Automotive Lighting sector
It is not a coincidence that ISR Specular Vision has specialized in automatic quality inspection in the automotive lighting sector. This sector is quite full of surfaces that need to be perfectly checked, which has been traditionally performed by manual inspection. As ISR Specular Vision’s mission is to be the eyes of the industry, automotive lighting’s mission is to be the eyes of the car and the main element to let us drive carefully on the road.
The market value of the lighting sector is approximately $35 Billion. This is divided into five groups in Europe: Valeo, Forvia Hella, Marelli Automotive Lighting, OPmobility and ZKW. Three main groups in America: Magna Lighting, Flex N Gate and North American Lighting. The other five groups in Asia: Koito Manufacturing, Stanley Electric, Hyundai Mobis, Hasco Vision and Xingyu. Maximum revenues yearly are between 5 and $6 Billions, and all the companies listed above have at least $1 Billion revenue. They are the valuable players, the TIER 1 companies following the automotive OEMs trends and creating the future of cars. This is clearly a great market to develop innovative technology and expand internationally, but why the lighting sector?
Question to the reader, what is the main characteristic of the lighting manufactured parts? They need to be transparent to let the light pass through, and transparent is the kind of surface where ISR Specular Vision has its innovative applications in the industry. This is the reason it is not only not a coincidence, but a great competitive advantage and niche for Specular Vision technology.
High-Quality modern vehicles
Lighting has been for a long time a critical component of vehicles on the roads. First for safety, figures from different resources had night vision as one of the first 3 causes for collisions in the US, and since the mid-80s as a focus for car designers to differentiate their brands. However, car manufacturers and suppliers are clearly entering a new lighting era, driven by several factors.
First, is fast electrification of new car sales, due to regulation and consumer demand in the light of decreasing battery costs (electric vehicles, a topic that will be written in future articles). Elimination of the radiator opens a large space to use lighting across the front grille to offer a specific signature to electric cars and illuminate the brand logo. Add to that, the integration of many sensors in the front of the vehicle, emerging new business model which provides the whole front as one integrated piece. These new signatures and design options, with slimmer shapes, will impact and enhance rear lighting too.
The direct consequence of the fact exposed above is the need of inspecting more surface all over the parts manufactured by the TIER 1 companies, headlamp or rearlamps. Manual inspection is no longer possible or feasible for inspection of parts up to 2 m long, in cycle times lower than 20/25 seconds.
Secondly, the luxury car segment is a growing sector. Not only the exterior of the car involves lighting in the OEMs designs. With the development of the autonomous vehicle, automotive interior lighting is being reinvented to reinforce the feeling of the comfort of being at home. Automotive interior lighting also has a role to play in the new communications between the increasingly automated vehicle and the driver/passenger, to create trust and reassure occupants.
Differentiation is achieved thanks to a dedicated visual identity, both outside and inside the vehicle. Onboard ambient lighting is a key element to this brand identity for a car. Current applications are what we call static ambient lighting. Whether monochromatic or color lights (RGB), direct or indirect, both premium and mainstream vehicles are now equipped with static ambient lighting solutions. All segments are concerned.
With the evolution towards a home-like cabin in the vehicle, one trend is to merge decorative components and lighting into one backlit system. Backlit decorations create a specific signature when activated, enabling a polymorphic interior, whether thanks to an “augmented” pattern (visible when off but highlighted when on) or reveal one that is hidden for a specific night signature.
Automotive interior lighting enables to change infinitely the design of the interior, enabling the owner or users to adapt the vehicle to their mood and taste and to deliver a personalized experience.
In the long term, the new developments and updates could deliver new “skin” packages or easter-eggs, offering an evolving experience throughout the lifetime of the vehicle, adding value to the travel experience. Beyond pure decoration, it also combines functional lighting with HMI (Human Machine Interface) projection, content, etc.
Overview of OIT Headlamps & Rearlamps Systems
OIT® Headlamps, OIT® Rearlamps are inspection systems that detect aesthetic defects in headlamps and realamps cover lenses. The system is fully integrated in-line after the injection, coating, and oven processes. Normally the parts are automatically introduced in the OIT cabin with the same injection or coating robot, which handles in parallel several tasks in the line. The system could be integrated right after injection or right after coating, or even after both processes, depending on the strictness of the quality control applied.
