Carrier rocket engine frame deformation compensation method

Abstract

The invention provides a carrier rocket engine frame deformation compensation method. The carrier rocket engine frame deformation compensation method comprises the steps that an additional swing angle estimated value caused by frame deformation of an engine frame under the action of different thrust is measured in advance through a static test; the length of the servo mechanism is adjusted, and on the basis of the original swing angle, swing angle pre-compensation is conducted on an engine rack; according to the additional swing angle estimated value and a pre-compensation angle of swing angle pre-compensation, compensation and amplitude limiting are conducted on the engine swing angle instruction, and the compensated and amplitude-limited engine swing angle instruction is obtained; and the compensated and amplitude-limited engine swing angle instruction is sent to a servo controller. According to the method, the tilt angle compensation amount changing along with time can be provided and used for offsetting the additional tilt angle caused by deformation of the engine frame, so that the attitude control precision is improved, and then the safety during stage separation is improved, the load injection precision is improved, or the propellant consumption of an auxiliary power system is reduced.

Description

Technical Field

[0001] The present application relates to the field of launch vehicle technology, and in particular to a method for compensating for the deformation of a launch vehicle engine frame. Background Art

[0002] At present, most launch vehicles use a swinging nozzle to control the attitude of the powered flight phase. With this control method, the main engine is installed on the engine frame, and the nozzle swing is controlled by the extension and contraction of the servo actuator. The swing makes the main engine thrust produce a lateral component perpendicular to the axis of the rocket body, thereby realizing the control of the rocket's attitude.

[0003] Due to the thrust of the main engine, the main engine frame will deform structurally, which will generate an additional swing angle on the engine nozzle. The traditional approach is to adjust the length of the servo actuator to preset a swing angle compensation amount for the main engine nozzle when the main engine and servo are installed. This compensation amount is used to offset or partially offset the additional swing angle caused by the frame deformation.

[0004] When the above control scheme is adopted, the swing angle compensation amount is a fixed value, and the thrust of the rocket main engine changes sharply during the startup and shutdown stages, and the frame deformation will also change sharply accordingly. The fixed compensation amount cannot compensate for the frame deformation well, which will cause a large interference torque, and then cause a large attitude control error and attitude angular velocity. Especially in the shutdown stage of the main engines of each stage, due to the disappearance of subsequent thrust, the attitude interference generated cannot be eliminated by swinging the nozzle control, which will cause the attitude error and attitude angular velocity to be too large during the subsequent interstage separation or load separation, affecting the safety during separation or the accuracy index of the load into orbit. If the attitude angle deviation and attitude angular velocity generated are eliminated by the auxiliary power system after shutdown, the propellant consumption of the auxiliary power system will increase. Summary of the invention

[0005] The purpose of the present application is to provide a method for compensating for the deformation of a launch vehicle engine frame, which can provide a swing angle compensation amount that varies with time, and is used to offset the additional swing angle caused by the deformation of the engine frame, so as to improve the attitude control accuracy, thereby improving the safety during stage separation, improving the accuracy of payload insertion into orbit, or reducing the propellant consumption of the auxiliary power system.

[0006] To achieve the above-mentioned purpose, the present application provides a method for compensating the deformation of a launch vehicle engine frame, the method comprising: pre-measuring, through a static test, an estimated additional swing angle caused by the deformation of the engine frame under different thrusts; pre-compensating the engine frame for the swing angle on the basis of the original swing angle by adjusting the length of the servo mechanism; compensating and limiting the engine swing angle command according to the estimated additional swing angle and the pre-compensation angle of the swing angle pre-compensation, to obtain the compensated and limited engine swing angle command; and sending the compensated and limited engine swing angle command to a servo controller.

[0007] The method for compensating the deformation of a launch vehicle engine frame as described above, wherein the engine swing angle instruction is compensated and limited according to the additional swing angle estimation value and the pre-compensation angle of the swing angle pre-compensation, and obtaining the compensated and limited engine swing angle instruction comprises:

[0008] The engine swing angle command is compensated by using the additional swing angle estimation value caused by the frame deformation measured by the ground static test;

[0009] The compensated engine swing angle command is limited according to the maximum swing angle of the servo actuator.

