WO2020069946A1 - Aircraft - Google Patents

Abstract

The invention relates to an aircraft having at least four ducted fan propulsion units, which are each arranged on wings assigned thereto or on the fuselage of the aircraft and are pivotable about a pivot axis extending parallel to the transverse axis of the aircraft. The invention proposes that the propulsion units be pivotable about their pivot axis independently of one another such that stable hovering flight is brought about.

Description

Aircraft

description

The invention relates to an aircraft with at least four mantle propeller engines, which are each arranged on their associated wings or on the fuselage of the aircraft and can be pivoted about a pivot axis running parallel to the transverse axis of the aircraft. In particular, the invention relates to a driverless aircraft, which is often referred to as a drone. It is therefore mainly spoken of a drone in the following, without any restriction being connected therewith.

Such aircraft or drones are often used nowadays. In addition to military purposes, the drones are also used for camera surveillance, for example of power lines and the like. Depending on the design and size of such a drone, it can also transport loads. In today's world, for example, it is often thought about whether parcels can be reliably delivered with drones. For such a task, however, it is necessary that the drone can take a stable hover. Hovering is used to describe a state in which the drone hovers on the spot at a certain height without any significant movements.

A drone of the type described at the outset is known, for example, from WO 2018/048574 A1. This aircraft has on four wings each a propeller and a mantle propeller, which is about a horizontal axis are pivotally held on stubs. This should make it possible to land or take off vertically. When the propellers or their axes of rotation are pivoted into the horizontal position, strong propulsion is achieved. Maintaining a suspended state is basically possible with such an aircraft. However, the additional engines increase the weight of the aircraft and reduce efficiency.

Another drone is described in WO 2016/178008 A1. Four propeller engines are provided here, the propellers of which rotate about a vertical axis. A swiveling of the propellers around a horizontal axis is not provided. WO 2017/108634 A1 also discloses an aircraft with a plurality of propellers which rotate about a vertical axis. The floating state can be achieved here by changing the speed, since the two-blade propellers used allow this. However, the efficiency of such propellers is lower than that of shell propellers.

From WO 2017/087841 Al it is known to articulate a propeller engine or a jacketed propeller engine on an aircraft. It is not described whether and how a hover should be achieved in this way. From DE 10 2016 104 517 A1 a jacketed propeller engine is known, in which the outlet opening of the engine can be widened or narrowed by a cone that can be displaced in the longitudinal axis. This means that the thrust can be changed while the speed remains the same.

Due to the inertia of the mantle propeller engines described at the outset, they are used relatively rarely in drones. Nevertheless, the mantle propeller engines have the advantage that they are especially at higher Speeds can work extremely efficiently. The susceptibility to wind is lower at higher speeds. Sheathed propellers also have a more favorable thrust-to-weight ratio than free-running propellers.

With unmanned and battery-operated drones, this has a major impact on the range that can be achieved. In principle, the use of jacketed propeller engines would therefore be desirable. Such engines are often referred to as EDF (Electric Ducted Fan) engines.

The invention is based on the object of designing an aircraft of the type described at the outset in such a way that a stable levitation position can also be achieved when using jacketed propeller engines.

The object is achieved according to the invention in that the engines can be pivoted about their pivot axis independently of one another in such a way that a stable hover is effected. The independent pivoting of the individual engines means that yawing, pitching or rolling movements of the aircraft can be compensated for well and in particular quickly. By changing the beam angle, the thrust changes immediately, so that a quick and direct compensation of the movement in question is possible.

In particular, it is expedient if the engines can be pivoted both forwards and backwards, starting from the position of the rotational axis that is vertical for maximum lift. This measure allows movements to be compensated for by different pivoting of the engines. It can be provided that when the aircraft rotates clockwise around the yaw axis (vertical axis), the engines are pivoted clockwise from the vertical position about their swivel axes. When the aircraft rotates counterclockwise, the engines are also pivoted counterclockwise. This compensates for the rotation of the aircraft.

The thrust is reduced in the vertical direction by pivoting the engines. To maintain the flight altitude, it can therefore be provided that the speed of the propellers is increased at the same time.

