Grape control accelerated by vision, AI and SMS

Karsten Europe handles the distribution of grapes from Africa and has recently started checking the quality of this fragile product fully automatically via a vision/AI system from Gearbox. Besides advanced hardware and software, at the heart of this machine is Festo's Simplified Motion Series with which products that do not meet the set quality standards are pushed to a parallel lane in a controlled manner. Gearbox deliberately chose the simple electric automation solution because it does not require compressed air and because electric drive is simply more accurate and reliable.

The Westland is a municipality in the Randstad conurbation where innovative companies are developing smart solutions to support AGF companies worldwide in growing and processing their products efficiently. Gearbox is a great example of a relatively young company from Maasdijk that is developing solutions centered around Vision, artificial intelligence (AI) and robotics.

Until recently, these solutions were developed completely customer-specific, but the company has now embarked on the road to standardization and increasingly uses standard modules that can be used in various solutions - with minimal modifications. Product owner Roy van Meel: "It is an advantage that we have all the necessary disciplines in-house. Knowledge about mechanical constructions, mechatronics, vision, robotics, AI and of course the knowledge to make various techniques work together. We have now defined five standard product groups: quality inspection systems GearVision, smart workstations GearStation, smart robot stations GearPerformer, harvest assistants GearRover and crop advisor GearSense."

Karsten Europe

One of its customers is Karsten Europe, which distributes fresh fruit for the European market, among others. Based in Hoek van Holland, it provides, among other things, forwarding and clearance services, cold storage and (re)packaging and distribution services. Among other things, it processes grapes from Africa which, after a three-week journey by ship, are delivered mainly to the Port of Rotterdam. An important step in this processing process is assessing the quality of the grapes packed in plastic punnets. After all, three weeks in a ship can affect quality.

To achieve "zero tolerance" grapes for the end customer, until recently a number of employees stood at an assembly line to visually check the grapes in the punnets for various aspects. A labor-intensive process requiring a strong arc of concentration because a good number of punnets per minute continuously pass by. An almost impossible task.

That can be smarter

Gearbox was approached to ask if quality control could not be smarter. After a development process, a compact machine was delivered and integrated into the existing line. The inspection process starts with punnets of grapes passing under the camera via a conveyor belt in the machine. The photos are reviewed by the AI and given a grading grade. Depending on the requirements of the product at that time, the decision then follows as to whether a punnet may proceed to retail or must disappear from the line. Roy van Meel: "Whether a punnet is found to be in order depends on several factors. The season, for example, the desired quality class or something else. You can incorporate these requirements into a so-called recipe that you can easily read in and that converts the AI's assessment grade into approve or reject. When a punnet is rejected, it is automatically removed from the line."

To keep the speed of the line up, the time span between assessment by the AI and the decision to approve or reject is only 0.3 seconds. Ultimately, this makes it possible to check up to ninety punnets per minute for, among other things, mold, cracks (leaks), color, moisture and deformed fruit. Roy van Meel: "Of course, even a vision solution is no 100% guarantee of grape quality assurance; like humans, this approach does not have a view of the grapes at the center of the punnet. On the other hand, that is also not where damage occurs or where mold forms first. That is mainly on the outside where the grapes are sitting against the walls and those you can see and judge very well. The quality and thus greater value of the end product is also the most important advantage for Karsten Europe in that respect."

Gently eject

To remove rejected product from the line, Gearbox opts for a "soft" solution. Roy van Meel: "Of course it is possible to 'shoot' these punnets out of the line with brute force - for example, a punch or a hard air pulse. Effective but also disrespectful towards a product in which the grower has put so much attention and love. When the conclusion 'reject' follows, an arm turns several degrees to the side and pushes the punnet onto a parallel conveyor belt. There the arm remains until it is clear how the next punnet will be judged. If this is also a reject, it remains in this position. If this punnet is judged OK, the arm is actively returned to the starting position to allow the punnet into the regular line. The rejected grapes can then be repacked where the bad grapes are removed and a new, high-quality punnet is created.

Simplified Motion Series

For the scissor movement of the arm, Gearbox chose Festo's Simplified Motion Series. What characterizes this simple automation solution is the fact that it is a complete drive and control solution. In this case, it is an all-electric drive unit that creates a linear motion and uses it to rotate two axes to swing the arm.

Roy van Meel: "We deliberately chose to perform this electrically and not pneumatically. After all, generating compressed air remains a relatively expensive business. Also, the compressed air must be of high quality to perform the movement reliably and accurately in all cases. After all, if this does not happen, the whole solution makes no sense. No matter how clever your vision system is. In the Netherlands, this quality of compressed air can often be achieved, but not everywhere in the world the necessary attention is paid to it, making compressed air a simple risk to the reliability of your complete solution.

Another advantage Roy sees in the additional possibilities offered by electric drive. Settings can be made easily and very accurately via a display, smartphone or tablet. In addition, it is possible to put the machine in 'failure' mode when the SMS - for whatever reason - is technically unable to perform the sorting. Roy van Meel: "Finally, the SMS communicates via IO-Link, allowing us to easily integrate our solution into the ecosystem of our machines but also to further develop it by adding functionalities. At Karsten Europe, for example, an additional setting to handle punnets of different widths."

Collaboration with Festo

The reason for finally choosing Simplified Motion Series was a logical one. Gearbox was already aware of this simple but complete drive solution and quickly made the decision when Festo was able to provide an SMS element - in this case an ELGS-BS-60 - for testing within one day. The testing phase was extensive and important to determine, among other things, whether the SMS was capable of pushing the punnets out of line at these speeds. Roy van Meel: "So it was an important advantage that Festo could respond at this short notice with an 'off the shelf' product. In addition, we work very pleasantly with Festo where specific knowledge and products are available that we can put to good use. In this way we have developed a solid basis for a machine that we can further develop for application worldwide.

For more information on Festo products and services, visit: www.festo.com