Carrier rocket trajectory safety margin design method based on calibration test run parameters

Abstract

The invention discloses a carrier rocket trajectory safety margin design method based on calibration test run parameters. The carrier rocket trajectory safety margin design method comprises the steps that the maximum safety margin x01 of a cluster binding level is estimated; performing equal-interval value taking in an interval of [0, x01] to obtain a safety margin value of a group of cluster binding stages; acquiring a reference trajectory corresponding to each cluster binding level safety margin value, performing targeting simulation based on the reference trajectory, and determining an optimal value of the cluster binding level safety margin value; estimating the maximum safety margin x02 of the second level; performing equal-interval value taking in the interval of [0, x02] to obtain a group of secondary safety margin values; and S3, obtaining a reference trajectory corresponding to each secondary safety margin value based on the optimal value of the cluster binding level safety margin value obtained in the step S3, performing targeting simulation based on the reference trajectory, determining the optimal value of the secondary safety margin value, and further obtaining the optimal value of the tertiary safety margin value. According to the method, the optimal distribution of the safety margins of all levels of the clustered carrier rocket can be realized, so that the carrying capacity is maximized.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid launch vehicle trajectory design, and relates to a safety margin design method for multi-stage liquid rocket propellant, and in particular to a launch vehicle trajectory safety margin design method based on calibration test parameters. Background Art

[0002] The carrying capacity is one of the most important core indicators of a launch vehicle and is also the main goal to be optimized in the overall design of the rocket. For liquid rockets, the carrying capacity is generally the total mass of the rocket's last stage entering orbit minus the structural mass of the stop point, the unusable amount of propellant, the safety margin, etc., so the choice of the safety margin is closely related to the carrying capacity.

[0003] The purpose of retaining a safety margin of propellant is to cope with various deviations that occur during the flight. If too little is retained, it will not be able to fully cope with flight deviations and the probability of the rocket entering orbit out of tolerance will increase. If too much is retained, it will affect the rocket's carrying capacity.

[0004] At present, some design methods for safety margin of liquid launch vehicle propellant have been publicly published. In the invention patent "A launch vehicle safety margin design method based on probability statistics" (patent number CN 116720257A), a safety margin design method based on probability statistics is given. This method optimizes the distribution of different fuel oxygen safety margins to achieve overall performance optimization. In the article "Safety Margin Analysis of a New Generation of Medium Launch Vehicles Based on Ballistic Guidance Joint Simulation" in the Journal of Ballistics, Ma Ying et al. proposed a safety margin design method based on ballistic guidance joint simulation, studied the impact of the safety margin of each stage of a two-and-a-half-stage configuration rocket on the carrying capacity, and optimized the rocket's carrying capacity. However, on the one hand, these methods do not provide a design method for the filling amount and safety margin of a cluster-separated bundled rocket. On the other hand, these methods are all aimed at launch vehicles with two-stage or two-and-a-half-stage configurations, and cannot be applied to cluster-type three-stage or multi-stage launch vehicles.

[0005] For clustered three-stage or multi-stage rockets, the filling amount and safety margin of the clustered stage need to be optimized. In addition, the deviation of the rocket is transferable. The deviation of the clustered stage, the second stage and the third stage will be transmitted from bottom to top, so the safety margins of each stage will be coupled with each other, and there will also be mutual influence between the modules of the clustered stage itself. For three-stage or multi-stage rockets, this coupling makes it difficult to optimize the safety margins of each stage. Therefore, the design method of the ballistic propellant safety margin of clustered three-stage or multi-stage launch vehicles is a technical problem that needs to be studied and solved.

