SOLUTION SHEETMulticamDIC System

Digital Image Correlation (DIC) system for the measurement of large-scale and complex (contoured) surface
testing of sub-(components) and structures

MulticamDIC (4-camera) Istra4D
2D-overlay visualization of theLagrangian Principle Strain 1(major strain) in mstrain for each
Camera Field-of-View (FoV).

A versatile & modular DIC system with up to 16 cameras
The MulticamDIC is a combined, stereo-rig array, Digital Image Correlation (DIC)
measurement system consisting of 4 or more (up to 16), USB3, or GigE cameras.
Possible material testing applications with the MulticamDIC system include:
simple, quasi-static tension, compression, buckling, bending, and fracture
mechanic testing, but also low-speed fatigue and inflation (pressure) testing.

Key benefits••

4 or more (up to 16), USB3, or GigE cameras
Five, core, advanced algorithms and concepts exclusive to Istra4D,including;o Clustered Bundle-Adjustments Algorithm (CBAA)
o Central Reference Camera Perspective (CRCP)o Multicamera Cluster Approach (MCA)o Object Aligned Parameterization (OAP)o Multicamera Subset Reference Tracking (MSURET)•••

Cross-section thickness measurement
Double-sided QR-coded calibration targets
Compatible with a Laptop PC or Tower PC

MulticamDIC (8-camera) IIstra4D
3D-model visualization of theZ-displacement (out-of-plane) withrigid body motion removed (RMBR)
in µm.

MulticamDIC (4-camera) Istra4D
2D-overlay visualization of theEng. Principal Strain 1 (mstrain)
for each camera FoV.

A real, multicamera metrology solution
Using the MulticamDIC system, multiple cameras can be arranged, configured &setup in a clustered array for specific materials testing applications. For example:•

a single-sided (planar) array can be configured for the testing of large-scaleand complex (contoured) surfaces (i.e. for wings, blades, beams, and walls),•

a single-sided (cylindrical/spherical) array can be configured for the testingof round/cylindrical/spherical surfaces (i.e. for pressurized cylinders or 		inflated objects), and•a double-sided (bi-planar) array can be configured for the testing of the truestrain via measurement of the cross-section

The advantage of a MulticamDIC system is that measurements can be performed
using DIC of large, complex (contoured) surfaces, and double-sided geometries,that would otherwise not be possible to measure using a single, stereo-rig DICsystem.

MulticamDIC (4-camera) system using a bi-planar setup for themeasurement of true strain.

MulticamDIC (4-camera) systemusing a cylindrical setup for themeasurement of 180° surface sectionof an inner 180° wall section.

MulticamDIC (16-camera) system using a planar setup forthe measurement of wall deformation.

The 4 key advantages to using a MulticamDIC system
1) Larger measurement area with the same spatial resolution as a traditional
2-camera setup
up to ca. 25-30 m2.
2) Lower & more homogenous measurement uncertainty (MU) of anycomponent, shape, or size using the Clustered Bundle-Adjustments
Algorithm (CBAA) for the projection calibration, and the Central Reference
Camera Perspective (CRCP) & Multicamera Cluster Approach (MCA) for thecorrelation evaluation.
3) Accurate measurements of complex shapes & structures of any component,
shape, or size using the Object Aligned Parameterization (OAP) for Planar,Bi-Planar, Cylindrical, and Spherical shapes.

MulticamDIC (8-camera) orientatedaround the cylinder (360°). Each camera observes a 45° degree segmentof the cylinder at the same standoff
distance.

4) Multicamera Subset Reference Tracking (MSURET) for large, full-scale tests ofmotion analysis, impact, ballistic, torsion, and fatigue testing.

An example of the MSURET used for point tracking of a rotated cylindrical object. The
four points are continuously tracked throughout the measurement.
Page 2MulticamDIC (4-camera) analysis of
3D-displacement deformations andstrain concentration in fractured
pelvic bones after surgical treatment
with selected mini-invasive fixators. Image of 3D Visualization ofLagrangian Principle Strain.

Istra4D Software Features
Multicamera Live Online Acquisition
Using one Tower PC within the online acquisition mode, Istra4D allows
up to: 4x CXP-12, or 16x USB3, or 16x GigE, 6x 10GigE cameras to beoperated.
Or using one Laptop PC within the online acquisition mode, Istra4D
allows up to: 4x GigE, or 4x USB3 cameras to be operated.

Clustered Bundle-Adjustments Algorithm (CBAA)The “Clustered Bundle-Adjustments Algorithm (CBAA)” is an extension of
the Bundle-Adjustments Algorithm (BAA), in that any camera that can
detect the calibration target will contribute to the projection calibration.
All cameras are simultaneously involved in the projection calibration process. The CBAA allows users to calibrate the projection with only one calibration target in one, online, measurement setup configuration
creating only one coordinate system.
The CBAA relinquishes the inaccurate approach of stitching multiple, individual datasets together known as the “Image Stitching Method (ISM)”.
The ISM is a common procedure that incorporates a high degree of imprecision, smoothing, and misrepresentation.