Thanks to their design, these solutions allow the inspection of different models with just a change of tooling (what is called Vision Jig), making it possible to inspect a wide variety of sizes and shapes. Per system and year, the average number of models inspected is 3. Every year, an average of 2 new models are integrated in the systems.
The automatic inspection is performed following the control plan of the end customer, the OEM. In this document, the main defects to be detected are clearly specified, the different areas to be controlled and the procedures for an operator to perform manual inspection.
This inspection cycle is divided into the following phases:
- 1st phase – Retro image. In this phase, images are obtained from the fixed cameras and the robot cameras to obtain a complete view of the part. The images from this phase are darker images which allow the inspection for black defects. Both fixed and robot cameras.
- 2nd phase – Aspect image. In this phase, the same images are obtained as in phase 1 with the difference that the images are brighter to improve the identification of white defects. Both fixed and robot cameras.
- 3rd phase – Catadioptric (in case of presence) using reflection. In this phase, images are obtained using robot cameras to analyze the catadioptric surfaces, to analyze white defects that cannot be detected in phase 2 due to the morphology of the catadioptric itself. Robot cameras are used.
The cycle time varies between 12 and 25 seconds. When the images have been processed, the defects are detected in the images showing the following information:
- The red color shows the defects whose size exceeds the marginal defects maximum size and, therefore, makes the part NOK.
- The pink color shows the defects whose size is between the marginal defects’ minimum and maximum size thresholds. More than one (threshold quantity can be adjusted using the user interface) defect of this size must be detected for the part being classified as NOK.
- Green shows a contour which is not considered a defect since its size is smaller than the marginal defect minimum size.
- The numbers indicate the biggest dimension (mm) of the defect.
- The purple area of the image indicates the area that is out of the Region of Interest (ROI) and is not inspected.
It must be pointed out that minimum and maximum size of marginal defects can be configured using the system user interface. In industrial conditions, typical values for limit defects are between 0.3 and 0.5 mm.
Nowadays, ISR Specular Vision systems inspecting headlamps and rearlamps are 10 all over the world, with 3 different customers. The main car models inspected by ISR are from the following OEMs: Volkswagen, BMW, and Renault.
Benefits using OIT and comparison with traditional inspection
Reached this point, it is difficult to argue against the benefits and potential of the automatic inspection of Specular Vision technology in lighting cover lenses inspection. In this section, we will focus first on the typical defects found with OIT HL/RL Systems, and, secondly, briefly present the payback cases in the investment of this Capex equipment for factories.
Typical defects found in injection process:
- Flow Marks or Lines.
- Air Bubbles or entrapments.
- Black dots.
- Cloudy swirls, Opacity or Haze.
- Weld Lines.
- Scratches, Scuffs or Cold Slugs.
- Warping or Distortions.
- Foreign Material Inclusions.
- Burn Marks or Discoloration.
- Lack of material.
Typical defects found in coating process:
- Orange Peel.
- Varnish Drops.
- Dust Inclusion.
- Stripes and Scratches in the Varnish.
- Opacity or Haze in the Varnish.
- Varnish Peeling.
- Uneven Gloss.
And finally, the clear benefit of the OIT Headlamp and OIT Rearlamp inspection systems is the quick payback obtained in the investment. The traditional inspection costs of these production lines are between 3 and 6 workers per line. The ISR Specular Vision, instead, offers an automatic system whose payback is under the year in the best cases, and between 1,5 and 2 years for worst cases.
As these two topics could be deeply treated, both will be further discussed in following articles.
Summarizing the key points
In today’s article, we gave an overview of the lighting sector and introduced the OIT HL and RL systems. It can be summarized in the following points:
- Specular Vision technology has a great competitive advantage and niche in the Automotive Lighting sector.
- Manual inspection is no longer possible or feasible for inspection of parts up to 2 m long, in cycle times lower than 20/25 seconds.
- OIT® Headlamps, OIT® Rearlamps are inspection systems that detect aesthetic defects in headlamps and realamps cover lenses.
- Nowadays, ISR Specular Vision systems inspecting headlamps and rearlamps are 10 all over the world, with 3 different customers. The main car models inspected by ISR are from the following OEMs: Volkswagen, BMW and Renault.
- The clear benefit of the OIT Headlamp and OIT Rearlamp inspection systems is the quick payback obtained in the investment. ISR Specular Vision offers an automatic system whose payback is under the year in the best cases.