[0006] In addition, the optimal design result of the safety margin is closely related to the engine performance parameters. In engineering practice, the original data of the rocket from the design stage to the actual launch stage may change, especially after the engine calibration test, the engine thrust, flow, specific impulse and other performance parameters will have a non-negligible impact on the design results. How to optimally design the rocket's filling volume and safety margin based on the engine calibration test parameters is also a technical difficulty in engineering. Summary of the invention

[0007] The purpose of the present invention is to overcome the above defects and provide a method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters, which solves the technical problem that the coupling of the existing clustered bundled stage, the second stage and the third stage makes it difficult to optimize the safety margin of each stage. The present invention can achieve the optimal allocation of the safety margin of each stage of the clustered launch vehicle, so as to maximize the carrying capacity.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] A method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters includes:

[0010] S1 estimates the maximum safety margin x of the bundled level 01 ;

[0011] S2 in [0, x 01 ] and obtain a set of safety margin values ​​of the bundled level;

[0012] S3 obtains the reference trajectory corresponding to each cluster-binding-level safety margin value, performs target shooting simulation based on the reference trajectory, and determines the optimal value of the cluster-binding-level safety margin value;

[0013] S4 Estimate the maximum safety margin x of the secondary 02 ;

[0014] S5 in [0, x 02 ] and obtain a set of secondary safety margin values;

[0015] S6 obtains the reference trajectory corresponding to each secondary safety margin value based on the optimal value of the cluster-level safety margin value obtained in step S3, performs target shooting simulation based on the reference trajectory, determines the optimal value of the secondary safety margin value, and then obtains the optimal value of the tertiary safety margin value.

[0016] Furthermore, the maximum safety margin is a safety margin under a 99.7% guided shutdown probability.

[0017] Furthermore, the maximum safety margin x of the cluster level is estimated based on the engine test performance parameters or theoretical performance parameters. 01Or the maximum safety margin x of the second level 02 ;

[0018] The engine test performance parameters or theoretical performance parameters include the flight average mixture ratio K and the mixture ratio deviation ΔK.

[0019] Furthermore, the maximum safety margin of the bundled level, the second level, or the third level is collectively referred to as x0:

[0020]

[0021] Where η is the constant safety factor, is the rated working reserve of oxidizer, is the rated working reserve of the fuel;

[0022] Maximum safety margin of oxidant Δm o and the maximum safety margin of the fuel Δm f =x0-Δm o The ratio is determined by the following formula:

[0023]

[0024] Furthermore, in step S3, when obtaining the reference trajectory corresponding to the safety margin value of each cluster binding level, the second-level safety margin is set to 0kg, and the third-level safety margin is set to the maximum safety margin x of the third level. 03 .

[0025] Furthermore, in step S3, the method for determining the optimal value of the safety margin value of the cluster bundling level according to the target shooting simulation result of the reference trajectory includes:

[0026] S3.1 Determine the guidance shutdown amount for each level of each reference trajectory and add the guidance algorithm to each reference trajectory to obtain a zero-interference guided trajectory;

[0027] S3.2 For each zero-interference guided trajectory, add various deviations in the actual flight process in the clustering and third levels, set the shutdown mode to guidance shutdown, do not add any deviation in the second level, set the shutdown mode to timed shutdown, and perform n target shooting simulations; n ≥ 10000;

[0028] S3.3 Based on the target shooting simulation results of each zero-interference guided trajectory, the exhaustion probability of the cluster bundle level and the corresponding carrying capacity of each corresponding reference trajectory are obtained;

[0029] S3.4 Select the preset safety margin of the cluster level corresponding to the reference trajectory with the largest carrying capacity, which is the optimal value of the safety margin of the cluster level.

[0030] Furthermore, in step S3.3, according to the target shooting simulation results, the method for obtaining the corresponding carrying capacity under different exhaustion probabilities of the cluster bundling level includes:

[0031] According to the target shooting simulation results of each zero-interference guided trajectory, the exhaustion probability of the cluster bundling level is calculated;

[0032] According to the target shooting simulation results, the remaining amount of propellant in the third stage under the 3σ orbital probability is calculated;

[0033] According to the remaining amount of propellant in the third stage, the third stage safety margin m under the 3σ orbital probability is obtained. sf :

[0034]

[0035] Among them, m f0 and m o0 They are the remaining amount of the third-stage incendiary agent and oxidizer for the zero-interference guidance trajectory, and is the statistical mean of the remaining amount of the three-stage combustor and oxidizer in n target shooting simulations, σ mf and σ of is the standard deviation of the remaining amount of the third-stage combustor and oxidizer for n target shooting simulations;

[0036] According to m sf The corresponding carrying capacity m under different exhaustion probabilities of the cluster bundling level is obtained c :

[0037] m c =m pl +(m ry -m sf -m un );

[0038] Among them, m pl is the effective load mass; m ry is the nominal total remaining amount of propellant, i.e. the total remaining amount of the reference ballistic propellant; m un The unusable amount of propellant.

