Introduction
2D and 3D vision systems are clubbed under the umbrella of machine vision. Their origin stretches back to the 1960s and the creation of the first CCD camera. Slowly, advances in technology and science led to the first 2D vision systems. By the 1980s, industry leaders had begun to develop intricate 3D vision systems. These were, however, too expensive to be used extensively.
Today, 2D and 3D vision systems are integral to manufacturing, automation, and Industry 4.0. Previously, photoelectric sensors helped achieve machine automation. However, they were only suitable for blind robots performing repetitive tasks. 2D and 3D vision allows machines to perform actions previously thought impossible. For this reason, several industries are phasing out of photoelectric sensors. But how can someone starting out in this industry know which vision system is for them?
What is a 2D Vision System?
A 2D Vision System captures the image of an object and represents it in a two-dimensional plane. It only measures distances in the x and y coordinates, meaning that it can only calculate an object’s length and width. 2D vision systems achieve several manufacturing tasks. They excel in scanning tasks like object recognition and surface inspection. Furthermore, 2D vision systems speed up production lines with barcode reading and item detection.
Because 2D vision systems have existed for a long time they are reliable, efficient, and inexpensive. Many factories have benefited from 2D vision systems and have built their production lines around them. However, one major drawback of 2D vision systems is that they cannot perceive the depth of an object. Therefore, they are inadequate for precise 3D measurements. They also cannot perform tasks like volumetric analysis and pick-and-place jobs.
The evolution of 3D vision has overcome these challenges. 3D vision represents a new generation of machine vision that can take industry automation to a new level.
What is a 3D Vision System?
A 3D vision system can measure all three-dimensional attributes of an object. It uses cameras and photogrammetric techniques to create a 3D model. It generates a point cloud that maps each coordinate to a point on the object’s exterior. Software tools analyze this 3D mapping to measure the object’s dimensions.
3D vision systems use four main techniques: structured light, time-of-flight, stereo vision, and laser triangulation. These methods use different tools and set-ups to gather information for a 3D model. 3D machine vision allows automation on a new level compared to 2D vision. Whereas previously robots were limited to repetitive tasks, now they can perform complex jobs in varying environments.
3D vision systems are used in factories to limit human involvement, increase efficiency and productivity, and ensure operator safety. They perform precise measurements, shape analysis, robot guidance, pick-and-place operations, bin-picking, and assembly verification.
Differences Between 2D and 3D Vision Systems
The technology of machine vision is seeing rapid growth and innovation each year. Although it may seem that 3D vision will replace 2D vision, it is not the case. By comparing these attributes, we will get a better understanding of what this means,
| 2D Vision System | 3D Vision System | |
| Measurement capabilities | It can measure the length and width of an object. It can also perform area analysis. Measurement is dependent on observing contrast and surface deviations. Measurement can be affected by a lack of lighting or uneven surfaces. | It can measure length, width, and depth. It is capable of performing volumetric analysis. The simulation tool creates a point cloud representation of the object. Software and AI tools take measurements from this representation. It is not affected by environmental inconsistencies. |
| Accuracy and precision | It provides good accuracy and precision in controlled environments. Performance may be affected by lighting conditions. If the object is shiny and lacks contrast, 2D vision systems may have difficulty recognizing them. | They are exceptionally accurate and precise. 3D vision systems are capable of modeling an object’s dimensions. They are able to perform well in low-light and low-contrast situations. |
| Inspection speed | They have a faster inspection speed. They are suitable for analyzing objects on assembly lines and in rapid production environments. | 3D inspection is a time-consuming process. Mapping and creating a 3D model is computationally expensive. |
| Data output and analysis | 2D vision machines generate a plan-view of the object on the x and y plane. Comparing the contrast in different sections of the image, we define contours. Measurements are performed on a 2D plane. | 3D vision machines produce a point cloud representation of the object that maps it to a coordinate system. Each point is represented on the three-dimensional coordinate system. Measurement is done on the x, y, and z axes. |
| Cost considerations | 2D vision is inexpensive and easy to install. It uses simple hardware and software equipment. | 3D vision is expensive and complex to set up. Sophisticated hardware and software simulation tools increase the price of 3D vision systems. |
| Ease of use and training requirements | 2D vision is relatively easy to use. Training time for operators is short. The equipment is straightforward and simple to use. | 3D vision systems are complex and require comprehensive operator training. Equipment can be diverse and difficult to use. |
FAQs about 2D and 3D Vision Systems
What are the advantages of 2D and 3D vision systems?
