SYSTEM FOR CONTROLLING FORCES APPLIED ON A HYDRODYNAMIC BODY ADHERED TO AND MOVING ALONG A HULL OF A SAILING SHIP

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. Provisional Patent Application No. 63/635,672, filed Apr. 18, 2024, the contents of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates generally to systems and methods for controlling forces on a hydrodynamic body adhered to and moving along a hull of a ship during sailing.

BACKGROUND

A marine environment brings challenges that do not exist in a terrestrial environment. When it comes to a body which is adhered to a ship yet needs to move along the ship's hull during the sailing of the ship, the challenges are even bigger. A sailing ship is subject to the influence of many forces, starting with the waves and ending with underwater currents which constantly change. While adhering a static body to the ship's hull is possible, the allowance of movement along the ship's hull brings to slipping or detachment of the body from the hull due to lift and drag forces operating on the body. Adding additional forces operating on the moving body resulting from the underwater currents and the ship's speed, makes the allowance of movement of the body along the ship's hull very challenging. Overcoming the problem of detachment and/or slipping of the body from the ship's hull opens a door to efficient solutions for cleaning and inspecting ships and their related equipment.

One example for such an efficient solution may be a cleaning equipment for ships which deals with the Biofouling problem. Biofouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that cause degradation to the primary purpose of said items. The problem of biofouling brings to an increased fuel consumption of ships and to time waste in port for cleaning the ship, as current cleaning methods require the ship to be stationary. In addition, small animals, plants and organisms accumulated on the ship due to biofouling may cause damage to natural environment in the port of destination of the ship, as being invasive species.

Therefore, providing a system and method which allows adhering a body to a ship's hull yet allowing movement of the body along the ship's hull, enables cleaning of the ship's hull during sailing of the ship, preventing biofouling creation, saving fuel consumption, and preventing time waste during porting for cleaning.

Thus, there is a need for a system and a method for controlling forces applied on a body adhered to a ship's hull, allowing movement along the hull during sailing, without detachment and/or sliding of the body from the ship's hull.

SUMMARY

According to some embodiments, systems and methods for controlling forces applied on a hydrodynamic body adhered to and moving along a hull of a sailing ship, are presented.

According to some embodiments, there is provided a system for controlling forces applied on a hydrodynamic body adhered to and moving along a hull of a sailing ship by manipulating water currents around the body. According to some embodiments, the hydrodynamic body comprises at least two wheels, a first wheel in a first side of the hydrodynamic body controlled by a first motor and a second wheel in a second side of the hydrodynamic body controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship. According to some embodiments, the control of the forces applied on the hydrodynamic body is done by using mechanical fingers and dynamic wings which are located at the sides of the hydrodynamic body and which deploy and/or open in different directions and angles. Advantageously, according to some embodiments, the mechanical fingers cope with situations where momentary extreme forces operate on the hydrodynamic body and prevent the detachment of the hydrodynamic body from the ship's hull.

Advantageously, according to some embodiments, the dynamic wings provide a stability system to the hydrodynamic body, by changing the torque balance according to the opening angle of the dynamic wings.

Advantageously, according to some embodiments, the hydrodynamic design of the body provides an attachment force which attaches the body to the ship's hull, as long as the body is underwater during sailing. This force is proportional to the ship's speed and increases as the sailing speed increases.

According to some embodiments, one example for a hydrodynamic body in which the system presented herein is integrated may be a cleaning robot. In this case the cleaning robot is adhered to the ship's hull and the system presented herein, which is integrated into the cleaning robot allows the cleaning robot to move along the ship's hull and clean the hull even during sailing of the ship and even underwater without being detached from the ship's hull.

Advantageously, according to some embodiments, in this case, the system presented herein allows the cleaning robot to clean the ship during sailing, and thus providing a solution to the problem of biofouling by removing the biofouling at a very early stage.

According to an aspect of some embodiments, a system for controlling forces applied on a hydrodynamic body adhered to and moving along a hull of a sailing ship is presented. The hydrodynamic body comprises at least two wheels, a first wheel in a first side of the hydrodynamic body controlled by a first motor and a second wheel in a second side of the hydrodynamic body controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship. The system comprises:

