An enhanced anti-interference control system and method for aircraft boost separation process

Abstract

The present invention discloses an enhanced anti-interference control system and method for a boost separation process of an aircraft, comprising the following steps: modeling the interference caused by the boost separation process to the aircraft; modeling the attitude dynamics of the aircraft under the action of boost separation and simplifying the model to obtain a system model for surface control; designing an adaptive enhanced anti-interference control law based on the control model and the influence of boost separation; completing a stability analysis of the designed adaptive enhanced anti-interference control law based on the Lyapunov function stability theory, and verifying the effectiveness of the present invention through simulation examples, thereby ensuring that the attitude of the aircraft reaches a desired value under the action of boost separation.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft, and in particular relates to an enhanced anti-interference control system and method for an aircraft boost separation process. Background Art

[0002] During the boost separation process, the interference experienced by the aircraft mainly includes the impact interference at the moment of boost separation and the flow field interference during the separation of the front and rear bodies. When the aircraft faces complex flight conditions, the interference caused by boost separation has a significant impact on the aircraft's attitude control. Traditional aircraft control methods are unable to effectively suppress the interference experienced by the aircraft during boost separation, affecting the aircraft's attitude movement. In addition, during the boost separation process, the aircraft's attitude must also meet constraints such as engine ignition and ballistic flight requirements, which increases the difficulty of achieving attitude stability control for the aircraft. Therefore, how to enhance the performance of flight attitude stability during boost separation has become a research hotspot in the current field of aircraft control. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide an enhanced anti-interference control system and method for the booster separation process of an aircraft, so as to solve the problem that it is difficult to effectively suppress the interference to the aircraft during the booster separation process in the prior art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] An enhanced anti-interference control method for an aircraft boost separation process includes the following steps:

[0006] During the boost separation process, the interference signal received by the aircraft is characterized as a step input signal; the step input signal is decomposed into three channels: roll, yaw and pitch;

[0007] Based on the step input signal, a dynamic model of the aircraft during the boost separation process is constructed. The dynamic model is linearized with small disturbances to establish a linear attitude dynamics model. The linear attitude dynamics model is decomposed into a longitudinal equation system and a lateral equation system. Combining the longitudinal motion equation system and the interference signal received by the aircraft during the boost separation process, the dynamic model of the aircraft is expressed as a linear disturbed system.

[0008] For linear disturbed systems, an adaptive anti-interference control law for boost separation is set. The adaptive anti-interference control law includes a conventional control law and an interference compensation rate. The interference compensation rate includes compensation for time-varying interference and time-invariant interference. During the boost separation process of the aircraft, the adaptive anti-interference control rate is executed.

[0009] A further improvement of the present invention is:

[0010] Preferably, the formula of the interference signal is:

[0011]

[0012] in, They are the maximum interference torques received by the hypersonic vehicle during the boost separation process, and t1 and t2 are the start and end times of the boost separation process, respectively.

[0013] Preferably, the dynamic model of the aircraft is:

[0014]

[0015] Among them, V,θ,ψ V are velocity modulus, ballistic inclination angle and velocity axis roll angle respectively, ψ,γ are pitch, yaw and roll angles respectively, ω x ,ω y ,ω z The angular velocities in three directions, I x ,I y ,I z are the moments of inertia in three directions respectively. M x ,M y ,M z are the aerodynamic moments around the x, y, and z axes, respectively, and d ZT,x ,d ZT,y ,d ZT,z are the additional disturbance torque generated by boost separation, T x ,T y ,T z It represents the components of thrust on the x, y, and z axes; α and β represent the angle of attack and sideslip angle; X, Y, and Z represent the components of aerodynamic force on the x, y, and z axes, which are drag, sideslip, and lift, respectively; m represents the mass of the aircraft; and g represents the acceleration due to gravity.