[0010] In the above-mentioned method for compensating the deformation of the launch vehicle engine frame, for a double-pendulum engine, the swing angle compensation and amplitude limiting method are shown in the following formula:

[0011]

[0012] in, Indicates the swing angle command of actuator A after swing angle compensation and limiting; Indicates the swing angle command of actuator B after swing angle compensation and limiting; It represents the estimated value of the additional swing angle caused by the deformation of the rack of channel A; It represents the estimated value of the additional swing angle caused by the deformation of the rack of channel B; Indicates the pre-compensation angle of the rack deformation of channel A; Indicates the pre-compensation angle of the rack deformation of channel B; Represents the original swing angle command of actuator A; Indicates the original swing angle command of actuator B; U δ Indicates the maximum swing angle of the servo actuator; represents the absolute value clipping function; |x| represents the absolute value of the independent variable.

[0013] The above-mentioned carrier rocket engine frame deformation compensation method, wherein: |x|≤U δ express The absolute value of the servo actuator is less than or equal to the maximum swing angle U δ .

[0014] The above-mentioned carrier rocket engine frame deformation compensation method, wherein: |x|≤U δ express The absolute value of the servo actuator is less than or equal to the maximum swing angle U δ .

[0015] The method for compensating the deformation of the launch vehicle engine frame as described above, wherein the swing angle pre-compensation of the engine frame is performed on the basis of the original swing angle by adjusting the length of the servo mechanism, including:

[0016] Measure the additional swing angle caused by the deformation of the engine frame under nominal thrust;

[0017] According to the nominal additional swing angle of the engine frame, the length of the servo mechanism is adjusted to pre-compensate the swing angle of the engine frame.

[0018] In the above-mentioned method for compensating the deformation of a launch vehicle engine frame, during the process of pre-compensating the swing angle of the engine frame, the preset compensation angle is compensated to the engine frame.

[0019] In the above-mentioned method for compensating the deformation of the launch vehicle engine frame, the preset compensation angle β 0 Satisfy 0≤β 0 ≤β norm ;

[0020] Among them, β norm is the additional swing angle caused by the frame deformation under the nominal thrust of the engine.

[0021] In the method for compensating the deformation of the launch vehicle engine frame as described above, during the static test, the thrust is gradually increased, and each time the thrust is increased, a period of time is waited to allow the deformation of the engine frame to stabilize, and the estimated value of the additional swing angle caused by the frame deformation under each thrust is recorded.

[0022] The method for compensating for the deformation of the launch vehicle engine frame as described above, wherein, after the engine is started, after the servo controller receives the engine swing angle instruction, the swing angle of the engine nozzle is adjusted to restore the swing angle of the engine nozzle to the swing angle state of the engine nozzle when there is no frame deformation.

[0023] The beneficial effects achieved by this application are as follows:

[0024] (1) After the frame deformation is compensated in this application, it can be ensured that there is no obvious additional swing angle in each working stage of the engine.

[0025] (2) The present application significantly reduces the attitude disturbance caused by the rapid change in frame deformation during engine startup and shutdown, and improves the safety during stage separation or the accuracy index when the payload enters orbit.

[0026] (3) If the auxiliary power system is used for attitude control after the main engine is shut down, the method for compensating the deformation of the launch vehicle engine frame of the present application can effectively reduce the propellant consumption of the auxiliary power system after shutdown. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For those skilled in the art, other drawings can also be obtained based on these drawings.

[0028] Figure 1 A flow chart of a method for compensating for deformation of a launch vehicle engine frame implemented in this application.

[0029] Figure 2 This is a schematic diagram of the positions of the nozzle and the frame when there is no frame deformation and when there is frame deformation implemented in this application.

[0030] Figure 3 This is a schematic diagram of the positions of the front nozzle for frame deformation compensation and the rear nozzle for frame deformation compensation implemented in this application. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0032] like Figure 1 As shown, the present application provides a method for compensating the deformation of a launch vehicle engine frame, the method comprising:

[0033] Step S1, pre-measuring an estimated value of an additional swing angle caused by the deformation of the engine frame under different thrusts through a static test.

[0034] Among them, the preparation before the static test: the engine frame is fixedly installed on the test platform, and a high-precision displacement sensor and an angle measuring instrument are installed on the engine frame. The displacement sensor is used to measure the deformation of the key position of the engine frame, and the angle measuring instrument is used to directly measure the additional swing angle caused by the deformation of the engine frame. Prepare a loading device that can accurately apply different thrusts, such as an electric push rod. The loading device provides a stable and adjustable thrust to the engine frame, which can be measured and recorded. The thrust measurement is achieved by connecting a force sensor.

