DE102019202137A1 - ANGLE CORRECTED LEVEL DETERMINATION - Google Patents

Abstract

The invention relates to a method and a device (100) for determining fill level. The device (100) has, inter alia, a distance measuring device (10) which can be attached to a container (11) and is designed to measure a distance (d) to a surface (14) in the interior (13) of the tank that defines a level (L) Measure container (11). The device (100) also has a position sensor (15) which is designed to determine an angle of inclination (α) relative to a reference plane (16) that is dependent on the position of the distance measuring device (14), as well as a controller (19) which is designed to measure the distance by means of the distance measuring device (10) taking into account the determined angle of inclination (α) in order to obtain an angle-corrected measurement result (H), and to determine a current filling level of the container (11) based on the angle-corrected measurement result ( H) to be determined.

Description

The invention relates to a device and a method for determining the fill level of a container, and in particular an angle-corrected fill level determination of the aforementioned type.

In various areas of everyday life, it can be desirable to determine the current level of certain containers. For example, the liquid level in a glass or a bottle, the level of bulk material in a container, or the level of a waste container can be of interest. A simple visual inspection can be sufficient for this in many cases.

However, if a visual inspection should not be possible, for example if the container is not transparent or difficult to access, other solutions for determining the fill level must be found. Automated level meters are known for this purpose, a distinction being made between level sensors and level limit switches.

A fill level limit switch can work, for example, with a light barrier aligned perpendicular to the surface of the fill material. When the filling material has reached a certain height, it interrupts the light barrier and the filling level limit switch emits a corresponding signal.

Level sensors, on the other hand, can continuously determine the current level of the product in the container. Known devices for this purpose are, for example, swimmers, which are used in particular with liquids. Furthermore, electronic level meters are known which use optics, ultrasound, microwaves or RADAR, for example.

The electronic level meters in particular achieve good to very good results in automated level monitoring. However, these level meters must be mounted at predefined mounting positions on the container to be monitored in order to provide correct results. Some of these level meters also need to be calibrated before being used. In addition, depending on the requirements, some high-resolution level meters are required, which are correspondingly expensive. Known level gauges can determine the level very well when the container is upright.

However, if the container is tilted, the level on the respective side walls of the container changes. This can lead to the fact that the actual fill level is no longer correctly detected when the container is tilted, particularly with fill level gauges attached to the side.

It would therefore be desirable to improve known level gauges so that they deliver accurate results regardless of their respective mounting position and / or regardless of any tilting of the container and at the same time have a simple and inexpensive design.

Therefore, a device for level determination with the features of claim 1 and a method for level determination with the features of claim 14 are proposed. Embodiments and further advantageous aspects are named in the respective dependent claims.

The device according to the invention has a distance measuring device that can be attached to a container. The distance measuring device is designed to measure a distance to a surface defining a filling level in the interior of the container. The container can be any container that is designed to be filled with filling material. All liquid, solid or gaseous components with which the respective container can be at least partially filled can be referred to as filling material. The filling material can, for example, be a bulk material or a liquid. The surface of the filling material within the container determines the filling level of the container, also referred to as the filling level or the filling level. If the container should be empty, the surface of the container bottom determines the level. In this case the level would be zero. The surface in the interior of the container that defines the current fill level can thus be the surface of the product (when the container is completely or partially filled) or a surface of the container, for example the container bottom (when the container is empty). The device according to the invention also has a position sensor. The position sensor is designed to determine the position of the distance measuring device relative to a reference plane and to determine an angle of inclination with respect to this reference plane. For this purpose, the position sensor can be physically coupled to the distance measuring device so that the position sensor can detect a change in position of the distance measuring device and an associated angular deviation of the distance measuring device relative to the reference plane in real time. The reference plane can be a reference plane that serves as a reference for measuring the distance to the surface defining the fill level. If the distance measuring device should be tilted at a specific angle to the reference plane, the position sensor can determine this specific angle as a corresponding angle of inclination with respect to the reference plane. The angle of inclination therefore gives the geometric positional deviation of the distance measuring device compared to that used as a reference usable reference plane. The device according to the invention also has a control which is designed to carry out the measurement of the distance by means of the distance measurement device, taking into account the inclination angle determined. The measurement taking into account the angle of inclination leads to an angle-corrected measurement result in which the measurement result is corrected by the previously determined angle of inclination. The measurement result is therefore comparable to a reference measurement in the reference plane. That is, if the distance measuring device is aligned obliquely to the surface defining the filling level, the measurement result of the distance measurement can differ by the corresponding angle of inclination compared to a reference distance measurement to the reference plane. The measured level can therefore deviate from the actual level. To compensate for this, the measurement result is corrected according to the invention by the previously determined inclination angle and the corresponding angle-corrected measurement result of the distance measurement is then used to determine the actual fill level of the container. The device according to the invention thus has an angle correction in order to correct angular deviations of the distance measuring device relative to the reference plane. A major advantage of the device according to the invention is, among other things, that the position sensor can determine the current position or spatial orientation of the distance measuring device relative to the reference plane at any time. Thus, no complex calibration of the device is necessary after it has been attached to the container.

According to one embodiment, the position sensor can be designed to determine a static angle of inclination of the distance measuring device relative to the reference plane, the static angle of inclination resulting from the mounting position of the distance measuring device on the container. The distance measuring device can for example be mounted on the container at an angle with respect to the reference plane. This leads to a permanent angular deviation of the distance measuring device relative to the reference plane, i.e. the distance measuring device is permanently tilted by a certain angle of inclination relative to the reference plane. This angle of inclination is permanent (at least for the period during which the distance measuring device is mounted on the container) and is therefore static, so that a static measurement error results which can be calculated and corrected using the angle correction according to the invention.

