Device and method for determining the orientation of a kite in flight.

Abstract

A method for determining the orientation of a kite (3) in flight, the kite being held by at least a first line (41) and a second line (42), the method comprising: - a step of determining the relative position of the first and second lines in a reference frame (R), in particular in a geocentric reference frame or in the reference frame of a device (2) towed by the kite (3), and - a step of determining the orientation values ​​of the kite (3) using the relative position of the first and second lines, the orientation values ​​of the kite including a yaw angle value of a wing (31) of the kite. Figure for the abstract: 1

Description

Title of the invention: Device and method for determining the orientation of a kite in flight. Technical field of the invention

[0001] The invention relates to kites used: - for towing a floating vessel, - for traction of a rolling and / or sliding land vehicle, - for the production of electrical energy by converting mechanical energy, - in pumping applications using mechanical energy produced by the kite, or - in desalination applications using mechanical energy produced by the kite.

[0002] The invention relates more specifically to a method for determining the orientation of a kite in flight. The invention also relates to a device for determining this orientation that implements such a method. The invention further relates to a computer program comprising code instructions for implementing such a method. The invention also relates to a data storage medium for implementing such a method. Finally, the invention relates to a signal from a data storage medium carrying such a computer program. Prior art

[0003] Kites are known for traction of a floating craft, such as a boat or ship. The kite can be piloted in different modes, in particular a flight mode in which it flies in figure-eights and a flight mode in which it is stationary or relatively fixed relative to its attachment point. Kites designed to convert mechanical energy into electricity may, in particular, exhibit similar flight modes.

[0004] To create and maintain such flight conditions, action is taken by applying forces and moving lines connecting a structure of a system (engine, boat, ship, energy converter) to the kite. To apply the correct force at the right time to a line, it is useful to know, in real time, one or more of the following pieces of information: - the position of the kite (for example the azimuth and elevation angles), and / or - the orientation of the kite (yaw angle or leading edge angle), - the incidence of the kite, - the speeds of the kite, - the wind direction, and - the wind strength.

[0005] To obtain such information, it is known to attach an inertial measurement unit (IMU) to the wing of the kite or to the wing itself. However, this solution has drawbacks. The IMU must have its own power source (such as a battery and / or a solar panel) to operate and transmit information. This makes the solution complex and cumbersome. Furthermore, attaching an IMU to the wing or to the wing disrupts the fluid flow around the wing and negatively impacts its aerodynamic performance. Additionally, this solution requires radio communication from the IMU, and this communication can be interrupted in certain kite configurations and / or be difficult to secure. Moreover, calibrating such an IMU is complicated. Finally, such an IMU vibrates at the wing.Consequently, the information gathered by the inertial measurement unit is very noisy. Presentation of the invention

[0006] The invention relates to a device and a method for determining the orientation of a kite in flight, improving upon known devices and methods. In particular, the invention provides a simple, robust device and method for determining the orientation of a kite in flight, enabling reliable and accurate information on the kite's orientation without disturbing the wing's aerodynamics. Summary of the invention

[0007] According to the invention, the method allows the orientation of a kite to be determined in flight, the kite being held by at least a first line and a second line, the determination method comprising: - a step of determining the relative position of the first and second lines in a reference frame, in particular in a geocentric reference frame or in the reference frame of a device towed by the kite, and - a step of determining kite orientation values ​​using the relative position of the first and second lines, the kite orientation values ​​including a kite yaw angle value of one wing of the kite.

[0008] The method may include a step of determining kite position values ​​using the relative position of the first and second lines, the kite position values ​​including: - an azimuth angle value of the kite wing, and / or - an elevation angle value of the kite wing.

[0009] The step of determining a relative position of the first and second lines in a reference frame may include a step of determining a relative position of a first point of the first line relative to a second point of the second line in the reference frame.

[0010] The first point can be kept at a constant distance from the second point or the first point and the second point can be movable relative to each other in a plane at least substantially perpendicular to the first and second lines.

[0011] The first point can be a fixed point or a moving point on the first line and / or the second point can be a fixed point or a moving point on the second line.

[0012] The step of determining a relative position of the first and second lines in a reference frame can be carried out by a measuring element linking the first point and the second point.

[0013] The measuring element may include a means for measuring the orientation of the measuring element in a geocentric reference frame, in particular an accelerometer, in particular a 3-axis accelerometer, and possibly a magnetometer.

[0014] The measuring element may include a means for measuring the orientation of the measuring element, in particular a sensor for measuring an angle of rotation around the direction of traction of the kite, of rotation.

