Weld Seam Tracking – Precise Seam Tracking During Welding
In weld seam tracking, the actual position of the joint is determined during the welding process. For this purpose, the MLZL 2D/3D profile sensors are used in combination with a machine vision controller with uniVision software. During the welding process, the sensor continuously determines the exact position of the seam and transmits the calculated tracking point as a coordinate to the robot control system. The robot then corrects the welding torch movement accordingly. The MLWL and MLSL 2D/3D profile sensors are also suitable for reliable weld seam tracking.
Precision is important in welding processes, as components can easily deform or move under the influence of heat. Manufacturing tolerances, different gap sizes or shape changes during the process can also occur. The weld seam tracking compensates for these deviations and ensures that the material is applied in the intended position.
Precision is important in welding processes, as components can easily deform or move under the influence of heat. Manufacturing tolerances, different gap sizes or shape changes during the process can also occur. The weld seam tracking compensates for these deviations and ensures that the material is applied in the intended position.
Advantages of Weld Seam Tracking with 2D/3D Profile Sensors
High Quality Weld Seam
The welding torch stays precisely on the intended path – even with component tolerances or position deviations. This reduces seam misalignment, defects and uneven weld seams.
Less Waste and Reworking
The improved weld seam quality leads to fewer faulty components and thus reduces material and repair costs.
Increased Productivity
Automatic path corrections during the welding process enable faster production processes, as there is no downtime due to manual readjustments.
Compatibility with Different Components
The 2D/3D profile sensors are ideal for welding series production parts with dimensional deviations as well as components from the pressing or casting process. Complex clamping devices and precise pre-assembly can thus be reduced, resulting in time and cost savings.
Essential for automated and robot-supported welding
The 2D/3D profile sensors form the basis for reliable welding processes in Industry 4.0 environments and reduce downtime and manual intervention to a minimum.
Real-time corrections
2D/3D profile sensors detect deviations in real time so that the welding head path can be corrected immediately.
Weld Seam Finding – Precise Position Determination before the Welding Process
The exact position of the joint before the welding process is determined during weld seam finding. Using the MLZL 2D/3D profile sensors and the machine vision controller with uniVision software, one or more measurements are carried out to calculate the actual seam position. The robot software then automatically adjusts the path points – shifting, twisting or inclination of the originally taught-in robot path is corrected. The sensors also enable fast and precise position determination of complex component geometries or in the case of tight radii. The MLZL sensors can also be used in applications where the sensor cannot be mounted directly on the welding torch and a larger distance is required. Weld seam finding is also possible with the MLSL or MLWL 2D/3D profile sensors or the laser distance sensors triangulation of the P3 series.
Advantages of Weld Seam Finding with wenglor Sensors
Precise positioning before welding
The sensors determine the exact position of the joint, regardless of component tolerances or assembly deviations. This means that the welding process always starts at the right place, avoiding misstarts or misalignments.
Compensation of dimensional deviations
The sensors also ensure consistent results for components with manufacturing tolerances, such as sheet metal or cast iron. This eliminates the need for complex clamping technology or precise manual alignment.
Automation and robotics capability
The 2D/3D profile sensors and laser distance sensors from the P3 series form the basis for fully automatic or robot-assisted welding. The robots recognize the component position, correct the taught-in path and automatically move to the correct position – without manual teaching.
Quick and easy initial startup
Since no manual calibration or visual adjustment is required, welding processes can be started faster. This is particularly advantageous in series production and with high cycle rates.
Less waste and reworking
Correct positioning of the welding torch significantly reduces the error rate. This reduces material costs and the cost of reworking.
Can be combined with seam tracking
Seam finding takes place before welding and seam tracking takes place during welding. Both processes together provide a comprehensive quality solution.