The adoption of 2D and 3D vision systems has revolutionized the manufacturing industry. 2D vision systems allow certain repetitive tasks like quality control, defect detection, and bar-code reading to be performed by machines. 3D vision systems enable robots to make autonomous decisions and perform high-complexity tasks like pick-and-drop, 3D inspection, and volumetric measurement. Overall, 2D and 3D vision systems have improved factory efficiency and productivity while reducing labor costs and waste.
2D vision system or 3D vision system, which one should I choose?
While it may seem that 3D vision systems may take over the market, this is not true. Both 2D and 3D vision systems excel in different areas and will remain relevant to manufacturers. Some things to keep in mind while purchasing a vision system are:
- 2D vision systems excel in low-complexity and high-speed tasks. They are highly suitable for barcode reading, label checking, quality inspection, and conveyor belt monitoring.
- 3D vision systems are highly accurate and precise. They excel at providing a higher level of automation in applications like 3D printing, robotic guidance, bin picking, and volumetric measurement.
- In low-light and dynamic environments, 2D vision systems do not perform well.
- Environmental factors do not affect the performance of 3D vision systems.
- 2D vision systems are cheaper to purchase. They are easier to install and upgrade since they are so widely used in factories.
- 3D vision systems are much more expensive to purchase. They are also challenging to install and maintain.
What industries commonly use vision measuring systems?
Vision systems are utilized by several industries, as can be seen from the market share of top machine vision companies. Despite this, it remains a highly competitive and fragmented market with many key players. These are the primary industries where you may see vision systems:
- Manufacturing: Machine vision automates factory and warehouse tasks such as quality control, pick-and-drop, label verification, barcode reading, etc.
- Healthcare: The medical industry has seen great implementation of machine vision. High-precision 3D vision systems are employed in surgical machines, scanning devices, testing stations, etc.
- Retail: The retail industry has adopted both 2D and 3D vision systems. 2D vision has enabled quick checkouts and order collection at shops. 3D vision has enabled virtual mirroring and advanced customer analysis.
- Transportation and Logistics: 2D and 3D vision systems enable efficient and consistent supply chain monitoring.
What are the advantages of machine vision over traditional measurement methods?
There are several benefits that machine vision offers over conventional measurement methods, such as:
- Contact-free measuring: Machine vision can effectively analyze deformable or delicate objects since it does not rely on physical probes.
- Diverse scanning: 2D and 3D vision systems can analyze various of objects, including flat, curved, spherical, uneven, or deformable surfaces.
- Recognition of defects: Sometimes, miniscule defects may arise out of manufacturing. Picking these out by eye is tough. Machine vision can detect even the smallest errors using simulation software.
- Robotic control: One of the best things about machine vision is that it interfaces perfectly with robotics. This enables automation and machine control in a variety of tasks.
- More productivity, less waste: Robotics enables manufacturers to attain a high level of precision and accuracy. 2D and 3D vision help increase factory output while decreasing operational costs and waste.
Conclusion
Thanks to the advent of 2D and 3D vision systems, humanity has taken one step closer to the era of automation and robotics.
At first glance, it may seem that 3D vision systems will take over 2D technology. However, this is not true. Both vision technologies have their own set of strengths and weaknesses.
If you require easy integration, rapid inspection, and ease of operation, go for a 2D vision system. If you require three-dimensional analysis, complex automation, or volumetric analysis, go for a 3D vision system.
Considering the key concepts behind these technologies will enable you to make the best decision for your business.