A method for applying parameter perturbation during machine-missile separation
By introducing a biased small quantity with a predetermined distribution law and a joint Gaussian probability distribution during the missile separation process, the problems of high cost and long cycle of traditional experimental methods are solved, and a simple assessment and accurate analysis of the safety of missile separation trajectory are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
- Filing Date
- 2023-03-01
- Publication Date
- 2026-06-30
AI Technical Summary
In the existing technology, traditional experimental methods for missile separation are costly and time-consuming, making it difficult to effectively assess the impact of perturbations of various design variables on the missile separation trajectory.
A method for applying parameter perturbations during missile-machine separation is adopted. By extracting design variables and adding biased small quantities with a set distribution law, perturbations are introduced using a joint Gaussian probability distribution, including missile initial state, environmental and control-related parameters. The effects of the perturbations are analyzed in combination with a Gaussian distribution model.
This provides a simple and practical engineering approach that can more accurately assess the safety of missile separation trajectories, improving assessment efficiency and accuracy.
Smart Images
Figure CN117057051B_ABST
Abstract
Description
Technical Field
[0001] This technology belongs to the field of aerospace technology and provides a reasonable method for applying disturbances to various design variables during aircraft-missile separation. Background Technology
[0002] Fighter jets and bombers are important air strike weapons relied upon by the world's major military powers. The ability of fighter jets to quickly strike targets by carrying weapons has become a key focus of defense research.
[0003] Currently, there are four main types of weapon mounting methods for fighter jets: external, semi-recessed, concealed, and internal. For all missile mounting methods currently available on fighter jets, the issue of safe separation between the aircraft and the missile needs to be addressed. Missile separation is accompanied by disturbances, primarily stemming from environmental factors, sensor measurement errors, and limitations imposed by control components.
[0004] Traditionally, experiments are used to determine the impact of perturbations of various design variables on the missile during separation. However, the progress of these experiments has been limited by factors such as high cost and long duration. Summary of the Invention
[0005] To address the problems in existing technologies, this invention aims to provide a method for applying disturbances during missile separation. In the missile separation problem, based on the analysis and research of the parameters affecting the safety of the missile separation trajectory, a reasonable method for applying disturbances to various design variables is provided. In most cases, this method is more in line with engineering practice, and its specific implementation process is relatively simple.
[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows:
[0007] A method for applying parameter perturbation during machine-to-missile separation, the method comprising:
[0008] S1, extract the design variables when the fighter jet body separates from the missile. The design variables include a first type of parameter, a second type of parameter, and a third type of parameter. The first type of parameter is the initial state-related parameter of the missile when it separates from the airframe. The second type of parameter is the initial environment-related parameter. The third type of parameter is the design variable parameter related to missile body control.
[0009] S2, based on the design variables in S1, select the parameters to be affected by the disturbance, and add a small bias quantity with a set distribution law to introduce the disturbance effect on the design variable. The small bias quantity is a preset independent distribution function, or the distribution relationship between the actual value and / or the distribution measured by the flight test.
[0010] When the bias is a preset independent distribution function, obtain the joint Gaussian probability distribution of each uncertainty in the distribution function;
[0011] Based on the obtained joint Gaussian probability distribution, the design variable containing the disturbance in S1 is a set of points close to the baseline value and distributed according to a specific probability. Thus, a small bias quantity with a certain distribution pattern can be added to introduce the disturbance to the design variable.
[0012] Furthermore, the first type of parameters includes the missile's initial ejection velocity V0, initial angular velocity ω0, and preset rudder deflection angle θ0 when the missile separates from the machine. The first type of parameters are denoted as: {V0, ω0, θ0}.
[0013] The second type of parameters includes the incoming Mach number Ma, flight altitude H, and Reynolds number Re. The second type of parameters are denoted as: {Ma, H, Re}.
[0014] The third type of parameters includes those involved in using lateral jets to assist in missile attitude control when the deflection angle is insufficient, including the lateral force F generated by the lateral jets. p The time t for the lateral jet to begin acting p0 And the duration T of the lateral jet p And so on, the third type of parameter is denoted as: {F p , t p0 T p}
[0015] Furthermore, the parameter value of the selected small amount of bias to be introduced is...
[0016]
[0017] in To correspond to the design parameter X that actually includes the disturbance, This represents the perturbation distribution value of the selected parameter.
[0018] Furthermore, the design variables for which disturbances need to be applied are defined as the initial launch velocity V0 and the lateral force F. p Due to disturbances caused by braking errors of the brake system and measurement errors of the sensors, the actual initial ejection velocity acting on the projectile, which includes the effects of these disturbances, is affected. and lateral force According to equation (3), they are expressed as follows:
[0019]
[0020]
[0021] in and This represents the probability distribution of the effects of initial launch velocity and lateral force disturbances.
