Technical Field

The invention relates to a motor-driven vessel for water transport of at least one person, in particular to a water surfboard, connected by a mast to an underwater wing, adapted for a ride or flight of a rider balancing on the board above the water surface, and further relates to a method of propulsion of such a vessel.

Background of the Invention

Hydrodynamic underwater wing, which enables the function of a water hovercraft using buoyancy generated when the hovercraft moves in the water in the direction of the ride, more often referred to in Czech as a hydrofoil, a term borrowed from English to mean an underwater wing, or vessel with an underwater wing, was in the early days used for motor boats, its use was later extended to water sports, such as jet skis, sailboats, surfing, paddleboarding, water skis, windsurfing, or water boards or surfboards driven in various methods, such as by a motorboat, a cableway, wind force using a “kite” in the case of the so-called kiteboarding for flights over water.

The latter is based on a water board connected by a mast to an underwater wing, whereby the buoyancy force is used for propulsion by the forward force of the wind and at the same time with the help of the underwater wing such that after the initial start-up only the wing and a part of the mast remain submerged under water during a normal ride, the remaining part of the mast, supporting the water board, protrudes above the water surface. The mast is oriented perpendicularly or substantially perpendicularly to the water board and the axis of the underwater wing. The rider balances on the board, holding a handle connected to the kite to the sails of which the wind pushes and pulls the board in the direction of the ride. The shape of the underwater wing in the case of wind-driven boards has surfaces resembling an aircraft without any additional drives, with the mast attached to the main body of the underwater wing. The biggest problem for riders in this case is starting up and bringing the board above the water surface using a paddle, which is complicated and discourages many riders in the beginning. The advantage over riding a classic water board without an underwater wing directly on the water surface is the significantly lower drag of the underwater wing moving under the water surface, because it occupies a much smaller area and a more hydrodynamic shape compared to the large bottom area of a water board. Riding with a float in the air also gives the rider a unique feeling of lightness of flight that cannot be experienced when riding with a float on the water surface.

The underwater wing was later extended to motor-driven water boards. In the case of such boards, the motor drive is typically attached to the lower part to the mast at a similar height as the underwater wing and properly oriented consistently with the direction of the underwater wing, as shown, for example, in the utility model application DE202017103703111 , i.e., in the direction of the normal forward ride. The motor drive is then controlled manually by the rider, for example by a wired or remote controller via a control unit. In the case of motorized boards with underwater wings, however, the startup is even more demanding and dangerous, and the rider’s entry onto the water board during start-ups above the water surface leads at some point to a sharp increase in the heeling moment and the board’s uprightness. In many cases, even an experienced rider loses stability and falls over. The fall of the rider on some solid parts of the vessel, especially on parts of the wing or propeller of the water drive, is dangerous. The problem described is caused mainly by the fact that while the board is on the water surface it has to overcome a large drag against the water, but as soon as the board is above the water surface the drag decreases sharply and the heeling moment increases.

The problem with motor-driven vessels, such as water surfboards having an underwater wing, known from the state of the art, operating only with a lower drive unit, is that they generate a large heeling moment during the start-up, which lifts the front part of the vessel and the person being transported - the rider - therefore has to work with the center of gravity during the start-up. For example, in the case of a water surfboard, they must first lie on the surfboard with the center of gravity as far forward as possible until the board has gained sufficient speed. The drive unit placed below, i.e., in or on the lower part of the mast in a permanently submerged part of the vessel, must produce considerable power to overcome the drag of the water and to overcome the increase in the heeling moment. This makes the start-up uncomfortable and makes it difficult for beginners to stand up on the water surfboard and experience the feeling of lightness of flight. The start-up must also be very slow, i.e., at lower power, and very careful, requiring demanding preparation and experience. Also, in the case of such a surfboard, getting to the water surface is difficult. A large area of the float in contact with the water surface creates a suddenly large drag force that often results in the rider tipping over the board into the water. In the case of these vessels, the electronics are placed in the float and the water must be pumped through the mast into the upper part and guided such as to cool it down. In its standard position, the mast is usually oriented vertically or substantially vertically to the water surface and perpendicularly or substantially perpendicularly to the float, or with a slight tilt. Horizontally and with respect to the forward direction of the ride, the following items are attached to the mast or implemented: the float, underwater wing, and a lower drive unit, where the longitudinal axes of these parts occupy the perpendicular or substantially perpendicular orientation to the longitudinal axis of the mast.

