Method for controlling an aircraft and aircraft (variant)

Abstract

An aircraft with a multi-spar design comprises at least one wing and three spar mounted transversely to the wing. The wing is mounted on the spar so that at least a portion of the wing can rotate about an axis extending substantially along the wing. A system for controlling the geometric twist of an aircraft wing comprises: a module for determining an optimal shape of the wing; a device for measuring the deformation of at least one wing; an analysis module capable of receiving data from the device for measuring the deformation of at least one wing and determining the current shape of the wing based on the data, and comparing the current shape of the wing with the optimal shape of the wing determined by the module for determining the optimal shape of the wing, and determining the need for adjusting the distribution of the angle of attack of the wing based on the comparison result, and sending a command to an actuation module to actuate at least one actuation mechanism; and an actuation module capable of actuating at least one actuation mechanism so that the current shape of the wing is optimized due to the redistribution of aerodynamic forces. The result is an increase in the efficiency of the aircraft.

Description

Field of the Invention

[0001] The present invention relates to a method for controlling a multi-spar aircraft using wings to generate lift, to a method of varying the twist of the wing geometry of such an aircraft, and to the design of such an aircraft. Background Art

[0002] One of the key parameters of an aircraft is the lift-to-drag ratio, which is the amount of lift generated by the wing divided by the drag created by the wing at a given angle of attack. The lift-to-drag ratio affects aircraft performance such as glide range, flight range, and endurance, fuel consumption, climb performance, etc.

[0003] The greater the wing aspect ratio, the greater the lift-to-drag ratio. Therefore, the lift-to-drag ratio of an aircraft can be increased by increasing the wing aspect ratio as much as possible, thereby improving aircraft performance.

[0004] The wing aspect ratio has a major effect on the use of aircraft as so-called atmospheric satellites (atmospheric satellites, pseudo-satellites). These are high-altitude aircraft with long flight endurance (high altitude long endurance, HALE). It is expected that atmospheric satellites will be suitable for performing tasks such as collecting meteorological data, communications (repeaters), mapping, defense tasks, etc. To perform these tasks, atmospheric satellites must fly for at least several weeks, preferably several months or even several years.

[0005] Currently, it is foreseen that atmospheric satellites will be powered by solar panels. The larger the surface area of ​​the aircraft on which solar panels can be installed, the more energy the aircraft will receive and the longer the aircraft will be able to perform its assigned functions. The aircraft uses the energy generated during the period when solar radiation is available, firstly for powering the electric motors, control systems and payload, and secondly for accumulating energy in so-called buffer batteries. When solar radiation is not available, the aircraft can then use the energy accumulated in the buffer batteries. In order to save energy during periods when solar radiation is not available, an atmospheric satellite can enable a glide mode (with its engines turned off), in which energy consumption will be used only for the operation of the control systems and payload (sensors, repeaters, etc.).

[0006] That is why the aspect ratio of the wings of atmospheric satellites is high, firstly, it provides the optimal lift-to-drag ratio possible, and secondly, it allows to create wings with large surface areas in order to install as many solar panels (photovoltaic panels) on them as possible.

[0007] In operation, aircraft wings are exposed to loads and are subject to bending and twisting deformations. According to the classical aerodynamic arrangement, when the mass is concentrated in the center and the load-bearing surfaces are arranged symmetrically, the bending moments are borne by the load-bearing elements extending along the entire length of the wing - the spars. The skin protects the wing from the effects of twisting deformations. When the weight of an aircraft built according to the classical aerodynamic arrangement increases in proportion to the cube of the linear dimensions, at a certain threshold of the wing aspect ratio, the aircraft is destroyed.

[0008] In the 1920s, a scheme was proposed that theoretically could increase the wing aspect ratio up to any desired value. The inventor proposed in his patent GB172980 the construction of a giant aircraft with wings having an ultra-high wing aspect ratio and connected to multiple fuselages. All loads of such an aircraft, including the empty weight of the aircraft, the weight of the cargo loaded, and the weight of all engines, are supposedly distributed relatively evenly along the wingspan, so that in flight, the load acting on the wing is evenly distributed along the wingspan. The elevator is arranged at the end of the fuselage. Like the elevator, the engine propeller should be arranged in front of or behind the wing, or in an alternating manner. Therefore, the aircraft presents a plurality of aircraft mechanically connected to each other by rigid connections. According to the inventor, such an arrangement minimizes bending and twisting deformations and provides a desired wing aspect ratio. However, if the wings of such an aircraft are rigid, the loads in flight due to aerodynamic interference may cause damage to the aircraft.

