WO2004043773A1

WO2004043773A1 - High speed and stability watercraft comprising a lift arrangement with a fully submerged hydrofoil

Info

Publication number: WO2004043773A1
Application number: PCT/IT2003/000734
Authority: WO
Inventors: Francesco Ramaioli
Original assignee: Francesco Ramaioli
Priority date: 2002-11-12
Filing date: 2003-11-12
Publication date: 2004-05-27
Also published as: ITPV20020012A1; AU2003288726A1

Abstract

A vessel has a hull (1 Fig. 1) joined to a sound strut (2. Fig. 1) which can bear the weight of the whole vessel. This strut is positioned tendentially behind as to the hull’s centre of gravity, in such a way that the thrust of the propulsion system (for example a propeller, 4 Fig. 1) can annul the bow sinking moment; this moment is generated by the weight of the whole vessel acting on the bottom part of the strut. In fact, a foil (3 Fig. 1) is allocated at the bottom part of the strut, which acts as lifting height plane that is able to pull-up, dive, yawn, turn, roll, and bears the entire weight of the vessel. This height plane with strut is very similar to an overturned airplane elevator. The thrust of the propeller and the position of mobile parts of the height plane maintain the hull of the vessel lifted as to the water surface. Height planes have to be fully immersed to allow the vessel lifted as to the water surface. Height planes have to be fully immersed to allow the vessel not to jerk on the waves. This navigation/motion condition allows the vessel to travel without any drawback or motion sensation that characterize conventional vessels, being insensitive to waves: the part that bears the hull travels under the waves. The vessel is stabilized thanks to several electronic controls and actuators which automatically and instantaneously compensate for every condition and position variation.

Description

HIGH SPEED AND STABILITY WATERCRAFT COMPRISING A LIFT ARRANGEMENT

WITH A FULLY SUBMERGED HYDROFOIL

OBJECT OF THE INVENTION An object of the present invention is to improve the quality and the speed of a vessel on the sea or on the water, by realizing specific vessels, or by realizing an accessorial system which can be adapted to the existing vessels, and which turns a conventional vessel into a stable and performing vessel, Thanks to this innovation it is possible to travel in all wave and sea conditions. In addition, the vessel is stabilized and it can reach high-speed without any repercussion on the vessel and on what is transported, thus solving the problem of conventional vessels, that jerk on the waves.

Another object of the present invention is the reduction of fuel consumption, friction, and resistance to motion. A further object of the present invention is the reduction of the waves generated by the vessel and the efficiency increase compared to, the prior ar DETAILED DESCRIPTION

The present invention relates to a nautical sustentation system based on fully submerged foil which allows a nautical locomotion which solves the problem of stability and high-speed on the water surface: in fact, the present invention overcomes technological limits which prevent ships to move at a high speed on the water surface, remarkably reducing water resistance to .the motion, contact surface with the water, slackening and shaking caused by the impact on the waves and also reducing fuel consumption. A vessel according to the invention can reach speeds which are unthinkable for classical ships (in an indicative way up to 200 km/h for cruise speed, up to 4.00 km/h and more for top speed), In particular, the invention allows a vessel to travel without any slinking and with maximum stability, independently of sea conditions and or with high waves, overcoming the hydrofoils functioning limit, which cannot skim in heavy sea. People or goods carried by the invention, do not notice sea conditions and have a lύgh level of comfort and stability, comparable with those obtained with tyre transport.

A nautical HULL (1 Fig. 1) of any shape and dimension can be used as container and/or support to transport persons, goods, engines, controls, gearing box, etc. A STRUT (2 Fig. 1; 5 Fig. 2) is integral with the bearing structure of the hull (non-rcstriclive example; it may be fixed to the bottom of the hull) which tnay develop vertically downwards, being under the water-line of the invention. The strut bears the whole weight of the vessel. A FOE. (2 Fig. 2), which works as a height or depth plane, is positioned in the bottom part of the strut Said foil has lifting features which are due to its profile (2 bis Fig, 2), to its inclinations as to the direction of motion, and also to the reciprocal positions of the ailerons (3 Fig, 2). This potentially horizontal surface has the task of maintaining itself to a definite and stable depth, and it maintains the hull lifted above the waves and the water surface.

