Method for automatically generating individual hydraulic element feature maps for individual hydraulic elements of hydraulic element type

Abstract

The invention provides a method for automatically generating individual hydraulic element feature maps for individual hydraulic elements V1, V2 of a hydraulic element type. According to the method of the invention, in order to automatically generate the individual hydraulic element feature maps, for example in the form of lookup tables, an automatic encoder and individual simplified data sets generated for the individual hydraulic elements V1, V2 are used, the autoencoder is trained using a training data set of the hydraulic element type.

Description

Technical Field

[0001] The invention relates to a method for automatically generating an individual hydraulic element characteristic map for an individual hydraulic element of a hydraulic element type, a method for embedding an individual hydraulic element characteristic map, a method for controlling an individual hydraulic element and a hydraulic system. Background Art

[0002] Various different types of hydraulic components are known, such as hydraulic valves or hydraulic pumps. These types of hydraulic components are configured to influence different parameters of the hydraulic system. For example, fluid parameters of a hydraulic fluid such as hydraulic oil may be parameters of the associated hydraulic system that are influenced by the corresponding hydraulic component. Fluid parameters may be understood as, for example, pressure, volume flow, temperature, flow rate, density or any other parameter for describing the properties of a hydraulic fluid. Other parameters, such as the valve piston position of a hydraulic valve, the rotation angle of a variable displacement pump or the stroke of a hydraulic cylinder piston rod, may also represent parameters of such a hydraulic system. Control parameters, such as control currents for actuating an actuator of a hydraulic valve or a variable displacement pump, may also represent parameters of a hydraulic system.

[0003] As is known, various parameters in a hydraulic system related to a specific hydraulic element type are related to each other via a hydraulic element characteristic map in order to characterize the specific behavior of said hydraulic element type in more detail. A hydraulic element characteristic map is any structure that establishes a functional relationship between at least two parameters of a hydraulic system. For example, a hydraulic element characteristic map can be a lookup table, a function or a collection of characteristic curves of different hydraulic elements of the same type in the form of a characteristic curve map. Such a hydraulic element characteristic map can then be embedded in a control unit, which uses the hydraulic element characteristic map to control individual hydraulic elements of this hydraulic element type.

[0004] The basic behavior and basic dynamics of individual hydraulic components of a hydraulic component type are similar. However, due to the manufacturing process, all individual hydraulic components of the same hydraulic component type can differ slightly in design from series to series. Each individual hydraulic component of the same hydraulic component type is therefore a unique hydraulic component due to the manufacturing process. These production-related structural deviations or the uniqueness of each individual hydraulic component means that the actual behavior of each individual hydraulic component differs slightly from the actual behavior of another individual hydraulic component of the same hydraulic component type and therefore also from the ideal behavior. Depending on the requirements profile, a generic hydraulic component profile created for one hydraulic component type may therefore not be accurate enough for the precise control of each individual hydraulic component of this hydraulic component type, i.e., a production-related unique hydraulic component. In this case, each hydraulic component of a hydraulic component type must be fully measured with a relatively high resolution in order to correctly determine the individual individual hydraulic component profiles of the individual hydraulic components.

[0005] An example of a hydraulic system parameter that is often relevant for the control of hydraulic systems is the volume flow. The volume flow in a hydraulic system is primarily influenced by the hydraulic valves. However, in practice, the measurement of the volume flow is very expensive and the corresponding sensor technology is prone to failure. However, in certain applications, for example when extending the piston rod of a hydraulic cylinder at a defined speed, it is necessary to know the volume flow currently flowing precisely. The volume flow currently flowing is directly related to the opening of the individual hydraulic valve and the pressure difference applied to the individual hydraulic valve. Although the applied pressure difference can generally be easily and reliably recorded, this does not necessarily apply to the actual opening of the individual hydraulic valve, for example, with pilot-controlled poppet valves. However, in order to be able to set the volume flow as required by the control unit of the hydraulic system assigned to the individual hydraulic valve, a comprehensive measurement of the individual hydraulic valve can be performed. In a test sequence, the applied current I of the individual hydraulic valve is slowly increased and reduced again after reaching a maximum value. The pressure difference dp at the control edge of the individual hydraulic valve is kept constant. In addition, the resulting volume flow Q can also be measured. This results in the Q(I) characteristic curve of the individual hydraulic valve measured at a constant pressure difference dp. If the above operation is repeated for a larger number of pressure differences dp, a set of Q(I) characteristic curves for the individual hydraulic valves is generated. This results in an individual valve characteristic diagram describing the relationship Q=f(I, dp) for the individual hydraulic valve (I is the current, dp is the pressure difference, Q is the volume flow, and f is the function). By inverting this function, a lookup table can be generated as an individual hydraulic element characteristic diagram describing the relationship I=f(Q, dp). The individual hydraulic element characteristic diagram in the form of a lookup table, a given desired volume flow Q and the currently measured pressure difference dp can therefore be used to determine the current I that must be applied to the individual hydraulic valve in order to obtain the desired volume flow Q. However, due to the production-related structural deviations between all individual hydraulic valves of the same hydraulic valve type mentioned above, each individual hydraulic valve must be completely measured with a sufficiently high resolution in order to generate an individual hydraulic element characteristic diagram that can control the volume flow with sufficient accuracy. In practice, this is usually too time-consuming and economically not feasible. Summary of the invention

