A self-propelled sport and recreational watercraft

Abstract

The self-propelled watercraft vehicle has a floating body (1), underwater holding structure that is connected to a propulsion device (8) and consists of a mast (6) and a beam (7) that is transverse to the mast, a hydrofoil (9), a stabilizing foil (10), a central control unit (5), speed and roll sensors. Hydrofoil panels (11) have an asymmetric streamlined profile, stabilizing foil panels (12) have a streamlined profile. On the trailing edge (14) of both hydrofoil panels (11) there are control elements (15) that enable a hydrodynamic lifting force. The central control unit (5) provides automatic roll elimination depending on the speed and is designed to interact with a remote control.

Description

[0001] A SELF-PROPELLED SPORT AND RECREATIONAL WATERCRAFT

[0002] The claimed invention relates to small-sized watercraft vehicles for sports, outdoor activities and transportation of passengers on water bodies, and it is a self-propelled watercraft that has a dynamic support principle and comprises a hydrofoil with control elements and a stabilizing foil which are arranged under a body. A movement principle of this vehicle implies that during a translational movement of this watercraft, the hydrofoil creates a dynamic lifting force that, once reached a certain speed, lifts the body of this watercraft above a water surface and maintains it in this state during movement.

[0003] Surfing and other sports based on using boards attract significant attention and became popular among outdoor activities enthusiasts. However, traditional surfing boards have limited capabilities in terms of their use in conditions of lack of sufficient waves or calm sea. In order to expand capabilities and to increase a comfort level during outdoor activities, a more advanced structure of the boards has been developed, and it implies equipping the boards with hydrofoils which can move due to the lifting force of the latter. This structure allows to increase mobility, speed and stability on the water, thereby offering new possibilities for water sports in various conditions.

[0004] One of key aspects for ensuring the watercraft stability is a control of a roll, i.e., a tilt angle of the watercraft in a vertical plane that is perpendicular to a longitudinal vertical symmetry plane of a body of this watercraft. This is important to ensure optimal operation of the watercraft and to avoid a risk of overturn or loss of control.

[0005] In view of this, systems have been developed which provide automatic tracking and control of a roll angle as well as perform required actions to ensure stability. One of mechanical components of these systems are pivot surfaces of the hydrofoil which ensure decrease of the lifting force of one panel of the hydrofoil during upward turning and increase of the lifting force of a second panel of the hydrofoil during downward turning. An automatic stabilization system controls pivots of these surfaces by adjusting the lifting force of the panels of the hydrofoil so as to balance the roll and to ensure optimal movement stability of the watercraft body. Therefore, improvement of the automatic stabilization systems is a crucial task for further increase of travel efficiency and safety with these watercrafts.

[0006] A specification of the invention application No. 102019129577 filed in Germany discloses a motorized sport and recreational watercraft structure comprising two parallel hydrofoils having panels which are both pivot panels. That is, in this case, this watercraft does not merely have two flat plates which, due to their angled arrangement, may allow to create a certain instable lifting force during horizontal movement in a water medium, but rather two parallel hydrofoils, while each of the hydrofoils has an asymmetric streamlined profile. This particular profile forms a holding surface that enables generation of a hydrodynamic lifting force that is perpendicular to a movement vector of the watercraft due to a counterflow of the water medium. This watercraft comprises a floating body in a form of a swimming board, and it may have various embodiments of a complex holding structure having said hydrofoils and a motor coupled thereto, the structure is mounted in a lower portion of the body.

[0007] This motorized vehicle also comprises one or more sensors selected from a group comprising gyroscopic sensors, speed sensors, position sensors for systems such as GPS, Galileo, Beidou and / or Glonass, distance sensors, e.g., in a form of an echo sounder or sonar sensors, infrared sensors and tilt sensors, as well as a central control unit. Based on data received from the sensors, the central control unit may determine a position of the motorized vehicle relative to a reference point or a reference state and generate corresponding control signals to change attack angles of the panels of the hydrofoils.

[0008] It is implied that the determination of various attack angles of the opposite panels of the hydrofoils allows to adjust the lifting force generated by these panels, thereby correcting an undesired offset from a balanced position and, thus, counteracting rocking of the motorized watercraft.

[0009] The description of this motorized watercraft discloses only structural features thereof. However, it mentions the most general form of the automatic stabilization system for stabilizing the watercraft body position due to pivot of the panels of the hydrofoils. The description of this watercraft does not comprise any detailed information about a specific way of correcting the roll except for the general indication of correction of the position of the pivot panels of the hydrofoils based on the data from the sensors. Also, no information about any other way of movement control of this watercraft is provided.

[0010] A main distinctive feature of the described motorized watercraft is a use of two hydrofoils with the pivot panels instead of one hydrofoil. This particular feature implies a presence of a very complex and massive underwater holding structure which said hydrofoils are connected to. Use of the pivot of the four panels of the hydrofoils results in significant loads acting on these large surfaces, thereby requiring to use a rather large number of mechanical large-sized elements that significantly increases weight and dimensions of the watercraft structure. This also requires to ensure synchronization of the pivot of the panels of the hydrofoils that significantly complicates the structure and possibility to control its movable parts. All these circumstances result in high manufacturing costs, significantly reduce the operation reliability of the structural elements of this watercraft and create a danger for users of such vehicle. A specification of the international application WO2023283274 discloses a much simpler and more reliable motorized sport and recreational watercraft structure. This vehicle comprises a floating body in a form of a board, an underwater holding structure that is connected to a propulsion device and consists of a mast and a beam that is transverse to the mast. Said mast is mounted in a lower portion of the body and oriented downwards, while said transverse beam is connected to a lower portion of the mast. A front portion of said underwater holding structure comprises a solid fixedly mounted hydrofoil having an asymmetric streamlined profile. A rear portion of the transverse beam of this structure comprises a stabilizing foil. At the same time, the stabilizing foil is embodied only with horizontal pivot elements or with horizontal and vertical pivot elements. Said elements of the stabilizing foil have a flat shape and a streamlined profile. This device is described primarily in terms of controlling a movement direction of the watercraft. However, at the same time, the specification of this device comprises a general indication of a body position stabilization system by means of the pivot elements of the stabilizing foil.

