Method and device for determining angular accuracy of rocket target, medium and equipment

Abstract

The invention provides a method and device for determining the angular accuracy of a rocket target, a medium and equipment. The method comprises the steps that the current mass, acceleration and aerodynamic parameters of a rocket are obtained; corresponding aerodynamic force is determined according to the current mass and the acceleration, and a total differential expression of the target angle is determined according to the relation between the aerodynamic force and aerodynamic force parameters; determining the precision of the rocket target angle based on the total differential expression of the target angle; therefore, due to the fact that a fixed relation exists between the aerodynamic force and the aerodynamic force parameters of the rocket, the total differential expression of the target angle can be determined based on the relation between the aerodynamic force and the aerodynamic force parameters, the identified target angle is subjected to precision analysis according to the total differential expression, and the precision of the target angle is judged according to the analysis result. And therefore, the large-attack-angle flight attitude control effect of the carrier rocket, the pneumatic load shedding control effect, the landing area attitude control effect of the separated body and the landing attitude control effect that the separated body can be repeatedly used and returned are ensured.

Description

Technical Field

[0001] The present application relates to the field of rocket attitude control technology, and in particular to a method, device, medium and equipment for determining the accuracy of a rocket target angle. Background Art

[0002] Aerodynamic force is the force on the surface of a launch vehicle when it moves in the air. During the flight of a launch vehicle, high-altitude winds will bring about a large aerodynamic angle of attack and sideslip angle. In the case of large angles of attack or large sideslip angles, the aerodynamic environment of the rocket body is relatively complex, the static instability of the rocket body is large, and the aerodynamic force and torque acting on the rocket body will have a large nonlinearity, which can easily lead to instability of the rocket body's attitude. Attitude control at large angles of attack is difficult. In the actual flight of the rocket body, the angle of attack generated by the rocket body's speed relative to the airflow will also bring a large aerodynamic load, causing the rocket body to bend, and aerodynamic load reduction control has always been a difficulty in the industry. In addition, with the development of launch vehicles, the demand for the control of the landing area of ​​the launch vehicle separation body and the reusability of the separation body has become more and more urgent. In the re-entry phase of the separation body, the angle of attack is large, the aerodynamic changes are drastic, and the characteristics are complex. Therefore, the control of the landing area attitude of the separation body and the control of the attitude of the separation body for reusable return landing are also difficult.

[0003] Whether it is attitude control at a large angle of attack (sideslip angle), aerodynamic load reduction control, attitude control of the landing area of ​​the separation body, or attitude control of the separation body for reusable return landing, the angle of attack (sideslip angle) must be measured first. Aerodynamic angle of attack measurement generally includes three methods: the first is the traditional pitot tube, which measures the speed and calculates the angle of attack through pressure difference; the second is the angle of attack sensor, which directly measures the angle of attack; the third is the accelerometer to measure the acceleration and calculate the angle of attack through reverse interpolation of aerodynamic data. The first method has a limited scope of application. It is generally used on airplanes or in wind tunnels, is easy to get clogged, and cannot be used by launch vehicles; the second method adds an angle of attack sensor, which will destroy the flow field and is very expensive. The third method uses the original accelerometer of the launch vehicle, which is economical and affordable, but the accelerometer is easily affected by various interferences (such as engine deflection, aerodynamic parameter deviation, tangential acceleration caused by the angular velocity of the rocket body, etc.), resulting in large changes in the accuracy of the calculated angle of attack and sideslip angle. However, there is no corresponding way in the prior art to analyze the accuracy of the angle of attack and sideslip angle identified by the above method, which limits the use of this method. If the accuracy of the identified angle of attack or sideslip angle cannot be guaranteed, uncertain risks will be introduced, which will directly affect the flight attitude control, aerodynamic load reduction control, landing area attitude control of the separation body and the reusable return landing attitude control of the separation body at large angles of attack of the launch vehicle. Summary of the invention

[0004] In response to the problems existing in the prior art, the embodiments of the present invention provide a method, device, medium and equipment for determining the accuracy of the rocket target angle, so as to solve the technical problem that the prior art is unable to analyze the accuracy of the identified attack angle and sideslip angle of the launch vehicle, thereby affecting the flight attitude control, aerodynamic load reduction, landing area attitude control of the separation body and the reusable return landing attitude control of the separation body at large attack angles of the launch vehicle.

[0005] In a first aspect of the present invention, a method for determining the accuracy of a rocket target angle is provided, wherein the target angle includes an angle of attack and a sideslip angle; the method comprises: Get the current mass, acceleration and aerodynamic parameters of the rocket; Determine the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determine the total differential expression of the target angle according to the relationship between the aerodynamic force and aerodynamic parameters; The accuracy of the rocket target angle is determined based on the total differential expression of the target angle; wherein, When the target angle is the angle of attack, the acceleration is the Y-direction acceleration; when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration.

[0006] In the above scheme, the aerodynamic force includes normal aerodynamic force and lateral aerodynamic force, and the corresponding aerodynamic force is determined according to the current mass of the rocket and the acceleration, including: When the aerodynamic force is a normal aerodynamic force, obtaining a first product value between the current mass and the Y-direction acceleration, wherein the first product value is the normal aerodynamic force; When the aerodynamic force is a transverse aerodynamic force, a second product value between the current mass and the Z-direction acceleration is obtained, and the second product value is the transverse aerodynamic force.

