Vision Sensing is Becoming More Accessible

AutomationDirect, Cumming, GA

Figure 1. Datalogic Smart-VS industrial vision sensors feature on-board processing in a compact and robust form factor, making them ideal for many automation applications. (Image: AutomationDirect)

Vision sensing systems are needed to improve operations in many industrial applications, where they can be arranged to detect the presence, position, and other characteristics of objects and products. However, the technology usually is implemented using finicky cameras, supported by significant, separately-located image processing and computing power.

A new breed of compact smart vision sensors with on-board intelligence has greatly simplified this situation by implementing essential vision-sensing technologies in a manner suitable for all types of manufacturing and other applications.

Cameras used with traditional vision systems are not always appropriate for the harsh conditions and tight confines found at industrial applications. A newer generation of smart vision sensors are designed specifically for industrial tasks, in a compact 80×50×40 mm form factor, and with a housing and electrical connectors rated for IP65/IP67 protection (Figure 1).

Equally important is the size of the “working area” where the smart vision sensor can detect targets. A 50 mm to 150 mm depth of field from the sensor face, with a 19-degree viewing angle, works well with the alignment and orientation found when detecting typical targets.

Standard cameras often require external lighting, which complicates installations. Smart vision sensors overcome this with onboard polarized white light sources, illuminating the targets right where the sensors need the light so they can “see” effectively.

Traditional vision systems are likely to employ video cables, along with separate computing systems which can be hard to install for industrial locations. Furthermore, the supervisory software is frequently PC-based and requires extensive training for setup and ongoing use. These systems can cost many thousands of dollars.

Figure 2. Any user can easily train “good/pass” and “no-good/fail” images using an on-board button, or a more capable web server graphical user interface. (Image: AutomationDirect)

Smart vision sensors are easier to apply for industrial tasks because they operate at an industry-standard 24VDC, with universal NPN/PNP discrete switching outputs for “data valid,” “good,” and “no-good.” Users can configure the most-needed vision features using a single “teach-in” button on-board the device, training up to four “good/pass” and four “no-good/fail” images. Or, if an Ethernet connection is available, smart vision sensors support an intuitive web server graphical user interface for setting up several “jobs”— so the sensor can be used in multiple roles — and for performing other maintenance (Figure 2).

Typical pass/fail scenarios needed by users include identifying whether or not:

A label is applied properly
A cap or part is installed and oriented as needed
The product color is correct
A container fill level is normal.

With advanced on-board intelligence, and an industry-focused form factor and design features, modern smart vision sensors can see moving targets and detect characteristics in a deterministic manner, returning pass/fail signals to a control system, which can respond as needed.

Machine vision sensing can be useful for many industries and applications, but until recently it has been an expensive specialty application. Modern smart vision sensors take advantage of edge-located processing to deliver key vision capabilities at a fraction of the cost and complexity associated with traditional systems, making the technology accessible to a much wider range of users.

This article was written by Kevin Kakascik, Technical Marketing Engineer, AutomationDirect (Cumming, GA). For more information, visit here .