FR3161411A1 - Aircraft with yaw management system and yaw management method - Google Patents

Abstract

Aircraft with yaw management system and yaw management method Aircraft 1 with vertical takeoff comprising at least one pair of wings, at least one horizontal thruster 3, vertical thrusters 5 arranged in the wings, said vertical thrusters 5 being configured to generate vertical thrust, a control surface 7 blown by said at least one horizontal thruster 3 and a control system arranged to receive instructions and thrust data, and to generate downstream commands to the horizontal thruster 3, to the vertical thrusters 5 and to the control surface 7, the control system comprising a controller arranged to convert the instructions into upstream control instructions, a yaw sensor arranged to determine data representative of the yaw of the aircraft 1, an input of data representative of the speed of the aircraft 1, and a computer arranged to receive the upstream control instructions, the data representative of the yaw and the speed data, the computer being arranged to generate downstream horizontal propulsion commands to horizontal thruster 3, downstream vertical thruster commands to vertical thrusters 5 and downstream rudder commands to rudder 7, the computer being arranged to determine yaw correction components for at least one downstream vertical thruster command.

Description

Aircraft with yaw control system and yaw control method

The invention relates to the field of vertical takeoff aircraft, more particularly to the field of electrically powered aircraft.

The aeronautics sector is currently undergoing significant changes, partly due to evolving environmental requirements and partly due to the development of electrically powered aircraft. In particular, the VTOL (Vertical Take-Off and Landing) sector is especially dynamic, offering very promising prospects as a new mode of transportation.

The field of VTOLs is quite old (VTOLs were developed as early as 1921), but their electrification has spurred a proliferation of new solutions, particularly hybrid-powered VTOLs. An example of a VTOL is described in FR 3134562. The advantages of this electric propulsion system include increased efficiency, reduced emissions, and greater flexibility in power management.

VTOL aircraft include horizontal propulsion for the flight phase and vertical propulsion for takeoff and landing. Horizontal and vertical propulsion are achieved by propulsion systems, including electric ones.

VTOL aircraft are sensitive to aerodynamic torques that induce yaw, specifically a vertical axis torque. Unwanted yaw movements are the source of various problems, including unwanted trajectory changes. Therefore, several methods exist for yaw correction.

On conventional aircraft, yaw is corrected by changing the orientation of a rudder mounted at the rear of the aircraft.

Some VTOL aircraft have yaw correction systems using thrusters inclined at different angles or tiltable to generate yaw correction torque. The varying angles result in a loss of power. Tiltable thrusters are heavy.

The Applicant sought to correct the unwanted yaw of the VTOLs by retaining mechanical propulsion and orientation components dedicated to these effects.

The invention improves the situation. To this end, it proposes a vertical takeoff aircraft comprising at least one pair of wings, at least one horizontal thruster, vertical thrusters arranged in the wings, said vertical thrusters being configured to generate vertical thrust, a rudder blown by said at least one horizontal thruster and a control system arranged to receive piloting instructions and thrust data, and generate downstream commands to the horizontal thruster, the vertical thrusters and the rudder.

The control system includes a control unit arranged to convert pilot instructions into upstream control instructions.

The control system includes a yaw sensor arranged to determine data representative of the aircraft's yaw.

The control system includes an input of data representative of the aircraft's speed.

The control system includes a computer configured to receive upstream control commands, yaw data, and airspeed data. The computer is configured to generate downstream horizontal thrust commands to the horizontal thruster, downstream vertical thruster commands to the vertical thrusters, and downstream rudder commands to the rudder. The computer is configured to determine yaw correction components for at least one downstream vertical thruster command.

In one embodiment, the computer is arranged to further determine yaw correction components for at least one of the downstream horizontal propulsion controls and the downstream rudder controls. The available power of the vertical thrusters, when present, can be used, while the rudder can be actuated in case of vertical thruster saturation.

In one embodiment, the computer is arranged to determine an angular data matrix from the upstream control instructions. Yaw correction is robust.

In one embodiment, the computer is arranged to receive representative yaw data and aircraft speed data and to process representative yaw data and aircraft speed data in such a way as to determine aircraft state data, the computer being arranged to compare the state data and the angular data matrix.

In one embodiment, the calculator includes a controller arranged to determine yaw correction torques as a function of state data and angular data matrix.

In one embodiment, the computer is configured to allocate a first yaw correction torque for the vertical propulsion controls and a second yaw correction torque for the rudder controls, the allocation depending on a threshold that varies according to flight conditions, vertical thruster saturation, maximum rudder orientation, and current horizontal thruster power. The yaw correction offers considerable flexibility.