One or more propellers (4 Fig. 2) are allocated in the bottom part of the strut, which provide an adequate thrust to the invention and allow to move the invention both horizontally and vertically in order to gain the most suitable position to guarantee efficiency, speed and stability, A possible RUDDER (6 Fig. 2) facilitates the turning of the invention, which may however turn through the exclusive use of tine ailerαn in tu-cning or pulliπg- up position. The shape of the hull is not particularly important as to the functioning of the invention (at low and average speed), however it lias to present appropriate aerodynamics and hydrodynamics characteristics. Increasing the speed, the aerodynamics efficiency aflects in a considerable way on fuel consumptions and on working conditions and it should be considered. The HULL can be divided into more parts or can be realized as a multihull structure. The hull provides the buoyancy for the vessel at rest, and also is a container and/or a support for persons and or goods/animals vvhich are to be transported, for technological parts, etc. The term "technological parts" means mechanical parts of control and motion (like actuators, engines, etc.), and also electronic parts like sensors, video cameras, computers, processors and controllers, etc. The technological parts can be allocated in whatever other part of the invention. The strut (5 Fig. 2) should have the smallest frontal surface. Like a vertical blade, inserted in the water perpendicularly to the horizontal plane of the water surface, it advances bearing the entire weight of the vessel. However, it can have different inclinations and, during the navigation, it can be partially immersed, It can have a limited lateral surface, thus minimizing the influence of possible lateral waves on the stability of the invention. Fo this p_tt_fpos_c, spaces or holes can be opened to reduce the impact area tvith lateral waves. Furthe^r accomplishments of the strut can be realized through the use of two beams, which realize a "V-shaped" strut (Part B Fig. 11), or through the use of a single beam, which realizes a "mono-beam" strut (Part. A Fig. 11). A further reduction of the frontal surface can be obtained realizing front cavities in the main body of the strut, which allow the outgoing flow (of the fluid) to be varied, to facilitate the positioning and the control of the invention (Fig, 3). This solution reduces the frontal surface that impacts on the water; moreover, these cavities realize an easier way for the water and tlie air, and increase the horizontal surface which generates aerodynamic and hydrodynamic lift (P Part. A and P Par B, Fig, 3). Part, D (Fig. 3) shows a further simplification of the submerged foiled strut: foils are integrated inside the strut rather than projecting from tlie strut itself, and are superimposed (see dark areas, Par D, Fig. 3).

So, parts A, B, C, D in Figure 3 are to be considered as multi-fail, with numerous aerodyπamicaUy and hydrodynarnically lifting surfaces, both inside or outside the strut (surfaces P).

Sensor wires, members for mechanical transmission of power and control can be positioned inside tlie strut. Various kind of level sensors can be positioned on the side of the strut, including "bath level" sensors, to facilitate the control of the invention, as described below. A possible rudder can be positioned on tlie strut,

A foil (3 Fig. 1 and 2 Fig. 2) is allocated in tlie bottom part of the strut, to farm an overturned cross in the bow frontal view of tlie invention. Tlie foil is inserted in tlie strut perpendicularly and or with a minimum angulation to form a dihedroπ, developing, in indicative way, in the horizontal plane, The foil has mobile parts, named ailerons (3 Fig 2). which can deviate the water flow and modify the profile of the foil itself. These mobile parts can be Independent of them; when a greater control of tlie invention is needed, a greater number of ailerons is needed. They work as tl e controls of "aileron" and "depth" of an airplane and/or in the well-known "flying wing" or "delta-shaped wing" layout As airplane wings, they can have tl e same control actuators, like spoilers, Haps, trimmers, etc. To an adequate cruise speed, the foil supplies a vertical upward lift which sustains out of tlie water exclusively t e hull and a part of the strut. In an indicative way, at low displacing speed, the foil and the strut are immersed, and the buoyancy is provided by tlie hull of tlie invention (1 Fig. 1), The whole strut-foil, as previously described, will be subsequently named foiled foot.

A vessel according to tlie invention can move on the water surface according to three conditions, two known conditions and a third condition which is defined in the present document: displacing condition, gliding skimming condition, subflyer condition, respectively, The known displacing condition is realized when the invention moves with the hull that cleaves the waves; the known gliding/skimming condition is realized when the vessel moves touching tlie water surface with a small part of tlie hull. The subflyer condition, which was unknown before tho present invention, is realized when the hull does not touch tlie water surface, and the foil, on which the strut is leaned is fully immersed to a proper depth. The motion condition named "subflyer" lias now been defined and it will be used from now on.

In tl e subflyer motion condition, the foil can influence the navigation positioning of tlie invention. The independent movement of die ailerons allows tl e control of tl e invention on the three axis, being the foil itself the pivot of the movement Tlie foil is facilitated in its task by the arm offeree of the propeller positioned under tlie foil itself and/or by further height planes. However, tlie propeller can be positioned in other points (of tlie invention). Different propelling systems can be used in addition or in alternation to tlie use of the propeller. In fact, as a non-restrictive example, turbines, aeronautical propelling systems, etc. can be used,

Description of the functioning and of the behaviour of the invention.

The depth of tlie foil as to tlie water surface is mainly determined by the height of the wave (of tlie sea, of the lake, o tlie river). The height of tl e wave is intended as tlie distance between the top (crest) and the bottom (saddle) of tlie wave itself. If no waves exist, tlie height which is to be maintained by the invention will be determined as the minimum safety-distance between the hull and the water surface (for example, 50 centimetres between the bottom of tlie hull and the water surface). Thanks to an appropriate measuring system, which uses, for example, ultrasound sensors or laser-meters, positioned at one or more points, at tl e bottom of or beside the hull (or in any other possible position), it is possible to calculate tl e average height (L2 Fig. 4) above the water surface which is to be maintained by tlie hull. The purpose of said device is to avoid any contact between tlie water surface and tlie hull, in order to avoid slowing, railing, pitching, sharp accelerations on various axes. In fact, the hull is characterized by a greater hydrodynamic friction than the only submerged "foiled foot", and, besides, it receives thrusts by tl e waves which tend to modify its trim according to Archimedes' principle. When conventional means move fast, the waves become springboards or true and actual walls that can destroy them. The foiled foot lias a very small frontal surface as compared to the frontal surface nπd tlie contact surface of tlie hull, Moreover, it has a very small water displacement volume, thus being almost entirely insensitive to Archimedes' principle; besides, it acts like a hydrodynamic blade, which cleaves tlie waves, preventing them from impacting on tlie hull. A further possiblo monitoring system, positioned on the strut, checks tho water level in order to gain abetter control of tlie invention. Said system can be realized through tlie use of further distance meters (for example; ultrasound meters) and feedback meters.

