Method for sorting out foreign bodies from a mass flow of sugar beets, and a device for sorting out foreign bodies from a mass flow of sugar beets

Abstract

The present invention relates to a method for sorting out foreign bodies from a mass flow of sugar beets, the mass flow being transported through a detection unit by means of a conveying unit having at least one conveyor belt, a sorting unit being arranged downstream of the conveying unit, and the sorting unit being controlled by means of the detection unit and being configured such that foreign bodies are diverted out of an ordinary trajectory of the mass flow, wherein the detection unit carries out at least the following steps: I. in a first method step, objects in the mass flow arranged on the conveying unit are detected by means of laser distance measurement, in particular laser triangulation; II. in a second method step following the first method step, the detected objects are optically captured at least in part by means of hyperspectral or multispectral imaging, with first pixels being generated; III. in a third method step following the second method step, the generated first pixels are evaluated in order to detect foreign bodies in the mass flow; and in a fourth method step following the third method step, the sorting unit is controlled by the detection unit such that detected foreign bodies are diverted out of the ordinary trajectory of the mass flow.

Description

[0001] 1 Our reference: PFL0042-WO

[0002] DESCRIPTION

[0003] title

[0004] Method for sorting out foreign bodies from a mass stream of sugar beets and a device for sorting out foreign bodies from a mass stream of sugar beets

[0005] State of the art

[0006] The present invention relates to a method for sorting out foreign bodies from a mass stream of sugar beets. A further aspect of the invention is a device for sorting out foreign bodies from a mass stream of sugar beets.

[0007] Sugar beets are typically harvested mechanically from the field and temporarily stored in beet storage areas or bunkers before further processing. During the harvesting process, the sugar beets are mechanically lifted from the ground, often resulting in the collection of unwanted foreign objects. These can include stones, soil, bottles (glass, plastic, and others), metals, plastics, wood, weeds, leaves, etc. Foreign objects also include poor-quality, undersized, or unripe sugar beets, as well as fragments of sugar beets. These are particularly undesirable during the subsequent processing of the sugar beets. To provide processable sugar beets, these foreign objects must be sorted out, and the usable sugar beets must be cleaned. Only then can the sugar beet be processed and the sugar extracted.

[0008] In industrial sugar production, the first step is typically beet processing, during which the aforementioned foreign matter is removed. According to current technology, the sugar beets are transported as a mass flow in water, for example, in flushing channels, during processing. The removal of foreign matter is achieved through physical separation processes such as stone catchers (e.g., belt and drum stone catchers) and washing drums, which require significant space and maintenance. While transporting the mass flow of sugar beets with water offers the advantage of cleaning them during the removal of foreign matter, this method also results in high water and energy consumption.Furthermore, sugar beets release a certain percentage of the sugar they contain into the water during contact with water (Our reference: PFL0042-WO). Therefore, wastewater treatment is often necessary to reduce its sugar content.

[0009] From EP 2 893 329 A1, a method for handling harvested root vegetables, particularly potatoes, is known, in which the root vegetables are optically detected in free fall. Using a hyperspectral or multispectral imaging system, image data consisting of image pixels is generated, each of which exhibits a spectral profile based on the reflectance intensity of the detected material. The image pixels are analyzed to identify individual objects. The categorization of the detected objects is achieved by generating a statistical profile associated with the object, based on the spectral profile of the image pixels grouped within the object. To separate acceptable root vegetables from unacceptable ones, image acquisition and subsequent evaluation must be completed within a very short time.Furthermore, particularly with larger mass flows, the problem of objects overlapping in flight and the simultaneous evaluation of image pixels for many identified objects arises. This impairs the accuracy of detection and sorting.

[0010] Disclosure of the invention

[0011] Against this background, the object of the present invention is to enable robust detection and sorting of foreign bodies while requiring little space.

[0012] The problem is solved by a method for sorting out foreign bodies from a mass stream of sugar beets, wherein the mass stream is transported by means of a conveying unit with at least one conveyor belt through a detection unit, wherein a sorting unit is arranged downstream of the conveying unit, wherein the sorting unit is controlled via the detection unit and is configured such that foreign bodies are deflected from an ordinary trajectory of the mass stream, wherein the detection unit performs at least the following steps:

[0013] I. In a first process step, objects arranged on the conveying unit are detected in the mass flow by means of laser distance measurement, in particular laser triangulation;

[0014] II. In a second process step following the first process step, the detected objects are at least partially optically recorded using hyperspectral or multispectral imaging, whereby initial image points are generated; 3 Our reference: PFL0042-WO

[0015] III. In a third process step following the second process step, the generated first pixels are evaluated to detect foreign bodies in the mass flow; and

[0016] IV. In a fourth process step following the third process step, the sorting unit is controlled by the recognition unit in such a way that detected foreign bodies are deflected from the ordinary trajectory of the mass flow.