MulticamDIC 16-camera visualization

Clustered Bundle-Adjustments
Algorithm (CBAA)

Multicamera Cluster Approach (MCA)The Multicamera Cluster Approach (MCA) defines the facets/subset notwith respect to a reference camera but rather to be on the object, itself.
As such, facets/subsets are reconstructed or parameterized with any
camera viewpoint combination on the object surface. Since facets/
subsets are defined from any camera viewpoint combination on theobject surface, all viewpoints contribute to the measurement. The camera
viewpoints that yields the smallest 3D-residuum for that facet/subset isthen employed in the evaluated result.

Multicamera Cluster Approach (MCA)

Object Aligned Parameterization (OAP)The MCA lends the possibility for the facets/subsets to be described/
parameterized using models other than a camera’s reference plane
giving way to the concept of the Object Aligned Parameterization (OAP).
The OAP allows users the possibility to select the parameterization definition model for the object which describes the evaluation grid of a measured surface. The available
models include; single-sided flat (planar), double-sided flat (bi-planar),single-sided cylindrical, and or, single-sided spherical.

Multicamera Subset Reference Tracking (MSURET)

Multicamera Subset Reference Tracking (MSURET) is a new feature in
Istra4D V4.10 for MulticamDIC systems that allows a subset/facet to becontinually tracked throughout the complete multicamera setup, even if
the subset is no longer visible in the reference image. As such, a subset/
facet can be tracked wherever it goes throughout a test, provided it canbe seen.

Application Notes & Success Stories

Page 3

Object Aligned Parameterization(OAP) configurations

Multicamera Subset Reference
Tracking (MSURET)

Technical specifications
MulticamDIC
Number of Cameras

4 to 16

Sensor, Frame Rate &Interface

5.0 Mpx
5.0 Mpx(2448 x 2048 px) (2448 x 2048 px)@ 77 Hz@ 24 Hz
USB3 CMOS
GiGE CMOS

Std. Lens Focal Length12.3 Mpx
12.3 Mpx(4096 x 3000 px) (4096 x 3000 px)@ 30 Hz@ 9 HzUSB3 CMOS
GiGE CMOS

24.4 Mpx(5312 x 4600 px)@ 5 HzGiGE CMOS

18 mm

Camera Setup Configuration

Adjustable

Std. Field-of-View (FoV)

2000 mm (H) x 1700 mm (V)1250 - 2200 mm

Std. Distance-to-Object (DtO)
Measurement PerformanceStd. Spatial
Resolution

4 cameras

449 µm/px

269 µm/px

207 µm/px

8 cameras

245 µm/px

146 µm/px

113 µm/px

Std. In-Plane
Resolution

4 cameras

5 µm

3 µm

2 µm

8 cameras

3 µm

2 µm

1 µm

9 µm – 55 µm

5 µm – 27 µm

4 µm – 21 µm

5 µm – 25 µm

3 µm – 15 µm

2 µm – 11 µm

4 cameras
Std. Out-ofPlane Resolution 8 cameras

5 µstrain

Strain Resolution

Order information
MulticamDIC
Cameras

4x6x8x10x12x14x16x

USB3 Cameras: 2.3 Mpx (DSM 15420) OR 5.0 Mpx (DSM 15450) OR 12.3 Mpx (DSM 15460)
GiGE Cameras: 2.3 Mpx (DSM 15523) OR 5.0 Mpx (DSM 15550) OR 12.3 Mpx (DSM 15512)
OR 24.4 Mpx (DSM 15524)
Lens

Any C-mount lens available from the portfolio

Hardware1x DSM 25022: DAQ & Triggering Controller
For USB3 Cameras
1x DSM 24210:
Tower PC 1A&
1x DSM 24630:
USB3 Network Card

1x DSM 24220:
Tower PC 1B&
2x DSM 24630:
USB3 Network Card

1x DSM 24220:
Tower PC 1B&
3x DSM 24630:
USB3 Network Card

1x DSM 24230:
Tower PC 2C&
4x DSM 24630:
USB3 Network Card

For GIGE Cameras
1x DSM 24210:
Tower PC 1A&
1x DSM 24620:
GigE Network Card
Software1x DSM 24210:
Tower PC 1A&
2x DSM 24620:
GigE Network Card

1x DSM 24220:
Tower PC 1B&
3x DSM 24620:
GigE Network Card

1x DSM 32000: Istra4D Software Platform
1x DSM 32021: Istra4D Camera Acquisition Module
1x DSM 32030: Istra4D Multicamera Expansion Acquisition Module
1x DSM 32050: Istra4D Advanced DAQ Triggering Module
1x DSM 32010: Istra4D 3D & 2D Correlation Evaluation Module
1x DSM 32070: Istra4D Multicamera Correlation Extension Module
1x DSM 32060: Istra4D Graphical Visualization ModuleSolution Sheet SS_0837_v1. Subject to change without notice. Copyright © 2023.
Dantec Dynamics. All Rights Reserved. www.dantecdynamics.com

1x DSM 24220:Tower PC 1B&4x DSM 24620:
GigE Network Card