Actuator system and method for operating an actuator system

Abstract

The present invention relates to a system and a method. The system includes a pneumatic actuator that can be loaded with compressed air and has an actuating element, and a compressed air supply device. The compressed air supply device is configured to perform position adjustment of the actuating element by loading the pneumatic actuator with compressed air so as to place the actuating element in a theoretical position. In addition, the compressed air supply device is configured to implement an assistance program and, within the scope of the assistance program, place the actuating element in a particularly sinusoidal oscillatory motion by loading the pneumatic actuator with compressed air. In the oscillatory motion, the actuating element moves alternately in a first motion direction and in a second motion direction. During the oscillatory motion, pressure values of the compressed air and position values of the actuating element are detected, and friction information and / or mass information are determined and / or verified based on the detected pressure values and the detected position values.

Description

Field of the Invention

[0001] The present invention relates to a system comprising a pneumatic actuator that can be loaded with compressed air and has an actuating element. The system further comprises a compressed air supply device configured to perform a position adjustment of the actuating element by loading the pneumatic actuator with compressed air in order to position the actuating element in a theoretical position. Background Art

[0002] The compressed air supply device includes, for example, a valve platform (Ventilinsel). The pneumatic actuator is, for example, a pneumatic drive cylinder.

[0003] The system is suitably applied in industrial automation, for example, in order to position drive objects, such as tools, workpieces, and / or machine components, by means of the actuating element.

[0004] The pneumatic actuator includes one or more pressure cavities that are pressurized by loading with compressed air within the range of the position adjustment in order to thereby effect the positioning of the actuating element. The position adjustment device loaded with compressed air is also referred to as a servo-pneumatic device.

[0005] Suitably, the compressed air supply device can be applied in a plurality of different applications and / or in combination with different pneumatic actuators. In order to achieve a good interaction between the compressed air supply device and the pneumatic actuator, it is advantageous for the compressed air supply device to have friction information that describes the friction occurring during the positioning of the actuating element and / or mass information that describes the mass to be set in motion during the positioning of the actuating element. For example, the compressed air supply device 4 takes into account the friction information and / or the mass information during the position adjustment of the actuating element.

[0006] Exemplarily, the friction information and / or the mass information can be input by the user into the compressed air supply device at the place of use (for example, when the system is put into operation), for example, into an application program by means of which the position adjustment is provided. Summary of the Invention

[0007] The object of the present invention is to improve the system mentioned at the beginning such that a good interaction between the compressed air supply device and the pneumatic actuator is more easily achievable for the user.

[0008] The task is solved by the following system: a system including a pneumatic actuator that can be loaded with compressed air and has an actuating link, and a compressed air supply device configured to perform position adjustment of the actuating link by loading the pneumatic actuator with compressed air so as to place the actuating link in a theoretical position. Additionally, the compressed air supply device is configured to execute an assistance program and, within the scope of the assistance program, place the actuating link in an oscillating motion by loading the pneumatic actuator with compressed air. In the oscillating motion, the actuating link moves alternately in a first motion direction and a second motion direction. During the oscillating motion, the pressure value of the compressed air and the position value of the actuating link are detected, and friction information and / or mass information is determined and / or verified based on the detected pressure value and the detected position value. The friction information describes the friction that occurs when positioning the actuating link, and the mass information describes the mass to be moved when positioning the actuating link. The compressed air supply device is configured to execute an assistance program and, within the scope of the assistance program, place the actuating link in an especially sinusoidal oscillating motion by loading the pneumatic actuator with compressed air. In the oscillating motion, the actuating link moves alternately in a first motion direction and a second motion direction. During the oscillating motion, the pressure value of the compressed air and the position value of the actuating link are detected, and friction information and / or mass information is determined and / or verified based on the detected pressure value and the detected position value.

[0009] It may be difficult for the user to determine the friction information and / or mass information by himself. The assistance program suitably provides the function that the friction information and / or mass information is automatically determined by the compressed air supply mechanism, that is, determined based on the oscillating motion of the actuating link. The compressed air supply device is especially configured to fully automatically determine the friction information and / or mass information by means of the assistance program.

[0010] Especially in the case where the user manually inputs the friction information and / or mass information, it can happen that (especially due to a fault or input error) the input friction information and / or mass information is incorrect, that is, especially does not match the system. Suitably, the assistance program provides the function of verifying the friction information and / or mass information (especially input by the user).

[0011] That is to say, the assistance program is used to ensure that there is correct friction information and / or correct mass information. By providing correct friction information and / or correct mass information, good interaction between the compressed air supply device and the pneumatic actuator can be obtained. For example, accurate and / or rapid position adjustment of the actuating link can be obtained by considering the friction information and / or mass information.

[0012] Another advantageous design is another subject matter.

[0013] The invention furthermore relates to a method for operating the system described above. The method comprises the following steps: implementing an assistance program.

[0014] The method is suitably designed corresponding to the improvement of the system. Description of the Drawings

[0015] Subsequently, exemplary details and exemplary embodiments are illustrated with reference to the figures. Here:

[0016] Figure 1 A schematic view of a system having a compressed air supply device, a hose assembly, and a pneumatic actuator is shown,

[0017] Figure 2 A schematic view of a valve mechanism is shown,

[0018] Figure 3 A line graph showing an oscillatory motion is shown,

[0019] Figure 4 A line graph showing an unoptimized friction curve, and

[0020] Figure 5 A line graph showing an optimized friction curve is shown. Detailed Description of the Invention

[0021] Figure 1 A system 100 is shown, which includes a pneumatic actuator 2 that can be loaded with compressed air and a compressed air supply device 4. Exemplarily, the system 100 furthermore includes a hose assembly 28 that connects the compressed air supply device 4 to the pneumatic actuator 2.