[0011] The specification of this watercraft states that the user may travel in a sitting position, in a prone position, on knees or in a standing position, while driving the watercraft without a need to balance his / her body and to change a center of gravity of his / her body. Vertical lifting, leftward and rightward roll, as well as longitudinal driving of the watercraft are carried out by means of pivots of movable elements of the stabilizing foil. A remote controller with a joystick may be used to control the movement direction of the watercraft.

[0012] As mentioned above, this motorized watercraft has a simpler and a more reliable structure in a certain way. However, it also has significant drawbacks which could make it impossible to use this watercraft. In view of forces which act, in the water environment, on the hydrofoil that is arranged afore and that is only one element that generates the lifting force, there is a huge doubt that it will be possible to create a roll for turning this watercraft or for stabilizing a position of its body. This structure allows to affect a pitch, however, it occurs as a result of lifting or lowering of the rear portion of the transverse beam, where the movable horizontal elements of the stabilizing foil which are simultaneously pivoted downwards or upwards are arranged. Also, turning of the watercraft may be performed by pivoting the vertical movable element of the stabilizing foil (a keel) in the same direction. As a result of this, the rear portion of the beam will move to an opposite direction, where the stabilizing foil is arranged. However, it is apparent that this turning of the watercraft will be too slow and implies too large radius which does not enable any quick maneuvering and has almost no sense. At the same time, making a sufficient influence onto the roll by the horizontal movable elements of the stabilizing foil is highly doubtful in view of a resistance of the massive hydrofoil arranged afore. Even if this stabilizing foil is able to influence the roll of the hydrofoil arranged afore, this influence will be very slow, and it will not be able to provide a sufficient response speed for stabilization of the roll. Besides, in this case, a significant twisting load acting onto the beam will be created, thereby making a negative influence both onto the reliability of the underwater holding structure and the operation reliability of the movable elements of the stabilizing foil, and this can result in a destruction of this vehicle structure.

[0013] In contrast to the above-described two analogues, a specification of the invention application US 2017349246 discloses the most reliable and rather simple structure of a self- propelled sport and recreational watercraft. Therewith, a system for automatic stabilization of a watercraft body position by eliminating a roll and a pitch by means of pivot control elements of a hydrofoil and stabilizing foil elevation rudders is described (fig. 7, fig. 8, fig. 9, fig. 10).

[0014] This self-propelled watercraft comprises a body with a seat arranged in its upper portion and an underwater holding structure that is connected to a propulsion device and consists of a mast and a beam that is transverse to the mast. Said mast is mounted in a lower portion of the body and oriented downwards, while said transverse beam is connected to a lower portion of the mast. A front portion of the underwater holding structure comprises a fixedly mounted hydrofoil having a center that is connected to a lower portion of said beam. A rear portion of the transverse beam of this structure comprises a fixedly mounted stabilizing foil. Panels of said hydrofoil have an asymmetric streamlined profile that ensures generation of a hydrodynamic lifting force during movement of the self-propelled watercraft. Said stabilizing foil has a flat shape and a streamlined profile of the panels with horizontal turning elevation rudders are mounted thereon.

[0015] Control elements are arranged on a rear edge of both panels of the hydrofoil, the control elements have a flat shape and a streamlined profile as well as they are mounted such that they are rotatable around a longitudinal axis adjacent to their front edge. Each of the control elements is configured to ensure a reduction of the lifting force of the hydrofoil during upward pivot of the control element and to ensure an increase of the lifting force of the hydrofoil during downward pivot of the control element.

[0016] Also, this watercraft comprises a central control unit as well as speed, roll and pitch sensors coupled thereto. In this case, the roll shall be understood as a tilt angle of the watercraft in a vertical plane that is perpendicular to a longitudinal vertical symmetry plane of the body. While the pitch shall be understood as a tilt angle of the watercraft in the longitudinal vertical symmetry plane of its body. When the central control unit receives data about a certain roll or pitch from the sensors, it will transmit corresponding commands to driving devices to perform a pivot of the control elements of the hydrofoil or the elevation rudders of the stabilizing foil. The roll is eliminated by pivoting the control elements of the hydrofoil by an identical angle in opposite directions. Thus, if there is a leftward roll, then in order to eliminate it, the control element of the left panel of the hydrofoil will lower downwards, thereby increasing the lifting force of the left panel of the hydrofoil, while the control element of the right panel of the hydrofoil will lift upwards, thereby reducing the lifting force of the right panel of the hydrofoil. If there is a rightward roll, then in order to eliminate it, the control element of the left panel of the hydrofoil will lift upwards, thereby reducing the lifting force of the left panel of the hydrofoil, while the control element of the right panel of the hydrofoil will lower downwards, thereby increasing the lifting force of the right panel of the hydrofoil.

[0017] The pitch is eliminated by simultaneous pivot of the elevation rudders in the same direction. Thus, if there is a forward tilt of the watercraft body, then in order to eliminate this tilt, the elevation rudders of the stabilizing foil will lift upwards. If there is a rearward tilt of the watercraft body, then in order to eliminate this tilt, the elevation rudders of the stabilizing foil will lower downwards.

[0018] The entire specification of this watercraft comprises only general references to correction movements of the above-described pivot elements of the hydrofoil and the stabilizing foil which are intended only to stabilize the watercraft body position. At the same time, only synchronous pivots of the control elements of the hydrofoil in opposite directions by the identical angle or synchronous pivots of the elevation rudders of the stabilizing foil in the identical direction by the identical angle are considered. Other possible movement options of these control elements are not considered.

