Rocket engine flexible nozzle cold swing test simulation test system and test method thereof

Abstract

The present application relates to the field of rocket engine nozzle testing, and particularly relates to a flexible rocket engine nozzle cold swing test simulation test system and a test method thereof, the system comprising a pressure vessel, a servo mechanism, an inclinometer, a linear displacement sensor and a real-time simulator, the pressure vessel provides a cold pressurized environment, the servo mechanism drives the nozzle to swing, the inclinometer calibrates the swing angle, and the linear displacement sensor detects the swing and outputs an analog signal. During testing, the swing angle-voltage relationship is calibrated through the inclinometer and the linear displacement sensor; then the real-time simulator sends a sine instruction to drive the nozzle to swing, and synchronously collects the displacement signal, analyzes the dynamic characteristics of the servo mechanism and the coordination with the nozzle. Through the swing angle-voltage equation obtained by calibrating the swing, combined with continuous attitude simulation controlled by the simulator, the nozzle swing angle data is calculated, and the dynamic response of the servo mechanism under the pressurized condition is evaluated, the present application can truly reflect the continuous swing working condition of the nozzle, and improve the reliability and authenticity of the test data.

Description

Technical Field

[0001] This invention relates to the field of rocket engine nozzle testing, and more particularly to a simulation test system and test method for cold swing test of flexible rocket engine nozzles. Background Technology

[0002] The rocket engine nozzle is a crucial component of the rocket engine's thrust chamber, changing the direction of propellant gas injection through nozzle oscillation. Cold oscillation testing of the flexible rocket engine nozzle is a core step in verifying the control performance of the servo mechanism. Current technologies mostly employ hardware-in-the-loop (HIL) simulation systems, using simulated commands to drive the nozzle oscillation and collect feedback data.

[0003] However, traditional simulation methods cannot simulate the continuously changing attitude commands of the control system during rocket flight, making it difficult to realistically reproduce the dynamic response of the servo mechanism under continuous oscillation conditions of the flexible nozzle in the cold swing test of the rocket engine. Summary of the Invention

[0004] This invention provides a simulation test system and test method for cold swing test of flexible nozzle of rocket engine, which is used to solve the defect of the servo mechanism dynamic response under continuous swing condition of flexible nozzle in the existing cold swing test of flexible nozzle of rocket engine. It can realize the working state of the servo mechanism controlling the continuous swing of nozzle under cold pressurization condition.

[0005] This invention provides a simulation test system for the cold swing test of a flexible nozzle for a rocket engine, comprising a flexible nozzle, a pressure vessel, a servo mechanism, an inclinometer, a linear displacement sensor, and a real-time simulator. The pressure vessel is connected to the flexible nozzle, providing a cold pressurized environment for the nozzle. The servo mechanism is connected to the flexible nozzle and drives it to swing, forming a swing plane. The inclinometer is detachably connected to the flexible nozzle and is positioned within its swing plane, used to calibrate the swing angle. The linear displacement sensor is also positioned within the swing plane and is connected to the nozzle, adapted to generate a simulated voltage signal under the swing action of the nozzle. The real-time simulator is connected to the linear displacement sensor, receiving the simulated voltage signal output by the sensor and generating swing angle data for the nozzle. The real-time simulator is also connected to the servo mechanism, sending control commands to control the swing attitude of the flexible nozzle.

[0006] According to the present invention, a simulation test system for cold swing test of a flexible nozzle of a rocket engine is provided. The flexible nozzle is connected to the pressure vessel through a flange. The center point of the flange is the swing center of the flexible nozzle. The connection point between the linear displacement sensor and the flexible nozzle is denoted as the lower support. The linear displacement sensor is mounted on a sensor bracket, and the axis of the linear displacement sensor is perpendicular to the connection line between the swing center and the lower support.

[0007] According to the present invention, a simulation test system for cold swing test of flexible nozzle of rocket engine is provided, wherein an AD data acquisition card is connected between the linear displacement sensor and the real-time simulator. The AD data acquisition card is used to receive the analog voltage signal of the linear displacement sensor and to convert the analog voltage signal into a digital quantity to be sent to the real-time simulator.

[0008] According to the present invention, a simulation test system for cold swing test of flexible nozzle of rocket engine is provided, wherein a low-pass filter is connected between the AD data acquisition card and the linear displacement sensor to remove high-frequency noise interference in the analog voltage signal.

[0009] According to the present invention, a simulation test system for cold swing test of flexible nozzle of rocket engine is provided, wherein the real-time simulator is connected to the servo mechanism via 1553B bus and is adapted to send swing angle calibration control command or swing angle test control command to the servo mechanism.