In one embodiment, the computer is configured to determine a force matrix upstream of the determination of the downstream commands, the force matrix including a yaw correction torque.

In one embodiment, the computer is arranged to determine the downstream commands of the vertical thrusters, differentiated for each of the vertical thrusters. The aircraft is stable.

In one embodiment, the computer is configured to receive representative pitch and roll data of the aircraft, and is configured to determine pitch and roll correction components for the downstream controls of the vertical thrusters. Pitch and roll are also corrected in a coordinated manner.

In one embodiment, the control system includes coupled control of the horizontal thruster, vertical thrusters, and rudder based on representative pitch and roll data, representative yaw data, and representative airspeed data, in order to correct induced pitch, roll, and yaw moments. The vertical thrusters furthest from the yaw axis can be used primarily for yaw correction.

In one embodiment, a method for correcting the yaw of an aircraft comprising the following operations: receiving piloting instructions, converting the piloting instructions into upstream control commands, receiving representative yaw data, determining aircraft state data, determining, using a controller, a yaw correction torque, decomposing the yaw correction torque into a first yaw correction torque and a second yaw correction torque, converting the first yaw correction torque into a first yaw correction component and converting the second yaw correction torque into a second yaw correction component, when the value of the correction torque exceeds a threshold, converting the first yaw correction component into vertical thruster power, converting the second yaw correction component into a rudder heading value, providing the vertical thruster power to the computer in order to generate downstream vertical thruster commands, providing the rudder heading value to the computer in order to generate downstream rudder commands.

In one embodiment, a computer program includes instructions for implementing the device or for executing the process when said computer program is run on a computer.

In one embodiment, a data storage medium on which the computer program is recorded.

Other features and advantages of the invention will become clearer upon reading the following description, drawn from illustrative and non-limiting examples taken from the drawings shown:

FIG. 1 is a perspective view of a VTOL according to an embodiment of the invention.

FIG. 2 is a block diagram of the control system according to one embodiment of the invention.

FIG. 3 is a block diagram of the computer according to another embodiment of the invention.

FIG. 4 is a block diagram of the computer according to another embodiment of the invention.

FIG. 5 is a block diagram of the computer according to another embodiment of the invention.

FIG. 6 is a process diagram according to an embodiment of the invention.

The drawings and description below contain, for the most part, elements of a definite nature. They can therefore not only serve to better explain the present invention, but also contribute to its definition, if necessary.

As illustrated on the FIG. 1 An aircraft 1 according to one aspect of the invention comprises at least one pair of wings, here two pairs of wings. Aircraft 1 includes a fuselage, a pair of forward wings, and a pair of rear wings. Alternatively, a flying wing is provided.

Aircraft 1 includes horizontal propulsion and vertical propulsion.

Horizontal propulsion is achieved by at least one horizontal propulsion system 3, in particular an engine equipped with a propeller. Here, aircraft 1 comprises two horizontal propulsion systems 3, one mounted in a forward position on the nose of aircraft 1, the other mounted in a high position on aircraft 1.

Vertical propulsion is achieved by a plurality of 5 vertical thrusters. Each of the 5 vertical thrusters comprises a rotor driven by a motor. The 5 vertical thrusters have a fixed rotor axis.

The vertical thrusters 5 are designed to generate vertical thrust, primarily to enable aircraft 1 to take off and land. Here, the vertical thrusters 5 are located in at least part of the wings of aircraft 1. The vertical thrusters 5 may also be located on or under other parts of aircraft 1, including the fuselage.

Here, the horizontal thrusters 3 and the vertical thrusters 5 are electric. Alternatively, the horizontal thrusters 3 are thermal.

An orthogonal frame of reference allows us to define the movements of aircraft 1. The orthogonal frame of reference includes a vertical Z axis, an X axis along a direction of movement of aircraft 1 during its flight phase and a Y axis, orthogonal to the X and Z axes. The orthogonal frame of reference includes the XY, XZ and YZ planes.

Aircraft 1 rotates using three rotational movements. A rotation of aircraft 1 around the X-axis is called roll. A rotation of aircraft 1 around the Y-axis is called pitch. A rotation of aircraft 1 around the Z-axis is called yaw. Pitch allows the longitudinal attitude of aircraft 1 to be changed. Yaw and roll allow aircraft 1 to turn relative to its initial flight direction, the X-axis. Yaw, roll, and pitch can be desired by a pilot. Yaw, roll, and pitch can also be involuntary movements of aircraft 1.

