FR3019912A1 - SYSTEM AND METHOD FOR DETERMINING FLIGHT PARAMETERS AND FUEL CONSUMPTION OF AT LEAST ONE FLIGHT PHASE OF AN AIRCRAFT - Google Patents

Abstract

The present invention relates to a method for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft. This method is according to the invention characterized in that it comprises, for said or each flight phase, the following steps: a step of defining a plurality of embodiments of said flight phase considered to be each a set of successive segments (Sn) having their own flight parameters (ISn) predetermined or determined randomly or pseudo-randomly; - a calculation step, for each embodiment of said flight phase considered, on the basis of the aerodynamic characteristics (IAV) of said airplane and flight parameters (Isn) of each segment (Sn) of the embodiment, the speeds (Vn) of the segments (Sn) and the fuel consumption (CFPm) of said aircraft for said embodiment, - an optimization step according to which, as flight parameters of the flight phase considered, only the flight parameters (IFPopt) of the segments constituting the realization of said flight phase for which fuel consumption (CFPopt) is minimized, as well as the speeds (VSnopt) of the segments of said embodiment and said resulting fuel consumption (CFPopt). The present invention also relates to a system for implementing said method.

Description

The present invention relates to a method and a system for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft, and a computer program provided for implementing said method. An airplane operator, prior to departure to a destination, prepares his flight to avoid any negligence that could lead to an incident or accident. This preparation makes it possible in particular to determine the air route to follow for the destination it has set and the fuel consumption that is necessary to complete this flight. This consumption includes various reserves to take into account possible situations, such as waiting in flight before being able to land at the destination airport, a diversion, due to bad weather conditions, to another airport near the airport. originally planned airport, etc. To do this, the operator first determines his flight strategy essentially defined by the air route followed with the chosen alternate aerodromes, the flight levels during the different phases of flight, and then, in a second step, determines the fuel consumption that results from such a strategy. This consumption is determined by means of charts which, for a type of aircraft specified in a particular configuration, give the fuel consumption as a function of the flight altitude, the air distance to be traveled, which depends on the speed of the aircraft. estimated wind during a weather analysis, the distance to be traveled between the destination airport and an alternate airport, the aircraft's landing weight and its mass without fuel. Each chart is also provided for constant data speeds for climb, cruise and descent.

Such charts are for example theoretically established by means of mathematical models of aircraft flight behavior. Software exists today that essentially reproduces the principle of these charts. The operator then enters the parameters of his flight strategy on his computer, selects an aircraft of a given type in a particular configuration and the software determines the fuel consumption resulting from this flight. The abacuses and software mentioned above consider constant flight conditions during each phase of a flight so that they are not at all concerned with a search for flight conditions ensuring optimum fuel consumption.

The present invention aims to solve this problem and, to do this, has the characteristics below exposed. Thus, the present invention relates to a method for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft which is characterized in that it comprises, for said or each phase of flight, the following steps: a step of defining a plurality of embodiments of said flight phase considered to be each a set of successive segments having their own predetermined flight parameters or determined randomly or pseudo-randomly, a calculation step, for each embodiment of said flight phase considered, on the basis of the aerodynamic characteristics of said aircraft and the flight parameters of each segment of the embodiment considered, the speeds of the segments and the fuel consumption of said aircraft for said embodiment, - a step optimization criteria that, as flight parameters of the flight phase considered, are flight meters segments that constitute the realization of said flight phase for which fuel consumption is minimized, as well as the speeds of the segments of said embodiment and the resulting fuel consumption.

According to an advantageous embodiment, the flight parameters of each segment which constitutes an embodiment of said flight phase include the reference altitude of said segment and the speed of said aircraft in said segment, but may also include the incidence of plane relative to its axis of progress and the slope of said aircraft.

According to an advantageous characteristic of the present invention, said optimization step uses, for example, a Monte-Carlo method, a genetic optimization method, or an IPOPT type internal-point optimization method. Similarly, said calculation step implements a mathematical modeling method of an aircraft.

According to an advantageous characteristic of the present invention, said method comprises a step of determining the aerodynamic parameters of said aircraft on the basis of the flight data recorded during previous flights of said aircraft.

