Method and electronic device for detecting a switching-off movement of a switching valve

Abstract

The present disclosure relates to a method and an electronic device for detecting a switch-off movement of a switching valve. The method for detecting a switch-off movement of a switching valve by means of an electronic device comprises several following steps. In a first step, a first lossy freewheeling circuit is switched by the electronic device for carrying an electrical signal of the switching valve. The first lossy freewheeling circuit is then switched to a second freewheeling circuit, wherein the second freewheeling circuit has a lower loss, in particular a loss reduced by a resistance threshold value, than the first lossy freewheeling circuit. In addition, the switch-off movement of the switching valve is detected by detecting the electrical signal of the switching valve with the second freewheeling circuit.

Description

The present disclosure relates to a method for detecting an off motion of a switching valve. The disclosure further relates to an electronic device for detecting a switch-off movement, to a computer unit for controlling an electronic device according to the disclosure, and to a computer program.Methods are known in the prior art for detecting a switching-on of a solenoid valve. The switch-on movement can manifest itself by a "dip" (outlier in the graph of a current characteristic curve) in the rising current edge. US 5 241 218 A discloses a circuit for detecting the movement of a magnet armature connected for example to a solenoid valve, wherein the correct or incorrect function of the armature and thus of the valve can be monitored, in particular from a remote location. Further, US 7 405 917 B2 shows a method and apparatus for monitoring and determining the operating state of a valve and for determining when a valve should be replaced in order to assist preventive maintenance. The above-mentioned method can likewise be used. Detect effect on voltage across a coil. This is proposed, for example, in U.S. Pat. No. 6,111,514 A, which relates to an electronic control device for anti-lock brake systems and shows, in particular, a current recirculation circuit and a method for monitoring the function of a solenoid valve in an anti-lock brake system. By calculating the linked flow (cf. U.S. Pat. No. 6,300,733 B1), the switching time of a valve can be derived from the measurement of current and voltage at the valve.It can furthermore be provided that a solenoid valve is not switched by applying a voltage, but rather that the flowing current is regulated. This can be realized using a PWM (Pulse Width Modulation) signal. A movement of the armature can then take place only when the current is regulated. The movement can then be observed only with difficulty (cf. DE 43 22 199 C2).It can be provided that valves which switch particularly fast are designed such that the current in the coil rises rapidly. In this case, it may occur that the soft magnetic iron of the valve is already completely saturated (hysteresis curve) when the armature moves. In this case, too, the so-called "dip" cannot be detected during the anchor tightening. The switching process cannot be detected even in a flow evaluation.It can furthermore be provided, although practically uncommon, to detect the armature movement during switching off. Thus, DE 10 2011 075 935 A1 proposes recording the full switching cycle. When the valve is switched off, it is attempted to allow the current to decay as quickly as possible. This can be achieved via a zener diode, opposite poles (H-bridge) or additional resistors. Here, there may be a problem that the current has completely decayed before the armature moves due to inertia.In the cases explained, it is not possible to observe either the switch-on movement or the switch-off movement of the armature.The document DE 10 2015 210 196 A1 describes a method for operating an electromagnetically actuated solenoid valve, which contains a solenoid coil and an electromagnetically actuated valve element. In particular, it is proposed, after the solenoid has been switched off, to close a first circuit containing the solenoid at a certain point in time during the movement of the valve element, wherein the current is measured from the certain point in time during the closed first circuit, and the resistance of the solenoid is determined from the current, the change over time in the current and the inductance of the magnetic circuit with the solenoid and the valve element.US 2021 / 0222795 A1 describes a method for energizing a coil in a valve assembly. It is proposed to first apply a positive overvoltage to actuate a movable piston in the flow path of the valve assembly and then apply a negative braking voltage to brake that piston.Against the background of this prior art, the object of the present disclosure is to specify a method and an electronic device, a computing unit, a system and a computer program, each of which is suitable for improving the prior art.The object is achieved by the features of the independent patent claims. The dependent claims each have optional developments of the disclosure.According to a first aspect, the object is achieved by a method for detecting a switch-off movement of a switching valve according to claim 1. A switch-off movement is detected by means of an electronic device. In a first step, a first lossy free-wheeling circuit is switched by the electronic device for carrying an electrical signal of the switching valve. In a further step, the first lossy free-wheeling circuit is switched over into a second free-wheeling circuit. The second free-wheeling circuit has a lower loss than the first lossy free-wheeling circuit. In particular, the loss difference can be defined by a preconfigurable resistance threshold value. In a further step, the switch-off movement of the switching valve is detected by detecting the electrical signal of the switching valve while the second free-wheeling circuit is active or with the switched-over active second free-wheeling circuit. The switch-off movement can be the derivation of a position of the switching valve.The changeover from the first free-wheeling circuit to the second free-wheeling circuit can also be referred to as activation or active switching of the second free-wheeling circuit.For purposes of the present disclosure, a switching valve is a component that can be used in various industrial applications to control a flow of fluids including gases or liquids. For example, a switching valve may be used in a piping system to regulate a flow rate, control a pressure, and / or change a flow path. A switching movement of a switching valve associated with the switching valve function can relate to the process of opening or closing the switching valve in order to control, enable or block the flow of the medium. This movement can be carried out manually or automatically. A shifting movement can comprise the movement and / or the transition of the shift valve from one shift position to another shift position and thus can comprise a shift position change of the shift valve. A switching movement, in particular a switch-off movement, comprising the transition from one switching position to another switching position, provides a signal which can be detected and evaluated.In the sense of the present disclosure, an electronic device can be an electronic circuit comprising electronic components and / or components for switching voltages and / or currents and / or for providing drive signals for controlling further electronic components.For purposes of the present disclosure, a free-wheeling (electric) circuit in conjunction with an inductance refers to a circuit that can be used to control an inductive load, such as a coil or an electromagnet, and / or simultaneously avoid feedback on the circuit. A coil supplied with current generates a magnetic field and thus stores energy. By shutting down the switching valve, the current flow in the coil is interrupted and the changing magnetic field generates a back emf (electromotive force) that attempts to maintain the current flow. This back EMF can lead to high voltage surges and damage the circuit or other components. A free-wheeling circuit, which can also be referred to as a free-wheeling diode or free-wheeling circuit, is used to break down and / or control the back electromotive force. The free-wheeling circuit can be constructed from a diode which is switched in the opposite direction to the current direction. When the current flow in the coil is interrupted, the induced