Method for determining the fill level value of contents in a container
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- VEGA GRIESHABER GMBH & CO
- Filing Date
- 2024-06-12
- Publication Date
- 2026-06-03
AI Technical Summary
Existing methods for determining the filling level in containers, especially with bulk materials, fail to accurately account for the topography of the filling surface, leading to inaccuracies due to the unknown bulk layer and varying cross-sectional areas of the container.
A procedure and system that use a filling amount distance curve, considering the geometric shape of the container and characteristic features of the filling goods, such as density and topography, to determine the filling level with improved accuracy by accounting for the non-linear relationship between fill distance and level value, using contactless distance measurement and sensors like radar or ultrasonic sensors.
This approach enhances the accuracy of filling level determination by up to 20% by considering the topography of the filling surface, reducing errors associated with linearization based solely on internal container geometry.
Smart Images
Figure EP2024066223_30012025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] title
[0003] Method for determining a fill level value of a filling material in a container
[0004] Reference to related applications
[0005] This application claims priority from German patent application No. 102023207 121.5, filed on July 26, 2023, which is incorporated in its entirety by reference into this document.
[0006] background
[0007] The invention relates to the determination of fill levels or volumes of filling materials in containers. When the filling material is a bulk material, the filling level determination using a distance sensor typically requires consideration of the bulk material's position. Since the position of the bulk material is typically unknown, the effect of the position of the bulk material on a measured distance can be advantageously reduced by a suitable installation position of the distance sensor relative to a surface of the bulk material.
[0008] Disclosure of the invention
[0009] A level value of a product in a container, determined using a distance sensor to determine the height of a surface of the product in the container, can be improved by taking into account the geometric shape of the container, since this geometric shape typically has a different cross-sectional area at different heights within the container. However, the topography of the surface of the product, which can be particularly pronounced in bulk materials, is not taken into account.
[0010] According to aspects of the invention, a method for determining a fill level of a product in a container, a system for determining a fill level, and a use of the system according to the features of the independent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.
[0011] Throughout this description of the invention, the sequence of method steps is presented in such a way that the method is easily understandable. However, those skilled in the art will recognize that many of the method steps can also be performed in a different order and lead to the same result. In this sense, the order of the method steps can be changed accordingly and is thus also disclosed. Throughout this description of the invention, some features are provided with numerical codes to improve readability or to make the assignment clearer; however, this does not imply the presence of certain features.
[0012] According to aspects of the invention, a method for determining a fill level value of a filling material in a container is proposed, which comprises the following steps:
[0013] In one step, at least one characteristic feature of the filling material is provided. In a further step, a filling material quantity-distance curve for the container and the at least one characteristic feature of the filling material are provided. In a further step, a filling distance between a filling material detector and a surface of the filling material is determined. In a further step, the filling level value of the filling material in the container is determined based on the filling material quantity-distance curve and the filling distance.
[0014] The fill level value can be a percentage indication of a fill level, based on a maximum volume for the respective fill material in the container, and / or an indication of a mass of the fill material and / or a volume of the respective fill material and / or a fill height of the fill material in the respective container.
[0015] A characteristic feature of the filling material can be a designation of the filling material and / or a flowability and / or a density and / or a bulk density and / or a raw density and / or an adhesion property inside the container and / or a granularity and / or a graininess and / or a surface roughness and / or a particle size distribution and / or a particle shape and / or a chemical composition of the particles and / or a humidity and / or a temperature and / or a container wall friction and / or any other information characterizing the filling material.
[0016] The container can be an open container or a closed container, such as a tank or a silo. In particular, the fill level can be determined horizontally and / or vertically for a closed or open container. The following description applies to a vertically upright container; the method and / or arrangements apply accordingly for horizontal filling or discharging.
[0017] The filling material quantity-distance curve can be provided by means of a table and / or a mathematical function and / or a simulation calculation, which can typically have a different course of the filling level value, plotted against the determined filling distance, for different characteristic features of the filling material.
