IMPROVED MANEUVERABILITY AERIAL VEHICLE AND A METHOD IMPLEMENTED FOR THIS PURPOSE

Abstract

Providing improved yaw maneuverability to an aerial vehicle of the multi-blade type, that enables modifying the pitch angle () of its rotors blades, and a method of implementation for this purpose, wherein the axis of movement of at least two pairs of the aerial vehicle's rotors are tilted in a symmetrical configuration in relation to the aerial vehicle's yaw plane, so that each pair converges towards another point on the same level along a longitudinal axis plane of the aerial vehicle while creating an angle () between the rotation planes of the rotors of each pair, which is less than 180 and greater than 140.

Claims

1. An aerial vehicle comprising a plurality of rotors, each of the plurality of rotors having at least one blade, wherein the aerial vehicle is enabled to modify the pitch angle () of the at least one blade of each of the plurality of rotors; wherein the axis of movement of at least two pairs of the aerial vehicle's rotors are tilted in a symmetrical configuration in relation to the aerial vehicle's yaw plane, so that each pair converges towards another point on the same level along a longitudinal axis plane of the aerial vehicle while creating an angle () between the rotation planes of the rotors of each pair, which is less than 180 and greater than 140.

2. The aerial vehicle according to claim 1, wherein the aerial vehicle is a quadcopter drone.

3. The aerial vehicle according to claim 2, wherein the aerial vehicle enables maneuvering in its yaw plane by modifying the pitch angles () of the blades, without changing the rotational speed of said blades.

4. The aerial vehicle according to claim 2, further comprising a propulsion system having an internal combustion engine.

5. The aerial vehicle according to claim 2, further comprising a propulsion system, wherein the propulsion system is a hybrid system, and is comprised of an internal combustion engine in tandem with an electric engine.

6. A method for providing improved maneuverability in the yaw plane of a multi-blade aerial vehicle comprising: providing the axis of movement of at least two pairs of rotors of the aerial vehicle, each rotor of the at least two pairs of rotors having a blade, wherein the at least two pairs of rotors are tilted in a symmetrical configuration in relation to the aerial vehicle's yaw plane so that the rotors converge in their direction, each pair towards another point on the same level along a longitudinal axis plane of the aerial vehicle, while creating an angle () between the rotation planes of the blades of each pair, which is less than 180 and greater than 140, wherein the aerial vehicle is enabled to modify the pitch angle () of the blades of the at least two pairs of rotors.

7. The method of claim 6, further comprising: maneuvering the aerial vehicle to yaw by increasing the pitch angle () of a diagonally opposite pair of rotor blades, each from another pair of said symmetrically tilted two pairs of rotors, and reducing the pitch angle () of the blades of the remaining pair of rotors that are also diagonally opposite each other, each from a different pair of said symmetrically tilted two pairs of rotors.

8. An aerial vehicle comprising a plurality of rotors, each of the plurality of rotors having at least one blade, wherein the aerial vehicle is enabled to modify the pitch angle () of the at least one blade of each of the plurality of rotors; wherein the plurality of rotors includes forward rotors and rearward rotors and said aerial vehicle is formed with a first geometrical dimension (x) between the forward rotors and the rearward rotors and a second geometrical dimension (y) between each rotor of the forward rotors and between each rotor of the rearward rotors.

9. The aerial vehicle according to claim 8, wherein the aerial vehicle is a quadcopter drone with four rotors, wherein the forward rotors comprise a forward pair of rotors and the rearward rotors comprise a rearward pair of rotors, and the first geometrical dimension (x) is between the forward pair of rotors and the rearward pair of rotors and the second geometrical dimension (y) is between the two rotors of the forward pair of rotors and between the two rotors of the rearward pair of rotors.

10. The aerial vehicle of claim 8, wherein the axis of movement of each of the plurality of rotors is tilted toward the center of the aerial vehicle.

