Introduction to Machine Vision for Controls Engineers

In today’s article, I will introduce you to machine vision. By the end of the article, you will know what machine vision is, why manufacturing companies use machine vision, and how you can level up your machine vision skills.

If you already know what machine vision is and you want to dive straight into using AI-powered machine vision algorithms to solve visual inspection applications, you can check out our course, MELSOFT VIXIO: AI-Powered Visual Inspection Software for Industrial Automation.

In that course, you will learn how to set up and deploy an AI-powered machine vision solution for a real-world application.

Let’s get started by talking about what machine vision is.

What is machine vision?

Machine vision, in the context of industrial automation, is the use of cameras to perform automated visual inspections on components.

Some common applications of machine vision include;

• Checking if the dimensions of parts are within specification before assembly,
• Checking the position of parts on a conveyor so that a robot can pick them, and
• Checking if parts are damaged so that they can be removed from the manufacturing line before value-added processes.

Now that we know what machine vision is, let’s look at how a machine vision system works.

How does a vision system work?

To capture images of parts, a machine vision system has a camera and a light source which are mounted over a production line.

The camera is connected to an industrial PC, or IPC, that runs specialized inspection software to analyze captured images.

The industrial PC is connected to the PLC that is running the production line.

When the PLC detects a part underneath the camera, it sends a trigger to the inspection software running on the IPC.

The IPC then sends a trigger to the camera.

The camera captures an image of the part and sends the image back to the IPC.

The machine vision software running on the IPC analyses the image to determine if this is a good or bad part and sends a pass-fail result back to the control system.

The control system receives the result and rejects the part from the production line or allows it to continue to the next process.

As you can see from this example, machine vision systems help manufacturers check the quality of parts on their line in an automated way.

Advantages of machine vision systems

The alternative to automated visual inspection with a machine vision system is manual inspection with an operator. Many companies prefer using automated visual inspection over manual inspection because;

• Machine vision systems are faster than people. A machine vision system can inspect many parts per second.
• Machine vision systems are more reliable than people. A machine vision system doesn’t get distracted or have a bad day so the results of automated inspections are consistent and reliable.
• Machine vision systems see more than people. Modern high-resolution cameras can accurately measure and inspect parts to detect minor flaws that people may miss.
• Machine vision systems reduce the amount of manual labor companies require. This helps companies to reduce their costs and to mitigate the effects of the labor shortage that many companies are facing.

Before moving on, I want to point out that machine vision systems do not always replace people working on production lines, in many cases, they complement the work of operators.

For example, a machine vision system may be used to do a first inspection of all parts on a production line and an operator may be used to inspect all of the rejected parts to confirm that they are really defective.

In this case, the machine vision system helps to reduce the operator's workload so that he has more time to do a thorough check on the parts that have been rejected.

The machine vision system can even help the operator to do his inspection by providing an image of the rejected part with a heat map highlighting the defective area.

Wrap-Up

In this article, you have learned:

• What machine vision is,
• How a machine vision system works,
• The advantages of machine vision over manual inspection

In the modern economy, more and more companies are facing pressure to reduce their costs and deal with labor shortages. One way they are doing this is by deploying machine vision systems to perform automated visual inspections on their production lines.

For this reason, more and more control engineers are expected to have knowledge of configuring, commissioning, and supporting machine vision systems.

If you are interested in working in fields like printing, assembly, manufacturing, or robotics, having machine vision skills is an advantage that could help you land your dream job.

If you want to continue learning about machine vision, then you can check out our course MELSOFT VIXIO: AI-Powered Visual Inspection Software for Industrial Automation.

In this course, you will learn how to build, deploy, and test an AI-powered machine vision algorithm to inspect parts coming off an assembly line.

This course was developed in partnership with Mitsubishi Electric. At the end of the course, you will receive a certificate of completion from Mitsubishi Electric.

I can’t wait to see you inside.

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