WO2022106028A1

WO2022106028A1 - Calibration-free radar-difference fill level measurement

Info

Publication number: WO2022106028A1
Application number: PCT/EP2020/082908
Authority: WO
Inventors: Clemens Hengstler; Matthias Schmidt
Original assignee: Vega Grieshaber Kg
Priority date: 2020-11-20
Filing date: 2020-11-20
Publication date: 2022-05-27
Also published as: DE112020007785A5

Abstract

The invention relates to a measurement sensor which is designed for fill level measurement of a medium in a container for process automation in the industrial or private environment and has a first sensor unit, a second sensor unit and an analysis unit. The first sensor unit is designed to transmit and to receive a first measurement signal, in order to detect a first distance (d1) between the measurement sensor and the medium, whereas a second sensor unit is designed to transmit and to receive a second measurement signal, in order to detect a second distance (d2) between the measurement sensor and the floor of the container. The analysis unit is designed to determine a fill level from a difference between the first distance (d1) and the second distance (d2). The invention also relates to a measurement system having a measurement sensor and a lift device, to the use of a measurement sensor or a measurement system for calibration-free fill level measurement or fill level monitoring of a medium in a container or for an ergonomic material removal from a container for process automation in the industrial environment.

Description

Adjustment-free radar differential level measurement

field of invention

The invention relates to process measurement technology and process automation in the industrial or private environment. In particular, the invention relates to a measuring sensor, set up for level measurement of a medium in a container for process automation in an industrial environment, the use of a measuring sensor for level measurement or level monitoring for process automation in an industrial environment, a measuring system set up for process automation in an industrial environment, the use a measuring system for calibration-free level measurement or level monitoring of a medium in a container or for ergonomic material removal from a container for process automation in an industrial environment, a method for level measurement of a medium in a container for process automation in an industrial environment, a program element and a computer-readable medium.

Technical background

Radar measuring devices are often used in process automation in industrial environments. For example, the filling level or the limit level of a filling material in a container can be determined according to the transit time principle. Typically, both the measuring device and the container are stationary and the fill level can be determined directly by measuring the distance between the measuring device and the surface of the filling.

summary It is an object of the present invention to specify a flexible measuring system for dynamic level measurement for process automation.

This object is solved by the features of the independent patent claim. Developments of the invention result from the dependent patent claims and the following description of embodiments.

A first aspect of the present disclosure relates to a measuring sensor that is set up to measure the fill level of a medium in a container for process automation in an industrial or private environment and has a first sensor unit, a second sensor unit and an evaluation unit. The first sensor unit is set up to emit and receive a first measurement signal in order to detect a first distance di between the measurement sensor and the medium. The second sensor unit is set up to emit and receive a second measurement signal in order to detect a second distance d2 between the measurement sensor and the bottom of the container. The evaluation unit is set up to determine a filling level from a difference between the first distance di and the second distance d2.

The measurement sensor can be a radar sensor that works according to the transit time principle in order to determine the fill level of the medium in the container. The medium can be a filling material, such as a fluid or a bulk material. The measuring sensor can be arranged and set up outside of the container or above the container in such a way that the first measuring signal for detecting the first distance di can be emitted by the first sensor unit in the direction of the medium inside the container and reflected directly by the surface of the medium, while the second measurement signal for detecting the second distance d2 is not directly in the direction of the bottom of the container, but outside the container in the direction of a reference surface which can be at the same height as the bottom of the container or on which the container can be arranged, can be emitted and reflected by the reference surface. This means that the detection of the second distance d2 can take place completely outside the container, while the detection of the first distance di can take place at least partially inside the container. The second distance d2 can therefore be a vertical or perpendicular distance between the measuring sensor and the bottom of the container. Furthermore, the measurement sensor can be set up to receive the first measurement signal and the second measurement signal, each of which is reflected by the surface of the medium or by the reference surface of the bottom of the container, through the first sensor unit and the second sensor unit and further to the evaluation unit transferred to. The evaluation unit can be set up to determine the first distance di based on the first measurement signal and the second distance d2 based on the second measurement signal and to form or calculate the difference f between the first distance di and the second distance d2. Since the difference corresponds to the filling level of the medium in the container, the evaluation unit can thus be set up to determine the filling level f of the medium from the difference using the formula f=d2−di.

The arrangement of two radar measurements by means of the first and second sensor units, which can be combined in one measuring sensor, can result in a filling level measuring system without adjustment or a differential radar measuring sensor. It is advantageous that the fill level of the medium can be determined by the differential measurement independently of the position or height of the measuring sensor and/or the container. In other words, a dynamic filling level measurement or filling level monitoring using the measuring sensor with the first and second sensor units can be possible, even if the measuring sensor and/or the container can/can move.