[0015] According to the invention, a device for determining the orientation of a kite in flight, comprises hardware and / or software elements implementing the method defined above, in particular hardware and / or software elements designed to implement the method defined above.

[0016] According to the invention, a device for determining the orientation of a kite in flight includes means for implementing a method defined previously.

[0017] According to the invention, an arrangement comprises: - a system, - a kite, - a lashing device, and - a determination device defined previously.

[0018] According to the invention, a computer program product comprises program code instructions recorded on a computer-readable medium to implement a previously defined process when said program runs on a computer.

[0019] According to the invention, a computer program product downloadable from a communication network and / or recorded on a data medium readable by a computer and / or executable by a computer, includes instructions which, when the program is executed by the computer, lead the latter to implement a process defined previously.

[0020] According to the invention, a computer-readable data recording medium on which a computer program is recorded includes program code instructions for implementing a previously defined method.

[0021] According to the invention, a computer-readable recording medium comprising instructions which, when executed by a computer, lead the computer to implement a previously defined process.

[0022] According to the invention, a signal from a data carrier carries the product computer program defined above. Presentation of the figures

[0023] Other advantages and features will become clearer from the following description of an embodiment of a device for determining the orientation of a kite in flight and the accompanying figures in which:

[0024] Fig. 1 is a schematic view of an arrangement according to a first embodiment.

[0025] Fig. 2 is a partial schematic view of an arrangement according to a second method of implementation. Detailed description

[0026] A first embodiment of an arrangement 200 according to the invention is described below with reference to [Fig.1].

[0027] Arrangement 200 comprises: - a system 2, - a kite 3, - a lashing device 1, and - a device 100 for determining the orientation of a kite in flight.

[0028] Kite 3 comprises: - a wing 31, - a first line 41, and - a second line 42.

[0029] Advantageously: - the first line 41 is fixed to a first lateral end of the wing 31 or in the vicinity of the first lateral end of the wing 31, and - the second line 42 is fixed to a second lateral end of the wing 31 or in the vicinity of the second lateral end of the wing 31, the second lateral end being opposite the first lateral end.

[0030] The first and second lines allow the wing 31 to be mechanically linked to the structure of the system 2, via the lashing device 1.

[0031] The arrangement may further include a control device (not shown) comprising: - one or more line control actuators, and - means of controlling this or these actuators.

[0032] System 2 can in particular be: - a floating vessel, such as a boat or ship, or - a rolling and / or sliding land vehicle, or - an energy converter, in particular a mechanical energy converter into electrical energy, i.e. an alternator, or - a pumping installation, or - a water desalination plant.

[0033] The kite 3 can be of different technologies. For example, the kite 3 may comprise only two lines 41 and 42, as shown in Figures 1 and 2. Alternatively, the kite 3 may comprise: - two front lines 41, 42 and - two rear lines.

[0034] Each line is preferably made of a cord. Each line is: - attached to wing 31 at a distal end of the line, and - fixed or linked to the lashing device 1 at a proximal end of the line.

[0035] For example, in the case of a four-line kite, a greater or lesser extension of the front lines 41 (relative to the rear lines) allows for a greater or lesser angle of incidence of the wing 31 in the airflow through which it moves. Consequently, the wing's lift and speed can be defined or adjusted.

[0036] For example, in the case of a four-line kite, a greater or lesser relative difference in the length of the rear lines 42 allows the wing 31 to be oriented and to involve variations in the trajectory of the wing, that is to say, to cause turns of the wing 31 (rotation around the yaw axis Z in the orthonormal frame X, Y, Z linked to the wing).

[0037] An axis A is generally or substantially parallel to the lines 41, 42 linking the wing 31 to the structure of the system 2 via the lashing device 1. This axis A is defined by the mechanical tensile forces of the lines. This direction can be identified by: - ​​an azimuth angle α, and - an elevation angle [3,

[0038] relative to the structure of system 2.

[0039] The device 100 for determining the orientation of a kite in flight comprises: - a measuring element 5 connecting a first point 43 of the first line 41 to a second point 44 of the second line 42, and - a logical processing unit 6 intended to process the information provided by the measuring element 5 and to use it to determine an orientation of the kite 3.

[0040] The logic processing unit 6 can also process the information provided by the measuring element 5 and use it to determine a position of the kite 3, such as azimuth and / or elevation.

