Control method of hybrid power helicopter and hybrid power helicopter

Abstract

The invention relates to a control method for a hybrid helicopter and a hybrid helicopter, the hybrid helicopter having at least one lift rotor (10), at least one forward propeller (15) and a tail provided with at least one tail active surface (26). The method comprises the following steps: determining the current value of a rotor parameter by means of a main sensor (50), the rotor parameter determining the current power consumed by the lift rotor (10), determining the current set point of the rotor parameter by means of an estimator (76), and adjusting the position of the tail active surface (26) by means of a steering regulator (77) according to the current value and the current set point.

Description

Technical Field

[0001] The invention relates to a method for controlling a hybrid helicopter having a fuselage with a constant angle of attack by adjusting the position of at least one tail active surface, and a hybrid helicopter implementing the method. The invention relates to the general technical field of automatic or semi-automatic flight control systems. Background Art

[0002] The project in which the present invention was presented received funding from the European Union's Horizon 2020 research and innovation programme under the CleanSky 2 subsidy agreement “Volume GAM-FRC-2014-001E”.

[0003] A rotorcraft is an aircraft equipped with rotating wings, or rotors for short. A rotorcraft generally includes a fuselage and at least one rotor driven to rotate by a power plant. Such a rotor may be called a "lift rotor" because it helps the aircraft rise, and the rotor may also help the aircraft move forward. A rotorcraft may also include one or more propellers that at least partially help the rotorcraft move forward. For simplicity, the term "propeller" is used below to refer to a propulsion or traction propeller.

[0004] Specifically, for convenience, a rotorcraft referred to as a "hybrid helicopter" includes a fuselage, at least one rotor, a tail, one or more forward propellers that may be arranged laterally relative to the fuselage, and may even include additional lifting devices, such as wings.

[0005] The wing or lifting surface may consist, for example, of two half-wings arranged on either side of the fuselage.

[0006] According to another aspect, the power unit of the hybrid helicopter may include at least one engine. The engine or engines may be connected to the propeller and the rotor by means of an interconnection mechanical system. The output rotational speeds of the engine, the propeller, the rotor and the mechanical interconnection system are, for example, proportional to each other, and the ratio is constant regardless of the flight configuration of the hybrid helicopter under normal operating conditions of the integral transmission chain.

[0007] Thus, in the normal flight configuration, the rotor is advantageously kept in constant rotation by the engine.

[0008] In order to control the hybrid helicopter, the total pitch component and the cyclic pitch component of the rotor blades can be controlled. Therefore, the helicopter can include a transmission chain with a pitch control actuator. Such a pitch control actuator can, for example, take the form of a servo control. The pitch control actuator is, for example, hinged to a set of annular swash plates, which are connected to each blade of the main rotor by a connecting rod. These transmission chains may include a controller operated by a human pilot and a jack controlled by an autopilot.

[0009] In addition, the hybrid helicopter may include at least one transmission chain to control the pitch of the propellers, thereby controlling the thrust generated by each propeller. Thus, the propellers can affect the forward speed of the hybrid helicopter and even its yaw motion.

[0010] In addition, the hybrid helicopter comprises a tail equipped with lifting members. These lifting members may be mobile. The expression "tail active surface" refers hereinafter to a member of the tail that can influence the pitch balance of the aircraft, in particular at high speeds. Such tail active surface may take the form of a horizontal or inclined tail that is completely movable in rotation, or even in the form of movable flaps articulated to a horizontal or inclined tail fixed surface or equivalent. The pitch control of the hybrid helicopter may be achieved by periodically controlling the pitch of the main rotor, while at least one tail active surface is required to adjust the pitch balance of the aircraft according to a predetermined criterion.

[0011] Documents US8181901 B2, US8170728 B2, US8052094 B2, US8113460 B2 describe hybrid helicopters.

[0012] Such hybrid helicopters are particularly advantageous in order to be able to reach high speeds and / or to cover large flight distances. However, due to their particularity and the presence of multiple controllable elements, it may be difficult to control the propellers and / or rotors during the steady flight phase in order to put the aircraft in optimal operating conditions without causing a heavy workload on the pilot.

[0013] The "steady flight phase" is defined as flight at a substantially constant forward speed, possibly at high speed, during which the aircraft follows a constant course while maintaining the fuselage at a constant angle of attack. In the specific case of zero climb speed, the steady flight phase occurs at a constant flight altitude, which is called cruising or level flight. A constant course corresponds to a course without acceleration or even changes in the direction of the aircraft.

[0014] The optimum operating conditions may correspond to operating points of the propeller and rotor to achieve minimum fuel consumption, maximum stress on the propeller, or to achieve other purposes.

[0015] In addition, the hybrid helicopter should always be controlled to follow a constant flight path at a constant angle of attack. The total lift generated by the lift elements of the hybrid helicopter should in particular be adjusted during flight to accommodate changes in the mass of the hybrid helicopter due to, for example, fuel consumption and changes in air density.

[0016] French patent document FR 2959205 describes a control and regulation method using a pitch or attitude regulation loop, a speed regulation loop by controlling the average pitch of the propeller blades, and a control and regulation loop for the steering angle of the horizontal tail. This control and regulation loop comprises the following steps: determining the initial power provided by the power unit after the control and regulation loop is activated, controlling the first movement speed of the driven tail element, and comparing the new power provided by the power unit with the initial power. Unlike the purpose of the present invention, the purpose of this patent is to minimize the total power generated by the power unit of the hybrid helicopter.

[0017] French patent document FR2990684 describes a method according to which a set point total pitch and a set point cyclic variable pitch of the main rotor blades of a hybrid helicopter are determined so that the hybrid helicopter approaches the optimal operating point of the main rotor during a stable phase while maintaining a constant vertical attitude target, such as a vertical speed or a constant angle of attack, and a constant longitudinal attitude target corresponding to the stable flight phase.

[0018] According to French patent document FR2990684, the lift exerted by the wings of a hybrid helicopter is regulated by acting on aerodynamic devices and by applying a regulation loop aimed at bringing the total pitch of the lift rotor towards a setpoint total pitch. In particular, the lift exerted by the wings is regulated to take into account variations in the mass of the aircraft due to fuel consumption.

