Method for performing a travel movement and pneumatic system

Abstract

Method for carrying out a displacement movement of a drive element (12) of a pneumatic drive unit (3), comprising the steps: - carrying out, by means of a first valve unit (19a) of a valve device (2), a pressure control of a first pressure chamber (22a) of the pneumatic drive unit (3) in order to effect the travel movement along a travel path (28), - providing, by means of a second valve unit (19b) of the valve device (2), a throttle function for compressed air escaping from a second pressure chamber (22b) of the pneumatic drive unit (3) during the travel movement in order to influence the travel movement, and - depending on a position of the drive element (12) and / or the time and / or a trigger signal, adjusting a pressure setpoint (30) of the pressure control and a throttle opening of the throttle function during the travel movement, wherein the travel path (28) is divided into several successive travel path zones (29), wherein the adjustment of the pressure setpoint (30) takes place in response to the drive element (12) moving from one of the travel path zones (29) into a subsequent travel path zone (29) during the travel movement, and wherein the adjustment of the throttle opening takes place in response to the drive element (12) moving from one of the travel path zones (29) into a subsequent travel path zone (29) during the travel movement, wherein one or more zone parameters are assigned to each travel path zone (29), wherein the zone parameters comprise a pressure setpoint (30), a Throttle opening value (31) and / or a zone limit value,which defines a start and / or an end of the respective travel zone (29), wherein one or more of the zone parameters are adjusted on the basis of a position signal relating to a position of the drive element (12), wherein the adjustment of the zone parameters is carried out by a control device (10) and / or a control unit (15) after the end of the travel movement and the next travel movement takes place using the adjusted zone parameters or one or more of the zone parameters are adjusted during the travel movement.

Description

[0001] The invention relates to a method for carrying out a travel movement of a drive element of a pneumatic drive unit.

[0002] The pneumatic drive unit is, for example, a pneumatic drive cylinder, and the drive element is, for example, a piston. Conventionally, the piston of a pneumatic drive cylinder is moved by applying the entire available supply pressure to a first pressure chamber of the drive cylinder via a switching valve, and by throttling the compressed air escaping from a second pressure chamber of the drive cylinder via an exhaust air throttle located on the drive cylinder. The exhaust air throttle serves to reduce excess force on the drive side (i.e., originating from the first pressure chamber). This conventional approach allows for a high level of interference stiffness of the drive; however, at the same time, efficiency with regard to compressed air consumption is reduced.

[0003] DE 10 2018 217 337 A1 relates to a movement device with a fluidic actuator having an actuator. While the actuator is moving toward a predetermined position, the pressure of a pressurized fluid and / or a throttle opening used to supply the pressurized fluid is successively changed according to a predetermined value profile to influence the movement of the actuator.

[0004] Jiang, Z. [et al.].: “Energy-saving methods in pneumatic actuator stroke using compressed air”, The Journal of Engineering, 2020 concerns methods for reducing air consumption in pneumatic systems.

[0005] An object of the invention is to enable a travel movement of the drive element to be carried out efficiently with respect to the compressed air consumed.

[0006] The object is achieved by a method according to claim 1. The method comprises the steps of: carrying out, by means of a first valve unit of a valve device, a pressure control of a first pressure chamber of the pneumatic drive unit in order to effect the travel movement along a travel path; providing, by means of a second valve unit of the valve device, a throttle function for compressed air escaping from a second pressure chamber of the pneumatic drive unit during the travel movement in order to influence the travel movement; and, depending on a position of the drive element and / or the time and / or a trigger signal, adjusting a pressure setpoint of the pressure control and a throttle opening of the throttle function during the travel movement. The travel path is divided into several consecutive travel zones, wherein the adjustment of the pressure setpoint takes place in response thereto,that the drive element moves during the travel movement from one of the travel zones to a subsequent travel zone, and wherein the adjustment of the throttle opening occurs in response to the drive element moving during the travel movement from one of the travel zones to a subsequent travel zone, wherein each travel zone is assigned one or more zone parameters, wherein the zone parameters comprise a pressure setpoint, a throttle opening value and / or a zone boundary value that defines a start and / or an end of the respective travel zone, wherein one or more of the zone parameters are adjusted based on a position signal that relates to a position of the drive element,wherein the adjustment of the zone parameters is carried out by a control device and / or a control unit after completion of the travel movement and the next travel movement takes place using the adjusted zone parameters or one or more of the zone parameters are adjusted during the travel movement.

