Method for performing a traversing movement and pneumatic system

Abstract

The invention relates to a method for performing a traversing movement of a drive element (12) of a pneumatic drive unit (3), comprising the steps of: performing, by means of a first valve unit (19a), a valve device (2), a pressure control of a first pressure chamber (22a) of the pneumatic drive unit (3) in order to effect the traversing movement along a travel path (28); providing, by means of a second valve unit (19b) of the valve device (2), a throttling function for compressed air escaping from a second pressure chamber (22b) of the pneumatic drive unit (3) during the traversing movement in order to influence the traversing 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 traversing movement.

Description

The invention relates to a method for carrying out a displacement movement of a drive element of a pneumatic drive unit.The pneumatic drive unit is, for example, a pneumatic drive cylinder and the drive element is, for example, a piston. Conventionally, a displacement movement of a piston of a pneumatic drive cylinder takes place in that a first pressure chamber of the drive cylinder is acted upon by the entire available supply pressure by means of a switching valve and the compressed air escaping from a second pressure chamber of the drive cylinder is throttled by means of an exhaust air throttle located on the drive cylinder. The exhaust air throttle serves to reduce an excess of force on the drive side (i.e. originating from the first pressure chamber). With this conventional approach, a high parasitic rigidity of the drive can be achieved; at the same time, however, the efficiency with respect to the consumption of compressed air is reduced.An object of the invention is to make it possible to carry out a displacement movement of the drive element efficiently with respect to the used compressed air.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 regulation of a first pressure chamber of the pneumatic drive unit in order to bring about 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, adapting a pressure setpoint value of the pressure regulation and a throttle opening of the throttle function during the travel movement.The fact that both the pressure setpoint value and the throttle opening are adjusted during the travel movement makes it possible for the travel movement to be carried out with less consumption of compressed air and thus more efficiently. For example, after an initial acceleration phase of the travel movement, the pressure setpoint value can be reduced in order to avoid a pressure unnecessarily high for the travel movement being provided in the first pressure chamber after this initial acceleration phase. Furthermore, for example, the throttle opening can be reduced towards the end of the travel movement in order to provide the braking action required in particular for a smooth retraction into an end position only at this point in time. Since the throttle opening is only reduced toward the end of the travel movement, the braking action is lower before this, so that a low driving force and thus a lower pressure in the first pressure chamber are required for the travel movement.According to a preferred embodiment, the travel path is divided into a plurality of successive travel path zones. Each travel zone is associated with one or more zone parameters. The zone parameters comprise a pressure setpoint value, a throttle opening value or a zone limit value which defines a start and / or an end of the respective travel path zone. By a corresponding selection of the zone parameters, the travel movement can be easily adapted to a present application.Expediently, no position control is carried out for the travel movement. In particular, no position control of the drive element is carried out during the travel movement. The pressure regulation does not take place in particular within the scope of position regulation.Advantageous refinements are the subject matter of the dependent claims.The invention further relates to a pneumatic system comprising a valve device and a pneumatic drive unit. The pneumatic system is configured to perform the method.Further exemplary details and exemplary embodiments are explained below with reference to the figures. This shows FIG. 1 is a schematic illustration of a pneumatic system, FIG. 2 shows a schematic illustration of a valve device, FIG. 3 is a schematic illustration of a pneumatic drive unit and two diagrams showing an adjustment of a pressure set point and a throttle opening value, FIG. 4 shows an arrangement with a pneumatic system, a machine tool, tools and a tool change flap.FIG. 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. Preferably, the pneumatic system 1 is used in industrial automation.The pneumatic system 1 expediently has a compressed air source 4, a compressed air sink 5, a position sensor device 6 and / or a hose arrangement 11. The compressed air sink 5 is pneumatically connected to the valve device 2. Compressed air which escapes 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 environment of the valve device 2.The position sensor device 6 is exemplarily arranged on the pneumatic drive unit 3 and is expediently used 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 distance measuring system, which expediently detects the position of the drive element 12 only in end position regions of the drive unit 3 by sensor means. 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 actuating signal, for example, by calculating a mass flow and / or taking into account a throttle opening. 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 travel measurement system which records the position of the drive element 12 in particular along the entire travel path 28 by sensor means, such that the position signal is provided on the basis of the position recorded by sensor means.