[0016] Preferably, the formula of the linear posture dynamics model is:

[0017]

[0018] Among them, V,θ,ψ V are velocity modulus, ballistic inclination and ballistic deviation, respectively. ψ,γ are pitch, yaw and roll angles respectively, ω x ,ω y ,ω z are the angular velocities in three directions respectively; α, β represent the angle of attack and sideslip angle; δ x ,δ y ,δ zIndicates I x ,I y ,I z are the moments of inertia in three directions respectively; M x ,M y ,M z are the aerodynamic moments around the x, y, and z axes respectively; X, Y, and Z represent the components of the aerodynamic forces on the x, y, and z axes, which are drag, sideslip, and lift respectively; m represents the mass of the aircraft; g represents the acceleration due to gravity; F gx ,F gy ,F gz is the introduced interference force, M gx ,M gy ,M gz is the corresponding disturbance torque, P V is the derivative of thrust with respect to velocity modulus, X V is the derivative of the drag with respect to the velocity modulus, γ V is the velocity roll angle, and Δ* represents the increment of the corresponding parameter.

[0019] Preferably, the linear attitude dynamics model is decomposed into a longitudinal equation group and a lateral equation group, specifically:

[0020]

[0021] Preferably, the linear disturbed system is:

[0022]

[0023] Where d is the interference signal generated by boost separation, and u is the control input signal;

[0024]

[0025] Preferably, the adaptive anti-interference control law is:

[0026]

[0027] in, is the estimated value of θ, is the estimation error of θ, which is defined as The adaptive law is: The K value is a coefficient.

[0028] Preferably, is the observed value of the disturbance d2, which is estimated and compensated by the linear disturbance observer;

[0029] The disturbance observer is expressed as:

[0030]

[0031] Preferably, in step 3, the adaptive anti-interference control law is subjected to stability analysis by Lyapunov function stability theory.

[0032] An enhanced anti-interference control system for a boost separation process of an aircraft, comprising:

[0033] The interference torque establishment unit is used to characterize the interference signal received by the aircraft during the boost separation process as a step input signal; the step input signal is decomposed into three channels: roll, yaw and pitch;

[0034] A dynamics establishment unit is used to construct a dynamics model of the aircraft during the boost separation process based on a step input signal, perform small-disturbance linearization on the dynamics model, establish a linear attitude dynamics model, decompose the linear attitude dynamics model into a longitudinal equation group and a lateral equation group, and combine the longitudinal motion equation group and the interference signal received by the aircraft during the boost separation process to express the dynamics model of the aircraft as a linear disturbed system;

[0035] The interference control law unit is used to set an adaptive anti-interference control law for boost separation for a linear disturbed system. The adaptive anti-interference control law includes a conventional control law and an interference compensation rate. The interference compensation rate includes compensation for time-varying interference and time-invariant interference. The adaptive anti-interference control rate is executed during the boost separation process of the aircraft.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention discloses an enhanced anti-interference control system and method for the boost separation process of an aircraft, including modeling of the interference caused by the boost separation process to the aircraft; modeling and simplifying the aircraft attitude dynamics under the action of boost separation to obtain a system model for surface control; designing an adaptive enhanced anti-interference control law based on the control model and the influence of boost separation; completing a stability analysis of the designed adaptive enhanced anti-interference control law based on the Lyapunov function stability theory, and verifying the effectiveness of the present invention through simulation examples, which can ensure that the attitude of the aircraft reaches the expected value under the action of boost separation. The present invention studies the problem of aircraft attitude control during the boost separation process, based on the analysis of the interference caused by boost separation, and targeting the characteristics and difficulties of aerodynamic shape mutations and impact interference in the control process, studies a new control method with better interference suppression capability and control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of the present invention;

[0039] Figure 2 is a system control block diagram of the present invention;

[0040] Figure 3 The speed change curve for the working condition is as follows;

[0041] Figure 4 The attack angle change curve for the working condition is as follows;

[0042] Figure 5 This is the speed change curve under working condition 2;

[0043] Figure 6 is the attack angle variation curve under working condition 2;

[0044] Figure 7 The speed change curves under three working conditions are shown below;

[0045] Figure 8 The attack angle change curves for the three working conditions. DETAILED DESCRIPTION

[0046] The present invention is described in further detail below with reference to the accompanying drawings:

[0047] The present invention discloses a method for enhancing anti-interference control of boost separation of an aircraft, comprising the following steps:

[0048] Step 1. Analyze the characteristics of the additional interference to the aircraft during the boost separation process. The interference generated by the boost separation can be abstracted as a step input signal and decomposed into three channels: roll, yaw, and pitch. The specific form is as follows Figure 1 shown.