• • at least two mechanical fingers having a wing shape with a leading edge and a trailing edge, wherein the fingers are located such that when deployed the trailing edge rises against the water current to position the fingers at an angle creating a force perpendicular to the ship's hull which attaches the hydrodynamic body to the ship, thereby preventing detachment of the hydrodynamic body from the ship, and wherein when the mechanical fingers open and close at a fluttering movement at a certain frequency a lift force reducing adhesion of the hydrodynamic body to the ship is created;
  • at least two dynamic wings located at each side of the hydrodynamic body, wherein each dynamic wing is parallel to the hydrodynamic body direction and when deployed each dynamic wing opens in a direction parallel to the ship's hull and at an angle such that an adhesion force is applied on the hydrodynamic body, adding stabilization to the hydrodynamic body;
  • an array of sensors comprising an Inertial Measurement Unit (IMU) and a motor consumption feedback sensor for providing information regarding the hydrodynamic body's adhesion status and the state of the mechanical fingers and dynamic wings; and
  • a controller receiving input from the array of sensors, controlling and monitoring the state of the mechanical fingers and dynamic wings and the hydrodynamic body's adhesion status, and providing instructions to each mechanical finger and dynamic wing to open to a desired position to increase or reduce adhesion of the hydrodynamic body to the ship, thereby optimizing the adhesion and stability of the hydrodynamic body.

According to some embodiments, the hydrodynamic body comprises a plurality of carts, each cart having one wheel in a first side controlled by a first motor and a second wheel in a second side controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship, and wherein the mechanical fingers are located in line with the length of the hydrodynamic body and/or on a downstream side of each of a wheelhouse of each cart, and/or on a top side of the cart, which is furthest from the ship's hull; and wherein the dynamic wing/s are located at each side of each cart of the hydrodynamic body.

According to some embodiments, the hydrodynamic body is adhered to the ship with magnets and with forces generated by a passive hydrodynamic design of the hydrodynamic body.

According to some embodiments, the hydrodynamic body is a robot.

According to some embodiments, the robot is a cleaning robot.

According to some embodiments, when the mechanical fingers are deployed, the trailing edge rises against the water current to position the mechanical fingers at an angle between 0 and 90 degrees.

According to some embodiments, the dynamic wing is opened by pivoting around the upstream end of the wing.

According to some embodiments, the system further comprises a plurality of additional mechanical fingers located along the hydrodynamic body and facing different directions, such that the moments of force acting on the plurality of carts are controlled by the controller to keep the hydrodynamic body stable.

According to some embodiments, the IMU sensor provides differences in the direction of the hydrodynamic body at a resolution of 0.001 deg.

According to some embodiments, the IMU sensor's sample rate is 400 samples/second.

According to some embodiments, the instructions from the controller to the mechanical fingers and dynamic wings contain more than one step, to stabilize the hydrodynamic body.

According to another aspect of some embodiments, a method for controlling forces applied on a hydrodynamic body adhere to and moving along a hull of a ship is presented. The hydrodynamic body comprises at least two wheels, a first wheel in a first side of the hydrodynamic body controlled by a first motor and a second wheel in a second side of the hydrodynamic body controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship, the method comprises the steps of:

• • receiving by a controller, signals from an array of sensors comprising and Inertial Measurement Unit (IMU) and a motor consumption feedback sensor providing information regarding forces applied on the hydrodynamic body;
  • controlling and monitoring by the controller the state of the mechanical fingers and dynamic wings and the hydrodynamic body's adhesion status, and accordingly instructing by the controller:
    • at least two mechanical fingers, controlled individually, having a wing shape with a leading edge and a trailing edge, to deploy such that the trailing edge rises against the water current to position the fingers in an angle creating a force perpendicular to the ship's hull which attaches the hydrodynamic body to the ship thereby preventing detachment of the hydrodynamic body from the ship, and such that when the mechanical fingers open and close at a fluttering movement at a certain frequency, a lift force reducing adhesion of the hydrodynamic body to the ship is created;
    • at least two dynamic wings located at each side of the hydrodynamic body, to open in a direction parallel to the ship's hull and at an angle such that an adhesion force is applied on the hydrodynamic body, adding stabilization to the hydrodynamic body.

According to some embodiments, the hydrodynamic body comprises a plurality of carts, each cart having one wheel in a first side controlled by a first motor and a second wheel in a second side controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship, and wherein the at least two mechanical fingers are located in line with the length of the hydrodynamic body and/or on a downstream side of each of a wheelhouse of each cart, and/or on a top side of the cart, which is furthest from the ship's hull, and wherein the dynamic wings are located at each side of each cart of the hydrodynamic body.