[0006] It is therefore an object of the present invention to provide a simpler and more cost-effective method for generating individual hydraulic element characteristic maps for individual hydraulic elements of one hydraulic element type.

[0007] The solution to the problem is firstly achieved by a method for automatically generating individual hydraulic element characteristic maps for individual hydraulic elements of a hydraulic element type, the method comprising the following steps:

[0008] - creating a training data set for said hydraulic component type,

[0009] - train an autoencoder using said training dataset,

[0010] - automatically generating individual simplified data sets for said individual hydraulic elements, and

[0011] - Automatically generating the individual hydraulic component characteristic map of the individual hydraulic component based on the trained autoencoder and the individual reduced data set.

[0012] An "individual hydraulic component" is understood to be a unique hydraulic component that belongs to a specific hydraulic component type due to the manufacturing process. An "individual hydraulic component characteristic map" is therefore a unique map of an individual hydraulic component relevant to production. An individual hydraulic component characteristic map can be in the form of a lookup table, a function or a collection of different hydraulic component characteristic maps of the same type in the form of a map. Preferably, the individual hydraulic component characteristic map is a lookup table.

[0013] An autoencoder is an artificial neural network. The autoencoder is used to learn a compressed representation of the training data set on the basis of the training data set, in particular to extract meaningful features from the training data set. Non-linear dependencies can also be identified. In the linear case, the autoencoder is comparable to principal component analysis. The autoencoder consists of an encoder and a decoder. The encoder learns the encoding from the training data set and the decoder learns to reconstruct the training data set from the encoding. If the training data set is large enough, the autoencoder can also learn the production-related structural deviations in the individual hydraulic components of one hydraulic component type and thus generate an accurate individual hydraulic component characteristic map for each individual hydraulic component based only on the individual simplified data set. Due to the trained autoencoder and the individual simplified data set, the production-related structural deviations are already taken into account when the individual hydraulic component characteristic map is automatically generated by the autoencoder. Therefore, it is no longer necessary to fully measure each individual hydraulic component to generate its individual hydraulic component characteristic map. This is a significantly simpler and more cost-effective way to generate the individual hydraulic component characteristic map than the previous need for a complete measurement of each individual hydraulic component.

[0014] Preferably, the training data set comprises a plurality of different hydraulic element characteristic maps of the same type, in particular characteristic maps in the form of a lookup table. In addition, the generation of the training data set comprises the following:

[0015] - generating at least part of said training data set using a virtual simulation model of said hydraulic component type, and / or

[0016] - generating at least a part of said training data set using actual measurement results of at least one individual training hydraulic element, preferably a plurality of individual training hydraulic elements, of said hydraulic element type.

[0017] The larger the training dataset based on the characteristic maps of different hydraulic components of the same type, the more accurate the compressed representation of this type of hydraulic component learned by the autoencoder. The training dataset can be generated purely from the virtual simulation model, purely from actual measurement data (i.e., complete measurement data of individual training hydraulic components), or a mixture of virtual simulation data and actual measurement data.

[0018] Preferably, generating at least a portion of the training data set using a virtual simulation model comprises the following:

[0019] - create a virtual simulation model of said hydraulic component type,

[0020] - identifying structural parameters of the hydraulic element type which have an influence on the actual behavior of the hydraulic element type due to the series dispersion,

[0021] - defining limit values ​​for these identified structural parameters, wherein these limit values ​​correspond in particular to the maximum practical deviations resulting from the series scatter,

[0022] - generating a plurality of different virtual training models by randomly varying the identified structural parameters of the virtual simulation model within the defined limit values, and

[0023] -Generate multiple different hydraulic component characteristic maps of the same type by simulating a defined test sequence on each generated virtual training model.