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, by means of which a first pressure chamber 22 aof the drive unit 3 is connected to the valve device 2, and a second hose, by means of which a second pressure chamber 22 bof the drive unit 3 is connected to the valve device 2.The valve device 2 preferably comprises a valve arrangement 7, which is exemplarily embodied as a valve island. The valve arrangement 7 expediently comprises a carrier section 8, which is in particular plate-shaped, and a plurality of valve modules 9, which are arranged next to one another on the carrier section 8, by way of example. According to an alternative embodiment, the valve modules can be arranged in the carrier section 8. The valve arrangement 7 has a plurality of working connections 13, which are exemplarily arranged on the carrier section 8. For the sake of better clarity, only two of the working connections are provided with the reference sign "13" in the figure. By way of 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 absorb compressed air escaping from the drive unit 3.By way of example, the valve arrangement 7 has a control section 14, which is arranged in particular on the carrier 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 exemplarily communicatively connected to the position sensor device 6. The valve arrangement 7 expediently has a compressed air inlet 16 (in particular arranged on the carrier section 8) (to which the compressed air source 4 is connected) and / or a compressed air outlet 17 (in particular arranged on the carrier section 8) (to which the compressed air sink 5 is connected by way of example).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 superordinate control device, in particular a programmable logic controller (PLC). Optionally, the control device 10 can be communicatively connected to the position sensor device 6.The pneumatic drive unit 3 is exemplarily designed as a pneumatic drive cylinder. The pneumatic drive unit 3 has the first pressure chamber 22 aand the second pressure chamber 22 b. The drive element 12 is exemplarily designed as a piston arrangement and comprises a piston 23 and preferably a piston rod 24 attached to the piston 23, Exemplarily, the piston 23 separates the first pressure chamber 22 aand the second pressure chamber 22 b. By venting the first pressure chamber 22 aand venting the second pressure chamber 22 bby means of the valve device 1, the drive element 12 can be set in a traversing movement, for example in a first traversing direction 25.FIG. 2 shows an exemplary embodiment of a valve device 18. Expediently, the valve device 2 has at least one such valve device 18. Each valve unit 19 is connected to a respective working connection 13 and expediently serves to pneumatically connect the respective working connection 13 selectively 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 in order to throttle the flow of compressed air effected through the respective valve unit 19.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 in particular designed as piezoelectric valves. By way of example, each valve unit 19 has a respective supply air valve 20 awhich is connected between the respectively associated working connection 13 and the compressed air source 4 and / or a respective exhaust air valve 20 bwhich is connected between the respectively associated working connection 13 and the compressed air sink 5.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. The valve device preferably has resolved control edges, in particular two working connections, which can be ventilated and vented independently of one another.The pneumatic system 1, in particular the valve device 2, preferably has a pressure sensor device 21 which serves to detect a compressed air pressure of the first pressure chamber 22 aand / or of the second pressure chamber 22 b. The pressure sensor device 21 can be part of the valve arrangement 7, for example, and can be arranged in particular in the carrier section 8. In particular, the pressure sensor device 21 serves to detect the compressed air pressures at the working connections 13.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 displacement movement takes place in particular in the first displacement direction 25. The displacement movement preferably takes place from a first end position of the drive element 12 into a second end position of the drive element 12. 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.The steps of the method explained below can be carried out in particular simultaneously with one another. All data processing carried out within the scope of the method, i.e., in particular calculations and / or adaptations of values, are expediently carried out by the control device 10 and / or the control unit 15.The method comprises the step that a pressure control of the first pressure chamber 22 aof the pneumatic drive unit 3 is carried out by means of the first valve unit 19 aof the valve device 2 in order to bring about 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 is effected in particular in that an actual pressure value of the first pressure chamber 22 ais detected by means of the pressure sensor device 21 and is compared (for example by the control unit 15 and / or the control device 10) with a desired pressure value and the first valve unit 19 ais activated on the basis of the comparison (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 desired pressure 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.The method comprises the further step that the throttle function for compressed air is provided by means of the second valve unit 19 bof the valve device 2, which air escapes from the second pressure chamber 22 bof the pneumatic drive unit 3 during the travel movement. The provision of the throttle function serves to influence the travel movement. During the travel movement, compressed air flows from the second pressure chamber 22 bvia the second valve unit 19 binto the compressed air sink 5, for example the surroundings of the valve device 2. The compressed air escapes from the second pressure chamber 22 bin particular for the reason that the compressed air pressure in the second pressure chamber 22 bis higher than the ambient pressure, in particular due to the second pressure chamber 22 bthat becomes smaller due to the displacement movement of the drive element 12. With the throttle function, a throttle opening-i.e. in particular a size of a flow cross section-can be set on the pneumatic path of the compressed air escaping from the second pressure chamber 22 bto thereby set how much the flow of the compressed air is throttled. For example, the throttle opening is adjustable by positioning a valve member of the exhaust valve 20 b.The method further comprises the step that, depending on a position of the drive element and / or the time and / or a trigger signal, the pressure setpoint value of the pressure control and the throttle opening of the throttle function are adjusted during the travel movement, for example by the control unit 15 and / or by the control device 10. 