Automatic Laser Marking Cell
This project was presented to SDC to design a robotic work-cell to pick a friction disk from an incoming cart and present the disk for vision inspection, thickness gauging and laser engraving. The disk would then be placed on an outgoing completed cart. Disks ranging in diameter from less than 4” to up to 55” were to be processed by the same work-cell. The incoming carts were stacked with like-sized disks. The stack heights were variable; therefore, the system had to detect the stack height of the incoming material. The outgoing carts were to be filled to a programmable height and number of stacks.
Programmable Logic Controller
Human Machine Interface
Vision Guidance Cameras
Vision Inspection System
Laser Marking System
Linear Displacement Probe Measurement
Robust Custom Machine Controls
SDC chose to use a 6-axis robot to move to disks around the workcell. The robot was sized to handle the large disk that was to be run. This required a large end effector for the robot. Quick-change couplers were used to automatically switch out different sized end effectors. The sequencing of the robot and other machine functions was executed used a programmable logic controller (plc). A human machine interface (hmi) would be connected to the plc and allow access to process and machine parameters. The hmi also allows for manual debug of devices and systems. Trouble-shooting the system was also made easier by displaying fault messages if they would occur.
A multi-camera vision system was used to verify the grooves in the material on the disks. If grooves were not detected, the disk would be placed for manual inspection. The next inspection was performed with two high-precision displacement probes. If the thickness measurement was not within tolerance, the disk would be placed for manual inspection. If both inspection passed, the disk would then be presented to the laser engravement chamber. Once inside, a vision camera would locate the disk. The location data was then sent to the laser engraver computer where adjustments would be made for the location of the part. Using this technique, all parts were marked in the same location on the part.
The resulting impact of the machine improved productivity greatly. Many of the disks were very large and previously had to be handled by two operators. Now one robot could move the parts around the cell with ease. Since the machine could run consistently through breaks and lunches, many more parts were now being processed.