Rapid trajectory planning method meeting overload expectation design
By establishing a basic table of overload angle of attack and side slip angles, designing the expected overload and calculating the corresponding trajectory angle, the problem of slow trajectory planning calculation speed and difficulty in meeting refined design in the existing technology is solved, and the rapid trajectory planning and boundaries are realized Performance improvement.
Patent Information
- Application Number
- CN202411235758.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2025-01-07
AI Technical Summary
In the prior art, the trajectory planning method with overload as a constraint is slower to calculate, and it is difficult to meet the requirements of overload fine design, and it is difficult to mine the boundary performance of the aircraft from the field of trajectory planning.
By establishing a calculation model of the normal overload attack angle basic table and/or the lateral overload side slip angle basic table, based on the aerodynamic parameters of the aircraft, designing the desired overload as the design value, calculate the corresponding angle of attack and/or side slip angle. To plan a trajectory that meets the requirements of overload refinement.
It realizes rapid trajectory planning, meets the requirements of fine overload design, improves calculation speed, and effectively mines and improves the boundary performance of the aircraft.
Smart Images
Figure CN119272485A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of aircraft trajectory planning, and in particular to a fast trajectory planning method that meets overload expectation design. Background Art
[0002] Considering the cost of engineering development, when exploring the boundary performance of the aircraft, the aircraft product itself should not be changed as much as possible. The first choice is to explore from the field of trajectory planning. Trajectory planning is described as repeatedly iterating based on differential equations under given constraints to finally find a feasible law of program angle change.
[0003] In order to successfully complete the flight of the aircraft, various process constraints must be fully considered in trajectory planning, such as overload constraints to meet structural strength requirements, dynamic pressure and stagnation heat flow constraints to meet thermal environment requirements, attitude change rate and maximum value constraints to meet control requirements, etc. Among them, the load constraint condition is generally that the absolute value of the overload during the flight does not exceed the maximum value.
[0004] Based on the above process constraints, if you want to explore the boundary performance of the aircraft from the field of trajectory planning, you need to design a more refined flight overload. In related technologies, the existing method is to design the program angle and then see whether the overload curve meets the maximum value constraint. However, this method of using overload as a constraint is not precise enough. It can only see whether the maximum value is met. The planned trajectory is also difficult to meet the overload refinement design requirements, which is not enough to achieve the purpose of exploring the boundary performance of the aircraft. Moreover, the calculation process requires repeated iterations, which will inevitably result in a large amount of calculation and slow calculation speed. However, in engineering research and development, even under the requirements of refined overload design, the calculation speed cannot be reduced. Summary of the invention
[0005] The technical problem to be solved by the present application is that the trajectory planning method using overload as a constraint in the related art has a slow calculation speed and is difficult to meet the requirements of overload refined design.
[0006] The present application provides a method for rapid trajectory planning that meets overload expectation design, including the following steps:
[0007] Based on the aerodynamic parameters of the aircraft, a calculation model of a normal overload angle of attack basic table and / or a lateral overload sideslip angle basic table is established;
[0008] An aircraft trajectory planning model is established, with the expected overload as the design value, and the corresponding attack angle and / or sideslip angle are calculated as the design program angle through the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table to obtain a trajectory that meets the expected overload design value.
[0009] In one embodiment, the method for quickly planning a trajectory that meets the expected overload design includes planning an active segment trajectory, and the planning of the active segment trajectory includes:
[0010] Based on the aerodynamic parameters of the active section of the aircraft, a calculation model of a basic numerical table of normal overload angle of attack and / or a basic numerical table of lateral overload sideslip angle of the active section is established;
[0011] A trajectory planning model for the active segment of the aircraft is established, and the expected overload of the active segment is designed according to the working time period of the aircraft engine. The corresponding attack angle and / or sideslip angle are calculated as the design program angle through the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the active segment, so as to obtain the active segment trajectory that meets the expected overload design value of the active segment.
[0012] In one embodiment, the calculation model for establishing the basic table of normal overload angle of attack of the active section based on the aerodynamic parameters of the active section of the aircraft includes:
[0013] discretize the normal overload of the active section of the aircraft into a series of values to form an array of expected normal overloads of the active section;
[0014] The mass of the active section of the aircraft is discretized into a series of values between the fully loaded mass and the unloaded mass to form an active section mass array;
[0015] Discretize the flight speed of the active section of the aircraft into a series of values to form an active section flight speed array;
[0016] Discretizing the flight altitude of the active segment of the aircraft into a series of values to form an active segment flight altitude array;
[0017] The active segment mass array, the active segment flight speed array and the active segment flight altitude array are used as the current state of the aircraft, and the normal overload and its corresponding angle of attack are calculated when the expected normal overload array constraint of the active segment is met, so as to form a calculation model of the basic numerical table of the normal overload angle of attack of the active segment.