[0007] By adjusting both the pressure setpoint and the throttle opening during the travel movement, it is possible to carry out the travel movement with less compressed air consumption and thus more efficiently. For example, after an initial acceleration phase of the travel movement, the pressure setpoint can be reduced to avoid an unnecessarily high pressure being provided in the first pressure chamber after this initial acceleration phase. Furthermore, the throttle opening can be reduced towards the end of the travel movement in order to only provide the braking effect, which is particularly necessary for a smooth approach to an end position, at this point in time. Since the throttle opening is only reduced towards the end of the travel movement, the braking effect is less beforehand, so that a lower drive force and therefore less pressure in the first pressure chamber is required for the travel movement.

[0008] The travel path is divided into several consecutive travel zones. Each travel zone is assigned one or more zone parameters. The zone parameters include a pressure setpoint, a throttle opening value, or a zone boundary value that defines the start and / or end of the respective travel zone. By selecting the appropriate zone parameters, the travel movement can be easily adapted to a specific application.

[0009] For practical purposes, no position control is performed during the travel movement. In particular, no position control of the drive element is performed during the travel movement. In particular, pressure control is not performed as part of a position control.

[0010] Advantageous further training is the subject of the subclaims.

[0011] The invention further relates to a pneumatic system comprising a valve device and a pneumatic drive unit. The pneumatic system is designed to carry out the method.

[0012] Further exemplary details and exemplary embodiments are explained below with reference to the figures. Fig. 1 a schematic representation of a pneumatic system, Fig. 2 a schematic representation of a valve device, Fig. 3 a schematic representation of a pneumatic drive unit and two diagrams showing an adjustment of a pressure setpoint and a throttle opening value, Fig. 4 an arrangement with a pneumatic system, a machine tool, tools and a tool change flap.

[0013] The Fig. Figure 1 shows an exemplary pneumatic system 1 comprising a valve device 2 and a pneumatic drive unit 3. The valve device 2 serves to pneumatically actuate the pneumatic drive unit 3. The pneumatic system 1 is, in particular, an industrial pneumatic system. The pneumatic system 1 is preferably used in industrial automation.

[0014] The pneumatic system 1 expediently comprises a compressed air source 4, a compressed air sink 5, a position sensor device 6, and / or a hose arrangement 11. The compressed air source 4 is pneumatically connected to the valve device 2 and expediently provides the compressed air required for the pneumatic actuation of the pneumatic drive unit 3. The compressed air sink 5 is pneumatically connected to the valve device 2. Compressed air escaping from the pneumatic drive unit 3 during the pneumatic actuation of the drive unit 3 is expediently discharged via the valve device 2 into the compressed air sink 5. The compressed air sink 5 is, for example, the area surrounding the valve device 2.

[0015] The position sensor device 6 is arranged, for example, on the pneumatic drive unit 3 and expediently serves to detect a position of a drive element 12 of the pneumatic drive unit 3. The position sensor device 6 can be designed as a partial-position measuring system that expediently only detects the position of the drive element 12 in end-position ranges of the drive unit 3. Between these end-position ranges, the position of the drive element 12 can be calculated, for example, by a control device 10 and / or control unit 15 of the pneumatic system 1, in particular using a detected pressure and / or a valve control signal, for example by calculating a mass flow and / or taking into account a throttle opening.Conveniently, a position signal relating to the position of the drive element 12 is provided based on the sensor-detected position of the drive element 12 and / or the calculated position of the drive element 12. The position signal is provided, for example, by the control device 10 or by the control unit 15. Furthermore, the position sensor device 6 can be designed as a full-path measuring system that sensor-detects the position of the drive element 12, in particular along the entire travel path 28, so that the position signal is provided based on the sensor-detected position.