[0007] In the above scheme, when the target angle is the angle of attack, the aerodynamic parameters include: the flight pressure of the rocket body, the aerodynamic characteristic area of ​​the rocket body and the normal aerodynamic coefficient; the total differential expression of the target angle is determined according to the relationship between the aerodynamic force and the aerodynamic parameters, including: Get the relationship between aerodynamic forces and aerodynamic parameters: ; according to The analytical expression of the angle of attack is determined by the Taylor first-order expansion of The angle of attack analytical expression is fully differentiated, and the corresponding angle of attack fully differential expression is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters; wherein, Said M is the current mass of the rocket, a y is the Y-axis acceleration, Ma is the Mach number of the rocket, To balance the rudder angle for the pitch channel, q is the flight pressure of the arrow body, a is the angle of attack, s is the aerodynamic characteristic area of ​​the rocket body, CN is the normal aerodynamic coefficient.

[0008] In the above scheme, the The Taylor first-order expansion of determines the analytical formula for the angle of attack, including: Determine the The Taylor first-order expansion of is: ; The angle of attack is determined according to the first-order expansion, and the analytical formula for the angle of attack is: ; wherein said is the value of the normal aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0. It is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the rocket body angle of attack is 0 and the sideslip angle is 0.

[0009] In the above solution, the angle of attack analytical expression is fully differentiated, and the corresponding angle of attack fully differential expression is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters, including: The angle of attack total differential expression is determined by performing total differentiation on the angle of attack analytical expression: ; According to the relationship between aerodynamic force and aerodynamic parameters Determine: ; according to Convert the angle of attack total differential expression to: ;in, Said is the value of the normal aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0. The normal aerodynamic coefficient is a And the value when the sideslip angle is 0, is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the angle of attack of the arrow body is 0 and the sideslip angle is 0. is the mass deviation of the arrow body, M is the current mass of the arrow body, is the Y-axis acceleration deviation, is the normal aerodynamic coefficient deviation, For the quality deviation , the Y-axis acceleration deviation is And the normal aerodynamic coefficient deviation is The total change in angle of attack corresponding to .

[0010] In the above scheme, the determination of the rocket target angle accuracy based on the total differential expression of the target angle includes: Determine the corresponding target angle change according to the total differential expression of the target angle; Determining a corresponding target angle deviation according to the target angle variation; If it is determined that the target angle deviation is greater than a preset deviation threshold, it is determined that the rocket target angle accuracy is insufficient; If it is determined that the target angle deviation is less than the deviation threshold, it is determined that the rocket target angle accuracy meets the requirements.

[0011] In the above scheme, when the target angle is the sideslip angle, the aerodynamic force parameters include: the flight pressure of the rocket body, the aerodynamic characteristic area of ​​the rocket body and the lateral aerodynamic force coefficient; the total differential expression of the target angle is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters, including: Get the relationship between aerodynamic forces and aerodynamic parameters: ; according to The sideslip angle is determined by the Taylor first-order expansion of The sideslip angle analytical expression is fully differentiated, and the corresponding sideslip angle fully differential expression is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters; wherein, Said M is the current mass of the rocket, a z is the Z-axis acceleration, Ma is the Mach number of the rocket, The yaw channel balance rudder angle is q is the flight pressure of the arrow body, is the sideslip angle, s is the aerodynamic characteristic area of ​​the rocket body, CZ is the lateral aerodynamic coefficient.

[0012] A second aspect of the present invention provides a device for determining the accuracy of a rocket target angle, wherein the target angle includes an angle of attack and a sideslip angle; the device comprises: An acquisition unit is used to obtain the current mass, acceleration and aerodynamic parameters of the rocket; A first determination unit is used to determine the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determine the total differential expression of the target angle according to the relationship between the aerodynamic force and the aerodynamic force parameters; The second determination unit is used to determine the accuracy of the rocket target angle based on the total differential expression of the target angle; wherein, when the target angle is the angle of attack, the acceleration is the Y-direction acceleration; when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration.

[0013] According to a third aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps of any one of the methods described in the first aspect are implemented.

[0014] According to a fourth aspect of the present invention, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any one of the methods described in the first aspect are implemented.

[0015] The present invention provides a method, device, medium and equipment for determining the accuracy of a rocket target angle, the method comprising: obtaining the current mass, acceleration and aerodynamic parameters of the rocket; determining the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determining the total differential expression of the target angle according to the relationship between the aerodynamic force and the aerodynamic parameters; determining the accuracy of the rocket target angle based on the total differential expression of the target angle; wherein, when the target angle is the angle of attack, the acceleration is the Y-direction acceleration; when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration; thus, since there is a fixed relationship between the rocket aerodynamic force and the aerodynamic parameters, the present embodiment can determine the total differential expression of the target angle based on the relationship between the aerodynamic force and the aerodynamic parameters, thereby performing accuracy analysis on the angle of the identified target angle according to the total differential expression, judging the accuracy of the identified target angle according to the analysis result, and thereby ensuring the flight attitude control effect of the carrier rocket at a large angle of attack, the aerodynamic load reduction control effect, the landing area attitude control effect of the separation body and the control effect of the reusable return landing attitude of the separation body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of a method for determining a rocket target angle accuracy according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of an arrow body coordinate system according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of a velocity coordinate system according to an embodiment of the present invention is shown; Figure 4A schematic diagram of the structure of a device for determining the target angle accuracy of a rocket according to an embodiment of the present invention is shown; Figure 5 A schematic diagram showing the effect of mass deviation on the angle of attack changing with flight time according to an embodiment of the present invention is shown; Figure 6 A schematic diagram showing the effect of the normal aerodynamic coefficient deviation on the angle of attack as the flight time changes according to one embodiment of the present invention is shown; Figure 7 A schematic diagram showing the effect of acceleration deviation on the angle of attack changing with flight time according to an embodiment of the present invention is shown; Figure 8 A schematic diagram of the structure of a computer device according to an embodiment of the present invention is shown; Fig. 9 A schematic diagram of the structure of a computer-readable storage medium according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0018] The embodiment of the present invention provides a method for determining the accuracy of a rocket target angle, such as Figure 1 As shown, the method comprises the following steps: S110, obtaining the current mass, acceleration and aerodynamic parameters of the rocket; The target angle in this embodiment includes the angle of attack and the sideslip angle. In order to better understand the technical solution of this embodiment, the concepts of the angle of attack and the sideslip angle are first introduced here.