[0010] This invention also provides a simulation test method for cold swing test of flexible nozzle of rocket engine, applicable to the simulation test system for cold swing test of flexible nozzle of rocket engine described in any of the above-mentioned embodiments, comprising: A pressurization device is used to pressurize the pressure vessel, and the pressure vessel is used to provide axial thrust and lateral load to the flexible nozzle, simulating the working state of a rocket engine.

[0011] The servo mechanism is controlled by sending swing angle calibration control commands to the servo mechanism through a real-time simulator, thereby controlling the flexible nozzle to swing.

[0012] The swing angle of the flexible nozzle is obtained by an inclinometer, and a calibration analog voltage signal is output to the real-time simulator by a linear displacement sensor.

[0013] Based on the swing angle of the flexible nozzle obtained by the inclinometer and the corresponding calibration analog voltage signal received by the real-time simulator, a swing angle-output voltage equation is fitted and generated.

[0014] The real-time simulator sends swing angle test control commands to the servo mechanism, and the servo mechanism controls the flexible nozzle to simulate the continuously changing swing posture.

[0015] The linear displacement sensor outputs a test simulation voltage signal to the real-time simulator, which calculates and generates the swing angle data of the flexible nozzle based on the swing angle-output voltage equation and the test simulation voltage signal.

[0016] The dynamic characteristics of the servo mechanism and the working coordination between the servo mechanism and the flexible nozzle are determined by analyzing the swing angle test control command and the calculated swing angle data.

[0017] According to the present invention, a simulation test method for cold swing test of a flexible nozzle of a rocket engine is provided. The swing angle calibration control command sent by the real-time simulator is a stepped swing angle control command formed by multiple swing angle control commands. The step interval of the multiple swing angle control commands is 1°~2°, and the swing angle of the maximum swing angle control command does not exceed the maximum swing angle allowed by the flexible nozzle.

[0018] The swing angle test control command sent by the real-time simulator is a continuously changing sinusoidal swing signal control command, which is suitable for characterizing the continuously changing swing posture of the flexible nozzle.

[0019] According to the present invention, a simulation test method for cold swing test of a flexible nozzle of a rocket engine is provided, wherein the frequency and amplitude of the sinusoidal swing signal of the swing angle test control command sent by the real-time simulator are adjustable, so as to test the response characteristics of the flexible nozzle under different swing angle test control commands.

[0020] According to the present invention, a simulation test method for cold swing test of a flexible nozzle of a rocket engine includes analyzing the swing angle test control command and the calculated swing angle data to determine the dynamic characteristics of the servo mechanism and the working coordination between the servo mechanism and the flexible nozzle, which includes: Adjust the frequency and amplitude of the sinusoidal swing signal of the swing angle test control command to obtain swing angle data under different swing angle test control commands.

[0021] The amplitude and phase of the fundamental component of the generated swing angle data are calculated by performing a discrete Fourier transform on the swing angle test control command and the swing angle data under different swing angle test control commands.

[0022] Based on the amplitude and phase of the fundamental component of the calculated swing angle data, logarithmic amplitude-frequency response curves and logarithmic phase-frequency response curves are plotted.

[0023] The bandwidth and resonant peak value are obtained based on the logarithmic amplitude-frequency response curve, and the phase margin is obtained based on the logarithmic amplitude-frequency response curve and the logarithmic phase-frequency response curve.

[0024] The dynamic response speed of the servo mechanism is determined based on the bandwidth, the dynamic response stability of the servo mechanism is determined based on the phase margin, and the working coordination between the servo mechanism and the flexible nozzle is determined based on the resonance peak value.

[0025] According to the present invention, a simulation test method for cold swing test of a flexible nozzle of a rocket engine is provided, wherein the fitting and generation of the swing angle-output voltage equation includes: Using linear regression equations opposite angle and output voltage Perform linear fitting and calculate the parameters. and parameters Based on parameters and parameters The swing angle-output voltage equation is obtained.

[0026] The swing angle The output voltage is the swing angle of the flexible nozzle obtained by the inclinometer. The corresponding calibration analog voltage signal received by the real-time simulator.