When the aircraft rolls over the roll axis (horizontal longitudinal axis in the direction of flight) to the right, the two left engines (seen in the direction of flight) are pivoted in opposite directions about their pivot axis in such a way that the lift on the left side is reduced. With a roll movement to the left, the right engines are pivoted in opposite directions. The opposite is understood here to mean that the engines on one side of the aircraft are pivoted once clockwise and once counterclockwise. This reduces the lift on the side in question without causing a yaw or pitch movement. At the same time, the speed of the non-swiveled engines can be increased in order to achieve a faster position correction.

Here, too, it can be provided that the rotational speed of the propellers is increased when the roll movement is compensated in such a way that the flight altitude is at least approximately maintained. Furthermore, it is provided that when a nodding movement of the missile is detected with the front part downward (rotation about the transverse axis), the two front engines are pivoted clockwise in order to produce a higher thrust in the vertical direction. In particular, the engines can be aligned essentially vertically. Accordingly, when the missile nodding movement is detected with the rear part downward, the two rear engines are pivoted counterclockwise in order to bring about a higher thrust in the vertical direction. In particular, the engines can be aligned essentially vertically. These measures increase the lift on the downward sinking side so that the aircraft is level again. Here, too, the speed of the swiveled engines can be increased to maintain the flight altitude.

In principle, these measures can be carried out manually by remote control by the operator. However, this requires some skill and practice in using the remote control for such drones.

It can also be provided that means for detecting the yaw movement and / or the pitching movement and / or the rolling movement of the aircraft are present. It is then expedient for the engines to be pivoted as a function of the yaw movement and / or the pitching movement and / or the rolling movement. In particular, it is provided according to the invention that a controller is present which, depending on the detected yaw movement and / or pitching movement and / or rolling movement, causes the individual engines to be pivoted. The controller can be designed as a vector controller that unites from the detected movements of the aircraft Direction vector determined in which a changed thrust must act so that the aircraft is held in a floating position. This flight vector can be achieved by pivoting the individual engines independently of one another about their pivot axis while assuming constant thrust. As already stated, the change in the direction of thrust has a direct impact on the orientation of the aircraft, so that the levitation position can be maintained quickly and reliably even in the event of sudden gusts of wind.

This vector control can be used with unmanned drones for a stable hover. It is basically arbitrary how the drone is designed. The engines can be arranged at the wing ends. It is also possible to arrange the engines closer to the fuselage or to the fuselage. It is essential that the engines can be pivoted up to 90 ° to 120 ° in both directions, starting from a vertical orientation, so that the vector control can be used in any flight position of the aircraft. A pivoting by more than 90 ° in one direction or the other is required, for example, in the case of a vertically aligned drone, so that the vector control can also be used in this extreme position.

When hovering, the jacketed propeller engines or their axes of rotation are aligned essentially vertically. During flight operations, the engines are swiveled into the horizontal position so that the aircraft can fly with high thrust.

Such a control also allows the aircraft to be held in a position other than a horizontal floating position. For example, the aircraft can be used in hover at a 45 ° incline by rotating the engines 45 ° in forward flight. It is also possible that the aircraft can fly vertically up or down. This makes it possible, for example, to move the aircraft in a narrow shaft. By swiveling the engines independently of one another, the flight attitude can be checked quickly.

It can also be achieved that the aircraft moves straight ahead in a straight flight position at low speed. This can be useful for camera shots, for example.

The invention is explained in more detail below with the aid of the schematic drawing. Show it:

Fig. 1 The top view of an aircraft according to the

 Invention,

2 shows the front view of the aircraft,

Fig. 3 is a side view of the aircraft and

Fig. 4 is a perspective view of the aircraft.

The aircraft 10 shown in the drawing has a fuselage 11 on which four wings 12, 13, 14, 15 are arranged. In detail, the arrangement is such that the wings 12, 13 form a rear pair of wings, and the

Wings 14, 15 form a front pair of wings. It can

Stabilizing wing 16 may be arranged at the rear of the fuselage 11. The wings 12, 13, 14, 15 can be of the same size or, as shown in the drawing, of different sizes. The roll axis 17, which extends in the longitudinal direction of the aircraft from front to rear, can be defined on such an aircraft. Furthermore, a transverse axis 18 and a vertical axis or yaw axis 19 can be defined on the aircraft. The names of these axes are generally known.

