A departure trajectory optimization method for noise reduction

Abstract

The present invention discloses a departure track optimization method for noise reduction, which belongs to the technical field of airport noise pollution prevention and control, and includes the following steps: obtaining atmospheric environment data of the aircraft departure area, and constructing a departure aircraft performance model; correcting the NPD data according to the atmospheric attenuation rate, and correcting the noise value to obtain the aircraft real-time noise correction value; establishing aircraft performance constraints; combining the population density at each noise observation point to obtain a real-time population noise impact index; optimizing the speed and path angle of the aircraft at each time according to the dynamic window method and genetic algorithm to obtain the optimal departure track for noise reduction. The present invention solves the problem that the aircraft noise reduction departure plan is not flexible and efficient enough.

Description

Technical Field

[0001] The invention belongs to the technical field of airport noise pollution prevention and control, and in particular relates to a departure track optimization method for noise reduction. Background Art

[0002] With the rapid growth of civil aviation transportation, the problem of aircraft noise pollution around airports has become increasingly prominent. It is urgent to reduce noise pollution and implement noise prevention and control. In recent years, the departure trajectory optimization solutions for noise reduction have been implemented by improving the standard departure procedure, but there is a certain gap in the continuous climb operation departure procedure.

[0003] The existing noise reduction optimization schemes include Noise Abatement Departure Climb Procedure 1 (NADP1) and Noise Abatement Departure Climb Procedure 2 (NADP2). The difference between the two methods is that they target different noise reduction targets. NADP1 is a method to reduce noise in the departure area close to the runway, while NADP2 is a method to reduce noise in the departure area far from the runway. Although both methods can achieve noise reduction for specific targets when aircraft depart, they lack flexibility. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a departure trajectory optimization method for noise reduction, which solves the problem that the noise reduction departure scheme of aircraft is not flexible and efficient enough.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] The present invention provides a departure track optimization method for noise reduction, comprising the following steps:

[0007] S1. Obtain the atmospheric environment data of the aircraft departure area and build a departure aircraft performance model;

[0008] S2. Correct the NPD data according to the atmospheric attenuation rate, and correct the noise value by combining the NPD correction value and the departure aircraft performance model to obtain the real-time aircraft noise correction value;

[0009] S3. Establish aircraft performance constraints based on the departure aircraft performance model;

[0010] S4, selecting the real-time noise correction value of the aircraft that is greater than the preset noise threshold, and combining it with the population density at each noise observation point to obtain the real-time population noise impact index;

[0011] S5. According to the dynamic window method and genetic algorithm, based on the departure aircraft performance model, aircraft performance constraints and real-time population noise impact indicators, the speed and path angle of the aircraft at each time are optimized to obtain the optimal departure track for noise reduction.

[0012] The beneficial effects of the present invention are as follows: the present invention provides a departure trajectory optimization method for noise reduction, which combines the departure procedure of an aircraft in continuous climb operation with the departure trajectory optimization for noise reduction, so that the planning of the departure trajectory is more diversified, and the planned departure trajectory can effectively reduce noise pollution; the present invention fully considers the noise impact around the aircraft according to parameters such as population density, and provides an evaluation index for the departure trajectory planning for noise reduction by setting a real-time population noise impact index, thereby realizing flexible adjustment of the departure trajectory; the present invention combines the dynamic window method and the genetic algorithm to optimize the departure trajectory of the planned aircraft for noise reduction, thereby realizing high-precision and high-speed trajectory planning under low resolution, and while ensuring the accuracy of the planned trajectory, it also ensures the flexibility and efficiency of the trajectory planning.

[0013] Furthermore, the S1 comprises the following steps:

[0014] S11. Construct an atmospheric environment model based on the atmospheric temperature, atmospheric pressure, and altitude from the reference surface in the aircraft departure area;

[0015] The calculation expression of the atmospheric environment model is as follows:

[0016] ,

[0017] Where T represents the atmospheric temperature at a height h from the reference surface, T0 represents the temperature at the reference surface, P represents the atmospheric pressure at a height h from the reference surface, P0 represents the atmospheric pressure at the reference surface, ρ represents the atmospheric density, and R represents the gas constant;

[0018] S12. According to the total energy calculation method of the aircraft and the resistance encountered by the aircraft at different times of departure, based on the atmospheric environment model, calculate the thrust required for the aircraft to depart at different times;

[0019] The calculation expression of the thrust required for the aircraft to depart at different times is as follows:

[0020] ,

[0021] ,

[0022] ,

[0023] Among them, F k represents the thrust required for the aircraft to depart at time k, D k is the resistance encountered by the aircraft at departure time k, m k represents the weight of the aircraft at time k, g represents the acceleration due to gravity, represents the aircraft path angle at time k, represents the change in the speed of the aircraft from time k to time k+1, represents the time interval between adjacent moments, represents the drag coefficient of the aircraft at time k, represents the atmospheric density at a height h from the reference surface at time k, V k represents the speed of the aircraft at time k, S represents the wingspan area of ​​the aircraft, is the parasitic drag coefficient, represents the induced drag coefficient, represents the lift coefficient of the aircraft at time k, represents the pitch angle of the aircraft at time k, It represents the change in the departure altitude of the aircraft from time k to time k+1;

[0024] S13. Calculate the maximum available thrust at the actual departure altitude of the aircraft based on the altitude of the aircraft from the reference surface, the temperature difference between the aircraft and the reference surface, and the maximum available thrust of the aircraft under standard atmosphere;

[0025] The calculation expression of the maximum available thrust at the actual departure altitude of the aircraft is as follows:

[0026] ,

[0027] in, It represents the maximum available thrust of the aircraft in standard atmosphere. represents the first thrust coefficient, represents the second thrust coefficient, represents the third thrust coefficient, represents the maximum thrust available for the aircraft in the actual atmosphere at time k at a height h above the reference surface, represents the fifth thrust coefficient, It represents the temperature difference between the reference surface and the point at a height h above the reference surface. represents the fourth thrust coefficient;

[0028] S14. Calculate the weight of the aircraft at different times based on the fuel consumption of the aircraft over time, the speed of the aircraft at different times, and the thrust required for the aircraft to depart at different times;

[0029] The calculation expression of the weight of the aircraft at different times is as follows:

[0030] ,

[0031] Among them, m k+1 represents the weight of the aircraft at time k+1, f k represents the fuel consumption of the aircraft from time k to time k+1, represents the fuel consumption coefficient of the aircraft at time k, C f1 Represents the first fuel consumption coefficient, V k represents the speed of the aircraft at time k, C f2 Indicates the second fuel consumption coefficient;

[0032] S15. The departure aircraft performance model is constructed by combining the atmospheric environment model, the thrust required for the aircraft to depart at different times, the maximum thrust available for the aircraft in the actual atmosphere, and the weight of the aircraft at different times.