[0019] This specification also does not disclose how a change of the movement direction, i.e., turning, of the watercraft is performed. There is only one indication that according to one of embodiments of the invention, this turning may be performed as a result of roll creation by a side displacement of a center of gravity due to changing a body position of a user of this watercraft as it is usually performed on such hydrofoil watercraft without any underwater control surfaces. However, at the same time, it is not clear how this turning may be performed, if there is the automatic stabilization system that eliminates the roll, i.e., counteracts the turning. The specification of this watercraft also briefly mentions that according to one of embodiments of the invention, this watercraft may be controlled by means of a remote controller (“hand-held device”). Functions of this device are disclosed in publicly available sources, in particular, in a publicly available video that is published in Internet and accessible via the following link: https: / / houstonkiteboarding.com / products / lift-elite-hand-controller. However, this remote controller for controlling the motorized hydrofoil watercraft does not imply any possibilities to change the movement direction of the watercraft. However, it may enable to switch the propulsion device off and on, to change the speed of the self-propelled watercraft, it may show information about the movement speed on a display, etc.

[0020] Apart from the fact that the described solution of the self-propelled watercraft does not solve the problem of counteraction of the automatic stabilization system against the roll to change the movement direction of this watercraft as well as does not provide any other ways to perform turning of this watercraft, this solution also bears a number of significant drawbacks.

[0021] So, the above-described method for eliminating the roll in no way protects the watercraft against the problem of an undesired yaw that consists in skidding of the front portion of the watercraft body in the direction that is opposite to the tilt direction of the body (roll). This effect is associated with occurrence of a head drag difference between the right panel and the left panel of the hydrofoil that is caused by a change of the lifting force upon tilt of the hydrofoil. Said undesired yaw results in an undesired course change of the watercraft and a loss of stability of its body position.

[0022] Furthermore, the above-described roll elimination method creates a high probability of losing the watercraft body position stability and its turnover during high-speed movement, thereby creating a real danger for users of these vehicles.

[0023] Besides, the above-described self-propelled watercraft structure implies that the stabilizing foil is provided with elevation rudders which is mostly caused by arrangement of the hydrofoil center on the symmetry axis of the mast of the underwater holding structure. However, the presence of the elevation rudders makes almost no influence onto protection of the rear portion of the watercraft body against its downward tilting. In contrast, when the hydrofoil and the stabilizing foil are arranged in this way, even the presence of the elevation rudders almost does not protect the front portion of the body against its downward tilting. Therewith, use of the elevation rudders complicates the watercraft structure significantly, causes provision of additional control devices, thereby resulting in additional costs for creation of this structure, reducing the operation reliability of this vehicle, as well as reducing its energy efficiency.

[0024] Therefore, a problem to be solved by the claimed technical solution is to provide a structure of the self-propelled sport and recreational watercraft that could ensure a maximum possible extent of convenient and safe stabilization of the body position, while reducing the yaw effect and providing a controlled change of the movement direction in a wide speed range.

[0025] With consideration of the above-disclosed information, the above-described solution of the self-propelled sport and recreational watercraft as disclosed in the specification of the invention application US 2017349246 is taken as the closest analogue of the claimed solution.

[0026] The claimed solution of the self-propelled sport and recreational watercraft and the closest analogue share the following features:

[0027] - the presence of the floating body that is symmetric relative to the longitudinal vertical plane, where the seat is arranged in the upper portion of the body;

[0028] - the presence of the underwater holding structure that is connected to the propulsion device and consists of the mast and the beam that is transverse to the mast;

[0029] - said mast is mounted in the lower portion of the body and oriented downwards, and said transverse beam is connected to the lower portion of the mast;

[0030] - the holding structure is symmetric relative to the longitudinal vertical symmetry plane of the body;

[0031] - the underwater holding structure is made such that the fixedly mounted hydrofoil is arranged in its front portion, and the fixedly mounted stabilizing foil is arranged in the rear portion of the transverse beam;

[0032] - the hydrofoil is made such that it has panels having an asymmetric streamlined profile that forms a holding surface that enables generation of a hydrodynamic lifting force that is perpendicular to a movement vector of the self-propelled watercraft due to a counterflow of a water medium, as well as the stabilizing foil is made such that it has a flat shape and a streamlined profile of the panels;

[0033] - the hydrofoil and the stabilizing foil are arranged horizontally such that their right and left panels are symmetric relative to the longitudinal vertical symmetry plane of the body;

[0034] - the symmetric arrangement of the control elements on the rear edge of both panels of the hydrofoil, the control elements have a flat shape and a streamlined profile as well as they are mounted such that they are rotatable around a longitudinal axis adjacent to their front edge;

[0035] - each of the control elements is configured to enable a reduction of a lifting force of the hydrofoil, when the control element pivots upwards due to rotation around said axis and its rear edge lifts upwards correspondingly, as well as it is configured to enable an increase of the lifting force of the hydrofoil, when the control element pivots downwards due to rotation around said axis and its rear edge lowers downwards correspondingly; - the presence of the central control unit as well as sensors for detecting the speed and the roll, i.e., the tilt angle of the self-propelled watercraft in the vertical plane that is perpendicular to the longitudinal vertical symmetry plane of the body, coupled thereto;

[0036] - the central control unit is configured to interact, via a radio channel, with a remote controller for controlling the self-propelled watercraft, and it is configured to receive at least propulsion device switch-off and switch-on commands, as well as self-propelled watercraft speed change commands;

[0037] - the central control unit is configured to automatically receive data from the roll sensor and to automatically transmit corresponding commands to eliminate the roll of the self- propelled watercraft to control devices for controlling the control elements to pivot these control elements in opposite directions.

