System and method for adjusting the position of an adjusting element

Abstract

The present invention relates to a system (100), comprising: a fluid actuator (2) having an adjusting element (3) which can be loaded with a pressure fluid; a pressure fluid supply device (4), the pressure fluid supply device being constructed to: perform position adjustment of the adjusting element (3) and to load the fluid actuator (2) with the pressure fluid within the scope of the position adjustment so as to move the adjusting element (3) to a predetermined position; and a hose device (28), the hose device comprising at least one hose (51, 52), the fluid actuator (2) being fluidically connected to the pressure fluid supply device (4) via the at least one hose, wherein the pressure fluid supply device (4) is constructed to: perform the position adjustment while taking into account a system model describing the hose device (28), the actuator (2) and / or the pressure fluid supply device (4).

Description

Technical Field

[0001] The present invention relates to a system, which comprises: a fluid actuator having an adjusting element that can be loaded with pressure fluid; a pressure fluid supply device, which is constructed to: perform position adjustment of the adjusting element and load the fluid actuator with pressure fluid within the range of the position adjustment so as to move the adjusting element to a predetermined position; and a hose device, which comprises at least one hose, and the fluid actuator is fluidically connected to the pressure fluid supply device via the at least one hose. Background Art

[0002] The pressure fluid supply device comprises, for example, a valve group, which is connected to a fluid actuator via a hose. The fluid actuator is, for example, a pneumatically driven cylinder.

[0003] The system is suitable for use in industrial automation, for example in order to position a driven object such as a tool, a workpiece and / or a machine part by means of an adjusting element.

[0004] The fluid actuator comprises one or more pressure chambers which are placed under pressure within the scope of position control by loading with a pressure fluid in order to thus bring about a positioning of the adjusting element. Advantageously, there is no pressure sensor on the fluid actuator itself, so that the pressure in the pressure chamber of the fluid actuator cannot be measured directly. The pressure fluid is preferably compressed air. Position control by means of compressed air loading is also referred to as servopneumatics. Summary of the invention

[0005] The object of the present invention is to provide a system which can be used more flexibly.

[0006] This object is achieved by a system according to claim 1. The pressure fluid supply device of the system is designed to carry out position control taking into account a system model describing the hose arrangement, the actuator and / or the pressure fluid supply device.

[0007] The pressure fluid supply device is particularly configured to provide a model-based position control. The system model includes the following system parameters, which, for example, describe physical properties such as the dimensions and / or mass of the hose device, the actuator and / or the pressure fluid supply device. For example, the system model includes the length, diameter and / or volume of the hose of the hose device as system parameters. The system model may also include the dimensions and / or the mass (to be moved during position control) of an actuator, which is particularly configured as a drive cylinder, as system parameters. The system model may also include the following system parameters, which describe the control characteristics of the pressure fluid supply device, in particular the control characteristics of the valve device of the pressure fluid supply device. Through the system model, it is also possible to take into account certain characteristics of the sensor device used for position control.

[0008] By using the system model, in particular by taking into account the system parameters of the hose describing the hose arrangement, it is possible, for example, to provide position control even when a longer hose is used between the pressure fluid supply device, for example the valve block, and the actuator, without having to provide a pressure sensor on the actuator itself. By means of the system model, in particular by means of a hose model of the system model, it is possible, for example, to calculate an actuator pressure from a measured pressure detected on the pressure fluid supply device, which actuator pressure corresponds to the pressure on the actuator, for example the pressure in the pressure chamber of the actuator. The hose model describes the physical properties of the hose, for example the length, diameter and / or volume of the hose. The calculated actuator pressure can also be referred to as the calculated chamber pressure.

[0009] In the case of a very short hose length, the difference between the measured pressure measured at the pressure fluid supply device and the actuator pressure present at the actuator is very small, so that the measured pressure can be used as the actuator pressure. In the case of an increased hose length, the difference between the current measured pressure and the current actuator pressure can increase. By means of the system model, in particular the hose model, the influence of the hose on the actuator pressure can be taken into account when calculating the actuator pressure, so that the actuator pressure can be accurately calculated based on the measured pressure even in the case of longer hoses. The calculated actuator pressure can then be used as a feedback variable in the position control.

[0010] In this way, it is possible to use the position control even in the case where a longer hose is used between the pressure fluid supply device and the actuator (without having to provide a pressure sensor on the actuator). Thus, the system can be used more flexibly (i.e. even in the case of longer hoses).

[0011] Advantageous embodiments are the subject matter of the dependent claims.

[0012] The invention also relates to a method for operating a system as described above. The method comprises the following steps: performing the position control taking into account the system model.

[0013] The method is expediently designed to correspond to the configuration of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the following, exemplary details and exemplary embodiments are explained with reference to the accompanying drawings.

[0015] Figure 1 A schematic diagram of a system having a pressure fluid supply device, a hose arrangement and a fluid actuator is shown;

[0016] Figure 2 A schematic diagram of a valve arrangement is shown;

[0017] Figure 3 shows a schematic diagram of a position regulator; and

[0018] Figure 4 A schematic diagram of a regulating unit of the position regulator is shown. DETAILED DESCRIPTION

[0019] Figure 1 A system 100 is shown. The system 100 comprises a fluid actuator 2 which can be acted upon by a pressure fluid and has an adjusting element 3 .

[0020] The system 100 further comprises a pressure fluid supply device 4, which comprises a valve mechanism 14, for example, configured as a valve group. The pressure fluid supply device 4 is configured to perform position adjustment of the adjusting element 3 and to load the fluid actuator 2 with pressure fluid within the scope of the position adjustment so as to move the adjusting element 3 to a predetermined position.

[0021] The system 100 further comprises a hose arrangement 28 which expediently comprises at least one hose 51, 52. The fluid actuator 2 is fluidically connected to a pressure fluid supply device 4 via the hose arrangement 28. The pressure fluid supply device 4 is designed to supply the fluid actuator 2 with pressure fluid via the hose arrangement 28.

[0022] The pressure fluid supply device 4 is designed to carry out a position control taking into account a system model which describes the hose arrangement 28 , the actuator 2 and / or the pressure fluid supply device 4 .

