Monitoring of combination scales through a 3D sensor

Abstract

The present invention deals with a filling device (1) and a weighing device, wherein at least one 3D sensor (2) is provided to capture at least a partial area of the transport surface, virtually dividing the detected area into a plurality of sectors (3) and zones (4). The at least one sensor (2) is adapted to determine a distance to the measuring point as well as a respective angle of incidence at which the measuring point of the detected surface is measured, The filling device (1) is adapted to make a division into sectors (3) and zones (4) dynamically as a function of at least one influencing variable (E) to derive relevant information for the regulation of the control parameters therefrom in order to achieve a controlled product distribution.

Claims

1. An apparatus comprising: a transport surface supplied with products by a feeding device, a sensor to detect and forward product occupation information on the transport surface and/or the feeding device and/or other surfaces, wherein the sensor is adapted to detect an area of at least one of the transport surface and the feeding device, and a control device and an evaluation unit to: virtually divide the area detected by the sensor into a plurality of sectors in order to assign the product occupation information to one sector of the plurality of sectors; virtually divide the sector into a plurality of zones; determine at least one measuring point, wherein the division into sectors and zones is performed dynamically as function of at least one of: a characteristic of the supplied products, a vibration frequency of the supplied products, and a vibration amplitude of the supplied products, measure a distance to the measuring point; and measure a respective angle of incidence under which the measuring point of the area.

2. The apparatus of claim 1, wherein the control device is adapted so that the division into sectors and zones is held based on a user selection made using a display.

3. The apparatus of claim 1, wherein at least one positioning mark is provided on the transport surface, and the sensor is adapted to detect the at least one positioning mark.

4. The apparatus of claim 1, wherein the evaluation unit is adapted to determine a product volume of a storage hopper positioned on at least one of: a dosing chute on the distribution plate on the feeding device and other parts of a combination weighing machine.

5. The apparatus of claim 1, wherein the evaluation unit is adapted to take a corresponding angle of the measuring point into account for a determination of an occupation height and a product volume.

6. The apparatus of claim 5, wherein the evaluation unit is further adapted to determine a product weight for a determination of the product volume, the product weight being determined at the transport surface or a storage hopper.

7. The apparatus of claim 1, wherein the evaluation unit is further adapted to determine a product movement speed on the transport surface in individual sectors or zones and to detect variations in product movement and/or product properties.

8. The apparatus of claim 1, wherein the evaluation unit is further adapted to detect and analyze at least one of a contour of the products, a colors of products, and a surface structures of the products.

9. The apparatus of claim 8, further comprising a memory unit configured to store the contour, the color and the surface structure, and to enable detecting a foreign objects by comparing the contours, color and surface structures, and to identify the products and/or the foreign objects with stored images or using image analysis.

10. The apparatus of claim 1, wherein a memory unit to store a dimension and a position of a component to be observed wherein the evaluation unit is adapted to detect and determine relevant points of the area, and wherein the evaluation unit is further adapted to automatically detect and determine a presence or a correct positioning of parts of a filling device, a combination scale, and an assembly of parts, upstream equipment, or downstream equipment.

11. The apparatus of claim 1, wherein the control device regulates dosing times and dosing amplitudes based on the product occupation.

12. A method of filling a combination scale, the method comprising: a) using at least one three-dimensional (3D) sensor; b) determining a positioning of the at least one 3D sensor relative to a filling device; c) dynamically dividing a transport area into sectors and zones based on at least one of: a characteristic of the supplied products, a vibration frequency of the supplied products, and a vibration amplitude of the supplied products; d) analyzing at least one part of the filling device with the at least one 3D sensor when there is no product flow; e) analyzing at least one part of the filling device with the at least one 3D sensor during product flow; f) comparing data measured with the at least one 3D sensor during steps d) and e) and a plausibility check of values measured in step e); and g) determining a product distribution, a volume and/or weight of transported products.

13. The method of claim 12, further comprising the following steps: h) assigning the information obtained in step g) to predetermined sectors and zones: i) calculating relevant features of the product distribution from the information, wherein the relevant features include at least one of: flow rates for mass and volume, average density, variations in product distribution comprising gaps or accumulations, detection of single pieces, foreign objects, interfering edges, presence of certain features comprising at least one of color, shape, surface structure, and number; and j) regulating control parameters of the combination scale using this information for a controlled product distribution.

14. The method of claim 12, whereby in step d) and/or e) deviations within a time span Δt1 are ignored by not using affected measuring points of corresponding sectors and/or zones in step e).