[0019] According to French patent document FR2990684, the lift exerted by the horizontal tail is further regulated by applying a regulation loop aimed at bringing the longitudinal cyclic pitch of the rotor blades towards a set point longitudinal cyclic pitch in order to take into account the variation in centering. Alternatively, the regulation may take into account the longitudinal bending moment of the main rotor mast (hereinafter referred to as "rotor mast") and the set point longitudinal bending moment. Summary of the invention

[0020] The present invention aims to propose a new method that allows a hybrid helicopter to follow a course with a substantially constant angle of attack, without increasing the workload on the pilot, by optimizing the work of the propellers and the so-called "lift" main rotor, thus making it possible, for example, to minimize fuel consumption or maximize the action on the propellers.

[0021] The invention therefore relates to a control method for a hybrid helicopter having at least one lift rotor provided with variable pitch blades, the hybrid helicopter having at least one forward propeller provided with blades, the hybrid helicopter having a tail provided with at least one tail active surface, the tail active surface being configured to generate a pitching moment at least on the fuselage of the hybrid helicopter, the hybrid helicopter having at least one tail actuator for, for example, at least rotating the at least one tail active surface.

[0022] The method includes a stable flight phase, which includes a rotor adjustment phase including a longitudinal attitude maintenance step and a climbing speed maintenance step, and a propeller adjustment phase including a forward speed maintenance step, wherein the stable flight phase includes a tail adjustment phase, which includes the following steps:

[0023] - determining, by means of a main sensor, the current value of a rotor parameter which determines the current power consumed by said lift rotor,

[0024] - determining by estimator a current set point of said fixed rotor parameter or a function of at least one monitored parameter value, said rotor parameter being the power consumed by the lift rotor and said current set point being a power set point, or said rotor parameter being the engine torque transmitted to the lift rotor and said current set point being a torque set point,

[0025] - adjusting the position of the active surface of the tail wing by means of a steering regulator according to the current value and the current set point.

[0026] The method proposes in an innovative way to establish current set points of rotor parameters, which are either fixed or a function of the current flight situation.

[0027] For example, unlike the method of determining the setpoint pitch, the rotor parameter is a representation of the power consumed by the lift rotor. The current setpoint of the rotor parameter is established, for example, by experiments and / or simulations, and is a representation of the power to be consumed by the lift rotor for the current flight situation, which power is considered to be the optimal power. For example, the current setpoint of the rotor parameter corresponds to the value that the rotor parameter should reach in order to minimize fuel consumption in the current flight.

[0028] Thus, during the same flight, the value of the current set point may be fixed or vary with the value of a monitored parameter, which is different from the rotor parameter.

[0029] In addition, according to the method, at least one tail active surface, or a plurality of or even all tail active surfaces, are regulated by the steering regulator, if necessary, so that the current value of the rotor parameter tends to its current set point. Optionally, and in the case of a plurality of tail active surfaces, the steering command issued to each tail active surface can also take into account another objective, such as a roll control auxiliary objective or asymmetry compensation of a hybrid helicopter. Changing the steering of the tail active surface may cause a pitching moment, causing the fuselage to dive or pitch up.

[0030] However, the stable flight phase includes a longitudinal attitude holding step. Therefore, during this longitudinal attitude holding step, the rotor disk formed by the blades of the lift rotor will tilt so as to re-establish the pitch balance after manipulating the tail active surface.

[0031] Furthermore, the steady flight phase includes a step in which the aircraft climbs at a speed-maintaining rate, which allows the slope of the route being followed to remain substantially constant.

[0032] However, the relationship between the fuselage angle of attack alpha, the pitch attitude angle theta of the hybrid helicopter and the course slope gamma is as follows: alpha = theta - gamma. Therefore, keeping the pitch attitude angle theta and the course slope gamma of the hybrid helicopter substantially constant is equivalent to changing with the constant angle of attack of the fuselage.

[0033] In addition, the angle of attack of the lift rotor's rotor circle determines the power consumed by the lift rotor. The angle of attack of the rotor circle depends on the fuselage angle of attack as well as the flapping angle of the lift rotor and the inclination of the rotor mast. For a given fuselage angle of attack, the periodic variation of the lift rotor pitch causes a change in the angle of attack of the rotor circle, which can make the current value of the rotor parameter tend to the established current set point.

[0034] In addition, the change in the angle of attack of the rotor circle causes a change in the forward speed of the aircraft. If the rotor circle is tilted toward the front of the aircraft, its effect on the forward speed will increase. Conversely, if the rotor circle is tilted toward the rear of the aircraft, its effect on the forward speed will decrease. Therefore, during the forward speed maintenance step, the propeller is automatically controlled to keep the forward speed substantially constant.

[0035] The method therefore proposes to control the position of the active tail surface as a function of the difference between the current set point and the current value of the rotor parameter of the power consumption type or of the engine torque type transmitted to the lift rotor. The active tail surface is controlled so that the fuselage angle of attack maintains a constant slope by automatically causing a variation in the pitch of the lift rotor blades so that the current value tends to the current set point. This causes a variation in the pitch and / or rotation speed of the propeller so that the forward speed remains substantially constant. The lift rotor and the propeller then operate according to a predetermined operating point considered to be optimal for flight.

[0036] The use of rotor parameters of the type of lift rotor power consumption or of the type of engine torque transmitted to the lift rotor has the advantage that rotor parameters can be determined relatively easily and reliably in flight. The term "reliable" means that the rotor parameters used can be determined by sensors that may be redundant and / or can be subjected to consistency tests or even both. Thus, the current values ​​of the rotor parameters can be used in the hybrid helicopter automatic control method without compromising flight safety due to approximate measurements.

[0037] In addition, the power consumed by the lift rotor is adjusted by adjusting the pitch attitude angle of the hybrid helicopter, which can be achieved by accurately and reliably measuring the current pitch attitude angle, such as using an inertial device.

[0038] Moreover, the method is indeed relatively simple and requires the use of devices that may already be used on hybrid helicopters.

[0039] In addition, the relationship between the power consumed by the lift rotor or the engine torque transmitted to the lift rotor and the position of the tail active surface is monotonic, that is, it always increases or decreases. Therefore, it is guaranteed that the adjustment tends to be optimal.

[0040] Finally, the method is insensitive to changes in the center of gravity of the hybrid helicopter, such as may be caused during flight due to fuel consumption or load delivery. Such changes in the center of gravity will actually cause a change in the pitch balance of the hybrid helicopter, which will automatically trigger new adjustments, such as cyclic adjustment of the lift rotor pitch.

[0041] The method may include one or more of the following features.

[0042] According to one feature, the position adjustment of the tail active surface may include the following steps:

[0043] - determining a steering command for the active surface of the tail wing by means of a steering regulator according to the current value and the current set point.