Outstanding Performance and Efficiency: Seam Tracking and Seam Finding with the MLZL 2D/3D Profile Sensor
The compact MLZL 2D/3D profile sensor features a slim, robust housing designed specifically for use in welding environments. The sensor is mounted directly on the welding torch via two mounting holes. During the ongoing process, the welding system runs the entire contour of the component and the MLZL measures the seam via laser triangulation. The measurement data recorded is processed in real time via the uniVision image processing software and transferred to the control system – synchronously with the welding process.
High Profile Quality for High Process Reliability
The high-performance optics and filters of the MLZL series ensure excellent imaging on the sensor camera, supported by a suitable protective screen.
Tool-Free Protective Screen Replacement
The sensor offers a simple protective screen change without any tools. To do this, slide on the protective screen retainer, replace the screen and reinsert the protective screen retainer.
Integrated Cooling and Air Flushing
The integrated cooling option with air or water prevents overheating of camera and laser due to the high ambient temperatures in welding applications. The air flushing prevents dirt from accumulating on the protective screen.
Compact and Robust Format
The slim and compact housing of the MLZL series is specially designed for weld seam tracking applications. Due to the IP67 degree of protection, the sensor is dust-tight and protected against short-term immersion, allowing it to be used in a wide range of working environments.
| Sensor/accessories | Medium | Unit of measure | |
|---|---|---|---|
| Integrated cooling and air flushing of the MLZL | Cooling: | Hose with 4 mm outer diameter | |
| Water | Max. 2 bar | ||
| Oil-free air | Max. 2 bar | ||
| Flushing: | |||
| Oil-free air | Max. 2 bar | ||
| Additional cooling units (ZLWK and ZLSK for MLSL and MLWL) |
Water | Max. 2 bar | Hose with 6 mm outer diameter and 4 mm inner diameter |
| Oil-free air | Max. 2 bar | ||
| ZLSS003 additional protective housing for MLSL1 series | Cooling: | Hose with 6 mm outer diameter and 4 mm inner diameter | |
| Water | Max. 2 bar | ||
| Oil-free air | Max. 2 bar | ||
| Flushing: | |||
| Oil-free air | Max. 2 bar | ||
|
Sensor/accessories
|
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Integrated cooling and air flushing of the MLZL
|
Water
|
Oil-free air
|
Flushing:
|
Oil-free air
|
Additional cooling units (ZLWK and ZLSK for MLSL and MLWL) |
Oil-free air
|
ZLSS003 additional protective housing for MLSL1 series
|
Water
|
Oil-free air
|
Flushing:
|
Oil-free air
|
||
|
Medium
|
|||||||||||||
|
Cooling:
|
Max. 2 bar
|
Max. 2 bar
|
Max. 2 bar
|
Water
|
Max. 2 bar
|
Cooling:
|
Max. 2 bar
|
Max. 2 bar
|
Max. 2 bar
|
||||
|
Unit of measure
|
|||||||||||||
|
Hose with 4 mm outer diameter
|
Max. 2 bar
|
Hose with 6 mm outer diameter and 4 mm inner diameter
|
|||||||||||
|
Hose with 6 mm outer diameter and 4 mm inner diameter
|
|||||||||||||
Additional Sensors and Accessories for Weld Seam Tracking and Finding
The 2D/3D profile sensors of the MLSL and MLWL series can also be used for welding applications. The wenglor portfolio offers suitable accessories such as display and control elements, various mounting options, cables and connector plugs, protective housings and disks as well as cooling units to withstand the harsh ambient conditions in welding applications.
Mounting Options for 2D/3D Profile Sensors
To ensure reliable weld seam tracking and finding, the following instructions must be observed when installing the MLZL, MLSL and MLWL 2D/3D profile sensors, as installation differs depending on the sensor type. The profile sensor camera should also not be directed directly at the welding point, as the light from the welding process can otherwise cause interference.
MLZL
MLSL
MLWL
To achieve a large or small forerun, the MLSL and MLWL 2D/3D profile sensors can be mounted at an angle of α.
MLSL with Large Forerun
MLWL with Large Forerun
Joint Types in Weld Seam Tracking
In weld seam tracking, there are different Joint types to reliably weld metal parts together and ensure a high-quality weld seam.
