WIND PROPULSION OPERATING SYSTEM FOR PROPELLING A VESSEL AND METHOD OF OPERATION THEREOF

Abstract

 A wind propulsion operation system for propelling a vessel comprising a wind propulsion system and at least one actuator arranged to operate the wind propulsion system and a processing unit configured to determine a set operating position and a current operating position of the wind propulsion system and determining a difference and/or a difference variation between the set operating position and the current operating position and based thereon carry out a set position adjustment procedure.

Description

Technical Field

[0001] The present disclosure relates to the operation of wind propulsion systems for land and marine vessels.

Background

[0002] Wind propulsion systems like sails and further apparatuses like flettner rotors or rigid sail elements have been revived lately due to the increasing fuel prices and more stringent environmental regulations. Different approaches have been pursued for their operation and automatization of calibration procedures which allow an efficient setting of their operating positions. However, due to the varying forces (e.g. wind and own weight) and diversity of operating conditions, wind propulsion systems suffer from different calibration and operation issues which hinder a reliable and safe operation. For the specific case in which these sail assemblies are situated in a marine vessel, the usual sizes (bigger than 10m) and the corresponding own weight of the sail assemblies which ensure the needed rigidity to deal with different wind speeds make the manual reparation of the sail elements or the actuator arrangements impossible at sea, hereby causing losses during these trips due to the suboptimal performance and even different hazards which can endanger the vessel and its crew.

Prior Art

[0003] The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.

[0004] Document WO2021/111147 A1 shows one propulsion device comprising a rigid sail element comprising a plurality of airfoils. The current document discloses different embodiments comprising a combination of rigid and movable airfoils to improve the lift-to-drag ratio. However, although the current document generally mentions the possibility of using different kinds of actuators, is silent about the different operating problems of actuator arrangements for systems of this size and interacting with wind forces.

[0005] Document WO 2018/087649 A1 discloses a double airfoil mounted on a structure controlled angularly around a generally vertical axis depending on conditions, where the double airfoil comprises a fore flap and an aft flap.

[0006] Document WO 2014/001824 A1 discloses a different constructional embodiment wherein three sail elements are rigidly connected, each of them presenting a movable airfoil element, wherein the set of sail elements are jointly rotatable arranged.

[0007] The above-mentioned documents are hereby incorporated by reference to support the current disclosure regarding the usual constructional arrangements present in the field of wind propulsion systems upon which the wind propulsion operation system of the current disclosure can be applied on.

[0008] Representations of different embodiments of the above cited documents are shown in Figure 1B as examples in the prior art to which the different embodiments of the current disclosure may be applied to.

Summary

[0009] Hence, it is a goal of the current disclosure to operate these wind propulsion systems in a safe and reliable way and aiming for an optimal configuration which maximizes the wind thrust and increases the safety operation.

[0010] According to a first aspect of the present disclosure, this and other objectives are achieved by a wind propulsion operation system for propelling a vessel, the wind propulsion operation system comprising a wind propulsion system comprising at least one sail element and a base plate, wherein the sail element is rotatably arranged on the base plate to set a wind angle, the sail element comprising a plurality of airfoil elements and at least one airfoil element is movable and configured to modify the camber line of the sail element; at least one actuator arranged to rotate the sail element relative to the base plate to a set wind angle and/or to move said at least one movable airfoil element to modify the camber line of the sail element; at least one position sensor configured to determine the actual operating position of at least one of: the at least one actuator, the sail element and the at least one movable airfoil element; a processing unit, the processing unit comprising at least one memory unit and at least one processor configured to carry out instructions to operate the at least one sail element and/or the at least one movable airfoil element by means of the at least one actuator; the wind propulsion operation system being configured to enter a fail-safe operation mode wherein the processing unit being configured to determine a difference and/or a difference variation between a set operating position and the actual operating position of at least one of: the at least one actuator, the sail element and the at least one movable airfoil element determined by the at least one position sensor; the wind propulsion operation system is configured to initiate a set position adjustment procedure for the at least one actuator in response to the determined difference and/or the determined difference variation being greater than a predetermined value for a predetermined amount of time; the set position adjustment procedure comprising the processing unit being configured to determine a new set operating position of the at least one of the at least one actuator, the at least one sail element and the at least one airfoil element, and to operate the at least one actuator based on the determined new set operating position.

[0011] Following this approach, the wind propulsion system can be operated reliably and in a safe manner.

[0012] According to a further aspect of the present disclosure, the at least one actuator is a hydraulic actuator, and the wind propulsion operation system further comprises a hydraulic power unit configured to operate the hydraulic actuator and an electric generation unit configured to provide electric power to the hydraulic power unit.

[0013] Following this approach, the high forces needed for the operation of said systems can be achieved.

[0014] According to a further aspect of the present disclosure, the base plate and the at least one sail element are operatively connected by means of a slew bearing and the hydraulic actuator comprises at least one slew bearing hydraulic motor configured to rotate the sail element to a set wind angle, wherein said at least one position sensor comprises a position sensor configured to determine the actual operating position of the sail element, and wherein the processing unit is configured to determine the difference between the set operating position and the determined actual operating position of the sail element, wherein the processing unit is configured to determine a new set operating position of the at least one sail element in response to the difference being greater than a predetermined value for a predetermined amount of time and to operate the slew bearing hydraulic motor to rotate the sail element to the new set operating position.

[0015] Following this approach, the sail element can be oriented correctly in order to determine a working angle which can be reached due to wind forces.

[0016] According to a further aspect of the present disclosure, the hydraulic actuator comprises at least two hydraulic rams and at least one cable operatively connected to the at least two hydraulic rams and operatively coupled to the movable airfoil element, and wherein said at least one position sensor comprises at least one of: a linear sensor for measurement of the current position of at least one of the at least two hydraulic rams, and a position sensor for measurement of the current angle of the movable airfoil element.

[0017] Following this approach, the movable airfoil elements can be rotated accurately and the position of the movable airfoil elements reliably determined.

[0018] According to a further aspect of the present disclosure, the processing unit is configured to determine a difference between the set operating position of at least one of the at least two hydraulic rams and/or the movable airfoil element and the actual operating position of the at least one of the two hydraulic rams and/or the airfoil element determined by said linear sensor and/or said position sensor, respectively, and wherein the processing unit is configured to operate the hydraulic actuator, in response to the determined difference being greater than a predetermined value for a predetermined amount of time, to adjust the set operating position of at least one of the two hydraulic rams so that the operating position of the movable airfoil element coincides with the set operating position.

[0019] Following this approach, an offset caused to stretching in one of the actuating hydraulic rams and/or connecting elements can be compensated.

[0020] According to a further aspect of the present disclosure, the processing unit is configured to determine a difference variation between the set operating position of the movable airfoil and the actual operating position of the movable airfoil determined by the position sensor, and wherein the processing unit is configured to operate the hydraulic actuator, in response to the determined difference variation being greater than a predetermined value for a predetermined amount of time, to adjust the set operating position of at least one of the two hydraulic rams.

