Flight performance improvement method based on aero-engine emergency control

Abstract

The invention discloses a flight performance improvement method based on aero-engine emergency control, and the method comprises the steps: calculating a flight envelope of an aircraft in an original limit state according to the parameters of the aircraft; according to the flight envelope in the original limit state, an engine thrust increasing controller is designed to carry out emergency control on the engine, and the flight performance is improved; and calculating the flight envelope of the aircraft after the flight performance is improved, comparing the flight envelope with the flight envelope in the original limit state, and carrying out quantitative evaluation on the flight performance improvement. By adjusting the control strategy of the aero-engine, higher engine thrust can be obtained by sacrificing part of the service life of the engine in emergency. The flight performance of the aircraft under the emergency condition can be effectively improved, the coping capacity and safety of the aircraft under the emergency condition can be improved, the application range of the aircraft in the complex environment is expanded, and greater safety guarantee is provided for pilots and passengers.

Description

Technical Field

[0001] The invention belongs to the field of aerospace and aviation, and relates to a flight performance improvement method based on emergency control of an aero-engine. Background Art

[0002] In the highly complex and technology-intensive field of aerospace, the flight performance of an aircraft is not only a key indicator to measure the success of its design, but also the cornerstone to ensure flight safety and improve mission execution efficiency and flexibility. Evaluating and improving the flight performance of aircraft has always been a key issue worthy of attention. Flight performance can be quantitatively described by the flight envelope, which defines the range and boundaries of parameters such as the maximum speed and maximum altitude that an aircraft can fly normally under various operating conditions, reflecting the adaptability and operating limits of the aircraft under different environmental conditions. It is determined by the performance of the aircraft itself and the performance of the aircraft engine installed on the aircraft, and directly affects the performance and safety of the aircraft in different flight phases. By accurately drawing and continuously optimizing the flight envelope, engineers can have a more comprehensive understanding of the performance boundaries of the aircraft, providing a scientific basis for flight planning, safety assessment and performance improvement.

[0003] However, in actual operation, the operating environment faced by aircraft is becoming increasingly complex and changeable, and the requirements for flight performance are also increasing. Aircraft may face various sudden emergencies, such as a short takeoff runway, insufficient lift due to damage to the aircraft wing surface, etc. At this time, the aircraft may need to exceed the performance level under the design conditions to cope with the crisis. Traditional flight technology often cannot provide sufficient response measures in these emergency situations, so it is necessary to find new ways to improve the performance of aircraft. Summary of the invention

[0004] The purpose of the present invention is to provide a flight performance improvement method based on aircraft engine emergency control to solve the problem that the existing aircraft performance level is difficult to cope with emergency crises.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The flight performance improvement method based on aircraft engine emergency control includes: According to the parameters of the aircraft, calculate the flight envelope of the aircraft under the original limit state; According to the flight envelope under the original limit state, the engine thrust increase controller is designed to implement emergency control of the engine to improve flight performance; Calculate the flight envelope of the aircraft after the flight performance is improved, compare it with the flight envelope under the original limit state, and make a quantitative evaluation of the improvement in flight performance.

[0006] Furthermore, the flight envelope calculation method includes: Calculate flight aerodynamic parameters, engine available thrust, residual thrust and specific residual power according to aircraft parameters; According to the flight aerodynamic parameters, engine available thrust, residual thrust and specific residual power, the contour line when the specific residual power is maximum is drawn using the contour plot function in Matlab, which is the flight envelope.

[0007] Further, the flight aerodynamic parameters include the aircraft's flight free stream speed, dynamic pressure, lift coefficient, drag coefficient and flight drag; The free flow speed of the aircraft is

[0008] in, represents the free stream speed of the aircraft. represents the Mach number, represents the specific heat ratio, is the gas constant, represents the atmospheric temperature; The dynamic pressure is

[0009] in, Indicates dynamic pressure, represents the atmospheric density, It indicates the free stream speed of the aircraft; The lift coefficient is

[0010] in, is the lift coefficient, Indicates the weight of the aircraft. Indicates dynamic pressure, represents the wing area; The drag coefficient is

[0011] in, represents the drag coefficient, is the zero-lift drag coefficient, is the lift-induced drag coefficient, represents the lift coefficient; The flight resistance is

[0012] in, represents the flight resistance, Indicates dynamic pressure, represents the wing area, Represents the drag coefficient.