Butt joints
Lap joints
Parallel joints
T-joints
Double-tee joints
Corner joints
Multiple joints
Angular joints
uniVision 3 Software for Seam Tracking and Seam Finding
The uniVision image processing software from wenglor offers a powerful and user-friendly option for processing data from two-dimensional height profile data. For welding applications, there is the “Profile Weld Seam Tracking” module, which enables quick and easy joint detection for seam tracking and seam finding.
“Profile Weld Seam Tracking” Module
All types of joint can be reliably detected based on the height profiles of 2D/3D profile sensors using the “Profile Weld Seam Tracking” module. The module supplies the guide point as well as other seam-specific measured values that are required for exact robot control. This makes it the basis for sensor-controlled seam tracking applications with robots or on linearization tables.
Preconfigured Templates
Quick integration into existing processes thanks to preconfigured templates for common joint types and robot calibration.
Direct Transfer of Results
Pre-configured transfer of measurement results to the robot control system for smooth process flows.
“History & Filter” Submodule
Reliable and stable output of tracking points with the “History & Filter” submodule.
Tutorials for Setting Up Templates
The following videos show step-by-step how to set the preconfigured templates for butt joint, overlap joint, T-joint and dent finding.
Web-Based Visualization
Each joint detection template job includes a web-based visualization that shows all relevant results at a glance. It is also possible to configure your own individual visualization. The Internet browser updates the content of the visualization at regular intervals so that operators receive visual feedback of the process. The following visualizations can be inserted by drag and drop:
- Live profile
- Guide point coordinates
- Status indicators
- Measured values (e.g. width, height, offset, area)
- Images/logos
- Overlays (e.g. lines, terms, values, labels, etc.)
High Precision on Shiny Surfaces
The type of material used plays a decisive role during welding, as different metals have different optical properties. Some metals have a matt surface that allows for clear detection, while other metals, such as aluminum, are extremely shiny. This creates many reflections that can impair the visibility of the weld seam. The shape of the component to be welded also influences the reflections. Round objects in particular generate more reflections than flat structures.
In combination with the uniVision software, the MLZL sensors accurately detect joint positions even on highly reflective metal surfaces. Special software algorithms effectively minimize light reflections so that the profile data can be reliably processed and evaluated to ensure exact weld seam tracking.
In combination with the uniVision software, the MLZL sensors accurately detect joint positions even on highly reflective metal surfaces. Special software algorithms effectively minimize light reflections so that the profile data can be reliably processed and evaluated to ensure exact weld seam tracking.
Easy Integration Thanks to Numerous Robot Interfaces
A variety of robot plug-ins ensure smooth and straightforward communication with all leading robot brands. The open interface also allows seamless integration of a wide range of third-party robots.
 |
 |
 |
 |
 |
|
|
|||
|
|
|
|
|
Overview of the System
2D/3D Profile Sensor with Machine Vision Controller and uniVision 3 Software
Recording of Profile Data
Processing in uniVision 3
Data Transfer to the Robot Controller
Execution of Corrections
Correction
Further System Design Options
Another option is to use the profile sensor in the “Smart profile sensor” operating mode. This means that the recorded profile data is processed further in the sensor.
How Does the “Smart Profile Sensor” Operating Mode Work?
The MLZL 2D/3D profile sensor records the data of the weld seam during the welding process. The uniVision 2 software with the “Profile Weld Seam Tracking” module is installed on the MLZL. Precise TP coordinates (tracking point) of the weld are calculated from the recorded profile information. These coordinates are then transferred to the robot controller via the configurable TCP or UDP interface. This then sends movement data to the robot to adjust its path tracking in real time.The MLZL 2D/3D profile sensor can also be used with customer or third-party software, rather than the wenglor uniVision software.
How Does the “Profile generator” Operating Mode Work with Third-Party IPC?