11. The aerial vehicle of claim 8, wherein the aerial vehicle is configured to maneuver in the yaw plane without changing the rotational speed of the blades.

12. The aerial vehicle of claim 8, further comprising a main body aligned with the first geometrical dimension, a first plane perpendicular to the main body, and a second plane perpendicular to the main body, wherein the first plane passes through a center of rotation on each of the blades of the forward rotors and the second plane passes through a center of rotation on each of the blades of the rearward rotors, wherein an axis of movement of each of the forward rotors passes through a first point located on the first plane, and wherein an axis of movement of each of the rearward rotors passes through a second point located on the second plane.

13. The aerial vehicle of claim 12, wherein each of the plurality of rotors has a rotation plane perpendicular to the axis of movement, an angle () between the rotation planes of the forward rotors is less than 180 and greater than 140, and an angle () between the rotation planes of the rearward rotors is less than 180 and greater than 140.

14. The aerial vehicle of claim 13, wherein the aerial vehicle is configured to maneuver in the yaw plane without changing the rotational speed of the blades.

15. The aerial vehicle of claim 12, wherein the first point is distinct from each of the centers of rotation on each of the blades of the forward rotors and the second point is distinct from each of the centers of rotation on each of the blades of the rearward rotors.

16. The aerial vehicle of claim 8, further comprising a first plane and a second plane each parallel to the second geometrical dimension, wherein the first plane passes through a center of rotation on each of the blades of the forward rotors and the second plane passes through a center of rotation on each of the blades of the rearward rotors, wherein an axis of rotation of each of the forward rotors passes through a first point located on the first plane, and wherein an axis of rotation of each of the rearward rotors passes through a second point located on the second plane.

17. The aerial vehicle of claim 16, wherein each of the plurality of rotors has a rotation plane perpendicular to the axis of rotation, an angle () between the rotation planes of the forward rotors is less than 180 and greater than 140, and an angle () between the rotation planes of the rearward rotors is less than 180 and greater than 140.

18. The aerial vehicle of claim 17, wherein the aerial vehicle is configured to maneuver in the yaw plane without changing the rotational speed of the blades.

19. The aerial vehicle of claim 16, wherein the first point is distinct from each of the centers of rotation on each of the blades of the forward rotors and the second point is distinct from each of the centers of rotation on each of the blades of the rearward rotors.

20. The aerial vehicle of claim 8, further comprising a propulsion system having an internal combustion engine.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

[0020] Different aspects of at least one embodiment of the invention that is the subject of the patent application will be described below, with reference to the accompanying figures (while no scale should be attributed to them). The figures are presented for illustrative purposes only and for facilitating an understanding of the different aspects of the invention and the possible embodiments for its actual utilization. The figures are part of the description, but should not be construed as limiting the invention in any way. In the figures, an identical or similar element that is visually depicted in several figures could be tagged by uniform numbering. For clarity, not every element was tagged in each of the figures. In the following figures:

[0021] FIGS. 1 and 1a are as stated (respectively) a schematic perspective view of a prior art quadcopter drone as well as schematic front and side views of said drone (as well as a prior art drone where the axis of movement of each of its rotors all slightly tilt toward the center of the drone).

[0022] FIGS. 2 and 2a are (respectively) a schematic perspective view of one example of a quadcopter drone according to the invention having improved maneuverability in the yaw plane, as well as front and side schematic views of said drone.

[0023] FIGS. 3 and 3a; 4 and 4a; and 5 and 5a are schematic perspective views and front and side schematic views of three other embodiments of quadcopter drones according to the invention, which, like the example drone illustrated in FIGS. 2 and 2a, also structurally embodies the distinct feature of the invention (although in different geometries), in a manner that gives them, as aforesaid, improved maneuverability in the yaw plane.

[0024] FIGS. 6 and 7 (respectively) depicts a perspective view of a quadcopter drone that structurally embodies the geometrical configuration of the invention, as schematically illustrated and by way of example only in FIG. 2, and an exploded view of its elements.

