System and method for controlling the blade pitch of a cycloidal ship propulsion system

Abstract

We provide a blade pitch control system for cycloidal ship propulsion systems. [Solution] The cycloidal ship propulsion system comprises 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 comprises at least one rotating wheel position sensor configured to provide a sensor signal indicating the measured position of the rotating wheel, a wheel position estimation unit configured to determine the estimated position of the rotating wheel based on the sensor signal of the at least one rotating wheel position sensor, and a blade pitch determination unit configured to determine the blade pitch setting 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 involves data processing of the sensor signal.

Description

Technical Field

[0001]

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

Background Art

[0002]

[0002] Cycloidal ship propulsion systems provide an efficient way to propel ships. Further, cycloidal ship propulsion systems can improve the maneuverability of ships. In a cycloidal ship propulsion system, a rotating wheel having rotatable blades attached thereto provides thrust. The direction and amount of thrust can be controlled via the rotational speed of the rotating wheel and via the pitch of the rotatable blades. In a cycloidal ship 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 rotating wheel. For efficient operation of a cycloidal ship propulsion system, it is essential to ensure the exact pitch of each of the rotating blades at every position of the rotating wheel. In particular, the pitch of the rotating blades is controlled based on the position of the rotating wheel.

[0003]

[0003] The position of the rotating wheel is typically determined by at least one position sensor. The sensor signal of at least one position sensor indicating the measured position of the rotating wheel is used to set a blade pitch setpoint or a blade pitch function. Inaccuracy of the sensor signal results in a sensor signal that misrepresents the position of the rotating wheel, resulting in the blade pitch not being set accurately, and thus can be associated with a decrease in efficiency, malfunctions, and higher wear and tear and breakage of the cycloidal ship propulsion system.

Summary of the Invention

[0004]

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

[0005]

[0005] According to one aspect of the present disclosure, a blade pitch control system for a cycloidal ship propulsion system is provided. The cycloidal ship propulsion system comprises a rotating wheel and a plurality of rotating blades mounted on the rotating wheel and individually rotatable relative to the rotating wheel. The blade pitch control system comprises 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 of 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 comprises data processing of the sensor signal.

[0006]

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

[0007]

[0007] According to another aspect of the present disclosure, a vessel is provided having a cycloidal ship propulsion system having a blade pitch control system according to any embodiment described herein.

[0008]

[0008] According to another aspect of the present disclosure, a method is provided for determining a blade pitch setpoint of a rotating blade in a cycloidal ship propulsion system. The cycloidal ship propulsion system comprises a rotating wheel and a plurality of rotating blades mounted on the rotating wheel and individually rotatable relative to the rotating wheel. The method comprises receiving a sensor signal indicating the 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 at least one rotating wheel position sensor, and determining a 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 comprises data processing of the sensor signal.

[0009]

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

[0010]

[0010] According to some embodiments, the cycloidal ship propulsion system is configured to propel a ship. The ship includes a seafaring ship or an inland ship. In particular, the ship includes ships and boats. In some embodiments, the ship includes ferries, in particular single-ended ferries and double-ended ferries, cruise ships, water buses, and yachts. In some embodiments, the ship includes offshore energy ships, in particular service work ships (SOVs), cable laying ships (CLVs), foundation-installing ships (FIVs), offshore structure (OCVs) and support ships (OSVs), platform supply ships (PSVs), and anchor handling tug supply ships (AHTS). In some embodiments, the ship includes survey and measurement ships or other special-purpose ships. According to some embodiments, the ship includes merchant ships, in particular for transporting goods.

[0011]

[0011] The vessel comprises a hull. According to some embodiments, the rotating wheel is mounted on the hull of the vessel, particularly on the bottom of the hull. In some embodiments, the hull comprises a recess. In particular, the recess of the hull is configured to receive the rotating wheel of the cycloidal ship propulsion system. The rotating wheel typically rotates relative to the hull of the vessel. The position of the rotating wheel relative to the hull may be indicated by the polar angle of the rotating wheel relative to the hull. In particular, the default configuration may be defined by a polar angle of 0°, and the rotation of the rotating wheel compared to the default configuration may be associated with the polar angle measured relative to the default configuration. In some embodiments, the default configuration may be fixed. In some embodiments, the default configuration may be defined initially at some point in time and may be redefined at regular time intervals at the request of the operator of the cycloidal ship propulsion system and / or after the rotating wheel has been set in motion.