[0009] In order to deal with the problem of aircraft damage caused by exceeding the threshold of acceptable deformation, it is proposed to use an adaptive flexible load-bearing surface (deformation structure), such as disclosed in US20110038727. It is expected that such a wing can be adaptively deformed in response to environmental conditions. Such a wing includes a driven movable frame component and / or an elastic composite material. The disadvantage of this construction is the insufficient strength of the material to be used and the complexity of manufacturing and control.

[0010] As is known to all, the spatial attitude of any aircraft is determined by three angular coordinates: tilt (rotation of the aircraft around its longitudinal axis), pitch (rotation of the aircraft around its lateral axis), and yaw (rotation of the aircraft around its vertical axis).

[0011] Usually, for yaw control (course control) a rudder is used, which is a surface that can rotate about its vertical axis. The rudder is usually mounted on the stabilizer behind the wing.

[0012] Usually, for pitch control, surfaces (ailerons) that can rotate about their horizontal axis are used. Usually, the ailerons are mounted symmetrically at the trailing edge of the wing.

[0013] Usually, for pitch control, an elevator is used, which is a surface that can rotate about its horizontal axis. Elevators for aircraft made according to the classical aerodynamic arrangement are arranged on the trailing edge of the stabilizer and are part of the tail. In canard aircraft, the elevator is part of the horizontal canard. In tailless aircraft or flying wing aircraft, these elevators are combined with ailerons (so-called elevons) and are arranged on the trailing edge of the wing.

[0014] Another important parameter of an aircraft is the V-shape (dihedral angle, anhedral angle) of the wing, which affects inter alia the dihedral stability of the aircraft.

[0015] Conventionally, aircraft structures are made to be as rigid and robust as possible so that the structural shape remains unchanged under external loads. The movable control devices are pivotally mounted to fixed structural components. In particular, the geometric wing twist, i.e. the change in the angle of attack and the V-shape along the wing, is set during the aircraft design phase and remains constant during flight.

[0016] An atmospheric satellite X-HALE having flexible wings and made of multiple spar is known (see, for example, link www.youtube.com / watch?v=qQbUJaQ94x0, accessed on July 25, 2018). The wings of the aircraft are equipped with sensors for monitoring flight parameters to scan changes in aerodynamic parameters during use of the aircraft.

[0017] The X-HALE atmospheric satellite was used as a prototype for the claimed invention. Summary of the invention

[0018] The device and method according to the invention are a further development of the above-mentioned prototype and are intended to address its known disadvantages and the disadvantages of other known technical solutions.

[0019] The essence of the present invention is as follows.

[0020] First, a multi-spar aircraft is claimed, which is configured to change wing geometric twist and includes at least one wing, at least three spar arranged transverse to the at least one wing, wherein each of the spar includes at least one actuator, and the at least one wing is mounted on the spar so that at least a portion of the corresponding wing can be pivoted about an axis extending substantially along the corresponding wing by the actuator.

[0021] Secondly, a system for controlling the geometric twist of the wings of such an aircraft is claimed, the system comprising a wing shape optimization module, means for measuring the deformation of at least one wing, an analysis module and an actuation module.

[0022] Thirdly, a method for controlling the wing geometric twist of at least one wing of such an aircraft by means of said system for controlling the wing geometric twist is claimed, the method comprising the following steps:

[0023] (i) determining, by a wing shape optimization module, an optimized shape of at least one wing according to current flight conditions and flight missions,

[0024] (ii) obtaining, by means of means for measuring the deformation of at least one wing, a current value of the deformation of the corresponding wing,

[0025] (iii) sending the current value of the deformation of the corresponding wing to the analysis module,

[0026] (iv) determining the current shape of the corresponding wing by means of an analysis module,

[0027] (v) comparing, by the analysis module, the current shape of the corresponding airfoil with a previously determined optimized shape of the corresponding airfoil, and

[0028] If the current shape of the corresponding wing is different from the optimized shape of the corresponding wing, at least one actuator is enabled by the actuation module to pivot at least a portion of at least one of the wings, so that the resulting change in the wing geometric twist of at least the corresponding wing causes a redistribution of the angle of attack of at least a portion of the corresponding wing, so that the wing with the current shape of the wing tends to reach its optimized shape due to the aerodynamic force redistribution.

[0029] Fourth, a multi-spar aircraft is claimed, the multi-spar aircraft being configured to change the wing geometry twist and comprising a wing, at least three spars arranged transversely to the wing, each spar being equipped with a horizontal stabilizer having an elevator. The wing is rigidly connected to the spars at the connection point of each of the spars to the wing. Each of the elevators is configured to change its position independently of the other elevators so as to change the force transmitted from the corresponding spar at the connection point of the spar to the wing substantially independently of the other spars.

[0030] Fifthly, a system for controlling the geometric twist of the wings of such an aircraft is claimed, the system comprising a wing shape optimization module, means for measuring the deformation of at least one wing, an analysis module and an actuation module.