[0023] In the following, other exemplary details shall be set forth.

[0024] First, the pressure fluid supply device 4 should be discussed:

[0025] The pressure fluid supply device 4 comprises a valve mechanism 14, which is exemplarily configured as a valve group, through which pressure fluid is provided for position adjustment of the actuator 2. The valve mechanism 14 does not necessarily have to be a valve group. The valve mechanism 14 can also be implemented as a single valve or other valve unit, for example.

[0026] Two pressure outputs 23, 24 are provided on the valve mechanism 14 for providing a pressure fluid, in particular compressed air. Each of the two pressure outputs 23, 24 is fluidically connected to a corresponding pressure chamber 8, 9 of the fluid actuator 2. In an alternative embodiment in which the actuator 2 has only one pressure chamber, only one pressure output is connected to one pressure chamber accordingly.

[0027] The valve mechanism 14 has a pressure sensor device 29, which has pressure sensors, with which the pressure at the pressure outputs 23, 24 and / or the pressure in the exhaust port 26 and / or the intake port 27 can be measured. These pressure sensors are preferably arranged on the valve mechanism 14, in particular on the valve group. Figure 2 As further explained, the pressure sensor device 29 exemplarily includes a first pressure output pressure sensor 45 , a second pressure output pressure sensor 46 , an exhaust pressure sensor 43 and / or an intake pressure sensor 44 .

[0028] Exemplarily, the valve mechanism 14 includes a plurality of modules, such as a valve module 17 and / or an I / O module 18. The valve mechanism 14 also includes a control unit 19, which is preferably also implemented as a module. Suitably, the valve mechanism 14 has a carrier 20, in particular a carrier plate, on which the control unit 19, the valve disk 17 and / or the I / O module 18 are arranged.

[0029] The valve mechanism 14 is exemplarily implemented as an inline module device and can also be referred to as a valve group in particular. The modules mentioned above are in particular inline modules, which are preferably implemented in a disk shape. The valve module 17 is in particular implemented as a valve disk. Suitably, these inline modules are arranged in a row, in particular in a row along the longitudinal axis of the valve mechanism 14.

[0030] The pressure fluid supply device 4 also includes, by way of example, a higher-level control device 15 and / or optionally a cloud server 16 and / or a user device 49 .

[0031] The valve mechanism 14 is suitably connected to the upper control device 15 and / or the cloud server 16. Preferably, the valve mechanism 14 is connected to the upper control device 15 via a bus 25, in particular a local bus, such as a field bus, and / or is optionally connected to the cloud server 16 via a wide area network 22, such as the Internet.

[0032] The valve mechanism 14 is communicatively connected to the position sensor device 10 of the actuator 2, in particular, via the I / O module 18. Exemplarily, the valve mechanism 14 is communicatively connected to the position sensor device 10 via one or more communication lines 91, 92. Suitably, the position sensor value detected by the position sensor device 10 is provided to the control unit 19, the superior control device 15 and / or the cloud server 16. Suitably, the pressure sensor values ​​of the pressure sensors 43, 44, 45, 46 are also provided to the control unit 19, the superior control device 15 and / or the cloud server 16.

[0033] In the following, the fluid actuator 2 shall be discussed further.

[0034] The fluid actuator 2 is preferably a pneumatic actuator that can be loaded with compressed air. Exemplarily, the fluid actuator 2 is configured as a drive device, in particular as a drive cylinder. Exemplarily, the fluid actuator 2 includes an actuator body 7, an adjustment element 3 and at least one pressure chamber 8, 9. Exemplarily, the fluid actuator 2 includes two pressure chambers 8, 9 that can be loaded with pressure fluid independently of each other, and is particularly configured as a double-acting actuator. Alternatively, the fluid actuator 2 can also have only one pressure chamber and accordingly be configured as a single-acting actuator.

[0035] The actuator body 7 is preferably embodied as a cylinder and has an inner volume. The adjusting element 3 comprises, for example, a piston 5 and / or a piston rod 6. The piston 5 is arranged in the actuator body 7 and divides the inner volume of the actuator body 7 into two pressure chambers 8,9.

[0036] Suitably, the fluid actuator 2 comprises a position sensing device 10. The position sensing device 10 is used in particular to detect the position of the adjusting element 3. Exemplarily, the position sensing device 10 is arranged outside the actuator body 7. The position sensing device 10 comprises, for example, two position sensing units 11, 12, which are arranged distributed along the movement path of the adjusting element 3. Exemplarily, the position sensing units 11, 12 together cover the entire movement path of the adjusting element 3.

[0037] Each position sensor unit 11, 12 may include, for example, one or more sensor elements (not shown in these figures), in particular magnetic sensor elements, such as Hall sensor elements. Preferably, a magnet is arranged on the adjustment element 3, the magnetic field of which can be detected by the magnetic sensor elements.

[0038] The position sensor device 10 is expediently designed to detect the position of the actuating element 3 over the entire displacement path of the actuating element 3 .

[0039] Expediently, no pressure sensor is present on the fluid actuator 2 , in particular no pressure sensor for measuring the pressure in one of the pressure chambers 8 , 9 .

[0040] The hose arrangement 28 exemplarily comprises two hoses 51, 52. The first hose 51 fluidically connects the first pressure output 23 to the first pressure chamber 8, and the second hose 52 fluidically connects the second pressure output 24 to the second pressure chamber 9. In an alternative design in which the fluid actuator 2 has only one pressure chamber, the hose arrangement 28 expediently comprises only one hose.

[0041] The length of one or both hoses 51, 52 is exemplarily longer than 1.5 m, in particular longer than 2 m. Exemplarily, the length of one or both hoses 51, 52 is up to 5 m long. Preferably, the length of one or both hoses 51, 52 is respectively longer than the sum of half the length of the actuator 2 configured as a drive cylinder and 40 cm. In particular, the length of one or both hoses 51, 52 is respectively longer than the sum of half the length of the movement path of the adjustment element 3 and 40 cm.

