The majority of applications for 3D sensors in factory automation involve in-line, 100% inspection of production parts, either in process or at final inspection. Automated in-line inspection is the desired solution for quality control and process monitoring.
An example of a standard in-line inspection process.
In-line inspection, however, may not be possible in all applications. Although today’s 3D sensors are compact in size, space limitations may preclude in-line implementation, particularly for retrofitting in existing lines. For very high speed manufacturing lines, typical 3D sensors may not be fast enough to keep up with production speeds. And, in such cases, off-line inspection based on statistical sampling is the next practical step to quality monitoring.
Ideally, a sampling inspection station should take place “at-line”, i.e., near production and not in a measurement room or inspection lab away from the factory floor so that results are available with minimum delay and fast response to process adjustment. Of course, at-line 3D inspection still requires implementation of robust sensors that are designed to handle the challenges imposed by ambient light, vibration, dirt, and thermal variation.
Independent inspection systems stationed at-line (near the assembly line) can be used to improve product quality control.
For random sampling, 3D smart sensors can offer many advantages over traditional probe-based or 2D inspection methods. 3D smart sensors are easy to mount and configure, non-contact, fast to scan, invariant to surface color, and pre-calibrated for out-of-the-box measurement. Process engineers can set up an at-line inspection system quickly, monitor a problem feature, and work to put in-process improvements in place to solve part variation problems.
All-in-one 3D sensors can easily export measurement information to statistical analysis software for trend analysis - either over the factory network or through Excel files. With high-speed operation, 3D smart sensors allow for maximum sampling frequency, which increases confidence that measurement data is representative of the production process. Plus, automated 3D sensor inspection eliminates operator error in data acquisition and recording, further increasing confidence in measurement precision.
Where in-line inspection is not possible, smart 3D sensors provide a number of at-line inspection advantages.
