DE102009060804A1 - Device, particularly flight controller, for controlling or stabilizing aircraft, particularly rotor aircraft or fuselage or chassis frame, by utilizing gyro effect, has rotors, where outer torque is applied vertically to rotor rotating axis - Google Patents

Abstract

The device, particularly flight controller, has rotors (1a,1b), where an outer torque is applied vertically to a rotor rotating axis. A reaction torque is generated in another axis by gyroscopic forces. The latter axis lies perpendicular to the rotor rotating axis and lies perpendicular to instantaneous rotation vector of outer rotational torque. An actuator (4a) is provided to displace a lateral center of gravity for controlling yaw axis (Z).

Description

The invention relates to a device based on rotors for aircraft, which are controlled and stabilized by means of centrifugal forces. Here, one makes use of the knowledge of the physical principle that a gyroscope changes the direction of its axis of rotation about 90 ° to an external torque vector exerted on it (precession).

Preferably, in this invention, fast rotating rotationally symmetric rotors are used, to which an external torque can be selectively applied, which then causes by precession a reaction torque in another non-parallel axis. The external torque can be realized here in different ways and with the usual force generators. These are, for example, conventional aerodynamic control surfaces, thrust vectoring but also gravity and inertial force can be used to generate the external moment.

High-speed rotors for generating propulsion or buoyancy, such as propellers or rotating cylinders, generate centrifugal forces on the aircraft, which are perceived as disturbing. For example, a rotation about the aircraft transverse axis (pitching motion) by the gyroscopic forces of a pusher propeller causes a yawing moment and thus a yawing motion. The dynamics of the yawing motion depend on the angular momentum of the thrust propeller and, for example, an elevator initiated pitching moment. Even with rotor aircraft, ie aircraft with rotors to generate the buoyancy by the Magnus effect, precession was previously seen as a problem, for which measures were provided to reduce the centrifugal forces. In the published patent application DE 3804415 A1 an aerodynamic control surface (ailerons) is proposed, which should override the centrifugal forces occurring. In particular, attention is drawn here to the low controllability in slow flight and proposed as a solution, the arrangement of aerodynamic control surfaces in the propeller jet. A disadvantage of this solution would show a reduced controllability in landing approach with reduced propeller thrust. For controlling the yawing motion, a conventional rudder is proposed in this publication.

In general one can say that in aviation with few exceptions centrifugal forces are not used. An exception is the use of a gyroscope in cockpit instruments for air navigation. In aerospace, however, gyros are used to stabilize and control spacecraft, for example, a speed change of a flywheel can be used to change the position. The application of external torques by an aerodynamic force or by a weight force is not possible in classic spacecraft outside an atmosphere and at a great distance from celestial bodies.

Furthermore, it should be mentioned that for the stabilization of aircraft in the classical teaching a state variable such as a rolling speed with sensors measured and fed to a control system which calculates a control variable as a function of a deviation from the target state, such as an aileron deflection by a Actuator is then set. As a result, vibrations of the aircraft can be damped.

The object of the invention is to design a controller according to the preamble of patent claim 1 such that aircraft with rotors can be effectively controlled and stabilized by utilizing centrifugal forces in the entire speed range.

According to the invention the object is achieved by a flight control with the features of claim 1. Accordingly, in a generic control by the application of an external torque perpendicular to a rotor axis of rotation caused by centrifugal forces a reaction torque in another axis, which is perpendicular to the rotor axis and perpendicular to the rotational vector of the external torque. By this way of utilizing the gyro effect, it is now possible to stabilize and control an aircraft equipped with rotors without, as previously reported, anticipating negative effects such as wobbling or unwanted persistence in attitude.

The application of external torques to a rotor can be generated by aerodynamic forces or inertial forces. Aerodynamic forces can be applied here by rudder deflections but also by thrust vector control. Particularly advantageous is the utilization of the weight for generating an external torque, since it acts independently of an air flow and thus can be used even at low speeds or levitation.

A flight control according to the invention comprises at least one rotor whose flywheel mass can be used in the form of centrifugal forces and at least one torque generator which applies an external torque to this rotor.

Flight tests with a rotor flight model, whose lift is generated by two so-called Flettner rotors, showed that a lateral displacement of the center of gravity led to a yaw moment. The same was the case when one of the two Flettner rotors was operated at a different target speed, and thus induced different buoyancy forces per rotor a rolling moment, which led to a yaw motion. These experiences led to the idea to use centrifugal forces targeted to control an aircraft.