[0013] Furthermore, the residual thrust is

[0014] in, represents the residual thrust, represents the available thrust of the engine, Indicates flight resistance.

[0015] Furthermore, the specific residual power is

[0016] in, Represents the specific residual power, Indicates the residual thrust, when When the remaining power is set is 0, Indicates the flight speed of the aircraft. Indicates the weight of the aircraft.

[0017] Furthermore, the engine thrust increase controller is a FADEC thrust increase controller, and the construction method of the FADEC thrust increase controller is: Build limit protection controller module, steady-state controller module and transition state controller module; According to the constructed limit protection controller module, steady-state controller module and transition state controller module, a FADEC thrust increase controller is built in combination.

[0018] Furthermore, the limit protection controller module is used to receive parameters transmitted by the engine in real time and output a low-pressure rotor speed limit instruction; The steady-state controller module is used to adjust the fuel flow supply to the engine by comparing the desired low-pressure rotor speed and the actual low-pressure rotor speed of the engine; The transient state controller module is used to provide fuel flow to the engine according to the expected low-pressure rotor speed, the actual low-pressure rotor speed of the engine and the compressor surge margin, in accordance with the set acceleration and deceleration control law.

[0019] Furthermore, the limit protection controller module includes a minimum surge margin limiter, a maximum oil-gas ratio limiter and a minimum oil-gas ratio limiter.

[0020] Further, the minimum surge margin limiter is used to avoid compressor surge during acceleration; The maximum oil-gas ratio limiter is used to prevent the combustion chamber from overheating or the high- and low-pressure rotors from overrotating; The minimum fuel-air ratio limiter is used to avoid flameout of the combustion chamber during deceleration.

[0021] Furthermore, the quantitative evaluation index of the flight performance improvement is the maximum altitude limit and the maximum speed limit of the flight envelope.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a flight performance improvement method based on emergency control of an aircraft engine. By adopting emergency control of an aircraft engine, some restrictions in the engine are reasonably released. After the engine is subjected to thrust increase control in an emergency, the original performance limit of the engine can be broken through, and the engine can be operated beyond the limit in a short time, so as to provide the aircraft with a greater available thrust than the maximum design state. The flight envelope is calculated based on the relative residual power method. The flight envelope shows the operating limits of the aircraft under various conditions, including the maximum speed, the maximum altitude, the maximum load, etc. After the engine thrust increase control, the overall performance of the aircraft is improved, and the flight envelope will also be expanded accordingly. The flight envelope is drawn and compared with the original flight envelope, so as to realize the quantitative evaluation research on the improvement of the flight performance of the aircraft by emergency control of the aircraft engine. By adjusting the control strategy of the aircraft engine, the present invention can sacrifice part of the engine life in exchange for higher engine thrust in an emergency. This method can effectively improve the flight performance of the aircraft in an emergency, help improve the response capability and safety of the aircraft in an emergency, use the engine emergency control to improve the flight performance of the aircraft in an emergency, and quantitatively evaluate the improvement effect, expand its application scope in complex environments, and provide greater safety protection for pilots and passengers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a flow chart of flight envelope calculation of the present invention.

[0025] Figure 2 It is a basic structural diagram of the aircraft engine control system of the present invention.

[0026] Figure 3 This is the fuel control envelope diagram of the aircraft engine of the present invention.

[0027] Figure 4 The present invention is a flow chart of a method for improving flight performance based on emergency control of an aircraft engine.

[0028] Figure 5This is a Simulink model diagram of a certain type of engine thrust increase controller of the present invention.

[0029] Figure 6 A thrust comparison diagram of a certain type of engine before and after thrust increase under a certain working condition of the present invention.

[0030] Figure 7 This is an overall comparison diagram of the flight envelope before and after the engine thrust increase control of the present invention.

[0031] Figure 8 It is a partial comparison diagram of the flight envelope before and after the engine thrust increase control of the present invention.