Besides, it is possible to provide a frontal runner that facilitates tho hull's take-off and tlie hull's water landing. This runner does not touch the water during motion, or it is retractable. The ability of the invention to negotiate rough seas is managed and optimized also via software; the aim of software control is to maintain tlie minimum height of the hull above the water surface (L2 Fig. 4) as a function of the height of tlie waves, so that tl e waves cannot impact on the hull. One or more electronic control circuits and/or one or more computers analyse the information co ing from several sensors, which observe the characteristic of the wave motion close to tlie invention and far from tl e invention. By means of an adequate computer programming, a global computer processing can be obtained, which controls the actuators in a semiautoinatic and/or in an automatic way; these actuators allow the invention to maintain the best position, in order to minimize tlie continuous height variations as to the water surface, which is explained below. In order to provide tlie greatest stability, it is necessary that the invention acts according to tl e following functioning scheme: assuming a perfectly plain marine backdrop, characterized by a constant depth, tlie immersed foiled foot has to lift the invention so that tlie bottom part of the hull is always above the maximum height of the waves (L2 minimum Fig. 4), maintaining tlie distance from the marine backdrop as constant as possible. The average height of the waves (mean value of the observed heights) and tho maximum height of the waves (L2 Maximum minus L2 Minimum) are calculated via software. The distance between the foil and tl e bottom of the hull (LI Fig. 4) has to be greater than the maximum height of the waves (L2 Maximum minus L2 Minimum) in order to gain the maximum comfort; said distance (LI Fig. 4) can be, if necessary, variable, through tlie use of a device which allows the foiled foot (5 Part, A Fig. 6) to elongate and shorten. In an indicative and non-restrictive way, the distance between the lifting surface of the foiled foot and the bottom part of the huU can vary between 0 meters (Part, C Fig. 6), that is in contact with tlie hull (or even inside), to several meters (Part. B Fig. 6). A solution exists, in which tl e distance between tl e foiled foot and the hull is fixed, and the strut is integrated and integral with the structure of tl e hull, as it is obvious in Figures 1 and 2. The best way to realize tlie nautical sustentation system based on fully submerged foil is tl e one described in Figure 12: a part, which is integrated in the hull, called from now on gearing box (1 Fig, 12) mαunt3 one or more engines and/or a connection to one or more external engines (6 Fig. 12), that transmit tlie movement to tlie parts in motion, including the propeller (5 Fig. 12). Inside tlie gearing box, some devices like gears, pistons, racks, a .be used to transfer the strut (2 Fig. 12) and the foil (3 Fig. 12). In this way, tlie extension of the strut and the distance between tlie hull of the vessel and the foil can be varied. Further actuators allow other mobile parts, like ailerons (4 Fig. 12) and rudders (7 Fig. 12) to be moved. The motion transfer to the propeller is realized, as a non-restrictive example, by means of gears, cardans, a hydraulic system, worm screw, pulley, straps, that are allocated inside tlie gearing box,

Other devices or sensors to determine parameters necessary to the functioning of the invention can be used in alternation or in combination to the ultrasound sensors, like radar and/or video cameras arranged either to observe thα horizon or, with increasing inclinations, to observe perpendicularly tlie foiled foot and/or other parts. Furtlier different sensors con be used to determine the distance between tlie foiled foot and the bottom of tl e hull, which work according to different principles. Navigation devices like sonic depth finders, compasses, positioning system (gps). etc. can be used.

Tlie constant trim on tlie horizontal plane is maintained by using different devices which can act singularly or in combination among them; these devices can be, as a non-restrictive example gyroscopes, meriial platforms, horizon optical stabilizers, video cameras, acceierometers, altimeters.

