AutoGrid comsmart

The AutoGrid® system is an essential tool to solve formability issues. The AutoGrid® comsmart model has been designed to meet the requirements of shop-floor use. The system is hand-held, quickly measuring surface strain and geometry on deformed parts. AutoGrid® comsmart serves the entire process chain of sheet metal forming - from tooling and tryout to production monitoring and quality assurance.

The new AutoGrid® comsmart has been developed to meet common user requirements for high mobility and flexibility, combined with robustness and ease of use. Employing latest camera technology, the solution is completely based upon digital imaging technology, while the new cable-free platform provides maximum mobility. Four cameras are rigidly placed inside the measuring head allowing for instant measurements without any setup or calibration stages. The operator makes handheld recordings by pressing the REC button just when pointing onto the object region of interest - and 4 CCD cameras are triggered to take a photogrammetric image. The object working distance is indicated by a laser and the high brightness LED illumination switches automatically during the recording.

The convenient AutoGrid® user interface provides software control of exposure time and camera gain settings. The AutoGrid® comsmart system takes advantage of high-resolution cameras recording 5.7 million pixels in total per snapshot. In connection with high-quality optics the system is able to take an area of up to 0.5x0.4 m² where up to 12,000 grid points can be rapidly evaluated in one picture set. Single measurements can be easily stitched together yielding the analysis of whole components without size limitations. In addition, the measuring head has been designed to firmly fit into a box meeting the international flight-cabin case dimensions.

AutoGrid in-process

The AutoGrid® in-process system is used for material analysis in sheet metal testing, tensile, bulge or pipe tests. ViALUX provides a fast and accurate tool for the determination of forming limit curves (FLCs) of sheet metal materials. Directly connected to the testing machine, the system gives precise access to the maximum strain value just before necking and subsequent cracking occurs.

The AutoGrid® software package allows to create FLCs from a set of specimens very effectively. With the knowledge of the original undeformed grid size, the system is able to determine a field of strain values in the range of 0.5 % to more than 100 % without any unambiguity. Grid sizes range between 1-5mm. Images sequences of up to 200x4 frames per second can be recorded. In case of the standard testing velocity of 25 mm ⁄ s, a punch depth resolution of 0.1 mm can be achieved. The system also features additional data inputs that can track different values from the testing machine. For example, press load and punch stroke can be stored with each measurement. Automatic evaluation helps to generate complete forming limit curves. All process variables of differently shaped specimen are provided to determine reliable FLC data. Advanced software features can be used to process an export the measurement data and to make reports.

AutoGrid in-process Specifications

Item Details
Measuring Head
  • 4 CCD cameras (progressive scan) 640 (H) x 480 (V) Pixel
  • C-mount lenses, focal length 16/25 mm; Single cable connection measuring head to PC (IEEE 1394b) including power supply, cable length 4 m, convenient transport case.
Computer Trademarked PC with worldwide service
Environmental Conditions Operating temperature: 10 … 35° C
Non-operating temperature: -40° to 70° C
Humidity: 20% …93% non-condensing
Software Microsoft Win7 64 Bit / full compatibility with MS Office applications
Maximum Frame Rate up to 200 image sets per second
Measuring Point Distance ≥ min 1 mm
Calibration Automated, robust self-calibration procedure (3 min)
Measuring Time 3-5 min
Results 3D shape with coordinates x,y,z [mm] at grid line crossing points,
engineering strain ε [%], true strain φ, v.Mises equivalent strain,
thinning [%], thickness [mm], safety strain, max. failure, position- or
time-dependent FLC values, flow curves from bulge tests
Graphs Color-encoded 3D visualization, 2D data profiles user defined,
Reports, Forming Limit Diagram (FLD) with Forming Limit Curves (FLC), Thinning Limit Diagram (FLD)
Strain Accuracy for grid size 2,0 mm: Δε = 0,1%
for grid size 1,0 mm: Δε = 0,2%
Graphic Export printer, clipboard, *.bmp, *.tif, *.png, *.jpg, *.vrml, *.ps, *.eps
Data Export MS Excel®, ASCII, AutoForm®, Pam-Stamp®, *.stl, AutoCAD®, LS-Dyna®
Grid Size / FoV
mm 1,0 2,0 2,5
mm³ 80x60x50 160x120x100 200x160x120