[0042] The superordinate control device 15 is designed as a programmable logic controller SPS by way of example and is communicatively connected to the valve mechanism 14, in particular to the control unit 19. The superordinate control device 15 is also expediently connected to the cloud server 16, in particular via a wide area network 22, preferably via the Internet. The superordinate control device 15 is expediently designed to provide a setpoint value signal SWS, which specifies the (setpoint) position to which the actuating element 3 is adjusted within the scope of position control.

[0043] Exemplarily, the user device 49 is a mobile device, such as a smart phone, a tablet computer and / or a laptop computer. The user device 49 can also be a desktop computer, such as a PC. Suitably, the user device 49 is communicatively connected to the control unit 19, the cloud server 16 and / or the superior control device 15, in particular via a wide area network 22, such as the Internet. The user device 49 is particularly configured for user input of one or more system parameters of the system model. Suitably, a user interface can be accessed via the user device 49, which user interface is provided, for example, on the cloud server 16, the control device 15 and / or the control unit 19. Suitably, the user interface is a web interface. The user interface is particularly used for inputting model parameters by the user. The user interface is also preferably used to select, activate and / or load an application onto the control unit 19, which provides a position regulator 50 further described below.

[0044] The cloud server 16 is preferably arranged remotely from the valve mechanism 14 and / or the fluid actuator 2, in particular at another geographical location. Preferably, the cloud server 16 is configured to provide an application program, with which the position adjustment can be performed. The application program can be loaded from the cloud server 16 to the superordinate control device 15 and / or the control unit 19, preferably as a response to a user input using the user device 49.

[0045] Figure 2 An exemplary valve device 21 is shown, with which the pressure can be provided for the pressure chambers 8 , 9 . The valve device 21 is part of the pressure fluid supply device 4 , in particular the valve mechanism 14 , preferably the valve module 17 .

[0046] The valve device 21 has two pressure outputs 23, 24, by means of which two independent pressure fluid pressures and / or two independent pressure fluid mass flows can be provided. The valve device 21 also has an exhaust connection 26 connected to an exhaust line and an intake connection 27 connected to an intake line. Preferably, the supply pressure is applied to the intake connection 27 and / or the atmospheric pressure is applied to the exhaust connection 26.

[0047] The valve device 21 comprises one or more valve elements 48 for each pressure output 23 , 24 , by means of which the size of the respective output opening through which the pressure fluid is provided at the respective pressure output 23 , 24 can be adjusted.

[0048] exist Figure 2 In the embodiment, the valve device 21 is exemplarily implemented as a full bridge composed of four 2 / 2-way valves 31, 32, 33, 34. The first 2 / 2-way valve 31 is connected between the intake connection 27 and the first pressure output 23, the second 2 / 2-way valve 32 is connected between the first pressure output 23 and the exhaust connection 26, the third 2 / 2-way valve 31 is connected between the exhaust connection 26 and the second pressure connection 24, and the fourth 2 / 2-way valve is connected between the second pressure output 24 and the intake connection 27.

[0049] The first pressure output end 23 can be selectively connected to the exhaust pipe via the first 2 / 2-way valve or to the intake pipe via the second 2 / 2-way valve, and the second pressure output end 24 can be selectively connected to the exhaust pipe via the third 2 / 2-way valve or to the intake pipe via the fourth 2 / 2-way valve.

[0050] Exemplarily, each 2 / 2-way valve 31, 32, 33, 34 is configured as a proportional valve; that is, each 2 / 2-way valve 31, 32, 33, 34 has a valve member 48, which can be placed in an open position, a closed position, and any intermediate position between the open position and the closed position. Preferably, the 2 / 2-way valve 31, 32, 33, 34 is a pre-adjusted valve, which has two pilot valves 41, 42 respectively, through which the valve member can be operated. The pilot valves 41, 42 are exemplarily configured as piezoelectric valves. The above-mentioned output port opening can be appropriately adjusted by the position of the corresponding valve member 48.

[0051] Exemplarily, the first and second 2 / 2-way valves 31, 32 form a first half-bridge and the third and fourth 2 / 2-way valves 33, 34 form a second half-bridge. Preferably, the output opening of the first pressure output 23 can be adjusted by the first half-bridge, and the output opening of the second pressure output 24 can be adjusted by the second half-bridge.

[0052] The valve device 14 expediently comprises a pressure sensor system 29 which has one or more pressure sensors in order to detect the pressure of the valve device 14 , in particular of the valve device 21 .

[0053] Exemplarily, the valve mechanism 14, in particular the valve device 21, comprises: a first pressure output pressure sensor 45 for detecting the pressure provided at the first pressure output 23; and / or a second pressure output pressure sensor 46 for detecting the pressure provided at the second pressure output 24. Suitably, the valve mechanism 14, in particular the valve device 21, further comprises: an intake pressure sensor 44 for detecting the pressure provided at the intake connection 27; and / or an exhaust pressure sensor 43 for detecting the pressure provided at the exhaust connection 26.

[0054] The valve mechanism 14, in particular the valve device 21, expediently comprises a travel sensor 47 for detecting the position of the valve element 48. The pressure fluid supply device 4 is designed in particular to determine the size of the output opening of the pressure outputs 23, 24 by means of the travel sensor 47.

[0055] In the following, reference should be made to Figure 3 Let us further discuss the position adjustment performed by the pressure fluid supply device 4.

[0056] The pressure fluid supply device 4 is preferably configured to perform position adjustment within the entire movement path of the adjustment element 3. Preferably, the pressure fluid supply device 4 is configured to position the adjustment element 3 to any position along the movement path by means of position adjustment. Preferably, the adjustment element 3 can be positioned at any arbitrary position along the movement path by position adjustment.

[0057] Figure 3 An exemplary position regulator 50 is shown for providing a position control of the actuating element 3. The position regulator is expediently implemented as a program, in particular as an application program, which is implemented in particular on the valve mechanism 14, preferably on the control unit 19. The position regulator 50 is implemented in particular on a microcontroller of the control unit 19. Alternatively or in addition thereto, the position regulator 50 can also be implemented on the cloud server 16 and / or the superordinate control device 15.