[0016] The pneumatic drive unit 3 is pneumatically connected to the valve device 2 via the hose arrangement 11. By way of example, the hose arrangement 11 comprises a first hose, with which a first pressure chamber 22a of the drive unit 3 is connected to the valve device 2, and a second hose, with which a second pressure chamber 22b of the drive unit 3 is connected to the valve device 2.

[0017] The valve device 2 preferably comprises a valve arrangement 7, which is embodied, for example, as a valve island. The valve arrangement 7 expediently comprises a support section 8, in particular in the form of a plate, and a plurality of valve modules 9, which are arranged next to one another, for example, on the support section 8. According to an alternative embodiment, the valve modules can be arranged in the support section 8. The valve arrangement 7 has a plurality of working connections 13, which are arranged, for example, on the support section 8. For the sake of better clarity, only two of the working connections are provided with the reference symbol "13" in the figure. For example, the drive unit 3 is connected to two working connections 13. Via the two working connections 13, the valve device 2 can output compressed air to the drive unit 3 and receive compressed air escaping from the drive unit 3.

[0018] For example, the valve arrangement 7 has a control section 14, which is arranged in particular on the support section 8. The control section 14 expediently has the control unit 15, which is designed, for example, as a microprocessor. The control section 14 is communicatively connected, for example, to the position sensor device 6. The valve arrangement 7 expediently has a compressed air inlet 16 (arranged in particular on the support section 8) (to which the compressed air source 4 is connected) and / or a compressed air outlet 17 (arranged in particular on the support section 8) (to which the compressed air sink 5 is connected, for example).

[0019] By way of example, the valve device 2 comprises a control device 10, which is expediently communicatively connected to the valve arrangement 7, in particular to the control unit 15. The control device 10 is, for example, a higher-level control device, in particular a programmable logic controller (PLC). Optionally, the control device 10 can be communicatively connected to the position sensor device 6.

[0020] The pneumatic drive unit 3 is exemplified as a pneumatic drive cylinder. The pneumatic drive unit 3 has the first pressure chamber 22a and the second pressure chamber 22b. The drive element 12 is exemplified as a piston arrangement and comprises a piston 23 and preferably a piston rod 24 attached to the piston 23. The piston 23 separates the first pressure chamber 22a from the second pressure chamber 22b. By venting the first pressure chamber 22a and venting the second pressure chamber 22b by means of the valve device 1, the drive element 12 can be set in a travel movement, exemplified in a first travel direction 25.

[0021] The Fig. 2 shows an exemplary embodiment of a valve device 18. The valve device 2 expediently has at least one such valve device 18. By way of example, each of the valve modules 9 comprises a respective valve device 18. The valve device 18 comprises two valve units 19, namely a first valve unit 19a and a second valve unit 19b. Each valve unit 19 is connected to a respective working connection 13 and expediently serves to pneumatically connect the respective working connection 13 optionally to the compressed air source 4 or the compressed air sink 5, or, optionally, to block the respective working connection 13. Furthermore, each valve unit 19 expediently has a throttle function to throttle the compressed air flow through the respective valve unit 19.

[0022] By way of example, the valve device 18 is designed as a pneumatic full bridge. The valve units 19 expediently form respective pneumatic half bridges. By way of example, the valve device 19 has four valves 20, in particular four 2 / 2-way valves, and / or each valve unit 19 has two valves 20, in particular two 2 / 2-way valves. The valves 20 are designed in particular as piezo valves. By way of example, each valve unit 19 has a respective supply air valve 20a, which is connected between the respective associated working connection 13 and the compressed air source 4, and / or a respective exhaust air valve 20b, which is connected between the respective associated working connection 13 and the compressed air sink 5.