[0018] In one embodiment, the calculation model of using the active segment mass array, the active segment flight speed array, and the active segment flight altitude array as the current state of the aircraft, calculating the normal overload and its corresponding angle of attack when the constraint of the active segment expected normal overload array is satisfied, and forming the normal overload angle of attack basic table of the active segment includes:
[0019] Taking the active segment mass array, the active segment flight speed array and the active segment flight altitude array as the current state of the aircraft;
[0020] Calculate the corresponding normal overload n according to the initial attack angle of the active section y, the sideslip angle is designed to be 0;
[0021] The calculation formula is: y =CN·Q z ·S z / mass;
[0022] Where, CN is the normal force coefficient; Q z is the dynamic pressure; S z is the characteristic area of the aircraft in the active section; mass is the mass of the aircraft;
[0023] If the calculated normal overload does not satisfy the constraint of the expected normal overload array of the active segment, adjust the angle of attack until the calculated normal overload satisfies the constraint of the expected normal overload array of the active segment, and record the angle of attack at this moment;
[0024] The above steps are repeated until the angles of attack of all states are calculated, thereby forming a calculation model of the basic numerical table of the normal overload angle of attack of the active section.
[0025] In one embodiment, when the angle of attack reaches the boundary value given by the aerodynamic parameters of the active section, and the calculated normal overload still does not satisfy the expected normal overload array constraint of the active section, the current angle of attack is replaced by the closest boundary angle of attack.
[0026] In one embodiment, the calculation of the corresponding attack angle and / or sideslip angle as the design program angle by the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the active section includes:
[0027] Reading a normal overload attack angle basic number table and / or a lateral overload sideslip angle basic number table of the active section;
[0028] According to the aircraft mass, flight altitude, flight speed and expected overload at the current moment, the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table of the active section are substituted for four-element interpolation to obtain the corresponding angle of attack and / or sideslip angle as the design program angle.
[0029] In one embodiment, the method for quickly planning a trajectory that meets the expected overload design includes planning a passive segment trajectory, and the planning of the passive segment trajectory includes:
[0030] Based on the aerodynamic parameters of the passive section of the aircraft, a calculation model of a basic numerical table of normal overload attack angle and / or a basic numerical table of lateral overload sideslip angle of the passive section is obtained;
[0031] A trajectory planning model for the passive section of the aircraft is established, and the expected overload of the passive section of the aircraft is designed. The corresponding attack angle and / or sideslip angle are calculated as the design program angle through a calculation model of a basic numerical table of normal overload attack angles and / or a basic numerical table of lateral overload sideslip angles of the passive section, so as to obtain a passive section trajectory that meets the design value of the expected overload of the passive section.
[0032] In one embodiment, the calculation model for establishing the basic table of normal overload angle of attack of the passive section based on the aerodynamic parameters of the passive section of the aircraft includes:
[0033] discretize the normal overload of the passive section of the aircraft into a series of values to form an array of expected normal overloads of the passive section;
[0034] Discretizing the flight speed of the passive section of the aircraft into a series of values to form a passive section flight speed array;
[0035] Discretizing the flight altitude of the passive segment of the aircraft into a series of values to form a passive segment flight altitude array;
[0036] The passive section flight speed array and the passive section flight altitude array are used as the current state of the aircraft, and the normal overload and its corresponding angle of attack are calculated when the passive section expected normal overload array constraint is met, so as to form a calculation model of the basic table of normal overload angle of attack of the passive section.
[0037] In one embodiment, before establishing the calculation model of the basic numerical table of the normal overload angle of attack of the passive section, the aerodynamic parameters of the passive section are trimmed.
[0038] In one embodiment, the calculation of the corresponding attack angle and / or sideslip angle as the design program angle by the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the passive section includes:
[0039] Reading the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the passive section;
[0040] According to the current flight altitude, flight speed and expected overload of the aircraft, the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table of the passive section are substituted for ternary interpolation to obtain the corresponding angle of attack and / or sideslip angle as the design program angle.