[0019] Specifically, please refer to Figure 2 ,exist Figure 2 In the rocket body coordinate system, the coordinate origin is located at the center of mass of the rocket, the OX1 axis is consistent with the longitudinal symmetry axis of the rocket body, pointing in the direction of the head, the OY1 axis is perpendicular to the OX1 axis, located in the longitudinal symmetry plane of the rocket, pointing upward, and the OZ1 axis, OX1 axis and OY1 axis form a right-handed rectangular coordinate system.

[0020] Figure 3 In the velocity coordinate system, the origin O of the velocity coordinate system is the center of mass of the rocket. The OXv axis is along the flight speed direction of the aircraft, the OYv axis is in the main symmetry plane of the rocket and is perpendicular to the OXv axis; the OZv axis is perpendicular to the XvOYv plane, and the Zv axis points to the right when looking along the flight direction. OXvYvZv is a right-hand rectangular coordinate system.

[0021] Then the angle of attack is the angle between the projection of the rocket body velocity vector on the main symmetry plane OX1Y1 of the rocket and the longitudinal axis of the rocket body (OX1 axis); the sideslip angle is the angle between the rocket body velocity vector and the longitudinal symmetry plane of the rocket body.

[0022] The forces on the rocket body in the Y and Z directions during flight mainly include: transverse aerodynamic force when the airflow angle is not zero, normal aerodynamic force, transverse normal force caused by the deflection of the engine thrust line, and tangential force caused by the angular velocity of the rocket body. Since the transverse normal force caused by the deflection of the engine thrust line is much smaller than the aerodynamic force, the transverse normal force can be ignored.

[0023] The tangential force caused by the angular velocity of the arrow body can be calculated according to the formula calculate, M The mass of the arrow body ， is the rocket body angular acceleration, l is the distance from the accelerometer to the center of mass of the arrow. Generally speaking, the value of the tangential force is also small, so it can be ignored here. Then the relationship between the lateral aerodynamic force, the normal aerodynamic force and the Y and Z acceleration of the arrow body can be shown as formula (1): (1) In formula (1), Ma is the rocket's Mach number, To balance the rudder angle, a is the angle of attack, is the sideslip angle, M is the current mass of the arrow body, a is the acceleration, F It is the aerodynamic force corresponding to the corresponding Mach number, balance rudder angle, angle of attack and sideslip angle.

[0024] Furthermore, when the aerodynamic coupling in the pitch channel and the yaw channel is neglected, the formula It can be decomposed into formula (2): (2) Specifically, since the rocket body has a normal aerodynamic force in the pitch channel and a lateral aerodynamic force in the yaw channel, the aerodynamic force F in formula (1) can be decomposed into the normal aerodynamic force in the lateral and normal directions: F y and lateral aerodynamic forces F z . In formula (2), Balance the rudder angle for the pitch channel, Balance the rudder angle for the yaw channel, a y is the Y acceleration of the arrow body, a zis the Z acceleration of the arrow body.

[0025] Therefore, if you want to determine the aerodynamic force at a certain moment, this embodiment needs to obtain the current mass and acceleration of the rocket at that moment. When the target angle is the angle of attack, the acceleration is the Y-direction acceleration; when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration.

[0026] Because there is a certain relationship between aerodynamic force and aerodynamic force parameters (which will be explained in detail in the subsequent steps), it is also necessary to obtain aerodynamic force parameters.

[0027] As can be seen from the above, aerodynamic force includes normal aerodynamic force and transverse aerodynamic force. If the aerodynamic force is normal aerodynamic force, the corresponding aerodynamic force parameters include: rocket body flight pressure, rocket body aerodynamic characteristic area and normal aerodynamic force coefficient. If the aerodynamic force is transverse aerodynamic force, the corresponding aerodynamic force parameters include: rocket body flight pressure, rocket body aerodynamic characteristic area and transverse aerodynamic force coefficient.

[0028] S111, determining the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determining the total differential expression of the target angle according to the relationship between the aerodynamic force and aerodynamic parameters.

[0029] In one embodiment, the aerodynamic force includes normal aerodynamic force and lateral aerodynamic force, and the corresponding aerodynamic force is determined according to the current mass and acceleration of the rocket, including: When the aerodynamic force is normal aerodynamic force, obtain the first product value between the current mass and the Y-axis acceleration. The first product value ( M * a y ) is the normal aerodynamic force; When the aerodynamic force is a lateral aerodynamic force, obtain the second product value between the current mass and the Z-axis acceleration. The second product value ( M * a z ) is the lateral aerodynamic force.