It can be provided that the detection of the first distance di and the detection of the second distance d2 can take place simultaneously or alternately, for example according to a predetermined sequence, by means of the first sensor unit and the second sensor unit.

The term "container" is to be interpreted broadly. The container can be set up for storing and transporting an object, which can be a liquid or a solid, for example. For example, the container can be an IBC container that is filled with liquid or bulk material. The container can also be a carrier, e.g. B. a support plate without container walls, on this several goods or packaging can be arranged. In this case, the second distance d2 can correspond to the distance between the support plate as a reference surface for the lower side of the medium and the measuring sensor. According to a further embodiment, the first sensor unit and the second sensor unit are designed to be integrated in the measuring sensor.

The first sensor unit and the second sensor unit can be arranged, for example, in a common housing of the measuring sensor and thus form a one-piece measuring sensor.

Alternatively, the first sensor unit and the second sensor unit can each be designed as an independent sensor. The evaluation unit can be in the form of a higher-level computing system or a higher-level computing unit, such as a PLC (programmable logic controller).

The first sensor unit and the second sensor unit can be arranged on the same side of the container in order to emit the first measurement signal and the second measurement signal from the same side of the container. In addition, the evaluation unit can also be integrated in the measurement sensor and at the same time be electrically connected to the first sensor unit and the second sensor unit in order to record the first measurement signal and the second measurement signal.

For example, the measuring sensor or the radar difference measuring sensor can be designed as a continuously measuring system, so that the measuring sensor can be supplied with energy by means of a cable. Furthermore, the measured values, namely the first distance di, the second distance d2 and/or the fill level f of the medium, can be communicated or transmitted to a receiver or a higher-level system via an interface that can be arranged in the measuring sensor.

Alternatively, the measuring sensor can be designed as a self-sufficient measuring sensor that has an internal power supply, such as a power supply. B. has a battery, a rechargeable battery or a solar cell.

Wireless communication, for example by radio, can thus take place between the self-sufficient measuring sensor and an external receiver, which can be a computer, a data center or a cloud system, for example. Compared to wired communication, in which the energy required for the measurement should always be in use, with the availability of advanced, energy-saving wireless technologies, battery-powered sensors can be used to an increasing extent Monitoring of fill level, limit level or pressure values are becoming increasingly important. There are particular advantages for applications in the area of process automation in the industrial or private environment, e.g. B. logistics.

The term "process automation in the industrial or private environment" can be understood as a sub-area of technology that includes all measures for the operation of machines and systems without human intervention. One goal of process automation is to automate the interaction of individual components of a plant in the chemical, food, pharmaceutical, petroleum, paper, cement, shipping or mining sectors. A large number of sensors can be used for this purpose, which are particularly adapted to the specific requirements of the process industry, such as mechanical stability, insensitivity to contamination, extreme temperatures and extreme pressures. Measured values from these sensors are usually transmitted to a control room, in which process parameters such as fill level, limit level, flow rate, pressure or density can be monitored and settings for the entire plant can be changed manually or automatically.

A sub-area of process automation in the industrial environment relates to logistics automation. With the help of distance and angle sensors, processes within a building or within a single logistics facility are automated in the field of logistics automation. Typical applications are found, for example, in systems for logistics automation in the area of baggage and freight handling at airports, in the area of traffic monitoring (toll systems), in retail, in parcel distribution or in the area of building security (access control). What is meant by the examples listed above is that presence detection in combination with a precise measurement of the size and position of an object is required by the respective application side. Sensors based on optical measuring methods using lasers, LEDs, 2D cameras or 3D cameras, which record distances according to the transit time principle (time of flight, ToF), can be used for this purpose.

Another sub-area of process automation in the industrial environment relates to factory/manufacturing automation. Use cases for this can be found in a wide variety of industries such as automobile manufacturing, food production, the pharmaceutical industry or generally in the field of packaging. The aim of factory automation is to enable the production of goods using machines, production lines and/or robots automate, ie run without human intervention. The sensors used here and the specific requirements with regard to the measurement accuracy when detecting the position and size of an object are comparable to those in the previous example of logistics automation.

For example, inventory management across locations can be implemented in a simple manner by continuous, automated monitoring of the fill levels in mobile containers and preferably wireless transmission of the values to a central evaluation point in the area of goods logistics. Using the recorded data, depending on the problem in question, significant cost reductions can be achieved if, for example, the route for delivery vehicles to supply supplies can be optimized.