[0033] The beneficial effect of adopting the above further scheme is as follows: based on the data changes of the atmospheric environment, the present invention realizes accurate calculation of the thrust required for the aircraft to take off at different times, the maximum available thrust at the actual departure altitude of the aircraft, and the weight of the aircraft at different times, and constructs a departure aircraft performance model based on this, providing a performance basis for reasonable trajectory planning for planning the aircraft's departure trajectory for noise reduction.

[0034] Furthermore, S2 comprises the following steps:

[0035] S21, obtaining a reference sound spectrum of an aircraft engine, and obtaining the NPD difference between the actual atmosphere and the standard atmosphere at different distances through sound spectrum analysis and A-weighting processing;

[0036] S22. Obtain the atmospheric temperature, atmospheric pressure and molar concentration of water vapor at different altitudes from the reference surface, and obtain the atmospheric attenuation rate between the atmosphere at the actual departure altitude of the aircraft and the standard atmosphere based on the atmospheric temperature, atmospheric pressure and molar concentration of water vapor on the reference surface;

[0037] S23, obtaining NPD data at different distances between the standard atmosphere and the aircraft engine, and correcting the NPD data based on the atmospheric attenuation rate and the NPD difference between the actual atmosphere and the standard atmosphere at different distances to obtain an NPD correction value;

[0038] S24, obtaining the distance between the noise observation point and the departure route;

[0039] The calculation expression of the distance between the noise observation point and the departure route is as follows:

[0040]

[0041] Among them, R ik represents the slant distance from the ith noise observation point at time k to the aircraft on the departure route, L i represents the vertical distance from the ith noise observation point to the ground projection of the track;

[0042] S25, obtaining a real-time noise value at the noise observation point according to the departure aircraft performance model, the distance between the noise observation point and the departure route, and the NPD correction value;

[0043] S26, correcting the real-time noise value at the noise observation point according to the aircraft configuration, the current aircraft attitude, and the difference between the current aircraft speed and the reference speed to obtain a real-time aircraft noise correction value;

[0044] The calculation expression of the aircraft real-time noise correction value is as follows:

[0045] ,

[0046] in, represents the noise correction value at the i-th noise observation point at time k, represents the noise value at the i-th noise observation point at time k, Represents the lateral attenuation factor.

[0047] The beneficial effect of adopting the above further scheme is: the present invention provides a method for correcting the aircraft NPD data and correcting the aircraft observation shape, providing a basis for accurate noise impact evaluation based on the actual accurately observed noise conditions, and indirectly providing a basis for accurately and efficiently planning departure trajectories for noise reduction.

[0048] Furthermore, the S21 comprises the following steps:

[0049] S211. Acquire a reference sound spectrum of an aircraft engine;

[0050] S212, analyzing and obtaining a sound source spectrum of an aircraft engine according to a reference sound spectrum of the engine;

[0051] S213, extracting, according to the sound spectrum of the aircraft engine sound source, the sound spectrum corresponding to different distances from the noise source in the standard atmosphere and the sound spectrum corresponding to different distances from the noise source in the actual atmosphere;

[0052] S214, calculating the NPD difference between the actual atmosphere and the standard atmosphere at different distances according to the sound spectra corresponding to the different distances from the noise source in the standard atmosphere and the sound spectra corresponding to the different distances from the noise source in the actual atmosphere based on A-weighting processing;

[0053] The calculation expression of the NPD difference between the actual atmosphere and the standard atmosphere at different distances in S214 is as follows:

[0054] ,

[0055] in, It represents the difference in NPD between the actual atmosphere and the standard atmosphere at different distances. lg represents the logarithm operation with a base of 10. Indicates the distance d from the noise source in the actual atmosphere i The corresponding spectrum at A i Indicates the distance d from the noise source i The A-weighting coefficient at the corresponding frequency, Indicates the distance d from the noise source in standard atmosphere i The corresponding spectrum at represents the spectrum at the aircraft engine sound source, d i represents the distance between the ith noise observation point and the aircraft engine noise source, Indicates the preset standard distance used when correcting NPD data. represents the spectral coefficient of aircraft in standard atmosphere, represents the spectrum coefficient of aircraft in the actual atmosphere, It represents the frequency spectrum at the aircraft engine sound source when correcting the NPD data at a preset standard distance in a standard atmosphere, and n represents the number of selected frequency levels.

[0056] The beneficial effect of adopting the above further scheme is as follows: the present invention provides a method of obtaining the noise source sound spectra corresponding to different distances in the standard atmosphere and the actual atmosphere by analyzing and extracting features from the reference sound spectrum of the aircraft engine, and obtaining the NPD difference between the actual atmosphere and the standard atmosphere at different distances through A-weighted processing and difference calculation, which provides a basis for correcting the aircraft NPD data and also provides a basis for further correcting the aircraft noise value.

[0057] Furthermore, S3 comprises the following steps:

[0058] S31. Set the path angle constraint conditions according to the departure aircraft performance model;

[0059] The calculation expression of the path angle constraint condition is as follows:

[0060] ,

[0061] ,

[0062] in, represents the lower limit of the path angle, represents the change in path angle from time k to time k+1, represents the upper limit of the path angle, represents the maximum acceleration of the aircraft, | | represents the absolute value;

[0063] S32. Set speed constraints according to the departure aircraft performance model;

[0064] The calculation expression of the speed constraint condition is as follows:

[0065] ,

[0066] ,

[0067] ,

[0068] in, Denotes the weight m of the aircraft at time k k and the aircraft stall speed corrected by the reference weight m0, Indicates the upper limit of aircraft speed. represents the stall speed of the aircraft at the reference weight m0, a l Indicates the maximum longitudinal acceleration of the aircraft;

[0069] S33. Constructing aircraft thrust and altitude constraints based on the departure aircraft performance model and the real-time position of the aircraft;

[0070] The calculation expressions of the aircraft thrust and altitude constraints are as follows:

[0071] , ,

[0072] Where h0 represents the initial departure altitude of the aircraft, h max Indicates the maximum departure altitude of the aircraft;

[0073] S34. The path angle constraint, speed constraint, and aircraft thrust and altitude constraint are used as aircraft performance constraints.

