A method for designing a self-excited oscillation suppression network of an erecting state launch vehicle
By establishing a dynamic model of the launch vehicle in the vertical state and designing a de-vibration network, the problem of self-excited oscillation in the vertical state was solved, the safety and stability of the rocket before takeoff were achieved, and the anti-interference capability of the attitude control system was enhanced.
Patent Information
- Application Number
- CN202411821394.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2044-12-11
AI Technical Summary
Self-excited oscillations occurred during range testing of the launch vehicle in an upright position, affecting the safety of rocket launch and the products loaded onto the rocket. Existing technologies cannot effectively suppress this phenomenon.
A dynamic model of the launch vehicle in vertical state is established, the state space of the attitude control system is constructed, and a de-jittering network for the pitch, yaw, and roll channels is designed. The self-excited oscillation of the rocket is suppressed by combining the PD control method and a low-pass filter.
It effectively eliminated the impact of periodic vibrations of the rocket structure on the rocket-mounted products, ensuring the safety of rocket ground testing and takeoff, and enhancing the anti-interference capability of the attitude control system.
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Figure CN119646946B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a vertical state launch vehicle self-excited oscillation suppression network design method, belonging to the field of launch vehicle control. BACKGROUND
[0002] Many launch vehicles are tested vertically at the test range. When the command polarity test, stable system zero position test, or the servo system is started before takeoff, the rocket body may appear self-excited oscillation under the excitation of engine nozzle swing, that is, the launch vehicle structure itself appears periodic vibration. If the self-excited oscillation occurs before takeoff, it may affect the rocket takeoff drift and tower safety.
[0003] Since the launch vehicle is in a vertical state at the test range, its modal frequency, mode shape, and engine operating state are different from those in the actual flight state, resulting in large differences in dynamic parameters in the two states. For example, the rocket engine is in an unignited state on the ground, while the rocket engine is in a normal operating state in flight. Therefore, after the attitude control loop is turned on during ground testing, the correction network designed based on the flight state may not be able to adequately attenuate the elastic vibration signal, and may not be suitable for the ground test state. SUMMARY
[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a vertical state launch vehicle self-excited oscillation suppression network design method for solving the self-excited oscillation phenomenon that occurs during testing at the test range in the vertical state of the launch vehicle, eliminating the influence of periodic vibration of the launch vehicle on the launched product, and effectively ensuring the safety of the launch vehicle during ground testing and takeoff.
[0005] The technical solution of the present application is: a vertical state launch vehicle self-excited oscillation suppression network design method, which comprises the following steps:
[0006] Establish a dynamic model of the vertical state launch vehicle according to the constraint conditions and force state of the vertical state rocket;
[0007] Based on the dynamic model of the vertical state launch vehicle, a state space of the attitude control system of the vertical state rocket is constructed;
[0008] Perform a pull-type transformation on the state space of the attitude control system of the vertical state rocket to obtain the open-loop transfer functions of the pitch channel, yaw channel, and roll channel of the attitude control system of the vertical state rocket;
[0009] Draw the open-loop rocket body characteristic Bode diagram of the open-loop transfer functions of the pitch channel, yaw channel, and roll channel of the attitude control system of the vertical state rocket, and design a pitch channel dithering network, a yaw channel dithering network, and a roll channel dithering network based on the open-loop rocket body characteristic Bode diagram to make the attitude control system meet the margin index requirements.
[0010] Preferably, the pitch channel anti-chatter network, the yaw channel anti-chatter network and the roll channel anti-chatter network respectively perform low-pass filtering on the control quantity obtained by using the PD control method for the pitch channel, the yaw channel and the roll channel of the attitude control system, and output the pitch, yaw and roll channel control swing angles.
[0011] Preferably, the transfer functions of the pitch channel anti-chatter network, the yaw channel anti-chatter network and the roll channel anti-chatter network are composed of a plurality of 2nd order link filters, and the form is as follows:
[0012]
[0013] Wherein, Ω j is the pole 2nd order link circular frequency, ζ j is the pole 2nd order link damping ratio, Ω' k is the zero 2nd order link circular frequency, ζ' k is the zero 2nd order link damping ratio, and M and K are integers.
