Controlling pitch angle of rotor blade of wind turbine

Abstract

A method for controlling a pitch angle of a rotor blade (6) of a wind turbine (1) with a hydraulic pitch actuator system (200) is provided. The method comprises: a step of receiving a current pitch signal of the rotor blade (6) and a pitch reference signal indicative of a desired pitch angle of the rotor blade (6); a step of receiving an operating parameter signal (63) from the hydraulic pitch actuator system (200); a step of generating a feedback signal based on the operating parameter signal (63); a step of providing a variable feedback gain using a gain scheduler (150); a step of generating a damping signal based on the feedback signal and the variable feedback gain; a step of generating a pitch control command based on a difference between the current pitch signal and the pitch reference signal and the damping signal; and a step of sending the pitch control command to the hydraulic pitch actuator system (200).

Description

Technical Field

[0001] The present invention relates to a controller for a wind turbine and a method for controlling the pitch angle of rotor blades of such a wind turbine. Background Art

[0002] Wind turbines known in the art include a wind turbine tower supporting a nacelle and a rotor having a plurality (typically three) pitch-adjustable rotor blades mounted thereto. The controller of the wind turbine is configured to adjust the pitch angles of all rotor blades together at once and / or to adjust the pitch angles of only one or more individual rotor blades. By pitching the rotor blades into the wind or downwind, the controller controls the rotational speed of the rotor. The controller may control a hydraulic pitch actuator system having a hydraulic cylinder coupled to the rotor blades. The control may involve opening and closing a proportional valve to extend or retract a piston in the hydraulic cylinder. By this piston movement, the rotor blades rotate about their longitudinal axis, which results in adjustment of their pitch angles. Typically, the controller is tuned to optimize the tracking performance of the pitch control process without compromising pitch position stability.

[0003] Large pitch adjustments can result in jerky movements in the pitch position of the rotor blades. Such large pitch corrections may occur, for example, when switching from part load to full load or when pitching the rotor blades to decelerate the rotor (e.g., in conjunction with stopping the operation of the wind turbine). Jerk movements are also known as "pitch hammering." In some wind turbines, mechanical dampers are provided to avoid such pitch hammering. Alternatively, damping may be provided by adding a damping signal to the pitch control signal, as described, for example, in European patent application EP 3 070 327 A1. The damping signal is based on the pitch angular acceleration, which is obtained by calculating the second derivative of the actual pitch angle value.

[0004] It is against this background that the present invention is set. Summary of the Invention

[0005] According to one aspect of the present invention, a method for controlling the pitch angle of a rotor blade of a wind turbine is provided. The wind turbine includes rotor blades and a hydraulic pitch actuator system operatively coupled to the rotor blades. The method comprises the following steps:

[0006] Receive the current pitch signal θ of the rotor blade,

[0007] Receives a pitch reference signal θ indicating a desired pitch angle for the rotor blades ref ,

[0008] receiving an operating parameter signal from a hydraulic pitch actuator system,

[0009] generating a feedback signal based on the operating parameter signal,

[0010] Use a gain scheduler to provide variable feedback gain,

[0011] generating a damping signal based on the feedback signal and a variable feedback gain,

[0012] Based on the current pitch signal θ and the pitch reference signal θ ref and generating a pitch control command based on the damping signal, and

[0013] Pitch control commands are sent to the hydraulic pitch actuator system.

[0014] The inventors have recognized that pitch hammer can be caused by sudden changes in the hydraulic pitch actuator system and the complex dynamics of the hydraulic fluid generated in the reconfigured hydraulic system. Due to these sudden changes, oscillations can occur at specific frequencies, depending on the system characteristics of the hydraulic pitch actuator system. According to the present invention, an operating parameter signal from the hydraulic pitch actuator system is used to generate a feedback signal that is fed back into the pitch control algorithm. A gain scheduler is used to ensure that a balance is found between optimal tracking performance and stability of the pitch control process. The gain scheduler ensures that damping is applied only when and to the required extent.

[0015] According to various embodiments of the present invention, the variable feedback gain depends on at least one of the following:

[0016] - Current pitch signal θ,

[0017] - Pitch reference signal θ ref ,

[0018] -Current pitch error ε,

[0019] - Current pitch rate,

[0020] - the position of the pitch control piston of the hydraulic pitch actuator system,

[0021] - rate of change of the pitch control piston position,

[0022] - wind speed,

[0023] - rotor speed or generator speed, and

[0024] - The operational status of the wind turbine.