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.With reference to FIG. 3, it will be discussed in more detail below how the adaptation of the pressure setpoint value and the throttle opening can be carried out by way of example.FIG. 3 shows the drive unit 3, a first graph 26 showing an adjustment of the pressure target value, and a second graph 27 showing an adjustment of the throttle opening.Preferably, the travel path 28 is divided into a plurality of successive travel path zones 29. In FIG. 3, the division is shown by dashed vertical lines intended to represent zone boundaries 36.By way of example, the travel path 28 is divided into three, in particular only three, successive travel path zones 29: a first travel path zone 29 a, a second travel path zone 29 band a third travel path zone 29 c. For example, during the travel movement in travel direction 25, drive element 12 travels first through first travel path zone 29 a, then through second travel path zone 29 band then through third travel path zone 29 c. The subdivision of the travel path 28 is expediently defined in the control device 10 and / or the control unit 15.Alternatively, the travel path 28 can also be divided into only two travel path zones 29 or into more than three travel path zones.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 relate, for example, to time periods which begin from the beginning of the travel movement. Further, zone boundaries 36 may be defined event-based. For example, one or more zone boundaries 36 are defined on the basis of a trigger signal, in particular in such a way that, for the travel path zone 29 in which the drive element 12 is currently located, in response to a trigger signal being present, a zone boundary 36 is pulled which defines the end of the travel path zone 29.The adaptation of the pressure setpoint value is preferably effected in response to the drive element 12 moving during the travel movement from one of the travel path zones 29 into a subsequent travel path zone 29. The adjustment of the throttle opening is expediently carried out 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. For example, the control device 10 and / or the control unit 15 (in particular on the basis of the position signal, i.e. preferably on the basis of a position of the drive element 12 detected and / or calculated by the position sensor device 6), detects that the drive element 12 has moved from one travel path zone 29 into the next travel path zone 29 and adjusts the pressure setpoint value and / or the throttle opening value in response thereto.As mentioned above, a measuring system for the complete travel path 28 can be used for the position signal or a partial travel measuring system (e.g. in the end positions). The position signal can preferably 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 range of the travel path 28 between the end positions, and the position is detected by sensors in the end positions. Expediently, no continuous return of the position of the drive element 12 takes place. for example, the position detection takes place 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 on the basis thereof. At the end positions, the position of the drive element 12 can be detected, for example, by means of end position switches.Preferably, one or more zone parameters are assigned to each travel path zone 29. The zone parameters comprise, for example, a pressure setpoint value 30 and / or a throttle opening value 31. Optionally, the zone parameters comprise a zone limit value which defines a start and / or an end of the respective travel path zone 29. For example, each zone limit value defines a position of the drive element 12 at which the respective travel path zone begins and / or a position of the drive element 12 at which the respective travel path zone ends. Further, each zone boundary value may define a time value.Preferably, each travel zone 29 is assigned a respective pressure setpoint value 30 for the pressure regulation and a respective throttle opening value 31 for the throttle opening. The pressure command values 30 and the throttle opening values 31 are shown as horizontal lines in the diagrams of FIG. 3. By way of example, a first pressure setpoint value 30 aand a first throttle opening value 31 aare assigned to the first travel path zone 29 a, a second pressure setpoint value 30 band a second throttle opening value 31 bare assigned to the second travel path zone 29 b, and a third pressure setpoint value 30 cand a third throttle opening value 31 care assigned to the third travel path zone 29 c.The pressure regulation in each travel path zone 29 is expediently carried out on the basis of the respectively assigned pressure setpoint value 30. Preferably, at least two of the pressure setpoint values 30 differ from one another and / or at least two of the throttle opening values 31 differ from one another.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 29 ain the travel direction 25 of the travel movement, the pressure setpoint value 30 is reduced. The formulation "the first travel path zone 29 ain the travel direction 25 of the travel movement" means that travel path zone which is first traversed during the travel movement in the travel direction. The second pressure setpoint 30 bis expediently smaller than the first pressure setpoint 30 a. This reduction of the pressure setpoint value 30 takes place in particular after an initial acceleration phase of the travel movement, in order to avoid that after this initial acceleration phase a pressure unnecessarily high for the travel movement is provided in the first pressure chamber 22 a.The throttle opening preferably remains constant during the transition from the first travel path zone 29 ato the second travel path zone 29 bin the travel direction 25 of the travel movement. The second throttle opening value 31 bis exemplarily equal to the first throttle opening value 31 a.