[0025] FIGS. 8 and 8a are (respectively) a schematic perspective view of drone where the axis of movement of each of its rotors all slightly tilt toward the center of the drone but wherein the improved yaw maneuverability of the aerial vehicle in accordance with the invention, is achieved by providing the aerial vehicle with one geometrical dimension between its forward pair of rotors and rearward pair of rotors and a second different dimension between the rotors of each of said pairs, and a schematic front and side views of said drone.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

[0026] Various devices and elements will be described below strictly for the purpose of giving an example of embodiment of the claimed invention. The embodiment described below does not limit the claimed invention, and the latter may also apply to devices and methods that differ from those described below. The claimed invention does not have to include all aspects of devices, elements and methods to be described below, and is not strictly limited to those that exist in all the embodiments described below. For the sake of integrity, it should be noted that the set of claims on the invention may be revised by way of amendment and/or by filing a divisional application. The skilled person will also understand that, for the sake of clarity, the embodiments are described without inundating the description with elements, methods and processes that are already considered to be common knowledge in the field, and in any case no tagged reference was provided to them in the figures.

[0027] Reference is made to FIGS. 2 and 2a. FIG. 2 is a schematic perspective view of one example of quadcopter drone 210 according to the invention, which, as explained below, has improved maneuverability in the yaw plane over the prior art (see and compare, for example, drones 10 and 10, as described above in reference to FIGS. 1 and 1a). FIG. 2a shows schematic front and side views of drone 210.

[0028] A prominent feature of drone 210 is that the axis of movement (235) of each of the four rotors 215, 220, 225 and 230 installed therein tilt from the outset in a symmetrical configuration in relation to x-y (yaw) plane, so that each pair of axis converge towards another point on the same level along the drone's longitudinal axis plane (in the illustrated examplealong x-z plane), in creating a angle between the yaw planes of the rotor blades that is less than 180.

[0029] As mentioned above in the Background of the Invention chapter, it is known that there are quadcopter drones in which the axis and rotors of their engines tilt towards the center of the drone in order to increase the drone's stability (the tilt improves the drone's stability at the expense of pitch and roll maneuverability) (see FIG. 1a for drone 10). However, in contrast in drone 210, this is not a case where all the axis of movement tilt towards the center of the drone, but a symmetrical tilt of pairs of axis towards different points on the same level, along the longitudinal axis of the drone (see the illustrated examplea tilt towards plane x-z).

[0030] Another feature of drone 210 is that it is a type of drone that enables modifying the pitch angle () of its rotor blades.

[0031] The symmetrical tilt of the axis of movement of the pairs of rotors in drone 210, which we pointed to earlier, in combination with the ability to dynamically modify the pitch angles of the blades of each of the rotor, enables producing torques in the (x-y) yaw plane, which give drone 210 improved yaw maneuverability, without having to adjust the rotors' rotation speed (in other wordswhile maintaining a constant RPM).

[0032] The symmetrical tilt of the axis of movement of the pairs of rotors generates side forces (F) that contribute to and increase the relative small torque due to the drag, which is usually generated by the modification of the pitch angle of the blades, in a way that provide the drone according to the invention, improved maneuverability in the yaw plane.

[0033] Thus, for example (see FIG. 2), the symmetrical tilt of the axis of movement of the pairs of rotors, which are built into the drone according to the invention, regularly generate side forces (F). At the same time, when increasing the pitch angle () of rotor blades 215 and 230 and reducing the pitch angle () of rotor blades 220 and 240, this produces a torque that together with side forces F.sub.1 and F.sub.4 (which will increase due to increasing of the pitch angle as stated) will maneuver drone 20 to yaw in x-y plane in the direction of arrow 250 (clockwise).