[0021] Following this approach, slack present in the set of actuating elements can be compensated.

[0022] According to a further aspect of the present disclosure, the movable airfoil element comprises a lower end and an upper end, wherein the at least two hydraulic rams comprise at least two hydraulic actuator rams at the upper end of the movable airfoil element and at least two hydraulic rams at the lower end of the movable airfoil element, wherein the at least one position sensor comprises a position sensor configured to measure the actual current angle of the upper end of the movable airfoil element and a position sensor configured to measure the actual current angle of the lower end of the movable airfoil element, and wherein the processing unit is further configured to determine a difference between the determined actual current angle of the upper end of the movable airfoil and the determined actual current angle of the lower end of the lower end of the movable airfoil, and wherein the processing unit is configured to operate at least one of the upper and lower end hydraulic actuator rams.

[0023] Following this approach, the twisting of the airfoil elements can be reduced.

[0024] According to a further aspect of the present disclosure, the processing unit is configured to determine if the determined difference is greater than a first predetermined value and/or if the determined difference variation is greater than a second predetermined value.

[0025] Following this approach, the different causes for malfunctioning of the sail element can be tackled appropriately.

[0026] According to a further aspect of the present disclosure, the processing unit is configured to determine if the difference is greater than a predetermined value for a first predetermined amount of time and if the difference variation is greater than a predetermined value for a second predetermined amount of time.

[0027] Following this approach, the different causes for malfunctioning can be compensated at the appropriate time.

[0028] According to a further aspect of the present disclosure, the sail element comprises a tilt plate, such that the sail element is configured to rotate over a horizontal axis towards a horizontal direction and the processing unit is configured to operate a further actuator to rotate the sail element towards the horizontal direction after carrying out the position adjustment procedure into the new set operating position.

[0029] Following this approach, the system can be stowed safely and herewith the risks of faulty operation which can lead to hazardous situations, e.g. in case of adverse weather conditions.

[0030] According to a further aspect of the present disclosure, the wind propulsion operation system comprises a plurality of sail elements.

[0031] According to further aspects, a method, a data processing apparatus, a (non-transitory) computer-readable storage medium, and a (non-transitory) computer program product configured to carry out the corresponding methods by the claimed systems are envisaged within the present disclosure.

Brief description of the Drawings

[0032] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

Figure 1a shows and embodiment of the current disclosure wherein the propulsion systems are mounted on a marine vessel deck.

Figure 1b shows different examples of wind propulsion systems to which the wind propulsion operation system of the current disclosure can be applied to.

Figure 2 shows a schematic representation of a wind operation system according to the current disclosure.

Figure 3 shows a schematic representation of a sail element according to one embodiment of the current disclosure.

Figure 4 shows a schematic representation of an actuating arrangement of a sail element according to another embodiment of the current disclosure.

Figure 5a shows a schematic representation of a marine vessel according to an embodiment of the current disclosure.

Figure 5b shows a schematic representation of a marine vessel with stowed sail elements according to an embodiment of the current disclosure.

Figure 6 shows a flow chart of a method of the current disclosure according to an embodiment of the present disclosure.

Detailed Description

[0033] As used below in this text, the singular forms "a", "an", "the" include both the singular and the plural, unless the context clearly indicates otherwise. The terms "comprise", "comprises" as used below are synonymous with "including", "include" or "contain", "contains" and are inclusive or open and do not exclude additional unmentioned parts, elements or method steps. Where this description refers to a product or process which "comprises" specific features, parts or steps, this refers to the possibility that other features, parts or steps may also be present, but may also refer to embodiments which only contain the listed features, parts or steps.

[0034] Whereas the terms "one or more" or "at least one", such as one or more or at least one member(s) of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, ≥4, ≥5, ≥6 or ≥7 etc. of said members, and up to all said members. The use of the expression "at least" or "at least one" suggests the use of one or more elements, as the use may be in one of the embodiments to achieve one or more of the desired objects or results.

[0035] In the following passages, different aspects of the application are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0036] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the application, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0037] The enumeration of numeric values by means of ranges of figures comprises all values and fractions in these ranges, as well as the cited end points. The term "approximately" as used when referring to a measurable value, such as a parameter, an amount, a time period, and the like, is intended to include variations of +/- 10% or less, preferably +/-5% or less, more preferably +/-1% or less, and still more preferably +/-0. 1% or less, of and from the specified value, in so far as the variations apply to the disclosure disclosed herein. It should be understood that the value to which the term "approximately" refers per se has also been disclosed.

[0038] Further, the terms "preferably", "more preferably", "particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities.

[0039] Unless defined otherwise, all terms present in the current disclosure, including technical and scientific terms, have the meaning which a person skilled in the art usually gives them. For further guidance, definitions are included to further explain terms which are used in the description of the disclosure.

[0040] In the following, the present disclosure is further described with reference to the enclosed figures.

[0041] Figure 1a shows an exemplary embodiment of a marine vessel 1 using wind propulsion systems 100.

[0042] Figure 1b shows different embodiment of publicly available wind propulsion systems for which the wind propulsion operation system of the current disclosure may be used. While the different constructional arrangements may differ in their shapes and dimensions, the current wind propulsion operation system as intended within the current disclosure aims at the operation of different wind propulsion systems for achieving a reliable and fail-safe operation. Within the represented wind propulsion systems, some common features are expected. The sail element 100 in Figure 1B i comprises a main spar, and a lower frame and an upper frame to which different airfoil elements are rotatably attached. In this case, all three airfoil elements depicted are movable. Figure 1B ii shows another embodiment wherein a central airfoil element is rigidly connected with lower and upper frames, whereas the two outer airfoil elements are movable. Figure 1B iii shows another constructional embodiment with only two movable airfoil elements rotatably supported on respective upper and lower frames.

[0043] It is to be remarked that these wind propulsion systems may amount to heights of up to 40 meters and beyond and due to the possible wind loads they might be subjected, they must be built with a considerable strength. Hence, these systems present a big weight, and their operation systems have to be reliable and secure to avoid failures and operating conditions which could endanger the vessels and even capsize them in the case of marine vessels.

[0044] The wind propulsion systems for which the operation system of the current disclosure is intended to serve comprise at least one sail element situated on a substantially horizontal surface of the vessel from which the at least one sail element extends upwards in order to offer a surface exposed to wind conditions which provide the necessary thrust to the vessel. Depending on the size of the vessel, one or more of these sail elements may be situated on the roof of terrestrial vessels or on the deck of marine vessels, arranged in such a way that they do not interfere with cargo handling and/or visibility for the operators.

