Sorting net product with Downs CropVision
The Downs CropVision is an optical sorting machine for potatoes and, more recently, for onions. This means that camera technology examines and evaluates each onion or potato—or more accurately, each object, as stones and clumps are also detected and separated.
The editorial team of Dutch agricultural magazine Boerderij observed the Downs CropVision in action at V.O.F. Van Bergeijk in the Dutch town of Lelystad, where the machine has been in use for 2 years. Optical sorting machines are on the rise, with multiple manufacturers now offering them, but what makes the Downs CropVision unique is its ability to process field-harvested crops. Moreover, it operates at a capacity that can generally keep up with a harvester.
Electronic detection and removal of stones and clumps have been around for some time, but Downs has added a third function: the CropVision can separate a batch into 3 categories:
For clarity: CropVision sorts objects based on appearance, not weight or size.
Sorting crops with CropVision
Sorting crops is the core function of the system. Cameras capture images of the product, and intelligent software, linked to an ultra-fast computer, analyses each image to determine whether it is net product, tare, or defective. Each object is photographed from all angles. This is achieved by guiding the product flow over a roller bed, causing bulbs or tubers to rotate under the camera for a full 360-degree capture.
A challenge with field crops is that soil can adhere to them, but the CropVision can handle this. Downs utilises a polyurethane spiral roller bed, similar to the cleaning rollers found in intake lines. If the rollers become dirty, they self-clean by temporarily stopping the intake, closing a protective flap over the cameras, and spinning at high speed to remove debris.
Rapid learning
The CropVision effectively differentiates clumps, stones, rotten, and cut potatoes and sorts them at high capacity. Downs is currently focused on enhancing its algorithms. This involves training the system using artificial intelligence (AI), feeding it images of potatoes and onions to improve recognition and classification. Over time, CropVision becomes increasingly adept at identifying and sorting products. It works well for coarse pre-sorting during intake and can also be used in final sorting to replace manual inspection in grading rooms.
Significant progress is being made in sorting potatoes and onions based on various external characteristics. Additionally, the user has a significant influence on the outcome, as they can define the quality parameters and adjust sorting sensitivity. For example, when sorting onions for skin blemishes, the user can set the acceptable threshold for discoloration size.
New interface
Downs recently introduced a new interface for the CropVision at Interpom. More important than the larger screen is the fact that Downs has now taken full control of its software development. Previously, it relied on software from Bilberry, which became part of Trimble, which was subsequently acquired by Agco. Downs opted for independence from these entities.
Capacity from width
The machine’s capacity is determined by its working width. Downs currently offers the CropVision in widths of 1.10, 2.40, and 2.80 meters. While we typically express machine capacity in tonnes per hour, for an optical sorter, it is the number of objects processed per hour that matters. The 2.40-meter model theoretically handles up to 12,000 objects per minute—assuming an optimal distribution of product across the rollers.
For seed potatoes in the 45-55mm size range, an individual tuber weighs approximately 100 grams. In a batch of clean product, this translates to 72 tons per hour. If 30% of the objects are clumps, the output drops to 50.4 tons of potatoes per hour. With larger product, this could be as much as 100 tons per hour. These are theoretical maximums. In practice, the CropVision has proven capable of keeping pace with a harvester without significantly limiting intake capacity. The true capacity limit is not the cameras or computer but rather the speed at which the system’s pneumatic finger rail can eject objects from the product stream.
Various configurations
While the CropVision has only been operating in the Netherlands for 2 seasons, Downs has been supplying the system for several years. Initially, it was only available as an integrated unit within a receiving hopper. Later, a standalone module was introduced for greater flexibility in sorting lines. Now, it is also available on a wheeled chassis for easier transport.
As for pricing, a standalone 2.40-meter-wide module, including a feed conveyor to the roller set, starts at approximately €240,000.
