DE102021213847A1 - Device for measuring weight - Google Patents

Abstract

Device (10, 23) for detecting a fill level (24) of a filling in a spring-loaded container (25, 51) and for detecting a weight of the spring-loaded container (25, 51), comprising: at least one distance measuring device (11, 21, 53) which is set up to detect a first distance between a surface (26) of the filling material in the spring-loaded container (25, 51) and the distance measuring device (11, 21, 53); wherein the distance measuring device (11, 21, 53) is further set up to detect a second distance (28) between the spring-loaded container (25, 51) and the distance measuring device (11, 21, 53); at least one evaluation unit (12, 22, 54), which is set up to calculate the filling level (24) of the filling material in the spring-mounted container from the first distance (27), the second distance (28) and container geometry data of the spring-mounted container (25, 51). to determine containers (25, 51), and wherein the evaluation unit (12, 22, 54) is also set up, from the second distance (28), a reference measurement of a distance between spring-loaded containers (25, 51) with a known reference weight and distance measuring device (11, 21, 53), and spring element data of the spring-loaded container (25, 51) to determine the weight of the spring-loaded container (25, 51).

Description

field of invention

The present invention relates to a device for detecting a fill level of a filling in a spring-loaded container and for detecting a weight of the spring-loaded container, a system for detecting a fill level of a filling in a spring-loaded container and for detecting a weight of the spring-loaded container, a use of a ToF Sensor in such a device or in such a system and use of an imaging sensor in such a device or in such a system.

background

In industrial plants, containers are used for the temporary storage of filling material (e.g. metal chips). For transport, logistics and/or further processing, knowledge of the fill level of the filling material in a container and of the weight of the container with filling material is necessary. Sensors for weight measurement are known in principle from the prior art. Sensors for level measurement are known in principle from the prior art.

In this context, it has now emerged that there is a need to provide a device for detecting the fill level of a filling in a container and a weight of a container; in particular, there is a need for an efficient, cost-effective and precise device for detecting a filling level of a filling in a container and a weight of a container. It is therefore an object of the present invention to provide a device for detecting a filling level of a filling material in a container and a weight of a container Provide weight of a container.

These and other objects that may be mentioned or recognized by a person skilled in the art upon reading the following description are solved by the subject matter of the independent claims. The dependent claims develop the central idea of the present invention in a particularly advantageous manner.

Summary of the Invention

A device according to the invention for detecting a fill level of a filling in a spring-loaded container and for detecting a weight of the spring-loaded container comprises: at least one distance measuring device that is set up to detect a first distance between a surface of the filling in the spring-loaded container and the distance measuring device ; wherein the distance measuring device is further set up to detect a second distance between the spring-loaded container and the distance measuring device; at least one evaluation unit which is set up to determine the filling level of the filling material in the spring-mounted container from the first distance, the second distance and container geometry data of the spring-loaded container, and wherein the evaluation unit is also set up to calculate from the second distance, a reference measurement, a Distance between spring-loaded container with known reference weight and distance measuring device, and spring element data of the spring-loaded container to determine the weight of the spring-loaded container.