[0018] Advantageously, a filling quantity-distance curve provided by means of a table saves computational effort and thus electrical energy.
[0019] When filling or removing bulk material, particularly granular material, into or from the container, the topography of the filling material surface can take on significantly different shapes, for example, changing from a conical shape to a funnel shape during removal. The filling material quantity-distance curve can be determined in such a way that an effect resulting from a distance measurement, particularly a non-contact one, directed in a constant direction towards the container is taken into account for determining the fill level value. This is because the change in the topography of the filling material surface, depending on a fill level value of the container and / or an orientation of the filling material detector with respect to the surface of the filling material, can result in a non-linear relationship between the fill distance and the fill level value in the container.
[0020] This can be attributed to the fact that the topography of the surface of the filling material varies depending on the filling level value, i.e. next to a point on the surface of the filling material to which the filling distance is determined, there can be a spatial surplus or a spatial shortage of filling material depending on the filling level value compared to a flat surface, which can be horizontally or vertically aligned depending on the container, since the filling distance, i.e. a distance, is typically determined at a measuring point.
[0021] According to one aspect, the fill quantity-distance curve can depend on a starting position for determining the fill distance and a direction for determining the fill distance. In other words, the fill quantity-distance curve can depend on a position of the fill material detector used as a distance sensor and on a measurement orientation of the fill material detector with respect to the fill material.
[0022] By providing the fill quantity-distance curve for at least one characteristic feature of the fill material, the described effects attributable to the topography of the fill material's surface can be taken into account. A multitude of characteristic features of the fill material can determine the fill quantity-distance curve, since the topography of the fill material's surface depends on a multitude of characteristic features of the fill material.
[0023] Advantageously, the method for determining the fill level value described here can achieve improved accuracy in determining the fill level value, since the topography of the surface of the respective filling material can be taken into account.
[0024] In other words, the method described here differs from a linearization for determining the fill level value based exclusively on the internal geometry of the container, since the method described here takes into account that the surface of the filling material may have a topography that can cause a significant error in the determination of the fill level value. In other words, based on a non-contact determination of the filling distance to a filling material, the fill level value can be determined using a previously determined material-dependent and / or application-dependent fill material quantity-distance curve to improve the determination of the fill level value.
[0025] For each filling material, which is described with the characteristic features, a filling material quantity-distance curve can be selected in order to determine the filling level value in the container.
[0026] According to one aspect, it is proposed that the filling material quantity-distance curve comprises a filling material quantity-distance curve and / or a removal material quantity-distance curve. In one step, a fill level gradient can be provided. Accordingly, when determining the fill level value of the filling material in the container, the fill level value can be determined for positive fill level gradients based on the filling material quantity-distance curve and the fill distance. Alternatively, the fill level value can be determined for negative fill level gradients based on the removal material quantity-distance curve and the fill distance.
[0027] By taking the fill level gradient into account, a different topography of the surface of the filling material, which may depend on the filling or removal of the filling material, can be taken into account.
[0028] Alternatively or additionally, the product quantity-distance curve can comprise a process-product quantity-distance curve, whereby the process-product quantity-distance curve characterizes a process that describes a consistent sequence with repeated removal and repeated filling of the product into the container. In a consistent sequence of removal and filling, the topography of the product surface can differ from removal of the product from a full container and / or filling into an empty container.
[0029] According to one aspect, it is proposed that the fill level gradient be determined by means of the fill level detector. For this purpose, the fill level detector can be configured to store a series of fill distances and evaluate them with respect to the fill level gradient. According to one aspect, it is proposed that the fill level detector determines the fill distance and / or the fill level gradient contactlessly.
[0030] To determine the fill distance, the fill level detector can have sensors that are immersed in the filling material and / or sensors that determine the fill distance in a contactless and / or non-contact manner. The fill distance can be determined by the distance between the filling material detector and the surface of the filling material. A sensor for contactless determination of the fill distance can be a radar sensor, with free or guided microwaves, and / or an ultrasonic sensor and / or an optical sensor, such as a laser sensor. The respective sensor can, in particular, be configured to determine the fill distance based on a time-of-flight measurement.