[0041] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:
[0042] The present application provides a method for rapid trajectory planning that meets overload expectation design. The overload is taken as the design expectation, and the overload function can be refined to design the planned trajectory to meet the overload refinement requirements, thereby solving the problem that the trajectory planning method with overload as a constraint is difficult to meet the overload refinement design requirements, and effectively explores and improves the boundary performance of the aircraft from the field of trajectory planning; at the same time, based on the aerodynamic parameters of the aircraft, a calculation model of the basic numerical table of the normal overload angle of attack and / or the basic numerical table of the lateral overload sideslip angle is established, without the need for repeated iterations, effectively improving the calculation speed. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0044] Figure 1 The figure is a calculation flow chart of the basic table of normal overload attack angle of the active section in one embodiment of the present invention.
[0045] Figure 2 The figure is a flow chart for calculating the aerodynamic parameters of the passive section balancing in one embodiment of the present invention.
[0046] Figure 3 The figure is a comparison curve diagram of expected overload and actual overload in one embodiment of the present invention. DETAILED DESCRIPTION
[0047] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0048] This embodiment provides a method for quickly planning a trajectory that meets the expected overload design, including the following steps:
[0049] Based on the aerodynamic parameters of the aircraft, a calculation model of a normal overload angle of attack basic table and / or a lateral overload sideslip angle basic table is established;
[0050] An aircraft trajectory planning model is established, with the expected overload as the design value. The corresponding attack angle and / or sideslip angle are calculated as the design program angle through the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table to obtain a trajectory that meets the expected overload design value.
[0051] This embodiment provides a method for rapid trajectory planning that meets overload expectation design. The overload is taken as the design expectation, and the overload function can be refined to design the planned trajectory to meet the overload refinement requirements, thereby solving the problem that the trajectory planning method with overload as a constraint is difficult to meet the overload refinement design requirements, and effectively explores and improves the boundary performance of the aircraft from the field of trajectory planning; at the same time, based on the aerodynamic parameters of the aircraft, a calculation model of the basic table of normal overload angle of attack and / or the basic table of lateral overload sideslip angle is established, without the need for repeated iterations, effectively improving the calculation speed.
[0052] Each step is described and explained in detail below.
[0053] In one embodiment, a method for quickly planning a trajectory that meets the expected overload design includes step S1, planning an active segment trajectory. Step S1, planning the active segment trajectory includes:
[0054] Step S11, based on the aerodynamic parameters of the active section of the aircraft, a calculation model of a basic numerical table of normal overload attack angle and / or a basic numerical table of lateral overload sideslip angle of the active section is established;
[0055] Step S12, establishing a trajectory planning model for the active segment of the aircraft, designing the expected overload of the active segment according to the working time period of the aircraft engine, and calculating the corresponding attack angle and / or sideslip angle as the design program angle through the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the active segment, so as to obtain the active segment trajectory that meets the expected overload design value of the active segment.
[0056] Through the above scheme, in the active segment, a calculation model of the relevant basic number table is first established, which can effectively improve the calculation speed; then the expected overload of the active segment is designed according to the working time period of the aircraft engine. The planned active segment trajectory can meet the expected overload design value of the active segment and is more refined.
[0057] If the design program angle of the active section involves the angle of attack, only the calculation model of the basic numerical table of the normal overload angle of attack of the active section can be established, and only the angle of attack can be calculated subsequently as the design program angle; if the sideslip angle is involved, only the calculation model of the basic numerical table of the lateral overload sideslip angle can be established, and only the sideslip angle can be calculated subsequently as the design program angle; if both are involved, both calculation models can be established at the same time.
[0058] Furthermore, when planning the active segment trajectory, it is applicable to adopt swing jet control in the active segment, and the aerodynamic parameters do not need to consider the rudder deflection angle.
[0059] In one embodiment, step S11, based on the aerodynamic parameters of the active section of the aircraft, a calculation model for establishing a basic table of normal overload angle of attack of the active section includes:
[0060] Step S111: discretize the normal overload of the active segment of the aircraft into a series of values to form an array n of expected normal overloads of the active segment yi (i=1,2,...,N).
[0061] Specifically, the normal overload of the active section of the aircraft is discretized into a series of values within the value range allowed by the aircraft. The value range allowed by the aircraft, that is, the maximum allowable value of the overload, is set according to the performance of the aircraft and is related to the design requirements. When the normal overload is discretized into a series of values, the values can be taken at equal intervals, such as an interval of 1m / s. 2 Or 0.1g0, g0=9.80665m / s 2 Or you can set different intervals yourself, and N is determined according to the overload range and interval.
[0062] Step S112: discretize the mass of the active section of the aircraft into a series of values between the fully loaded mass and the unloaded mass to form an active section mass array mass j (j=1,2,...,J).