The autonomous measuring sensor can also have a timer, a logic circuit, arranged between the timer of the evaluation unit, and a switching element, set up to connect the power supply, the logic circuit and the evaluation unit. In addition, it can be provided that an evaluation unit or a processor can set up a self-locking signal for activating the energy supply.

According to a further embodiment, the first sensor unit has a first antenna for emitting and receiving the first measurement signal, and the second sensor unit has a second antenna for emitting and receiving the second measurement signal.

The first antenna or the second antenna can be a horn antenna, a parabolic antenna or an array antenna. In addition, the first antenna and the second antenna can be designed in the same way or as a combination of two different types of antenna.

It can also be provided that the evaluation unit can be designed as a common electronics and the electronics further an HF unit for generating a radio frequency (HF) wave signal and for guiding the HF signal in the first antenna or in the second Antenna can be set up, may have. Furthermore, the electronics can have a power pack for connecting to an external power supply or an internal, self-sufficient power supply. The electronics can also have a communication unit, which can be wired as an interface for connecting to the external receiver for the measurement sensor, or can be wireless communication, such as B. by radio, can be set up with the external receiver.

A distance unit can be provided, which can be arranged in the measuring sensor between the first antenna and the second antenna and configured to connect the first antenna and the second antenna and to change the distance between the first antenna and the second antenna in such a way that the first measurement signal for detecting the first distance di can be emitted in the direction of the medium and reflected by the surface of the medium and that the second measurement signal for detecting the second distance d2 in the direction of the reference surface, which is located outside the container or on the can be arranged at the same height as the container bottom, can be emitted and reflected from the reference surface. The spacer unit can have a rail, by means of which the distance between the first antenna and the second antenna can be designed to be adjustable electronically or mechanically.

According to a further embodiment, the first sensor unit and the second sensor unit are arranged in such a way that the first measurement signal from the first sensor unit and the second measurement signal from the second sensor unit are transmitted and/or received in parallel to one another.

The first antenna and the second antenna of the measuring sensor can be arranged in such a way that the first antenna and the second antenna can be directed downwards in a same direction or in parallel along the vertical direction. For example, the first antenna and the second antenna can be arranged on the same side or the lower side of the measurement sensor or the evaluation unit, so that the first measurement signal and the second measurement signal are parallel to one another along the vertical direction or perpendicular to the surface of the medium or the reference surface of the container bottom can be emitted. In addition, the first measurement signal and the second measurement signal can run upwards along the opposite vertical direction due to the reflection on the surface of the medium and on the reference surface of the container bottom and can be received by the first antenna and the second antenna.

According to a further embodiment, the measurement sensor also has a deflection device which is set up to deflect the beam direction of the second measurement signal of the second sensor unit in order to determine the second distance d2.

The deflection device can be a reflector or a mirror, for example. According to a further embodiment, the deflection device is arranged at a distance from the first sensor unit and the second sensor unit.

For example, the deflection device can be provided as a separate unit outside the housing, in which the first sensor unit, the second sensor unit and the evaluation unit can be integrated or arranged in a compact manner. The deflection device can be arranged at a predetermined distance from the first sensor unit and the second sensor unit. Alternatively, it can be provided that the distance between the deflection device and the entirety of the first sensor unit, the second sensor unit and the evaluation unit can be changed manually or automatically.

According to a further embodiment, the deflection device is designed to be adjustable. The first sensor unit and the second sensor unit are arranged in such a way that the second measurement signal is emitted perpendicularly or at an angle to the first measurement signal and, after being deflected by the deflection device, runs parallel to the first measurement signal.

The first sensor unit and the second sensor unit can be arranged on different sides of the measuring sensor or the evaluation unit. For example, the first sensor unit or the first antenna can be arranged on the underside of the expanding device in order to emit the first measurement signal in the direction of the container or the surface of the medium or along the vertical direction, and the second sensor unit or the second antenna on the side or be arranged on the right-hand side in order to emit the second measurement signal in the direction of the deflection device or the reflector, for example perpendicularly or at an angle to the first measurement signal. In other words, the orientation of the second antenna of the measurement sensor can be offset by 90° or at a predetermined angle relative to the first antenna. For example, the second measurement signal can be emitted by the second sensor unit along a substantially horizontal direction. The deflection device can be set up to reflect and deflect the second measurement signal or to change the beam direction of the second measurement signal after the reflection in such a way that the second measurement signal after the reflection or the deflection is parallel to the first measurement signal, i.e. along the vertical direction or in Can be sent down towards the reference surface of the container bottom and reflected on the reference surface. The second measurement signal reflected by the reference surface can run in the opposite direction of the measurement beam before being reflected on the reference surface and can be received again by the second sensor unit or the second antenna by means of the deflection device.

