Method and device for planning lunar sampling, fixed-time fixed-point landing and fixed-time takeoff

Abstract

The invention discloses a method and device for planning fixed-time fixed-point landing and fixed-time takeoff of lunar sampling, and the method comprises the steps: determining the six orbit elements and orbit injection time of an orbit in which a first control stage is located, and the nominal parameters of fixed-time fixed-point landing and fixed-time takeoff in the lunar sampling task according to the first control stage in the lunar sampling task; and according to the nominal parameter, the six orbit elements and the orbit injection time, performing joint planning on the first control stage and the subsequent control stage to obtain a first deviation, and performing iteration on the first deviation according to the first variable. And when the first deviation is smaller than a convergence threshold, determining a target variable of the first control stage, so that the satellite achieves fixed-time fixed-point landing and fixed-time takeoff based on the target variable of each control stage, thereby realizing dynamic joint planning by taking fixed-time fixed-point landing and fixed-time takeoff as a final target in each control. The control reconstruction capability of the task is effectively improved, additional control is avoided, and meanwhile resource consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the field of aerospace, and in particular to a method and a device for planning lunar sampling, landing at a fixed time, and taking off at a fixed point. Background Art

[0002] Landing and takeoff control is one of the risks and technical challenges faced by extraterrestrial exploration missions, and has always been a hot topic for scholars and engineers at home and abroad. The flight practice of the later period of the "Apollo" project showed that the probe can accurately land at the predetermined position on the lunar surface and achieve a fixed-point landing.

[0003] The entire orbital flight process of the lunar sample return mission includes launch, Earth-Moon transfer, near-Moon braking, circumlunar flight, lunar powered descent, lunar work, lunar powered ascent, rendezvous and docking, lunar-Earth transfer, and reentry and recovery. Many scholars at home and abroad have conducted in-depth research on the design methods of lunar fixed-point landing orbits, including aiming at the predetermined landing point longitude by adjusting the number of lunar landing circles and the circumlunar orbital plane, and aiming at the predetermined lunar landing point latitude and powered descent point altitude by adjusting the velocity increment and orbit change position in the circumlunar descent plane. Among them, the adjustment of the circumlunar orbital plane can be achieved by adjusting the ascending node right ascension and correcting the orbital inclination. However, there are problems that require additional control and additional resource consumption.

[0004] Therefore, how to achieve scheduled, fixed-point, and scheduled takeoff while avoiding additional control and reducing resource consumption is a problem that needs to be solved urgently. Summary of the invention

[0005] The embodiment of the present invention provides a method and device for planning lunar sampling timed, fixed-point, landing and timed takeoff, which are used to realize dynamic joint planning with timed, fixed-point, landing and timed takeoff as the ultimate goal for each control from the first mid-course correction of the Earth-Moon transfer stage to the last orbit descent before landing, effectively improving the control reconstruction capability of the mission, avoiding additional control, and reducing resource consumption.

[0006] In a first aspect, an embodiment of the present invention provides a method for planning a lunar sampling timing, fixed-point, landing, and timing takeoff, comprising:

[0007] For the first control phase of the lunar sampling mission, determine the six orbital numbers and orbit entry time of the orbit in which the first control phase is located, as well as the nominal parameters of the timed, point-fixed landing and timed takeoff in the lunar sampling mission. The six orbital numbers are the parameters required to describe the movement of the satellite in the Keplerian orbit, and the nominal parameters include the nominal landing time, the nominal landing point and the nominal takeoff time.

[0008] According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control stage and the subsequent control stage in the lunar sampling mission are jointly planned to obtain a first deviation, and the first deviation is iterated according to a first variable; the first deviation is a deviation between the satellite and the nominal parameters when landing and taking off on the moon, and the first variable is a variable related to time and / or orbital plane in the first control stage and the subsequent control stage in the lunar sampling mission;

[0009] When the first deviation is less than the convergence threshold, the target variable of the first control stage is determined so that the satellite can achieve the timing, point, and take-off based on the target variables of each control stage.