According to some embodiments, when the controller receives from the motor consumption sensor a signal that the motor consumption of electrical current is above a predetermined range, the controller instructs each mechanical finger to open and close at a fluttering movement at a certain frequency which creates a lift force such that the adhesion force is reduced and the friction on the relative wheel is reduced; and

• • when the controller receives from the motor consumption sensor a signal that the motor consumption of electrical current is below a predetermined range, the controller instructs each mechanical finger and/or dynamic wing to open in an angle creating a down force such that the adhesion force is increased and the friction on the relative wheel is increased to eliminate sliding and disconnection of the hydrodynamic body from the ship.

Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more other technical advantages may be readily apparent to those skilled in the art from the figures, descriptions, and claims included herein. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In case of conflict, the patent specification, including definitions, governs. As used herein, the indefinite articles “a” and “an” mean “at least one” or “one or more” unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE FIGURES

Some embodiments of the disclosure are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments may be practiced. The figures are for the purpose of illustrative description and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the disclosure. For the sake of clarity, some objects depicted in the figures are not drawn to scale. Moreover, two different objects in the same figure may be drawn to different scales. In particular, the scale of some objects may be greatly exaggerated as compared to other objects in the same figure.

In the figures:

FIG. 1 schematically shows a block diagram of a system for controlling forces on a hydrodynamic body adhered to and moving along a hull of a sailing ship, according to some embodiments;

FIG. 2A schematically shows an example of a hydrodynamic body adhered to and moving along a hull of a sailing ship, on which the system of FIG. 1 is integrated, according to some embodiments;

FIG. 2B schematically shows an example of a mechanical finger and a dynamic wing and the direction of the adhesion force F applied thereon, according to some embodiments;

FIG. 2C schematically shows the direction of the lift force F′ created by the deployment of mechanical finger 203b′, according to some embodiments;

FIG. 2D schematically shows the pivoting direction of the dynamic wings, according to some embodiments;

FIGS. 2E-2F schematically show an example of a top view and a front view respectively of a cart with two open wings and the direction of the forces created by the wings opening, according to some embodiments;

FIGS. 3A-3B schematically show examples of a hydrodynamic body which is a cleaning robot in which system 100 is integrated, according to some embodiments; and

FIG. 4 schematically shows a method for controlling forces on a hydrodynamic body adhered to and moving along a hull of a sailing ship, according to some embodiments.

DETAILED DESCRIPTION

The principles, uses, and implementations of the teachings herein may be better understood with reference to the accompanying description and figures. Upon perusal of the description and figures present herein, one skilled in the art will be able to implement the teachings herein without undue effort or experimentation. In the figures, same reference numerals refer to same parts throughout.

In the description and claims of the application, the words “include” and “have”, and forms thereof, are not limited to members in a list with which the words may be associated.

As used herein, the term “about” may be used to specify a value of a quantity or parameter (e.g. the length of an element) to within a continuous range of values in the vicinity of (and including) a given (stated) value. According to some embodiments, “about” may specify the value of a parameter to be between 80% and 120% of the given value. For example, the statement “the length of the element is equal to about 1 m” is equivalent to the statement “the length of the element is between 0.8 m and 1.2 m”. According to some embodiments, “about” may specify the value of a parameter to be between 90% and 110% of the given value. According to some embodiments, “about” may specify the value of a parameter to be between 95% and 105% of the given value.

As used herein, according to some embodiments, the terms “substantially” and “about” may be interchangeable.

According to some embodiments, there is provided a system and method for controlling forces on a hydrodynamic body adhered to and moving along a hull of a sailing ship, by manipulating water currents around the hydrodynamic body.

As used herein, according to some embodiments, in the description and claims the term “mechanical finger/s” relates to a wing-shaped mechanism with a leading edge and a trailing edge, which opens perpendicular to the water current. As used herein the term “mechanical finger/s” and “finger/s” may be interchangeable.

As used herein, according to some embodiments, in the description and claims the term “dynamic wing/s” relates to a wing-shaped mechanism with a converging profile, which is located in parallel to the hydrodynamic body and which opens in parallel to the ship's hull as will be further described below.

FIG. 1 schematically shows a block diagram of a system 100 for controlling forces on a hydrodynamic body adhered to and moving along a hull of a sailing ship, according to some embodiments. According to some embodiments, the hydrodynamic body comprises at least two wheels, a first wheel in a first side of the hydrodynamic body controlled by a first motor and a second wheel in a second side of the hydrodynamic body controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship. According to some embodiments, the wheels may be a caterpillar tread or any other conveyance/movement mechanism.

According to some embodiments, the hydrodynamic body may be adhered to the ship's hull with magnets, which keep the hydrodynamic body attached to the ship's hull yet allow movement of the hydrodynamic body. In addition, the hydrodynamic design of the body also contributes to the adhesion of the hydrodynamic body to the ship's hull by creating an attachment force which attaches the body to the ship's hull, as long as the body is underwater during sailing, resulting from the hydrodynamic design. This force is proportional to the ship's speed and increases as the sailing speed increases.