[0022] Furthermore, the probability distribution of the perturbation and This refers to the defined distribution function, or the relationship between the actual values and the distribution measured by flight tests.
[0023] Furthermore, the impact of initial launch velocity disturbances The mean is m v0 The variance is n v0 Gaussian distribution, influence of lateral force disturbance The mean is variance is The Gaussian distribution, that is:
[0024]
[0025]
[0026] The distribution of the initial ejection velocity, including the disturbance, is obtained at this point:
[0027]
[0028] And the distribution of lateral forces including disturbances:
[0029]
[0030] The initial launch velocity and the disturbance effects of lateral force are assumed to be independent, i.e. and For two independent events, we obtain the joint Gaussian probability distribution of the Mach number and Reynolds number, which are simultaneously perturbed:
[0031]
[0032] Similarly, designers can also calculate and solve the continuous Gaussian probability distribution for other parameters according to their needs.
[0033] Beneficial effects
[0034] (1) The present invention provides a reasonable method for applying disturbances to various design variables in the separation of machine and missile. In most cases, it is more in line with engineering practice, and its specific implementation process is relatively simple.
[0035] (2) The uncertainty probability distribution of the present invention is more flexible, and the perturbation probability distribution is more flexible. and It can be a pre-analyzed distribution function, or it can be the distribution relationship between actual values and / or measurements from flight tests. Attached Figure Description
[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.
[0037] Figure 1 This is a schematic diagram of the first type of parameters of the present invention;
[0038] Figure 2 This is a schematic diagram of the second type of parameters of the present invention;
[0039] Figure 3 In this example, the impact on 1000 sample points is uncertain. Joint probability distribution diagram. Detailed Implementation
[0040] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:
[0041] This application provides a method for applying parameter perturbation during machine-to-bullet separation, the method comprising:
[0042] S1, extract the design variables when the fighter jet body separates from the missile. The design variables include a first type of parameter, a second type of parameter, and a third type of parameter. The first type of parameter is the initial state-related parameter of the missile when it separates from the airframe. The second type of parameter is the initial environment-related parameter. The third type of parameter is the design variable parameter related to missile body control.
[0043] S2, based on the design variables in S1, select the parameters to be affected by the disturbance, and add a small bias quantity with a set distribution law to introduce the disturbance effect on the design variable. The small bias quantity is a preset independent distribution function, or the distribution relationship between the actual value and / or the distribution measured by the flight test.
[0044] When the bias is a preset independent distribution function, obtain the joint Gaussian probability distribution of each uncertainty in the distribution function;
[0045] Based on the obtained joint Gaussian probability distribution, the design variable containing the disturbance in S1 is a set of points close to the baseline value and distributed according to a specific probability. Thus, a small bias quantity with a certain distribution pattern can be added to introduce the disturbance to the design variable.
[0046] Furthermore, the first type of parameters includes the missile's initial ejection velocity V0, initial angular velocity ω0, and preset rudder deflection angle θ0 when the missile separates from the machine. The first type of parameters are denoted as: {V0, ω0, θ0}.
[0047] The second type of parameters includes the incoming Mach number Ma, flight altitude H, and Reynolds number Re. The second type of parameters are denoted as: {Ma, H, Re}.
[0048] The third type of parameters includes those involved in using lateral jets to assist in missile attitude control when the deflection angle is insufficient, including the lateral force F generated by the lateral jets. p The time t for the lateral jet to begin acting p0 And the duration T of the lateral jet p And so on, the third type of parameter is denoted as: {F p , t p0 T p}
[0049] Furthermore, the parameter value of the selected small amount of bias to be introduced is...
[0050]
[0051] in To correspond to the design parameter X that actually includes the disturbance, This represents the perturbation distribution value of the selected parameter.
[0052] Furthermore, the design variables for which disturbances need to be applied are defined as the initial launch velocity V0 and the lateral force T. p Due to disturbances caused by braking errors of the brake system and measurement errors of the sensors, the actual initial ejection velocity acting on the projectile, which includes the effects of these disturbances, is affected. and lateral force According to equation (1), they are expressed as follows:
[0053]
[0054]
[0055] in and This represents the probability distribution of the effects of initial launch velocity and lateral force disturbances.
[0056] Furthermore, the probability distribution of the perturbation and This refers to the defined distribution function, or the relationship between the actual values and the distribution measured by flight tests.