[0024] For example, the limit values ​​of the identified structural parameters represent manufacturing tolerances. By identifying and simulating changes in the structural parameters of the hydraulic component type, it is possible to simulate series changes in the individual hydraulic components, which structural parameters influence the actual behavior of the hydraulic component type due to the series changes. In this way, a realistic training data set can be generated for training the autoencoder without having to perform complex high-resolution series measurements of real individual hydraulic components. However, such simulated training data sets can be supplemented or verified by existing real measurement data or completely replaced by existing real measurement data.

[0025] Preferably, the individual simplified data set comprises characteristic diagram data of at least one defined measuring point. Furthermore, the automatic generation of the individual simplified data set of the individual hydraulic element comprises the following steps:

[0026] - Automatically recording said characteristic map data of said individual hydraulic component at said at least one defined measuring point during final production testing of said individual hydraulic component.

[0027] Thus, the individual simplified data set comprises a subset of the individual hydraulic component characteristic map to be generated. Preferably, the individual simplified data set comprises characteristic map data for a plurality of determined measurement points. Generally speaking, during the production of each individual hydraulic component, a final production test is performed, e.g. for quality control reasons, the intended functionality of each individual hydraulic component produced is automatically checked. Since such a final production test has to be performed anyway, one or more clearly defined measurement points can be approached during the final production test and the required characteristic map data recorded, which forms the individual simplified data set without the need for additional work. Using the individual simplified data set, the decoder of the trained autoencoder can generate the individual hydraulic component characteristic map, preferably a lookup table, in a simple and cost-effective manner.

[0028] Preferably, the individual hydraulic element is a hydraulic valve or a hydraulic pump. Therefore, the individual hydraulic element characteristic map is a valve characteristic map or a pump characteristic map, in particular a valve characteristic map or a pump characteristic map in the form of a lookup table.

[0029] The method can thus be used to generate individual hydraulic element characteristic maps for individual hydraulic elements of different types of known hydraulic elements in a simple and cost-effective manner.

[0030] Preferably, the hydraulic valve is a poppet valve, in particular a pilot-controlled poppet valve. The valve characteristic diagram, in particular in the form of a lookup table, maps the relationship between the control current of the poppet valve, the volume flow and the pressure difference on the control edge of the poppet valve.

[0031] For poppet valves, in particular pilot-controlled poppet valves, it is often difficult to determine the actual volume flow through the poppet valve. At the same time, production-related structural deviations in each poppet valve have a particularly large influence on the actual volume flow through the poppet valve. The method is therefore particularly suitable for simply and cost-effectively generating individual valve characteristic maps for individual poppet valves, in particular in the form of a lookup table.

[0032] Furthermore, the solution to the problem is achieved by a method for embedding an individual hydraulic component characteristic map of an individual hydraulic component, the method comprising the following steps:

[0033] - generating the individual hydraulic element characteristic map according to the above-described method for automatically generating an individual hydraulic element characteristic map for an individual hydraulic element of a hydraulic element type, and

[0034] - embedding the individual hydraulic element characteristic maps in the control units assigned to the individual hydraulic elements.

[0035] Furthermore, the solution to the problem is achieved by a method for controlling an individual hydraulic element, the method comprising the following steps:

[0036] - embedding an individual hydraulic element characteristic map of an individual hydraulic element according to the above-described method for embedding an individual hydraulic element characteristic map of an individual hydraulic element, and

[0037] - controlling the individual hydraulic element based on the individual hydraulic element characteristic map.

[0038] Furthermore, the solution to the problem is achieved by a hydraulic system having an individual hydraulic element and a control unit, wherein the control unit is assigned to the individual hydraulic element and is configured to control the individual hydraulic element, wherein an individual hydraulic element characteristic map of the individual hydraulic element is embedded in the control unit, the individual hydraulic element characteristic map being generated according to the above-described method for automatically generating an individual hydraulic element characteristic map for an individual hydraulic element of one hydraulic element type. In particular, the control unit controls the individual hydraulic element using the individual hydraulic element characteristic map, in particular a lookup table.

[0039] With this hydraulic system, precise individual control of individual hydraulic components can be easily and economically achieved through individual hydraulic component characteristic maps.

[0040] In the hydraulic system, the control unit is preferably integrated into the individual hydraulic elements. This means that the individual hydraulic element characteristic maps can not only be generated during the production of the individual hydraulic elements, but can also be directly embedded in the integrated control unit during the production process. Optionally, the individual hydraulic element characteristic maps can also be subsequently embedded in the control unit assigned to the individual hydraulic elements, for example by downloading them from the Internet. It is also conceivable that the individual hydraulic element characteristic maps embedded in the control unit assigned to the individual hydraulic elements are updated after a certain time, for example, in order to map changes in the individual hydraulic element characteristic maps over time. For example, complete switching cycles can be used to map changes in the individual hydraulic element characteristic maps.