[0045] A wind propulsion system according to the present disclosure comprises at least one sail element 100 and a base plate 110, wherein the at least one sail element 100 is rotatably arranged on the base plate 110 to set a wind angle of the sail element. The sail element 100 may for example be rotatable about a (substantially vertical) axis Y1 as defined by the main spar 111. The sail element comprises a plurality of airfoil elements 120, wherein at least one of the airfoil elements is movable and configured to modify the camber line of the sail element.

[0046] Within the present disclosure an airfoil element is to be understood as an elongate rigid member configured to receive in one of its surfaces the force of wind. While usual shapes in the field of aerodynamics are preferred due to the high lift to drag ratio, these comprising a cambered shape, wherein the leading edge is thicker than the trailing edge as usual in planes, other shapes which allow the formation of a surface which acts as a sail, hereby capturing the wind force, are considered within the present disclosure. The airfoil elements 120 may be substantially vertical.

[0047] According to one embodiment, as it can be seen in Figure 2, the sail element comprises a main spar 111 rotatably connected with the base plate 110. The sail element may comprise a main lower frame 112, attached to the main spar 111, on which the plurality of airfoil elements 120 are arranged and operatively connected to in order to elevate the sail element to increase the surface available to the wind. However, such a construction is for orientation and the airfoil elements 120 may as well be directly connected on to the base plate 110. While in the schematic representation the different airfoil elements 120 and 125 have been represented with a clearly observable distance between them, as present in the different Figures showing the more accurate and true representation of the sail elements, the gap between the airfoil elements is intended to allow the necessary play for the airfoil elements to rotate without colliding while regenerating the air flow generating the thrust, keeping the air flow attached.

[0048] The wind propulsion system comprises at least one of the airfoil elements being movable. While the general orientation of the sail element 100 can be changed as the sail element is rotatably arranged on the base plate 110, at least one of the airfoil elements 120 (e.g. airfoil element 125) is movable in order to be able to modify the camber line of the sail element 100, and herewith provide different configurations which optimize the wind thrust at different wind and travelling directions, hereby optimizing the lift-to-drag ratio of the sail element.

[0049] A wind propulsion operation system 10 according to the present disclosures comprises a processing unit 200, wherein the processing unit comprises at least one memory unit 220 and at least one processor 210 configured to carry out instructions to operate the wind propulsion system 100 by means of at least one actuator and a communication unit 250, configured to operatively communicate, by means of wired or wireless communication with the wind propulsion system and other external devices. The wind propulsion operation system of the present disclosure may as well comprise an input/output unit 230, a location determining unit or GPS unit 240 or equivalent, a wind sensor 260 and any other components customary to electronic processing devices on transport vessels. The processing unit may as well be configured to received wind and/or weather data by means of the communication unit 250.

[0050] In the context of the present disclosure, a processing unit 200 may refer to any electronic processing device as known in the art. Examples of a processing unit may be a microprocessor, a microcontroller or the like, or a processing unit like a computer, a laptop, a mobile device, a dedicated electronic control unit or the like. However, other electronic processing or controlling devices like a programmable logic computer (PLC) or electronic control unit (ECU) are included within the present disclosure. The processing unit 200 may be a local device present on the vessel, or a remote device, connected by means of satellite communications or a distributed computing device.

[0051] In the context of the present disclosure, an actuator 300 may refer to any components responsible for moving and controlling an element, a mechanism, the wind propulsion system or a part or a sub-part thereof. In this sense, an actuator 300 might be an electric solenoid or motor configured to displace or rotate a specific part, a hydraulic or pneumatic actuator which, upon operation of respective valves comprised in a hydraulic system, may be configured to rotate or displace specific elements of the wind propulsion system by means of a pressurized fluid, as it will be described below. Different actuators are comprised within the current disclosure and based on their specific nature and properties, the wind propulsion operation system 10 of the current disclosure is configured to perform the necessary adjustments which improve the respective performance of each actuator.

[0052] A wind propulsion operation system 10 according to the present disclosure may comprise at least one actuator 301 to rotate the sail element 100 to a set wind angle or operating position. The sail element 100 may further comprise at least one actuator 302 to move or rotate the at least one movable airfoil element 125 and herewith modify the operating position of the movable airfoil 125 to modify the camber line of the sail element 100. According to the different embodiments, the wind propulsion operation system may comprise at least one actuator for each movable airfoil element.

[0053] As it can be seen in Figure 2, a sail element 100 according to the present disclosure may comprise a plurality of airfoil elements, wherein at least one airfoil element is movable, whereas the remaining airfoil element/s or a subset of them may be not movable. In a further embodiment, all airfoil elements may be movable. This allows to invert the camber and have a more flexible configuration according to the incoming wind directions.

[0054] According to the present disclosure, movable may mean rotatable over at least one usually vertical axis Y2, wherein the rotation axis may or may not be located inside the body of the movable airfoil element 125. The movable airfoil element may be configured to rotate over a first axis Y2 located inside the body of the airfoil element and may be further configured to rotate over a second axis located outside the body, hereby increasing the degrees of freedom for the movable airfoil element 125 to modify the camber line of the sail element.

[0055] A wind propulsion operation system 10 according to the current disclosure comprises at least one position sensor (e.g., 401, 402, 410, 411, 412, 415) to determine the operating position of the at least one actuator 300 and/or the sail element 100 and/or the at least one movable airfoil element 125.

[0056] In the context of the present disclosure, a position sensor may be a linear or rotary encoder configured to determine the position of a movable element. A position sensor according to the present disclosure is not limited to any specific detecting principle and may be of an optical, electric, capacitive or resistive, electro-magnetic or any other suitable nature.

[0057] The processing unit 200 of the current disclosure may be configured to acquire the position as determined by the at least one position sensor and may further be configured to store the values in the memory unit 220 for further analysis in order to determine variations of the position of at least one of the at least one actuator, the sail element or the movable airfoil element.

[0058] According to the main embodiment, and following the reference signs of Figure 2, the processing unit 200 is configured to determine a difference and/or a difference variation between the set operating position and the actual operating position of at least one of: the at least one actuator (e.g., 301, 302), the sail element 100 and the at least one movable airfoil 215 element determined by the at least one position sensor (e.g., 401, 402, 411, 412). In response to the determined difference and/or a difference variation being greater than a predetermined value for a predetermined amount of time, the processing unit 200 is configured to determine a new set operating position of the at least one actuator (e.g., 301 or 302).

[0059] Within the current disclosure, a set operating position is an operating position as instructed by the processing unit related to the position the sail element or the movable airfoil element should take during the operation of the wind propulsion system. The set operating position may be determined according to a manual instruction of the operators via the input unit 230. However, the set operating position may be determined by the processing unit 200 according to predetermined configurations of the wind propulsion system 200 stored in the memory unit 220, directly received by the communication unit 250 or may be determined on real time based on inputs from the GPS unit 240 and/or the wind sensor 260 in order to maximize the wind thrust or according to navigational requirements to maintain the most efficient route. The set operating positions may be determined for a specific moment in time or for a plurality thereof, forming a sequence of time ranges for future operation, wherein the processing unit 200 may be configured to store them in the memory unit 220. The processing unit may as well be configured to store past values of the set operating position in the memory unit 220.

