System and method for blade pitch control of cycloidal marine propulsion system

Abstract

A blade pitch control system for a cycloidal marine propulsion system is provided. A cycloidal marine vessel propulsion system includes a rotating wheel and a plurality of rotating blades attached to the rotating wheel and individually rotatable relative to the rotating wheel. The blade pitch control system includes: at least one rotating wheel position sensor configured to provide a sensor signal indicative of a measured position of a rotating wheel; a wheel position estimation unit configured to determine an estimated position of the rotating wheel based on a sensor signal of the at least one rotating wheel position sensor; and a blade pitch determination unit configured to determine a blade pitch set point of at least one of the plurality of rotating blades based on the estimated position of the rotating wheel. Determining the estimated position of the rotating wheel includes data processing of the sensor signals.

Description

Systems and methods for blade pitch control in cycloidal ship propulsion systems Technical Field

[0001] Embodiments of this disclosure relate to a system for controlling the blade pitch in a cycloidal ship propulsion system. Further embodiments relate to a method for controlling the blade pitch in a cycloidal ship propulsion system. Background Technology

[0002] Cycloidal propulsion systems provide an efficient means of propelling seagoing vessels. Furthermore, they enhance the maneuverability of the vessel. In a cycloidal propulsion system, a rotating wheel with rotatable blades attached to a rotating impeller provides thrust. The direction and magnitude of the thrust can be controlled via the rotational speed of the impeller and the pitch of the rotatable blades. In a cycloidal propulsion system, the pitch of the rotating blades can be controlled individually. The pitch of the rotating blades is determined based on the position of the impeller. For the effective operation of a cycloidal propulsion system, ensuring the correct pitch of each rotating blade at each position of the impeller is crucial. Specifically, the pitch of the rotating blades is controlled based on the position of the impeller.

[0003] The position of the cycloidal propulsion system is typically determined by at least one position sensor. The sensor signal from at least one position sensor, indicating the measured position of the cycloidal propulsion system, is used to set the blade pitch setpoint or blade pitch function. Inaccuracy in the sensor signal causes it to incorrectly represent the position of the cycloidal propulsion system, which can lead to inaccurate blade pitch setting and, consequently, reduced efficiency, interference, and increased wear and breakage in cycloidal propulsion systems. Summary of the Invention

[0004] In view of the above, this disclosure relates to a blade pitch control system for a cycloidal ship propulsion system, and a method for determining the blade pitch setpoint of the rotating blades of the cycloidal ship propulsion system.

[0005] According to one aspect of this disclosure, a blade pitch control system for a cycloidal ship propulsion system is provided. The cycloidal ship propulsion system includes a rotating wheel and a plurality of rotating blades attached to and individually rotatable relative to the rotating wheel. The blade pitch control system includes: at least one rotating wheel position sensor configured to provide a sensor signal indicating a measured position of the rotating wheel; a wheel position estimation unit configured to determine an estimated position of the rotating wheel based on the sensor signal from the at least one rotating wheel position sensor; and a blade pitch determination unit configured to determine a blade pitch setpoint for at least one of the plurality of rotating blades based on the estimated position of the rotating wheel. Determining the estimated position of the rotating wheel includes data processing of the sensor signal.

[0006] According to another aspect of this disclosure, a cycloidal ship propulsion system is provided, comprising a rotary wheel, a plurality of rotating blades attached to the rotary wheel and rotatable individually relative to the rotary wheel, and a blade pitch control system according to any of the embodiments described herein.

[0007] According to another aspect of this disclosure, a marine vessel is provided that includes a cycloidal propulsion system, the cycloidal propulsion system including a blade pitch control system according to any of the embodiments described herein.

[0008] According to another aspect of this disclosure, a method is provided for determining the blade pitch setpoint of a rotating blade in a cycloidal ship propulsion system. The cycloidal ship propulsion system includes a rotating wheel and a plurality of rotating blades attached to and individually rotatable relative to the rotating wheel. The method includes receiving a sensor signal indicating a measured position of the rotating wheel from at least one rotating wheel position sensor; determining an estimated position of the rotating wheel based on the sensor signal from the at least one rotating wheel position sensor; and determining the blade pitch setpoint of at least one of the plurality of rotating blades based on the estimated position of the rotating wheel. Determining the estimated position of the rotating wheel includes data processing of the sensor signal.