[0035] Among them, during the static test, start with a smaller thrust and gradually increase the thrust. Each time the thrust is increased, wait for a period of time to allow the engine frame deformation to stabilize. The stabilization time is determined by observing the data changes of the displacement sensor and the angle measuring instrument. When the data changes very little over a period of time, it can be considered that the engine frame deformation has reached a stable state. Under each thrust, record the frame deformation measured by the displacement sensor and the additional swing angle recorded by the angle measuring instrument (as an estimated value of the additional swing angle).

[0036] Step S2, pre-compensating the swing angle of the engine frame based on the original swing angle by adjusting the length of the servo mechanism.

[0037] Specifically, when each engine is installed, the swing angle pre-compensation is performed by adjusting the length of the servo mechanism, that is, by adjusting the length of the servo mechanism, the additional swing angle caused by the deformation of the engine frame under the nominal thrust is pre-compensated.

[0038] Step S2 includes:

[0039] Step S210, measuring the additional swing angle caused by the deformation of the engine frame under the nominal thrust.

[0040] Step S220, adjusting the length of the servo mechanism according to the nominal additional swing angle of the engine frame, and performing swing angle pre-compensation on the engine frame.

[0041] It is understandable that the servo mechanism needs to extend or shorten a certain length for each degree change in the swing angle of the engine frame.

[0042] Among them, the swing angle pre-compensation is to eliminate the additional swing angle by adjusting the length of the servo actuator based on the additional swing angle caused by the deformation of the engine frame under the nominal thrust. Since the additional swing angle of the engine frame will generate additional interference torque, which will reduce the attitude control accuracy of the launch vehicle and increase the angular velocity of the first and second stage separation, the present application can reduce the additional interference torque after eliminating the additional swing angle, ensure a higher attitude control accuracy, and have a good technical effect.

[0043] Among them, the compensation angle β 0 Satisfy 0≤β 0 ≤βnorm β norm is the additional swing angle caused by the frame deformation under the nominal thrust of the engine.

[0044] As a preferred embodiment of the present invention, when adjusting the length of the servo mechanism, the swing angle change of the engine frame is monitored in real time until the swing angle reaches the expected compensation result.

[0045] Step S3, compensating and limiting the engine swing angle command according to the additional swing angle estimation value and the pre-compensation angle of the swing angle pre-compensation, to obtain the compensated and limited engine swing angle command.

[0046] Step S3 includes:

[0047] Step S310, compensating the engine swing angle command by using the additional swing angle estimation value caused by the frame deformation measured by the ground static test.

[0048] Step S320, limiting the compensated engine swing angle command according to the maximum swing angle of the servo actuator.

[0049] Among them, for the double-swing engine, the swing angle compensation and limiting method are shown in the following formula:

[0050]

[0051] in, Indicates the swing angle command of actuator A after swing angle compensation and limiting; Indicates the swing angle command of actuator B after swing angle compensation and limiting; It represents the estimated value of the additional swing angle caused by the deformation of the rack of channel A; It represents the estimated value of the additional swing angle caused by the deformation of the B channel rack; the estimated value of the additional swing angle caused by the deformation of the A and B channel racks is measured through ground static tests.

[0052] in, Indicates the pre-compensation angle of the rack deformation of channel A; Indicates the pre-compensation angle of the rack deformation of channel B; Represents the original swing angle command of actuator A; Indicates the original swing angle command of actuator B; U δ Indicates the maximum swing angle of the servo actuator; represents the absolute value clipping function; |x| represents the absolute value of the independent variable.

[0053] in, |x|≤U δ express The absolute value of the servo actuator is less than or equal to the maximum swing angle U δ .

[0054] in, |x|≤U δ express The absolute value of the servo actuator is less than or equal to the maximum swing angle U δ .

[0055] Step S4, sending the compensated and limited engine swing angle command to the servo controller.

[0056] Specifically, after the engine is started, the servo controller controls the extension and retraction of the servo mechanism according to the received engine swing angle command, thereby adjusting the swing angle of the engine nozzle to the swing angle state of the engine nozzle when there is no frame deformation.

[0057] It needs to be explained that the servo controller sends a control signal to the servo actuator based on the received engine swing angle command, and the servo actuator converts the control signal from the servo controller into mechanical motion, thereby adjusting the swing angle of the engine nozzle, and adjusting the swing angle of the engine nozzle to the swing angle state of the engine nozzle when there is no frame deformation.