[0060] The wind propulsion operation system of the current disclosure is configured to enter a fail-safe operation mode when the wind propulsion system is unable of following or maintaining the set operating positions of at least one of the at least one actuator, the at least one sail element and the at least one movable airfoil element. This fail-safe operation mode will be made clear below and the different embodiments further specified.

[0061] Within the current disclosure, a difference between the set operating position and the actual operating position is determined understood to be the absolute offset between the position where the processing unit 200 aims for the element to be, i.e., the airfoil element 125 or the sail element 100, and where the element is at the moment, this being captured by the position sensor. Within the current disclosure, a difference variation is understood to be the additive amount of the modulus of the offset between the position where the processing unit 200 aims for the element to be, i.e. the airfoil element 125 or the sail element 100, and where the element is at the moment, this being captured by the position sensor, between a starting time t and the predetermined time ti, which may be the first predetermined or second predetermined time amount. As such, the difference variation can capture when slight differences between the set operating position and the current operating position can be present in the wind propulsion system due to the oscillations. Hence, while the airfoil element 125 may only differ a small amount, e.g., +- 1 degree, a continuous variation leads to reduced performance and may lead to further instabilities. The difference and the difference variation are expressed mathematically below for clarification following exemplary functions which may represent such a difference and difference variation as used within the current disclosure. However, the following equations are not meant to be limiting and any other mathematical relations determining a difference and or a difference variation may be used. For the equations below, D₁ represents the expressed difference and ΔD₁ and ΔD₂ represent the difference variation, POS_set would represent the set operation position, POS_act would represent the actual operating position as captured by the position sensor, and POS_act-1 and POS_set-1 would represent the actual and the set operating position at a previously sensed moment in time.

[0062] For example, for a given set operating position of a movable airfoil element of +10 degrees, wherein the sail element actual operating position is fixed at +12 degrees, this would deliver a difference of 2 degrees, wherein a difference variation would be 0 degrees. In another example, when a set operating position for a movable airfoil is -15 degrees and the movable airfoil oscillates continuously between -14.5 and 15.5 degrees, while D₁ may be comprised between 0.5 and 0.5 and therefore not go over any of the predetermined values chosen as threshold for initiating the set position adjustment procedure, using a further parameter to determine the correct operation of the wind propulsion system like the difference variation, wherein the difference variation for example as expressed by ΔD₂, which corresponds to ΔD₁ for the specific case in which the set operating position has not changed within the time ti and can be used as well as an indicator of difference variation, will keep increasing and eventually within the specified predetermined time amount reach the predetermined value.

[0063] According to a further embodiment, the processing unit is configured to determine if the difference is greater than a predetermined value for a first predetermined amount of time and if the difference variation is greater than a predetermined value for a second predetermined amount of time. Depending on the different embodiments considered, e.g. when the sail element and/or airfoil element operating position is considered, and the difference between the set operating position and the actual operating position is considered, a first predetermined value may be chosen to be +-10 degrees for the predetermined amount of time. More preferably, the first predetermined value is +-5 degrees. In a further embodiment, when the difference variation between the set operating position and the actual operating position is considered, a second predetermined value may be chosen to be 3 degrees per predetermined amount of time. More preferably, the second predetermined value may be chosen to be 2 degrees per predetermined amount of time, i.e., the difference variation during the predetermined amount of time is in any case smaller than the second predetermined value. According to a further embodiment, as explained below, when the linear position of the hydraulic actuators may be considered, a first predetermined value may be chosen such that the difference of the may be limited to a 5% of the absolute value of the position of the hydraulic actuator.

[0064] In the above case, when the actuator 301 is configured to rotate the sail element 100 relative to the base plate 110, the wind forces effectuated on the sail element 100 may be too big to be overcome by the at least one actuator 301 due to the set wind angle of the sail element 100. If the actuator 301 is unable of reaching the set operating position (the set wind angle of the sail element) for more than a predetermined amount of time, the processing unit 200 is configured to determine a new set operating position of the at least one actuator 301 for the sail element 100 to adopt a new wind angle. The new set operating position may be at least one of: a fail-safe position, a predetermined position determined on the incoming wind and a stowage position. Within the present disclosure, a fail-safe position may be an end position of the actuator (e.g., 301), wherein when the actuator has reached the position, the position sensor may be reset, certain of the operating position or may be a neutral position. Within the present disclosure, a predetermined position determined on the incoming wind may comprise (the processing unit 200) determining based on weather and/or wind data and the inability of the sail element 100 to achieve the set operating position a further operating position which outside of the previous set operating position maximizes the thrust of the sail element 100. A predetermined position may as well be determined to reduce wind thrust and/or drag based on weather and/or wind data. Determining a new set operating position may comprise determining a new set operating position for the plurality of movable airfoil elements for those embodiments comprising more than one movable airfoil element and/or the working angle of the sail element 100. For example, regarding the sail element present in Figure 1B i and iii, the position of the different airfoil elements may be determined in different ways. While the sail assembly depicted in case i may adapt the angle of all three movable airfoil elements individually and further change the working angle rotating the main spar, the sail element of depicted in ii may change the working angle of the sail element rotating the main spar, hereby changing the position of the middle airfoil element and then adapt the two exterior movable airfoil elements. Within the present disclosure, a stowage position is a predetermined position configured to allow the stowage of the sail element 100, hereby reducing the risk of colliding or achieving a more compact arrangement of the plurality of airfoil elements.

[0065] In a further embodiment, wherein the set position adjustment procedure involves setting a new position for at least the one actuator configured to rotate the sail element and involves setting as well a new position for the at least one actuator configured to rotate the airfoil element, i.e. the set position adjustment procedure involves actuating a plurality of actuators, the set position adjustment procedure may comprise adjusting the position of each actuator in a sequential order. Due to the big amount of hydraulic liquid needed to operate these wind propulsion systems, and the limited pressure available, achieving a first operation of the most critical actuator for guaranteeing the safety of the vessel is crucial. For example, setting a working angle of the sail element may be prioritized over adjusting the position of a movable airfoil element, since that might have a greater influence in the resulting wind thrust, whether if it is to achieve a quicker response in order to maximize the thrust or in case of an excessive wind, diminish it. This is further advantageous when a plurality of sail elements are present on the vessel, since the amount of pressurized fluid needed increases accordingly and it is further advantageous to fully operate one of the sail elements and/or movable airfoil elements first to the new set operating position rather than slowly operating all sail elements/movable airfoil elements.

[0066] Hence, the wind propulsion operation system being configured to initiate a set position adjustment procedure may comprise determining a new set operating position of at least one of the at least one actuator, the at least one sail element and the at least one movable airfoil element. Based on the specific discrepancies pointed out by the relevant differences or difference variations of at least one of the at least one actuator, at least one sail assembly or the at least one movable airfoil element, different issues along the actuating elements and actuated elements can be unequivocally ascertained and herewith the specific cause of the malfunction remedied.