[0009] According to another aspect of this disclosure, a method for controlling a cycloidal ship propulsion system is provided, the method using blade pitch information obtained from a blade pitch control system according to any of the embodiments described herein.

[0010] According to some embodiments, the cycloidal propulsion system is configured to propel seagoing vessels. Seagoing vessels include ocean-going or inland vessels. Specifically, seagoing vessels include steamships and small boats. In some embodiments, seagoing vessels include ferries, particularly single- and double-boom ferries, cruise ships, water buses, and yachts. In some embodiments, seagoing vessels include offshore energy vessels, particularly service operation vessels (SOVs), cable-laying vessels (CLVs), foundation installation vessels (FIVs), offshore construction vessels (OCVs) and support vessels (OSVs), platform supply vessels (PSVs), and anchor handling tug supply vessels (AHTSs). In some embodiments, seagoing vessels include research and survey vessels or other special-purpose vessels. According to some embodiments, seagoing vessels include merchant ships, particularly merchant ships used for transporting cargo.

[0011] A seagoing vessel includes a hull. According to some embodiments, a rotating wheel is attached to the hull of the seagoing vessel, particularly at the bottom of the hull. In some embodiments, the hull includes a recess. Specifically, the recess of the hull is configured to receive the rotating wheel of a cycloidal propulsion system. The rotating wheel typically rotates relative to the hull of the seagoing vessel. The position of the rotating wheel relative to the hull can be indicated by the polar angle of the rotating wheel relative to the hull. In particular, a default configuration can be defined by a polar angle of 0°, and the rotation of the rotating wheel can be associated with a polar angle measured relative to the default configuration. In some embodiments, the default configuration can be fixed. In some embodiments, the default configuration can be initially defined at a certain point in time and can be redefined at regular time intervals upon request from the operator of the cycloidal propulsion system and / or after the rotating wheel begins to move.

[0012] Multiple electrically driven rotating blades are attached to a rotating wheel. Specifically, two, three, four, five, six, or more rotating blades may be attached to the rotating wheel. The rotating blades are rotatable relative to the rotating wheel. In particular, each rotating blade can rotate individually relative to the rotating wheel. In other words, each of the multiple rotating blades can be controlled individually, particularly the pitch of each rotating blade. For each rotating blade, the rotating wheel includes a rotating blade electric motor that drives the corresponding rotating blade. In some embodiments, the pitch of the multiple rotating blades can be adjusted without angular limitations. In particular, the multiple rotating blades can rotate at least 360 degrees. The rotating wheel includes multiple recesses to receive the multiple electrically driven rotating blades.

[0013] A blade pitch control system controls the blade pitch of at least one rotating blade. Typically, a blade pitch control system controls the blade pitch of each rotating blade. A blade pitch control system may include multiple subsystems, specifically one subsystem for each rotating blade. Typically, a blade pitch control system is an integrated system that controls the blade pitch of at least one rotating blade within an integrated controller, exemplarily in a programmable logic controller.

[0014] A blade pitch control system includes at least one rotor position sensor. In some embodiments, the blade pitch control system includes multiple rotor position sensors, particularly at least 2, 3, 4, 5, 8, or more sensors. At least one rotor position sensor may include a magnetic rotation sensor, a rotary variable differential transformer, or a rotary potentiometer. The rotor position sensor may be substantially arranged on the axis of rotation of the rotor. In some embodiments, the rotor sensor may be configured to sense the presence of a signaling device in its vicinity. Exemplarily, the rotor sensor may be fixedly positioned, with the rotor passing over it. The rotor sensor may be configured to sense the presence of at least one signaling device attached to the rotor. The sensing signal sensed by the at least one signaling device may indicate a specific polar angle of the rotor. Blade pitch control systems including multiple rotor sensors typically include multiple rotor sensors of different types. Having multiple different types of rotor sensors can advantageously allow for compensation of the disadvantages of a particular rotor sensor type.

[0015] At least one rotating wheel position sensor is configured to provide a sensor signal indicating the measured position of the rotating wheel. The sensor signal may include direct rotational position information, i.e., polar angle, or the sensor signal may include a sensor output that must be converted to indicate the measured position of the rotating wheel; exemplary, the sensor output may include voltage or current. The sensor signal may include analog or digital signals.