[0012]

[0012] Multiple electrically driven rotary blades are mounted on a rotary wheel. In particular, two, three, four, five, six, or more rotary blades may be mounted on the rotary wheel. The rotary blades are rotatable relative to the rotary wheel. In particular, the rotary blades are individually rotatable relative to the rotary wheel. In other words, each of the multiple rotary blades can be controlled individually, and in particular, the pitch of each rotary blade can be controlled individually. For each of the rotary blades, the rotary wheel is provided with a rotary blade electric motor that drives the respective rotary blade. In some embodiments, the pitch of the multiple rotary blades can be adjusted without angular limitations. In particular, the multiple rotary blades may be rotatable by at least 360°. The rotary wheel is provided with multiple recesses for receiving the multiple electrically driven rotary blades.

[0013]

[0013] The blade pitch control system controls the blade pitch of at least one of the rotating blades. Typically, the blade pitch control system controls the blade pitch of each of the rotating blades. The blade pitch control system may comprise multiple subsystems, in particular one subsystem for each blade of the rotating blades. Typically, the blade pitch control system is an integrated system in which an integrated controller, exemplary a programmable logic controller, controls the blade pitch of at least one of the rotating blades.

[0014]

[0014] The blade pitch control system comprises at least one rotary wheel position sensor. In some embodiments, the blade pitch control system comprises a plurality of rotary wheel position sensors, in particular at least two, three, four, five, or eight or more sensors. The at least one rotary wheel position sensor may be a magnetic rotary sensor, a rotary variable differential transformer, or a rotary potentiometer. The rotary wheel position sensor may be substantially located on the rotation axis of the rotary wheel. In some embodiments, the rotary wheel sensor may be configured to sense the presence of a signaling device in its vicinity. Exemplarily, the rotary wheel sensor may be stationary and positioned as the rotary wheel passes by the rotary wheel sensor. The rotary wheel sensor may be configured to sense the presence of at least one signaling device attached to the rotary wheel. The sensing signal induced by at least one signaling device may indicate a particular polar angle of the rotary wheel. A blade pitch control system comprising a plurality of rotary wheel sensors typically comprises a plurality of different types of rotary wheel sensors. Having a plurality of different types of rotary wheel sensors can advantageously compensate for the shortcomings of a particular type of rotary wheel sensor.

[0015]

[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 comprise direct rotational position information, i.e., the polar angle, or the sensor signal may comprise a sensor output that needs to be converted to indicate the measured position of the rotating wheel, and exemplary the sensor output may comprise a voltage or current. The sensor signal may comprise an analog signal or a digital signal.

[0016]

[0016] In some embodiments, the sensor signal may include additional sensor information, such as the sensor status, e.g., whether the sensor is operating, a timestamp, or a sensor identification signal. The sensor signal may be provided continuously or at intervals. In particular, 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 every 10 μs, 50 μs, 200 μs, 1 ms, or 5 ms.

[0017]

[0017] Based on the sensor signals of at least one rotating wheel position sensor, the wheel position estimation unit determines the estimated position of the rotating wheel. Determining the estimated position involves data processing of the sensor signals. In particular, the data processing may involve editing, selecting, deleting, merging, verifying, or aggregating the sensor signals. The data processing of the sensor signals can advantageously enable improvements in the data quality of the sensor signals and reduce the impact of noise or interruptions in data transmission to the blade pitch setpoint.

[0018]

[0018] The estimated position of the rotating wheel determined by the wheel position estimation unit is based on the sensor signal. Data processing of the sensor signal is advantageous in that it is possible to improve the quality of the sensor signal and thus provide an estimated position that better represents the actual position of the rotating wheel compared to the sensing signal that indicates the measured position of the rotating wheel. In particular, errors in the sensed signal that may be due to sensor noise, or interruptions in communication between at least one rotating wheel position sensor and the wheel position estimation unit can be omitted 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 the multiple rotating blades. In particular, the estimated position of the rotating wheel can provide a smoother and more continuous signal.