[0074] The beneficial effect of adopting the above further scheme is as follows: the present invention provides a method for constraining the speed, path angle and thrust of an aircraft when it takes off according to an aircraft performance model, so that when planning the aircraft's departure trajectory, it can be planned based on accurate and objective aircraft performance data, thereby ensuring the reliability of the departure trajectory for noise reduction.

[0075] Furthermore, the S4 comprises the following steps:

[0076] S41, selecting the real-time noise correction value of the aircraft that is greater than the preset noise threshold, and obtaining the number of noise observation points where the noise exceeds the threshold;

[0077] S42, performing index normalization processing according to the real-time noise correction value, real-time speed and real-time path angle of the aircraft, and combining the number of noise observation points where the noise exceeds the threshold, to obtain a real-time noise impact index;

[0078] The calculation expression of the real-time noise impact index is as follows:

[0079] ,

[0080] Among them, U k represents the noise impact index at time k, represents the number of noise observation points where the noise exceeds the threshold, represents the first noise impact index coefficient, represents the second noise impact index coefficient;

[0081] S43, obtaining the population density at each noise observation point, and adjusting the real-time noise impact index based on the population density at each noise observation point to obtain a real-time population noise impact index;

[0082] The calculation expression of the real-time population noise impact index is as follows:

[0083] ,

[0084] in, represents the real-time population noise impact indicator, represents the population density at the i-th noise observation point.

[0085] The beneficial effect of adopting the above further scheme is that when evaluating aircraft departure noise, the present invention not only considers aspects such as noise duration and noise loudness changing with aircraft speed, but also fully considers the population density at the noise observation point, thereby setting a real-time population noise impact index, providing an evaluation basis for efficiently and accurately planning departure tracks for noise reduction.

[0086] Furthermore, the S5 comprises the following steps:

[0087] S51, taking the projection of the line between the departure starting point and the target end point on the ground as the X-axis, taking the axis perpendicular to the X-axis as the H-axis, and obtaining the real-time speed and real-time path angle of the aircraft at time k;

[0088] S52. Obtain the speed range and the path angle range of the aircraft at time k+1 according to the aircraft performance constraint and based on the aircraft real-time speed and real-time path angle at time k;

[0089] S53, generating an initialization population according to the speed range and the path angle range of the aircraft at time k+1;

[0090] S54, according to the genetic algorithm, based on the initialization population, obtaining the target speed and target path angle at time k+1;

[0091] S55, calculating the real-time position of the aircraft at time k+1 according to the real-time speed and real-time path angle of the aircraft at time k;

[0092] S56, judging whether the real-time position of the aircraft at time k+1 is the target destination when the aircraft leaves the airport, if so, proceeding to S58, otherwise proceeding to S57;

[0093] S57, let k+1=k, then the target speed and target path angle at time k+1 are the real-time speed and real-time path angle of the aircraft at time k, the real-time position of the aircraft at time k+1 is the real-time position of the aircraft at time k, and return to S53;

[0094] S58. Generate a departure track for noise reduction based on the position of the aircraft at each moment in the process from the departure starting point to the target destination.

[0095] The beneficial effect of adopting the above further scheme is as follows: the present invention uses the real-time population noise impact index as the evaluation basis, and optimizes the speed and path angle at each moment based on the departure aircraft performance model and aircraft performance constraints, thereby ensuring that the noise impact generated by the aircraft position at each moment in the departure track for noise reduction is as low as possible, and also achieving efficient and accurate planning of the departure track at each moment in the case of rough solution set.

[0096] Further, the S54 comprises the following steps:

[0097] S541, let the first Individual , and each individual contains two chromosomes, where the two chromosomes are The speed of an individual and path angle , the two chromosomes are represented as , V j represents the jth chromosome velocity, represents the path angle of the jth chromosome;

[0098] S542, according to the real-time population noise impact index corresponding to each individual in the initialization population, select individuals in the initialization population for replication, crossover and mutation based on the roulette wheel method to obtain generated individuals, wherein the probability of selecting an individual in the initialization population for replication, crossover and mutation is inversely proportional to the real-time population noise impact index corresponding to the individual;

[0099] S543, judging whether the speed and path angle corresponding to the generated individual meet the aircraft performance constraints, if so, proceeding to S545, otherwise proceeding to S544;

[0100] S544. According to the departure aircraft performance model, , calculate the speed and path angle of the aircraft at time k+1 as the speed and path angle corresponding to the generated individual;

[0101] S545, judging whether the number of iterations of replication, crossover and mutation of the initialized population reaches a preset iteration threshold, if so, proceeding to S546, otherwise, returning to S541;

[0102] S546. According to the speeds and path angles corresponding to all generated individuals, the real-time population noise impact index corresponding to each set of speeds and path angles is calculated respectively, and the speed and path angle when the real-time population noise impact index is minimum are selected as the target speed and target path angle at time k+1.

[0103] The beneficial effects of adopting the above-mentioned further scheme are as follows: the present invention provides a method for calculating the target speed and target path angle of the aircraft when it leaves the airport at the next moment based on a genetic algorithm, which effectively improves the efficiency and accuracy of trajectory planning. When performing trajectory planning, the present invention ensures that the planned trajectory is within the range of the aircraft's objective performance through aircraft performance constraints. For speeds and path angles that exceed the aircraft performance, the departure aircraft performance model is used to restore them, effectively ensuring the reliability of trajectory planning at each moment.

[0104] Furthermore, the calculation expressions for crossover and mutation of individuals in the initialized population are as follows:

[0105] ,

[0106] ,

[0107] Among them, rand represents a random number, V min Indicates the lower limit of aircraft speed.

[0108] The beneficial effect of adopting the above further scheme is: the present invention provides a calculation method for crossover and mutation of individuals in the initial population, which provides a basis for enriching the aircraft departure path as much as possible, and also effectively increases the probability of lower noise impact at the aircraft track at the next moment.

[0109] Furthermore, the calculation expression of the real-time position of the aircraft at time K+1 in S55 is as follows:

[0110] ,

[0111] Among them, x k+1 represents the displacement of the aircraft on the X axis at time k+1, x k represents the displacement of the aircraft on the X axis at time k, h k+1 Represents the displacement of the aircraft on the H axis at time k+1.