[0041] Preferably, the individual hydraulic element is a hydraulic valve, preferably a lift valve, more preferably a pilot-controlled lift valve, and the individual hydraulic element characteristic diagram is an individual valve characteristic diagram, which maps the relationship between the control current of the hydraulic valve, the volume flow rate and the pressure difference on the control edge of the hydraulic valve, particularly in the form of a lookup table.

[0042] Preferably, the hydraulic system further comprises at least one pressure sensor for determining a current pressure difference on a control edge of the individual hydraulic valve. The control unit applies a control current to the individual hydraulic valve based on the individual valve characteristic map, the current pressure difference and a predetermined volume flow.

[0043] Production-related structural deviations in hydraulic valves often have a particular influence on the actual volume flow through an individual hydraulic valve. Therefore, it is particularly preferred to generate an individual valve characteristic map with reference to the volume flow through the individual hydraulic valve, embed it in the control unit, and use the individual valve characteristic map in conjunction with a specified desired volume flow and a current pressure difference across the individual hydraulic valve to determine the control current with which the control unit must actuate the individual hydraulic valve to achieve the desired volume flow. This provides a simple and cost-effective way of precisely controlling the volume flow in a hydraulic system through the individual hydraulic valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be explained in more detail below with reference to the embodiments shown in the accompanying drawings. The drawings schematically show:

[0045] Figure 1 is a hydraulic system having a plurality of individual hydraulic elements and a control unit according to a first embodiment of the present invention;

[0046] Figure 2 is a hydraulic system having a plurality of individual hydraulic elements and a plurality of control units according to a second embodiment of the present invention;

[0047] Figure 3 is a schematic diagram of an exemplary valve characteristic curve;

[0048] Figure 4 is an exemplary individual valve characteristic map in the form of a lookup table for an individual hydraulic valve; and

[0049] Figure 5 A flow chart of a method according to the invention is shown. DETAILED DESCRIPTION

[0050] Figure 1 A hydraulic system 10 according to a first embodiment of the present invention is shown.

[0051] The hydraulic system 10 comprises a first hydraulic valve V1 and a second hydraulic valve V2, which are two separate hydraulic elements belonging to the same hydraulic valve type. This means that, although the separate first hydraulic valve V1 and the separate second hydraulic valve V2 belong to the same hydraulic valve type, they are each unique due to production-related structural deviations (series variations). In the present example, both the separate first hydraulic valve V1 and the separate second hydraulic valve V2 are pilot-controlled poppet valves. In other words, the hydraulic element type of the separate first hydraulic valve V1 and the second hydraulic valve V2 is a pilot-controlled poppet valve.

[0052] The hydraulic system 10 also includes a control unit C, a hydraulic pump P (configured as a variable displacement pump in this exemplary embodiment), a first hydraulic cylinder device Z1, a second hydraulic cylinder device Z2, a first pressure sensor PS11, a second pressure sensor PS12, a third pressure sensor PS21 and a fourth pressure sensor PS22.

[0053] like Figure 1 Schematically shown by solid lines in FIG, the hydraulic pump P delivers hydraulic fluid for actuating the first hydraulic cylinder device Z1 and the second hydraulic cylinder device Z2. A first hydraulic valve V1 and a separate second hydraulic valve V2 are respectively arranged in the flow path from the hydraulic pump P to the first hydraulic cylinder device Z1 and the second hydraulic cylinder device Z2 to control the actuation of the hydraulic cylinder devices Z1 and Z2.

[0054] Figure 1 The control unit C of the hydraulic system 10 is a central control unit C, which is assigned to the hydraulic pump P, the first hydraulic valve V1 and the second hydraulic valve V2 so as to control them.

[0055] Figure 2 A hydraulic system 10' according to a second embodiment is shown. The hydraulic system 10' is similar to the hydraulic system according to Figure 1 The hydraulic system 10 of the first embodiment in the embodiment differs only in that it comprises a first valve control unit C1, a second valve control unit C2 and a pump control unit CP. The first valve control unit C1 is assigned to the first hydraulic valve V1, the second valve control unit C2 is assigned to the second hydraulic valve V2, and the pump control unit CP is assigned to the hydraulic pump P. In particular, the first valve control unit C1 can be integrated into the individual first hydraulic valve V1, so that the individual first hydraulic valve V1 and the first valve control unit C1 form an integral element, for example, in the form of a valve core. In particular, the second valve control unit C2 can be integrated into the individual second hydraulic valve V2, so that the second hydraulic valve V2 and the second valve control unit C2 form an integral element, for example, in the form of a valve core. The pump control unit CP can also be integrated into the hydraulic pump P. If necessary or desired, the first valve control unit C1, the second valve control unit C2 and the pump control unit CP can be connected to each other directly or through a higher-level control unit (not shown) of the hydraulic system 10' for data transmission between each other.