15. The method of claim 12, whereby in step d) and/or e) deviations of a distance between the 3D sensor and an individual measuring point is determined over time if a time period Δt1 is exceeded, and if an offset does not exceed a predetermined minimum value, a correction value for the distance is determined and used for subsequent measurements, and if the offset exceeds the predetermined minimum value, corresponding measuring points are no longer considered for subsequent measurements.

16. The method of claim 12, wherein in steps d) and e) an angle of each measuring point relative to the axis of incidence of the sensor as well as a distance are determined, and a corrected height of a product is determined by the evaluation unit, which allows the determination of a correct product volume, and product dimensions and/or empty spaces between products are detected and determined by comparing the measured distances between several measuring points.

17. The apparatus of claim 1, wherein the product volume is determined using a product weight of the product on the transport surface or on a storage hopper.

18. The apparatus of claim 1, where the transport area is divided into sectors and zones based on a product density or an external product dimension.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE INVENTION

(1) In the following, preferred embodiments of the present invention are described in more detail by means of the attached drawings.

(2) FIG. 1 shows a general view of a combination scale.

(3) FIG. 2 shows a top view of a distribution plate and the dosing chutes of a combination scale.

(4) FIG. 3 shows the filling device for a combination scale with one sensor.

(5) FIG. 4 shows a filling device for a combination scale with two sensors.

(6) FIG. 5 shows the dividing of a feeding device into sectors and zones.

(7) FIGS. 6a, 6b, 6c and 6d show different subdivisions of distribution plates, dosing chutes, storage hoppers and additional equipment in sectors and zones.

(8) FIG. 7 shows the measurement of several points of a dosing channel with one sensor.

(9) FIG. 8 shows the height calculation of a measured product.

(10) FIG. 9 shows the calculation of voids between two products using the sensor according to the invention.

(11) FIG. 10 shows the volume calculation for lumpy products with measurement of cavities using two sensors each.

(12) FIG. 11 a) and FIG. 11 b) show the migration of product accumulations and product valleys over time.

(13) FIG. 12 shows the detection of irregularities of assemblies in a combination weighing device, wherein in FIG. 12 a) a dosing chute is missing and in FIG. 12 b) the feeding device is arranged at an angle.

(14) FIG. 13 is a flowchart of a method of filling a combination scale.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

(15) FIG. 1 shows a classical combination scale K according to the state of the art. Here a distribution plate V is present, from which products can fall onto dosing chutes D.

(16) At the end of the dosing chutes, storage hoppers VB are arranged, below them corresponding weighing hoppers WB. These can discharge products into a chute R, from where products can enter a packaging unit.

(17) FIG. 2 shows a top view of a combination scale K, whereby the distribution plate V and the arrangement of the dosing chutes D around it is shown.

(18) FIG. 3 shows a detailed view of a filling device 1, which consists of the feeding device A, the distribution plate V and the dosing chutes D. At a point outside the dosing chutes D, a sensor 2 is located, which in this case overlooks the entire distribution plate V and all dosing chutes D.

(19) FIG. 4 shows a further distribution device 1, however consisting of feeding device A, dosing chutes D and distribution plate V. However, two sensors 2 are installed here, which overlook all the dosing chutes D and the distribution plate V, whereby the dosing chutes D covered by the feeding device A for one sensor 2 are detected by the other sensor.

(20) FIG. 5 shows the division of two feeding devices A into sectors 3 and zones 4 (here: two possibilities to divide a sector 3 into different zones 4). In this case, the entire feeding device A is a sector 3, and sector 3 is divided into several zones 4.

(21) FIG. 6a shows a division of a distribution plate V, which is a sector 3, into several zones 4.

(22) FIG. 6b shows the division of a dosing chute D, which is a sector 3, into several zones 4, and FIG. 6c shows the division of a storage hopper VB, which also represents a sector 3, into several zones 4. In FIG. 6d an additional device is shown, which represents a sector 3. This sector 3 is divided into several zones 4. The division into sectors 3 and zones 4 can be done dynamically as described above. It is therefore also possible to create sectors and/or zones outside the actual transport area of the combination scale.

(23) In FIG. 7 a sensor 2 is shown, which is located above a dosing chute D. A positioning mark 5 is located at both ends of the dosing chute D. Here, an angle α and β of the individual positioning marks 5 can be measured accordingly, and thus the sensor 2 can determine whether the dosing channel D is positioned correctly. To be more precise, the angle between the connecting line from the sensor to the respective positioning mark 5 and the perpendicular from the sensor to the dosing chute is determined. The sensor can measure from one point (point sensor) or from several points—therefore it is depicted in a rod-shaped manner in FIG. 7.

