The EXScan Pro software supports 3 scanning modes: Fixed, Handheld HD and Handheld Rapid Modes.
This article introduces these 3 scanning modes and intends to serve as a handy reference guide to help on the selection of the most suitable mode for each project.
TABLE OF CONTENTS
The Scan Modes Overview
The main differences between modes are regarding the scan accuracy and the point distance or resolution that can be obtained. The following table summarizes the main differences between modes, for each scanner model:
|Fixed Scan||Handheld HD Scan||Handheld Rapid Scan|
|Model||2X||2X Plus||2X 2020||HD||2X||2X Plus||2X 2020||HD||2X||2X Plus||2X 2020||HD|
|Scan Accuracy||0.04 mm|
(Single shot accuracy)
|Up to 0.05 mm||Up to 0.045 mm||Up to 0.1 mm|
|Volumetric Accuracy||N/A||0.3 mm/m*||0.3 mm/m*|
|Point Distance (mm)||0.16||0.24||0.16||0.24||0.2 - 2||0.2 - 3||0.2 - 3||0.2 - 2||0.25 - 3||0.2 -3||0.25 - 3|
As it can be observed, among other differences which are exposed below, each mode provides different values for accuracy and resolution. These will dictate which Scan Mode fits each project requirements.
Fixed Scan Mode
Fixed Scan Mode is designed for achieving the highest resolution and the highest accuracy scans for small (from 30*30*30 mm) to medium size objects.
In this mode, the scanner and the object are fixed during a single scan. The relative position between the scanner and the object can be changed to capture different area of the object on separated single scans. Successive single scans are aligned automatically or manually based on the common area or markers to generate a whole scanned data.
This Scan Mode offers the highest accuracy and resolution. To achieve this, the scanner makes use of a Phase Shifting Coded Structured Light (CSL).
The projector emits a sinusoidal continuous pattern which will deform when projected on a 3D shape. This process will allow the software to reconstruct the surface.
The continuous nature of this pattern, along with the shifted effect, provides high resolution and accuracy. Nevertheless, this method requires the scanner to be static. For this reason, the scanning process is slow and restricted in movement.
The add on Industrial Pack is dedicated to this mode, with a tripod and a turntable*. It is perfect for object fitting on a Ø 150 mm disc.
The Fixed Scan Mode supports the following alignment modes:
- Turntable Coded Targets (only with Industrial Pack)
- Manual Alignment
*Note: The weight limit of the turntable is 5KG.
Handheld HD Scan Mode
Handheld HD Scan Mode provides high resolution and high accuracy, while offering the flexibility and freedom of movement of a handheld scanner.
When the operator holds the scanner in hand and moves around the object, the data is instantaneously captured and matched with previously captured data.
Ensuring such resolution and accuracy while maintaining the flexibility and freedom of movement of handheld scanners, is possible thanks to the Lines CSL.
This line pattern consists of continuous and constantly located lines that provides accurate and detailed data.
For the EinScan Pro 2X, this pattern consists of 7 lines:
Nevertheless, the EinScan Pro 2X Plus uses 100 lines, which makes it faster capturing data but also makes it difficult for the software to prevent errors in detecting and locating the data in the 3D Space.
For this reason, the EinScan Pro 2X Plus uses a hybrid pattern consisting of the 100 lines and the speckle pattern, which is a so-called "Perfect map", that makes it possible to locate the lines without unambiguity.
The Handheld HD Scan Mode supports the following alignment modes, which depend on the scanner model:
|Scanner||Available Alignment Modes|
|EinScan Pro 2X|
|EinScna Pro 2X Plus|
|EinScan Pro 2X 2020|
EinScan Pro HD
Scanning texture in Handheld HD Scan mode can only be achieved with the EinScan Pro 2X 2020 or EinScan Pro HD and the Color Pack add-on.
Handheld Rapid Scan Mode
Handheld Rapid Scan Mode is the fastest handheld scanning mode but its resolution and accuracy are lower than the HD Mode.
This mode is handheld, so the operator moves the scanner around the object, and the data is instantaneously captured and matched with previously captured data.
The Handheld Rapid Scan Mode makes use of the Speckle Pattern, which is a "Perfect map". This pattern can cover large areas, depending on each scanner model FOV, without unambiguity. Therefore it can gather data at a higher rate.
By contrast, the Speckle Pattern is a discrete pattern, which causes a loss of detail and accuracy.
The Handheld Rapid Scan Mode supports the following alignment modes:
- Markers Alignment
- Feature Alignment
- Hybrid Alignment
- Texture Alignment (with Color Pack add-on)
Each scan mode provides not only different values of accuracy and resolution, but also they imply different scanning operation and aligning modes.
At the same time, the different values for accuracy and resolution, as well as the operation for each mode, are dictated by each pattern and data gathering process.
First step, prior to selecting a Scan Mode, would be analysing both the part to be scanned and the project requirements to select the most suitable mode.
Keep in mind that, additionally, there might be differences between the devices for each mode.