[0019]

[0019] In some embodiments, data processing of the sensor signal includes storage, or in other words, recording, of the sensor signal. In particular, the sensor signal may be stored by the blade pitch determination unit. Storage may include, exemplary, temporary storage in volatile computer memory, or exemplary, non-temporarily permanent storage in non-volatile computer memory. Recording of the sensor signal may include recording over time, particularly over predetermined time amounts, exemplary, over at least 200 μs, 1 ms, 5 ms, 50 ms, 500 ms, 1 s, or 10 s. Recording of the sensor signal may include recording over at least one rotation cycle. Exemplarily, the sensor signal may be recorded over 1, 2, 3, 4, 5, 8, 10, 50, 100 or more rotation cycles. The stored or recorded sensor signal may be used by the wheel position estimation unit to advantageously identify patterns in the sensor signal. In particular, it may be possible to identify irregularities that are repeatedly present in the sensor signal. Exemplary, irregularities in the sensor signal may occur at specific positions or frequencies of the rotating wheel, particularly in the time domain. Identifying such patterns can advantageously allow for the identification of sources of noise or interruptions in the sensor signal. Thus, data processing can be performed on the sensor signal to remove identified noise or interruptions and provide an estimated position of the rotating wheel.

[0020]

[0020] In some embodiments, data processing includes smoothing of sensor data. In particular, sensor data may be averaged over a predetermined time. Exemplaryly, sensor data may be averaged over 200 μs, 1 ms, 5 ms, 50 ms, 500 ms, or 1 s. Sensor data may be averaged as a moving average. Typically, stored sensor data can be smoothed. Averaging sensor data can, in particular, reduce the effects of random noise that overlaps with the sensor signal, more specifically, with the measurement position of the rotating wheel.

[0021]

[0021] In some embodiments, data processing includes filtering of sensor data. Filtering sensor data can lead to the smoothing of the sensor data. In some embodiments, filtering may be selected to achieve smoothing of the sensor data. Filtering of the sensor signal may involve applying a filter to at least a portion of the sensor signal. Typically, stored sensor data may be filtered. Filtering the sensor signal may involve 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 the sensor signal may involve including information about the settings of the rotating wheel. In particular, the frequency range of the filter may be selected based on the rotation frequency of the rotating wheel. The blade pitch control system may communicate with a rotating wheel controller or a cycloidal ship propulsion system controller to receive information about the rotation frequency and / or rotation frequency setpoint of the rotating wheel. In typical embodiments, filtering the sensor signal may, in particular, allow for the reduction or removal of random noise overlapping the sensor signal. Filtering sensor signals, particularly using filters optimized for shot noise (e.g., percentile filters), can reduce or eliminate inaccuracies in sensor signals resulting from transmission errors, such as losses in the transmission of sensor signals.

[0022]

[0022] In some embodiments, data processing comprises extrapolation of sensor data. In particular, the future position of the rotating wheel may be estimated based on the current and / or past position of the rotating wheel. Typically, the extrapolation comprises using a mathematical model of the rotating wheel, in particular the rotation of the rotating wheel. In particular, the extrapolation comprises fitting a mathematical function or a set of mathematical functions to the sensor signal. Exemplarily, the mathematical function may comprise a sinusoid function or an n-th degree polynomial. The mathematical function comprises at least one variable determined by the fitting procedure. The function determined by the fitting may be extrapolated to estimate the estimated future position of the rotating wheel. In some embodiments, the function determined by the fitting may be extrapolated to estimate the estimated position of the rotating wheel in the event that no sensor signal is transmitted or an incorrect sensor signal is transmitted. In some embodiments, extrapolation, smoothing, and / or filtering of the sensor data may be combined. Typically, the extrapolation of sensor data comprises extrapolation of at least 1 ms, 5 ms, 50 ms, 500 ms, or 1 s. In some embodiments, the extrapolated estimated position of the rotating wheel may be compared to the measured position of the rotating wheel at a later point in time to improve the extrapolation.