[0014] Preferably, the vertical state launch vehicle dynamics model is as follows:
[0015]
[0016] Wherein:
[0017] q i represents the i-th order generalized displacement of the rocket body, i=1, 2, …, n, and n represents the total order of modes;
[0018] represents the i-th order generalized velocity of the rocket body;
[0019] represents the i-th order generalized acceleration of the rocket body;
[0020] ω i represents the i-th order elastic circular frequency of the rocket body;
[0021] ξ i represents the i-th order elastic damping ratio of the rocket body;
[0022] D″ ψ_3i , D″ γ_3i respectively represent the i-th order elastic generalized force coefficient corresponding to the pitch, yaw and roll channel engine nozzle swing inertia force;
[0023] R zi (x GZ ), R zi (x ST ) respectively represent the i-th order elastic rotation angle in the Z direction at the inertial device and the rate gyroscope;
[0024] R yi (x GZ ), R yi (x ST ) represent the i-th order elastic rotation angle in the Y direction at the inertial navigation system and the rate gyroscope, respectively;
[0025] R yi (x GZ ), R yi (x ST ) represent the i-th order elastic rotation angle in the X direction at the inertial navigation system and the rate gyroscope, respectively;
[0026] These represent the angular rates measured in the Z direction by the inertial navigation system and the rate gyroscope, respectively.
[0027] These represent the angular rates measured in the Y direction by the inertial navigation system and the rate gyroscope, respectively.
[0028] These represent the angular rates measured in the X direction by the inertial navigation system and the rate gyroscope, respectively.
[0029] These represent the pitch, yaw, and roll channel engine nozzle equivalent angular acceleration, respectively.
[0030] Preferably, the state space of the vertical attitude control system is:
[0031]
[0032] in, The rocket's state vector includes the generalized displacement and generalized velocity of the rocket's elastic modes.
[0033] A = diag(A) i ),
[0034] diag() is a diagonal matrix function;
[0035]
[0036] C = [C1 C2 … C] n ],
[0037] κ=z, Let κ = y and η = ψ represent the pitch channel, κ = x and η = γ represent the roll channel, and λ is a coefficient defined by the three-channel output matrix C. For pitch and roll channels, λ = 1, and for yaw channel, λ = 2.
[0038] Preferably, the open-loop transfer function calculation formulas for the pitch, yaw, and roll channels are as follows:
[0039]
[0040]
[0041] where s denotes the Laplace transformed complex frequency, κ = z, denote the pitch channel, κ = y, η = ψ the yaw channel, κ = x, η = γ the roll channel, and E is the identity matrix.
[0042] denote the transfer functions from the state space derived servo equivalent swing angles to the attitude angular rates at the IMU for the pitch, yaw, and roll channels, respectively.
[0043] denote the transfer functions from the state space derived servo equivalent swing angles to the attitude angular rates at the rate gyros for the pitch, yaw, and roll channels, respectively.
[0044] denote the static amplification factors for the pitch, yaw, and roll attitude angular channels, respectively.
[0045] denote the dynamic amplification factors for the pitch, yaw, and roll attitude angular rate channels, respectively.
[0046] W GZ (s), W ST (s) denote the IMU and rate gyro transfer functions, respectively.
[0047] W sf (s) denote the servo transfer functions.
[0048] Preferably, the pitch, yaw, and roll channel dither networks satisfy the following conditions:
[0049]
[0050] where W jzψ (s), W jzγ (s) are the transfer functions of the pitch, yaw, and roll channel dither networks, respectively; L zb denotes the amplitude margin index, are the open loop transfer functions for the pitch, yaw, and roll channels, respectively.
[0051] Compared with the prior art, the present application has the following advantages and beneficial effects:
[0052] (1) The present application establishes a vertical state dynamics model aiming at the self-excited oscillation phenomenon occurring in the target range test of a vertical state rocket, and reveals the causes of the self-excited oscillation of the rocket.
[0053] (2), the present application is directed to the vertical state of the launch vehicle self-excited oscillation phenomenon, a vertical state of the launch vehicle self-excited oscillation suppression network design method is proposed, the influence of the periodic vibration of the structure of the launch vehicle itself on the launch product is eliminated, and the safety of the rocket ground test and take-off is effectively ensured. BRIEF DESCRIPTION OF DRAWINGS
[0054] Figure 1 The vertical state of the launch vehicle attitude control system simulation verification flowchart for the embodiment of the present application.
