Cycle Times of Structured Light Inspection

Single Snapshots with Structured Light 

Structured light 3D scanners digitize full-field point cloud data from targets by projecting several light patterns in a rapid sequence onto the target with a single snapshot. These scanners can be mounted on robots for flexible inspection applications, or to inspect larger objects by taking multiple snapshots in zones. To capture a complete set of 3D point cloud data, the scan target has to remain stationary during the camera exposure of these structured light patterns.

Single snapshot technology makes data acquisition significantly faster than laser line scanners that have to pass over the scan target gradually. In order to determine if structured light solutions will keep up with factory production rates, scanner cycle times need to be assessed.

Cycle Times of Structured Light Inspection

Structured light scanners will acquire a full frame 3D scan in around 0.5 seconds, depending on the shape, color, and reflectiveness of the target. An additional 3.5-4.5 seconds are required for analysis and production of a full 3D point cloud, resulting in one complete inspection in 4-5 seconds.

Cycle Times for Structured Light Scanning

Typical cycle time for a structured light scanner to generate a complete inspection of a single target object.

Note, however, that the target need only be stationary for the approximately 0.5 seconds of the snapshot acquisition time. Similarly, a robot-mounted sensor must also be stationary during the snapshot acquisition. The part transport mechanism, or robot, can be in motion to the next station or position during the analysis time.

Current technological developments aim to reduce structured light scanner total cycle times to 2 seconds.

If 3D structured light scanning does not meet your production rates, consider inspection with laser line profiling sensors, which can measure profiles at 2 to 5kHz. Profile sensors require targets to be in motion, such as on a conveyor or other transport mechanism and can accommodate very high-speed production lines.