Automotive Glass Verification System

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"LabVIEW helped us develop scalable, readable, and maintainable software."

- Mohammed Hassan Miah , TBG Solutions

The Challenge:
Designing and developing a reliable, repeatable system to scan automotive glass and highlight any deformed areas detected through comparison with original equipment manufacturer automotive glass.

The Solution:
Using NI LabVIEW software and the NI PCI-6519 digital I/O board to make detailed comparisons of automotive glass; building an integrated mounting system to ensure repeatable positions of the glass and scanning it with a high-precision laser; and developing an algorithm to highlight any areas of deformation.

Mohammed Hassan Miah - TBG Solutions

TBG Solutions

TBG Solutions Ltd, an NI Gold Alliance partner, specialises in solutions based on LabVIEW for a wide variety of industries, including rail, aerospace, defence, power generation, automotive, and general manufacturing.             


Distortion in the glass used for automotive windscreens can cause optical issues for drivers as incorrect refraction of light reduces visibility. Automotive glass distortion has also resulted in windscreen fitters making huge claims for stock rejection from their suppliers. These claims can be difficult to settle because shape distortion is a challenging phenomenon to prove.

The Approach

The Automotive Glass Verification System scans automotive windscreens to test whether or not they meet a predefined shape. The system operates in a two-step process. The gold scan examines a known good glass and saves the data for the comparison stage. The verification scan examines windscreens to be tested. Once the verification scan is completed, the two scans are compared to get the difference between the two data sets. A threshold value for the difference is set with an allowable tolerance, giving a pass or a fail result.



Figure 1. Automotive Glass Verification System


Figure 1 shows the Automotive Glass Verification System with the bespoke mounting system, which holds and fixes the position of the glass. We designed and built the mounting system in-house. For the scanning process, the system breaks the windscreen down into a series of columns defined by a region of interest generated from the dimensions of the windscreen. For a gold scan, the laser scans the windscreen column by column at a set resolution, whereas a verification scan can be carried out at various different resolutions.

Developing and Testing With NI

We implemented the system using LabVIEW to control the positional motors, communicate with the laser, and process and interpret the data. We used prebuilt drivers to develop the system to communicate with the laser, which cut development time. Customised, professional user interfaces can be designed quickly with LabVIEW to display data in a way that is intuitive to the user. For the inputs and outputs of the system, we used a digital I/O PCI card from NI as it provided seamless integration with LabVIEW. We configured the card using NI Measurement & Automation Explorer (MAX) and used NI-DAQmx to set all the required inputs and outputs of the system through a single programming interface.



Figure 2. One User Interface for Automotive Glass Verification System


Figure 2 shows one of the user interfaces displaying a windscreen that was scanned by the Automotive Glass Verification System. The user can see the curvature of the windscreen represented by the intensity of colours. The purple boxes indicate masks that ignore sections of the data dependant on where the user places the two cursors (shown at the top left corner and the bottom right corner of the lower purple box).



Figure 3. Displaying Comparisons to the User


Figure 3 shows the comparisons for scans carried out by the Automotive Glass Verification System. The left of the image shows the difference between the two windscreens. The right of the image shows the differences passed through a predefined tolerance. Any differences greater than the tolerance are shown as red. Depending on the size of the red area, the windscreen is classed as a pass or fail.

Benefits of the Automotive Glass Verification System

Windscreen fitters can check to see if a windscreen has been manufactured to an appropriate safety standard using the Automotive Glass Verification System. Indirectly, the system also benefits manufacturers as highlighting faults in the glass helps them make better quality windscreens and reduces the number of claims from windscreen fitters.


LabVIEW helped us develop scalable, readable, and maintainable software. It also helped us design professional user interfaces that use colour to display the curvature of the windscreens being tested. We used LabVIEW to design complex mathematical algorithms to compare the OEM glass with the test windscreens. We have deployed the Automotive Glass Verification System in the windscreen industry to ensure driver safety and reduce manufacturing cost.

Further Information

The user for this project is Belron Group. In the UK we are more familiar with one of their brands—Autoglass. There are links below to both Belron Group and their brands.

Author Information:
Mohammed Hassan Miah
TBG Solutions
3A Midland Court
United Kingdom
Tel: 01246 819100

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