Track control safety shutdown time calculation method suitable for deep space exploration

Abstract

The invention discloses an orbit control safety shutdown time calculation method suitable for deep space exploration, and belongs to the field of deep space exploration. The method comprises the steps that firstly, the theoretical speed increment of orbit control is calculated, and a sinking engine, an orbit control engine, an attitude control engine and related engine thrust and specific impulse parameters are determined; secondly, the actual orbit control speed increment is obtained, and the orbit control nominal starting time length is determined; thirdly, calculating time error deviation, and giving out engine shutdown forbidding time and forced shutdown time in the orbit control process; if the task is a conventional orbit control task, taking the two times as final safe shutdown time; for the orbit control task related to safety, multiple groups of shutdown forbidding time and forced shutdown time under the nominal working condition and the pulling deviation working condition are given, and finally the safety shutdown time of the orbit control task related to safety is determined. According to the method, the track safety and task safety of the detector are ensured by selecting proper shutdown forbidding time and forced shutdown time.

Description

Technical Field

[0001] The invention relates to a method for calculating orbit control safety shutdown time suitable for deep space exploration, and belongs to the technical field of spacecraft orbit control. Background Art

[0002] Orbital control is the most common flight action in the probe's on-orbit mission. As deep space exploration missions gradually reflect the characteristics of multi-target and multi-task, future exploration missions may involve dozens of orbital control missions. The implementation results of the previous orbital control mission directly affect the subsequent orbital control strategy. For example, if the previous orbital control ignition time is too long, it will cause changes in key parameters such as orbital configuration and propellant consumption, affecting the subsequent key exploration links. Therefore, the completion of each orbital control will directly determine whether the entire mission can be carried out normally as planned.

[0003] During the orbit control execution process, the length of time the orbit control engine is turned on directly affects the final orbit control effect. Usually, the probe determines the orbit control speed increment by integrating the accelerometer measurement results, and when the target speed increment is reached, the orbit control engine is automatically triggered to shut down. However, due to factors such as the measurement error of the accelerometer itself, the calculation deviation of the onboard computer, and the control error of the orbit control actuator, the probe may not be able to shut down accurately according to the established target speed increment during the orbit control process. In order to ensure the safety of the probe's orbit and the implementation of subsequent tasks according to the established goals, the orbit control engine shutdown prohibition time T is set during the orbit control process. offmin And forced shutdown time T offmax , and recorded to the control system computer as the orbit control startup time safety threshold to protect the detector orbit safety and mission safety. For different types of orbit control tasks, the shutdown time T is prohibited. offmin And forced shutdown time T offmax The design process is different. Track control includes different types of track control such as mid-course correction, braking, track lowering, track lifting, and phase adjustment.

[0004] In early lunar exploration missions, the safety design of orbital control was achieved through the prohibited shutdown ignition duration proportional factor and the forced shutdown ignition duration proportional factor in orbital control. The proportional factor was determined by formula or engineering experience, and there was no risk for most orbital controls. However, for some orbital controls involving safety, it is not safe to determine only by formula or engineering experience. Before the orbit lowering process of Russia's Luna-25 probe, the forced shutdown ignition duration proportional factor was set to 1.5 according to engineering experience, which caused the probe to eventually hit the moon and the mission failed. Therefore, for this kind of dangerous orbital control, it is necessary to set the operating conditions according to the range of engine thrust, specific impulse and probe mass, and confirm through multiple orbital extrapolations that the prohibited shutdown time and forced shutdown time are set reasonably, and confirm that the orbit is safe and there is no risk of hitting celestial bodies and escaping.

[0005] Track control involving safety includes braking, lowering the track, etc. For this type of track control, the engine shutdown time T offmin And forced shutdown time T offmax The rationality of parameter design will affect the results of track control implementation:

[0006] 1) If the track control start time is short, it will cause changes in the track cycle, track height, and track configuration after control. For example, if the shutdown time T is prohibited offmin The design is small, and the speed increment is low after the engine shutdown is triggered at this point in time. The probe will not be able to orbit the moon normally if it does not enter the influence of the moon's gravitational field, or the altitude of the lunar orbit is high after the shutdown is triggered at this time, and the semi-major axis and period of the orbit will change, which will have a direct impact on subsequent key links.