[0027] The rocket engine flexible nozzle cold swing test simulation system provided by this invention first uses a servo mechanism to calibrate the swing of the flexible nozzle. Combining the swing angle measured by the inclinometer and the voltage signal measured by the linear displacement sensor, a swing angle-output voltage equation is fitted. Then, a real-time simulator controls the servo mechanism to simulate and reproduce the continuously changing attitude of the flexible nozzle. Based on the swing angle-output voltage equation, the swing angle data of the flexible nozzle is calculated. Subsequently, the dynamic response of the servo mechanism under the continuous swing condition of the flexible nozzle is analyzed, which truly reflects the working state of the servo mechanism controlling the continuous swing of the flexible nozzle under cold pressurization conditions, thus improving the authenticity and reliability of the test data. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the rocket engine flexible nozzle cold swing test simulation system provided by the present invention.

[0030] Figure 2 This is a flowchart illustrating the simulation test method for the cold swing test of the flexible nozzle of a rocket engine provided by the present invention.

[0031] Reference numerals: 1. Flexible nozzle; 2. Pressure vessel; 3. Servo mechanism; 4. Inclinometer; 5. Linear displacement sensor; 6. Real-time simulator; 7. AD data acquisition card; 8. Low-pass filter. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0035] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0037] The following is combined with Figure 1 and Figure 2 This invention describes the simulation test system and test method for the cold swing test of the flexible nozzle of a rocket engine.

[0038] One embodiment of the present invention provides a simulation test system for cold swing test of flexible nozzle of rocket engine, see [link to documentation]. Figure 1 As shown, the rocket engine flexible nozzle cold swing test simulation system includes a flexible nozzle 1, a pressure vessel 2, a servo mechanism 3, an inclinometer 4, a linear displacement sensor 5, and a real-time simulator 6. The pressure vessel 2 is connected to the flexible nozzle 1, providing a cold pressurized environment for the flexible nozzle 1. The servo mechanism 3 is connected to the flexible nozzle 1 and is used to drive the flexible nozzle 1 to swing, thereby forming the swing plane of the flexible nozzle 1. The inclinometer 4 is detachably connected to the flexible nozzle 1 and is located within the swing plane of the flexible nozzle 1, used to calibrate the swing angle of the flexible nozzle 1. The linear displacement sensor 5 is also located within the swing plane of the flexible nozzle 1 and is connected to the flexible nozzle 1, suitable for generating a simulated voltage signal under the swing action of the flexible nozzle 1. The real-time simulator 6 is connected to the linear displacement sensor 5 and is used to receive the simulated voltage signal output by the linear displacement sensor 5 and generate the swing angle data of the flexible nozzle 1. The real-time simulator 6 is also connected to the servo mechanism 3 and is used to send control commands to the servo mechanism 3 to control the swing attitude of the flexible nozzle 1.

[0039] It is understood that the rocket engine flexible nozzle cold swing test simulation system of this embodiment includes a flexible nozzle 1, a pressure vessel 2, a servo mechanism 3, an inclinometer 4, a linear displacement sensor 5, and a real-time simulator 6. The pressure vessel 2 provides a cold pressurized environment for the flexible nozzle 1 to simulate the actual working conditions of the flexible nozzle 1 under axial thrust and lateral load. The servo mechanism 3 drives the flexible nozzle 1 to swing. The inclinometer 4 is used to calibrate the swing angle to fit the swing angle-output voltage equation. The linear displacement sensor 5 detects the swing of the flexible nozzle 1 and outputs a simulated voltage signal. The real-time simulator 6 generates swing angle data by sending control commands to the servo mechanism 3 and receiving signals from the linear displacement sensor 5. Specifically, firstly, the swing angle-voltage relationship is calibrated using the inclinometer 4 and the linear displacement sensor 5. Then, the real-time simulator 6 sends continuous sinusoidal commands to drive the flexible nozzle 1 to swing, while simultaneously acquiring the swing displacement signal. Based on the continuous sinusoidal commands sent by the real-time simulator 6 and the obtained swing displacement signal, the dynamic characteristics of the servo mechanism 3 and the working coordination between the servo mechanism 3 and the flexible nozzle 1 are analyzed.

[0040] It should be understood that the rocket engine flexible nozzle cold swing test simulation system of this embodiment first uses the servo mechanism 3 to calibrate the swing of the flexible nozzle 1. Combining the swing angle measured by the inclinometer 4 and the voltage signal measured by the linear displacement sensor 5, the swing angle-output voltage equation is fitted. Then, the real-time simulator 6 controls the servo mechanism 3 to simulate and reproduce the continuously changing attitude of the flexible nozzle 1. Based on the swing angle-output voltage equation, the swing angle data of the flexible nozzle 1 is calculated. Then, the dynamic response of the servo mechanism 3 under the continuous swing condition of the flexible nozzle 1 is analyzed, which truly reflects the working state of the servo mechanism 3 controlling the continuous swing of the flexible nozzle 1 under cold pressurization conditions, thus improving the authenticity and reliability of the test data.