[0038] The posed problem is solved by providing a self-propelled sport and recreational watercraft that comprises a floating body that is symmetric relative to a longitudinal vertical plane and has a seat in its upper portion. It comprises an underwater holding structure that is connected to a propulsion device and consists of a mast and a beam that is transverse to the mast, wherein said mast is mounted in a lower portion of the body and oriented downwards, while said transverse beam is connected to a lower portion of the mast. This underwater holding structure is symmetric relative to a longitudinal vertical symmetry plane of the body. A front portion of said underwater holding structure comprises a fixedly mounted hydrofoil, while a rear portion of the transverse beam of this structure comprises a fixedly mounted stabilizing foil. Said hydrofoil has an asymmetric streamlined profile of panels that forms a holding surface that enables generation of a hydrodynamic lifting force that is perpendicular to a movement vector of the self-propelled watercraft due to a counterflow of a water medium. Said stabilizing foil has a flat shape and a streamlined profile of panels. The hydrofoil and the stabilizing foil are arranged horizontally such that their right and left panels are symmetric relative to the longitudinal vertical symmetry plane of the body.

[0039] Besides, control elements are symmetrically arranged on a rear edge of both panels of the hydrofoil, the control elements have a flat shape and a streamlined profile as well as they are mounted such that they are rotatable around a longitudinal axis adjacent to their front edge. Each of these control elements is configured to enable a reduction of a lifting force of the hydrofoil, when the control element pivots upwards due to rotation around said axis and its rear edge lifts upwards correspondingly, as well as it is configured to enable an increase of the lifting force of the hydrofoil, when the control element pivots downwards due to rotation around said axis and its rear edge lowers downwards correspondingly. Besides, the self-propelled watercraft comprises a central control unit as well as sensors for detecting a speed and a roll, i.e., a tilt angle of the self-propelled watercraft in the vertical plane that is perpendicular to the longitudinal vertical symmetry plane of the body, coupled thereto. The central control unit is configured to interact, via a radio channel, with a remote controller for controlling the self-propelled watercraft, and it is configured to receive at least propulsion device switch-off and switch-on commands, as well as self-propelled watercraft speed change commands. Besides, the central control unit is configured to automatically receive data from the roll sensor and to automatically transmit corresponding commands to eliminate the roll of the self-propelled watercraft to control devices for controlling the above-mentioned control elements to pivot these control elements in opposite directions.

[0040] Therewith, according to the claimed solution, the above-mentioned transverse beam of the holding structure is protruded forwards relative to the mast of the underwater holding structure, and the hydrofoil is connected to the front portion of this beam. The seat is made as a chair that is movable longitudinally along the upper portion of the body to take fixed positions for locating a combined center of gravity in between the front edge of the hydrofoil and the above-mentioned mast of the underwater holding structure. The central control unit is configured to automatically receive data from the roll sensor and to automatically transmit corresponding commands to eliminate the roll of the self-propelled watercraft to the control devices for controlling the above-mentioned control elements to pivot these control elements in opposite directions such that the downward pivot of the control element is made by an angle that is smaller than an angle of the upward pivot of the opposite control element. Therewith, a difference between these pivot angles is a constant value that is a function of a ratio between a surface area of the hydrofoil panel and a surface area of the control element arranged thereon.

[0041] Furthermore, the central control unit is configured to receive commands to perform turning of the self-propelled watercraft from the above-mentioned remote controller. Also, the central control unit is configured to automatically terminate the transmission of the commands to eliminate the roll of the self-propelled watercraft in response to receipt of the command to perform turning of the self-propelled watercraft from the remote controller as well as to simultaneously transmit the corresponding commands to perform turning of the self-propelled watercraft to the control devices for controlling the control elements of the hydrofoil for pivoting these control elements in opposite directions such that the downward pivot of the control element is performed by the angle that is smaller than the angle of the upward pivot of the opposite control element. Therewith, a difference between these pivot angles is a constant value that is a function of a ratio between a surface area of the hydrofoil panel and a surface area of the control element arranged thereon. Furthermore, the central control unit is configured to automatically receive the data from the roll sensor and to automatically transmit the corresponding commands to eliminate the roll of the self- propelled watercraft to control devices for controlling the control elements of the hydrofoil in response to receipt of the command to terminate turning of the self-propelled watercraft from the remote controller. Besides, the central control unit is configured to automatically receive the data from the speed sensor and to automatically transmit the above-described commands to eliminate the roll and to perform turning of the self-propelled watercraft which imply reduction of the pivot angles of the control elements of the hydrofoil proportionally to increase of the speed of the self-propelled watercraft.

[0042] In separate embodiments, the self-propelled sport and recreational watercraft may comprise a power supply unit that is mounted inside the floating body, while locating the combined center of gravity of this unit in between the front edge of the hydrofoil and the above- mentioned mast of the underwater holding structure.

[0043] Besides, in separate embodiments, a housing of the above-mentioned seat in the form of the chair may be made so as to form a luggage compartment. Furthermore, in separate embodiments, the above-mentioned propulsion device may be arranged on the mast of the underwater holding structure and formed as an electric motor with a propeller screw.

[0044] Also, in separate embodiments, the central control unit may be configured to receive, from the above-mentioned remote controller, a command to stop the movement of the self- propelled watercraft, if the remote controller is submerged in the water medium.

[0045] In separate embodiments, the central control unit may be configured to receive, from the above-mentioned remote controller, commands to terminate and to resume the transmission of the commands to eliminate the roll of the self-propelled watercraft.

[0046] Besides, in separate embodiments, the central control unit may be configured to receive, from the above-mentioned remote controller, commands to maintain and to terminate the maintaining of a constant movement speed of the self-propelled watercraft.

[0047] Furthermore, in separate embodiments, the central control unit may be configured to receive data from a location-based device for subsequent transmission of corresponding commands to the control devices for controlling the control elements of the hydrofoil and the propulsion device.

[0048] Also, in separate embodiments, the central control unit may be configured to transmit, to the above-mentioned remote controller, data for displaying, on its display, information about the movement speed of the self-propelled watercraft and about a charge state of the power supply unit.