[0112] The beneficial effect of adopting the above further scheme is: the present invention provides a method for calculating the real-time unknown of the aircraft at the next moment. The heading of the aircraft remains unchanged when it leaves the airport, and the position of the aircraft at each moment can be accurately calculated based on its speed and path angle, thereby providing a basis for continuous planning of the aircraft's departure trajectory.

[0113] Other advantages of the present invention will be analyzed in more detail in subsequent embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] 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.

[0115] Figure 1 The present invention is a flowchart of a method for optimizing a departure trajectory for noise reduction in an embodiment of the present invention.

[0116] Figure 2 Schematic diagram of population distribution in an embodiment of the present invention.

[0117] Figure 3 4 is a graph comparing the algorithm performance of noise impact and number of iterations in an embodiment of the present invention.

[0118] Figure 4 4 is a track thrust comparison diagram in an embodiment of the present invention.

[0119] Figure 5 This is a track altitude comparison diagram in an embodiment of the present invention. DETAILED DESCRIPTION

[0120] 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 only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0121] like Figure 1 As shown, in one embodiment of the present invention, the present invention provides a departure track optimization method for noise reduction, comprising the following steps:

[0122] S1. Obtain the atmospheric environment data of the aircraft departure area and build a departure aircraft performance model;

[0123] The S1 comprises the following steps:

[0124] S11. Construct an atmospheric environment model based on the atmospheric temperature, atmospheric pressure, and altitude from a reference surface in the aircraft departure area. As the altitude from the reference surface increases, changes in factors such as temperature and air pressure will affect the performance of the aircraft and the propagation of sound. In this embodiment, the atmosphere in the aircraft flight departure area is analyzed as a homogeneous atmosphere, and the ground is selected as the reference surface.

[0125] The calculation expression of the atmospheric environment model is as follows:

[0126] ,

[0127] Where T represents the atmospheric temperature at a height h from the reference surface, T0 represents the temperature at the reference surface, P represents the atmospheric pressure at a height h from the reference surface, P0 represents the atmospheric pressure at the reference surface, ρ represents the atmospheric density, and R represents the gas constant;

[0128] S12. According to the total energy calculation method of the aircraft and the resistance encountered by the aircraft at different times of departure, based on the atmospheric environment model, the thrust required for the aircraft to depart at different times is calculated, so as to analyze the vertical profile information of the aircraft's departure flight track;

[0129] The calculation expression of the thrust required for the aircraft to depart at different times is as follows:

[0130] ,

[0131] ,

[0132] ,

[0133] Among them, F k represents the thrust required for the aircraft to depart at time k, D k is the resistance encountered by the aircraft at departure time k, m k represents the weight of the aircraft at time k, g represents the acceleration due to gravity, represents the aircraft path angle at time k, represents the change in the speed of the aircraft from time k to time k+1, represents the time interval between adjacent moments, represents the drag coefficient of the aircraft at time k, represents the atmospheric density at a height h from the reference surface at time k, V krepresents the speed of the aircraft at time k, S represents the wingspan area of ​​the aircraft, is the parasitic drag coefficient, represents the induced drag coefficient, represents the lift coefficient of the aircraft at time k, represents the pitch angle of the aircraft at time k, represents the change in the altitude of the aircraft taking off from time k to time k+1; in this embodiment, the pitch angle and the path angle of the aircraft are considered to be equal.

[0134] S13. Calculate the maximum available thrust at the actual departure altitude of the aircraft based on the altitude of the aircraft from the reference surface, the temperature difference between the aircraft and the reference surface, and the maximum available thrust of the aircraft under standard atmosphere;

[0135] The calculation expression of the maximum available thrust at the actual departure altitude of the aircraft is as follows:

[0136] ,

[0137] in, It represents the maximum available thrust of the aircraft in standard atmosphere. represents the first thrust coefficient, represents the second thrust coefficient, represents the third thrust coefficient, represents the maximum thrust available for the aircraft in the actual atmosphere at time k at a height h above the reference surface, represents the fifth thrust coefficient, It represents the temperature difference between the reference surface and the point at a height h above the reference surface. represents the fourth thrust coefficient;

[0138] S14. Calculate the weight of the aircraft at different times based on the fuel consumption of the aircraft over time, the speed of the aircraft at different times, and the thrust required for the aircraft to depart at different times;

[0139] The calculation expression of the weight of the aircraft at different times is as follows:

[0140] ,

[0141] Among them, m k+1 represents the weight of the aircraft at time k+1, f k represents the fuel consumption of the aircraft from time k to time k+1, represents the fuel consumption coefficient of the aircraft at time k, C f1 Represents the first fuel consumption coefficient, V k represents the speed of the aircraft at time k, C f2 Indicates the second fuel consumption coefficient;

[0142] S15. The departure aircraft performance model is constructed by combining the atmospheric environment model, the thrust required for the aircraft to depart at different times, the maximum thrust available for the aircraft in the actual atmosphere, and the weight of the aircraft at different times.

[0143] S2. Correct the NPD data according to the atmospheric attenuation rate, and correct the noise value by combining the NPD correction value and the departure aircraft performance model to obtain the real-time aircraft noise correction value;

[0144] The S2 comprises the following steps:

[0145] S21, obtaining a reference sound spectrum of an aircraft engine, and obtaining the NPD difference between the actual atmosphere and the standard atmosphere at different distances through sound spectrum analysis and A-weighting processing;

[0146] S21 includes the following steps:

[0147] S211. Acquire a reference sound spectrum of an aircraft engine;

[0148] S212, analyzing and obtaining a sound source spectrum of an aircraft engine according to a reference sound spectrum of the engine;

[0149] S213, extracting, according to the sound spectrum of the aircraft engine sound source, the sound spectrum corresponding to different distances from the noise source in the standard atmosphere and the sound spectrum corresponding to different distances from the noise source in the actual atmosphere;

[0150] S214, calculating the NPD difference between the actual atmosphere and the standard atmosphere at different distances according to the sound spectra corresponding to the different distances from the noise source in the standard atmosphere and the sound spectra corresponding to the different distances from the noise source in the actual atmosphere based on A-weighting processing;

[0151] The calculation expression of the NPD difference between the actual atmosphere and the standard atmosphere at different distances in S214 is as follows:

[0152] ,

[0153] in, It represents the difference in NPD between the actual atmosphere and the standard atmosphere at different distances. lg represents the logarithm operation with a base of 10. Indicates the distance d from the noise source in the actual atmosphere i The corresponding spectrum at A i Indicates the distance d from the noise source i The A-weighting coefficient at the corresponding frequency, Indicates the distance d from the noise source in standard atmosphere i The corresponding spectrum at represents the spectrum at the aircraft engine sound source, d irepresents the distance between the ith noise observation point and the aircraft engine noise source, Indicates the preset standard distance used when correcting NPD data. represents the spectral coefficient of aircraft in standard atmosphere, represents the spectrum coefficient of aircraft in the actual atmosphere, It represents the frequency spectrum at the sound source of the aircraft engine when the NPD data is corrected at a preset standard distance in a standard atmosphere, and n represents the number of selected frequency levels; in this embodiment, the A-weighted curve is a standard weight curve for audio measurement, which can reflect the response characteristics to sound, and the A-weighted coefficient is the corresponding coefficient in the A-weighted curve.

[0154] S22. Obtain the atmospheric temperature, atmospheric pressure, and molar concentration of water vapor at different heights from the reference surface, and obtain the atmospheric attenuation rate between the atmosphere at the actual departure altitude of the aircraft and the standard atmosphere based on the atmospheric temperature, atmospheric pressure, and molar concentration of water vapor at the reference surface. In this embodiment, according to SAE-ARP-5534, the atmospheric attenuation rate in the actual atmosphere and the standard atmosphere is calculated using the air temperature, atmospheric pressure, and molar concentration of water vapor at the actual departure altitude of the aircraft.

[0155] S23, obtaining NPD data at different distances between the standard atmosphere and the aircraft engine, and correcting the NPD data based on the atmospheric attenuation rate and the NPD difference between the actual atmosphere and the standard atmosphere at different distances to obtain an NPD correction value;

[0156] S24, obtaining the distance between the noise observation point and the departure route;

[0157] The calculation expression of the distance between the noise observation point and the departure route is as follows:

[0158]

[0159] Among them, R ik represents the slant distance from the ith noise observation point at time k to the aircraft on the departure route, L i represents the vertical distance from the ith noise observation point to the ground projection of the track;

[0160] S25, obtaining a real-time noise value at the noise observation point according to the departure aircraft performance model, the distance between the noise observation point and the departure route, and the NPD correction value;

[0161] S26, correcting the real-time noise value at the noise observation point according to the aircraft configuration, the current aircraft attitude, and the difference between the current aircraft speed and the reference speed to obtain a real-time aircraft noise correction value;

[0162] The calculation expression of the aircraft real-time noise correction value is as follows:

[0163] ,

[0164] in, represents the noise correction value at the i-th noise observation point at time k, represents the noise value at the i-th noise observation point at time k, Represents the lateral attenuation factor.

[0165] S3. Establish aircraft performance constraints based on the departure aircraft performance model;

[0166] The S3 comprises the following steps:

[0167] S31. Set the path angle constraint conditions according to the departure aircraft performance model;

[0168] The calculation expression of the path angle constraint condition is as follows:

[0169] ,

[0170] ,

[0171] in, represents the lower limit of the path angle, represents the change in path angle from time k to time k+1, represents the upper limit of the path angle, represents the maximum acceleration of the aircraft, | | represents the absolute value;

[0172] S32. Set speed constraints according to the departure aircraft performance model;

[0173] The calculation expression of the speed constraint condition is as follows:

[0174] ,

[0175] ,

[0176] ,

[0177] in, Denotes the weight m of the aircraft at time k k and the aircraft stall speed corrected by the reference weight m0, Indicates the upper limit of aircraft speed. represents the stall speed of the aircraft at the reference weight m0, a l Indicates the maximum longitudinal acceleration of the aircraft;

[0178] S33. Constructing aircraft thrust and altitude constraints based on the departure aircraft performance model and the real-time position of the aircraft;

[0179] The calculation expressions of the aircraft thrust and altitude constraints are as follows:

[0180] , ,

[0181] Where h0 represents the initial departure altitude of the aircraft, h max Indicates the maximum departure altitude of the aircraft;

[0182] S34. The path angle constraint, speed constraint, and aircraft thrust and altitude constraint are used as aircraft performance constraints.

[0183] S4, selecting the real-time noise correction value of the aircraft that is greater than the preset noise threshold, and combining it with the population density at each noise observation point to obtain the real-time population noise impact index;

[0184] The S4 comprises the following steps:

[0185] S41. Select the real-time noise correction value of the aircraft that is greater than the preset noise threshold to obtain the number of noise observation points where the noise exceeds the threshold. In this embodiment, the preset noise threshold is selected based on the restrictions of the daytime Class 1 functional area in the "Social Living Environment Noise Emission Standard" (GB22337-2008).

[0186] In this embodiment, the impact of noise is mainly reflected by two main factors, namely loudness and duration. The louder the loudness and the longer the duration, the greater the impact. Although low-thrust and low-speed flight can reduce the loudness of aircraft noise, the exposure time will increase. In order to balance the two, an indicator is proposed. The total flight time is difficult to reflect in each step, so this solution uses speed to indirectly reflect the impact of navigation time. The higher the speed, the shorter the duration of noise in theory. At the same time, during the aircraft departure phase, the aircraft needs to climb to a certain altitude to complete the next navigation mission, so there are certain requirements for the size of the path angle.

[0187] S42, performing index normalization processing according to the real-time noise correction value, real-time speed and real-time path angle of the aircraft, and combining the number of noise observation points where the noise exceeds the threshold, to obtain a real-time noise impact index;

[0188] The calculation expression of the real-time noise impact index is as follows:

[0189] ,

[0190] Among them, U krepresents the noise impact index at time k, represents the number of noise observation points where the noise exceeds the threshold, represents the first noise impact index coefficient, represents the second noise impact index coefficient;

[0191] In this embodiment, in addition to the aircraft's own performance and departure process, the impact of population distribution is also considered. When other conditions are the same, the greater the population density, the greater the noise impact.

[0192] S43, obtaining the population density at each noise observation point, and adjusting the real-time noise impact index based on the population density at each noise observation point to obtain a real-time population noise impact index;

[0193] The calculation expression of the real-time population noise impact index is as follows:

[0194] ,

[0195] in, represents the real-time population noise impact indicator, represents the population density at the i-th noise observation point.