current can flow via the diode in a closed circuit which absorbs the energy of the coil.A lossy free-wheeling circuit, also referred to as a dissipative free-wheeling circuit, can, within the meaning of the present disclosure, contain a specific configuration of an electrical free-wheeling circuit, in which a part of the energy can be dissipated in the form of losses or heat. In contrast to and / or in addition to a lossless or low-loss (electrical) free-wheeling circuit, in which the energy stored in the inductive load is at least largely retained at least for a limited period of time, a lossy free-wheeling circuit can have losses and / or cause these which can be caused by components used and / or the circuit configuration of the lossy free-wheeling circuit. These losses may be attributed to various factors including an internal resistance of the free-wheeling diode, other provided parasitic resistances, and / or other inefficient components in the circuit. These factors can be turned on or off by dedicated circuitry. The losses in a lossy free-wheeling circuit can result in a portion of the energy not being retained but being dissipated as heat. The energy can be dissipated more quickly by the losses than in the case without or with lower losses. A lossy free-wheeling circuit can therefore be used for rapidly switching off the inductive load. In practice, apart from the case of superconducting which is not relevant here, all free-wheeling circuits can be more or less lossy due to ubiquitous ohmic losses. By adjusting the losses or adding additional losses, the time during which the energy originally stored in the inductive load can be dissipated, i.e. converted into heat, can be influenced.A first lossy free-wheeling circuit and a second free-wheeling circuit can be provided. The first and the second free-wheeling circuit can differ in their loss characteristics (losses). In particular, the first and the second free-wheeling circuit can differ in that by switching a circuit technology further components (resistors) are connected which generate a different value for the loss. A second free-wheeling circuit may have a reduced loss resistance threshold than the first lossy free-wheeling circuit. In principle, a reduced loss compared to the first free-wheeling circuit or essentially no loss can occur in the second free-wheeling circuit. The second free-wheeling circuit can also be referred to as a simple free-wheeling circuit and / or can be largely loss-free. The first and second lossy free-wheeling circuits may alternatively or cumulatively have the same or similar characteristics. Switching from a first free-wheeling circuit to a second free-wheeling circuit may include actively switching the second free-wheeling circuit. The electrical signal can thus be detected in the second free-wheeling circuit. An active free-wheeling circuit conducts the electrical signal. The first free-wheeling circuit is not active in this case.A free-wheeling circuit with reduced loss is a free-wheeling circuit which has reduced losses-in particular electrical losses-in particular reduced compared to the first free-wheeling circuit. The losses can be reduced in particular by a resistance threshold value. The resistance threshold may be configurable and is preferably greater than 0. The free-wheeling circuit can be controllable, in particular electronically controllable, so that the second free-wheeling circuit can be operated with less loss (than the first).The method described above offers a number of advantages. Among other things, a rapid lowering of the switch-off current does not have to take place until the end of the actual current flow. The lowering of the switch-off current can be stopped and the switch-off movement of the armature of the switching valve can be detected. In particular, the disconnection current can be quickly reduced via the first lossy free-wheeling circuit; by switching to the second free-wheeling circuit, which can be configured to be less lossy than the first lossy free-wheeling circuit, the disconnection movement of the armature of the switching valve and thus the movement from a first position into a second position can be detected and detected.Possible refinements of the method described above are explained in detail below.It can be provided that the switching takes place as soon as a configurable switching condition is fulfilled. It can be provided that the configurable switching condition comprises a time-triggered switching, in particular is or comprises a switching time or a switching time interval. The switching time or the switching time interval can be determined by means of a reference switching process in the first free-wheeling circuit. The switching time may represent a predetermined time in the operation of the switching valve. The switching time can be determined and established experimentally in a reference switching process. The switching time can be set such that after the switching from a detected electrical signal, the movement of the switching valve can be detected. The switching time can be between 600 μs and 800 μs and can take place after the disconnection from the supply voltage. Furthermore, it can be provided that a switching time interval is used. The switching time interval can be determined experimentally in a reference switching process. The switching time interval may refer to a time period in which a change or a switching from one valve state to another valve state takes place. When the switching time interval is reached, the first lossy free-wheeling circuit is switched over into the second free-wheeling circuit and the movement of the switching valve can be detected. It can further be provided that the configurable switching condition includes a time-triggered switching.It can be provided that the switching time relates to the decay time and represents a fraction of the decay time. The decay time of the coil of the switching valve refers to the time required for the current through the coil to drop to zero after shut down. When current flow through a coil is abruptly interrupted, the self-induction of the coil creates a reaction that maintains the current flow. The decay time may depend on the inductance of the coil, the resistance in the circuit, and the turn-off mechanisms used. The decay time may be the time required for the feedback current to decay to a certain percentage of the maximum value. A decay time of 5 times the time constant (5τ) may be used to decay the feedback current to about 99.3% of its maximum value. Alternatively or additionally, the decay time can be determined by means of the time constant (τ) of the coil. The time constant is the product of the resistance (R) in the circuit and the inductance (L) of the coil (τ = L / R). The decay time is then five times the time constant (decay time=5τ) in the above example. Alternatively or additionally, it can be provided that the lossy free-wheeling circuit is optimized for a maximum drop. The shortest decay time is then present. Alternatively or additionally, it can be provided that no losses occur in the free-wheeling circuit. Then, no decay takes place and / or a maximum decay time is provided. This decay time can be higher by a factor of 10 to 30. It can be provided that in the reference switching process the decay time is determined until the current has reached a preferred value in the case of a maximum lossy free-wheeling circuit. The decay time is a property of the switching valve and must be determined when a switching valve is changed.It can be provided that the configurable switching condition is or comprises reaching a current threshold. The current wave can be determined in a reference switching process and / or be defined for the operation of the electronic device. The current threshold may include a value for a current that must be present to switch from a first lossy free-wheeling circuit to a second free-wheeling circuit to detect movement of the switching valve. The electrical signal can be recorded and the faster the switching movement of the switching valve is detected, the faster it is available for triggering (for example for braking the switching movement).It can be provided that the current threshold is determined from the electrical signal, in particular a valve current of the switching valve and a current offset, and wherein the valve current of the switching valve is detected by means of a reference switching process in the second free-wheeling circuit. In the reference switching process, the current in the second free-wheeling circuit