Device for controlling valves

Abstract

Device for controlling a valve, wherein the valve has an electromagnet with a coil and is configured in such a way that the valve controls the pressure of the system as a function of the dead volume of the system by supplying the coil with current, wherein the device comprises: a control unit and a dead volume regulating unit, the control unit being configured in such a way that the control unit controls the current for actuating the valve using a control circuit, the control circuit having a plurality of elements regulated by control parameters, thereby obtaining a pressure actual value at the valve that is particularly dependent on the dead volume, wherein the dead volume and the control parameters have a non-proportional and non-linear relationship and a plurality of control parameters must be changed in order to adapt to the dead volume; the dead volume regulating unit being configured in such a way that the dead volume regulating unit simultaneously regulates a plurality of control parameters using separate dead volume parameters in order to adapt to the dead volume of the customer system, taking into account the relationship between the control parameters and the dead volume.

Description

Technical Field

[0001] The invention relates to a device for controlling a valve, in particular for controlling a proportional pressure-limiting valve. Background Art

[0002] Nowadays, digital valves are increasingly used, which are controlled using digital control units. The control unit is used to control the current that actuates the valve, which can be adjusted individually for the application via a large number of control parameters. The pressure that occurs at the valve depends primarily on the current, which in turn depends on the dead volume in the system, as does the behavior of the pressure buildup. However, if the dead volume is now to be adjusted in an application-specific manner via the control unit, a large number of control parameters must be adjusted. In this case, the change in the dead volume is not proportional and linear to the change in the control parameters. Therefore, it is difficult for the user or impossible to achieve the optimal adjustment for the control parameters with reasonable efforts. Summary of the invention

[0003] It is therefore an object of the present invention to provide a device for controlling a valve which makes it possible to adjust the dead volume in the valve in a simple manner.

[0004] This object is achieved by the features of claim 1. Further advantageous embodiments are given in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The embodiments of the present invention are described below with reference to the accompanying drawings, wherein:

[0006] Figure 1 A device according to the invention for controlling a valve is shown. DETAILED DESCRIPTION

[0007] The valve used in the hydraulic system has an electromagnet 270, by means of which the valve is actuated, ie, thus opened or closed. For this purpose, the coil of the electromagnet 270 is supplied with a corresponding current I. A force is generated in the valve due to the supplied current I. The pressure occurring at the valve - actual value p ist The diameter of the valve seat is essential here. If the dead volume in the user system changes, the way in which the current I is built up must be adjusted by the control unit 200 .

[0008] The current I supplied to the coil is controlled by a control unit 200 in which a control circuit is implemented. The control circuit detects the pressure actual value p ist and pressure-rated value p soll As input variable, the pressure actual value p istThe pressure sensor integrated in the valve is used to detect the pressure. The control circuit is to be used only as an example in the following text, and it should be noted that any other control circuit designed to control the current I for the actuation of the valve can be used. The control unit 200 also has a communication interface (not shown), such as a wired connection (e.g. Ethernet) and / or a wireless interface (e.g. Bluetooth), and if necessary, other components (not shown).

[0009] exist Figure 1 The control unit 200 shown in FIG. 1 has the following elements which are regulated by the control variables associated therewith. Firstly, the pressure setpoint value p soll is input into the setpoint value generator 210. The setpoint value signal mixer 220, the I component 230, the P component 240 and the speed feedback 250 follow the setpoint value generator 210. The output from these components is the current setpoint value I soll This is then input into the current controller 260 , which provides the current I that should be supplied to the electromagnet 270 .

[0010] In the illustrated embodiment, the dead volume-related behavior of the control unit 200 depends on the following parameters: kpt1 of the PT1 filter 212 , kr of the ramp 214 , ki of the I-component 230 , kvi of the velocity feedback of the I-component 230 , kp of the P-component 240 and kv of the velocity feedback for the P-component 250 .

[0011] Therefore, these control parameters must be changed in order to adapt the valve control behavior to the dead volume of the user's system. In addition, when the dead volume changes, it is necessary not to adjust only one control parameter, but multiple control parameters simultaneously. However, since there is a non-proportional and non-linear relationship between the control parameters and the dead volume, it is difficult or complex for the user to find the optimal setting for the control parameters.

[0012] For this reason, the device 10 according to the invention has a dead volume regulating unit 100 which is configured such that it uses a single dead volume parameter to simultaneously adjust the control parameter in order to adapt to the dead volume, taking into account the relationship between the control parameter and the dead volume. This results in a great advantage for the user: when the dead volume in the user's system changes, only this one parameter must be readjusted.