[0044] - According to the steering command, the tail movable surface is steered by the tail actuator.

[0045] According to features compatible with the preceding features, the steering regulator may be a calculus proportional regulator, for example a function of the current value minus said current setpoint value, or vice versa.

[0046] Such a steering regulator can reliably bring the current value towards or even to the current set point and follow a movement that does not conflict with the longitudinal attitude, ie the pitch movement.

[0047] According to features compatible with the preceding features, the current set point may be variable and established according to one or more monitored parameters, which may be of the following type.

[0048] Thus, the at least one monitored parameter may include the forward speed of the hybrid helicopter.

[0049] The at least one monitored parameter may include lift generated by the lift rotor.

[0050] The at least one monitored parameter may include a rotational speed of the lift rotor.

[0051] The at least one monitored parameter may include the flight altitude or height of the hybrid helicopter.

[0052] The at least one monitored parameter may include an external air temperature of the hybrid helicopter.

[0053] The at least one monitored parameter may include a deflection angle of a flap of the wing relative to a reference object.

[0054] The at least one monitored parameter may comprise a value representative of the current mass of the hybrid helicopter, which value may be estimated based on, for example, take-off mass and fuel consumption and supplemented during flight by information input by the pilot.

[0055] According to one example, the current set point may be established based on pre-tabulated values, through experimentation, calculations, and / or simulations, that are a function of one or more of the aforementioned monitored parameters.

[0056] According to another example, the current set point may be established based on a polynomial stored through experimentation, calculation, and / or simulation, which is a function of one or more of the aforementioned monitored parameters.

[0057] According to features compatible with the preceding features, the method may include a standby phase of a stable flight phase if at least one of the following conditions is met:

[0058] - the pilot applies a force to the cyclic pitch controller to cyclically control the pitch of the lift rotor blades, for example applying a force above a first force threshold,

[0059] - the pilot applies a force to the collective pitch controller to collectively control the pitch of the lift rotor blades, for example applying a force above a second force threshold,

[0060] - the component of the load factor of the hybrid helicopter in the direction perpendicular to the ground is greater in absolute value than the specified load factor threshold,

[0061] - The roll angle of the fuselage is greater than a specified roll threshold in absolute value.

[0062] This feature is advantageous in that the method does not interfere with the control of the hybrid helicopter by the human pilot. For example, if the pilot manipulates the controller of the cyclic pitch or the collective pitch, the method is disabled, which may be temporary and required to meet this condition. For example, the steering command may not be calculated or transmitted, or it may not be taken into account.

[0063] According to features compatible with the aforementioned features, the method may include the following steps: measuring a measured forward speed of the hybrid helicopter, and comparing the measured forward speed with a preset speed threshold, and executing the stable flight phase when the measured forward speed is greater than or equal to the speed threshold.

[0064] The tail active surface is unlikely to generate a pitching moment sufficient to cause a lift rotor pitch change until a higher forward speed is reached. Therefore, steering adjustments to the tail active surface are optionally implemented when the measured forward speed is greater than or equal to the activation threshold. For example, the activation threshold is about 150 knots, or about 277 kilometers per hour.

[0065] Optionally, the method may include the step of, when the measured forward speed is lower than a speed threshold, deflecting the tail active surface to a stored safe steering angle by means of the at least one tail actuator.

[0066] For example, below the activation threshold, the tail active surface is deflected to a predetermined angle, such as an angle of zero degrees (0°) relative to a reference object.

[0067] According to features compatible with the preceding features, the longitudinal attitude maintaining step may include adjusting the pitch attitude angle of the fuselage according to a reference angle by varying a cyclic pitch component of the pitch of the lift rotor blades.

[0068] This longitudinal attitude holding step can be accomplished in a conventional manner by using a plurality of jacks capable of controlling a plurality of servo controllers which periodically control the pitch of the lift rotor blades.

[0069] For example, the reference angle may be an angle set by the pilot using a human-machine interface, or a pitch attitude angle of the fuselage reached at the beginning of a stable flight phase or, if necessary, after the above-mentioned standby.

[0070] Optionally, the climb speed maintaining step may include adjusting the climb speed of the hybrid helicopter according to the vertical reference speed by changing the total pitch component of the lift rotor.

[0071] For example, the vertical reference speed may be the speed set by the pilot using the human-machine interface, or the climb angle of the fuselage reached at the beginning of a stable flight phase or, if necessary, after the above-mentioned standby.

[0072] Optionally, the movement during the tail adjustment phase may be slower than the movement during the rotor adjustment phase.

[0073] Therefore, the tail adjustment phase is less likely to conflict with or interfere with the rotor adjustment phase.

[0074] According to features compatible with the preceding features, the forward speed maintaining step may comprise adjusting the forward speed of the hybrid helicopter according to a reference forward speed by controlling at least the pitch or rotation speed of the at least one forward propeller.

[0075] The expression "at least the pitch or the rotational speed of the at least one forward propeller is controlled" means that the pitch and / or the rotational speed of at least one propeller is controlled according to, for example, known methods.

[0076] For example, the reference forward speed may be the speed set by the pilot using the human-machine interface, or the forward speed reached at the beginning of a stable flight phase or, if necessary, after the above-mentioned standby.

[0077] The present invention also relates to a hybrid helicopter having at least one lift rotor provided with variable pitch blades, the hybrid helicopter having at least one forward propeller provided with blades, the hybrid helicopter having a tail provided with at least one tail active surface, the tail active surface being configured to generate a pitch moment at least on the fuselage of the hybrid helicopter, the hybrid helicopter having at least one tail actuator for, for example, at least rotating the at least one tail active surface.

[0078] The hybrid helicopter includes a constant angle of attack route tracking system configured to implement the method of the present invention, the constant angle of attack route tracking system comprising:

[0079] - a primary sensor configured to measure said current value,

[0080] - at least one measuring system configured to determine said value of at least one monitored parameter,

[0081] - an estimator configured to determine said current set point,

[0082] a steering regulator configured to regulate said position of said tail active surface as a function of said current value and said current set point, said steering regulator being in communication with said tail actuator.

[0083] In case there is a fixed current set point, the estimator can be, for example, a simple memory.

[0084] In the presence of a current set point that varies with the value of at least one monitored parameter, the estimator can be a calculator or a function included in an existing calculator. The steering regulator can thus regulate the position of the active surface of the tail in particular as a function of the speed of the device, the flight altitude, the pressure and / or the temperature via the current set point.