• – ein konventionelles Seitenruder zur Rollsteuerung zu verwenden.
• – ein konventionelles vertikal angebrachtes Querruder zur Giersteuerung zu verwenden.
• – eine laterale Schwerpunktsverschiebung zur Giersteuerung zu verwenden.
• – mindestens einen Rotor durch asymmetrisches Anströmen mit Hilfe mindestens eines Propellers zur Roll- oder Giersteuerung zu verwenden.
• – mindestens zwei Rotoren mit unterschiedlicher Drehzahl zur Roll- oder Giersteuerung zu verwenden.

As preferred embodiments of the invention it is proposed:

• - To use a conventional rudder for roll control.
• - To use a conventional vertically mounted aileron for yaw control.
• To use a lateral center of gravity shift for yaw control.
• - To use at least one rotor by asymmetric flow using at least one propeller for roll or yaw control.
• - To use at least two rotors with different speeds for rolling or yaw control.

Furthermore, it is proposed to combine the flight control according to the invention with a conventional flight control for the longitudinal movement.

For the Queranströmung the rotating cylinder each type of blower can be used, so z. As a propeller blower or an axial fan in the manner of a so-called fan, as it comes in modern jet engine aircraft used. Even cross-flow fans or the use of beating wings can be used as a blower.

Furthermore, it is proposed to use a digital flight control, based on sensors for detecting the state of flight and actuators for applying the external torques on rotors. When designing the digital flight control, the centrifugal forces must be taken into account. Similar to the derivatives for aerodynamic roll-yaw couplings, derivatives for the gyroscopic forces can be introduced into the flight mechanics model, and based thereon a flight controller can be designed.

The flight control according to the invention is suitable for use in all types of aircraft, provided they are equipped with rotating bodies of revolution, whereby an angular momentum can be used. Particularly advantageously, the flight control according to the invention can be used in rotor aircraft, in which the rotors are used for lift generation.

Reference to the accompanying drawings, embodiments of the invention will be explained. The illustrated aircraft should mean no restrictions in the variety of configurations. They can be supplemented with conventional components of an aircraft such as a fuselage, a landing gear, etc.

In the drawings shows

1 A first embodiment according to the invention of a controller for an aircraft with two rotors ( 1a . 1b ) and one by an actuator ( 4a ) laterally displaceable weight ( 5 ) for controlling the yaw axis (Z).

2 1 shows a further embodiment of a controller for an aircraft with two rotors (FIG. 1a . 1b ) and a rudder ( 6 ) actuated by an actuator ( 4b ) for generating an aerodynamic yawing moment (N) for controlling the roll axis (X).

3 1 shows a further embodiment of a controller for an aircraft with two rotors (FIG. 1a . 1b ) and an aileron ( 8th ) actuated by one or two actuators ( 4c ) for generating an aerodynamic rolling moment (L) for controlling the yaw axis (Z).

4 a further embodiment of a controller for an aircraft with two propellers ( 7a . 7b ) for changing the flow velocity of the rotors ( 1a . 1b ) And thus their aerodynamic forces to generate torques about the roll axis (X) and / or yaw axis (Z). The ratio of the rotational speeds ( 10a . 10b ) to the flow velocity through the propeller ( 7a . 7b ) determines the size and direction of the rolling moment (L) and the yawing moment (N).

This in 1 schematically represented aircraft comprises two rotors 1a and 1b by a drive unit 2 be set in rotation. The directions of rotation 10a and 10b the rotors are chosen in the same direction. The main axes of the aircraft are a longitudinal axis or roll axis X, a transverse axis Y and a vertical axis or yaw axis Z. When the aircraft moves in the positive X direction, the rotors generate 1a and 1b the necessary buoyancy for a horizontal flight. An embodiment according to the invention consists of a drive unit 2 , a joint 3 , a crowd 5 , an actuator 4a and the rotors 1a . 1b , At the joint 3 is a crowd 5 attached via an actuator 4a that is attached to the drive unit 2 is attached, can be deflected laterally. The mass in deflected position 5 * is drawn with a dashed line. The weight of the mass 5 * works in the deflected position as an external torque on the rotors 1a . 1b , Due to the centrifugal forces of the rotors 1a and 1b However, no rolling moment L but a yawing moment N is exercised and this leads to a yaw motion about the yaw axis Z.