[0013] The control parameters of the control loop are then adjusted accordingly, wherein the relationship between the control parameters and the dead volume is automatically taken into account. The non-proportional and non-linear relationship is realized here according to the invention by characteristic curves 101 to 106, which exist separately for each control parameter. The different characteristic curves 101 to 106 for adjusting the individual control parameters are determined in advance by a series of tests for the corresponding hydraulic pressure of a valve of a type. In this case, the characteristic curves 101 to 106 are interpolated by mathematical function equations. However, the characteristic curves 101 to 106 can also be stored in the dead volume control unit 100 in other known methods and ways.

[0014] The dead volume adjustment unit 100 is implemented in the form of software with a graphical user interface. Figure 1 The dead volume adjustment unit 100 is displayed by a slide control showing values ​​from 50% to 200%, where 50% corresponds to a large dead volume (slow) and 200% corresponds to no dead volume (aggressive). A value of 100% corresponds to a normal state. However, the dead volume adjustment unit 100 can be implemented in other ways, such as a knob or a text input in the software.

[0015] In addition, the control unit 200 has a communication interface so that an external device (not shown) can be connected to the control unit 200 in a communicative manner. The external device is also designed so that the dead volume adjustment unit 100 is implemented in the external device. After establishing a connection with the control unit 200, the dead volume adjustment unit 100 reads out the dead volume parameters and displays the dead volume parameters in the dead volume adjustment unit 100 (for example, the slide control is moved to the corresponding position). The external device can be a smartphone, a tablet or a laptop, on which the dead volume adjustment unit 100 is implemented as an application or application program (App). However, the dead volume adjustment unit 100 can also be implemented as part of an application.

[0016] Although the relationship between the dead volume and the control variable is taken into account in the regulation by the dead volume regulating unit 100, it may nevertheless occur that the control of the pressure at the valve becomes unstable. For this reason, the dead volume regulating unit 100 has a connection 110, via which the pressure actual value p ist is input into the dead volume regulating unit 100. The dead volume regulating unit 100 is thus able to determine the pressure actual value p istInstability of the control. In this case, the dead volume cannot remain adjusted to the momentarily selected value. According to the invention, the dead volume parameter is reset to the previous value for which the pressure actual value p is determined. ist The control is stable. Therefore, the present invention provides an additional benefit: monitoring the pressure-actual value p ist The stability of the control, and when the pressure-actual value p ist Take countermeasures when control becomes unstable.

Claims

1. A device (10) for controlling a valve, wherein the valve has an electromagnet (270) with a coil and is configured such that the valve controls the pressure of the system as a function of the dead volume of the system by supplying the coil with current, wherein the device (10) has a control unit (200) and a dead volume regulating unit (100), the control unit (200) being configured such that the control unit (200) controls the current for actuating the valve using a control circuit having a plurality of elements regulated by control parameters, thereby obtaining a pressure actual value (p) at the valve that is primarily dependent on the dead volume. ist ), wherein the dead volume and the control parameter have a non-proportional and non-linear relationship, and multiple control parameters must be changed to adapt to the dead volume; the dead volume-adjustment unit (100) is configured so that the dead volume-adjustment unit (100) uses a single dead volume-parameter to simultaneously adjust the multiple control parameters in order to adapt to the dead volume of the user system while taking into account the relationship between the control parameter and the dead volume.

2. The device (10) according to claim 1, wherein the relationship between the dead volume and the plurality of control parameters is taken into account by means of corresponding characteristic curves (101 to 106).

3. The device (10) according to claim 2, wherein the corresponding characteristic curves (101 to 106) are determined by a series of tests.

4. The device (10) according to claim 3, wherein the corresponding characteristic curves (101 to 106) are interpolated as functional equations.

5. The device (10) according to claim 1 further comprises: An external unit in which a dead volume regulating unit (100) is implemented and which is configured such that it is communicatively connected to the control unit (200).

6. The device (10) according to claim 1, wherein the pressure actual value (p ist ) checks the adjustment of the dead volume adjustment unit (100).

7. The device (10) according to claim 6, wherein: When the pressure at the valve - actual value (p ist ) becomes unstable, the dead volume regulating unit (100) is regulated to a previous dead volume parameter at which the pressure actual value (p ist ) control is stable.

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