HIGH-QUALITY INSPECTION WITH 3D MACHINE VISION

Traditional 3D vision technologies perform well in simple inspection tasks, but some applications require more. When you have a more complex application, a flexible and customizable solution is often required. Streaming 3D cameras that offer flexible geometry and camera setup provide a number of benefits to more complex inspection tasks. Using laser triangulation, these solutions can help you overcome challenges related to low contrast and poor lighting. In this paper, we’ll explore ways 3D vision technologies can provide high-quality inspection in high resolution at a high speed. And how it can all be configured to your specific application.





Precise and Fast Error Detection

Many manufacturers simply need a vision system that can more reliably detect a part’s presence or absence, especially in low-light or low-contrast situations. However, in applications like the production of consumer electronics, the fast and precise detection of any errors like a bent pin is vital to meeting production demands. Many 3D machine vision systems on the market are designed to perform high precision inspection and measurement applications, such as detecting fine scratches in a part’s finish. But many of these do not offer the flexibility and configurability needed in very precise applications. 


But, the reality is, you no longer need to worry about finding a solution that can perform in such high-precision environments. Now, there are alternatives that can provide a high-level of resolution and height information needed to detect changes in color or part differences with speed and precision.

The 3D Advantages Of Laser Triangulation


A streaming, high-resolution 3D camera, SICK’s Ranger3 uses an external laser mixed with 3D vision technology to provide reliable and accurate measurement on dark and bright surfaces to enable flexible production. Utilizing laser triangulation technology, the device works by projecting a laser light onto the object being measured. Then, a light sensitive element — in this case, the camera sensor — maps out the reflection. 

Based on the position of the mapped light spots and known geometry of the sensor optics, the device determines the object’s height profile. In addition to performing single-height profile analysis, the Ranger3 can generate 3D images, which you can evaluate in terms of dimension, volume or shape. By moving the camera or object, the device collects multiple contour profiles of the object at equal intervals and assembles them as one, coherent 3D image.

Instead of a flat, two-dimensional image, the Ranger3 provides you with point cloud data, or pixel positions within a given volume, along with intensity information. Because the toolkits are defined in a 3D volume, the system adds depth to your inspection process — enabling you to see certain features that would otherwise be impossible to detect using 2D sensors. 

The device also overcomes two common challenges for many 2D machine vision users: 

Low contrast. In many 2D applications, systems rely on contrast, or light versus dark regions for two-dimensional image processing. When verifying part presence, however, challenges arise when these 2D systems must detect dark pieces against a dark background. By adding a depth dimension, the Ranger3 avoids this problem and performs its analysis based on height, allowing reliable detection when minimal contrast is present. 

Poor lighting. Whereas 2D systems rely on separate internal or external lighting sources, adding cost and often creating glare, the Ranger3 utilizes a laser line that doubles as a light source. Not only does this laser eliminate the glare associated with external lighting sources, but it improves image resolution— allowing you to better inspect the smaller details of your object. 

In addition to its 3D evaluation capabilities, vision systems like the Ranger3 provide a variety of other benefits, including: 

  • Reliable 3D inspection—even when part color, position and height varies
  • Quick device replacement due to guaranteed field of view and reuse of saved settingsFlexible geometry to configure camera setup for your application • Reduction of occlusion with higher resolution processing and more accurate data • Rugged IP 67-rated metal casing for demanding industrial environments
  • Flexible geometry to configure camera setup for your application
  • Reduction of occlusion with higher resolution processing and more accurate data
  • Rugged IP 67-rated metal casing for demanding industrial environments

Flexible Configuration for Any Application

Measurement speed, resolution, and image quality are all important considerations when selecting a vision system for electronics production. Powered by SICK’s Rapid On-Chip Calculation, the Ranger3 accomplishes demanding 3D inspection tasks in electronics, including solder paste or component coplanarity inspection. 

As a streaming camera, the Ranger3 also provides continuous high-quality data acquisition for external analysis on an image-processing device. This combined with the high-spatial resolution and high-light sensitivity, it is able to detect fine details even within a large field of view, providing quality images that ensure accurate shape, volume, and position measurements. 

In addition, because the laser is external from the actual camera, the Ranger3 provides flexible geometry to setup the camera and laser configuration to meet your exact specifications. You can even connect multiple cameras to one another to stitch together images at a higher resolution. Because of this flexible geometry, the Ranger3 is able to adapt to all different types of inspections. 

Some specific examples of inspections include: 

  • Measuring height and flatness of an object
  • Confirming glue height, area, and volume 
  • Confirming components are there and in good condition
  • Detecting broken, bent, or missing pins
  • Detecting misprints before mounting or soldering

To learn more about 3D Machine Vision Solutions from SICK, please email us at info@sick.com or visit our website at www.sick.com.