[0030] It is understandable that since the target angle includes the angle of attack and the sideslip angle, the relationship between the aerodynamic force and the aerodynamic force parameters is slightly different when the target angle is different, which will be introduced one by one below.

[0031] When the target angle is the angle of attack, the relationship between the aerodynamic force and the aerodynamic force parameters can be expressed as formula (3): (3) In formula (3), a is the angle of attack, q Provides pressure for the arrow body to fly. s is the aerodynamic characteristic area of ​​the rocket body, CN is the normal aerodynamic coefficient, M is the current mass of the rocket,a y is the Y-axis acceleration, Ma is the rocket's Mach number, Balance rudder angle for pitch channel.

[0032] Then, when the target angle is the angle of attack, the total differential expression of the target angle is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters, including: Get the relationship between aerodynamic forces and aerodynamic parameters: ; according to The Taylor first-order expansion of determines the analytical expression of the angle of attack; The angle of attack analytical expression is fully differentiated, and the corresponding angle of attack total differential expression is determined based on the relationship between aerodynamic force and aerodynamic parameters.

[0033] In one embodiment, according to The Taylor first-order expansion of determines the analytical formula for the angle of attack, including: Sure The Taylor first-order expansion of is: ; The analytical formula for the angle of attack is determined based on the first-order expansion: ;in, is the value of the normal aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0, Close to 0, can be ignored; is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the angle of attack of the rocket body is 0 and the sideslip angle is 0, a is the angle of attack.

[0034] Specifically, according to Taylor's first-order expansion, ignoring the higher-order terms, we can get formula (4): (4) In formula (4), is the value of the normal aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0, The value of is also close to 0 and can be ignored. It is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the rocket body angle of attack is 0 and the sideslip angle is 0.

[0035] Based on formula (4), the angle of attack can be determined a The analytical expression of is shown in formula (5): (5) That is to say .

[0036] When the angle of attack is known, the balanced pitch channel balance rudder deflection angle can be obtained. At the target time, the flight pressure of the rocket body is q and Mach number are known quantities, so the total differential expression of the angle of attack can be obtained by fully differentiating the analytical expression of the angle of attack in formula (5): (6) According to formula (3), we can determine: ; then Substituting into formula (6) we get the final total differential expression of the angle of attack: (7) In formula (7), is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the angle of attack of the rocket body is 0 and the sideslip angle is 0, is the mass deviation of the rocket body (the mass difference between the current mass of the rocket body and the theoretical mass), M is the current mass of the arrow body, is the acceleration deviation in the Y direction, is the normal aerodynamic coefficient deviation, For the quality deviation , the Y-axis acceleration deviation is And the normal aerodynamic coefficient deviation is The total change in angle of attack corresponding to .

[0037] The total change in angle of attack actually includes three changes in angle of attack, namely: the first change in angle of attack obtained when the mass deviation affects the angle of attack, the second change in angle of attack obtained when the Y-axis acceleration deviation affects the angle of attack, and the third change in angle of attack obtained when the normal aerodynamic coefficient deviation affects the angle of attack. Therefore, according to formula (7), the first change in angle of attack obtained when the mass deviation of the rocket body affects the angle of attack can be determined: ; When the Y-axis acceleration deviation affects the angle of attack, the second angle of attack change is obtained ; The third angle of attack change obtained when the normal aerodynamic coefficient deviation affects the angle of attack .

[0038] That is, if we want to analyze the accuracy of a certain angle of attack, we can determine the first angle of attack change, the second angle of attack change, and the third angle of attack change according to formula (7), and then judge whether the angle of attack accuracy meets the expected requirements according to the change of each angle of attack. And from formula (7), we can see that the main factors affecting the accuracy of the angle of attack include the mass deviation of the arrow body. , Y-axis acceleration deviation and the normal aerodynamic coefficient deviation .

[0039] It should be noted that the first and third angle of attack changes have little influence on the angle of attack accuracy and can be ignored. Generally speaking, the angle of attack accuracy is determined based on the second angle of attack change.

[0040] Similarly, when the target angle is the sideslip angle, the relationship between the aerodynamic force and the aerodynamic force parameters can be expressed as formula (8): (8) In formula (8), CZ is the lateral aerodynamic coefficient, is the sideslip angle, q Provides pressure for the arrow body to fly. s is the aerodynamic characteristic area of ​​the rocket body, M is the current mass of the rocket, a z is the Z-axis acceleration, Ma is the rocket's Mach number, Balance the rudder angle for the yaw channel.

[0041] Then, the total differential expression of the target angle is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters, including: Get the relationship between aerodynamic forces and aerodynamic parameters: ; according to The Taylor first-order expansion of determines the analytical expression of the sideslip angle; The sideslip angle analytical expression is fully differentiated, and the corresponding sideslip angle total differential expression is determined based on the relationship between aerodynamic force and aerodynamic parameters.

[0042] In one embodiment, according to The Taylor first-order expansion of determines the analytical formula for the angle of attack, including: Sure The Taylor first-order expansion of is: ; The analytical formula of the sideslip angle is determined according to the first-order Taylor expansion. The sideslip angle is: ;in, is the value of the lateral aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0, The value is close to 0 and can be ignored. It is the value of the derivative of the lateral aerodynamic coefficient with respect to the angle of attack when the rocket body angle of attack is 0 and the sideslip angle is 0.