[0032] Fig. 9 The structure diagram of the flight performance improvement system based on aircraft engine emergency control according to the preferred embodiment of the present invention is shown.

[0033] Fig.10 It is a schematic diagram of the structure of an electronic device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0037] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0038] It should be noted that the terminals involved in the embodiments of the present application may include but are not limited to mobile phones, personal digital assistants (PDAs), wireless handheld devices, tablet computers, personal computers (PCs), MP3 players, MP4 players, wearable devices (for example, smart glasses, smart watches, smart bracelets, etc.), smart home devices and other smart devices.

[0039] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 4 The present invention provides a method for improving flight performance based on emergency control of an aircraft engine, comprising the following steps: Step 1: Calculate the flight envelope of the aircraft under the original limit state. The calculation process is as follows: Figure 1 The flight envelope determines the operating limits of the aircraft under various conditions, including maximum speed, maximum altitude, and maximum load. These limits ensure that the aircraft does not exceed its structural and safety limits during operation, thereby ensuring the safety of pilots and passengers, and are an important criterion for flight performance evaluation.

[0041] (1) The main parameters of the aircraft include weight and The wing area is , the atmospheric temperature is The atmospheric density is The gas constant is and the specific heat ratio is .

[0042] (2) Calculate various aerodynamic parameters required for the flight envelope based on the parameters in (1). is the Mach number, is the zero lift drag coefficient, is the lift induced drag coefficient.

[0043] The free stream speed of the aircraft is

[0044] Dynamic pressure is

[0045] The lift coefficient is

[0046] The drag coefficient is

[0047] The flight resistance is

[0048] (3) Calculate the thrust of a certain type of aircraft engine under different operating conditions and different powers using GasTurb software , that is, the available thrust of the aircraft.

[0049] (4) The residual thrust is

[0050] The remaining power is

[0051] when When the remaining power is set is 0, Indicates the flight speed of the aircraft.

[0052] (5) Use the contour function in Matlab, with altitude, Mach number and specific residual power as function inputs, to draw the contour line when the specific residual power Z is maximum, which is the flight envelope.

[0053] Step 2: Design an engine thrust increase controller to implement emergency control of the engine (i.e. thrust increase control) to achieve engine performance improvement, thereby improving the overall performance of the aircraft, and laying the foundation for subsequent quantitative comparative research on the flight envelope after the flight performance is improved.

[0054] (1) Engine thrust increase control principle: The original engine controller is a variable gain PID controller, which can complete the steady-state and transitional control of the entire flight envelope. In the non-afterburner operation mode, the low-pressure rotor speed is the controlled quantity, fuel quantity As a control quantity, Figure 2 shown.

[0055] like Figure 3As shown in the figure, when the engine is started, it will run in the safe working area (the green area in the figure), which is surrounded by the maximum fuel limit, the minimum fuel limit, the slow speed and the maximum power. According to the above envelope, in order to ensure the safe and reliable operation of the engine, three limit controllers are designed in the designed controller: minimum surge margin, maximum oil-gas ratio and minimum oil-gas ratio. Among them, the purpose of the minimum surge margin limit is to avoid compressor surge, which mainly works in the acceleration process; the maximum oil-gas ratio limit is used to avoid overheating of the combustion chamber or overspeed of the high and low pressure rotors; the purpose of the minimum oil-gas ratio limit is to avoid flameout of the combustion chamber, which mainly works in the deceleration process.

[0056] Table 1 Main parameters of the engine at maximum thrust

[0057] It can be seen from Table 1 that under the existing maximum thrust state, the engine high and low pressure rotor speeds, turbine front and rear temperatures, compressor stability margins, maximum and minimum oil-gas ratios, etc. have not reached the existing limit values. This is because when designing the controller, in addition to considering engine performance, it is also necessary to consider factors such as engine component life, safe operation, and control accuracy, and usually a certain margin is left.

[0058] Therefore, in an emergency, the designed minimum surge margin and maximum fuel-gas ratio limit controller can be adjusted upward to reduce the reserved margin and control the engine to run close to the surge boundary. At this time, a larger fuel flow rate can be provided to the engine, and the engine can provide greater thrust for the aircraft, thereby achieving thrust increase control.