The term fill level is to be understood broadly in the present case and means the height of a filling in a container. In the present case, the term filling material is to be understood broadly and includes a material of any shape that can be stored or stored in a container. The filling material preferably has a solid state of aggregation, but can also have a liquid state of aggregation. The filling material can be, for example, a plastic granulate, a ceramic powder, a metal chip, an agricultural product (e.g. beet pulp), an industrial liquid (e.g. waste oil). The term spring-mounted container is to be understood broadly in the present case and means a container for storing filling material, which is mounted via at least one spring element. The storage can be designed to be suspended, ie the container is suspended from a spring element. The storage can be designed to be lying or supporting, ie the container lies on a spring element or is supported on a spring element. The spring element can be a metal spring (for example a bending spring, disc spring, torsion spring) or a non-metal spring (for example a rubber spring, air spring or gas pressure spring). The term distance measuring device is to be understood broadly in the present case and means a measuring device that is set up to detect a distance. The distance measuring device can include an optical measuring sensor. The distance measuring device can include a ToF sensor (ie Time of Flight sensor). The ToF sensor can be a 1D radar sensor, for example. The distances are recorded by evaluating the echo curves of the 1D radar sensor. For example, the upper edge of the container, the surface of the filling material and the floor above which the container is stored show characteristic echo peaks, which are used in combination with the propagation time of the signal to determine the respective distance. The distance measuring device is placed above the container, for example, in such a way that it can detect the aforementioned characteristic echo peaks. The distance measuring device can include a LIDAR sensor. The distance measuring device can use a triangulation method to detect the distance. The distance measuring device can use a transit time measurement to record the distance. The distance measuring device can include a laser interferometer. The distance measuring device is preferably arranged above the container. The distance measuring device can be a single unit or can be divided into several units. The distance measuring device can include several measuring principles. The distance measuring device can include a computing unit, a data interface and a storage medium. The distance measuring device is set up to exchange data with the evaluation unit of the device via the data interface. The term evaluation unit is to be understood broadly in the present case and means an evaluation unit that is set up to determine the weight and fill level from the recorded distances, the reference measurement and container geometry data (eg container height). The evaluation unit can be one of the following: a CPU, a controller, an arithmetic logic unit, a microcomputer, a field programmable gate array (FPGA), a system-on-chip (SoC), a microprocessor, a PLC. The term container geometry data is to be understood broadly in the present case and specifically means a height of the container. The container geometry data can also include volume, external and/or internal dimensions. The term reference measurement is to be understood broadly here and means a measurement of the distance between the spring-loaded container (eg upper edge surface of the spring-loaded container) and the distance measuring device with a known weight. The weight can be, for example, the weight when the container is empty. The reference measurement is used to record the distance between the distance measuring device and the spring-loaded container without filling material, in order to determine whether the spring is elongating or compressing in the unloaded state (ie reference). The term spring element data is to be understood broadly in the present case and means here spring characteristic values that are suitable for inferring the force or the corresponding weight with the help of a spring deflection. The spring characteristic values can be transferred to the system via parameterization or the system can learn them itself or be determined by calibration. The spring element data include, for example, a spring constant and/or a spring characteristic. In the present case, the second distance preferably means the distance between an upper container edge of the spring-loaded container and the distance measuring device.

The present invention is based on the finding that knowledge of the filling level and the weight is necessary for the smooth handling of containers in logistics. These two measured variables normally require two measuring devices, a weight measuring device and a level measuring device. With the present invention, both measured values can be determined via a single measuring device, the distance measuring device of the device, and by means of an intelligent evaluation, the evaluation unit of the device. A path measurement is used as the only physical measuring principle. The basis for this is that the container stands on a spring element or is suspended from a spring element. The weight of the container changes the deflection of the spring element. The device determines the fill level directly from the distances and, based on knowledge of the spring element data, the weight. The fill level can be determined from the difference between the first distance and the second distance if the height of the container is known. The weight can be calculated by knowing the second distance, an optionally performed reference measurement and/or spring element data. Ultimately, the weight is determined via the spring compression or spring elongation and the spring characteristic. The spring compression or spring elongation is determined from the second distance and the reference measurement. Overall, a reliable and precise measurement of the filling level and the weight can thereby be made possible in an efficient manner. The omission of a second measuring device results in reduced acquisition, operating and maintenance costs. The determined weight and the determined filling level can advantageously be used as a trigger for collection in the logistics of containers in waste management and/or in recycling management. For example, if the container is overfilled with shavings as filling material, the shavings would fall out. If the container is too heavy, for example, it might no longer be possible to transport it. This problem could be advantageously solved by the trigger.

The device is preferably designed in such a way that the distance measuring device is also set up to determine a third distance between a floor above which the container is stored and the distance measuring device, and the evaluation unit is set up to determine the third distance to determine the fill level and/or or weight to use. By detecting the third distance, the accuracy in determining the filling level and the weight can be increased since any errors in determining the first distance and second distance can be minimized if the third distance is known.

