Methods for controlling a flight path and an aircraft

Abstract

Method for controlling a flight path (30) of an aircraft (20), wherein the aircraft (20) comprises a propulsion system (28) with at least one rotor (42), wherein the aircraft (20) is configured to provide a first flight path (30), wherein the first flight path (30) comprises a vertical component (32), wherein the vertical component (32) is part of a descent or a climb, the method comprising the steps: Controlling the propulsion system (28) with the at least one rotor (42) to provide the first trajectory (30), wherein the first trajectory (30) comprises a movement along a first axis (31) at a first rotational speed, wherein the first axis (31) has the vertical component (32) and passes through the aircraft (20), wherein the aircraft (20) rotates about the first axis (31) at a first rotational speed (33).

Description

[0001] The invention relates to a method for controlling a flight path and an aircraft.

[0002] CN 112 306 077 A discloses a take-off or landing procedure of a vertically taking-off and landing aircraft (20) with at least one rotor, wherein a take-off or landing trajectory is arranged around a vertical axis and is spiral in shape.

[0003] WO 2021 / 195 828 A1 discloses a method and a device for controlling the descent of an unmanned aircraft, the method comprising: acquiring position information about a current position of the unmanned aircraft and position information about a target descent position of the unmanned aircraft; determining a strategy for the descent of the unmanned aircraft according to the position information; and controlling the descent of the unmanned aircraft according to the strategy for the descent, wherein the strategy includes at least a spiral descent or an inclined descent.

[0004] CN 114 578 837 A discloses a method for tracking the trajectory of a vertically launching and landing aircraft with at least one rotor, wherein a trajectory is arranged around a vertical axis and is helical in shape.

[0005] FR 3 080 362 A1 shows a landing procedure of an aircraft (20) wherein a landing trajectory comprises a trajectory arranged around a vertical axis and helically shaped.

[0006] Therefore, one objective of the invention is to provide a new method for controlling a flight path and a new aircraft.

[0007] The objective is achieved through the subject matter of the independent claims.

[0008] Method for controlling the flight path of an aircraft, wherein the aircraft comprises a propulsion system with at least one rotor, wherein the aircraft is configured to provide a first flight path, wherein the first flight path includes a vertical component, wherein the vertical component is part of a descent or a climb, the method comprising the steps: Controlling the propulsion system with the at least one rotor to provide the first flight path, wherein the first flight path comprises a movement along a first axis at a first rotational speed and a rotation about the first axis at a first rotational speed, wherein the first axis has the vertical component and passes through the aircraft.

[0009] The first axis running through the aircraft provides a compact power range of the flight path, and the flight path improves the efficiency of the rotors.

[0010] According to a preferred embodiment, the aircraft includes a rotary control, wherein the rotary control controls the propulsion system to maintain the initial rotational speed at a reference rotational speed.

[0011] The rotary control can steer the propulsion system to achieve the desired flight path.

[0012] According to a preferred embodiment, the rotary control is designed as a rotary control with a closed control loop.

[0013] Since aircraft are exposed to external influences such as wind and rain, a closed-loop rotary control system results in better quality.

[0014] According to a preferred embodiment, the aircraft comprises a first motion speed control, wherein the first motion speed control controls the drive system to maintain the first motion speed at a first target motion speed.

[0015] The first motion speed control can control the drive system to achieve the desired lifting or dropping speed.

[0016] According to a preferred embodiment, the first motion speed control is designed as a first motion speed control with a closed control loop.

[0017] Since aircraft are exposed to external influences such as wind and rain, a closed-loop control system for speed control results in better quality.

[0018] According to a preferred embodiment, the first axis is a vertical axis. This results in a small power range of the trajectory.

[0019] According to a preferred embodiment, the at least one rotor has a second rotational speed, wherein the second rotational speed is reduced during the first flight path compared to a second rotational speed required for movement along the first axis at the same first rotational speed, but without rotating the aircraft about the first axis. The ability to reduce the rotational speed reduces noise and saves energy.

[0020] According to a preferred embodiment, the aircraft is a drone. A small power range of the flight path is very advantageous for drones.

[0021] According to a preferred embodiment, the drive system is controlled using at least one of the following data from a first data group consisting of - Rotational speed of at least one rotor, - spatial position of the aircraft, - Aircraft orientation, - Aircraft speed, - Yaw rate, - Gradient rate and - Roll rate.

[0022] This allows for good control of the movement along the first trajectory.

[0023] In a preferred embodiment, the aircraft has a maximum extent in any direction, and the flight performance range of the first flight path lies within a cylinder, wherein the cylinder has a radius less than or equal to the maximum extent. Restricting the flight path to this performance range results in various possible uses for the aircraft.

[0024] According to a preferred embodiment, the drive system comprises at least two rotors, preferably at least four rotors, and particularly preferably at least six rotors. The plurality of rotors improves the ability to follow the desired flight path.

[0025] According to a preferred embodiment, at least one rotor is located outside the first axis. This allows the rotor to move at least partially outside its own wake, which is generated by the rotation of the aircraft.