[0017] According to the invention, during beet processing, foreign objects in the mass flow are detected by the detection unit and then sorted out of this mass flow by the sorting unit. In this way, the usable portion of sugar beets can be separated from the foreign objects without resorting to physical separation methods such as belt or drum stone catchers and haulm catchers. This reduces the space requirements and mechanical maintenance effort for beet processing. Furthermore, the use of the detection and sorting units eliminates the need for water transport, allowing the mass flow, including both sugar beets and foreign objects, to be transported dry. This drastically reduces water consumption during beet processing.

[0018] According to the invention, objects in the mass flow are detected by means of laser distance measurement while they are arranged on the conveying unit. The conveying unit can, in particular, serve as a reference or zero plane for the laser distance measurement, so that an object lying on the conveying unit is detected if it is raised above this reference or zero plane. Once an object has been detected, it is subsequently at least partially optically recorded using hyperspectral or multispectral imaging. The first pixels generated during this recording are then evaluated to detect foreign bodies in the mass flow. If a foreign body is detected, the detection unit controls the sorting unit in such a way that the detected foreign bodies are deflected from the normal trajectory of the mass flow.An advantage of the method according to the invention is that the detection and classification of objects in the mass flow are carried out based on two separate measurements – laser distance measurement and optical imaging. Therefore, equipment specialized for each measurement can be used, thereby increasing the accuracy of the detection and sorting results. A further advantage of the method according to the invention is that only the foreign bodies are deflected from the trajectory. The sugar beets are preferably guided along a trajectory that reduces or avoids any damage to the sugar beets. 4 Our reference: PFL0042-WO.

[0019] According to the invention, foreign bodies such as stones, soil, bottles (glass, plastic and others), metals, plastics, wood, weeds, leaves, etc., are separated from the usable portion of sugar beets. Furthermore, undersized, spoiled, or rotten sugar beets are also separated from the usable portion.

[0020] In a further advantageous embodiment of the invention, the second process step is only carried out if a detected object in the first process step exceeds a quantitative threshold, in particular a predefined height, preferably the minimum height of an average sugar beet. It is conceivable that all detected parts below this threshold are considered foreign bodies and can therefore be sorted out directly by the sorting unit. This can save, in particular, energy and computing power for evaluation.

[0021] According to an advantageous embodiment of the invention, the optical acquisition of the detected objects is carried out using hyperspectral or multispectral imaging with a line scan camera configured for hyperspectral or multispectral imaging. The line scan camera can be part of the detection unit and, in particular, can be arranged essentially vertically above the conveyor unit. Firstly, a line scan camera requires minimal hardware, and secondly, it only provides a single scan line. A line scan camera can have the same number of pixels or more pixels than a conventional area sensor, distributing these pixels across a single image line, thus enabling better spatial resolution for a given object field.The detected object can thus be at least partially captured optically using hyperspectral or multispectral imaging, which can provide better spatial resolution. To determine the detected objects as precisely as possible, the scan line is arranged perpendicular to the direction of the mass flow; preferably, the conveyor belt surface serves as the reference plane. This allows the entire width of the conveying unit and / or the conveyor belt to be optically captured.

[0022] According to an advantageous embodiment of the invention, in the second process step, the detected objects are additionally at least partially optically recorded using an RGB camera, generating second image points. In the third process step, these second image points are further evaluated to detect foreign bodies in the mass flow. The RGB camera can provide second image points, which, during evaluation in the third process step, enhance the detection performance of the detection unit with regard to the foreign bodies in the mass flow. The term RGB refers to the color model used by the camera. This color model adds the red, green, and blue primary colors of light to produce various colors. The RGB camera preferably records light with a wavelength of 400 to 700 nm.Alternatively, an RGB-IR camera can be used, which additionally records an infrared component. This camera can be particularly advantageous when used in environments with changing day and night conditions. Furthermore, the quality of the RGB output or the second pixels can be improved, as the proportion of IR light in the RGB component of the second pixels can be measured and a corresponding color correction can be applied.

[0023] According to an advantageous embodiment of the invention, the detection unit comprises at least one laser sensor, a camera for hyperspectral or multispectral imaging, and an RGB camera, wherein the detection unit is configured to monitor only one conveyor belt or several conveyor belts simultaneously. If the conveyor unit comprises several conveyor belts, each conveyor belt can be assigned to a detection unit, with each conveyor belt transporting the respective mass flow through the respective detection unit. Alternatively, the multiple conveyor belts are transported through a single detection unit, which controls the sorting unit in such a way that the detected foreign object on a conveyor belt is deflected from the normal trajectory of the mass flow.

