is a feature called tactile seam tracking.

Laser Brazing with Tactile Seam Tracking

Tactile seam tracking, as applied by some of the current laser solutions on the market, uses the actual filler metal to track the joint. Optical paths for these types of optics are set such that the collimation lens (the lens that straightens the beam path as it comes from the fiber) and focal lens (beam is focused to a point providing a tool center point essentially) are separated by a swivel axis.

The swivel axis is designed such that the focal lens and associated telescoping arm and wire guiding module stay fixed in relation to the focal lens. Servo motors and encoders control the amount of force applied to the swivel axis, thus providing an inherent level of control to a rotational force between the wire and the joint to be brazed or welded.

The most versatile aspect of this application is that the robot can essentially travel a straight path regardless of the part variation. The coordination of the swivel axis, telescoping arm/wire guiding module, and additionally an auto focus feature provides a tool that can accommodate a relatively wide range of parts variation due to the Y rotation of the swivel axis and the Z stroke of the telescoping arm. The auto focus feature is another aspect for ensuring good part quality. This feature allows you to set the spot size at a given tool center point, or 0 point of the Z axis on the telescoping arm.

Adaptive Laser Brazing to Combat Part Variance

As the part varies either in Y or Z (assuming travel direction of X), the corresponding position of the telescoping arm can be translated such that the collimation lens moves to match the telescopic arm position, ensuring a common spot size.

In the case of energy density, variances in spot size will change the amount of energy applied at a given point in the process and could lead to quality issues such as holes in the base metal, pores in the melted material, or uneven edges to the brazed joint.

Aesthetics are typically very critical in laser brazed joints as the intention is to take these products directly from the process to paint with little to no post finishing.

So Where is Laser Brazing Best Used?

This type of application is especially useful in areas such as deck lids for trunks and roof seams. The evolution of this technology has enabled car designers to address certain limitations from other processes in the past (e.g. spot and arc welding) providing sleeker body lines and more innovative designs.

The window opens even further with the ability to use other materials like laser brazing aluminum, enabling aesthetically suitable products that can be applied to other areas of the vehicle. In addition, joint design is not limited to simple fillets or lap joints. Other joint designs capable of being fit to this process include flange butt, reverse flange butt and corner joints.

Tactile seam tracking provides the solution to battling parts variance as it positions the tool optimally at the seam joint. Programming complexity and costs reduce dramatically since two path points on the robot are often sufficient and the seam tracking is in charge of making the fine adjustments.

Tactile Laser Brazing's Added Benefits

Tactile seam tracking offers additional benefits as it is not sensitive to welding spatter or extraneous light, it occurs in real time and does not require time for pre-detection as may be the case with other sensing technologies and with the filler wire serving as the "tactile probe," wear is not an issue as it is self-regenerating.

In order to be competitive in today's global market, it is imperative to have robust yet flexible processes ... tactile seam tracking is one item that can provide your operations both of these valuable advantages.

For more Laser Vision Seam Tracking Systeminformation, please contact us. We will provide professional answers.

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