Scanning with Control Points

Note: The scanner can use a control point more than once within a Dataset if it is passed multiple times during scanning.

Note: The term Control Points is used in this documentation, but they can also be known as SLAM anchors.

Adding Control Points

Using control points while scanning is not a requirement, but using control points can:

• Register the scans to a specific coordinate system

• Automatically register the scans with other scans

• Verify the results for accuracy

• Optimize accuracy at very long corridors where loop closures are not possible

Note: Take at least three control points per dataset

Note: To increase the quality of the datasets, use more control points. Note that there are no benefits if control points are closer than 25m to each other.

The following video is a short extract from the training module available from the NavVis Academy on how to add a control point while scanning.

Procedure

1. Select the control point button from the right menu on the screen.

2. NavVis VLX 1 and 2 only: From the NavVis VLX size screen, select the size of your belt settings. Tap Next.

   

3. From the Control Point screen, enter a unique control point ID in the field. Tap Next.

   Note: The ID entered must match the ID on the control point marker.

   

4. Remove the NavVis VLX from the belt hook while holding the frame and handle. Make sure the area above your head is clear. Avoid fast or jerky movements while moving the device.

5. Position the NavVis VLX into the correct position (refer to next section) and tap Add.

   

6. The screen displays that the control point has been successfully added and that you need to add two more control points. Tap Continue.

   

7. Edit or delete control points from the dashboard screen.

   

Adding Ground Control Points

1. Hold the NavVis VLX by the frame. Position the belt hook at the center of the marker.

   

2. Press the Control Point button on top of the NavVis VLX to add the location.

   

3. The user interface indicates the control point is added.

Adding Wall Control Points at Head Height or Above

1. Tilt the NavVis VLX and let it rest on your shoulders. Hold the handle with one hand. Use the other hand to position the belt hook at the center of the marker.

   

2. Press the trigger button above the handle to add the location.

3. The user interface indicates the control point is added.

Adding Wall Control Points at Hip Height

1. Hold the NavVis VLX frame with one hand and the handle with the other hand.

   

2. Align the mark on the belt hook with the center of the wall control point.

3. Press the trigger button above the handle to add the location.

4. The user interface indicates the control point is added. From the user interface, select Add to confirm or Cancel to undo and go back to the mapping screen.