[0043] Specifically, according to Taylor's first-order expansion, ignoring the higher-order terms, we can obtain formula (9): (9) In formula (4), is the value of the lateral aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0, The value is close to 0 and can be ignored. It is the value of the derivative of the lateral aerodynamic coefficient with respect to the sideslip angle when the rocket body angle of attack is 0 and the sideslip angle is 0.

[0044] Based on formula (4), the analytical formula of the sideslip angle can be determined: is the sideslip angle, as shown in formula (10): (10) That is to say .

[0045] When the sideslip angle is known, the trimmed yaw channel balance rudder deflection angle can be obtained. At the target time, the flight pressure of the rocket body is q and Mach number are known quantities, so the total differential expression of the sideslip angle can be obtained by fully differentiating the analytical expression of the sideslip angle in formula (10): (11) According to formula (8), we can determine: ; then Substituting into formula (11) we get the final total differential expression of the sideslip angle: (12) In formula (12), is the value of the derivative of the lateral aerodynamic coefficient with respect to the sideslip angle when the angle of attack of the rocket body is 0 and the sideslip angle is 0, is the mass deviation of the rocket body (the mass difference between the current mass of the rocket body and the theoretical mass), M is the current mass of the arrow body, is the Z-axis acceleration deviation, is the lateral aerodynamic coefficient deviation, For the quality deviation , Z-axis acceleration deviation is And the lateral aerodynamic coefficient deviation is The total change of sideslip angle corresponding to .

[0046] The total sideslip angle variation actually includes three sideslip angle variations, namely: the first sideslip angle variation obtained when the mass deviation affects the sideslip angle, the second sideslip angle variation obtained when the Z-axis acceleration deviation affects the sideslip angle, and the third sideslip angle variation obtained when the lateral aerodynamic coefficient deviation affects the sideslip angle. Therefore, the first sideslip angle variation obtained when the mass deviation of the rocket body affects the sideslip angle can be determined according to formula (12): When the Y-axis acceleration deviation affects the sideslip angle, the second sideslip angle change is , the third side slip angle change obtained when the lateral aerodynamic coefficient deviation affects the side slip angle .

[0047] It should be noted that the first sideslip angle variation and the third sideslip angle variation have little influence on the sideslip angle accuracy and can be ignored. Generally speaking, the sideslip angle accuracy is determined based on the second sideslip angle variation.

[0048] That is, if you want to analyze the accuracy of a certain sideslip angle, you can determine the first sideslip angle change, the second sideslip angle change, and the third sideslip angle change according to formula (12), and then judge whether the sideslip angle accuracy meets the expected requirements based on each sideslip angle. And from formula (12), it can be seen that the main factors affecting the sideslip angle accuracy include the mass deviation of the rocket body. , Z-axis acceleration deviation and the lateral aerodynamic coefficient deviation .

[0049] It can be seen that the present invention can analyze the influencing factors on the angle of attack and the sideslip angle from a mechanism perspective, and establish a functional expression of the influencing factors (as shown in Formula 7 and Formula 12), providing a basis for determining the accuracy of the angle of attack and the sideslip angle.

[0050] S112, determining the accuracy of the rocket target angle based on the total differential expression of the target angle.

[0051] It can be seen from the above formula (7) that the main factors affecting the angle of attack accuracy include the mass deviation of the arrow body: , Y-axis acceleration deviation and the normal aerodynamic coefficient deviation .

[0052] Therefore, the corresponding change in angle of attack can be determined by the deviation of rocket mass, Y-axis acceleration and normal aerodynamic coefficient (one parameter corresponds to one change in angle of attack).

[0053] Similarly, it can be seen from the above formula (12) that the main factors affecting the sideslip angle accuracy include the mass deviation of the arrow body , Z-axis acceleration deviation and the lateral aerodynamic coefficient deviation .

[0054] Therefore, the corresponding sideslip angle change can be determined by the rocket mass deviation, Z-axis acceleration deviation and lateral aerodynamic coefficient deviation (one parameter corresponds to one sideslip angle change).

[0055] Then in one embodiment, determining the rocket target angle accuracy based on the total differential expression of the target angle includes: Determine the corresponding target angle change according to the total differential expression of the target angle; Determining a corresponding target angle deviation according to the target angle variation; If it is determined that the target angle deviation is greater than a preset deviation threshold, it is determined that the rocket target angle accuracy is insufficient and the identified target angle cannot be used; If it is determined that the target angle deviation is less than the deviation threshold, it is determined that the rocket target angle accuracy meets the requirements and the identified target angle can be used.

[0056] Specifically, since the above three deviations correspond to three target angle changes, generally speaking, it is necessary to determine the target angle change that has the greatest impact on the target angle from the three target angle changes, and determine the target angle deviation corresponding to the target angle change with the greatest impact, and compare the target angle deviation with the deviation threshold. If the target angle deviation is greater than the deviation threshold, it means that the target angle accuracy is insufficient.

[0057] Taking the angle of attack as an example, the first angle of attack change corresponding to the mass deviation and the third angle of attack change corresponding to the normal aerodynamic coefficient have little effect on the angle of attack and can be ignored. The second angle of attack change corresponding to the acceleration deviation has the greatest impact on the angle of attack. Therefore, the corresponding angle of attack deviation is generally determined based on the second angle of attack change, and then the angle of attack deviation corresponding to the second angle of attack change is used to determine whether the accuracy of the identified angle of attack meets the requirements.