According to some embodiments, system 100 includes an array of sensors 101, a controller 102, at least two mechanical fingers 103, and at least two dynamic wings 104. According to some embodiments, system 100 controls the forces on a hydrodynamic body which is adhered to and moving along a hull of a sailing ship, by manipulating water currents around the hydrodynamic body, using the at least two mechanical fingers and the at least two dynamic wings. According to some embodiments, array of sensors 101 indicates the state of the hydrodynamic body to controller 102 and provides information regarding the environmental changes and especially changes in the forces applied to the hydrodynamic body. Controller 102 monitors the hydrodynamic body's adhesion status and controls the state of the mechanical fingers and dynamic wings. Controller 102 in response to the information received from array of sensor 101, analyzes the information and instructs each mechanical finger 103 and each dynamic wing 104 to open to a desired position in order to increase or reduce adhesion of the hydrodynamic body to the ship, thereby optimizing the adhesion and stability of the hydrodynamic body. According to some embodiments, controller 102 may be or may include a computer, a processing unit or a processing circuitry or the like.

According to some embodiments, array of sensors 101 includes an Inertial Measurement Unit (IMU) which senses the acceleration of the hydrodynamic body, therefore relevant forces on the hydrodynamic can be derived.

According to some embodiments, array of sensor 101 includes a motor consumption feedback sensor, which provides a signal regarding the consumption of electrical current of the motor that controls the wheel, to controller 102. According to some embodiments, each motor has its own motor consumption feedback sensor. According to some embodiments, when controller 102 receives from the motor consumption sensor a signal that the motor consumption of electrical current is above a first predetermined range, controller 102 is configured to instruct each mechanical finger to open and close at a fluttering movement at a certain frequency which creates a lift force such that the adhesion force is reduced and the friction on the relative wheel is reduced. According to some embodiments, when controller 102 receives from the motor consumption sensor a signal that the motor consumption of electrical current is below a second predetermined range, controller 102 is configured to instruct each or the relevant mechanical finger and/or dynamic wing to open in an angle creating a down force such that the adhesion force is increased and the friction on the relative wheel is increased to eliminate slipping and disconnection of the hydrodynamic body from the ship. According to some embodiments the first and second predetermined thresholds may be the same threshold, however, according to some other embodiments the first and second threshold are different and there is a gap between the first and second thresholds wherein when the motor consumption sensor indicates the electrical consumption of the motor is in said gap, no action is taken.

According to some embodiments, at least two mechanical fingers 103 are a wing-shaped mechanism with a leading edge and a trailing edge. When mechanical fingers 103 are deployed, the trailing edge rises against the water current to position mechanical fingers 103 in any angle between 0 and 90 degrees. According to some embodiments, the angle is determined by controller 102, which is configured to decide whether the hydrodynamic body needs to be adhered to the ship's hull with an additional force or if the hydrodynamic body is stable, but the stress on the motors is too high. According to some embodiments, the positioning of mechanical fingers 103 in an angle between 0 and 90 degrees creates a force perpendicular to the ship's hull which affects the adhesion of the hydrodynamic body to the ship, thereby preventing detachment of the hydrodynamic body from the ship. According to some embodiments, mechanical fingers 103 may also open and close at a fluttering movement at a certain frequency to create a lift force which reduces stress on the motors and which reduces adhesion of the hydrodynamic body to the ship.

According to some embodiments, system 100 may be integrated in any hydrodynamic body, which is adhered to a hull of a ship, yet moving along the hull of the ship, including during sailing. According to some embodiments the hydrodynamic body may include one cart or a plurality of carts, which are connected to each other with a flexible joint, allowing movement of the hydrodynamic body.