[0022] The pneumatic actuator 2 has an actuating link 3. The compressed air supply device 4 is configured to perform position adjustment of the actuating link 3 in order to position the actuating link 3 in a theoretical position. Within the scope of the position adjustment, the compressed air supply device 4 supplies compressed air to the actuator 2 through the hose assembly 28 in order to place the actuating link 3 in the theoretical position.

[0023] Suitably, the system 100 is used in industrial automation, for example for positioning drive objects such as tools, workpieces, and / or machine components by means of the actuating link 3.

[0024] The compressed air supply device 4 includes a valve assembly 14 that provides compressed air for the position adjustment of the actuator 2. Exemplarily, the valve assembly 14 is implemented as a valve platform. Alternatively, the valve assembly 14 can also be implemented as a single valve or as other valve mechanisms.

[0025] There are two pressure outlets 23, 24 at the valve assembly 14 for supplying compressed air. Each of these two pressure outlets 23, 24 is pneumatically connected to a respective pressure cavity 8, 9 of the pneumatic actuator 2. The valve assembly 14 can ventilate and exhaust these two pressure outlets 23, 24 independently of each other.

[0026] In an alternative design, the actuator 2 has only a single pressure cavity. In this alternative design, the pressure cavity is connected to the pressure outlet.

[0027] The valve assembly 14 has a pressure sensor assembly 29 with a pressure sensor (shown in Figure 2 ), by means of which the pressure at the pressure outlets 23, 24 and / or the pressure in the exhaust connection 26 and / or the ventilation connection 27 can be measured. The pressure sensor is suitably arranged at the valve assembly 14, in particular at the valve platform.

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

[0029] The valve assembly 14 is exemplarily implemented as a row module assembly and can in particular also be referred to as a valve platform. The previously mentioned modules particularly relate to row modules, which are preferably implemented in a disk shape. The valve module 17 is in particular implemented as a valve disk. Suitably, the row modules are arranged in particular along the longitudinal axis of the valve assembly 14 adjacent to each other.

[0030] Exemplarily, the compressed air supply device 4 further includes a higher-level control unit 15 and / or optionally includes a cloud server 16 and / or a user device 49.

[0031] The valve assembly 14 is suitably communicatively connected to the higher-level control unit 15 and / or the cloud server 16. Preferably, the valve assembly 14 is connected to the higher-level control unit 15 via a bus 25, in particular a backbone bus, such as a fieldbus, and / or optionally to the cloud server 16 via a wide area network 22, such as the Internet.

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

[0033] Exemplarily, the pneumatic actuator 2 is configured as a drive, in particular as a drive cylinder. The pneumatic actuator 2 exemplarily comprises an actuator body 7, an actuating member 3 and two pressure chambers 8, 9. Suitably, the two pressure chambers 8, 9 can be charged with compressed air separately from each other. The pneumatic actuator 2 is in particular configured as a double-acting actuator. Alternatively, the pneumatic actuator 2 can also have only one pressure chamber and accordingly be configured as a single-acting actuator.

[0034] The actuator body 7 is preferably designed as a cylinder and has an inner volume. The actuating member 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.

[0035] The pneumatic actuator 2 expediently comprises a position sensor mechanism 10. The position sensor mechanism 10 is used in particular to detect the position of the actuating member 3. The position sensor mechanism 10 provides a position value that describes the position of the actuating member 3. The position sensor mechanism 10 is preferably implemented as an analog position transmitter. The position sensor mechanism 10 is exemplarily arranged externally at the actuator body 7. The position sensor mechanism 10 comprises, for example, two position sensor units 11, 12, which are arranged distributed along the movement path of the actuating member 3. Exemplarily, the position sensor units 11, 12 together cover the entire movement path of the actuating member 3.

[0036] Each position sensor unit 11 , 12 can include, for example, one or more sensor elements (not shown in the figure), in particular magnetic sensor elements, such as Hall sensor elements. A magnet is expediently arranged on the actuating member 3 , the magnetic field of which can be detected by means of the magnetic sensor elements.

[0037] The position sensor device 10 is expediently designed to detect the position of the actuating member 3 over the entire movement path of the actuating member 3 .

[0038] Expediently, no pressure sensor is present on the pneumatic actuator 2 , in particular no pressure sensor for measuring the pressure in one of the pressure chambers 8 , 9 .

[0039] The system 100 advantageously comprises a hose assembly 28, by means of which the compressed air supply device 4, in particular the valve assembly 14, is pneumatically connected to the pneumatic actuator 2. A first hose 51 pneumatically connects the first pressure outlet 23 to the first pressure chamber 8 and a second hose 52 pneumatically connects the second pressure outlet 24 to the second pressure chamber 9. In an alternative design, in which the pneumatic actuator 2 has only one pressure chamber, the hose assembly 28 advantageously comprises only one hose.