[0057] Furthermore, the impact of initial launch velocity disturbances The mean is m v0 The variance is n v0 Gaussian distribution, influence of lateral force disturbance The mean is variance is The Gaussian distribution, that is:
[0058]
[0059]
[0060] The distribution of the initial ejection velocity, including the disturbance, is obtained at this point:
[0061]
[0062] And the distribution of lateral forces including disturbances:
[0063]
[0064] The initial launch velocity and the disturbance effects of lateral force are assumed to be independent, i.e. and For two independent events, we obtain the joint Gaussian probability distribution of the Mach number and Reynolds number, which are simultaneously perturbed:
[0065]
[0066] Similarly, designers can also calculate and solve the continuous Gaussian probability distribution for other parameters according to their needs.
[0067] Example 1
[0068] This embodiment details the specific implementation process of a method for applying parameter perturbation during machine-missile separation:
[0069] (I) Analysis and Extraction of Design Variables
[0070] To model the safety of the missile separation trajectory, the design parameters that may be involved in the problem must first be pre-analyzed and extracted. For ease of description, all design variables are denoted as:
[0071] X = {x1, x2, ..., x} d} (9)
[0072] Where d represents the total number of design variables, which is set according to the actual engineering conditions.
[0073] In general, the design variables affecting the separation trajectory during the separation process can be mainly divided into the following three categories:
[0074] First, the first type of parameters are parameters related to the initial state of the missile when it separates from the airframe. For example... Figure 2 As shown, this includes the missile's initial ejection velocity V0, initial angular velocity ω0, and preset rudder deflection angle θ0 during missile separation. Therefore, we can derive the first type of parameters for this problem as: {V0, ω0, θ0}.
[0075] Secondly, the second type of parameters affecting the missile-machine separation trajectory are parameters related to the initial environment, such as the incoming Mach number Ma, flight altitude H, and Reynolds number Re. Therefore, we can obtain the second type of parameters, denoted as: {Ma, H, Re}.
[0076] Finally, the third type of parameters are design variables related to projectile control. For example... Figure 3 The diagram mainly illustrates the parameters involved in using lateral jets to assist in missile attitude control when the deflection angle is insufficient, including the lateral force F generated by the lateral jets. p The time t for the lateral jet to begin acting p0 And the duration T of the lateral jet p Therefore, the third type of parameter can be denoted as: {F} p , t p0 T p}
[0077] Based on the above analysis, we can derive the possible design variables involved in the full-scale modeling of the missile separation trajectory as follows:
[0078] X={V0,ω0,θ0,Ma,H,Re,F p , t p0 T p ,…} (10)
[0079] Subsequent research will strategically select appropriate design variables from the above-mentioned design variables to conduct missile separation trajectory safety modeling research based on specific engineering needs.
[0080] (ii) Disturbance application method
[0081] Due to the complexity of the actual engineering environment for machine-missile separation, the actual machine-missile separation process is usually a disturbance problem accompanied by various random disturbances. These disturbances mainly originate from environmental factors, disturbances caused by sensor measurement errors, and disturbances in the control signal output of control components.
[0082] Environmental disturbances mainly manifest as deviations in incoming flow parameters relative to actual baseline values. For example, actual incoming flow is typically not a constant, uniform flow, but rather a flow accompanied by certain disturbances. Therefore, parameters such as the incoming Mach number (Ma) and Reynolds number (Re) are values within a certain range accompanied by these disturbances. Similarly, due to limitations in design technology and manufacturing processes, the actual values of design variables measured by sensors and the output values of control signals from control components always deviate from the theoretical design levels. For instance, due to limitations in the manufacturing process and control of the launch rail, the initial angular velocity ω0 of the missile launch always deviates to some extent from the set value. The control angle of the missile servo motor and the velocity of the jet stream also always have a certain degree of influence from the actual set parameter values. Given these widespread disturbances, the modeling process for missile-machine separation must fully consider the impact of these disturbances to approximate the actual operating conditions as closely as possible. The primary task in studying these disturbances is to investigate how to incorporate their effects.
[0083] Although disturbances to each parameter are widespread, they are typically small quantities with a certain distributional pattern compared to the baseline values of the parameters. Therefore, the project team adopted a method of introducing disturbances into the design variables by adding a small, regularly distributed bias to the baseline values of these design variables that contain the influence of disturbances.
[0084]
[0085] in To correspond to the design parameter X that actually includes the disturbance, This represents the disturbance distribution value of the corresponding design variable. It can be seen that this application method is characterized by maintaining the original baseline value to the greatest extent possible; the disturbance is applied to the original baseline value only as a small disturbance. Therefore, in most cases, it is more in line with engineering practice, and its implementation process is relatively simple.