Modern systems attempt to solve the rider balance problems by active motorized tilt of the float at different angles relative to the mast, which is an overly complicated solution that comprises a complex measuring system followed by a sophisticated tilt algorithm that, however, still gives delayed responses. By tilting the float relative to the mast, the sharp increase in the vessel’s heeling moment is neither eliminated nor decreased, only the impact on the balance of the rider themselves is decreased by generating counteracting forces of the float’s turning moment when tilting relative to the mast, acting against the rider’s fall from the vessel. It is therefore only a matter of balancing the forces acting on the rider, not on the vessel itself, i.e., smooth overcoming of differently large drag of the water depending on the changing size of the wetted areas of the vessel through the regulation of the speed of suitably placed drive motors is not addressed here. A disadvantage is that the tilt of the vessel is a response to the current state of the vessel, the measurement, evaluation, and subsequent action of which requires a certain response time and a perfect estimation of the direction and size of the tilt angle of the float and the speed of the tilt. Flawless, perfect, and timely implementation is almost impossible or very expensive. A secondary consequence is that after this action the vessel has to be re-aligned again to a stable position for the subsequent ride mode, which can be a problem in fast maneuvers, during turning etc.

Summary of the Invention

The above shortcomings and disadvantages are solved by a method of propulsion of a vessel, which includes an upper water drive unit with an upper electric motor placed in the float, a mast connected to the float by its upper end, where the mast has a lower water drive unit with a lower electric motor connected or integrated in its lower part, and further where the float is connected via the mast to an underwater wing, where both drive units are functionally and communicatively connected to a control and communication system further connected to a control device, wherein in the flight mode, when the float is kept above the water surface, the vessel is driven only by a permanently submerged lower water drive unit, and in the transitional ride mode, in particular during the start-up, finish, or tilt of the vessel, for example during sharp turns, when at least a part of the float is in contact with the water surface and at the same time the water at least partially floods the upper water drive unit, the vessel is driven simultaneously by both of these drive units.

The mast means a connecting means that carries the water drive unit and/or the underwater wing and connects them to the float. It can take various shapes, for example, the shape of a vertical board, a bar, a column, the letter V, U, Y, A, H, these letters inverted, etc. It can also perform a supporting function for other components. The mast with the underwater wing may be a single solid integral part, suitably shaped, or they may be separate parts that connect to each other. The mast may also be integrally formed with, for example, a housing or some other parts of the lower water drive unit for insertion and fastening of the remaining components of the lower water drive unit. Electronics, cooling channel, etc. may pass through the mast.

The lower water drive unit and the underwater wing are always submerged under the water surface during the start-up and ride, while the bottom part of the float, into which water enters and also floods the upper water drive unit, and the mast are at least partially submerged under the water surface before the start or after the finish, but during the startup, the float and the part of the mast rise above the water surface and the upper water drive unit thus loses its water supply and no longer contributes to the driving of the vessel such that it can run idly or, more preferably, in order to save energy, decrease the noise, and decrease the environmental burden, can be transiently deactivated.

The flight mode is achieved mainly during a fast ride. The transitional ride mode is such a ride mode in which the upper water drive unit is at least partially flooded, i.e., in particular start-up, finish before a stop, sharp turning, slow ride, etc.

The upper water drive unit is best placed in the axis of the float in its rear bottom part.

An essential feature of the invention is that in the transitional ride mode, both water drive units are operated simultaneously, each having its own electric motor. Both the lower water drive unit which is common in the devices of the state of the art and in addition, according to this invention, also an added upper water drive unit, which greatly simplifies the start-up and stop of the vessel or its control during sharp turning, are operated. A significant improvement lies in the fact that the upper water drive unit decreases or eliminates the heeling moment of the float and at the same time of the rider, provides smoother start-up of the vessel and smoother speed changes during other transitional ride modes, facilitates control of the vessel, provides the rider with greater stability and allows for a safer ride and a comfortable ending of the ride with minimized falls of the rider or multiple persons present on the float and thus becomes attractive to a wider range of users, even the less skilled ones. The device of this invention responds in a simple way to a step change in the size of the drag of the wetted areas during the ride, even without a complex system for evaluating the vessel’s deflection from its rest/balanced position, height, coordinates, etc., and without compiled electronics for tilting the float relative to the mast. In this basic, simple embodiment, it is a balancing of the forces without further active intervention, i.e., by the upper water drive unit simply emerging above the water surface level by the buoyancy force, the forces are balanced by the upper water driver unit not being flooded with water, i.e., in its essence it passively ceases to counteract the decreased drag of the water of the float that occurs when rising above the water surface. A part of the control and communication system is a control unit, which may stand alone or be embedded in one of the motor regulators, and a wired or wireless connection to the components that the control unit controls and/or collects data therefrom or sends data thereto. For example, the control unit may be placed in the float, in the mast, or in the main body of the underwater wing, preferably it is placed in the float as a part of the upper regulator but may also be placed in the lower part of the vessel as a part of the lower regulator. The placement in the float is preferable because the float can then be used independently after disconnecting the mast for a ride on the water only, not for a flight above the water surface.