[0059] (2) Design of aircraft engine thrust increase controller: The thrust increase controller of aircraft engines is the FADEC controller. First, the limit protection controller module in the FADEC controller is built, which is also the key to the thrust increase controller. The limit protection controller includes three limiters: minimum surge margin limiter, maximum oil-gas ratio limiter and minimum oil-gas ratio limiter. It receives the minimum surge margin, maximum oil-gas ratio, minimum oil-gas ratio and other parameters transmitted by the engine in real time, and outputs the low-pressure rotor speed limit instruction.

[0060] Secondly, build the steady-state controller module in the FADEC controller. The purpose of the steady-state controller is to keep the engine running stably under a certain fixed condition. It compares the expected low-pressure rotor speed The engine fuel flow supply is adjusted according to the actual low-pressure rotor speed of the engine. The input parameters include the desired low-pressure rotor speed and the real-time low-pressure rotor speed, and the output parameter is the steady-state fuel flow.

[0061] Then build the transition state controller module in the FADEC controller. The transition state controller receives the expected low-pressure rotor speed. , the actual low-pressure rotor speed of the engine, the compressor surge margin and other parameters are used as input values, and the fuel flow is provided to the engine according to the set acceleration and deceleration control law (i.e. the fuel flow-engine low-pressure rotor percentage speed curve), ensuring that the engine can smoothly and steadily transition to a new working state, while avoiding excessive engine load or unstable performance.

[0062] Finally, the FADEC thrust increase controller is assembled, including the limit protection controller module, the steady-state controller module and the transient controller module. It accepts the desired low-pressure rotor speed , the engine real-time feedback (low-pressure rotor speed, compressor surge margin, oil-air ratio, turbine front temperature, etc.), the output is the final fuel flow supplied to the engine. According to the needs, the limit values ​​of the minimum surge margin limiter and the maximum oil-air ratio limiter in the limit protection controller module can be adjusted to control the engine to operate close to the surge boundary and achieve thrust increase control.

[0063] Step 3: By increasing the limit values ​​of the minimum surge margin limiter and the maximum fuel-gas ratio limiter in the limit protection controller in step 2, the engine is subjected to thrust increase control, which can increase the engine's limit thrust under different working conditions, thereby making the aircraft have higher available thrust and improving the overall flight performance of the aircraft. At this time, the flight envelope after the flight performance is improved is calculated according to step 1.

[0064] Step 4: Use the flight envelope calculated in step 3 after the engine implements thrust increase control and flight performance improvement, and compare it with the flight envelope of the aircraft under the original limit conditions calculated in step 1. Use the maximum altitude limit and maximum speed limit of the flight envelope as flight performance indicators to quantitatively evaluate the flight performance improvement achieved by thrust increase control.

[0065] The present invention is further described in detail below in conjunction with specific embodiments: Embodiment 1: In this embodiment, a certain type of aircraft equipped with a certain type of twin-rotor turbofan engine is taken as an example to illustrate a method for improving flight performance based on emergency control of an aircraft engine, which specifically includes the following steps: Step 1: Calculate the flight envelope of a certain type of aircraft equipped with a certain type of twin-rotor turbofan engine under the original limit state.

[0066] (1) The weight of a certain type of aircraft is =100000 The wing area is =1100 The atmospheric temperature is , the atmospheric density is , the gas constant is , the specific heat ratio is .

[0067] (2) Calculate various aerodynamic parameters required for the flight envelope based on the parameters in (1). is the Mach number, is the available thrust of the engine. , is the zero-lift drag coefficient, , is the lift induced drag coefficient.

[0068] The free stream speed of the aircraft is

[0069] Dynamic pressure is

[0070] The lift coefficient is

[0071] The drag coefficient is

[0072] The flight resistance is

[0073] (3) The bypass ratio of a certain type of twin-rotor turbofan engine is 0.3, the total pressure ratio is 28, and the temperature before the turbine is 1800K. The thrust of this type of engine under different working conditions and different powers is calculated using the GasTurb software. , that is, the available thrust of the aircraft.

[0074] (4) The residual thrust is

[0075] The remaining power is

[0076] when When the remaining power is set is 0, Indicates the flight speed of the aircraft.