[0024] According to an advantageous embodiment of the invention, the RGB camera is a line scan camera. The RGB camera is preferably arranged such that the scan line generated by the RGB camera is essentially parallel to the scan line of the line scan camera, which is configured to acquire the detected objects using hyperspectral or multispectral imaging. The RGB camera can be arranged either upstream or downstream of the line scan camera, which is configured to acquire the detected objects using hyperspectral or multispectral imaging. The same advantages described above for the use of the line scan camera apply here to the use of a line scan camera as an RGB camera.

[0025] According to an advantageous embodiment of the invention, a computing unit, which is in particular comprised of the recognition unit, determines one or more statistical parameters based on the first and, if applicable, second pixels, wherein the statistical parameters are in particular a percentage conveyor belt occupancy, a quantity of the mass- 6 Our reference: PFL0042-WO

[0026] The data collected includes the flow rate, the weight of a usable portion of the mass flow, an average weight, or a number of usable sugar beets within the mass flow, and / or the proportion of foreign matter in the mass flow. The processing unit can either be part of the recognition unit or positioned externally, maintaining only a data connection to the recognition unit. External positioning of the processing unit allows for a more compact design of the recognition unit and provides more installation space for the processing unit to handle computationally intensive tasks in a shorter time. Based on the available first and / or second pixels, the processing unit can determine several statistical parameters relevant to the user. For example, the utilization of the conveying unit and the transported weight can be used to assess the service status of the device.A heavily used machine, primarily loaded with heavy objects, requires more maintenance than one that is significantly less stressed. Advantageously, the statistical parameters also allow for an assessment of production efficiency. Furthermore, by determining the quantity of sugar beets or foreign objects, an automated processing or collection process can be initiated. It is conceivable that the user would not need to initiate a further process step; instead, the machine or the processing unit could recognize when there are enough or too many sugar beets or foreign objects stored. For this to work, the processing unit would only need to know the size of the storage area for foreign objects or sugar beets. Consequently, the processing unit could issue a notification that, for example, the foreign object storage area needs to be emptied or initiate the direct collection of the objects.

[0027] According to an advantageous embodiment of the invention, the conveying unit conveys the mass flow of sugar beets and foreign matter at a velocity in the range of 3 m / s to 4 m / s, preferably in the range of 3.5 m / s to 4 m / s. The velocity of the mass flow advantageously allows the sugar beets to trajectory downstream of the conveying unit. This trajectory can, in particular, describe the usual trajectory of the mass flow. The seemingly high velocity of the mass flow initially enables a substantially horizontal trajectory before the acceleration due to gravity primarily generates a trajectory that is essentially vertical downwards.The mass flow of sugar beets can be collected downstream of the conveying unit by a collection chute, this collection chute preferably being arranged substantially horizontally along the trajectory of the mass flow, so that the impact of the sugar beets on the collection chute results in no or only minor damage to the sugar beet. In particular, the distance between the collection chute and the conveying unit is preferably designed such that the 7 Our reference: PFL0042-WO.

[0028] The detection unit can control the sorting unit, and foreign objects can be deflected from their usual trajectory. Furthermore, the high velocity of the mass flow enables a more economical process.

[0029] According to a further embodiment of the invention, a feed chute is arranged upstream of the conveying unit, being positioned at an angle to the conveying unit such that the mass flow through the feed chute is accelerated to approximately the speed of the conveying unit. Advantageously, due to the angled arrangement, no additional energy input is required to accelerate the mass flow.

[0030] According to an advantageous embodiment of the invention, the conveying unit comprises several conveyor belts, in particular those arranged essentially in parallel. The advantage of multiple conveyor belts lies primarily in the increased mass flow that can be conveyed simultaneously. The arrangement of the conveyor belts relative to one another allows for a compact design, and the small distances between them, due to their parallel arrangement, enable foreign objects in the mass flows on each conveyor belt to be detected by a single detection unit. Alternatively, a separate detection unit can be assigned to each conveyor belt. This increases the cost but can improve detection accuracy.

[0031] In a further advantageous embodiment of the invention, the conveyor belts are separated by partitions and / or have carriers configured such that the movement of the conveyor belt is transferred to the objects in the mass flow. The carriers are preferably designed as cleats with a blunt tip. Preferably, the carriers are arranged at a predefined distance from one another. An advantage of the partitions is that the mass flow remains on the respective conveyor belt and thus preferably ends up in a predetermined detection area of ​​the detection unit.

[0032] According to an advantageous embodiment of the invention, the sorting unit has at least one deflection unit per conveyor belt, wherein the deflection unit is controlled such that the foreign objects are deflected from the trajectory of the mass flow, in particular upwards. According to the invention, the deflection unit is controlled by the detection unit, so that the detected foreign objects are deflected from the ordinary trajectory of the mass flow. If the conveyor unit has several conveyor belts, a deflection unit can be assigned to each conveyor belt. The respective deflection units can preferably be controlled separately by the detection unit and thus allow for better and faster sorting of foreign objects from the mass flow.The deflection unit is preferably arranged below the trajectory of the mass flow, wherein the deflection unit then deflects a detected foreign body from the trajectory, particularly upwards.