[0016] In some embodiments, the sensor signal may include additional sensor information, such as sensor status, exemplarily whether the sensor is operating, a timestamp, or a sensor identification signal. The sensor signal may be provided continuously or intermittently. Specifically, the sensor signal may be provided after a predetermined change in the position of the rotating wheel or at regular time intervals. Exemplarily, the sensor signal may be provided at least once every 10 microseconds, every 50 microseconds, every 200 microseconds, every 1 millisecond, or every 5 milliseconds.

[0017] Based on sensor signals from at least one rotating wheel position sensor, the wheel position estimation unit determines the estimated position of the rotating wheel. Determining the estimated position includes data processing of the sensor signals. Specifically, data processing may include editing, selecting, deleting, merging, verifying, or aggregating the sensor signals. Data processing of the sensor signals can advantageously allow for improved data quality of the sensor signals and reduce the impact of noise or interruptions in data transmission on the blade pitch setpoint.

[0018] The estimated position of the rotating wheel, determined by the wheel position estimation unit, is based on sensor signals. Data processing of the sensor signals advantageously allows for improved signal quality, thereby providing an estimated position that better represents the actual position of the rotating wheel compared to the sensing signal indicating the measured position. Specifically, errors in the sensing signal, which may originate from sensor noise or communication interruptions between at least one rotating wheel position sensor and the wheel position estimation unit, can be ignored and / or corrected. The estimated position of the rotating wheel provides an improved basis for determining the blade pitch setpoint of at least one of a plurality of rotating blades. In particular, the estimated position of the rotating wheel can provide a smoother and more continuous signal.

[0019] In some embodiments, data processing of the sensor signals includes the storage, i.e., recording, of the sensor signals. Specifically, the sensor signals may be stored by a blade pitch determination unit. Storage may include, exemplarily, temporary storage in volatile computer memory, or exemplarily, non-temporary permanent storage in non-volatile computer memory. Recording of the sensor signals may include recording over time, particularly within a predetermined period of time, exemplarily within at least 200 microseconds, 1 millisecond, 5 milliseconds, 50 milliseconds, 500 milliseconds, 1 second, or 10 seconds. Recording of the sensor signals may include recording within at least one rotation cycle. Exemplarily, the sensor signals may be recorded over 1, 2, 3, 4, 5, 8, 10, 50, 100, or more rotation cycles. The wheel position estimation unit may utilize the stored or recorded sensor signals to advantageously identify patterns in the sensor signals. In particular, recurring irregularities in the sensor signals may be identified. Exemplarily, irregularities in the sensor signals may occur at specific locations on the rotating wheel or at specific frequencies, particularly in the time domain. Identifying such patterns may advantageously allow the identification of noise sources or interruption sources in the sensor signals. Therefore, data processing can be performed on the sensor signal to remove noise or interruptions identified in the sensor signal, thereby providing an estimated position of the rotating wheel.

[0020] In some embodiments, data processing includes smoothing the sensor data. Specifically, the sensor data may be averaged over a predetermined time period. Exemplarily, the sensor data may be averaged over 200 microseconds, 1 millisecond, 5 milliseconds, 50 milliseconds, 500 milliseconds, or 1 second. The sensor data may be averaged as a moving average. Typically, the stored sensor data may be smoothed. Averaging the sensor data can particularly allow for reduction of the effects of random noise superimposed on the sensor signal, and more particularly, the effects of random noise superimposed on the measurement position of the rotating wheel.

[0021] In some embodiments, data processing includes filtering sensor data. Filtering sensor data can also result in smoothing of the sensor data. In some embodiments, filtering may be selected to achieve smoothing of the sensor data. Filtering sensor signals may include applying a filter to at least a portion of the sensor signal. Typically, stored sensor data may be filtered. Filtering sensor signals may include applying a phase-locked loop (PLL), Kalman filter, fast Fourier transform (FFT) filter, low-pass filter, Savitzky-Golay filter, median filter, percentile filter, or particle filter. Filtering sensor signals may include information containing settings about the rotor. In particular, the frequency range of the filter may be selected based on the rotor's rotational frequency. The blade pitch control system may communicate with the rotor controller or cycloidal propulsion system controller to receive information about the rotor's rotational frequency and / or rotational frequency setpoint. In typical embodiments, filtering sensor signals may particularly allow for the reduction or removal of random noise covering the sensor signal. Filtering sensor signals, particularly using filters optimized for shot noise (e.g., percentile filters), may allow for the reduction or elimination of inaccuracies in the sensor signal originating from transmission errors, exemplarily originating from transmission losses in the sensor signal.