In a preferred embodiment, the vessel comprises at least one sensor of wetting functionally connected to the control and communication system that deactivates the electric motor of the upper water drive unit when all such sensors of wetting emerge above the water surface, and conversely, when at least one such sensor of wetting is flooded with water, the control and communication system activates the upper water drive unit. It is economically inefficient for the upper water drive unit to be in operation in the flight mode and run idly. The sensor of wetting connected to said control and communication system is advantageous because it enables reliable and automated deactivation and activation of the electric motor of the upper water drive unit at the appropriate time, thereby decreasing noise and saving energy and environment. Such an appropriate time occurs mainly during a fast and straight ride, i.e., in the flight mode of the float. Said sensors of wetting are placed on the vessel such that they are not wetted by water in the flight mode, but at least one of the sensors of wetting is wetted in the transitional ride mode. Preferably, the sensor of wetting is placed on the vessel at such a place that the water surface reaches at the moment when the sharpest change in the size of the surface of the wetted areas occurs as the float rises above the water surface, or at a place where the motor of the upper water drive unit ceases to be flooded with water as a result of the motor rising or water entering the upper water drive unit above the water surface. Most often, the sensors of wetting are placed on the bottom part of the float or at a level that is 0 to 20 cm below the float, for example, they are attached to the upper part of the mast. A single sensor of wetting is sufficient to achieve the effect, but for improved maneuvering multiple sensors of wetting may be placed, in particular at the same height level, for example on opposite sides of the mast, which is preferable, for example, for turning, such that when at least one of these sensors is wetted, the upper water drive unit is activated, and when all the sensors of wetting are pulled out of the water, the upper water drive unit is deactivated. Means for the implementation of the switching on/off of the electric motors, which are connected to the control and communication system, are a common part of vessels with an electric motor. For example, these can be switches. The control unit then receives signals not only from the controller but also from the sensor(s) of wetting. According to these or other signals, it sends the signals to the regulators, which then control the motors in terms of speed, power, voltage, etc.

The bottom part of the float for the placement of the sensor of wetting means the part of the float that is submerged in the water when the vessel is at rest in its normal position, for example before the start-up, when the float is not yet loaded by a person - the rider.

It will be apparent to a person skilled in the art that each electric motor is functionally connected to a separate regulator to increase or decrease the speed of the electric motor. Both the lower regulator functionally connected to the lower electric motor and the upper regulator functionally connected to the upper electric motor are controlled by the control and communication system. Preferably, the control and communication system is implemented such that each regulator with electric motor is functionally and communicatively connected to the control unit, most preferably the control unit is implemented as a part of the upper regulator, wherein both regulators are connected to the control unit by two-way functional communication, either wired or wireless. The upper regulator is then preferably placed near the upper electric motor and the lower regulator near the lower electric motor. In a preferred embodiment, in the transitional ride mode, the control and communication system regulates by means of a special implemented algorithm the mutual power ratio of the upper electric motor and the lower electric motor by means of at least one of said regulators in order to achieve a stable ride, i.e., such that after subtracting the counteracting drag forces, the partial thrust force acting on the float with the rider is as large as the partial thrust force acting on the underwater wing. In other words, so that the upper part of the vessel does not overtake the bottom part, or vice versa, i.e., so that both resulting acting forces generated by the lower and upper water drive units are approximately the same and the heeling moment is minimal, i.e., close to zero. Maintaining the correct ratio of speed and power by regulating them on one or both electric motors increases the effect of achieving smooth changes in the movement speed of the vessel in the transitional ride modes and allows to comfortably perform various maneuvers with the vessel.

In the most preferred embodiment, the activation and deactivation of the upper water drive unit and/or speed regulation is controlled by the control and communication system connected to, among other things, the user’s control device, furthermore, to the sensor of wetting by water, to the means for activating/deactivating the lower and upper electric motors, and the lower and upper regulators. The instruction of the control and communication system to activate/deactivate the electric motor of the upper water drive unit based on the wetting status of the sensor of wetting takes priority over the speed regulation of the electric motors. For example, the user enters instructions via the control device to increase/decrease the speed or stop, i.e., enters requests for power changes. In the control unit it is pre-set and pre-programmed how the power ratio of the individual electric motors should be set at the given speeds. The control unit can be reprogrammed.

The data entered by the user into the control device and the data from the electric motors and the sensor of wetting, transmitted to the control and communication system, allow the control system to evaluate this data and respond to a sharp decrease in the drag after the float is raised above the water surface and to activate or deactivate the upper electric motor or to regulate the power in the transitional ride mode such that a large heeling moment does not occur. Compared to a surfboard with an underwater wing driven only by an electric motor placed in the lower part of the underwater wing, which was used for the comparison tests to represent the vessels known from the state of the art, the heeling moment in the transitional ride mode is decreased by approximately 50 % during the start-up under the same conditions and other vessel parameters.