FIG. 2A schematically shows a hydrodynamic body 200, which is adhered to and moving along a hull of a sailing ship, into which system 100 is integrated, according to some embodiments. Hydrodynamic body 200 includes, according to some embodiments, four carts 211a, 211b, 211c, 211d, and is adhered to the ship's hull with magnets (not shown). Each cart includes two wheels (not shown) which are covered with wheelhouses, one on each side of the cart, such that cart 211a includes wheelhouses 212a and 212a′, cart 211b includes wheelhouses 212b and 212b′, cart 211c includes wheelhouses 212c and 212c′ and cart 211d includes wheelhouses 212d and 212d′. According to some embodiments, each wheel is controlled by a separate motor (not shown), thus enabling hydrodynamic body 200 to move along the hull of the ship. According to some embodiments, mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ have a wing shape with a leading edge and a trailing edge and are located on the downstream side of each of wheelhouses 212a, 212a′, 212b, 212b′, 212c, 212c′, 212d and 212d′ respectively, of each cart. According to some embodiments, additional mechanical fingers such as mechanical fingers 203e, 203f, 203g, 203h, 203i, 203j, 203k, 203l, 203m, 203n, 203o, 203p may be located on a top side of the cart, which is furthest from the ship's hull. According to some embodiments, a plurality of additional mechanical fingers may be located along the hydrodynamic body and facing different directions, such that the moments of force acting on each one of carts 211a, 211b, 211c, 211d, are controlled by a controller such as controller 102 to keep the hydrodynamic body stable and attached to the ship.

According to some embodiments, mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ are set in line with the length of hydrodynamic body 200. When the mechanical fingers are deployed, the trailing edge rises against the water current to position each of mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ at an angle creating either a adhesion force, which is a force perpendicular to the ship's hull, which attaches the hydrodynamic body to the ship, thus preventing detachment of hydrodynamic body 200 from the ship, or creating a lift force reducing adhesion of hydrodynamic body 200 to the ship. According to some embodiments, mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ operate (open and close) at a fluttering movement at a certain frequency, which disturbs the flow on the top side of hydrodynamic body 200 and changes the pressure field, such that the lift force is created.

According to some embodiments, when mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ are deployed, the trailing edge rises perpendicular to the water current to position mechanical finger 203 in any angle between 0 and 90 degrees, creating a force perpendicular to the ship's hull which affects the adhesion of hydrodynamic body 200 to the ship, thereby preventing detachment of hydrodynamic body 200 from the ship. According to some embodiments, in other cases, where hydrodynamic body 200 is well adhered to the ship's hull and the stress on the motors of the wheels is above a predetermined threshold—the trailing edge rises perpendicular to the water current, and then lowers perpendicular to the water current at a fluttering movement at a certain frequency that a lift force is created, which reduces adhesion of hydrodynamic body 200 to the ship, thus reducing the stress on the motors.

In FIG. 2A it can be seen that mechanical fingers 203b′ and 203d are open to an angle of about 30 degrees, and mechanical fingers 203a, 203a′, 203b, 203c, 203c′ and 203d′ are closed (i.e. open to 0 degrees).

FIG. 2B schematically shows the direction of the adhesion force created by the deployment of mechanical finger 203d, according to some embodiments.

Wheelhouse area 231 of wheelhouse 212d seen in FIG. 2B is an area with a rounded curvature. Mechanical finger 203d is located on a downstream side of wheelhouse 212d and opens perpendicular to the water current. Mechanical finger 203d may be open in any angle between 0 and 90 degrees. By locating mechanical finger 203d on the downstream side of wheelhouse 212d the water current which tends to accelerate in area 231 of the rounded part of wheelhouse 212d is blocked and routed upward by mechanical finger 203d. The redirection of current leads to a transfer of momentum between the water and the upper part of the wing 203d(a), following Newton's third law. Due to the angle of mechanical finger 203d the transfer of momentum turns into an adhesion force F. In parallel, slot 210 between mechanical finger 203d and wheelhouse 212d increases the acceleration of water current to the bottom part 203d(b) of mechanical finger 203d, which creates a low pressure on the rear part of mechanical finger 203d, according to Bernoulli's law, thus creating a positive pressure differential between the top part 203d(a) and bottom part 203d(b) of mechanical finger 203d, resulting in a lift force. As a result of the water current cutoff by mechanical finger 203d, turbulence is created under/behind 203d(b) mechanical finger 203d, in area 233.

The turbulence decreases the pressure behind mechanical finger 203d. The water current on the external side of wheelhouse 212d accelerates also to the rear part of mechanical finger 203d and contributes to the decrease of pressure behind mechanical finger 203d. The shape of mechanical finger 203d, which is as a wing profile with a rounded leading edge and a pointed trailing edge enables the Coanda effect to exist and an optimal flow over mechanical finger 203d. Due to the pressure differences between the upward part and the downward part of mechanical finger 203d, an attachment force is created on mechanical finger 203d, which adheres wheelhouse 212d to the ship.

According to some embodiments, a plurality of additional mechanical fingers such as mechanical fingers 203e, 203f, 203g, 203h, 203i, 203j, 203k, 203l, 203m, 203n, 203o, 203p may be located along the hydrodynamic body and facing different directions, such that the forces and their associated moments acting on the plurality of carts are controlled by the controller to keep the hydrodynamic body stable and attached to the ship's hull.

