Your food manufacturing business depends heavily on inspection and quality control systems to ensure every product leaving your facility meets your quality standards. Vision inspection systems take images of your products to look for discrepancies and defects. But what’s the difference between 1D, 2D, and 3D vision inspection systems, and which is best suited for your product line?
While it might seem intuitive to assume that 3D imaging is superior due to its level of detail, this isn’t always the case. Understanding the features, benefits, and drawbacks of each system can help you make an informed decision tailored to your quality assurance process.
Understanding the Basics
Before diving into the differences between 1D, 2D, and 3D vision inspection systems, it’s important to grasp the fundamentals of each. As expected, the primary distinction lies in the type of images they capture.
- 1D vision systems scan only one line at a time. They use a laser sensor to scan items as they move down a conveyor belt. By stitching together the line images, a cohesive 2D picture is formed.
- 2D vision systems take full, flat images of the object. They capture the object’s length and width but lack depth information.
- 3D vision systems use multiple cameras to compile a three-dimensional image of an object. The object can be rotated around an axis within the digitized model, allowing you to inspect it from every angle and identify even the smallest defects during the manufacturing phase.
Most vision inspection systems store their images in a computer, enabling your team to refer back to previous images. Some systems automatically identify specific data points with each scan; for instance, 3D systems can measure an object’s thickness, volume, and height while detecting angles, curves, and holes for accurate comparisons.
Capabilities and Applications
Although 3D vision systems offer the most detail, they aren’t always the best choice for your company. Understanding each system’s capabilities and recommended applications can help you select the right one for your quality assurance process without overspending on unnecessary features.
1D Vision Systems
For conducting surface inspections of products moving along a conveyor belt, 1D vision systems are often sufficient. Since 1D vision systems stitch together the line images they gather, they can function similarly to 2D vision systems, resulting in a two-dimensional image of the entire item. One major advantage over 2D systems is that they don’t blur.
Instead of halting the conveyor belt to take a 2D image of a food item, a 1D vision system allows items to continue moving down the line. This can be particularly useful in high-volume production environments where time is critical.
Applications of 1D vision systems include:
- Inspecting items in continuous motion on a conveyor belt
- “Unwrapping†cylindrical objects like cans and bottles
- Scanning barcodes
However, the scans produced by these systems are not as detailed or precise as those from other systems.
2D Vision Systems
If your manufacturing process uses pick-and-place machines rather than conveyor belts, a 2D vision system might be ideal. These cameras take photos of the item from one angle, usually the top. They don’t typically provide depth information but instead focus on identifying visual defects.
You can choose between black-and-white or color 2D cameras. Color cameras provide more detailed scans but require longer processing times. Both options can help you identify high-contrast differences in a product’s texture or color.
These systems are widely used in the automotive industry to confirm the position and location of features, verify labels, and detect scratches in polish. However, they cannot perform depth scans, have limited light sensitivity, and may struggle to identify low-contrast variations.
3D Vision Systems
Your company might benefit from 3D vision inspection systems if verifying an object’s depth, precise spatial location, volume, and surface angles is crucial. These systems use multiple cameras or lasers to create a 3D digitized model of each product on your line.
These vision systems can measure and detect a wide range of features, such as:
- Thickness
- Height
- Angles
- Curves
- Surface and assembly defects
- Volume
- Shape
- Holes
They can also guide robots in assembly lines by verifying the position of an item.
Due to their detailed capabilities, 3D vision inspection systems are essential in critical industries like aerospace, precision engineering, and automotive manufacturing. However, 3D inspection systems are more expensive and complex to install and maintain compared to simpler 1D and 2D systems.
Data Acquisition and Processing
Understanding the difference between 1D, 2D, and 3D vision inspection systems also involves knowing how each system collects and processes data.
How Data Is Collected in Each System
One-dimensional vision inspection systems use laser triangulation to take measurements of products. They project a laser point onto the object, reflect the laser back to the sensor on the scanner, and gather line images that can be stitched into 2D images.
Both 2D and 3D cameras also leverage laser triangulation to create comprehensive images from basic scans. While 2D systems use one camera to capture a single image, 3D systems utilize several cameras to capture images from all angles. These machines use structured light imaging to extract three-dimensional shapes.
Image Processing Techniques Used in Each System
Vision inspection systems rely on image processing software to analyze the images taken by their lasers or cameras. The software employs algorithms to analyze pixel patterns, contrasting colors, and other visual details based on the system’s capabilities.
- 1D vision systems combine the images a laser takes into one 2D image. Some systems create distinct images for each object, while others create an “infinite width image†that continuously compiles all line images.
- 2D vision systems capture and process a two-dimensional map with an X and Y axis, comparing variations in intensity for defect detection.
- 3D vision systems use software that compiles the images taken from various angles into one 3D model of the object. The software records precise measurements of the item based on this model.
Accuracy, Precision, and Cost
These three vision inspection systems vary in terms of precision, accuracy, and cost. Consider these differences before deciding on the right system for your company.
Factors Affecting Accuracy and Precision
Several factors can influence the accuracy and precision of a vision inspection system:
- The type of image it captures (laser imagery vs. camera imagery)
- The speed of image capture
- Whether the item is in motion or stationary
- The lighting conditions in the manufacturing facility
- The saturation of the image (color vs. black and white)
- The quality of the lens
- The number of pixels captured in the image
- The working distance
- The field of view
Comparing Performance Metrics
Selecting a high-quality vision inspection system means capturing precise and accurate photos, whether in 1D, 2D, or 3D. However, these systems have varying performance capabilities, so you should choose the one that best meets your needs for accuracy and precise measurements.
One-dimensional systems analyze an image line by line, offering precise yet straightforward analysis. Two-dimensional systems taking black-and-white images may be less precise than those taking color images due to differences in contrast between the two. Meanwhile, 3D systems offer the highest accuracy and precision, capturing high-detail, comprehensive images showing the entire item.
Cost Considerations for Each System and ROI
Cost is another significant difference between 1D, 2D, and 3D vision inspection systems. The more features and capabilities they include, the higher their price will be.
If your business relies on producing items with extreme precision requirements, a 3D vision inspection system could provide a worthwhile return on investment (ROI). Consider this system if even a small discrepancy in depth or size could be costly to resolve if left undetected.
On the other hand, 1D and 2D inspection systems have similar capabilities, though 1D systems are generally more affordable. If your items move on a conveyor belt, a 1D system could meet your needs and save you money.
Integrations and Considerations
Finally, consider the following before choosing a vision inspection system.
Integration With Other Systems
Your new vision inspection system should integrate seamlessly with your existing machinery. For example, if you use a moving conveyor belt, a 1D system might be preferable. If the lighting in your facility is dim, a 3D system may be necessary to capture low-contrast differences effectively.
Compatibility and Ease of Use
Choose a vision inspection system that aligns with your workflow and requires minimal downtime. Constant troubleshooting or frequent bug fixes can harm your production time.
Operator Training Requirements
Operators will need training on your new vision inspection system, but complex systems require more extensive training. Keep this in mind when planning to adopt your new system.
Contact TDI Packsys Today
Now that you understand the differences between 1D, 2D, and 3D vision inspection systems, are you searching for high-performance systems for food production? Our line of vision systems at TDI Packsys features top-tier artificial vision equipment for 100% quality control and object recognition. Contact us today at 877-834-6750 to learn more.