[0085] The term sensor should be understood in a broad sense as a device or system that emits an electrical or optical signal, such as a carrier of the desired information. For example, a sensor may emit an electrical signal with a voltage that varies with the value of the information. The term sensor may refer to one or more sensors that work together, or even an assembly comprising at least one sensor and at least one analyzer that emits a measurement signal.

[0086] In addition, the at least one measurement system may include at least one of the following components: a forward speed sensor of the hybrid helicopter, a lift sensor that generates an image signal of the lift generated by the lift rotor, a rotation speed sensor that generates an image signal of the rotation speed of the lift rotor, a flight altitude or height sensor of the hybrid helicopter, an external air temperature sensor of the hybrid helicopter, an angle sensor that measures the deflection angle of the flap of the wing relative to a reference object, and a steering sensor that measures the deflection angle of the active surface of the tail wing.

[0087] The hybrid helicopter may include at least one of the following components: a cyclic controller force sensor that generates a signal, which changes when a pilot applies a force to a cyclic variable pitch controller to periodically control the pitch of the lift rotor blades, an overall controller force sensor that generates a signal, which changes when a pilot applies a force to a collective pitch controller to overall control the pitch of the lift rotor blades, a load factor sensor that generates a signal that varies with a component of the load factor of the hybrid helicopter in a direction perpendicular to the ground, and a roll angle sensor.

[0088] According to the feasibility of the aforementioned internal compatibility, the hybrid helicopter may include a system for adjusting the attitude angle of the fuselage according to a reference angle, and a system for adjusting the climbing speed of the hybrid helicopter according to a vertical reference speed, each system being configured to act on at least one jack of at least three servo controllers for changing the pitch of the lift rotor. The hybrid helicopter may include a system for adjusting the forward speed of the hybrid helicopter according to a reference forward speed, and the adjustment system may be configured to act on the pitch of the propeller and / or the rotation speed of the propeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] The present invention and its advantages are described in more detail below by way of examples and in conjunction with the accompanying drawings, in which:

[0090] Figure 1 is a view of a hybrid helicopter according to the present invention,

[0091] Figure 2 It is a constant angle of attack route tracking system.

[0092] Figure 3 is a view of a method according to the invention,

[0093] Figure 4 : An example table showing the determination of the current set point of the rotor parameter is shown in FIG.

[0094] Figure 5 : An example table showing the determination of the current set point of the rotor parameter is shown in FIG.

[0095] Figure 6 This is the view of the tail wing active surface turning according to the steering command when pitching up.

[0096] Figure 7 This is a view of the tail wing's active surface turning according to the turning command during a dive. DETAILED DESCRIPTION

[0097] Therefore, in this application, the expression "hybrid helicopter" refers to an aircraft equipped with at least one propulsion or traction propeller. Unless otherwise explicitly or implicitly stated, the term "rotor" or "main rotor" or "lift rotor" refers to the rotor of a rotorcraft. Unless otherwise explicitly or implicitly stated, structurally and functionally identical elements appearing in different figures are denoted by the same unique reference numeral.

[0098] Figure 1 An example of a hybrid helicopter 1 according to the invention is shown.

[0099] Regardless of the implementation, the hybrid helicopter 1 comprises a fuselage 2 extending along a longitudinal axis from a rear end of a tail 4 to a front end to a nose 3. In the front part of the fuselage 2, the hybrid helicopter 1 may comprise a cockpit 7.

[0100] In any implementation, the hybrid helicopter 1 comprises at least one lift rotor 10. The lift rotor 10 comprises a plurality of blades 11 driven to rotate by a rotor mast 12 via a rotor hub 13, for example.

[0101] Regardless of implementation and reference Figure 1 The hybrid helicopter 1 comprises at least one propeller 15 equipped with blades 16. The blades 16 may have a variable pitch and / or a variable rotation speed. For example, at least two propellers 15 are arranged on both sides of the fuselage 2, i.e., transversely opposite to the aforementioned longitudinal axis.

[0102] In order to rotate the rotor mast 12 and the propeller 15, the hybrid helicopter 1 includes Figure 220 is shown in the figure. The power plant 20 is equipped with at least one engine 21, for example at least one turbine engine. In addition, the power plant 20 may include a mechanical interconnection system 22, which kinetically connects the engine 21 with the rotor mast 12 or the propeller 15. For example, at least one propeller can be driven alternatively by its own engine or its own transmission chain. Such a mechanical interconnection system 22 may include at least one power transmission box 23, at least one shaft 24, and the like.

[0103] The output rotational speeds of the engine 21 , the propeller 15 , the lift rotor 10 and the mechanical interconnection system 22 are, for example, proportional to each other, which ratio is constant whatever the flight configuration of the hybrid helicopter 1 under normal integral transmission chain operating conditions.

[0104] Regardless of implementation and reference Figure 1 , the hybrid helicopter 1 comprises at least one wing 5 or other lifting surface, such as a top wing 5 according to the example shown. The wing 5 is provided with two half-wings 6, 7, which are arranged on the left and right sides of the fuselage 2 when the observer observes in the forward direction of the hybrid helicopter 1. For example, each propeller 15 is carried by a half-wing 6, 7. Thus, according to the example in FIG. 1 , the hybrid helicopter 1 comprises two propellers 15, which are respectively carried by two half-wings 6, 7, which are arranged on the left and right sides of the fuselage 2 when the observer observes.

[0105] According to an example not shown, the propeller or propellers may be carried laterally by one or more arms or equivalent means, or may be arranged in a different way.

[0106] Regardless of implementation and reference Figure 1 The hybrid helicopter 1 has a tail 25 equipped with stabilizing and control surfaces. Specifically, the tail 25 includes at least one tail movable surface 26, which is configured to generate a pitch moment at least on the fuselage 2. This tail movable surface 26 can take the form of a flap or an elevator hinged to a fixed surface 28, or a movable tail in its assembly. In order to control the position of at least one tail movable surface 26 relative to a reference object and, for example, a steering angle, the hybrid helicopter 1 may include at least one tail actuator 27. For example, this tail actuator 27 includes a rotary engine or other device capable of rotating at least one or more tail movable surfaces 26 relative to one or more axes AX.

[0107] The stabilizing and control surfaces may also include yaw, movable and / or fixed stabilizing surfaces. The tail 25 may have various shapes, for example according to Figure 1 The inverted U shape shown.

[0108] In addition to these aspects and referring to Figure 2The blades 11 of the lift rotor 10 are variable pitch blades and can be controlled overall and periodically.