The present invention also relates to a system for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft which is characterized in that it comprises: a unit for defining a plurality embodiments of said flight phase considered to be each a set of successive segments having their own predetermined flight parameters or determined randomly or pseudo randomly, - a processing unit which, for each embodiment of said flight phase, on the basis of the characteristics aerodynamics of said aircraft and the flight parameters of each segment of the embodiment considered, calculates the speeds of the segments and the fuel consumption of said aircraft for said embodiment, - an optimization unit which does not retain, as flight parameters of the phase of flight considered, that the flight parameters of the segments that constitute the realization of the said phase for which said fuel consumption is minimized, as well as the speeds of the segments of said embodiment and the resulting fuel consumption. According to an advantageous characteristic of the present invention, said system comprises a unit for delivering the aerodynamic parameters of said aircraft, said unit being designed to collect flight data recorded during previous flights of said aircraft. Finally, the present invention relates to a computer program loaded into a memory of a computer, said program comprising instructions or parts of code for implementing the steps of the method for determining the flight parameters and the fuel consumption of the engine. at least one flight phase of a previously described aircraft, when said program is executed by said computer. The characteristics of the invention mentioned above, as well as others, will emerge more clearly on reading the following description of an exemplary embodiment, said description being given in relation to the attached drawings, among which: FIG. . 1 is a diagram showing the different phases of flight during a flight of an aircraft, FIG. 2 is a block diagram of a system for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft according to the present invention; FIG. 3 is a diagram showing two embodiments of the same phase of flight of an aircraft, FIG. 4 is a view illustrating the balance of forces acting on an aircraft when the aircraft is in flight, FIG. 5 is a diagram illustrating a method of determining the flight parameters and fuel consumption of at least one flight phase of an aircraft according to the present invention, and FIG. 6 is a block diagram of a computer which, when provided with a program according to the present invention, implements a determination method according to the invention. It is shown in FIG. 1 a diagram showing the different phases of a flight: a taxi phase I during which the aircraft rolls from its parking area to the runway, a take-off phase II, generally up to an altitude of 5000 feet (also FL 50 for flight level 50, ie flight level 50, the level being the hundredth of the altitude in feet) which is followed by a climb phase III, for example up to at an altitude of 31000 feet (FL 310). After this, there follows a cruise phase IV at a substantially constant level, for example FL 310. At the end of the cruise phase IV, it is the descent phase V followed by the landing phase VI .

All phases of flight have flight parameters of their own. Nevertheless, because the present invention is essentially concerned with the fuel consumption of the aircraft and the climbing phase is that for which, during a flight, the present invention is essentially based on this climbing phase, although adapted to each of the other phases of flight.

The system shown in FIG. 2 essentially comprises a processing unit 10, an IAV avionics parameter delivery unit 20, a user interface 30, an IFP flight phase parameter delivery unit 40, and an optimization unit 50. The processing unit 10 is provided to receive from the unit 20 aerodynamic parameters IAV specific to the aircraft to which the user is interested. These aerodynamic parameters are, for example without limitation, the mass m of the aircraft empty and without fuel, its aerodynamic coefficients Cx and C, the nominal thrust of the To engines and the wing surface S of the aircraft.

The user interface 30 allows the user to enter flight conditions, such as departure airport, destination airport, alternate airport (s), flight altitudes, including cruise altitude. , as well as the type and configuration of the aircraft considered. The type and configuration of the aircraft in question are transmitted to the unit 20 for delivering, to the processing unit 10, the corresponding aerodynamic parameters. The unit 40 successively considers K flight phases (K may be equal to 1) FPk, at the user's choice by means of the user interface 30, or predetermined. The flight phases in question are those which are the object of FIG. 1. Thus, the user could use the system of the present invention only to optimize the rise phase and therefore to be interested only in this phase. In this case, K would be equal to 1. Or, he could be interested only in the phases of rise III, cruise IV and descent V. In this case, K is equal to 3. For the or each phase of FPK, the unit 40 defines M realizations thereof which are respectively named FPink with m = 1 to M. For the sake of simplicity, except when necessary, each FPink realization is now implicitly called a phase of flight k. In addition, the unit 40 divides each flight phase embodiment FP, thus defined into a number N of flight phase segments. This number N is for example entered by the user by means of the user interface 30 or is a predetermined number. In FIG. 3, there are shown two flight phase embodiments FP, i and FP, 2 which are each divided into three flight phase segments Sn '', S21 and S31 and S, m2, S72 and S3. Following the description, the exponent m is no longer mentioned because implicit, unless necessary. Each segment Sn (n = 1 to N, implicitly a flight phase embodiment of index m) is defined by segment flight parameters' Sn which are specific to it, such as an altitude of segment start Hn (which constitutes, for example, a reference altitude of said segment) and an end of segment altitude Hn + 1 which is equal to the start altitude of the segment following Sn + i or the altitude HFPUP of the end of the phase FP flight considered. It will be noted that the flight phase commencement altitude HFPDW FP and the flight phase end altitude FP are identical for all FPm flight phase embodiments, with m = 1 to M. This segment flight information Sn may also incorporate, for each Sn segment, other parameters, such as the angle of attack and yn of the aircraft, or the center of gravity of the aircraft. In an exemplary embodiment of the invention, one can write: Isn = OEn, yn} for all n between 1 and N.