[0031] Sixth, a method for controlling the wing geometric twist of such an aircraft by means of the system for controlling the wing geometric twist is claimed, the method comprising the following steps:

[0032] (i) determining, by a wing shape optimization module, an optimized shape of at least one wing according to current flight conditions and flight missions,

[0033] (ii) obtaining, by means of means for measuring the deformation of at least one wing, a current value of the deformation of the corresponding wing,

[0034] (iii) sending the current value of the deformation of the corresponding wing to the analysis module,

[0035] (iv) determining the current shape of the corresponding wing by means of an analysis module,

[0036] (v) comparing, by the analysis module, the current shape of the corresponding airfoil with a previously determined optimized shape of the corresponding airfoil, and

[0037] If the current shape of the corresponding wing differs from the optimal shape of the corresponding wing, at least one elevator of the horizontal stabilizer is activated by the actuation module to change the force transmitted to the wing by a spar equipped with the horizontal stabilizer at the connection point of the spar with the wing, and to change the wing geometric twist of at least a part of the wing accordingly, so that the resulting change in the wing geometric twist of the entire wing causes a redistribution of the angle of attack of the at least a part of the wing, so that the wing with the current shape of the wing tends to reach its optimal shape due to the aerodynamic force redistribution.

[0038] Preferred but non-limiting embodiments of the present invention will be described in further detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A first preferred embodiment of an aircraft according to the invention is shown.

[0040] Figure 2 A second preferred embodiment of the aircraft according to the invention is shown.

[0041] Figure 3a and Figure 3b A variant of the second preferred embodiment of the aircraft according to the invention is shown.

[0042] Figure 4 Another preferred embodiment of the aircraft according to the invention is shown.

[0043] Figure 5 A system for controlling the twist of the wing geometry of an aircraft is schematically shown.

[0044] Figure 6 A method for controlling the twist of an aircraft's wing geometry is schematically represented.

[0045] Figure 7 is another preferred embodiment of the aircraft according to the invention.

[0046] Figure 8is a schematic representation of a system for controlling the geometric twist of the wings of an aircraft with reference to one of the embodiments of the aircraft according to the invention.

[0047] Fig. 9 A method for controlling the geometric twist of a wing of an aircraft according to one of the embodiments of the invention is schematically represented.

[0048] Fig.10 A solution for controlling the tilting of an aircraft is shown with reference to one of the embodiments of the aircraft according to the invention.

[0049] Fig.11 A solution for controlling the V-shape of an aircraft is shown with reference to one of the embodiments of the aircraft according to the invention.

[0050] In order to facilitate readers to read and better understand the present invention, the wings and spars (fuselage) of an aircraft are schematically shown in the accompanying drawings. DETAILED DESCRIPTION

[0051] A first embodiment of the present invention.

[0052] Figure 1 One of the preferred embodiments of the invention is shown. Here, the wing (1) is connected to a spar (2) or fuselage arranged transversely to the wing (1). According to this embodiment of the invention, a horizontal tail (3) including a fixed stabilizer is mounted on each of the spar (2).

[0053] The wing (1) is connected to a spar (2) and is configured to pivot at least a portion of the wing about an axis extending along the span line of the wing (1) by means of an actuator (4). Possible pivoting directions are Figure 1 The actuator (4) is mounted on the truss (2) and may be acted upon by a servo motor or other drive known to those skilled in the art.

[0054] The optimum number of spar (2) is at least three, and the wing (1) is connected to each of the spar (2) via a corresponding actuator (4). The actuators (4) are made so that they can operate independently of each other when pivoting a certain part of the wing (1) independently of other parts of the wing (1). Thus, at least one part of the wing (1) can be pivoted about a horizontal axis, while other parts of the wing, in particular parts away from said at least one part, can remain substantially or almost stationary.

[0055] The large aspect ratio makes the wing (1) sufficiently flexible and capable of supporting bending and twisting deformation, that is, supporting the distribution of the wing geometric torsion along the wing (1) to change over a large range without being destroyed.

[0056] Since the wing (1) has sufficient elasticity, the deformation caused by the rotation of the wing (1) at the point of action of the actuator (4) extends further along the wing (1) to the area (area, part) adjacent to the point of action of the actuator (4). As a result, the wing geometric torsion, that is, the distribution of geometric torsion along the wing (1) will be changed. The controllable change of the wing geometric torsion will cause a controllable distribution of the angle of attack along the wing (1). The controllable change of the angle of attack (controllable change of the geometric torsion) causes a redistribution of the aerodynamic forces acting on the aircraft. Therefore, it becomes possible to offset or compensate for the deformation in flight caused by external conditions (actions), and it is possible to control the spatial attitude of the aircraft.

