Self-amplitude-limiting PD control method for nonlinear gain saturation of carrier rocket

Abstract

The invention belongs to the technical field of carrier rocket control, and provides a carrier rocket nonlinear gain saturation self-limiting PD control method for the phenomenon that the attitude control precision is poor due to the fact that a carrier rocket is interfered by aerodynamic loads in a strong wind area, and the method comprises the steps that firstly, a gain saturation self-limiting nonlinear variable gain function is constructed; substituting the three-channel real-time attitude angle information of the carrier rocket into the variable gain function, and obtaining a three-channel variable gain coefficient through low-pass filtering; and finally, multiplying the variable gain coefficient by a controller gain coefficient designed offline to obtain a three-channel nonlinear control gain. The method can effectively reduce the phenomenon that the attitude angle deviation of the carrier rocket in the strong wind area is large, and the rocket attitude control precision is effectively guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of launch vehicle control and relates to a launch vehicle nonlinear gain saturation self-limiting PD control method. Background Art

[0002] Traditional launch vehicle attitude control design employs the "fixed coefficient method," which performs frequency domain analysis on selected characteristic second points and employs a "PD + correction network" control approach for offline controller design. However, actual launch vehicle flight presents significant uncertainties, such as engine thrust drop and heavy loads in windy areas. If these phenomena exceed the offline design envelope, they can lead to insufficient control system margins and significant deviations in the rocket's attitude, seriously compromising flight safety.

[0003] In order to ensure that the launch vehicle can fly smoothly even if the engine experiences a large thrust drop and the aerodynamic load is large during flight during actual flight, and to improve the launch vehicle's adaptability to large deviations in engine thrust and uncertainties in aerodynamic loads in strong wind areas, it is necessary to study a new method for launch vehicle attitude control to solve the above problems. Summary of the Invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and propose a nonlinear gain saturation self-limiting PD control method for a carrier rocket, which is used to improve the adaptability of the carrier rocket's attitude control system to large deviations of engine thrust and uncertainties of aerodynamic loads in strong wind areas, thereby enhancing the flight adaptability of the carrier rocket.

[0005] The technical solution of the present invention is: a nonlinear gain saturation self-limiting PD control method for a launch vehicle, comprising the following steps:

[0006] 1) constructing a gain saturation self-limiting nonlinear variable gain function, wherein the variable gain function has an even function characteristic, a saturation characteristic, and an increasing function characteristic in the range [0, +∞];

[0007] 2) The real-time attitude angle information of the three channels of the launch vehicle is introduced into the variable gain function, and the three-channel variable gain coefficient is obtained by low-pass filtering;

[0008] 3) Multiply the three-channel variable gain coefficients with the offline designed controller gain coefficients to obtain the three-channel nonlinear control gains, realize nonlinear gain saturation self-limiting PD control, and reduce the attitude angle deviation.

[0009] Furthermore, the gain saturation self-limiting nonlinear variable gain function is:

[0010]

[0011] Among them: α, β are constant parameters in the gain saturation self-limiting nonlinear variable gain function;

[0012] x is the independent variable in the gain saturation self-limiting nonlinear variable gain function;

[0013] m is the order of the independent variable in the gain saturation self-limiting nonlinear variable gain function, m = 2 1 ,2 2 ,…,2 n , n is a positive integer;

[0014] y is the dependent variable in the gain saturation self-limiting nonlinear variable gain function.

[0015] Furthermore, the calculation method of the three-channel variable gain coefficient is:

[0016]

[0017] in: represents the pitch channel, η=ψ represents the yaw channel, and η=γ represents the roll channel; Y is the coefficient of the discrete difference equation of the η channel low-pass filter transfer function; 1η (nT), Y 2η (nT), Y 3η (nT) is the intermediate value calculated by the low-pass filter difference equation of the current beat of channel η; Y is the η channel 1η (nT) calculated value of the previous i beats; Y is the η channel 2η (nT) calculated value of the previous i beats; Y is the η channel 3η (nT) calculated value of the previous i beats;

[0018] The current pitch attitude angle deviation of the launch vehicle;

[0019] Δη(nT)=Δψ(nT) is the current yaw attitude angle deviation of the launch vehicle;

[0020] Δη(nT)=Δγ(nT) is the current roll attitude angle deviation of the launch vehicle;

[0021] is the current beat-variable gain coefficient of the pitch channel before low-pass filtering;