Aircraft 1 includes a rudder 7. The rudder 7 is located at the rear of aircraft 1. The rudder 7 pivots about a fin supporting said rudder 7. During a straight and level flight phase of aircraft 1, the rudder 7 is aligned with an airflow circulating from front to back around aircraft 1. The airflow is generated in part by the movement of aircraft 1 relative to its external environment. Here, at least one of the horizontal thrusters 3 is capable of generating an airflow around the rudder 7. The horizontal thruster 3 in the raised position includes a propeller mounted upstream of the rudder 7 in the direction of the airflow. This propeller sweeps a surface located in front of a portion of the rudder 7. This propeller generates air streams that interact with the rudder 7. The horizontal thruster 3 can be mounted at the top of the fin.

Thus, the airflow around control surface 7 includes the airflow related to the movement of aircraft 1 and the airflow generated by the horizontal thruster 3. The orientation of control surface 7 allows aircraft 1 to yaw. When the orientation of control surface 7 changes, a low-pressure area is created on one side of the control surface 7 and a high-pressure area on the other side. This generates an aerodynamic yaw moment about the Z-axis. Aircraft 1 rotates about the Z-axis.

Aircraft 1 includes ailerons 8 on the wings whose differential orientation generates a roll of aircraft 1. The ailerons 8 are arranged on a trailing edge of the front wing pair and the rear wing pair.

Aircraft 1 includes at least one elevator 10, the orientation of which enables pitching of aircraft 1. The elevator 10 is pivotally mounted relative to the top of the fin to form a movable stabilizer or relative to a stabilizer rigidly fixed to the top of the fin. Aircraft 1 may include actuators for controlling the orientation of the control surface 7, the ailerons 8, and the elevator 10. Like the control surface 7, the elevator 10 is blown by the horizontal thruster 3 in its raised position. The elevator 10 may include several parts on either side of the longitudinal axis. In other words, the elevator 10 may include an upstream portion hinged to a frame of the aircraft and a downstream portion hinged to the upstream portion.

The pilot of aircraft 1 provides flight instructions 100 to aircraft 1 via a cockpit 9. The cockpit 9 includes at least one steering wheel or joystick 11, pedals 13, at least one horizontal propulsion power lever 15 and at least one vertical propulsion power lever 17. Alternatively, the flight instructions 100 are determined and provided by a piloting device, for drones for example, receiving instructions via radio waves or following a trajectory determined or calculated in real time.

The pilot provides pitch instructions 101 and roll instructions 102 via control stick 11. The pilot provides yaw instructions 103 via the pedals 13. Alternatively, the pilot provides yaw instructions 103 via control stick 11 or a second control stick. The pilot provides horizontal thrust instructions 104 via the horizontal thrust power lever 15 or one of the two control sticks. The pilot provides vertical thrust instructions 105 via the vertical thrust power lever 17. The piloting instructions 100 include pitch instructions 101, roll instructions 102, yaw instructions 103, horizontal thrust instructions 104, and vertical thrust instructions 105.

Aircraft 1 includes a control system 21 illustrated in FIG. 2 . The control system 21 allows, in particular, the correction of the yaw of aircraft 1 which is not desired by the pilot.

During takeoff, landing and flight phases, aircraft 1 may be subjected to lateral moments causing unwanted yaw movement, particularly in the case of crosswinds.

In Figures 2 and 3, the functional links related to yaw correction are represented by solid lines. The other, optional links are represented by dashed lines.

The control system 21 includes a control element 19. The control element 19 is configured to receive at least the vertical propulsion instructions 105 from the vertical propulsion power lever 17. Here, the control element 19 receives the pitch instructions 101, the roll instructions 102, the yaw instructions 103 and the horizontal propulsion instructions 104. The control element 19 is configured to generate upstream control commands 200 from the piloting instructions 100. The upstream control commands 200 can be provided directly to the actuators or provided via management systems, such as power management or fault management systems.

The control unit 19 is configured to generate pitch commands 201, roll commands 202, yaw commands 203, horizontal propulsion commands 204 and vertical propulsion commands 205.

The control system 21 includes a yaw sensor for aircraft 1. The yaw sensor is configured to determine and provide representative yaw data 301 for aircraft 1. The representative yaw data 301 can be angular position data for aircraft 1 in the XY plane and/or angular velocity data for aircraft 1 about the Z-axis. The representative yaw data 301 corresponds to an actual angular position of aircraft 1 relative to a fictitious position of aircraft 1 defined by the yaw commands 103.

Aircraft 1 includes a computer 25. Computer 25 is configured to receive upstream control instructions 200, namely pitch instructions 201, roll instructions 202, yaw instructions 203, horizontal propulsion instructions 204 and vertical propulsion instructions 205. Computer 25 is further configured to receive representative yaw data 301, speed data 303 of aircraft 1 and, where applicable, representative pitch and roll data 302, in particular provided by a pitch and roll sensor.