[0031] According to one aspect, it is proposed that the characteristic filling material quantity-distance curve is determined by means of the following steps: iteratively filling a filling subset of a maximum filling material quantity into the at least partially emptied container, wherein with each iterative filling of the filling subset the filling distance and a corresponding quantity of the filling material are determined in order to determine the respective filling material quantity-distance curve.
[0032] According to one aspect, it is proposed that the characteristic withdrawal-filling material quantity-distance curve is determined by means of the following steps: iteratively withdrawing a withdrawal subset of the maximum filling material quantity into the at least partially filled container, wherein for each iterative withdrawal of the withdrawal subset, the filling distance and a corresponding quantity of the filling material are determined in order to determine the withdrawal-filling material quantity-distance curve.
[0033] By means of the process steps of iterative filling or iterative removal described here, the filling material quantity-distance curve can be determined for a specific filling material that has at least one characteristic feature.
[0034] To determine the process-filling material quantity-distance curve, the filling and removal of the filling material can be carried out with corresponding partial quantities according to the respective process. According to one aspect, it is proposed that the filling material quantity-distance curve be determined based on the internal geometry of the container, in particular mathematically. Based on the at least one characteristic feature of the filling material, the respective fill level value resulting from the internal geometry is shifted by a constant value that is specific to the respective characteristic feature of the filling material.
[0035] According to one aspect, it is proposed that the filling material quantity-distance curve for a container having a cone or other shape in the lower part of the container has or is described thereby, a linear region and / or a transition region and / or a removal region.
[0036] The linear range can be based on the internal geometry of the container, which, depending on at least one characteristic feature of the filling material, is shifted by a constant value to higher or lower filling level values.
[0037] The transition region can exhibit a linear progression of the fill level value as a function of the filling distance, whereby the gradient of the linear progression of the transition region can deviate from an increase in the linear range. A fill level value of the transition region of the fill quantity-distance curve can be based on a fill level value corresponding to the cone volume. The progression of the discharge region of the fill quantity-distance curve can be based on the internal geometry of the container.
[0038] According to one aspect, it is proposed that the determined filling material quantity-distance curve be stored in the filling material detector and / or in an evaluation unit coupled to the filling material detector for determining the filling level value, and / or in a database. The database can be coupled to the evaluation unit for determining the filling level value in the container via a cloud connection.
[0039] Advantageously, a stored fill quantity-distance curve for at least one characteristic feature of the fill material, such as a name of the fill material, can be retrieved via the database each time the container, such as a silo, is filled with a new fill material. A suitable fill quantity-distance curve can then be provided via the cloud connection for determining the fill level value of the respective fill material in the container.
[0040] According to one aspect, it is proposed that the characteristic withdrawal-filling material quantity-distance curve and / or the characteristic withdrawal-filling material quantity-distance curve is determined based on the at least one characteristic feature of the filling material and based on at least one characteristic property of the container by means of model calculations and / or simulation calculations.
[0041] Advantageously, the filling level value can be determined using the filling material quantity-distance curve and assigned to the at least one characteristic feature.
[0042] Advantageously, the respective filling material quantity-distance curve can be determined using model calculations and / or simulation calculations, since for a large number of filling materials an iterative determination with partial withdrawal quantities and / or partial filling quantities requires a great deal of effort.
[0043] According to one aspect, it is proposed that the filling material quantity-distance curve be determined by means of a simulation calculation based on the at least one characteristic feature of the filling material by determining an additive shift for a filling material quantity-distance curve that is based exclusively on the geometric shape of the container. The additive shift can have a positive or negative value for the fill level, and this additive shift.
[0044] According to one aspect, it is proposed that the characteristic properties of the container include geometric dimensions of the container and / or an internal shape of the container and / or a relative position of at least one filling opening in the container and / or a relative position of at least one removal opening in the container.