According to some embodiments, dynamic wings 204b, 204c, 204d and 204b′ are located at either side of each cart 212a, 212a′, 212b, 212b′, 212c and 212c′, 212d and 212d′ respectively, of hydrodynamic body 200. Dynamic wings 204a, 204a′, 204c′ and 204d′ are not shown as they are covered with the mechanical fingers, however they can be seen in FIG. 2D. According to some embodiments, dynamic wings 204a, 204a′, 204b, 204b′, 204c, 204c′, 204d and 204d′ are parallel to hydrodynamic body 200 direction, and when deployed, dynamic wings 204a, 204a′, 204b, 204b′, 204c, 204c′, 204d and 204d′ open in a direction parallel to the ship's hull and at an angle such that an adhesion force is applied on hydrodynamic body 200, adding adhesion and stabilization to hydrodynamic body 200.

FIG. 2C schematically shows the direction of the lift force created by the deployment of mechanical finger 203b′, according to some embodiments. When mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ open and close at a fluttering movement at a certain frequency the flow on the top side of hydrodynamic body 200 is disturbed, and that leads to changes in the pressure field around hydrodynamic body 200. Local turbulences such as turbulences 234a and 234b are created such that the pressure around wheelhouse 212b′ is reduced, leading to lower pressure above hydrodynamic body 200 relative to under it, which creates lift force F′, which decrease the adhesion of hydrodynamic body 200 to the ship's hull.

According to some embodiments, each dynamic wing opens by pivoting the upstream end of the dynamic wing. FIG. 2D schematically shows different pivoting examples of dynamic wings 204a, 204a′, 204b, 204b′, 204c, 204c′, 204d and 204d′, according to some embodiments. As can be seen FIG. 2D presents a top view of hydrodynamic body 200. According to some embodiments, each of dynamic wings 204a, 204a′, 204b, 204b′, 204c, 204c′, 204d and 204d′ are installed on a dynamic wing opening mechanism such as pivot 220, which allows the dynamic wings pivoting to different angles between 0 and 90 degrees. For example, and as can be seen in FIG. 2D, dynamic wing 204d is installed on pivot 220 and is open at an angle of 90 degrees, which is a fully open dynamic wing. Dynamic wings 204c and 204b are installed on pivots 221 and 222 respectively and are open at an angle of 45 degrees. Dynamic wings 204a, 204a′, 204b′, 204c′, 204d′ are installed on pivots 223, 224, 225, 226 and 227 respectively and are at 0 degrees opening, which means dynamic wings 204a, 204a′, 204b′, 204c′, 204d′ are closed or at a rest state.

According to some embodiments, the dynamic wings have a converging wing profile and they open and close on the sides of the hydrodynamic body in parallel to the water current direction. The profile of the wings is similar to wings of an airplane, and it creates a perpendicular force by creating a pressure differential between the top and bottom sides of the wings. The dynamic wings are used as a continuous stabilization and adhesion system and open as needed in different angles while the hydrodynamic body remains underwater. In case there is a difference in the forces on two symmetric wheels, such that the cart experiences undesired moment of force, the dynamic wings open to the relevant position to counteract the moment and balance the torque on said cart. For example, if a force differential exists such that a cart tends to roll (i.e., one wheel lifts off the ship's hull), a wing could open to balance the force and improve adhesion where required. FIGS. 2E-2F schematically show an example of a top view and a front view respectively of a cart with two open wings and the direction of the forces created by the wings opening, according to some embodiments. M_ext is an external torque operating on cart 211d, such that cart 211d experiences a difference in the forces on the two symmetric wheels 213 and 213′ of cart 211d, and such that the force on the side of dynamic wing 204d acts as a lift force, while the force on the side of dynamic wing 204d acts as an adhesion force. In response, dynamic wings 204d opens in an angle of 90 degrees which creates an adhesion force F1 and dynamic wings 204d′ opens in an angle of 45 degrees which creates a weaker adhesion force F2, such that F1>F2 in order to counteract the external torque M_ext. As a result of the wings opening hydrodynamic body 200 remains stabilized and adhered to the ship's hull.

Referring back to FIG. 1, according to some embodiments, array of sensor 101 is responsible for providing information regarding the hydrodynamic body's adhesion status and the state of mechanical fingers 103 and dynamic wings 104, by sensing changes in specific parameters of the hydrodynamic body's operation (such as changes on motor consumption and feedback from IMU sensors regarding forces applied on the hydrodynamic body). The array of sensors includes an Inertial Measurement Unit (IMU) and a motor consumption feedback sensor for monitoring the hydrodynamic body's adhesion status and for providing feedback regarding the position of the fingers and dynamic wings.