[0063] Specifically, when the mass is discrete into a series of values, the values can be taken at equal intervals, and J takes values according to the mass range and interval.
[0064] Step S113: discretize the flight speed of the active segment of the aircraft into a series of values to form an active segment flight speed array V k (k=1,2,...,K).
[0065] Specifically, the flight speed of the active section of the aircraft is discretized into a series of values according to the flight speed range; the discrete flight speed can be taken at equal intervals, and K is taken according to the flight speed range and the interval.
[0066] Step S114: discretize the flight altitude of the active segment of the aircraft into a series of values to form an active segment flight altitude array h m (m=1,2,...,M).
[0067] Specifically, the flight altitude of the active section of the aircraft is discretized into a series of values according to the flight altitude range; the discrete flight altitude can be taken at equal intervals, and M is taken according to the flight altitude range and interval. For example, if the flight altitude range of the design overload is required to be 10000m to 20000m, with an interval of 1000m, then h1 = 10000m, h2 = 11000m, ..., h M =20000m,M=11.
[0068] Step S115: Set the active segment mass array mass j , Active segment flight speed array V k and the active segment flight altitude array h mAs the current state of the aircraft, the normal overload and its corresponding angle of attack are calculated when the expected normal overload array constraint of the active segment is met, forming a calculation model of the basic table of normal overload angle of attack of the active segment.
[0069] Through the above scheme, an engineering method for establishing a calculation model of the basic table of normal overload attack angle of the active section is provided, and subsequent calculations do not need to be repeated, which can speed up the calculation speed. Moreover, when forming the calculation model of the basic table, in addition to considering the influence of flight altitude and speed, the influence of changes in aircraft mass on overload is also considered, and mass is included as an independent variable as a one-dimensional variable, which facilitates the active section to carry out rapid trajectory planning that meets the overload design function.
[0070] like Figure 1 As shown, Figure 1 The figure is a calculation flow chart of the basic table of normal overload attack angle of the active section in one embodiment of the present invention.
[0071] In one embodiment, step S115, the active segment mass array mass j , Active segment flight speed array V k and the active segment flight altitude array h m As the current state of the aircraft, the normal overload and its corresponding angle of attack are calculated when the expected normal overload array constraint of the active segment is satisfied. The calculation model for forming the basic table of normal overload angle of attack of the active segment includes:
[0072] Step S1151: Set the active segment mass array mass j , Active segment flight speed array V k and the active segment flight altitude array h m As the current state of the aircraft;
[0073] Step S1152: Calculate the corresponding normal overload n according to the initial attack angle of the active segment. y , the sideslip angle is designed to be 0;
[0074] The calculation formula is: y =CN·Q z ·S z / mass;
[0075] Q z =0.5pv 2 ;
[0076] Among them, CN is the normal force coefficient, which is related to the Mach number, angle of attack, and sideslip angle; Q z is the dynamic pressure, p is the atmospheric density, according to the discrete height h m Calculation; S z is the characteristic area of the aircraft in the active section; mass is the mass of the aircraft.
[0077] Specifically, Figure 1 As shown, according to the discrete height h m Calculate the atmospheric density p; based on the atmospheric density p and the flight speed V k Calculate the dynamic pressure and Mach number; take the initial value of the initial angle of attack, such as 0, and the sideslip angle is designed to be 0; interpolate the active section aerodynamic parameters according to the initial angle of attack, sideslip angle, and Mach number to obtain the aerodynamic force; according to the aerodynamic force and mass j Calculate the corresponding normal overload n y . Such as n y1 =1g, mass1=1000kg, v1=1000m / s, h1=10000m, calculate the angle of attack α that meets the conditions through this step 1,1,1,1 That is, the angle of attack corresponding to an aircraft mass of 1000kg, a speed of 1000m / s, an altitude of 10000m, and a normal overload of 1g.
[0078] Step S1153: If the calculated normal overload does not satisfy the expected normal overload array constraint of the active segment, adjust the angle of attack until the calculated normal overload satisfies the expected normal overload array constraint of the active segment, and record the angle of attack α at this moment. i,j,k,m .
[0079] Specifically, Figure 1 As shown, it is determined whether the calculated normal overload is consistent with the expected normal overload, that is, whether it satisfies the expected normal overload array constraint of the active segment (such as |N y -N yi |<ε), if yes, then output the current angle of attack; if no, then adjust the angle of attack and recalculate.
[0080] Repeat the above steps until the angles of attack of all states are calculated, forming a calculation model for the basic table of normal overload angles of attack of the active section.
