Intelligent Collision Avoidance

The latest developments for fiber laser cutting machines allow for fast cutting and cutting increasingly thick materials, thanks to the power they use. At the end of each hole or part cutting process, the most common next step is for them to remain in the same place (without interfering with other cutting areas). If the contour is small enough, it usually falls into the area under the machine, which is for collecting scrap.

However, in order to increase the speed as mentioned at the beginning of this article, the new machines use high-pressure gases while cutting. As it comes from the laser nozzle, said gas pushes the holes and parts that are being cut so that it is possible for them to hop onto the sheet metal, like a spring, right when the cutting is finished.

If that hole or part remains on top of a contour that is going to be subsequently cut (either immediately after or at any time in subsequent machining), the head will collide with the material that fell onto the sheet metal, with the risk of damaging the cutting head. Even if the hole or part is not shot onto the sheet metal, another significant hazard lies in it being rotated (from below and above the sheet metal at the same time), so that the cutting head may collide with the piece that is on top of the sheet metal during a movement. These kids of collisions can also damage the cutting head.

Until now, Lantek Expert had several measures to prevent collisions between the cutting head and previously-cut holes and parts, e.g., the use of micro-cuts (or fasteners). With this technique, the holes and parts are fastened to the sheet metal and therefore there is no risk of collision. However, this method requires longer part extraction times for the machine operator. A part polishing process is also necessary to eliminate the fins left by the fasteners.

Another technique available on Lantek Expert is so-called "Head Lift Testing," which stops the head from going over holes or previously cut components, which may have been tilted at the end of cutting, making them a danger to a head passing over them. In the event a potential collision is detected, the algorithm decides to lift the head over said section or even create alternative routes to be able to go to from one point to another without having to lift the head (since this operation takes quite some time). Said testing also allows the input drive position to be changed to reduce the possibility of the head moving over previously-cut components.

Finally, another advanced technique already available on Lantek Expert consists of detecting potentially unstable contours, based on their position compared to the grate supporting the sheet metal. In the event a potential tilt of the hole or component is detected, the system puts a fastener on that contour. The difficulty of applying this algorithm lies in the precision with which the place where sheet metal would be set was predicted compared to the support grate.

Lantek recently developed a new algorithm called ICA “Intelligent Collision Avoidance,” that combines the techniques described above and adds new strategies that include cutting control based on nearby contours (configurable with a buffer), in order to minimize potential collisions between the head and unstable contours. When the new algorithm detects which contours pose a potential risk of falling and being positioned on top of nearby contours, the system automatically assigns a micro-cut at the end of said contour. Subsequently, as the sheet metal is cut, the system detects the moment when they can be completed without risk, and the user can choose to cut them as soon as possible or at the end of machining. Additionally, if this last micro-cutting finalization process conflicts with potentially unstable contours, the system moves the drive to an area free of conflict.

Thanks to this new algorithm, the cutting process has taken another step toward full automation and unattended cutting, minimizing the risk of machine shutdowns due to collisions.