[0041] In some embodiments of the rocket engine flexible nozzle cold swing test simulation system of the present invention, the flexible nozzle 1 and the pressure vessel 2 are connected by a flange, the center point of the flange is the swing center of the flexible nozzle 1, the connection point of the linear displacement sensor 5 and the flexible nozzle 1 is called the lower support, the linear displacement sensor 5 is set on the sensor bracket, and the axis of the linear displacement sensor 5 is perpendicular to the connection line between the swing center and the lower support.

[0042] It is important to understand that in the simulation test system for the cold swing test of the flexible nozzle of a rocket engine, the installation angle of the linear displacement sensor 5 directly affects the accuracy of the swing angle measurement of the flexible nozzle 1. Its core design principle is to ensure that the output voltage of the linear displacement sensor 5 has a linear relationship with the swing angle of the flexible nozzle 1, thereby simplifying the calibration process and improving test accuracy. In this embodiment, the flexible nozzle 1 and the pressure vessel 2 are rigidly connected by a flange, where the center point of the flange is defined as the swing center (swing center) of the flexible nozzle 1. The linear displacement sensor 5 is coplanar with the swing plane of the flexible nozzle 1 to avoid lateral force interference. The linear displacement sensor 5 is fixed on a dedicated bracket, and its other end is connected to the lower support of the flexible nozzle 1. The axial stretching / contraction direction of the linear displacement sensor 5 is perpendicular to the line connecting the swing center and the lower support. When the flexible nozzle 1 swings, the lower support swings around the swing center, causing the linear displacement sensor 5 to stretch or compress. This structural design ensures that when the servo mechanism 3 drives the flexible nozzle 1 to swing around the swing center, the stretching displacement of the linear displacement sensor 5 has a linear proportional relationship with the swing angle of the flexible nozzle 1. ,in This refers to the extension and retraction displacement of the linear displacement sensor 5. The distance from the center of the arm to the lower auricle. The swing angle of the flexible nozzle 1 When smaller (Approximately linear), thus directly reflecting the actual swing angle of the flexible nozzle 1, eliminating nonlinear errors in traditional installation, improving calibration accuracy, and providing a high-precision displacement reference signal for subsequent dynamic performance testing.

[0043] In some embodiments of the rocket engine flexible nozzle cold swing test simulation system of the present invention, an AD data acquisition card 7 is connected between the linear displacement sensor 5 and the real-time simulator 6. The AD data acquisition card 7 is used to receive the analog voltage signal from the linear displacement sensor 5 and to convert the analog voltage signal into a digital quantity for transmission to the real-time simulator 6. It is understood that the AD data acquisition card 7 between the linear displacement sensor 5 and the real-time simulator 6 forms a high-precision signal acquisition channel. When the flexible nozzle 1 swings, the analog voltage signal (0~10V) output by the linear displacement sensor 5 is first transmitted to the AD data acquisition card 7. The AD data acquisition card 7 converts the analog signal into a sixteen-bit digital quantity (for example, a sampling rate of 200kHz) at a sampling rate of not less than 1kHz and transmits it to the real-time simulator 6 for processing via a high-speed data bus. This achieves accurate digital acquisition of the sensor signal. Simultaneously, by isolating the analog and digital circuits, electromagnetic interference during signal transmission is effectively suppressed, ensuring the measurement accuracy of the swing angle data and providing a reliable data foundation for the dynamic performance analysis of the system.

[0044] Furthermore, a low-pass filter 8 is connected between the AD data acquisition card 7 and the linear displacement sensor 5. The low-pass filter 8 is a fourth-order low-pass filter used to eliminate high-frequency noise interference in the analog voltage signal. It can be understood that by connecting a fourth-order low-pass filter (low-pass filter 8) in series between the AD data acquisition card 7 and the linear displacement sensor 5, a pre-stage signal conditioning circuit is formed. The low-pass filter 8 adopts a Sallen-Key active filter architecture, achieving an attenuation slope of -80dB / octave through four cascaded operational amplifiers, suppressing high-frequency noise above 1kHz (including electromagnetic interference, power supply ripple, etc.) to below 0.1%. Specifically, the millivolt-level analog signal output by the linear displacement sensor 5 first undergoes impedance matching through an input buffer stage, then passes through a fourth-order filter network to eliminate high-frequency interference components, and finally is sent to the AD data acquisition card 7 for digital conversion via an output driver stage. This pre-stage filtering design enables the system to maintain a swing angle measurement accuracy of ±0.05° even in environments with strong electromagnetic interference, reducing signal distortion compared to traditional second-order filter schemes.