[0033] According to an advantageous embodiment of the invention, the at least one deflection unit comprises at least one pivotable deflection flap. The deflection unit can be designed as a pivotable deflection flap, preferably actuated by a pneumatic cylinder or an electric cylinder. Actuation can be initiated by controlling the detection unit.

[0034] In a further embodiment of the invention, the deflection unit can extend across the entire width of the conveying unit and be arranged essentially perpendicular to the conveying direction of the mass flow. The deflection unit is divided into several sections, each of which is designed as a deflection flap and is actuated by a pneumatic cylinder. Thus, there is no direct dependency on the respective conveyor belts; instead, the detection unit can actuate one or more sections or deflection flaps based on the position of the detected foreign object on any conveyor belt. For example, in the case of a stone or a larger detected foreign object, two or more deflection flaps can be actuated to deflect the foreign object in a controlled manner from its trajectory, particularly upwards.

[0035] According to an advantageous embodiment of the invention, the at least one deflection unit has at least one selectively activatable nozzle for expelling air. The activatable nozzle can deflect, in particular, smaller or lighter foreign objects, such as soil, small stones, or weeds. The nozzle can be controlled by the detection unit to deflect the detected foreign object from the usual trajectory of the mass flow. The activatable nozzle can be configured as a nozzle array consisting of several openings for delivering air.

[0036] In a further advantageous embodiment of the invention, the activatable nozzle is designed as a nozzle array and extends over the entire width of the conveying unit and is arranged essentially perpendicular to the conveying direction of the mass flow. Preferably, the nozzle array or the nozzles can be permanently activated, whereby the detection unit advantageously does not need to detect foreign objects below a certain size. These smaller or lighter parts can be deflected by the permanently activated nozzles, at least during operation, so that no activatable nozzles or deflection flaps need to be activated.

[0037] According to an advantageous embodiment of the invention, the at least one activatable nozzle is arranged downstream of the pivotable deflector flap. The deflection unit can thus comprise at least one nozzle and one deflector flap. Preferably, the nozzle is arranged downstream of the deflector flap. The advantage of this arrangement is that light and / or small foreign particles are not sufficiently deflected by the deflector flap, whereas the downstream nozzle deflects these foreign particles again, preventing them from re-entering the normal trajectory of the mass flow. Additionally or alternatively, a nozzle can be arranged upstream of the pivotable deflector flap, preferably being permanently activated during operation. This prevents small particles from jamming the pivotable deflector flaps. Consequently, the small particles can be deflected upwards before reaching the deflector flap.

[0038] According to an advantageous embodiment of the invention, an alignment unit is arranged upstream of the conveying unit, wherein the alignment unit has one opening for each conveyor belt, and this opening is adjustable in height and / or width so that the mass flow is aligned onto the conveyor belts. If the conveying unit has a feed chute upstream of the conveyor belts, the alignment unit is arranged upstream of the feed chute or at least partially on the feed chute. The alignment unit enables targeted alignment and distribution of the mass flow onto one or more conveyor belts. Based on experience, the one or more openings can be adjusted to a maximum sugar beet size, including a safety buffer, by adjusting the height and width.Objects larger than this opening are not guided onto the conveyor unit, presumably because their weight is too high for the device. This can damage either the conveyor unit or the deflection unit. Preferably, the height of the alignment unit can be adjusted so that the detection unit remains functional and is not damaged.

[0039] According to an advantageous embodiment of the invention, the detection unit comprises a radiation source, in particular an infrared radiation source, wherein the radiation source is configured such that the mass flow is at least partially illuminated in a measuring area for the detection unit. The detection unit can have a 10 Our reference: PFL0042-WO

[0040] The measurement area is defined as follows: the optical imaging according to the invention, using hyperspectral or multispectral imaging and / or the RGB camera, is directed towards this area. This area is to be illuminated by the radiation source in such a way that the generated first and / or second pixels can be used to detect foreign bodies in the mass flow.

[0041] In a further advantageous embodiment of the invention, each detection unit can have a radiation source, wherein the respective radiation sources are specifically aligned with the respective measuring areas of the detection units. This allows the accuracy of the detection to be further increased, since the relevant areas for the detection units are illuminated appropriately for the respective detection unit.

