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About Virtual Gauges

TECHNOLOGY: About Virtual Gauges

How LaserGauge® Technology Yields Accurate Measurements with Virtual Gauges

While the wide variety of laser line imaging methods provides flexibility on how scan data is obtained, the scans are meaningless unless useful measurements can be made from them. This is where the Virtual Gauges come into play. The LaserGauge® technology provides two different ways for users to configure measurements.

Standard Virtual Gauges

The LaserGauge® comes standard with a set of built-in Virtual Gauges that are used mostly for Gap/Flush and Sheet Metal applications in the automotive industry. Each Virtual Gauge utilizes several configuration parameters to affect the calculation method of the gauge.

  • Auto Gap/Flush Gauge

  • Min Ball Gauge

Custom Virtual Gauges

Custom Virtual Gauges are developed/created according to customer requirements and measurement methodology. LaserGauge® creates custom Virtual Gauges using the LGBasic program. An LGBasic program describes the procedural steps for extracting features and/or measurements from the profile sample, logging and displaying the data, and controlling external devices, either through digital I/O and/or serial I/O. Written using either a standard text editor or LGBasicStudio, the powerful LGBasic programs can identify the most complex features and extract measurements based on the most stringent requirements. All LaserGauge® sensors come preloaded with a set of Virtual Gauges.

  • Scratch Gauge

  • Fastner Gauge

Learn more about:

  • Benefits of LaserGauge® technology

  • How LaserGauge® Works

  • How to choose a LaserGauge® Sensor

  • Who uses LaserGauge® in the field

How LaserGauge Works

TECHNOLOGY: How LaserGauge® Works

How LaserGauge® acquires a 2-D Surface Contour through Laser Triangulation

The LaserGauge® acquires a 2-D contour of the surface to be measured, much like a linear “point cloud”, such that all of the points line up in the same measurement plane. In a typical LaserGauge®, up to 1280 points in a contour can be acquired. Since these contours are taken at a fixed scan width, the point spacing in the contour is dependent upon the scan width and the number of sample points. For example, for a 1-inch scan width with 500 points per scan, the sample spacing of the contour is 0.002”. Typical depth resolution is 0.001” for a 1” scan but can be as small as 0.0002” for smaller scan widths.

Scanning Methods available with the LaserGauge® DSP Sensors

LaserGauge® is not limited to the single laser stripe technology. Other structured light methods are utilized to allow for measurements on different types of components, each with its own advantages.

Single Stripe Scanning

Several LaserGauge® sensors use single-line imaging for surface contour measurement. While not able to provide 3D information of a surface, it is the most compact, fastest, and most multi-purpose of the laser imaging models.

Scanning Diagram

Sample Scan

  • Advantages:

    • Portable
    • Very fast
    • Line-of-sight scanning

  • Available Sensors:

Cross-Vector Scanning

Cross-Vector sensors utilize lasers angled toward the inside edges of the gap, crossing in the middle. This allows the sensor to see around edges of the radius to the vertical tangent and beyond. The result is a complete surface profile and the most accurate gap measurements.

Scanning Diagrams

Sample Scan

Leading Edge Scanning

The leading edge imaging method yields scans on both sides of a part simultaneously. The structured light reflects off one surface, around the edge, then onto the other surface, giving true leading edge scans that can then be processed. The traditional laser triangulation method is unable to do this.

Learn more about Leading Edge Sensors.

Understanding LaserGauge® Red and Blue Laser Technology

Selection of Red vs Blue laser technology comes down to a question of the surface material being measured. Red Laser technology is used on solid surfaces, such as painted or unpainted, non-shiny surfaces. Blue laser technology works accurately on all kinds of surfaces including painted, unpainted, translucent, transparent, some plastic, composite, and shiny.

The photos below show the difference between the blue laser (left) and the red laser capability on a red translucent lens:

BLUE LASER ON AMBER TRANSLUCENT LENS

  • Blue laser on red translucent lents

  • Red laser on red translucent lens

Learn more about:

  • Benefits of LaserGauge® technology

  • How to choose a LaserGauge® sensor

  • LaserGauge® measurement methodology

  • Who uses LaserGauge® in the field

Technology

LaserGauge® bridges the gap between mechanical inspection tools and 3-D CMMs, bringing advantages from each of the types of gauging: portability, flexibility and traceability.