can be detected with the least loss and, before the switch-off movement of the switching valve begins, the value for the current can be determined and provided with a current offset.It can be provided that the detected electrical signal comprises a current signal and / or a voltage signal. The detection of the switch-off movement of the switching valve can be effected by evaluating a characteristic variable of the electrical signal, wherein the electrical signal is selected from the group consisting of a signal behavior over time, i.e. for example a current rise or fall, a current maximum, a current minimum, a derivative change of the electrical signal, an induction voltage and / or a linked flow.The electrical signal can be, in particular, a current and / or a voltage profile. The switch-off movement can be determined from this electrical signal. The change in inductance can also be taken into account. In addition, the 2nd or 3rd derivative of the current or voltage signal can be evaluated.A characteristic is provided to detect the current. An increase in current may be indicative of a switching operation or activity in the system. This ramp can be used to detect the beginning of an action or to initiate a response to an external trigger. The detection of current maxima or minima can provide information about the operating state of a system. The derivative change may indicate changes or events in the system. Induction voltages may occur when a magnetic field is changed by a coil or a conductor. They can be used to obtain information about changes in the magnetic field or about the movement or position of objects. The linked flux caused by the inductance of a coil may provide information about the magnetic energy in the system.It is provided that the method further comprises providing movement information if an opening movement of the switching valve is detected and / or comprises providing fault information if no opening movement of the switching valve is detected. In the sense of the present disclosure, movement information may refer to information about the change in the position of the armature of the switching valve. The movement information provides information about the movement characteristics and parameters of the switching valve. The movement information may include information about the movement. Furthermore, the movement information can contain information about the fact that no movement of the switching valve has been detected and / or provide it as fault information. The switch-off movement and / or the fault information can be provided on an output unit. The movement information can be provided via a switching movement arrangement. The switching movement arrangement can communicate with the output unit and exchange data via a communication interface and communication connection.It can be provided that the detection of the switching position of the switching valve takes place by detecting the electrical signal, in particular a value for the valve current, and / or while a current threshold is reached, which functions as a limit value and / or is preconfigurable. The current threshold may be configured from the current signal by addition with an off-set in the second free-wheeling circuit. It can furthermore be provided that the detection of the shift position takes place during or downstream of the detection of the electrical signal while the second free-wheeling circuit is actively switched. The detected electrical signal may be recorded. The faster the switch-off movement is detected, the faster this information is available for controlling the switching valve. The movement of the armature can thus be braked when it is switched off.With the present disclosure, the detection of the off motion can be enabled. For this purpose, a circuit is used which can be switched back and forth between a simple free-wheeling circuit without high losses and a lossy free-wheeling circuit. For this purpose, circuits can be used for switching between lossless and lossy free-wheeling circuits. A first transistor connects the valve to the supply voltage and also disconnects it therefrom. If the first transistor is turned off, the current driven by the valve must travel a different path than through the source. By switching a second transistor, a third transistor is switched to the conductive state. As a result, the free-wheeling current driven by the valve can flow unimpeded via a diode. If the second transistor is blocked, the voltage at the source terminal falls to the negative. The connection via a first resistor to the gate terminal of the third transistor also draws the latter into the negative, so that the current flow via the third transistor is inhibited and energy is dissipated in the third transistor. The free-wheeling current of the valve thus falls more quickly. It is provided that the rapid lowering of the current is not carried out until the complete end of the current flow, but can be interrupted beforehand. Thus, the movement of the armature can nevertheless be detected.Further provided is an electronic device for detecting an off movement of a switching valve as claimed. The electronic device is designed to carry out the method according to the disclosure in its different embodiment variants described above. A first lossy free-wheeling circuit for carrying an electrical signal, in particular a valve current of the switching valve, is provided. The electronic device comprises a switch-on arrangement which is designed to switch the switching valve by applying a voltage via the first lossy free-wheeling circuit. Furthermore, a control arrangement is provided in the electronic device, which is configured to actively switch a first switch element and to couple it to the first lossy free-wheeling circuit in such a way that, in the switched state of the first switch element, the first lossy free-wheeling circuit is switched over into a second free-wheeling circuit for guiding the valve current of the switching valve, wherein the second free-wheeling circuit has a lower loss, in particular a loss reduced by a resistance threshold value, than the first lossy free-wheeling circuit. In addition, a switch detection arrangement is provided in the electronic device, which is designed to detect the switch-off movement of the switching valve by detecting the electrical signal of the switching valve while the second free-wheeling circuit is active (switched) or to detect it with the second free-wheeling circuit.By using the device with the control arrangement, switching can be carried out or switched back and forth between a "simple" free-wheeling circuit without high losses and a lossy free-wheeling circuit.It can be provided that at least one current measuring unit is connected in series with the switching valve. In the sense of the present disclosure, a current measuring unit can be designed as a device or a component which is used to measure the current flow in an electrical circuit. The current measuring unit can be used in conjunction with a measuring instrument such as an ammeter or an ammeter. The current measurement unit may be used to quantitatively detect the electric current flowing through the circuit. The current measurement unit may include a shunt resistor. A shunt resistor is a specific type of resistor that can be used in current measurements. The shunt resistor is connected in series and generates a defined voltage drop (measured voltage) that is proportional to the current flow. The shunt resistor may have a low resistance value in order to minimize the current flow and thus the loss at the shunt resistor and to keep the voltage drop low. The general functional principle of a shunt resistor is based on Ohm's law. The shunt resistor may be configured such that the voltage drop across the shunt resistor is proportional to the current flow it is to measure. When the current flows through the circuit to be measured, the shunt resistor generates a voltage drop corresponding to the current value. This voltage drop can then be measured with a measuring instrument to determine the current value. Since the shunt resistor may have a low resistance value, the majority of the current flows through the shunt resistor, while only a small portion of the current flows through the measurement instrument. As a result, the measurement error remains small, since the voltage drop across the shunt resistor is proportional to the total current flow.It can be provided that the first lossy free-wheeling circuit comprises a diode, in particular a free-wheeling diode and at least one second