[0007] 2) If the orbit control startup time is too long, the orbit height after control is too low, resulting in a small height margin for the subsequent orbit lowering mission of the probe or the orbit height being lower than the safety threshold, and there is a risk of collision with the moon. offmax The design is large. After the shutdown is triggered at this time, when the probe's flight orbit altitude is reduced, the risk of subsequent orbit reduction missions will increase, and it may even collide with the surface of a celestial body.

[0008] Therefore, for orbit control tasks involving safety, further orbit safety analysis and safety analysis of subsequent tasks are needed. Summary of the invention

[0009] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose a method for calculating the safe shutdown time of orbital control suitable for deep space exploration, so as to ensure the orbital safety and mission safety of the probe by selecting appropriate prohibited shutdown time and forced shutdown time.

[0010] The technical solution of the present invention is:

[0011] A method for calculating orbit control safety shutdown time applicable to deep space exploration, comprising:

[0012] S1: Determine the initial mass m of the probe before orbit control 0 and initial mass deviation Δm 0 ;

[0013] S2: According to the nominal orbit control time, the probe's orbit is accurately determined in advance, and the orbital elements at the orbit control time are predicted. According to the orbit control target, the theoretical velocity increment of the orbit control is calculated, and the bottom engine, orbit control engine and attitude control engine, as well as the related engine thrust and specific impulse parameters are determined.

[0014] S3: According to the theoretical speed increment and the above engine specification parameters, the bottom speed increment and the aftereffect speed increment are calculated to obtain the actual orbit control speed increment and determine the orbit control nominal start-up time;

[0015] S4: According to the orbit control objectives, the orbit control tasks are divided into conventional orbit control tasks and orbit control tasks involving safety;

[0016] S5: For the two orbit control tasks, the time error deviation is calculated according to the nominal start-up time of orbit control, and the engine shutdown prohibition time T of the orbit control process is given. offmin And forced shutdown time T offmax ; If it is a regular orbit control task, the engine shutdown prohibition time T will be given offmin And forced shutdown time T offmax As a final safe shutdown time;

[0017] S6: For track control tasks involving safety: determine the set of safety threshold constraints, and give multiple sets of shutdown prohibition times T under nominal conditions and deviation conditions through track dynamics simulation offmin And forced shutdown time T offmax , and then compared with the engine shutdown prohibition time T given in step S5 offmin And forced shutdown time T offmax The comparison was performed to determine the safe shutdown time for safety-related track control tasks.

[0018] Furthermore, in step S3, the method for calculating the bottom velocity increment and the aftereffect velocity increment is:

[0019] The speed increment of the bottom engine is:

[0020]

[0021] Where, t cis the total working time of the bottom engine, F c To perform bottom engine thrust, I c Control engine specific impulse for orbit;

[0022] Calculate the mass of the detector after sinking to the bottom and update it to the initial quality of orbital control;

[0023] The after-effect velocity increment is:

[0024] ΔV h =ΔV s1 +ΔV s2 +ΔV s3 +ΔV p

[0025] Where ΔV s1 , ΔV s2 , ΔV s3 The speed increment caused by the shutdown command generation delay, the shutdown command sending delay, and the shutdown command execution delay for the control system; is the aftereffect impulse I of the thrust reduction process after the engine is shut down p The speed increase caused.

[0026] Furthermore, in step S3, the actual track control speed increment is:

[0027] ΔV=ΔV 0 -ΔV c -ΔV h

[0028] Where ΔV 0 is the theoretical speed increment for orbit control;

[0029] The nominal start-up time of track control is:

[0030]

[0031] Where g is the gravitational acceleration, F g is the thrust of the orbit control engine, Δm is the propellant consumption during the orbit control process, expressed as:

[0032]

[0033] Further, in step S2, the engine use strategy for orbit control and the attitude control engine use strategy during orbit control are determined according to the probe engine use principle, and the bottom engine thrust F is determined. c and deviation ΔF c , bottom engine specific impulse I c and deviation ΔI c , orbit control engine thrust Fg and deviation ΔF g 、Orbit Control Engine Specific Impulse I g and deviation ΔI g , attitude control engine thrust F z and deviation ΔF z 、Attitude control engine specific impulse I z and deviation ΔI z .

[0034] Further, in step S5, the time error deviation is calculated according to the nominal start-up time of the track control, specifically:

[0035] The time error deviation is divided into the time error caused by parameter uncertainty, the time error caused by sinking, and the time error caused by attitude control;

[0036] Time deviation dt caused by parameter uncertainty g It is the sum of the time errors caused by the detector mass deviation, orbit control engine thrust deviation, and orbit control engine specific impulse deviation;

[0037] Time error dt caused by sinking c It is the sum of the time errors caused by the detector mass deviation, the bottom engine thrust deviation, and the bottom engine specific impulse deviation;

[0038] Time error dt caused by attitude control z The time deviation caused by the attitude control engine maintaining the probe attitude.