[0058] The embodiment of the present invention can determine the total differential expression of the target angle based on the relationship between the aerodynamic force and the aerodynamic force parameters, and then perform accuracy analysis on the identified target angle according to the total differential expression, and judge the accuracy of the identified target angle according to the analysis result, thereby ensuring the flight attitude control effect of the launch vehicle at a large angle of attack, the aerodynamic load reduction control effect, the landing area attitude control effect of the separation body, and the control effect of the reusable return landing attitude of the separation body.

[0059] Based on the same inventive concept as the above-mentioned embodiment, this embodiment also provides a device for determining the accuracy of the rocket target angle, such as Figure 4 As shown, the device comprises: The acquisition unit 41 is used to obtain the current mass, acceleration and aerodynamic parameters of the rocket at the target time; A first determination unit 42 is used to determine the corresponding aerodynamic force according to the current mass and acceleration of the rocket, and to determine the total differential expression of the target angle according to the relationship between the aerodynamic force and the aerodynamic force parameters; The second determination unit 43 is used to determine the accuracy of the rocket target angle based on the total differential expression of the target angle; wherein, When the target angle is the angle of attack, the acceleration is the Y-direction acceleration; when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration.

[0060] Since the device introduced in the embodiment of the present invention is a device used to implement the method for determining the rocket target angle accuracy of the embodiment of the present invention, based on the method introduced in the embodiment of the present invention, the person skilled in the art can understand the specific structure and deformation of the device, so it is not repeated here. All devices used in the method of the embodiment of the present invention belong to the scope of protection of the present invention.

[0061] In practical applications, when the embodiment of the present invention uses the method and device provided in the above embodiment to perform precision analysis on the identified angle of attack (angle is 3.5°) of a certain type of rocket, the specific implementation is as follows: First, it is necessary to determine the pitch channel balance rudder deflection angle The pitch channel balance rudder deflection angle refers to the angle of attack at which the arrow body maintains the pitch moment. M z The required rudder deflection angle when is 0. That is, this embodiment can be based on the formula To determine when M z is 0, and the angle of attack is The corresponding pitch channel balance rudder deflection angle ;in, is the identified angle of attack.

[0062] Secondly, the Mach number can be directly determined based on the trajectory Ma , Arrow body flight pressure q , the current mass of the rocket body M ; Then use the interpolation algorithm to determine the normal aerodynamic coefficient and the derivative of the normal aerodynamic coefficient with respect to the angle of attack .

[0063] Specifically, the normal aerodynamic force coefficient and the derivative of the normal aerodynamic force coefficient with respect to the angle of attack can be calculated using a four-dimensional difference method. For example, the interpolation function interpn can be used to determine the normal aerodynamic force coefficient and the derivative of the normal aerodynamic force coefficient with respect to the angle of attack.

[0064] Taking the normal dynamic coefficient as an example, the four-dimensional interpolation function can be obtained: in, Ma ch , , a ch , are column vectors, CN ch The four-dimensional aerodynamic data of the wind tunnel test is Ma ch =[ 0.3 0.6 1.0 2.0 3.0 4.0 5.0 ]; =[-10.0 -5.0 0 5.0 10.0 ]; a ch =[-9.0 -6.0 -3.0 0 3.0 6.09.0]; =[-9.0 -6.0 -3.0 0 3.0 6.0 9.0].

[0065] Ma , , a is the specific value at the current moment. Use the function interpn. to perform interpolation calculation to obtain the normal force coefficient CN_cal corresponding to the current moment. CN_cal is equivalent to .

[0066] The theoretical aerodynamic data includes three-channel force coefficients and moment coefficients for pitch, yaw and roll, with a total of 6 components. The aerodynamic data is the data obtained by the wind tunnel test of the rocket body before the actual flight. Each component is determined by the four-dimensional variables of Mach number, rudder deflection angle, angle of attack and sideslip angle. Ma ch , , a ch , β ch , CN ch This is equivalent to forming a theoretical aerodynamic database. If the Mach number, rudder angle, angle of attack, and sideslip angle at a certain moment are obtained, ， The three-channel force coefficient or moment coefficient can be interpolated. The normal force coefficient is one of the three-channel force coefficients, so after the interpolation is completed, the normal force coefficient at the current moment is also obtained.

[0067] In this way, the Mach number corresponding to the current moment (for example, the moment when the rocket body flies for 40 seconds) Ma , Arrow body flight pressure q , characteristic area s, current mass of the rocket body M、 After the normal aerodynamic coefficient and the derivative of the normal aerodynamic coefficient with respect to the angle of attack are determined, formula (7) is used to calculate the following equations: 2 , when the deviation of the normal aerodynamic coefficient is 0.21 (the maximum deviation of the normal aerodynamic coefficient is 10%, and the maximum value of the normal aerodynamic coefficient is 2.1), the first angle of attack change, the second angle of attack change, and the third angle of attack change are determined, as shown in Table 1: Table 1 It can be seen from Table 1 that the mass deviation and the normal aerodynamic coefficient deviation have little effect on the angle of attack accuracy, while the acceleration deviation has a greater impact on the angle of attack accuracy.