[0058] The position regulator 50 is configured to provide a set value signal SGS based on a set value signal SWS. The set value signal SWS is provided, for example, by the control unit 19, the control device 15 and / or the cloud server 16. Suitably, the set value signal SWS includes a position set value signal. The valve mechanism 14 is configured to control the valve device 21, in particular the 2 / 2-way valves 31, 32, 33, 34, in particular the pilot valves 41, 42 of these 2 / 2-way valves, based on the set value signal SGS. Exemplarily, one or more conductance values ​​are specified by the set value signal SGS, according to which the position of the valve member 48 is adjusted and thus the output end opening of the pressure output ends 23, 24 is adjusted.

[0059] In particular, the position controller 50 is designed to provide a setpoint signal SGS as a function of the setpoint value signal SWS, the measured variable signal MGS and / or a system parameter SP of a system model.

[0060] The measured variable signal MGS expediently comprises the measured values ​​of the position sensor device 10, the pressure sensor device 29, in particular the pressure sensors 43, 44, 45, 46 and / or the travel sensor 47. The measured variable signal MGS thus comprises in particular the measured position of the actuating element 3, the pressure measured at the exhaust port 26, the pressure measured at the intake port 27, the pressure measured at the pressure output 23, the pressure measured at the pressure output 24 and / or the measured position of the valve element 48. The measured pressure can expediently be provided in the measured variable signal MGS as a pressure difference. Furthermore, the measured position can be provided in the measured variable signal MGS as a conductance value.

[0061] The system parameters SP are, in particular, parameters of the system model which are input by a user, for example via a user device 49 .

[0062] The position controller 50 exemplarily comprises a trajectory planner part 60 and a controller part 70. The trajectory planner part 60 provides a trajectory signal TS based on the setpoint value signal SWS. For example, the trajectory planner part 60 applies a speed and / or acceleration limit and / or a jerk limit to the setpoint value signal SWS and provides a trajectory signal TS as a result. In this way, signal changes that may be contained in the setpoint value signal SWS can be smoothed so that these signal changes can be better used by the controller part 70. The trajectory signal TS is supplied to the controller part 70.

[0063] According to an alternative embodiment, trajectory planner part 60 is not present. In this case, the setpoint value signal SWS supplied to position controller 50 is expediently used as trajectory signal TS, which is supplied to controller part 70 .

[0064] Exemplarily, the trajectory signal includes a position change process, a speed change process, an acceleration change process and / or an impact change process.

[0065] Expediently, controller part 70 is designed to compare the trajectory signal, in particular the position curve, speed curve, acceleration curve and / or jerk curve, with a state signal ZS1 obtained based on the measured variable signal and to provide a set value signal SGS based on this comparison.

[0066] Exemplarily, the regulator part 70 comprises a state determination unit 77 which provides one or more state signals ZS1, ZS2 based on the measured variable signal SGS. Exemplarily, a first state signal ZS1 is supplied to the regulator unit 72 and a second state signal ZS2 is supplied to the conversion and / or regulation unit 82. The state signals ZS1 and ZS2 may contain the same or different state variables.

[0067] Exemplarily, the controller part 70 comprises a pilot unit 71 and a regulating unit 72, to which the track signal TS is supplied respectively. The pilot unit 71 provides the pilot signal VS based on the track signal TS. Preferably, the pilot unit 71 performs pure control, i.e., "open-loop control", wherein feedback variables, in particular measured variable signals MGS and / or state signals, are preferably not taken into account.

[0068] The control unit 72 provides a control unit signal RES based on the trajectory signal TS and on the feedback variable. The control unit 72 in particular performs a control, i.e. a "closed-loop control", in which feedback variables, in particular the measured variable signal MGS and / or the state signal ZS1, are taken into account. By way of example, the control unit 71 compares the trajectory signal TS with the first state signal ZS1 and provides a control unit signal RES based on the comparison.

[0069] The pilot signal VS and the regulating unit signal RES are added by the summing element 83 to form a sum signal SS. Based on the sum signal SS, the regulating quantity signal SGS is provided. The sum signal SS expediently specifies the mass flow of the pressure outputs 23, 24. The sum signal SS can also be referred to as a mass flow signal and / or a regulating signal.

[0070] Exemplarily, the regulator part 70 further comprises a scaling and / or regulating unit 82. Exemplarily, the regulator part 70 further comprises a frequency filter 79. Exemplarily, the scaling and / or regulating unit 82 and / or the frequency filter 79 are connected between the regulating unit 72 and the output of the regulator part 70. Exemplarily, the scaling and / or regulating unit 82 and / or the frequency filter 79 are connected between the summing element 83 and the output of the regulator part 70. Suitably, the regulation quantity signal SGS output by the regulator part 70 has been subjected to the scaling and / or regulating unit 82 and / or the frequency filter 79.

[0071] The conversion and / or control unit 82 is designed to convert the signal supplied to it, for example the sum signal SS, from a mass flow specification into a flow conductance specification and output it as a conversion signal URS. The conversion signal URS can then be used, for example, as a set quantity signal SGS or as in Figure 3 As shown in FIG. 7 , it first passes through a frequency filter 79 .

[0072] By way of example, the conversion and / or regulation unit 82 is designed to carry out regulation, wherein the conversion and / or regulation unit 82 compares, for example, a signal supplied to it, here the sum signal SS, with the second state signal ZS2 and outputs a conversion signal URS as a result.

[0073] The frequency filter 79 is designed, for example, as a band-stop filter. For example, a conversion signal URS is supplied to the frequency filter 79, on the basis of which the frequency filter 79 provides a filtered signal, here the control quantity signal SGS.

[0074] Optionally, the controller part 70 also includes a controller parameter calculation unit 78. The controller parameter calculation unit 78 is designed to provide one or more controller parameters, in particular one or more controller gain factors, to the control unit 72 and / or the conversion and / or control unit 82 based on the system parameters SP of the system model.

[0075] In the following, exemplary embodiments of individual components of the position controller 50 will be discussed and, in particular, how the system model is used in the position control will be explained using various examples.

[0076] The system model comprises in particular a hose model having hose parameters. Hose parameters are system parameters. Exemplarily, hose parameters are physical properties, in particular dimensions, in particular hose length, hose diameter and / or hose volume of the hose arrangement 28, in particular the hose 51 or 52. The hose parameters are preferably input by a user and in particular not determined by means of a learning operation.