[0049] A cause-and-effect relationship between the set of features of the claimed solution of the self-propelled sport and recreational watercraft structure and the technical effect will be provided herein below. Since the transverse beam of the holding structure is protruded forwards relative to its mast and since the hydrofoil is connected to the front portion of this beam, a fulcrum is offset rearwards beyond the hydrofoil, thereby reducing the probability of the downward tilt of the front portion of the body and allowing to increase the distance between the hydrofoil and the stabilizing foil. This possibility avoids a need to use an elevation rudder on the stabilizing foil. Therewith, due to enabling longitudinal movement of the chair along the upper portion of the body to take fixed positions, while locating the combined center of gravity in between the front edge of the hydrofoil and the mast of the underwater holding structure, it is allowed to eliminate the lifting of the front portion of the body that may occur, for example, if the chair takes its rearmost position, while the user and the luggage, if present, have a weight that is significant for occurrence of said lifting, or the downward tilt of the front portion of the body, when the chair takes its foremost position and the corresponding weight of the user and the luggage is present. In the first case, before starting the movement, the chair merely must be moved forwards and fixed in the position that will ensure the corresponding location of the combined center of gravity and, thus, will eliminate said lifting of the body quickly and safely. In the second case, the chair is moved rearwards until it reaches the corresponding position, while eliminating the downward tilt of the front portion of the body. Cavities may be provided in order to fix the chair in the upper portion of the watercraft body. Therefore, the above-mentioned features of the claimed solution allow to achieve the self-propelled watercraft structure that is more stable against oscillations in the longitudinal vertical symmetry plane of its body (downward tilt of the rear or fore portion of the body), thereby in fact avoiding a need to use an elevation rudder on the stabilizing foil as it is implied in the closest analogue which, in turn, simplifies the overall watercraft structure and makes it more reliable and energy efficient. Therewith, the longitudinal stabilization will depend on the user weight, luggage weight in the luggage compartment, if present, and the chair fixation position.

[0050] The downward pivot of the control element by the angle that is less than the angle of the upward pivot of the opposite control element in order to eliminate the roll, while maintaining the constant difference between these pivot angles (that depends on a ratio between the surface area of the hydrofoil panel and the surface area of the control element arranged thereon) in order to eliminate the roll of the self-propelled watercraft, protects the watercraft against the problem of undesired yaw during stabilization of the roll, thereby reducing the head resistance difference between the left and the right hydrofoil panels that is caused by the change of the lifting force during pivots of the control elements.

[0051] Turning of the self-propelled watercraft by means of transmission of the corresponding commands to the central control unit from the remote controller allows to avoid creation of the roll for this purpose by lateral displacing the center of gravity due to change of the user body position and, thus, it is convenient for the latter.

[0052] Therewith, the automatic termination of the transmission of the commands to eliminate the roll of the self-propelled watercraft to the control devices for controlling the above- mentioned control elements in response to receipt of the command to perform turning of the self-propelled watercraft from the remote controller resolves the problem of counteraction of the automatic stabilization system against rolling for changing the movement direction of the watercraft, i.e., it eliminates an inconsistency that could exist in case of simultaneous transmission, to the control devices for controlling the control elements of the hydrofoil, of the commands to eliminate the undesired roll and the commands to perform rolling for turning. Therewith, the downward pivot of the control element by the angle that is less than the angle of the upward pivot of the opposite control element, while maintaining the constant difference between these pivot angles (that depends on a ratio between the surface area of the hydrofoil panel and the surface area of the control element arranged thereon) in order to perform turning of the self-propelled watercraft, as in case of elimination of its roll, protects the watercraft against the problem of undesired yaw during turning, thereby reducing the head resistance difference between the left and the right hydrofoil panels that is caused by the change of the lifting force during pivots of the control elements.

[0053] Due to providing the automatic receipt of the data from the roll sensor and the automatic transmission of the corresponding commands to eliminate the roll of the self-propelled watercraft to the control devices for controlling the control elements of the hydrofoil in response to receipt of the command to terminate turning of the self-propelled watercraft from the remote controller, the watercraft substantially returns to the movement in the mode of the automatic stabilization of the watercraft body position which provides maximum user convenience and safety.

[0054] Reduction of the pivot angles of the control elements of the hydrofoil is proportional to increase of the movement speed of the self-propelled watercraft, and it avoids any loss of the watercraft body position stability and its turnover during high-speed movement. For example, upon execution of the command to eliminate the roll and to perform turning of the watercraft at low-range speeds, the control elements pivot in opposite directions by angles from 0° to 30°, at mid-range speeds - by angles from 0° to 15°, and at high-range speeds - by angles from 0° to 5°. Therewith, in the mode of the automatic stabilization of the watercraft body position, the user does not experience any effects of tilting and alignment of the body that are caused by operation of the control elements, while if the mode of the automatic stabilization of the watercraft body position during turning is disabled, the correction functions of the central control unit will allow to ensure predictable and comfortable tilting effect of the body towards a center of the turning circle, thereby reducing the influence of centrifugal forces onto the user.

[0055] Therefore, said features of the claimed solution allow to ensure convenient and safe stabilization of the watercraft body position, while reducing the yaw effect and providing the controlled change of the movement direction in the entire speed range.

[0056] Due to mounting the power supply unit inside the floating body and locating the combined center of gravity of this unit in between the front edge of the hydrofoil and the above- mentioned mast of the underwater holding structure, provision of the balance as well as maintaining of the horizontal position of the floating body are facilitated. Depending on needs, said unit may comprise two waterproof lithium-ion accumulators having a total capacity of more than 40 Ah.

[0057] Due to making the seat housing in the form of the chair and forming the luggage compartment, the user is allowed to place necessary belongings into the latter. Besides, the luggage compartment may allow to connect a smartphone to a watercraft control network. Alternatively, the luggage compartment may have a separate housing that is also movable longitudinally along the upper portion of the watercraft body to take fixed positions, e.g., into the cavity provided in the upper portion of the watercraft body.

[0058] Receipt of the command to stop movement of the self-propelled watercraft from the remote controller, if the remote controller is sank into the water medium, increases the user safety in case a corresponding emergency situation occurs and does not allow any non-controlled movement of the watercraft.