[0041] By "logic processing unit," we preferably mean all the hardware and / or software means that enable the kite control actions to be determined, in particular motor control commands, from raw data from elementary sensors (such as an accelerometer or a magnetometer 54) included in the measuring element. A first part of these means may include elements capable of determining the complete orientation of the measuring element 5, that is to say, for example, determining the orientation angles of the measuring element 5 relative to the geocentric reference frame. A second part of these means may include elements capable of determining the control actions based on the complete orientation of the measuring element 5, that is to say, determining the motor control commands for the kite.The first part of the resources can be in a first case and the second part of the resources can be in a second case, the first and second cases being physically separate.

[0042] The measuring element 5 includes for example a frame 55 rigidly fixed: - on the one hand, to the first line 41 at the first point 43, and - on the other hand, to the second line 42 at the second point 44.

[0043] These two points define an orientation of the measuring element, this orientation being characterized by a straight line B passing through the first and second points.

[0044] The chassis 55 incorporates a means 51 for measuring the orientation of the measuring element 5. The measuring element 5 can thus comprise: - a chassis 55, and - a means 51 for measuring the orientation of the measuring element 5, the measuring means 51 being fixed on the chassis 55. For example, the measuring means 51 is an inertial measurement unit or a three-axis accelerometer. The measuring means 51 determines the direction of the line B in a geocentric reference frame R. The information is transmitted wirelessly, for example, via an antenna 63. Alternatively, the measuring element 5 can be powered and can communicate via a wired connection. Power supply and communication can be easily achieved via a wired connection, since the measuring element 5 is for example fixed less than 5 m, in particular less than 2 m, from the structure of system 2.

[0045] The direction of line B and the distance separating the first and second points constitute information of relative position of the first and second lines.

[0046] Furthermore, the lashing device 1 may optionally include a directional force sensor 11 for determining the direction of the kite's traction line A. To do this, the movements of system 2 may need to be taken into account. Indeed, in this case, the directional sensor allows a direction to be determined in a reference frame of system 2. In the case of a vessel 2, system 2 can move (roll and / or pitch) relative to a geocentric reference frame. The direction that we seek to determine is, in fact, that relative to the geocentric reference frame.

[0047] Finally, the control device knows the difference in length of the first and second lines.

[0048] All this information (direction of line B, direction of line A, difference in length between the first and second lines) is sent to the logic processing unit 6, which determines the complete orientation of line B and the orientation of the leading edge of the kite wing. This information also makes it possible to determine the yaw angle (or leading edge orientation angle) of the wing and, in particular, its temporal variations.

[0049] However, preferably, the yaw angle (or leading edge angle) of the wing is directly determined by processing only the information provided by the measuring element 5. Even more preferably, the azimuth angle and the elevation angle are also directly determined by processing only the information provided by the measuring element 5. Preferably, by way of example, it can be exploited that: - the leading edge of the wing and line B are parallel or substantially parallel, or - the leading edge of the wing and line B are in the same plane or substantially in the same plane.

[0050] The logic processing unit comprises a microprocessor 61, a memory 62, and optionally an antenna 63 for receiving various data and sending relevant information, such as the leading edge orientation of the kite's wing 31, to the control device. As previously mentioned, the information can alternatively be transmitted via wire between the different elements.

[0051] A second embodiment of an arrangement 200 according to the invention is described below with reference to [Fig.2].

[0052] Arrangement 200 comprises: - a system 2, - a kite 3, - a lashing device 1, and - a device 100 for determining the orientation and, possibly, the position of a kite in flight.

[0053] Kite 3 comprises: - a wing 31, - a first line 41, and - a second line 42.

[0054] Preferably, the second embodiment differs from the first embodiment only in that the lashing device comprises: - a mechanical linkage 8 allowing for a ball joint, which is for example achieved by two pivot joints mounted in series and having non-parallel axes, and - a pivot joint 7 guiding in rotation, around the axis A, a guide element 59 of the first and second lines 41, 42.

[0055] Consequently, the measuring element 5 is different. It comprises: - the guide element 59, which is for example a plate with two holes 57, 58 for guiding or passing the first and second lines 43, 44, and - a sensor 52 which allows to determine or measure the angular position of the guide element 59 around the axis A.

[0056] In this second embodiment, the device 100 for determining the orientation of the kite in flight also includes a measuring element 5 connecting a first point 43 of the first line 41 to a second point 44 of the second line 42. However, here, the first point 43 is movable relative to the first line 41 and the second point 44 is movable relative to the second line 42. Indeed, the lines can slide in the guide holes 57 and 58.

[0057] Determining or measuring the angular position of the guide element 59 around the axis A allows us to determine the direction of the line B passing through the first and second points 43 and 44. The direction of the line B and the distance separating the first and second points constitute relative position information of the first and second lines.