Thus, a flight phase embodiment FPm is defined by flight phase realization parameters IFPm which consist of a set of N segment flight parameters' Sn, that is, = {Isi, - IsN} and, in The example mentioned above, IFpm = 111, 711, {Hn, yr, 7n}, {HN, OEN, yN} 1. More specifically, using the flight phase index m, one should write: IFpn , = {{Hm {HN, aNin, yNin}} For each flight phase embodiment, the value given by the unit 40 to each of the segment flight parameters' Sn, such as the reference altitude Hn, l incidence an and the slope yn of the aircraft considered is either predetermined, or determined randomly or pseudo-randomly. For the or each flight phase considered FPk, the unit 40 determines, on the basis of the flight conditions entered by the user by means of the user interface 30, a sequence of M flight phase realization information {IFpi , IFPM} which is then transmitted to the processing unit 10. The processing unit 10, on the basis of each IFPm flight phase realization information present in the sequence transmitted to it by the unit 40, determines the CFpm consumption resulting from this FPm phase of flight realization.

To do this, the processing unit 10 can proceed as follows. For each Siim segment (hereinafter referred to as Sn) of the realization of the FPm flight phase considered, it determines, initially, on the basis of the set of segment flight parameters Isn of the segment Sn contained in FIG. IFPm flight phase realization information considered by the unit 40 as well as the aerodynamic parameters IAv delivered by the unit 20, the speed Vn of the aircraft in this Sn segment and the resulting fuel consumption Csn. For example, the processing unit 10 uses, to calculate the speed Vn of the aircraft in a segment S, a mathematical model of an aircraft. It is shown in FIG. 4 an aircraft 100 whose slope relative to the ground is y and which has an incidence with respect to its axis of displacement dd '. The following vectors are represented: T is the thrust that is parallel to the axis of displacement dd ', mg the weight of the aircraft at the moment considered, L the lift which is perpendicular to the axis of the aircraft aa' and D the trail that is parallel to the axis of the aircraft aa '. To translate the fact that this plane is in equilibrium and moves at a speed V. parallel to its axis of displacement dd ', the following equations can be written: T cos a - D - mg sin y = m Vn T sin The thrust T depends on the nominal thrust To when the air density is po, the speed of the aircraft expressed in Mach M, the density of the airspeed. air p at the moment considered, according to the equation: M2 T = T - (1- M - -) Po The drag D and the lift L depend on the density of the air p at the place considered, the speed V , of the wing surface S of the aircraft, and respectively of two aerodynamic coefficients Cx and C, also called drag coefficient and lift coefficient. We therefore have: D = 1 2 pV2SC "(CC, M) L = 1 2 pV2SC" (CC, M) It will be noted that the aerodynamic coefficients Cx and C, themselves depend on the speed of the aircraft expressed Mach M and the angle of incidence of the aircraft with respect to its axis of displacement dd '. Moreover, it should also be noted that the density of the air p depends on the altitude of the place considered. So-called barometric leveling formulas allow to know this variation of air density with altitude. For example, without temperature variation, one has: Ah -RT p (H1) = p (H) eh 'with h = mg R being the specific heat of the air, T the temperature in Kelvin degree, M the mass molar air and gravity.