According to a further exemplary embodiment, the position sensor can be designed to determine a dynamic angle of inclination of the distance measuring device relative to the reference plane, the dynamic angle of inclination resulting from a tilting of the container and changing as the tilting of the container varies. As an alternative or in addition to the aforementioned static angle of inclination, a dynamic angle of inclination can also be determined. If, for example, the container is tilted, the orientation of the distance measuring element changes dynamically with respect to the reference plane. This is especially and especially the case when the orientation of the filling material changes within the container when it is tilted. For example, when a glass is tilted, liquid surfaces always remain horizontal, so that the liquid surface rises on one side of the glass and at the same time drops on the opposite side of the glass. One can also say that while the glass is tilted out of the horizontal, the liquid remains in one and the same orientation, namely in the horizontal. A distance measuring device mounted on the container would tilt together with the container and would thus be deflected with respect to the liquid surface remaining in the horizontal by an angle of inclination that changes or dynamic with the tilt. This results in a dynamic or temporally variable measurement error which can be calculated out and corrected by means of the angle correction according to the invention.

According to a further exemplary embodiment, the controller can be designed to combine the dynamic angle of inclination and the static angle of inclination with one another in order to determine a common angle of inclination, and to carry out the measurement of the distance by means of the distance measuring device taking into account the common angle of inclination in order to obtain the angle-corrected measurement result receive. For example, the distance measuring device can be arranged tilted in a first direction relative to the reference plane on the container and have a corresponding static angular deviation. If the container is now tilted in this same direction, the tilting leads to an increase in the angular deviation of the distance measuring device relative to the reference plane. In this case, the controller can add the current (ie considered at a point in time t ₁ ) dynamic inclination angle and the static inclination angle to one another in order to obtain a common inclination angle. This common angles of inclination then forms the basis for the angle correction. If, on the other hand, the container is tilted in the opposite direction, this tilting leads to a decrease in the angular deviation of the distance measuring device relative to the reference plane. In this case, the control can subtract the current (ie considered at a point in time t ₁ ) dynamic inclination angle from the static inclination angle in order to determine a common inclination angle. This common angle of inclination then forms the basis for the angle correction. In the best case, the angular deviations or the dynamic and static angles of inclination can compensate each other.

According to a further exemplary embodiment, the reference plane can be a horizontal plane running horizontally. A horizontal plane running horizontally is understood to be a plane which extends essentially horizontally in the earth's gravity field, which is essentially oriented on the horizon and is perpendicular to the perpendicular in the earth's gravity field. This is particularly advantageous for liquids, but also for other filling goods that can behave like bulk goods, for example, since this type of filling material always tries to align itself with the horizontal plane even when the container is tilted. Thus, the horizontally running horizontal plane can serve very well as a reference for determining the angle of inclination in order to carry out an angle-corrected fill level measurement according to the invention of filling material which behaves essentially like bulk material.

According to a further exemplary embodiment, the controller can be designed to recognize one or more container areas that are outside the surface defining the filling level and to leave these one or more container areas unconsidered when measuring the distance. Such a container area lying outside the surface can be, for example, a container wall. Since the distance to the surface of the product is to be measured when measuring the distance, the container wall is generally of no interest, since it does not contribute to the distance measurement of the product surface. In particular in the case of simply constructed distance measuring devices, the inclusion of the container wall in the distance measurement to the product surface can even lead to incorrect measurement results when determining the fill level. In order to exclude this, the control can recognize these container areas and ignore them in the distance measurement. Thus, only the distance to the actual product surface is measured. The container wall can be identified, for example, by comparing several distance measurement results with one another. If, for example, two or more measuring points have an approximately similar or preferably the same perpendicular distance to the product surface, this indicates that both measuring points are on the same surface, e.g. on the product surface. If another measuring point deviates from this, this can indicate that this measuring point is not on the surface of interest but on other container areas, for example on a container wall. This is also referred to herein as edge detection.

According to a further exemplary embodiment, the distance measuring device can have an optical distance measuring device which has at least one emitter device and at least one detector device, the emitter device being designed to emit electromagnetic radiation into the interior of the container and the detector device being designed to be at the level defining the level Surface to detect reflected portions of the emitted radiation. The emitter device can, for example, have one or more light sources, such as, for example, light-emitting LEDs (Light Emitting Diode) or surface emitters or VCSEL (vertical-cavity surface-emitting laser) diodes. The detector device can, for example, have one or more light detectors, such as photodiodes and, in particular, SPADs (single-photon avalanche diodes) or multipixel image sensors. One advantage of the concept according to the invention is, among other things, that very inexpensive components, such as the aforementioned SPADs, can be used as detectors. There is thus no compelling need to use an expensive camera.

According to a further exemplary embodiment, the controller can be designed to determine the distance to the surface in the interior of the container that defines the filling level by means of triangulation or by means of a transit time measurement of the electromagnetic radiation. With triangulation, electromagnetic radiation is emitted at a first point and portions of the electromagnetic radiation reflected on the surface of the product are detected at a second point. By means of the distance between the first and second point and the angle of entry and / or exit of the electromagnetic radiation, the distance to the surface of the product and the current level can be determined. With the transit time measurement, which can also be referred to as time-of-flight (ToF) measurement, pulsed light flashes are emitted into the interior of the container and onto the surface of the product. The transit time that a transmitted light pulse needs to arrive at the detector determines the distance to the product surface, from which the current fill level can be determined.

According to a further exemplary embodiment, the emitter device can be designed to emit the electromagnetic radiation in the form of a directed single beam and the controller can be designed to measure the distance to the surface defining the fill level based on a transit time measurement of the directed single beam. These types of emitter devices are also referred to as one-dimensional emitter devices. A point-like light beam, preferably pulsed, is emitted into the interior of the container. The one at the Part of the light beam partially reflected on the product surface is detected by the detector device and the transit time of the light beam is determined. This can be used to determine the distance to the product surface and thus the current level.

According to a further embodiment, the emitter device can be designed to emit the electromagnetic radiation in the form of a beam cone and the controller can be designed to measure the distance to the surface defining the fill level based on a transit time measurement based on an exposure of the fill level defining surface by means of the jet cone. It is preferably a pulsed electromagnetic radiation by means of which the interior of the container and thus the surface defining the fill level is flashed. The emitter device can have an opening angle which is dimensioned such that the emitted beam cone completely covers the container bottom. It is also conceivable that the emitter device has an opening angle which is dimensioned such that the emitted beam cone covers not only the container bottom but also sections of the container walls, whereby a larger area within the container can be measured, even if it is tilted. For example, the greater the tilting of the container, the more advantageous a large opening angle. However, since the container walls do not contribute to the measurement of the product surface and can even falsify the distance measurement, this can be recognized according to the invention using the edge recognition described above, so that the recognized container wall sections are not taken into account in the distance measurement.