[0081] Through the above scheme, the impact of changes in the mass of the aircraft on the overload is taken into account, and the mass is included as an independent variable as a one-dimensional variable, which facilitates the active segment to carry out rapid trajectory planning that meets the overload design function, and the expected overload and actual overload are relatively close.
[0082] In one embodiment, when the angle of attack reaches the boundary value given by the aerodynamic parameters of the active section, and the calculated normal overload still does not satisfy the expected normal overload array constraint of the active section, the current angle of attack is replaced by the closest boundary angle of attack.
[0083] Through the above scheme, a solution is determined when the angle of attack reaches the boundary value but the calculated normal overload still does not meet the constraints.
[0084] In one embodiment, when establishing a calculation model of the active section lateral overload sideslip angle basic numerical table based on the aerodynamic parameters of the active section of the aircraft, the steps are the same as the steps of establishing a calculation model of the active section normal overload attack angle basic numerical table, the difference is that the independent variable is the lateral overload array n zn (n=1,2,...,N), aircraft mass array mass j (j=1,2,...,J), flight speed array V k (k=1,2,...,K), flight height array h m (m=1,2,...,M), the dependent variable is the sideslip angle β i,j,k,n .
[0085] Step S12, establishing an aircraft active segment trajectory planning model, designing the expected overload of the active segment according to the aircraft engine working time period, calculating the corresponding attack angle and / or sideslip angle as the design program angle through the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the active segment, so as to obtain the active segment trajectory that meets the expected overload design value of the active segment, including:
[0086] Step S121: Establish a trajectory planning model for the active phase of the aircraft, and design the expected overload n of the active phase according to the working time period of the aircraft engine. y =f(t).
[0087] Specifically, since the mass of the aircraft changes with the operation of the engine, the expected overload of the active section is designed according to the aircraft engine operating time period, and the influence of multiple factors such as flight speed, flight altitude, and aircraft mass can be considered simultaneously.
[0088] Step S122, calculate the corresponding attack angle and / or sideslip angle as the design program angle through the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table of the active segment, so as to obtain the active segment trajectory that meets the expected overload design value of the active segment.
[0089] In one embodiment, in step S122, calculating the corresponding attack angle and / or sideslip angle as the design program angle by using the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table of the active section includes:
[0090] Step S1221, reading the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table of the active section;
[0091] Step S1222: according to the aircraft mass, flight altitude, flight speed and expected overload at the current moment, substitute into the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table of the active segment for quaternion interpolation to obtain the corresponding angle of attack and / or sideslip angle as the design program angle.
[0092] Specifically, if an angle of attack turn is used, the normal overload angle of attack basic table of the active segment is read, and the normal overload angle of attack basic table is calculated according to the aircraft mass m, flight altitude h, flight speed v, and expected overload n at the current time t. y , substituted into the normal overload attack angle basic table α of the active section i,j,k,m Perform four-element interpolation to the corresponding attack angle as the design program angle. If the sideslip angle is used for turning, substitute it into the basic table of lateral overload sideslip angle of the active section for four-element interpolation to obtain the corresponding sideslip angle as the design program angle.
[0093] Through the above scheme, the aircraft mass factor is taken into account, and a specific method for designing the program angle is provided, which is more suitable for the trajectory planning design of the active segment.
[0094] After determining the design program angle of the active section, the Mach number, angle of attack, and sideslip angle are used as inputs, and the active section aerodynamic parameter array is interpolated to calculate the aerodynamic force at the current time t, thereby obtaining the acceleration parameters of the aircraft, integrating the speed parameters and position parameters, and obtaining the active section trajectory that meets the corresponding overload design value. This part is the prior art and will not be described in detail here.
[0095] In one embodiment, a method for quickly planning a trajectory that meets the expected overload design includes step S2, planning a passive segment trajectory. Step S2, planning the passive segment trajectory includes:
[0096] Step S21, based on the aerodynamic parameters of the passive section of the aircraft, obtaining a calculation model of a basic numerical table of normal overload attack angle and / or a basic numerical table of lateral overload sideslip angle of the passive section;
[0097] Step S22, establish a trajectory planning model for the passive segment of the aircraft, design the expected overload of the passive segment according to the flight altitude of the aircraft, calculate the corresponding attack angle and / or sideslip angle as the design program angle through the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table of the passive segment, so as to obtain the passive segment trajectory that meets the passive segment expected overload design value.