The device is preferably designed in such a way that the third distance is measured indirectly by measuring a distance between the distance measuring device and a reference point, with the reference point being arranged elevated above the ground. By arranging the reference point above the ground, interference (eg unwanted reflections) can be reduced. This can have an advantageous effect on the measurement accuracy. In this case, the reference measuring point can be implemented via a reflector, for example a corner reflector. This can simplify the evaluation of the measurement signals and increase the accuracy.

The device is preferably designed in such a way that the second distance includes a measurement of a distance between a reflector, which is arranged on the container, and the distance measuring device.

The device is preferably designed in such a way that the distance measuring device comprises a ToF sensor. The ToF sensor is, for example, an infrared sensor or a PMD sensor.

The device is preferably designed in such a way that the distance measuring device comprises a plurality of ToF sensors for detecting the first distance, the second distance and the third distance, and/or the ToF sensors are based on different measuring principles. The large number of ToF sensors in combination with different measuring principles can have a positive effect on the accuracy. The large number of ToF sensors are each geared differently to the respective distance to be measured. This can have a positive effect on accuracy.

The device is preferably designed in such a way that the distance measuring device comprises an imaging sensor. The imaging sensor is, for example, a 3D radar sensor or a lidar sensor. This can have an advantageous effect on the accuracy when determining the filling level and the weight.

The device is preferably designed in such a way that the evaluation unit is also set up to receive weight data of the container and to correct the spring element data of the spring-loaded container from the received weight data and the second distance. For example, after the container has been weighed in another downstream process step, the weight data is transmitted to the device directly or to the device via a cloud. In combination with the second distance, the device can learn whether the measurement is correct and, if necessary, correct changes in the spring element data (e.g. due to wear). This enables continuous calibration. The device can thus be designed as a self-learning device. This can have a positive effect on the reliability and accuracy of the device. This also enables easy commissioning, since special knowledge of the spring element is not absolutely necessary.

The device is preferably designed such that the distance measuring device is set up to detect a fourth distance between an inner base of the spring-loaded container when empty and the distance measuring device and to derive a container height of the spring-loaded container from the fourth distance and the second distance. The second distance is preferably a distance between an upper container edge of the spring-loaded container and the distance measuring device. By detecting the fourth distance, the device can learn different, unknown container types, since it is able to determine or learn the container geometry data, here the container height, itself. This advantageously increases the flexibility of the device when using new, unknown container types for which there is no knowledge of a volume, a shape or a height.

Furthermore, the present invention relates to a system for detecting a filling level of a filling material in a spring-loaded container and for detecting a weight of the spring-loaded container, comprising: a device described in more detail above; a spring-loaded container.

The system is preferably designed in such a way that the spring-loaded container comprises a container which is arranged standing on a spring element.

The system is preferably designed in such a way that the spring-loaded container comprises a container which is arranged hanging on a spring element.

Preferably, the system further comprises a first reflector arranged on the container and/or a second reflector arranged on a floor above which the container is arranged.

Furthermore, the present invention relates to the use of a ToF sensor in a device described in more detail above or in a system described in more detail above.

Furthermore, the present invention relates to the use of an imaging sensor in a device described in more detail above or in a system described in more detail above.

Description of the Preferred Embodiments

• 1 eine schematische Teilansicht einer ersten bevorzugten Ausführungsform einer erfindungsgemäßen Vorrichtung;
• 2 eine schematische Teilansicht einer ersten bevorzugten Ausführungsform eines erfindungsgemäßen Systems; und
• 3 eine schematische Teilansicht einer zweiten bevorzugten Ausführungsform eines erfindungsgemäßen Systems.

A detailed description of the figures is given below

• 1 a schematic partial view of a first preferred embodiment of a device according to the invention;
• 2 a schematic partial view of a first preferred embodiment of a system according to the invention; and
• 3 a schematic partial view of a second preferred embodiment of a system according to the invention.