component, wherein the diode is connected in the reverse direction. The diode can be designed as a free-wheeling diode or a protective diode. Unwanted voltage spikes or feedback can be limited and the circuit or connected components protected from damage. The diode is reverse biased because it has high impedance in this direction and blocks current flow. If a coil or inductive load resistor is provided in a circuit and this is disconnected, the self-induction of the coil creates a reaction which causes the current to continue to flow and attempt to maintain its direction. This reaction can lead to voltage peaks which can greatly increase the voltage values in the circuit. By means of the reverse-connected free-wheeling diode, a path is provided for the reaction current generated by the self-induction. Thus, the feedback current can be redirected and reliably decayed. By allowing the free wheeling diode to reverse current flow, the voltage across the circuit is limited because the diode maintains a voltage difference that typically corresponds to the forward voltage drop of the diode. The second component can be formed as a resistor. The free-wheeling resistor is designed to support the energy dissipation in the free-wheeling circuit. If the current flow is interrupted, the reaction current flows through the free-wheeling diode and the free-wheeling resistor. The resistor allows a controlled current path that receives the feedback current and causes it to decay rapidly. The resistance converts the energy of the reaction into heat and dissipates it. The free-wheeling resistor can be dimensioned according to the inductance of the load, the maximum current intensity, the desired attenuation and / or the permissible power loss.It can be provided that the control arrangement controls the first switch element in such a way that the first switch element is switched in a lossy state when the control arrangement is actively switched. The first switch element can be formed as a MOS-FET switch or bipolar switch. The control arrangement may relate to a device or mechanism used to enable and / or activate the functionality of the first switch element. The control arrangement may comprise various electronic components which cooperate to perform certain functions and achieve the desired state or behavior of the first switch element.It can be provided that the first switch element is switched in a lossy state reduced by a resistance threshold value if a determined value for the valve current has reached a predetermined current threshold and / or a certain / predetermined time has elapsed and / or a switching condition (e.g. event-based) is fulfilled. Thus, for example, a time-triggered switchover can take place. The first switch element is switched so that its resistance is low and is in a conductive state. In this state, the MOSFET allows a low resistance path for the current flow between drain and source.It can be provided that the control arrangement comprises a second switch element, in particular a MOS-FET switch, the second switch element is actively driven and / or is configured to provide a gate signal for switching the first switch element. The second switch element may be connected via a controller. The controller may be provided as an PLC, computer, microcontroller of the disclosed system and provide corresponding drive signal for switching the second switch element.It can be provided that the first switch element is a MOS-FET switch and is coupled at its control terminal to a third component and a fourth component and the third component is coupled to the freewheeling arrangement and the drain terminal of the second switch element. The third and fourth component can be formed as a resistor. A voltage divider for adjusting the gate signal is provided via the third component. The current flow via the first switch element is inhibited via the fourth component.It can be provided that the control arrangement is configured to provide the source signal of the first switch element at the control input of the first switch element by actively switching off the second switch element. When the second switch element is switched off, the negative voltage which is formed by the current flow at the source terminal of the first switch element is applied to the gate of the first switch element via the voltage divider consisting of the third and fourth components in magnitude-reduced magnitude. As a result, the first switch element enters a lossy state (neither conducting nor blocking), whereby the negative voltage at the source terminal is pulled further into the negative by the first switch element. The voltage divider makes the gate voltage equally more negative, as a result of which the first switch element remains in the lossy state. The energy is dissipated in the first switch element. This occurs until the free-wheeling current has decayed.It can be provided that the switch-on arrangement comprises a third switch element, in particular a MOS-FET switch. The switching valve can be switched for the actual function via the third switch element. A voltage supply of the switching valve is switched via the third switch element.It can be provided that the second component, the third component, the fourth component are selected from the group containing a resistance element and / or a resistor stack.It can be provided that the switching valve is designed as a switching valve of automation technology, in particular industrial automation and / or process automation and / or laboratory automation. Switching valves must, for example, enable a rapid and precise control of the flow of liquids or gases. Switching valves must open or close in milliseconds, for example, which offers the advantage of a high reaction speed and precise control, especially in processes requiring rapid regulation or adaptation. Switching valves must provide consistent performance over long operating times and require minimal maintenance. Switching valves can be used in different applications. They may be applied in various sizes, materials, and / or configurations to meet the requirements of different processes. Precise control of flow, pressure and / or other parameters in automation technology may be achieved. By combining sensors and control systems, switching valves can be set to precise values in order to control the process precisely and to ensure consistency in production or in the laboratory. Switching valves can be integrated into automated systems.It can be provided that the current measuring unit provides a detected switch-off current of the switching valve via a current tapping point to a switching detection arrangement. Furthermore, it can be provided that the switching detection arrangement detects the switching-off movement of a switching valve on the basis of the detected switching-off current. It can be provided that the switching detection arrangement is provided as a unit with or in the electronic device. Alternatively, it can be provided that the switching detection arrangement is designed as a separate arrangement and is electrically connected to the electronic device. The switching detection arrangement may comprise a logical implementation which can process the input signals and perform corresponding logical operations or calculations. It can be a unit based on a microprocessor, a microcontroller or an FPGA (field-programmable gate array). The switching detection arrangement may provide signals to the control arrangement. The switching detection arrangement can provide movement information to an output unit, for example. Via the output unit, it is possible to output whether a movement of the switching valve has been detected. The movement information contains the information as to whether the switching valve has moved from a first switching position to a second switching position.Furthermore, a computing unit for driving an electronic device according to the disclosure is provided. The electronic device is designed to carry out the method according to the disclosure. The computing unit has a first interface to the control arrangement and a second interface to the switching detection device. The computing unit can comprise a third interface for transmitting data and in particular for reading in the detected electrical signal. Control data and / or data are transmitted via the interfaces mentioned. Thus, for example, control signals are transmitted via the first interface in order to actively switch off the first switch element when the ascertained value for the valve current has reached a predefined current