[0022] Y η (nT) = Y ψ (nT) is the current beat gain coefficient of the yaw channel before low-pass filtering;

[0023] Y η (nT) = Yγ (nT) is the current beat-variable gain coefficient before low-pass filtering of the rolling channel;

[0024] is the current beat-variable gain coefficient after low-pass filtering of the pitch channel;

[0025] y η (nT) = y ψ (nT) is the current beat gain coefficient of the yaw channel after low-pass filtering;

[0026] y η (nT) = y γ (nT) is the current beat-variable gain coefficient after low-pass filtering of the rolling channel;

[0027] Furthermore, the calculation method of the three-channel nonlinear control gain is:

[0028]

[0029] in: κ=z represents the pitch channel, η=ψ, κ=y represents the yaw channel, η=γ, κ=x represents the roll channel;

[0030] is the current nonlinear control gain of the attitude angle channel;

[0031] is the current nonlinear control gain of the angular rate channel;

[0032] k is the ratio coefficient of the offline designed angular rate channel amplification factor to the attitude angle channel amplification factor;

[0033] Static amplification factor of the pitch attitude angle channel designed for offline use;

[0034] Static amplification factor of the yaw attitude angle channel designed for offline operation;

[0035] The static amplification factor of the roll attitude angle channel designed for offline use;

[0036] Dynamic amplification factor of pitch attitude angular rate channel designed for offline use;

[0037] Dynamic amplification factor of yaw attitude angular rate channel designed for offline operation;

[0038] Dynamic amplification factor of the roll attitude angular rate channel designed for offline use;

[0039] Δω κ (nT)=Δωz (nT) is the current pitch attitude angular rate deviation of the launch vehicle;

[0040] Δω κ (nT)=Δω y (nT) is the current yaw attitude angular rate deviation of the launch vehicle;

[0041] Δω κ (nT)=Δω x (nT) is the current roll attitude angular rate deviation of the launch vehicle;

[0042] Control the swing angle of the current pitch channel of the launch vehicle;

[0043] Control the swing angle of the launch vehicle's current yaw channel;

[0044] Control the swing angle of the current rolling channel of the launch vehicle.

[0045] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a carrier rocket nonlinear gain saturation self-limiting PD control method.

[0046] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of a method for controlling a nonlinear gain saturation self-limiting PD of a carrier rocket are implemented.

[0047] A computer program product includes a computer program, which, when executed by a processor, implements the steps of a carrier rocket nonlinear gain saturation self-limiting PD control method.

[0048] The beneficial effects of the present invention compared with the prior art are:

[0049] Compared with the conventional PD control effect, the present invention can increase the system gain according to the rocket body attitude information when the external system interference is large, overcome the influence of the external interference on the system, reduce the attitude angle deviation, and enhance the flight adaptability of the carrier rocket. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of a nonlinear gain saturation self-limiting PD control method for a launch vehicle according to the present invention;

[0051] Figure 2 This is the flow chart of time domain simulation verification of launch vehicle attitude control system. DETAILED DESCRIPTION

[0052] like Figure 1 As shown, the present invention proposes a nonlinear gain saturation self-limiting PD control method for a launch vehicle, comprising the following steps:

[0053] 1) constructing a gain saturation self-limiting nonlinear variable gain function, wherein the variable gain function has an even function characteristic, a saturation characteristic, and an increasing function characteristic in the range [0, +∞];

[0054] 2) The real-time attitude angle information of the three channels of the launch vehicle is introduced into the variable gain function, and the three-channel variable gain coefficient is obtained by low-pass filtering;

[0055] 3) Multiply the three-channel variable gain coefficients with the offline designed controller gain coefficients to obtain the three-channel nonlinear control gains, realize nonlinear gain saturation self-limiting PD control, and reduce the attitude angle deviation.

[0056] The present invention will be further described below in conjunction with the embodiments.

[0057] Example 1

[0058] Step 1: Construct a gain saturation self-limiting nonlinear variable gain function

[0059] 1. Construct a gain saturation self-limiting nonlinear variable gain function, which has an even function characteristic, a saturation characteristic, and an increasing function characteristic in [0, +∞]. The variable gain function is specifically as follows:

[0060]

[0061] in:

[0062] α is the constant parameter in the gain saturation self-limiting nonlinear variable gain function;

[0063] β is the constant parameter in the gain saturation self-limiting nonlinear variable gain function;

[0064] x is the independent variable in the gain saturation self-limiting nonlinear variable gain function;

[0065] m is the order of the independent variable in the gain saturation self-limiting nonlinear variable gain function, m = 2 1 ,2 2 ,…,2 n , n is a positive integer;

[0066] y is the dependent variable in the gain saturation self-limiting nonlinear variable gain function.

