Driving assistance system, driving assistance method and aircraft

Abstract

A driving assistance system for an aircraft comprises: a measuring module (4) for measuring the vertical maneuver of the aircraft; a calculating module (5) for calculating a first load factor according to the measured vertical maneuver and according to a set point vertical maneuver; a measuring module (6) for measuring the tilt angle, the pitch rate and the pitch acceleration; a protection module (7) comprising a calculating submodule (71) and a comparing submodule (72), the calculating submodule being configured to calculate a second load factor, the comparing submodule being configured to compare the first load factor with the second load factor to determine an applicable load factor, the applicable load factor being equal to the minimum value between the first load factor and the second load factor; a calculating module (8) being configured to calculate an elevator control according to the applicable load factor; and a sending module (9) being configured to send the elevator control to the autopilot (2). A driving assistance method for an aircraft and such an aircraft are also disclosed.

Description

Technical Field

[0001] The invention relates to an automatic method and system for assisting in piloting an aircraft, in order to control at least the autopilot of the aircraft when no wind speed measurement data and no wind speed measurement estimator are available. Background Art

[0002] In the context of this specification, autopilot corresponds to:

[0003] - an autopilot system, which automatically acts on the control surfaces of the aircraft to guide the aircraft,

[0004] - or a flight director which automatically displays information on a screen in the cockpit of an aircraft in order to assist the manual piloting performed by the pilot of the aircraft.

[0005] It is known that the autopilot of an aircraft uses information on the forward speed of the aircraft (for example, airspeed) when it is optionally coupled to a thrust regulating device, the purpose of which is to maintain the pilot's choice and / or to keep the speed range at acceptable values ​​for the aircraft. If, during the piloting process, this speed information is lost, i.e. if it becomes unavailable, incorrect or unreliable, the autopilot and / or the thrust regulating device are automatically disengaged, while maintaining the current state of the aircraft (attitude and thrust), and returning control to the crew. This may occur in particular in the case of common failure modes due to, for example, severe or poor environmental conditions. However, this case is special because most aircraft are equipped with systems for limiting the impact of said environmental conditions in order to improve the availability of speed information. In the case of an abnormal loss of speed information, disengaging the autopilot and / or the thrust regulating device results in an additional workload for the crew, who, in addition to their normal tasks, must deal with the cause of the failure. The forward speed information is the main parameter used by the autopilot system or the flight director to define the flight envelope (upper and lower limits) of the aircraft and the dynamic characteristics of the aircraft. An autopilot or thrust regulating device that may not comply with these speed limits may cause the aircraft to deviate from its flight envelope. For this reason, autopilots and thrust regulating devices are provided with a number of different conventional means of protecting the speed range.

[0006] Document FR 2 960 659 A1 proposes a solution that is not entirely satisfactory. In fact, this solution does not allow stable flight over the entire flight envelope without adding additional mechanisms that exceed the attitude limits. Summary of the invention

[0007] The object of the present invention is to overcome these drawbacks by proposing a piloting assistance method for an aircraft capable of ensuring at least the availability of the autopilot and / or thrust regulation means in situations where there is no air data or where data from an air data estimator are unavailable or unnecessary.

[0008] To this end, the invention relates to a piloting assistance method for an aircraft capable of ensuring at least the availability of an autopilot that can be controlled without information on the forward speed of the aircraft.

[0009] According to the present invention, the method comprises:

[0010] - a first measurement step, performed by a first measurement module, consisting in measuring the vertical maneuvers of said aircraft;

[0011] - a first calculation step, performed by a first calculation module, comprising calculating a first load factor as a function of the measured vertical manoeuvre and as a function of a set point vertical manoeuvre;

[0012] - a second measurement step, performed by a second measurement module, comprising measuring the tilt angle, pitch rate and pitch acceleration of the aircraft;

[0013] - The protection step, performed by the protection module, includes:

[0014] o a calculation sub-step, performed by a calculation sub-module, comprising calculating a second load factor according to the measured tilt angle, according to the measured pitch rate and according to the measured pitch acceleration,

[0015] o a comparison sub-step, performed by a comparison sub-module, comprising comparing the first load factor with the second load factor to determine an applicable load factor, the applicable load factor being equal to a load factor having a minimum value between the first load factor and the second load factor;

[0016] - a second calculation step, performed by a second calculation module, consisting in calculating the elevator control according to said applicable load factor;

[0017] - A first sending step, performed by a first sending module, comprises sending the elevator control calculated in the second calculating step to the autopilot.