threshold value.Another object is a system for detecting a switching-off motion of a switching valve as claimed. The system comprises a unit for executing the method, in particular the electronic device. Optionally, the computing unit can be included in the system with corresponding data and / or control interfaces and optionally further digital processing units, such as a memory and / or a user interface.Alternatively or additionally, the system can be designed to provide movement information for a switching-off movement of a switching valve and / or fault information about the switching valve, having an electronic device according to the disclosure for detecting a switching-off movement of a switching valve and at least one output unit for providing the movement information. For purposes of the present disclosure, an output unit may be a component or device that outputs information or results to a user or other systems. It may allow data, texts, graphics, audio or other formats to be presented to provide information to or interact with the user. The output unit can be designed as a screen / monitor. The screen / monitor may be configured to display visual information in the form of texts, graphics, or videos. Computer monitors, televisions, smartphones, touchscreens or tablets may be provided.The disclosure further relates to a computer program. The embodiments of the method described above can also be embodied as a computer program, wherein a computing unit (for example a computer, microcontroller, DSP, FPGA and / or PLC) is caused to carry out the method according to the disclosure when the computer program is executed on a computing unit or on a processor of the computing unit. The computer program can be provided as a signal by download or can be stored in a memory unit of the computing unit with computer-readable program code contained therein in order to cause a computing unit to execute instructions according to the above-mentioned method. The computer program can also be stored on a machine-readable storage medium.An alternative solution to the problem therefore provides a storage medium, in particular a computer-readable storage medium, which is intended for storing the method according to the disclosure (as program code) and is readable by a computer or a processor of the computer. The program code, when executed by a processor circuit of a computer or a computer group, causes an embodiment of the method according to the disclosure to be executed. The storage medium can be provided, for example, at least partially as a nonvolatile data memory (for example as a flash memory and / or as an SSD-solid state drive) and / or at least partially as a volatile data memory (for example as a RAM-random access memory). The storage medium can be arranged in the processor circuit in its data memory. However, the storage medium can also be operated, for example, as a so-called Appstore server on the Internet. A processor circuit with at least one microprocessor can be provided by the computer or computer network. The program code can be provided as binary code or assembler and / or as source code of a programming language (e.g. C) and / or as a program script (e.g. Python).Brief Description of the FiguresIn the following detailed description of the figures, exemplary embodiments, which are to be understood as non-limiting, with the features thereof and further advantages thereof, are shown in the drawing, discussed on the basis of the latter: FIG. 1 is a diagram of an exemplary electronic device according to the disclosure for carrying out the method; FIG. 2 shows a flow diagram of a method according to the disclosure; FIG. 3 shows a schematic illustration of an electronic device according to the disclosure; FIG. 4 shows a schematic illustration of a computing unit; FIG. 5 shows a diagram of the current curve during the switching off; and FIG. 6 is a diagram of the switch-off delay.The accompanying drawings are intended to provide further understanding of the embodiment of the disclosure. They illustrate further developments and serve, in conjunction with the description, to explain principles and concepts of the disclosure. Other developments and many of the mentioned advantages result with regard to the drawings. The elements of the drawings are not necessarily shown to scale with respect to each other.In the figures of the drawing, identical, functionally identical, and identically acting elements, features and components-unless stated otherwise-are to be provided with the same reference symbols in each case.DETAILED DESCRIPTION OF THE INVENTIONFIG. 1 shows, as an example, a schematic illustration of an electronic device 100 according to the disclosure. The electronic device 100 is provided to detect a switch-off movement of a switching valve 200. The electronic device is configured to carry out the method according to the disclosure. A first lossy free-wheeling circuit for carrying an electrical signal, in particular a valve current of the switching valve, is provided. The electronic device 100 may include a power-on arrangement 110. The switch-on arrangement 110 has a third switch element 111. The third switch element 111 can be formed as a MOSFET switch (MOSFET transistor). Alternatively, a bipolar transistor may be provided. The third switch element 111 is coupled to the VCC via its source terminal in the embodiment of FIG. 1. VCC is the voltage at the common collector and denotes the voltage at the positive supply line of the electronic device 100. VCC is the voltage used to power the components in the electronic device 100. In addition, in the illustrated embodiment of FIG. 1, the third switch element 111 is coupled via its drain connection to the switching valve 200. The switching valve 200 can be designed as a quick-action switching valve. The switching valve 200 can be designed as a switching valve of automation technology, industrial automation and / or laboratory automation. Via the third switch element 111, the switching valve 200 can be acted upon with a voltage corresponding to the switching valve 200 in the switched-on state. Furthermore, the switch-on arrangement 110 has a gate control voltage via a voltage source 113. By means of the voltage source 113 and the series resistor 114, a gate signal for switching the third switch element 111 can be provided. Via the third switch element 111, the switching valve 200 is switched on and off.The switch-on arrangement 110 is provided for switching on and the switching valve 200. The voltage source 113 is coupled to the zero potential 112. The switch-on arrangement 110 is designed to switch on the switching valve 200 by applying a voltage to the switching valve 200. The second switch element 132 and the third switch element 111 may receive at the gate terminal a control signal from a microcontroller corresponding to the voltage signal of the voltage source 113. By switching off the control signal, the switch-on arrangement 110 is switched off and the switching valve 200 switches off.Further, the electronic device 100 comprises a control arrangement 130. The control arrangement 130 comprises a second switch element 132. The second switch element 132 can be formed as a MOSFET switch (MOSFET transistor). Alternatively, the second switch element 132 can be designed as a bipolar transistor. The second switch element 132 is coupled to the supply voltage VP. The supply voltage VP denotes the voltage that is switched via the second switch element 132. In addition, the control arrangement 130 has a gate control voltage via a voltage source 113. By means of the voltage source 113 and the series resistor 114, a gate signal for switching the second switch element 132 can be provided. The voltage source 113 is coupled to the zero potential 112. The control arrangement 130 is configured to actively switch the first switch element 131 and to couple it to the first lossy free-wheeling circuit 120 in such a way that, in the switched state of the first switch element 131, a second free-wheeling circuit for carrying the valve current of the switching valve 200 is provided, wherein the second free-wheeling circuit has a lower loss, in particular a loss reduced by a resistance threshold value, than the first lossy free-wheeling circuit 120. The second switch element 132 may be actively driven and / or is configured to provide a gate signal for switching the first switch element 131. The active control can be effected via a microcontroller.The control arrangement 130 is configured to control the first switch element 131 such that the