As a function of tlie signals transmitted by these devices, stabilizer circuits can act either on each single axis or on the three axis, even in an automatic and autonomous way, or as a result of a processing of a computer system, which can simultaneously process several parameters (for example: the distance among several points of the hull and the water surface) in order to act in a more complex and effective way on the axis. As a non-restrictive example, three or more gyroscopes can be used, which are connected to one or more computers that control and order actuators connected to tlie ailerons; these actuators execute continuous corrections to minimize and to oppose moments (for example: rotative) to moments that would alter the position of tlie invention. In the case of an undesired forward inclination of the invention, the gyroscope which controls tlie pitching axis will order ailerons and immersed planes to yaw, in order to cause an opposite motion and to restore the initial height condition of tlie invention. In tlie same manner, in case of sideward inclination, the gyroscope which controls tho rolling axis will impart said variation to one or more computers and/or one or more electronic circuits, that will cause an opposing motion of tlie invention to the motion that is occurring. Even in the case of undesired changes in the direction (turnings) of tlie invention, tlie gyroscope that controls the rotation round that axis will enable tlie compensation of tlie motion. To stabilize the vessel, mobile masses can be used, for example loads on worm screws which are moved by engines, or water masses, which are loaded from the water surface and put into containers; these containers are positioned in different points of tl e hull; they communicate with each other, and can be emptied and filled automatically by means of actuators, according to the compensation that is necessary to reach tlie dynamic balance during tlie motion. To provide a better control of tlie trim of tlie invention, external and not immersed foils can be provided, which are integral to the hull and or to the strut, and which can supply stability and aerodynamic lift to tlie invention, Tl e control of the height variation of the Invention will he provided by the Information which will be supplied to the main computer and/or to servo eclianisms by suitable sensors, which control tlie height variation, like, as a non-restrictive example, one or more accelerometers. These sensors will work in such a manner as to avoid the variation of the height of tlie invention due to wave motion, to the wind, to currents, etc. which could continuously move upwards and downwards tlie hull. In order to maintain the belter height indicated by the computer, tlie cited accelerometers will recognize a vertical sinking of tlie invention (wave saddle), asking servomochamsms of the ailerons and/or of tlie height planes to increase the emersion of the foiled foot (of the invention) to compensate for tlie opposite noticed motion. In case of an undesired rise (wave crest), accelerometers will notice the motion and will ask devices for a greater immersion of tlie foiled foot As a result of these continuous instantaneous corrections, tlie hull will not undergo accelerations and/or motions that can be felt and appreciated by people and by tlie goods transported, that will have tlie impression to travel on an cartlily mean of transport. The necessary variations of tlie "cniising height" to adequate the invention to the changed conditions of tlie water surface, will be performed with an adequate slowness.

Tlie instantaneous and automatic/independent variations on the axis can concern exclusively tlie short period events. These variations concern the excursions and the changes as to trims and parameters which have been settled for the invention, and that are to be maintained during navigation.

The long and middle period events will be compensated for by means of speed regulation (reduction and/or increase), and/or by a greater or smaller distance of the hull from tlie ater surface, and also by changes of the trim on tlie axis, which will be less sudden and less quick than tl e instantaneously compensated changes. Long period events arc defined as sea conditions and or waves which are recognized in the distance, like, for example, to the horizon, and that will be experienced by tlie invention within a long time (long period); during this time period the invention con change its trim to fit with tlie foreseen sea conditions. Middle period events arc defined as conditions observed among distant points and closest points.

The computer plans tlie suitable height (L2 Fig. 4), which is to be maintained, and the necessary time to reach said height on (lie basis of tlie speed and amplitude of tlie trim changes, according to the above said information which integrates the information from sensors of distance and from sensors of level. Tlie length of tlie movable strut will be as greater as greater is the wave height Normal navigation tools can be used in aid to the functions of process.

Furtlier details about the control of tlie invention and about the function of Hie sensors, Sensors and behaviour, brief summary:

Instantaneous: autonomous and independent automatisms control instantaneous compensations; these automatisms work controlling limited movements of tlie actuators, to provide the stability of ie invention. They can cany out small trim changes, in order not to cause inconvenience to the navigation, to people and/or to goods. Short period anticipations; tlie sensors can measure tlie height of the waves near the hull or approaching it, to supply data that are necessary to provide sudden changes. They can carry out and/or command and/or exact slightly greater variations as to independent control variations.

Middle-long period anticipations: other sensors have to foresee and anticipate the farthest waves. Video cameras can help for this purpose, thanks to the artificial sight and to tlie automatic analysis of tlie profiles of the waves. Moreover, video cameras can help in the stabilization of the invention by means of tlie analysis of the horizon, and can compensate tlie stability on tlie horizontal piano. The minimum height of the hull above tlie water surface in a particular moment will be calculated based on the anticipatory measure of tlie height of tlie waves and of the time necessary to meet them in tlie motion direction. Thanks to the artificial sight and to the analysts of tlie digital photogπvmmetrical contrasts, many parameters referred to tlie conditions of the water surface can be determined in many points close to the invention or far from the invention. The analysis of tlie wave profiles extrapolated thanks to the colours and to tlie contrasts in tlie visible radiation and non-visible radiation (for example infrared) can also determine tlie measures of the levels and the differences among levels and among planes, useful in the calculation of tlie trim of the invention. In the same way, thanks to the video cameras, the water mass which could impact on tlie hull can be calculated; in the case of a small mass, like small wave crests, it is possible to decide to impact on the , because they are not influential as compared to tlie mass of tlie hull and comparable widi tlie safety; besides, the software can recognize the outline of possible obstacles and their position, effecting suitable variations of tlie route of the vessel. Video cameras are considered and indicated as sensors. P T/IT2003/000734

The speed of tlie invention will be conditioned by safety parameters: in tlie case of sea conditions which go beyond the parameters of motion reduction, which can be controlled by the automatisms, the speed of tlie invention will be decreased to fit with safety margins, to avoid undesired jerks. The invention can however travel in sea conditions which are terrible for conventional vessels, but a safety functioning limit exists, which is referred to the realization and to die dimensioning of tlie invention, but also to the accelerations which are to be accepted during the navigation.