The computer 25 can include an input for aircraft speed data 303 from aircraft 1. The speed data 303 can be measured by a speed sensor. The speed sensor can be, for example, a Pitot tube and a static pressure port.

Representative yaw data 301, and where appropriate representative pitch and roll data 302, can be provided to computer 25 by an inertial or gyroscopic unit.

Pitch can be corrected by the elevator 10 and/or by the vertical thrusters 5. Roll can be corrected by the ailerons 8 and/or by the vertical thrusters 5.

Yaw can be corrected by the vertical thrusters 5, the horizontal thruster 3 and/or the rudder 7. Yaw correction can be carried out by one of the vertical thrusters 5, the horizontal thruster 3 and the rudder 7, or two of the vertical thrusters 5, the horizontal thruster 3 and the rudder 7 or even the vertical thrusters 5, the horizontal thruster 3 and the rudder 7.

Computer 25 is arranged to process upstream control instructions 200, yaw data 301, aircraft speed data 303, and, where applicable, pitch and roll data 302, in order to determine downstream controls 400. Computer 25 is arranged to provide the downstream controls 400 to the horizontal thruster 3, the vertical thrusters 5, the rudder 7, the ailerons 8, and the elevator 10. The downstream controls 400 include downstream horizontal thruster controls 404, downstream vertical thruster controls 405, downstream rudder controls 407, downstream aileron controls 408, and downstream elevator controls 410.

The downstream commands 400 each comprise a primary component and one or more correction components. The primary component corresponds to the component determined by the computer 25 to respond to the upstream command instructions 200. The correction components are calculated by the computer 25 to correct a yaw, roll, or pitch unwanted by the pilot.

The components of each downstream control 400 correspond to a portion of the downstream control 400 dedicated to a specific function. The primary components correspond to the downstream control portions responding to the piloting instructions 100. The correction components correspond to the downstream control portions used to correct unwanted yaw, and possibly unwanted pitch and roll.

The downstream controls of the vertical thrusters 405 may include a main component 405P determined from the vertical propulsion instructions 205. The downstream controls of the vertical thrusters 405 may include yaw correction components 405L, roll correction components 405R and pitch correction components 405T.

The downstream controls of the vertical thrusters 405 may include different downstream controls for each vertical thruster 5. Since the downstream controls of each vertical thruster 5 are distinct from one another, the vertical propulsion is then differential. The differential vertical propulsion is determined to generate yaw, roll, and pitch correction torques.

The downstream rudder controls 407 may include a main component 407P and yaw correction components 407L.

Calculator 25 is detailed in FIG. 3 , 4 and 5 according to three modes of embodiment.

The computer 25 is configured to receive representative yaw data 301, speed data 303 of aircraft 1, and, where applicable, representative pitch and roll data 302. The computer 25 includes an input of representative yaw data 301, speed data 303 of aircraft 1, and, where applicable, representative pitch and roll data 302, forming state data 304 of aircraft 1 at a given time. The state data 304 allows the calculation of position, linear velocity, angular velocity, linear acceleration, and angular acceleration.

Computer 25 is arranged to receive and process pitch commands 201, roll commands 202, yaw commands 203, horizontal propulsion commands 204 and vertical propulsion commands 205.

Based on the pitch commands 201, roll commands 202, and yaw commands 203, the computer 25 is configured to determine an angular data matrix 300. The angular data matrix 300 may include angles to define or define a desired angular position of the aircraft 1. The angular data matrix 300 may include angular velocities. The angular data matrix 300 includes a yaw component, a pitch component, and a roll component.

The computer 25 includes a comparator 900 arranged to receive and compare the angular data matrix 300 and the state data 304 of aircraft 1. The comparator 900 is arranged to provide the compared data to a controller 910. The controller 910 may be a PID controller. The controller 910 is arranged to determine a yaw correction torque 503 and optionally a roll correction torque 501 and a pitch correction torque 502.

Computer 25 is arranged to convert the vertical propulsion commands 205 into the principal component 405P by means of a converter 801. Computer 25 is arranged to determine a force matrix 600 for the vertical thrusters 5 from the roll correction torque 501, the pitch correction torque 502, and the principal component 405P of the downstream commands for the vertical thrusters 405. Computer 25 is arranged to convert the forces from the force matrix 600 into at least the first powers 701 dedicated to each vertical thruster 5.