According to some embodiments, controller 102 receives input from array of sensors 101 and provides instructions to each of mechanical finger 103 and to each of dynamic wings 104 to open to a desired position to increase or reduce adhesion of the hydrodynamic body to the ship, thereby optimizes the adhesion and stability of the hydrodynamic body.

According to some embodiments, the IMU sensor provides differences in the direction of the hydrodynamic body in a resolution of 0.001 deg at most.

According to some embodiments, the IMU sensor's sample rate is at least 400 samples/second.

According to some embodiments, the instructions from controller 102 to mechanical fingers 103 and dynamic wings 104 contain more than one step, to stabilize the hydrodynamic body. That is, the instructions to mechanical fingers 103 and/or dynamic wings 104 may be to open to a first angle, for example 30 degrees, for 5 seconds and then to open to a second angle, for example 90 degrees. According to some embodiments, the instructions from controller 102 to mechanical fingers 103 and dynamic wings 104 may contain two steps, three steps, four steps or more steps.

According to some embodiments, controller 102 is configured to receive input from an array of sensors 101 and provides commands/instructions to each mechanical finger and dynamic wing to open to a desired position, such that the adhesion and stability are optimized. Optimized adhesion can mean either increased adhesion (creating additional downforce) when it is needed, for example in case of a strong drag force on the hydrodynamic body, or reduced adhesion (creating additional lift force) to reduce stress on the motors.

According to some embodiments, one example for a hydrodynamic body in which system 100 is integrated may be a cleaning robot. In this case the cleaning robot is adhered to the ship's hull with magnets and achieves additional adhesion due to its hydrodynamic design. System 100, which is integrated into the cleaning robot allows the cleaning robot to move along the ship's hull and clean the hull even during sailing of the ship and even underwater without being detached from the ship's hull, thereby allowing the cleaning robot to clean the ship during sailing and remove existing biofouling on the ship's hull, typically at an early stage of the biofouling when it is easy to remove.

FIGS. 3A-3B schematically show examples of a hydrodynamic body which is a cleaning robot in which system 100 is integrated, according to some embodiments. In FIG. 3A cleaning robot 300 is attached/adhered to a ship's hull 320 and includes three carts 311a, 311b and 311c. Cart 311a includes wheelhouses 312a and 312a′, dynamic wings 304a and 304a′, and mechanical fingers 303a and 303a′. Cart 311b includes wheelhouses 312b and 312b′, dynamic wing 304b and 304b′ and mechanical fingers 303b and 303b′. Cart 311c includes wheelhouses 312c and 312c′, mechanical fingers 303c and 303c′ and dynamic wings 304c and 304c′.

FIG. 3B presents an example of a cleaning robot 350 which is attached/adhered to a ship's hull 360 and includes four carts 361a, 361b, 361c and 361d, according to some embodiments.

According to some embodiments, a method for controlling forces applied on a hydrodynamic body adhered to and moving along a hull of a sailing ship, is presented herein. According to some embodiments, the control is achieved by manipulating water currents around the body.

FIG. 4 schematically shows a method for controlling forces applied on a hydrodynamic body adhere to and moving along a hull of a sailing ship, according to some embodiments. The hydrodynamic body includes at least two wheels, a first wheel in a first side of the hydrodynamic body controlled by a first motor and a second wheel in a second side of the hydrodynamic body controlled by a second motor, enabling the hydrodynamic body to move along the hull of the ship. According to some embodiments, at step 401, controller 102 is configured to receive signals from array of sensors 101 regarding forces applied on the hydrodynamic body. According to some embodiments, array of sensors 101 includes an Inertial Measurement Unit (IMU), and a motor consumption feedback sensor. At step 402, in response to the received signals, controller 102 is configured to instruct the at least two mechanical fingers 103, which have a wing shape with a leading edge and a trailing edge, to deploy such that the trailing edge rises against the water current to position the mechanical fingers at an angle creating a force perpendicular to the ship's hull, which attaches the hydrodynamic body to the ship. Thus, preventing detachment of the hydrodynamic body from the ship. According to some embodiments, in case the stress on the motors is too high and the hydrodynamic body is not tending to detach, the at least two mechanical fingers are configured to create a lift force reducing adhesion of the hydrodynamic body to the ship by opening and closing at a fluttering movement at a certain frequency, thereby decreasing the stress in the motor.