By arranging the first and second sensor units on different sides of the measuring sensor or the evaluation unit, the measuring sensor can be made compact.

Furthermore, the measurement sensor can have a control unit that can be set up to adjust the deflection device mechanically or electronically and to change the orientation of the deflection device relative to the first sensor unit and/or the second sensor unit.

Alternatively or additionally, it can be provided that the arrangement of the second sensor unit or the second antenna can be rotated from the vertical direction by 90° or by a predetermined angle of less than 90° by means of the control unit. The control unit can be set up to teach and control the adjustment of the deflection device and/or the rotation of the second antenna to optimize the alignment of the second measurement signal when the measurement sensor is started up using a button or a software button. However, it should be noted that the lateral arrangement of the second sensor unit or the at least partially lateral detection of the second measurement signal by means of the deflection device cannot be implemented for all frequency bands, but for example in 60 GHz technology.

Alternatively, the deflection device can be designed to be adjustable and the first sensor unit and the second sensor unit can be arranged in such a way that the first measurement signal is emitted perpendicularly or at an angle to the second measurement signal and, after deflection by the deflection device, parallel to the second measurement signal in the direction of the medium , i.e. along the vertical direction, can be retransmitted.

A further aspect relates to the use of a measuring sensor for level measurement of a medium in a container or for level monitoring for process automation in an industrial environment. By forming the difference between the two distance values, namely the first distance di and the second distance d2, the fill level of the medium in the container can advantageously be determined in real time, even if the first distance and the second distance change. As a result, dynamic fill level monitoring using the measuring sensor can be made possible without arranging the container or the measuring sensor at a fixed location.

A further aspect relates to a measuring system which is set up for process automation in an industrial environment and has a measuring sensor set up for measuring the fill level of a medium in a container and a lift device. The lifting device is set up to change the second distance d2 between the measuring sensor and the bottom of the container. The measuring system is set up to determine the fill level from the difference between the first distance di and the second distance d2 when the second distance d2 changes.

The measuring sensor can thus be in the form of a radar difference sensor, which has a first sensor unit for determining a first distance di between the measuring sensor and the surface of the medium, a second sensor unit for determining a second distance di between the measuring sensor and the bottom of the container and have an evaluation unit for determining the fill level of the medium by calculating the difference between the first and second distances and can be used in a flexible measuring system. The filling level measurement in the measuring system can advantageously be independent of the position or height of the container.

In addition, the installation position of the measurement sensor can be flexibly spaced apart from the container. The measuring sensor can be arranged, for example, above the container at a specified height or at a specified distance from a specified fill level or a limit level of the medium.

Alternatively, the measuring sensor can be arranged in the measuring system in such a way that the relative distance between the measuring sensor and the container or the bottom of the container or the medium in the container can be made variable or changeable, for example by means of the lift device or the lift system .

The lift device can also have a control element for changing the height of the measuring sensor or of the container. For example, the lift device can do this be set up to change the height of the measuring sensor, which can be attached or mounted on the lift device, by means of the control element. In addition, the lifting device can be set up to change the height of the container, which can be arranged on the lifting device, for example, at the same time.

According to a further embodiment, the lift device is arranged below the container and set up to change the second distance d2 between the measuring sensor and the bottom of the container in order to keep the first distance di between the measuring sensor and the medium constant.

The lift device can be arranged below the container. Provision can also be made for the measuring sensor to be fastened or arranged above the container in the measuring system and for the container to be able to move by means of the lifting device, for example along the direction of the first measuring signal or the vertical direction. The reference surface for determining the second distance d2 can be implemented on the upper side or surface of the lift device. The movement vector of the container can thus be aligned parallel or anti-parallel to the vertical beam direction of the first measurement signal.

The lift device can be set up to move the container during the change in the fill level of the medium, namely during the filling or emptying of the container, in such a way that the surface of the medium can always be at the same height. Thus, the measuring system with the filling material surface that is kept constant can be used advantageously in automated production, for example, especially when the filling material or the medium is to be removed ergonomically by a worker. As soon as the filling material is removed from the container, the lift device can be set up to adjust the height of the container in such a way that the surface of the medium can be at the same height and the material layer or the removal height remain the same for the worker and the worker the contents can be removed ergonomically.

