A rolling channel self-adaptive variable structure control method under weak steering efficiency

Abstract

The application provides a weak-manipulation-efficiency rolling channel adaptive variable structure control method, which comprises the following steps: step one, calculating rolling channel control parameters in real time according to aircraft parameters such as a Mach number, a dynamic pressure and a speed calculated by an inertial navigation calculation unit; step two, calculating rolling channel rudder commands according to a rolling angle command of the aircraft calculated by a guidance instruction calculation unit, real-time rolling Euler angles calculated by the inertial navigation calculation unit, a Mach number and a rolling angular velocity sensed by an inertial measurement sensor according to a rolling channel adaptive variable structure strategy; and step three, sending the rolling channel rudder commands to a rudder to drive a missile rudder surface deflection, so as to realize the suppression of rolling interference and the tracking of a rolling attitude angle under weak-manipulation efficiency. The weak-manipulation-efficiency rolling channel adaptive variable structure control method can change the rolling channel control structure in real time according to flight conditions, improve the robustness of the aircraft under weak-manipulation efficiency of ailerons and improve control quality.

Description

Technical Field

[0001] This invention relates to the field of aircraft flight control, and in particular to an adaptive variable structure control method for a roll channel under weak control efficiency, which addresses the degradation of control performance under low Mach aileron weak control efficiency and strong aerodynamic uncertainty. Background Technology

[0002] For ground- or rocket-launched aircraft, an acceleration process from low to high Mach number is required. To address the issue of low rudder efficiency at low speeds, a control scheme using gas-fueled rudders can be employed to improve control efficiency. However, some aircraft have strict limitations on launch methods. For example, rocket-launched aircraft typically require barrel launches. In the overall design, for the boost phase, the yaw channel generally uses a swaying nozzle to ensure sufficient control efficiency. The roll channel can only use the aerodynamic control of the preceding missile stage. This results in a risk of instability during the initial boost phase, where the aileron control efficiency is low due to the low Mach number, making it difficult to effectively suppress initial angular velocity interference that causes inter-channel coupling, affecting flight control quality. Therefore, control strategies or methods with low maneuverability at low Mach numbers are particularly important.

[0003] Currently, there is no adaptive variable structure control method in the field of aircraft control methods in China that addresses the issue of low aileron rudder effectiveness during the initial launch phase. Summary of the Invention

[0004] The purpose of this invention is to address the problem of low aileron efficiency and difficulty in ensuring control quality such as interference suppression and attitude response at low Mach numbers during the initial launch phase. This invention provides an adaptive variable structure control method for the roll channel under weak control efficiency. This method adaptively changes the control structure according to the flight state, improves interference suppression performance, ensures decoupling between channels, and improves stability in the low-speed phase. As the speed increases, it adaptively improves attitude control accuracy and improves flight control quality.

[0005] The present invention provides an adaptive variable structure control method for rolling channels under weak manipulation efficiency, comprising:

[0006] Step 1: Based on the aircraft parameters such as Mach number, dynamic pressure, and speed calculated by the inertial navigation calculation unit, the roll channel control parameters g2, g3, and g4 are calculated in real time.

[0007] Step 2: Calculate the aircraft roll angle command γ from the guidance command calculation unit. c The real-time roll Euler angle γ and Mach number Ma calculated by the inertial navigation unit, and the roll angular velocity ω sensed by the inertial measurement unit. x The rolling channel rudder command δ is calculated based on the adaptive variable structure strategy of the rolling channel. r ;

[0008] Step 3: Send the roll channel rudder command δ r to the steering gear to drive the deflection of the missile control surface, so as to realize the suppression of roll interference and the tracking of roll attitude angle under low control efficiency.

[0009] Further, the adaptive variable structure control strategy for the roll channel described in Step 2 is: a) when Ma < Ma_down, the stability augmentation control loop is used to calculate the roll rudder deflection command; b) when Ma_min ≤ Ma < Ma_up, the roll rudder deflection command is calculated by gradual transition from stability augmentation control to attitude control; c) when Ma_up ≤ Ma, the complete attitude control loop is used to calculate the roll rudder deflection command.