According to a further exemplary embodiment, the detector device can have a multiplicity of detector elements arranged in an array. This increases the potential detection area and is particularly advantageous when using an emitter device which emits a beam cone. For example, the array can have an arrangement of 15x15 detector elements (e.g. SPADs). The emitter device (e.g. VCSEL) can for example be arranged centrally in the array.

According to a further exemplary embodiment, the position sensor can be an acceleration sensor. Such acceleration sensors are available very inexpensively nowadays. It is preferably a three-dimensional acceleration sensor which measures the acceleration in all three spatial directions. If there is no movement of the acceleration sensor, the acceleration sensor only measures the acceleration due to gravity and delivers a signal that represents the orientation in space. If the acceleration sensor is functionally coupled to the distance measuring device, the acceleration sensor can thus also display the position of the distance measuring device in space.

According to a further exemplary embodiment, the position sensor and the distance measuring device can be arranged on a common substrate. This is preferably a rigid substrate, such as a printed circuit board or PCB. After performing a calibration of the position sensor relative to the distance measuring device on the common substrate, the position sensor can display the spatial orientation of the substrate and thus the spatial orientation of the position sensor and the distance measuring device on the substrate.

Another aspect relates to a corresponding method for determining the fill level. The method includes, inter alia, measuring a distance to a surface defining a fill level inside a container by means of a distance measuring device attached to the container. A further step of the method includes determining the position of the distance measuring device relative to a reference plane and determining an angle of inclination of the distance measuring device with respect to this reference plane. According to the invention, the distance is measured taking into account the determined angle of inclination in order to obtain an angle-corrected measurement result. According to the invention, a current fill level of the container is determined based on the angle-corrected measurement result.

• 1 eine schematische Ansicht einer Vorrichtung zur Füllstandsermittlung gemäß einem Beispiel,
• 2A-2C schematische Ansichten einer Vorrichtung zur Füllstandsermittlung gemäß einem weiteren Beispiel,
• 3A, 3B Draufsichten auf eine Distanzmessvorrichtung und einen damit funktional gekoppelten Lagesensor,
• 4A-4D schematische Ansichten einer Vorrichtung zur Füllstandsermittlung gemäß einem weiteren Beispiel,
• 5A, 5B schematische Ansichten einer Vorrichtung zur Füllstandsermittlung zur Erläuterung der Winkelkorrektur gemäß einem Beispiel,
• 6A-6D schematische Ansichten einer Vorrichtung zur Füllstandsermittlung gemäß einem weiteren Beispiel, und
• 7 ein schematisches Blockdiagramm zur Verdeutlichung eines Verfahrens zur Füllstandsermittlung gemäß einem Beispiel.

Some exemplary embodiments are shown by way of example in the drawing and are explained below. Show it:

• 1 a schematic view of a device for level determination according to an example,
• 2A-2C schematic views of a device for level determination according to a further example,
• 3A , 3B Top views of a distance measuring device and a position sensor functionally coupled therewith,
• 4A-4D schematic views of a device for level determination according to a further example,
• 5A , 5B schematic views of a device for level determination to explain the angle correction according to an example,
• 6A-6D schematic views of a device for level determination according to a further example, and
• 7th a schematic block diagram to illustrate a method for level determination according to an example.

In the following, exemplary embodiments are described in more detail with reference to the figures, elements with the same or similar function being provided with the same reference symbols.

Method steps that are shown in a block diagram and explained with reference to the same can also be carried out in a sequence other than that shown or described. In addition, method steps that relate to a specific feature of a device are interchangeable with this same feature of the device, which also applies the other way around.

In some exemplary embodiments, optical distance measuring devices are mentioned that can measure distances by means of electromagnetic radiation. Here light is mentioned as an example of electromagnetic radiation. This light can have proportions in the visible as well as in the ultraviolet and infrared spectral range. Accordingly, LEDs and laser diodes for emitting light are described herein by way of example. However, electromagnetic radiation in other wavelength ranges can also be used with the device according to the invention, e.g. High frequency waves such as microwaves. Instead of electromagnetic radiation, sound waves can also be used. Accordingly, systems with corresponding emitter devices and detector devices would then have to be used, such as radar, sonar or ultrasound systems.

1 Figure 3 shows a first example of a device 100 for level determination. The device 100 has a distance measuring device 10 on. The distance measuring device 10 can on a container 11 to be ordered. This container 11 can be any container for holding solid, liquid and / or gaseous substances. The container 11 can be filled with these same substances, which is why these substances are also referred to here as filling goods 12 are designated. The distance measuring device 10 can, as shown, on a top, such as a lid 11a , the container 11 be arranged. Alternatively, the distance measuring device 10 but also on side walls 11b , 11c or on the ground 11d of the container 11 be arranged.

The distance measuring device 10 however, should preferably be so on the container 11 be arranged that the distance measuring device 10 Distances inside 13th of the container 11 can measure. So can the distance measuring device 10 for example on one of the container interior 13th facing side of the lid 11a , the container walls 11b , 11c or the bottom of the container 11d be arranged. Alternatively, it would be conceivable that the distance measuring device 10 on an outside of the container 11 is arranged, and an opening in the container 11 access to the distance measuring device 10 to the interior 13th of the container 11 allowed.

The distance measuring device 10 is designed to be a distance d to a level L ₁ defining surface 14th inside the container 11 to eat. This surface 14th for example, as shown, a surface of in the container 11 the contents 12 his and the level L ₁ would be the current level of the container 11 correspond. Should the container 11 be empty, this would correspond to this surface 14th the container bottom 11d and the level L ₁ would be zero.

The device 100 also has a position sensor 15th on. The position sensor 15th is designed to one of the location of the distance measuring device 10 dependent angle of inclination with respect to a reference plane 16 to investigate. The position sensor 15th can adjust the alignment of the distance measuring device 10 for example parallel to the reference plane 16 determine what is in 1 with the horizontal dashed line 17th (Horizontal plane) is shown. Alternatively or additionally, the position sensor 15th the alignment of the distance measuring device 10 perpendicular to the reference plane 16 determine what is in 1 with the vertical dashed line 18th (Perpendicular) is indicated. For determining angular deviations of the distance measuring device 10 compared to the reference plane 16 can therefore use the horizontal 17th and / or the plumb bob 18th serve as a reference. These angular deviations are also referred to herein as the angle of inclination α with respect to the reference plane 16 and explained in more detail below.