[0067] Step 2: Calculate the three-channel variable gain coefficient based on the three-channel attitude angle information of the launch vehicle

[0068]

[0069] in: represents the pitch channel, η=ψ represents the yaw channel, and η=γ represents the roll channel; Y is the coefficient of the discrete difference equation of the η channel low-pass filter transfer function, bound by constants; 1η (nT), Y 2η (nT), Y 3η (nT) is the intermediate value calculated by the low-pass filter difference equation of the current beat of channel η; Y is the η channel 1η (nT) calculated value of the previous i beats; Y is the η channel 2η (nT) calculated value of the previous i beats; Y is the η channel 3η (nT) calculated value of the previous i beats;

[0070] The current pitch attitude angle deviation of the launch vehicle;

[0071] Δη(nT)=Δψ(nT) is the current yaw attitude angle deviation of the launch vehicle;

[0072] Δη(nT)=Δγ(nT) is the current roll attitude angle deviation of the launch vehicle;

[0073] is the current beat-variable gain coefficient of the pitch channel before low-pass filtering;

[0074] Y η (nT) = Y ψ (nT) is the current beat gain coefficient of the yaw channel before low-pass filtering;

[0075] Y η (nT) = Y γ (nT) is the current beat-variable gain coefficient before low-pass filtering of the rolling channel;

[0076] is the current beat-variable gain coefficient after low-pass filtering of the pitch channel;

[0077] y η (nT) = y ψ (nT) is the current beat gain coefficient of the yaw channel after low-pass filtering;

[0078] y η (nT) = y γ (nT) is the current beat-variable gain coefficient after low-pass filtering of the rolling channel;

[0079] Step 3: Calculate the three-channel nonlinear control gain based on the three-channel variable gain coefficient and offline design parameters, implement nonlinear gain saturation self-limiting PD control, reduce attitude angle deviation, and perform time domain simulation verification based on the flow chart

[0080] 310. Multiply the variable gain coefficient with the offline designed controller gain coefficient to obtain the three-channel nonlinear control gain

[0081]

[0082] in: κ=z represents the pitch channel, η=ψ, κ=y represents the yaw channel, η=γ, κ=x represents the roll channel;

[0083] is the current nonlinear control gain of the attitude angle channel;

[0084] is the current nonlinear control gain of the angular rate channel;

[0085] k is the ratio coefficient of the offline designed angular rate channel amplification factor to the attitude angle channel amplification factor;

[0086] Static amplification factor of the pitch attitude angle channel designed for offline use;

[0087] Static amplification factor of the yaw attitude angle channel designed for offline operation;

[0088] The static amplification factor of the roll attitude angle channel designed for offline use;

[0089] Dynamic amplification factor of pitch attitude angular rate channel designed for offline use;

[0090] Dynamic amplification factor of yaw attitude angular rate channel designed for offline operation;

[0091] Dynamic amplification factor of the roll attitude angular rate channel designed for offline use;

[0092] Δω κ (nT)=Δω z (nT) is the current pitch attitude angular rate deviation of the launch vehicle;

[0093] Δω κ (nT)=Δω y (nT) is the current yaw attitude angular rate deviation of the launch vehicle;

[0094] Δω κ(nT)=Δω x (nT) is the current roll attitude angular rate deviation of the launch vehicle;

[0095] Control the swing angle of the current pitch channel of the launch vehicle;

[0096] Control the swing angle of the launch vehicle's current yaw channel;

[0097] Control the swing angle of the current rolling channel of the launch vehicle.

[0098] 320, adopt Figure 2 The time domain simulation verification flow chart of the launch vehicle attitude control system shown in the figure completes the time domain simulation verification.

[0099] The present invention proposes a nonlinear gain saturation self-limiting PD control method for a launch vehicle. When the external interference is small, the effect is consistent with that of conventional PD control. When the external system interference is large, the system gain can be increased according to the rocket body attitude information to overcome the influence of the external interference on the system, reduce the attitude angle deviation, and enhance the flight adaptability of the launch vehicle.