[0045] In some embodiments of the rocket engine flexible nozzle cold swing test simulation system of the present invention, the real-time simulator 6 is connected to the servo mechanism 3 via a 1553B bus, and is adapted to send swing angle calibration control commands or swing angle test control commands to the servo mechanism 3. It is understood that the real-time simulator 6 can use the VxWorks real-time simulation system to realize continuous transmission of rocket attitude control commands. The real-time simulator 6 establishes a deterministic communication link with the servo mechanism 3 via the 1553B bus, adopts a dual-redundant bus architecture of the MIL-STD-1553B protocol, and periodically sends control commands at a transmission rate of 1MHz, wherein the time-triggered mechanism ensures that the command transmission jitter is less than 100μs. Specifically, the real-time simulator 6 sends 16-bit precision swing angle commands (stepped waves for calibration or swept sine waves for testing) through the bus controller (BC) according to a predetermined timing sequence. The servo mechanism 3, acting as a remote terminal (RT), receives and parses the commands, drives the flexible nozzle 1 to move through the built-in PID controller, and simultaneously feeds back the execution status to the real-time simulator 6 through the same bus. This achieves strict synchronization between command transmission and status feedback, reduces control latency compared to the traditional CAN bus scheme, ensures closed-loop control is completed within a 100Hz control cycle, and improves the authenticity and reliability of data communication.

[0046] In another aspect, the present invention provides a simulation test method for cold swing test of flexible nozzle of rocket engine, applicable to the simulation test system for cold swing test of flexible nozzle of rocket engine in any of the above embodiments. For some specific examples, see [link to specific examples]. Figure 2 As shown, the simulation test method for the cold swing test of the flexible nozzle of the rocket engine includes the following steps S1 to S7.

[0047] S1. Pressurize the pressure vessel 2 using an air-pressurizing device, and use the pressure vessel 2 to provide axial thrust and lateral load to the flexible nozzle 1 to simulate the working state of a rocket engine.

[0048] S2. The real-time simulator 6 sends the swing angle calibration control command to the servo mechanism 3, and the servo mechanism 3 controls the flexible nozzle 1 to swing.

[0049] S3. Obtain the swing angle of the flexible nozzle 1 through the inclinometer 4, and output the calibration analog voltage signal to the real-time simulator 6 through the linear displacement sensor 5.

[0050] S4. Based on the swing angle of the flexible nozzle 1 obtained by the inclinometer 4 and the corresponding calibration analog voltage signal received by the real-time simulator 6, the swing angle-output voltage equation is fitted and generated.

[0051] S5. Send the swing angle test control command to the servo mechanism 3 through the real-time simulator 6, and use the servo mechanism 3 to control the flexible nozzle 1 to simulate the continuously changing swing posture.

[0052] S6. The test simulation voltage signal is output to the real-time simulator 6 through the linear displacement sensor 5. The real-time simulator 6 calculates and generates the swing angle data of the flexible nozzle 1 based on the swing angle-output voltage equation and the test simulation voltage signal.

[0053] S7. Analyze the swing angle test control command and the calculated swing angle data to determine the dynamic characteristics of the servo mechanism 3 and the working coordination between the servo mechanism 3 and the flexible nozzle 1.

[0054] It is understood that the rocket engine flexible nozzle cold swing test simulation test method of this embodiment includes the flexible nozzle cold swing test swing angle calibration implementation process and the flexible nozzle cold swing test simulation test implementation process.

[0055] The process of calibrating the swing angle in a cold swing test of a flexible nozzle can specifically include the following steps.

[0056] (1) Pressurize the pressure vessel 2 through the inflation and pressurization device, provide power to the servo mechanism 3 through the 100KW ground power supply, and power the linear displacement sensor 5 through the ±12V regulated DC power supply.

[0057] (2) The real-time simulator 6 sends the swing angle calibration control command to the servo mechanism 3 through the 1553B bus. The servo mechanism 3 controls the swing of the flexible nozzle 1 based on the swing angle calibration control command. The swing angle calibration control command is a stepped swing angle control command formed by multiple swing angle control commands. The step interval of the multiple swing angle control commands is 1°~2°, and the swing angle of the maximum swing angle control command does not exceed the maximum swing angle allowed by the flexible nozzle 1.

[0058] (3) The flexible nozzle 1 swings, causing the linear displacement sensor 5 to stretch, which causes the output voltage value to change. The low-pass filter 8 removes high-frequency noise interference in the analog voltage. The AD data acquisition card 7 acquires the voltage value and converts it into a digital quantity, which is then sent to the real-time simulator 6.