The object of the invention is also a program implemented in a data carrier connected integrated in the control and communication system, for example in a memory of the control unit or an external memory disk, furthermore, this data carrier or control unit with an integrated data carrier carrying said program, where the program is adapted to perform the above methods of propulsion of said vessel controlled by the control and communication system, which can also process instructions entered by the user via the control device.

Another object of the invention is a passenger motor-driven vessel for performing the above mentioned methods of propulsion thereof, where this vessel comprises a mast, a float attached to the upper end of the mast, an underwater wing integrated in the lower part of the mast or connected to the mast, a lower water drive unit integrated in the lower part of the mast or attached to the lower part of the mast with a lower electric motor functionally connected via the lower regulator to the control and communication system, to which a control device and a means for activating and deactivating the lower water drive unit are functionally and communicatively connected, where the essence of the invention lies in the fact that the vessel further comprises an upper water drive unit with an upper electric motor placed in the float, which is, via the upper regulator, functionally and communicatively connected to the control and communication system, which is functionally connected to the means for activating and deactivating the upper water drive unit.

The mast serves as a fixed connection of the lower water drive unit to the float and optionally also connection of the supporting areas of the underwater wing. Sufficient stiffness is a priority, especially at the place of connection of the mast to the float. The mast is suitably hydrodynamically shaped such as to cause the least possible drag and at the same time to allow the cabling for the lower water drive unit to pass through its inner part.

The underwater wing can be as commonly known from the state of the art, it contains supporting areas connected by a truss or the main body of the underwater wing or a similar body, most often in the shape of an aircraft, i.e., the front supporting areas are larger than the rear ones, and it is placed in the lower part of the mast, preferably attached to the lower part of the mast or connected to the lower end of the mast, where the mast extends from the truss or main body of the underwater wing vertically perpendicularly and the axis of the truss is parallel to the direction of the ride of the vessel, or the underwater wing may be an integral part of the lower part of the mast with the supporting areas extending. During the start-up, the supporting areas of the wing allow the upper part of the vessel to be raised above the water surface by the buoyancy force. During a forward movement, it exerts a buoyancy force which, at sufficient speed, keeps the rider above the water surface by the float, i.e., in the “flight” mode. The supporting areas are usually composed of a front and rear wing but may be supplemented by additional wings or elements or areas modifying the flow. Their appropriate mutual arrangement is necessary for force and moment balance to occur, but such an arrangement is known to one skilled in the art from the state of the art. The lower water drive unit may be attached to or integrated into the lower part of the mast, and preferably it is integrated directly into the underwater wing connected by the mast to the float. For example, the lower electric motor and shaft may be placed in the main body of the underwater wing and the engagement means is connected to the shaft and is in a housing attached to the main body of the underwater wing in the rear part of the underwater wing. The supporting areas can then be connected to the main body of the underwater wing and/or the housing of the water engagement means.

The engagement means of the upper and lower water drive units is most preferably the propeller, blades of which allow the forward movement of the float with the rider during the forceful engagement into the water. The lower water drive unit can ensure the forward movement of the vessel even if the float rises above the water surface.

The lower water drive unit and, if applicable, the lower regulator placed therein or both regulators are preferably at least partially encapsulated to prevent accidents and the ingress of unwanted objects or dirt, impacts of water, and corrosion in the water environment. The main body of the underwater wing can therefore also serve partially as a housing of the lower electric motor and the shaft connected to it. Alternatively, the lower water drive unit can be attached to or integrated into the mast above the underwater wing, in a part that is during the start-up and during the ride permanently submerged under the water surface. For example, the lower water drive unit is approximately 60 cm below the lowest point of the float.

The orientation and attachment of the mast to the float and the correct orientation of the underwater wing and drive units are known to one skilled in the art from the state of the art.

The float can be a water surfboard, the shell of a small boat, boat, motorized paddleboard, or other smaller water vessels.

The upper water drive unit is preferably placed in the rear part of the float, taken in the direction of the ride, and provides the forward movement of the float when the float is on the water surface.

The upper water drive unit comprises the upper electric motor connected to the shaft and the engagement means, such as the propeller. It accelerates the flow of the water in the backward direction and thus creates a forward force acting on the surfboard with the rider.

The forward force of the vessel is affected by the amount of water in the upper and lower water drive units. While the lower water drive unit is still submerged, the upper water drive unit gradually emerges above the water surface during the start-up and has no water supply for the engagement, so the upper electric motor preferably switches off or runs idly for a certain period of time.