[0023]

[0023] According to some embodiments, a wheel position estimation unit can determine the estimated position of a rotating wheel based on a plurality of rotating wheel position sensors. Typically, data processing comprises analyzing the differences between the respective sensor signals of the plurality of rotating wheel position sensors. In some embodiments, data processing may comprise sorting the sensor signals of the plurality of rotating wheel position sensors in particular by measurement time and / or sensor type. Typically, data processing comprises standardization of sensor data in particular with respect to the data format and / or unit used.

[0024]

[0024] Data processing may include sensor fusion of multiple rotary wheel position sensors. In particular, sensor fusion may include improving the overall accuracy of the estimated position of the rotary wheel using information from multiple rotary wheel position sensors. Exemplary, sensor fusion may include averaging the sensor signals of multiple rotary wheel position sensors, or determining the median of the sensor signals of multiple rotary wheel position sensors, particularly for sensor signals determined at the same time or very similar time points. Averaging the sensor signals may include calculating a weighted average of the sensor signals. The weighting may be performed along an accuracy metric of the multiple rotary wheel position sensors. In some embodiments, sensor fusion may include selecting sensor data from at least one of the multiple rotary wheel position sensors for further data processing. In particular, sensor fusion may include ignoring the sensor signal of at least one of the multiple rotary wheel position sensors when inaccuracy is detected for a particular sensor. In some embodiments, sensor fusion may include combining information from different frequency ranges from different sensors. Exemplary, 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 involve controlling a selected sensor signal with other sensor signals from among multiple sensor signals. Exemplarily, a generally reliable sensor may be controlled by different sensors, based exemplary on different sensor technologies, to identify and mitigate the inaccuracies of the generally reliable sensor. Sensor fusion can advantageously enable the merging of information obtained from multiple rotary wheel position sensors and the utilization of preferred characteristics of different types of rotary wheel position sensors. Thus, sensor fusion can enable the determination of a more accurate estimated position of the rotary wheel.

[0025]

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

[0026]

[0026] In some embodiments, analyzing the sensor signal may involve using a trained machine learning (ML) model. In particular, the trained ML model may be trained on a sensor signal indicating the measured position of a rotating wheel having a labeled noise signal.

[0027]

[0027] In some embodiments, the blade pitch control system includes a noise sensor. The noise sensor is configured to sense a background noise signal present in the rotational wheel position sensor. The noise sensor may include a sensor configured to measure an electromagnetic interference signal. In particular, the noise sensor may be configured to sense a high-frequency electromagnetic field. In some embodiments, the noise sensor may act on at least one rotational wheel position sensor and may include a vibration sensor configured to measure mechanical vibrations resulting from, for example, an electric motor of a cycloidal marine propulsion system, which can overlay the measured position of the rotational wheel in the sensor signal. Typically, the noise sensor is disposed in the vicinity of at least one rotational wheel position sensor.

[0028]

[0028] Typically, the data processing includes a deconvolution of the sensor signal. In particular, the wheel position estimation unit may perform a deconvolution of the sensor signal and may use the background noise signal to obtain an estimated position of the rotational wheel as a result of the deconvolution. Deconvolving the sensor signal using a known and / or measured noise signal may advantageously at least partially remove the noise present in the sensor signal and make it possible to obtain an estimated position of the rotational wheel that more represents the actual position of the rotational wheel.

[0029]

[0029] The estimated position of the rotational wheel is used by a blade pitch determination unit to determine the blade pitch of at least one of the plurality of rotational blades. In particular, determining the blade pitch includes determining a blade pitch setpoint at each point in time. Typically, the plurality of blade pitch setpoints form a blade pitch function that defines the blade pitch angle for each position of the rotational wheel. Typically, the blade pitch setpoint is determined by using the estimated position of the rotational wheel and the blade pitch function, for example, by inserting the estimated position of the rotational wheel into the blade pitch function and thereby calculating the blade pitch setpoint.

[0030]

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

[0031]

[0031] Typically, the blade pitch set point is sent to the motor controller of the rotating blade. The motor controller determines the mechanical movement required to rotate the rotating blade according to the blade pitch set point. In particular, the motor controller determines the current required to induce the movement of the electric motor of the blade. The power stage supplies the electric motor of the rotating blade with the power required to rotate the rotating blade. The rotation of the rotating blade is measured by a blade pitch sensor or a blade rotation sensor. The signal of the blade pitch sensor is used by the motor controller as feedback for controlling the movement and pitch of the rotating blade.