A jacketed propeller engine 22, 23, 24, 25 is arranged at the ends of the blades 12, 13, 14, 15. Each engine is pivotally mounted about a pivot axis 26, 27, 28, 29 on the associated wings 12, 13, 14, 15. The pivot axes 26, 27, 28, 29 run parallel to the transverse axis 18 of the aircraft 10.

The individual jacketed propeller engines can be pivoted about these pivot axes independently of one another by servomotors, not shown. In the drawing, the jacketed propeller engines 22, 23, 25 are shown in their vertical position, in which the axis of rotation of the propeller runs vertically. The mantle propeller engine 24 is shown in Figures 1 and 2 in the horizontal position, the flight position.

With the servomotors, the jacketed propeller engines can be pivoted from the vertical position counterclockwise or clockwise by up to 90 ° - 120 ° and vice versa. This allows vector control regardless of the position of the aircraft, which can then also be aligned vertically.

In the position of the engines shown, the maximum thrust in the vertical direction is reached. This makes it possible for the aircraft to land and take off almost vertically. Furthermore, after the engines are swiveled into the flight position (horizontal position), the maximum Thrust to move quickly reached. To this extent, such an aircraft is known and therefore requires no further explanation.

With the orientations of the engines in the vertical position shown in the figures, a stable hover flight in the horizontal position of the aircraft would be possible with optimal ambient conditions and the same thrust performance of all the engines. However, such aircraft are generally used outdoors, so that the aircraft is exposed to the ambient conditions there. In particular, winds and wind gusts in particular cause problems since these have a direct effect on the floating position and must be compensated for.

It is provided here that the mantle propeller engines as a function of a yaw movement (rotation about the vertical axis 19), and / or a pitching movement (rotation about the transverse axis 18) and / or roll movement (rotation about the longitudinal axis 17) about their pivot axes be pivoted so that the movement in question is balanced. The direction of thrust is changed directly by the swiveling of the engines, so that a timely and almost immediate compensation of the movement in question can take place. This compensates for the inertia that is otherwise inherent in the jacketed propeller engines.

The aircraft 10 can comprise a controller 30 with which the required pivoting of the individual engines 22, 23, 24, 25 is effected. Means 31 for detecting the pitching movement, means 32 for detecting the rolling movement and means 33 for detecting the yaw movement can also be present. These means 31, 32, 33 can use the control 30 in such a _Z usammenwirken that the controller in Depending on the movements detected, the individual engines are pivoted accordingly. The floating position can thus be reached without manual readjustment.

For example, it can be provided that when the aircraft yaws in a clockwise direction 34 about the vertical axis 19, all of the engines 22, 23, 24, 25 are pivoted about their pivot axes in a clockwise direction. As a result, the thrust, which is otherwise directed vertically downward, is directed partially counterclockwise, so that the yaw movement is compensated for. If the yaw movement is counter-clockwise, the engines are also turned counter-clockwise. In the case of a pure yaw movement, the engines are pivoted uniformly, so that with the thrust remaining the same, there is no change in the position of the aircraft 10 up to the flight altitude.

When the aircraft 10 rolls to the right as seen in the direction of flight 36, the engines 23, 24 on the left in the direction of flight 36 are pivoted toward one another. This means that one engine 24 is pivoted clockwise and the other engine 23 counterclockwise to the same extent. This reduces the thrust in the lift direction, so that the missile lowers on the left side and the roll movement to the right is compensated for. It can be provided here that the rotational speeds of the pivoted engines 23, 24 are increased in order to maintain the flight altitude, so that the overall flight altitude is maintained. It is not relevant here that the change in speed affects the thrust only slowly. With a rolling movement to the left, the two right motors 22, 25 are pivoted accordingly. To compensate for a pitching movement 37 about the transverse axis 18 with the front end of the aircraft 10 downward, the front engines 24, 25 are rotated clockwise in such a way that the axis of rotation of the propellers of these engines have a steeper and in particular vertical profile. As a result, the lift of the aircraft 10 at its front end is increased in comparison to the lift at the rear end, so that the aircraft 10 aligns itself again in the horizontal position. Here, too, the speed of the swiveled propellers can be increased to stabilize the flight altitude.