[0055] Figure 2 The vertical state of the launch vehicle dynamics model construction and self-excited oscillation suppression method flowchart for the embodiment of the present application.
[0056] Figure 3 The three-channel attitude angle rate deviation (without adopting the dithering network) for the embodiment of the present application.
[0057] Figure 4 The four servo swing angle commands (without adopting the dithering network) for the embodiment of the present application.
[0058] Figure 5 The three-channel attitude angle deviation (adopting the dithering network) for the embodiment of the present application.
[0059] Figure 6 The four servo swing angle commands (adopting the dithering network) for the embodiment of the present application. DETAILED DESCRIPTION
[0060] The present application will be further described in detail below.
[0061] The vertical state of the launch vehicle dynamics model construction and self-excited oscillation suppression method provided by the present application has the following steps:
[0062] According to the constraint conditions and force state of the vertical state rocket, a vertical state of the launch vehicle dynamics model is established;
[0063] Based on the vertical state of the launch vehicle dynamics model, a vertical state of the rocket attitude control system state space is constructed;
[0064] The vertical state of the rocket attitude control system state space is subjected to a pull-type transformation, and the vertical state of the rocket attitude control pitch channel, yaw channel and roll channel open-loop transfer functions are obtained;
[0065] The vertical state of the rocket attitude control pitch channel, yaw channel and roll channel open-loop transfer functions are drawn into open-loop body characteristic Bode diagrams, and based on the open-loop body characteristic Bode diagrams, a pitch channel dithering network, a yaw channel dithering network and a roll channel dithering network are designed, so that the attitude control system meets the margin index requirements.
[0066] Step one: Establishing the vertical state launch vehicle dynamics model
[0067] The vertical state launch vehicle dynamics model is:
[0068]
[0069] Wherein:
[0070] q i represents the i-th order generalized displacement of the rocket body, i = 1, 2, …, n, n represents the total order of the mode;
[0071] represents the i-th order generalized velocity of the rocket body;
[0072] represents the i-th order generalized acceleration of the rocket body;
[0073] ω i represents the i-th order elastic circular frequency of the rocket body;
[0074] ξ i represents the i-th order elastic damping ratio of the rocket body;
[0075] D″ ψ_3i , D″ γ_3i respectively represent the i-th order elastic generalized force coefficient corresponding to the pitch, yaw, roll channel engine nozzle swing inertia force;
[0076] R zi (x GZ ), R zi (x ST ) respectively represent the i-th order elastic rotation angle at the Z direction of the inertial unit and the rate gyro;
[0077] R yi (x GZ ), R yi (x ST ) respectively represent the i-th order elastic rotation angle at the Y direction of the inertial unit and the rate gyro;
[0078] R yi (x GZ ), R yi (x ST ) respectively represent the i-th order elastic rotation angle at the X direction of the inertial unit and the rate gyro;
[0079] respectively represent the measured angular velocity at the Z direction of the inertial unit and the rate gyro;
[0080] respectively represent the measured angular velocity at the Y direction of the inertial unit and the rate gyro;
[0081] denotes the X direction measured angular rate of the rate gyroscope;
[0082] denotes the equivalent pitch, yaw, roll channel engine nozzle gimbal angular acceleration.
[0083] Step 2: Construct the state space of the vertical state rocket attitude control system according to the dynamic model
[0084]
[0085] wherein, is the rocket state vector, including the elastic modal generalized displacement and the elastic modal generalized velocity of the rocket body;
[0086] A = diag(A i ),
[0087] diag() is a diagonal matrix function
[0088]
[0089] C = [C1 C2 … C n ],
[0090] The above state space represents the pitch channel, λ = 1, κ = z, The state space represents the yaw channel, λ = 2, κ = y, η = ψ; the state space represents the roll channel, λ = 1, κ = x, η = γ; i = 1, 2, …, n, n represents the total order of the mode.