Preferably, the vessel comprises at least one sensor of wetting placed on the vessel such that it is not wetted in the flight mode but at least one of the sensors of wetting is wetted in the transitional ride mode, where the sensors of wetting are functionally connected to the control and communication system adapted to deactivate the upper electric motor when all of the sensors of wetting emerge above the water surface and, conversely, to activate the upper electric motor when at least one of the sensors of wetting is flooded with water.

The upper part of the mast may be branched, and one or more sensors of wetting are preferably placed in this part at the place of connection of this upper end of the mast to the float. These can be optoelectronic reflective sensors or electrodes measuring conductivity/drag of the environment, etc., or sensors based on another known principle that detect whether these sensors are fully wetted by water or whether they have gotten above the water surface and are in contact with air. These sensors can be placed one on each of the branches in a split mast in the upper part such that they can detect at least partial submergence or complete emergence of the float from the water.

The control and communication system is preferably adapted to regulate the mutual power ratio of the lower electric motor with the help of the lower regulator and the upper electric motor with the help of the upper regulator by adjusting the speed of each of these electric motors.

In a preferred arrangement, the control and communication system comprises a mutually communicatively connected control unit with an upper and a lower regulator, wherein the underwater wing comprises supporting areas connected by the main body of the underwater wing, where the lower water drive unit with the lower electric motor and the lower regulator are placed in this main body, where the control unit is placed as a part of the upper regulator, and furthermore, the upper regulator and the communication module are placed in the float.

The control and communication system is adapted for controlling the above methods, is connected to the user’s control device, to the means allowing activation/deactivation of the upper and lower water drive units or the upper and lower electric motors, is further connected to the lower and upper regulator, or, in a preferred embodiment, also to the sensor of wetting, if it is a part of the vessel, so as to be able to receive and process data from these parts of the device, evaluate whether and in what order to perform sub-actions according to predetermined priorities, and control the drive of the vessel. The control and communication system contains a program for controlling both drive units on the basis of inputs from the measuring devices, for example from the thrust wetting, when all such sensors of wetting emerge, the control unit switches off the upper electric motor of the upper water drive unit in which the engagement means is already idle without the presence of water and no longer supplies any thrust for the forward movement of the float. This decreases noise and energy consumption. If at least one sensor of wetting is submerged below the water surface level, the upper electric motor is switched on again. If both drive units are in engagement, i.e., both have water supply, the control and communication system connected to the lower and upper regulator of the speed of the electric motor modifies their mutual ratio according to the pre-entered rules by changing the speed on one or both electric motors of the drive units. Both regulators have a software-limited maximum power and maximum speed, which can be reached if the rider adds a 100% power requirement on the manual control, i.e., presses the pedal or button with a similar function to accelerate the vessel to the maximum. Values for partially added power are then derived from these maximum values by the set dependency in the control and communication system. The control and communication system controls both the speed regulation and the activation and deactivation of the upper water drive unit during transitions between ride modes, and preferably of both drive units during the start and completion of the ride or unexpected interruption of the ride, for example due to a fall, etc.

Most preferably, the upper and/or lower water drive unit is a waterjet comprising an electric motor and a water engagement means, for example a propeller, which are connected by a shaft. The longitudinal axis of the electric motors of the water drive units is most preferably parallel to the longitudinal axis of the float, i.e., in the normal standard position of the vessel at rest before the start when it is not, for example, overturned due to an accident, the electric motors are thus positioned substantially horizontally.

The mast and underwater wing can be removable from the float. The mast and the underwater wing attached to it or integrated in it, or alternatively the wing connected by other connecting means, can be easily dismounted from the float and reattached, which allows both for space-saving transport and for the use of the float with an upper water drive unit for the classic ride of the motor-driven float on the water surface without the wing and the mast, thus, the rider can use both variants, a ride on the motor-driven float without the underwater wing, which is, along with the mast, dismounted, and flight on the float using the underwater wing attached to the mast.

The float can be a motor-driven surfboard, for example, its base is composed of a laminate chassis sealed against the ingress of water into the inner spaces which house the upper water drive unit and other components necessary for the operation of the water surfboard. The float is suitably hydrodynamically shaped such as to allow comfortable ride in a straight direction while also being effective when turning. On the upper area of the float lies, kneels, or stands the rider who controls the water surfboard. The surfboard turns by transferring the rider’s weight and the forward force is regulated by the rider using a manual controller, for example with remote or wired transmission.