[0032]

[0032] Typically, the pitch of the blade and the position of the rotating wheel vary continuously. Therefore, the blade pitch control system continuously provides the motor controller with blade pitch set points, particularly along a blade pitch function.

[0033]

[0033] Embodiments of the present disclosure enable advantageous improvement of blade pitch control of the rotating blades of a cycloidal ship propulsion system. Reducing inaccuracies in the sensor signals of the rotating wheel advantageously improves the precision of the blade pitch setpoint. The cycloidal ship propulsion system can be operated more efficiently, particularly with respect to hydrodynamic efficiency, and mechanical overload can be minimized or avoided. [Brief explanation of the drawing]

[0034]

[0034] The attached drawings are described below with respect to embodiments of the present disclosure. [Figure 1] Figure 1 schematically illustrates a cycloidal ship propulsion system having a blade pitch control system according to the embodiment described herein, embedded in the hull of a ship. [Figure 2] Figure 2 schematically illustrates a cycloidal ship propulsion system equipped with the blade pitch control system shown in Figure 2, and having additional optional features. [Figure 3] Figure 3 schematically illustrates a blade pitch control system according to an embodiment described herein. [Figure 4] Figure 4 schematically illustrates a method for determining the blade pitch setting point of the rotating blades of a cycloidal ship propulsion system according to the embodiments described herein. [Modes for carrying out the invention]

[0035]

[0035] Hereinafter, various embodiments of the present disclosure are given in detail, and one or more examples thereof are illustrated in the drawings. Generally, only differences relating to individual embodiments are described. Each example is provided as an example of the present disclosure and is not intended to be an limitation of the present disclosure. Furthermore, features illustrated or described as part of one embodiment may be used on or in conjunction with other embodiments to bring about further embodiments. This specification is intended to include such modifications and variations. In the drawings, elements may be depicted in exaggerated dimensions to improve understanding of the detailed description of the embodiments. In particular, the relationship between the length and width of the shown components may be distorted. Furthermore, some elements may be depicted in enlarged dimensions, while other elements in the same figure are depicted in relatively reduced dimensions.

[0036]

[0036] Figure 1 schematically illustrates a cycloidal ship propulsion system 1000 in which a blade pitch control system 100 according to an embodiment described herein is embedded in the hull 40 of a ship. The cycloidal ship propulsion system 1000 comprises a rotating wheel 20 having four rotating blades 30a-30d. The blade pitch control system 100 comprises a rotating wheel position sensor 110. The rotating wheel position sensor 110 is configured to provide a sensor signal indicating the measured position of the rotating wheel. The rotating wheel position sensor 110 is positioned substantially 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.

[0037]

[0037] The 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 the blade pitch determination unit 130. The blade pitch determination unit 130 determines at least one blade pitch setpoint of the plurality of rotating blades 30a-30d. The blade pitch determination unit 130 transmits each blade pitch setpoint of the rotating blades 30a-30d to the rotating blades 30a-30d, in particular to the motor controller of the rotating blades 30a-30d. The wheel position estimation unit 120 and the blade pitch determination unit 130 may be integrated into the programmable logic controller 150.

[0038]

[0038] Figure 2 illustrates a cycloidal ship propulsion system 1000 having the blade pitch control system 100 of Figure 1 having 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 located at the end of the rotating wheel 20. However, different positions of the second rotating wheel position sensor 211 may be appropriate in embodiments not shown in the figure. The sensor signal of the second rotating wheel position sensor 211 is transmitted to a wheel position estimation unit 120. The blade pitch control system 100 further includes a noise sensor 220 configured to sense background noise signals present in the rotating wheel 20, particularly 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.

[0039]

[0039] 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 wheel position estimation unit determines the estimated position of the rotating wheel and provides the estimated position of the rotating wheel to the blade pitch determination unit 130. In Figure 3, only two rotating blades 30a, 30b are illustrated exemplarily. The following description of the first blade 30a is also applicable to the second blade 30b and to cycloidal ship propulsion systems having more rotating blades. The blade pitch determination unit 130 provides a blade pitch setpoint to the motor controller 350 of the rotating blade 30a, in particular to the electric motor 360 of the rotating blade 30a. In the motor controller 350, the 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 an appropriate current to be supplied by the current controller 352. The current setting can be determined based on feedforward motion compensation provided by the blade pitch determination unit, and in particular based on the pitch function of the rotating blade. The current determined by the current controller 352 may have a current function that defines the current for a certain period of time. Power is supplied in the power stage 353 to power the electric motor 360 of the rotating blade 30a, thereby inducing the mechanical rotation of the rotating blade 30a. The blade pitch sensor 361 provides feedback to the motor controller 350.