[0039] Furthermore, in step S3.2, various deviations during the actual flight process include method error, tool error and unguided error;

[0040] Method errors include deviations in mass parameters and mass characteristics, engine parameters or aerodynamic parameters;

[0041] Tool errors include errors of inertial devices plus meters and gyroscopes;

[0042] Unguided errors include initial rocket alignment errors and engine aftereffect deviations.

[0043] Furthermore, in step S6, when obtaining the reference trajectory corresponding to each secondary safety margin value, the safety margin of the clustering level is set to the optimal value of the safety margin value of the clustering level determined in step S3;

[0044] In step S6, the method for determining the optimal value of the cluster-binding level safety margin value according to the target shooting simulation result of the reference trajectory includes:

[0045] S6.1 Determine the guidance shutdown amount for each level of each reference trajectory and add the guidance algorithm to each reference trajectory to obtain a zero-interference guided trajectory;

[0046] S6.2 For each zero-interference guided trajectory, add various deviations in the actual flight process to the cluster bundle level, second level, and third level at the same time, and set each level to be guided off, and perform n target shooting simulations; n ≥ 10000;

[0047] S6.3 Based on the target shooting simulation results of each zero-interference guided trajectory, the corresponding secondary exhaustion probability and corresponding carrying capacity of each reference trajectory are obtained;

[0048] S6.4 Select the reference trajectory with the largest carrying capacity. The corresponding second-level preset safety margin is the optimal value of the second-level safety margin. The corresponding third-level safety margin m under the 3σ orbital probability is sf It is the optimal value of the third-level safety margin.

[0049] Furthermore, the engine calibration test parameters mainly include fuel flow, oxidant flow, specific impulse, mixture ratio, etc.;

[0050] Furthermore, the reference theoretical filling amount of each stage of the rocket is determined according to the following method:

[0051] First, all modules of this level are set to full filling state, then a standard trajectory is calculated, the working time of the module that is exhausted first is set as the common working time of all modules, the filling amount of this module is set to full filling state, and then the filling amount of other modules is reduced until all modules are exhausted at the same time;

[0052] The module is a fuel box or an oxygen box.

[0053] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0054] (1) The present invention provides for the first time an optimal safety margin design method for each module of the basic stage of a cluster-type rocket, thereby maximizing the use of the carrying capacity of the cluster-type rocket;

[0055] (2) The present invention takes into account the matching of the filling amount of each module of the basic stage of the clustered bundled rocket with the safety margin and the calibration test, which can further improve the resource utilization rate and the carrying capacity of the rocket;

[0056] (3) The present invention decouples the optimization of the cluster bundling level and the secondary safety margin to solve the problem, thus avoiding the problem scale surge caused by too many optimization levels and making it difficult to solve;

[0057] (4) Compared with existing methods, this method is not only applicable to two-stage rockets, but also to three-stage and multi-stage rockets, and it realizes the decoupling of the safety margin optimization problem at each stage, thereby maximizing the rocket's carrying capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a schematic diagram of a cluster-type three-stage rocket;

[0059] Figure 2 This is a safety margin optimization flow chart of the present invention. DETAILED DESCRIPTION

[0060] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0061] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0062] The safety margin design method of the cluster three-stage rocket based on the engine calibration test is to first optimize the safety margin of the cluster bundled stage, that is, the booster stage and the core stage according to the test parameters, and then optimize the safety margin of the core stage 2 on this basis, and at the same time obtain the safety margin of the core stage 3. Figure 1 The process of this method is shown in Figure 2 This method is also applicable to cluster multi-stage rockets. The following takes a three-stage cluster rocket as an example to give the specific implementation steps.