[0067] Correspondingly, same may happen with the at least one actuator configured to move said at least one movable airfoil element 125, in which case the processing unit 200 may be configured to determine a new set operating position for the at least one movable airfoil element 125. It is to be remarked that such a control differs greatly from normal closed-loop approaches, in which a set operating position and a current operating position are compared to achieve an accurate steering of the actuators. In view of the required amount of time during which the difference and/or the difference variation may be greater than the predetermined value, said difference and/or the difference variation is not caused by the usual lag in hydraulic systems but due to malfunctioning of the actuators and/or slack present in the actuating elements and/or external conditions or blockages present in the vicinity of the sail element. According to a further embodiment, the predetermined amount of time may be comprised between 0 seconds and 3 minutes, preferably between 5 seconds and 3 minutes, more preferably between 5 seconds and 1 minute, more specifically between 5 seconds and 30 seconds, and more specifically between 5 seconds and 10 seconds.

[0068] Further, due to slack present in the different actuating arrangements formed by the actuator (e.g. 301, 302) and actuating elements and/or due to varying wind forces, the position of at least one of the at least one actuator, the at least one sail element 100 and the at least one movable airfoil element 125 maybe oscillating such that the difference between the set operating position and the actual operating position of said at least one actuator, the at least one sail element 100 and the at least one movable airfoil element 125 varies more than a predetermined value for a predetermined amount of time. Due to the present slack and/or the varying wind forces, said oscillations reduce the performance of the sail elements 110 and introduce vibrations to the base plate 110 and through that to the main frame of the vessel. Hence, adjusting at least one of: the at least one actuator, the sail element and the at least one movable airfoil element to a new set operating point the performance and reliability of the wind propulsion system is increased. For example, if the oscillations are originated due to the slack of one cable present in an actuating chain as it will be made clear below, adjusting the respective actuator will reduce the slack and herewith the vibrations of the wind propulsion system. If the oscillations are caused by aeroelastic effects due to the wind speeds and directions together with the structural elements forming the airfoils, adjusting the position of the sail element 100 and/or the airfoil element 125 will reduce the oscillations of the wind propulsion system.

[0069] According to an embodiment, the at least one actuator is a hydraulic actuator, wherein the wind propulsion operation system further comprises a hydraulic power unit 260 configured to operate the hydraulic actuator and an electric generation unit 270 configured to provide electric power to the hydraulic power unit 260. Hydraulic systems comprising the necessary amount of shut-off valves, accumulators or gas struts to ensure the steering of the hydraulic fluid through pipes, even on emergency conditions, onto the actuating elements belong to the state of the art and will not be described any further here nor are specifically represented in the figures, apart from the schematic representation in Figure 2.

[0070] According to an embodiment, the sail element 100 may further comprise a tilt plate 115 on which the base plate 110 may be arranged, wherein the tilt plate 115 is arranged on a (usually) horizontal surface by means of a hinged surface, allowing that the sail element 100 is rotated over a horizontal axis which could be seen to be represented by an axis perpendicular to the figure passing by the center of the circle representing the hinge of tilt plate 115., achieving a more compact position in wind direction due to the slender shape of the airfoil elements 120, 125. According to this embodiment, the sail element 100 may be stowed, i.e., tilted towards a horizontal orientation, in order to reduce the wind resistance during extreme weather conditions or when the wind direction is not favorable. Following this embodiment, the wind propulsion operation system may further comprise an actuator 320 configured to tilt and/or stow the sail element 100. Actuator 320 may be at least one hydraulic cylinder configured to lift and/or displace one side of the tilt plate 115, wherein the tilt table 115 may be configured to rotate over the horizontal axis X1 as defined before opposite to the displaced and/or lifted side or over a horizontal axis formed by supporting elements attached to the vessel, as it can be see depicted in Figure 5a and 5b, wherein 5a shows the sail elements in the substantially vertical position and Figure 5b shows the sail elements 100 in the substantially horizontal position. Following this embodiment, the processing unit 200 is configured to operate the actuator 320 and tilt the at least one sail element 100 towards a horizontal direction after carrying out the position adjustment procedure into the new set operating position.

[0071] According to a further embodiment, the wind propulsion system comprises a slew bearing integrated in the base plate 110 configured to allow rotation of the sail element with respect to the base plate and the at least one actuator 301 comprises at least one slew bearing hydraulic motor configured to rotate the at least one sail element rotatably arranged on the base plate. According to one embodiment, the wind propulsion operation system comprises at least a rotary encoder 401 to determine the operating position of the sail element and herewith the wind angle. Direct transmission of movement by means of slew bearings and gear wheels allow a precise positioning of heavy weight systems and are preferred for the rotation of the sail element.

[0072] In a further embodiment, the wind propulsion operation system comprises at least one further position sensor 401 to verify that the sail element is at a predetermined position, e.g., at the fail-safe position, or the predetermined position for stowing operation. While, due to the usual size of these sail elements and their weight, the base plate is configured to comprise the slew bearing connecting the main spar 111 in this advantageous embodiment, other arrangements are as well envisaged within the scope of the present disclosure. For example, a gear wheel may be operatively connected to the base plate and/or the sail element to which a hydraulic motor and a hydraulic brake as defined above may be operatively connected.

[0073] According to a further embodiment, the airfoil element being rotatably supported by the lower frames 112 is allowed by means of a slew bearing configured to allow rotation of the at least one movable airfoil element, wherein the actuator 302 configured to rotate the movable airfoil element 125 is a hydraulic motor. Following this embodiment, analogously to the previous embodiment where the rotation of the sail element with respect to the base plate is described, analogous constructions can be thought for operating the at least one movable airfoil element.

[0074] According to a further embodiment, as it can be seen in Figure 3, the wind propulsion system may comprise a lower frame 112 and an upper frame 113. The lower and upper frames may be connected by means of a rigid structure, wherein the rigid structure may be built inside one or more airfoil elements, hereby increasing the stiffness of the sail element 100. According to a further embodiment, the lower frame 112 and/or upper frame 113 are only rotatably supported connected to the at least one movable airfoil element 125, wherein the movable airfoil elements 125 are rotatably supported by the lower and upper frames 112 and 113.

[0075] According to a further embodiment, the wind propulsion operation system comprises at least one hydraulic cylinder 310, 311 or hydraulic ram to move the at least one movable airfoil element. Hydraulic cylinders are well known and usually comprise an enclosure and a piston slidably inserted in the enclosure, wherein the pressure of a liquid comprised in the enclosure, which is fed by means of the hydraulic power unit 260, exerts pressure on the piston and herewith displaces the piston connected to an actuating rod. The at least one hydraulic cylinder may be arranged on the lower and/or upper frame, depending on the constructional arrangement of the sail element. The at least one hydraulic cylinder may be directly or indirectly connected to the movable airfoil element 125 by means of connecting rods or other rigid connections which push or pull the movable airfoil elements in a specific direction. Establishing direct or indirect rigid connections between the at least one hydraulic cylinder increase the stiffness of the airfoil element.