[0042] A further object of the invention is a device for sorting out foreign bodies from a mass stream of sugar beets, comprising a detection unit and a conveying unit with at least one conveyor belt for transporting the mass stream through the detection unit, as well as a sorting unit arranged downstream of the conveying unit, which can be controlled by the detection unit and is configured such that foreign bodies are deflected from an ordinary trajectory of the mass stream, wherein the detection unit comprises:

[0043] I. an object recognition device for recognizing objects arranged on the conveying unit in the mass flow by means of laser distance measurement, in particular laser triangulation;

[0044] II. an imaging device for at least partially optically recording the detected objects by means of hyperspectral or multispectral imaging with the generation of first image points;

[0045] III. a processing unit for evaluating the generated first pixels in order to detect foreign bodies in the mass flow; and

[0046] IV. a control device for controlling the sorting unit in such a way that detected foreign bodies are deflected from the ordinary trajectory of the mass flow.

[0047] The same advantages can be achieved with the device as have been described in connection with the method.

[0048] An advantageous embodiment of the device provides that the imaging device is a line scan camera. Additionally, the imaging device can include an RGB camera, in particular a line scan camera, wherein this RGB camera generates second pixels. 11 Our reference: PFL0042-WO

[0049] The device can also be used with the advantageous designs and features described in connection with the method, either alone or in combination.

[0050] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept.

[0051] Brief description of the characters

[0052] Fig. 1 shows a schematic device for sorting out foreign bodies from a mass stream of sugar beets according to a first embodiment of the invention.

[0053] Fig. 2 shows a second embodiment of a device for sorting out foreign bodies from a mass stream of sugar beets according to the invention.

[0054] Fig. 3 shows a sorting unit in conjunction with two different collection chutes according to the second embodiment.

[0055] Fig. 4 shows a recognition unit in conjunction with a sorting unit and two different collection chutes according to the second embodiment.

[0056] Fig. 5 shows an alignment unit for one or both embodiments.

[0057] Embodiments of the invention

[0058] Figure 1 shows a first embodiment of a device 1 for sorting out foreign bodies 2' from a mass stream 3 of sugar beets 2. During the mechanical harvesting of sugar beets, foreign bodies such as stones, soil, bottles (glass, plastic, and others), metals, plastics, wood, weeds, leaves, etc., are frequently and unintentionally picked up. It is advantageous to sort these out from the mass stream of sugar beets 3. Furthermore, undersized, unripe, or rotten sugar beets should also be removed from the mass stream. Our reference: PFL0042-WO

[0059] The mass flow of sugar beets 3 must be removed. These are therefore also considered foreign bodies 2', which must be sorted out. This requires particularly precise and robust detection and identification of foreign bodies 2'.

[0060] Fig. 1 shows a device 1 suitable for carrying out the method according to the invention. For this purpose, the device 1 comprises a conveying unit 4, at least one detection unit 5, and a sorting unit 6. The conveying unit 4 has at least one conveyor belt for transporting a mass flow of sugar beets 3, wherein this initial mass flow 3 can consist of sugar beets 2 and foreign bodies 2'. The detection unit 5 enables the detection of the respective foreign bodies 2', whereupon a sorting unit 6 is activated and sorts out these detected foreign bodies 2'. As can be seen from Fig. 1, the sorting unit 6 is arranged downstream of the conveying unit 4.

[0061] First, the conveying unit 4 transports the mass flow of sugar beets 3 through the detection unit 5. In the first embodiment, the detection unit 5 is represented as a single element and can monitor several essentially parallel conveyor belts simultaneously. According to the invention, the detection unit 5 first detects in a first process step whether or not objects are present in the mass flow 3. For this purpose, the detection unit 5 uses laser distance measurement, in particular a laser triangulation method, whereby the surface of the conveyor belt can represent the reference plane for the measurement. Consequently, the detection unit 5 can detect when an object is lying on the conveyor belt. For the laser distance measurement, the detection unit 5 can have a laser sensor or laser scanner, which is preferably arranged vertically above the conveying unit 4. Provided that in the first step an object is present on the conveyor belt, the detection unit 5 can detect the presence of an object on the conveyor belt.Once the object has been detected by conveyor unit 4, it is at least partially captured optically in a second process step using hyperspectral or multispectral imaging. Initial pixels are generated from this optical image. The optical capture of the detected objects using hyperspectral or multispectral imaging is preferably performed with a line scan camera specifically designed for hyperspectral or multispectral imaging. The line scan camera captures only one line of pixels, with a pixel count that is larger or similar to that of conventional area scan sensors. This allows for a higher spatial resolution for the optical image capture, in addition to requiring less hardware. It is conceivable that the use of a line scan camera might not capture the entire object optically, but this does not pose a significant disadvantage for the detection process.The detected object is accordingly at least partially optically recorded. In a third process step, 13 Our reference: PFL0042-WO, which follows the optical recording, the generated first pixels are evaluated. The evaluation of the first pixels makes it possible to distinguish foreign bodies 2' from the sugar beets 2. If a foreign body 2' has been detected by the process, the detected foreign body 2' is sorted out in a fourth process step by means of the sorting unit 6. The sorting unit 6 deflects the detected foreign body 2' from the usual trajectory of the mass flow 8. For this purpose, the sorting unit 6 is controlled by the detection unit 5 when a foreign body 2' has been detected. The detection process is preferably carried out by means of a processing unit, which is in particular included in the detection unit 5.Additionally, the processing unit can determine one or more statistical parameters for the user or for the further processing of the foreign objects 2' or the sugar beets 2. These statistical parameters include, in particular, the percentage of conveyor belt occupancy, the quantity of the mass flow, the weight of a usable portion of the mass flow, the average weight or number of usable sugar beets 2 within the mass flow 3, and / or the proportion of foreign objects 2' in the mass flow 3. A significant advantage is that such a process can be automated with the respective statistical parameters. For example, the processing unit can determine when the storage of sugar beets 2 or foreign objects 2' is full, so that they can be collected. Furthermore, it is conceivable that the foreign objects 2' can be classified, at least roughly, which can be relevant for the further processing of the collected foreign objects 2'.Furthermore, the economic aspect may be of particular interest to the operator of device 1. For example, the operator can monitor the quantity of sugar beets 2 available at any time.