Knowing the altitude H. (which determines the density of the air p and the thrust T), the incidence an and the slope yn as well as the avionic parameters (wing area S, aerodynamic coefficients Cx and C '), it is possible, by solving the differential equations presented above, to calculate the speed V. of the plane. For example, it is possible to use a resolution algorithm (solver) of differential equations. From the knowledge of the speed V. of the aircraft, it is possible to determine the fuel consumption of the aircraft. For example, the following formulation can be used: Cs. = a (H.) Vii + b (H) where a and b are coefficients that depend on the altitude H. In a second step, the processing unit 10 sums the fuel consumption values Csn of the segments Si to SN which constitute the realization of the flight phase FPm considered. The processing unit 10 thus delivers, to the optimization unit 50, for each flight phase FPk, a series of consumption values CFpm corresponding to the flight phase implementations FPm (m = 1 to M) considered to which are appended the values of or of certain flight parameters IFpm (for example, the speeds VI 'to VZ, heights HNm, etc.) of all the segments Sn: to SN which compose this flight phase realization FPm : {CFpi, IFPl; CFPm, IFPm; CFPM, IFPM}, ie, in the example mentioned above: {CFpi,; H, ...,; ; HNI; ; cFpNI, viM H; ; vNi \ A; The aim of the optimization unit 50 is to determine the segment flight parameters Isn "t with n = 1 to N, in whole or in part, of a FP ° Pt embodiment of a flight phase for the CFp ° Pt fuel consumption resulting therefrom is minimized, the segment flight parameters selected are, for example, the elevations Hi ° pt to HNo pl of each of the N segments which constitute the optimal embodiment FP ° Pt. to add, a sequence of incidence values aiopt to OENopt and a series of slope values opt to 7Nopt or any other flight phase parameter considered.

The optimization unit 50 then delivers the segment flight parameters Is. ° Pt, the speeds Vs ° Pt of the segments S. which constitute the optimal realization Frt as well as the minimized consumption CFp ° Pt. For its operation, the optimization unit 50 may, for example, use a genetic optimization algorithm or an optimization algorithm using a Monte Carlo method. It can also use a method of the IPOPT interior point optimization method type. An arrow is shown between the optimization unit 50 and the unit 40 because, according to the optimization method implemented by the unit 50, information can be transmitted by the unit 50 to the unit 40. so that it can deliver sequences of flight phase realization information IFpn, and this, during the course of the optimization treatment implemented by the unit 50. In a particular embodiment, the avionics parameter issuing unit IAv is provided for collecting the data flight data which has been recorded during previous flights of the aircraft in question. For example, these data recorded during flight, are the speed of the aircraft V, its flight altitude H, its slope y and its incidence a, the mass m, its consumption C, its engine speed from which it is easy to determine the thrust, etc. and this at every moment. By reinjecting these Data data into a mathematical model of the aircraft and by solving the equations that make up this model, it is possible to determine the avionics parameters of this model for the aircraft in question. For example, by taking up the equations of the model developed above in relation to the processing unit 10, from data flight data recorded during previous flights that are the speed V, its flight altitude H, its slope y and its incidence a, mass m, its thrust, it is possible to determine the aerodynamic coefficients Cx and C, which minimize the difference between the different quantities that this model calculates and these Data data. For example, an algorithm for solving differential equations can be used to do this. Note that the aerodynamic parameter delivery unit 20 could be used not only to supply these parameters to the processing unit 10 which is described above, but also to any processing unit, regardless of its operation, requiring such aerodynamic parameters. The advantage of such an avionics parameter delivery unit IAv is that it can take into account the actual physical characteristics of the aircraft in question and not the nominal characteristics of an airplane of the same type and in the same configuration. The present invention relates to a method for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft, among the phases which are the subject of FIG. This process is briefly described in connection with FIG. 5, its details or examples of embodiments having already been mentioned in the description of the system for determining the flight parameters of at least one flight phase of an aircraft according to the invention which has been made in relation with FIG. 2. The method of the present invention comprises, for said or each phase of flight for which it is implemented, the following steps: a step El0 of defining a plurality of embodiments of said phase of flight considered as being each a set of successive segments having their own predetermined flight parameters or determined randomly or pseudo-randomly, - a calculation step E20, for each embodiment of said flight phase considered, on the basis of the avionics characteristics of said aircraft and the flight parameters of each segment of the embodiment considered, the speeds of the segments and the fuel consumption of said aircraft for said embodiment, - an optimization step E30 according to which are retained, as flight parameters of the flight phase considered, that the flight parameters of the segments constituting the achievement of said phase of flight for which the fuel consumption urant is minimized, as well as the speeds of the segments of said embodiment and said resulting fuel consumption. In the system shown in FIG. 2, said step El0 is implemented by the unit 40, the step E20 is implemented by the processing unit 10 and the optimization step E30 is implemented by the optimization unit 50 Thus, as already mentioned for these units, the flight parameters of each segment which constitutes an embodiment of said flight phase include the reference altitude of said segment. They can include the incidence of the aircraft relative to its axis of progress and the slope of said aircraft. Likewise, said optimization step E30 can implement a Monte Carlo method, a genetic optimization method, or an IPOPT type internal point optimization method.