Provision can also be made for the height of the container to be changed in a scalable manner by the control element of the lifting device by means of the adjustment-free measuring system. For example, the change in height between the minimum or empty level and the maximum level or the limit level of the medium can be scaled from 0 - 100% be executed. The lifting device can thus be set up to keep the height of the container constant at a predetermined height from the scale of 0-100%.

It can be provided that the height change of the measuring sensor can be carried out manually or automatically. With the automatic height change of the container, the measuring system can be designed as a non-contact filling level measuring system, in which the measuring sensor measures the filling level of the filling material from above, the measured value, namely the change in the first distance di or the filling level, to the lift device or to the control element of the Lift device can be transmitted and the lift device can adjust the height of the container by the change in the first distance di or the fill level based on the measured value.

According to a further embodiment, the measuring sensor is attached to the lifting device and the lifting device is set up to move the measuring sensor and to change the second distance d2 between the measuring sensor and the bottom of the container and the first distance di between the measuring sensor and the medium at the same time. The measuring system is set up to determine the filling level from the difference between the first distance di and the second distance d2, independently of the movement of the measuring sensor by means of the lifting device.

Alternatively, the lifting device can be arranged above the container and above the measuring sensor. The measuring sensor can, for example, be attached to the lift device or on the underside of the lift device. The lift device can thus be set up, for example, to change the measurement sensor along the vertical direction, ie parallel or antiparallel to the beam direction of the first measurement sensor. A flexible measuring system with a height-adjustable measuring sensor can thus be formed. This can result in an adjustment-free level measurement system since the measurement sensor can move simultaneously and with an equal change in distance relative to the medium and the bottom of the container. The fill level can therefore be determined by calculating the difference between the first distance di between the measuring sensor and the surface of the medium and the second distance d2 between the measuring sensor and the container bottom, independently of the set height of the measuring sensor.

The measuring system can thus enable the flexibly adaptable installation of the measuring sensor, for example the installation of a measuring sensor below a height-adjustable desk to measure the fill level of a wastepaper basket. A further aspect relates to the use of a measuring system for calibration-free level measurement or level monitoring of a medium in a container.

Furthermore, the calibration-free measuring system or the calibration-free measuring sensor, which works after the difference is formed by means of two sensor units, namely the first sensor unit and the second sensor unit, can be used to measure the fill level or to monitor a water/wastewater system or to measure the level of a sluice be. Compared to the conventional measuring system, in which two separate sensors can be used and the comparison of the measured values of the two sensors can be calculated manually, the measuring system or the measuring sensor with the integrated first and second sensor units and the integrated evaluation unit can be a simple, efficient and precise level measurement system.

Another aspect relates to the use of a measuring system for ergonomic material removal from a container for process automation in an industrial environment.

A further aspect relates to a method using a measuring sensor for measuring the fill level of a medium in a container for process automation in an industrial environment. The method has the following steps: sending and receiving a first measurement signal by means of a first sensor unit in order to detect a first distance di between the measurement sensor and the medium, sending and receiving a second measurement signal by means of a second sensor unit in order to to detect the second distance d2 between the measuring sensor and the bottom of the container and to determine a filling level from a difference between the first distance di and the second distance d2 by means of an evaluation unit.

A further aspect relates to a program element which, when executed on a processor of a measuring sensor, instructs the measuring sensor to carry out the following steps: sending and receiving a first measuring signal by means of a first sensor unit in order to determine a first distance di between the measuring sensor and the medium, sending and receiving a second measurement signal by means of a second sensor unit in order to record a second distance d2 between the measurement sensor and the bottom of the container, and determining a level from a difference between the first distance di and the second distance d2 by means of an evaluation unit. Another aspect relates to a computer-readable medium on which a program element is stored.

Embodiments of the present disclosure are described below with reference to the figures. If the same reference symbols are used in the description of the figures, they describe the same or similar elements. The representations in the figures are schematic and not to scale.

Brief description of the figures

1 schematically shows a measuring system with a measuring sensor for measuring the fill level of a medium in a container for process automation in an industrial environment according to an embodiment.

2a schematically shows a measuring system with a measuring sensor for measuring the fill level of a medium in a container for process automation in an industrial environment according to a further embodiment.

2b schematically shows a measuring system with a measuring sensor for measuring the fill level of a medium in a container for process automation in an industrial environment according to a further embodiment.

3 schematically shows a structure of a measurement sensor according to an embodiment.

4 schematically shows a flow chart of a method for measuring the fill level of a medium in a container for process automation in an industrial environment according to one embodiment.