[0049] Therefore, the interference signal d generated by boost separation on the attitude motion of the hypersonic vehicle ZT Can be characterized as

[0050]

[0051] d ZT,x ,d ZT,y ,d ZT,z Represent the interference torque in the three directions of roll, yaw and pitch, respectively, and their specific forms are as follows:

[0052]

[0053] in, They are the maximum disturbance torques in the roll, pitch and yaw directions that the hypersonic vehicle is subjected to during the boost separation process, and t1 and t2 are the start and end times of the boost separation process, respectively.

[0054] Step 2: Based on the above maximum torque, construct the kinematic and dynamic model of the aircraft under the action of boost separation, and simplify the model to obtain a control-oriented system model. The kinematic and dynamic model of the aircraft during the boost separation process can be expressed as:

[0055]

[0056] Among them, V,θ,ψ V are velocity modulus, ballistic inclination angle and velocity axis roll angle respectively, ψ,γ are pitch, yaw and roll angles respectively, ω x ,ω y ,ω z The angular velocities in three directions, I x ,I y ,I z are the moments of inertia in three directions respectively. M x ,M y ,M z are the aerodynamic moments around the x, y, and z axes, respectively, and d ZT,x ,d ZT,y ,d ZT,z are the additional disturbance torque generated by boost separation, T x ,T y ,T z It represents the components of thrust on the x, y, and z axes; α and β represent the angle of attack and sideslip angle; X, Y, and Z represent the components of aerodynamic force on the x, y, and z axes, which are drag, sideslip, and lift, respectively; m represents the mass of the aircraft; and g represents the acceleration due to gravity.

[0057] According to the flight environment and force conditions during the flight of the aircraft, the aircraft's attitude dynamics model, that is, formula (3), is subjected to small disturbance linearization processing to establish the aircraft's linear attitude dynamics model, as shown in formula (4) below:

[0058]

[0059] Among them, V,θ,ψ V are velocity modulus, ballistic inclination and ballistic deviation, respectively. ψ,γ are pitch, yaw and roll angles respectively, ω x ,ω y ,ω z are the angular velocities in three directions respectively; α, β represent the angle of attack and sideslip angle; δ x ,δ y ,δ z Indicates I x ,I y ,I z are the moments of inertia in three directions respectively; M x ,M y ,M zare the aerodynamic moments around the x, y, and z axes respectively; X, Y, and Z represent the components of the aerodynamic forces on the x, y, and z axes, which are drag, sideslip, and lift respectively; m represents the mass of the aircraft; g represents the acceleration due to gravity; F gx ,F gy ,F gz is the introduced interference force, M gx ,M gy ,M gz is the corresponding disturbance torque, P V is the derivative of thrust with respect to velocity modulus, X V is the derivative of the drag with respect to the velocity modulus, γ V is the velocity roll angle, and Δ* represents the increment of the corresponding parameter.

[0060] At the moment of boost separation, the rolling work and lateral motion amplitude of the aircraft are very small, and the influence on the attitude of the aircraft can be ignored. Therefore, the linearized equation group is decomposed into two equation groups, longitudinal and lateral. Considering the longitudinal motion equation group of the aircraft, the deflections Δx and Δy in the longitudinal equation group are made independent, and the formula (4) is simplified to obtain:

[0061]

[0062] Take the pitch angular velocity Then the above equation (5) can be rewritten into the following matrix form:

[0063]

[0064] in,

[0065]

[0066] Defining state variables The input signal is u=Δδ z ,definition

[0067]

[0068] Considering the additional disturbance imposed on the aircraft by the boost separation, the aircraft boost separation dynamics model (6) can be expressed as the following control-oriented linear disturbance system:

[0069]

[0070] Where d is the interference signal generated by boost separation.

[0071] Step 3, the adaptive anti-interference control law design of boost separation is to design the control input signal u of the system model (9) so that the state variable x in formula (9) reaches the expected value. First, the interference generated by boost separation can be regarded as a combination of time-varying interference and time-invariant interference, which is in the form of:

[0072] d=d1+d2 (10)

[0073] Where d1 is the time-varying interference and d2 is the time-invariant interference. For the time-varying interference d1, uncertainty quantification is performed: d1(t) = θ T φ(t,x), where φ(t,x) is bounded, i.e.

