Outcome summary
We solved a reading problem that others had not solved: a single camera with a catadioptric lens reads the code on the side of each cell in one shot, in under 7 ms. It replaced costly multi-camera systems.
Starting situation
A major battery manufacturer needed to read the DataMatrix code laser-etched on the side of each 21700 cell. Nobody had managed to read it reliably in a single shot. The usual answer was a costly multi-camera system.
The system
- One camera looking at the cell from above.
- A catadioptric lens, much wider than the cell, that lets that single camera see the side of the cell, where the code is, in one shot.
- Software that compensates for the distortion caused by the lens and reads the DataMatrix as if it were undistorted.
Implementation
The catadioptric lens lets one camera see the side of the cell in a single shot. The software corrects the distortion the lens introduces, so the DataMatrix is read correctly. Reading takes less than 7 milliseconds.
Results and evidence
The code on the side of the cell is read in a single shot in under 7 ms. One camera with a catadioptric lens replaced costly multi-camera systems.