[0026] According to a preferred embodiment, the at least one rotor comprises at least two rotors, all of which are located outside the first axis. Thus, all rotors benefit from the rotation about the first axis.

[0027] An aircraft comprises a control device and a propulsion system with at least one rotor, the control device being designed to perform such a procedure. This enables the aircraft to fly along the first flight path.

[0028] According to a preferred embodiment, the aircraft comprises two wings, wherein the at least one rotor comprises at least two rotors and wherein at least one of the at least two rotors is assigned to each of the wings.

[0029] This is advantageous for maintaining the trajectory around the axis.

[0030] Further details and advantageous embodiments of the invention will become apparent from the examples of embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, as well as from the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention. Fig. Figure 1 shows, in a top view, an aircraft. Fig. Figure 2 shows the aircraft in a spatial representation. Fig. 1 and a flight path, Fig. Figure 3 shows a first simulation of the noise of a rotor in a first flight path, Fig. Figure 4 shows a second simulation of the noise of a rotor in a second flight path, Fig. Figure 5 shows a schematic representation of the aircraft, and Fig. Figure 6 shows a performance range of a flight path.

[0031] In the following, parts that are identical or have the same effect are marked with the same reference symbols and are generally described only once. The description builds upon itself across all figures to avoid unnecessary repetition.

[0032] Fig. Figure 1 shows an aircraft 20. The aircraft 20 is preferably a drone.

[0033] The aircraft 20 has a fuselage 24 and two wings 22, a left wing 22 and a right wing 22.

[0034] The aircraft has a propulsion system 28, wherein the propulsion system 28 comprises rotors 42, rotors 46 and / or other propulsion means.

[0035] The drive system 28 preferably comprises at least two rotors 42, more preferably at least four rotors 42, and most preferably at least six rotors 42. The rotors 42 can also be referred to as a lifting unit.

[0036] The wings 22 have cutouts 40. The rotors 42 are assigned to the cutouts 40 and enable the movement of the aircraft 20 along a flight path 30 to be controlled by blowing air through the cutouts 40.

[0037] The rotors 42, 46 can also be referred to as propellers.

[0038] The rotors 42 can preferably provide movement along a z-axis (up / down) and movement perpendicular to the z-axis, i.e., with a movement component along the x-axis and y-axis. This can be achieved by tilting the rotors 46 or by controlling the position of the lower vanes mounted below the rotor 42. Another solution to enable movement perpendicular to the z-axis is to provide additional lateral rotors on the aircraft 20. The rotors 42 have a rotational speed 48. The rotational speed 48 and the direction of rotation can differ between the various rotors 42.

[0039] The rotors 46 are located at the rear of the aircraft to generate thrust and to utilize the aerodynamically effective wing profiles for lift.

[0040] The diagram shows a first flight path 30 of the aircraft. The first flight path 30 corresponds to the movement of a point 44. As shown from above, the first flight path 30 has an axis of rotation 31, and the aircraft 20 rotates about the axis 31 at a speed 33. The point 44 is the center point of one of the rotors 42, which is located outside the axis 31.

[0041] The speed 33 can be specified as revolutions per minute.

[0042] The axis 31 runs through the aircraft 20, i.e., it is not arranged laterally to the aircraft 20. This creates a space-saving performance area for the first flight path 30.

[0043] The rotors 42 are preferably arranged at least partially outside the first axis 31. Preferably, the axis 31 is selected such that all rotors 42 lie outside the first axis 31.

[0044] Fig. 2 shows the aircraft of Fig. 1 in a spatial representation.

[0045] As can be seen, the trajectory 30 is not only circular, but also allows movement along the axis 31 with a rotational speed 34.

[0046] The axis 31 corresponds to a vertical axis 32. Alternatively, the axis 31 can be inclined relative to the vertical axis 32, but it should still have a vertical component.

[0047] The vertical component 32 can run towards the ground (descent) or towards the sky (climb). Fig. Figure 3 shows a simulation of the pressure distribution below one of the rotors with a purely vertical flight path, i.e., without rotation about an axis 31.

[0048] The rotor noise is particularly loud during vertical landings, as rotor 42 has to operate in its own wake. This leads to a pressure change on the rotor surface of rotor 42, which generates further noise.

[0049] To reduce noise, an inclined flight path can be chosen. However, the increased power output of such a flight path may not be compatible, especially in inner-city areas.

[0050] Fig. Figure 4 shows a simulation of the pressure distribution under one of the rotors with the flight path 30. Fig. 2.

[0051] Since the rotor 42 is located outside the axis 31, it has a helical trajectory around the axis 31. The helical trajectory allows the rotor 42 to displace the air into an area that was previously unaffected by the wake caused by the rotor 42. The pressure distribution is laterally inclined, and most of the wake is not located directly below the rotor 42.

[0052] This has several advantages.

[0053] The rotational speed 48 of the rotor 42 can be reduced during the first flight path 30 compared to a second rotational speed 48, which is required for movement along the axis 31 with the same initial rotational speed 34, but without rotating the aircraft 20 around the first axis 31. Reducing the rotational speed 48 saves energy and reduces noise. This noise reduction can also be considered a reduction in the overall sound pressure level (OASPL).

