What is Specular Vision?
Specular Vision is the brand name created by the company ISR at the beginning of its technology developments (https://isr.es/en/specular-vision-en/). It refers to the property of the light in which a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray. This is only theory (first described by Hero of Alexandria AD c. 10-70), but the surfaces that ISR inspect are not all strictly specular, but it reminds us of this effect of the light.
The importance of Specular Vision technology resides in solving efficiently the automatic aesthetic inspection of the surface that is transparent or reflective, even glossy. We inspect and detect defects in manufacturing parts with industrial cameras, as simple as that. And we make it for several industry cases: automotive, steel, glass, etc.
It is a hard task to inspect manually thousands of components/parts a day looking for tiny defects, with little rest, sleepy eyes, or after 8 standing hours under the heavy temperatures of summer. The added value of the technology is related to the change of vision for inspection tasks, together with the financial benefits, of course, that could report positively to factories and companies’ productivity.
Besides this, Specular Vision is intended not only to check quality isolated from the rest of the process but also to optimize the production. Data regarding quality checks, however, has not been traditionally easy to collect in the factories. Specular Vision comes to help with:
- Automatize the process.
- Detect and identify the defects.
- Collect the data for a better understanding of the production process and its quality.In this article we will try to help you understand how it works, its applications in industry, and examples of ISR Specular Vision. Let’s go for it!
How Specular works?
Specular Vision technology is based on artificial vision intelligence. But just that? Not. The technology is not only about artificial vision; it doesn’t remain only at the software level. One of the most valuable keys of ISR Specular Vision is the deep knowledge acquired over the years of the mechatronics environment that surrounds the vision algorithm (A machine vision system for defect characterization on transparent parts with non-plane surfaces).
Why is this important? Well, imagine taking a picture of the Eiffel Tower, in reverse, dark, and blurred. Would you think this picture is something you can post on your social media? No, it’s not! So just the same thing applies to Specular Vision Technology: we are obsessed with image acquisition.
The images in our vision systems are acquired by a number of cameras that synchronize perfectly together to achieve a high-resolution final image of the part inspected. This final image is divided into areas, as many areas as the manufacturing part inspected requires (depending on its size). In each of these sub-areas, the local defects present on/in the surface are identified properly. With this information, our customers can sort the parts whether they are OK or KO (scrap parts) into different conveyor belts or outputs.
This is the base of the technology. But what happens inside our systems? Well, we need to make a difference between two types of vision systems:
1. Matrix systems: the parts inspected leave the production process (for a short period) and enter our cabin to be inspected.
2. Linear systems: the part/surface inspected passes over/under/through our system of cameras to be inspected.
In future articles, we’ll explain the differences between these two approaches.
In general terms, each system has a matrix of fixed cameras (https://www.stemmer-imaging.com/) Their goal is to acquire a bunch of images of the parts or surface, playing with the lighting system. Yes, there are also several lighting systems (which are patented) to create the optimal conditions for the inspection cycle in the cabin. The fixed cameras are not alone, at least in matrix systems. They are supported by one, two, three, or even four robotic arms, each one, having a camera also integrated. The aim of having dynamic cameras is to gain flexibility and speediness in the process.
How much time does it need to inspect 100% of the parts? This concept is called cycle time. The cycle time is the time needed in each production cycle to inspect completely the part surface, regarding the acquisition plus processing phase. Normally ISR Specular technology needs an average of between 10 and 25 seconds to complete the inspection and detection of defects.
After this first approach, it’s important to talk about the differences between the results when the acquisition phase of the vision systems is affected or not by external conditions, such as dust, unstable production, defects on the mold, etc. As said before, acquiring a good image is essential for the processing of the defects, and the external conditions could lead, occasionally, to false positives. A false positive is everything detected in the image that is not really a defect, but the system has “confused” it. It’s a very important topic in machine vision systems. One of the benefits of Specular Vision technology is that this topic is attacked with AI algorithms, able to cope with different situations when facing a decision of OK vs KO parts.
Applications of Specular Vision
Made the introduction! Where are we? Let’s see in this section what are the main applications where Specular Vision technology is used and what benefits it brings:
- Automotive sector.
ISR Specular Vision technology has been applied to automotive sector since 2016, starting with the surface inspection of lighting lenses. The benefits of Specular Vision have been also found in the same TIER1 companies, manufacturers of headlamps and rearlamps, with the inspection of their covers (https://isr.es/en/solutions/lighting-inspection/), as well as interior decorative parts. Normally, all these parts are injected in tech plastic, which is also a topic for another article.
- Steel sector.
In 2018, Specular Vision was applied to steel processes. With the use of linear systems, the coils were laminated under the eyes of our systems.
- Glass sector.
After some iterations with different customers, ISR Specular Vision entered the market of glass inspection (construction or automotive glass). A great market with a huge need for inspection because of its particular and quick payback coming from automatization.
ISR Specular keeps innovating in sectors such as aluminum, metalized parts for decorative purposes, thin plastic material and even EV batteries.
Examples of Specular Vision in use
The success case that represents the best example of Specular Vision technology is the automatic inspection systems of headlamp covers. It is widely implemented in factories of TIER 1 companies. The system can adapt with highly flexibility to different models in the production process. This is made with what is called Vision Jigs, adaptative elements for the integration of the models. A system handles between 3 and 4 models, all of them interchangeable in serial production. The time needed to change a model varies between 5 and 10 minutes, and the integration development can be implemented in days!
Main features:
- Automatic detection of defects in serial production.
- Classification of defects in real-time.
- Data analysis of your production performance.
- High flexibility for new models’ integration.
- Autonomy of the factory workers on production vs quality decisions.
- Quick payback.
Summarizing the key points
In today’s article we have seen the potential of Specular Vision technology, summarized in the following points:
1. Specular Vision technology efficiently solves the automatic aesthetic inspection of transparent, reflective and glossy surfaces.
2. The benefits of Specular Vision mainly are,
a. Adding value to the inspection task in the industry.
b. Obtaining amortization in the short term.
c. Having data about your production quality in real-time.
3. Specular Vision technology combines industrial cameras, lighting systems, and mechatronics.
4. Markets and sectors of applications are a huge variety.