[0068] Further, please refer to Figure 5 , Figure 5 The effect of mass deviation on the angle of attack as a function of flight time is shown. Figure 5 It can be seen that the maximum change in the first angle of attack corresponding to the mass deviation is 0.014 o The impact is small.

[0069] Figure 6 The effect of the normal aerodynamic coefficient deviation on the angle of attack varies with flight time. Figure 6 It can be seen that the maximum change in the third angle of attack corresponding to the deviation of the normal aerodynamic coefficient is 0.07 o The impact is small.

[0070] Figure 7 The effect of acceleration deviation on the angle of attack varies with flight time. Figure 7 It can be seen that the influence of the second angle of attack change corresponding to the acceleration deviation on the angle of attack changes concavely with the flight time, that is, the acceleration deviation has a greater influence on the angle of attack at the beginning and end of the flight, and the acceleration deviation has a smaller influence on the angle of attack during the flight.

[0071] Based on this, since the first angle of attack change corresponding to the mass deviation and the third angle of attack change corresponding to the normal aerodynamic coefficient have little effect on the angle of attack and can be ignored, the second angle of attack change corresponding to the acceleration deviation has the greatest impact on the angle of attack. Therefore, the corresponding angle of attack deviation is generally determined based on the second angle of attack change, and then the accuracy of the identified angle of attack is determined based on the angle of attack deviation corresponding to the second angle of attack change.

[0072] For example, continue to refer to Figure 7 , when the arrow body is flying around 40s, the angle of attack deviation can be controlled within 5%. If it is around 65s, the angle of attack deviation is about 14%, which is a large deviation.

[0073] In practical applications, when using the identified angle of attack, in order to ensure that the identified angle of attack has a high accuracy, the initial and final stages of the flight should be avoided as much as possible, and the identified angle of attack in the middle stage should be selected. In fact, during the flight of the rocket body, the period when the maximum aerodynamic load needs to be overcome or the control difficulty is relatively high is basically in the section with the maximum dynamic pressure, generally in the middle stage of the flight, and the two just fit. That is, the identified angle of attack can be introduced at the point where the control difficulty is the greatest for load reduction control or attitude control. Due to the high accuracy of the identified angle of attack, load reduction control or attitude control at large angles of attack can be effectively achieved.

[0074] For example, if the accuracy requirement is 10%, that is, the deviation of the 3.5° attack angle requirement is no more than 0.35°, according to Figure 7 It can be seen that the identified angle of attack can be used for load reduction or attitude control in about 30s to 50s, and the accuracy of the angle of attack can be guaranteed to be within 0.2°. If after 65s, the change in the second angle of attack caused by the acceleration deviation is 0.49°, then the corresponding angle of attack deviation is 14%. In engineering, the accuracy is expected to be as high as possible, and it is generally limited to about 10%. Therefore, after 65s, it is no longer suitable to use the identified angle of attack for load reduction or attitude control. The error is too large, which will introduce uncertain control risks.

[0075] In other words, the method provided by the present invention provides a theoretical basis for the analysis of angle of attack identification, provides reliable guidance for the engineering use of angle of attack identification based on the accuracy of the ultimately determined angle of attack identification, clarifies the applicable boundaries and risks of use of the method, and further provides support for the large-scale use of the angle of attack identification method, thereby providing a strategy for solving engineering aerodynamic load problems or high angle of attack flight attitude control problems.

[0076] Based on the same inventive concept, this embodiment provides a computer device 800, such as Figure 8 As shown, it includes a memory 810, a processor 820, and a computer program 811 stored in the memory 810 and executable on the processor 820. When the processor 820 executes the computer program 811, any step of the method described above is implemented.

[0077] Based on the same inventive concept, this embodiment provides a computer-readable storage medium 900, such as Fig. 9 As shown, a computer program 911 is stored thereon, and when the computer program 911 is executed by a processor, the steps of any of the methods described above are implemented.

[0078] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages: The present invention provides a method, device, medium and equipment for determining the accuracy of a rocket target angle, the method comprising: obtaining the current mass, acceleration and aerodynamic parameters of the rocket at the target moment; determining the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determining the total differential expression of the target angle according to the relationship between the aerodynamic force and the aerodynamic parameters; determining the accuracy of the rocket target angle based on the total differential expression of the target angle; wherein, when the target angle is the angle of attack, the acceleration is the acceleration in the Y direction; when the target angle is the sideslip angle, the acceleration is the acceleration in the Z direction; thus, since there is a fixed relationship between the rocket aerodynamic force and the aerodynamic parameters, the present embodiment can determine the total differential expression of the target angle based on the relationship between the aerodynamic force and the aerodynamic parameters, thereby performing an accuracy analysis on the angle of the identified target angle according to the total differential expression, judging the accuracy of the angle of the identified target angle according to the analysis result, thereby ensuring the flight attitude control effect of the carrier rocket at a large angle of attack, the aerodynamic load reduction control effect, the landing area attitude control effect of the separation body, and the reusable return landing attitude control effect of the separation body.

[0079] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the present invention is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the description of the above specific languages ​​is for disclosing the best mode of the present invention.

[0080] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0081] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those explicitly recited in each claim. More specifically, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0082] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device so disclosed may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0083] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

[0084] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all functions of some or all components of a gateway, proxy server, or system according to an embodiment of the present invention. The present invention may also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0085] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0086] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining the accuracy of a rocket target angle, characterized in that: The target angle includes an angle of attack and a sideslip angle; the method includes: Get the current mass, acceleration and aerodynamic parameters of the rocket; Determine the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determine the total differential expression of the target angle according to the relationship between the aerodynamic force and aerodynamic parameters; The accuracy of the rocket target angle is determined based on the total differential expression of the target angle; wherein, when the target angle is the angle of attack, the acceleration is the Y-direction acceleration; and when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration.