[0023] Alternatively, the valve device can also be designed differently, in particular not as a full bridge. For example, the valve device (as the two valve units) can comprise respective 3 / 2-way valves or 3 / 3-way valves. Preferably, the valve device has separate control edges, in particular two working ports that can be pressurized and vented independently of one another.

[0024] Preferably, the pneumatic system 1, in particular the valve device 2, has a pressure sensor device 21, which serves to detect a compressed air pressure of the first pressure chamber 22a and / or the second pressure chamber 22b. The pressure sensor device 21 can, for example, be part of the valve arrangement 7 and can, in particular, be arranged in the support section 8. In particular, the pressure sensor device 21 serves to detect the compressed air pressures at the working connections 13.

[0025] The pneumatic system 1 is designed to carry out the method described below for carrying out a travel movement of the drive element 12. The travel movement takes place in particular in the first travel direction 25. Preferably, the travel movement takes place from a first end position of the drive element 12 to a second end position of the drive element 12. The end position is to be referred to as a position of the drive element 12 in which the drive element 12 cannot be moved any further. In the second end position, the drive element 12 cannot be moved any further in the first travel direction 25. In the first end position, the drive element 12 cannot be moved any further in the direction opposite to the first travel direction 25.

[0026] The steps of the method explained below can, in particular, be performed simultaneously. All data processing performed within the scope of the method, i.e., in particular, calculations and / or adjustments of values, are expediently performed by the control device 10 and / or the control unit 15.

[0027] The method comprises the step of regulating the pressure of the first pressure chamber 22a of the pneumatic drive unit 3 by means of the first valve unit 19a of the valve device 2 in order to effect the travel movement along a travel path 28. The pressure regulation is expediently carried out by the control device 10 or the control unit 15. The pressure regulation takes place in particular in that an actual pressure value of the first pressure chamber 22a is detected by means of the pressure sensor device 21 and compared (for example by the control unit 15 and / or the control device 10) with a pressure setpoint value and, on the basis of the comparison, the first valve unit 19a is controlled (for example by the control unit 15 and / or the control device 10) in order to cause the actual pressure value to change towards the pressure setpoint value.The travel path 28 is in particular the entire distance from the first end position of the drive element 12 to the second end position of the drive element 12. Expediently, the compressed air pressure in the first pressure chamber 22a is increased by the pressure control, so that a pneumatic force is exerted on the piston 23, which causes the drive element 12 to carry out the travel movement.

[0028] The method comprises the further step of providing the throttle function for compressed air, which escapes from the second pressure chamber 22b of the pneumatic drive unit 3 during the travel movement, by means of the second valve unit 19b of the valve device 2. The provision of the throttle function serves to influence the travel movement. During the travel movement, compressed air flows from the second pressure chamber 22b via the second valve unit 19b into the compressed air sink 5, for example the area surrounding the valve device 2. The compressed air escapes from the second pressure chamber 22b in particular because the compressed air pressure in the second pressure chamber 22b is higher than the ambient pressure, in particular due to the second pressure chamber 22b becoming smaller due to the travel movement of the drive element 12.The throttle function allows a throttle opening—in particular, the size of a flow cross-section—to be set on the pneumatic path of the compressed air escaping from the second pressure chamber 22b, thereby adjusting the degree to which the flow of compressed air is throttled. For example, the throttle opening can be adjusted by positioning a valve element of the exhaust air valve 20b.

[0029] The method further comprises the step of adjusting the pressure setpoint of the pressure control and the throttle opening of the throttle function during the travel movement, for example, by the control unit 15 and / or the control device 10, depending on a position of the drive element and / or the time and / or a trigger signal. The further pressure control (performed for the travel movement) is then carried out on the basis of the adjusted pressure setpoint, and the further throttle function (performed for the travel movement) is then carried out on the basis of the adjusted throttle opening. The throttle opening to be used is specified, for example, by means of a throttle opening value, in particular by the control device 10 and / or the control unit 15.

