Production decisions
In machine vision, the enclosure is half the system
Inspection software gets all the attention. But no algorithm can fix a camera that sees differently at nine in the morning and six in the evening. The physical environment must be designed, not improvised.
When people discuss a machine vision system, they discuss the software: what it detects, which model it uses, whether it uses artificial intelligence, how accurate it is.
Almost nobody talks about the box.
Yet much of what a vision system does well or badly in production depends not on software, but on something far more physical: what light reaches the camera, from where, and whether it stays the same.
The case
A machine that encodes, personalises both sides of, and inspects RFID tickets on a reel. As output increased, the operator's visual checks were no longer sufficient, and AI-based vision inspection was incorporated into the process itself.
The system checks both sides of the ticket, personalisation and the position of the chip inside the material. If it finds an incorrect ticket, the machine stops; the operator invalidates it and continues, and the fault is logged.
The division of work was clear: the inspection software came from a specialist supplier the customer already worked with. We built the physical enclosure and integrated it into the machine.
That division is precisely what this article is about: the part that is not software is also part of the system, and it matters a great deal.
What a vision enclosure does
The enclosure on this machine performs two functions that seem opposite but are complementary.
It isolates the inspection from room lighting. Light in a factory changes throughout the day: windows, lights switching on and off, someone walking past and casting a shadow, a door opening. To the human eye, none of that matters. To a camera, every change creates a different image.
It contains the system's own light. Vision lighting is often intense, and frequently pulsed. Without an enclosure, that light spills into the workstation and disturbs the people nearby, eight hours a day.
Keep outside light out and inside light in. The same component solves both problems.
Why stable lighting matters more than it seems
An inspection system decides whether a part is good or bad by comparing what it sees with what it expects to see. If the image changes for reasons unrelated to the part, the decision becomes unstable.
In practice, that produces the two errors that matter in any inspection system:
- False rejects: good parts marked as bad because there was more light that afternoon.
- Escapes: bad parts that pass because a reflection concealed the defect.
There is a third, less visible effect: the settings stop being reliable. If the system was adjusted under one lighting condition and operates under another, any threshold is calibrated for conditions that no longer exist.
A stable lighting environment allows today's settings to remain valid tomorrow.
What the design needs to resolve
A vision enclosure is not just a box over a camera. Inside a compact machine, several things compete for the same space.
The product path. Here, the web must pass through the enclosure without deviating from its defined path. Inspection requires the product to pass through the same place, at the same height and in the same orientation every time.
Access. A vision system needs adjustment, and readjustment. This enclosure has two hinged smoked-polycarbonate doors that provide access for setup and keep the inspection space separate during operation. The tint allows a view inside without letting the light become a nuisance.
Coexistence with other stations. The enclosure shares space with encoding, printing and transport. The more compact the machine, the harder it is to fit everything without one part obstructing another.
Here is an honest lesson: the compact assembly constrained access during initial adjustment. A compact machine is an advantage on the factory floor, but every centimetre counts when you need to get your hands in to adjust a camera.
When someone else supplies the software
In many vision projects, the mechanical integrator and the software supplier are different companies. That is normal and often sensible: each does what they know best.
But that division has a practical consequence: the system is not finished until both parts have been tested together, in place.
In this project, the machine was tested in the workshop with the web running continuously, but final vision checks were completed at the customer's site, coordinated with the software supplier. Not because of inadequate preparation, but because final integration with the customer's systems can only happen there.
If you are commissioning a project like this, clarify these points from the outset:
- Who does what. The enclosure, lighting, camera mount, machine signals, software. Each part needs an owner.
- What the software needs from the physical environment. Ask the supplier before designing the enclosure, not afterwards.
- Where and when final setup takes place, and who must attend.
- What happens when something is detected. Does it stop the machine? Reject the part? Log it? That is an integration decision, not a software decision.
The summary
If you are considering machine vision for a line:
- Do not assess only the software. Ask what environment it will be looking into.
- You do not control room lighting. If inspection depends on it, one day it will fail.
- The system's light can be disruptive. Containing it is part of the design, not an extra.
- Design access for adjustment, particularly on a compact machine.
- Plan final setup on site, with the software supplier present.
The software makes the decision. But it decides based on what the camera sees, and what the camera sees depends on the enclosure.
At 7Axis Industrial, we design and integrate the physical environment of vision systems: enclosures, mounts, product paths and machine signals. We work with your existing software supplier or the one you choose.
See the full CCPB7 case study → Quality, inspection and mistake-proofing →