[0196] S5. According to the dynamic window method and genetic algorithm, based on the departure aircraft performance model, aircraft performance constraints and real-time population noise impact indicators, the speed and path angle of the aircraft at each time are optimized to obtain the optimal departure track for noise reduction.

[0197] The S5 comprises the following steps:

[0198] S51, taking the projection of the line between the departure starting point and the target end point on the ground as the X-axis, taking the axis perpendicular to the X-axis as the H-axis, and obtaining the real-time speed and real-time path angle of the aircraft at time k;

[0199] S52. Obtain the speed range and the path angle range of the aircraft at time k+1 according to the aircraft performance constraint and based on the aircraft real-time speed and real-time path angle at time k;

[0200] S53, generating an initialization population according to the speed range and the path angle range of the aircraft at time k+1;

[0201] S54, according to the genetic algorithm, based on the initialization population, obtaining the target speed and target path angle at time k+1;

[0202] The S54 comprises the following steps:

[0203] S541, let the first Individual , and each individual contains two chromosomes, where the two chromosomes are The speed of an individual and path angle , the two chromosomes are represented as , V j represents the jth chromosome velocity, represents the path angle of the jth chromosome;

[0204] S542, according to the real-time population noise impact index corresponding to each individual in the initialization population, select individuals in the initialization population for replication, crossover and mutation based on the roulette wheel method to obtain generated individuals, wherein the probability of selecting an individual in the initialization population for replication, crossover and mutation is inversely proportional to the real-time population noise impact index corresponding to the individual;

[0205] The calculation expressions for crossover and mutation of individuals in the initialized population are as follows:

[0206] ,

[0207] ,

[0208] Among them, rand represents a random number, V min Indicates the lower limit of aircraft speed. In this embodiment, when the random number is greater than or equal to 0.5, the speed is selected for crossover and mutation operations, and when the random number is less than 0.5, the path angle is selected for crossover and mutation operations.

[0209] S543, judging whether the speed and path angle corresponding to the generated individual meet the aircraft performance constraints, if so, proceeding to S545, otherwise proceeding to S544;

[0210] S544. According to the departure aircraft performance model, , calculate the speed and path angle of the aircraft at time k+1 as the speed and path angle corresponding to the generated individual;

[0211] S545, judging whether the number of iterations of replication, crossover and mutation of the initialized population reaches a preset iteration threshold, if so, proceeding to S546, otherwise, returning to S541;

[0212] S546. According to the speeds and path angles corresponding to all generated individuals, the real-time population noise impact index corresponding to each set of speeds and path angles is calculated respectively, and the speed and path angle when the real-time population noise impact index is minimum are selected as the target speed and target path angle at time k+1.

[0213] S55, calculating the real-time position of the aircraft at time k+1 according to the real-time speed and real-time path angle of the aircraft at time k;

[0214] In this embodiment, since the aircraft does not change its heading during the departure climb, the projection of the line between the starting point and the target point of the aircraft when it leaves the airport on the ground is taken as the X-axis, and the axis perpendicular to the X-axis in the vertical direction is taken as the H-axis, that is, the aircraft only has displacement changes on the X-axis and the H-axis when it leaves the airport.

[0215] The calculation expression of the real-time position of the aircraft at time K+1 in S55 is as follows:

[0216] ,

[0217] Among them, x k+1 represents the displacement of the aircraft on the X axis at time k+1, x k represents the displacement of the aircraft on the X axis at time k, h k+1 Represents the displacement of the aircraft on the H axis at time k+1.

[0218] S56, judging whether the real-time position of the aircraft at time k+1 is the target destination when the aircraft leaves the airport, if so, proceeding to S58, otherwise proceeding to S57;

[0219] S57, let k+1=k, then the target speed and target path angle at time k+1 are the real-time speed and real-time path angle of the aircraft at time k, the real-time position of the aircraft at time k+1 is the real-time position of the aircraft at time k, and return to S53; in this embodiment, k is a natural number, and when k is equal to 0, the aircraft is at the starting point of departure;

[0220] S58. Generate a departure track for noise reduction based on the position of the aircraft at each moment in the process from the departure starting point to the target destination.

[0221] In a practical example of the present invention, this patent takes the departure direction of BOKIR-8T at Chengdu Shuangliu Airport as an example, selects the A320-214 model, and plans the optimal departure route according to the departure trajectory optimization method for noise reduction provided by the present invention.

[0222] like Figure 2As shown in the figure, this scheme analyzes the aircraft departure route from the perspective of aircraft performance parameters, and analyzes the impact of population distribution on the departure route. The open population distribution data provided by the WorldPop website is used as the population density data for aircraft noise impact, and the accuracy of the population distribution data is 1km. The study area is divided into 51×49 grids, and the spatial resolution of each grid unit is 1km×1km. The density level is divided when the number of people reaches 2649, 7073, 11500, 15922, 20347, 28771 and 135933 respectively. In order to simplify the problem, it is assumed that all the population enclosed in the grid cell is concentrated at the geometric center of the grid cell, so the noise impact on the grid cell will be calculated using the noise value received at this single point.

[0223] The accuracy of the solution of the traditional dynamic window method is affected by the speed resolution. Speed ​​resolution refers to the size of the interval of speed values ​​considered when generating a speed candidate set. The higher the speed resolution, that is, the denser the speed values ​​considered, the higher the accuracy of the solution process. This solution uses a genetic algorithm to select the optimal navigation state in the speed space. Select a dt in the entire solution process, compare this solution with the traditional dynamic window method, set the speed resolution of the dynamic window method to 0.5m / s, and the path angle resolution to 0.06°. Then, within the selected dt time range, 48 sets of , here the number of individuals in each generation in the genetic algorithm is set to 12 and the number of iterations is 4.

[0224] like Figure 3 As shown in the figure, each individual is regarded as a generation under the traditional dynamic window method. For intuitive comparison, the noise impact values ​​are marked at iterations 1, 12, 24, 36 and 48. It can be seen from the change of noise impact values ​​with the number of iterations under the two algorithms that the noise impact under the traditional dynamic window method shows periodic changes. The figure shows three incomplete cycles. The changes in each cycle can be understood as the change of noise impact with the change of aircraft speed under a fixed path angle. With the change of the path angle, the noise impact gradually increases in each cycle within this dt. However, the noise impact value under this scheme decreases significantly with the number of iterations.