Manual controls in alternation to automatic controls:

If necessary, a vessel characterized by tlie features and the geometries indicated in tlie present document can be realized, which can be entirely manually controlled, or it can provide a limited series of stabilization automatisms, as a support, that can be excluded. The control characteristics of such a development of tlie invention will be bound to tlie ability of the pilot.

Possible scenario: one or more joysticks control directly tlie actuators and die εervomechanisms, or pull cables or levers that act on mobile parts. Besides, the decisions of the pilot can influence tlie software and/or the hardware, allowing the govemableness of tlie vessel according to tlie intentions of die pilot. The vessel reacts by maintaining tlie lifted trim of tlie hull and following the variations of the route and of tlie speed exacted by tlie pilot, simultaneously maintaining either comfort definitions and safety definitions. General scheme of the electronic circuit of control (hardware scheme):

Sensors (I Fig. 9) represented in Figure 9 that, as a non-restrictive example, can be: sensors of distance (ex.: ultrasounds sensors), sensors of rotadon (for example: gyroscopes), sensors of level (ex.: altimeters, satellite altimeters, inertial platforms), sensors of sight (for example: video cameras, ccd), sensors of acceleration, sensors of speed, sensors of meteorological parameters. Said sensors are connected to one or more computers, which can vary from small and less powerful microprocessors to medium/high power computers. It is possible to use a simple electric circuit instead of a microprocessor, as tlie well-known "window comparator", to stabilize a control in a specific range of functioning: if the parameter measured by a sensor increases or decreases, tlie comparator recognizes the signal which is superior or inferior to predetermined binding values in tlie borders of tlie window or "rcccpUon hysteresis", and activates a feedback circuit to contrast the increasing or decreasing parameter; for example it can move an actuator. The computer (3 Fig. 9) can use a software (2 Fig, 9), described, in non-limitative way, in Figure 10. which processes die incoming information provided by tlie sensors. On the basis of madiematical calculations and or parameters settled by tlie pilot and/or by the programmer, the computer provides indications about the behaviour which best fits the sequence of commands that each actuator will have to follow, in tlie form of a suitable analogical or digital electrical signal. The actuators (5 Fig, 9) receive die information, also by means of possible interface circuits, and then position the mobile parts of tlie invention, which they are mechanically joined to, following die indications supplied by circuits which control die whole process. , Thanks to die actuators, it will be possible to regulate, in a non-limitative way, die immersion depdi of the strut (7 Fig. 9), it will be possible to realize die control of tlie axis (8 Fig. 9) and also die trim of the hull (9 Fig. 9). The computers) will control the speed of tlie invention by acting on die engine (4 Fig. 9).

Suitable/proper sensors of verification or feedback (6 Fig. 9) can confirm die adaptation of die invention to die physical definitions indicated by the computer(s), in terms of trims, depth, etc.

Software process example (software scheme):

Figure 10 shows a non-restrictive example of software development and software processing to control the invention, This scheme represents a draft, which simplifies comprehension and facilitates a possible software development.

Blocks A, B, C, D (Fig. 10) represent the decision-making part, tiiat is delegated to a software- process, while block E can be entrusted both to a software processing or to a reaction delegated to solely hardware circuits. The block can be positioned in one or more computers, also in redundant systems which perform tlie same process. Tlie software process which supplies the information referred to die height that tlie hull is to maintain above die water surface (out A Fig. 10), is realized tiirough die decisional function A (A Fig. 10): die computer receives the information from sensors like, as a non-restrictive example, ccd, horizon video cameras, water surface video cameras, sensors of distance (from the wave), sensors of rαinimum and maximum height of die wave. Images are analyzed in each frame, and through die recognition of the contrasts and/or of the colours, the profile and die features of Oie waves and also die mean plane of the water surface and its height arc pointed out Sensors, for example ultrasound sensors, supply die information about die closest waves; on the basis of Uiese information and of tlie supplied data, block A (A Fig. 10) processes the height strategy. The strategy of "height maintenance'' is necessary to optimize die changes of the cruising height As an example, if all the analysed waves distant from or close to die invention are characterized by a similar height, die software (analysis) will supply an indication of constant cruising height, which is equal to die maximum wave height, increased by a safety height

On the other hand, if a height difference among distant and close waves exists, the software analysis will supply an indication of variation of the cruising height, which is to be realized widύn die necessary time period and witii the adequate sequence. Tlie time period will be determined by die distance of the wave characterized by a different height and by die speed of the invention, and also by die slowness of die variation rate of die cruising height, necessary to maintain the comfort of navigation,

Sensors like inertia! platforms, gyroscopes, horizon analyzers, light stabilizers, electronic levels, altimeters, accelerometers, sensors diat recognize sea currents and winds, etc. supply software part B the necessary information to command and control die horizontal trim of the invention (out B Fig, 10). In particular, the intervention on die horizontal trim is veiy important during the turnings, to oppose die centrifugal force and obtain tlie greatest comfort, This intervention is obtained by inclining (banking) the invention toward tho

"tack" that indicate the direction which is to proceed in.