[0059] (4) Record the voltage collected by the linear displacement sensor 5 and the swing angle value of the sensitive nozzle measured by the inclinometer 4 respectively.

[0060] (5) Linear regression method was used to determine the swing angle. and output voltage Perform linear fitting and calculate parameters. and parameters The swing angle-output voltage equation is obtained. .

[0061] After the swing angle of the flexible nozzle cold swing test is calibrated, the inclinometer 4 is removed (the weight of the inclinometer 4 is negligible compared to the weight of the flexible nozzle 1). The swing angle-output voltage equation is set in the simulation software of the real-time simulator 6, and the simulation test of the flexible nozzle cold swing test is carried out.

[0062] The simulation test implementation process of the flexible nozzle cold swing test can specifically include the following steps.

[0063] (1) Pressurize the pressure vessel 2 through the inflation and pressurization device, provide power to the servo mechanism 3 through the 100KW ground power supply, and power the linear displacement sensor 5 through the ±12V regulated DC power supply.

[0064] (2) The real-time simulator 6 sends a swing angle test control command to the servo mechanism 3 via the 1553B bus. The servo mechanism 3 controls the flexible nozzle 1 to swing based on the swing angle test control command. The swing angle test control command is a continuously changing sinusoidal swing signal control command, which is suitable for characterizing the continuously changing swing attitude of the flexible nozzle 1. The amplitude of the sinusoidal swing signal of the swing angle test control command sent by the real-time simulator 6 is adjustable to test the response characteristics of the flexible nozzle 1 under different swing amplitudes.

[0065] (3) The swing of the flexible nozzle 1 causes the linear displacement sensor 5 to stretch, which causes the output voltage value to change. The low-pass filter 8 removes high-frequency noise interference in the analog voltage. The AD data acquisition card 7 collects the voltage value and converts it into a digital quantity, which is then sent to the real-time simulator 6. The real-time simulator 6 directly obtains the swing angle data of the flexible nozzle 1 through the swing angle-output voltage equation.

[0066] (4) Using the swing angle test control command and the calculated swing angle data, analyze and judge the dynamic characteristics of the servo mechanism 3 and the working coordination between the servo mechanism 3 and the flexible nozzle 1.

[0067] The process of analyzing and judging the dynamic characteristics of servo mechanism 3 and the working coordination between servo mechanism 3 and flexible nozzle 1 is as follows: First, adjust the frequency and amplitude of the sinusoidal swing signal of the swing angle test control command to obtain swing angle data under different swing angle test control commands.

[0068] Secondly, the discrete Fourier series of the fundamental component is calculated for the swing angle control command and the acquired sinusoidal swing angle data of different frequencies and amplitudes. and ,in , Thus, the amplitude of the fundamental component is obtained. phase .

[0069] Next, logarithmic amplitude-frequency response curves and logarithmic phase-frequency response curves are plotted based on the amplitude and phase of the fundamental component of the swing angle generation data. Specifically, the swing angle test control command and the acquired sinusoidal swing angle data of different frequencies and amplitudes are respectively recorded as input signals. and output signal For each frequency point input signal and output signal Perform Discrete Fourier Transform to extract the amplitude of the fundamental component. and Fundamental component phase and Input signal and output signal The gain ratio is Input signal and output signal The phase difference is The vertical axis of the converted logarithmic amplitude-frequency response curve is... The horizontal axis is (Frequency logarithmic coordinates); the vertical axis of the converted logarithmic phase frequency response curve is... The horizontal axis is (Frequency logarithmic coordinates).

[0070] The next step is to obtain the bandwidth and resonant peak value based on the logarithmic amplitude-frequency response curve, and the phase margin based on the logarithmic amplitude-frequency response curve and the logarithmic phase-frequency response curve. Here, the bandwidth is the frequency corresponding to the gain decaying to -3dB in the logarithmic amplitude-frequency response curve, the resonant peak value is the amplitude at which the maximum gain exceeds 0dB in the logarithmic amplitude-frequency response curve, and the phase margin is the difference between the logarithmic phase-frequency response curve corresponding to the cutoff frequency (gain of 0dB) of the logarithmic amplitude-frequency response curve and -180°.