[0022] In some embodiments, data processing includes extrapolation of sensor data. Specifically, the future position of the rotating wheel can be estimated based on its current and / or past position. Typically, extrapolation involves employing a mathematical model of the rotating wheel, particularly a mathematical model of its rotation. In particular, extrapolation involves fitting one or more mathematical functions to the sensor signal. Exemplarily, the mathematical function may include a sine function or an nth-degree polynomial. The mathematical function includes at least one variable determined by the fitting process. The function determined by the fitting can be extrapolated to estimate the estimated future position of the rotating wheel. In some embodiments, the function determined by the fitting can be extrapolated to estimate the estimated position of the rotating wheel, such as when no sensor signal is transmitted or an erroneous sensor signal is transmitted. In some embodiments, extrapolation, smoothing, and / or filtering of sensor data can be combined. Typically, extrapolation of sensor data includes extrapolation of at least 1 millisecond, 5 milliseconds, 50 milliseconds, 500 milliseconds, or 1 second. In some embodiments, the extrapolated estimated position of the rotating wheel can be compared with the measured position of the rotating wheel measured at a later time point to improve the extrapolation.

[0023] According to some embodiments, a wheel position estimation unit can determine the estimated position of a rotating wheel based on multiple rotating wheel position sensors. Typically, data processing includes analyzing the differences between the sensor signals of each of the multiple rotating wheel position sensors. In some embodiments, data processing may include classifying the sensor signals of the multiple rotating wheel position sensors, particularly according to measurement time and / or sensor type. Typically, data processing includes standardizing the sensor data, particularly regarding data format and / or the units used.

[0024] Data processing may include sensor fusion of multiple rotating wheel position sensors. Specifically, sensor fusion may include using information from multiple rotating wheel position sensors to improve the overall accuracy of the estimated position of the rotating wheel. Exemplarily, sensor fusion may include averaging sensor signals from multiple rotating wheel position sensors, or determining the median of the sensor signals from multiple rotating wheel position sensors, particularly for sensor signals determined at the same or very similar time points. Averaging sensor signals may include calculating a weighted average of the sensor signals. Weighting may be performed along an accuracy metric of the multiple rotating wheel position sensors. In some embodiments, sensor fusion may include selecting sensor data from at least one of the multiple rotating wheel position sensors for further data processing. Specifically, sensor fusion may include ignoring sensor signals from at least one of the multiple rotating wheel position sensors, exemplary when an inaccuracy of a particular sensor is detected. In some embodiments, sensor fusion may include combining information from different frequency ranges from different sensors. Exemplarily, a first sensor may provide low-frequency sensor signal information, and a second sensor may provide high-frequency information. In some embodiments, sensor fusion may include controlling the selected sensor signal using other sensor signals among the multiple sensor signals. For example, a generally reliable sensor may be controlled by different sensors, based on different sensor technologies, to identify and mitigate the inaccuracies of the generally reliable sensor. Sensor fusion can advantageously allow the combination of information obtained from multiple rotating wheel position sensors and utilize the advantageous characteristics of different types of rotating wheel position sensors. Therefore, sensor fusion can allow for the determination of a more accurate estimated position of the rotating wheel.

[0025] According to some embodiments, data processing may include analyzing sensor signals to identify the type of noise in the sensor signals covering the rotating wheel. Specifically, analyzing the sensor signals may include analyzing the spectrum of the signal, exemplarily by performing a Fast Fourier Transform (FFT), and by comparing the signal spectrum with a reference spectrum. In some embodiments, the derivative of the sensor signal may be analyzed to determine the sensor's transmission loss. Specifically, the derivative of the sensor signal exceeding a threshold may indicate the sensor's transmission loss (exemplarily, communication loss). Based on the analysis of the sensor signals, data processing may include filtering or modifying the sensor signals according to the analysis results, particularly removing noise or inaccuracies identified by the analysis, to obtain an improved estimated position of the rotating wheel. Exemplarily, for a specific frequency range associated with noise in the FFT analysis, those frequencies may be removed before the inverse transform of the signal from the frequency domain to the time domain.