Detailed Description of Embodiments

1 schematically shows a measuring system 10 for process automation in an industrial environment. The measuring system has a measuring sensor 100, which is set up for level measurement of a medium in a container 50, and a lift device 200, which can be set up to move the container 50, for example, up or down along a move in vertical direction. The container 50 can be arranged on the lift device 200 . The lifting device 200 can therefore be set up to carry the container 50 .

The measuring sensor 100 has a sensor unit 110 , a second sensor unit 120 and an evaluation unit 130 . The first sensor unit 110 is set up to transmit and receive a first measurement signal 115 in order to detect a first distance di between the measurement sensor 100 and the medium 55 or the surface of the medium. The second sensor unit 120 is set up to emit and receive a second measurement signal 125 in order to detect a second distance d2 between the measurement sensor 100 and the bottom of the container 50 . The evaluation unit 130 is set up to determine a filling level of the medium 55 from a difference between the first distance di and the second distance d2.

In FIG. 1, the first sensor unit 110, the second sensor unit 120 and the evaluation unit 130 can be integrated and combined in a common housing of the measuring sensor 100. In addition, the first sensor unit 110 can have a first antenna for emitting and receiving the first measurement signal 115 and the second sensor unit 120 can have a second antenna for emitting and receiving the second measurement signal 125. For example, the first antenna and the second antenna in Fig. 1 can each be designed as a horn antenna. Alternatively, the first antenna and the second antenna can each be designed as a parabolic antenna or an array antenna.

The first sensor unit 110 and the second sensor unit 120 can be arranged in the measuring sensor 100 in such a way that the first antenna and the second antenna can be aligned parallel to one another and arranged on the same side or the lower side of the expansion unit 130, and that the first measurement signal 115 of the first sensor unit 110 and the second measurement signal 125 of the second sensor unit 120 can be transmitted and/or received in parallel to one another. Thus, the first measurement signal 115 and the second measurement signal 125 can run along the vertical direction, i.e. respectively be emitted downwards through the first sensor unit 110 and the second sensor unit 120, and after the reflections upwards in the direction of the first sensor unit 110 and the second sensor unit 120 further.

The measurement sensor 110 can be set up to emit the first measurement signal 115 in the direction of the medium 55 or the surface of the medium in order to measure the first distance di between the measuring sensor 100 and the medium 55 to be detected directly by the reflection on the surface of the medium. In addition, the measurement sensor 110 can be set up to emit the second measurement signal 125 in the direction of a reference surface that is at the same height as the bottom of the container 50, outside the container, by the second distance d2 between the measurement sensor 100 and the container bottom capture. For example, the reference surface can be the top surface or side of the lift device 200 on which the container 50 can be arranged.

A distance unit can additionally be provided in order to change the distance between the first antenna and the second antenna and to adapt the measurement sensor 100 for use in a flexible measurement system 10 .

The lift device 200 can therefore be set up, the second distance d2 between the measuring sensor 100 and the bottom of the container 50 even during the change in the level of the medium 55, such as. B. during the filling or emptying of the container 50 to change. For example, the lifting device 200 can be set up to change the second distance d2 between the measuring sensor 100 and the bottom of the container 50 in order to keep the first distance di between the measuring sensor 100 and the medium 55 constant. In other words, the lift device 200 can adjust the height of the container 50 according to the change in fill level, so that the surface of the medium 55 can be kept constant at an unchanged height.

Provision can also be made for the height of the container 55 to be changed in a scalable manner by the control element of the lift device 200 by means of the measuring system 10 . For example, the change in height between the minimum or empty fill level and the maximum fill level or the limit level of the medium can be designed to be scalable from 0-100%. The lifting device can thus be set up to keep the height of the container constant at a predetermined height from the scale of 0-100%.

Such a measuring system 10 can advantageously be used in automated production, in particular when the filling material or the medium can be removed ergonomically by a worker and further conveyed by a conveyor belt 60 which is located nearby.

As an alternative to the arrangement in FIG. 1, in which the lifting device 200 is arranged below the container 50, the lifting device 200, as shown in FIG. 2a, can be arranged in such a way that the measuring sensor 100 can be attached or mounted on the lift device 200 . The lifting device can be set up to move the measuring sensor 100 instead of the container and to change the second distance d2 between the measuring sensor 100 and the bottom of the container 50 and the first distance di between the measuring sensor 100 and the medium 55 at the same time. The measuring system 10 can be set up to determine the fill level from the difference between the first distance di and the second distance d2 independently of the movement of the measuring sensor 100 by means of the lift device 200 .