[0056] To keep it simple, Figure 1 The hydraulic system 10 and Figure 2 Other components of the hydraulic system 10', such as the LS line, the hydraulic oil tank, and the return line to the hydraulic oil tank or other hydraulic valves, are not shown here. Generally, it is clear to those skilled in the art of hydraulics that Figure 1 The hydraulic system 10 and Figure 2The hydraulic system 10' in FIG. 1 is merely an exemplary schematic diagram, and other combinations of individual hydraulic elements of one hydraulic element type (eg, hydraulic valves, hydraulic pumps and / or hydraulic cylinder devices) may also constitute a hydraulic system suitable for the present invention.

[0057] To avoid repetition, the following mainly describes Figure 1 The hydraulic system 10, and only discusses Figure 1 The hydraulic system 10 and Figure 2 The difference between the hydraulic system 10'. Figure 1 The corresponding description of the hydraulic system 10 also applies to Figure 2 The hydraulic system 10'.

[0058] The first pressure sensor PS11 and the second pressure sensor PS12 are assigned to the first hydraulic valve V1 in order to detect the current pressure difference across the individual first hydraulic valve V1. The third pressure sensor PS21 and the fourth pressure sensor PS22 are assigned to the second hydraulic valve V2 in order to detect the pressure difference across the individual second hydraulic valve V2. In the hydraulic system 10, the pressure sensors PS11 to PS22 are also connected to the control unit C for data transmission, but for simplicity, Figure 1 In the hydraulic system 10', for example, the first pressure sensor PS11 and the second pressure sensor PS12 are connected to the first valve control unit C1 for data transmission, and the third pressure sensor PS21 and the fourth pressure sensor PS22 are connected to the second valve control unit C2 for data transmission, but for simplicity, Figure 2 Not shown in FIG.

[0059] For example, if the output pressure of the hydraulic pump P is detected, only the second pressure sensor PS12 and the fourth pressure sensor PS22 need to be provided in the hydraulic system 10, 10' to detect the current pressure difference on the separate first hydraulic valve V1 and the separate second hydraulic valve V2 respectively.

[0060] The piston rod of the first hydraulic cylinder device Z1 will extend at a defined speed. To this end, the volume flow through the separate first hydraulic valve V1 must be precisely controlled. This needs to be achieved through a defined opening of the separate first hydraulic valve V1. To this end, the control unit C applies a defined control current to the separate first hydraulic valve V1 to open the separate first hydraulic valve V1. In addition, the piston rod of the second hydraulic cylinder device Z2 will extend at a defined speed. To this end, the flow through the separate second hydraulic valve V2 must be precisely controlled. This needs to be achieved through a defined opening of the second hydraulic valve V2. To this end, the control unit C places the separate second hydraulic valve V2 under a defined control current to open the separate second hydraulic valve V2.

[0061] Therefore, the control unit C of the first embodiment is assigned to the individual hydraulic valves V1, V2 and is configured to control the individual hydraulic valves V1, V2. To this end, a first individual valve characteristic map for the individual first hydraulic valve V1 and a second individual valve characteristic map for the individual second hydraulic valve V2 are embedded in the control unit C. The first individual valve characteristic map and the second individual valve characteristic map are different from each other and are both generated according to the method for automatically generating individual hydraulic element characteristic maps for individual hydraulic elements of one hydraulic element type described below.

[0062] First, refer to Figure 3 and Figure 4 , described by taking a single valve characteristic diagram of a single hydraulic valve as an example.

[0063] Figure 3 A diagram of the volume flow Q as a function of the control current I is shown. The figure also shows an example of a Q(I) characteristic curve of an individual hydraulic valve (e.g. an individual first hydraulic valve V1 or an individual second hydraulic valve V2). It can be clearly seen from the figure that as the control current I increases, the opening of the individual valves becomes larger and larger, and the flow Q also increases accordingly, until the valves are fully open and the flow reaches a maximum value. It can then be seen that the control current I decreases again. The individual hydraulic valves are then closed and the volume flow Q eventually drops back to zero. This Q(I) characteristic curve of the individual hydraulic valves was recorded under quasi-static conditions, i.e. the control current I increases and decreases slowly. During the entire test, the pressure difference dp across the individual hydraulic valves remained constant. The measured hysteresis of the individual hydraulic valves can be seen in Figure 3 When the control current I increases, the volume flow Q subsequently increases (upward path, Figure 3 When the control current I decreases, the volume flow Q decreases (downward path, Figure 3 In order to generate a lookup table, such as Figure 4 As shown, for example, these hysteresis Q(I) curves are averaged. Depending on how significant the hysteresis effect of the relevant hydraulic valve type is and how high the control accuracy of the individual hydraulic valves of the relevant hydraulic valve type is required, the hysteresis compensation can be performed in individual steps using the directional differentiation method.