[0057] Second embodiment of the present invention.

[0058] Figure 2 Another preferred embodiment of the invention is shown. Here, the horizontal tail surface is of such dimensions that it can be mounted on all the spar (2) at the same time and is essentially a second wing (1') arranged behind and parallel to the first wing (1). In this way, a tandem arrangement of the aircraft is formed. The second wing (1') can be identical to the first wing (1) or can have dimensions, profiles, etc. that are different from those of the first wing (1).

[0059] The advantage of the tandem arrangement compared to the first embodiment of the invention is the improved structural rigidity. A severe external impact on one of the wings (1, 1') caused by the elastic properties of the structural components will extend to the second of the wings (1, 1'). The aircraft will be more resistant to destructive external effects. That is why, at a given design strength, the rigidity requirements of each of the wings (1, 1') and therefore the weight of the wings (1, 1') can be reduced to a certain extent.

[0060] In an aircraft powered by solar panels, it is desirable to maximize the surface area of ​​the aircraft suitable for mounting solar panels. With an aircraft of predetermined strength and a predetermined surface area of ​​solar panels, the specific weight of the tandem aircraft will be lower than the weight of a single-wing aircraft (monoplane). Therefore, the payload weight of the tandem arrangement can also be higher than the payload weight of the aircraft according to the first embodiment.

[0061] Another advantage of a tandem aircraft is that, given a given surface area, the wingspan of a tandem aircraft is smaller than that of a monoplane aircraft. Therefore, under other conditions being the same, a tandem aircraft can move around a smaller radius of a circle and has higher maneuverability than a monoplane aircraft.

[0062] The second wing (1') may be rigidly and non-pivotally connected to the truss (2), such as Figure 3a shown.

[0063] Alternatively, the second wing (1') can be connected to the spar (2) via an actuator (4) in order to change the angle of attack of the second wing (1') identically and synchronously for the entire second wing (1'). In this embodiment, the surface of the horizontal tail acts as a stabilizer or elevator ( Figure 3b ).

[0064] In addition, the second wing (1') can be fixed to the spar (2) similarly to the first wing (1). That is, each of the spar (2) is connected to the second wing (1') by an actuator (4), which is configured to operate independently of each other by causing a certain part of the wing (1') to pivot independently of other parts of the wing (1') about an axis extending substantially along the wing (1'). Figure 3b ).

[0065] In general, according to the method, an aircraft can be provided with any number of wings (1, 1', 1" ...) configured to independently pivot relative to each of the spar (2) about an axis extending along the span line. Figure 4 ).

[0066] A wing (1, 1', 1" ...) with a large aspect ratio is made of a high-strength structural material. Such a wing can have any planform suitable for achieving the purpose of the invention. The wing can have a static wing geometric twist and / or an aerodynamic wing twist, or the wing can have neither. Preferably, but not necessarily, the weight of the wing should be evenly distributed over the span. Also preferably, the wing is made without any articulated joints and when bending, the deformation of the wing is distributed over the entire wing according to the elasticity of the wing.

[0067] In any embodiment of the aircraft according to the invention, the spar (2) or the fuselage is used to arrange thereon the engine-propeller combination, landing gear, payload, control system components, etc. Furthermore, according to a possible embodiment of the invention, the spar (2) can receive a horizontal tail and / or a vertical tail, a fin and a stabilizer.

[0068] Each actuator (4) is actuated by a separate drive unit to function independently of the other actuators (4). The actuator (4) may be a lever actuator. The drive unit may be electric, hydraulic or pneumatic. More preferably, the drive unit is made in the form of a servo motor. The specific embodiments of the drive unit and the actuator are well known to those skilled in the art and do not represent the purpose of the present invention.

[0069] The power unit of the aircraft comprises at least one electric motor driving a propeller. In taxiing mode, the propeller blades can be folded to reduce aerodynamic drag. The concept and arrangement options of the power unit are well known to those skilled in the art and do not represent the purpose of the present invention.

[0070] Any of the embodiments of the aircraft according to the invention may also be equipped, based on the designer's choice, with one or more rudders and / or spoilers mounted on the panels of at least one of the wings (1, 1', 1" ...) to perform yaw control (for changing the yaw attitude). The construction and arrangement options of the rudders and / or spoilers are well known to those skilled in the art and do not represent the purpose of the present invention.

[0071] The designer may decide to also equip the aircraft with a spoiler arranged at the tip of at least one wing. Here, the spoiler only acts as a speed reducer and does not affect lift.

[0072] The wing geometry twist and wing deformation are controlled by a system for controlling the wing geometry twist of an aircraft ( Figure 5 ), the system comprises a wing shape optimization module, a device for measuring the deformation of at least one wing, an analysis module and an actuation module.