[0040]

[0040] 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 an embodiment described herein. The cycloidal ship propulsion system comprises a rotating wheel and a plurality of rotating blades mounted on the rotating wheel and individually rotatable relative to the rotating wheel. Method 400 comprises receiving a sensor signal 410 from at least one rotating wheel position sensor indicating the measured position of the rotating wheel. The received sensor signal 410 is used 420 to determine the estimated position of the rotating wheel based on the sensor signals of at least one rotating wheel position sensor. The estimated position of the rotating wheel is used 430 to determine the blade pitch setpoint of at least one of the plurality of rotating blades based on the estimated position of the rotating wheel.

Claims

1. A blade pitch control system (100) for a cycloidal ship propulsion system (1000), wherein the cycloidal ship propulsion system (1000) comprises 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), and the blade pitch control system (100) is, At least one rotating wheel position sensor (110, 211) configured to provide a sensor signal indicating the measurement position of the rotating wheel (20), A wheel position estimation unit (120) is configured to determine the estimated position of the rotating wheel based on the sensor signals of at least one of the rotating wheel position sensors (110, 211), The system includes a blade pitch determination unit (130) configured to determine at least one blade pitch setting point among the plurality of rotating blades (30a-d) based on the estimated position of the rotating wheel, Determining the estimated position of the rotating wheel is performed by a blade pitch control system (100) that includes data processing of the sensor signal.

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 or 2, wherein the data processing comprises storing the sensor signal.

4. The blade pitch control system (100) according to any one of claims 1 to 3, wherein the data processing comprises smoothing of the sensor signal.

5. The blade pitch control system (100) according to any one of claims 1 to 4, wherein the data processing comprises filtering of the sensor signal.

6. The blade pitch control system (100) according to any one of claims 1 to 5, wherein the data processing comprises extrapolation of the sensor signal.

7. A blade pitch control system (100) according to any one of claims 1 to 6, comprising a plurality of rotating wheel position sensors (110, 211), wherein the data processing comprises 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 7, wherein the data processing comprises analyzing the sensor signal to identify the type of noise overlapping the sensor signal of the rotating wheel (20).

9. The blade pitch control system (100) further includes a noise sensor (220) configured to sense background noise signals present in the rotating wheel position sensor (110), The blade pitch control system (100) according to any one of claims 1 to 8, wherein the data processing comprises deconvolution of the sensor signal.

10. A cycloidal ship propulsion system (1000) comprising a rotating wheel (20), a plurality of rotating blades (30a-d) attached to the rotating wheel (20) and individually rotatable relative to the rotating wheel (20), and a blade pitch control system (100) according to any one of claims 1 to 9.

11. A ship comprising the cycloidal ship propulsion system (1000) described in claim 10.

12. A method (400) for determining the blade pitch setting point of a rotating blade of a cycloidal ship propulsion system (1000), wherein the cycloidal ship propulsion system (1000) comprises 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), and the method (300) is Receiving a sensor signal (410) indicating the measured position of the rotating wheel from at least one rotating wheel position sensor (110, 211), Based on the sensor signals of the at least one of the rotating wheel position sensors (110, 211), the estimated position of the rotating wheel is determined (420), The method includes determining the blade pitch setting point of at least one of the plurality of rotating blades based on the estimated position of the rotating wheel (20) (430), A method (400) for determining the estimated position of the rotating wheel, comprising data processing of the sensor signal.

13. The method according to claim 12 (400), wherein the data processing comprises one of storing, smoothing, filtering, or extrapolating the sensor signal.

14. The method according to claim 12 or 13 (400), wherein the data processing comprises analyzing the sensor signal to identify the type of noise overlapping the sensor signal of 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 9.

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