[0025] For example, the gain scheduler may be designed such that the damping signal provides the strongest damping effect when the rotor blades are pitched to near a complete stop and / or near full load, while applying no damping or minimal damping at part load. Alternatively, when the pitch error increases, i.e., when the current pitch signal (θ) is closer to the pitch reference signal (θ), the gain scheduler may be designed such that the damping signal provides the strongest damping effect when the rotor blades are pitched to near a complete stop and / or near full load, while applying no damping or minimal damping at part load. ref ) increases, or when rapid pitch changes are applied. For example, the pitch value and pitch value changes can be measured using linear or rotational position and / or acceleration sensors coupled to the rotor blades, or using sensors that monitor the position or movement in the hydraulic actuators used to adjust the pitch angle. There may also be certain operating ranges where stronger damping is required than in other operating ranges. For example, it may be beneficial to apply stronger damping at rotor speeds lower than the rated rotor speed. The rotor speed can be used as an indicator of the operating state, and stronger damping may be required for states with lower rotational speeds, such as service or safety states. The rotor speed can be used as the rotor speed itself or as the generator speed. In another embodiment, the feedback gain can be set based on the operating state of the wind turbine. In this embodiment, for a given operating state, the feedback gain can be set to a specific value, for example, zero for an operating state where the damping signal is not enabled and one for an operating state where the damping signal is fully enabled. In embodiments where the gain scheduling is based on more than one operating parameter signal, the combined gain can be determined by multiplying the individual gains from selected operating parameter signals. In this way, full enablement of gain scheduling based on a given operating state may still result in a gain value below 1 if gain scheduling based on another operating parameter signal is additionally used.

[0026] Preferably, the operating parameter signal is a pressure signal from the hydraulic pitch actuator system. The pressure signal may, for example, indicate the pressure in a chamber of a hydraulic actuator of the hydraulic pitch actuator system, or the pressure difference between two chambers of the hydraulic actuator. Such a pressure signal provides a direct indication of oscillations and hydraulic disturbances occurring in the hydraulic pitch actuator system and is therefore a very suitable input signal for determining the effective damping signal.

[0027] In some embodiments, the generation of the feedback signal can include applying a high-pass filter to the operating parameter signal. The high-pass filter can help ensure that only high-frequency fluctuations in hydraulic pressure and oscillations of rotor blade pitch are damped, while lower-frequency adjustments to the pitch angle remain unchanged. The high-pass filter acts as an observer for the dynamic portion of the operating parameter signal and ensures that the feedback signal provided to the gain scheduler is independent of the absolute value of the operator parameter signal representing the state of the hydraulic pitch actuator system. Alternatively, instead of a high-pass filter, a combination of a differentiator and a low-pass filter, an observer that provides a time derivative of the hydraulic pressure, or any other algorithm that mimics a high-pass filter can be used.

[0028] When a high-pass filter is used, the corner frequency of the high-pass filter may depend, as well as the variable feedback gain, on at least one of the following:

[0029] - Current pitch signal θ,

[0030] - Pitch reference signal θ ref ,

[0031] -Current pitch error ε,

[0032] - Current pitch rate,

[0033] - the position of the pitch control piston of the hydraulic pitch actuator system,

[0034] - rate of change of the pitch control piston position,

[0035] - wind speed,

[0036] - rotor speed or generator speed, and

[0037] - The operational status of the wind turbine.

[0038] Tuning the corner frequency of the high pass filter according to this and other conditions can help provide optimal damping performance for the most prevalent oscillation frequencies in the rotor blades and hydraulic pitch actuator system.

[0039] In a preferred embodiment, a proportional valve in a hydraulic pitch actuator system is controlled according to the pitch control command. While rapid opening and closing of such a proportional valve can cause oscillations in the hydraulic pressure and corresponding mechanical oscillations in the rotor blades, the inventors have discovered that the damping signal provided according to the present invention effectively counteracts such oscillations. This enables smooth and accurate adjustment of the rotor blade pitch angle.

