Laser Automation: What You Need to Know

Robots can control the laser head with extreme precision, making it possible to use the perfect laser angle every time. 

Controlling the laser head with a robot is ideal when parts have multiple surfaces, complex shapes, or large surfaces. Robots are also easy to program to treat multiple types of parts, making production processes more flexible to design changes.

Robots can carry parts to the right position in front of the laser. They can also rotate parts without having to move the laser head.

Handling parts with robots also makes it possible to work in an open-air configuration without the need for a large enclosure. With this type of configuration, the workpiece is used to shut the enclosure, providing complete laser safety.

Finally, robots can simply place parts onto a fixture into the laser enclosure.

Robots can control clamping tools used in laser welding to adjust their position to localized deviations as well as control the amount of pressure applied on each weld. This is useful for high-precision applications like battery laser welding.

To make this possible, the robots and vision system are calibrated together with sub-millimetre precision, ensuring that they are synchronized in their work.

The laser head can be mounted on a gantry system (or a Cartesian robot) to move it along the X-Y axes. Gantries are more affordable than robots, making them a preferred automation solution for many applications.

Gantry systems can be used to process large surfaces as well as parts with multiple areas. They are often complemented by a 3D laser head to make automatic focus adjustments on the Z-axis.

Rotary tables are used to create a more efficient loading-unloading system and represent an interesting option to reduce cycle time. 

Without a rotary table, robots that place parts onto fixtures need to wait until laser processing is finished to unload parts and load new ones. The same is true for the laser, which needs to wait until a new part is loaded to start working.

With a rotary table, robots can unload and load a new part while the laser is processing another part on the other side. As a result, part loading is faster, and the laser has more uptime.

Good part positioning can eliminate the need for complex vision systems, which helps reduce the cost of an automated laser solution.

Fixtures and clamping systems are used to consistently position parts for the laser process. A rotary indexer can be added to rotate fixtured parts, allowing the laser to access different areas.

Laser heads have an ideal distance at which the laser beam has the right size and energy density for the laser process. They have a tolerance on the Z-axis, meaning that small deviations (up to ±3 mm) are acceptable.

When imprecisions on the Z-axis are too large, or when surfaces need to be processed at different heights, a 3D head needs to detect Z-variations and automatically adjust the optical configuration. 

This adjustment is similar to moving a magnifying glass up and down when trying to set a piece of paper on fire (until you reach the right concentration of light).

On-the-fly configurations are used to process parts that are in movement. They are configured by supplying the laser with an encoder signal to actively compensate for the part’s linear speed.

Here are a few examples:

• Aluminum extrusions moving at 230 ft/min. (or 70 m/min.) are marked on the fly.
• Primary metal manufacturers mark ingots moving on conveyor lines.
• Manufacturers clean and texture parts of various shapes and sizes while they are moving on the conveyor.

Vision systems are used to support automated laser processes in various ways. They are used to:

• Analyse part positioning to adjust the laser process.
• Guide the laser head outside its field of view.
• Guide robots used for part positioning.
• Validate that parts are positioned correctly before beginning the laser process.
• Validate the integrity of parts before beginning the laser process.
• Detect different types of parts to use the corresponding laser sequence.
• Perform 2D and 3D measurements.

During laser welding, laser weld monitoring (LWM) systems are used to detect bad welds and send them for rework. 

These systems are installed directly in the welding cell. They are advantageous compared to physical tests because they analyze weld quality during welding, adding no time to the operation.

Barcode readers are used to validate the readability of identifiers used for traceability, such as QR codes, data matrix codes, and serial numbers.

Barcode readers can be installed directly on the laser head to automatically validate the code’s readability just after laser marking. Alarms can be programmed to let manufacturers know when laser marking quality diminishes, indicating a need for maintenance.

Vision cameras can validate that the surface is sufficiently cleaned after each operation. By performing a visual inspection of the surface, they ensure that no contaminants remain. 

To do this, vision cameras are positioned at different angles to compare surface results with your requirements.

Laser processes generate dust and fumes that must be extracted to maintain the high quality of the laser process, minimize maintenance, and protect workers. The fume extraction nozzle is positioned as close as possible to the surface being treated to remove contaminants more effectively. It can also be moved to different positions during the process to maintain an optimal extraction.

Air blowers can also be installed on the laser’s lens to blow dust away, preventing it from building up on the lens. They also help reduce maintenance frequency.

HMI control panels are essential to bridge the gap between human operators and automated lasers. 

Operators can initiate calibration sequences, choose from multiple laser sequences (when working with multiple part models), manually adjust laser parameters (for research and development), view results from the quality validation tools, troubleshoot, and more.