Moments generated on die axis and detected by the sensors, are processed by software diat immediately opposes diem, according to a corrective strategy of minimization of sharp motions, which can imply very wide corrections on die excursion of die controls of mobile parts, especially at middle/low speed. Sensors diat notice tlie speed of tlie invention, the speed and die direction of die wind, and also sensors that notice sea conditions, etc. supply incoming information to tlie part C (C Fig. 10) of the software process which returns the possible maximum speed of the invention in diat particular condition, to maintain the safety conditions planned by the programmer and or by die user (out C Fig, 10),

In particular, the software can drastically decrease die speed, ordering an appropriate actuator, if die distance between the hull and the water surface is too small, to avoid a possible impact which could lead to a situation of discomfort and/or danger (defined as drawback). The software processing can consider die temporary drawback and then resume the previous speed, or it can consider die anticipatory drawback that will happen when die invention arrives at that very point on die water surface which has been observed by far, or in the middle, or in die short distance. In this case, the speed of die invention will be reduced within a proper time period, calculated on die basis of die information concerning the speed of the invention and the distance between die invention and the point of the water surface characterized by exacting conditions. Tlie sensors Uiat control limited instantaneous variations ("out E. E/bis" Fig. 10) can activate specific actuators, directiy through an appropriate hardware circuit (E Fig. 10), or tiirough a software processing (E/bis Fig. 10). In the case of software process, die system lias to guarantee a high calculation rapidity to control die stability scrvomechanisms with almost void reaction time.

The control information "out A", "out B", "out C" are sent to die software process section D (D Fig. 10), which avoids that a particular mobile part (6 to 16 Fig. 10), which is controlled by the actuators, is ordered to assume different consecutive positions that could not be accepted and/or reached within a proper time limit Thus, tlie software section D acts as a mediator as to die requests of die previous software process; in tins way, the maximum efficiency of die mobile part motion, and safety checks about requests, which are not in conformity with die trim and/or die speed of die invention, are obtained, Figure 5 and figure 8 represents non-restrictive examples about die opportunities of practical realization of die invention.

PREVIOUS STATE OV THE ART

Conventional nautical means of transport are based on gliding and displacing motions: displacing like ships and motorboats, gliding like swift motorboats and hydrofoils, A chapter apart are the hovercrafts, which travel on an air cushion and which cannot move in slighdy agitated seas. The hydrofoils lean on foils which travel on the water surface and lift die hull to decrease frictions; they can reach a maximum speed which is not comparable to die maximum speed of the invention; besides, they cannot travel in this way in slighdy agitated seas. Hydrofoil is completely different from die present invention as in the invention die foil of die foiled foot is always entirely immersed, and no foils lean on the water surface as in die hydrofoil. Moreover, the invention can travel also in the presence of important waves and in wavy sea. Immersed foil stabilization systems exist which could be interpreted as if they were tlie present invention, but tiiey work in a completely different way. S_W_A_S and S_W_A_T_H vessels have a completely submerged part, which is connected to die hull and has a total water displacement volume that contributes to the buoyancy of the vessel.

ANALYSIS OF THE RESULT

The gained results fit with die objectives and die features which have been expected for die present innovation: die invention allows a very swift, stable and coinfortable motion on die water surface. Prototypes have been realized in small scale, characterized by different motorizations, different sliapes and dimensions of die strut and of die immersed foil. The invention can travel at high speed, is stable and can negotiate waves and otiier water surface conditions.

At a parity of engine power, the speed of die invention, in comparison widi a gliding and/or displacing vessel, is remarkably greater. So also consumptions are gready reduced compared to traditional vessels. At a parity of speed, a reduction of consumptions near 40% can be estimated.

High environmental impact consequences, connected with die consumption reduction, can be estimated, which are related to a smaller pollution of die vessels.

Frictions are greatly reduced, but die very innovative feature is represented by die stability in wavy sea, as well as by die speed value which can be maintained widi rough sea.

Claims

P T/IT2003/000734

Claim 1: A nautical sustentation system based on fully submerged foil made by the following parts: a) a partially immersed strut b) a fully submerged foil, which does not contribute to the buoyancy of die vessel c) sensors of stability control and position d) sensors to delect die water surface conditions e) actuators of mobile Surfaces of Hie foil and of the strut f) hardware computers g) control software h) electronic processing box i) members to transfer die mechanical power necessary for tlie motion 1) a gearing box m) a connection system between die strut and die hull; the foil and the strut, at adequate speed, supply a vertical upwards lift that sustains/supports the hull and/or a part of die strut out of tlie water. Claim 2: A nautical sustentation system based on fully submerged foil according to claim n, 1, cliaracterized by the fact that the length of the strut can be varied and die distance between the hull of the vessel and the submerged foil can be varied dirough gearing or die use of a hydraulic system.

