You must have heard of the concept of machine vision, which refers to the technology and methods used to provide automatic image inspection and analysis for a wide array of industrial applications like inspection, process control, and robotic navigation. But often the images captured and processed by the camera are two-dimensional, lacking the third-dimension information such as the thickness, height or surface smoothness of an object. Therefore, there is a great constraint on its applications in this era of automation.
With the advancement of technology, 3D machine vision is rising to be an unstoppable trend, especially in industrial inspection. It is commonly acknowledged that the transition from 2D to 3D vison would become the fourth vision revolution following black-and-white image to color image, low resolution to high resolution, and static image to dynamic image. Compared with 2D techniques, 3D techniques can capture shapes faster and is better at capturing moving objects. When inpecting objects with low contrast, 3D techniques also have better performance. What’s more, 2D inspection is based on the grayscale value, so it is highly dependent on light and color conditions, while 3D inspection is interfered less by the lighting condition.
All the 3D machine vision techniques on the market are generally categorized into contact and non-contact type. The contact 3D inspection requires contact with the measured object. Contact 3D machine vision devices are often large and works slow, and may cause modification or damage to the measured objects, especially artifacts, treasures and small workpiece. In this case, non-contact 3D methods like binocular vision, ToF, structured light and laser triangulation are more popular. Each method has its pros and cons. In the case of industrial applications requiring higher accuracy and stability, structured light and laser triangulation are more common. Structured light technique boasts high accuracy, fast speed and low cost, while the limits include indoor use restriction and strict calibration requirement. Laser triangulation has advantages of high accuracy and low cost, but it retains high accuracy only in short range. Revopoint recently launched its industrial-grade 3D cameras Areascan and Rayscan. Areascan is a structured light 3D camera offering 4 scan range and an accuracy up to 0.1mm. The dust and water-resistant design and the Ethernet interface allow its use in various applications like palletizing, sorting and path tracking. The 3D laser camera Rayscan is able to automatically inspect an area within 1-10 seconds without any mechanical movement. It offers repeatability up to 5μm. Thanks to the embedded proprietary AI chip, the 3D cameras can directly output depth map. In the era of 3D machine vision, high accuracy, cost effectiveness and stability of 3D cameras will be deemed more and more important in the market.