[0040] The step of generating a pitch control command may, for example, include comparing the current pitch signal θ with the pitch reference signal θ ref The difference between is fed to the pitch reference controller, and a damping signal is added to the output of the pitch reference controller. The pitch reference controller preferably uses a form of deadband compensation. By adding the damping signal to the output of the pitch reference controller, rather than directly to the pitch error, it is ensured that the deadband compensation does not reduce the intended effect of the damping signal. In an embodiment, the pitch reference controller is a proportional (P) controller, a PI controller, or a PID controller. It may be beneficial to implement the pitch reference controller as a proportional controller, but a PI controller or a PID controller may be used as an alternative to a proportional controller. A P controller may be beneficial in providing a fast response.

[0041] According to another aspect of the present invention, a controller for a wind turbine is provided. The wind turbine includes rotor blades and a hydraulic pitch actuator system operably coupled to the controller and the rotor blades for controlling the pitch angle of the rotor blades. The controller is configured to perform the method described above.

[0042] According to yet another aspect of the present invention, there is provided a wind turbine comprising such a controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Examples of the present invention will now be described with reference to the accompanying drawings, in which:

[0044] Figure 1 A wind turbine is illustrated schematically.

[0045] Figure 2 A block diagram of a pitch control system according to an embodiment of the present invention is shown.

[0046] Figure 3 A block diagram of a pitch control system according to an alternative embodiment of the present invention is shown.

[0047] Figure 4 Schematically shows that Figure 2 and Figure 3 The scheduling algorithm used in the pitch control system.

[0048] Figure 5 Some test signal values ​​are shown during a pitch adjustment operation in a wind turbine not using the present invention.

[0049] Figure 6 Some test signal values ​​are shown during a pitch adjustment operation in a wind turbine using the present invention. DETAILED DESCRIPTION

[0050] Figure 1 An example of a wind turbine 1 is illustrated in a schematic diagram. The wind turbine 1 includes a tower 2, a nacelle 3 disposed at the top or end of the tower 2, and a rotor 4 operatively coupled to a generator housed within the nacelle 3. In addition to the generator, the nacelle 3 houses other components required to convert wind energy into electrical energy, as well as various components required to operate, control, and optimize the performance of the wind turbine 1. The rotor 4 of the wind turbine 1 includes a central hub 5 and three rotor blades 6 projecting outwardly from the central hub 5. In addition, the wind turbine 1 includes a control system or controller 100 (in FIG. Figure 1Controllers (not shown) can be located inside nacelle 3, in tower 2, or distributed at several locations inside (or outside) turbine 1 and communicatively connected to one another. Rotor blades 6 are individually pitch-adjustable, but can also be adjusted according to a common pitch setting, where each blade is set to the same pitch value. The rotational speed of rotor 4 can be increased by pitching rotor blades 6 into the wind, or reduced by pitching them downwind.

[0051] Figure 2 : A block diagram of a pitch control system according to an embodiment of the present invention is shown. The pitch control system includes a controller 100 configured to receive a current pitch signal θ from a pitch sensor 61 coupled to a rotor blade 6. The controller 100 also receives a pitch reference signal θ indicating a desired pitch angle of the rotor 6. ref . The subtractor 110 can then use these two signals to calculate the pitch error ε. Based on the pitch error, the pitch control command is calculated using a pitch reference controller 120, which has the function of minimizing any pitch error from the reference. In a preferred embodiment, the pitch reference controller is implemented as a proportional controller, which utilizes some form of deadband compensation to prevent oscillations and unnecessary pitch adjustments when the pitch error is very small. In other embodiments, a PI controller or a PID controller may be used as an alternative to the proportional controller. Figure 2 In FIG, deadband compensation is shown as part of the pitch reference controller, but in embodiments may be implemented as a dedicated computation block placed at the input side or the output side of the pitch reference controller.

[0052] The pitch control command instructs the hydraulic pitch actuator system 200 to control the hydraulic actuator 210 to adjust the pitch angle of the rotor blade 6 and reduce the difference between the current pitch signal θ and the pitch reference signal θ ref The difference between the two. Hydraulic actuator 210 can be, for example, a hydraulic cylinder whose piston rod or barrel is mounted to the rotor blade 6 and whose other side is mounted to the central hub 5. Controlling hydraulic actuator 210 can involve opening and closing a proportional valve to extend or retract its piston. With this piston movement, rotor blade 6 rotates about its longitudinal axis, which results in adjustment of its pitch angle. Typically, controller 100 is tuned to optimize the tracking performance of the pitch control process without compromising pitch position stability.