The device 100 also has a controller 19th on. The control 19th is configured to measure the distance d between the distance measuring device 10 and the surface 14th to carry out taking into account a determined inclination angle α in order to obtain an angle-corrected measurement result and to obtain a current level L ₁ of the container 11 based on the angle-corrected measurement result. This is also referred to herein as angle correction. The angle-corrected measurement result is the actual distance H between the distance measuring device 10 and the surface 14th , measured directly along the vertical 18th , ie without angular deviations.

In the in 1 The example shown is the distance measuring device 10 exactly perpendicular to the reference plane 16 aligned, ie there is no angular deviation from the perpendicular 18th and the angle of inclination α is thus zero. The measured distance d therefore corresponds to the actual distance H between the distance measuring device 10 and the surface 14th , ie d = H, and the device 100 can accordingly refrain from an angle correction.

The 2A , 2 B and 2C show examples of the implementation of angle corrections according to the concept described herein. For the sake of clarity, only the distance measuring device is shown here 10 , each without the position sensor 15th and without the controller 19th , drawn.

2A shows a container 11 who is essentially standing straight. The distance measuring device 10 is arranged in such a way that its measuring beam 21st essentially perpendicular to the reference plane 16 is aligned. In the example shown here, the container is 11 empty. The surface defining the fill level 14th in this case would be the floor 11d of the container 11 . If there is a product 12 in the container 11 would be, the surface of the product would 12 define the level. Surfaces of filling goods that behave like bulk goods as well as surfaces of liquids will be aligned essentially horizontally or parallel to the earth's horizon. It is therefore advantageous if the reference plane 16 is also a horizontal plane that is always aligned horizontally to the earth's horizon. The angular deviations or the angles of inclination α are, as mentioned above, preferably perpendicular to the horizontal reference plane 16 certainly.

The horizontal reference plane 16 accordingly forms a reference plane with respect to which the angular deviation of the measuring beam of the distance measuring device is present 10 is determined. In 2A is the distance measuring device 10 central (based on the width of the container 11 ) on the container 11 arranged and the measuring beam 21st meets perpendicular to the horizontally aligned reference plane 16 on. Thus, by definition, there is no angular deviation between the distance measuring device 10 and the reference plane 16 available.

In 2 B is an example of a case in which the distance measuring device 10 obliquely on the container 11 is arranged. The measuring device 10 , and thus also the measuring beam it emits 21st , thus has an angular offset α _S with respect to the reference plane 16 on. The measuring beam 21st has the same angular offset α _S and therefore meets the reference plane obliquely, ie at angle α _S 16 on. This angle α _S is also referred to as the angle of inclination. The angle of inclination α _S can be determined by means of the position sensor 15th to be determined.

Due to the inclination angle α _S that is present due to the assembly, for example, the distance measuring device deviates 10 measured distance d between the distance measuring device 10 and the surface defining the fill level 14th from the actual distance H along the vertical 18th from. This deviation can be determined using trigonometric relationships. Since the angle of inclination α _S by means of the position sensor 15th can be determined and is therefore known, the actual distance can be calculated using the cosine set H to the surface defining the fill level 14th can be calculated, where H = cos (α) * d. This is also known as the angle correction, and the calculated distance H corresponds to an angle-corrected measurement result. The angle-corrected measurement result H again represents the actual filling level in the container 11

The in 2A The case described is also referred to as angle correction with a static angle of inclination. The static angle of inclination α _S can be derived, for example, from the mounting position of the differential measuring device 10 on the container 11 surrender. If the distance measuring device 10 obliquely on the container 11 is mounted, a corresponding angle of inclination α _{S is established} , which usually remains unchanged for the duration of the installation and is therefore also referred to as the static angle of inclination α _S.

2C shows an example of a further conceivable case that describes an angle correction with a dynamic inclination angle α _D. As can be seen, changes when the container is tilted 11 the angle of incidence of the measuring beam by the angle α _D 21st on the product surface 14th , which in this example defines the fill level, to the same extent. That is, between the distance measuring device 10 and the reference plane 16 an angle of inclination α _D arises, which in this case affects the tilting of the container 11 is due.

Since the tilting of the container 11 compared to the fixed mounting position of the distance measuring device 10 on the container 11 can be variable, the angle of inclination α _D can vary accordingly. Therefore, this is due to the variable tilting of the container 11 caused angles of inclination also referred to as dynamic angle of inclination α _D.

The dynamic angle of inclination α _D can occur as an alternative or in addition to the static angle of inclination α _S described above. In the in 2C example shown are both the dynamic and static angles of inclination α _D , α _{S are} shown.

In order to carry out an angle correction, the dynamic and static angles of inclination α _D , α _S should be taken into account together in this case. That is, the dynamic and static angles of inclination α _D , α _S can be combined in this case to form a common angle of inclination α _G. For example, the dynamic and static angles of inclination α _D , α _S can be added up or subtracted from one another for this purpose. The dynamic and static angles of inclination α _D , α _{S are} usually added up when both angles of inclination α _D , α _{S have the} same mathematical sign, for example when the container is tilted 11 in comparison to the merely static angle of inclination α _S, an increase in the angle of incidence of the measuring beam 21st on the product surface 14th causes. The dynamic and static angles of inclination α _D , α _{S are} generally subtracted from one another when the two angles of inclination α _D , α _{S have} different mathematical signs, for example when the container is tilted 11 In comparison to the merely static angle of inclination α _S, a reduction in the angle of incidence of the measuring beam 21st on the product surface 14th causes.

As mentioned at the beginning, the surface of the product strives 14th always after a horizontal alignment parallel to the reference plane 16 and thus the respective angle of inclination α _D , α _S with respect to the product surface also changes accordingly 14th . When tilting an empty container 11 the bottom of the container naturally tilts 11d to the same extent with. In this case, despite tilting the container 11 of course no dynamic angle of inclination α _D result because the distance measuring device 10 always fixed to the container bottom 11d is aligned and thus only the static angle of inclination α _{S is} of interest.