[0071] Finally, the dynamic response speed of servo mechanism 3 is judged based on bandwidth, the dynamic response stability of servo mechanism 3 is judged based on phase margin, and the working coordination between servo mechanism 3 and flexible nozzle 1 is judged based on resonance peak value. Bandwidth reflects the highest effective frequency at which servo mechanism 3 tracks commands. The higher the bandwidth, the faster the dynamic response. For example, if the design requires a bandwidth ≥ 5Hz and the actual measurement is 6Hz, then the speed requirement is met. Phase margin characterizes system stability. The larger the phase margin (usually > 45°), the stronger the anti-disturbance capability. For example, a measured phase margin of 50° indicates that the system has no risk of oscillation, and the dynamic response of servo mechanism 3 is relatively stable. Resonance peak value reflects the damping characteristics of the system. The higher the resonance peak value, the easier it is for flexible nozzle 1 and servo mechanism 3 to resonate. For example, a resonance peak value < 3dB indicates that there is no abnormal vibration in nozzle oscillation, the mechanism is well matched, and the working coordination between servo mechanism 3 and flexible nozzle 1 is good.

[0072] Based on the above description of the rocket engine flexible nozzle cold swing test simulation system and test method of the present invention in the embodiments or examples, the present invention uses a real-time simulator 6 to realistically simulate the swing working state of the servo mechanism 3 and the flexible nozzle 1 when the rocket control system continuously sends attitude control commands; it uses the rocket electrical system 1553B bus to realize communication between the real-time simulator and the servo actuator, improving the authenticity and reliability of data communication; and it adds a fourth-order low-pass filter 8 between the online displacement sensor 5 and the AD data acquisition card 7 to effectively solve the influence of high-frequency noise interference on the final data. The rocket engine flexible nozzle cold swing test simulation test method of the present invention has been applied to the flexible nozzle cold swing test, and the test system is in good condition with accurate and reliable test results.

[0073] The rocket engine flexible nozzle cold swing test simulation system provided by the present invention first uses a servo mechanism 3 to calibrate the swing of the flexible nozzle 1. Combining the swing angle measured by the inclinometer 4 and the voltage signal measured by the linear displacement sensor 5, the swing angle-output voltage equation is fitted. Then, the servo mechanism 3 is controlled by the real-time simulator 6 to simulate and reproduce the continuously changing attitude of the flexible nozzle 1. The swing angle data of the flexible nozzle 1 is calculated based on the swing angle-output voltage equation. Subsequently, the dynamic response of the servo mechanism 3 under the continuous swing condition of the flexible nozzle 1 is analyzed, which truly reflects the working state of the servo mechanism 3 controlling the continuous swing of the flexible nozzle 1 under cold pressurization conditions, thereby improving the authenticity and reliability of the test data.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation test system for cold swing test of a flexible nozzle for a rocket engine, characterized in that, include: Flexible nozzle (1); Pressure vessel (2) is connected to the flexible nozzle (1) to provide a cold pressurization environment for the flexible nozzle (1); Servo mechanism (3) is connected to the flexible nozzle (1). The servo mechanism (3) is used to drive the flexible nozzle (1) to swing so as to form the swing plane of the flexible nozzle (1). Inclinometer (4) is detachably connected to the flexible nozzle (1), and the inclinometer (4) is located in the swing plane of the flexible nozzle (1) for calibrating the swing angle of the flexible nozzle (1). A linear displacement sensor (5) is located in the swing plane of the flexible nozzle (1). The linear displacement sensor (5) is connected to the flexible nozzle (1) and is adapted to generate an analog voltage signal under the swing action of the flexible nozzle (1). The real-time simulator (6) is connected to the linear displacement sensor (5) and is used to receive the analog voltage signal output by the linear displacement sensor (5) and generate the swing angle data of the flexible nozzle (1); the real-time simulator (6) is also connected to the servo mechanism (3) and is used to send control commands to the servo mechanism (3) to control the swing posture of the flexible nozzle (1).

2. The rocket engine flexible nozzle cold swing test simulation system according to claim 1, characterized in that, The flexible nozzle (1) is connected to the pressure vessel (2) via a flange. The center point of the flange is the pivot of the flexible nozzle (1). The connection point between the linear displacement sensor (5) and the flexible nozzle (1) is called the lower support. The linear displacement sensor (5) is mounted on a sensor bracket, and the axis of the linear displacement sensor (5) is perpendicular to the connection line between the pivot and the lower support.

3. The rocket engine flexible nozzle cold swing test simulation system according to claim 1 or 2, characterized in that, An AD data acquisition card (7) is connected between the linear displacement sensor (5) and the real-time simulator (6). The AD data acquisition card (7) is used to receive the analog voltage signal from the linear displacement sensor (5) and to convert the analog voltage signal into a digital quantity to be sent to the real-time simulator (6).

