A method of ground correction for rocket separation test

Abstract

The present invention discloses a method for correction of the earth and sky of a rocket separation test, including simulating the separation between stages in the rocket flight state, collecting the horizontal separation speed #imgabs0# acceleration #imgabs1# of the lower stage test piece, establishing a dynamic simulation model according to the mass m1 of the slide rail vehicle, the mass m2 of the lower stage test piece, the thrust F of the reverse thrust engine, and the equivalent pendulum length l, and obtaining the simulated horizontal resultant force of the lower stage test piece according to the dynamic simulation model; obtaining the test horizontal resultant force according to the collected acceleration #imgabs2#, adjusting the equivalent friction coefficient μ, so that the error between the simulated horizontal resultant force of the lower stage test piece and the test horizontal resultant force is less than a set value, and obtaining the corresponding equivalent friction coefficient μ; adjusting the pendulum length l to a set value according to the obtained corresponding equivalent friction coefficient μ, correcting the ground separation speed to the separation speed in the rocket flight state, and completing the earth and sky correction of the rocket separation test. Through the present invention, the ground test data can be corrected to simulate the rocket separation process under the free separation condition more realistically.

Description

Technical Field

[0001] The invention relates to the field of aerospace, and in particular to a ground-to-space correction method for a rocket separation test. Background Art

[0002] In order to ensure the smooth separation of the rocket stages and the head body during the flight, the reverse thrust engine is usually used to push the lower stage of the rocket to separate from the upper stage at a certain speed. The separation speed is obtained through ground tests or simulation analysis to verify the feasibility of the separation system design. In terms of ground tests, the main test methods include horizontal separation by slings, vertical separation by slings, and air flotation separation. Horizontal separation by slings approximately balances the vertical gravity through the tension of the slings. The test device is simple, but the swing angle of the slings during the separation process will cause the vertical gravity to not be completely balanced with the tension of the slings, and there is a risk of reverberation and collision of the test piece; vertical separation by slings can truly simulate the free separation process, but additional control and protection devices are required to control the safe release of the test piece, which greatly increases the complexity and cost of the test; air flotation separation balances the vertical gravity through the air flotation device, which can better simulate the free separation process, but different separation tests require the design of matching pressure cabins and floating blocks. The test equipment is highly restricted, the versatility is low, and the test cost is high. In terms of simulation analysis, a dynamic simulation model can be established based on the thrust of the reverse thrust engine and the mass of the separation test piece, and the separation speed can be obtained through simulation. However, this process ignores factors such as the installation deviation of the reverse thrust engine and the asynchrony of the connection and separation device. It still cannot replace the ground test and it is difficult to fully and accurately simulate the free separation process in the sky. Therefore, it is of great significance to design a reasonable ground test and make appropriate corrections to simulate the separation process of the rocket in a free state in the air as realistically as possible to ensure the success of the flight. Summary of the invention

[0003] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for space-ground correction of a rocket separation test, comprising the following steps:

[0004] Step 1: Use the slide rail vehicle to hoist the test piece, and use the reverse thrust engine to push the lower stage test piece to simulate the interstage separation under the rocket flight state, and collect the horizontal separation speed of the lower stage test piece. Acceleration

[0005] Step 2: Establish a dynamic simulation model based on the mass of the slide rail vehicle m1, the mass of the lower stage test piece m2, the thrust of the reverse thrust engine F, and the equivalent pendulum length l, and obtain the simulated horizontal resultant force of the lower stage test piece based on the dynamic simulation model;

[0006] Step 3: Based on the collected acceleration The test horizontal resultant force is obtained, and the equivalent friction coefficient μ is adjusted so that the error between the simulated horizontal resultant force of the lower-level test piece and the test horizontal resultant force is less than the set value, and the corresponding equivalent friction coefficient μ is obtained;

[0007] Step 4: According to the corresponding equivalent friction coefficient μ, adjust the pendulum length l to the set value, correct the ground separation speed to the separation speed under the rocket flight state, and complete the ground correction of the rocket separation test.