LaserGauge® 2-D Laser Contour Sensors

LaserGauge® 2-D Laser Contour Inspection

  • High Flexibility, High Portability, Reasonable Cost
  • Tools: Handheld and portable sensors with options for stationery fit-gates
  • Benefits: Rapid on-line inspection of 2-dimensional features, such as gap/flush, welds or edge radius, with almost no setup time. Affordable for industry.
  • Weaknesses: Unable to acquire 3-dimensional part information

Compare to:

  • Traditional 1-D mechanical tools

    Low Flexibility, High Portability, Low Cost

    • Low Flexibility, High Portability, Low Cost
    • Tools: calipers, micrometers, feeler standard and custom gages, etc.
    • Benefits: precise measurements on standard geometrical shapes
    • Weaknesses: inflexible and inadequate when measuring features on complex surfaces

  • 3-D surface mapping tools

    High Flexibility, Low Portability, High Cost

    • High Flexibility, Low Portability, High Cost
    • Tools: Stationary and portable CMMs
    • Benefits: Provide a great deal of information on surface geometries and contours, which are great for verifying part shape
    • Weaknesses: Cumbersome and time consuming to use for measuring simple features, such as the gap between two complex panels. Very high cost.

Learn more about:

  • Benefits of LaserGauge® technology

  • How LaserGauge® Works

  • LaserGauge® measurement methodology

  • Who uses LaserGauge® in the field

Why LaserGauge

TECHNOLOGY: Why LaserGauge®

Why choose LaserGauge® for precision inspection and measurement in automotive, aerospace, and other industries?

  • Generates accurate virtual gauge measurements

    Settings can be customized for each inspection point to simulate almost any measurement method imaginable such as caliper, minimum gap, nearest point and other virtual methodologies. Complex features can be measured according to design criteria, making the data much more meaningful than that generated by mechanical or manual methods.

  • Consistently and accurately handles a wide scope of measurements

    Sensors can perform precise measurements on a variety of design features ranging up to 2.5” (63mm).

  • Accurate measurements on a wide range of materials and surfaces

    Rapid on-line inspection of 2-dimensional features on solid, translucent, transparent and shiny surfaces. Works well on flat surfaces and edges, as well as contoured and rounded.

  • Achieves repeatable results

    Operators are able to use the instrument competently and consistently after a day or two of training.

  • Able to run inspection routines

    Settings can be configured for each individual point established along the inspection routing. An image of the object being inspected is shown with an arrow pointing to the location for the next measurement.

  • The only solution available on the market that wirelessly displays measurement data on monitors overhead or along the assembly line

    Results are displayed in real time and can also be displayed downstream at a fitters’ station.

  • Generates meaningful graphical feedback

    As the measurements are made, the profile momentarily replaces the image of the object and is displayed on the sensor itself or on a computer monitor, depending on model.

  • Flags out of spec measurements

    Operators are alerted to out-of-spec conditions with both visual and audio alerts and can be required to verify those conditions before continuing.

  • Traceable data capture

    All data files are saved automatically and available for documentation purposes or additional analysis. Each measurement is tracked to a unique identifier or label and recorded in a data file.

  • The LaserGauge® Automation System brings the power of LaserGauge® sensors to robotics along the moving assembly line

    Hundreds of measurements are made over the course of minutes along a moving assembly line.

  • Bar Code Reader

    A barcode module can be installed on the front of some LaserGauge® sensor models to scan the identification number of assemblies or parts, such as the VIN or serial number.

  • Saves Time

    Measurement of individual points is completed within seconds. Inspection routines consisting of hundreds of points can be completed in minutes instead of hours.

Learn more about:

  • About the technology

  • How LaserGauge® Works

  • LaserGauge® measurement methodology

  • Who uses LaserGauge® in the field