The solution of the invention substantially decreases or eliminates the problem of starting and ending the ride of the motor-driven vessels with underwater wing known from the state of the art operating only with the lower water drive unit, since activation of the upper water drive unit in combination with the operated lower water drive unit does not cause a step change in the drag force but rather a more gradual change in the drag force occurs more smoothly. The upper water drive unit thus compensates for the heeling moment during the start-up and the step drag force, thus eliminating most rider falls, especially in the case of beginners, and significantly increasing the safety of the ride. These are mainly side falls, during which there is a risk of contact of the rider the sharp edges of the supporting areas. The engagement means, most often the propeller of the lower water drive unit, is completely covered to avoid contact with the rotating blades of the propeller. Vessels driven by an electric motor may include other important or implicitly include standard components for the overall operation of the vessel, but these do not contribute to the solution of the given problem and their enumeration is not necessary to protect the invention, and a person skilled in the art knows that they are automatically included in such a vessel. For example, an implicitly included part of vessels driven by an electric motor is an accumulator as an energy source for the electric motor and for powering communication device and electronics. The accumulator is placed in the float by quickrelease mechanisms such that it can be quickly and conveniently taken out and connected to a charger without having to disassemble other parts of the float. The accumulator is during the ride cooled by the surrounding water, which flows around the battery by means of special inlet channels by means of a suitably shaped float.

The start-up and completion of the ride are so-called transitional modes, in which the upper water drive unit is used.

During the start-up or slow speeds, when the float lies and then moves on the water surface similarly to riding a standard water motor-driven board without a wing, both water drive units are engaged in the operating mode and both drive units provide the optimal amount of thrust for a stable ride. The upper water drive unit eliminates the large heeling moment caused by the lower water drive unit. The start-up is comfortable and the same as on a standard water motor board in a kneeling position with the rear foot in the binding. For beginners, it is also possible to start lying down and put feet in the bindings after the float has a certain speed.

When the speed of the ride increases above a certain limit, the buoyancy force from the supporting areas increases so much that the float lifts off the water surface and the vessel enters the flight mode on the supporting areas. In such a case, its emergence above the water surface is preferably detected by the sensor of wetting and the control and communication system switches off the upper water drive unit. The vessel is thus driven only by the lower water drive unit, which remains submerged below the water surface and the float is in the flight mode above the water surface.

When slowing down from these higher speeds below a certain limit, or in larger waves, the sensor of wetting gets wet, when the upper water drive unit is activated and the upper water drive unit is partially or completely flooded with water, the vessel enters the landing and water intake mode, i.e., the transitional ride mode. Alternatively, the float can be a jet ski or a small boat for multiple people. In the case of large ships that do not have such a heeling moment and that can often afford to contain a plurality of drives at the same height level, these problems of low stability and overturning do not occur, and therefore the invention is not of such importance for them.

Description of Drawings

A summary of the invention is further clarified using exemplary embodiments thereof, which are described with reference to the accompanying drawings, in which: fig. 1 schematically shows a vessel of the invention with a float, a mast, and a lower water drive unit integrated into a main body of an underwater wing, fig. 2 shows the vessel of the invention floating on the water surface 2A and in the flight mode 2B, fig. 3 shows a front view of the vessel of the invention, fig. 4 is a schematic representation of the functional and communication connection of the components to the control and communication system comprising a control unit placed as a part of the upper regulator of the fourth exemplary embodiment.

Exemplary Embodiments of the Invention

The invention will be further clarified using exemplary embodiments with reference to the respective drawings.

One example of an embodiment is a passenger motor-driven water surfboard, shown in fig. 1 , having a mast 2 branched at its upper part, a float 1 is attached to the upper end of the mast 2, a main body 10 of an underwater wing 3 in which a lower water drive unit 4 is encapsulated with a lower electric motor 14 connected by a shaft and propeller, a so-called waterjet, is attached at the lower part of the mast 2 60 cm below the float 1, a propeller of the lower water drive unit 4 is seated in the extended cylindrical part of the main body 10 of the underwater wing 3. Supporting areas 9 extend from the main body 10 of the underwater wing 3. In the float 1, an upper water drive unit 5 with its own upper electric motor 15, shaft, and propeller, which is therefore also a waterjet, is embedded in the rear part thereof, into which water enters through an opening when this opening is at least partially below the water surface 7 level. Furthermore, this water surfboard has a user’s control device connected by a wire, which is used for example for starting, stopping, or controlling the speed of the vessel, which is connected via a control and communication system, which comprises a control unit 13 connected to the lower and upper water drive units 4, 5, or to the means for activating and deactivating said electric motors 14, 15, i.e., a switch. The lower electric motor 14 is functionally and communicatively connected to the control unit 13 via a lower regulator 12 and the upper electric motor 15 is functionally and communicatively connected to the control unit 13 via an upper regulator 16. The upper and lower electric motors 14, 15 are oriented with their axis substantially parallel to the axis of the float T The longitudinal axis of the lower and upper electric motors 14, 15 is parallel to the longitudinal axis 8 of the float, i.e. in the normal standard position of the vessel at rest before the start when it is not, for example, overturned due to an accident, the electric motors are therefore positioned substantially horizontally 14, 15. This exemplary embodiment further comprises the following optional and preferred features: The mast 2 connected removably, i.e., here for example by means of screw connections that allow it to be removed from the float 1 or attached to the float 1 if required or in the case of transport.