[0010] Further, the typical algorithm of the adaptive variable structure control strategy for the roll channel described in Step 2 is:

[0011] a) when Ma < Ma_down, a stability augmentation control method is adopted, and the calculation method is: δ r (k) = g2 × U ωx (k);

[0012] b) when Ma_down ≤ Ma < Ma_up, first calculate the attitude angle deviation command U Δγ (k), the calculation method is: U Δγ (k) = 0.5 × h × g4 × [Δγ1(k)+Δγ1(k-1)] + U Δγ (k-1), where Δγ1 is the roll attitude deviation after limiting the rate of change of the roll angle command, and the calculation method is Then, according to the attitude deviation angle command U Δγ (k) and U ωx (k) calculate the roll rudder command δ r (k), the method is: δ r (k) = g2 × U ωx (k) + g3 × (1.6667 × Ma - 0.6667) × (Y ir (k) - U Δγ (k)), where Y ir (k) = 0.5 × h × [U ωx (k) + U ωx (k-1)] + Y ir (k-1).

[0013] c) when Ma_up ≤ Ma, a complete attitude control loop is adopted, and the calculation method of roll rudder command δ r (k) is: δ r (k) = g2 × U ωx (k) + g3 × (Y ir (k) - U Δγ(k))

[0014] In the above formula, h represents the calculation of compensation in a typical algorithm, with a typical value of 0.0025, and k represents the current time.

[0015] In the above formula, U ωx (k) represents the roll angular velocity ω x The filtered value, a typical filtering algorithm is

[0016] U ωx (k)=-E1U ωx (k-1)-E2U ωx (k-2)+F0ω x (k)+F1ω x (k-1)+F2ω x (k-2), where E1, E2, F0, F1, and F2 are constant values, typically E1 = -1.709, E2 = 0.7304, F0 = 0.01729, F1 = -0.009606, and F2 = 0.01345.

[0017] Furthermore, in the typical algorithm of the rolling channel adaptive variable structure control strategy, the values ​​of Ma_down and Ma_up are determined according to the aerodynamic characteristics, overall parameters and flight requirements of the aircraft. Typically, Ma_down is 0.3 and Ma_up is 1.2.

[0018] The advantages of this invention include: addressing the problems of low aileron efficiency and decreased control quality such as interference suppression and attitude response at low Mach numbers during the initial launch phase, this invention provides an adaptive variable structure control method for the roll channel under weak control efficiency. This method adaptively changes the control structure according to the flight Mach number. In the low Mach number stage, a stability-enhancing control loop structure is adopted to improve interference suppression performance, ensure decoupling between channels, and improve stability. After the speed increases, an attitude control loop structure is adopted to adaptively improve attitude control accuracy and improve flight control quality. Attached Figure Description

[0019] Figure 1 The control structure diagram of the adaptive variable structure control method for a rolling channel under weak manipulation efficiency provided by the present invention;

[0020] Figure 2 A flowchart of an adaptive variable structure control method for a rolling channel under weak manipulation efficiency provided by the present invention. Detailed Implementation

[0021] The control structure of an adaptive variable structure control method for a rolling channel under weak manipulation efficiency according to an embodiment of the present invention is as follows: Figure 1 As shown, and in combination Figure 2 .

[0022] With reference to the accompanying drawings, the implementation process of the present invention is as follows.

[0023] Step 1: Calculate rolling channel control parameters g2, g3 and g4 in real time according to aircraft parameters including aircraft Mach number, dynamic pressure and velocity calculated by an inertial navigation solution unit;

[0024] Step 2: According to the aircraft roll angle command γ calculated by a guidance command solution unit c , the real-time roll Euler angle γ and Mach number Ma calculated by the inertial navigation solution unit, and the roll angular velocity ω measured by an inertial measurement sensor x , calculate a rolling channel rudder command δ according to the rolling channel adaptive variable structure control strategy r ; wherein the rolling channel adaptive variable structure control strategy is as follows: a) when Ma<Ma_down, calculate a rolling rudder deflection command by using a stability augmentation control loop; b) when Ma_down ≤ Ma<Ma_up, calculate the rolling rudder deflection command through gradual transition from stability augmentation control to attitude control; c) when Ma ≥ Ma_up, calculate the rolling rudder deflection command by using a complete attitude control loop. In this case, the value of Ma_down is 0.3, and the value of Ma_up is 1.2. The specific implementation case of the adaptive variable structure control strategy is as follows:

[0025] a) when Ma<Ma_down, a stability augmentation control method is adopted, and the calculation method is: δ r (k) = g2 × U ωx (k);

[0026] b) when Ma_down ≤ Ma<Ma_up, first calculate an attitude angle deviation command U Δγ (k), and the calculation method is: U Δγ (k) = 0.5 × h × g4 × [Δγ1(k)+Δγ1(k-1)] + U Δγ (k-1), wherein Δγ1 is a roll angle attitude deviation after amplitude limiting of a change rate of the roll angle command, and the calculation method is then, according to the attitude deviation angle command U Δγ (k) and U ωx (k) calculate the roll rudder command δ r (k), and the method is: δ r (k) = g2 × U ωx (k) + g3 × (1.6667 × Ma - 0.6667) × (Y ir (k) - U Δγ (k)), wherein Y ir (k) = 0.5 × h × [U ωx (k) + U ωx (k-1)] + Y ir (k-1).