4. The rocket engine flexible nozzle cold swing test simulation system according to claim 3, characterized in that, A low-pass filter (8) is connected between the AD data acquisition card (7) and the linear displacement sensor (5) to remove high-frequency noise interference in the analog voltage signal.

5. The rocket engine flexible nozzle cold swing test simulation system according to claim 1, characterized in that, The real-time simulator (6) is connected to the servo mechanism (3) via a 1553B bus and is adapted to send swing angle calibration control commands or swing angle test control commands to the servo mechanism (3).

6. A simulation test method for cold swing test of a flexible nozzle of a rocket engine, characterized in that, The simulation test system for cold swing test of flexible nozzle of rocket engine according to any one of claims 1 to 5 includes: The pressure vessel (2) is pressurized by an air-pressurizing device, and the pressure vessel (2) is used to provide axial thrust and lateral load to the flexible nozzle (1) to simulate the working state of the rocket engine; The real-time simulator (6) sends the swing angle calibration control command to the servo mechanism (3), and the servo mechanism (3) controls the flexible nozzle (1) to swing. The swing angle of the flexible nozzle (1) is obtained by the inclinometer (4), and the calibration analog voltage signal is output to the real-time simulator (6) by the linear displacement sensor (5). Based on the swing angle of the flexible nozzle (1) obtained by the inclinometer (4) and the corresponding calibration analog voltage signal received by the real-time simulator (6), the swing angle-output voltage equation is fitted and generated. The real-time simulator (6) sends a swing angle test control command to the servo mechanism (3), and the servo mechanism (3) controls the flexible nozzle (1) to simulate the continuously changing swing posture. The line displacement sensor (5) outputs a test simulation voltage signal to the real-time simulator (6), and the real-time simulator (6) calculates and generates the swing angle data of the flexible nozzle (1) based on the swing angle-output voltage equation and the test simulation voltage signal. The dynamic characteristics of the servo mechanism (3) and the working coordination between the servo mechanism (3) and the flexible nozzle (1) are determined by analyzing the swing angle test control command and the calculated swing angle data.

7. The simulation test method for cold swing test of flexible nozzle of rocket engine according to claim 6, characterized in that, The swing angle calibration control command sent by the real-time simulator (6) is a stepped swing angle control command formed by multiple swing angle control commands. The step interval of the multiple swing angle control commands is 1°~2°, and the swing angle of the maximum swing angle control command does not exceed the maximum swing angle allowed by the flexible nozzle (1). The swing angle test control command sent by the real-time simulator (6) is a continuously changing sinusoidal swing signal control command, which is suitable for characterizing the continuously changing swing posture of the flexible nozzle (1).

8. The simulation test method for cold swing test of flexible nozzle of rocket engine according to claim 7, characterized in that, The frequency and amplitude of the sinusoidal swing signal sent by the real-time simulator (6) for the swing angle test control command are adjustable, so as to test the response characteristics of the flexible nozzle (1) under different swing angle test control commands.

9. The simulation test method for cold swing test of flexible nozzle of rocket engine according to claim 8, characterized in that, The analysis based on the swing angle test control command and the calculated swing angle data to determine the dynamic characteristics of the servo mechanism (3) and the working coordination between the servo mechanism (3) and the flexible nozzle (1) includes: Adjust the frequency and amplitude of the sinusoidal swing signal of the swing angle test control command to obtain swing angle data under different swing angle test control commands; The amplitude and phase of the fundamental component of the generated swing angle data are calculated by performing a discrete Fourier transform on the swing angle test control command and the swing angle data under different swing angle test control commands. Based on the amplitude and phase of the fundamental component of the calculated swing angle data, logarithmic amplitude-frequency response curves and logarithmic phase-frequency response curves are plotted. The bandwidth and resonant peak value are obtained based on the logarithmic amplitude-frequency response curve, and the phase margin is obtained based on the logarithmic amplitude-frequency response curve and the logarithmic phase-frequency response curve. The dynamic response speed of the servo mechanism (3) is determined based on the bandwidth, the dynamic response stability of the servo mechanism (3) is determined based on the phase margin, and the working coordination between the servo mechanism (3) and the flexible nozzle (1) is determined based on the resonance peak value.

10. The simulation test method for cold swing test of flexible nozzle of rocket engine according to claim 6, characterized in that, The fitted equation for generating the swing angle-output voltage includes: Using linear regression equations opposite angle and output voltage Perform linear fitting and calculate the parameters. and parameters Based on parameters and parameters The swing angle-output voltage equation is obtained; The swing angle The output voltage is the swing angle of the flexible nozzle (1) obtained by the inclinometer (4). The corresponding calibration analog voltage signal received by the real-time simulator (6).

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