[0059] Due to enabling, by means of the controller, termination and resuming the transmission of the commands to eliminate the roll of the self-propelled watercraft, it is allowed to use the watercraft preferably for sports, to maintain a body balance and to correct the position of the floating body in a standing position. Due to enabling maintaining and termination of maintaining of the constant movement speed of the self-propelled watercraft, the range of available user options for operating the watercraft is broadened and, thus, the comfort level is increased.

[0060] Due to enabling the receipt of the data from the location-based device (that is an integrated or, e.g., a location-based device of the smartphone that is connected to the watercraft operation network), it is allowed to determine a distance between the watercraft and a destination for further transmission of the corresponding commands to the control devices for controlling the control elements of the hydrofoil and the propulsion device. In this way, the automatic movement according to a built route is enabled. Due to displaying, on the display of the remote controller, the information about the movement speed of the self-propelled watercraft and about the charge state of the power supply unit, the user’s amount of control of the watercraft movement parameters is increased, as well as an unintended discharge of the power supply unit is avoided, and it is allowed to implement a power saving mode in order to increase a drive range which is crucial if the watercraft is located far away from a coast.

[0061] The self-propelled watercraft according to the claimed technical solution may have a modular structure, thereby enabling quick mounting or replacement of the components of the body, the mast and the transverse beam with the hydrofoil and the stabilizing foil, and, thus, its maintenance and transportation convenience.

[0062] The essence of the claimed technical solution shall be explained by the following schematic drawings in which:

[0063] Fig. 1 illustrates a schematic view of one of preferable embodiments of the self-propelled sport and recreational watercraft according to the claimed technical solution;

[0064] Fig. 2 illustrates a general view of one of preferable embodiments of the transverse beam with the hydrofoil and the stabilizing foil of the underwater holding structure of the self- propelled sport and recreational watercraft according to the claimed technical solution;

[0065] Fig. 3 illustrates a front view and a side view of one of possible embodiments of the remote controller for controlling the self-propelled sport and recreational watercraft according to the claimed technical solution;

[0066] Fig. 4 illustrates a general view of one of possible embodiments of the self-propelled sport and recreational watercraft according to the claimed technical solution.

[0067] These drawings are in no way intended to depict a precise structure of the realistic self- propelled sport and recreational watercraft, as well as in no way limit a possible implementation of the watercraft structure in other embodiments thereof within the scope of the technical solution disclosed in the claims. The provided drawings (Fig. 1 - 4) explain the essence of implementation of the solution using a provisional material object that is characterized by the features included into the claims.

[0068] A self-propelled sport and recreational watercraft comprises a floating body 1 having a seat in a form of a chair 2 that is arranged in its upper portion, and a housing of the chair is made so as to form a luggage compartment 3. Said body 1 has a streamlined shape and is symmetric relative to a longitudinal vertical plane. The upper portion of the body 1 is provided with cavities to enable a longitudinal movement of the chair 2 and the luggage compartment 3 along said upper portion of the body 1 to take fixed positions. A power supply unit comprising two accumulators 4 and a central control unit 5 are mounted inside the floating body 1 (Fig. 1).

[0069] The self-propelled sport and recreational watercraft also comprises an underwater holding structure that is symmetric relative to the longitudinal vertical symmetry plane of the body 1 and consists of a mast 6 and a beam 7 that is transverse to the mast.. Said mast 6 is mounted in a lower portion of the body 1 and oriented downwards, while said transverse beam 7 is connected to a lower portion of the mast 6 and protruded forwards relative to the mast. A propulsion device in a form of an electric motor 8 with a propeller screw is arranged on the mast 6 (Fig. 1).

[0070] A front portion of the underwater holding structure, namely, a front portion of the transverse beam 7, comprises a fixedly mounted hydrofoil 9, while a rear portion of the beam 7 comprises a fixedly mounted stabilizing foil 10 (Fig. 1, 2). As depicted in Fig. 2, the hydrofoil 9 is characterized by having an asymmetric streamlined profile of panels 11, while the stabilizing foil 10 is characterized by having a flat shape and a streamlined profile of panels 12. The hydrofoil 9 and the stabilizing foil 10 are arranged horizontally such that their right and left panels 11 and 12 are symmetric relative to the longitudinal vertical symmetry plane of the body 1.

[0071] The panels 11 of the hydrofoil 9 are characterized by having a front edge 13 (Fig. 1, 2) and a rear edge 14 (Fig. 2). Control elements 15 are symmetrically arranged on the rear edge 14 of both panels 11 of the hydrofoil 9, the control elements have a flat shape and a streamlined profile as well as they are mounted such that they are rotatable around a longitudinal axis 16 adjacent to their front edge 17. Each of these control elements 15 is configured to enable a reduction of a lifting force of the hydrofoil 9, when the control element 15 pivots upwards due to its rotation around said axis 16 and its rear edge 18 lifts upwards correspondingly, as well as it is configured to enable an increase of the lifting force of the hydrofoil 9, when the control element 15 pivots downwards due to rotation around said axis 16 and its rear edge 18 lowers downwards correspondingly.

[0072] A dotted line in Fig. 1 denotes a connection between the central control unit 5, the electric motor 8 and control devices (e.g., in a form of servomotors) for controlling the control elements 15 on the panels 11 of the hydrofoil 9. Also, the central control unit is connected to speed and roll sensors. Said servomotors and sensors are not depicted in Fig. 1. Besides, the central control unit 5 is configured to interact, via a radio channel, with a remote controller for controlling the self-propelled watercraft. An exemplary embodiment of the remote controller is depicted in Fig. 3.