[0109] According to the example given for describing the invention, the hybrid helicopter 1 comprises a plurality of transmission chains 40, connecting, for example, a collective pitch controller 46 and a cyclic pitch controller 45 with at least three servo controllers 35. Each transmission chain 40 should be controllable by one or more actuators, for example by a series jack 41 and / or a parallel jack 42, and these transmission chains cannot be completely independent. Each servo controller 35 can be hinged to a non-rotating disk 31 of a set of annular swash plates 30. Thus, the rotating disks 32 of a set of annular swash plates 30 are connected to the blades 11 of the lift rotor 10 via a connecting rod of a corresponding pitch. The movement of the collective pitch controller 46 then causes the same change in the length of each servo controller 35, so that the pitch of the blades 11 of the lift rotor 10 can be changed in the same way overall. The movement of the cyclic pitch controller 45 causes a change in the length of at least one servo controller 35, which is different from the change in the length of at least one other servo controller 35, so that the pitch of the blades 11 of the lift rotor 10 can be changed periodically according to the azimuth angle.

[0110] According to another aspect, the pitch of the blades 16 of the propeller 15 can be controlled by at least one propeller transmission chain, which includes at least one propeller transmission chain that is not in the Figure 1 The actuator 91 shown in FIG. Additionally or alternatively, the rotation speed of the propeller 15 may be controlled by an actuator 91 , for example an actuator 91 of the variable speed motor type that moves the propeller.

[0111] Regardless of how it is implemented, the hybrid helicopter 1 comprises a constant angle of attack trajectory tracking system 70 configured to implement the method of the invention described below.

[0112] The system 70 comprises a main sensor 50 which measures the current value of a rotor parameter.

[0113] The rotor parameters may be the power consumed by the lift rotor 10 or the engine torque delivered to the lift rotor, and the moment applied to the rotor mast 12, for example. In general, various onboard avionics systems may measure and / or calculate the values ​​of the rotor parameters used in the present invention, and are listed below. These rotor parameters may be of a general type, so a detailed description of the primary sensors is not required.

[0114] However, if the rotor parameter is the power consumed by the lift rotor 10, the main sensor 50 may include, for example, an angular velocity sensor 53 and a torque meter 54, respectively directly or indirectly measuring the rotation speed of the rotor mast 12 and the torque applied to the rotor mast 12, and a multiplier for multiplying said rotation speed and said torque of the rotor mast 12. The main sensor for estimating the power consumed by the lift rotor may also take the form of a system comprising an engine sensor for estimating the power produced by the power plant and a propeller sensor for estimating the power consumed by the propeller, for example, the power consumed by the lift rotor 10 being considered equal to the difference between the power produced by the power plant and the power consumed by the propeller, minus the losses of the plant.

[0115] When the rotor parameter is the engine torque transmitted to the lift rotor, the main sensor 50 may, for example, only comprise a torque meter 54. Alternatively, a torque meter arranged upstream of a movable member rotating with the rotor mast may be used, with a proportionality factor if necessary.

[0116] In addition, the system 70 may include at least one measurement system configured to determine at least one monitoring parameter value, namely including at least one of the following components:

[0117] - a forward speed sensor 51, measuring the forward speed of the hybrid helicopter 1, such as a pitot tube sensor or a satellite positioning system,

[0118] a lift sensor 52 generating an image signal of the lift generated by the lift rotor 10, such as a force measuring system on a power turning box rod driving the rotor mast as described in the literature,

[0119] - a rotation speed sensor 53, generating a rotation speed image signal of the lift rotor 10,

[0120] a flight altitude or height sensor 55 of the hybrid helicopter 1 , for example a barometer system such as a radiosonde, or a satellite positioning system, or even a radar system or equivalent,

[0121] - an external air temperature sensor 56 of the hybrid helicopter 1, such as a thermometer or an equivalent device,

[0122] - an angle sensor 57 measuring the deflection angle of the flap 8 of the wing 5 relative to a reference,

[0123] A steering sensor 58 measures the steering angle of at least one active surface of the tail wing.

[0124] Optionally, the system 70 may include at least one of the following measurement components:

[0125] a cyclic controller force sensor 60 generating a signal which changes when the pilot applies a force to the cyclic pitch controller 45 in order to cyclically control the pitch of the blades 11 of the lift rotor 10,

[0126] a total controller force sensor 61 generating a signal which changes when the pilot applies a force to the total pitch controller 46 in order to control the pitch of the blades 11 of the lift rotor 10 as a whole,

[0127] a load factor sensor 62 generating a signal that varies with the component of the load factor of the hybrid helicopter 1 in a direction perpendicular to the ground, such a sensor 62 may be a device of the type known by the acronym AHRS, which stands for “Attitude and Heading Reference System”.

[0128] a roll angle sensor 63, measuring the roll angle of the hybrid helicopter 1, such a sensor 63 can be an inclinometer or part of an inertial device,

[0129] a pitch angle sensor 64, measuring the pitch angle of the hybrid helicopter 1, such a sensor 64 can be an inclinometer or part of an inertial device,

[0130] a sensor 65 which generates, for example by means of a variometer, a signal which varies with the climbing speed VZ of the hybrid helicopter.

[0131] - A hybrid helicopter current mass sensor 66, which may include a fuel gauge for estimating the current fuel in the aircraft, and the sensor 66 may have a human-machine interface so that the mass of the aircraft at take-off can be stored, or other information that allows a calculator of the sensor 66 to infer the mass of the aircraft according to conventional methods.

[0132] Furthermore, for convenience, the system 70 may include a processing unit, referred to as a “computer 75 ”, which implements the method by means of signals transmitted by one or more of the aforementioned sensors to control the tail actuator or actuators 27 and the jacks 41 , 42 so that the pitch of the blades 11 of the lift rotor 10 can be acted upon.

[0133] The calculator 75 may include, for example, at least one processor and at least one memory, at least one integrated circuit, at least one programmable system, at least one logic circuit, and these examples do not limit the scope of the expression “computer”. The term processor may refer to a central processing unit known by the acronym CPU, a graphics processing unit GPU, a digital unit known by the acronym DSP, a microcontroller, and the like.

[0134] The calculator 75 may include various modules, which may include, for example, independent units or lines of code. Each module may include at least one processor and / or at least one memory, at least one integrated circuit, at least one programmable system, at least one logic circuit, and these examples do not limit the scope of the expression "module". The calculator may be a calculator of a known system with the acronym AFCS and the English name "Aircraft Flight Control System".