[0074] In response to the interference imposed on the aircraft by the boost separation, the following enhanced anti-interference control law is designed, and the separation process is controlled according to the following formula (11):

[0075]

[0076] Among them, K value is the gain coefficient, is the estimated value of θ, is the estimation error, which is defined as The adaptive law is:

[0077]

[0078] is the observed value of the time-invariant disturbance d2, which is estimated and compensated by the linear disturbance observer.

[0079] The disturbance observer is expressed as:

[0080]

[0081] The error dynamic equation of the disturbance observer (13) is expressed as:

[0082]

[0083] The control block diagram of the system is as follows Figure 2 shown.

[0084] Step 4: Complete the stability analysis of the designed enhanced anti-interference control law based on the Lyapunov function stability theory. Select the following Lyapunov function:

[0085]

[0086] Where P1, P2, Γ are symmetric positive definite matrices. Taking the derivative of the Lyapunov function (15) and substituting it into the control law (11) and the adaptive law (12), we get:

[0087]

[0088] The boost separation closed-loop system meets the exponential stability condition The following inequalities hold:

[0089]

[0090] By performing contract transformation on formula (17), we can obtain:

[0091]

[0092] Define Q = P1 -1 ,X=KQ,Y=P2L, it can be seen that the above formula (18) can be expressed as:

[0093]

[0094] From the above derivation, we can know that:

[0095]

[0096] When the above inequality (20) holds, the system satisfies Lyapunov stability. Further, according to the above linear inequality, the matrix P2, Q, X, Y can be solved. According to Q = P1 -1 , X=KQ, Y=P2L, the calculation formula of control gain and interference observation gain matrix can be obtained:

[0097]

[0098] To implement the above method, the present invention is implemented through the following system:

[0099] The interference torque establishment unit is used to characterize the interference signal received by the aircraft during the boost separation process as a step input signal; the step input signal is decomposed into three channels: roll, yaw and pitch;

[0100] A dynamics establishment unit is used to construct a dynamics model of the aircraft during the boost separation process based on a step input signal, perform small-disturbance linearization on the dynamics model, establish a linear attitude dynamics model, decompose the linear attitude dynamics model into a longitudinal equation group and a lateral equation group, and combine the longitudinal motion equation group and the interference signal received by the aircraft during the boost separation process to express the dynamics model of the aircraft as a linear disturbed system;

[0101] The interference control law unit is used to set an adaptive anti-interference control law for boost separation for a linear disturbed system. The adaptive anti-interference control law includes a conventional control law and an interference compensation rate. The interference compensation rate includes compensation for time-varying interference and time-invariant interference. The adaptive anti-interference control rate is executed during the boost separation process of the aircraft.

[0102] Example

[0103] The designed boost separation enhanced anti-interference control law was simulated and verified using MATLAB. The simulations were performed under three different working conditions. The model parameters for the three different working conditions were selected as follows:

[0104] Working condition 1:

[0105]

[0106] Working condition 2:

[0107]

[0108] Working condition three:

[0109]

[0110] The simulation results are shown in the figure below:

[0111] Comparison of simulation results under three different working conditions Figure 3-Figure 8 As shown in the figure, it can be seen that the designed linear anti-interference controller has strong adaptability and can effectively suppress the additional interference caused by boost separation under different working conditions.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An enhanced anti-interference control method for an aircraft boost separation process, characterized in that: The following steps are involved: During the boost separation process, the interference signal received by the aircraft is characterized as a step input signal; the step input signal is decomposed into three channels: roll, yaw and pitch; Based on the step input signal, a dynamic model of the aircraft during the boost separation process is constructed. The dynamic model is linearized with small disturbances to establish a linear attitude dynamics model. The linear attitude dynamics model is decomposed into a longitudinal equation system and a lateral equation system. Combining the longitudinal motion equation system and the interference signal received by the aircraft during the boost separation process, the dynamic model of the aircraft is expressed as a linear disturbed system. The linear disturbed system is: （9） in, To help separate the interference signal generated, u is the control input signal; （8） in, (7) represents the mass of the aircraft, is the derivative of thrust with respect to velocity modulus, is the derivative of the drag with respect to the velocity modulus, represents the acceleration due to gravity; represents the ballistic inclination angle, Indicates that the aerodynamic force The components on the three axes are drag, sideslip and lift; For the linear disturbed system, an adaptive anti-interference control law with boost separation is set, which includes a conventional control law and an interference compensation rate. The interference compensation rate includes the time-varying interference and time-invariant interference Compensation; During the boost separation process of the aircraft, the adaptive anti-interference control rate is executed; The adaptive anti-interference control law is: （11） in, for The estimated value of is the ballistic inclination angle, K value is the coefficient, is a state variable; Time-invariant interference The observed value of is estimated and compensated by the linear disturbance observer; The disturbance observer is expressed as: （12）。 2. The enhanced anti-interference control method for the aircraft boost separation process according to claim 1, characterized in that: The formula of the interference signal is: （2） in, are the maximum disturbance torques on the hypersonic vehicle during the boost separation process, are the start and end times of the boost separation process, respectively.

3. The enhanced anti-interference control method for the boost separation process of an aircraft according to claim 1, characterized in that: The dynamic model of the aircraft is: （3） in, are velocity modulus, ballistic inclination angle and velocity axis roll angle respectively, are pitch, yaw, and roll angles, are the angular velocities in three directions, are the moments of inertia in three directions respectively; Respectively around Aerodynamic moments about the three axes, are the additional disturbance torques caused by boost separation, Indicates thrust in Components on three axes; represents the angle of attack and sideslip angle; Indicates that the aerodynamic force The components on the three axes are drag, sideslip and lift; Indicates the mass of the aircraft; Represents the acceleration due to gravity.

4. The enhanced anti-interference control method for the boost separation process of an aircraft according to claim 3, characterized in that: The formula of the linear posture dynamics model is: （4） in, are velocity modulus, ballistic inclination and ballistic deviation, respectively. are pitch, yaw, and roll angles, are the angular velocities of rotation in three directions respectively; represents the angle of attack and sideslip angle; express are the moments of inertia in three directions respectively; Respectively around Aerodynamic moments about three axes; Indicates that the aerodynamic force The components on the three axes are drag, sideslip and lift; Indicates the mass of the aircraft; represents the acceleration due to gravity; is the introduced interference force, is the corresponding disturbance torque, is the derivative of thrust with respect to velocity modulus, is the derivative of the drag with respect to the velocity modulus, is the velocity roll angle, Indicates the increment of the corresponding parameter.

5. The enhanced anti-interference control method for the boost separation process of an aircraft according to claim 4, characterized in that: The linear attitude dynamics model is decomposed into a longitudinal equation group and a lateral equation group, specifically: （5）。 6. The enhanced anti-interference control method for the aircraft boost separation process according to claim 1, characterized in that: In step 3, the adaptive anti-interference control law is subjected to stability analysis through Lyapunov function stability theory.

7. An enhanced anti-interference control system for an aircraft boost separation process for implementing the enhanced anti-interference control method according to claim 1, characterized in that: include: The interference torque establishment unit is used to characterize the interference signal received by the aircraft as a step input signal during the boost separation process; The step input signal is decomposed into three channels: roll, yaw and pitch; A dynamics establishment unit is used to construct a dynamics model of the aircraft during the boost separation process based on a step input signal, perform small-disturbance linearization on the dynamics model, establish a linear attitude dynamics model, decompose the linear attitude dynamics model into a longitudinal equation group and a lateral equation group, and combine the longitudinal motion equation group and the interference signal received by the aircraft during the boost separation process to express the dynamics model of the aircraft as a linear disturbed system; The interference control law unit is used to set an adaptive anti-interference control law for boost separation for a linear disturbed system. The adaptive anti-interference control law includes a conventional control law and an interference compensation rate. The interference compensation rate includes compensation for time-varying interference and time-invariant interference. The adaptive anti-interference control rate is executed during the boost separation process of the aircraft.

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