[0026] In some embodiments, analyzing sensor signals may include employing a trained machine learning (ML) model. In particular, the trained ML model may be trained based on sensor signals indicating the measurement position of a rotating wheel with labeled noise signals.

[0027] In some embodiments, the blade pitch control system includes a noise sensor. The noise sensor is configured to sense background noise signals present at the rotating wheel position sensor. The noise sensor may include a sensor configured to measure electromagnetic interference signals. Specifically, the noise sensor may be configured to sense high-frequency electromagnetic fields. In some embodiments, the noise sensor may include a vibration sensor configured to measure mechanical vibrations, exemplarily originating from an electric motor in a cycloidal marine propulsion system, which may act on at least one rotating wheel position sensor and may overlay the measured position of the rotating wheel in the sensor signal. Typically, the noise sensor is positioned near at least one rotating wheel position sensor.

[0028] Typically, data processing includes deconvolution of sensor signals. Specifically, the wheel position estimation unit may use a background noise signal to perform deconvolution of the sensor signals and obtain the estimated position of the rotating wheel as a result of the deconvolution. Deconvolution of the sensor signals using known and / or measured noise signals advantageously allows for at least partial removal of noise present in the sensor signals and yields an estimated position of the rotating wheel that more accurately represents its true position.

[0029] The blade pitch determination unit uses the estimated position of the rotating impeller to determine the blade pitch of at least one of a plurality of rotating blades. Specifically, determining the blade pitch includes determining a blade pitch setpoint at each time point. Typically, the plurality of blade pitch setpoints form a blade pitch function that defines the blade pitch angle for each position of the rotating impeller. Typically, the blade pitch setpoint is determined using the estimated position of the rotating impeller and the blade pitch function, exemplarily calculated by interpolating the estimated position of the rotating impeller into the blade pitch function.

[0030] In some embodiments, the blade pitch determination unit is configured to determine the blade pitch setpoints of a plurality of rotating blades, particularly each rotating blade of a cycloidal ship propulsion system. Typically, a cycloidal ship propulsion system includes a blade pitch determination unit configured to determine the blade pitch of each rotating blade of the cycloidal ship propulsion system. In some embodiments, the blade pitch control system may include a plurality of blade pitch determination units, particularly one blade pitch determination unit for each rotating blade.

[0031] Typically, the blade pitch setpoint is transmitted to the motor controller of the rotating blade. The motor controller determines the mechanical motion required to rotate the blade based on the blade pitch setpoint. Specifically, the motor controller determines the current required to cause the electric motor of the blade to move. The power stage provides the necessary power to the electric motor of the rotating blade to rotate it. The rotation of the blade is measured by a blade tilt sensor or a blade rotation sensor. The motor controller uses the signal from the blade pitch sensor as feedback to control the movement and pitch of the rotating blade.

[0032] Typically, the blade pitch and the position of the rotor change continuously. Therefore, the blade pitch control system continuously provides the motor controller with the blade pitch setpoint, particularly along the blade pitch function.

[0033] The embodiments disclosed herein facilitate improved pitch control of the rotating blades in a cycloidal ship propulsion system. Reducing the inaccuracy of sensor signals from the rotating wheel advantageously improves the accuracy of the blade pitch setpoint. The cycloidal ship propulsion system can operate more efficiently, particularly in terms of hydrodynamic efficiency, and mechanical overload can be minimized or avoided. Attached Figure Description

[0034] The accompanying drawings relate to embodiments of this disclosure and are described below:

[0035] Figure 1 schematically illustrates a cycloidal ship propulsion system having a blade pitch control system embedded in the hull of a ship, according to an embodiment described herein.