Computer 25 is configured to decompose the yaw correction torque 503 to determine a first yaw correction torque 503a and a second yaw correction torque 503b. Computer 25 is configured to convert the first yaw correction torque 503a into yaw correction components 405L for the vertical thrusters 5 using a converter 803a. Optionally, computer 25 is configured to convert the second yaw correction torque 503b into yaw correction components 407L for the control surface 7 using a converter 803b. A distribution law may be provided. Computer 25 is arranged to convert the yaw correction components 405L of the vertical thrusters 5 into second powers 702 dedicated to each vertical thruster 5 by a converter 806. Computer 25 can be arranged to convert the yaw correction components 407L of the rudder 7 into a rudder 7 orientation value.

The first powers 701 translate the piloting instructions 100. The second powers 702 translate the yaw correction, and, where applicable, the pitch and roll correction.

The computer 25 is arranged to determine the downstream commands of the vertical thrusters 405 from the first powers 701 and the second powers 702 by a converter 805.

The computer 25 can be arranged to determine the downstream rudder controls 407 from the main component 407P of the downstream rudder controls 407 and the yaw correction components 407L of the rudder 7 by a converter 807.

The computer 25 can be arranged to receive the horizontal propulsion instructions 204 and convert them to obtain the downstream horizontal thruster commands 404 by a converter 804.

Computer 25 can be arranged to receive pitch commands 201 and roll commands 202 and convert them to obtain downstream aileron commands 408 and downstream elevator commands 410.

Yaw correction method, cf. FIG. 6

• recevoir 1001 les instructions de pilotage 100 ,
• convertir 1002 les instructions de pilotage 100 en consignes de commande amont 200,
• recevoir 1003 les données représentatives du lacet 301,
• déterminer 1004 des données d’état 304 de l’aéronef 1
• déterminer 1005, à l’aide d’un correcteur, notamment PID, le couple de correction de lacet 503 à partir de données d’état 304 de l’aéronef 1 et des consignes de commande amont 200,
• décomposer 1006 le couple de correction de lacet 503 en un premier couple de correction de lacet 503a et un deuxième couple de correction de lacet 503b,
• convertir 1007 le premier couple de correction de lacet 503a en une première composante de correction de lacet 405L et convertir le deuxième couple de correction de lacet 503b en une deuxième composante de correction de lacet 407L, lorsque la valeur du couple de correction dépasse un seuil,
• convertir 1008 la première composante de correction de lacet 405L en puissance 702 de propulseurs verticaux 5,
• convertir 1009 la deuxième composante de correction de lacet 407L en valeur d’orientation de la gouverne 7,
• fournir 1010 la puissance 702 au au calculateur 25 afin de générer des commandes aval de propulseurs verticaux 405,
• fournir 1011 la valeur d’orientation de la gouverne 7 au calculateur 25, afin de générer des commandes aval de gouverne 407.

To correct the unwanted yaw of aircraft 1, the control system 21 performs the following operations:

• receive 1001 flight instructions 100,
• convert pilot instructions 1002 into upstream control instructions 200,
• receive 1003 representative data for loop 301,
• determine 1004 of the aircraft's 304 status data 1
• determine 1005, using a controller, in particular PID, the yaw correction torque 503 from aircraft 1 state data 304 and upstream control instructions 200,
• Decompose the yaw correction pair 503 into a first yaw correction pair 503a and a second yaw correction pair 503b,
• convert the first yaw correction torque 503a into a first yaw correction component 405L and convert the second yaw correction torque 503b into a second yaw correction component 407L, when the correction torque value exceeds a threshold,
• convert 1008 the first yaw correction component 405L into 702 power of 5 vertical thrusters,
• convert 1009, the second yaw correction component 407L, into a rudder orientation value of 7.
• supplying 1010 the power 702 to the computer 25 in order to generate downstream commands for vertical thrusters 405,
• provide 1011 the orientation value of the rudder 7 to the computer 25, in order to generate downstream rudder commands 407.

To correct the yaw, calculator 25 performs the following steps:
1. Determine the target angular position of aircraft 1 from flight instructions 100.
2. Determine the actual angular position of aircraft 1 from the representative yaw data 301, the speed data 303 and, where applicable, the representative pitch and roll data 302.
3. Determine the yaw correction pairs using a controller, in particular PID.
4. Determine a 600 effort matrix.
5. Allocate a correction torque to each vertical thruster 5, to the horizontal thruster 3 and to the rudder 7.
6. Convert the correction torques into dedicated power for each vertical thruster 5 and/or into power for the horizontal thruster 3 and/or into orientation for the rudder 7.
7. Provide downstream correction commands.

The control unit 19 converts the piloting instructions 100, in particular the yaw instructions 103, into upstream control instructions 200. The control unit 19 provides the computer 25 with the upstream control instructions 200, and more specifically the pitch instructions 201, the roll instructions 202, the yaw instructions 203, the horizontal propulsion instructions 204 and the vertical propulsion instructions 205.