first switch element 131 is switched to a lossy state when the control arrangement 130 is actively switched. The first switch element 131 is switched into another state, in particular when a determined value for the valve current has reached a predefined current threshold. Alternatively, the first switch element 131 may be switched to another state when a predetermined time period has elapsed after the third switch element 111 has been switched off and / or when a switching condition (e.g. not time-triggered) is fulfilled. The switching condition may be preconfigured. The other state is different from the lossy state in terms of losses. In particular, the other state may be less lossy.In the illustrated embodiment of FIG. 1, the second switch element 132 is coupled to a third component 133 and a fourth component 134 via the source terminal. The third component 133 and the fourth component 134 may be formed as a resistor. The fourth device 134 is coupled to the zero potential 112. The third component 133 is coupled to the free-wheeling diode 121 in the lossy free-wheeling circuit 120. Furthermore, in the illustrated embodiment of FIG. 1, the third component 133 is coupled to the source terminal of the first switch element 131. The first switch element 131 may be formed as a MOSFET switch (MOSFET transistor). Alternatively, a bipolar transistor may be provided. The first switch element 131 is coupled at its gate terminal to the fourth device 134. The fourth device 134 provides a gate current for switching the first switch element 131. The drain terminal of the first switch element 131 is coupled to the zero potential 112.The electronic device 100 includes components forming the first lossy free-wheeling circuit 120 that is switched across this electronic device 100. The first lossy free-wheeling circuit 120 comprises a free-wheeling diode 121. In the embodiment shown in FIG. 1, the free-wheeling diode 121 can be connected in the reverse direction. Further, the first lossy free-wheeling circuit 120 comprises a resistor 122. The resistor is coupled to the zero potential 112. It is provided that coupling to the first switch element 131 takes place at an application point between the free-wheeling diode 121 and the resistor 122. The free wheeling diode 121 is coupled to the drain terminal of the third switch element 111 and the switching valve 200. The first lossy free-wheeling circuit 120 is configured to conduct an electrical signal, in particular a valve current of the switching valve 200, after the third switch element 111 has become non-conductive.The electronic device 100 may be coupled to the switching valve 200. Furthermore, the electronic device 100 can have at least one current measuring unit 201. The current measurement unit 201 may be connected in series with the switching valve 200. It can be provided that the current measuring unit 201 is designed as a resistor in the illustrated embodiment of FIG. 1. The resistor may be a shunt resistor. A voltage drops across the resistor. At the tap point 300, a voltage proportional to the current flow may be tapped. Furthermore, it can be provided that the second component 122, the third component 133 and / or the fourth component 134 is or comprises in each case a resistance element or a resistor stack.The electronic device 100 may be coupled to a switching detection arrangement 140. The switching detection arrangement 140 may be coupled to the electronic device 100 via the current tap point 300. The switching detection arrangement 140 is provided with the tapped electrical signal as an input signal. The electrical signal may include the cut-off current of the switching valve 200. A disconnection movement of the switching valve 200 can be detected by means of the switch detection arrangement 140 via the disconnection current. Motion information may be transmitted to an output unit (not shown). It can be provided that the switching detection arrangement 140 has a corresponding interface for coupling to an output unit for displaying the movement of the switching valve 200 and / or fault information.The electronic device 100 is configured to switch the first lossy free-wheeling circuit 120 into a second free-wheeling circuit, wherein the second free-wheeling circuit has a lower loss, in particular reduced by a resistance threshold value, than the first lossy free-wheeling circuit 120. The first free-wheeling circuit is formed by the current measuring unit 201, the switching valve 200, the free-wheeling diode 121, the second component 122, and the common ground connection of the second component 122 and the current measuring unit 201. The second free-wheeling circuit is provided by the switching of the first switch element 131. The first switch element 131 is switched by the second switch element 132. The second free-wheeling circuit is established via the current measuring unit 201, the switching valve 200, the free-wheeling diode 121, the coupling between the free-wheeling diode 121 and the switched first switch element 131, and the common ground connection of the first switch element 131 and the current measuring unit 201.The electronic device 100 can be used to detect the switch-off movement. The electronic device 100 provides switching (switching back and forth) between a first lossy free-wheeling circuit and a second free-wheeling circuit. The second free-wheeling circuit can have losses; however, these are lower than in the case of the first free-wheeling circuit. The second free-wheeling circuit has, in particular, a lower loss, in particular reduced by a resistance threshold value, than the first lossy free-wheeling circuit 120. Via the third switch element 111, the switching valve 200 is coupled to the supply voltage and can also be disconnected therefrom. If the third switch element 111 is blocked, the current which is driven further by the switch valve 200 must take a different path than through the source. By switching the second switch element 132, the first switch element 131 is switched to the conductive state. As a result, the free-wheeling current driven by the switching valve 200 can flow unimpeded via the free-wheeling diode 121. If the first switch element 131 is blocked, the voltage at the source falls to the negative. The coupling via the third component 133 to the gate of the first switch element 131 also draws the latter into negatives, so that the current flow via the first switch element 131 is inhibited and energy is dissipated in the second component 122. The free-wheeling current of the switching valve 200 thus falls more quickly.A resistance of 4.75 kOhm may be provided for resistor 122. The resistance in the lossy free-wheeling circuit can be designed to be variable. The resistance is adjusted by the control arrangement 130 such that the voltage is not greater than, for example. 30 V. In the case of large currents, the resistor can be formed to be quite small, in the case of small currents, the resistor can be formed to be quite large. The resistance can assume the value of 122 at most. In the second free-wheeling circuit, the resistor is bypassed by the switched-on first switch element 131 and therefore, apart from the shunt resistor 201 and the ohmic resistance of the load 200, only the diode 121 is responsible for the loss. This can have a forward voltage of 0.7 V. Apart from this voltage offset, its resistance is also independent of the current, i.e. the diode 121 essentially acts as an ohmic resistance. The ohmic resistance of a diode 121 which is operated in the forward direction is referred to as the through resistance and has a value of less than one ohm, preferably less than 0.5 ohm. For the same current, the second free-wheeling circuit can have a resistance which is lower by a factor of 43.FIG. 2 shows a flow diagram of a method according to the disclosure. In FIG. 2, reference symbol V denotes an embodiment of the method according to the disclosure. Method V for detecting a switch-off movement of a switching valve 200 by means of an electronic device 100 comprises a plurality of steps in the embodiment shown. The electronic device 100 may be configured to execute method V. In a first step S 1, the method V can switch a first lossy free-wheeling circuit 120 by the electronic device 100 for carrying an electrical signal of the switching valve 200. In a second step S 2, the first lossy free-wheeling circuit 120 can be switched over into a second free-wheeling circuit, wherein the second free-wheeling circuit has a lower loss, in particular reduced by a resistance threshold value, than the first lossy free-wheeling circuit 120. In a further step S 3, the switch-off movement of the switching valve 200 can be detected by detecting the electrical signal of the switching valve 200 using the second free-wheeling circuit.The switching from the first lossy free-wheeling circuit to the second free-wheeling circuit takes place as soon as a configured switching condition is fulfilled. The configurable switching condition may be or comprise a switching time or a switching time interval. The switching time and the switching interval can be determined by means of a reference switching process in the first free-wheeling circuit. In this case, the first curve G 5 (lossy) can be recorded (cf. FIG. 5 ). After t*, the current has decayed. The switching time at t.beta. is then selected such that t.beta.