[0018] Thus, thanks to the invention, the autopilot has an increased usability, for example maintaining continuous cruising flight, and proposing a satisfactory level of automatic operation in deteriorating situations when forward speed information is not available.

[0019] According to a characteristic feature, the vertical maneuver corresponds to a vertical speed of the aircraft or a gradient of the aircraft.

[0020] Advantageously, the protection step further comprises a sub-step for reducing the nose pitch dynamics, which is performed by a reduction sub-module and comprises reducing the nose pitch dynamics when the measured tilt angle approaches the maximum tilt angle, so that the measured tilt angle remains below the maximum tilt angle.

[0021] According to a preferred embodiment, the method further comprises:

[0022] - a third calculation step, performed by a third calculation module, consisting in calculating a static term of thrust control capable of reaching the equilibrium point of the aircraft, said static term depending on the current flight level of the aircraft, the mass of the aircraft and the number of engines operating on the aircraft;

[0023] - a fourth calculation step, performed by a fourth calculation module, consisting in calculating, from said inclination angle measurements, a dynamic term of said thrust control capable of maintaining the equilibrium point of said aircraft;

[0024] - a fifth calculation step, performed by a fifth calculation module, comprising calculating the thrust control as the sum of the static term and the dynamic term;

[0025] - A second sending step, performed by a second sending module, comprises sending said thrust control to a thrust regulating device.

[0026] According to a characteristic feature, the fourth calculation step comprises calculating the dynamic terms of the thrust control in the following way:

[0027] - when the measured inclination angle is greater than the inclination angle of the equilibrium point, the dynamic term of the thrust control has a positive value;

[0028] - when the measured inclination angle is less than the inclination angle of the equilibrium point, the dynamic term of the thrust control has a negative value;

[0029] - the further the measured inclination angle differs from the inclination angle of the equilibrium point, the greater the absolute value of the dynamic term of the thrust control;

[0030] The dynamic term of the thrust control is between a maximum threshold and a minimum threshold.

[0031] For example, the equilibrium point corresponds to a configuration of the aircraft having a speed corresponding to a recommended "turbulent air" speed or a recommended "turbulent air" Mach number for entering a turbulent region.

[0032] Furthermore, the reduced inclination angle is used in the fourth calculation step in order to calculate the dynamic terms of the thrust control.

[0033] Furthermore, the maximum tilt angle corresponds to a configuration of the aircraft having a speed with a lift / drag ratio greater than a predetermined value.

[0034] Furthermore, the autopilot includes an autopilot system and a flight director,

[0035] The method further comprises a control step, which is performed by a control module and comprises controlling the thrust regulating device, the autopilot system and the flight director in at least the following manner:

[0036] - if the pilot of the aircraft activates the thrust regulating device, sending an activation command to the flight director in order to activate the flight director;

[0037] - if the autopilot system and the flight director are deactivated, a deactivation command is sent to the thrust regulating means in order to deactivate the thrust regulating means.

[0038] The invention also relates to a piloting assistance system for an aircraft capable of ensuring at least the availability of an autopilot, which autopilot can be controlled without information on the forward speed of the aircraft.

[0039] According to the present invention, the system comprises:

[0040] - a first measurement module configured to measure the vertical maneuvers of the aircraft;

[0041] - a first calculation module configured to calculate a first load factor as a function of the measured vertical manoeuvre and as a function of a setpoint vertical manoeuvre;

[0042] - a second measurement module, configured to measure the tilt angle, pitch rate and pitch acceleration of the aircraft;

[0043] - Protection module, including:

[0044] a calculation submodule configured to calculate a second load factor as a function of the measured tilt angle, as a function of the measured pitch rate and as a function of the measured pitch acceleration,

[0045] o a comparison submodule, the comparison submodule being configured to compare the first load factor with the second load factor so as to determine an applicable load factor, the applicable load factor being equal to a load factor having a minimum value between the first load factor and the second load factor;

[0046] - a second calculation module configured to calculate the elevator control according to said applicable load factor;

[0047] - a first sending module, the first sending module being configured to send the elevator control calculated by the second calculating module to the autopilot.