[0036] Figure 2 schematically illustrates a cycloidal ship propulsion system with the blade pitch control system of Figure 2 with additional optional features;

[0037] Figure 3 schematically illustrates a blade pitch control system according to an embodiment described herein; and

[0038] Figure 4 schematically illustrates a method for determining the blade pitch setpoint of the rotating blades of a cycloidal ship propulsion system according to an embodiment described herein. Detailed Implementation

[0039] Reference will now be made in detail to various embodiments of this disclosure, one or more of which are illustrated in the figures. Generally, only differences with respect to the various embodiments are described. Each example is provided by way of explanation of this disclosure and is not intended to limit the scope of this disclosure. Furthermore, features illustrated or described as part of one embodiment may be used in or in combination with other embodiments to produce another embodiment. This specification is intended to include such modifications and variations. In the drawings, elements may be depicted at enlarged dimensions to improve the comprehensibility of the detailed description of the embodiments. In particular, the relationship between the length and width of the illustrated components may be distorted. Furthermore, some elements may be depicted at enlarged dimensions, while other elements in the same drawing may be depicted at relatively reduced dimensions.

[0040] Figure 1 schematically illustrates a cycloidal ship propulsion system 1000 having a blade pitch control system 100 embedded in a ship's hull 40 according to an embodiment described herein. The cycloidal ship propulsion system 1000 includes a rotating wheel 20 having four rotating blades 30a-30d. The blade pitch control system 100 includes a rotating wheel position sensor 110. The rotating wheel position sensor 110 is configured to provide a sensor signal indicating a measured position of the rotating wheel. The rotating wheel position sensor 110 is substantially arranged on the axis of rotation of the rotating wheel 20, typically at the center of the rotating wheel 20. The sensor signal from the rotating wheel position sensor 110 is transmitted to a wheel position estimation unit 120.

[0041] Wheel position estimation unit 120 is configured to determine the estimated position of the rotating wheel. The estimated position of the rotating wheel is transmitted to blade pitch determination unit 130. Blade pitch determination unit 130 determines the blade pitch setpoint of at least one of the plurality of rotating blades 30a-30d. Blade pitch determination unit 130 transmits the blade pitch setpoint of each rotating blade 30a-30d to the rotating blades 30a-30d, and particularly to the motor controllers of the rotating blades 30a-30d. Wheel position estimation unit 120 and blade pitch determination unit 130 can be integrated into programmable logic controller 150.

[0042] Figure 2 illustrates a cycloidal ship propulsion system 1000 with a blade pitch control system 100 of Figure 1, featuring additional optional features. The blade pitch control system 100 includes a second rotating wheel position sensor 211. In Figure 2, the second rotating wheel position sensor 211 is arranged at the edge of the rotating wheel 20. However, in embodiments not shown in the figure, different positions of the second rotating wheel position sensor 211 may be suitable. The sensor signal from the second rotating wheel position sensor 211 is transmitted to a wheel position estimation unit 120. The blade pitch control system 100 also includes a noise sensor 220 configured to sense background noise signals present at the rotating wheel 20, particularly at the rotating wheel position sensor 110 and / or the second rotating wheel position sensor 211. The wheel position estimation unit 120 is configured to determine the estimated position of the rotating wheel based on the signals from the rotating wheel position sensor 110, the second rotating wheel position sensor 211, and / or the noise sensor 220.

[0043] Figure 3 schematically illustrates a blade pitch control system 100 according to an embodiment described herein. Sensor signals from at least one rotating wheel position sensor 110, 211 are transmitted to a wheel position estimation unit 120. The rotating wheel position estimation unit determines an estimated position of the rotating wheel and provides the estimated position of the rotating wheel to a blade pitch determination unit 130. In Figure 3, only two rotating blades 30a, 30b are illustrated by way of example only. The following discussion of the first blade 30a applies to the second blade 30b and cycloidal ship propulsion systems with a large number of rotating blades. The blade pitch determination unit 130 provides a blade pitch setpoint to the motor controller 350 of the rotating blade 30a, particularly to the electric motor 360 of the rotating blade 30a. In the motor controller 350, a motion control stage 351 compares the blade pitch setpoint with the current blade pitch provided by the blade pitch sensor 361. The motor controller 351 determines the appropriate current supplied by the current controller 352. The current settings can be determined based on feedforward motion compensation provided by the blade pitch determination unit, specifically based on the pitch function of the rotating blade. The current determined by the current controller 352 may include a current function defining the current over a period of time. In the power stage 353, electrical power is provided to power the electric motor 360 of the rotating blade 30a, causing the rotating blade 30a to rotate mechanically. The blade pitch sensor 361 provides feedback to the motor controller 350.