[0034] At the same time and as previously noted, the improved maneuverability in the yaw plane of the drone according to the invention is achieved even without having to modify the relative speeds of the rotors. Therefore, a drone according to the invention could be fitted with a propulsion system that is based on an internal combustion engine (gasoline-powered), which as mentioned in the Background of the Invention chapter, is preferred for achieving long flight time and carrying a relatively heavy effective weight (payload).

[0035] The skilled person will understand that the tilt of the pairs of rotors, so that each pair of axis converge towards different points on the same level in the drone's longitudinal axis plane (x-z plane according to the illustrated example), while creating a angle between the rotation planes of the blades, somewhat impairs the lifting performances of the drone in which the invention will be implemented (and therefore shortens its flight time). However, it was found that in order to achieve the improved maneuvering advantage in the yaw plane (and the advantage of the ability to fly the drone by means of an internal combustion engine (gasoline-powered) at a constant blade speed (constant RPM)), it is enough to slightly tilt the rotors' axis so that the angle of the drone according to the invention will be 140<<180, without significantly impairing the drone's performances (as dependent of course on other rather familiar design considerations, such as engine power, drone geometry (e.g. distance of the rotors from the drone's longitudinal axis, etc.). At most, and given the advantage of propulsion at constant blade speed, the constant speed (RPM) may be increased to compensate for the loss of lift performances.

[0036] The skilled person will also understand that in the said embodiment of the tilt of the axis of the pairs of rotors, so that each pair of axis converge towards different points on the same level along the drone's longitudinal axis plane (x-z plane according to the illustrated example), in creating a angle between the rotation planes of the rotor blades, the invention may also be applied to drones having a hybrid propulsion system (drones that combine an internal combustion engine (gasoline-powered) with a backup electric engine).

[0037] The skilled person will also understand that in the said aspect of the tilt of the rotors' axis, so that each pair of axis converge towards different points on the same level along the drone's longitudinal axis plane (x-z plane according to the illustrated example), in creating a angle between the yaw planes of the rotor blades, the invention may also be applied not only in quadcopter drones (which by definition comprise an array of four rotors), such as drone 210, but also in other multirotor drones (e.g. drones having arrays of 6, 8, 10 or 12 rotors).

[0038] Furthermore, according to the illustrated example, the tilt of the pairs of rotors, so that each pair of axis converge towards different points on the same level along the drone's longitudinal axis plane, takes place on the x-z plane in the upward direction, but the skilled person will understand that the tilt of these pair of axis, according to the invention, could be also applied on the same plane also downwards or on other planes of the drone (upward or downward).

[0039] Reference is made to FIGS. 3 and 3a; 4 and 4a; And 5 and 5a. FIGS. 3 and 3a; 4 and 4a; and 5 and 5a are side views of three other configurations of quadcopter drones according to the invention (respectively)310, 410 and 510, in which, like drone 210 that we pointed to previously (in reference to FIG. 2), the distinct feature of the invention is also implemented in the structure of these drones, i.e. the symmetrical tilt of the axis of movement of pairs of rotors, whereby each pair of axis converges towards different points on the same level along the drone's longitudinal axis plane. However, unlike drone 210, in drones 310, 410, and 510, the tilt is in different directions and/or in other planes (compared to the initial axis, as defined in FIGS. 1, 2 and 2a).

[0040] In drone 310, which is illustrated in FIGS. 3 and 3a, the axis of movement (335) of the pairs of rotors (315, 320, 325, 330) are tilted outward and converge downward (as opposed to the axis of movement of the pairs of rotors of drone 210, which tilt inward and converge upward). In drone 410 illustrated in FIGS. 4 and 4a, the axis of movement (435) of the pairs of rotors are tilted to create a angle between the rotation planes of pair of rotors 420 and 430 and create a angle between the rotation planes of pair of rotors 415 and 425. In other words, the axis converge upward towards another longitudinal axis plane of the drone (to y-z plane, as opposed to the x-z plane to which the pairs of axis converged in drone 210). In drone 510, illustrated in FIGS. 5 and 5a, the axis of movement (535) of pairs of rotors tilt outward and converge downward to create a angle between the yaw planes of pair of rotors 520 and 530 and create a angle between the rotation planes of pair of rotors 515 and 525 (while in addition to and similar to drone 410, they converge towards another longitudinal axis plane of the drone (to y-z plane as opposed to the x-z plane to which the pairs of rotors axis converged in drone 210).