[0098] Through the above scheme, in the passive segment, the calculation model of the relevant basic number table is first established, which can effectively improve the calculation speed; then the expected overload of the passive segment is designed, and the planned passive segment trajectory can meet the expected overload design value of the active segment, which is more refined. When planning the trajectory of the aircraft, the active segment trajectory can be planned first, and then the passive segment trajectory; the order can also be changed; or only one of the methods can be used.
[0099] Similar to the active segment, during the planning of the passive segment trajectory, a corresponding calculation model is established based on whether the angle of attack or the sideslip angle, or both, is involved.
[0100] In one embodiment, step S21, based on the aerodynamic parameters of the passive section of the aircraft, establishing a calculation model of a basic table of normal overload attack angles of the passive section includes:
[0101] Step S211, discretize the normal overload of the passive section of the aircraft into a series of values to form an array of expected normal overloads of the passive section.
[0102] Step S212: discretize the flight speed of the passive segment of the aircraft into a series of values to form a passive segment flight speed array.
[0103] Step S213: discretize the flight altitude of the passive segment of the aircraft into a series of values to form a passive segment flight altitude array.
[0104] Step S214, using the passive segment flight speed array and the passive segment flight altitude array as the current state of the aircraft, calculate the normal overload and its corresponding angle of attack when the passive segment expected normal overload array constraint is met, and form a calculation model of the passive segment normal overload angle of attack basic table.
[0105] Through the above scheme, an engineering method is provided for establishing a calculation model of the basic numerical table of the normal overload angle of attack of the passive section, taking into account the influence of the flight altitude and speed on the overload. When the corresponding overload design action needs to be completed during the flight phase, the angle of attack and the sideslip angle can be quickly obtained without iteration, and the expected overload and the actual overload are very close.
[0106] In the process of establishing the calculation model of the basic numerical table of normal overload attack angle of the passive section and the calculation model of the basic numerical table of lateral overload sideslip angle of the passive section, except that the mass array is not formed (during the passive section, the engine does not work and the mass of the aircraft remains unchanged), the specific contents corresponding to the active section are basically the same and will not be repeated here.
[0107] In one embodiment, before establishing the calculation model of the basic numerical table of the normal overload angle of attack of the passive section, the aerodynamic parameters of the passive section are trimmed in advance to facilitate faster calculation.
[0108] like Figure 2 As shown, Figure 2 The figure is a flow chart for calculating the aerodynamic parameters of the passive section balancing in one embodiment of the present invention.
[0109] Step S20, pre-balancing the aerodynamic parameters of the passive section, includes:
[0110] Step S201, read the Mach number array Ma of aerodynamic parameters o (o=1,2,...,O), angle of attack array α p (p=1,2,...,P), sideslip angle array β q (q=1,2,...,Q);
[0111] Step S202: Set the initial height value and the initial values of the three-channel rudder deflection angles. The initial values of the three-channel rudder deflection angles are the initial pitch rudder deflection angle dlt p0 , the initial yaw rudder deflection angle dlt y0 , and the initial roll rudder deflection angle dlt r0 ;
[0112] Step S203: Interpolate the aerodynamic parameter table according to the nodal parameters of Mach number, angle of attack, sideslip angle, and rudder deflection angles Ma o , α p , β q , δ, δ, δ to obtain the aerodynamic force coefficients and aerodynamic moment coefficients;
[0113] pyr
[0114] Step S204: Calculate the aerodynamic moment;
[0115] Step S205: Determine whether the aerodynamic moment meets the threshold requirement;
[0116] If not, adjust the rudder deflection angle of the corresponding channel and return to Step S203 until the threshold requirement is met. Taking the calculation of the pitch moment M z as an example, the threshold condition for satisfaction is |M z | < M0. In engineering calculations, M0 takes a relatively small value, such as 0.1 N·m to 2 N·m.
[0117] Step S206: Record the rudder deflection angle arrays δ p(o,p,q) , δ y(o,p,q) , δ r(o,p,q) and the aerodynamic coefficient arrays that meet the moment threshold requirement. The axial force, normal force, and side force coefficient arrays are denoted as CA o,p,q , CN o,p,q , CZ o,p,q , as the trimmed rudder deflection angle arrays and aerodynamic coefficient arrays, i.e., the aerodynamic parameters in the passive section.
[0118] Step S22: Establish a trajectory planning model for the passive section of the aircraft, design the expected overload in the passive section, and calculate the corresponding angle of attack and / or sideslip angle as the designed program angle through the calculation model of the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table in the passive section to obtain the passive section trajectory that meets the designed value of the expected overload in the passive section, including:
[0119] Step S221: Establish a trajectory planning model for the passive section of the aircraft, and design the expected overload n y = f(h) according to the flight height of the aircraft.