Since the filling level of the medium 55 can be determined by calculating the difference between the first distance di and the second distance d2 and the filling level can be measured by means of the measuring sensor 100 independently of the height of the container 50, the measuring system 10 can be a measuring system that does not require calibration .

For example, a lift device 200 can be a height-adjustable desk, on the underside of which a calibration-free measurement sensor 100 is attached. The measuring sensor 100 can be set up, the level in the container 50, such. B. a wastepaper basket to determine. The container 50 can be placed on the floor. While the first distance di can be determined directly by the reflection of the first measurement signal 115 on the medium 55 inside the container 50, the second distance d2 between the measurement sensor 100 and the container bottom outside of the container 50 can be determined by the reflection of the second measurement signal 125 on the Ground, which can be felt as the reference surface, are determined for the container bottom. As a result, the measuring system 10 can enable the flexibly adaptable installation of the measuring sensor.

Alternatively or additionally, FIG. 2b shows that the measuring system 10 or the measuring sensor 100 can also have a deflection device 150 . The deflection device 150 can be set up, for example, to deflect the beam direction of the second measurement signal 125 in order to determine the second distance d2. The deflection device 150 can be arranged at a distance from the first sensor unit 110 and the second sensor unit 120 .

The deflection device 150 can be a reflector or a mirror and can be designed to be adjustable. First sensor unit 110 and second sensor unit 120 can be arranged in such a way that second measurement signal 125 can be emitted perpendicularly or at an angle to first measurement signal 115 and, after being deflected by deflection device 150, can run parallel to first measurement signal 115. The first sensor unit 110 and the second sensor unit 120 can be arranged on different sides of the measuring sensor 100 or the evaluation unit 130 . In other words, the orientation of the second sensor unit 120 of the measuring sensor 100 can be offset by 90° or at a predetermined angle relative to the first sensor unit 100 . Thus, the measurement sensor 100 can be made compact by relocating the deflection device 150 .

2b shows that the first sensor unit 110 or the first antenna can be arranged on the lower side of the expansion device 130 in order to emit the first measurement signal 115 in the direction of the container 50 or the surface of the medium 55 along the vertical direction downwards , and the second sensor unit 120 or the second antenna can be arranged to the side or to the right of the expanding device 130 in order to emit the second measurement signal 125 in the direction of the deflection device 150, for example perpendicularly or at an angle to the first measurement signal 115. After the deflection by means of the deflection device 150 , the beam direction of the second measurement signal 125 is oriented downward along the vertical direction.

Furthermore, the measuring sensor 100 can have a control unit which can be set up to mechanically or electronically adjust the deflection device 150 and to change the alignment of the deflection device 150 relative to the first sensor unit 110 and/or the second sensor unit 120 . The control unit can be set up to teach and control the adjustment of the deflection device 150 and/or the rotation of the second sensor unit 120 or antenna to optimize the alignment of the second measurement signal 125 when the measurement sensor 100 is put into operation by means of a button or a software button.

3 shows the electrical connection of the structure of measurement sensor 100. First sensor unit 110 and second sensor unit 120 are each electrically connected to evaluation device 130 in order to transmit the received first and second measurement signals to the evaluation device.

The evaluation unit 130 can be embodied as common electronics for the measuring sensor 100 . In addition, the electronics can continue to be an HF unit, which can be set up to generate an HF signal and to guide the HF signal into the first and second antennas, a power supply unit, which can be connected to an external Power supply can be set up, or have an internal self-sufficient power supply and a communication unit. The communication unit can, for example, be wired as an interface for connecting to the external receiver for the measurement sensor or for wireless communication, such as. B. by radio, set up with the external receiver.

With the integrated first and second sensor units 110, 120 and the integrated evaluation unit 130, the measuring system 10 or the measuring sensor 100 can enable a simple, efficient and precise level measurement.

FIG. 4 shows a flow chart of a method for measuring the fill level of a medium 55 in a container 50 for process automation in an industrial environment. In step 401 a first measurement signal 115 is transmitted and received by means of a first sensor unit 110 in order to detect a first distance di between the measurement sensor 100 and the medium 55 . In step 402 a second measurement signal 125 is transmitted and received by a second sensor unit 120 in order to detect a second distance d2 between the measurement sensor 100 and the bottom of the container 50 . In step 403 the filling level of the medium 55 can be determined by means of an evaluation unit 130 of the measuring sensor 100 from a difference between the first distance di and the second distance d2.