The water surfboard of this first exemplary embodiment is driven in such a way that in the flight mode, when the float 1 is kept above the water surface 7, the vessel is driven only by the permanently submerged lower water drive unit 4, and in the transitional ride mode, in particular during the start-up, finish, or tilt of the vessel, when at least a part of the float 1 is in contact with the water surface 7 and at the same time the water at least partially floods the upper water drive unit 5, the vessel is driven simultaneously by both mentioned drive units 4, 5. Said method is also used in the following exemplary embodiments.

Persons who tested the device of this exemplary embodiment handled start-ups, finish, and sharp turns satisfactorily and more easily compared to an identical device driven only by the lower water drive unit 4 in the transitional ride modes. During the ride, they entered requests to change the speed of the vessel using the control unit, wherein the control unit 13 further evaluated and controlled the increase or decrease of the power of both electric motors 14, 15.

In an alternative of this exemplary embodiment, the main body 10 of the underwater wing 3 in which the lower water drive unit 4 is placed is directly non-removably integrated into the mast 2, or only the housing carrying the lower water drive unit 4 is integrated into the mast 2, and the underwater wing 3 is connected to the bottom area of the float 2 via separate telescopic bracket.

In the second exemplary embodiment, the water surfboard differs from the first exemplary embodiment in that it additionally comprises a sensor 6_of wetting, placed at the interface of the mast 2 and the float 1, see figs. 2 and 3, and functionally connected to the control unit 13 deactivating or decreasing the speed of the upper electric motor 15 when the sensor 6 of wetting emerges above the water surface 7, and conversely activating the upper electric motor 15 when the sensor 6 of wetting is flooded with water.

Alternatively, two or more sensors 6 of wetting may be placed for example 5 cm or 20 cm below the lowest point of the float 1 on the mast 2 or on the bottom side of the float 1_, wherein the activation of the upper water drive unit 5 occurs when at least one of them is wetted by water and the deactivation occurs when all the sensors 6 of wetting present emerge above the water surface 7.

The ride on this device was much more enjoyable due to the lower noise in the ride modes when the upper electric motor 15 was switched off compared to the ride when the upper electric motor 15 was running for the entire duration of the ride. In addition, the driving distance was increased due to battery saving when the upper electric motor 15 was switched off and the overall energy consumption was lower.

In the third exemplary embodiment, the control and communication system comprises the control unit 13 placed as a part of the upper regulator 16, and the lower regulator 12 connected to this control unit 13, wherein this control and communication system is further adapted to regulate the mutual power ratio of the upper electric motor 15 and the lower electric motor 14 by setting the speed of each of these electric motors 14, 15. Using a wirelessly connected control device 17, the rider enters the requests for changing the speed of the vessel during the ride, wherein the control and communication system further evaluates and controls the increase or decrease of power independently on each of the electric motors 14, 15 according to a predetermined algorithm so as to achieve the optimal power ratio of the electric motors 14, 15 to minimize the heeling moment and stable ride of the vessel.

The advantage of this solution lies in the fact that if the upper electric motor 15 emerges above the water surface 7, the upper electric motor 15 does not increase the speed to the maximum but maintains the same speed, i.e., it rotates “idly” and has only minimal energy consumption. When the upper electric motor 15 is submerged under the water surface 7, the upper electric motor 15 tries to maintain the same speed and thus immediately generates the required thrust. The lower regulator 12 functionally connected to the lower electric motor 14 is placed in the body of the lower electric motor 14. Alternatively, it may be placed near the lower electric motor 14 in the housing of the lower water drive unit 4 or anywhere in/on the lower part of the mast 2, which is in the flight mode permanently submerged below the water surface 7. The upper regulator 16 is placed in the float 1_.

Persons who tested the device of this exemplary embodiment noted an improvement over the first exemplary embodiment and were able to handle start-ups, finish, and sharp turns even more easily.

The upper regulator 16 or even both regulators 12, 16 may be placed in the float 1 near the upper electric motor 15 of the upper water drive unit 5, but in that case it is also desirable to bring cooling water to the speed regulators 12, 16.

The fourth exemplary embodiment is a combination of features of the second and third exemplary embodiments and enjoys all their advantages and the steps of the method of propulsion of the vessel, see fig. 4.