[0008] Furthermore, the process of hoisting the test piece by the slide rail vehicle and pushing the lower stage test piece by the reverse thrust engine to simulate the stage separation under the rocket flight state includes the following process:

[0009] The rocket ground separation test uses a gantry crane slide rail and double slings for parallel lifting and separation to simulate the interstage separation process in flight. During the test, after the connection and separation device is unlocked, the reverse thrust engine pushes the lower stage test piece and the slide rail car to move to the right, and the locking mechanism prevents the slide rail car from moving back. During the process, a high-speed camera and a combined tester are used to measure the horizontal separation speed of the lower stage test piece. Acceleration

[0010] Furthermore, the dynamic simulation model is established according to the mass m1 of the slide rail vehicle, the mass m2 of the lower stage test piece, the thrust F of the reverse thrust engine, and the equivalent pendulum length l, including:

[0011] Establish a rectangular coordinate system with the slide car as the origin, and get the dynamic differential equation:

[0012]

[0013] Constraint equations:

[0014]

[0015] Geometric equations:

[0016]

[0017] The linear equations consisting of the combined dynamics and constraint equations are:

[0018]

[0019] Solving this linear equation system yields Then the dynamic differential equations are established:

[0020]

[0021] Where m1 is the mass of the slide rail car, m2 is the mass of the lower test piece, x1 is the horizontal displacement of the slide rail car, y1 is the vertical displacement of the slide rail car, x2 is the horizontal displacement of the lower test piece, y2 is the vertical displacement of the lower test piece, T is the tension of the sling, μ is the equivalent sliding friction coefficient, N is the support force of the slide rail, F is the thrust of the reverse thrust engine, g is the acceleration of gravity, l is the equivalent pendulum length, is the swing angle, Measured acceleration of the lower test piece, t f The observation time.

[0022] Furthermore, the adjustment of the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force of the lower-level test piece and the test horizontal resultant force is less than a set value includes:

[0023] Adjust the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force and the experimental horizontal resultant force of the lower-level test piece is less than the set value, using the following formula:

[0024]

[0025] The beneficial effects of the present invention are as follows: the method of the present invention corrects the simulation model parameters through ground separation test data, the ground test involved is simple, the posture of the test piece separation process is stable, and the collision of the test piece can be effectively avoided. After the ground test data is corrected, it can more realistically simulate the rocket separation process under free separation conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure is a flow chart of a method for space-ground correction in a rocket separation test;

[0027] Figure 2 Schematic diagram of the ground separation test principle;

[0028] Figure 3 Schematic diagram of the force analysis of the slide rail car and the lower test piece;

[0029] Figure 4 Ground test and simulation horizontal thrust and resultant force-time curve;

[0030] Figure 5 Ground test and simulation horizontal speed-time curve;

[0031] Figure 6 Corrected simulation horizontal velocity-time curve.

[0032] Among them, 1-upper stage test piece, 2-sling, 3-slide car, 4-castor, 5-gantry crane slide, 6-lower stage test piece, 7-reverse thrust engine, 8-ground, 9-high-speed camera. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention. It should be noted that relational terms such as the terms "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0036] Moreover, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a list of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus. In the absence of more restrictions, an element defined by the phrase "comprises a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0037] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0038] like Figure 1 As shown, a method for space-ground correction of a rocket separation test comprises the following steps:

[0039] Step 1: Use the slide rail vehicle to hoist the test piece, and use the reverse thrust engine to push the lower stage test piece to simulate the interstage separation under the rocket flight state, and collect the horizontal separation speed of the lower stage test piece. Acceleration

[0040] Step 2: Establish a dynamic simulation model based on the mass of the slide rail vehicle m1, the mass of the lower stage test piece m2, the thrust of the reverse thrust engine F, and the equivalent pendulum length l, and obtain the simulated horizontal resultant force of the lower stage test piece based on the dynamic simulation model;

[0041] Step 3: Based on the collected acceleration The test horizontal resultant force is obtained, and the equivalent friction coefficient μ is adjusted so that the error between the simulated horizontal resultant force of the lower-level test piece and the test horizontal resultant force is less than the set value, and the corresponding equivalent friction coefficient μ is obtained;

[0042] Step 4: According to the corresponding equivalent friction coefficient μ, adjust the pendulum length l to the set value, correct the ground separation speed to the separation speed under the rocket flight state, and complete the ground correction of the rocket separation test.