According to some embodiments, at step 403, which may take place before, after, instead of or in parallel to step 402, controller 102 is configured to instruct at least one of the at least two dynamic wings 104 located at each side of the hydrodynamic body, to open in a direction parallel to the ship's hull and at an angle such that an adhesion force is applied on the hydrodynamic body, adding stabilization to the hydrodynamic body.

According to some embodiments, the hydrodynamic body may include a plurality of carts, for example, four carts as in hydrodynamic body 200. Each cart includes two wheels, one in each side of the cart, and each wheel is controlled by a separate motor, to enable the hydrodynamic body to move along the hull of the ship. According to some embodiments, in this case of a plurality of carts, controller 102, is configured to receive signals from array of sensors 101, regarding forces applied on the hydrodynamic body, for example, forces applied on each wheel in each cart. The array of sensor includes Inertial Measurement Unit (IMU), a motor consumption feedback sensor, and the like. The IMU measures the acceleration of different parts of the hydrodynamic body, the angular rate and the orientation of the hydrodynamic body, thus providing viable information as to the stability and adhesion status of each side of the hydrodynamic body. According to some embodiments, when controller 102 receives from the motor consumption sensor a signal that the motor consumption of electrical current is above a predetermined range, controller 102 is configured to instruct each mechanical finger to open at a fluttering movement at a certain frequency which creates a lift force such that the adhesion force is reduced and the friction on the relative wheel is reduced.

According to some embodiments, when controller 102 receives from the motor consumption sensor a signal that the motor consumption of electrical current is below a predetermined range, controller 102 is configured to instruct each mechanical finger and/or dynamic wing to open in an angle creating a down force such that the adhesion force is increased and the friction on the relative wheel is increased to eliminate sliding and disconnection of the hydrodynamic body from the ship.

According to some embodiments, in case of a plurality of carts for example as shown in FIG. 2A, controller 102 instructs each of mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ which have a wing shape with a leading edge and a trailing edge, and which are located on a downstream side of each of a wheelhouse of each cart, to deploy such that the trailing edge rises against the water current to position the fingers in an angle creating a force perpendicular to the ship's hull which attaches the hydrodynamic body to the ship thereby preventing detachment of the hydrodynamic body from the ship. The angle of each mechanical finger may be different. Alternatively or additionally, according to some embodiments, controller 102, in accordance with the signals received from array of sensor 101, may instruct each of the mechanical fingers 203a, 203a′, 203b, 203b′, 203c, 203c′, 203d and 203d′ to deploy such that the trailing edge rises and lowers against the water current at a fluttering movement at a certain frequency to create a lift force reducing adhesion of the hydrodynamic body to the ship. According to some embodiments, additional mechanical fingers may be located on a top side of each cart, which is furthest from the ship's hull, such as mechanical fingers 203e, 203f, 203g, 203h, 203i, 203j, 203k, 203l, 203m, 203n, 203o, 203p.

According to some embodiments, in case of a plurality of carts for example as shown in FIG. 2A, controller 102 instructs each of dynamic wings 204a, 204a′, 204b, 204b′, 204c, 204c′, 204d and 204d′ which are located at each side of each cart of the hydrodynamic body, to open in a direction parallel to the ship's hull and at an angle such that an adhesion force is applied on the hydrodynamic body, adding stabilization and adhesion to the hydrodynamic body.

It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. No feature described in the context of an embodiment is to be considered an essential feature of that embodiment, unless explicitly specified as such.

Although stages of methods, according to some embodiments, may be described in a specific sequence, the methods of the disclosure may include some or all of the described stages carried out in a different order. In particular, it is to be understood that the order of stages and sub-stages of any of the described methods may be reordered unless the context clearly dictates otherwise, for example, when a later stage requires as input an output of a former stage or when a later stage requires a product of a former stage. A method of the disclosure may include a few of the stages described or all of the stages described. No particular stage in a disclosed method is to be considered an essential stage of that method, unless explicitly specified as such.

Although the disclosure is described in conjunction with specific embodiments thereof, it is evident that numerous alternatives, modifications, and variations that are apparent to those skilled in the art may exist. Accordingly, the disclosure embraces all such alternatives, modifications, and variations that fall within the scope of the appended claims. It is to be understood that the disclosure is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth herein. Other embodiments may be practiced, and an embodiment may be carried out in various ways.

The phraseology and terminology employed herein are for descriptive purpose and should not be regarded as limiting. Citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the disclosure. Section headings are used herein to case understanding of the specification and should not be construed as necessarily limiting.