In all exemplary embodiments, the control and communication system is functionally connected, either by a wire or wirelessly, to the user’s control device 17, to the upper and lower water drive units 4, 5, or to the switches of the respective electric motors 14, 15 as means for activating/deactivating them, to the lower regulator 12, and the upper regulator 16. In addition, it is functionally connected to:

- the sensor(s) 6 of wetting in the second exemplary embodiment, or

- the lower and upper speed regulators 12, 16 in the third exemplary embodiment, or

- all these mentioned components, as based on the fourth exemplary embodiment, see fig. 4.

The control and communication system then controls the activation and deactivation of the upper water drive unit 5, the regulation of power of the electric motors 14, 15, and possibly also the mutual power ratio of the electric motors 14, 15, using a program implemented in a data carrier connected to or integrated into the control and communication system, in which algorithms for prioritization or order of tasks are predefined. For example, in the fourth exemplary embodiment: The control and communication system receives signals from the sensor 6 of wetting and also from the wirelessly connected remote control device 17 controlled by the rider. The signal from the remote control device 17 is evaluated and power is dosed accordingly to the lower and upper electric motor 15. If the sensor 6 of wetting emerges from the water, this sensor 6 sends a higher-priority signal to the control and communication system, and the control unit 13 slows down or switches off the upper electric motor 15. The lower electric motor 14 can be set by the control unit 13 at this stage of the control to deliver the same power regardless of the switching off or on of the upper electric motor 15.

The fourth exemplary embodiment uses all the advantages of the invention and thus produced the best results, as the rider had a significantly easier start-up and entry onto the vessel, had significantly less difficulty in maintaining stability during the ride and turning by transferring the balance. In their hand, they had only the remote control device 17 for increasing or decreasing the speed, starting, or stopping the vessel.

The optimal power ratio of the lower and upper regulators 12, 16 was during the initial testing achieved during different operations by experimentally setting this ratio to different values and then, according to the results, the ratio was set to the optimal value at which the best results of improved stability in the transitional ride mode were recorded. These tests were also preceded by estimation with simplified simulated calculations. For an approximate calculation of the heeling moment under ideal conditions, where during the start-up it is assumed that the rider is lying on the float 1 approximately in the middle and that the center of gravity of the rider and vessel assembly is located approximately in the middle of the float 1 in both the horizontal and vertical directions, the approximate value of the heeling moment M in newton meters when using only the lower electric motor 14 for individual speeds can be calculated according to the following formula: where

- r is the distance of the center of gravity of the lower electric motor 14 from the center of gravity of the rider-vehicle assembly, in meters,

- F is the heeling force in Newtons,

- P is the power in Watts,

- v is the speed in meters per second.

The biggest problems with the stability occur during the start-up from 0 km/h to 10 km/h. A minimum total power of approximately 4 kW is required for the start-up. For example, at a distance of the center of gravity of the lower electric motor 14 from the center of gravity of the rider-vehicle assembly of r = 0.572 m and at a specific speed of 2.78 m/s, the approximate value of the heeling moment is 847.4 Nm. This is only an approximate, simplified calculation.

P 4000 W

M = F * r = — * r = - * 0,572m = 847,4 Nm v 2,78 — s

For individual speeds, the dependencies can be plotted in a graph and the sizes of the heeling moment can be estimated - where this simulation assumes the use of only the lower electric motor 14.

When the vessel of the invention was used and the power distributed evenly between the upper electric motor 15 and the lower electric motor 14, the heeling moment was decreased to approximately half of that when the vessel was driven only by the lower electric motor 14 with the same total power, because the upper electric motor 15 exerts its force approximately in the plane of the center of gravity of the rider-vehicle assembly. Riders who tested this improvement experienced a significant increase in comfort during the start-up, had fewer problems with stability, and experienced a significantly higher frequency of successful start-ups without falling. Riders were even able to start up faster on such a vessel with evenly distributed powers using, for example, 5 kW of power, i.e., 20 % higher than the minimum power required, which is also in favor of the higher stability of the starting vessel of the invention. During further speed increases above 10 km/h, the heeling moment decreases noticeably and the rider is able to rise, for example, to a kneeling or standing position.

This fourth exemplary embodiment was also implemented on a small motorboat with underwater wing 3 for two persons instead of a water surfboard, where it also significantly reduced the number of boat overturns during handling in the transitional ride modes.

List of Reference Signs - Float - mast - underwater wing - Lower water drive unit - Upper water drive unit - Sensor of wetting - Water surface - Longitudinal axis of the float - Supporting areas - Main body of the underwater wing - Lower regulator - Control unit - Lower electric motor - Upper electric motor - Upper regulator - Control device