1 shows a schematic partial view of a first embodiment of a device 10 according to the invention. The device 10 is used to detect a filling level (cf. 24 2 ) of a filling in a spring-loaded container (cf. 25 2 ) and used to detect a weight of the spring-loaded container. The device 10 includes a distance measuring device 11, which is set up to measure a first distance (cf 2 ) between a surface (cf. 26 2 ) of a product in the spring-loaded container of the distance measuring device. In the present case, the distance measuring device is a ToF sensor, for example. The distance measuring device 11 is also set up to measure a second distance (cf 2 ) between the spring-loaded container and the distance measuring device. The device 10 also includes an evaluation unit 12, which is set up to calculate from the first distance, the second distance and container geometry data, in this case the container height (cf. 29 2 ) of the spring-loaded container to determine the filling level of the filling material in the spring-loaded container, and wherein the evaluation unit 12 is also set up to, from the second distance, a reference measurement of a distance between spring-loaded containers with a known reference weight and distance measuring device, and spring element data of the spring-loaded container, the determine the weight of the spring-loaded container. The distance measuring device 11 can also be set up to measure a third distance (cf. 30 2 ) between a floor above which the container is stored and the distance measuring device, and the evaluation unit is set up to use the third distance to determine the filling level and/or the weight. The third distance can be determined indirectly by measuring a distance between the distance measuring device and a reference point (cf. 33 2 ) are carried out, with the reference measuring point being arranged elevated above the ground. The second distance can be a measurement of a distance between a reflector (cf. 32 2 ), which is arranged on the spring-loaded container, and the distance measuring device. The distance measuring device 11 can include several ToF sensors. The ToF sensors can be based on different measuring principles. The distance measuring device 11 can also include an imaging sensor, for example a lidar sensor or a 3D radar sensor. The evaluation unit 12 can also be set up to receive weight data of the spring-loaded container and to correct the spring element data of the spring-loaded container from the received weight data and the second distance. The spring element data relate to a spring constant and/or a spring curve of a spring element (cf. 31 2 ) of the spring-loaded container. The distance measuring device 11 can also be set up to measure a fourth distance (cf. 29 2 ) between an inner floor of the spring-loaded container in the empty state and the distance measuring device and the evaluation unit can also be set up to calculate a container height (cf. 29 2 ) of the spring-loaded container.

2 shows a first schematic view of a system 20 according to the invention for detecting a fill level 24 of a filling in a spring-loaded container 25. The spring-loaded container 25 comprises an in 1 Device 23 described in more detail comprising a distance measuring device 21 and an evaluation unit 22. The spring-loaded container 25 is mounted upright on a spring element 31. The system 20 includes a first reflector 32 which is arranged on the container 25 . The system 20 further includes a second reflector 33 positioned above the floor. The second reflector 32 serves as a reference point for measuring the third distance. The first reflector is used to measure the second distance. The reflectors are, for example, corner reflectors.

3 shows a schematic partial view of a second preferred embodiment of a system 50. In contrast to that in 2 The system shown is the spring-loaded container 51 mounted hanging on a spring element 52. The device comprises a distance measuring device 53 and an evaluation unit 54 which are arranged above the spring-loaded container 51 . The remarks of 2 apply to 3 analogous.

However, the present invention is not limited to the preceding preferred exemplary embodiments, as long as it is covered by the subject matter of the following claims. In addition, it is pointed out that the terms "comprising" and "having" do not exclude other elements or steps and the indefinite articles "a" or "a" do not exclude a plurality. In addition, the concept of unity to be understood broadly, in particular this term should not be understood to mean that the respective units must be designed as integral components. The respective units can also be positioned differently. Finally, different units can also be combined in one assembly. Furthermore, it is pointed out that features or steps that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above.