[0120] Specifically, in this embodiment, the expected overload of the passive section is designed according to the flight altitude of the aircraft, and other independent variables such as time can also be flexibly selected.
[0121] Step S222, calculate the corresponding attack angle and / or sideslip angle as the design program angle through the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table of the passive section, so as to obtain the passive section trajectory that meets the expected overload design value of the passive section.
[0122] In one embodiment, in step S222, calculating the corresponding attack angle and / or sideslip angle as the design program angle by using the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the passive section includes:
[0123] Step S2221, reading the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table of the passive section;
[0124] Step S222: according to the current flight altitude, flight speed and expected overload of the aircraft, substitute the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table of the passive section for ternary interpolation to obtain the corresponding angle of attack and / or sideslip angle as the design program angle.
[0125] Specifically, if an angle of attack turn is used, the normal overload angle of attack basic table of the passive segment is read, and the normal overload angle of attack basic table is calculated according to the flight altitude h, flight speed v, and expected overload n at the current time t. y , substitute it into the basic table of normal overload angle of attack of the passive section (three-dimensional table) for three-dimensional interpolation, and obtain the corresponding angle of attack as the design program angle. If the sideslip angle is used for turning, substitute it into the basic table of lateral overload angle of attack of the passive section for three-dimensional interpolation, and obtain the corresponding sideslip angle as the design program angle.
[0126] After determining the design program angle of the passive section, the Mach number, angle of attack, and sideslip angle are used as inputs, and the aerodynamic parameter array of the passive section that has been trimmed in advance is interpolated to calculate the aerodynamic force at the current time t, and then the acceleration parameters of the aircraft are obtained, and the speed parameters and position parameters are obtained by integration, and the passive section trajectory that meets the corresponding overload design value is obtained. This part is the existing technology and will not be repeated here.
[0127] In one embodiment, the expected overload of the active segment design is The expected overload of the passive section design is Figure 3 The comparison curve between expected overload and actual overload is given, such as Figure 3 As shown, the actual overload value of the passive section is very close to the expected overload value. Taking the influence of mass into consideration, the actual overload value of the active section is relatively close to the expected overload value, but it is sufficient to meet the design requirements of overload refinement.
[0128] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.
[0129] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.
[0130] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.
[0131] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.
Claims
1. A fast trajectory planning method that meets overload expectation design, characterized in that: The following steps are involved: Based on the aerodynamic parameters of the aircraft, a calculation model of a normal overload angle of attack basic table and / or a lateral overload sideslip angle basic table is established; An aircraft trajectory planning model is established, with the expected overload as the design value, and the corresponding attack angle and / or sideslip angle are calculated as the design program angle through the calculation model of the normal overload attack angle basic table and / or the lateral overload sideslip angle basic table to obtain a trajectory that meets the expected overload design value.
2. The fast trajectory planning method for satisfying overload expectation design as claimed in claim 1, characterized in that: The method for quickly planning a trajectory that meets the expected overload design includes planning an active segment trajectory, and the planning of the active segment trajectory includes: Based on the aerodynamic parameters of the active section of the aircraft, a calculation model of a basic numerical table of normal overload angle of attack and / or a basic numerical table of lateral overload sideslip angle of the active section is established; A trajectory planning model for the active segment of the aircraft is established, and the expected overload of the active segment is designed according to the working time period of the aircraft engine. The corresponding attack angle and / or sideslip angle are calculated as the design program angle through the calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the active segment, so as to obtain the active segment trajectory that meets the expected overload design value of the active segment.
3. The fast trajectory planning method for satisfying overload expectation design as claimed in claim 2, characterized in that: The calculation model for establishing the basic numerical table of normal overload angle of attack of the active section based on the aerodynamic parameters of the active section of the aircraft includes: discretize the normal overload of the active section of the aircraft into a series of values to form an array of expected normal overloads of the active section; The mass of the active section of the aircraft is discretized into a series of values between the fully loaded mass and the unloaded mass to form an active section mass array; Discretize the flight speed of the active section of the aircraft into a series of values to form an active section flight speed array; Discretizing the flight altitude of the active segment of the aircraft into a series of values to form an active segment flight altitude array; The active segment mass array, the active segment flight speed array and the active segment flight altitude array are used as the current state of the aircraft, and the normal overload and its corresponding angle of attack are calculated when the expected normal overload array constraint of the active segment is met, so as to form a calculation model of the basic numerical table of the normal overload angle of attack of the active segment.