[0048] Advantageously, the protection module further comprises a reduction submodule configured to reduce the nose-up pitch dynamics when the measured tilt angle approaches a maximum tilt angle, so that the measured tilt angle remains below the maximum tilt angle.

[0049] According to an embodiment, the system further comprises:

[0050] - a third calculation module configured to calculate static terms of thrust control capable of reaching the equilibrium point of the aircraft, said static terms depending on the current flight level of the aircraft, the mass of the aircraft and the number of engines operating on the aircraft;

[0051] a fourth calculation module configured to calculate, from the inclination angle measurements, a dynamic term of the thrust control capable of maintaining the balance point of the aircraft;

[0052] - a fifth calculation module configured to calculate thrust control as the sum of the static term and the dynamic term;

[0053] - a second sending module configured to send said thrust control to a thrust regulating device.

[0054] Furthermore, the autopilot includes an autopilot system and a flight director,

[0055] The system further comprises a control module configured to control the thrust regulating device, the autopilot system and the flight director in at least the following manner:

[0056] - if the pilot of the aircraft activates the thrust regulating device, the control module sends an activation command to the flight director in order to activate the flight director;

[0057] If the autopilot system and the flight director are deactivated, the control module sends a deactivation command to the thrust regulating means in order to deactivate the thrust regulating means.

[0058] The present invention also relates to an aircraft, in particular a transport aircraft, comprising the above-mentioned driving assistance system. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The invention and its features and advantages will appear more clearly after reading the description given with reference to the accompanying drawings, in which:

[0060] - Figure 1 The driving assistance system is schematically shown.

[0061] - Figure 2 The driving assistance method is schematically shown.

[0062] - Figure 3 An aircraft equipped with an onboard pilot assistance system is shown. DETAILED DESCRIPTION

[0063] Figure 1 The aircraft AC ( Figure 3 )An embodiment of an onboard driving assistance system 1.

[0064] The pilot assistance system 1 is capable of ensuring at least the availability of the autopilot POLIT (POLIT stands for “automatic pilot” in English) 2 and / or the thrust regulation device THRUST (THRUST stands for “thrust regulation device” in English) 3, and can control the autopilot and the thrust regulation device without forward speed information, that is, without air data or without the availability of data from an air data estimator capable of determining the forward speed (e.g. airspeed).

[0065] The autopilot 2 includes an autopilot system SYS (SYS stands for “automatic piloting system” in English) 21 and / or a flight director DIR (DIR stands for “flight director” in English) 22 .

[0066] The driver assistance system 1 comprises a measuring module MEAS1 (MEAS stands for “measuring module” in English) 4 configured to measure vertical maneuvers of the aircraft AC.

[0067] According to a first alternative embodiment, the measurement module 4 comprises an inertial unit.

[0068] According to a second alternative embodiment, the measurement module 4 comprises a satellite geographic navigation system, such as the Global Positioning System (GPS for “Global Positioning System” in English).

[0069] According to a third alternative, the measurement module 4 comprises a satellite geographic navigation system and an inertial unit.

[0070] The pilot assistance system further comprises a calculation module COMP1 (COMP for "computational module") 5 configured to calculate a first load factor according to the vertical maneuver measured by the measurement module 4 and according to a setpoint vertical maneuver. The setpoint vertical maneuver may correspond to a vertical maneuver selected by the pilot of the aircraft AC. The first load factor corresponds to the vertical load factor.

[0071] Furthermore, the driver assistance system 1 comprises a measurement module MEAS2 6 configured to measure the bank angle of the aircraft AC, the pitch rate of the aircraft AC and the pitch acceleration of the aircraft AC.

[0072] The driving assistance system 1 further comprises a protection module PROT (PROT stands for “protection submodule” in English) 7, which comprises:

[0073] a calculation submodule COMP 71 configured to calculate a second load factor as a function of the tilt angle measured by the measurement module 6, as a function of the measured pitch rate and as a function of the measured pitch acceleration. The second load factor corresponds to the vertical load factor;

[0074] - a comparison submodule COMPA (COMPA stands for "comparison submodule" in English) 72, which is configured to compare the first load factor calculated by the calculation module 5 with the second load factor calculated by the calculation submodule 7 in order to determine an applicable load factor, which is equal to the load factor having the minimum value between the first load factor and the second load factor.