[0091] Step 3: Design three-channel open-loop transfer function
[0092] The calculation formula of the open-loop transfer function of the pitch, yaw, and roll channels is as follows:
[0093]
[0094] wherein, s represents the Laplace transform complex frequency, κ = z, represents the pitch channel, κ = y, η = ψ represents the yaw channel, and κ = x, η = γ represents the roll channel;
[0095] s represents the Laplace transform complex frequency;
[0096] denotes the open-loop transfer function of the pitch, yaw, and roll channels, respectively;
[0097] W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively; W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively;
[0098] W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively;
[0099] W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively;
[0100] W GZ W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively; ST W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively;
[0101] W sf W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively;
[0102] Step four, design a three-channel dithering network
[0103] (1) The system margin meets the index requirements
[0104] In step (3), the missile characteristic diagram is drawn based on the three-channel transfer function, the dithering network is designed, and the system margin meets the index requirements:
[0105]
[0106] wherein, W jzψ W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively; jzγ W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively; zb W (s) and W (s) represent the transfer functions of the inertial measurement unit and the rate gyroscope, respectively; zb It should be less than or equal to -6dB.
[0107] (2) Dithering network
[0108] As shown in Figure 2 , the pitch channel dithering network, the yaw channel dithering network and the roll channel dithering network respectively perform low-pass filtering on the control quantity obtained by the PD control method of the pitch channel, the yaw channel and the roll channel of the attitude control system (attenuate the elastic vibration signal of the vertical state launch vehicle), output the pitch, yaw and roll channel control swing angle, perform servo swing angle distribution matrix operation on the pitch, yaw and roll channel control swing angle, and output to the servo controller, the servo controller outputs the servo control instruction to the servo mechanism to control the engine nozzle swing, thereby controlling the vertical state rocket attitude.
[0109] The pitch channel anti-shake network, the yaw channel anti-shake network and the roll channel anti-shake network are composed of a plurality of 2nd order link filters, the number of 2nd order link filters can be selected according to the elastic peak value and the number of specific rocket body characteristics, and the number of 2nd order link filters is consistent with the number of 2nd order link filters of the flight correction network after take-off, so that overshoot does not occur when the network is switched before or at the moment of take-off. The pitch channel anti-shake network, the yaw channel anti-shake network and the roll channel anti-shake network are as follows:
[0110]
[0111] Wherein, Ω j is the pole 2nd order link circular frequency, ζ j is the pole 2nd order link damping ratio, Ω' k is the zero 2nd order link circular frequency, ζ' k is the zero 2nd order link damping ratio, M and K are integers.
[0112] In a specific embodiment of the present application:
[0113]
[0114] Wherein, mainly suppress low-frequency elastic vibration, mainly suppress mid-frequency elastic vibration, mainly suppress high-frequency elastic vibration, the overall low-frequency phase of W(s) is not prone to lag too severely, the step response difference with the first set of network after take-off is not prone to be too large, to prevent overshoot when the network is switched, so as to prevent the servo swing angle command from being not smooth.
[0115] Embodiment:
[0116] The embodiment of the present application uses the designed anti-shake network parameters and dynamic model, adopts Figure 1 The vertical state launch vehicle attitude control system simulation verification flow chart completes time domain simulation verification. In the simulation, the attitude angular velocity rate deviation is superimposed and injected, and the anti-interference of the system after being subjected to external impact is verified, Figures 3-6 is a comparison chart of self-excitation oscillation suppression effect before and after the anti-shake network is adopted.
[0117] The simulation results show that the elastic vibration signals in the angular rate deviation signal and the servo swing angle command signal are effectively suppressed and attenuated after the anti-shake network is adopted, and the design method can well suppress the self-excitation oscillation of the rocket body, so that the attitude control system has strong anti-interference.
[0118] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solutions of the present application shall fall within the protection scope of the technical solutions of the present application.
Claims
1. A design method for a self-excited oscillation suppression network of a vertical launch vehicle, characterized in that... Including the following: Based on the constraints and stress conditions of the rocket in the vertical state, a dynamic model of the launch vehicle in the vertical state is established. Based on the dynamic model of the vertical launch vehicle, the state space of the vertical launch vehicle attitude control system is constructed. By performing a Laplace transform on the state space of the vertical rocket attitude control system, the open-loop transfer functions of the pitch, yaw, and roll channels of the vertical rocket attitude control system are obtained. The open-loop transfer functions of the pitch, yaw and roll channels of the rocket attitude control system in the vertical state are plotted as open-loop rocket body characteristic Bode plots. Based on the open-loop rocket body characteristic Bode plots, pitch channel de-jittering networks, yaw channel de-jittering networks and roll channel de-jittering networks are designed to ensure that the attitude control system meets the margin index requirements. The pitch channel de-jitter network, yaw channel de-jitter network, and roll channel de-jitter network respectively perform low-pass filtering on the control quantities obtained by the PD control method in the pitch channel, yaw channel, and roll channel of the attitude control system, and output the pitch, yaw, and roll channel control angles. The transfer functions of the pitch channel de-jitter network, yaw channel de-jitter network, and roll channel de-jitter network are composed of multiple second-order stage filters, as follows: Among them, Ω j ζ is the angular frequency of the second-order element at the pole. j Let Ω' be the damping ratio of the second-order element at the pole. k The angular frequency of the second-order element at zero point, ζ' k The damping ratio of the zero-point second-order element is given, where M and K are both integers, and s represents the complex frequency of the Laplace transform.