[0062] Fig. 1 clearly shows the difference between the trajectory of the sugar beets 8 and the trajectory of the detected foreign objects 8'. It is clearly evident that the detected foreign object 2' initially follows the trajectory of the sugar beet 8 and is deflected upwards at, or by, the sorting unit 6. The foreign objects 2' are preferably collected by a foreign object collection chute 1T. The sugar beets 2 are collected, in particular, by a sugar beet collection chute 11, and it can be seen from Fig. 1 that the sugar beet collection chute 11 is substantially adapted to the trajectory of the sugar beets 8. The sugar beets 2 are preferably transported by the conveying unit 4 at a speed in the range of 3 m / s to 4 m / s. Thus, the sugar beet 2 initially exhibits a considerable horizontal velocity component during flight.The sugar beet collection chute 11 can be arranged relative to the trajectory of the sugar beets 8 such that the sugar beets 2 experience the softest possible impact upon landing. For this purpose, the angle of the sugar beet collection chute 11 is preferably adapted to the angle of the sugar beet 8's trajectory. This angle can be determined by simple calculations if the horizontal distance between the sugar beet collection chute 11 and the conveying unit 4 is known. It is highly desirable that the sugar beets 2 suffer as little damage as possible upon impact with the collection chute 11.

[0063] Figure 1 also shows that the conveying unit 4 can have several drivers 4", which in particular can transmit the motion of the velocity to the mass flow 3. The drivers 4 are preferably designed as cleats and carry the respective individual objects of the mass flow 3 along with them.

[0064] Fig. 2 shows a second embodiment of the device 1. The essential difference between the second embodiment and the first is that the detection unit 5 is not designed as a single element. Rather, Fig. 2 shows four detection units 5, each assigned to a detection unit 5 above a conveyor belt of the conveyor unit 4. The detection unit 5 can extend a measuring area 5' on the surface of the respective conveyor belt, whereby an object on the conveyor belt is first detected by this measuring area 5' and then an optical image is taken using hyperspectral or multispectral imaging. Therefore, the object detection can take place directly on the conveyor belt.Hyperspectral or multispectral imaging preferably takes place in a wavelength range of 780–3000 nm, whereby one or more radiation sources, in particular infrared radiation sources, are arranged such that the mass flow 3 is illuminated at least in the measurement range 5' for the detection unit 5. After optical imaging, initial image points are generated, which are then evaluated in the next process step. However, it is conceivable that the detected object(s) are also at least partially optically imaged using an RGB camera. This RGB camera can generate additional image points beyond the initial ones, which are preferably also taken into account during evaluation. Thus, the accuracy of the detection of foreign bodies 2' in the mass flow 3 can be increased.To reduce hardware requirements and achieve better spatial resolution, a line scan camera can be used. The light source, especially the infrared light source, is primarily relevant for the RGB camera.

[0065] Furthermore, Fig. 2 shows a feed chute 9. The feed chute 9 is arranged such that the mass flow of sugar beets 3 is approximately equal to the speed of the conveying unit 15. Our reference: PFL0042-WO

[0066] 4 or the conveyor belts. Thus, no or only low relative velocities arise between the mass flow 3 and the conveyor belt, so that no or fewer sugar beets 2 are damaged. The conveying unit 4 is preferably driven by a drive 7.