[0058] As a specific embodiment of the present invention, compensating the engine frame deformation during the main engine startup, stable operation, and shutdown stages includes the following steps:

[0059] Step T1, obtaining the thrust variation curve of the main engine startup and shutdown stages.

[0060] Specifically, a thrust sensor is installed on the thrust output shaft of the main engine or at a position where the thrust is directly measured, and the thrust sensor collects the thrust of the main engine and converts the thrust into a thrust variation curve, and obtains the thrust variation curve of the main engine during the start-up and shutdown stages.

[0061] Step T2, based on the thrust variation curve of the main engine startup and shutdown stages, calculate the estimated value of the additional swing angle of the frame deformation during the main engine startup and shutdown stages that varies with time, as well as the estimated value of the additional swing angle of the frame deformation during the stable working stage.

[0062] Among them, according to the relationship between the engine thrust and the additional swing angle of the engine frame deformation, as well as the thrust change curve of the main engine startup and shutdown sections, the estimated value of the frame deformation additional swing angle of the main engine startup and shutdown sections that changes with time, as well as the estimated value of the frame deformation additional swing angle of the stable working section are calculated.

[0063] The relationship between the engine thrust and the additional swing angle of the engine frame deformation is obtained based on the data of the engine frame deformation and the additional swing angle measured under different thrusts obtained in the static test.

[0064] Step T3, before sending the swing angle command to the servo controller, the engine swing angle command is compensated and limited according to the frame deformation additional swing angle of the main engine startup and shutdown sections that changes with time, and the frame deformation additional swing angle of the stable working section, and the compensated and limited engine swing angle command is sent to the servo controller.

[0065] Step T3 comprises:

[0066] Step T310, real-time compensation of the engine swing angle command is performed based on the additional swing angle of the frame deformation during the start-up and shutdown stages of the main engine, and the additional swing angle of the frame deformation during the stable working stage, which changes with time.

[0067] Specifically, before sending a swing angle instruction to the servo controller, the launch vehicle performs real-time compensation for the engine swing angle instruction according to various data of the frame deformation during flight.

[0068] Step T320, limiting the compensated engine swing angle command according to the maximum swing angle of the servo actuator.

[0069] like Figure 2 The figure shows the positions of the nozzle and the frame when there is no frame deformation and when there is frame deformation. When there is no frame deformation, the thrust of the nozzle is in the vertical direction, and the engine nozzle is in the vertical direction. When there is frame deformation, the thrust direction of the nozzle is inclined at a certain angle relative to the vertical direction, and the engine nozzle is deflected at a certain angle relative to the vertical direction.

[0070] like Figure 3 The figure shows the position of the front nozzle of the frame deformation compensation and the rear nozzle of the frame deformation compensation. The thrust direction of the front nozzle of the frame deformation compensation is inclined at a certain angle relative to the vertical direction, and the engine nozzle is deflected at a certain angle relative to the vertical direction. The thrust of the rear nozzle of the frame deformation compensation is along the vertical direction, and the engine nozzle is along the vertical direction.

[0071] The present application provides a launch vehicle engine frame deformation compensation system, the system comprising:

[0072] A pre-measurement module is used to pre-measure an estimated value of an additional swing angle caused by the deformation of the engine frame under different thrusts through a static test;

[0073] A swing angle pre-compensation module is used to pre-compensate the additional swing angle caused by the engine frame deformation by adjusting the length of the servo mechanism;

[0074] A swing angle command acquisition module is used to compensate and limit the engine swing angle command according to the additional swing angle estimation value and the pre-compensation angle of the swing angle pre-compensation, so as to obtain the engine swing angle command after compensation and limitation;

[0075] The sending module is used to send the engine swing angle command after compensation and limiting to the servo controller.

[0076] The present application also provides a computer storage medium, wherein the computer storage medium stores computer instructions, and when the computer instructions are called, they are used to execute the address mapping method of the large-capacity solid-state hard disk. The computer storage medium contains one or more program instructions, and the one or more program instructions are used by the processor to execute a method for compensating the deformation of a launch vehicle engine frame.

[0077] An embodiment of the present invention provides a processor for processing the above-mentioned method for compensating the deformation of a carrier rocket engine frame.