[0073] The wing shape optimization module is designed to define the optimized shape of at least one wing of the aircraft at a given point in time, depending on the current flight conditions, the flight mission and the maximum allowed (threshold) wing deformation - above which the aircraft will be destroyed. In particular, threshold deformations may occur under the influence of external effects, such as passing through turbulent areas, updrafts, strong winds, etc. Usually, the allowed deformation of the wing is defined by the construction of the wing, and a person skilled in the art will understand how to measure or calculate these values. In particular, the flight mission may require changing the attitude and bank angle of the aircraft and the V-shape of the wing.

[0074] The means for measuring deformation are deformation sensors. Such sensors may include inertial position sensors (attitude indicators), different strain sensors. One of the preferred variants of deformation sensors includes optical fiber strain sensors using Bragg gratings. The means for measuring deformation may include a device for analyzing deformation by optical markings. For example, such means may be a camera and specific markings placed on the wing. However, the type of strain sensor to be used is usually chosen by the designer.

[0075] In order to provide maximum efficiency, the deformation sensors are mounted on those sections of the wing where the measured values ​​are largest or are expected to be largest, for example, in areas of (expected) maximum deformation, areas of (expected) maximum stress, areas of (expected) maximum displacement, which can be predetermined by calculation or by experiment.

[0076] Preferably, the system for controlling the twisting of the wing geometry comprises means for measuring deformations of at least two independent systems or types. It is important to ensure fault tolerance in the event of failure of the means for measuring any one type of deformation. However, depending on the task, the designer may utilize means for measuring only one type of deformation, for example, only strain sensors or only attitude indicators.

[0077] In order to enable proper operation, deformation data need to be collected at a plurality of points of the corresponding wing, preferably at least at three points of the corresponding wing.

[0078] A device for measuring deformation is mounted on each wing connected to a spar (2) so as to be independently pivotable relative to each spar (2) about an axis extending along the span line.

[0079] The analysis module is configured to: receive deformation values ​​determined by a device for measuring deformation; determine the current shape of at least one wing (1, 1', 1" ...) based on the received deformation values; compare the current shape of at least one wing (1, 1', 1" ...) with the optimized shape of the wing determined by the wing shape optimization module; if the current shape of the corresponding wing is different from the optimized shape of the wing, send a command to the actuation module to make at least one actuator act so that the current shape of the wing will tend to reach the optimized shape due to the redistribution of aerodynamic forces. Typically, the analysis module processes data from a device for measuring deformation, which is installed on each of the wings (1, 1', 1" ...) connected to a truss (2) so as to pivot independently relative to each truss (2) around an axis extending along the span line.

[0080] The actuation module is configured to activate the actuator.

[0081] In the following, for the sake of simplicity, each of the wings (1, 1', 1" ...) can be conditionally divided into several parts: half a wing and the other half a wing; or a left wing part, a central wing part and a right wing part.

[0082] Changing the relationship of the geometric twist angles at different parts of the wing makes it possible to control the aircraft and change or maintain a given deflection or shape of the wing.

[0083] The pitch angle can be changed by changing the geometric twist of the wing across the span so that the wing angle of attack at each point along the span increases relative to the initial angle of attack, or so that the wing angle of attack at each point along the span decreases relative to the initial angle of attack.

[0084] The tilt angle can be changed by changing the wing geometry twist so that the angle of attack of half of the wing decreases relative to the initial angle of attack, or so that the angle of attack of said half of the wing increases relative to the initial angle of attack. In this task, the minimum number of controlled sections (parts) of the wing is two.

[0085] To control the V-shape of the wing, the wing geometry is twisted so that the angle of attack of the right wing section and the angle of attack of the left wing section are changed relative to the angle of attack of the central wing section. For example, to reduce the V-shape of the wing, the angle of attack of the right wing section and the angle of attack of the left wing section are reduced relative to the angle of attack of the central wing section; or to increase the V-shape of the wing, the angle of attack of the right wing section and the angle of attack of the left wing section are increased relative to the angle of attack of the central wing section. This control of the V-shape can be performed on an aircraft having at least three controlled wing sections (parts).

[0086] The control of the wing geometry torsion distribution of a multi-struwer aircraft aims to offset the deformation in flight and the spatial position of the aircraft by optimizing the wing shape. The following steps are performed: Figure 6 ):

[0087] (i) determining, with the aid of a wing shape optimization module, an optimized shape of at least one wing according to the current flight conditions and the flight mission,

[0088] (ii) determining, by means of means for measuring the deformation of at least one wing, a current value of the deformation of the corresponding wing,

[0089] (iii) sending the current value of the deformation of the corresponding wing to the analysis module,

[0090] (iv) determining the current shape of the corresponding wing with the aid of an analysis module based on the received current deformation value of the corresponding wing,

[0091] (v) comparing the current shape of the corresponding airfoil with a previously determined optimized shape of the corresponding airfoil by means of the analysis module, and

[0092] If it is determined that the current shape of the corresponding wing is different from the optimized shape of the corresponding wing, at least one actuator is activated by means of an actuation module to pivot at least a portion of at least one of the wings, so that the resulting change in the wing geometric twist of at least the corresponding wing causes a redistribution of the angle of attack of at least a portion of the corresponding wing, so that the wing with the current shape of the wing tends to reach the optimized shape due to the aerodynamic force redistribution.