[0041] The skilled person will understand that the symmetrical tilts of the axis of movement of pairs of rotors, as illustrated in drones 310, 410 and 510, in combination with the dynamic ability to modify the pitch angles of the blades of each of the rotors fitted therein, enable producing torques in the yaw plane (x-y), which provide each of them, similar to drone 210, improved yaw maneuverability, without having to adjust the rotors' rotation speed (in other wordswhile maintaining a constant RPM). All that is needed for drones 310, 310 and 510 to perform a yaw maneuver is to increase the pitch angle () of diagonally opposite pair of rotors, each from another pair of the two symmetrically tilted pairs, and reduce the pitch angle () of the remaining diagonally opposite pair of rotors, each from another pair of the symmetrically tilted pairs, in a way that recruit the side forces (F), the end products of the symmetrical tilts of pairs of rotors, to increase the required torque for an efficient yaw maneuver.

[0042] Reference is made to FIGS. 6 and 7. FIGS. 6 and 7 (respectively) show a perspective view of quadcopter drone 610, which structurally embodies a specific geometrical configuration of the invention, as described above for drone 210 (in reference to FIGS. 2 and 2a that show a schematic illustration of drone 210 by way of example only); and an exploded view depicting the elements of drone 610.

[0043] As to be described below in reference to the figures, drone 610 is a quadcopter having a hybrid propulsion system (internal combustion engine fitted alongside an electric engine to be operated as a backup should one of them fail) and enables modifying the pitch angle () of the blades of the four rotors615, 620, 625 and 630 fitted therein (each having a two-blade configuration). In drone 610, the propulsion system propels all four rotors at an equal speed at a given time (i.e. a drone having a constant RPM).

[0044] As previously noted, drone 610 structurally embodies a specific geometric configuration of the invention, as described above for drone 210from the time it is assembled, the axis of movement (635) of each of the four rotors are symmetrically tilted in relation to the x-y yaw plane, so that each pair of axis converge towards different points on the same level along a longitudinal axis plane of the drone (x-z plane), while creating a angle between the rotation planes of the rotor blades that is less than 180.

[0045] Drone 610 is comprised of chassis element 752, which may be manufactured, for example, from aluminum or composite materials. Main drive shaft 755 serves to shift drive from propulsion system 758, on either side, to the rotors. The propulsion system of drone 610 is as stated a hybrid system, and is comprised of electric engine 761, which is fitted in tandem configuration with and parallel to internal combustion engine 764 (according to the illustrated example, in a tandem configurationside by sideat the center of the drone). In the case of a failure, electric engine 761 may be actuated by clutch assembly 777, which enables propelling the main drive shaft by the electric engine in the event of a malfunction/failure of the internal combustion engine (and vice versa). Clutch assembly 777 may also include reduction gears to adjust the number of revolutions of the propulsion system as required. Shelf 780 is also formed on chassis element 752. The shelf serves for mounting the drone's avionic assemblies on it (assemblies that are not illustrated, but usually include communication, navigation, autopilot and command systems). Landing gear 783 is fitted under the chassis element. The skilled person will understand that the chassis element may also be made with reinforcement rods (not illustrated) extending from it towards each of the rotors. The propulsion generated from propulsion system 758 is transferred through main drive shaft 755, simultaneously to two gear assemblies 786 and 789. The gear assemblies are each formed in a T configuration as conical cogwheel gears to enable splitting the propulsion simultaneous with angularly tilting its direction.