2. The method according to claim 1, characterized in that The aerodynamic force includes normal aerodynamic force and lateral aerodynamic force, and the corresponding aerodynamic force is determined according to the current mass of the rocket and the acceleration, including: When the aerodynamic force is a normal aerodynamic force, obtaining a first product value between the current mass and the Y-direction acceleration, wherein the first product value is the normal aerodynamic force; When the aerodynamic force is a transverse aerodynamic force, a second product value between the current mass and the Z-direction acceleration is obtained, and the second product value is the transverse aerodynamic force.

3. The method according to claim 1, characterized in that When the target angle is the angle of attack, the aerodynamic parameters include: the flight pressure of the rocket body, the aerodynamic characteristic area of ​​the rocket body and the normal aerodynamic coefficient; the total differential expression of the target angle is determined according to the relationship between the aerodynamic force and the aerodynamic parameters, including: Get the relationship between aerodynamic forces and aerodynamic parameters: ; according to The analytical expression of the angle of attack is determined by the Taylor first-order expansion of The angle of attack analytical expression is fully differentiated, and the corresponding angle of attack fully differential expression is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters; wherein, M is the current mass of the rocket, a y is the Y-axis acceleration, Ma is the Mach number of the rocket, To balance the rudder angle for the pitch channel, q is the flight pressure of the arrow body, a is the angle of attack, s is the aerodynamic characteristic area of ​​the rocket body, CN is the normal aerodynamic coefficient.

4. The method according to claim 3, characterized in that The basis The Taylor first-order expansion of determines the analytical formula for the angle of attack, including: Determine the The Taylor first-order expansion of is: ； The angle of attack is determined according to the first-order expansion, and the analytical formula for the angle of attack is: ; wherein said is the value of the normal aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0. is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the angle of attack of the rocket body is 0 and the sideslip angle is 0, a is the angle of attack.

5. The method according to claim 3, characterized in that The method of performing total differentiation on the angle of attack analytical expression and determining the corresponding angle of attack total differential expression according to the relationship between the aerodynamic force and the aerodynamic force parameters includes: The angle of attack total differential expression is determined by performing total differentiation on the angle of attack analytical expression: ； According to the relationship between aerodynamic force and aerodynamic parameters Determine: ; according to Convert the angle of attack total differential expression to: ;in, Said is the value of the normal aerodynamic coefficient when the rocket body angle of attack is 0 and the sideslip angle is 0. The normal aerodynamic coefficient is a And the value when the sideslip angle is 0, is the value of the derivative of the normal aerodynamic coefficient with respect to the angle of attack when the angle of attack of the arrow body is 0 and the sideslip angle is 0. is the mass deviation of the arrow body, M is the current mass of the arrow body, is the Y-axis acceleration deviation, is the normal aerodynamic coefficient deviation, For the quality deviation , the Y-axis acceleration deviation is And the normal aerodynamic coefficient deviation is The total change in angle of attack corresponding to .

6. The method according to claim 1, characterized in that Determining the rocket target angle accuracy based on the total differential expression of the target angle includes: Determine the corresponding target angle change according to the total differential expression of the target angle; Determining a corresponding target angle deviation according to the target angle variation; If it is determined that the target angle deviation is greater than a preset deviation threshold, it is determined that the rocket target angle accuracy is insufficient; If it is determined that the target angle deviation is less than the deviation threshold, it is determined that the rocket target angle accuracy meets the requirements.

7. The method according to claim 1, characterized in that When the target angle is a sideslip angle, the aerodynamic force parameters include: the flight pressure of the rocket body, the aerodynamic characteristic area of ​​the rocket body and the lateral aerodynamic force coefficient; the total differential expression of the target angle is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters, including: Get the relationship between aerodynamic forces and aerodynamic parameters: ; according to The sideslip angle analytical expression is determined by using the Taylor first-order expansion of The sideslip angle analytical expression is fully differentiated, and the corresponding sideslip angle fully differential expression is determined according to the relationship between the aerodynamic force and the aerodynamic force parameters; wherein, Said M is the current mass of the rocket, a z is the Z-axis acceleration, Ma is the Mach number of the rocket, The yaw channel balance rudder angle is q is the flight pressure of the arrow body, is the sideslip angle, s is the aerodynamic characteristic area of ​​the rocket body, CZ is the lateral aerodynamic coefficient.

8. A device for determining the accuracy of a rocket target angle, characterized in that: The target angle includes an angle of attack and a sideslip angle; the device includes: An acquisition unit is used to obtain the current mass, acceleration and aerodynamic parameters of the rocket; A first determination unit is used to determine the corresponding aerodynamic force according to the current mass of the rocket and the acceleration, and determine the total differential expression of the target angle according to the relationship between the aerodynamic force and the aerodynamic force parameters; The second determination unit is used to determine the accuracy of the rocket target angle based on the total differential expression of the target angle; wherein, when the target angle is the angle of attack, the acceleration is the Y-direction acceleration; when the target angle is the sideslip angle, the acceleration is the Z-direction acceleration.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 7 are implemented.

Images