[0040] The upper-level control unit 15 is exemplarily designed as a control unit capable of storing programming, SPS, and is communicatively connected to the valve assembly 14, in particular to the control unit 19. The upper-level control unit 15 is also preferably connected to the cloud server 16, in particular via a wide area network 22, preferably via the Internet. The upper-level control unit 15 is preferably designed to provide a target value signal, which predetermines a target position, and the actuating member 3 is adjusted to the target position within the scope of position control.

[0041] The user device 49 exemplarily relates to a mobile device, such as a smart phone, a tablet computer and / or a laptop computer. In addition, the user device 49 can relate to a desktop computer, such as a PC. The user device 49 is appropriately connected to the control unit 19, the cloud server 16 and / or the upper-level control unit 15 in a communicative manner, in particular via a wide area network 22, such as the Internet. The user device 49 is particularly configured to be used for user input of friction information and / or quality information. Suitably, a user interface can be used through the user device 49, which is provided, for example, on the cloud server 16, the control unit 15 and / or the control unit 19. The user interface suitably relates to a network interface. The user interface is particularly used to input friction information and / or quality information by the user. In addition, the user interface is preferably used to select, activate and / or load an application onto the control unit 19, which provides a position regulator and / or an auxiliary program that is subsequently explained. In addition, the user device 49 is suitably configured to be used to operate and / or display an auxiliary program.

[0042] The cloud server 16 is preferably arranged away from the valve assembly 14 and / or the pneumatic actuator 2, in particular at another geographical location. Preferably, the cloud server 16 is configured to provide an application program, by means of which the position adjustment and / or assistance program is provided. The application program can be loaded from the cloud server 16 onto the higher-level control unit 15 and / or the control unit 19, and preferably reacts to user inputs implemented by means of the user device 49.

[0043] Figure 2An exemplary valve device 21 is shown, by means of which the pressure for the pressure chambers 8 , 9 can be provided. The valve device 21 is part of the compressed air supply device 4 , in particular the valve arrangement 14 , preferably the valve module 17 .

[0044] The valve mechanism 21 has two pressure outlets 23, 24, by means of which two separate compressed air pressures and / or two separate compressed air mass flows can be provided. The valve mechanism 21 also has an exhaust connection 26 connected to the exhaust line and a ventilation connection 27 connected to the ventilation line. Preferably, the supply pressure is adjacent to the ventilation connection 27 and / or the atmospheric pressure is adjacent to the exhaust connection 26.

[0045] The valve device 21 comprises, for each pressure outlet 23 , 24 , one or more valve members 48 , by means of which the size of the respective outlet opening through which compressed air is passed when being supplied or discharged at the respective pressure outlet 23 , 24 can be adjusted.

[0046] exist Figure 2 In the embodiment, the valve mechanism 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 ventilation connection 27 and the first pressure outlet 23, the second 2 / 2-way valve 32 is connected between the first pressure outlet 23 and the exhaust connection 26, the third 2 / 2-way valve is connected between the exhaust connection 26 and the second pressure outlet 24, and the fourth 2 / 2-way valve is connected between the second pressure outlet 24 and the ventilation connection 27.

[0047] The first pressure outlet 23 can be connected to the exhaust line via a first 2 / 2-way valve or to the ventilation line via a second 2 / 2-way valve, and the second pressure outlet 24 can be connected to the exhaust line via a third 2 / 2-way valve or to the ventilation line via a fourth 2 / 2-way valve.

[0048] Each 2 / 2-way valve 31, 32, 33, 34 is designed as a proportional valve by way of example; 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 and closed positions. Preferably, the 2 / 2-way valve 31, 32, 33, 34 is a pilot-controlled valve, which has two pilot-control valves 41, 42 respectively, by which the valve member can be actuated. The pilot-control valves 41, 42 are designed as piezo valves by way of example. The aforementioned outlet opening can be adjusted appropriately by the position of the corresponding valve member 48.

[0049] Exemplarily, the first and second 2 / 2 directional valves 31, 32 form a first half-bridge and the third and fourth 2 / 2 directional valves 33, 34 form a second half-bridge. Preferably, the outlet opening of the first pressure outlet 23 can be adjusted by the first half-bridge and the outlet opening of the second pressure outlet 24 can be adjusted by the second half-bridge.

[0050] The valve assembly 14 suitably includes a pressure sensor assembly 29 having one or more pressure sensors in order to detect the pressure of the valve assembly 14, in particular the valve mechanism 21.

[0051] Exemplarily, the pressure sensor assembly 29 includes a first pressure outlet pressure sensor 45 for detecting the pressure provided at the first pressure outlet 23 and / or a second pressure outlet pressure sensor 46 for detecting the pressure provided at the second pressure outlet 24. Suitably, the pressure sensor assembly 29 further includes a supply air pressure sensor 44 for detecting the pressure provided at the air change connection 27 and / or an exhaust pressure sensor 43 for detecting the pressure provided at the exhaust connection 26.

[0052] Suitably, the valve assembly 14, in particular the valve mechanism 21, includes a travel sensor 47 for detecting the position of the valve link 48. The compressed air supply device 4 is in particular configured to determine the size of the outlet openings of the pressure outlets 23, 24 by means of the travel sensor 47.

[0053] The position adjustment performed by the compressed air supply device 4 will be explored in more detail below:

[0054] The compressed air supply device 4 is suitably configured to perform position adjustment over the entire movement path of the actuating element 3. Preferably, the compressed air supply device 4 is configured to position the actuating element 3 at any position along the movement path by means of position adjustment. Suitably, the actuating element 3 can be positioned at any position along the movement path by means of position adjustment.