[0076] According to a further embodiment as depicted in Figure 4, the actuator 302 as depicted in Figure 2 is formed by at least two hydraulic cylinders or rams 310 and 311 to move the at least one movable airfoil element 125. According to a further embodiment, the hydraulic cylinders 310 and 311 may be connected to the movable airfoil element 125 by means of at least one cable 313 or a steel wire or the like. According to a further embodiment, the wind propulsion operation system comprises an airfoil element quadrant 325, rotatably supported on the lower frame 112 allowing the movable airfoil element to rotate around axis Y2. The airfoil element quadrant 325 may in turn be rotatable or rigidly connected to the airfoil element 125, allowing in the first case a further rotation around a second axis Y3, wherein a further actuator 315 may be configured to rotate the airfoil element 125 around said second axis Y3. By means of such a quadrant 325, the movable airfoil elements may have an axis of rotation or pivot point at a different location inside or outside the airfoil element, hereby allowing the airfoil element to have different axis of rotations depending on the specific constructional arrangement best suited for the sail assemblies and allowing compact stowing arrangements.

[0077] According to the embodiment shown in Figure 4, said at least one position sensor comprises at least one position sensor 412 configured to determine the position of the airfoil element quadrant 325 and with it the position or current angle of the movable airfoil element 125. According to a further embodiment, the airfoil element may comprise another position sensor 415 configured to determine the operating position of the further actuator 315.

[0078] In a further embodiment, said at least one position sensor further comprises a sensor 410 or 411 configured to measure the current position of at least one of the at least two hydraulic rams or cylinders 310 and 311. The at least two hydraulic cylinders 310 and 311 may be connected to the airfoil element quadrant 325 by means of at least one cable 313. In an embodiment, a single cable may be attached to the airfoil element quadrant 325 directly, increasing the flexibility of the actuating arrangement and allowing a fixed point of thrust determined by the radius/diameter of the pulley or airfoil element quadrant 325. The cable 313 may be slidingly connected to the or rigidly connected to the pulley or airfoil element quadrant 325 to avoid slip. In another embodiment, the airfoil element comprises an arrangement with at two cables, wherein each cable is connected to the airfoil element quadrant 325 at a specific connection point by means of clamping or any attachment means or the like.

[0079] Following this embodiment, the cables may present slack due to stretching of the cables or, in a worst-case scenario, rupture due to wear caused by their operation. An appropriate control of the actuating mechanism which is able of tackling said disadvantages caused by the more flexible arrangement using cables should be introduced to improve the performance of the sail elements and, if necessary, warn the crew of the vessel since the integrity of the sail element and with it the vessel may be at risk.

[0080] According to a further embodiment, the processing unit 200 is configured to determine a difference between the set operating position and the actual operating position of at least one of the two hydraulic cylinders 310 and 311and/or the airfoil element 125, wherein if the difference variation is greater than a predetermined value for a predetermined amount of time, the processing unit is configured to adjust the operating position of at least one of the two hydraulic rams 310 and 311 so that the operating position of the airfoil element 125 coincides with the set operating position. The advantages of this embodiment will be made clear below.

[0081] The position of the airfoil element 125 is always an indicator of the correct functioning of the actuator arrangement. If the operating position of the airfoil element 125 differs from the set operating position for a predetermined amount of time, this might indicate that the hydraulic actuators are unable of achieving the set operating position for other reasons than the existing inertia of the sail or airfoil element. For example, due to a high wind speed certain positions of the airfoil element 125 in operating positions of the sail element 100 may not be able to be reached, but this might as well indicate blockages in the wind propulsion system. However, there are cases in which with the airfoil element 125 being in the correct set operating position, a certain slack may still be present in the actuator arrangement. Due to the own weight of the airfoil or sail elements and wind propulsion system hysteresis, the need for the set position adjustment procedure may only be derivable from the position of the actuators 310 and 311. If both pistons are supposed to be extended to a specific set operating position, e.g., 50% of the stroke, this meaning that the airfoil position is at a specific position as well, which however might be different according to the specific constructional arrangement of the airfoil element and therefore not to be limiting in this example. Following this example and if the actual operating position of the hydraulic cylinders 310 and 311 correspond to the set operating position, the values of operating position of both pistons add up to a specific value, e.g., 100% in this case. This means, however, that there is no slack only if the current operating position of the airfoil element is stable and corresponds to the set operating position of the airfoil element and is therefore needed to consider both factors. However, when the airfoil element is in the set operating position, but at least one of the wires is stretched up, the pistons of the hydraulic actuators might be in different operating positions which do not add up to 100% due to the hydraulic load imbalance, hereby indicating the existing slack, which can be detected by determining the difference between the set and current operating position of at least one hydraulic cylinder 310, 315.

[0082] The predetermined value may be fixed according to different parameters. In an embodiment, if the predetermined value exceeds a first value, the wind propulsion system may suffer slack and therefore the set position adjustment procedure may be initiated. In another embodiments, upon the predetermined value exceeding the first value, the processing unit may be configured to output a warning to the crew to check the wires. In a further embodiment, if the predetermined value exceeds a second value, bigger than the first value, the processing unit may be configured to output and error and/or stop the operation of the actuating arrangement, since this would detect the risk of an instable airfoil element.

[0083] In a further embodiment, when the hydraulic cylinders 310 and 311 are extended at an operating position which coincides with the set operating position of the hydraulic cylinders for the set operating position of the airfoil element 125, due to the hysteresis of the hydraulic actuators 310 and 311, the wind propulsion system still might present some slack which causes an oscillation of the airfoil element 125, being this indicative of the slack.

[0084] In this embodiment, the processing unit is configured to determine a difference variation between the set operating position and the actual operating position of the airfoil element 125, wherein if the difference variation is greater than a predetermined value for a predetermined amount of time, the processing unit is configured to adjust the set operating position of at least one of the two hydraulic cylinders 310 and 311 such that the cables are re-tensioned without affecting the operating position of the airfoil element 125.

[0085] According to a further embodiment, as depicted in Figure 3, the at least one movable airfoil element 125 comprises a lower end 140 and an upper end 150, wherein the wind propulsion operation system comprises at least one actuator 302 at the lower end and at least one actuator 303 in the upper end. In a further embodiment, the movable airfoil element comprises at least two hydraulic cylinders at the lower end 140 and at least two hydraulic cylinders at the upper end 150, wherein the arrangement can be as explained with respect to Figure 4, wherein a set of two hydraulic cylinders 310 and 311 as displayed supported by lower frame 112 and configured to move the airfoil element are as well present on the upper end 150 of the movable airfoil element 125 and attached to the upper frame 113. In this embodiment, the at least one movable airfoil element may be rotatably supported by the lower frame, to which the hydraulic cylinders may be operatively connected to in order to exert the necessary forces to move the airfoil elements. At the top end, the wind propulsion system may comprise accordingly an upper frame to which the at least one movable airfoil 125 is as well rotatably connected, to which the hydraulic cylinders at the upper end may be connected, as explained above, in an arrangement equivalent as the one shown in Figure 4.