[0093] If the flight mission includes a pitch change, then in step (v) at least a portion of at least one of the wings is pivoted so that the angle of attack along the wingspan increases relative to the initial angle of attack, or so that the angle of attack along the wingspan decreases relative to the initial angle of attack.

[0094] If the flight mission includes a bank change, then in step (v) at least a portion of at least one of the wings is pivoted such that the angle of attack of half the wings increases relative to the initial angle of attack, or such that the angle of attack of half the wings decreases relative to the initial angle of attack.

[0095] If the flight mission includes changing the V-shape of the wings, then in step (v), at least a portion of at least one of the wings is pivoted so that the angle of attack of the left portion of the corresponding wing and the angle of attack of the right portion of the corresponding wing increase relative to the angle of attack of the center portion of the corresponding wing, or the angle of attack of the left portion of the corresponding wing and the angle of attack of the right portion of the corresponding wing decrease relative to the angle of attack of the center portion of the corresponding wing.

[0096] The deformation data of each wing are collected and analyzed at predetermined time intervals. The designer establishes a frequency at which the deformation data of each wing are collected and at which the control system analyzes these data and controls the actuators. It is desirable to continuously monitor the wing deformation and the time interval between two consecutive measurements of the wing deformation is defined only based on the technical characteristics of the devices, sensors, connections, etc. included in the system for controlling the geometric twist of the wing.

[0097] In general, the method for piloting an aircraft may be applicable not only to multi-struder aircraft, but also to other known aircraft arrangements, such as "canard", "triplex" (aircraft with three wings arranged parallel to each other), etc.

[0098] In general, the device for measuring deformation can be installed on any number of wings. The designer decides whether to adopt this method taking into account the specific operating conditions of the aircraft. It is feasible to install the device for measuring deformation only on the largest wing; however, other options are also possible.

[0099] In addition, it is practical and usually sufficient to pivotally connect only one wing to the spar (2) about an axis extending along the span line relative to each spar (2). In this case, it is recommended to rigidly connect the other wing to the spar (2). However, other options are also possible.

[0100] In fact, the optimized controlled implementation of the present invention is as follows:

[0101] - A multi-spar aircraft having only one wing, the wing being connected to the spar (2) by means of actuators (4) so ​​as to pivot independently relative to each spar (2) about an axis extending along the span line, and each spar (2) being equipped with a horizontal tail which is a stabilizer without an elevator ( Figure 2 ),

[0102] - A multi-spar aircraft with a front wing and a rear wing in a tandem arrangement, wherein the front wing is connected to the spar (2) by means of actuators (4) so ​​as to pivot independently relative to each spar (2) about an axis extending along the span line, and the rear wing is rigidly fixed, wherein the front wing is larger than the rear wing (Figure 3).

[0103] In both optimized controlled embodiments, the wing with controlled geometric twist changes the aerodynamic force substantially instantly as a result of the execution of the commands from the system for controlling the geometric twist of the wing, and generates a yaw rotation moment in the desired direction according to the difference between the aerodynamic drag of the panel (end portion of the wing) when entering and exiting the turn. This reduces the need to use the rudder to glide and reduces losses.

[0104] Figure 7 is a schematic diagram of another embodiment of an aircraft according to the invention. In contrast to the above-described embodiment, in this embodiment, a wing (1) with a higher aspect ratio is rigidly mounted on a spar (2), and each spar (2) has a horizontal stabilizer (3) with an elevator, which allows it to be adjusted in altitude by means of the elevator. When the position of the horizontal stabilizer (3) is changed, in particular by controlling the position of each elevator, the corresponding control force is transmitted through the corresponding spar (2) to the rigid part of the wing (1) rigidly connected to the spar (2). The deformation generated in this part of the wing (1) tends to change the angle of attack of the entire wing (1), which occurs because this deformation, due to the flexible and elastic properties of the wing (1), extends further along the wing (1) to the area adjacent to the specific point where the wing (1) is connected to the corresponding spar (2), that is, the area adjacent to a given part of the wing (1). As a result, the wing geometric twist, ie the distribution of the geometric twist along the wing (1), will be changed, and correspondingly the distribution of the angle of attack along the wing (1) will be changed.