[0078] The beneficial effects achieved by this application are as follows:

[0079] (1) After the frame deformation is compensated in this application, it can be ensured that there is no obvious additional swing angle in each working stage of the engine.

[0080] (2) The present application significantly reduces the attitude disturbance caused by the rapid change in frame deformation during engine startup and shutdown, and improves the safety during stage separation or the accuracy index when the payload enters orbit.

[0081] (3) If the auxiliary power system is used for attitude control after the main engine is shut down, the method for compensating the deformation of the launch vehicle engine frame of the present application can effectively reduce the propellant consumption of the auxiliary power system after shutdown.

[0082] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0083] In the description of the present application, the word "for example" is used to mean "used as an example, illustration or explanation". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any technician in the field to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0084] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for compensating the deformation of a launch vehicle engine frame, characterized in that: The method includes: The estimated value of the additional swing angle caused by the deformation of the engine frame under different thrusts is measured in advance through static tests; By adjusting the length of the servo mechanism, the swing angle of the engine frame is pre-compensated based on the original swing angle; According to the additional swing angle estimation value and the pre-compensation angle of the swing angle pre-compensation, the engine swing angle command is compensated and limited to obtain the engine swing angle command after compensation and limitation; The compensated and limited engine swing angle command is sent to the servo controller.

2. The method for compensating the deformation of a launch vehicle engine frame according to claim 1, characterized in that: The engine swing angle command is compensated and limited according to the additional swing angle estimation value and the pre-compensation angle of the swing angle pre-compensation, and the engine swing angle command after compensation and limitation is obtained, including: The engine swing angle command is compensated by using the additional swing angle estimate caused by the frame deformation measured by the ground static test; The compensated engine swing angle command is limited according to the maximum swing angle of the servo actuator.

3. The method for compensating the deformation of a launch vehicle engine frame according to claim 2, characterized in that: For a double-swing engine, the swing angle compensation and limiting method are shown in the following formula: in, Indicates the swing angle command of actuator A after swing angle compensation and limiting; Indicates the swing angle command of actuator B after swing angle compensation and limiting; It represents the estimated value of the additional swing angle caused by the deformation of the rack of channel A; It represents the estimated value of the additional swing angle caused by the deformation of the rack of channel B; Indicates the pre-compensation angle of the rack deformation of channel A; Indicates the pre-compensation angle of the rack deformation of channel B; Represents the original swing angle command of actuator A; Indicates the original swing angle command of actuator B; U δ Indicates the maximum swing angle of the servo actuator; represents the absolute value clipping function; |x| represents the absolute value of the independent variable.

4. The method for compensating the deformation of a launch vehicle engine frame according to claim 3, characterized in that: |x|≤U δ express The absolute value of the servo actuator is less than or equal to the maximum swing angle U δ .

5. The method for compensating the deformation of a launch vehicle engine frame according to claim 3, characterized in that: |x|≤U δ express The absolute value of the servo actuator is less than or equal to the maximum swing angle U δ .

6. The method for compensating the deformation of a launch vehicle engine frame according to claim 1, characterized in that: By adjusting the length of the servo mechanism, the engine frame is pre-compensated for the swing angle based on the original swing angle, including: Measure the additional swing angle caused by the deformation of the engine frame under nominal thrust; According to the nominal additional swing angle of the engine frame, the length of the servo mechanism is adjusted to pre-compensate the swing angle of the engine frame.

7. The method for compensating the deformation of a launch vehicle engine frame according to claim 6, characterized in that: During the process of pre-compensating the swing angle of the engine frame, the preset compensation angle is compensated to the engine frame.

8. The method for compensating the deformation of a carrier rocket engine frame according to claim 7, characterized in that: Preset compensation angle β 0 Satisfy 0≤β 0 ≤β norm ; Among them, β norm is the additional swing angle caused by the frame deformation under the nominal thrust of the engine.

9. The method for compensating the deformation of a launch vehicle engine frame according to claim 1, characterized in that: During the static test, the thrust is gradually increased. Each time the thrust is increased, wait for a while to allow the deformation of the engine frame to stabilize, and record the estimated value of the additional swing angle caused by the frame deformation under each thrust.

10. The method for compensating for the deformation of a launch vehicle engine frame according to claim 1, characterized in that: After the engine is started, the servo controller receives the engine swing angle instruction and adjusts the swing angle of the engine nozzle to restore the swing angle of the engine nozzle to the swing angle state of the engine nozzle when there is no frame deformation.

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