(24) In FIG. 8 a volume calculation with angle correction is illustrated. Here it can be seen that at least both corners of a product part P are detected by sensor 2. At the left corner shown in the figure, the sensor recognizes that this corner is positioned exactly on the axis of incidence of the sensor on the corresponding surface. The other corner is positioned at an angle β from it. An intermediate point is also measured, which encloses an angle α with the axis of incidence. Thus a volume can be determined exactly, since a sensor can measure an angle and a distance at different points and can calculate the height of the product P accordingly. Here, the ground is measured without the product (here: the point under the axis of incidence and points with the angles α and β to the axis of incidence), and then, if a product is lying on the transport surface, its corners are measured and the corresponding distances are corrected with the laws of trigonometry (the measured distance corresponds to the hypotenuse here, the actual distance to the adjacent leg)

(25) It is also possible to scan a measuring field in constant angle steps and thus assign an angle to each measuring point. If in the example of FIG. 8 the angle β is exceeded, there would be a sudden increase of the measured distance—therefore the system recognizes that the product end is present at the angle β.

(26) For each of the measured points a height information can be determined, from which again a total volume can be calculated. The angle correction is used for the correct recording of height, volume, possible void volumes or shadow volumes with the corresponding corrections and conclusions.

(27) In FIG. 9, sensor 2 also calculates the volume, but here for lumpy products P1 and P2. The measuring principle is similar to FIG. 8, but for product P1 two different angles α and β are measured, for product P2 a third angle γ. The individual distances and angles can be used to determine how high certain products protrude upwards, and even if they lie obliquely, an appropriate correction can be made here, so that the actual volume can be determined. Also the volume of the void space (shown here with the reference sign H) can be measured at least partially (provided that the products P1 and P2 are rectangular or have a known shape), so that a usable statement about the volume of the void space H can be obtained. For this purpose, similar to FIG. 8, the distance of the corresponding measuring point from sensor 2 is measured—and if the measured distance increases abruptly, the end of the product can be determined approximately—or if it falls abruptly, the beginning of a new product can be determined approximately.

(28) In FIG. 10 a) and b) the volume calculation is shown for an accumulation of lumpy products. Here two sensors 2 are used, which scan the outer contours of the accumulation of products P. Here it should be tried to detect and determine the filled areas as well as the void spaces between the products as exactly as possible, at least approximately. Each of the two sensors 2 scans one side of the accumulated products P.

(29) FIG. 11 a) shows a product accumulation of a small-sized product P, here for example grain. Here, for example, the migration speed of the highest point can be followed. Due to the vibration of the distribution plate and/or dosing chutes, the shape of the product also changes—in all views a peak or a mountain is visible, and this is moving; however, the shape of the product also changes.

(30) In FIG. 11 b) there are two product piles P1 and P2, with a corresponding valley or depression between them. Here, by recognizing and detecting this contour, the movement or “wandering” of this valley can be followed.

(31) FIG. 12 a) again shows a combination scale K in top view, whereby a dosing chute D is missing here. As the combination scale is captured by sensor 2, sensor 2 can detect the missing dosing chute D and output an error message.

(32) In FIG. 12 b) a combination scale K is also shown in top view, whereby a feeding device A is present here, which however is not arranged straight as actually desired and does not run through the center of the distribution plate V, but is obliquely oriented. This can also be captured by the sensor 2 and recorded accordingly.

(33) The present invention is not limited to the described embodiments.

(34) More complex algorithms can be used for the calculation of void spaces and migration velocities, and much more detailed detections can be provided.

(35) It is also not necessary to use one or two sensors, if necessary many more sensors can be used, so that the whole distribution area of the combination scale is scanned pixel by pixel.

(36) The present invention deals with a filling device 1 and a weighing device, wherein at least one 3D sensor 2 is provided to capture at least a partial area of the transport surface, virtually dividing the detected area into a plurality of sectors 3 and zones 4. The at least one sensor 2 is adapted to determine a distance to the measuring point as well as a respective angle of incidence at which the measuring point of the detected surface is measured, The filling device 1 is adapted to make a division into sectors 3 and zones 4 dynamically as a function of at least one influencing variable E, to derive relevant information for the regulation of the control parameters therefrom in order to achieve a controlled product distribution.