[0053] In existing pitch control systems, it has been observed that large pitch adjustments can cause jerky movements in the pitch position of rotor blades 6. Such large pitch corrections can occur, for example, when switching from part load to full load or when pitching rotor blades 6 to stop wind turbine operation. This phenomenon is also known as "pitch hammer." One possible cause of such jerky movements can be the rapid opening or closing of a proportional valve, which can lead to oscillations in the hydraulic pressure and corresponding mechanical oscillations in rotor blades 6.

[0054] According to one embodiment of the present invention, such pitch hammer is avoided or at least significantly reduced by introducing a feedback loop that uses an operating parameter signal from hydraulic pitch actuator system 200 to generate a damping signal that is used to correct the initial undamped pitch control command. By adding the damping signal to the output of pitch reference controller 120, and not directly to the pitch error, it is ensured that any deadband compensation that may be used does not reduce the intended effect of the damping signal.

[0055] The operating parameter signal may be, for example, a pressure signal from the hydraulic pitch actuator system 200. The pressure signal may be proportional to the pressure in a chamber of the hydraulic actuator 210 of the hydraulic pitch actuator system 200, or to the pressure difference between two chambers of the hydraulic actuator 210. Such a pressure signal provides a direct indication of the oscillations and hydraulic disturbances occurring in the hydraulic pitch actuator system 200 and is therefore a very suitable input signal for determining the effective damping signal. Other signals representing aspects of the fluid dynamics and changes in the fluid dynamics in the hydraulic pitch actuator system 200 may alternatively be used as the operating parameter signal to be fed into the feedback loop. Alternatively, a pitch signal or a pitch error signal, both of which are directly related to the position of the hydraulic actuator 210, may be used as the operating parameter signal.

[0056] Preferably, only the dynamic portion of the pressure signal, or any other operating parameter signal being used, is used as the basis for generating the damping signal. For example, the high-pass filter 140 can process the pressure signal to ensure that only high-frequency fluctuations in the hydraulic pressure and oscillations of the rotor blade pitch are damped, while the lower-frequency adjustments of the pitch angle remain unchanged. The high-pass filter 140 acts as an observer for the dynamic portion of the operating parameter signal and ensures that the feedback signal used to generate the damping signal is independent of the absolute value of the pressure signal. Alternatively, instead of the high-pass filter 140, a combination of a differentiator and a low-pass filter, an observer that provides the time derivative of the hydraulic pressure, or any other algorithm that mimics the high-pass filter 140 can be used.

[0057] The corner frequency of high-pass filter 140 may depend on one or more parameters related to the pitch angle of rotor blades 6, the configuration of hydraulic pitch actuator system 200, weather conditions, wind turbine power output, or other relevant aspects of the operation of wind turbine 1. A predetermined formula or lookup table may be used to determine a suitable corner frequency based on one or more of these parameters. The corner frequency of high-pass filter 140 may depend, for example, on at least one of the following:

[0058] - Current pitch signal θ,

[0059] - Pitch reference signal θ ref ,

[0060] -Current pitch error ε,

[0061] - Current pitch rate,

[0062] - the position of the pitch control piston of the hydraulic pitch actuator system,

[0063] - rate of change of the pitch control piston position,

[0064] - wind speed,

[0065] - rotor speed or generator speed, and

[0066] - The operational status of the wind turbine.

[0067] Tuning the corner frequency of the high pass filter in accordance with this situation can help provide optimal damping performance for the most prevalent oscillation frequencies in the rotor blades 6 and the hydraulic pitch actuator system 200. Figure 2 In the embodiment shown, the pitch reference signal θ ref Serves as a basis for determining the corner frequency of the high-pass filter 140. Figure 3 In the alternative embodiment shown, the current pitch signal θ determines the corner frequency.

[0068] Gain scheduler 150 provides a variable feedback gain that may depend on one or more parameters related to the pitch angle of rotor blades 6, the configuration of hydraulic pitch actuator system 200, weather conditions, wind turbine power output, or other relevant aspects of wind turbine 1 operation. Based on the variable feedback gain from gain scheduler 150 and the feedback signal from high-pass filter 140 or a surrogate observer of the dynamic portion of the operating parameter signal, amplifier 160 generates a damping signal. The damping signal is then added by adder 160 to produce a damped pitch control command. Finally, the damped pitch control command is sent to hydraulic pitch actuator system 200 to allow pitch errors to be corrected with minimal undesirable oscillations.