It is obvious that such a control ensures stable hovering even under unfavorable environmental conditions. In particular, it is possible to compensate for the sudden pitching, rolling or yawing movements caused by gusts of wind or the like relatively quickly, so that a stable hover is possible.

Furthermore, the independent movement of the individual engines around their swivel axes makes it possible to move the aircraft safely up or down even in confined spaces. The aircraft can change its position in the relevant direction by pivoting the individual engines in one direction or the other. Furthermore, it is possible to keep the aircraft stable in a floating state in a position other than the horizontal position. For example, it is possible to hold the aircraft at a 45 ° angle by swiveling the engines forward or backward. Furthermore, the aircraft can fly straight ahead at low speed due to the swiveling of the engines. It is also possible to turn the aircraft on the spot. Naturally, the movements described in detail above will occur together. This means that in addition to a yaw movement, additional pitching or rolling movements can occur. The controller is therefore designed as a vector controller, so that a compensation vector can be determined from the movements detected about the axes 17, 18, 19, which can be set by correspondingly pivoting the engines. This makes it possible to keep the aircraft in a stable hover position without having to change the thrust of the individual engines. This makes it possible to use the more efficient ones

Sheathed propeller engines can also be used in aircraft such as drones.

Claims

Aircraft claims 1. Aircraft with at least four mantle propeller engines (22, 23, 24, 25), the wings assigned to them (12, 13, 14, 15) or on the fuselage (11) and arranged parallel to the transverse axis (18) pivot axis (26, 27, 28, 29) of the aircraft (10) can be pivoted, characterized in that the engines can be pivoted independently of one another about their pivot axes in such a way that a stable hover is effected. 2. Aircraft according to claim 1, characterized in that an engine (22, 23, 24, 25) starting from the vertical position for maximum lift is pivotable both forward and backward. 3. Aircraft according to claim 1 or 2, characterized in that means (31, 32, 33) for detecting the yaw movement and / or the pitching movement and / or the rolling movement of the aircraft (10) are present. 4. Aircraft according to one of claims 1 to 3, characterized in that the pivoting of the engines (22, 23, 24, 25) takes place as a function of the yaw movement and / or the pitching movement and / or the rolling movement. 5. Aircraft according to one of claims 1 to 4, characterized in that a controller (30) is present, which is a function of the detected yaw movement and / or Pitching movement and / or rolling movement causes the individual engines (22, 23, 24, 25) to pivot. 6. Aircraft according to one of claims 1 to 5, characterized in that a controller (30) is present which changes the speed of the propellers in dependence on the angular position of the engines in order to maintain the flight altitude of the aircraft. 7. Aircraft according to one of claims 1 to 6, characterized in that when the aircraft rotates (34) around the yaw axis (19) in a clockwise direction, the engines (22, 23, 24, 25) clockwise about their pivot axes (26 , 27, 28, 29) are pivoted, and vice versa. 8. Aircraft according to one of claims 1 to 6, characterized in that in the case of a detected roll movement of the aircraft about the roll axis (17) in the flight direction (36) to the right, the two left engines (23, 24) about their pivot axis (27, 28 ) can be pivoted in opposite directions to reduce the lift on the left side and vice versa. 9. Aircraft according to claim 8, characterized in that the speed of the engines is increased when compensating for the rolling movement such that the flight altitude is at least approximately maintained. 10. Aircraft according to one of claims 1 to 6, characterized in that in a detected pitching movement (37) of the missile (10) with the front part down, the two front engines (24, 25) are pivoted clockwise by a higher To cause thrust in the vertical direction. 11. Aircraft according to one of claims 1 to 6, characterized in that when a detected pitching movement of the missile with the rear part down, the two rear engines are pivoted counterclockwise in order to bring about a higher thrust in the vertical direction. 12. Aircraft according to claim 10 or 11, characterized in that the speed of the pivoted Engines is increased to at least approximately maintain the altitude.