[0086] To visually demonstrate how the disturbance is applied, we will use the initial launch velocity V0 and the lateral force F as examples. p For example, if the initial ejection velocity and lateral force applied during the separation of the projectile and the machine gun are V0 = 6 m / s and F, respectively... p =1200N, due to the influence of braking error of the brake and measurement error of the sensor, the actual initial ejection velocity acting on the projectile, including disturbance, is 1200N. and lateral force According to equation (3), they can be expressed as follows:
[0087]
[0088]
[0089] in and This is a probability distribution of the disturbances to the initial launch velocity and lateral force, which is typically a small amount relative to the reference initial launch velocity and lateral force. Disturbance probability distribution and It can be a pre-analyzed distribution function, or a distribution relationship between actual values and / or measurements from flight tests. Taking the Gaussian distribution, most common in practical engineering problems, as an example, if the initial ejection velocity disturbance term... It follows a Gaussian distribution with a mean of 0 and a variance of 0.001, and the disturbance term of the lateral force... It follows a Gaussian distribution with a mean of 0 and a variance of 0.1, that is:
[0090]
[0091]
[0092] Furthermore, we can obtain the distribution of the initial ejection velocity, including the disturbance, at this point:
[0093]
[0094] And the distribution of lateral forces including disturbances:
[0095]
[0096] Assuming that the initial launch velocity and the disturbance of the lateral force are uncorrelated, i.e. and These are two independent events. Therefore, we can obtain the joint Gaussian probability distribution of the Mach number and Reynolds number, which are simultaneously perturbed:
[0097]
[0098] Its joint Gaussian probability distribution based on 1000 machine-missile separation sample points is as follows: Figure 3 As can be seen, unlike deterministic problems, the design variables involving disturbances are no longer fixed values, but rather a set of points close to the baseline value and distributed according to a specific probability. Similarly, disturbances to other parameters such as the initial angular velocity ω0 at missile launch and the preset rudder deflection angle θ0 can be introduced in a similar way, which will not be elaborated here.
[0099] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can make various modifications and adjustments within the technical scope disclosed in the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for applying parameter perturbation during machine-to-bullet separation, characterized in that, The method includes: S1, extract the design variables when the fighter jet body separates from the missile. The design variables include a first type of parameter, a second type of parameter, and a third type of parameter. The first type of parameter is the initial state-related parameter of the missile when it separates from the airframe. The second type of parameter is the initial environment-related parameter. The third type of parameter is the design variable parameter related to missile body control. S2, based on the design variables in S1, select the parameters to be affected by the disturbance, and add a small bias quantity with a predetermined distribution law to introduce the disturbance effect on the design variable. The small bias quantity is a preset independent distribution function, or a distribution relationship between actual values and / or measurements from flight tests; the parameter value of the selected small bias quantity to be introduced is: ； in To correspond to the design parameters that actually include disturbances , The perturbation distribution value of the selected parameter; When the bias is a preset independent distribution function, obtain the joint Gaussian probability distribution of each uncertainty in the distribution function; The design variable to be perturbed is set as the initial launch velocity. and lateral force Due to disturbances caused by braking errors of the brake system and measurement errors of the sensors, the actual initial ejection velocity acting on the projectile, which includes the effects of these disturbances, is affected. and lateral force They are represented as follows: ； ； in and The probability distribution of the effects of initial launch velocity and lateral force disturbances; The effect of initial launch velocity disturbance The mean is The variance is Gaussian distribution, influence of lateral force disturbance The mean is The variance is The Gaussian distribution, that is: ； ； The distribution of the initial ejection velocity, including the disturbance, is obtained at this point: ； ； ； And the distribution of lateral forces containing disturbances: ； ； ； The initial launch velocity and the disturbance effects of lateral force are assumed to be independent, i.e. and For two independent events, we obtain the joint Gaussian probability distribution of the Mach number and Reynolds number, which are simultaneously perturbed: ； Similarly, designers can also calculate and solve the consecutive Gaussian probability distribution for other parameters according to their needs; Based on the obtained joint Gaussian probability distribution, the design variable containing the disturbance in S1 is a set of points close to the baseline value and distributed according to a specific probability. Thus, a small bias quantity with a certain distribution pattern can be added to introduce the disturbance to the design variable.
2. The method for applying parameter perturbation during machine-missile separation according to claim 1, characterized in that, The first type of parameter includes the missile's initial ejection velocity at the time of missile separation. Initial angular velocity and the missile's preset rudder deflection angle Let the first type of parameter be denoted as: ; The second type of parameters includes the incoming Mach number Ma, flight altitude H, and Reynolds number Re. These second type of parameters are denoted as: ; The third type of parameters includes those involved in using lateral jets to assist in missile attitude control when the deflection angle is insufficient, including the lateral force generated by the lateral jets. The time when the lateral jet begins to act And the duration of the lateral jet The third type of parameter is denoted as: .
3. The method for applying parameter perturbation during machine-missile separation according to claim 1, characterized in that, Perturbation probability distribution and This refers to the defined distribution function, or the relationship between the actual values and the distribution measured by flight tests.