[0069] Therefore, the purpose of the variable feedback gain is to dampen the initial pitch control command from the pitch reference controller 120 only if pitch hammer occurs or is expected to occur. Therefore, the gain scheduler 150 is used to ensure a balance between optimal tracking performance and stability of the pitch control process. Damping is applied only when and to the required extent.

[0070] Figure 4 Schematically shows that Figure 2 and Figure 3 The scheduling algorithm 40 used in the pitch control system of the exemplary scheduler is shown in FIG. In this exemplary scheduler, the variable feedback gain depends on the pitch reference signal θ ref ( Figure 2 ) or the current pitch signal θ( Figure 3 ). Up to a first pitch (reference) angle θ1, the variable feedback gain is minimum (i.e., zero or some low base value) and the damping will be minimal, resulting in a high responsiveness of the damping algorithm. As the pitch (reference) angle becomes higher, the variable feedback gain begins to increase and the damping becomes stronger. Starting from a second pitch (reference) angle θ2, the variable feedback gain is at its maximum value, e.g., 1, and maximum damping is applied.

[0071] In other embodiments, the scheduling algorithm 40 may be, for example, nonlinear and / or dependent on more than one variable. The variables defining the variable feedback gain may include one or more parameters related to the pitch angle of the rotor blades 6, the configuration of the hydraulic pitch actuator system 200, weather conditions, wind turbine power output, or other relevant aspects of the operation of the wind turbine 1. A predetermined formula or lookup table may be used to determine an appropriate variable feedback gain based on one or more of these parameters. The variable feedback gain may, for example, depend on at least one of the following:

[0072] - Current pitch signal (θ),

[0073] - pitch reference signal (θ ref ),

[0074] - Current pitch error,

[0075] - Current pitch rate,

[0076] - the position of the pitch control piston of the hydraulic pitch actuator system,

[0077] - rate of change of the pitch control piston position,

[0078] - wind speed,

[0079] - rotor speed or generator speed, and

[0080] - The operational status of the wind turbine.

[0081] For example, the gain scheduler 150 can be designed so that the damping signal provides the greatest damping effect when the rotor blades 6 are pitched to a near-full stop and / or near full load, while applying no damping or minimal damping in a partially loaded configuration. Alternatively, damping can be increased as pitch error increases or when rapid pitch changes are applied. For example, the pitch value and pitch value change can be measured using linear or rotational position and / or acceleration sensors coupled to the rotor blades 6, or using sensors that monitor the position or movement of the hydraulic actuator 210 to adjust the pitch angle.

[0082] Figure 4A piecewise linear function is shown, but the gain function can also be implemented as a smooth function or a step function. For example, if the input variable is the operating state, the gain can be set to a given value based on the operating state, such as zero for a state where gain scheduling is not enabled and one for a state where gain scheduling is fully enabled.

[0083] Figure 5 Some test signal values ​​51 , 52 , 53 are shown during a pitch adjustment operation in a wind turbine 1 without the present invention. Figure 5 The top graph in FIG shows what the pitch signal, or pitch reference signal 51, looks like when the rotor blades 6 are pitched from a pitch angle of approximately 70° to a pitch angle of 0° and back to 70° over a total period of just under 70 seconds. The second graph shows what the pitch error signal 52 looks like during this transition. Pitch error signal 52 indicates that, in this test for this particular wind turbine 1, the actual pitch angle typically lags slightly (less than 1°) behind the pitch reference while the pitch angle is being adjusted, and is close to or equal to 0° when the rotor pitch angle is held constant. It can be seen from this pitch error signal 52 that the rotor blade pitch begins to oscillate as the rotor 5 approaches or moves away from a complete stop. In the third graph, which shows a pressure signal 53 from one of the chambers of hydraulic actuator 210, it can be seen that these rotor blade pitch oscillations occur simultaneously with the oscillations in pressure signal 53. This pressure signal 53, or any other suitable operating parameter signal from hydraulic pitch actuator system 200, can be used as an input to the feedback loop that provides the damping signal of the present invention.

