Vision Inspection Systems
Machine Vision Basics
Machine vision encompasses all industrial and non-industrial applications in which a combination of hardware and software provide operational guidance to devices in the execution of their functions based on the capture and processing of images.
What is Machine Vision
To achieve accurate, reliable, and repeatable results, a vision system’s part location tools must include enough intelligence to quickly and accurately compare training patterns to the actual objects (pattern matching) moving down a production line.
Machine Vision Lenses
The lens captures the image and delivers it to the image sensor in the camera. Lens will vary in optical quality and price, the lens used determines the quality and resolution of the captured image. Most vision system cameras offer two main types of lenses: interchangeable lenses and fixed lenses.
Guidance
Guidance may be done for several reasons. First, machine vision systems can locate the position and orientation of a part, compare it to a specified tolerance
Identification
A machine vision system for part identification and recognition reads barcodes (1-D), data matrix codes (2-D), direct part marks (DPM), and characters printed on parts, labels, and packages.
Gauging
A machine vision system for gauging calculates the distances between two or more points or geometrical locations on an object and determines whether these measurements meet specifications.
Components of Machine Vision
The major components of a machine vision system include the lighting, lens, image sensor, vision processing, and communications. Lighting illuminates the part to be inspected allowing its features to stand out so they can be clearly seen by camera. The lens captures the image and presents it to the sensor in the form of light. The sensor in a machine vision camera converts this light into a digital image which is then sent to the processor for analysis.
Vision processing consists of algorithms that review the image and extract required information, run the necessary inspection, and make a decision. Finally, communication is typically accomplished by either discrete I/O signal or data sent over a serial connection to a device that is logging information or using it.
Connecting machine vision components
Since vision systems often use a variety of off-the-shelf components, these items must coordinate and connect to other machine elements quickly and easily. Typically this is done by either discrete I/O signal or data sent over a serial connection to a device that is logging information or using it. Discrete I/O points may be connected to a programmable logic controller (PLC), which will use that information to control a work cell or an indicator such as a stack light or directly to a solenoid which might be used to trigger a reject mechanism.
DIFFERENT TYPES OF VISION SYSTEMS
Choosing the right vision system is essential to meeting the needs of your specific vision applications. Broadly speaking the different types of vision systems include 1D Vision Systems, 2D Vision Systems, Line Scan or Area Scans and 3D Vision Systems.
1D Vision Systems
2D Vision Systems
Area Scan vs. Line Scan