Claim 3: A nautical sustentation system based on fully submerged foil, according to the previous claims, characterized by the fact that it uses a propulsion system which can be positioned in-line or under a fully submerged foil.

Claim 4; A nautical sustentation system based on fully submerged foil according to claims n. 1 and n, 2, characterized by the fact dial it uses one or more propulsion systems that can be positioned in every suitable part/point, including the hull and/or the strut and/or die foil and that can use any otiier propulsion system in alternation or in addition to propellers, like turbines and or propulsors also outside die water, Claim 5: A nautical sustentation system based on fully submerged foil according to claim n. 1, characterized by the fact that it uses a hull of whatever shape and dimension which are suitable to support/sustain and/or contain the invention when tlie vessel is at rest or is travelling at low speed.

Claim 6; A nautical sustentation system based on fully submerged foil, according to the previous claims, characterized by the fact that die foil can act as height level and direction level, being able to make the vessel yaw, roll, turn.

Claim 7: A nautical sustentation system based on fully submerged foil, according to die previous claims, cliaracterized by tlie fact that the foil has a surface which is potentially horizontal anάVor witii a suitable angle of incidence and that it works to a fixed depdi, being able to sustain the hull outside die water surface and above the waves during the motion. Claim 8: A nautical sustentation system based on fully submerged foil, according to die previous claims, cliaracterized by die fact diat tlie foil lias one or more of die following features: a) it can be delta-shaped, with variable profile, variable geometry, variable inclination, b) mobile parts can be ailerons, spoilers, trimmers, flaps, positioned on the foil surface or on die foil ends, c) mobile parts cited in point b) can be positioned near die foil, d) the foil can be subdivided in more parts, also with different inclinations and different dihedrons,

Claim 9: A nautical sustentation system based on fully submerged foil, according to claim n. 8, characterized by die fact diat die foil lifting abilities can be due to the foil profile, to the foil inclination as to die motion direction, and also to the reciprocal position of the ailerons or other mobile parts, including die struts. Claim 10: A nautical sustentation system based on fully submerged foil according to claim n. 1, characterized by the fact tiiat it uses a software tiiat controls die stability and maintains the dynamic balance of die vessel based on die invention as a consequence of die reading of some sensors and of some video cameras, and that provides one or more of the following functions and activities: a) it commands actuators able to move die mobile parts of control and positioning; b) it controls die speed of tlie vessel dirough the control of die engine; c) it calculates and maintains the average distance between die water surface and die hull of the lifted vessel; d) it calculates and maintains die average deptii of die foϋ positioned in die bottom part of the strut; e) it foresees the condition of tlie incoming water surface, and conscqucntiy adapts die excursion of the strut, and or the depth of die foil and/or the distance between die hull and the water surface; f) it withdraws the mobile strut in case of short depth of tiie sea or of the lake; g) it moves die hull, die strut, die foil on tiiree Cartesian axis x, y, 2, including rotations on said axis.

Claim 11: A nautical sustentation system based on fully submerged foil, according to the previous claims, cliaracterized by the fact that it uses software widi a suitable user interface tiiat receives from die user some or all of the following information, tike: route, speed, comfort level, safety level, minimum height above die water surface, maximum height above tlie water surface, compensation speed of die anomalies, maximum accelerations on specific axis, maximum rotation couples, maximum cruising wave, measure of die alarm wave, maximum wind speed, maximum wind gust, maximum load unbalance, maximum static stresses, maximum dynamic stresses; said software using received parameters to control die dynamic behaviour, adapting, as a result, die behaviour of the invention. Claim 12: A nautical sustentation system based on fully submerged foil according to claim n. 1, characterized by the fact that it uses simple hardware electronic parts without software, or with simple software, which can autonomously order motions opposing unwanted motions pointed out during the movement that modify tlie dynamic stability definitions made by the user or by the software process; said simple electronic parts being also limited in the movements of command and/or reaction on the mobile parts and on the engine, said simple electronic parts read die sensors and can command actuators and can be used in aid to die main computer or in the place of it.