[0044] Figure 4 schematically illustrates a method 400 for determining the blade pitch setpoint of a rotating blade in a cycloidal ship propulsion system according to embodiments described herein. The cycloidal ship propulsion system includes a rotating wheel and a plurality of rotating blades attached to and individually rotatable relative to the rotating wheel. Method 400 includes receiving, at least 410, a sensor signal indicating a measured position of the rotating wheel from at least one rotating wheel position sensor. Based on the sensor signal from the at least one rotating wheel position sensor, the received sensor signal 410 is used to determine, at least 420, an estimated position of the rotating wheel. The estimated position of the rotating wheel is used to determine, based on the estimated position of the rotating wheel, the blade pitch setpoint of at least one of the plurality of rotating blades, at least 430.

Claims

1. A blade pitch control system (100) for a cycloidal ship propulsion system (1000), the cycloidal ship propulsion system (1000) comprising a rotating wheel (20) and a plurality of rotating blades (30a-d) attached to the rotating wheel (20) and individually rotatable relative to the rotating wheel (20), the blade pitch control system (100) comprising: At least one rotating wheel position sensor (110, 211) configured to provide a sensor signal indicating the measured position of the rotating wheel (20), and a wheel position estimation unit (120) configured to determine the estimated position of the rotating wheel based on the sensor signal of the at least one rotating wheel position sensor (110, 211); And a blade pitch determination unit (130) configured to determine the blade pitch setpoint of at least one of the plurality of rotating blades (30a-d) based on the estimated position of the rotating wheel. Determining the estimated position of the rotating wheel includes data processing of the sensor signals.

2. The blade pitch control system (100) according to claim 1, wherein the measurement position indicates the polar angle of the rotating wheel (20).

3. The blade pitch control system (100) according to claim 1, wherein the data processing includes the storage of the sensor signals.

4. The blade pitch control system (100) according to claim 1, wherein the data processing includes smoothing the sensor signals.

5. The blade pitch control system (100) according to claim 1, wherein the data processing includes filtering of the sensor signals.

6. The blade pitch control system (100) according to claim 1, wherein the data processing includes extrapolation of the sensor signals.

7. The blade pitch control system (100) according to any one of the preceding claims includes a plurality of rotating wheel position sensors (110, 211); and the data processing includes sensor fusion of the plurality of rotating wheel position sensors (110, 211).

8. The blade pitch control system (100) according to any one of claims 1 to 6, wherein the data processing includes analyzing the sensor signals to identify the type of sensor signal noise superimposed on the rotating wheel (20).

9. The blade pitch control system (100) according to any one of claims 1 to 6, wherein the blade pitch control system (100) further comprises a noise sensor (220) configured to sense a background noise signal present at the rotating wheel position sensor (110); and wherein the data processing comprises deconvolution of the sensor signal.

10. A cycloidal ship propulsion system (1000) comprising a rotary wheel (20), a plurality of rotating blades (30a-d) attached to the rotary wheel (20) and individually rotatable relative to the rotary wheel (20), and a blade pitch control system (100) according to any one of claims 1 to 6.

11. A seagoing vessel comprising the cycloidal ship propulsion system (1000) according to claim 10.

12. A method (400) for determining the blade pitch setpoint of a rotating blade of a cycloidal ship propulsion system (1000), the cycloidal ship propulsion system (1000) comprising a rotating wheel (20) and a plurality of rotating blades (30a-d) attached to the rotating wheel (20) and individually rotatable relative to the rotating wheel (20), the method (300) comprising: Receive (410) a sensor signal indicating the measured position of the rotating wheel from at least one rotating wheel position sensor (110, 211); The estimated position of the rotating wheel is determined (420) based on the sensor signals from the at least one rotating wheel position sensor (110, 211); And based on the estimated position of the rotating wheel (20), determine (430) the blade pitch set point of at least one of the plurality of rotating blades; wherein determining the estimated position of the rotating wheel includes data processing of the sensor signal.

13. The method (400) of claim 12, wherein the data processing includes at least one of storing, smoothing, filtering, or extrapolating the sensor signal.

14. The method (400) according to any one of claims 12 to 13, wherein the data processing includes analyzing the sensor signal to identify the type of noise in the sensor signal superimposed on the rotating wheel.

15. A method for controlling a cycloidal ship propulsion system (1000) according to claim 10, using blade pitch information obtained from a blade pitch control system (100) according to any one of claims 1 to 6.

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