[0063] first step:

[0064] After the calibration test of the engine of the whole rocket is completed, the benchmark theoretical filling amount of each stage of the rocket is designed according to the fuel flow rate and oxidizer flow rate of the calibration test. If there is no calibration test parameter, the theoretical rated value of the engine is used.

[0065] The design principle of the cluster stage's filling quantity is to enable each module to shut down simultaneously under the standard theoretical performance parameters, so as to reduce the flight dead weight and carrying capacity loss caused by unequal engine working time. The specific design method is to first set each fuel tank and oxygen tank of the cluster stage to a full filling state, then calculate a standard trajectory, set the working time of the module that is exhausted first as the common working time of all modules, and the filling quantity of this module is set to a full filling state, and then reduce the filling quantity of other modules until all modules are exhausted at the same time. The filling quantity design method of the second and third stages of the rocket is the same as that of the cluster stage.

[0066] Step 2:

[0067] Estimate the safety margin of the cluster-binding stage under the 99.7% (3σ) guidance shutdown probability, which is called the maximum safety margin. According to the engine test performance parameters or theoretical performance parameters, mainly the flight average mixture ratio K and the mixture ratio deviation ΔK, estimate the maximum safety margin of each module of the cluster-binding stage.

[0068] The estimation formula for the maximum safety margin of each level is as follows:

[0069]

[0070] Where η is a constant safety factor, which is 1.2 in the initial optimization. is the rated working reserve of oxidizer, is the rated working reserve of the fuel. The maximum safety margin of the oxidizer is Δm o and the maximum safety margin of the fuel Δm f =x0-Δm o The ratio is determined by the formula

[0071]

[0072] After the maximum safety margin is calculated, a set of safety margins are taken at equal intervals between 0 and the maximum safety margin, such as 100%, 80%, 60%, 40%, 20%, and 0% of the maximum safety margin, and then the optimal value of this set of safety margins is optimized.

[0073] Step 3:

[0074] According to the different safety margins that need to be optimized in the previous step, the benchmark trajectory cluster design is carried out. In this round of benchmark trajectory design, the second-level safety margin is set to 0kg, and the third-level safety margin is temporarily set to the maximum safety margin according to the estimation method in the previous step (Formula (1)).

[0075] Step 4:

[0076] According to the design results of the benchmark trajectory, the guidance shutdown amount of each stage of each trajectory is determined, and the guidance algorithm is added to complete the design of the zero-interference guided trajectory.

[0077] Next, we consider the various deviations in the actual flight process, which can be roughly divided into method errors, tool errors and unguided errors. Method errors mainly include mass parameter and mass characteristic deviations, engine parameter deviations, aerodynamic parameter deviations, etc.; tool errors mainly include inertial device table and gyroscope errors; unguided errors mainly consider the initial alignment error of the rocket and the aftereffect deviation of the engine. Generate pseudo-random numbers based on the statistical characteristics of each deviation and add them to the mathematical model of rocket flight.

[0078] For the above deviations that exist at all levels, these deviations are taken into account in the cluster and third levels, and the shutdown mode is set to guided shutdown, while the second level does not add any deviations and the shutdown mode is set to timed shutdown. Then, 10,000 Monte Carlo target simulations are carried out for each reference trajectory to obtain 10,000 interference trajectories.

[0079] Step 5:

[0080] The target shooting simulation results of the previous step are counted. For each benchmark trajectory, the exhaustion probability of the cluster bundle stage is counted, and the remaining amount of the three-stage propellant is counted under the premise of ensuring the probability of 3σ guidance shutdown and orbit entry. The mean and variance of the remaining amount of the three-stage propellant are as follows

[0081]

[0082] Where n is the number of simulated shooting, m is fi is the actual remaining amount of the incendiary agent for the i-th target shooting, is the mean of the residual quantity; σ mf is the standard deviation of the residual amount. The mean of the residual amount of oxidant and standard deviation σ mo The third-level safety margin m under the 3σ orbital probability is calculated in the same way. sf for

[0083]

[0084] Where m f0 and m o0 are the remaining amount of the third-stage incendiary agent and oxidizer of the zero-interference ballistic trajectory. Thus, the corresponding carrying capacity under different exhaustion probabilities of the cluster bundle stage can be obtained.

