Data Processing
The obtained surface data contains irrelevant data and noise. To increase the stability and accuracy of data, you can filter and denoise the surface data before measurement.
Preprocessing workflow: Filtering ➡ Rough locating ➡ Filtering again
1) Filtering
Use the Filter Surface Points by Normals Step to extract pin data from the acquired surface data and then perform data filtering to remove noise.
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Use a feature region to select the pin data.
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In the parameter configuration panel of the Step, adjust parameters to remove noise.
After the Step is run, it will output the processed surface data:
- Tuning experience
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The Filter Surface Points by Normals Step is very effective in removing noise, especially for obtaining flat surface data. When the noise is slanted or consists of irregularly scattered points, this Step can achieve good denoising results.
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You can adjust the Max Polar Angle parameter to filter out slanted noise of varying degrees (recommended value: 60°) and adjust the Remove Noise parameter to filter out irregular points of varying degrees. Adjusting both parameters can produce better results. For more information on the parameters, see Angle-Based Filtering.
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2) Rough Locating
Use the Blob Analysis Step to roughly locate pin tips from the filtered surface data.
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In the parameter configuration panel of the Step, set appropriate height thresholds and area thresholds to detect the surface data of pin tips, i.e., multiple blobs.
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Set the blob ordering method to number the detected blobs so that each blob can be accurately located in subsequent processes.
As shown in the figure, blobs are ordered “Row-wise.” The blob numbers (index) are for reference only.
Order blobs according to the actual needs. - Tuning experience
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The Blob Analysis Step is essential for locating and outputting the surface data of each pin tip. In most cases, you can obtain good surface data of pin tips by setting reasonable height thresholds and area thresholds.
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If data adhesion occurs, you can address the issue in the previous filtering process.
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3) Filtering again
Use the Process Surface by Filter Step to filter the surface data of pin tips obtained from rough locating by removing the highest and lowest points in the data to effectively reduce data fluctuations.
Select the filter type of Percentile, and set the low and high thresholds of percentiles, respectively, to 10% and 90%.
Then, run the Step to obtain the filtered surface data.
Next, you can start to measure the positions of pins.