The detection of an empty container 11 thus prevents the container from tilting 11 unaffected.

In principle, the angle of inclination α can therefore be composed of a static angle of inclination α _S and a dynamic angle of inclination α _D. The angle of inclination α can, for example, be an angle between the reference plane 16 and an observed measuring beam 21st the distance measuring device 10 represent. As mentioned at the outset, the angle of inclination α can be defined, for example, in such a way that when the observed measuring beam hits perpendicularly 21st on the reference plane 16 the angle of inclination is assumed to be zero, ie α = 0 °. This can, as in the 2A-2C mapped, for example, be the case with the static angle of inclination α _S , the perpendicular 18th as a reference for determining angular deviations from the reference plane 16 serves. Alternatively, angular deviations can be parallel to the reference plane 16 determine what is in the 2A-2C is shown using the example of the dynamic angle of inclination α _D.

The one from the distance measuring device 10 emitted measuring beam 21st can for example be an optical beam. As in the 3A and 3B is shown, provide some embodiments that the distance measuring device 10 an optical distance measuring device 30th having the at least one emitter device 31 and at least one detector device 32 having, the emitter device 31 is designed to take electromagnetic radiation into the interior 13th of the container 11 to send out and the detector device 32 is designed to be on the surface defining the fill level 14th to detect reflected components of the emitted radiation.

The position sensor 15th can be along a horizontal plane 35a , 35b around the distance measuring device 10 be arranged around. Alternatively, the position sensor 15th in a vertical plane on or below the distance measuring device 10 to be ordered. The position sensors are advantageous 15th and the distance measuring device 10 mechanically rigidly connected to each other, so that a change in position of the position sensor 15th directly with a change in position of the distance measuring device 10 goes hand in hand. Some exemplary embodiments provide for this that the position sensor 15th and the distance measuring device 10 can be arranged together on one and the same substrate.

The emitter device 31 may have one or more emitters, such as an LED or a laser diode, for example a VCSEL diode. The emitter device 31 can be a one-dimensional emitter device which is designed to emit the electromagnetic radiation in the form of a directed single beam 21st send out, as well as this exemplarily in the 2A , 2 B and 2C is shown. In this case the controller can 19th be designed to measure the distance to the surface defining the fill level 14th based on a time of flight measurement of the directed single beam 21st execute. This optical time-of-flight measurement is also known as a time-of-flight (ToF) measurement.

Alternatively or in addition to that in the 2A-2C discussed one-dimensional emitter device 31 can be a three-dimensional emitter device 31 be provided. The 4A-4D show an example of a three-dimensional emitter device 31 which is designed to emit electromagnetic radiation in the form of a beam cone 41 to send out. Here, too, is only for the sake of clarity the distance measuring device 10 without the position sensor 15th and without the controller 19th drawn.

The control (not explicitly shown here) 19th is designed in this case to measure the distance to the surface defining the fill level 14th to perform based on a transit time measurement based on an exposure of the surface defining the fill level 14th by means of the jet cone 41 based. The emitter device 31 emit the electromagnetic radiation advantageously in a time-pulsed form, for example in the form of light flashes.

As in 4A is shown as an example, is the jet cone 41 the interior of the container 13th facing oriented. The jet cone 41 can have multiple sections, e.g. individual rays A. , B. , C. , D. , E. , exhibit. The drawn beam sections A. , B. , C. , D. , E. each correspond to a measuring distance d _A , d _B , d _C , d _D , d _E between the distance measuring device 10 and the surface 14th .

Depending on the mounting position of the distance measuring device 10 on the container 11 can be individual beam sections B. directly perpendicular to the surface 14th be aligned and thus have no static angle of inclination, and again other beam sections A. , C. , D. , E. can have a certain static angle of inclination with respect to the reference plane 16 exhibit. This is explained in more detail below with reference to FIG 5A described.

Some of the beam sections A. , B. , C. of the jet cone 41 can on the surface defining the fill level 14th hit. Because the container 11 in the in 4A is empty, represents the container bottom 11d the surface defining the fill level 14th . The one on the bottom of the container 11d impacting sections A. , B. , C. of the jet cone 41 are circled and marked with the reference symbol Y at the appropriate point. Along these beam sections A. , B. , C. of the jet cone 41 can measure distance using the distance measuring device 10 be carried out in the manner described above.

Other sections D. , E. of the jet cone 41 can on container sections outside the surface defining the fill level 14th hit. For example, these other sections D. , E. of the jet cone 41 on a container wall 11b , 11c hit. These, for example, on the side walls of the container 11b , 11c impacting sections D. , E. of the jet cone 41 are circled and marked with the reference symbol X at the appropriate point.

These sections D. , E. of the jet cone 41 do not contribute to the distance measurement to the surface 14th and thus contribute to the level determination and can negatively influence the level determination or even completely falsify it and thus make it invalid.

According to conceivable exemplary embodiments, the controller can 19th therefore be designed to accommodate one or more container areas 11b , 11c that are outside the surface that defines the level 14th lie, to recognize and these one or more container areas 11b , 11c not be taken into account when determining the fill level

For a more detailed explanation, refer temporarily to the 5A and 5B referenced. Here are examples of several beam sections, e.g. several individual beams, A. , B. , C. , D. , E. of the jet cone 41 drawn. Some beam sections A. , B. , C. meet on the container bottom 11d on, which in this case is the surface defining the fill level 14th represents. The container bottom 11d is in this case parallel to the reference plane 16 . Other beam sections D. , E. meet on the side walls of the container 11b , 11c on.

The first beam section A. has a static angle of inclination α with respect to the reference plane 16 on. The second beam section B. has a static angle of inclination β with respect to the reference plane 16 on. The third beam section C. has a static angle of inclination γ with respect to the reference plane 16 on. The fourth beam section D. has a static angle of inclination δ with respect to the reference plane 16 on. The fifth beam section E. has a static angle of inclination ε with respect to the reference plane 16 on. The angles of inclination α, β, γ, δ, ε are determined by means of the position sensor 15th determinable and therefore known.