[0086] Due to the size of the sail assemblies present in marine vessels, this embodiment provides the necessary forces to securely actuate the airfoil elements, which can amount to heights of up to 40 m and more, and due to the needed rigidity of the constructing frames for the airfoils, weigh up to several tons. In this specific embodiment, offsets between the upper and the lower ends of the airfoil element are of critical importance since these offsets may cause torsion of the airfoil elements, on one side reducing the performing of the sail element and as well reducing the resistance of the material to the inherent vibrations caused by aeroelastic deformations of the airfoil elements due to the wind.

[0087] Following this embodiment, the processing unit may be configured to determine a difference between the position of the upper end of the airfoil element and the lower end 140, directly on the airfoil element or as indicated by the lower or upper quadrant wheels to which the airfoil element is attached. If the difference between the operating position of the upper end 150 hydraulic cylinders and/or the upper end of the airfoil element or the upper quadrant and the operating position of the lower end hydraulic cylinders and/or the lower end 140 of the airfoil element is bigger than a predetermined value, e.g. +- 5 degrees, more specifically +- 3 degrees, the processing unit is configured to adjust the position of at least one of the hydraulic actuators at the upper and and/or lower end of the airfoil element. In some cases, it might suffice to just adjust one actuator from the end which deviates most from the set operating position, however this might need further adjustments at the different hydraulic cylinders to maintain the current operating position of the airfoil being the optimal for the sail element to produce the maximum thrust, since due to the deformation of the airfoil element correcting one end's position may affect the other end's position.

[0088] According to a further embodiment, the processing unit is configured to determine if the difference and/or the difference variation as determined above are greater than a first and a second predetermined value, respectively. As it is to be seen for the examples explained above, whether a difference between the set operating position and an actual operating position may amount to 2 degrees, a difference variation of only 1 degree as a result of the present oscillations of the sail and/or movable airfoil element may have as well detrimental consequences. Hence, setting different first and second predetermined values which can appropriately capture the dynamics in view of the predetermined times used for executing the set position adjustment procedure is of further advantage. Following this embodiment, adjustment procedures can be adapted upon the specific behavior of the sail element, hereby fine tuning the adjustment procedures for the specific malfunctioning. As such, while differences caused by offsets present in the movements of the hydraulic actuators due to the slow dynamic constants of hydraulic systems cannot be reacted upon that quickly, difference variations caused by oscillations of the sail and/or movable airfoil element shall be reacted upon quickly despite the smaller magnitude, as it will be further made clear below when adapting the predetermined times for each of the difference and the difference variation.

[0089] According to a further embodiment, the processing unit is configured to determine if the difference is greater than a predetermined value for a first predetermined amount of time and if the difference variation is greater than a predetermined value for a second predetermined amount of time. Following this embodiment, the processing unit can react with the appropriate swiftness based on the causes of the problem. In a further embodiment, the first predetermined amount of time is set to be bigger than the second predetermined amount of time.

[0090] For example, following the above-mentioned embodiment, the predetermined amount of time may be comprised between 0 seconds and 3 minutes, preferably between 5 seconds and 3 minutes, more preferably between 5 seconds and 1 minute, more specifically between 5 seconds and 30 seconds, and more specifically between 5 seconds and 10 seconds, the first predetermined amount may be chosen with the same parameters. The second predetermined amount of time may be comprised between 0 seconds and 1 minute, more preferably between 2 seconds and 30 seconds, more specifically between 2 seconds and 10 seconds, and more specifically between 2 and 5 seconds. As such, while the slow movement of the airfoil elements can be still guided smoothly, the wind propulsion operation system is determined to swiftly correct the difference variation which can be the product from oscillations of the airfoil elements, which could cause problems of resonance and loss of performance due to transient aerodynamics.

[0091] In a further embodiment, wherein the sail element comprises a tilt plate 115, the processing unit 200 is configured to instruct actuator 310 to stow the sail element 100, such that the sail element 100 is configured to rotate over a horizontal axis X1, represented as being perpendicular to the figure plane, towards a horizontal direction after carrying out the set position adjustment procedure into the new set operating position, wherein the new set operating position of the at least one sail element 100 and/or the airfoil element 120, 125 is the stowage position.

[0092] Figure 6 shows a flowchart of a method of the current disclosure according to an embodiment of the present disclosure. The method of operation of a wind propulsion operation system 10 for propelling a vessel comprises operating (3000) an actuator to set an operating position of at least one of the sail element and/or the movable airfoil element. Further, the method comprises determining (3100) by the processing unit a position of the at least one of the at least one actuator, the at least one sail element and/or the at least one movable airfoil element and determining (3200) by the processing unit a difference and/or a difference variation between the set operation position and the determined operating position of at least one of the at least one actuator, the at least one sail element and/or the movable airfoil element; wherein if the difference and/or the difference variation is greater than a predetermined value for a predetermined amount of time, the method further comprises determining (3300, 3400) by the processing unit a new set operating position of at least one of the at least one actuator, the sail element, and the movable airfoil element.

[0093] According to the different embodiments, the method may further comprise the processing unit determining a new set operating position (3300) when the processing unit has determined that difference is greater than a first predetermined value for a first predetermined amount of time, as explained above, and determining a new set operating position (3400) when the processing unit that the difference variation is greater than a predetermined value for a second predetermined amount of time.

[0094] All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference.

[0095] In the present description of the application, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration only of specific embodiments in which the application may be practiced. Parenthesized or emboldened reference numerals affixed to respective elements merely exemplify the elements by way of example, with which it is not intended to limit the respective elements. It is to be understood that other embodiments may be utilized, and structural or logical changes may be made without departing from the scope of the present application. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims. Accordingly, the detailed description thereof should not be construed as restrictive in all aspects but considered as illustrative. The scope of the disclosure should be determined by reasonable interpretation of the appended claims and all changes that come within the scope are included in the scope of the current disclosure.

[0096] While the present disclosure has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The disclosure in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described.