Likewise, said calculation step E20 implements a mathematical modeling method of an aircraft, such as that described with reference to FIG. 4. Said method can also implement a step E40 for determining the aerodynamic parameters of said aircraft on the basis of the flight data recorded during previous flights of said aircraft. This step E40 is for example implemented by the unit 20 described with reference to FIG. 2. FIG. 6 is a block diagram of a computer 100 which includes a man-machine interface 110 which includes the functions of the user interface 30 of the system of the present invention described in connection with FIG. 2, a central unit 120 and a memory 130, connected together by means of a bus 140. In the memory 130 is loaded a computer program which, when executed by said computer 100, implements the steps of a method for determining the flight parameters of at least one flight phase of an aircraft according to the present invention. In the embodiment described here, the units 10, 20, 40 and 50 described in connection with FIG. 2 are software units integral parts of this computer program. The optimized flight parameters Is. "And the resulting fuel consumption CFPOPt of the or each flight phase considered are displayed, for the flight phases required by the user, by means of the man-machine interface 110.

Claims (9)

CLAIMS1) A method for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft, characterized in that it comprises, for said or each flight phase, the following steps: - a step (E10) of defining a plurality of embodiments of said flight phase considered to be each a set of successive segments (S.) having their own predetermined or randomly or pseudo-randomly determined flight parameters (Is.), a step (E20) of calculation, for each realization of said flight phase considered, on the basis of the aerodynamic characteristics (IAV) of said aircraft and the flight parameters (Is.) of each segment (S.) of the embodiment considered, velocities (V.) of segments (S.) and fuel consumption (CFpr.) of said aircraft for said embodiment, - an optimization step (E30) according to which are retained, as parameters of flight of the phas the flight parameters (IFp ") of the 15 segments which constitute the realization of said phase of flight for which the fuel consumption (CFp") is minimized, as well as the speeds (Vs. ") of the segments of said embodiment and said resulting fuel consumption (CFp "). 2) Method according to claim 1, characterized in that the flight parameters of each segment (Is.) Which constitutes an embodiment of said flight phase considered include the reference altitude (H.) of said segment (S.) . 3) Method according to claim 2, characterized in that said flight parameters of each segment (Is.) Which constitutes an embodiment of said flight phase include the incidence (an) of the aircraft relative to its axis of flight. advancement dd 'and the slope (711) of said aircraft with respect to its axis aa'. 4) Method according to one of the preceding claims, characterized in that said optimization step implements a Monte Carlo method, a genetic optimization method, or an IPOPT type internal point optimization method. 5) Method according to one of the preceding claims, characterized in that said calculation step implements a mathematical modeling method of an aircraft. 6) Method according to one of the preceding claims, characterized in that it comprises a step of determining the aerodynamic characteristics (IAV) of said aircraft on the basis of the flight data recorded during previous flights of said aircraft. 7) System for determining the flight parameters and the fuel consumption of at least one flight phase of an aircraft, characterized in that it comprises: - a unit (40) for defining a plurality of embodiments said flight phase considered to be each a set of successive segments (S.) having their own flight parameters (Is.) predetermined or determined randomly or pseudo-randomly, - a processing unit (10) which, for each embodiment of said flight phase considered, on the basis of the aerodynamic characteristics (IAV) of said aircraft and the flight parameters (Is.) of each segment (S.) of the embodiment in question, calculates the velocities (V.) of the segments (S .) and the fuel consumption (CFpr.) of said aircraft for said embodiment, - an optimization unit (50) which retains, as flight parameters of the flight phase considered, only the flight parameters (IFp ") segments that constitute performing said flight phase for which the fuel consumption (CFp ") is minimized, as well as the speeds (Vs.") of the segments of said embodiment and said resulting fuel consumption (CFp "). 8) System according to claim 7, characterized in that it comprises a unit (20) for delivering the aerodynamic characteristics of said aircraft, said unit being provided to collect flight data recorded during previous flights of said aircraft. 9) computer program loaded into a memory (130) of a computer (100), said program comprising instructions or parts of code for implementing the steps of a method for determining the flight parameters and the consumption in fuel of at least one flight phase of an aircraft according to one of claims 1 to 6, when said program is executed by said computer (110).