[0046] According to the illustrated example, the angular tilt occurs in the gear assemblies in a manner that leads to tilting the axis of movement (635) of each of the four rotors in a symmetrical configuration in relation to the x-y yaw plane, so that each pair of axis converge towards different points on the same level along a longitudinal axis plane of the drone (x-z plane), while creating a angle between the rotation planes of the rotor blades that is less than 180. The skilled person will understand that this is only an example, and that the tilt sought can also be produced by other means, e.g. by installing gears that enable such tilting near each of the rotors.

[0047] The propulsion from the gear assemblies towards each of the rotors is transferred by driveshaft bars 792, 795, 798 and 801. Each of the driveshaft bars is connected to gear assembly L, which is aligned on its side to propel a rotor. Driveshaft bar 792 is connected to gear assembly L 804 (propelling rotor 615), driveshaft bar 795 is connected to gear assembly L 807 (propelling rotor 620), driveshaft bar 798 is connected to gear assembly L 811 (propelling rotor 625), and driveshaft bar 801 is connected to gear assembly L 814 (propelling rotor 630).

[0048] The gear assemblies are each formed in an L configuration as a gear implementing conical cogwheels in a way that enable angularly tilting the direction of the propulsion. According to the illustrated example, the angular tilt achieved by gear assembly L is 90 (since the angular tilt needed to obtain a angle between the rotation planes of the blades is already produced by the T gear assemblies (786 and 789)). However, the skilled person will understand that also the L gear assemblies may be formed as gears, for example, of conical cogwheels, in a way that enable achieving the sought tilt required for obtaining the angle, in whole or in part, at this site.

[0049] L gear assemblies each also comprise an assembly for actuating the modification of the pitch angle () of the rotor blades to which it is connected. The skilled person is familiar with a range of such actuating assemblies, which could be based, for example, on a tiny electric servo engine with a transmission that translates the engine's movement into opposite linear movements of pairs of arms that are connected to the rotor blades and modify their pitch angle in a pivotal movement. Fitting each of the rotors as illustrated, with a pitch angle modification actuator enables as said, dynamically, during flight, modification of the pitch angle, for each specific rotor, of said specific rotor blades.

[0050] As noted, drone 610 is only an example of how the invention is implemented. A drone such as drone 610 has already been tested and proven to have improved efficiency in yaw plane maneuvering. The angle between the rotation planes of the test drone designed to be within the range according to the invention173 in the test drone. The test drone was fitted with an electric engine, type AXI-F3A-53XX (2500W) and a two-stroke piston internal combustion engine type ZENOAH 26 cc (2.5 HP). As stated, the test drone comprised of four two-blade rotors, each with a blade length of 330 mm During its flight and in achieving the improved maneuverability, it was enough to exploit the possibility of modifying the blades pitch angle () within an angle range of 0-6 (wherein the pitch angle modification (a) actuators allow for a much larger angular modification (23-+35). In other words, operating the test drone according to the invention at a constant RPM merely required a relatively slight modification of the blades' pitch angle, in a manner that maintained a relatively low drag and did not affect their efficiency in order to achieve improved yaw performance (as a result of the contribution of side forces (F) achieved according to the invention, see FIG. 2 and the explanations provided above in this context). The dimensions of the test drone were 90 cm*90 cm (distance between the rotors blades rotational planes axis). The takeoff weight was 11 kg. The test drone carried a 3 kg payload in a flight mission profile for about three hours, and was designed for flight at altitudes of up to 12,000 feet at an average cruising speed of 65 knots, while demonstrating improved yaw maneuverability as stated, in light of the implementation of the invention in the drone' structure.

[0051] Therefore, drone 610 as described above in relation to FIGS. 6 and 7 is a practical and proven example of the application of the invention, but any skilled person will understand that this is only an example, and the invention could also be applied in other geometrical configurations (see, for example, the different geometries of drones 310, 410 and 510, as described above in reference to FIGS. 3 and 3a; 4 and 4a; and 5 and 5a).