Reference List

10, 23

contraption

11, 21, 53

distance measuring device

12, 22, 54

evaluation unit

20, 50

system

24

level

25, 51

spring-loaded container

26

surface of filling material

27

first distance

28

second distance

29

fourth distance or container height

30

third distance

31, 52

spring element

32

first reflector

33

second reflector

Claims (15)

Device (10, 23) for detecting a level (24) of a filling in a spring-loaded container (25, 51) and for detecting a weight of the spring-loaded container (25, 51), comprising: at least one distance measuring device (11, 21, 53) which is set up to detect a first distance between a surface (26) of the filling material in the spring-loaded container (25, 51) and the distance measuring device (11, 21, 53); wherein the distance measuring device (11, 21, 53) is further set up to detect a second distance (28) between the spring-loaded container (25, 51) and the distance measuring device (11, 21, 53); at least one evaluation unit (12, 22, 54), which is set up to calculate the filling level (24) of the filling material in the spring-mounted container from the first distance (27), the second distance (28) and container geometry data of the spring-mounted container (25, 51). determine containers (25, 51), and wherein the evaluation unit (12, 22, 54) is also set up to, from the second distance (28), a reference measurement of a distance between spring-loaded containers (25, 51) with a known reference weight and distance measuring device (11, 21, 53), and spring element data of the spring-loaded container (25, 51) to determine the weight of the spring-loaded container (25, 51). Device (10, 23) after claim 1 , wherein the distance measuring device (11, 21, 53) is further set up to detect a third distance (30) between a floor above which the spring-loaded container (25, 51) is mounted and the distance measuring device (11, 21, 53), and wherein the evaluation unit (12, 22, 54) is set up to use the third distance (30) to determine the filling level (24) and/or the weight. Device (10, 23) after claim 2 , wherein the third distance (30) takes place indirectly via a measurement of a distance between the distance measuring device (11, 21, 53) and a reference point (33), the reference point being arranged elevated above the ground. Device (10, 23) according to one of the preceding claims, wherein the second distance (28) is a measurement of a distance between a reflector (32) which is arranged on the spring-loaded container (25, 51) and the distance measuring device (11, 21 , 53). Device (10, 23) according to one of the preceding claims, wherein the distance measuring device (11, 21, 53) comprises a ToF sensor. Device (10, 23) according to one of the preceding claims, wherein the distance measuring device (11, 21, 53) comprises a plurality of ToF sensors for detecting the first distance (27), the second distance (28) and the third distance (30), and /or where the ToF sensors are based on different measurement principles. Device (10, 23) according to one of the preceding claims, wherein the distance measuring device (11, 21, 53) comprises an imaging sensor. Device (10, 23) according to one of the preceding claims, wherein the evaluation unit (12, 22, 54) is also set up to receive weight data of the spring-loaded container and from the received weight data and the second distance (28) the spring element data of the spring-loaded container (25, 51) to correct. Device (10, 23) according to one of the preceding claims, wherein the distance measuring device (11, 21, 53) is set up to measure a fourth distance (29) between an inner base of the spring-loaded container (25, 51) in the empty state and the distance measuring device (11, 21, 53) and from the fourth distance (29) and the second distance (28) a container height of the spring-loaded container ( 25, 51). System (20, 50) for detecting a fill level (24) of a filling in a spring-loaded container (25, 51) and for detecting a weight of the spring-loaded container (25, 51), comprising: Device (10, 23) according to one of Claims 1 until 9 ; a spring-loaded container (25, 51). system (20, 50) after claim 10 , wherein the spring-loaded container (25, 51) comprises a container which is arranged standing on a spring element (31). system (20, 50) after claim 10 wherein the spring-loaded container (25, 51) comprises a container which is suspended from a spring element (52). System (20, 50) according to one of Claims 10 until 12 , further comprising a first reflector (32) arranged on the spring loaded container (25, 51) and/or a second reflector (33) arranged on the floor or elevated above the floor above which the spring loaded container (25, 51). , is arranged. Use of a ToF sensor in a device (10, 23) according to one of Claims 1 until 9 or in a system (20, 50) according to any one of Claims 10 until 13 . Use of an imaging sensor in a device (10, 23) according to one of Claims 1 until 9 or in a system (20, 50) according to any one of Claims 10 until 13 .

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