[0054] Another advantage is the small flight performance range. This allows landings on small landing areas such as flat roofs.

[0055] Fig. Figure 5 shows a schematic diagram of aircraft 20.

[0056] The aircraft 20 has a control device 80 for controlling the propulsion system 28. The propulsion system 28 has rotors 42 and 46.

[0057] A data unit 82 provides input data from the data group, comprising - Rotor speed 42, - Rotor speed 46, - spatial position of the aircraft 20, e.g. GPS coordinates - Aircraft orientation 20, e.g. yaw, pitch and roll, - Aircraft speed 20, - Yaw rate, pitch rate, roll rate.

[0058] Preferably, unit 82 provides at least data from the data group.

[0059] A communication unit 84 provides a means of communication between the aircraft 20 and a control center. The means of communication preferably provides wireless transmission via a wireless transmitter, e.g., using radio frequency or mobile communication technology.

[0060] The control device implements a rotary control 91 and a motion speed control 93.

[0061] The rotary control 91 is implemented to control the drive system 28 in order to maintain the rotational speed 33 at a reference speed. The reference speed 33 can be a function of the altitude of the aircraft 20. Preferably, the reference speed is reduced before landing.

[0062] The rotary control 91 is implemented as a rotary control with a closed control loop.

[0063] The movement speed control 93 is implemented to control the drive system to maintain the movement speed 34 at a reference movement speed. The reference movement speed can be a function of the aircraft's altitude 20. Preferably, the reference movement speed is reduced before landing.

[0064] The motion speed control 93 is implemented as a motion speed control with a closed control loop.

[0065] Fig.Figure 6 shows the aircraft 20 and a performance range of the flight path 30.

[0066] In the present example, the widest extent 72 of the aircraft 20 extends from wing to wing in every direction.

[0067] The method, as implemented by the control device 80, provides a flight performance range of the first flight path 30 within a cylinder 70, wherein the cylinder 70 has a radius 71, the radius 71 being less than or equal to the widest extent 72 of the aircraft 20.

[0068] This small flight performance range allows the aircraft to land and take off in a very confined space.

[0069] Naturally, numerous variations and modifications are possible within the scope of the invention. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 112 306 077 A

[0002] WO 2021 / 195 828 A1

[0003] CN 114 578 837 A

[0004] FR 3 080 362 A1

[0005]

Claims

[1] Method for controlling a flight path (30) of an aircraft (20), wherein the aircraft (20) comprises a propulsion system (28) with at least one rotor (42), wherein the aircraft (20) is designed to provide a first flight path (30), wherein the first flight path (30) comprises a vertical component (32), wherein the vertical component (32) belongs to a descent or a climb, the method comprising the steps: Controlling the drive system (28) with the at least one rotor (42) to provide the first flight path (30), wherein the first flight path (30) comprises a movement along a first axis (31) at a first movement speed and a rotation about the first axis (31) at a first speed (33), wherein the first axis (31) has the vertical component (32) and extends through the aircraft (20). [2] The method of claim 1, wherein the aircraft (20) comprises a rotation controller (91), the rotation controller (91) controlling the drive system (28) to maintain the first rotational speed (33) at a reference rotational speed. [3] The method of claim 2, wherein the rotation control (91) is implemented as a closed-loop rotation control. [4] A method according to any one of the preceding claims, wherein the aircraft (20) comprises a first motion speed controller (93), the first motion speed controller (93) controlling the propulsion system (28) such that the first motion speed (34) is maintained at a first reference motion speed. [5] The method of claim 4, wherein the first motion speed controller (93) is implemented as a first closed-loop motion speed controller. [6] Method according to one of the preceding claims, wherein the first axis (31) is a vertical axis. [7] Method according to one of the preceding claims, wherein the at least one rotor (42) has a second speed (48), wherein the second speed (48) is reduced during the first flight path (30) compared to a second speed (48) required for movement along the first axis (31) with the same first movement speed (34) but without rotation of the aircraft (20) about the first axis (31). [8] Method according to one of the preceding claims, wherein the aircraft (20) is a drone. [9] Method according to one of the preceding claims, wherein the aircraft (20) has a widest extent (72) in each direction, and wherein the flight performance range of the first flight path (30) lies within a cylinder (70), the cylinder (70) having a radius (71), the radius (71) being less than or equal to the widest extent (72). [10] Method according to one of the preceding claims, wherein the drive system (28) comprises at least two rotors (42), preferably at least four rotors (42) and most preferably at least six rotors (42). [11] Method according to one of the preceding claims, wherein the at least one rotor (42) lies outside the first axis (31). [12] Method according to one of the preceding claims, wherein the at least one rotor (42) comprises at least two rotors (42), wherein all rotors (42) lie outside the first axis (31). [13] Aircraft (20) with a control device (80) and a drive system (28) with at least one rotor (42), wherein the control device (80) is designed to carry out a method according to one of the preceding claims. [14] An aircraft (20) according to claim 13, comprising two wings (22), wherein the at least one rotor (42) comprises at least two rotors (42), and wherein at least one of the at least two rotors (42) is associated with each of the wings (22).

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