[0039] Further, in step S5, the engine shutdown prohibition time T of the track control process is given according to the calculated time error deviation. offmin And forced shutdown time T offmax :

[0040] T offmin =t-dt g -dt c -dt z

[0041] T offmax =t+dt g +dt c +dt z

[0042] Where t is the nominal start-up time of track control.

[0043] Furthermore, in step S6, a security threshold constraint set is determined, and the constraints in the set include:

[0044] Constraint 1: The additional consumption caused by the shutdown time design may be less than the remaining propellant of the probe;

[0045] Constraint 2: Constraints for different orbital control mission objectives: For the gravitational capture mission, the minimum ignition duration of the probe to capture the target celestial body’s gravitational region is given; for the orbit lowering mission, the minimum safe threshold for the orbital altitude is given; for the orbital control mission with multiple targets on orbit, the safe distance threshold between the two probes is given; if there are complex mission-related requirements, a set of constraints on orbit, time, and fuel consumption is given.

[0046] Furthermore, in step S6, for the track control task involving safety: multiple groups of shutdown prohibition times T under nominal working conditions and pull-off working conditions are given through track dynamics simulation. offmin And forced shutdown time T offmax Among them, the pulling deviation working conditions include at least two types, namely, the working condition considering the minimum thrust, maximum specific impulse and the maximum initial mass of the detector, and the working condition considering the maximum thrust, minimum specific impulse and the minimum initial mass of the detector.

[0047] Furthermore, in step S6, the track dynamics simulation of the nominal operating condition and all the pull-away operating conditions must satisfy the safety threshold constraint set.

[0048] Further, in step S1, the initial mass m of the detector before orbit control is determined 0 , the calculation method is:

[0049] m 0 =m fs -Δm g -Δm z -Δm other

[0050] In the formula, m fs is the mass characteristic measurement data of the detector before launch, Δm g is the propellant consumption for orbit control, Δm z is the attitude control propellant consumption, Δm other Factors that affect the quality of the detector include possible separation of the instrument and the rocket, and separation between instruments.

[0051] The advantages of the present invention compared with the prior art are:

[0052] The present invention improves the reliability of the shutdown time design of the probe by carrying out theoretical calculations on the safe duration of orbital control and verifies it through multi-operating condition simulation analysis, thereby achieving safe shutdown of the orbital control during the probe's in-orbit flight process. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0054] Figure 1 This is a flow chart of a method for calculating the safety shutdown time of track control according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0056] The present invention proposes a method for calculating the orbit control safety shutdown time suitable for deep space exploration, such as Figure 1 As shown, including:

[0057] S1: Based on the mass characteristics of the detector before launch, m is measured fs , orbit control propellant consumption Δm g , attitude control propellant consumption Δm z And possible factors affecting the detector quality such as instrument-arrow separation, separation between instruments, sample transfer, etc. other , determine the initial mass m of the detector before orbit control 0 =m fs -Δm g -Δm z -Δm other and initial mass deviation Δm 0 ;

[0058] S2: According to the nominal orbit control time, the probe is accurately orbited in advance, and the orbital elements F = (a, e, i, Ω, ω, γ) are predicted at the orbit control time, where a, e, i, Ω, ω, γ represent the orbital semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee and true anomaly respectively. According to the orbit control target and the current orbit determination data, the theoretical velocity increment ΔV of the orbit control is calculated. 0 According to the theoretical speed increment ΔV 0 , determine the engine use strategy for orbit control and the attitude control engine use strategy during orbit control, and determine the bottom engine thrust F c and deviation ΔF c , bottom engine specific impulse I cand deviation ΔI c , orbit control engine thrust F g and deviation ΔF g 、Orbit Control Engine Specific Impulse I g and deviation ΔI g , attitude control engine thrust F z and deviation ΔF z 、Attitude control engine specific impulse I z and deviation ΔI z The engine thrust and specific impulse related parameters are determined by the ground hot test results.

[0059] S3: According to the theoretical speed increment and engine selection during the orbit control process, calculate the orbit control speed increment ΔV after deducting the bottom speed increment and the aftereffect speed increment = ΔV 0 -ΔV c -ΔV h .