Knowing the respective angles of inclination α, β, γ, δ, ε, the actual distance H to the surface 14th (in this case to the bottom of the container 11d) can be determined in the manner described at the outset, ie using the angle correction. 5B shows an example of an isolated beam section B. with the static angle of inclination β to determine the actual distance H . According to the cosine equation described above H = cos (β) * B. the angle correction can be made and the actual distance H the distance measuring device 10 perpendicular to the surface 14th to be determined.

Coming back to 5A it can thus be determined that the beam sections A. , B. , C. after the angle correction has taken place all the same (or at least a very similar) actual distance H perpendicular to that parallel to the reference plane 16 trending surface 14th , ie to the container bottom 11d , exhibit. This suggests that these beam sections A. , B. , C. on a common level lie. This in turn is an indication that these beam sections A. , B. , C. on the surface defining the fill level 14th lie.

The beam sections E. , D. however, each meet on a lateral container wall 11b , 11c on. After the angle correction has taken place, these two beam sections point E. , D. a different (usually shorter) actual distance compared to that on the surface 14th incident beam sections A. , B. , C. on. Than the actual distance H becomes the angle-corrected distance of the respective beam section A. , B. , C. , D. , E. perpendicular to the reference plane 16 or perpendicular to the surface 14th Roger that. The angle corrected distance H is also referred to herein as the angle-corrected measurement result of the distance measurement.

Coming back to 4A So can the controller 19th Container areas not of interest in the manner described above, such as, for example, lateral container walls 11b , 11c , and ignore them when determining the level. That is, the controls 19th can be designed to allow a comparison between several individual angle-corrected measurement results H perform and, based on the result of the comparison, individual of the compared angle-corrected measurement results H to be discarded or to be disregarded for the purpose of determining the fill level.

4B shows another example, with filling material here 12 in the container 11 is available. The surface of the product 12 in this example represents the surface defining the fill level 14th . The level in the container 11 has not yet risen to the extent that the beam sections E. , D. on the surface 14th would hit. That is, the beam sections E. , D. still hit the side walls of the container 11b , 11c and can, as described above, be disregarded when determining the level.

4C shows another example where the level in the container 11 has increased so far that the beam sections E. , D. on the product surface 14th hit. These beam sections E. , D. can now also contribute to determining the fill level. In the example shown here, all beam sections hit A. , B. , C. , D. , E. of the jet cone 41 on the surface defining the fill level 14th so that all beam sections A. , B. , C. , D. , E. can also contribute to determining the level. The more beam sections of the beam cone 41 are taken into account when determining the fill level, the more accurate the result will be.

4D shows another example in which, in addition to the aforementioned static angles of inclination α, β, γ, δ, ε, the container is now also tilted 11 conditional dynamic inclination angle α _{D is} added. For the purpose of angle correction, the dynamic angle of inclination α _D can be used for each individual distance measurement with the respective beam section-individual static angle of inclination α, β, γ, δ, ε of the respective beam section A. , B. , C. , D. , E. combined (eg added) to obtain a common angle of inclination α _G. The angle correction then takes place taking into account the common angle of inclination α _G , as has already been explained above.

In the case of a multi-dimensional emitter device 31 , the electromagnetic radiation in the form of a beam cone 41 can emit, so can individual beam sections A. , B. , C. , D. , E. each has its own static angle of inclination α, β, γ, δ, ε with respect to the reference plane 16 exhibit. This depends, among other things, on the design of the emitter device 31 as well as the mounting position of the distance measuring device 10 on the container 11 from.

As in the 6A-6D is shown, the distance measuring device can alternatively or additionally 10 overall skewed compared to the reference plane 16 be mounted. A further static angle of inclination α _{S can be} set here, which is caused by tilting the distance measuring device 10 relative to the reference plane 16 and thus also from the mounting position of the distance measuring device 10 on the container 11 depends. However, in the case of the angle correction, the individual beam section-individual static angles of inclination α, β, γ, δ, ε of the individual beam sections A. , B. , C. , D. , E. must be taken into account individually for each beam section is the tilting of the distance measuring device 10 Conditional static angle of inclination α _{S in} general for the entire beam cone 41 valid. The angle correction can therefore be carried out taking into account a common angle of inclination α _G , which is made up of a combination of one of the existing beam section-individual static angles of inclination α, β, γ, δ, ε, the generally applicable static angle of inclination α _S and, if available, the dynamic angle of inclination α _D can be composed.

That in the 6A-6D The example shown differs from the previous one with reference to the 4A-4D discussed example to the extent that the distance measuring device 10 compared to the reference plane 16 is arranged tilted. Accordingly, a generally applicable static angle of inclination α _S must also be taken into account here for the angle correction.

In 6A hit individual beam sections A. , B. , C. , E. on the surface defining the fill level 14th , in this case on the bottom of the container 11d , on. A beam section D. meets on the side of the container wall 11c on. This beam section D. can be disregarded when determining the fill level according to the above statements.

For angle correction with the individual beam sections A. , B. , C. , E. The respective static angles of inclination α, β, γ, ε ( 5A) and the generally applicable static angle of inclination α _S combined, for example added up, to form a common static angle of inclination α _G , so that for example for the beam section B. the following applies: α _G = β + α _S.

In 6B is the container 11 partly with filling material 12 filled. The surface of the product 12 in this example represents the surface defining the fill level 14th . The level in the container 11 has not yet risen as far as that the beam section D. on the surface 14th would hit. That is, the beam section D. still hits the side container wall 11c and can, according to the description above, remain unconsidered when determining the level.

6C shows another example where the level in the container 11 has increased so far that the beam section has now also increased D. on the product surface 14th hits. This beam section D. can now also contribute to determining the fill level. In the in 6C the example shown hit all beam sections A. , B. , C. , D. , E. of the jet cone 41 on the surface defining the fill level 14th so that all beam sections A. , B. , C. , D. , E. can contribute to determining the fill level. The more beam sections of the beam cone 41 are taken into account when determining the fill level, the more accurate the result will be.

6D shows another example in which, in addition to the aforementioned beam section-individual static angles of inclination α, β, γ, δ, ε and the generally applicable static angle of inclination α _S, the container is now also tilted 11 conditional dynamic inclination angle α _D with respect to the reference plane 16 is available. For the purpose of angle correction, the dynamic angle of inclination α _D can be used for each individual distance measurement with the respective static angle of inclination α, β, γ, δ, ε of the respective beam section A. , B. , C. , D. , E. and the generally applicable static angle of inclination α _{S are} combined (for example added) in order to obtain a common angle of inclination α _G. The angle correction then takes place taking into account the common angle of inclination α _G , as has already been explained above.