[0105] Similar to the above embodiment, Figure 7 In the aircraft shown, the wing geometric twist and wing deformation are controlled by a system for controlling the wing geometric twist of the aircraft ( Figure 8 ), the system comprises a wing shape optimization module, a device for measuring the deformation of at least one wing, an analysis module and an actuation module.

[0106] The Wing Shape Optimization module is designed to define the optimal shape of the aircraft's wing at a given point in time, depending on the current flight conditions, the flight mission, and the maximum allowed (threshold) wing deformation above which the aircraft will be destroyed. In particular, the flight mission may require changes to the aircraft's attitude and bank angles as well as the wing V-shape.

[0107] The means for measuring deformation are deformation sensors, such as inertial position sensors, or attitude indicators, different strain sensors, optical fiber strain sensors using Bragg gratings, etc. The means for measuring deformation may include devices for analyzing deformation using optical markers, such as cameras and specific markers on the wing. Similar to the above embodiment, the type of strain sensor is selected by the designer. The strain sensors are installed on those sections (parts) of the wing where the measured values ​​are expected to be the largest, for example, in areas of possible maximum deformation, areas of (expected) maximum stress, areas of (expected) maximum displacement. In order to ensure the fault tolerance of the system, it is preferred that the system for controlling the geometric torsion of the wing includes means for measuring deformation of at least two independent systems or types.

[0108] To enable proper operation, it is preferred to collect deformation data at least at three points of the corresponding wing.

[0109] The analysis module is configured to: receive deformation values ​​determined by a device for measuring deformation; determine the current shape of the wing (1) based on the received deformation values; compare the current shape of the wing (1) with the optimized shape of the wing determined by the wing shape optimization module; if the current shape of the wing differs from the optimized shape of the wing, send a command to the actuation module to act on at least one elevator so that the wing with the current shape of the wing tends to reach the optimized shape due to the redistribution of aerodynamic forces. Typically, the analysis module processes data from a device for measuring deformation mounted on the wing (1) connected to a spar (2).

[0110] The actuation module is configured to activate each elevator of the tail plane of the spar (2).

[0111] Similar to the above disclosure with reference to the first two embodiments of the aircraft according to the present invention, for the sake of simplicity and convenience, in the third embodiment described below ( Figure 7 ), the wing (1) can be divided into several parts: half a wing and the other half a wing; or a left wing part, a central wing part and a right wing part.

[0112] Changing the relationship of the geometric twist angles of different parts of the wing enables the aircraft to be controlled and a given wing deflection or shape to be varied or maintained.

[0113] The control of the wing geometry torsion distribution of a multi-struder aircraft aims to counteract or compensate for the deformation in flight and control the spatial attitude of the aircraft by optimizing the wing shape, which is achieved by the following steps: Fig.11 ):

[0114] (i) using the wing shape optimization module to determine the optimal shape of the wing according to the current flight conditions and flight mission,

[0115] (ii) determining, by means of a device for measuring the deformation of the wing, a current value of the deformation of the corresponding wing,

[0116] (iii) sending the current value of the obtained deformation to the analysis module,

[0117] (iv) determining the current shape of the wing with the aid of an analysis module based on the received current value of the wing deformation,

[0118] (v) comparing the current shape of the wing with a previously determined optimized shape of the wing by means of the analysis module, and

[0119] If it is determined that the current shape of the wing differs from the optimal shape of the wing, at least one elevator is activated by means of an actuation module so that the force transmitted to the wing by a spar equipped with the elevator at the connection point of the spar to the wing is changed, and the wing geometric twist of at least a part of the wing is changed accordingly, so that the resulting change in the wing geometric twist of the entire wing causes a redistribution of the angle of attack of at least a part of the wing, so that the wing with the current shape of the wing tends to reach the optimal shape due to the aerodynamic force redistribution.

[0120] If the flight mission includes a pitch change, then in step (v), at least one elevator is pivoted such that the angle of attack along the wingspan increases relative to the initial angle of attack, or such that the angle of attack along the wingspan decreases relative to the initial angle of attack ( Figure 7 ).

[0121] If the flight mission includes a bank change, then in step (v) at least a portion of one elevator is pivoted such that the angle of attack of half the wing increases relative to the initial angle of attack, or such that the angle of attack of half the wing decreases relative to the initial angle of attack ( Figure 8 ).

[0122] If the flight mission includes changing the V-shape of the wing, then in step (v), at least one elevator is pivoted so that the angle of attack of the left portion of the corresponding wing and the angle of attack of the right portion of the corresponding wing increase relative to the angle of attack of the center portion of the corresponding wing, or so that the angle of attack of the left portion of the corresponding wing and the angle of attack of the right portion of the corresponding wing decrease relative to the angle of attack of the center portion of the corresponding wing. Fig. 9 ).