[0064] Figure 4 An exemplary illustration of an individual lookup table (individual hydraulic element characteristic map) for an individual first hydraulic valve V1 is then shown. Figure 4 The lookup table in shows the relationship between the volume flow Q and the control current I under different current differential pressure dp conditions. Figure 4 From the lookup table in , it is possible to determine the control current I that must be applied to the individual first hydraulic valve V1 in order to obtain the desired flow Q at the current pressure difference dp and the specified desired flow Q. Figure 4As can be seen from FIG. 1 , the lookup table is a collection of discrete data points, which represents the relationship I=f(Q, dp). The interpolation between the data points enables the control current I to generate a continuous signal without jumps.

[0065] Figure 4 The basis for the lookup table in is a large number of Q(I) characteristic curves of the individual first hydraulic valves V1 recorded at different constant pressure differences dp. For example, if the pressure difference dp in the range of 0 to 300 bar is to be mapped step by step or with a resolution of 10 bar, then Figure 4 As shown in Figure 1, the characteristic curve graph containing 30 Q(I) characteristic curves forms the basis of the lookup table. The characteristic curve graph containing 30 Q(I) characteristic curves maps the relationship Q = f(I, dp). Reversing it can generate a similar Figure 4 A lookup table is created to map the relationship I = f(Q, dp). Previously, to create such a separate lookup table for a single hydraulic valve, 30 full measurements of the single hydraulic valve must be performed to generate 30 Q(I) characteristic curves.

[0066] Refer to the following Figure 5 The method described for automatically generating individual hydraulic element characteristic maps for individual hydraulic elements of a hydraulic element type eliminates the need for time-consuming measurements of each individual hydraulic element. The method is described using the example of an individual first hydraulic valve V1, but can also be applied by analogy to an individual second hydraulic valve V2 or any other individual hydraulic element of a hydraulic element type.

[0067] In step S1 , a virtual simulation model of the valve type to which the individual first hydraulic valve V1 belongs is generated, ie, a virtual simulation model of an ideal pilot-controlled poppet valve of this hydraulic element type.

[0068] In step S2 , structural parameters of the pilot-controlled poppet valve are identified, which structural parameters have an influence on the actual behavior of the pilot-controlled poppet valve due to the series dispersion.

[0069] In step S3, limit values ​​are defined for the identified structural parameters. These limit values ​​correspond to the maximum actual deviations due to the series dispersion. In particular, the limit values ​​correspond to the manufacturing tolerances of the pilot control poppet valve.

[0070] In step S4 , a plurality of different virtual training models are generated by randomly changing the identified structural parameters of the virtual simulation model within a limited range.

[0071] In step S5, a plurality of different valve characteristics of the same type are generated in the form of a lookup table by simulating a defined test sequence on each virtual training model generated. This results in a plurality of different Q(I) characteristics for each virtual training model generated at a plurality of defined pressure differences dp. These Q(I) curves are averaged to obtain a clear correlation between the volume flow Q, the control current I and the pressure difference dp, i.e. to determine the hysteresis effect. The plurality of different Q(I) curves are then inverted to obtain a separate lookup table for each virtual training model generated. In this way, a separate lookup table is generated for each virtual training model created.

[0072] Therefore, in steps S1 to S5, at least a portion of the training data set is generated using a virtual simulation model of the pilot-controlled poppet valve. In particular, in steps S1 to S5, a plurality of different individual lookup tables are simulated and generated, for example, Figure 4 to use as part of the training dataset.

[0073] Alternatively or additionally, in step S6, at least part of the training data set is generated using actual measurements of at least one individual training hydraulic valve of the pilot controlled poppet type. In step S6, a plurality of individual pilot controlled poppet valves are fully measured to generate a plurality of individual lookup tables, e.g. Figure 4 These individual lookup tables will be part of the training dataset.

[0074] Therefore, the training data set includes several different lookup tables of the same type, some of which are generated by simulation on separate virtual training models of pilot-controlled poppet valves and others are generated by full or partial measurements of separate training hydraulic valves.

[0075] In step S7, the training data set generated in this way is used to train the autoencoder. The encoder of the autoencoder receives as input the training data set (i.e., multiple different lookup tables of the same type) and learns encodings based on them. The decoder of the autoencoder then learns to reconstruct the training data set from the encodings. In this way, the autoencoder learns a compressed representation of the training data set.