The robot arm with the MLZL 2D/3D profile sensor moves along the intended weld seam, the sensor is in the “Profile generator” operating mode and records the profile data of the seam. This data is then transferred from the MLZL to the third-party IPC via the TCP/IP interface. Several options are available for integrating the profile sensor into third-party software:- Among other things, an SDK is available for Windows and Linux.
- Alternatively, integration can take place via the standard GigE Vision.
Weld Seam Tracking and Finding without Robots
Even for welding applications without robots, our 2D/3D profile sensors offer a powerful solution for reliable weld seam tracking and finding. The uniVision software provides numerous interfaces for this purpose, which enable flexible integration into different control systems.
- Communication interfaces such as TCP/IP and UDP are available in the “Smart profile sensor” operating mode.
- In the “Profile generator” operating mode in combination with the machine vision controller, direct connection via Industrial Ethernet (Profinet, EtherNet/IP, EtherCAT) is also possible.
Versatile for Welding Processes
For example, 2D/3D profile sensors can also be used for the following types of welding.
MIG (Metal Inert Gas)
MIG (Metal Inert Gas)
Metal welding with inert, i.e. inactive gases
MAG (Metal Active Gas)
MAG (Metal Active Gas)
Metal welding with active gases
TIG (Tungsten Inert Gas)
TIG (Tungsten Inert Gas)
Metal welding with a non-melting pure or alloy tungsten electrode
Laser welding
Laser welding
Laser welding permits high welding speeds with highly precise results
Weld Seam Finding with the P3 Series Laser Distance Sensors Triangulation
In addition to the 2D/3D profile sensors, the P3 series laser distance sensors triangulation can also be used for weld seam finding. These sensors work according to the triangulation principle. This means that they measure the distance to the surface continuously and thus detect even small differences in distance. Thanks to this technology, even extremely thin weld seams are accurately detected, including on shiny metal surfaces.
Functions at a Glance
- Analog output 4…20 mA
- Wireless settings via Bluetooth
- Graphic display for simple operation
- Measured value independent of material, color and brightness
- Robust aluminum housing
Industries and Applications for Weld Seam Tracking and Finding
Automotive industry
Shipbuilding
Steel and bridge construction
Pipe and tank construction
Aviation industry
Welding cells in series production
Production with changing component geometries
Application Options for Weld Seam Tracking
Weld Seam Tracking in Robot Cells
In fully automatic robot welding cells, it is necessary to determine the exact position of joints before the welding process. For this purpose, a 2D/3D profile sensor is mounted directly in front of the welding torch on the robot. The sensor now detects the joint via laser triangulation. The guide point is determined via uniVision software, sent to the control system, and the weld seam is positioned.
Automated Weld Seam Tracking During Container Welding
During automated welding of steel tanks, the exact positioning of the weld seam is of great importance. A 2D/3D profile sensor installed on the welding torch determines the contour and transmits the position data via an analysis module to the linear axes for guiding the torch. The sensors are protected against welding spatter and ambient light with a special protective housing.
Weld Seam Tracking in Submerged Arc Welding Systems
In the steel industry, the so-called submerged arc welding process is used for material thicknesses of over six millimeters. In order to accurately guide the welding torch installed on a linear axis, the joint must be precisely measured. A 2D/3D profile sensor with cooling unit and protective screen installed in front of the welding head determines the contour of the joint with micrometer precision, even at high temperatures.
Weld Seam Inspection
The type of material, the welding technique used and the ambient conditions are decisive for the welding result. It is therefore important to check the welded connections afterwards. The 2D/3D profile sensors ensure precise weld seam tracking and finding, as well as reliable weld seam inspection. This ensures the highest quality and safety during and after the welding process.
Free Rental Devices
To enable you to check in advance whether our products are suitable for your application, we offer you the opportunity to test wenglor devices free of charge. On request, we will be happy to provide you with rental, test or demo devices from our entire portfolio. Feel free to contact us if you are interested in rental equipment.
Thank you for your request.
Successfully sent