[0055] Preferably, the compressed air supply device includes a position regulator by means of which the position adjustment of the actuating element 3 is provided. The position regulator is suitably implemented as a program, in particular as an application program, which program is in particular implemented on the valve assembly 14, preferably implemented on the control unit 19. The position regulator 50 is in particular implemented on the microcontroller of the control unit 19. Alternatively or additionally thereto, the position regulator 50 can also be implemented on the cloud server 16 and / or on the higher-level control unit 15.

[0056] The position regulator is suitably configured to provide a calibration variable signal based on a target value signal. The target value signal is provided, for example, by the control unit 19, the control unit 15 and / or the cloud server 16. The target value signal presets a target position. The valve assembly 14 is configured to control the valve mechanism 21, in particular the 2 / 2 directional valves 31, 32, 33, 34, in particular the pilot valves 41, 42 thereof, based on the calibration variable signal. Exemplarily, one or more conductance values ​​are preset by the calibration variable signal, according to which the position of the valve member 48 is adjusted and thereby the outlet openings of the pressure outlets 23, 24 are adjusted.

[0057] In particular, the position controller is designed to provide the control variable signal as a function of the setpoint value signal and / or the measured variable signal.

[0058] The measured variable signal expediently comprises the measured values ​​of the position sensor device 10, the pressure sensor assembly 29, in particular the pressure sensors 43, 44, 45, 46 and / or the travel sensor 47. That is, the measured variable signal in particular comprises the measured position of the actuation member 3, the measured pressure at the exhaust connection 26, the measured pressure at the ventilation connection 27, the measured pressure at the pressure outlet 23, the measured pressure at the pressure outlet 24 and / or the measured position of the valve member 48. Expediently, the measured pressure can be provided in the measured variable signal as a pressure difference. In addition, the measured position can be provided in the measured variable signal as a conductance value.

[0059] The compressed air supply device 4 , in particular the position controller, is designed to take into account friction information and / or mass information when adjusting the position of the actuating member 3 .

[0060] The friction information describes the friction, in particular the friction coefficient and / or the friction force, which occurs when positioning the actuating member 3. Preferably, the friction information comprises a friction parameter describing the friction. The friction comprises, for example, the friction between the actuating member 3 and the actuator body 7, in particular between the piston 5 and the actuator body 7. Alternatively or in addition thereto, the friction preferably comprises the friction between a driven object driven by the actuating member and a guide, at which the driven object is supported.

[0061] The mass information describes the mass to be set in motion when positioning the actuating element 3. Suitably, the mass information comprises a mass parameter describing the mass. The mass comprises, for example, the mass of the actuating element 3. Alternatively or in addition thereto, the mass suitably comprises the mass of a driven object driven by the actuating element 3.

[0062] The compressed air supply device 4, in particular the position controller, is expediently designed to calculate one or more controller parameters for position control, such as a controller gain, based on the friction information and / or the mass information. And the controller parameters are applied during position control. Preferably, the compressed air supply device 4, in particular the position controller, is configured to perform a controller design based on the friction information and / or the quality information in order to calculate controller parameters, in particular the controller gain, for position control. Suitably, the compressed air supply device 4 is configured to perform automatic parameterization of position control based on the friction information and / or the quality information.

[0063] The position control can be adapted to a particular application and / or to the pneumatic actuator 2 with the aid of mass information and / or friction information.

[0064] The system 100 preferably has a user interface for manually inputting friction information and / or quality information. Preferably, the input is carried out directly at the place of use of the system 100, exemplarily when the system 100 is put into operation. Preferably, the position controller and / or the auxiliary program are provided in an application and the input of the friction information and / or quality information is carried out with the aid of or in the application. Exemplarily, the user device 49 mentioned above serves as the user interface.

[0065] The quality information and / or the friction information are, in particular, parameters that can be input by a user, for example via a user device 49 .

[0066] The assistance process should be explored in more detail below.

[0067] The compressed air supply device 4 is expediently designed to automatically trigger the assistance program, for example in the startup mode. Alternatively or additionally, the user interface of the system 100, for example the user device 49, includes a function for manually (ie, selectively caused by explicit user input) triggering the assistance program.

[0068] The assistance program is expediently implemented on the control unit 19 , the control unit 15 , the external cloud server 16 and / or the user device 49 , in particular as an application.

[0069] The compressed air supply device 4 is designed to act on the pneumatic actuator 2 with compressed air within the scope of the assistance procedure in order to set the actuating member 3 into an oscillating movement 60, in which the actuating member 3 is moved alternately in a first movement direction 61 and in a second movement direction 62. The compressed air supply device 4 is designed to detect pressure values ​​of the compressed air and position values ​​of the actuating member 3 during the oscillating movement 60 and to determine and / or verify friction information and / or quality information based on the detected pressure values ​​and the detected position values.

[0070] Figure 3 The diagram shows an exemplary oscillating movement 60 in which the actuating member 3 is set during the assistance procedure.Figure 3 In the line graph, the position x of the actuating element 3 is plotted against time t.

[0071] In the case of the oscillating movement 60, the actuating element 3 moves along the movement path. The oscillating movement 60 is in particular sinusoidal. The oscillating movement 60 has a plurality of periods 63.