This in 2 schematically illustrated aircraft includes in addition to the two rotors 1a and 1b by a drive unit 2 be set in rotation, one on the drive unit 2 attached rudder 6 , which by an actuator 4b can be knocked out. This rash builds up an aerodynamic moment about the vertical axis Z, which acts as an external torque on the rotors 1a and 1b acts. Due to the centrifugal forces of the rotors 1a and 1b However, no yaw moment N but a rolling moment L is exercised and this leads to a rolling movement about the roll axis X.

This in 3 schematically illustrated aircraft includes in addition to the two rotors 1a and 1b by a drive unit 2 be set in rotation, one on the drive unit 2 attached aileron 8th , which is powered by two actuators 4c can be knocked out. The asymmetric deflection creates an aerodynamic moment about the longitudinal axis X, which acts as external torque on the rotors 1a and 1b acts. Due to the centrifugal forces of the rotors 1a and 1b However, no rolling moment L but a yawing moment N is exercised and this leads to a yawing motion about the vertical axis Z.

This in 4 schematically illustrated aircraft includes in addition to the two rotors 1a and 1b by a drive unit 2 be set in rotation, two on the drive unit 2 attached propellers 7a and 7b , These propellers can be used not only to generate a propulsive force, but also by different speed an asymmetric flow of the rotors 1a and 1b produce. This leads to different dynamic pressure on the cylindrical rotors and thus to different sized aerodynamic forces such as buoyancy and resistance. Depending on the ratio of the rotational speed of the rotors 1a and 1b to the flow velocities through the propellers 7a and 7b Act different outer torques (in direction and strength) in the roll axis X and in the yaw axis Z, which lead to a yaw and / or rolling motion. The non-linear characteristic of the rotating cylinders as aerodynamic bodies can be found in the literature and their knowledge is required for the successful design of a flight control according to the invention. This in 4 illustrated aircraft is also alone by different speeds of the rotors 10a . 10b controllable about the yaw axis Z and the roll axis X. These speeds must be calculated depending on the flight condition and the required roll or yaw command and on the drive unit 2 be set.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3804415 A1 [0003]

Claims (11)

Device based on rotors for controlling and / or stabilizing aircraft, in particular rotor aircraft, characterized in that the application of an external torque perpendicular to the rotor axis, by centrifugal forces causes a reaction torque in another axis perpendicular to the rotor axis and perpendicular to the Rotational vector of the external torque is. Flight control according to claim 1, characterized in that a lateral center of gravity displacement by an actuator ( 4a ) is used to control the yaw axis (Z). Flight control according to one or more of the preceding claims, characterized in that a speed difference ( 10a . 10b ) between at least two or more rotors ( 1a . 1b ) is used to control the yaw axis (Z). Flight control according to one or more of the preceding claims, characterized in that an aerodynamic yawing moment (N) due to a rudder deflection ( 6 ) is used to control the roll axis (X). Flight control according to one or more of the preceding claims, characterized in that an aerodynamic rolling moment (L) due to a Querruderausschlags ( 8th ) is used to control the yaw axis (Z). Flight control according to one or more of the preceding claims, characterized in that an aerodynamic yaw moment (N) due to an asymmetric blowing at least one or more rotors ( 1a . 1b ) with the help of one or more blowers ( 7a . 7b ) is used to control the roll axis (X). Flight control according to one or more of the preceding claims, characterized in that an aerodynamic rolling moment (L) due to an asymmetric blowing at least one or more rotors ( 1a . 1b ) with the help of one or more blowers ( 7a . 7b ) is used to control the yaw axis (Z). Flight control according to one or more of the preceding claims, characterized in that it is combined with a conventional device for controlling aircraft. Flight control according to one or more of the preceding claims, characterized in that with the aid of an electronic unit control commands are calculated and to actuators ( 4a . 4b . 4c ) or to a drive unit ( 2 ) for controlling the rotational speeds of rotors ( 1a . 1b ) and / or propellers ( 7a . 7b ) to get redirected. Flight control according to one or more of the preceding claims, characterized in that for stabilizing the aircraft, state variables of the rolling movement about the roll axis (X) are measured and processed in a system, whereby then, for example, by an actuator ( 4b ) generates a yaw moment (N) and thus a stabilization of an aircraft in the roll axis (X) is achieved. Flight control according to one or more of the preceding claims, characterized in that for stabilizing the aircraft, state variables of the yawing motion about the yaw axis (Z) are measured and processed in a system, whereby then, for example, an actuator ( 4a ) generates a rolling moment (L) and thus a stabilization of an aircraft in the yaw axis (Z) is achieved.

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