[0075] The comparison submodule 72 thus determines the minimum value between the first load factor and the second load factor. The applicable load factor thus corresponds to the minimum value of the two load factors, or in other words, to the maximum dive load factor.

[0076] According to a preferred embodiment, the protection module 7 includes a reducing submodule RED (RED stands for “reducing submodule” in English) 73, which is configured to reduce the nose-up pitch dynamic characteristics when the measured tilt angle approaches the maximum tilt angle, so that the measured tilt angle remains lower than the maximum tilt angle.

[0077] By way of example, the maximum inclination angle corresponds to a configuration of the aircraft AC having a speed with a lift / drag ratio greater than a predetermined value, or so-called "green spot" speed. The predetermined value may be selected so that this lift / drag ratio has a maximum value.

[0078] The driver assistance system further comprises a calculation module COMP2 8 configured to calculate the elevator control (or to calculate the pitch control for automatic control of the elevator) according to the applicable load factor determined by the comparison submodule 72 .

[0079] The elevator control calculated by the calculation module 8 is then sent to the autopilot 2 by a sending module SEND1 (SEND stands for “sending module” in English) 9 , which is included in the driver assistance system 1 .

[0080] This elevator control makes it possible to perform automatic control of vertical maneuvers of the aircraft AC.

[0081] A vertical maneuver may correspond to a vertical speed or gradient.

[0082] If the autopilot 2 is operating, for example, in a guidance mode of the aircraft AC corresponding to a HDG lateral guidance mode called “Heading”, the vertical manoeuvre corresponds to the vertical speed. The automatic control corresponds to an automatic vertical speed control.

[0083] If the autopilot 2 is operated, for example, in a guidance mode of the aircraft AC corresponding to the TRK guidance mode known as “tracking”, the vertical manoeuvre corresponds to a gradient. The automatic control is therefore an automatic gradient control.

[0084] The TRK lateral guidance mode is associated with the FPA vertical guidance mode called "flight track angle" and makes it possible to use the velocity vector (or "inertial bird") displayed on the aircraft AC's Primary Flight Display (PFD).

[0085] Advantageously, the driving assistance system 1 is also capable of performing automatic thrust control.

[0086] Thus, the pilot assistance system 1 may comprise a calculation module COMP3 10 configured to calculate a static term of thrust control capable of reaching a balance point of the aircraft AC. This static term depends on the current flight level of the aircraft AC, the mass of the aircraft AC and the number of engines operating on the aircraft AC.

[0087] By way of example, this static term corresponds to the controlled rotation speed of the engine blades of the aircraft AC. According to other examples, this static term may be the pressure ratio or the power.

[0088] Furthermore, the piloting assistance system 1 may comprise a calculation module COMP4 11 configured to calculate, as a function of the inclination angle measurements, dynamic terms of the thrust control capable of maintaining the equilibrium point of the aircraft AC.

[0089] The measured inclination angle determined by the protection module 7 can be used to calculate the dynamic terms of the thrust control.

[0090] Advantageously, the calculation module 11 is configured to calculate the dynamic terms of the thrust control in the following manner:

[0091] - when the measured inclination angle is greater than the inclination angle of the equilibrium point, the dynamic term of the thrust control has a positive value;

[0092] - when the measured inclination angle is less than the inclination angle of the equilibrium point, the dynamic term of the thrust control has a negative value;

[0093] - the further the measured inclination angle differs from the inclination angle of the equilibrium point, the greater the absolute value of the dynamic term of the thrust control;

[0094] The dynamic term of the thrust control is between a maximum threshold and a minimum threshold.

[0095] When the measured bank angle is approximately equal to the attitude of the balance point, the dynamic term of thrust control is approximately zero.

[0096] The thrust control may then be calculated by a calculation module COMP5 12 included in the driving assistance system 1. The calculation module 12 calculates the thrust control as the sum of the static term calculated by the calculation module 10 and the dynamic term calculated by the calculation module 11.