[0135] Thus, the calculator 75 may comprise a module called “estimator 76” configured to determine a current set point, and a module called “steering regulator 77” configured to determine a steering command and transmit it to the tail actuator 27. The estimator 76 may simply comprise a memory in the case of a current set point, or may take the form of a code segment, for example, in the case of a variable set point.

[0136] In addition to these aspects, the computer 75 may include a system 78 for regulating the attitude angle of the fuselage 2 according to a reference angle, and / or a system 79 for regulating the climbing speed VZ of the hybrid helicopter 1, which communicate with the aforementioned jacks 41, 42 to control the servo-controller 35. The system 78 is thus an attitude angle regulator, while the system 79 is a climbing speed regulator.

[0137] The calculator 75 may comprise a system 90 for regulating the forward speed VA of the hybrid helicopter 1 as a function of the reference forward speed VA*, the system communicating for example with at least one actuator 91 acting in the same way on the pitch of the blades 16 of each propeller or on the rotational speed of each propeller.

[0138] Figure 3 A method according to the invention is shown.

[0139] The method comprises a stabilization flight phase STP1 including a tail adjustment phase STP1 aimed at adjusting the position of the tail active surface 26 and, for example, the steering angle relative to a reference object.

[0140] This tail regulation phase STP1 comprises a step STP1.1 of determining the current value of the rotor parameter by means of the main sensor 50. Specifically, the main sensor 50 can emit an electrical signal or an optical signal carrying said current value of the rotor parameter.

[0141] Before, during or after, the method comprises a step STP1.2 of determining a current set point that this rotor parameter should reach by means of an estimator 76. The current set point may be fixed and, for example, already stored, or may be established by the estimator 76 according to the value of at least one monitoring parameter measured by a suitable sensor.

[0142] When there is a current set point that varies with the value of at least one monitored parameter, the estimator 76 can implement a preset law of variation, such as a linear or polynomial step-wise variation. According to one feasibility, the estimator 76 can implement a law obtained by interpolation based on one or more values ​​of one or more monitored parameters. Various examples of the estimator 76 for determining the current set point based on a flight case are given below.

[0143] according to Figure 4 In the first example shown, the estimator 76 stores rotor parameters according to a forward speed list of the hybrid helicopter 1, which is measured by the forward speed sensor 51. Therefore, when the current forward speed is within the range of the first speed V1 (including the first speed) to the second speed V2 greater than the first speed V1, the rotor parameter takes the first stored value Wrotor*1; when the current forward speed is within the range of the second speed V2 (including the second speed) to the third speed V3 greater than the second speed V2, the rotor parameter takes the second stored value Wrotor*2; when the current forward speed is within the range of the third speed V3 (including the first speed) to the fourth speed V4 greater than the third speed V3, the rotor parameter takes the third stored value Wrotor*3; and when the current forward speed is higher than or equal to the fourth speed V4, the rotor parameter takes the fourth stored value Wrotor*4.

[0144] according to Figure 5 In the second example shown, the estimator 76 stores rotor parameter values ​​of dens1 , dens2 , dens3 that are tabulated according to the forward speed and air density of the hybrid helicopter 1 .

[0145] Alternatively, the current density can be estimated in a conventional manner using information provided by a flight altitude or height sensor 55 and a temperature sensor 56 of the hybrid helicopter 1 .

[0146] According to a variant, more complex tables can be created using other monitored parameter values, such as the lift of lift rotor 10 determined by lift sensor 52 or even the steering angle of at least one flap of wing 5 measured by steering sensor 58 .

[0147] In a third example, the estimator 76 stores a polynomial having, for example, as variables the forward speed VA and the rotational speed of the lift rotor 10 measured by the air density and rotational speed sensor 54 and the steering angle of the flap 8 of the wing measured by the angle sensor 57 .

[0148] In addition, refer to Figure 3 The estimator 76 stores the value of the current set point or applies, for example, at least one line of code to determine, for each calculated pitch, the current set point that the rotor parameter should reach.

[0149] Thus, the tail regulating phase STP1 shown comprises regulating the position of the tail active surface 26. For example, this phase comprises a step STP1.3 of determining a steering order for the tail active surface 26 by means of the steering regulator 77 according to the current values ​​and the current set points of the rotor parameters.

[0150] For example, subtractor 770 establishes the difference between the current value and the current set point of the rotor parameter and inputs it into steering regulator 77. Steering regulator 77 is optionally a calculus proportional regulator as a function of the difference between the current value and the current set point. Thus, the steering command may be equal to the result of the following relationship:

[0151] kp*(Wrotor-Wrotor*)+ki*int(Wrotor-Wrotor*)+kd*d(Wrotor-Wrotor*) / dt

[0152] Wherein "kp", "ki", and "kd" represent gains that may be determined experimentally, calculated, and / or simulated, "Wrotor" represents the current value, "Wrotor*" represents the current set point, "int" represents the integral with respect to time, "d / dt" represents the derivative with respect to time, " / " represents the division sign, "*" represents the multiplication sign, "+" represents the addition sign, and "-" represents the subtraction sign.

[0153] The tail adjustment phase STP1 then comprises a step STP1.4 of steering the tail movable surface 26 by means of the tail actuator 27 according to the steering command. For example, the steering regulator 77 sends a signal carrying the steering command, the tail actuator 77 receives the signal and thus steers the tail movable surface 26, provided that the steering angle delta measured by the steering sensor 58 does not correspond to the expected steering angle. For example, the expected steering angle corresponds to the angle by which the tail movable surface 26 should be turned.

[0154] In addition, in the presence of multiple tail active surfaces 26 , differential steering can be performed by another control loop or by superposition to meet additional objectives, such as compensation of wake asymmetries interfering with the tail or assistance in the roll control of the hybrid helicopter 1 .

[0155] According to an alternative, the method comprises a standby phase STP0 of a stable flight phase STP1 if at least one of the following conditions is met:

[0156] - the pilot applies a force detected by the controller force sensor 60 to the cyclic pitch controller 45,

[0157] - the pilot applies to the collective pitch controller 46 a force detected by the controller force sensor 61 ,

[0158] - the component Nz of the load factor in the vertical direction along the ground measured by the load factor sensor 62 is greater than the load factor threshold stored in the suppressor 80 in absolute value,

[0159] The roll angle of the fuselage 2 measured by the roll angle sensor 63 is greater than the roll angle threshold stored in the suppressor 80 in absolute value.