[0067] Figures 3 and 4 each show different perspectives of the sorting unit 6 and the collection chutes for sugar beets and foreign objects 11, 11' of the second embodiment of the device 1. Figure 3 shows how the mass flow 3 is accelerated downstream of the detection unit 5 and the measuring area 5' by the respective conveyor belt. The trajectories of the sugar beets 8 and the foreign objects 8' initially pass over the sorting unit 6 in the same way. If a foreign object 2' is detected by the detection unit 5, a deflection unit 6' can be controlled such that the foreign objects 2' are deflected upwards from the normal trajectory of the mass flow 8. The deflection unit 6' can be controlled by the detection unit 5 and / or the processing unit. It is clearly visible in Figures 3 and 4 that the trajectory of the foreign object 8' has a deflection, a slight kink, upwards.It is also evident that a deflection unit 6' is in an extended position. This position can be reached reversibly by a pneumatic or electric cylinder. After the foreign object 2' has been deflected, the deflection unit 6' can be returned to a retracted position.

[0068] Fig. 4 shows the collection chutes for the foreign objects 11' and for the sugar beets 11. It should be noted again that only the usable sugar beets follow trajectory 8 onto the collection chute for sugar beets 11. Poor, unripe, or undersized sugar beets are also recognized as foreign objects 2' and follow the trajectory of the foreign objects 8'. The collection chute for the foreign objects 1T is located above the collection chute for the sugar beets 11 and directs the foreign objects 2' away from the sugar beets 2. Fig. 4 also shows the deflection unit 6' in an extended position. The foreign objects 2' are preferably deflected in flight by the deflection unit 6'. One or more deflection units 6' can be assigned to each conveyor belt, and these are selectively activated by the respective detection unit 5 when a foreign object 2' is detected on the respective conveyor belt.In the second embodiment, the deflection unit 6' is designed as a pivotable deflection flap. However, it is conceivable that the deflection unit 6' has an activatable nozzle and / or a pivotable deflection flap. The nozzle can also be controlled by means of one or the respective detection unit 5. The nozzle can expel air so that, in particular, lighter foreign objects 2' are deflected by the deflection unit 6'. Preferably, the deflection unit 6' has at least one activatable 16 Our reference: PFL0042-WO.

[0069] The device 1 has a nozzle and a pivoting deflector flap. The nozzle can also be permanently activated as long as the device 1 is in operation, so that foreign objects below a certain size or weight do not need to be detected by the detection unit 5, but are automatically deflected by the nozzle. It is also conceivable that the sorting unit 6 has a line of nozzles 12 extending across the entire width of the conveyor unit 4, which is permanently activated during operation. Such a line of nozzles is indicated in Fig. 4 by the line marked with reference numeral 12. Thus, the one or more deflection units 6' do not require a nozzle. If the deflection unit 6' has an activatable nozzle and a pivoting deflector flap, the nozzle is arranged downstream of the deflector flap.

[0070] Furthermore, Fig. 4 shows that partitions 4' are arranged between the multiple conveyor belts of the conveying unit 4. These prevent objects from rolling from one conveyor belt to another and force the objects to pass through the measuring area 5' of the detection unit 5. Thus, no object in the mass flow 3 can pass through the measuring area 5 without being detected. This significantly increases the robustness of the foreign object detection 2'.

[0071] Fig. 5 shows an alignment unit 10 arranged upstream of the conveying unit 4 and the feed chute 9. The alignment unit 10 preferably directs the mass flow 3 onto the respective conveyor belts. For this purpose, the alignment unit 10 has an opening for each conveyor belt, the height and / or width of which is adjustable, in particular by means of mechanical fixings. It is conceivable that excessively large objects in the mass flow 3 are stopped by the alignment unit 10, whereby such objects could potentially cause damage to the feed chute 9, the conveying unit 4, the detection unit 5, and / or the sorting unit 6. The respective openings can be adjusted to the sugar beets 2 within the mass flow 3.