[0097] The thrust control calculated in this way by the calculation module 12 can then be sent to the thrust regulating device 3 via a sending module SEND2 13 included in the driving assistance system 1 .

[0098] By way of example, the equilibrium point corresponds to a flow with a velocity corresponding to that of the flow entering the turbulent zone (V RA / M RA ) or a configuration of aircraft AC at a speed corresponding to a recommended “turbulent air” Mach number.

[0099] According to a preferred embodiment, the driving assistance system 1 further comprises a control module CONTROL (CONTROL stands for “controlling module” in English) 14, which is configured to control the thrust regulating device 3. The autopilot system 21 and the flight director 22 are controlled by the control module 14 in at least the following manner:

[0100] - if the pilot of the aircraft AC activates the thrust regulating device 3 , an activation command is sent to the flight director 22 in order to activate the flight director 22 ;

[0101] If the autopilot system 21 and the flight director 22 are deactivated, a deactivation command is sent to the thrust regulating device 3 in order to deactivate the thrust regulating device 3 .

[0102] Automatic thrust control is not mandatory. The pilot assistance system 1 retains the ability to enable automatic control of vertical maneuvers in the absence of thrust regulation device 3, whether deactivated by the pilot or already inoperative. In this case, the pilot manually adjusts the position of the throttle lever in order to define the thrust level. If the thrust level is insufficient, low speed protection and the associated warning inform the crew of the deviation from the vertical maneuver (or gradient) set point.

[0103] Controlled thrust can be adjusted to account for the effects of an engine failure.

[0104] The pilot assistance system 1 is based on the basic guidance modes taught and practiced by the pilots, namely the HDG and TRK lateral guidance modes, the VS ("vertical speed hold" mode) and the FPA vertical guidance mode, and the THR thrust regulation mode. This simplifies its use and reduces the workload of the crew.

[0105] In situations where the pilot aids are limited to zero gradient or vertical speed set point holding, the usefulness of the inertial bird is enhanced to provide a level change that is subsequently performed by manual piloting. A means for automatically disconnecting the autopilot 21, flight director 22 and thrust regulating device 3 may be required to cover the situation where a fault occurs that causes the pilot aids 1 to be activated while:

[0106] -An automatic collision avoidance maneuver is in progress;

[0107] - The aircraft AC has a climbing attitude. In this case, in the event of a release, it is preferred to disconnect the automatic operation in order to maintain the current climbing attitude of the aircraft AC. A specific condition confirming that the aircraft AC is above the highest landing geographical point can advantageously be met to prevent this type of disconnection at the cruising flight level.

[0108] The availability of setting a set of vertical speed or gradient set points makes it possible to handle the above situations without having to disengage the autopilot 21 , the flight director 22 and the thrust regulating device 3 .

[0109] Furthermore, the piloting assistance device 1 may be limited to a retracted slats and flaps and a retracted landing gear configuration in order to limit the complexity of the setup while maintaining climb, descent and cruise usability.

[0110] The present invention also relates to a driving assistance method ( Figure 2 ).

[0111] The driving assistance method includes:

[0112] - the measurement method E1 , performed by the measurement module 4 , consists in measuring the vertical maneuvers of the aircraft AC;

[0113] - a calculation step E2 , performed by the calculation module 5 , consisting in calculating a first load factor as a function of the measured vertical manoeuvres and as a function of a setpoint vertical manoeuvre;

[0114] - a measurement step E3, performed by the measurement module 6, consisting in measuring the tilt angle, the pitch rate and the pitch acceleration;

[0115] - Protection step E4, performed by protection module 7, comprising:

[0116] o a calculation sub-step E41 , performed by the calculation sub-module 71 , consisting in calculating a second load factor as a function of the measured tilt angle, as a function of the measured pitch rate and as a function of the measured pitch acceleration,

[0117] o a comparison sub-step E42 , performed by the comparison sub-module 72 , consisting in comparing the first load factor with the second load factor in order to determine an applicable load factor, which is equal to the load factor having the minimum value between the first load factor and the second load factor;

[0118] - a calculation step E5, performed by the calculation module 8, consisting in calculating the elevator control according to the applicable load factor;

[0119] A sending step E6 , performed by the sending module 9 , consists in sending the elevator control calculated in the calculation step E5 to the autopilot 2 .