As the emitter device 31 Depending on the design, it can be designed in such a way that, for example, the radiation angle or aperture angle of the beam cone to be emitted 41 is fixed, the individual beam section-individual static angles of inclination α, β, γ, δ, ε of the control 19th be known permanently. In this case, the individual beam section-individual static angles of inclination α, β, γ, δ, ε would not have to be considered and taken into account separately for the angle correction. In this case, it would be sufficient to only use the generally valid static angle of inclination α _S , which results from a static tilting of the distance measuring device 10 compared to the reference plane 16 as well as when the container is tilted 11 occurring dynamic inclination angle α _D must be taken into account.

7th shows a block diagram for the schematic representation of a method for determining the fill level according to the concept described herein.

In block 701 becomes a distance to a surface defining a fill level 14th internally 13th a container 11 by means of one on the container 11 attached distance measuring device 10 measured.

In block 702 becomes the position of the distance measuring device 10 relative to a reference plane 16 determined and an angle of inclination α of the distance measuring device 10 compared to this reference plane 16 is determined. The aforementioned measurement of the distance takes place taking into account the determined angle of inclination α in order to obtain an angle-corrected measurement result.

In block 703 becomes a current filling level of the container 11 determined based on the angle-corrected measurement result.

• Das erfinderische Konzept beschreibt eine selbstnivellierende Multizonen-basierte Füllstandsermittlung.

In the following, the invention is to be summarized again in other words:

• The inventive concept describes a self-leveling multi-zone-based level determination.

A calibration of a simple one- or three-dimensional distance sensor 10 can with the help of a position determination in space through the combination of several sensors, including here in particular through a multi-dimensional acceleration sensor 15th , guaranteed. A reliable level determination of liquids and bulk goods, or goods that behave like bulk goods, should also be available for measurement setups with a measuring element attached at any angle 10 guaranteed.

For example, the 2A-2C this application initially using a one-dimensional sensor 10 . The absolute measured distance d in 2A and 2 B deviates due to the positioning of the sensor 10 from each other. In order to achieve reliable measurement results, the location of the acceleration sensor 15th the angle to the zero plane 16 calculated. Any point in the measuring container can be used 11 are recorded and a real image of the surface structure can be determined. To 2C Not only the sensor can do 10 moved and tilted from the zero position, but also the container 11 , in which it is measured, itself. The position is arbitrary in all three dimensions. 2C also shows the error caused by the absolute measured value when the container is tilted 11 is produced. This error is corrected via the angle correction described here.

The 4A-4D show in this context an example of a measuring setup with a centered measuring element 10 . First, according to the invention, the edge regions X of the reflection field of the sensor 10 determined and identified as irrelevant measured values. This is independent of the filling level of the container 11 ( 4A , 4B) . In particular, it is a matter of the determination using coarse-resolution sensors 10 can be carried out. There is no need to create an image recording, such as that provided by a camera, for example. If a threshold value is exceeded by the degree of filling, the correction of the edge areas can be omitted ( 4C ).

zunächst die Höhe „h“ aufgrund der gemessenen Distanz „B“ im Feld bestimmt werden. (5B) „h“ entspricht hierbei der Ankathete des aufgespannten Dreiecks des Winkels zur Lotrechten „α“ und der Hypotenuse „B“.The correction of the edge areas requires a prior recognition of the edge areas. The 5A and 5B show an exemplary embodiment of edge area detection. Because the angle of the emitted rays A. , B. , C. , D. , E. to the perpendicular 18th of the three-dimensional distance sensor 10 is known (determined by the acceleration sensor 15th ), with the angle equation: $$H=cOs\left(\alpha \right)\ast \mathrm{B.}$$

first the height " H "Based on the measured distance" B. “Can be determined in the field. ( 5B) " H "Corresponds to the adjacent side of the spanned triangle of the angle to the perpendicular" α "and the hypotenuse" B. ".

The calculation is with the angles β, γ, δ, ε and the corresponding distance values " A. , C. , D. " and " E. “Of the sensor 10 and the resulting heights " H "Transferable accordingly. ( 5A)

Assuming that at least two adjacent measured values in the measuring field have the same distance, a level can be assumed that corresponds to the actual level. The edge areas can thus be determined as such and excluded from the distance calculation.

In the 4D The oblique position shown can be corrected in accordance with the concept for angle correction described herein. Both the position of the sensor 10 as well as the position of the container 11 in all degrees of freedom is arbitrary. The correction of the edge areas X of the container 11 is not affected by this.

The 6A-6D show this behavior through an optimized and, due to the local conditions, necessary lateral attachment of the measurement setup on the container 11 .

So that the position of the distance measuring element 10 can be correctly determined is the position of the acceleration sensor 15th in relation to the measuring element 10 crucial. The 3A and 3B show two useful arrangements. 3A shows a vertical alignment of the measuring element 10 to the accelerometer 15th . 3B shows a horizontal alignment of the measuring element 10 to the accelerometer 15th .

The above-described embodiments are merely illustrative of the principles of the present invention. It is to be understood that modifications and variations of the arrangements and details described herein will be apparent to other skilled persons. It is therefore intended that the invention be limited only by the scope of protection of the following patent claims and not by the specific details presented herein with reference to the description and explanation of the exemplary embodiments.

Although some aspects have been described in connection with a device, it goes without saying that these aspects also represent a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Analogously, aspects that have been described in connection with or as a method step also represent a description of a corresponding block or details or features of a corresponding device.

Some or all of the method steps can be performed by hardware apparatus (or using hardware apparatus) such as a microprocessor, programmable computer, or electronic circuit. In some embodiments, some or more of the most important process steps can be performed by such apparatus.

Depending on the specific implementation requirements, exemplary embodiments of the invention can be implemented in hardware or in software or at least partially in hardware or at least partially in software. The implementation can be carried out using a digital storage medium such as a floppy disk, a DVD, a BluRay disk, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, a hard disk or some other magnetic or optical memory Memory are carried out on which electronically readable control signals are stored, which can interact with a programmable computer system or cooperate in such a way that the respective method is carried out. Therefore, the digital storage medium can be computer readable.