[0030] With reference to the Fig. 3 will explain in more detail how the pressure setpoint and the throttle opening can be adjusted.

[0031] The Fig. 3 shows the drive unit 3, a first diagram 26 showing an adjustment of the pressure setpoint, and a second diagram 27 showing an adjustment of the throttle opening.

[0032] Preferably, the travel path 28 is divided into several consecutive travel path zones 29. In the Fig. 3, the subdivision is shown by dashed vertical lines, which are intended to represent zone boundaries 36.

[0033] By way of example, the travel path 28 is divided into three, in particular only three, consecutive travel path zones 29: a first travel path zone 29a, a second travel path zone 29b, and a third travel path zone 29c. By way of example, during the travel movement in the travel direction 25, the drive element 12 first moves through the first travel path zone 29a, then through the second travel path zone 29b, and then through the third travel path zone 29c. The subdivision of the travel path 28 is expediently defined in the control device 10 and / or the control unit 15.

[0034] Alternatively, the travel path 28 can also be divided into only two travel path zones 29 or into more than three travel path zones.

[0035] The subdivision of the travel path zones 29 is expediently defined by the zone boundaries 36. The zone boundaries 36 are expediently stored by corresponding zone boundary values, for example, in the control device 10 and / or the control unit 15. The zone boundaries 36 are expediently defined as positions along the travel path 28; for example, each zone boundary 36 is stored as a respective position value. Furthermore, the zone boundaries 36 can be defined in terms of time and accordingly stored as time values. The time values ​​refer, for example, to time periods that begin from the start of the travel movement. Furthermore, the zone boundaries 36 can be defined on an event-based basis.For example, one or more zone boundaries 36 are defined on the basis of a trigger signal, in particular such that for the travel zone 29 in which the drive element 12 is currently located, in response to the presence of a trigger signal, a zone boundary 36 is drawn which defines the end of the travel zone 29.

[0036] Preferably, the pressure setpoint is adjusted in response to the drive element 12 moving from one of the travel zones 29 to a subsequent travel zone 29 during the travel movement. Expediently, the throttle opening is adjusted in response to the drive element 12 moving from one of the travel zones 29 to a subsequent travel zone 29 during the travel movement. For example, the control device 10 and / or the control unit 15 detects (in particular based on the position signal, i.e., preferably based on a position of the drive element 12 detected and / or calculated by the position sensor device 6) that the drive element 12 has moved from one travel zone 29 to the next travel zone 29 and, in response, adjusts the pressure setpoint and / or the throttle opening value.

[0037] As mentioned above, a measuring system for the entire travel path 28 or a partial travel measuring system (e.g. in the end positions) can be used for the position signal. Preferably, the position signal can be provided on the basis of an estimated position. The position is estimated, for example, on the basis of pressure signals and valve positions or volume flow signals. For example, the position is estimated for a middle section of the travel path 28 between the end positions, and the position is detected by sensors in the end positions. Advantageously, there is no continuous feedback of the position of the drive element 12. For example, the position is detected only at individual points along the travel path 28 in order to determine a transition from one travel path zone 29 to the next travel path zone 29 based thereon. At the end positions, the position of the drive element 12 can be detected, for example, by means of limit switches.

[0038] Preferably, each travel zone 29 is assigned one or more zone parameters. The zone parameters include, for example, a pressure setpoint 30 and / or a throttle opening value 31. Optionally, the zone parameters include a zone boundary value that defines a start and / or an end of the respective travel zone 29. For example, each zone boundary value defines a position of the drive element 12 at which the respective travel zone begins and / or a position of the drive element 12 at which the respective travel zone ends. Furthermore, each zone boundary value can define a time value.