[0084] Figure 6 Some test signal values ​​are shown during a pitch adjustment operation in a wind turbine 1 using the present invention. As shown by the pitch or pitch reference signal 61, the same pitch rate of approximately 3° per second is performed. Figure 5 The same pitch adjustment as shown in the test. Figure 6 It can be seen from the pitch error signal 62 that the damping provided by the present invention effectively removes the Figure 5 2. Rotor blade pitch oscillations observed in the pitch error signal 52 of the undamped test. As can be observed in the pressure signal 63 from one of the chambers of the hydraulic actuator 210, the damping provided in accordance with the present invention ensures more stable fluid dynamics in the hydraulic pitch actuator system 200.

Claims

1. A method for controlling the pitch angle of a rotor blade (6) of a wind turbine (1), the wind turbine (1) comprising the rotor blade (6) and a hydraulic pitch actuator system (200) operatively coupled to the rotor blade (6), the method comprising: receiving a current pitch signal (θ) of the rotor blade (6), receiving a pitch reference signal (θ) indicating a desired pitch angle for the rotor blades (6) ref ), receiving an operating parameter signal (63) from the hydraulic pitch actuator system (200), generating a feedback signal based on the operating parameter signal (63), Using a gain scheduler (150) to provide a variable feedback gain, generating a damping signal based on the feedback signal and the variable feedback gain, Based on the current pitch signal (θ) and the pitch reference signal (θ ref ) and generating a pitch control command based on the damping signal, and The pitch control command is sent to the hydraulic pitch actuator system (200).

2. The method according to claim 1, wherein The variable feedback gain depends on at least one of the following: - the current pitch signal (θ), - the pitch reference signal (θ ref ), -Current pitch error (ε), - Current pitch rate, - the position of the pitch control piston of the hydraulic pitch actuator system (200), - the rate of change of the position of the pitch control piston, - wind speed, - rotor speed or generator speed, and - The operational status of the wind turbine.

3. The method according to claim 1 or 2, wherein: The operating parameter signal (63) is a pressure signal (63) from the hydraulic pitch actuator system (200).

4. The method according to claim 3, wherein: The pressure signal (63) indicates the pressure in a chamber of a hydraulic actuator of the hydraulic pitch actuator system (200), or indicates the pressure difference between two chambers of the hydraulic actuator (210).

5. The method according to claim 1 or 2, wherein: The current pitch signal (θ) or the current pitch error signal (ε) is the operating parameter signal.

6. The method according to any one of the preceding claims, wherein The generation of the feedback signal includes applying a high pass filter (140) to the operating parameter signal (63).

7. The method according to claim 6, wherein: The corner frequency of the high-pass filter (140) depends on at least one of the following: - the current pitch signal (θ), - the pitch reference signal (θ ref ), -Current pitch error (ε), - Current pitch rate, - the position of the pitch control piston of the hydraulic pitch actuator system (200), - the rate of change of the position of the pitch control piston, - wind speed, - rotor speed or generator speed, and - The operational status of the wind turbine.

8. The method according to any one of claims 1 to 5, wherein: The generation of the feedback signal comprises applying to the operating parameter signal (63) a combination of a differentiator and a low-pass filter or an observer providing a time derivative of the hydraulic pressure.

9. The method according to any one of the preceding claims, further comprising: A proportional valve in the hydraulic pitch actuator system (200) is controlled according to the pitch control command.

10. The method according to any one of the preceding claims, wherein The step of generating a pitch control command comprises: converting the current pitch signal (θ) and the pitch reference signal (θ ref ) is fed to a pitch reference controller (120), and the damping signal is added to the output of the pitch reference controller (120).

11. The method according to claim 10, wherein: The pitch reference controller (120) uses deadband compensation.

12. A controller (100) for a wind turbine (1), the wind turbine (1) comprising rotor blades (6) and a hydraulic pitch actuator system (200), the hydraulic pitch actuator system (200) being operatively coupled to the controller (100) and to the rotor blades (6) for controlling the pitch angle of the rotor blades (6), the controller (100) being configured to perform the method according to any of the preceding claims.

13. A wind turbine (1) comprising a controller (100) according to claim 12.

14. A non-transitory computer-readable storage medium having stored thereon instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of claims 1 to 11.

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