[0077] The system 100 advantageously has a user interface, for example a user device 49, via which a user can input system parameters, in particular hose parameters, into the pressure fluid supply device 4. The system parameters, in particular hose parameters, are advantageously taken into account by the position controller 50 when carrying out the position control.

[0078] As already mentioned above, the pressure fluid supply device 4 comprises a pressure sensor device 29 (exemplarily pressure sensors 43, 44, 45, 46). The pressure sensor device 29 is designed to measure the pressure of the pressure fluid in the pressure fluid supply device 4, in particular in the valve mechanism 14. The measured pressure should also be referred to as measured pressure. For example, the measured variable signal MGS includes the measured pressure.

[0079] The pressure fluid supply device 4 is also designed to calculate the pressure of the pressure fluid in the fluid actuator 2 based on the measured pressure using a hose model, in particular hose parameters. This calculated pressure should also be referred to as calculated pressure, actuator pressure or chamber pressure.

[0080] The measured pressure corresponds in particular to the pressure of the pressure fluid at one end of the hose 51, 52, which is arranged on the pressure output 23, 24 of the valve mechanism 14. The calculated pressure corresponds in particular to the pressure of the pressure fluid at the other end of the hose 51, 52, which is arranged on the fluid actuator 2. Advantageously, the hose model depicts the pressure drop and / or time delay, such as dead time, which may occur between the two ends of the hose 51, 52. The calculated pressure is calculated based on the hose model, so that the calculated pressure has a pressure drop and / or time delay relative to the measured pressure. Advantageously, the hose model, in particular the pressure drop and / or the time delay, is determined based on hose parameters, in particular by the position regulator 50.

[0081] The state determination unit 77 is expediently designed to carry out a calculation of the calculated pressure.

[0082] The pressure fluid supply device 4 is expediently designed to perform position control using the calculated pressure. Exemplarily, the pressure fluid supply device 4 uses the calculated pressure as a feedback variable for position control. In particular, the adjustment quantity signal SGS is generated taking into account the calculated pressure. Exemplarily, the first state signal ZS1 and / or the second state signal ZS2 include the calculated pressure. Preferably, the control unit 72 and / or the conversion and / or control unit 82 performs its control taking into account the calculated pressure, in particular taking into account the calculated pressure as a feedback variable.

[0083] Preferably, the pressure fluid supply device 4 is designed to use a model-assisted filter, in particular a hose model, in order to calculate the chamber pressure from the measured pressure, for example the valve pressure, so as to perform the position control using the reconstructed chamber pressure. In this way, it is particularly possible to use longer hoses for the hoses 51 and / or 52 without having to provide a pressure sensor on the fluid actuator 2. In particular, by means of a control based on the calculated pressure, a high control performance can be achieved even with longer hoses. In this case, it is not necessary to use a pressure sensor on the fluid actuator 2, so that the installation and commissioning costs associated therewith can be avoided.

[0084] According to a preferred embodiment, the pressure fluid supply device 4 is designed to provide an acceleration signal that describes the acceleration of the adjustment element 3 within the scope of the position control. The acceleration signal is preferably provided by the state determination unit 77. The position regulator 50 is particularly designed to take into account the acceleration signal as a feedback variable in the case of position control. Exemplarily, the acceleration signal is contained in the first state signal ZS1 and is supplied to the adjustment unit 72.

[0085] The pressure fluid supply device 4 , preferably the state determination unit 77 , is designed in particular to provide an acceleration signal based on the second derivative of the position signal and based on the pressure signal.

[0086] The position signal describes the position of the actuating element 3 and is expediently based on the position of the actuating element 3 detected by the position sensor device 10. The position signal is expediently contained in the measured variable signal MGS.

[0087] The pressure signal expediently describes the pressure of the pressure fluid provided by the pressure fluid supply device 4. The pressure signal is in particular a calculated pressure which describes the pressure of the pressure fluid in the fluid actuator 2.

[0088] Preferably, the pressure fluid providing device 4, in particular the state determination unit 77, is constructed such that when providing an acceleration signal, the second differential position signal and the pressure signal are weighted in relation to the frequency, respectively, so that within a first frequency range the second differential position signal dominates and within a second frequency range the pressure signal dominates, wherein the second frequency range is higher than the first frequency range.

[0089] Exemplarily, the pressure fluid supply device 4, in particular the state determination unit 77, is configured to subject the second differential position signal to low-pass filtering and the pressure signal to high-pass filtering, and to provide an acceleration signal based on the second differential position signal after low-pass filtering and based on the pressure signal after high-pass filtering. In particular, the acceleration signal is provided as the sum of the second differential position signal after low-pass filtering and the pressure signal after high-pass filtering. Suitably, in the acceleration signal, at low frequencies, the component from the second differential position signal is dominant, while at high frequencies, the component from the pressure signal is dominant.

[0090] The position sensing units 11, 12 of the position sensing device 10 may have a low signal quality. Due to the low signal quality, the position signal from the position sensing device 10 may be contaminated by noise, which leads to high noise components, especially at higher frequencies, in particular in the case of a second differentiation of the position signal. By low-pass filtering, this noise component can be reduced.

[0091] From the pressure signal, the calculated pressure, in particular the calculated chamber pressure of the fluid actuator 2, the acceleration of the adjustment element 3 can also be calculated. However, static offsets may exist here, for example due to low-frequency external forces, in particular disturbing forces and / or parameter uncertainties. These static offsets can be reduced by high-pass filtering.

[0092] Therefore, a sensor fusion is performed, in which the low-noise high-frequency range of the pressure signal and the substantially offset-free low-frequency range of the acceleration signal are combined or fused for the acceleration signal. The noisy high-frequency range of the second differential position signal and the offset-free low-frequency range of the pressure signal are suppressed.

[0093] The position control can therefore also be used in the case of position sensor units with low signal quality which are not originally designed for servopneumatic systems.