[0039] Preferably, each travel zone 29 is assigned a respective pressure setpoint 30 for pressure control and a respective throttle opening value 31 for the throttle opening. The pressure setpoints 30 and the throttle opening values ​​31 are shown in the diagrams of Fig. 3 as horizontal lines. For example, a first pressure setpoint 30a and a first throttle opening value 31a are assigned to the first travel zone 29a, a second pressure setpoint 30b and a second throttle opening value 31b are assigned to the second travel zone 29b, and a third pressure setpoint 30c and a third throttle opening value 31c are assigned to the third travel zone 29c.

[0040] The pressure control in each travel zone 29 is expediently carried out on the basis of the respectively assigned pressure setpoint 30. The throttle function is expediently provided in each travel zone 29 according to the respectively assigned throttle opening value 31. Preferably, at least two of the pressure setpoints 30 differ from one another and / or at least two of the throttle opening values ​​31 differ from one another.

[0041] Preferably, in response to the drive element 12 leaving a travel zone 29 located in a front region of the travel path 28, the pressure setpoint 30 is reduced. For example, in response to the drive element leaving the first travel zone 29a in the travel direction 25 of the travel movement, the pressure setpoint 30 is reduced. The phrase "the first travel zone 29a in the travel direction 25 of the travel movement" refers to the travel zone that is first traversed during the travel movement in the travel direction. The second pressure setpoint 30b is expediently smaller than the first pressure setpoint 30a. This reduction in the pressure setpoint 30 occurs in particular after an initial acceleration phase of the travel movement in order to avoid an unnecessarily high pressure being provided in the first pressure chamber 22a after this initial acceleration phase for the travel movement.

[0042] Preferably, the throttle opening remains constant during the transition from the first travel zone 29a to the second travel zone 29b in the travel direction 25 of the travel movement. The second throttle opening value 31b is, for example, equal to the first throttle opening value 31a.

[0043] Preferably, in response to the drive element entering a travel zone 29 located in a rear region of the travel path, the throttle opening is reduced.

[0044] For example, in response to the drive element 12 entering the third travel zone 29c in the travel direction 25 of the travel movement, the throttle opening is reduced. The third throttle opening value 31c is expediently smaller than the second throttle opening value 31b. A braking effect can be achieved by reducing the throttle opening.

[0045] Preferably, the pressure setpoint 30 remains constant during the transition from the second travel zone 29b in the travel direction 25 of the travel movement to the third travel zone 29c.

[0046] Optionally, the zone parameters can include a locking state parameter, for example, a locking state flag. The locking state parameter expediently indicates a locking state of the first pressure chamber 22a for the respective travel zone. In the locking state, the first pressure chamber 22a is locked by means of the first valve unit 19a, so that supplying or discharging compressed air into / from the first pressure chamber 22a is not possible. Expediently, if the locking state parameter is set for a travel zone 29, the pressure control for this travel zone 29 is suspended and the first pressure chamber 22a is closed while the drive element 12 is located in this travel zone 29. For example, the locking state parameter is set for the second travel zone 29b and / or the third travel zone 29c.

[0047] Optionally, after the end of the travel movement - that is to say in particular when the drive element 12 is in the second end position - a pressure control of the first pressure chamber 22a and / or the second pressure chamber 22b takes place, in particular in such a way that a force directed in the direction of the second end position is generated, which force expediently holds the drive element 12 in the second end position.

[0048] The following will explain in more detail how the zone parameters can be defined.

[0049] Optionally, the zone parameters can be entered by a user, for example by means of a user device and / or an input device of the valve device 2.

[0050] The zone parameters can be determined, for example, based on a simulation and / or through an optimization procedure. Optionally, the zone parameters can be determined using machine learning.

[0051] Preferably, one or more of the zone parameters are adjusted based on the position signal relating to a position of the drive element 12. The adjustment is preferably performed automatically, in particular by the control device 10 and / or the control unit 15. For example, the adjustment is performed based on a comparison of a recorded trajectory (i.e., a distance-time diagram) of the drive element 12 with a desired trajectory. The adjustment is expediently performed model-supported, in particular by means of an adaptation routine.