[0058] Thanks to the solutions described below, it is possible to implement an execution method of a process for determining the orientation of a kite 3 in flight as described below.

[0059] The determination method comprises: - a step of determining the relative position of the first and second lines in a reference frame R, in particular in a geocentric reference frame or in the reference frame of a device 2 towed by the kite 3, and - a step of determining kite orientation values ​​3 using the relative position of the first and second lines, the kite orientation values ​​including a kite yaw angle value or a kite leading edge orientation value 31.

[0060] Preferably, the method further comprises a step of determining the position values ​​of the kite 3 using the relative position of the first and second lines, the position values ​​of the kite including: - an azimuth angle value of wing 31 of the kite, and / or - a wing elevation angle value of 31 of the kite.

[0061] Preferably, the step of determining a relative position of the first and second lines in a reference frame R includes a step of determining a relative position of a first point 43 of the first line 41 relative to a second point 44 of the second line 42 in the reference frame R.

[0062] Preferably, the first point is maintained at a constant distance from the second point.

[0063] Advantageously: - the first point 43 is a fixed point (as in the first embodiment) or a moving point on the first line 41 (as in the second embodiment), and / or - the second point 44 is a fixed point (as in the first embodiment) or a moving point on the second line 42 (as in the second embodiment).

[0064] Alternatively, the first point and the second point can be movable relative to each other in a plane at least substantially perpendicular to the first and second lines.

[0065] The step of determining a relative position of the first and second lines in a reference frame R is advantageously carried out by the measuring element 5 linking the first point 43 and the second point 44 and by the logic processing unit 6.

Claims

Demands

1. Method for determining the orientation of a kite (3) in flight, the kite being held by at least a first line (41) and a second line (42), the method of determination comprising: - a step of determining a relative position of the first and second lines in a reference frame (R), in particular in a geocentric reference frame or in a reference frame of a device towed by the kite (3), and - a step of determining orientation values ​​of the kite (3) using the relative position of the first and second lines, the orientation values ​​of the kite including a yaw angle value of the kite of a wing (31) of the kite.

2. A method according to claim 1, characterized in that it comprises a step of determining kite position values ​​(3) using the relative position of the first and second lines, the kite position values ​​including: - an azimuth angle value of the wing (31) of the kite, and / or - an elevation angle value of the wing (31) of the kite.

3. Method according to claim 1 or 2, characterized in that the step of determining a relative position of the first and second lines in a reference frame (R) includes a step of determining a relative position of a first point (43) of the first line (41) relative to a second point (44) of the second line (42) in the reference frame (R).

4. A method according to claim 3, characterized in that the first point is maintained at a constant distance from the second point or in that the first point and the second point are movable relative to each other in a plane at least substantially perpendicular to the first and second lines.

5. Method according to claim 3 or 4, characterized in that: - the first point (43) is a fixed point or a moving point on the first line (41), and / or - the second point (44) is a fixed point or a moving point on the second line (42).

6. A method according to any one of the preceding claims and according to claim 3, characterized in that the step of determining a relative position of the first and second lines in a reference frame (R) is achieved by a measuring element (5) connecting the first point (43) and the second point (44).

7. Method according to claim 6, characterized in that the measuring element (5) comprises a means (51) for measuring the orientation of the measuring element in a geocentric reference frame, in particular an accelerometer (51), in particular a 3-axis accelerometer, and optionally a magnetometer (54).

8. Method according to claim 6 or 7, characterized in that the measuring element (5) comprises a means (52) for measuring the orientation of the rotation measuring element, in particular a sensor (52) for measuring an angle of rotation around the direction (A) of traction of the kite.

9. Device (100) for determining the orientation of a kite (3) in flight, characterized in that it comprises hardware and / or software elements (5, 51, 52, 53, 55, 54, 6, 61, 62, 63) implementing the method according to one of the preceding claims, in particular hardware (5, 51, 52, 53, 54, 55, 6, 61, 62, 63) and / or software elements designed to implement the method according to one of the preceding claims.

10. Arrangement (200) comprising: - a system (2), - a kite (3), - a lashing device (1), and - a determination device (100) according to the preceding claim.

11. Product computer program comprising program code instructions recorded on a computer-readable medium to implement the method according to any one of claims 1 to 8 when said program is running on a computer.

12. Computer-readable data recording medium (62) on which is recorded a computer program comprising program code instructions for implementing the method according to any one of claims 1 to 8.

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