In addition, it should be noted that "comprising" and "having" do not exclude other elements or steps and the indefinite articles "a" or "an" do not exclude a plurality. Furthermore, it should be 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. Any reference signs in the claims should not be construed as limitations.

Claims

patent claims

1. Measuring sensor (100), set up for measuring the fill level of a medium (55) in a container (50) for process automation in an industrial or private environment, having: a first sensor unit (110) for sending and receiving a first measuring signal (115) is set up to detect a first distance (di) between the measuring sensor (100) and the medium (55); a second sensor unit (120) which is set up to transmit and receive a second measurement signal (125) in order to detect a second distance (d2) between the measurement sensor (100) and the bottom of the container (50); an evaluation unit (130) which is set up to determine a filling level from a difference between the first distance (di) and the second distance (d2).

2. Measuring sensor (100) according to claim 1, wherein the first sensor unit (110) and the second sensor unit (120) are integrated into the measuring sensor (100).

3. Measurement sensor (100) according to claim 1 or 2, wherein the first sensor unit (110) has a first antenna for transmitting and receiving the first measurement signal (115); wherein the second sensor unit (120) has a second antenna for transmitting and receiving the second measurement signal (125).

4. Measuring sensor (100) according to one of the preceding claims, wherein the first sensor unit (110) and the second sensor unit (120) are arranged such that the first measurement signal (115) of the first sensor unit (110) and the second measurement signal (125) of the second sensor unit (120) are transmitted and/or received in parallel to one another.

5. Measuring sensor (100) according to one of Claims 1 to 3, further comprising: a deflection device (150) which is set up to deflect the beam direction of the second measurement signal (125) of the second sensor unit (120) by the second distance (d2) to determine.

6. Measuring sensor (100) according to claim 5, wherein the deflection device (150) is arranged at a distance from the first sensor unit (110) and the second sensor unit (120).

7. Measuring sensor (100) according to claim 5 or 6, wherein the deflection device (150) is designed to be adjustable; and wherein the first sensor unit (110) and the second sensor unit (110) are arranged in such a way that the second measurement signal (115) is emitted perpendicularly or obliquely to the first measurement signal (115) and after deflection by the deflection device (150) parallel to the first measurement signal.

8. Use of a measuring sensor (100) according to any one of claims 1 to 7 for level measurement of a medium (55) in a container (50) or for level monitoring for process automation in an industrial environment.

9. Measuring system (10), set up for process automation in an industrial environment, comprising: a measuring sensor (100) according to one of claims 1 to 7, set up for level measurement of a medium (55) in a container (50); a lift device (200) which is set up to change the second distance (d2) between the measuring sensor (100) and the bottom of the container (50); wherein the measuring system is set up to determine the fill level from the difference between the first distance (di) and the second distance (d2) when the second distance (d2) changes.

10. Measuring system (10) according to claim 9, wherein the lift device (200) is arranged below the container and is set up to change the second distance (d2) between the measuring sensor (100) and the bottom of the container (50) in order to to keep the first distance (di) between the measuring sensor (100) and the medium (55) constant.

11. Measuring system (10) according to claim 10, wherein the measuring sensor (100) is attached to the lifting device (200) and the lifting device is set up to move the measuring sensor (100) and to measure the second distance (d2) between the measuring sensor (100 ) and the bottom of the container (50) and to change the first distance (di) between the measuring sensor (100) and the medium (55) at the same time; wherein the measuring system is set up to determine the filling level from the difference between the first distance (di) and the second distance (d2) independently of the movement of the measuring sensor (100) by means of the lifting device (200).

12. Use of a measuring system according to one of claims 9 to 11 for level measurement or level monitoring of a medium (55) in a container (50) without adjustment.

13. Use of a measuring system according to one of claims 9 to 11 for an ergonomic removal of material from a container (50) for process automation in an industrial environment.

14. Method using a measuring sensor (100) for measuring the fill level of a medium (55) in a container (50) for process automation in an industrial environment, comprising the steps:

Sending and receiving (401) a first measurement signal (115) by means of a first sensor unit (110) in order to detect a first distance (di) between the measurement sensor (100) and the medium (55);

Sending and receiving (402) a second measurement signal (125) by means of a second sensor unit (120) in order to detect a second distance (d2) between the measurement sensor (100) and the bottom of the container (50);

Determine a fill level from a difference between the first distance (di) and the second distance (d2) using an evaluation unit (130).

A program element which, when executed on a processor of a measurement sensor (100), instructs the measurement sensor to carry out the steps of the method according to claim 14.

16. Computer-readable medium on which a program element according to claim 15 is stored.