[0076] In step S8, an individual simplified data set is automatically generated for the individual first hydraulic valve V1. In the present example, a plurality of well-defined measuring points are approached during the final production test of the individual first hydraulic valve V1 and the corresponding characteristic diagram data of the individual valve characteristic diagram to be generated are recorded. In particular, the resulting volume flow Q is measured at a plurality of defined pressure differences dp on the control edge of the individual first hydraulic valve V1 and a plurality of defined currents I of the individual first hydraulic valve V1. The discrete data points obtained in this way from the control current I, the volume flow Q and the pressure difference dp constitute an individual simplified data set for the individual first hydraulic valve V1, which is automatically generated during the final production test of the individual first hydraulic valve V1.

[0077] In step S9, an individual valve characteristic map (see FIG. 1 ) for the individual first hydraulic valve V1 is automatically generated using the trained autoencoder (step S7) and the individual reduced data set (step S8). Figure 4 ). More precisely, the decoder of the autoencoder generates the complete Figure 4 The lookup table shown.

[0078] The method according to steps S1 to S9 can be applied to many other individual pilot-controlled poppet valves, for example, the individual second hydraulic valve V2, in a simple and cost-effective manner. In this way, the trained autoencoder and the automatically generated individual simplified data set can be used to generate individual valve characteristic maps for other individual pilot-controlled poppet valves in a simple and cost-effective manner.

[0079] Finally, in step S10, the individual valve characteristic map of the individual first hydraulic valve V1 is embedded in the control unit C of the hydraulic system 10 or in the first valve control unit C1 of the hydraulic system 10'. The embedding in the control unit C, C1 assigned to the individual first hydraulic valve V1 can be done directly during production, for example if the individual first hydraulic valve V1 is configured as a valve core with an integrated first valve control unit C1, or can also be done subsequently, for example by downloading the characteristic map to the central control unit C of the hydraulic system 10, e.g. Figure 1 shown.

[0080] In step S11 , each control unit C or C1 controls an individual first hydraulic valve V1 using an individual valve characteristic map.

[0081] In this example, the control unit C applies a control current I to the individual first hydraulic valve V1 in order to set a desired volume flow Q through the individual first hydraulic valve V1. The control unit C determines the control current I using the individual valve characteristic diagram of the individual first hydraulic valve V1 in combination with the current pressure difference across the individual first hydraulic valve V1 measured by the pressure sensors PS11 and PS12 and the desired volume flow Q.

[0082] The control unit C, C2 similarly controls the individual second hydraulic valve V2 assigned thereto using the individual valve characteristic diagram of the individual second hydraulic valve V2. The description of the control of the individual first hydraulic valve V1 is equally applicable to the control of the individual second hydraulic valve V2.

[0083] It is also conceivable to repeat steps S1 to S9 after a defined number of switching cycles in order to "adjust" the individual hydraulic element characteristic map or to update the individual hydraulic element characteristic map after the end of a defined number of switching cycles has been completed. In other words, the method according to the invention makes it possible not only to draw a series of dispersion maps, but also to draw individual hydraulic element characteristic maps that age or change over time. The generation of an individual simplified data set (step S8) for an individual hydraulic element (e.g. an individual first hydraulic valve V1) is independent of the manufacturing process of the individual hydraulic element. Thus, for example, in order to draw an aging process map or to apply the method according to the invention to an already produced individual hydraulic element, step S8 can in principle also be (repeatedly) performed after the relevant individual hydraulic element has been put into service.

[0084] Reference numerals list 10, 10' hydraulic system C Control Unit C1 first valve control unit C2 Second Valve Control Unit CP Pump Control Unit PS11 First Pressure Sensor PS12 Secondary Pressure Sensor PS21 Third Pressure Sensor PS22 Fourth Pressure Sensor S1 to S10 method steps V1 first hydraulic valve V2 Second Hydraulic Valve Z1 first hydraulic cylinder equipment Z2 second hydraulic cylinder equipment dp pressure difference I Control current Q Volume flow

Claims

1. A method for automatically generating individual hydraulic element characteristic maps for individual hydraulic elements (V1, V2) of a hydraulic element type, the method comprising the following steps: - (S1 to S5; S6) generating a training data set for said hydraulic element type, -(S7) training an autoencoder using the training data set, - (S8) automatically generating individual simplified data sets for said individual hydraulic elements (V1, V2), and -(S9) automatically generating the individual hydraulic element characteristic map of the individual hydraulic element (V1, V2) using the trained autoencoder and the individual simplified data set.