[0043] The process of hoisting the test piece by the slide rail vehicle and pushing the lower stage test piece by the reverse thrust engine to simulate the interstage separation under the rocket flight state includes the following steps:

[0044] The rocket ground separation test uses a gantry crane slide rail and double slings for parallel lifting and separation to simulate the interstage separation process in flight. During the test, after the connection and separation device is unlocked, the reverse thrust engine pushes the lower stage test piece and the slide rail car to move to the right, and the locking mechanism prevents the slide rail car from moving back. During the process, a high-speed camera and a combined tester are used to measure the horizontal separation speed of the lower stage test piece. Acceleration

[0045] The dynamic simulation model is established according to the mass m1 of the slide rail vehicle, the mass m2 of the lower stage test piece, the thrust F of the reverse thrust engine, and the equivalent pendulum length l, including:

[0046] Establish a rectangular coordinate system with the slide car as the origin, and get the dynamic differential equation:

[0047]

[0048] Constraint equations:

[0049]

[0050] Geometric equations:

[0051]

[0052] The linear equations consisting of dynamics and constraint equations are obtained:

[0053]

[0054] Solving the linear equations together, we get Then the dynamic differential equations are established:

[0055]

[0056] Where m1 is the mass of the slide rail car, m2 is the mass of the lower test piece, x1 is the horizontal displacement of the slide rail car, y1 is the vertical displacement of the slide rail car, x2 is the horizontal displacement of the lower test piece, y2 is the vertical displacement of the lower test piece, T is the tension of the sling, μ is the equivalent sliding friction coefficient, N is the support force of the slide rail, F is the thrust of the reverse thrust engine, g is the acceleration of gravity, l is the equivalent pendulum length, is the swing angle, Measured acceleration of the lower test piece, t f The observation time.

[0057] The adjustment of the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force and the test horizontal resultant force of the lower-level test piece is less than a set value includes:

[0058] Adjust the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force and the experimental horizontal resultant force of the lower-level test piece is less than the set value, using the following formula:

[0059]

[0060] Specifically, the present invention discloses a method for ground correction of rocket separation test, which uses ground test data to determine the relevant parameters of the dynamic simulation model, and corrects the ground separation speed to the separation speed in flight. The test adopts the gantry crane slide rail double sling parallel lifting separation. After the connection separation device is unlocked during the test, the reverse thrust engine pushes the lower stage to move to the right together with the slide rail car, and the locking mechanism prevents the slide rail car from moving back. During the process, a high-speed camera and a combined tester are used to measure the displacement, acceleration and other motion parameters. After the test, a dynamic simulation model is established, and the unknown parameters of the simulation model are corrected using the ground test data. Finally, the equivalent pendulum length of the corrected simulation model is adjusted to correct the ground separation speed to the separation speed in flight. The ground test of the method of the present invention is simple, the posture of the test piece separation process is stable, and the collision of the test piece can be effectively avoided. It can more realistically simulate the rocket separation process under free separation conditions.

[0061] The rocket ground separation test uses a gantry crane slide rail and double slings for parallel lifting and separation, thus simulating the interstage separation and head-body separation process under flight conditions. The separation test pieces mainly include the surface stage test pieces and the lower stage test pieces, such as Figure 2 During the test, after the connection and separation device is unlocked, the reverse thrust engine pushes the lower stage test piece and the slide vehicle to move to the right, and the locking mechanism prevents the slide vehicle from moving back. During the process, a high-speed camera and a combined tester are used to measure the displacement, acceleration and other motion parameters.

[0062] According to the test principle, the lower test piece performs a planar compound motion (ignoring the influence of the caster rotation), the involved motion is the horizontal motion of the slide rail car, and the relative motion is the rotation around the midpoint of the line connecting the two suspension points of the slide rail car. The rotation can be equivalent to a single pendulum motion with a pendulum length of l. The simplified force analysis of the slide rail car and the lower test piece is as follows: Figure 3 shown.

[0063] Establish as Figure 3 The rectangular coordinate system shown in the figure establishes the dynamic differential equation for the particle system:

[0064]

[0065] Constraint equations:

[0066]

[0067] Geometric equations:

[0068]

[0069] Combining the above equations, we get a linear system of equations consisting of dynamics and constraint equations:

[0070]

[0071] Solving this linear equation system yields Then the dynamic differential equations are established:

[0072]

[0073] Adjust the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force and the experimental horizontal resultant force of the lower-level test piece is minimized. Based on this, the following optimization problem can be established:

[0074]

[0075] After determining the equivalent friction coefficient μ of the simulation model, the pendulum length l is set to a sufficiently large value (such as l=1000m), so that the vertical direction is approximately balanced by force, and the horizontal direction is almost only subject to the thrust of the reverse thrust engine, thereby correcting the ground test data to the data of free separation during flight in the sky.

