What is Vision?

Omron FQ2 Vision SystemMachine vision (MV) is the technology and methods used to provide imaging-based automatic inspection and analysis for such applications as automatic inspection, process control, and robot guidance in industry. (Wikipedia).

We prefer the slightly simpler version: "Automated extraction and analysis of relevant information from digital images", as today Vision can be used in a much broader range of applications than mentioned above.

We will simply use the word Vision instead of "Machine Vision".

What is Vision Used for?

Positioning by use of laserAlmost everything we are in touch with in our daily life has at some point been in touch with Vision. Maybe directly within the production process, where the item has been located or its size or quality has been determined. Or in the handling process where the item has been registered, controlled or identified.

Roughly, Vision is used in the following processes:

  • Localisation (position, orientation)
  • Measuring (demensions, shape)
  • Counting (items, item parts)
  • Identification and registering (bar codes, text, shape)
  • Quality control (defects)

Why Using Vision?

Quality and productivity are determining factors in all production processes. Often they are conflicting such that increasing of productivity leads to decreasing quality.

As Vision has become more intelligent, it is allowing measuring and image analysis in a very short time. Vision systems can be used for a fast and very reliable analysis of various crucial factors in the production. Thereby, critical decisions can be made automatically, based on Vision, while at the same time maintaining even high cycle times.

In many cases, Vision can help improving the quality by detecting and eliminating errors, such that defective items are isolated from continuing in the production flow. Also, items can be followed individually and identified correctly. Counting of items can be done to secure that items are not missing.

In robot based installations, Vision can help localizing the items such that the robot can handle them without time consuming search operations and tools for physical detection of items.

Today, Vision systems work at high speeds. Thus high cycle times can be achieved which is increasing the production volume and reducing the costs.

We can summarize the above by saying that Vision helps improving the quality and productivity while at the same time reducing the costs.

How to Use Vision?

When using Vision in a production environment it is essential that all complicated processes must be executed fully automatically by the Vision system. Once the system has been installed and commissioned all complicated processes must be executed automatically and without interruptions.

The operator should not need being a Vision expert in order to operate the equipment in daily production. Operating of the equipment should be intuitive and a new operator should only require a short training in order to be able to learn to operate the equipment.

Is Vision Difficult?

A number of factors are essential for a Vision system to operate well. Apart the obvious, like choosing the correct camera and lens type, a number of other units need to be selected correctly for the task in question.

The Lighting is crucial in most tasks in order to secure the optimal working conditions for the image analysis and the decisions that should be made. Both direct and indirect lighting need to be considered.

In tasks with high cycle times, the processing time is critical as only limited time is available for making the correct decisions in the Vision system.

Integration with other equipment and units in the production is Paramount. This is valid for physical units such as servo motors, conveyors, robots, process equipment etc. but also data exchange with other systems in the company, such as order information, logging, statistics etc.

Add to this the user interface which needs to be clear and intuitive, providing the operator with necessary means to control the equipment and at the same time avoiding incorrect operation.

Understanding the nature and variations of the task to be performed is essential for adequate flexibility of the Vision system when changes in production occur. In case of low production series, switching to new products should be possible without losing the investment. Possibly, the installation should be able to handle different products and processes in a continuous flow.

For a Vision installation to be successful it is necessary that many different factors all work together, which will only happen when having the correct understanding of the task and making correct choice of solutions.