[0094] According to another preferred design, the pressure fluid supply device 4, in particular the position regulator 50, is configured to configure the frequency filter 79 based on a system model, in particular a hose model, so that the pressure fluid vibration in the hoses 51, 52 is suppressed. Suitably, the pressure fluid supply device 4, in particular the position regulator 50, is configured to calculate the vibration frequency, in particular the natural frequency, of the pressure fluid in the hoses 51, 52 based on the hose model, in particular hose parameters, such as hose length and / or hose volume, and configure the frequency filter 79 so that the calculated frequency is suppressed. The frequency to be suppressed can also be referred to as the hose natural frequency. The frequency filter 79 is, for example, a band stop filter, which is set up to suppress the calculated frequency. Preferably, the frequency filter 79, in particular the band stop filter, is a variable frequency filter, wherein the frequency to be suppressed can be continuously updated and suitably continuously updated.

[0095] Preferably, the pressure fluid supply device 4, in particular the position controller 50, is designed to configure the frequency filter 79 also taking into account the actuator model, in particular actuator parameters, such as the volume of the actuator 2. The actuator parameter is, for example, the pressure chamber volume of the actuator 2.

[0096] Preferably, the pressure fluid supply device 4, in particular the position regulator 50, is configured to configure the frequency filter 79 also based on the position of the adjusting element 3. In particular, the frequency to be suppressed by the frequency filter 79 is continuously updated based on the current position of the adjusting element 3. For example, the hose model and the position of the adjusting element 3 are used together to calculate the vibration frequency to be suppressed, in particular the natural frequency to be suppressed.

[0097] Exemplarily, the pressure fluid supply device 4, in particular the position regulator 50, is configured to calculate the frequency to be suppressed based on the hose model, the actuator model and the position of the adjusting element 3. For example, the total volume (including the vibration volume of the hose volume and the pressure chamber volume) and / or the total length are calculated, more precisely based on the hose model, in particular the hose volume and / or the hose length, the actuator model, in particular the pressure chamber volume and / or the pressure chamber length, and the reduction of the pressure chamber volume and / or the pressure chamber length resulting from the current position of the adjusting element 3, the total volume (including the vibration volume of the hose volume and the pressure chamber volume) and / or the total length are calculated, more precisely based on the hose model, in particular the hose volume and / or the hose length. Then, based on the total volume and / or the total length, the frequency to be suppressed can be calculated and / or the frequency filter 79 can be configured.

[0098] In the case of pressure fluid loading 51, 52, an excitation of the fluid in the hose, in particular compressed air, at the hose natural frequency can occur. This can lead to humming and / or reduced controller performance. With a frequency filter 79, in particular a notch filter with a variable notch frequency (exemplarily depending on the hose and volume parameters), the quantity control signal SGS can be filtered so that an excitation of the hoses 51, 52 at the hose natural frequency can be prevented or reduced. As a result, humming can be eliminated. In addition, a performance increase can be achieved, in particular with longer hoses 51, 52.

[0099] According to another preferred design, the pressure fluid supply device 4, in particular the position regulator 50, is configured to calculate a regulator parameter for position regulation, in particular a regulator gain, based on a system model, in particular a system parameter / the system parameter, and use the regulator parameter within the scope of the position regulation. Preferably, the calculation of the regulator parameter is performed by a regulator parameter calculation unit 78.

[0100] By automatically calculating the controller parameters, a large number of application variants can be covered in particular. The parameterization of the position control is usually very strongly dependent on physical parameters such as mass, in particular the mass of the control element and / or the drive cylinder size. The user is usually not aware of the connection between the physical parameters and the controller parameters.

[0101] In the above-mentioned design, the user can input physical parameters as model parameters, for example, via the user device 49. Then, the position controller 50, in particular the controller parameter calculation unit 78 (in particular on the valve mechanism 14, in particular the valve group), performs the calculation of the controller parameters and configures the position control according to the calculated controller parameters. Preferably, a plurality of controller parameters are calculated.

[0102] In particular, automatic parameterization is performed based on system parameters. In particular, the controller design is performed in the controller, that is, for example, the controller design is performed by the valve mechanism 14, in particular, the valve group, for example, the control unit 19. Suitably, the controller parameter calculation unit 78 is constructed to calculate the controller gain for the position regulation. Therefore, the controller characteristics can be adapted in a simple way by a small number of "adjustment screws", that is, by inputting one or more parameters known to the user, in particular model parameters. For example, the hardness of the position regulation, that is, the stiffness and / or the flexibility of the position regulation can be specified as parameters, in particular model parameters. Suitably, for the use of the position regulation, user input of the controller gain and / or a learning operation for providing the controller gain are not required.

[0103] According to a preferred design, the pressure fluid supply device 4, in particular the pilot unit 71, is configured to provide a pilot signal VS while taking into account the system model, in particular the hose model. Suitably, the pilot unit 71 is configured to additionally take into account one or more model parameters of the system model in the case of a conventional pilot control with precise state linearization. Exemplarily, the pilot unit 71 is configured to take into account the hose volume of the hoses 51, 52 and / or the dead volume of the actuator 2, in particular the drive cylinder, when providing the pilot signal VS. Exemplarily, the pilot unit 71 is configured to add the hose volume to the dead volume as a system parameter and to take into account the volume obtained therefrom when providing the pilot signal VS. Exemplarily, the pilot unit 71 is configured to take into account the pressure drop that exists, in particular due to air friction in the hoses 51, 52, when providing the pilot signal VS as a system parameter.

[0104] By taking the hose parameters into account in the pilot control, a higher regulator quality can be achieved, in particular in the case of long hoses 51 , 52 .

[0105] The conversion and / or regulating unit 82 is preferably designed to perform mass flow regulation. This mass flow regulation is preferably carried out within the scope of the position regulation of the adjusting element 3. For the purpose of mass flow regulation, the conversion and / or regulating unit 82 compares, for example, the set mass flow, for example the sum signal SS, with the actual mass flow, and provides a signal based on this comparison, here, for example, the conversion signal URS, and finally controls the valve device 21, in particular the individual 2 / 2-way valves 31, 32, 33, 34, based on this signal. The actual mass flow is, for example, part of the second state signal ZS2 and is preferably calculated by the state determination unit 77, in particular based on the output opening of the valve device 21 detected by means of the travel sensor 47 and / or based on the detected measured pressure of the pressure sensor device 29. The conversion and / or regulating unit 82 is particularly designed to use the detected output opening for a forward simulation of a valve model, in particular a model of the valve device 21. The valve model is preferably part of the system model. By way of example, the setpoint mass flow is compared with the calculated actual mass flow and fed back in a weighted manner.