[0120] The method may further comprise:

[0121] - a calculation step E7, performed by the calculation module 10, consisting in calculating a static term of thrust control capable of reaching the equilibrium point of the aircraft AC, this static term depending on the current flight level of the aircraft AC, the mass of the aircraft AC and the number of engines operating on the aircraft AC;

[0122] - a calculation step E8 , performed by the calculation module 11 , consisting in calculating, from the inclination angle measurements, the dynamic terms of the thrust control capable of maintaining the equilibrium point of the aircraft AC;

[0123] - a calculation step E9 , performed by the calculation module 12 , consisting in calculating the thrust control as the sum of a static term and a dynamic term;

[0124] A sending step E10 , performed by the sending module 13 , consists in sending the thrust control to the thrust regulating device 3 .

[0125] The method may further include a control step E11, which is performed by the control module 14 and includes controlling the thrust regulating device 3, the autopilot system 21 and the flight director 22 in at least the following manner:

[0126] - if the pilot of the aircraft AC activates the thrust regulating device 3 , an activation command is sent to the flight director 22 in order to activate the flight director 22 ;

[0127] If the autopilot system 21 and the flight director 22 are deactivated, a deactivation command is sent to the thrust regulating device 3 in order to deactivate the thrust regulating device 3 .

Claims

1. A method for assisting an aircraft in driving, capable of ensuring at least the availability of an autopilot (2), characterized in that: The method comprises: - a first measurement step (E1), performed by a first measurement module (4), consisting in measuring the vertical manoeuvres of said aircraft (AC); - a first calculation step (E2), performed by a first calculation module (5), consisting in calculating a first load factor as a function of the measured vertical manoeuvres and as a function of a set point vertical manoeuvre; - a second measurement step (E3), performed by a second measurement module (6), consisting in measuring the inclination angle, the pitch rate and the pitch acceleration of the aircraft (AC); - A protection step (E4), performed by a protection module (7), comprising: o a calculation sub-step (E41), performed by a calculation sub-module (71), comprising calculating a second load factor according to the measured tilt angle, according to the measured pitch rate and according to the measured pitch acceleration, o a comparison sub-step (E42), performed by a comparison sub-module (72), comprising comparing the first load factor and the second load factor in order to determine an applicable load factor, the applicable load factor being equal to the load factor having the minimum value between the first load factor and the second load factor; - a second calculation step (E5), performed by a second calculation module (8), consisting in calculating the elevator control according to said applicable load factor; - a first sending step (E6), performed by a first sending module (9), consisting in sending the elevator control calculated in the second calculation step (E5) to the autopilot (2), The autopilot (2) comprises an autopilot system (21) and a flight director (22). The method further comprises a control step (E11), which is performed by the control module (14) and comprises controlling the thrust regulating device (3), the autopilot system (21) and the flight director (22) in at least the following manner: - if the pilot of the aircraft (AC) activates the thrust regulating device (3), sending an activation command to the flight director (22) in order to activate the flight director (22); - if the autopilot system (21) and the flight director (22) are deactivated, a deactivation command is sent to the thrust regulating device (3) in order to deactivate the thrust regulating device (3).

2. The method according to claim 1, It is characterized in that The vertical manoeuvre corresponds to the vertical speed of the aircraft (AC) or the gradient of the aircraft (AC).

3. The method according to claim 1 or 2, It is characterized in that The protection step (E4) further includes a sub-step (E43) for reducing the nose pitch dynamic characteristics, which is performed by a reduction sub-module (73), including reducing the nose pitch dynamic characteristics when the measured tilt angle approaches the maximum tilt angle, so that the measured tilt angle remains lower than the maximum tilt angle.