[0077] (5) Using the contour function in Matlab, with altitude, Mach number, and specific residual power as function inputs, draw the contour line when the specific residual power Z is maximum (here the specific residual power is 500), which is the flight envelope.

[0078] Step 2: Use the engine thrust controller to achieve engine thrust control, thereby improving the overall performance of the aircraft. The thrust controller is as follows: Figure 5 shown.

[0079] Under different Mach numbers and altitude conditions, by increasing the limit values ​​of the designed minimum surge margin controller and the maximum fuel-gas ratio limit controller, different fuel flows are provided to the engine to achieve the designed low-pressure compressor speed. Improve the expected value by 7%, thereby controlling the engine from running beyond the limit and making the overall performance of the aircraft break through the original limit. Figure 6 As shown, when the altitude is 15000m and the Mach number is 0.8, the engine thrust increases from 73870N to 84803N, and the thrust increase is about 15%.

[0080] Step 3: After the engine implements thrust increase control in step 2, the engine's maximum thrust under different working conditions is increased so that the aircraft has a higher available thrust. At this time, the flight envelope is calculated according to step 1.

[0081] Step 4: Compare the flight envelope after the engine implements thrust-increasing control to improve flight performance with the original flight envelope, and conduct a quantitative evaluation of the flight performance improvement achieved by thrust-increasing control.

[0082] like Figure 7 As shown in the figure, it can be seen that the engine thrust control is implemented under different working conditions. After the engine thrust limit is increased, the aircraft breaks through the original performance limit, and the maximum altitude limit and maximum speed limit of the flight envelope are improved. The specific analysis is as follows Figure 8 As shown, at Mach number 0.8, the maximum altitude limit of the flight envelope is increased by 3000ft, an increase of 7% based on the original maximum altitude limit.

[0083] Embodiment 2: Embodiment 2 provided by the present invention is an embodiment of a flight performance improvement system based on aircraft engine emergency control provided by the present invention, such as Fig. 9 As shown, an embodiment of the system includes: a calculation module, a promotion module and an evaluation module.

[0084] A calculation module, the calculation module is used to calculate the flight envelope of the aircraft under the original limit state according to the parameters of the aircraft; An enhancement module, wherein the enhancement module is used to design an engine thrust increase controller to implement emergency control of the engine according to the flight envelope under the original limit state, thereby improving the flight performance; An evaluation module is used to calculate the flight envelope of the aircraft after the flight performance is improved, compare it with the flight envelope under the original limit state, and quantitatively evaluate the improvement of flight performance.

[0085] It can be understood that the flight performance improvement system based on aircraft engine emergency control provided by the present invention corresponds to the flight performance improvement method based on aircraft engine emergency control provided by the aforementioned embodiments. The relevant technical features of the flight performance improvement system based on aircraft engine emergency control can refer to the relevant technical features of the flight performance improvement method based on aircraft engine emergency control, which will not be repeated here.

[0086] Another object of the present invention is to provide an electronic device, such as Fig.10 As shown, it includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the steps of the flight performance improvement method based on aircraft engine emergency control.

[0087] The flight performance improvement method based on aircraft engine emergency control comprises the following steps: According to the parameters of the aircraft, calculate the flight envelope of the aircraft under the original limit state; According to the flight envelope under the original limit state, the engine thrust increase controller is designed to implement emergency control of the engine to improve flight performance; Calculate the flight envelope of the aircraft after the flight performance is improved, compare it with the flight envelope under the original limit state, and make a quantitative evaluation of the improvement in flight performance.

[0088] The fourth object of the present invention is to provide a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the flight performance improvement method based on aircraft engine emergency control are implemented.

[0089] The flight performance improvement method based on aircraft engine emergency control comprises the following steps: According to the parameters of the aircraft, calculate the flight envelope of the aircraft under the original limit state; According to the flight envelope under the original limit state, the engine thrust increase controller is designed to implement emergency control of the engine to improve flight performance; Calculate the flight envelope of the aircraft after the flight performance is improved, compare it with the flight envelope under the original limit state, and make a quantitative evaluation of the improvement in flight performance.