Some exemplary embodiments according to the invention thus include a data carrier which has electronically readable control signals which are able to interact with a programmable computer system in such a way that one of the methods described herein is carried out.

In general, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being effective to carry out one of the methods when the computer program product runs on a computer.

The program code can for example also be stored on a machine-readable carrier.

Other exemplary embodiments include the computer program for performing one of the methods described herein, the computer program being stored on a machine-readable carrier. In other words, an exemplary embodiment of the method according to the invention is thus a computer program which has a program code for carrying out one of the methods described here when the computer program runs on a computer.

A further exemplary embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for performing one of the methods described herein is recorded. The data carrier or the digital storage medium or the computer-readable medium are typically tangible and / or non-transitory.

A further exemplary embodiment of the method according to the invention is thus a data stream or a sequence of signals which represents or represents the computer program for performing one of the methods described herein. The data stream or the sequence of signals can, for example, be configured to be transferred via a data communication connection, for example via the Internet.

Another exemplary embodiment comprises a processing device, for example a computer or a programmable logic component, which is configured or adapted to carry out one of the methods described herein.

Another exemplary embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

A further exemplary embodiment according to the invention comprises a device or a system which is designed to transmit a computer program for performing at least one of the methods described herein to a receiver. The transmission can take place electronically or optically, for example. The receiver can be, for example, a computer, a mobile device, a storage device or a similar device. The device or the system can for example comprise a file server for transmitting the computer program to the recipient.

In some exemplary embodiments, a programmable logic component (for example a field-programmable gate array, an FPGA) can be used to carry out some or all of the functionalities of the methods described herein. In some exemplary embodiments, a field-programmable gate array can interact with a microprocessor in order to carry out one of the methods described herein. In general, in some exemplary embodiments, the methods are performed by any hardware device. This can be universally applicable hardware such as a computer processor (CPU) or hardware specific to the method such as an ASIC.

Claims (15)

Device (100) for determining the filling level, comprising: a distance measuring device (10) which can be attached to a container (11) and is designed to measure a distance (d) to a filling level (L ₁ ) defining surface (14) inside (13) of the container (11) to measure a position sensor (15) which is designed to an angle of inclination (α) relative to a reference plane (16) dependent on the position of the distance measuring device (14) determine, and a controller (19) which is designed to measure the distance (d) by means of the distance measuring device (10) taking into account the determined inclination angle (α) to obtain an angle-corrected measurement result (H), and to a to determine the current level of the container (11) based on the angle-corrected measurement result (H). Device (100) after Claim 1 , wherein the position sensor (15) is designed to determine a static angle of inclination (α _S ) of the distance measuring device (10) relative to the reference plane (16), the static angle of inclination (α _S ) from a static mounting position of the distance measuring device (10) depends on the container (11). Device (100) after Claim 1 or 2 , the position sensor (15) being designed to determine a dynamic angle of inclination (α _D ) of the distance measuring device (10) relative to the reference plane (16), the dynamic angle of inclination (α _D ) resulting from a tilting of the container (11) and is variable with varying tilting of the container (11). Device (100) after Claim 3 , wherein the controller (19) is designed to combine the dynamic angle of inclination (α _D ) and the static angle of inclination (α _S ) with one another in order to determine a common angle of inclination (α _G ), and to measure the distance (d) by means of the distance measuring device (10) taking into account the common angle of inclination (α _G ) in order to obtain the angle-corrected measurement result (H). Device (100) according to one of the Claims 1 to 4th , wherein the reference plane (16) is a horizontally extending horizontal plane. Device (100) according to one of the Claims 1 to 5 , wherein the controller (19) is designed to recognize one or more container areas (11b, 11c) which lie outside the surface (14) defining the filling level (L ₁ ) and to recognize these one or more container areas (11b, 11c) not be taken into account when determining the fill level. Device (100) according to one of the Claims 1 to 6th , wherein the distance measuring device (10) has an optical distance measuring device (30) which has at least one emitter device (31) and at least one detector device (32), wherein the emitter device (31) is designed to emit electromagnetic radiation into the interior (13) of the The container (11) and the detector device (32) being designed to detect portions of the emitted radiation that are reflected on the surface (14) defining the filling level (L ₁ ). Device (100) after Claim 7 , the controller (19) being designed to determine the distance (d) to the surface (14) in the interior (13) of the container (11) defining the filling level (L ₁ ) by means of triangulation or by means of a transit time measurement of the electromagnetic radiation . Device (100) after Claim 7 or 8th , wherein the emitter device (31) is designed to emit the electromagnetic radiation in the form of a directed single beam (21) and wherein the controller (19) is designed to measure the distance (d) to the level (L ₁ ) defining the level Execute surface (14) based on a travel time measurement of the directed single beam (21). Device (100) according to one of the Claims 7 to 9 , wherein the emitter device (31) is designed to emit the electromagnetic radiation in the form of a beam cone (41) and wherein the controller (19) is designed to measure the distance (d) to the surface defining the fill level (L ₁ ) (14) based on a transit time measurement based on an exposure of the surface (14) defining the fill level (L ₁ ) by means of the beam cone (41). Device (100) according to one of the Claims 7 to 10 wherein the detector device (32) has a plurality of detector elements arranged in an array. Device (100) according to one of the Claims 1 to 11 , wherein the position sensor (15) is an acceleration sensor. Device (100) according to one of the Claims 1 to 12 , wherein the position sensor (15) and the distance measuring device (10) are arranged on a common substrate. Method for determining the filling level with the following steps: measuring a distance (d) to a surface (14) defining a filling level (L ₁ ) inside (13) of a container (11) by means of a distance measuring device (10) that can be attached to the container (11) , Determining the position of the distance measuring device (10) relative to a reference plane (16) and determining an angle of inclination (α) of the distance measuring device (10) with respect to this reference plane (16), wherein the measurement of the distance (d) takes place taking into account the determined inclination angle (α) in order to obtain an angle-corrected measurement result (H), and determination of a current filling level of the container (11) based on the angle-corrected measurement result (H). Computer program with a program code for carrying out the method Claim 14 when the program is running on a computer.

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