Overview
The profile processing pipeline transforms raw scanner data into smooth, reliable zone values suitable for control. Each stage addresses specific data quality issues.
Processing Pipeline
Raw scanner data passes through these processing stages:
Edge Detection
Identify valid profile region by detecting web edges
Spike Removal
Remove outlier values caused by sensor noise or defects
Hole Filling
Interpolate missing data points in the profile
Exponential Filter
Smooth profile data to reduce measurement noise
Zone Mapping
Map databox values to actuator zone positions
Filtering Settings
Spike Removal
Removes sudden outlier values that exceed the expected variation:
Spike Detection Settings
| Spike Threshold | 3.0 |
Standard deviations from mean |
| Max Spike Width | 3 |
Maximum spike width (databoxes) |
| Spike Replacement | Interpolate |
How to fill removed spikes |
Hole Filling
Fills missing or invalid data points by interpolation:
Hole Filling Settings
| Max Hole Size | 5 |
Maximum databoxes to interpolate |
| Interpolation Method | Linear |
Linear or spline interpolation |
Exponential Filter
The exponential filter smooths profile variations over time:
Higher values = more smoothing, slower response to real changes
Start with a filter depth of 0.3. Increase if profile is noisy, decrease if control response seems sluggish. The filter should smooth measurement noise without hiding real process variations.
Spatial Filter
Optional cross-profile smoothing:
Spatial Filter Settings
| Spatial Filter | Disabled |
Cross-profile smoothing |
| Filter Width | 3 |
Databoxes for averaging |
Profile Statistics
The system calculates and displays key profile statistics:
| Statistic | Description | Target |
|---|---|---|
| Mean | Average basis weight across profile | Match target |
| 2-Sigma | Profile variation (2 × standard deviation) | Minimize |
| Range | Maximum minus minimum value | Minimize |
| High/Low | Maximum and minimum readings | Within spec |
The 2-Sigma value is the primary measure of CD profile quality. Lower 2-Sigma indicates better uniformity. Target values depend on grade but typically range from 0.5-2.0 g/m².
Statistics Display
Profile statistics are shown in real-time on the main display:
- Profile Chart: Shows current, filtered, and target profiles
- Statistics Panel: Displays mean, 2-sigma, range
- Trend Chart: Historical 2-sigma trend over time