[0085] m c =m pl +(m ry -m sf -m un ) (5)

[0086] In the formula, m pl is the effective load mass, m ry is the nominal total remaining amount of propellant, m un The unusable amount of propellant.

[0087] The preset safety margin of the cluster-bundling level with the largest carrying capacity among the reference trajectories is selected, and the optimal value in the group of safety margins is the preset safety margin of the corresponding cluster-bundling level.

[0088] This determines the optimal safety margin for the cluster bundling level.

[0089] Step 6:

[0090] The same method is used for the second level. First, the maximum safety margin of the second level is calculated according to formula (1), and then a set of safety margins are taken at equal intervals between 0 and the maximum safety margin. When designing this round of benchmark trajectory, the safety margin of the cluster bundling level is set to the optimal safety margin of the cluster bundling level obtained in the previous step, and there is no need to set the third level safety margin. Then, all deviations are added to the cluster bundling level, the second level, and the third level at the same time. All levels are set to guidance shutdown, and 10,000 Monte Carlo target simulations are carried out.

[0091] Step 7:

[0092] The secondary exhaustion probability is calculated, and the tertiary safety margin is calculated under the premise of ensuring the 3σ orbital probability, so as to obtain the carrying capacity under different secondary exhaustion probabilities, and then the one with the largest carrying capacity in each benchmark trajectory is selected, and the corresponding secondary preset safety margin is the optimal value in the group of safety margins. In this way, the optimal safety margin of the secondary is determined. At the same time, the corresponding tertiary safety margin m sf It can also be calculated.

[0093] This results in the optimal safety margin for each stage of the cluster launch vehicle.

[0094] The present invention is a design method for the ballistic propellant safety margin of a clustered three-stage or multi-stage launch vehicle based on engine calibration test parameters. By matching the booster and first-stage filling amounts and decoupling and optimizing the safety margins of the basic stage, the second stage and the third stage, the optimal allocation of the safety margins of each stage of the clustered launch vehicle is achieved, thereby maximizing the carrying capacity.

[0095] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0096] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters, characterized in that: include: S1 estimates the maximum safety margin x of the bundled level 01 ; S2 in [0, x 01 ] and obtain a set of safety margin values ​​of the bundled level; S3 obtains the reference trajectory corresponding to each cluster-binding-level safety margin value, performs target shooting simulation based on the reference trajectory, and determines the optimal value of the cluster-binding-level safety margin value; S4 Estimate the maximum safety margin x of the secondary 02 ; S5 in [0, x 02 ] and obtain a set of secondary safety margin values; S6 obtains the reference trajectory corresponding to each secondary safety margin value based on the optimal value of the cluster-level safety margin value obtained in step S3, performs target shooting simulation based on the reference trajectory, determines the optimal value of the secondary safety margin value, and then obtains the optimal value of the tertiary safety margin value.

2. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 1, characterized in that: The maximum safety margin is the safety margin under 99.7% guided shutdown probability.

3. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 1, characterized in that: Estimate the maximum safety margin x of the cluster level based on the engine test performance parameters or theoretical performance parameters 01 Or the maximum safety margin x of the second level 02 ; The engine test performance parameters or theoretical performance parameters include the flight average mixture ratio K and the mixture ratio deviation ΔK.

4. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 3 is characterized in that: The maximum safety margin of the bundled, secondary or tertiary level is collectively referred to as x0: Where η is the constant safety factor, is the rated working reserve of oxidizer, is the rated working reserve of the fuel; Maximum safety margin of oxidant Δm o and the maximum safety margin of the fuel Δm f =x0-Δm o The ratio is determined by the following formula:

5. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 1, characterized in that: In step S3, when obtaining the reference trajectory corresponding to the safety margin value of each cluster binding level, the second-level safety margin is set to 0kg, and the third-level safety margin is set to the maximum safety margin x of the third level. 03 .

6. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 1, characterized in that: In step S3, the method for determining the optimal value of the cluster bundling level safety margin value according to the target shooting simulation result of the reference trajectory includes: S3.1 Determine the guidance shutdown amount for each level of each reference trajectory and add the guidance algorithm to each reference trajectory to obtain a zero-interference guided trajectory; S3.2 For each zero-interference guided trajectory, add various deviations in the actual flight process in the clustering and third levels, set the shutdown mode to guidance shutdown, do not add any deviation in the second level, set the shutdown mode to timed shutdown, and perform n target shooting simulations; n ≥ 10000; S3.3 Based on the target shooting simulation results of each zero-interference guided trajectory, the exhaustion probability of the cluster bundle level and the corresponding carrying capacity of each corresponding reference trajectory are obtained; S3.4 Select the preset safety margin of the cluster level corresponding to the reference trajectory with the largest carrying capacity, which is the optimal value of the safety margin of the cluster level.

7. A method for designing a launch vehicle trajectory safety margin based on calibration test parameters according to claim 6, characterized in that: In step S3.3, according to the target shooting simulation results, the method for obtaining the corresponding carrying capacity under different exhaustion probabilities of the cluster bundling level includes: According to the target shooting simulation results of each zero-interference guided trajectory, the exhaustion probability of the cluster bundling level is calculated; According to the target shooting simulation results, the remaining amount of propellant in the third stage under the 3σ orbital probability is calculated; According to the remaining amount of propellant in the third stage, the third stage safety margin m under the 3σ orbital probability is obtained. sf : Among them, m f0 and m o0 They are the remaining amount of the third-stage incendiary agent and oxidizer for the zero-interference guidance trajectory, and is the statistical mean of the remaining amount of the three-stage combustor and oxidizer in n target shooting simulations, σ mf and σ of is the standard deviation of the remaining amount of the third-stage combustor and oxidizer for n target shooting simulations; According to m sf The corresponding carrying capacity m under different exhaustion probabilities of the cluster bundling level is obtained c : m c =m pl +(m ry -m sf -m un ); Among them, m pl is the effective load mass; m ry is the nominal total remaining amount of propellant, i.e. the total remaining amount of the reference ballistic propellant; m un The unusable amount of propellant.

8. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 6, characterized in that: In step S3.2, the various deviations in the actual flight process include method error, tool error and unguided error; Method errors include deviations in mass parameters and mass characteristics, engine parameters or aerodynamic parameters; Tool errors include errors of inertial devices plus meters and gyroscopes; Unguided errors include initial rocket alignment errors and engine aftereffect deviations.

9. The method for designing the trajectory safety margin of a launch vehicle based on calibration test parameters according to claim 1, characterized in that: In step S6, when obtaining the reference trajectory corresponding to each secondary safety margin value, the safety margin of the clustering level is set to the optimal value of the safety margin of the clustering level determined in step S3; In step S6, the method for determining the optimal value of the cluster-binding level safety margin value according to the target shooting simulation result of the reference trajectory includes: S6.1 Determine the guidance shutdown amount for each level of each reference trajectory and add the guidance algorithm to each reference trajectory to obtain a zero-interference guided trajectory; S6.2 For each zero-interference guided trajectory, add various deviations in the actual flight process to the cluster bundle level, second level, and third level at the same time, and set each level to be guided off, and perform n target shooting simulations; n ≥ 10000; S6.3 Based on the target shooting simulation results of each zero-interference guided trajectory, the corresponding secondary exhaustion probability and corresponding carrying capacity of each reference trajectory are obtained; S6.4 Select the reference trajectory with the largest carrying capacity. The corresponding second-level preset safety margin is the optimal value of the second-level safety margin. The corresponding third-level safety margin m under the 3σ orbital probability is sf It is the optimal value of the third-level safety margin.

10. A method for designing a launch vehicle trajectory safety margin based on calibration test parameters according to claim 9, characterized in that: Also includes: Engine calibration test parameters mainly include fuel flow, oxidant flow, specific impulse, mixing ratio, etc. The baseline theoretical filling amount for each stage of the rocket is determined as follows: First, all modules of this level are set to full filling state, then a standard trajectory is calculated, the working time of the module that is exhausted first is set as the common working time of all modules, the filling amount of this module is set to full filling state, and then the filling amount of other modules is reduced until all modules are exhausted at the same time; The module is a fuel box or an oxygen box.

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