[0060] The speed increment of the bottom engine is expressed as:

[0061]

[0062] Among them, t c is the total working time of the sinking engine. If two engines are used to sink for 30 seconds, then t c = 60s. Calculate the mass of the detector after sinking to the bottom And update it to the initial mass of the track control.

[0063] The aftereffect velocity increment is expressed as:

[0064] ΔV h =ΔV s1 +ΔV s2 +ΔV s3 +ΔV p

[0065] Where, ΔV s1 , ΔV s2 , ΔV s3 The speed increment caused by the shutdown command generation delay, the shutdown command sending delay, and the shutdown command execution delay for the control system; is the aftereffect impulse I of the thrust reduction process after the engine is shut down p The speed increase caused.

[0066] The track control startup time can be expressed as:

[0067]

[0068] Where g is the gravitational acceleration, which is 9.80665 m / s 2, Δm is the propellant consumption during orbit control, expressed as:

[0069]

[0070] S4: According to different orbital control objectives, orbital control tasks are divided into conventional orbital control tasks and orbital control tasks involving safety. Orbital control tasks include different types of orbital control such as mid-course correction, braking, orbit lowering, phase adjustment, and orbit raising. Orbital control involving safety includes orbital control tasks such as braking and orbit lowering that may directly lead to failure of the exploration mission, such as escaping from the gravitational sphere of celestial bodies and colliding with the moon, and also orbital control tasks involving multiple probes operating in orbit at the same time.

[0071] S5: For the two orbital control tasks in step S4, calculate the engine shutdown prohibition time T of the orbital control process according to the orbital control strategy and the engine selection. offmin And forced shutdown time T offmax , which includes time errors caused by factors such as parameter uncertainty, sinking, attitude control, and actuators:

[0072] 1) Based on theoretical analysis and a large number of experimental verifications, combined with engineering experience, the time error dt caused by parameter uncertainty g It can be expressed as the sum of the time errors caused by the detector mass deviation, orbit control engine thrust deviation, and orbit control engine specific impulse deviation.

[0073]

[0074] Where m and dm are the mass and mass deviation of the detector after sinking to the bottom, respectively. g and dF g are the thrust and thrust error of the orbit control engine, I g and dI g are the specific impulse and specific impulse error of the orbit control engine, respectively, and ΔV is the orbit control velocity increment. It should be noted that when the probe uses two 150N engines to ignite, the thrust and deviation should be the sum of the two engines.

[0075] 2) The time error caused by sinking can be expressed as the sum of the time errors caused by the detector mass deviation, the sinking engine thrust deviation, and the sinking engine specific impulse deviation.

[0076]

[0077]

[0078] Among them, m c and DM c are the initial mass of the detector m 0and initial mass deviation, F c and dF c are respectively the thrust and thrust error of the bottom engine, dI c is the specific impulse error of the bottom engine, ΔV c is the sinking velocity increment.

[0079] 3) Since the orbit control process needs to maintain the probe's attitude, the attitude control engine will generate additional thrust, affecting the minimum and maximum orbit change durations. The time error caused by attitude control is:

[0080]

[0081] Where m is the mass of the detector after sinking to the bottom, ΔV 1 is the attitude control velocity increment, which can be considered as the maximum orbit control velocity increment. max The maximum disturbance torque of the orbit control process, D is the lever arm of the probe attitude control engine.

[0082] 4) The time error caused by the actuator includes the delay of the control system generating the shutdown command, the delay of the control system sending the shutdown command, dt s3 is the execution delay of the engine shutdown command and the aftereffect impulse I generated by the thrust reduction process after the engine is shut down p This part of the time error has been considered in step S3 by deducting the aftereffect speed increment, and will not be considered again here.

[0083] 5) The prohibited shutdown time and the forced shutdown time can be expressed as the nominal startup time t of the track control and the time error dt g ,dt c ,dt z The relationship between

[0084] T offmin =t-dt g -dt c -dt z

[0085] T offmax =t+dt g +dt c +dt z

[0086] S6: For orbital control tasks involving safety, determine the safety threshold constraints according to different orbital control mission objectives. In order to ensure that the subsequent missions of the probe can be executed, it is necessary to make a detailed budget for the propellant consumption and ensure that the additional consumption that may be caused by the shutdown time design is f Less than the remaining propellant in the probe It should be noted that the remaining propellant of the probe needs to be updated during the flight mission according to the execution of the previous orbital control during the mission execution. For the gravity capture mission, the minimum ignition time t of the probe captured in the gravity region of the target celestial body is given min ; For the orbit lowering mission, the minimum safe threshold of orbit height h is given min ; For the orbit control task of multiple targets on orbit, the safe distance threshold d between the two detectors is given min ; If the subsequent mission has complex mission requirements such as timed and fixed-point landing, the constraint set of orbit elements and time is given through dynamic simulation data. The above type of orbit control safety threshold can be expressed as a set of constraint items:

[0087]

[0088] S7: Set simulation conditions according to the deviation range of engine thrust, specific impulse and initial mass of the probe to verify orbit control safety and mission safety. In addition to the nominal conditions, consider the conditions of minimum thrust, maximum specific impulse and maximum initial mass of the probe and the conditions of maximum thrust, minimum specific impulse and minimum initial mass of the probe. The orbital dynamics simulation of the nominal condition and the two conditions of deviation should meet the safety threshold constraint set C determined in step S6, that is:

[0089]

[0090] Adjust the shutdown prohibition time T in track dynamics simulation offmin And forced shutdown time T offmax , so that the above constraints are satisfied, and three groups of shutdown prohibition times T under nominal working conditions and two pull-bias working conditions are given offmin And forced shutdown time T offmax ;

[0091] By comparing the multiple groups of shutdown prohibition time T given in step S5 and step S7 offmin And forced shutdown time T offmax , and finally determine the safe shutdown time of the track control task involving safety. Among them, the shutdown time T offmin Take the calculated value in step S5 and the maximum value of the three sets of simulation values ​​in step S7, and the forced shutdown time T offmax The calculated value in step S5 and the minimum value of the three groups of simulation values ​​in step S7 are taken to ensure the safe execution of the probe orbit control process.

[0092] The orbital control safety shutdown time calculation method proposed in the present invention can be applied to complex deep space exploration missions, especially orbital control missions involving safety. By selecting appropriate prohibited shutdown time and forced shutdown time, the orbital safety and mission safety of the detector can be ensured while ensuring the achievement of orbital control goals, thereby improving the safety of the implementation of the exploration mission.

[0093] The above-described embodiments are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating orbital control safety shutdown time suitable for deep space exploration, characterized in that: include: S1: Determine the initial mass m0 and initial mass deviation Δm0 before the detector orbit control; S2: According to the nominal orbit control time, the probe's orbit is accurately determined in advance, and the orbital elements at the orbit control time are predicted. According to the orbit control target, the theoretical velocity increment of the orbit control is calculated, and the bottom engine, orbit control engine and attitude control engine, as well as the related engine thrust and specific impulse parameters are determined. S3: According to the theoretical speed increment and the above engine specification parameters, the bottom speed increment and the aftereffect speed increment are calculated to obtain the actual orbit control speed increment and determine the orbit control nominal start-up time; S4: According to the orbit control objectives, the orbit control tasks are divided into conventional orbit control tasks and orbit control tasks involving safety; S5: For the two orbit control tasks, the time error deviation is calculated according to the nominal start-up time of orbit control, and the engine shutdown prohibition time T of the orbit control process is given. offmin And forced shutdown time T offmax ; If it is a conventional orbit control task, the engine shutdown prohibition time T will be given offmin And forced shutdown time T offmax As a final safe shutdown time; S6: For track control tasks involving safety: determine the set of safety threshold constraints, and give multiple sets of shutdown prohibition times T under nominal conditions and deviation conditions through track dynamics simulation offmin And forced shutdown time T offmax , and then compared with the engine shutdown prohibition time T given in step S5 offmin And forced shutdown time T offmax The comparison was performed to determine the safe shutdown time for safety-related track control tasks.

2. The method for calculating the track control safety shutdown time according to claim 1, characterized in that: In step S3, the method for calculating the bottom velocity increment and the aftereffect velocity increment is: The speed increment of the bottom engine is: Where, t c is the total working time of the bottom engine, F c To perform bottom engine thrust, I c Control engine specific impulse for orbit; Calculate the mass of the detector after sinking to the bottom and update it to the initial quality of orbital control; The after-effect velocity increment is: ΔV h =ΔV s1 +ΔV s2 +ΔV s3 +ΔV p Where ΔV s1 , ΔV s2 , ΔV s3 The speed increment caused by the shutdown command generation delay, the shutdown command sending delay, and the shutdown command execution delay for the control system; is the aftereffect impulse I of the thrust reduction process after the engine is shut down p The speed increase caused.