[0225] like Figure 4 and Figure 5 As shown in the figure, the track solved by this scheme is more accurate. However, due to the low resolution of the dynamic window method, the number of speeds and path angles that can be selected in each iteration is too small, and the track cannot be solved in the same number of iterations.

[0226] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A departure track optimization method for noise reduction, characterized in that: The steps include: S1. Obtain the atmospheric environment data of the aircraft departure area and build a departure aircraft performance model; The S1 comprises the following steps: S11. Construct an atmospheric environment model based on the atmospheric temperature, atmospheric pressure, and altitude from the reference surface in the aircraft departure area; The calculation expression of the atmospheric environment model is as follows: ， in, T Indicates the height from the reference surface h The atmospheric temperature at T 0 represents the temperature at the reference surface, P Indicates the height from the reference surface h The atmospheric pressure at P 0 represents the atmospheric pressure at the reference surface, ρ represents the atmospheric density, R represents the gas constant; S12. According to the total energy calculation method of the aircraft and the resistance encountered by the aircraft at different times of departure, based on the atmospheric environment model, calculate the thrust required for the aircraft to depart at different times; The calculation expression of the thrust required for the aircraft to depart at different times is as follows: ， ， ， in, F k express k The thrust required for the aircraft to depart at the time, D k express k The resistance encountered by the aircraft at departure time, m k express k The weight of the aircraft at the time, g represents the acceleration due to gravity, express k The aircraft's path angle at the moment, express k Time has come k +1 The change in the speed of the aircraft at time represents the time interval between adjacent moments, express k The aircraft's drag coefficient at time, express k At the time when the height from the reference surface is h The atmospheric density at V k express k The speed of the aircraft at that moment, S represents the wingspan area of ​​the aircraft, is the parasitic drag coefficient, represents the induced drag coefficient, express k The lift coefficient of the aircraft at time express k The pitch angle of the aircraft at time express k Time has come k +1 The altitude change of the aircraft at departure; S13. Calculate the maximum available thrust at the actual departure altitude of the aircraft based on the altitude of the aircraft from the reference surface, the temperature difference between the aircraft and the reference surface, and the maximum available thrust of the aircraft under standard atmosphere; The calculation expression of the maximum available thrust at the actual departure altitude of the aircraft is as follows: ， in, It represents the maximum available thrust of the aircraft in standard atmosphere. represents the first thrust coefficient, represents the second thrust coefficient, represents the third thrust coefficient, express k At the time when the height from the reference surface is h The maximum thrust available for an aircraft in the actual atmosphere at represents the fifth thrust coefficient, Indicates the height from the reference surface is h The temperature difference between the reference surface and represents the fourth thrust coefficient; S14. Calculate the weight of the aircraft at different times based on the fuel consumption of the aircraft over time, the speed of the aircraft at different times, and the thrust required for the aircraft to depart at different times; The calculation expression of the weight of the aircraft at different times is as follows: ， in, m k+1 express k +1 The weight of the aircraft at the time, f k express k Time has come k +1 The fuel consumption of the aircraft during the time period, express k The fuel consumption coefficient of the aircraft at the time, C f1 represents the first fuel consumption coefficient, V k express k The speed of the aircraft at that moment, C f2 Indicates the second fuel consumption coefficient; S15, constructing a departure aircraft performance model by combining the atmospheric environment model, the thrust required for departure of the aircraft at different times, the maximum thrust available for the aircraft in the actual atmosphere, and the weight of the aircraft at different times; S2. Correct the NPD data according to the atmospheric attenuation rate, and correct the noise value by combining the NPD correction value and the departure aircraft performance model to obtain the real-time aircraft noise correction value; The S2 comprises the following steps: S21, obtaining a reference sound spectrum of an aircraft engine, and obtaining the NPD difference between the actual atmosphere and the standard atmosphere at different distances through sound spectrum analysis and A-weighting processing; S22. Obtain the atmospheric temperature, atmospheric pressure and molar concentration of water vapor at different altitudes from the reference surface, and obtain the atmospheric attenuation rate between the atmosphere at the actual departure altitude of the aircraft and the standard atmosphere based on the atmospheric temperature, atmospheric pressure and molar concentration of water vapor on the reference surface; S23, obtaining NPD data at different distances between the standard atmosphere and the aircraft engine, and correcting the NPD data based on the atmospheric attenuation rate and the NPD difference between the actual atmosphere and the standard atmosphere at different distances to obtain an NPD correction value; S24, obtaining the distance between the noise observation point and the departure route; The calculation expression of the distance between the noise observation point and the departure route is as follows: in, R ik express k Moment i The slant distance from the noise observation point to the aircraft on the departure route is L i Indicates i The vertical distance from the noise observation point to the ground projection of the track; S25, obtaining a real-time noise value at the noise observation point according to the departure aircraft performance model, the distance between the noise observation point and the departure route, and the NPD correction value; S26, correcting the real-time noise value at the noise observation point according to the aircraft configuration, the current aircraft attitude, and the difference between the current aircraft speed and the reference speed to obtain a real-time aircraft noise correction value; The calculation expression of the aircraft real-time noise correction value is as follows: ， in, express k Moment i The noise correction value at the noise observation point is express k Moment i The noise value at the noise observation point is represents the lateral attenuation factor; S3. Establish aircraft performance constraints based on the departure aircraft performance model; The S3 comprises the following steps: S31. Set the path angle constraint conditions according to the departure aircraft performance model; The calculation expression of the path angle constraint condition is as follows: ， ， in, represents the lower limit of the path angle, express k Time has come k +1 The change in path angle at time, represents the upper limit of the path angle, represents the maximum acceleration of the aircraft, | | represents the absolute value; S32. Set speed constraints according to the departure aircraft performance model; The calculation expression of the speed constraint condition is as follows: ， ， ， in, Indicates based on k Aircraft weight at the time m k and reference weight m 0 Corrected aircraft stall speed, Indicates the upper limit of aircraft speed. Indicates reference weight m 0, the aircraft stall speed, a l Indicates the maximum longitudinal acceleration of the aircraft; S33. Constructing aircraft thrust and altitude constraints based on the departure aircraft performance model and the real-time position of the aircraft; The calculation expressions of the aircraft thrust and altitude constraints are as follows: ， ， in, h 0 indicates the initial departure altitude of the aircraft. h max Indicates the maximum departure altitude of the aircraft; S34, taking the flight path angle constraint, speed constraint, and aircraft thrust and altitude constraint as aircraft performance constraints; S4, selecting the real-time noise correction value of the aircraft that is greater than the preset noise threshold, and combining it with the population density at each noise observation point to obtain the real-time population noise impact index; The S4 comprises the following steps: S41, selecting the real-time noise correction value of the aircraft that is greater than the preset noise threshold, and obtaining the number of noise observation points where the noise exceeds the threshold; S42, performing index normalization processing according to the real-time noise correction value, real-time speed and real-time path angle of the aircraft, and combining the number of noise observation points where the noise exceeds the threshold, to obtain a real-time noise impact index; The calculation expression of the real-time noise impact index is as follows: ， in, U k express k The noise impact index at each moment, represents the number of noise observation points where the noise exceeds the threshold, represents the first noise impact index coefficient, represents the second noise impact index coefficient; S43, obtaining the population density at each noise observation point, and adjusting the real-time noise impact index based on the population density at each noise observation point to obtain a real-time population noise impact index; The calculation expression of the real-time population noise impact index is as follows: ， in, represents the real-time population noise impact indicator, Indicates i Population density at each noise observation point; S5. According to the dynamic window method and genetic algorithm, based on the departure aircraft performance model, aircraft performance constraints and real-time population noise impact indicators, the speed and path angle of the aircraft at each time are optimized to obtain the optimal departure track for noise reduction.