[0100] The present application provides a computer-readable storage medium storing computer instructions. When the computer instructions are executed on a computer, the computer executes Figure 1 The method described.

[0101] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) that contain computer-usable program code.

[0102] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0105] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

[0106] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A launch vehicle nonlinear gain saturation self-limiting PD control method, characterized in that: The following steps are involved: 1) constructing a gain saturation self-limiting nonlinear variable gain function, wherein the variable gain function has an even function characteristic, a saturation characteristic, and an increasing function characteristic in [0, +∞]; 2) Bringing the real-time attitude angle information of the three channels of the launch vehicle into the variable gain function, and obtaining the three-channel variable gain coefficients through low-pass filtering; 3) Multiply the three-channel variable gain coefficients with the offline designed controller gain coefficients to obtain the three-channel nonlinear control gains, realize nonlinear gain saturation self-limiting PD control, and reduce the attitude angle deviation.

2. A launch vehicle nonlinear gain saturation self-limiting PD control method according to claim 1, characterized in that: The gain saturation self-limiting nonlinear variable gain function is: Among them: α, β are constant parameters in the gain saturation self-limiting nonlinear variable gain function; x is the independent variable in the gain saturation self-limiting nonlinear variable gain function; m is the order of the independent variable in the gain saturation self-limiting nonlinear variable gain function, m = 2 1 ,2 2 ,…,2 n , n is a positive integer; y is the dependent variable in the gain saturation self-limiting nonlinear variable gain function.

3. A launch vehicle nonlinear gain saturation self-limiting PD control method according to claim 2, characterized in that: The calculation method of the three-channel variable gain coefficient is: in: represents the pitch channel, η=ψ represents the yaw channel, and η=γ represents the roll channel; Y is the coefficient of the discrete difference equation of the η-channel low-pass filter transfer function; 1η (nT), Y 2η (nT), Y 3η (nT) is the intermediate value calculated by the low-pass filter difference equation of the current beat of the η channel; Y is the η channel 1η (nT) calculated value of the previous i beats; Y is the η channel 2η (nT) calculated value of the previous i beats; Y is the η channel 3η (nT) calculated value of the previous i beats; The current pitch attitude angle deviation of the launch vehicle; Δη(nT)=Δψ(nT) is the current yaw attitude angle deviation of the launch vehicle; Δη(nT)=Δγ(nT) is the current rolling attitude angle deviation of the launch vehicle; is the current beat variable gain coefficient before low-pass filtering of the pitch channel; Y η (nT) = Y ψ (nT) is the current beat variable gain coefficient before low-pass filtering of the yaw channel; Y η (nT) = Y γ (nT) is the current beat variable gain coefficient before low-pass filtering of the rolling channel; is the current beat-variable gain coefficient after low-pass filtering of the pitch channel; y η (nT) = y ψ (nT) is the current beat gain coefficient after low-pass filtering of the yaw channel; y η (nT) = y γ (nT) is the current beat gain coefficient after low-pass filtering of the rolling channel.

4. A launch vehicle nonlinear gain saturation self-limiting PD control method according to claim 3, characterized in that: The calculation method of the three-channel nonlinear control gain is: in: κ=z represents the pitch channel, η=ψ, κ=y represents the yaw channel, η=γ, κ=x represents the roll channel; The current nonlinear control gain of the attitude angle channel; is the current nonlinear control gain of the angular rate channel; k is the ratio coefficient between the offline designed angular rate channel magnification factor and the attitude angle channel magnification factor; Static amplification factor of the pitch attitude angle channel designed for offline use; Static amplification factor of yaw attitude angle channel designed for offline use; The static amplification factor of the roll attitude angle channel designed for offline use; Dynamic amplification factor of pitch attitude angular rate channel designed for offline use; Dynamic amplification factor of yaw attitude angular rate channel designed for offline; Dynamic amplification factor of roll attitude angular rate channel designed for offline use; Δω κ (nT) = Δω z (nT) is the current pitch attitude angular rate deviation of the launch vehicle; Δω κ (nT) = Δω y (nT) is the current yaw attitude angular rate deviation of the launch vehicle; Δω κ (nT) = Δω x (nT) is the current roll attitude angular rate deviation of the launch vehicle; Control the swing angle of the launch vehicle's current pitch channel; Control the swing angle for the current yaw channel of the launch vehicle; Control the swing angle of the launch vehicle's current rolling channel.

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

6. An electronic 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 computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 4 are implemented.

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