[0090] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0091] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0092] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0093] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for improving flight performance based on emergency control of an aircraft engine, characterized in that: include: According to the parameters of the aircraft, calculate the flight envelope of the aircraft under the original limit state; According to the flight envelope under the original limit state, the engine thrust increase controller is designed to implement emergency control of the engine to improve flight performance; Calculate the flight envelope of the aircraft after the flight performance is improved, compare it with the flight envelope under the original limit state, and make a quantitative evaluation of the improvement in flight performance.

2. The method for improving flight performance based on emergency control of an aircraft engine according to claim 1, characterized in that: The flight envelope calculation method comprises: Calculate flight aerodynamic parameters, engine available thrust, residual thrust and specific residual power according to aircraft parameters; According to the flight aerodynamic parameters, engine available thrust, residual thrust and specific residual power, the contour line when the specific residual power is maximum is drawn using the contour plot function in Matlab, which is the flight envelope.

3. The flight performance improvement method based on aircraft engine emergency control according to claim 2, characterized in that: The flight aerodynamic parameters include the aircraft's flight free stream speed, dynamic pressure, lift coefficient, drag coefficient and flight drag; The free flow speed of the aircraft is in, represents the free-flow speed of the aircraft. represents the Mach number, represents the specific heat ratio, is the gas constant, represents the atmospheric temperature; The dynamic pressure is in, Indicates dynamic pressure, represents the atmospheric density, It indicates the free stream speed of the aircraft; The lift coefficient is in, is the lift coefficient, Indicates the weight of the aircraft. Indicates dynamic pressure, represents the wing area; The drag coefficient is in, represents the drag coefficient, is the zero-lift drag coefficient, is the lift-induced drag coefficient, represents the lift coefficient; The flight resistance is in, represents the flight resistance, Indicates dynamic pressure, represents the wing area, Represents the drag coefficient.

4. The method for improving flight performance based on emergency control of an aircraft engine according to claim 2, characterized in that: The residual thrust is in, represents the residual thrust, represents the available thrust of the engine, Indicates flight resistance.

5. The flight performance improvement method based on aircraft engine emergency control according to claim 2, characterized in that: The specific residual power is in, Represents the specific residual power, Indicates the residual thrust, when When the remaining power is set is 0, Indicates the flight speed of the aircraft. Indicates the weight of the aircraft.

6. The flight performance improvement method based on aircraft engine emergency control according to claim 1, characterized in that: The engine thrust increase controller is a FADEC thrust increase controller, and the construction method of the FADEC thrust increase controller is: Build limit protection controller module, steady-state controller module and transition state controller module; According to the constructed limit protection controller module, steady-state controller module and transition state controller module, a FADEC thrust increase controller is built in combination.

7. The method for improving flight performance based on emergency control of an aircraft engine according to claim 6, characterized in that: The limit protection controller module is used to receive parameters transmitted by the engine in real time and output a low-pressure rotor speed limit instruction; The steady-state controller module is used to adjust the fuel flow supply to the engine by comparing the desired low-pressure rotor speed and the actual low-pressure rotor speed of the engine; The transient state controller module is used to provide fuel flow to the engine according to the expected low-pressure rotor speed, the actual low-pressure rotor speed of the engine and the compressor surge margin, in accordance with the set acceleration and deceleration control law.

8. The method for improving flight performance based on emergency control of an aircraft engine according to claim 6, characterized in that: The limit protection controller module includes a minimum surge margin limiter, a maximum oil-gas ratio limiter and a minimum oil-gas ratio limiter.

9. The method for improving flight performance based on emergency control of an aircraft engine according to claim 8, characterized in that: The minimum surge margin limiter is used to avoid compressor surge during acceleration; The maximum oil-gas ratio limiter is used to prevent the combustion chamber from overheating or the high- and low-pressure rotors from overrotating; The minimum fuel-air ratio limiter is used to avoid flameout of the combustion chamber during deceleration.

10. The flight performance improvement method based on aircraft engine emergency control according to claim 1, characterized in that: The quantitative evaluation indicators for the improvement of the flight performance are the maximum altitude limit and the maximum speed limit of the flight envelope.

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