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. For example, in response to the drive element 12 entering the third travel zone 29 cin the travel direction 25 of the travel movement, the throttle opening is reduced. The third throttle opening value 31 cis preferably smaller than the second throttle opening value 31 b. By reducing the throttle opening, a braking effect can be achieved.The pressure setpoint value 30 preferably remains constant during the transition from the second travel path zone 29 bto the third travel path zone 29 cin the travel direction 25 of the travel movement.Optionally, the zone parameters may comprise a disable state parameter, for example a disable state flag. The blocking state parameter expediently indicates a blocking state of the first pressure chamber 22 afor the respective travel path zone. In the locked state, the first pressure chamber 22 ais locked by the first valve unit 19 a, so that supplying or discharging compressed air into / from the first pressure chamber 22 ais not possible. Expediently, when the locked state parameter is set for a travel path zone 29, the pressure control for this travel path zone 29 is suspended and the first pressure chamber 22 ais closed, while the drive element 12 is located in this travel path zone 29. For example, the locked state parameter is set for the second travel path zone 29 band / or the third travel path zone 29 c.Optionally, after termination of the travel movement-i.e. in particular when the drive element 12 is in the second end position-a pressure control of the first pressure chamber 22 aand / or of the second pressure chamber 22 bis carried out, in particular in such a way that a force directed in the direction of the second end position is generated, which expediently holds the drive element 12 in the second end position.In the following, it will be discussed in more detail how the zone parameters can be defined.Optionally, the zone parameters can be input by a user, for example by means of a user device and / or an input device of the valve device 2.The zone parameters can be determined, for example, on the basis of a simulation and / or by an optimization procedure. Optionally, the zone parameters can be determined by means of machine learning.Preferably, one or more of the zone parameters are adjusted based on the position signal relating to a position of the driving element 12. The adaptation is preferably carried out automatically, in particular by the control device 10 and / or the control unit 15. The adaptation is expediently carried out in a model-assisted manner, in particular by means of an adaptation routine.A travel path characteristic is preferably detected, in particular on the basis of the position signal. The travel path characteristic comprises, for example, a swinging of the drive element, a rebound of the drive element, a travel duration of the travel movement and / or a premature standstill of the drive element 12. The premature standstill means, for example, that the drive element 12 remains stationary during the travel movement before it reaches the second end position. Preferably, one or more of the zone parameters is adapted on the basis of the travel path characteristic, in particular in such a way as to avoid or reduce an undesired travel path characteristic.Preferably, one or more of the zone parameters is adjusted by means of an optimization algorithm in order to optimize a quality criterion. For example, the optimization of the quality criterion comprises a minimization of a trajectory error of the drive element 12 and / or a minimization of a final value error of the drive element 12.The trajectory error is, for example, a deviation of a recorded trajectory of the drive element 12 from a setpoint trajectory. For example, the trajectory error is calculated as the sum of the square deviation of the recorded trajectory from the setpoint trajectory.The travel duration error is in particular a deviation of a detected travel duration that the drive element 12 requires for the travel movement from a desired travel duration.The end position speed error is in particular a deviation of a detected end position speed at which the drive element 12 moves into the second end position from a target end position speed.The final position pressure error is in particular a deviation of a detected final position pressure, which prevails in the first pressure chamber 22 aor the second pressure chamber 22 bwhen the drive element 12 is in the second final position, from a setpoint final position pressure.The optimization algorithm is preferably model-based and / or uses machine learning, e.g. reinforcement learning.The adjustment of the zone parameters preferably takes place after the end of the travel movement. For example, after termination of the travel movement, the final value error is determined and, on the basis of the final value error, the zone parameters are adjusted in order to reduce the final value error in the next travel movement. The next travel movement takes place using the adjusted zone parameters.Optionally, one or more of the zone parameters is adjusted during the travel movement. Preferably, the pressure regulation and / or the throttle function for this travel movement is carried out after the adaptation according to the one or more adapted zone parameters. In this way, a disturbance can be compensated directly during the travel movement. Preferably, a model predictive control (MPC) is used for this purpose. Alternatively, a reinforcement learning approach may be used.With reference to Figure 4, an arrangement 35 will be discussed which illustrates an exemplary application environment for the pneumatic system 1. The assembly 35 comprises the pneumatic system 1, a machine tool 33, tools 34 for the machine tool and a tool change flap 32.The drive element 12 serves to actuate the tool change flap 32. In particular, the displacement movement of the drive element 12 can be used to move the tool change flap from a first position, for example a closed position, into 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 for the purpose of the tools 34 not being contaminated during a machining operation carried out with the machine tool 33. In the open position, the tool change flap 32 releases access to the tools 34, so that (in particular for the purpose of tool exchange) one of the tools 34 can be conveyed to the machine tool 33, for example with a tool handling device (not shown), for example a robot arm.By the above-described adaptation of the pressure setpoint value 30 and the throttle opening, a rapid opening and / or closing of the tool change flap 32 can be achieved with a low consumption of compressed air.