<t*.Alternatively or additionally, the configurable switching condition can be or comprise reaching a current threshold. The current threshold can be determined from the electrical signal, in particular a valve current of the switching valve 200 and a current offset. The valve flow of the switching valve 200 can be detected by means of a reference switching process in the second free-wheeling circuit. Provision can be made to record curve G 1 (cf. FIG. 5 ). The I* is identified as the waste stream. The I is then chosen depending on I*, for example such that I<I*. The detected electrical signal can be selected from the group comprising a current rise, a current maximum, a current minimum, a derivative change of the electrical signal, an induction voltage and / or a linked flux. The switching-off movement of the switching valve 200 is detected during the detection of the electrical signal and reaching the current threshold. The detection of the switch-off movement can be provided by means of movement information. If no switch-off movement of the switching valve 200 is detected, fault information can be provided.FIG. 3 shows a schematic illustration of an electronic device 100. The electronic device 100 can carry out the method according to the disclosure. The electronic device 100 comprises a switch-on arrangement 110, a control arrangement 130 and a switching detection device 140. The control signals may be provided via corresponding interfaces. Alternatively or cumulatively, the electronic device 100 can communicate with a computing unit 400 via a further interface. In addition, the electronic device 100 and / or the computing unit 400 can have a memory unit for storing data and / or signals.FIG. 4 shows a schematic illustration of a computing unit 400. The computing unit 400 may include a storage unit 403. Alternatively, the storage unit may be provided off-site in a cloud and communicatively connected to the electronic device 100. The computing unit 400 can have an interface 401. A communication connection, in particular a 5G interface 401, to the electronic device 100 can be established via the telematics module. The communication connection can be designed as a mobile connection to a mobile radio network, WLAN network and / or cable-bound connection. The computing unit 400 is configured to provide control signals for driving the gate terminal of the switch element 132 and the switch element 111. The control signals may be provided via a processor unit 402. The processor unit 402 is designed to provide a corresponding method for providing the control signals. The processor unit 402 can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (field programmable gate array) and / or at least one DSP (digital signal processor).FIG. 5 shows a diagram of the current profile when switching off the switching valve 200. The falling current of the switching valve 200 is shown. The function G1 represents the current signal when the lossy free-wheeling circuit is not connected and the free-wheeling diode is directly connected to the zero potential. Curve G 1 shows the case that the first switch element 131 is permanently conductive and the current is dissipated only by the voltage of the freewheeling diode 121 and in the switching valve 200 itself. Curve G1 can be used as a reference for determining I*. There is no acceleration of the switch-off process. In the other functions or curves shown, G2 and G3, G4 and G5, the first switch element 131 is blocked for a specific time at a switch-off point and then switched to the conducting state again. In curve G2, the switch element 131 for the first 300us is lossy after switch element 111 is turned off and then becomes conductive. In curve G3, the switch element 131 for the first 600us is lossy and in curve G4 for 800 μs. The curves G3 to G4 represent optimum acceleration of the switch-off time (4.2 ms), with a dip which is at the same time readily visible. In curve G4, the size of the dip is already clearly limited. A further shortening is therefore not expedient. It can also be seen with reference to FIG. 5 that no further acceleration of the switch-off process can be achieved. In these curves, the switch-off movement of the switching valve 200 can be seen as an increase in the current ("dip") which falls per se. Only at curve G5 is the flow completely dropped before the armature of the shift valve 200 has reached its neutral position. Curve G5 shows the current in a maximally lossy free-wheeling circuit. In curve G5, the current is lossy for 1100 μs, it also being possible for the current profile to be identical for longer times. In addition, the curve G 5 can be used as a reference for determining t*.FIG. 6 shows a diagram of the switch-off delay. The time between the switch-off time and the maximum of the current curve is plotted over the duration of the active dissipation. It can be seen that, in the case of the switching valve 200 used, after approximately 600 μs, the switch-off delay cannot be reduced any further by keeping the second switch element 132 blocked for a longer time. From this time on, the ensuing advantages of the rapid current reduction are fulfilled and the conductive switching of the second switch element 132 has no influence on the switch-off delay. The determination of the switching time or of a switching time interval can be carried out differently. It can be determined variably via a current threshold value and is therefore robust with respect to parameter changes of the switching valve actuation or of the environment of the switching valve 200. In this case, the current can be monitored live and, if a threshold value is undershot, the active dissipation can be ended. Alternatively, if an active observation cannot be made, a fixed value may be assumed for the current threshold. In the event of a parameter change, the switching time or the switching interval can be determined on the basis of the last switching process. Inaccuracies can occur in the case of larger parameter changes between the switching operations, since it is possible to react to the parameter changes only in a subsequent switching of the switching valve 200.In FIG. 6, t(bs) describes the timing at which the switching valve 200 is turned off. The t(rmax) is the time at which the current signal in the dip is maximum. The difference of t(bs) and T(rmax) describes the turn-off delay, the time between the turn-off of the power supply by the switching of the switch element 111 and the actual movement of the switching valve 200. T(burn) is the time during which the second free-wheeling circuit is active.REFERENCE NUMERALS100 Electronic device 110 Switch-on arrangement 111 Third switch element 112 Zero potential 113 Control voltage source 114 Series resistor 120 First lossy free-wheeling circuit 121 Diode 122 Second component 130 Control arrangement 131 First switch element 132 Second switch element 133 Third component 134 Fourth component 140 Switching detection arrangement 200 Switching valve 201 Current measuring unit 300 Current tapping point 400 Arithmetic unit 401 a- 401 c Schnittstelle 402 Processor unit 403 Memory unit V Method S 1-S 3 Method steps G 1-G 5 Graph

Claims