[0045] In particular, a position of the filling opening and / or the removal opening relative to a centerline of the container can be characterized. The container can have a cylindrical symmetry, at least in a partial area, based on which the centerline is defined. The container can have a plurality of filling openings. The filling material quantity-distance curve can be determined and / or selected according to a used filling opening and / or a used removal opening.
[0046] Advantageously, by using the filling material quantity-distance curve to determine the filling level value, properties of the filling material and the container can be taken into account in addition to the geometry of the container, such as the flowability and / or the density and / or the filling position and / or the removal opening, etc. The influence of the respective characteristic features of the filling material can influence the determination of the filling distance in that the topographical surface of the filling material is different.
[0047] According to one aspect, it is proposed that the characteristic properties of the container include a position of the filling material detector and / or a measurement orientation of the filling material detector, in particular for the filling distance to be determined. In particular, the characteristic property of the container can include a relative position of the filling material detector and / or a relative measurement orientation of the filling material detector to a center line of the container.
[0048] According to one aspect, it is proposed that the relative position of a filling opening in the container and / or the relative position of a removal opening in the container is determined based on a control signal and / or an opening sensor signal for the relative position in order to determine the filling material quantity-distance curve.
[0049] In other words, the filling material quantity-distance curve can be configured to be specific to the geometric shape of the container and / or a precisely described filling process and / or a precisely described emptying process of the container and / or all material properties of the filling material and / or all process steps of filling and / or emptying for determining the filling level value of the filling material. In particular, the filling material quantity-distance curve can be specific to an emptying speed and / or a filling speed of the filling material.
[0050] According to one aspect, it is proposed that the characteristic feature of the filling material has a flowability and / or a density and / or an adhesion property inside the container and / or a granularity and / or a grain size and / or a grain distribution and / or a surface roughness and / or a designation of the filling material.
[0051] According to one aspect, it is proposed that the characteristic filling material quantity-distance curve for the geometric dimensions and / or a geometric shape of the container and for the at least one characteristic feature of the filling material is provided by means of a query to a database and / or by means of a simulation calculation.
[0052] According to one aspect, it is proposed that the fill level value of the filling material in the container is determined using a cloud-based system, wherein the filling material detector is signal-coupled to the cloud-based system and the database in order to determine the fill level value based on the fill distance determined using the filling material detector.
[0053] A system for determining a fill level value of a filling material in a container is proposed, comprising: a detector interface for providing a fill distance between a filling material detector and a surface of the filling material; an input interface for providing at least one characteristic feature of the filling material and / or characteristic properties of the container; a provision interface for providing a filling material quantity-distance curve for the container; and a calculation unit that is signal-coupled to the input interface and / or the provision interface; and wherein the calculation unit is set up and configured to carry out one of the methods for determining a fill level value of a filling material in the container according to one of the methods for determining the fill level value described above;
[0054] According to one aspect, it is proposed that the system comprises the filling material detector: a database for providing the filling material quantity-distance curve for the filling material having at least one characteristic feature in the container having the characteristic properties; and / or a simulation unit configured to determine the characteristic filling material quantity-distance curve for the characteristic properties of the container and for the at least one characteristic feature of the filling material.
[0055] It is proposed to use the system described above for determining a fill level value of a filling material in a container.
[0056] A computer program is proposed, comprising instructions which, when the computer program is executed by a computer, cause the computer to carry out one of the methods described above for determining the fill level value.
[0057] A machine-readable storage medium is proposed on which the computer program described above is stored.
[0058] It should also be noted that the various embodiments described above and / or below can be combined with one another.
[0059] Examples of implementation
[0060] Embodiments of the invention are illustrated with reference to Figures 1 and 2 and explained in more detail below. It shows:
[0061] Figure 1 is a sketch of a cross-section through a container with two different topographies of the bulk material surface; and
[0062] Figure 2 experimentally determined dependences of a bulk material volume on a filling material distance.
[0063] Figure 1 schematically outlines a cross-section through a container 100 having a filling opening 102 that is laterally offset from a center line 109 of the container 100. The center line 109 is defined by an axis of symmetry of the cylindrical part of the container 100. The removal opening 104 of the container 100 is laterally offset from the center line 109.