[0076] In the above formulas, m1 is the mass of the slide rail car, m2 is the mass of the lower test piece, x1 is the horizontal displacement of the slide rail car, y1 is the vertical displacement of the slide rail car, x2 is the horizontal displacement of the lower test piece, y2 is the vertical displacement of the lower test piece, T is the tension of the sling, μ is the equivalent sliding friction coefficient, N is the support force of the slide rail, F is the thrust of the reverse thrust engine, g is the acceleration of gravity, l is the equivalent pendulum length, is the swing angle, is the acceleration of the lower test piece measured by the combined tester, t fis the observation time. The superscripts “·” and “··” represent the first-order derivative and second-order derivative of the corresponding variable with respect to time, respectively.

[0077] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for space-ground correction in a rocket separation test, characterized in that: The steps include: Step 1: Use the slide rail vehicle to hoist the test piece, and use the reverse thrust engine to push the lower stage test piece to simulate the interstage separation under the rocket flight state, and collect the horizontal separation speed of the lower stage test piece. Acceleration Step 2: Establish a dynamic simulation model based on the mass of the slide rail vehicle m1, the mass of the lower stage test piece m2, the thrust of the reverse thrust engine F, and the equivalent pendulum length l, and obtain the simulated horizontal resultant force of the lower stage test piece based on the dynamic simulation model; Step 3: Based on the collected acceleration The test horizontal resultant force is obtained, and the equivalent friction coefficient μ is adjusted so that the error between the simulated horizontal resultant force of the lower-level test piece and the test horizontal resultant force is less than the set value, and the corresponding equivalent friction coefficient μ is obtained; Step 4: According to the corresponding equivalent friction coefficient μ, the pendulum length l is adjusted to the set value, and the ground separation speed is corrected to the separation speed under the rocket flight state, so as to complete the ground correction of the rocket separation test; The dynamic simulation model is established according to the mass m1 of the slide rail vehicle, the mass m2 of the lower stage test piece, the thrust F of the reverse thrust engine, and the equivalent pendulum length l, including: Establish a rectangular coordinate system with the slide car as the origin, and get the dynamic differential equation: Constraint equations: Geometric equations: The linear equations consisting of dynamics and constraint equations are obtained: Solving this linear equation system yields Then the dynamic differential equations are established: Where m1 is the mass of the slide rail car, m2 is the mass of the lower test piece, x1 is the horizontal displacement of the slide rail car, y1 is the vertical displacement of the slide rail car, x2 is the horizontal displacement of the lower test piece, y2 is the vertical displacement of the lower test piece, T is the tension of the sling, μ is the equivalent sliding friction coefficient, N is the support force of the slide rail, F is the thrust of the reverse thrust engine, g is the acceleration of gravity, l is the equivalent pendulum length, is the swing angle, Measured acceleration of the lower test piece, t f The observation time.

2. The method for space-ground correction of a rocket separation test according to claim 1, characterized in that: The process of hoisting the test piece by the slide rail vehicle and pushing the lower stage test piece by the reverse thrust engine to simulate the interstage separation under the rocket flight state includes the following steps: The rocket ground separation test uses a gantry crane slide rail and double slings for parallel lifting and separation to simulate the interstage separation process in flight. During the test, after the connection and separation device is unlocked, the reverse thrust engine pushes the lower stage test piece and the slide rail car to move to the right, and the locking mechanism prevents the slide rail car from moving back. During the process, a high-speed camera and a combined tester are used to measure the horizontal separation speed of the lower stage test piece. Acceleration 3. The method for space-ground correction of a rocket separation test according to claim 1, characterized in that: The adjustment of the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force and the test horizontal resultant force of the lower-level test piece is less than a set value includes: Adjust the equivalent friction coefficient μ so that the error between the simulated horizontal resultant force and the experimental horizontal resultant force of the lower-level test piece is less than the set value, using the following formula:

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