[0072] The compressed air supply device 4 is preferably configured to change the speed of the actuating element 3 during the oscillating movement 60, such that the plurality of periods 63 of the oscillating movement 60 are different from one another in terms of their speed profiles, in particular their maximum speeds, and pressure values and position values are detected over the plurality of periods 63. The compressed air supply device 4 in particular uses the pressure values and position values detected over a plurality of periods 63 that are different from one another in terms of their speed profiles, in particular their maximum speeds, for determining and / or verifying friction information and / or mass information.

[0073] As shown in Figure 3 the plurality of periods 63 of the oscillating movement 60 are different from one another in terms of their speed profiles. The plurality of periods 63 are in particular different from one another in terms of their maximum speeds.

[0074] Exemplarily, the oscillating movement 60 includes a plurality of speed phases 67A, 67B, 67C, each of which includes a plurality of periods 63. Alternatively, one, several or all of the speed phases 67A, 67B, 67C can also include only a respective single period 63. Suitably, the respective periods 63 of the speed phases have the same speed profile, in particular the same maximum speed. The speed phases 67A, 67B, 67C are suitably different from one another in terms of their speed profiles, in particular their maximum speeds. In Figure 3 three different speed phases 67A, 67B, 67C are shown. Preferably, the oscillating movement 60 includes at least three, in particular at least six, different speed phases.

[0075] The different speed phases or periods 63 can in particular be generated by one or more frequency sweeps.

[0076] The compressed air supply device 4 is preferably configured to perform at least one frequency sweep of the oscillating movement 60 and to detect pressure values and position values during the frequency sweep. Exemplarily, different speed phases and / or periods with different speed profiles are obtained by performing a frequency sweep, that is to say by changing the frequency of the oscillating movement 60.

[0077] Exemplarily, the compressed air supply device 4 is configured to perform at least one first frequency scan 64 and a second frequency scan 65 of the oscillating movement 60 and to detect pressure values and position values during these two frequency scans 64, 65. The first frequency scan 64 is exemplarily a frequency scan with an increasing frequency and the second frequency scan 65 is exemplarily a frequency scan with a decreasing frequency.

[0078] The speed phases 67A, 67B, 67C of the oscillating movement 60 are exemplarily different from one another in terms of their frequency. The frequency of the second speed phase 67B is greater than the frequency of the first speed phase 67A and the frequency of the third speed phase 67C is greater than the frequency of the second speed phase 67B. In each frequency scan 64, 65, the plurality of speed phases 67A, 67B, 67C are carried out at different frequencies.

[0079] The compressed air supply device 4 is configured to detect the pressure value of the compressed air and the position value of the actuating element 3 during the oscillating movement 60, in particular during each frequency scan 64, 65. The detected pressure values suitably include the pressures at the pressure outlets 23, 24 detected by means of the pressure sensor assembly 29. Friction information and / or mass information is calculated based on the pressure values and position values detected during the frequency scans 64, 65.

[0080] As will be explained in detail subsequently, the compressed air supply device 4 is suitably configured to calculate the frictional force acting on the actuating element 3 based on the pressure values and position values. The compressed air supply device 4 is in particular configured to calculate a frictional force curve 66 of the frictional force acting on the actuating element 3 (shown in Figure 4 and 5 ).

[0081] The compressed air supply device 4 is suitably configured to calculate friction information and / or mass information based on the frictional force curve 66, as will also be explained in detail subsequently. First, the calculation of the frictional force curve 66 should be explored in more detail.

[0082] Exemplarily, the compressed air supply device 4 is configured to calculate the frictional force of the frictional force curve 66 as the difference between a first pneumatic force acting on the actuating element 3 in the first movement direction 61, a second pneumatic force acting on the actuating element 3 in the second movement direction 62, an inertial force caused by the acceleration of the actuating element 3 and / or the gravitational force acting on the actuating element 3. The compressed air supply device 4 is in particular configured to calculate the first pneumatic force and / or the second pneumatic force based on the detected pressure values.

[0083] For example, the compressed air supply device 4 is configured to calculate the frictional force curve 66 based on the following equation of motion:

[0084]

[0085] F R is the frictional force.

[0086] F AD is the first pneumatic force acting along the first movement direction 61, and the force is provided by the compressed air loading of the first pressure cavity 8. For example, F AD is calculated as the pressure p of the first pressure cavity 8 AD and the first acting surface A of the actuating link 3 AD The product of, the pressure p AD acts on the first acting surface. That is to say, F AD As F AD = p AD * A AD is obtained. The pressure p AD is preferably calculated based on the pressure value of the first pressure outlet 23 detected by the pressure sensor assembly 29. According to an alternative design (where there is a pressure sensor at the actuator 2), the pressure p AD can also be measured directly at the actuator 2 as the pressure value.