Computer 25 receives the yaw data 301, the speed data 303 of aircraft 1 and, where applicable, the pitch and roll data 302. Computer 25 converts the yaw data 301, the speed data 303 of aircraft 1, and, where applicable, the pitch and roll data 302 and determines the state data 304 of aircraft 1.

The computer 25 determines the objective angular position of the aircraft 1 from the pitch commands 201, the roll commands 202 and the yaw commands 203 from the control unit 19 in order to form the angular data matrix 300.

The angular data matrix 300 can include angles to define a desired angular position of aircraft 1. The angular data matrix 300 can include angular velocities.

The comparator 900 receives and compares the angular data matrix 300 and the state data 304 of aircraft 1. The comparator 900 provides the comparison data to the corrector 910.

Computer 25 also receives horizontal propulsion commands 204 and vertical propulsion commands 205. Computer 25 converts the vertical propulsion commands 205 into a main component 405P of the vertical thrusters 5.

In a first embodiment, illustrated in FIG. 3 , the yaw correction of aircraft 1 is achieved by the vertical thrusters 5 alone.

The corrector 910 determines the roll correction torque 501, the pitch correction torque 502 and the yaw correction torque 503. The calculator 25 determines the force matrix 600 of the vertical thrusters 5 from the roll correction torque 501, the pitch correction torque 502 and the main component 405P of the vertical thrusters 5.

From the effort matrix 600 and the yaw correction torque 503, the calculator 25 determines the first powers 701 and the second powers 702.

Computer 25 receives the first powers 701 and the second powers 702. Computer 25 processes the first powers 701 and the second powers 702 in order to determine the downstream commands of the vertical thrusters 405.

Computer 25 provides the downstream commands of the vertical thrusters 405 to the vertical thrusters 5.

Computer 25 determines the downstream rudder commands 407 from the yaw component of the angular data matrix 300.

Computer 25 provides the downstream control commands from control 407 to control 7. In this embodiment, the yaw of aircraft 1 can also be manually corrected by the pilot via control 7.

In a second embodiment, illustrated in FIG. 4 , the yaw correction of aircraft 1 is achieved by the rudder 7 alone.

The computer 25 determines the objective angular position of the aircraft 1 from the pitch commands 201, the roll commands 202 and the yaw commands 203 from the control unit 19 in order to form the angular data matrix 300.

The angular data matrix 300 can include angles to define a desired angular position of aircraft 1. The angular data matrix 300 can include angular velocities.

In addition, the computer 25 receives representative yaw data 301 from the yaw sensor 23. The computer 25 also receives horizontal propulsion commands 204 and vertical propulsion commands 205. The computer 25 converts the vertical propulsion commands 205 into a main component 405P of the vertical thrusters 5.

The calculator 25 processes the compared data from the comparator 900, via the corrector 910 in order to determine the yaw correction torque 503 and, where applicable, the roll correction torque 501 and the pitch correction torque 502.

Calculator 25 determines the force matrix 600 of the vertical thrusters 5 from the roll correction torque 501, the pitch correction torque 502 and the main component 405P of the vertical thrusters 5.

Calculator 25 determines the first powers 701 from the effort matrix 600.

Computer 25 receives the first powers 701. Computer 25 converts the first powers 701 into downstream commands of the vertical thrusters 405 by the converter 805.

Computer 25 provides downstream commands from vertical thrusters 405 to vertical thrusters 5 in order to correct roll and pitch.

From the yaw correction couple 503, the calculator 25 determines the yaw correction components 407L of the rudder 7.

Computer 25 receives the main component 407P of the downstream rudder commands 407 and the yaw correction components 407L of the rudder. Computer 25 processes the main component 407P of the downstream rudder commands 407 and the yaw correction components 407L of the rudder 7 in order to determine the downstream rudder commands 407.

Computer 25 provides the downstream rudder commands 407 to rudder 7.

Alternatively, computer 25 determines the yaw correction components of the horizontal thruster 3. These yaw correction components correspond to a variation in the horizontal propulsion power. From the yaw correction torque 503, computer 25 determines the yaw correction components 407L at the rudder 7 and the yaw correction components of the horizontal thruster 3.

In a third embodiment illustrated in FIG. 5 , the yaw correction of aircraft 1 is achieved by a combination of the effect of the rudder 7 with the effect of the horizontal thruster 3.

Yaw correction may require significant vertical propulsion power. If the required yaw correction torque is high, the vertical thrusters 5 may saturate, particularly during takeoff and landing phases when they are under considerable stress. Furthermore, at low speeds, the yaw correction effect of the control surface 7 may be limited. Therefore, it is advantageous to design corrections with limitations that are significantly different in flight regimes.