2. The method according to claim 1, It is characterized in that The training data set includes a plurality of different hydraulic component characteristic maps of the same type, and The creation of the training data set includes the following: - (S1 to S5) generating at least a portion of the training data set using a virtual simulation model of the hydraulic component type, and / or - (S6) generating at least a part of the training data set using actual measurements of at least one individual training hydraulic element of the hydraulic element type.

3. The method according to claim 2, It is characterized in that Generating at least a portion of the training data set using a virtual simulation model includes the following: -(S1) generating a virtual simulation model of the hydraulic component type, (S2) identifying structural parameters of the hydraulic element type which, due to the series dispersion, have an influence on the actual behavior of the hydraulic element type, - (S3) defining limit values ​​for the identified structural parameters, wherein the limit values ​​correspond in particular to the maximum actual deviations resulting from the series dispersion, -(S4) generating a plurality of different virtual training models by randomly changing the identified structural parameters of the virtual simulation model within a limited range, and -(S5) generating a plurality of different hydraulic component characteristic diagrams of the same type by simulating a defined test sequence on each generated virtual training model.

4. The method according to any one of the preceding claims, It is characterized in that The separate simplified data set includes map data of at least one defined measurement point, and The automatic generation of the individual simplified data sets of the individual hydraulic elements (V1, V2) comprises the following: - Automatically recording the characteristic map data of the individual hydraulic element (V1, V2) at the at least one defined measuring point during final production testing of the individual hydraulic element (V1, V2).

5. The method according to any one of the preceding claims, It is characterized in that The individual hydraulic element is a lift valve (V1, V2), in particular a pilot-controlled lift valve (V1, V2), and the individual hydraulic element characteristic diagram is a valve characteristic diagram, which maps the relationship between the control current (I) of the lift valve (V1, V2), the volume flow (Q) and the pressure difference (dp) on the control edge of the lift valve (V1, V2).

6. The method according to any one of the preceding claims, It is characterized in that The individual hydraulic component characteristic maps are configured as look-up tables.

7. A method for embedding a separate hydraulic element characteristic map of a separate hydraulic element (V1, V2), comprising the following steps: - generating the individual hydraulic element characteristic map according to the method for automatically generating an individual hydraulic element characteristic map for an individual hydraulic element (V1, V2) of a hydraulic element type as claimed in any one of the preceding claims, and - (S10) embedding the individual hydraulic element characteristic map into a control unit (C, C1, C2) assigned to the individual hydraulic element (V1, V2).

8. A method for controlling a single hydraulic element (V1, V2), comprising the following steps: - a method for embedding an individual hydraulic element characteristic map of an individual hydraulic element (V1, V2) according to claim 7, embedding an individual hydraulic element characteristic map of an individual hydraulic element (V1, V2), and - (S11) controlling the individual hydraulic components (V1, V2) using the individual hydraulic component characteristic maps.

9. A hydraulic system (10, 10') comprising individual hydraulic elements (V1, V2) and a control unit (C, C1, C2), wherein: The control unit (C, C1, C2) is associated with the individual hydraulic element (V1, V2) and is configured to control the individual hydraulic element (V1, V2), wherein an individual hydraulic element characteristic map of the individual hydraulic element (V1, V2) generated by the method for automatically generating an individual hydraulic element characteristic map for an individual hydraulic element (V1, V2) of a hydraulic element type according to any one of claims 1 to 6 is embedded in the control unit (C, C1, C2).

10. The hydraulic system (10, 10') according to claim 9, It is characterized in that The control unit (C1, C2) is integrated into the individual hydraulic elements (V1, V2).

11. The hydraulic system (10, 10') according to claim 9 or 10, It is characterized in that The individual hydraulic element is a hydraulic valve (V1, V2), and the individual hydraulic element characteristic diagram is an individual valve characteristic diagram. The individual valve characteristic diagram, in particular the individual valve characteristic diagram in the form of a lookup table, maps the relationship between the control current (I) of the hydraulic valve (V1, V2), the volume flow (Q) and the pressure difference (dp) on the control edge of the hydraulic valve (V1, V2).

12. The hydraulic system (10, 10') according to claim 11, It is characterized in that The separate hydraulic valve is a lift valve (V1, V2), in particular a pilot-controlled lift valve (V1, V2).

13. The hydraulic system (10, 10') according to claim 11 or 12, It is characterized in that The hydraulic system (10, 10') further comprises at least one pressure sensor (PS11, PS12, PS21, PS22) for determining a current pressure difference (dp) at the control edges of the individual hydraulic valves (V1, V2), The control unit (C, C1, C2) applies a control current (I) to the individual hydraulic valves (V1, V2) based on the individual valve characteristic diagram, the current pressure difference (dp) and a predetermined volume flow (Q).

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