[0087] F LD is the second pneumatic force acting along the second movement direction 62, which is provided by the compressed air loading of the second pressure cavity 9 and / or by the ambient pressure acting on the actuating link 3, especially the piston rod 6. For example, F LD includes the pressure p of the second pressure cavity 9 LD and the second acting surface A of the actuating link 3 LD The product of, the pressure p LD acts on the second acting surface. Exemplarily, F LD further includes the product of the ambient pressure p AMB , especially the atmospheric pressure and the third acting surface of the actuating link 3, and the ambient pressure p AMB acts on the third acting surface. Exemplarily, the third acting surface is obtained as the difference between the first acting surface A AD and the second acting surface A LD That is to say, F LD As F LD = p LD * A LD + p AMD *(A AD - A LD ) is obtained. The pressure p LD is preferably calculated based on the pressure value of the second pressure outlet 24 detected by the pressure sensor assembly 29. According to an alternative design (where there is a pressure sensor at the actuator 2), the pressure p LDIt is also possible to measure directly at the actuator 2 as a pressure value.

[0088] m is the mass to be set in motion when positioning the actuating member 3; m represents in particular mass information, such as a mass parameter. M is, for example, the mass of the actuating member 3 plus the mass of the drive object to be driven by the actuating member 3 (if any).

[0089] is the acceleration of the actuating member and is obtained, for example, by secondarily differentiating a position value of the actuating member 3 , which is detected in particular by means of the position sensor device 10 .

[0090] g is the acceleration due to gravity.

[0091] α is the installed position of the actuating member 3. In particular, α is the angle between the movement path of the actuating member 3 and the horizontal plane (oriented perpendicularly to the gravitational acceleration).

[0092] As explained above, the pressure p of the pressure chambers 8, 9 is AD and p LD Exemplarily, the pressure p is calculated based on the pressure values ​​of the pressure outlets 23, 24 detected by means of the pressure sensor assembly 29. The pressure value detected by means of the pressure sensor assembly 29 can also be referred to as the measured pressure and the pressure p calculated based on the measured pressure is AD and p LD It can also be referred to as calculated pressure. The calculated pressure is in particular an estimated pressure.

[0093] That is, the compressed air supply device 4 is preferably designed to measure a measured pressure of the compressed air supply device 4 by means of the pressure sensor assembly 29, to provide the measured pressure as a pressure value, and to calculate a calculated pressure based on the measured pressure, which describes the pressure prevailing in the pressure chambers 8, 9 of the pneumatic actuator 2. The compressed air supply device 4 is further designed to determine and / or verify friction information and / or quality information based on the calculated pressure.

[0094] Preferably, the compressed air supply device 4 is configured to use a hose module of the hose assembly 28 to calculate the calculated pressure. The hose module describes the influence of the hose on the pressure. The hose module describes the relationship between the corresponding pressure in the pressure chambers 8, 9 and the corresponding pressure at the pressure outlets 23, 24. Preferably, the calculated pressure is calculated based on the pressure value and the position value.

[0095] In the following, reference should be made to Figure 4 and 5 We will now discuss in more detail how friction information and / or mass information can be determined based on friction force curve 66 .

[0096] exist Figure 4 and5 The friction force curve 66 shown in FIG. 6 is a parameter curve by way of example. The points of the friction force curve 66 are respectively represented by the time-dependent friction force F R (t) and the time-dependent speed v(t) of the actuating element 3. The points of the friction force curve are plotted as a function of the time t. The time-dependent friction force F is plotted on the y-axis. R The time-dependent velocity v of the actuating member 3 during the oscillating movement 60 is plotted on the x-axis. The velocity v is also referred to as oscillation velocity v. The time-dependent velocity v is calculated, for example, by differentiating the detected position of the actuating member 3 .

[0097] exist Figure 4 The friction curve 66 shown in FIG. 6 is also referred to as a non-optimized friction curve 66A. As explained below, the non-optimized friction curve 66A is based on incorrect assumptions about the quality information, in particular about the quality parameter m. Figure 5 The friction curve 66 shown in FIG. 6 is also referred to as an optimized friction curve 66B. As explained below, the optimized friction curve 66B is based on a correct assumption about the quality information, in particular about the quality parameter m. That is, the friction curves 66A, 66B differ by the correspondingly selected quality parameter m, with which the corresponding friction Fr is calculated.

[0098] As mentioned above, the friction force curve 66 is calculated using the pressure values ​​detected during the oscillating movement 60. In this regard, it should be mentioned that for better representation, Figure 3 Shown in Figure 4 and 5 The oscillating motion on which the friction force curve 66 shown in FIG. 6 is based is different from the oscillating motion 60 . Thus, for example Figure 3 The oscillating motion 60 has a ratio Figure 4 The friction force curve 66 has a small speed stage.

[0099] The non-optimized friction curve 66A has a plurality of speed stages, which correspond to the speed stages of the oscillating motion on which it is based. Exemplarily, the friction curve 66A has speed stages 67A, 67B, 67C, 67D, 67E and 67F. Each of the speed stages extends over one or more periods of the oscillating motion. The non-optimized friction curve has a plurality of periods, which correspond to the periods of the oscillating motion on which it is based.

[0100] The unoptimized friction force curve 66A has a spiral shape. In each cycle, the friction force curve 66A encircles the zero point once. In each cycle, that is, for each encirclement around the zero point, the friction force curve 66A passes through each of the four quadrants of the line graph. With the increasing maximum speed of the speed phase, especially of the cycle, that is, exemplarily with increasing frequency, the distance of the friction force curve 66A from the origin of coordinates increases, so that the friction force curve has a spiral shape. For each speed value v of the friction force curve 66A, multiple different friction force values are given. The friction force curve 66A has hysteresis. Depending on whether the speed v becomes larger or smaller, (for the same speed v) friction forces of different intensities are obtained. For example, due to hysteresis, not only a positive friction force but also a negative friction force is obtained for the same speed v. This shape of the friction force curve 66A results from a wrong assumption about the mass parameter m.