[0160] Such a suppressor 80 can be, for example, a module of the computer 75 of the system 70, which sends or does not send a steering command to the tail actuator 27 according to the above conditions. According to another example, the suppressor can be an external additional module of the computer 75; the module can be inserted between the computer 75 and the tail actuator 27 to achieve the same effect.

[0161] Alternatively, the suppressor 80 may instead suppress the entire stable flight phase STP1 .

[0162] According to an alternative solution, if necessary compatible with the above, the method may comprise a step STP0.1 of measuring the forward speed VA of the hybrid helicopter 1 measured by means of the sensor 51 .

[0163] Therefore, the system module and, for example, the inhibitor 80 can compare the measured forward speed VA with a stored speed threshold. In this case, the stable flight phase STP1 can optionally be implemented only when the measured forward speed VA is greater than or equal to the threshold speed.

[0164] Otherwise, the inhibitor 80 or other modules may send a command to the tail actuator 27 to turn the tail movable surface 26 to the stored safe steering angle.

[0165] According to an optional scheme that is compatible with the above content if necessary, the method includes a rotor adjustment phase STP2, which includes a longitudinal attitude maintenance step STP2.1. The longitudinal attitude maintenance step STP2.1 may include adjusting the pitch attitude angle theta of the fuselage 2 according to the reference angle theta* and the current attitude angle measured by the sensor 64. The subtractor 781 calculates the difference between the reference angle theta** and the current attitude angle theta. The attitude regulator 782 establishes an error signal based on this difference, for example, by calculus proportional regulation, and then inputs it into the adder 783, which adds the error signal to the control signal theta0pil that changes with the position of the cyclic pitch controller. The adder 783 then transmits a set point signal to the control module 750, such as the control module of the calculator 75, to obtain the cyclic variation of the pitch of the blades 11 of the lift rotor 10.

[0166] The rotor regulation phase STP2 may include a climb speed maintenance step STP 2.2. The climb speed maintenance step STP2.2 may include regulating the climb speed VZ of the hybrid helicopter 1 relative to the vertical reference speed VZ* and the climb speed VZ measured by the sensor 65. The subtractor 791 determines the difference between the vertical reference speed VZ* and the climb speed VZ. The vertical speed regulator 792 establishes an error signal based on this difference, for example by calculus proportional regulation, and then inputs it into the adder 793, which adds the error signal to the control signal theta1pil that varies with the position of the collective pitch controller. The adder 793 then transmits a set point signal to the control module 750 to obtain the overall change in the pitch of the blades 11 of the lift rotor 10.

[0167] The vertical reference speed VZ* and the reference angle θ* may be equal, for example, to the climbing speed VZ and the steering angle theta reached at the beginning of the method.

[0168] In addition, the stable flight phase may include a forward speed maintaining step STP3. The forward speed maintaining step STP3 may include adjusting the forward speed VA measured by the forward speed sensor 51 according to the reference forward speed VA* by automatically controlling the pitch 16 and / or the rotation speed of each forward propeller 15.

[0169] For example, the regulation system 90 includes a subtractor that finds the difference between the reference forward speed VA* and the measured forward speed VA. From this difference, the system speed regulator 90 creates an error signal, for example, by calculus proportional regulation, which is then input into an adder that adds the error signal to the control signal that varies with the propulsion controller. The adder then transmits a setpoint signal to each actuator 91 to obtain an overall change in the pitch and / or speed of the propeller.

[0170] The reference advancement speed VA* may be equal, for example, to the advancement speed achieved at the beginning of the method or even, if necessary, after a standby phase of the method, to a speed set via the human-machine interface.

[0171] Therefore, refer to Figure 6, the steering command given can cause the tail active surface 26 to move to a position where a lift F is generated, which generates a moment that causes the fuselage 2 to pitch up. In order to maintain a constant attitude and a constant route and thus a constant angle of attack, this adjustment causes a periodic control command during the dive through a longitudinal attitude maintenance step STP2.1, which is transmitted to tilt the rotor circle, thereby offsetting the effect on the tail 25 of the fuselage 2 and even the total pitch of the lift rotor 10 to follow the desired route. According to this example, the lift rotor 10 is therefore in a propulsion mode, and a component of its aerodynamic force P is used for the propulsion of the hybrid helicopter 1. The power consumed by the main rotor 10 is thereby increased. In order to maintain a substantially constant forward speed, the propeller 6 is then unloaded. In the forward speed maintenance step, the pitch of the blades 16 and / or the rotation speed of the propeller 6 will be reduced. The power consumed by these propellers 6 is thereby reduced. The change in rotor lift that occurs with the change in the inclination of the rotor circle is offset by the climb speed maintenance step, which results in a change in the total pitch. The course is thus kept constant, and the angle of attack and any wing lift therefore also remain substantially constant.

[0172] exist Figure 7 In the opposite case shown, the tail active surface 26 generates a dive moment of the hybrid helicopter 1. In order to maintain a constant attitude, a periodic control of the pitching occurs while maintaining the pitch attitude. The power consumed by the lift rotor 10 is reduced, and this consumed power may become low or even zero or negative. In order to maintain a substantially constant forward speed, the propeller 6 is then loaded in reverse. The pitch of the blades 16 of the propeller 6 and / or their rotational speed and the power consumed by these propellers will increase.

[0173] Therefore, the present invention can adjust the power distribution between the lift rotor 10 and the propeller 6 while maintaining equal incidence angles, equal flight paths and constant speeds to achieve an optimized operating point under normal flight conditions.

[0174] The method according to the invention, more particularly describing an application comprising a lift rotor 10 and two propellers 6, can be easily converted to an application comprising, for example, a single propeller 6 with or without wings and / or two lift rotors, without departing from the scope of the invention.

[0175] Of course, the present invention has many modifications in its implementation. Although several embodiments have been described, it is understood that it is impossible to exhaustively determine all possible modes. Without departing from the scope of the present invention, it is obvious that the device can be replaced by an equivalent device.