4. The fast trajectory planning method for satisfying overload expectation design as claimed in claim 3 is characterized in that: The calculation model of using the active segment mass array, the active segment flight speed array and the active segment flight altitude array as the current state of the aircraft, calculating the normal overload and its corresponding angle of attack when the expected normal overload array constraint of the active segment is satisfied, and forming the basic numerical table of the normal overload angle of attack of the active segment includes: Taking the active segment mass array, the active segment flight speed array and the active segment flight altitude array as the current state of the aircraft; Calculate the corresponding normal overload n according to the initial attack angle of the active section y , the sideslip angle is designed to be 0; The calculation formula is: y =CN·Q z ·S z / mass; Where, CN is the normal force coefficient; Q z is the dynamic pressure; S z is the characteristic area of the aircraft in the active section; mass is the mass of the aircraft; If the calculated normal overload does not satisfy the constraint of the expected normal overload array of the active segment, adjust the angle of attack until the calculated normal overload satisfies the constraint of the expected normal overload array of the active segment, and record the angle of attack at this moment; The above steps are repeated until the angles of attack of all states are calculated, thereby forming a calculation model of the basic numerical table of the normal overload angle of attack of the active section.
5. The method for rapid trajectory planning that meets overload expectation design as claimed in claim 4, characterized in that: When the angle of attack reaches the boundary value given by the aerodynamic parameters of the active section, and the calculated normal overload still does not satisfy the expected normal overload array constraint of the active section, the angle of attack at this moment is replaced by the closest boundary angle of attack.
6. The method for rapid trajectory planning that meets overload expectation design as claimed in claim 2, characterized in that: The calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the active section for calculating the corresponding attack angle and / or sideslip angle as the design program angle includes: Reading a normal overload attack angle basic number table and / or a lateral overload sideslip angle basic number table of the active section; According to the aircraft mass, flight altitude, flight speed and expected overload at the current moment, the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table of the active section are substituted for four-element interpolation to obtain the corresponding angle of attack and / or sideslip angle as the design program angle.
7. The fast trajectory planning method for satisfying overload expectation design according to claim 1 or 2, characterized in that: The method for quickly planning a trajectory that meets the expected overload design includes planning a passive segment trajectory, and the planning of the passive segment trajectory includes: Based on the aerodynamic parameters of the passive section of the aircraft, a calculation model of a basic numerical table of normal overload attack angle and / or a basic numerical table of lateral overload sideslip angle of the passive section is obtained; A trajectory planning model for the passive section of the aircraft is established, the expected overload of the passive section is designed, and the corresponding attack angle and / or sideslip angle are calculated as the design program angle through a calculation model of a basic numerical table of normal overload attack angle and / or a basic numerical table of lateral overload sideslip angle of the passive section, so as to obtain a passive section trajectory that meets the design value of the expected overload of the passive section.
8. The method for rapid trajectory planning that meets overload expectation design as claimed in claim 7, characterized in that: The calculation model for establishing the basic numerical table of normal overload attack angle of the passive section based on the aerodynamic parameters of the passive section of the aircraft includes: discretize the normal overload of the passive section of the aircraft into a series of values to form an array of expected normal overloads of the passive section; Discretizing the flight speed of the passive section of the aircraft into a series of values to form a passive section flight speed array; Discretizing the flight altitude of the passive segment of the aircraft into a series of values to form a passive segment flight altitude array; The passive section flight speed array and the passive section flight altitude array are used as the current state of the aircraft, and the normal overload and its corresponding angle of attack are calculated when the passive section expected normal overload array constraint is met, so as to form a calculation model of the basic table of normal overload angle of attack of the passive section.
9. The method for rapid trajectory planning that meets overload expectation design as claimed in claim 8, characterized in that: Before establishing the calculation model of the basic numerical table of the normal overload attack angle of the passive section, the aerodynamic parameters of the passive section are trimmed.
10. The fast trajectory planning method for satisfying overload expectation design according to claim 7, characterized in that: The calculation model of the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the passive section for calculating the corresponding attack angle and / or sideslip angle as the design program angle includes: Reading the normal overload attack angle basic number table and / or the lateral overload sideslip angle basic number table of the passive section; According to the current flight altitude, flight speed and expected overload of the aircraft, the normal overload angle of attack basic table and / or the lateral overload sideslip angle basic table of the passive section are substituted for ternary interpolation to obtain the corresponding angle of attack and / or sideslip angle as the design program angle.