[0097] The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of processes described herein may be performed in any order practical. Further, some steps may be performed simultaneously, in parallel, or concurrently. Various methods described herein may be practiced by combining one or more machine-readable storage media containing the code according to the present disclosure with appropriate standard computer hardware to execute the code contained therein. An apparatus for practicing various embodiments of the present disclosure may involve one or more computers (or one or more processors within a single computer) and storage systems containing or having network access to computer program(s) coded in accordance with various methods described herein, and the method steps of the disclosure could be accomplished by modules, routines, subroutines, or subparts of a computer program product. While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

Claims

1. A wind propulsion operation system (10) for propelling a vessel (1), wherein the wind propulsion operation system comprises:

- a wind propulsion system comprising at least one sail element (100) and a base plate (110), wherein the sail element is rotatably arranged on the base plate to set a wind angle, wherein the sail element comprises a plurality of airfoil elements (120) and at least one airfoil element (125) is movable and configured to modify the camber line of the sail element;

- at least one actuator (301, 302) arranged to rotate the sail element relative to the base plate to a set wind angle and/or to move said at least one movable airfoil element to modify the camber line of the sail element;

- at least one position sensor (401, 402, 410, 411, 412, 415) configured to determine the actual operating position of at least one of: the at least one actuator, the sail element and the at least one movable airfoil element;

- a processing unit (200), wherein the processing unit comprises at least one memory unit (220) and at least one processor (210) configured to carry out instructions to operate the at least one sail element and/or the at least one movable airfoil element by means of the at least one actuator;

the wind propulsion operation system being configured to enter a fail-safe operation mode wherein:

- the processing unit is configured to determine a difference and/or a difference variation between a set operating position and the actual operating position of at least one of: the at least one actuator, the sail element and the at least one movable airfoil element determined by the at least one position sensor;

- the wind propulsion operation system is configured to initiate a set position adjustment procedure for the at least one actuator in response to the determined difference and/or the determined difference variation being greater than a predetermined value for a predetermined amount of time;

- the set position adjustment procedure comprises the processing unit being configured to determine a new set operating position of at least one of the at least one actuator, the at least one sail element and the at least one airfoil element, and to operate the at least one actuator based on the determined new set operating position.

2. A wind propulsion operation system according to claim 1, wherein the at least one actuator is a hydraulic actuator, and wherein the wind propulsion operation system further comprises a hydraulic power unit (260) configured to operate the hydraulic actuator and an electric generation unit (270) configured to provide electric power to the hydraulic power unit.

3. A wind propulsion operation system according to claim 2, wherein the base plate and the at least one sail element are operatively connected by means of a slew bearing and wherein the hydraulic actuator comprises at least one slew bearing hydraulic motor configured to rotate the sail element to a set wind angle, wherein said at least one position sensor comprises a position sensor configured to determine the actual operating position of the sail element, and wherein the processing unit is configured to determine the difference between the set operating position and the determined actual operating position of the sail element, wherein the processing unit is configured to determine a new set operating position of the at least one sail element in response to the difference being greater than a predetermined value for a predetermined amount of time and to operate the slew bearing hydraulic motor to rotate the sail element to the new set operating position.

4. A wind propulsion operation system according to claim 2, wherein the hydraulic actuator comprises at least two hydraulic rams (310, 311) and at least one cable (313) operatively connected to the at least two hydraulic rams and operatively coupled to the movable airfoil element (125), and wherein said at least one position sensor comprises at least one of: a linear sensor (410, 411) for measurement of the current position of at least one of the at least two hydraulic rams, and a position sensor (412) for measurement of the current angle of the movable airfoil element.

5. A wind propulsion operation system according to claim 4, wherein the processing unit is configured to determine a difference between the set operating position of at least one of the at least two hydraulic rams and/or the movable airfoil element and the actual operating position of the at least one of the two hydraulic rams and/or the airfoil element determined by said linear sensor and/or said position sensor, respectively, and wherein the processing unit is configured to operate the hydraulic actuator, in response to the determined difference being greater than a predetermined value for a predetermined amount of time, to adjust the set operating position of at least one of the two hydraulic rams so that the operating position of the movable airfoil element coincides with the set operating position.

6. A wind propulsion operation system according to claim 4, wherein the processing unit is configured to determine a difference variation between the set operating position of the movable airfoil and the actual operating position of the movable airfoil determined by the position sensor, and wherein the processing unit is configured to operate the hydraulic actuator, in response to the determined difference variation being greater than a predetermined value for a predetermined amount of time, to adjust the set operating position of at least one of the two hydraulic rams.

7. A wind propulsion operation system according to claim 4, wherein the movable airfoil element comprises a lower end (140) and an upper end (150), wherein the at least two hydraulic rams comprise at least two hydraulic actuator rams at the upper end of the movable airfoil element and at least two hydraulic rams (310, 311) at the lower end of the movable airfoil element, wherein the at least one position sensor comprises a position sensor configured to measure the actual current angle of the upper end of the movable airfoil element and a position sensor (412) configured to measure the actual current angle of the lower end of the movable airfoil element, and wherein the processing unit is further configured to determine a difference between the determined actual current angle of the upper end of the movable airfoil and the determined actual current angle of the lower end of the lower end of the movable airfoil, and wherein the processing unit is configured to operate at least one of the upper and lower end hydraulic actuator rams.

8. A wind propulsion operation system according to claim 1, wherein the processing unit is configured to determine if the determined difference is greater than a first predetermined value and/or if the determined difference variation is greater than a second predetermined value.

9. A wind propulsion operation system according to claim 1, wherein the processing unit is configured to determine if the difference is greater than a predetermined value for a first predetermined amount of time and if the difference variation is greater than a predetermined value for a second predetermined amount of time.

10. A wind propulsion operation system according to claim 1, wherein the sail element comprises a tilt plate (115), such that the sail element is configured to tilt over a horizontal axis (X1) towards a horizontal direction, and wherein the processing unit is configured to operate a further actuator to tilt the sail element towards the horizontal direction after carrying out the position adjustment procedure into the new set operating position.

11. A vessel comprising a wind propulsion operation system according to any one of claims 1 to 10, wherein the wind propulsion operation system comprises a plurality of sail elements.

12. A method of operation of a wind propulsion operation system according to any one of claims 1 to 10 for propelling a vessel, the method comprising the steps of:

- operating an actuator (3000) to set an operating position of at least one of the sail element and/or the movable airfoil element;

- determining (3100) by the processing unit a position of the at least one of the at least one actuator, the at least one sail element and/or the at least one movable airfoil element;

- determining (3200) by the processing unit a difference and/or a difference variation between the set operation position and the determined operating position of at least one of the at least one actuator, the at least one sail element and/or the movable airfoil element;

- wherein if the difference and/or the difference variation is greater than a predetermined value for a predetermined amount of time, the method further comprises determining (3300, 3400) by the processing unit a new set operating position of at least one of the at least one actuator, the sail element, and the movable airfoil element.

13. A data processing apparatus comprising means for carrying out the method of claim 12.

14. A computer-readable storage medium comprising instructions which, when executed by a computer system, cause the computer to carry out the method claim 12.

15. A computer program product comprising instructions which, when the program is executed by a computer system, cause the computer to carry out the method of claim 12.

Drawing