Advanced Laser Control for Complex Tool Path

The Pulsing-Unit software option is a powerful tool to precisely time digital outputs at certain axis positions. It is the essential tool to control pulsed lasers for laser material processing as well as optical devices that rely on precise activation. 

Pulsing along a complex tool path (e.g. laser cutting)

How do we solve pulsing along a complex tool path? The most straightforward example is the use of the Pulsing Unit to trigger equidistant pulses of a cutting laser. The path of the laser across the workpiece cannot be tracked by a single encoder, but is the combination of two (or more) encoder feedbacks. Hence, the approach to use the Pulsing Unit with a single encoder falls short. The situation is schematically shown in the figure above, where we can clearly see the challenge: The pulses are not equidistant in X- or Y-direction, but equidistant along the path. Otherwise, there is larger heat deposition in the corners and turning points, leading to unwanted changes to the material properties.

We can tackle this challenge by using the path-planner source of the Pulsing Unit. Together with the option to configure a servo drive axis with no motor or encoder attached, we get the freedom to pulse along any trajectory we like. In this application, this trajectory is the covered path of the laser, which can be determined by different means. We can calculate the covered path from the encoder positions of the X- and Y-axis and feed it as commanded positions to the pulsing axis using a Tama program. Or we can calculate the path beforehand from known trajectories and command it in sync with the motion axes over EtherCAT. The possibilities are manifold and can be tailored to your trajectory-generation method and machining needs.