[0106] The conversion and / or control unit 82 expediently performs regulation and pilot control within the scope of mass flow control. The position controller 50, in particular the conversion and / or control unit 82, is expediently designed to detect the dynamic characteristics, in particular the frequency response and / or the bandwidth, of the valve arrangement 21, in particular the 2 / 2-way valves 31, 32, 33, 34 and / or the mass flow control, in particular during (normal) operation, i.e. "online". The position controller expediently determines one or more dynamic parameters, which describe the dynamic characteristics.

[0107] The position regulator 50, in particular the conversion and / or regulation unit 82, is preferably configured to adapt the mass flow regulation based on the detected dynamic characteristics, in particular based on one / multiple dynamic parameters, so that the dynamic characteristics of the mass flow regulation, in particular the frequency response and / or the bandwidth, are improved or increased, and the dynamic characteristics of the mass flow regulation, in particular the frequency response and / or the bandwidth, are preferably improved or increased by increasing the regulator gain of the mass flow regulation. The position regulator 50, in particular the conversion and / or regulation unit 82, is preferably configured to perform the detection and adaptation of the dynamic characteristics multiple times during the service life of the valve device 21, so that the deterioration of the dynamic characteristics due to aging is reduced.

[0108] The position controller 50 is expediently designed to increase the bandwidth during the control and / or pilot control of the mass flow control, more precisely, in particular based on dynamic parameters of the dynamic behavior of the valve device 21 detected during operation. The position controller 50 is expediently designed to reduce the influence of dynamic stroke controller deviations when using a valve model. The valve model is in particular part of the system model. Furthermore, the position controller 50 is in particular designed to increase the bandwidth in a closed position control loop.

[0109] Expediently, the pressure fluid supply device 4 is also designed to calculate the (remaining) service life of the valve mechanism 14 , in particular the valve device 21 , based on the detected dynamic properties, in particular on the dynamic parameters.

[0110] In the following, reference should be made to Figure 4 An exemplary embodiment of the regulating unit 72 is described below.

[0111] The control unit 72 comprises two control elements, which are expediently connected in parallel, namely a first control element 73 and a second control element 74 .

[0112] The first regulator element 73 is expediently designed to provide a first regulator element signal RGS1 based on the trajectory signal TS and the state signal ZS1A. The first regulator element 73 expediently provides the first regulator element signal RGS1 based on an acceleration error determined by the first regulator element 73. Expediently, the regulator element signal RGS1 is an acceleration error, in particular an acceleration error of the regulating element 3. The first regulator element 73 can also be referred to as an acceleration-based regulator. Expediently, the state signal ZS1A is provided by a state determination unit 77 and is in particular a part of the first state signal ZS1. The state signal ZS1A in particular comprises a position and / or a velocity and / or an acceleration of the regulating element 3 provided by means of the position sensor device 10. Expediently, the state signal ZS1A also comprises a calculated average pressure or average pressure, i.e. a pressure level, of the fluid actuator 2 based on a plurality of (in particular calculated) chamber pressures. Expediently, the first regulator element 73 comprises a low-pass filter 75, to which the first regulator element signal RGS1 is subjected.

[0113] The second regulator element 74 is preferably configured to provide a second regulator element signal RGS2 based on the trajectory signal TS and the state signal ZS1B. The second regulator element 74 preferably provides the second regulator element signal RGS2 based on a pressure error determined by the second regulator element 74. The second regulator element signal RGS2 is preferably a pressure error, in particular a pressure error of the pressure chambers 8, 9 of the actuator 2. The second regulator element 73 may also be referred to as a pressure-based regulator. The state signal ZS1B is preferably provided by the state determination unit 77 and is in particular a part of the first state signal ZS1. The state signal ZS1B is preferably different from the state signal ZS1A. The state signal ZS1B comprises in particular a position and / or a speed of the regulating element 3 provided by means of the position sensor device 10. The state signal ZS1A also preferably comprises one or more (in particular calculated) chamber pressures of the fluid actuator 2. The second regulator element 74 expediently comprises a high-pass filter 76 , to which the second regulator element signal RGS2 is subjected.

[0114] The low pass filter 75 and the high pass filter 76 may also be collectively referred to as a frequency divider.

[0115] Exemplarily, the regulating unit signal RES is provided based on the first regulating element signal RGS1 and the second regulating element signal RGS2. The first regulating element signal RGS1 and the second regulating element signal RGS2 are preferably added to form the regulating unit signal RES via a summing element 84. Alternatively, the regulating element signals RGS1 and RGS2 can also be directly supplied to the summing element 83 in order to be added there to form the pilot signal VS.

[0116] The pressure fluid supply device 4 is suitably configured to provide a control quantity signal SGS for the position control based on the first control signal RGS1 and the second control signal RGS2. The pressure fluid supply device 4, in particular the control unit 72, is configured to provide the first control signal RGS1 according to the acceleration of the control element 3 and to provide the second control signal RGS2 according to the pressure, in particular the calculated pressure / the calculated pressure, of the actuator 2. The pressure fluid supply device 4 is configured to weight the first control signal RGS1 and the second control signal RGS2 in a frequency-dependent manner when providing the control quantity signal SGS, so that the first control signal RGS1 is dominant in the first frequency range and the second control signal RGS2 is dominant in the second frequency range, wherein the second frequency range is higher than the first frequency range.

[0117] Expediently, in a first frequency range, the attenuation caused by the low-pass filter 75 is less than the attenuation caused by the high-pass filter 76, while in a second frequency range, the attenuation caused by the low-pass filter 75 is greater than the attenuation caused by the high-pass filter 76. In particular, a frequency-dependent weighting is performed such that the first controller element signal RGS1 (as a component of the control unit signal RES) is weighted more strongly than the second controller element signal RGS2 in the first frequency range, while the second controller element signal RGS2 (as a component of the control unit signal RES) is weighted more strongly than the first controller element signal RGS1 in the second frequency range.