Claims

Method for carrying out a travel movement of a drive element (12) of a pneumatic drive unit (3), comprising the steps of: - 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 bring about 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, adapting a pressure setpoint value (30) of the pressure control and a throttle opening of the throttle function during the travel movement.The method of claim 1, wherein the travel path (28) is divided into a plurality of successive travel path zones (29), wherein the adjusting of the pressure setpoint (30) is effected in response to the drive element (12) moving from one of the travel path zones (29) into a successive travel path zone (29) during the travel movement, and wherein the adjusting of the throttle opening is effected in response to the drive element (12) moving from one of the travel path zones (29) into a successive travel path zone (29) during the travel movement.Method according to Claim 2, wherein each travel path zone (29) is assigned a respective pressure setpoint value (30) for the pressure regulation and a respective throttle opening value (31) for the throttle opening, wherein the pressure regulation in each travel path zone (29) takes place on the basis of the respectively assigned setpoint value (30) and the throttle function is provided in each travel path zone in accordance with the respectively assigned throttle opening value (31), wherein at least two of the pressure setpoint values (30) differ from one another and / or wherein at least two of the throttle opening values (31) differ from one another.The method of claim 2 or 3, wherein in response to the drive member (12) exiting a travel zone (29) located in a forward region of the travel path (28), the pressure set point (30) is reduced.The method of any of claims 2 to 4, wherein the throttle opening is reduced in response to the drive member (12) entering a travel zone (29) located in a rear region of the travel path (28).Method according to one of Claims 2 to 5, wherein the travel path (28) is divided into three successive travel path zones (29).The method of claim 6, wherein in response to the drive member (12) leaving the first travel zone (29a) in the direction of travel, the pressure set point (30) is reduced.The method of claim 6 or 7, 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.Method according to one of Claims 6 to 8, wherein the pressure setpoint value (30) remains constant during the transition from the second travel path zone (29b) in the travel direction (25) of the travel movement to the third travel path zone (29c), and / or the throttle opening remains constant during the transition from the first travel path zone (29a) in the travel direction (25) of the travel movement to the second travel path zone (29b).Method according to one of Claims 2 to 9, wherein one or more zone parameters are assigned to each travel path zone (29), wherein the zone parameters comprise a pressure setpoint value (30), a throttle opening value (31) or a zone limit value which defines a start and / or an end of the respective travel path zone (29).The method of claim 10, wherein one or more of the zone parameters is adjusted based on a position signal related to a position of the driving member (12).Method according to claim 10 or 11, wherein one or more of the zone parameters is adjusted during the travel movement and the pressure regulation and / or the throttle function for this travel movement is performed after the adjustment according to the one or more adjusted zone parameters.Method according to one of Claims 10 to 12, wherein at least one travel path characteristic is detected which comprises oscillation of the drive element (12), rebound of the drive element (12), a travel duration of the travel movement and / or premature standstill of the drive element (12), and wherein one or more of the zone parameters are adapted on the basis of the travel path characteristic.Method according to any of claims 10 to 13, wherein one or more of the zone parameters is adjusted by means of an optimization algorithm to optimize a quality criterion.Method according to claim 14, wherein the optimization of the quality criterion comprises a minimization of a trajectory error of the drive element (12) and / or a minimization of a final value error of the drive element (12), wherein the final value error comprises a travel duration error, a final position speed error and / or a final position pressure error.Method according to one of the preceding claims, wherein a tool change flap (32) is actuated by the drive element (12), said tool change flap separating a machine tool (33) from one or more tools (34) for the machine tool (33).Pneumatic system (1) comprising a valve device (2) and a pneumatic drive unit (3), wherein the pneumatic system (1) is configured to perform a method according to any one of claims 1 to 14.

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