Method (V) for detecting a switch-off movement of a switching valve (200) by means of an electronic device (100), having the following steps: - switching (S1) a first lossy free-wheeling circuit (120) for carrying an electrical signal of the switching valve (200) for rapidly lowering a switch-off current, wherein the rapid lowering of the switch-off current is not carried out as far as the complete end of the current flow; - switching (S2) the first lossy free-wheeling circuit (120) into a second free-wheeling circuit, wherein the second free-wheeling circuit has a lower loss, in particular a loss reduced by a resistance threshold value, than the first lossy free-wheeling circuit (120); and - detecting (S3) the switch-off movement of the switching valve (200) by detecting the electrical signal of the switching valve (200) with the switched-over active second free-wheeling circuit; and - providing movement information if a switch-off movement of the switching valve (200) is detected and / or providing fault information if no switch-off movement of the switching valve (200) is detected, wherein the movement information provides information about movement features of the switching valve.Method (V) according to the immediately preceding claim, wherein the switching (S2) takes place as soon as a configurable switching condition is fulfilled.Method (V) according to the immediately preceding claim, wherein the configurable switching condition comprises a time-triggered switching and / or is or comprises a switching time or a switching time interval which is / is determined in particular by means of a reference switching process in the first active free-wheeling circuit.Method (V) according to at least one of the preceding claims 2 or 3, wherein the configurable switching condition is or comprises reaching a current threshold.Method (V) according to the immediately preceding claim, wherein the current threshold is determined from the electrical signal, in particular from a valve current of the switching valve (200) and a current offset, and / or wherein the valve current of the switching valve (200) is detected by means of a reference switching process in the second free-wheeling circuit.Method (V) according to at least one of the preceding claims, wherein the detected electrical signal comprises a current signal and / or a voltage signal and / or the detection of the switch-off movement of the switching valve (200) is effected by evaluating a characteristic variable of the electrical signal selected from the group consisting of: - a current increase or current decrease; - a current maximum; - a current minimum; - a derivative change of the electrical signal; - an induction voltage; and / or - a linked flow.Method (V) according to at least one of the preceding claims 4 to 6, wherein the switching-off movement of the switching valve (200) is detected by detecting the electrical signal, in particular a value for the valve current, and / or while a current threshold is reached.Electronic device (100) for detecting a switch-off movement of a switching valve (200), which is designed to carry out a method according to one of the preceding method claims, wherein a first lossy free-wheeling circuit (120) for carrying an electrical signal, in particular a valve current of the switching valve (200), is provided, and wherein the electronic device (100) comprises: - a switch-on arrangement (110), which is designed to switch the switching valve (200) by applying a voltage via the first lossy free-wheeling circuit; - a control arrangement (130), which is configured to actively switch a first switch element (131) and to couple it to the first lossy free-wheeling circuit (120) in such a way that, in the switched state of the first switch element (131), the first lossy free-wheeling circuit is switched over to a second free-wheeling circuit for carrying the valve current of the switching valve (200), wherein a rapid lowering of the switch-off current is not carried out until the complete end of the current flow, and wherein the second free-wheeling circuit has a lower loss, in particular a loss reduced by a resistance threshold value, than the first lossy free-wheeling circuit (120), and - a switch detection arrangement (140) which is designed to detect the switch-off movement of the switch valve (200) by detecting the electrical signal of the switch valve (200) with the second free-wheeling circuit and to provide movement information if a switch-off movement of the switch valve (200) is detected and / or to provide fault information if no switch-off movement of the switch valve (200) is detected, wherein the movement information provides information about movement features of the switch valve.Electronic device (100) according to the immediately preceding claim, wherein at least one current measurement unit is connected in series with the switching valve (200).Electronic device (100) according to at least one of the preceding claims 8 or 9, wherein the first lossy free-wheeling circuit (120) comprises a diode (121), in particular a free-wheeling diode and at least one second component (122), wherein the diode (121) is connected in the reverse direction.The electronic device (100) according to at least one of the preceding claims 8 to 10, wherein the control arrangement (130) controls the first switch element (131) such that the first switch element (131) is switched in a lossy state when the control arrangement (130) is actively switched.Electronic device (100) according to the immediately preceding claim, wherein the first switch element (131) is switched into a lossy state reduced by a resistance threshold value by means of a time-triggered switching and / or if a determined value for the valve current has reached a predetermined current threshold and / or if a preconfigurable switching condition is fulfilled.Electronic device (100) according to at least one of the preceding claims 8 to 12, wherein the control arrangement (130) comprises a second switch element (132), in particular a MOS-FET switch, wherein the second switch element (132) is actively driven and / or is configured to provide a gate signal for switching the first switch element (131).The electronic device (100) of at least one of the preceding claims 8 to 13, wherein the first switch element (131) is a MOS-FET switch and is coupled at its control terminal to a third device (133) and a fourth device (134), and the third device (133) is coupled to the first lossy free-wheeling circuit (120) and the drain terminal of the second switch element (132).Electronic device (100) according to the immediately preceding claim, wherein the control arrangement (130) is configured to provide the source signal of the first switch element (131) at the control input of the first switch element (131) by actively turning off the second switch element (132).Electronic device (100) according to at least one of the preceding claims 8 to 15, wherein the switch-on arrangement (110) comprises a third switch element (111), in particular a MOS-FET switch.Electronic device (100) according to at least one of the preceding claims 14 to 16, wherein the second component (122), the third component (133) and the fourth component (134) is selected from the group comprising a resistance element or a resistor stack.Electronic device (100) according to at least one of the preceding claims 8 to 17, wherein the switching valve (200) is designed as a switching valve of automation technology, in particular industrial automation and / or laboratory automation and / or process automation.Electronic device (100) according to at least one of the preceding claims 9 to 18, wherein the current measuring unit provides a detected switch-off current of the switching valve via a current tapping point (300) to the switch detection arrangement (140), and wherein the switch detection arrangement (140) detects the switch-off movement of a switching valve on the basis of the detected switch-off current.Computing unit (400) for driving an electronic device (100) according to at least one of Claims 8 to 19, having: - a first interface (401a) to the control arrangement (130); - a second interface (401b) to the switching detection arrangement (140) and optionally: - a third interface (401c) for transmitting, in particular for receiving data, in particular the detected electrical signal.System for providing movement information for a switching-off movement of a switching valve and / or fault information about the switching valve (200), having an electronic device (100) according to at least one of Claims 8 to 19 for detecting a switching-off movement of a switching valve (200) and at least one output unit for providing the movement information.Computer program, wherein the computer program is loadable into a memory unit (403) of a computing unit (400) according to claim 20 and contains program code sections for causing the computing unit (400) to execute the method for detecting a switching position of a switching valve (100) according to one of the method claims when the computer program is executed in the computing unit (400).

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