[0118] In particular, the control unit 72 is designed to provide a feedback of the acceleration and pressure error weighted by a frequency divider in the context of a conventional feedback for an exact state linearization.

[0119] The advantages of the respective controls can thereby be combined with one another and the disadvantages can be suppressed. The acceleration feedback, which is performed by way of example by the first regulator element 73, can achieve advantages in particular in terms of static accuracy and interference immunity. However, the acceleration signal can be strongly contaminated by noise (for example, because it is obtained by differentiation of the position signal). Re-pumping of the chamber pressure due to stick-slip effects can also occur. By means of the pressure feedback provided by the second regulator element 74, a higher performance can be achieved in dynamic processes. In particular, re-pumping can be prevented.

Claims

1. A system (100) for adjusting the position of an adjusting element, comprising: A pneumatic actuator (2) having an adjusting element (3) which can be loaded with compressed air; a pressure fluid supply device (4) configured to: perform position adjustment of the adjusting element (3) and to supply the pneumatic actuator (2) with the compressed air within the scope of the position adjustment so as to move the adjusting element (3) to a predetermined position; and A hose device (28) comprising at least one hose (51, 52), wherein the pneumatic actuator (2) is fluidically connected to the pressure fluid supply device (4) via the at least one hose, wherein The pressure fluid supply device (4) is designed to carry out the position control taking into account a system model describing the hose arrangement (28). The system model comprises a hose model having hose parameters, wherein the hose parameters are the hose length, the hose diameter and / or the hose volume of at least one hose (51, 52) of the hose arrangement (28).

2. The system (100) according to claim 1, wherein the system (100) has a user interface via which the hose parameters can be input into the pressure fluid supply device (4) by a user.

3. A system (100) according to claim 1, wherein the pressure fluid supplying device (4) has a pressure sensing device (29), which is constructed to: measure the pressure of the compressed air in the pressure fluid supplying device (4) and provide the pressure as a measured pressure, and wherein the pressure fluid supplying device (4) is constructed to: calculate the pressure of the compressed air in the pneumatic actuator (2) using the hose model and the measured pressure and provide the pressure as a calculated pressure.

4. The system (100) according to claim 3, wherein the pressure fluid supply device (4) is configured to perform the position adjustment using the calculated pressure.

5. A system (100) according to claim 1 or 2, wherein the pressure fluid supply device (4) includes a frequency filter (79) and is constructed to provide a regulation signal (SGS) within the range of the position adjustment while using the frequency filter (79), and wherein the pressure fluid supply device (4) is also constructed to configure the frequency filter (79) based on the hose model so that the pressure fluid vibration in the hose (51, 52) is suppressed.

6. The system (100) of claim 5, wherein the frequency filter (79) is a band-stop filter.

7. The system (100) according to claim 5, wherein the pressure fluid supply device (4) is constructed to: detect the position of the adjustment element (3) and configure the frequency filter (79) based on the detected position of the adjustment element (3).

8. The system (100) according to claim 1 or 2, wherein the pressure fluid supply device (4) is constructed to calculate regulator parameters for the position regulation based on the hose parameters and to use the regulator parameters in the case of the position regulation.

9. The system (100) of claim 8, wherein the regulator parameter is a regulator gain.

10. A system (100) according to claim 1 or 2, wherein the pressure fluid supply device (4) is constructed to provide a regulating quantity signal (SGS) / the regulating quantity signal (SGS) for the position adjustment based on a first regulator signal (RGS1) and a second regulator signal (RGS2), wherein the pressure fluid supply device (4) is constructed to provide the first regulator signal (RGS1) according to the acceleration of the adjusting element (3) and to provide the second regulator signal (RGS2) according to the pressure of the actuator (2).

11. The system (100) of claim 10, wherein the pressure is a calculated pressure / the calculated pressure.

12. A system (100) according to claim 10, wherein the pressure fluid providing device (4) is constructed such that, when providing the adjustment quantity signal (SGS), the first regulator signal (RGS1) and the second regulator signal (RGS2) are weighted in a frequency-dependent manner, respectively, so that in a first frequency range the first regulator signal (RGS1) is dominant and in a second frequency range the second regulator signal (RGS2) is dominant, wherein the second frequency range is higher than the first frequency range.

13. A system (100) according to claim 1 or 2, wherein the pressure fluid supply device (4) is constructed to provide a regulating signal (SGS) / the regulating signal (SGS) for the position adjustment based on a pilot signal (VS), wherein the pressure fluid supply device (4) is constructed to provide the pilot signal while taking into account the hose model.

14. The system (100) according to claim 13, wherein the pressure fluid supply device (4) is designed to provide the pilot signal while taking into account a hose volume and / or a pressure drop in the hose.

15. A system (100) according to claim 1 or 2, wherein the pressure fluid supply device (4) is constructed to provide an acceleration signal depicting the acceleration of the adjusting element (3) within the range of the position adjustment, wherein the pressure fluid supply device (4) is constructed to provide the acceleration signal based on a position signal depicting the position of the adjusting element (3) based on a second differential and based on a pressure signal.

16. A system (100) according to claim 15, wherein the pressure fluid providing device (4) is constructed such that, when providing the acceleration signal, the second differential position signal and the pressure signal are weighted respectively in relation to the frequency, so that within a first frequency range the second differential position signal is dominant and within a second frequency range the pressure signal is dominant, wherein the second frequency range is higher than the first frequency range.

17. A system (100) according to claim 1 or 2, wherein the pressure fluid providing device (4) is constructed to: detect dynamic parameters that describe the dynamic characteristics of the position regulation; and adapt regulator parameters of the position regulation based on the dynamic parameters.

18. The system (100) according to claim 17, wherein the dynamic characteristic is a dynamic characteristic of a mass flow control performed within the scope of the position control and the controller parameter is a controller gain of the mass flow control.

19. A system (100) according to claim 1 or 2, wherein the pressure fluid providing device (4) has a valve device (14) constructed as an in-line module device, and the valve device includes one or more disc-shaped valve modules (17) arranged in a row for providing the compressed air. 20 . A method for operating a system according to claim 1 , comprising the step of carrying out the position control taking into account the hose model.

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