The computer 25 determines the objective angular position of the aircraft 1 from the pitch commands 201, the roll commands 202 and the yaw commands 203 from the control unit 19 in order to form the angular data matrix 300.

The angular data matrix 300 can include angles to define a desired angular position of aircraft 1. The angular data matrix 300 can include angular velocities.

In addition, the computer 25 receives representative yaw data 301 from the yaw sensor 23. The computer 25 also receives horizontal propulsion commands 204 and vertical propulsion commands 205. The computer 25 converts the vertical propulsion commands 205 into a main component 405P of the vertical thrusters 5 by the converter 801.

Calculator 25 processes the compared data from comparator 900, via corrector 910, in order to determine the yaw correction torque 503 and, where applicable, the roll correction torque 501, the pitch correction torque 502.

Calculator 25 determines the force matrix 600 of the vertical thrusters 5 from the roll correction torque 501, the pitch correction torque 502 and the main component 405P of the vertical thrusters 5.

Calculator 25 determines from the force matrix 600 the first powers 701 of the vertical thrusters 405.

From the yaw correction torque 503, the computer 25 determines the yaw correction components 407L of the rudder 7 and the yaw correction components 405L of the vertical thrusters 5.

To achieve this, computer 25 decomposes the yaw correction torque 503 into a first yaw correction torque 503a and a second yaw correction torque 503b. Computer 25 converts the first yaw correction torque 503a into yaw correction components 405L for the vertical thrusters 5 via converter 803a. Computer 25 converts the second yaw correction torque 503b into yaw correction components 407L for the rudder 7 via converter 803b.

Calculator 25 performs the decomposition of the yaw correction torque 503 when the yaw correction torque 503 exceeds a predetermined threshold.

The threshold can be fixed or variable. The threshold can depend on the saturation of the vertical thrusters 5, a current power of the horizontal thruster 3, the maximum permissible orientation of the rudder 7, the flight conditions, a calculation of failure cases and the speed of the aircraft 1.

The calculator 25 converts the yaw correction components 405L of the vertical thrusters 5 into second powers 702 of the vertical thrusters 5 by the converter 806.

Computer 25 converts the first powers 701 and the second powers 702 into downstream commands of the vertical thrusters 405 by the converter 805.

Computer 25 provides the downstream commands of the vertical thrusters 405 to the vertical thrusters 5.

Computer 25 receives the main component 407P of the downstream rudder commands 407 and the yaw correction components 407L of the rudder 7. Computer 25 converts the main component 407P of the downstream rudder commands 407 and the yaw correction components 407L of the rudder 7 into downstream rudder commands 407 by the converter 807.

Alternatively, computer 25 determines the yaw correction components of the horizontal thruster 3. These yaw correction components correspond to a variation in the horizontal propulsion power. From the yaw correction torque 503, computer 25 determines the yaw correction components 407L at the rudder 7 and the yaw correction components of the horizontal thruster 3.

Computer 25 receives horizontal propulsion instructions 204 and converts them into downstream horizontal thruster commands 404.

The control system 21 may include coupled control of the horizontal thruster 3, the vertical thrusters 5 and the rudder 7.

The computer 25 may include a link between the roll correction torque 501 and the pitch correction torque 502 on the one hand, and the yaw correction torque 503 on the other. This link or automatic coupling allows for the dynamic correction of moments induced by the action of the actuators controlling the orientation of the control surface 7, the ailerons 8, and the elevator 10. For example, a roll moment may be induced by a movement of the control surface 7 and thus be corrected by this link.

Alternatively, computer 25 can determine the yaw correction components of the horizontal thruster 3. The yaw correction components of the horizontal thruster 3 correspond to a variation in the horizontal thruster power. Computer 25 provides the yaw correction components of the horizontal thruster 3 to the horizontal thruster 3 in such a way as to ensure airflow around the control surface 7. The airflow is capable of generating an aerodynamic yaw moment.

The power of the horizontal thruster 3 is controlled by the pilot but can be adapted by the control system 21 by providing the yaw correction components of the horizontal thruster 3. The yaw correction components of the horizontal thruster 3 correspond to a variation in the power of the horizontal propulsion.

Computer 25 is configured to adapt the yaw correction components 407L of the rudder 7 and the yaw correction components of the horizontal thruster 3 to each other in order to improve the performance of aircraft 1, in particular by reducing drag.

The adaptation between the yaw correction components 407L of the rudder 7 and the yaw correction components of the horizontal thruster 3 depends on the speed of the aircraft 1, the torque generated by external forces and by the saturation of the vertical thrusters 5.