[0123] The deformation data of the wing are collected and analyzed at predetermined time intervals. The designer establishes a frequency at which the deformation data are collected and at which the control system analyzes these data and controls the actuators. It is desirable to continuously monitor the wing deformation and the time interval between two consecutive measurements of the wing deformation is defined only on the basis of the technical characteristics of the devices, sensors, connections, etc. included in the system for controlling the geometrical twist of the wing.

Claims

1. A multi-truss aircraft with adjustable wing geometry twist, the aircraft comprising: a first wing and a second wing, the second wing being arranged rearward of and parallel to the first wing, and at least three spar arranged transversely to each of the first wing and the second wing, Each of the trusses comprises at least one actuator. wherein the first wing is mounted on the truss so that at least a portion of the first wing is configured to pivot by the at least one actuator about an axis extending substantially along the first wing, and the second wing is rigidly mounted on the truss, and wherein each of the actuators is actuated by a separate drive unit to act independently of the other actuators, and each of the actuators is configured to pivot at least a portion of the first wing about an axis extending substantially along the first wing independently of other portions of the first wing, and to change or maintain a given deflection or shape of the first wing by changing the relationship of the geometric twist angles at different portions of the first wing.

2. The aircraft according to claim 1, wherein: The at least one actuator is actuated by a servo motor.

3. A system for controlling the geometric twist of the wing of an aircraft according to claim 1 or 2, the system comprising: a wing shape optimization module for determining an optimized shape of said first wing, means for measuring deformation of said first wing, an actuation module configured to actuate the at least one actuator, and an analysis module configured to receive data from means for measuring the deformation of the first wing, to determine the current shape of the first wing based on the data, to compare the current shape of the first wing with the optimized shape of the first wing and, if the current shape of the first wing is inconsistent with the optimized shape of the first wing, to make a decision to change the distribution of the angle of attack of the first wing, and to send a command to the actuation module so that the at least one actuator is actuated so that, due to the redistribution of aerodynamic forces, the current shape of the first wing tends to reach the optimized shape of the first wing.

4. The system according to claim 3, wherein: The actuation module includes a servo motor.

5. The system according to claim 3, wherein: The means for measuring the deformation of the first wing is mounted on a section of the first wing where the deformation is greatest or is expected to be greatest.

6. The system according to claim 3, wherein: The means for measuring the deformation of the first wing are selected from the group consisting of: fiber optic deformation sensors spread over the entire length of the first wing, attitude indicators spread over the entire length of the first wing, and cameras.

7. A method for controlling the wing geometric twist of an aircraft according to claim 1 or 2 by means of a system for controlling wing geometric twist according to any one of claims 3 to 6, the method comprising the following steps: (i) determining the optimized shape of the first wing according to the current flight conditions and the flight mission with the aid of the wing shape optimization module, (ii) determining, by means of said means for measuring the deformation of said first wing, a current value of the deformation of said first wing, (iii) sending the obtained current value of the deformation of the first wing to the analysis module, (iv) determining the current shape of the first wing by the analysis module based on the received current value of the deformation of the first wing, (v) comparing, by the analysis module, the current shape of the first wing with the determined optimal shape of the first wing, and In case it is determined that the current shape of the first airfoil is different from the optimized shape of the first airfoil, The at least one actuator is actuated by the actuation module to pivot at least a portion of the first wing such that a resulting change in the wing geometry twist of the first wing causes a redistribution of the angle of attack of at least a portion of the first wing such that, due to aerodynamic force redistribution, a current shape of the first wing tends to reach an optimized shape of the first wing.

8. The method according to claim 7, wherein: In order to change the pitch of the aircraft, in step (v), at least a portion of the first wing is pivoted so that the angle of attack of the first wing produced along the wingspan of the first wing increases relative to the initial angle of attack of the first wing, or the angle of attack of the first wing produced along the wingspan of the first wing decreases relative to the initial angle of attack of the first wing.

9. The method according to claim 7, wherein: In order to change the tilt of the aircraft, in step (v), at least a portion of the first wing is pivoted so that the angle of attack of half of the first wing increases relative to the initial angle of attack of the first wing, or so that the angle of attack of half of the first wing decreases relative to the initial angle of attack of the first wing.

10. The method according to claim 7, wherein: To change the wing V-shape of the first wing, in step (v), at least a portion of the first wing is pivoted such that the angle of attack of the left portion of the first wing and the angle of attack of the right portion of the first wing are increased relative to the angle of attack of the central portion of the first wing, or The angle of attack of the left portion of the first wing and the angle of attack of the right portion of the first wing are reduced relative to the angle of attack of the central portion of the first wing.

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