[0064] After filling the filling material 120, this arrangement of the filling opening 102 results in a topography of the surface 122 of the filling material 120 corresponding to a pouring cone, which is conical and shifted to the side of the filling opening 102.
[0065] After partial emptying of the filling material 120 via the removal opening 104, a topography of the surface 124 of the filling material 120 can be established that is funnel-shaped, corresponding to a removal funnel, and is shifted to one side of the removal opening 104. The filling material detector 130 can be arranged in a lid 108 of the container 100, laterally shifted from the center line 109. The filling material detector 130 can be aligned along a measuring line 132 to determine a filling distance to the respective surface 104, 105 of the filling material 120. The alignment of the filling material detector 130 can be such that a filling material quantity above the measuring point 134 on the respective surface 104, 105 corresponds as far as possible to a filling material quantity below the measuring point 134 on the surface 122, 124 of the filling material 120.The funnel-shaped topography of the surface 124 of the filling material 120 after emptying can be influenced by a funnel-shaped geometry of the container 100 in a lower region 106 of the container 100.
[0066] Figure 2 outlines, in a diagram 200, a plurality of filling material quantity-distance curves 202, 204, 206, 208 of a container, in which fill level values V, corresponding to a volume of the filling material in the container, are plotted against a measured fill distance D. The filling material quantity-distance curve 202 was determined using a liquid as the filling material in the container and is based essentially exclusively on a geometric dimension of the container, in particular from the internal shape of the container. A fill distance between a filling material detector and the surface of the liquid was determined iteratively after each filling of a partial amount of the liquid.
[0067] Point 210 in diagram 200 is determined by the volume of the container in a lower region, which is conical, along with a corresponding filling distance of the liquid. The further nonlinear course of the filling-filling quantity-distance curve 202 can be attributed to the conical shape in the lower region of the container.
[0068] The filling material quantity-distance curves 204, 208 were determined by iteratively filling a partial quantity of a filling material with a maximum filling material quantity. During each iterative filling of the partial quantity, the filling distance was measured and / or determined to determine the corresponding filling material quantity-distance curve. Since the filling material used here was a bulk material, the filling material quantity-distance curves 204, 208 are highly nonlinear from a maximum filling material quantity 212 to a zero filling material quantity.
[0069] In comparison with the filling material quantity-distance curve 202, which is dominated by the inner shape of the container, it can be seen that the bulk material exhibits an upward shift in relation to the respective filling distance. In the area of the conical part of the container, which is characterized by the conical volume 210 in the respective diagram, the gradient of the filling material quantity-distance curve 204, 208 changes during filling compared to a cylindrical part of the container, which is arranged above the conical part. In the example curves in Figure 2, a partial filling quantity of 1 ton of the filling material was filled in each case and then the respective filling distance was determined. The volume V is expressed in m 3 and the filling distance in m.
[0070] To determine a fill level value of the filling material used, an average fill level-fill level-distance curve 206 can be determined from the fill level-fill level-distance curves 204 and 208. Compared to curve 202, which can be derived from the internal shape of the container, the average fill level-fill level-distance curve 206 can improve the determination of the fill level value of the filling material by up to 20%.
[0071] Typically, this results in an error for determining the level value, depending on the type of filling material, in a range of + / - 5%.
Claims
Claims 1 . A method for determining a fill level value of a filling material (120) in a container (100), comprising: Providing at least one characteristic feature of the filling material (120); Providing a filling material quantity-distance curve (202, 204, 206, 208) for the container (100) and the at least one characteristic feature of the filling material (120); Determining a filling distance between a filling material detector (130) and a surface of the filling material (122, 124); and Determining the fill level value of the filling material (120) in the container (100) based on the filling material quantity-distance curve (202, 204, 206, 208) and the filling distance.