Claims

1. A control method for a hybrid helicopter (1), the hybrid helicopter (1) having at least one lift rotor (10) provided with blades (11) with variable pitch, the hybrid helicopter (1) having at least one forward propeller (15) provided with blades (16), the hybrid helicopter (1) having a tail (25) provided with at least one tail active surface (26), the tail active surface being configured to generate a pitch moment at least on a fuselage (2) of the hybrid helicopter (1), the hybrid helicopter (1) having at least one tail actuator (27) for rotating the at least one tail active surface (26), the control method comprising a stable flight phase, including a rotor adjustment phase including a longitudinal attitude maintenance step and a climbing speed maintenance step, and a propeller adjustment phase including a forward speed maintenance step, It is characterized in that The stable flight phase includes a tail adjustment phase, which includes the following steps: - determining, by means of a main sensor (50), the current value of a rotor parameter which determines the current power consumed by the lift rotor (10), - determining, by means of an estimator (76), a current set point of the rotor parameter, the current set point being fixed or being a function of the value of at least one monitored parameter, wherein the rotor parameter is the power consumed by the lift rotor (10) and the current set point is a power set point, or the rotor parameter is the engine torque delivered to the lift rotor (10) and the current set point is a torque set point, - According to the current value and the current set point, the position of the tail active surface (26) is adjusted by means of a steering regulator (77).

2. The control method according to claim 1, It is characterized in that The position adjustment of the tail wing movable surface (26) comprises the following steps: - determining a steering command for the active surface of the tail (26) by means of the steering regulator (77) according to the current value and the current set point, - According to the steering command, the tail wing movable surface (26) is steered by the tail wing actuator (27).

3. The control method according to claim 1 or 2, It is characterized in that The steering regulator (77) is a calculus proportional regulator.

4. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter includes the forward speed of the hybrid helicopter (1).

5. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter includes the lift generated by the lift rotor (10).

6. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter includes the rotational speed of the lift rotor (10).

7. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter comprises the flight altitude of the hybrid helicopter (1).

8. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter includes the external air temperature of the hybrid helicopter (1).

9. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter comprises a deflection angle of a flap (8) of the wing (5) relative to a reference object.

10. The control method according to claim 1 or 2, It is characterized in that The at least one monitored parameter includes a value representative of a current mass of the hybrid helicopter.

11. The control method according to claim 1 or 2, It is characterized in that The control method includes a standby phase of the stable flight phase if at least one of the following conditions is met: - the pilot applies force to the cyclic pitch controller (45) to periodically control the pitch of the blades (11) of the lift rotor (10), - the pilot applies force to the collective pitch controller (46) to collectively control the pitch of the blades (11) of the lift rotor (10), - the component of the load factor of the hybrid helicopter in the direction perpendicular to the ground is greater in absolute value than the specified load factor threshold, - The roll angle of the fuselage (2) is greater than a specified roll threshold in absolute value.

12. The control method according to claim 1 or 2, It is characterized in that The control method comprises the following steps: measuring the measured forward speed of the hybrid helicopter (1), and comparing the measured forward speed with a preset speed threshold, and executing the stable flight phase when the measured forward speed is greater than or equal to the speed threshold.

13. The control method according to claim 12, It is characterized in that The control method comprises the step of deflecting the tail active surface to a stored safe steering angle by means of the at least one tail actuator when the measured forward speed is lower than the speed threshold.

14. The control method according to claim 1 or 2, It is characterized in that The longitudinal attitude maintaining step includes adjusting the pitch attitude angle of the fuselage (2) according to a reference angle by periodically controlling the blades (11) of the lift rotor (10).

15. The control method according to claim 1 or 2, It is characterized in that The climbing speed maintaining step includes adjusting the climbing speed of the hybrid helicopter (1) according to the vertical reference speed by overall controlling the total pitch of the blades of the lift rotor.

16. The control method according to claim 1 or 2, It is characterized in that The movements in the tail adjustment phase are slower than the movements in the rotor adjustment phase.

17. The control method according to claim 1 or 2, It is characterized in that The forward speed maintaining step includes adjusting the forward speed of the hybrid helicopter (1) according to a reference forward speed by at least controlling the pitch of at least one of the forward propellers (15) or the rotation speed of at least one of the forward propellers (15).

18. A hybrid helicopter (1) having at least one lift rotor (10) provided with blades (11) of variable pitch, the hybrid helicopter (1) having at least one propeller (15) provided with blades (16), the hybrid helicopter (1) having a tail (25) provided with at least one tail active surface (26), the tail active surface being configured to generate a pitch moment at least on a fuselage (2) of the hybrid helicopter (1), the hybrid helicopter (1) having at least one tail actuator (27) for rotating the at least one tail active surface (26), It is characterized in that The hybrid helicopter (1) comprises a constant angle of attack trajectory tracking system (70), the system being configured to implement the control method according to any one of claims 1 to 16, the constant angle of attack trajectory tracking system (70) comprising: - a main sensor (50) configured to measure said current value, - at least one measuring system configured to determine said value of at least one monitored parameter, - an estimator (76) configured to determine said current set point, A steering regulator (77) configured to regulate the position of the tail active surface (26) as a function of the current value and the current set point, the steering regulator (77) being in communication with the tail actuator (27).

19. The hybrid helicopter according to claim 18, It is characterized in that The at least one measuring system comprises at least one of the following components: a forward speed sensor (51) of the hybrid helicopter (1), a lift sensor (52) generating an image signal of the lift generated by the lift rotor (10), a rotation speed sensor (54) generating an image signal of the rotation speed of the lift rotor (10), a flight altitude sensor (55) of the hybrid helicopter (1), an external air temperature sensor (56) of the hybrid helicopter (1), an angle sensor (57) measuring the deflection angle of the flap (8) of the wing (5) relative to a reference object, and a steering sensor (58) measuring the deflection angle of the active surface of the tail wing.

20. The hybrid helicopter according to claim 18 or 19, It is characterized in that The hybrid helicopter (1) includes at least one of the following components: a cyclic controller force sensor (60) generating a signal, the signal changes when a pilot applies a force to a cyclic variable pitch controller (45) to periodically control the pitch of the blades (11) of the lift rotor (10), a total controller force sensor (61) generating a signal, the signal changes when a pilot applies a force to a total pitch controller (46) to overall control the pitch of the blades (11) of the lift rotor (10), a load factor sensor (62) generating a signal, the signal changes with the component of the load factor of the hybrid helicopter (1) in a direction perpendicular to the ground, and a roll angle sensor (63).

21. A hybrid helicopter according to claim 18 or 19, It is characterized in that The hybrid helicopter (1) comprises a system (78) for adjusting the attitude angle of the fuselage according to a reference angle, and a system (79) for adjusting the climbing speed of the hybrid helicopter (1) according to a vertical reference speed, wherein the hybrid helicopter (1) comprises a system (90) for adjusting the forward speed of the hybrid helicopter (1) according to a reference forward speed.

Images