[0027] c) When Ma_up <= Ma, a complete attitude control loop is used, and the roll rudder command δ is applied. r (k) is calculated as follows: δ r (k)=g2×U ωx (k)+g3×(Y ir (k)-U Δγ (k))

[0028] In the above formula, h represents the calculation of compensation in a typical algorithm, with a typical value of 0.0025, and k represents the current time.

[0029] In the above formula, U ωx (k) represents the roll angular velocity ω x The filtered value, a typical filtering algorithm is

[0030] U ωx (k)=-E1U ωx (k-1)-E2U ωx (k-2)+F0ω x (k)+F1ω x (k-1)+F2ω x (k-2), where E1, E2, F0, F1, and F2 are constant values, typically E1 = -1.709, E2 = 0.7304, F0 = 0.01729, F1 = -0.009606, and F2 = 0.01345.

[0031] Step 3: Transfer the roll channel rudder command δ r The signal is sent to the servo motor, which drives the aircraft's control surfaces to deflect, thereby suppressing roll interference and tracking the roll attitude angle under low control efficiency.

[0032] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A rolling channel adaptive variable structure control method under weak manipulation efficiency, characterized in that, The steps are as follows: Step 1: Calculate the roll channel control parameters in real time based on the aircraft's Mach number, dynamic pressure, and velocity parameters calculated by the inertial navigation unit. ; Step 2: Calculate the aircraft roll angle command from the guidance command calculation unit. The real-time roll Euler angle calculated by the inertial navigation unit Mach number Ma, roll angular velocity measured by inertial measurement unit The rolling channel rudder command is calculated based on the adaptive variable structure strategy of the rolling channel. The adaptive variable structure control strategy for the rolling channel described in step two is as follows: a) When Ma < Ma_down, the stability augmentation control loop is used to calculate the roll rudder deflection command; b) When Ma_down ≤ Ma < Ma_up, the roll rudder deflection command is calculated through gradual transition from stability augmentation control to attitude control; c) When Ma_up ≤ Ma, the complete attitude control loop is used to calculate the roll rudder deflection command; Step 3: Issue the roll rudder deflection command The signal is sent to the servo motor, which drives the aircraft's control surfaces to deflect, thereby suppressing roll interference and tracking the roll attitude angle under low control efficiency.

2. The adaptive variable structure control method for a rolling channel under weak manipulation efficiency according to claim 1, characterized in that, The algorithm of the described adaptive variable structure control strategy for the roll channel is: a) When Ma < Ma_down, the stability augmentation control method is adopted, and the calculation method is: ; b) When Ma_down ≤ Ma < Ma_up, first calculate the attitude angle deviation command , and the calculation method is: , where in the formula is the roll angle attitude deviation after amplitude limiting on the change rate of the roll angle command, and the calculation method is ; Then, based on the attitude deviation angle command... and Calculate the roll rudder deflection command The method is as follows: ,in In the above formula, the algorithm for the adaptive variable structure control strategy of the rolling channel... This indicates the calculation step size, with a value of 0.0025. Indicates the current moment. For real-time rolling Euler angles; c) When Ma_up <= Ma, use the complete attitude control loop and roll rudder deflection command. The calculation method is as follows: In the above formula, Represents roll angular velocity The filtered value, the filtering algorithm is as follows ,in It is a constant value.

3. The adaptive variable structure control method for a rolling channel under weak manipulation efficiency according to claim 2, characterized in that, The value can be: .

4. The adaptive variable structure control method for a rolling channel under weak manipulation efficiency according to claim 2, characterized in that, In the algorithm of the described adaptive variable structure control strategy for the roll channel: the values of Ma_down and Ma_up are determined according to the aerodynamic characteristics, overall parameters and flight requirements of the aircraft.

5. The adaptive variable structure control method for a rolling channel under weak manipulation efficiency according to claim 4, characterized in that, Ma_down takes a value of 0.3 and Ma_up takes a value of 1.2.

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