2. The design method for a self-excited oscillation suppression network of a vertical launch vehicle according to claim 1, characterized in that, The dynamic model of the vertical launch vehicle is as follows: in: q i Let i represent the i-th generalized displacement of the arrow body, where i = 1, 2, ..., n, and n represents the total modal order. This represents the i-th generalized velocity of the arrow body; This represents the i-th order generalized acceleration of the arrow body; ω i This represents the i-th order elastic circular frequency of the arrow body; ξ i This represents the i-th order elastic damping ratio of the arrow body; D″ ψ_3i D″ γ_3i These represent the i-th order elastic generalized force coefficients corresponding to the pitch, yaw, and roll channel engine nozzle oscillation inertial forces, respectively. R zi (x GZ ), R zi (x ST ) represent the i-th order elastic rotation angle in the Z direction at the inertial navigation system and the rate gyroscope, respectively; R yi (x GZ ), R yi (x ST ) represent the i-th order elastic rotation angle in the Y direction at the inertial navigation system and the rate gyroscope, respectively; R yi (x GZ ), R yi (x ST ) represent the i-th order elastic rotation angle in the X direction at the inertial navigation system and the rate gyroscope, respectively; These represent the angular rates measured in the Z direction by the inertial navigation system and the rate gyroscope, respectively. These represent the angular rates measured in the Y direction by the inertial navigation system and the rate gyroscope, respectively. These represent the angular rates measured in the X direction by the inertial navigation system and the rate gyroscope, respectively. These represent the pitch, yaw, and roll channel engine nozzle equivalent angular acceleration, respectively.
3. The design method for a self-excited oscillation suppression network of a vertical launch vehicle according to claim 2, characterized in that, The state space of the vertical rocket attitude control system is: in, The rocket's state vector includes the generalized displacement and generalized velocity of the rocket's elastic modes. A=diag(A i ), diag() is a diagonal matrix function; C=[C1 C2…C n ], κ=z, κ = y, η = ψ represents the pitch channel, κ = x, η = γ represents the roll channel, and λ is a coefficient defined by the three-channel output matrix C. For pitch and roll channels, λ = 1, and for yaw channel, λ = 2.
4. The design method for a self-excited oscillation suppression network of a vertical launch vehicle according to claim 3, characterized in that, The formulas for calculating the open-loop transfer function of the pitch, yaw, and roll channels are as follows: Where s represents the complex frequency of the Laplace transform, and κ = z, Let κ = y and η = ψ represent the pitch channel, κ = x and η = γ represent the roll channel, and E is the identity matrix. These represent the transfer functions from the pitch, yaw, and roll channel servo equivalent yaw angles obtained from the state space to the attitude angular rate at the inertial navigation system, respectively. These represent the transfer functions from the pitch, yaw, and roll channel servo equivalent yaw angles obtained from the state space to the attitude angular rate at the rate gyroscope, respectively. These represent the static amplification factors for the pitch, yaw, and roll attitude angle channels, respectively. These represent the dynamic amplification coefficients for the pitch, yaw, and roll attitude angular rate channels, respectively. W GZ (s), W ST (s) represent the transfer functions of the inertial navigation system and the rate gyroscope, respectively; W sf (s) represents the servo transfer function.
5. The design method for a self-excited oscillation suppression network of a vertical launch vehicle according to claim 1, characterized in that, The pitch, yaw, and roll channel debouncing network satisfies the following conditions: in, W jzψ (s), W jzγ (s) are the transfer functions of the pitch, yaw, and roll channel de-jitter networks, respectively; L zb Indicates the gain margin index, These are the open-loop transfer functions for the pitch, yaw, and roll channels, respectively.