[0101] The compressed air supply device 4 is configured to perform parameter optimization of the mass parameter m in the case of the friction force curve 66 in order to obtain an optimized friction force curve 66B. For example, the compressed air supply device 4 performs the recursive least squares method in order to obtain the optimized friction force curve 66B based on the unoptimized friction force curve 66A. The compressed air supply device 4 is configured to calculate for which value of the mass parameter m the deviation, especially the hysteresis, of the friction force curve 66 between different cycles, especially between different speed phases, is minimal, and to provide the following value of the mass parameter as mass information, especially the mass parameter m, for which the deviation is minimal.

[0102] Exemplarily, the compressed air supply device 4 is configured to apply a cost function in order to calculate for which value of the mass parameter the deviation is minimal. For example, the compressed air supply device 4 performs the minimization of the cost function, e.g., min∑F R 2 in order to obtain the value of the mass parameter. Appropriately, the compressed air supply device 4 performs the minimization of the cost function under the additional condition that the mass parameter m is greater than zero.

[0103] In Figure 5 the optimized friction force curve 66B shown is the result of the minimization of the cost function. Here, different cycles, especially different speed phases, basically have a unique friction force characteristic, where a (basically) clear assignment between the speed value v and the friction force value Fr is obtained, so that each speed value v is assigned only one friction force value Fr.

[0104] Exemplarily, the optimized friction curve 66B has a substantially S-shaped course. The course of the optimized friction curve 66B passes through the zero point. The course of the optimized friction curve 66B exemplarily passes through the first and third quadrants (and in particular does not pass through the second and fourth quadrants). The optimized friction curve 66B has a negative curvature in the first quadrant and a positive curvature in the third quadrant.

[0105] The compressed air supply device 4 is configured to determine friction information based on the optimized friction curve 66B. For example, the compressed air supply device 4 generates a friction force function based on the optimized friction curve 66B, which describes the friction force Fr depending on the speed v and lies on the optimized friction curve 66B. The friction force function suitably presents the friction information.

[0106] In addition, the compressed air supply device 4 can be configured to calculate the Coulomb friction LBD of the actuating link 3 that is particularly independent of the speed based on the friction information. As shown in Figure 5 it is possible, for example (in particular by means of a straight line), to extrapolate the end region of the friction curve 66B spaced apart from the zero point towards the y-axis. The friction force Fr is suitably provided as the Coulomb friction LBD, in the case of which the extrapolation cuts the y-axis. Suitably, the compressed air supply device 4 is configured to store the Coulomb friction LBD, where, for example, position adjustment is applied and / or issued by the user device 49.

[0107] As explained above, that is to say, the compressed air supply device 4 is configured to calculate a friction force curve 66 acting on the actuating link 3 depending on the oscillating motion 60, in particular the oscillating speed v, based on the pressure value and the position value, over a plurality of periods 63 of the oscillating motion 60, and to calculate friction information and / or mass information in the case of applying the friction force curve 66. The friction force of the friction force curve depends on a mass parameter m, which describes the mass to be set in motion when positioning the actuating link 3. The compressed air supply device 4 is configured to calculate for which mass parameter value of the mass parameter m the deviation of the friction force curve 66 between different periods 63 of the oscillating motion is minimal, and to provide the following mass parameter value as the mass information m, in the case of which the deviation is minimal. The compressed air supply device 4 is configured to determine the friction information based on the following friction force curve 66, in the case of which the deviation is minimal.

[0108] According to a preferred design, the compressed air supply device 4 is configured to verify the friction information input by the user, such as friction parameters and / or the quality information input by the user, such as quality parameters. For example, the compressed air supply device 4 is configured to compare the input friction information with the measured friction information. If the input friction information is inconsistent with the measured friction information, the compressed air supply device 4 appropriately issues a warning to the user, such as issuing a warning through the user device 49, and / or applies the measured friction information instead of the input friction information for position adjustment.

[0109] For example, the compressed air providing device 4 compares the input quality information with the measured quality information. If the input quality information is inconsistent with the measured quality information, the compressed air providing device 4 issues a warning to the user, for example, via the user device 49, and / or applies the measured quality information instead of the input quality information for position adjustment.

[0110] According to a preferred design, the compressed air supply device 4 is configured to apply the friction information and / or quality information determined by means of the auxiliary program to determine the wear state, for example, the aging state, of the compressed air supply device 4 and / or the pneumatic actuator 2. The compressed air supply device 4 is particularly configured to provide a predictive maintenance function and, for example, identify aging and / or faults when applying the determined wear state. As a basis for determining the wear state, the friction information and / or quality information is particularly used.

[0111] As explained above, that is to say, the compressed air supply device 4 is expediently designed to calculate the friction information and / or the quality information when applying the equation of motion of the actuating member 3 and the detected pressure value and the detected position value of the actuating member. Exemplarily, the compressed air supply device 4 estimates the pressure in the pressure cavities 8, 9 based on the detected pressure value when applying the hose module and applies the estimated pressure to the calculation of the friction information and / or the quality information. Preferably, the compressed air supply device 4 does not use an additional function for the calculation of the friction information and / or the quality information. In addition, it is expedient to freely select the cost function, by means of which the optimized friction curve is calculated.