[0052] Moreover, the skilled person will understand that this as stated is only an example also with respect to the type of drone (quadcopter in this specific case) and with respect of the various structural components usedpropulsion systems, transmissions/gears, blades, etc. as well as commercially known components and assemblies.

[0053] In fact, in view of the description provided above in referring to the accompanying figures, the skilled person will understand that the invention is also embodied in a general method. A general method applicable in a wide range of multi-blade drones which provide the ability to modify the pitch angle of the rotor blades fitted therein (a) for providing those drones with improved yaw maneuverability and while enabling easy installation of a clearly preferred propulsion systeman internal combustion engine (gasoline-powered). This is achieved in light of achieving the improved maneuverability also at a constant RPM (therefore, avoiding the need to install the drone with unwieldy reduction gears).

[0054] A method that includes the stage of providing the axis of movement (235, 335, 435, 5353, 635) of each of the rotors installed therein, wherein they are tilted in a symmetrical configuration in relation to the aerial vehicle's yaw plane (x-y) so that each pair of axis converge towards another point on the same level along a longitudinal axis plane of the drone while creating a angle between the rotation planes of the blades of each pair, which is less than 180 but greater than 140.

[0055] In the second state, the method could include maneuvering the aerial vehicle to yaw by increasing the pitch angle () of the blades of diagonally opposite pair of rotors, each from another pair of said symmetrically tilted pairs of rotors, and reducing the pitch angle () of the blades of the remaining rotors that are also diagonally opposite each other, each from a different pair of said symmetrically tilted two pairs of rotors.

[0056] Furthermore, in light of the description given above with reference to the accompanying figures, the skilled person will understand that the invention can be applied not only to unmanned multi-blade aerial vehicles (drones according to the examples provided here), but also to manned multi-blade aircraft, (i.e. that include a team such as a pilot or even medicin the event of a multi-blade aircraft that is flown by remote control, but serves for rescuing an injured person and treating him in flight).

[0057] In addition, in light of the description provided hereinabove while referring to the accompanying figures, a skilled person will also understand that generating side forces (F) that contribute to and increase the relative small torque due to the drag, which is usually generated by the modification of the pitch angle of the aerial vehicle rotors blades, in a way that provide the aerial vehicle according to the invention, with improved maneuverability in the yaw plane, is also achievable in the design of multi-blade aerial vehicle of the type wherein the axis of each of its rotors are all tilted towards the center of the aerial vehicle (see for example quadcopter drone 10 as depicted in FIGS. 1 and 1a and described hereinabove in the Background of the Invention chapter).

[0058] Reference is made to FIGS. 8 and 8a. FIGS. 8 and 8a are (respectively) a schematic perspective view of quadcopter drone 810 and a schematic front and side views of said drone. Similarly to drone 10, the axis of movement (835) of each of drone 810 four rotors 815, 820, 825, and 830, all slightly tilt toward the center of the drone. Another feature of drone 810 is that it is a type of drone that enables modifying the pitch angle () of its rotor blades. The improved yaw maneuverability of drone 810 is achieved by providing drone 810 with one geometrical dimension (x) between its forward pair of rotors 815, 820 and its rearward pair of rotors 825, 830. and a second different geometrical dimension (y) between the rotors of each of said pairs.

[0059] a skilled person will understand that by providing drone 810 with such geometrically different dimensions (x, y) will also generate side forces (F) that contribute to and increase the relative small torque due to the drag, which is usually generated by the modification of the pitch angle () of drone 810 rotors blades, in a way that provide drone 810 according to the invention, with improved maneuverability in the yaw plane.

[0060] The patent applicant provided the above description in referring to the accompanying figures for illustrative purposes only. The description above should not be limited to the illustrated embodiments. On the contrary, the description provided should be seen as also covering a wide range of alternatives, modifications and equivalents, all without deviating from the configurations defined in the following set of claims.