[0073] The remote controller has a housing 19 with a joystick 20 to control movement speed and direction of the watercraft. The following components are arranged on the housing 19: a display 21 for displaying information about said movement speed and about a charge state of the power supply unit, a button 22 for termination and resuming of the remote control of the self-propelled watercraft, a button 23 for termination and resuming of transmission of commands to eliminate the roll of the self-propelled watercraft, and a button 24 for maintaining and termination of maintaining of a constant movement speed of the self- propelled watercraft. Also, an alarm signal button 25 is arranged on the housing 19.

[0074] Fig. 4 illustrates a general view of one of possible embodiments of the self-propelled sport and recreational watercraft according to the claimed technical solution. The abovedescribed self-propelled sport and recreational watercraft operates in the following way.

[0075] Before start of the watercraft movement, necessary belongings are placed in the luggage compartment, as well as its chair 2 is moved along the upper portion of the body 1, and said chair 2 is fixed in the cavity in the upper portion of said body 1, while locating the combined center of gravity in between the front edge 13 of the hydrofoil 9 and the mast 6 of the underwater holding structure. If necessary, the chair 2 is moved again with consideration of the user and luggage weight in order to eliminate the downward tilt of the rear or front portion of the body.

[0076] Once the chair 2 is occupied, the remote control of the watercraft is switched on by means of the button 22 for termination and resuming of the remote control of the self-propelled watercraft on the remote controller, the mode of the automatic stabilization of the watercraft body 1 position is switched on by means of the button 23 for termination and resuming of transmission of commands to eliminate the roll of the self-propelled watercraft, and the watercraft movement is initiated by means of the joystick 20 of said remote controller.

[0077] When the watercraft moves at speed greater than 5 km / h, the automatic receipt of the data from the roll sensor and the automatic transmission of the corresponding commands to eliminate the roll of the self-propelled watercraft to the control devices for controlling the control elements 15 are initiated automatically. At the same time, said control elements 15 are pivoted in opposite directions such that the downward pivot of the control element 15 is performed by the angle that is smaller than the angle of the upward pivot of the opposite control element 15, wherein the difference between these angles is a constant value that is a function of a ratio between a surface area of the hydrofoil 9 panel 11 and a surface area of the control element 15 arranged thereon.

[0078] If it is necessary to change the movement direction, the command to perform turning of the watercraft is transmitted by means of the joystick 20 of the remote controller to the central control unit 5. Therewith, the transmission of the commands to eliminate the roll of the self-propelled watercraft is automatically terminated, while at the same time transmitting the corresponding commands to perform turning of the self-propelled watercraft to the control devices for controlling the control elements 15 of the hydrofoil 9. Said control elements 15 are pivoted in opposite directions such that the downward pivot of the control element 15 is performed by the angle that is smaller than the angle of the upward pivot of the opposite control element 15, wherein the difference between these angles is a constant value that is a function of a ratio between a surface area of the hydrofoil 9 panel 11 and a surface area of the control element 15 arranged thereon.

[0079] The above-described control of the pivot of the control elements 15, namely, by pivoting them by certain angles, while maintaining the constant difference between them, reduces the yaw effect that may occur during elimination of the roll of the self-propelled watercraft or when the latter performs turning.

[0080] Once the turning is completed (once the command about termination of the turning is received from the remote controller), the watercraft is automatically returned to the operation in the mode of the automatic stabilization of the body 1 position. At the same time, the automatic receipt of the data from the roll sensor and the automatic transmission of the corresponding commands to eliminate the roll of the self-propelled watercraft to the control devices for controlling the control elements 15 of the hydrofoil 9 are resumed.

[0081] When the movement speed of the self-propelled watercraft is increased, the pivot angles of the control elements 15 of the hydrofoil 9 are reduced proportionally both in the mode of the automatic stabilization of the body 1 position and during turning of the self-propelled watercraft, thereby avoiding the loss of the stability of the watercraft body 1 position as well as ensuring predictable and comfortable tilting effect of the body 1 towards a center of the turning circle.

[0082] Due to the automatic termination of the transmission of the commands to eliminate the roll, if it is necessary to change the movement direction, and due to the proportional reduction of the pivot angles of the control elements 15 of the hydrofoil 9, if the movement speed is increased, the controlled change of the movement direction in the entire range of the watercraft speeds is achieved.

[0083] If the remote controller is submerged in the water medium, the movement of the self- propelled watercraft will be stopped.

[0084] If the position on the body 1 is changed from the sitting position to the standing position, the transmission of the commands to eliminate the roll of the self-propelled watercraft will be terminated by means of the button 23 for termination and resuming of transmission of commands to eliminate the roll of the self-propelled watercraft that is provided on the remote controller. Covering of the upper portion of the body 1 is performed with consideration of compliance with requirements for reliable engagement of a sole or a shoe in the standing position.

[0085] The movement speed of the watercraft may be maintained constant by means of the button 24 for maintaining and termination of maintaining of the constant movement speed of the self-propelled watercraft that is provided on the remote controller. In case of termination of maintaining of the constant movement speed of the watercraft, the control of said speed will be performed by means of the joystick 20 of the remote controller. The information about the movement speed and the charge state of the power supply unit may be received from the display 21 of the remote controller.

[0086] Due to hydrodynamic structural features of the watercraft, the user may stably move, while being in the standing or sitting positions, at the speed up to 55 km / h above a water surface with a height of waves up to 1 m to a distance up to 50 km.

[0087] Depending on the temperature, the body 1 may reside on the water surface in a wait mode, while waiting for the control commands, during more than 4 h and update its operational capability according to a passport specification.

[0088] As it may be seen, the above-described technical solution allows to provide the structure of the self-propelled sport and recreational watercraft that ensures the maximum possible extent of convenient and safe stabilization of the body position, while reducing the yaw effect and providing a controlled change of the movement direction in the entire speed range.