[0112] The described measures advantageously allow simplified commissioning of the system 100. The compressed air supply device 4 identifies the friction, in particular the friction information, of the actuating element 3 by learning the movement, in particular by the oscillating movement 60. The parameter identification of the friction is performed by optimizing the parameters of the equation of motion for the actuating element (for example by a recursive least squares method). The equation of motion can also be referred to as a dynamic equation. Preferably, the user does not have to determine the friction information himself.

[0113] The quality information is made reliable (i.e., verified) or confirmed by learning movements, in particular by oscillating movements. The parameter identification is carried out by applying parameter optimization for the motion equation of the actuating link (e.g., by recursive least squares).

Claims

1. An actuator system (100), comprising a pneumatic actuator (2) that can be loaded with compressed air and has an actuating link (3), and a compressed air supply device (4), the compressed air supply device being configured to perform a position adjustment of the actuating link (3) by loading the pneumatic actuator (2) with compressed air in order to position the actuating link (3) in a theoretical position, wherein, The compressed air supply device (4) is further configured to execute an assistance program and, within the scope of the assistance program, place the actuating link (3) in an oscillating motion (60) by means of compressed air loading of the pneumatic actuator (2), in which oscillating motion the actuating link (3) moves alternately in a first direction of motion (61) and in a second direction of motion (62), detect a pressure value of the compressed air and a position value of the actuating link (3) during the oscillating motion (60), and determine and / or verify friction information and / or mass information based on the detected pressure value and the detected position value, the friction information describing the friction occurring during positioning of the actuating link (3), and the mass information describing the mass to be set in motion during positioning of the actuating link (3).

2. The actuator system (100) according to claim 1, wherein, The compressed air supply device (4) is configured to change the speed of the actuating link (3) during the oscillating motion (60) such that a plurality of periods (63) of the oscillating motion (60) differ from one another in terms of their speed profile, and detect the pressure value and the position value over the plurality of periods (63).

3. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) is configured to perform at least one frequency sweep of the oscillating motion (60) and detect the pressure value and the position value during the frequency sweep.

4. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) is configured to perform at least one first frequency sweep (64) of the oscillating motion (60) and a second frequency sweep (65) of the oscillating motion and detect the pressure value and the position value during these two frequency sweeps (64, 65), wherein the first frequency sweep (64) is a frequency sweep with an increasing frequency and the second frequency sweep (65) is a frequency sweep with a decreasing frequency.

5. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) is configured to determine and / or verify the friction information and / or the mass information based on the detected pressure value, the equation of motion describing the motion of the actuating link (3), and the detected position value of the actuating link (3).

6. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) is configured to calculate a friction force curve (66) extending over a plurality of periods (63) of the oscillating motion (60) of the friction force acting on the actuating link (3) depending on the oscillating motion (60) based on the pressure value and the position value and calculate the friction information and / or the mass information in the case of application of the friction force curve (66).

7. The actuator system (100) according to claim 6, wherein, The friction force of the friction force curve (66) depends on a mass parameter, which describes the mass to be set in motion during positioning of the actuating link (3), and the compressed air supply device (4) is configured to calculate for which mass parameter value of the mass parameter the deviation of the friction force curve (66) between different periods (63) is minimal and provide as the mass information the mass parameter value for which the deviation is minimal.

8. The actuator system (100) according to claim 7, wherein, The compressed air supply device (4) is configured to determine the friction information based on a friction force curve (66) in which the deviation is minimal.

9. The actuator system (100) according to claim 6, wherein, The compressed air supply device (4) is configured to calculate the friction force of the friction force curve (66) as the difference between a first pneumatic force acting on the actuating element (3) in the first movement direction (61), a second pneumatic force acting on the actuating element (3) in the second movement direction (62), an inertial force caused by the acceleration of the actuating element (3), and / or the gravitational force acting on the actuating element (3).

10. The actuator system (100) according to claim 9, wherein, The compressed air supply device (4) is configured to calculate the first pneumatic force and / or the second pneumatic force based on the pressure value.

11. The actuator system (100) according to claim 7, wherein, The compressed air supply device (4) is configured such that no additional auxiliary function is used for the calculation of the friction information and / or the mass information.

12. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) is configured to perform the position adjustment taking into account the friction information and / or the mass information.

13. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) includes a pressure sensor assembly (29) and is configured to measure the measurement pressure of the compressed air supply device (4) by means of the pressure sensor assembly (29), provide the measurement pressure as the pressure value, and calculate a calculated pressure based on the pressure value, the calculated pressure representing an estimate of the pressure present in the pressure cavities (8, 9) of the pneumatic actuator (2), and determine and / or verify the friction information and / or the mass information based on the calculated pressure.

14. The actuator system (100) according to claim 1 or 2, wherein, The compressed air supply device (4) is configured to calculate the Coulomb friction of the actuating element (3) based on the determined friction information.

15. The actuator system (100) according to claim 1, wherein, The oscillatory movement is a sinusoidal oscillatory movement (60).

16. The actuator system (100) according to claim 6, wherein, The friction force curve (66) is a friction force curve of the friction force acting on the actuating element (3) depending on the oscillation speed (v).

17. A method for operating an actuator system (100) according to any one of the preceding claims, comprising the step of: executing the assistance program.

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