[0072] 17 Our reference: PFL0042-WO

[0073] Reference symbol list

[0074] 1 - Device

[0075] 2 - Sugar beets

[0076] 2' - Foreign body

[0077] 3 - Mass flow of sugar beets

[0078] 4 - Conveyor unit

[0079] 4' - Partitions

[0080] 4" - drive

[0081] 5 - Recognition unit

[0082] 5' - measuring range

[0083] 6 - Sorting unit

[0084] 6' - Deflection unit

[0085] 7 - Drive conveyor unit

[0086] 8 - ordinary trajectory of the mass flow

[0087] 8' - deflected trajectory of the foreign bodies

[0088] 9 - Feed chute

[0089] 10 - Alignment unit

[0090] 11 - Sugar beet collection chute

[0091] 1 T - Foreign object collection chute

[0092] 12 - Nozzle row

Claims

18 Our reference: PFL0042-WO PATENT CLAIMS 1. A method for sorting out foreign bodies (2') from a mass stream of sugar beets (3), wherein the mass stream (3) is transported by means of a conveying unit (4) with at least one conveyor belt through a detection unit (5), wherein a sorting unit (6) is arranged downstream of the conveying unit (4), wherein the sorting unit (6) is controlled via the detection unit (5) and is configured such that foreign bodies (2') are deflected from an ordinary trajectory of the mass stream (8), characterized in that the detection unit (5) performs at least the following steps: I. In a first process step, objects of the mass flow (3) arranged on the conveying unit (4) are detected by means of laser distance measurement, in particular laser triangulation; II. In a second process step following the first process step, the detected objects are at least partially optically recorded using hyperspectral or multispectral imaging, whereby first image points are generated; III. In a third process step following the second process step, the generated first image points are evaluated in order to detect foreign bodies (2') in the mass flow (3); and IV. In a fourth process step following the third process step, the sorting unit (6) is controlled by the recognition unit (5) in such a way that detected foreign bodies (2') are deflected from the ordinary trajectory of the mass flow (8).

2. Method according to claim 1, characterized in that the optical recording of the detected objects is carried out by means of hyperspectral or multispectral imaging with a line scan camera which is set up for hyperspectral or multispectral imaging.

3. Method according to one of the preceding claims, characterized in that in the second method step the detected objects are additionally at least partially optically recorded by means of an RGB camera, wherein second image points are generated, wherein in the third method step the second image points are additionally evaluated in order to detect foreign bodies (2') in the mass flow (3) 19 Our reference: PFL0042-WO.

4. Method according to one of claim 3, characterized in that the RGB camera is a line scan camera.

5. Method according to one of the preceding claims, characterized in that a computing unit, which is in particular comprised of the recognition unit (5), determines one or more statistical parameters on the basis of the first and optionally second pixels, wherein the statistical parameters in particular comprise a percentage conveyor belt occupancy, a quantity of the mass flow (3), a weight of a usable portion of the mass flow (3), an average weight or number of usable sugar beets (2) within the mass flow (3) and / or the proportion of foreign bodies (2') in the mass flow (3).

6. Method according to one of the preceding claims, characterized in that the conveying unit (4) conveys the mass flow of the sugar beets (3) and foreign bodies (2') at a speed in the range of 3 m / s to 4 m / s, preferably in the range of 3.5 m / s to 4 m / s.

7. Method according to one of the preceding claims, characterized in that the conveying unit (4) has several, in particular substantially parallel, conveyor belts.

8. Method according to one of the preceding claims, characterized in that the sorting unit (6) has at least one deflection unit (6') per conveyor belt, wherein the deflection unit (6') is controlled in such a way that the foreign bodies (2') are deflected from the trajectory of the mass flow (8), in particular upwards.

9. Method according to claim 8, characterized in that the at least one deflection unit (6') each has at least one pivotable deflection flap.

10. Method according to claim 8 or 9, characterized in that the at least one deflection unit (6') each has at least one selectively activatable nozzle for expelling air. 20 Our reference: PFL0042-WO 11. Method according to claim 10, characterized in that the at least one activatable nozzle is arranged downstream of the pivotable deflector flap.

12. Method according to one of the preceding claims, characterized in that an alignment unit (9) is arranged upstream of the conveying unit (4), wherein the alignment unit (9) has an opening for each conveyor belt, wherein this opening is adjustable in height and / or width so that the mass flow (3) is aligned onto the conveyor belts.

13. Method according to one of the preceding claims, characterized in that the detection unit (5) has a radiation source, in particular an infrared radiation source, wherein the radiation source is configured such that the mass flow (3) is at least partially illuminated in a measuring area (5') for the detection unit (5).

14. Device (1) for sorting out foreign bodies (2') from a mass stream of sugar beets (3), comprising a detection unit (5) and a conveying unit (4) with at least one conveyor belt for transporting the mass stream (3) through the detection unit (5), and a sorting unit (6) arranged downstream of the conveying unit (4), which can be controlled by the detection unit (5) and is configured such that foreign bodies (2') are deflected from an ordinary trajectory of the mass stream (8), characterized in that the detection unit (5) comprises: I. an object recognition device for recognizing objects of the mass flow (3) arranged on the conveying unit (4) by means of laser distance measurement, in particular laser triangulation; II. an imaging device for at least partially optically recording the detected objects by means of hyperspectral or multispectral imaging, generating first pixels; III. a computing unit for evaluating the generated first pixels in order to detect foreign bodies (2') in the mass flow (3); and IV. a control device for controlling the sorting unit (6) such that detected foreign bodies (2') are deflected from the ordinary trajectory of the mass flow (8).

15. Device according to claim 14, characterized in that the imaging device is a line scan camera.

Images