Claim 13: A nautical sustentation system based on fully submerged fail, according to the previous claims, characterized by die fact that it uses one or more software and one or more computers which realize and work according to one or more of die following dispositions: a) one or more sensoτs and video cameras are connected dirough a suitable interface to one or more computers; b) through the software process of die information from some sensors and video cameras, bl) the height of the hull above die water surface and b2) die height which is to be maintained by die hull above the water surface are determined; c) through the software process of die information from some sensors and video cameras, tlie position and the maintenance of a horizontal cruising trim of Uic vessel and/or of die foil are determined; d) through die software process of die information from some sensors and video cameras, the maximum safety speed of die vessel is determined, with regard to die height of the noticed wave and/or of die observed and forecasted wave or of the incoming wave; said observations and predictions can be used for the processing in points b) and c); e) dirough die process of die uiforrøation from some sensors and video cameras, by means of independent and autonomous circuits with a low-level software and/or dedicated hardware, limited or limitable automatic instantaneous variations are determined; f) a software process which receives the process made in point b), c), d), and, possibly, e); such software process has die purpose of mediating and filtering the opposing movements in case of simultaneous orders or transmittals to die actuators by die above-cited single process; g) a series of actuators able to receive die commands sent via software and/or via hardware, which receive and execute commands of points f) and e); said series of actuators can be assisted by a common interface or by several interfaces, Claim 14: A nautical sustentation system based on fully submerged foil according to claim n, 1. cliaracterized by the fact diat it uses a software diat receives information by one or more of die following sensors: gyroscopes. accelerometers, level sensors, position sensors, height sensors, speed sensors, wind speed sensors, wind direction sensors, current sensors, rev counters, depth sensors, pressure sensors, distance sensors, video cameras, ccd, gps, depth finders, radars, navigation sensors; said software elaborates die signals from these sensors, realizing one or more of the following functions, also adapting itself to parameters manually inserted by a user/programmer: a) it determines die maximum speed diat can be reached in the desired conditions of comfort and safety; b) it determines die movement of the compensation masses to maintain the balances as a function of die position of the cargo or of other loads in the hull and/or of the engine thrust; c) it determines die trim on die horizontal plane and its maintenance, or it receives the definition of the new plane of trim, potentially horizontal (inclination of motion), or it determines die trim that favours the sight and/or the aerodynamics and/or the hydrodynamics during die motion; d) it determines die progressivencss of die hull's take off from the water surface during departure, as well as water landing of the hull during arrival or in die case of slowing; e) it determines die variations on die position of the horizontal plane to compensate for accelerations and decelerations, either during rectilinear motion or during turnings; said function compensates also die centripetal acceleration during turnings by inclining the vessel towards die same tack of die raπiing; f) it detennincs die minimum and maximum lifting height of the hull above the water surface as a function of die waves diat it overhangs, as a function of die next waves, as a function of die distant waves; said function lifts and lowers the hull so as to early adapt it to the incoming conditions; g) it determines die extension and tlie shortening of die strut, if a mobile strut is used, causing the variation of the distance between the foil and die hull; said feature works according to the conditions measured in point f), thus allowing a greater flexibility in the use of die invention; h) it can make the vessel to follow a determined route; i) it can allow the vessel to avoid collisions widi odicr vessels performing route variations in an autonomous way;

I) it can allow the vessel to perform sudden route variations, including emergency slowing, to avoid collision widi unexpected obstacles pointed out by video cameras or otiier sensors; m) to carry out these functions and definitions, said software can control, dirough suitable hardware, one or more of he following controls: direction rudder, ailerons, flaps, spoilers, trimmer, elevator, pull up rudder, dive rudder, lifting rudder, variable geometry rudder, duust engines, control engines, otiier controls. Claim 15: A nautical sustentation system based on fully submerged foil according to tlie previous claims, characterized by die fact diat it uses software programs and hardware circuits which, through die use of video cameras, distinguishes contrasts of colour and/or of brightness αnd/or of distance to recognize die shape and the dimension of the waves, a) by measuring the distance between die planes of the crests and the planes of the depressions, supplying in tiiis way the measure close waves, average waves, distant waves; b) by calculating die water mass that could impact on tlie hull and in case of small masses can decide to impact on them equally; ,c) by recognizing die oudine and/or die position of obstacles and carrying out suitable modifications of the route of the vessel. Claim 16: A nautical sustentation system based on fully submerged foil, cliaracterized by the fact that it uses some electronic circuits, like electronic switchboards, dedicated computers, standard computers, data acquisition systems, signal conditioning systems, data transmission systems, analogical-digital interfaces, digital«analogical interfaces, adapter circuits, circuits of comparison, according to die following hardware scheme, if necessary wit the aid of one or more software: A series of level sensors, vision sensors, height sensors, depth sensors, altitude sensors, distance sensors, rotation sensors, speed sensors, acceleration sensors, position sensors, direction sensors, are connected to one or more computers through one or more signal transmission systems; said computers, with the aid of a possible software, control the engine and a series of actuators which work on die strut (immersion) depth, on axis control, on the tπm of the hull, managing the maintenance and the variations of die tack and Ihc stability; said electronic parts consider also the actions of the pilot, diat influence also die software, allowing the means govemableness according to die intention of die same pilot; said vessel reacts maintaining the hull lifted trim and following the variations of route and speed which are required by die pilot, which are required by comfort definitions, which are required by safety definitions. Claim 17: A nautical sustentation system based on fully submerged foil, cliaracterized by die fact tiiat the gearing box is realized as a hull of whatever shape and dimension.

Claim 18: A nautical sustentation system based on fully submerged foil, characterized by die fact diat it can be controlled through different levels of automatism, from an entirely manual control to a complete automatic control, as well as intermediate levels, Claim 19: A nautical sustentation system based on fully submerged foil, characterized by die fact that it can use runners that facilitate the hull's take-off and die hull's water landing, and diat, during die motion, are not in contact widi die water or can be retractable,