2. The noise reduction-oriented departure track optimization method according to claim 1, characterized in that: The S21 comprises the following steps: S211. Acquire a reference sound spectrum of an aircraft engine; S212, analyzing and obtaining a sound source spectrum of an aircraft engine according to a reference sound spectrum of the engine; S213, extracting, according to the sound spectrum of the aircraft engine sound source, the sound spectrum corresponding to different distances from the noise source in the standard atmosphere and the sound spectrum corresponding to different distances from the noise source in the actual atmosphere; S214, calculating the NPD difference between the actual atmosphere and the standard atmosphere at different distances according to the sound spectra corresponding to the different distances from the noise source in the standard atmosphere and the sound spectra corresponding to the different distances from the noise source in the actual atmosphere based on A-weighting processing; The calculation expression of the NPD difference between the actual atmosphere and the standard atmosphere at different distances in S214 is as follows: ， in, It represents the difference in NPD between the actual atmosphere and the standard atmosphere at different distances. lg represents the logarithm operation with a base of 10. Indicates the distance from the noise source in the actual atmosphere d i The corresponding spectrum at A i Indicates the distance from the noise source d i The A-weighting coefficient at the corresponding frequency, Indicates the distance from the noise source in standard atmosphere d i The corresponding spectrum at represents the spectrum at the aircraft engine sound source, d i Indicates i The distance between each noise observation point and the aircraft engine noise source, Indicates the preset standard distance used when correcting NPD data. represents the spectral coefficient of aircraft in standard atmosphere, represents the spectrum coefficient of aircraft in the actual atmosphere, It represents the frequency spectrum at the aircraft engine sound source when the NPD data is corrected at a preset standard distance in a standard atmosphere. n Indicates the number of selected frequency levels.

3. The noise reduction-oriented departure track optimization method according to claim 1, characterized in that: The S5 comprises the following steps: S51, take the projection of the line between the departure point and the destination point of the aircraft on the ground as the X-axis, take the axis perpendicular to the X-axis as the H-axis, and obtain k Real-time aircraft speed and real-time path angle at all times; S52. Based on aircraft performance constraints and k The real-time speed and real-time path angle of the aircraft at this moment are obtained k +1 aircraft speed range and path angle range; S53, according to k +1 time aircraft speed range and path angle range, generate the initialization population; S54. According to the genetic algorithm, based on the initialization population, we get k Target speed and target path angle at time +1; S55, according to k The real-time speed and real-time path angle of the aircraft at the moment are calculated k +1 The real-time position of the aircraft at the moment; S56, Judgment k Whether the real-time position of the aircraft at time +1 is the target destination when the aircraft departs, if so, proceed to S58, otherwise proceed to S57; S57, Order k+ 1= k ,but k The target speed and target path angle at time +1 are k The real-time speed and real-time path angle of the aircraft at the moment, k The real-time position of the aircraft at time +1 is k The real-time position of the aircraft at that moment and return to S53; S58. Generate a departure track for noise reduction based on the position of the aircraft at each moment in the process from the departure starting point to the target destination.

4. The noise reduction-oriented departure track optimization method according to claim 3, characterized in that: The S54 comprises the following steps: S541, let the first Individual , and each individual contains two chromosomes, where the two chromosomes are The speed of an individual and path angle , the two chromosomes are represented as , V j Indicates j Chromosome speed, Indicates j Chromosome path angle; S542, according to the real-time population noise impact index corresponding to each individual in the initialization population, select individuals in the initialization population for replication, crossover and mutation based on the roulette wheel method to obtain generated individuals, wherein the probability of selecting an individual in the initialization population for replication, crossover and mutation is inversely proportional to the real-time population noise impact index corresponding to the individual; S543, judging whether the speed and path angle corresponding to the generated individual meet the aircraft performance constraints, if so, proceeding to S545, otherwise proceeding to S544; S544. According to the departure aircraft performance model, , calculated k The speed and path angle of the aircraft at time +1 are used as the speed and path angle corresponding to the generated individual; S545, judging whether the number of iterations of replication, crossover and mutation of the initialized population reaches a preset iteration threshold, if so, proceeding to S546, otherwise, returning to S541; S546. According to the speeds and flight path angles corresponding to all generated individuals, the real-time population noise impact index corresponding to each set of speeds and flight path angles is calculated respectively, and the speed and flight path angle when the real-time population noise impact index is the smallest are selected as k Target speed and target path angle at time +1.

5. The noise reduction-oriented departure track optimization method according to claim 4, characterized in that: The calculation expressions for crossover and mutation of individuals in the initialized population are as follows: ， ， in, rand Represents a random number, V min Indicates the lower limit of aircraft speed.

6. The noise reduction-oriented departure track optimization method according to claim 4, characterized in that: The S55 K The calculation expression of the real-time position of the aircraft at time +1 is as follows: ， in, x k+1 express k The displacement of the aircraft on the X axis at time +1, x k express k At time the aircraft is X The displacement of the axis, h k+1 express k The displacement of the aircraft on the H axis at time +1.

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