[0052] Preferably, a travel characteristic is detected, in particular based on the position signal. The travel characteristic includes, for example, oscillation of the drive element, rebound of the drive element, a travel duration of the travel movement, and / or a premature stop of the drive element 12. The rebound of the drive element 12 means, for example, that the drive element 12 moves into the second end position at too high a speed and is therefore rebounded—i.e., moves out of the second end position in the direction opposite to the travel movement 25. The premature stop means, for example, that the drive element 12 stops during the travel movement before reaching the second end position. Preferably, one or more of the zone parameters are adjusted based on the travel characteristic, in particular in such a way as to avoid or reduce undesirable travel characteristics.

[0053] Preferably, one or more of the zone parameters are adjusted using an optimization algorithm to optimize a quality criterion. For example, the optimization of the quality criterion includes minimizing a trajectory error of the drive element 12 and / or minimizing a final value error of the drive element 12. The final value error includes, in particular, a travel time error, an end-position speed error, and / or an end-position pressure error.

[0054] The trajectory error is, for example, a deviation of a recorded trajectory of the drive element 12 from a desired trajectory. For example, the trajectory error is calculated as the sum of the squared deviation of the recorded trajectory from the desired trajectory.

[0055] The travel time error is in particular a deviation of a detected travel time required by the drive element 12 for the travel movement from a target travel time.

[0056] The end position speed error is in particular a deviation of a detected end position speed, with which the drive element 12 moves into the second end position, from a target end position speed.

[0057] The end position pressure error is in particular a deviation of a detected end position pressure, which prevails in the first pressure chamber 22a or the second pressure chamber 22b when the drive element 12 is in the second end position, from a desired end position pressure.

[0058] The optimization algorithm is preferably model-based and / or uses machine learning, e.g. reinforcement learning.

[0059] Preferably, the zone parameters are adjusted after the end of the travel movement. For example, the final value error is determined after the end of the travel movement, and based on the final value error, the zone parameters are adjusted to reduce the final value error during the next travel movement. The next travel movement takes place using the adjusted zone parameters.

[0060] Optionally, one or more of the zone parameters are adjusted during the travel movement. Preferably, the pressure control and / or the throttle function for this travel movement are performed after the adjustment according to the one or more adjusted zone parameters. In this way, a disturbance can be compensated directly during the travel movement. Model Predictive Control (MPC) is preferably used for this purpose. Alternatively, a reinforcement learning approach can be used.

[0061] With reference to the Fig. 4, an arrangement 35 will be discussed, which represents an exemplary application environment for the pneumatic system 1. The arrangement 35 comprises the pneumatic system 1, a machine tool 33, tools 34 for the machine tool, and a tool change flap 32.

[0062] The drive element 12 serves to actuate the tool change flap 32. In particular, the travel movement of the drive element 12 can move the tool change flap from a first position, for example a closed position, to a second position, for example an open position. In the closed position, the tool change flap 32 separates the tools 34 from the machine tool 33, in particular to prevent the tools 34 from becoming contaminated during a machining operation carried out with the machine tool 33. In the open position, the tool change flap 32 provides access to the tools 34 so that (in particular for the purpose of a tool exchange) one of the tools 34 can be conveyed to the machine tool 33, for example using a tool handling device (not shown), for example a robot arm.

[0063] By adjusting the pressure setpoint 30 and the throttle opening as described above, a rapid opening and / or closing of the tool change flap 32 can be achieved with low consumption of compressed air.

