The Dutch company OptiServe maintains, manufactures and designs optical sorting machines. These sorting machines are used for sorting cut products in food and non-food processes. For OptiServe's new belt sorting machines, Xcalibur, NI (National Instruments) Integration partner VI Technologies developed the machine control, data acquisition, vision algorithms and valve control. NI distribution partner CN Rood spoke with Antoine van Kasteren (CEO of Optiserve) about this project and the collaboration with VI Technologies and CN Rood.
Development of an own optical belt sorter
Antoine van Kasteren: "After 15 years of maintenance and refurbishment, it was time to develop our own belt sorter: the Xcalibur. We wanted to develop a machine that can sort better than the current machines on the market, has a longer up-time, uses less energy/air and is easy to clean. We succeeded! The Xcalibur is a belt sorter for cut products. Some examples are fries, diced apples and snack carrots. The Xcalibur sorts these products by length and discolouration by using 4 cameras above the belt. These cameras take continuous photos of the products to be sorted at different angles. As a result, all sides except the underside are photographed and most defects can be detected. After taking the photos, they are analysed and processed at lightning speed. If it is determined that a product is not the right quality, it is ejected via a fast switching air valve."
Intelligence in Xcalibur
In the past, a product's defect was determined purely on colour intensity. If there was a dark stain on a product it would be detected and the appropriate air valve(s) would be controlled to blow out the product. Because there is no intelligence in this, that blowout cloud is always too big, blowing out not only faulty but sometimes also surrounding good products.
Antoine van Kasteren: "With the Xcalibur, we do this in a different way. With the Xcalibur, the product is first recognised as an object and distinguished from the background. Then it looks at where the defect (discolouration, length or shape) is. This allows it to create a blow cloud that has exactly the shape of the product. As a result, you have less chance of accidentally blowing out another (good) product. This results in lower air consumption and less waste. This principle has therefore been patented."
VI Technologies for reliable technology
Making the Xcalibur work so intelligently requires smart and very fast software.
Antoine van Kasteren: "In cooperation with Wageningen University (WUR), we made a proof of concept. However, this was not sufficiently reliable and user-friendly for practical application. To industrialise the technology, we contacted VI Technologies. They redesigned the software and system set-up so that it is stable and reliable in a production environment, and in addition improved a lot upon the vision recognition algorithms.
Used NI Products
In machine control, HMI, vision and data acquisition and vision algorithms and valve control, NI's hardware and software solutions play an important role. The MXI-Express RIO-High-Performance Expansion chassis with its I/O modules provide a robust and a modular system. For valve control, the FPGA in the RIO backplane is used. The FPGA is programmed with LabVIEW.
Future developments
The first system was aimed at fries. To make the system suitable for other products, algorithms were later added. A double discharge line also provides an extra sorting option. Antoine: "We are currently working on two parts to improve the vision system. First, we want to broaden the spectrum to be analyzed by using infrared (IR) cameras. This will allow us to better sort for foreign objects and structures. With this, we want to measure the starch content in potato products. We are also working on various illumination techniques that will allow us to reduce shadows and thus detect even smaller colour differences."
Cooperation with CN Rood and VI Technologies
Antoine is very pleased with the cooperation with VI Technologies: "We like the cooperation with VI Technologies. We worked intensively together to meet all our and our customers' requirements. Now the technology is stable and reliable and we only have contact when we want to add new features to the platform. We now order the NI products we need when building the machines directly through CN Rood. CN Rood thinks well with us, especially in the period of component scarcity, that was very valuable."
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