3. The method for calculating the track control safety shutdown time according to claim 2, characterized in that: In step S3, the actual track control speed increment is: ΔV=ΔV0-ΔV c -ΔV h Where ΔV0 is the theoretical speed increment of orbit control; The nominal start-up time of track control is: Where g is the gravitational acceleration, F g is the thrust of the orbit control engine, Δm is the propellant consumption during the orbit control process, expressed as:

4. The method for calculating the track control safety shutdown time according to claim 2, characterized in that: In step S2, the engine use strategy for orbit control and the attitude control engine use strategy during orbit control are determined according to the probe engine use principle, and the bottom engine thrust F is determined. c and deviation ΔF c , bottom engine specific impulse I c and deviation ΔI c , orbit control engine thrust F g and deviation ΔF g 、Orbit Control Engine Specific Impulse I g and deviation ΔI g , attitude control engine thrust F z and deviation ΔF z 、Attitude control engine specific impulse I z and deviation ΔI z .

5. The method for calculating the track control safety shutdown time according to claim 1, characterized in that: In step S5, the time error deviation is calculated according to the nominal start-up time of the track control, specifically: The time error deviation is divided into the time error caused by parameter uncertainty, the time error caused by sinking, and the time error caused by attitude control; Time deviation dt caused by parameter uncertainty g It is the sum of the time errors caused by the detector mass deviation, orbit control engine thrust deviation, and orbit control engine specific impulse deviation: Where dm is the mass deviation of the detector after sinking to the bottom, dF g is the thrust error of the orbit control engine, dI g is the specific impulse error of the orbit control engine; Time error dt caused by sinking c It is the sum of the time errors caused by the detector mass deviation, the bottom engine thrust deviation, and the bottom engine specific impulse deviation: Where, dm c is the detector initial mass deviation, F c and dF c are respectively the thrust and thrust error of the bottom engine, dI c is the specific impulse error of the bottom engine, F g Control engine thrust for orbit; Time error dt caused by attitude control z The time deviation caused by the attitude control engine to maintain the probe attitude: Where, dF z is the attitude control engine thrust error, T max is the maximum disturbance torque in the orbit control process, and D is the lever arm of the probe attitude control engine.

6. The method for calculating the track control safety shutdown time according to claim 1, characterized in that: In step S5, the engine shutdown prohibition time T of the track control process is given according to the calculated time error deviation. offmin And forced shutdown time T offmax : T offmin =t-dt g -dt c -dt z T offmax =t+dt g +dt c +dt z Where t is the nominal start-up time of track control.

7. The method for calculating the track control safety shutdown time according to claim 1, characterized in that: In step S6, a security threshold constraint set is determined, and the constraints in the set include: Constraint 1: The additional consumption caused by the shutdown time design may be less than the remaining propellant of the probe; Constraint 2: Constraints for different orbital control mission objectives: For the gravitational capture mission, the minimum ignition duration of the probe to capture the target celestial body’s gravitational region is given; for the orbit lowering mission, the minimum safe threshold for the orbital altitude is given; for the orbital control mission with multiple targets on orbit, the safe distance threshold between the two probes is given; if there are complex mission-related requirements, a set of constraints on orbit, time, and fuel consumption is given.

8. The method for calculating the track control safety shutdown time according to claim 1, characterized in that: In step S6, for the track control task involving safety: multiple groups of shutdown prohibition times T under nominal working conditions and yaw working conditions are given through track dynamics simulation. offmin And forced shutdown time T offmax Among them, the pulling deviation working conditions include at least two types, namely, the working condition considering the minimum thrust, maximum specific impulse and the maximum initial mass of the detector, and the working condition considering the maximum thrust, minimum specific impulse and the minimum initial mass of the detector.

9. The method for calculating the track control safety shutdown time according to claim 1 or 8, characterized in that: In step S6, the track dynamics simulation of the nominal operating condition and all the pull-away operating conditions must satisfy the safety threshold constraint set.

10. The method for calculating the track control safety shutdown time according to claim 1, characterized in that: In step S1, the initial mass m0 of the detector before orbit control is determined, and the calculation method is: m0=m fs -Δm g -Δm z -Δm other In the formula, m fs is the mass characteristic measurement data of the detector before launch, Δm g is the propellant consumption for orbit control, Δm z is the attitude control propellant consumption, Δm other Factors that affect the quality of the detector include possible separation of the instrument and the rocket, and separation between instruments.

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