Claims

[1] Method for carrying out a displacement movement of a drive element (12) of a pneumatic drive unit (3), comprising the steps: - carrying out, by means of a first valve unit (19a) of a valve device (2), a pressure control of a first pressure chamber (22a) of the pneumatic drive unit (3) in order to effect the travel movement along a travel path (28), - providing, by means of a second valve unit (19b) of the valve device (2), a throttle function for compressed air escaping from a second pressure chamber (22b) of the pneumatic drive unit (3) during the travel movement in order to influence the travel movement, and - depending on a position of the drive element (12) and / or the time and / or a trigger signal, adjusting a pressure setpoint (30) of the pressure control and a throttle opening of the throttle function during the travel movement, wherein the travel path (28) is divided into several successive travel path zones (29), wherein the adjustment of the pressure setpoint (30) takes place in response to the drive element (12) moving from one of the travel path zones (29) into a subsequent travel path zone (29) during the travel movement, and wherein the adjustment of the throttle opening takes place in response to the drive element (12) moving from one of the travel path zones (29) into a subsequent travel path zone (29) during the travel movement, wherein one or more zone parameters are assigned to each travel path zone (29), wherein the zone parameters comprise a pressure setpoint (30), a Throttle opening value (31) and / or a zone limit value,which defines a start and / or an end of the respective travel zone (29), wherein one or more of the zone parameters are adjusted on the basis of a position signal relating to a position of the drive element (12), wherein the adjustment of the zone parameters is carried out by a control device (10) and / or a control unit (15) after the end of the travel movement and the next travel movement takes place using the adjusted zone parameters or one or more of the zone parameters are adjusted during the travel movement. [2] Method according to claim 1, wherein each travel zone (29) is assigned a respective pressure setpoint (30) for the pressure control and a respective throttle opening value (31) for the throttle opening, wherein the pressure control in each travel zone (29) is carried out on the basis of the respectively assigned setpoint (30) and the throttle function is provided in each travel zone according to the respectively assigned throttle opening value (31), wherein at least two of the pressure setpoints (30) differ from one another and / or wherein at least two of the throttle opening values ​​(31) differ from one another. [3] Method according to claim 1 or 2, wherein in response to the drive element (12) leaving a travel zone (29) located in a front region of the travel path (28), the pressure setpoint (30) is reduced. [4] Method according to one of claims 1 to 3, wherein in response to the drive element (12) entering a travel zone (29) located in a rear region of the travel path (28), the throttle opening is reduced. [5] Method according to one of claims 1 to 4, wherein the travel path (28) is divided into three successive travel path zones (29). [6] Method according to claim 5, wherein in response to the drive element (12) leaving the first travel zone (29a) in the direction of the travel movement, the pressure setpoint (30) is reduced. [7] Method according to claim 5 or 6, wherein in response to the drive element (12) entering the third travel zone (29c) in the travel direction (25) of the travel movement, the throttle opening is reduced. [8] Method according to one of claims 5 to 7, wherein the pressure setpoint (30) remains constant during the transition from the second travel zone (29b) in the travel direction (25) of the travel movement to the third travel zone (29c) and / or the throttle opening remains constant during the transition from the first travel zone (29a) in the travel direction (25) of the travel movement to the second travel zone (29b). [9] A method according to any preceding claim, wherein one or more of the zone parameters are adjusted during the travel movement and the pressure control and / or the throttling function for this travel movement is carried out after the adjustment in accordance with the one or more adjusted zone parameters. [10] Method according to one of the preceding claims, wherein at least one travel path characteristic is detected, which comprises a vibration of the drive element (12), a rebound of the drive element (12), a travel duration of the travel movement and / or a premature stoppage of the drive element (12), and wherein one or more of the zone parameters are adapted on the basis of the travel path characteristic. [11] Method according to one of the preceding claims, wherein one or more of the zone parameters are adjusted by means of an optimization algorithm in order to optimize a quality criterion. [12] Method according to claim 11, wherein the optimization of the quality criterion comprises minimizing a trajectory error of the drive element (12) and / or minimizing a final value error of the drive element (12), wherein the final value error comprises a travel time error, an end position speed error and / or an end position pressure error. [13] Method according to one of the preceding claims, wherein the drive element (12) actuates a tool change flap (32) which separates a machine tool (33) from one or more tools (34) for the machine tool (33). [14] Pneumatic system (1) comprising a valve device (2) and a pneumatic drive unit (3), wherein the pneumatic system (1) is designed to carry out a method according to one of claims 1 to 13.

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