2. Method according to claim 1, wherein the filling quantity-distance curve comprises a filling quantity-distance curve (202, 204, 206, 208) and / or a removal quantity-distance curve; comprising: Providing a fill level gradient; and wherein, when determining the fill level value of the filling material (120) in the container (100), the fill level value is determined based on the filling material quantity-distance curve (202, 204, 206, 208) and the fill distance in the case of a positive fill level gradient; or, in the case of a negative fill level gradient, is determined based on the removal material quantity-distance curve and the fill distance.
3. Method according to claim 1 or 2, wherein the fill level gradient is determined by means of the fill level detector (130).
4. Method according to one of the preceding steps, wherein the fill level detector (130) determines the fill distance contactlessly.
5. Method according to claim 1 or 2, wherein the characteristic filling material quantity-distance curve (202, 204, 206, 208) is determined by means of the following steps: iteratively filling a filling subset of a maximum filling quantity into the at least partially emptied container, wherein the filling distance is determined for each iterative filling of the filling subset in order to determine the filling quantity distance curve (202, 204, 206, 208).
6. Method according to one of the preceding claims, wherein the characteristic withdrawal-filling material quantity-distance curve is determined by means of the following steps: iteratively withdrawing a withdrawal subset of the maximum filling material quantity into the at least partially filled container, wherein the filling distance is determined for each iterative withdrawal of the withdrawal subset in order to determine the withdrawal-filling material quantity-distance curve.
7. Method according to one of the preceding claims, wherein the characteristic filling material quantity-distance curve (202, 204, 206, 208) and / or the characteristic removal material quantity-distance curve is determined based on the at least one characteristic feature of the filling material (120) and based on at least one characteristic property of the container (100) by means of simulation calculations.
8. The method according to claim 7, wherein the filling material quantity-distance curve (202, 204, 206, 208) is determined by means of a simulation calculation based on the at least one characteristic feature of the filling material, by determining an additive displacement to a filling material quantity-distance curve which is based exclusively on the geometric shape of the container.
9. Method according to one of the preceding claims, wherein the characteristic properties of the container comprise geometric dimensions of the container (120) and / or an internal shape of the container (120) and / or a relative position of a filling opening (102) in the container (120) and / or a relative position of a removal opening (104) in the container (120).
10. The method according to claim 9, wherein the relative position of a filling opening (102) in the container (100) and / or the relative position of a removal opening (104) in the container (100) is determined based on a sensor signal is determined to determine the filling quantity-distance curve (202, 204, 206, 208).
11. Method according to one of the preceding claims, wherein the characteristic feature of the filling material (120) comprises a flowability and / or a density and / or an adhesion property inside the container and / or a granularity and / or a graininess and / or a surface roughness and / or a designation of the filling material (120).
12. Method according to one of the preceding claims, wherein the filling material quantity-distance curve (202, 204, 206, 208) for the geometric dimensions of the container (100) and for the at least one characteristic feature of the filling material (120) is provided by means of a query to a database and / or by means of a simulation calculation.
13. A system for determining a fill level value of a filling material (120) in a container (100), comprising: a detector interface for providing a fill distance between a filling material detector (130) and a surface of the filling material (122, 124); an input interface for providing at least one characteristic feature of the filling material (120) and / or characteristic properties of the container (100); a provision interface for providing a filling material quantity-distance curve (202, 204, 206, 208) for the container; and a calculation unit that is signal-coupled to the input interface and / or the provision interface; and wherein the calculation unit is set up and configured to carry out one of the methods for determining a fill level value of the filling material (120) in the container (100) according to one of claims 1 to 10.
14. System according to claim 11, wherein the system comprises: the filling material detector (130); a database for providing the filling material quantity-distance curve (202, 204, 206, 208) for the filling material (120), having the at least one characteristic feature, in the container (100) having the characteristic properties; and / or a simulation unit which is configured to generate the characteristic filling material quantity-distance curve (202, 204, 206, 208) for the characteristic Properties of the container (100) and for the at least one characteristic feature of the filling material (120).
15. Use of the system according to claim 11 or 12 for determining a fill level value of a filling material (120) in a container (100).