Claims (13)

Vertical takeoff aircraft (1) comprising at least one pair of wings, at least one horizontal thruster (3), vertical thrusters (5) disposed in the wings, said vertical thrusters (5) being configured to generate vertical thrust, a control surface (7) blown by said at least one horizontal thruster (3) and a control system (21) arranged to receive flight instructions (100) and thrust data, and to generate downstream commands (400) to the horizontal thruster (3), the vertical thrusters (5) and the control surface (7), the control system (21) comprising:

• a control unit (19) arranged to convert piloting instructions (100) into upstream control instructions (200),
• a yaw sensor arranged to determine representative yaw data (301) of the aircraft (1),
• an input of representative data of the speed (303) of the aircraft (1), and
• a computer (25) arranged to receive upstream control instructions (200), representative yaw data (301) and speed data (303), the computer (25) being arranged to generate downstream horizontal propulsion commands (404) to the horizontal thruster (3), downstream vertical thruster commands (405) to the vertical thrusters (5) and downstream rudder commands (407) to the rudder (7), the computer (25) being arranged to determine yaw correction components for at least one downstream vertical thruster command (405).

Aircraft (1) according to claim 1, wherein the computer (25) is arranged to further determine yaw correction components for at least one of the downstream horizontal propulsion controls (404) and the downstream rudder controls (407). Aircraft (1) according to claim 1 or 2, wherein the computer (25) is arranged to determine an angular data matrix (300) from the upstream control instructions (200). Aircraft (1) according to claim 3, wherein the computer (25) is arranged to receive representative yaw data (301) and speed data (303) of the aircraft (1) and to process representative yaw data (301) and speed data (303) of the aircraft (1) so as to determine state data (304) of the aircraft (1), the computer (25) being arranged to compare the state data (304) and the angular data matrix (300). Aircraft (1) according to claim 4, wherein the computer (25) includes a controller (910) arranged to determine yaw correction torques as a function of the state data (304) and the angular data matrix (300). Aircraft (1) according to any one of the preceding claims, wherein the computer (25) is arranged to allocate a first yaw correction torque (503a) for the vertical propulsion controls (405) and a second yaw correction torque (503b) for the rudder controls (407), the allocation depending on a threshold varying according to flight conditions, vertical thruster saturation (5), maximum rudder orientation (7) and current horizontal thruster power (3). Aircraft (1) according to any one of the preceding claims, wherein the computer (25) is configured to determine a force matrix (600) upstream of the determination of the downstream controls (400), the force matrix (600) comprising a yaw correction torque (503). Aircraft (1) according to any one of the preceding claims, wherein the computer (25) is arranged to determine the downstream controls of the vertical thrusters (405) differentiated for each of the vertical thrusters (5). Aircraft (1) according to any one of the preceding claims, wherein the computer (25) is arranged to receive representative pitch and roll data (302) of the aircraft (1), the computer (25) being arranged to determine pitch and roll correction components for the downstream controls of the vertical thrusters (405). Aircraft (1) according to any one of the preceding claims, wherein the control system (21) includes coupled control of the horizontal thruster (3), vertical thrusters (5) and rudder (7) as a function of representative pitch and roll data (302), representative yaw data (301) and representative speed data (303) so as to correct induced pitch, roll and yaw moments. Method for yaw correction of an aircraft (1) comprising the following operations:

• receive (1001) piloting instructions (100),
• convert (1002) the piloting instructions (100) into upstream control instructions (200),
• receive (1003) representative data of the (301) loop,
• determine (1004) aircraft (304) state data (1)
• determine (1005), using a corrector, a yaw correction torque (503),
• decompose (1006) the yaw correction pair (503) into a first yaw correction pair (503a) and a second yaw correction pair (503b),
• convert (1007) the first yaw correction couple (503a) into a first yaw correction component (405L) and convert the second yaw correction couple (503b) into a second yaw correction component (407L), when the correction couple value exceeds a threshold,
• convert (1008) the first yaw correction component (405L) into power (702) of vertical thrusters (5),
• convert (1009) the second yaw correction component (407L) into a rudder orientation value (7),
• supply (1010) the power (702) of the vertical thrusters to the computer (25) in order to generate downstream commands for the vertical thrusters (405),
• provide (1011) the orientation value of the rudder (7) to the computer (25), in order to generate downstream rudder commands (407).

Computer program comprising instructions for implementing the device of claims 1 to 9 or for carrying out the process according to claim 10 when said computer program is run on a computer. Data storage medium on which the computer program according to claim 11 is recorded.