4. The method according to claim 1 or 2, It is characterized in that The method further comprises: - a third calculation step (E7), performed by a third calculation module (10), comprising calculating a static term of thrust control capable of reaching the equilibrium point of the aircraft (AC), said static term depending on the current flight level of the aircraft (AC), the mass of the aircraft (AC) and the number of engines operating on board the aircraft (AC); - a fourth calculation step (E8), performed by a fourth calculation module (11), consisting in calculating, from said inclination angle measurement, a dynamic term of said thrust control capable of maintaining the equilibrium point of said aircraft (AC); - a fifth calculation step (E9), performed by a fifth calculation module (12), comprising calculating the thrust control as the sum of said static term and said dynamic term; - a second sending step (E10), performed by a second sending module (13), consisting in sending said thrust control to the thrust regulating device (3).

5. The method according to claim 4, It is characterized in that The fourth calculation step (E8) comprises calculating the dynamic terms of the thrust control in the following manner: - when the measured inclination angle is greater than the inclination angle of the equilibrium point, the dynamic term of the thrust control has a positive value; - when the measured inclination angle is less than the inclination angle of the equilibrium point, the dynamic term of the thrust control has a negative value; - the further the measured inclination angle differs from the inclination angle of the equilibrium point, the greater the absolute value of the dynamic term of the thrust control; The dynamic term of the thrust control is between a maximum threshold and a minimum threshold.

6. The method according to claim 4, It is characterized in that Said equilibrium point corresponds to a configuration of said aircraft (AC) having a speed corresponding to a "turbulent air" speed recommended for entering a turbulent zone or a recommended "turbulent air" Mach number.

7. The method according to claim 4, It is characterized in that The reduced inclination angle is used in the fourth calculation step (E8) in order to calculate the dynamic terms of the thrust control.

8. The method according to claim 3, It is characterized in that Said maximum inclination angle corresponds to a configuration of said aircraft (AC) having a speed with a lift / drag ratio greater than a predetermined value.

9. A piloting assistance system for an aircraft capable of ensuring at least the availability of an autopilot (2), characterized in that The system comprises: - a first measurement module (4) configured to measure vertical manoeuvres of said aircraft (AC); - a first calculation module (5) configured to calculate a first load factor as a function of the measured vertical manoeuvre and as a function of a set point vertical manoeuvre; - a second measurement module (6) configured to measure the tilt angle, pitch rate and pitch acceleration of the aircraft (AC); - A protection module (7), comprising: o a calculation submodule (71) configured to calculate a second load factor based on the measured tilt angle, based on the measured pitch rate and based on the measured pitch acceleration; o a comparison submodule (72) configured to compare the first load factor and the second load factor to determine an applicable load factor, the applicable load factor being equal to a load factor having a minimum value between the first load factor and the second load factor; - a second calculation module (8) configured to calculate the elevator control according to the applicable load factor; - a first sending module (9) configured to send the elevator control calculated by the second calculation module (8) to the autopilot (2), The autopilot (2) comprises an autopilot system (21) and a flight director (22). The system (1) further comprises a control module (14) configured to control the thrust regulating device (3), the autopilot system (21) and the flight director (22) in at least the following manner: - if the pilot of the aircraft activates the thrust regulating device (3), the control module (14) sends an activation command to the flight director (22) in order to activate the flight director (3); If the autopilot system (21) and the flight director (22) are deactivated, the control module (14) sends a deactivation command to the thrust regulating device (3) in order to deactivate the thrust regulating device (3).

10. The system according to claim 9, It is characterized in that The protection module (7) further comprises a reduction submodule (73), which is configured to reduce the nose-up pitch dynamics when the measured tilt angle approaches the maximum tilt angle, so that the measured tilt angle remains below the maximum tilt angle.

11. The system according to claim 9, It is characterized in that The system further comprises: - a third calculation module (10) configured to calculate static terms of thrust control capable of reaching a point of equilibrium of the aircraft (AC), said static terms depending on the current flight level of the aircraft (AC), the mass of the aircraft (AC) and the number of engines operating on board the aircraft (AC); - a fourth calculation module (11) configured to calculate, from said inclination angle measurements, dynamic terms of said thrust control capable of maintaining a point of equilibrium of said aircraft (AC); - a fifth calculation module (12) configured to calculate the thrust control as the sum of the static term and the dynamic term; - a second sending module (13) configured to send said thrust control to the thrust regulating device (3).

12. An aircraft, It is characterized in that The aircraft comprises a pilot assistance system (1) according to any one of claims 9 to 11.

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