Claims

CLAIMS1. A self-propelled sport and recreational watercraft comprising a floating body that is symmetric relative to a longitudinal vertical plane, where a seat is arranged in an upper portion of the body, an underwater holding structure that is connected to a propulsion device and consists of a mast and a beam that is transverse to the mast, where said mast is mounted in a lower portion of the body and oriented downwards, while said transverse beam is connected to a lower portion of the mast, and this underwater holding structure is symmetric relative to a longitudinal vertical symmetry plane of the body, a front portion of said underwater holding structure comprises a fixedly mounted hydrofoil, while a rear portion of the transverse beam of this structure comprises a fixedly mounted stabilizing foil, said hydrofoil is made such that it has an asymmetric streamlined profile of panels that forms a holding surface that enables generation of a hydrodynamic lifting force that is perpendicular to a movement vector of the self-propelled watercraft due to a counterflow of a water medium, as well as the stabilizing foil is made such that it has a flat shape and a streamlined profile of the panels, the hydrofoil and the stabilizing foil are arranged horizontally such that their right and left panels are symmetric relative to the longitudinal vertical symmetry plane of the body, besides, control elements are symmetrically arranged on a rear edge of both panels of the hydrofoil, the control elements have a flat shape and a streamlined profile as well as they are mounted such that they are rotatable around a longitudinal axis adjacent to their front edge, each of these control elements is configured to enable a reduction of a lifting force of the hydrofoil, when the control element pivots upwards due to rotation around said axis and its rear edge lifts upwards correspondingly, as well as it is configured to enable an increase of the lifting force of the hydrofoil, when the control element pivots downwards due to rotation around said axis and its rear edge lowers downwards correspondingly, besides, the self-propelled watercraft comprises a central control unit as well as sensors for detecting a speed and a roll, i.e., a tilt angle of the self-propelled watercraft in the vertical plane that is perpendicular to the longitudinal vertical symmetry plane of the body, coupled thereto,the central control unit is configured to interact, via a radio channel, with a remote controller for controlling the self-propelled watercraft, and it is configured to receive at least propulsion device switch-off and switch-on commands, as well as self-propelled watercraft speed change commands, besides, the central control unit is configured to automatically receive data from the roll sensor and to automatically transmit corresponding commands to eliminate the roll of the self-propelled watercraft to control devices for controlling the above-mentioned control elements to pivot these control elements in opposite directions, wherein the above-mentioned transverse beam of the holding structure is protruded forwards relative to the mast of the underwater holding structure, and the hydrofoil is connected to the front portion of this beam, the seat is made as a chair that is movable longitudinally along the upper portion of the body to take fixed positions for locating a combined center of gravity in between the front edge of the hydrofoil and the above-mentioned mast of the underwater holding structure, the central control unit is configured to automatically receive data from the roll sensor and to automatically transmit corresponding commands to eliminate the roll of the self- propelled watercraft to the control devices for controlling the above-mentioned control elements to pivot these control elements in opposite directions such that the downward pivot of the control element is made by an angle that is smaller than an angle of the upward pivot of the opposite control element, and a difference between these pivot angles is a constant value that is a function of a ratio between a surface area of the hydrofoil panel and a surface area of the control element arranged thereon, furthermore, the central control unit is configured to receive commands to perform turning of the self-propelled watercraft from the above-mentioned remote controller, the central control unit is configured to automatically terminate the transmission of the commands to eliminate the roll of the self-propelled watercraft in response to receipt of the command to perform turning of the self-propelled watercraft from the remote controller as well as to simultaneously transmit the corresponding commands to perform turning of the self-propelled watercraft to the control devices for controlling the control elements of the hydrofoil for pivoting these control elements in opposite directions such that the downward pivot of the control element is performed by the angle that is smaller than the angle of the upward pivot of the opposite control element, and a difference between these pivot angles is a constant value that is a function of a ratio between a surface area of the hydrofoil panel and a surface area of the control element arranged thereon,furthermore, the central control unit is configured to automatically receive the data from the roll sensor and to automatically transmit the corresponding commands to eliminate the roll of the self-propelled watercraft to control devices for controlling the control elements of the hydrofoil in response to receipt of the command to terminate turning of the self-propelled watercraft from the remote controller, besides, the central control unit is configured to automatically receive the data from the speed sensor and to automatically transmit the above-described commands to eliminate the roll and to perform turning of the self-propelled watercraft which imply reduction of the pivot angles of the control elements of the hydrofoil proportionally to increase of the speed of the self-propelled watercraft.

2. The self-propelled sport and recreational watercraft according to claim 1, wherein it comprises a power supply unit that is mounted inside the floating body, while locating the combined center of gravity of this unit in between the front edge of the hydrofoil and the above-mentioned mast of the underwater holding structure.

3. The self-propelled sport and recreational watercraft according to claim 1, wherein a housing of the above-mentioned seat in the form of the chair is made so as to form a luggage compartment.

4. The self-propelled sport and recreational watercraft according to claim 1, wherein the above-mentioned propulsion device is arranged on the mast of the underwater holding structure and formed as an electric motor with a propeller screw.

5. The self-propelled sport and recreational watercraft according to claim 1, wherein the central control unit is configured to receive, from the above-mentioned remote controller, a command to stop the movement of the self-propelled watercraft, if the remote controller is submerged in the water medium.

6. The self-propelled sport and recreational watercraft according to claim 1, wherein the central control unit is configured to receive, from the above-mentioned remote controller, commands to terminate and to resume the transmission of the commands to eliminate the roll of the self-propelled watercraft.

7. The self-propelled sport and recreational watercraft according to claim 1, wherein the central control unit is configured to receive, from the above-mentioned remote controller, commands to maintain and to terminate the maintaining of a constant movement speed of the self-propelled watercraft.

8. The self-propelled sport and recreational watercraft according to claim 1, wherein the central control unit is configured to receive data from a location-based device forsubsequent transmission of corresponding commands to the control devices for controlling the control elements of the hydrofoil and the propulsion device.

9. The self-propelled sport and recreational watercraft according to claim 1, wherein the central control unit is configured to transmit, to the above-mentioned remote controller, data for displaying, on its display, information about the movement speed of the self- propelled watercraft and about a charge state of the power supply unit.

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