[0010] In the above technical scheme, the lunar sampling mission includes multiple control stages. For the first control stage, it is first necessary to determine the six orbital numbers and the orbit entry time of the current orbit. The six orbital numbers are the parameters required to describe the movement of the satellite on the Kepler orbit, specifically including the semi-major axis, eccentricity, orbital inclination, ascending node ecliptic longitude, perigee argument, and true anomaly. Then determine the nominal parameters for the scheduled landing and takeoff in the lunar sampling mission. Then, according to the nominal parameters, the six orbital numbers of the orbit in the first control stage and the orbit entry time, the first control stage and the subsequent control stage are jointly planned to obtain the first deviation. The first deviation is the deviation between the satellite and the nominal parameters when landing and taking off on the moon. The nominal parameters include the planned landing time, landing site, and take-off site. Therefore, the first deviation can include the landing time deviation, the landing site deviation, and the take-off site deviation. Then, the first deviation is iterated according to the first variable. The landing time deviation in the first deviation is related to the orbital time, and the landing site deviation and take-off site deviation are related to the orbital plane. Therefore, the first variable is a variable related to time and / or orbital plane in the first control stage and the subsequent control stages in the lunar sampling mission. Finally, when the first deviation is iterated to be less than the convergence threshold, the target variable of the first control stage is determined. When each control stage executes the above process, the target variable of each control stage is obtained, and the timed, fixed-point, and timed landing and take-off can be achieved based on the target variables of each control stage. From the first mid-course correction of the Earth-Moon transfer stage to the last orbit reduction before landing, each control is dynamically jointly planned with the ultimate goal of timed, fixed-point, and timed landing and take-off, which effectively improves the control reconstruction capability of the mission, avoids additional control, and reduces resource consumption.

[0011] Optionally, the control phase of the lunar sampling mission includes: mid-course correction, first near-moon braking, second near-moon braking, third near-moon braking, first circumlunar orbit descent, second circumlunar orbit descent, phase adjustment of the orbit-return assembly, powered descent, and lunar takeoff.

[0012] Optionally, according to the nominal parameters, the six orbital numbers, and the orbital entry time, jointly planning the first control phase with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and iterating the first deviation according to a first variable, including:

[0013] For the mid-course correction control phase in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the mid-course correction control phase is located and the orbit entry time, the mid-course correction control phase is jointly planned with the first near-moon braking, the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control phases in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the take-off longitude deviation;

[0014] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the orbital inclination after mid-course correction, the yaw angle of three near-moon brakings and the semi-major axis of the target orbit after the third near-moon braking.

[0015] Optionally, according to the nominal parameters, the six orbital numbers, and the orbital entry time, jointly planning the first control phase with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and iterating the first deviation according to a first variable, including:

[0016] For the first near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the first near-moon braking control stage is located and the orbit entry time, the first near-moon braking control stage is jointly planned with the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation;

[0017] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the first near-moon braking, the yaw angles of the second and third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

[0018] Optionally, according to the nominal parameters, the six orbital numbers, and the orbital entry time, jointly planning the first control phase with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and iterating the first deviation according to a first variable, including:

[0019] For the second near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the second near-moon braking control stage is located, and the orbit entry time, the second near-moon braking control stage is jointly planned with the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent, and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation, and the takeoff longitude deviation;

[0020] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the second near-moon braking, the yaw angle of the third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

[0021] Optionally, according to the nominal parameters, the six orbital numbers, and the orbital entry time, jointly planning the first control phase with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and iterating the first deviation according to a first variable, including:

[0022] For the third near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the third near-moon braking control stage is located and the orbit entry time, the third near-moon braking control stage is jointly planned with the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation;

[0023] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the third near-moon braking, the yaw angles of the two circumlunar descent orbits and the semi-major axis of the target orbit after the third near-moon braking.

[0024] Optionally, according to the nominal parameters, the six orbital numbers, and the orbital entry time, jointly planning the first control phase with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and iterating the first deviation according to a first variable, including:

[0025] For the first lunar orbit descent control phase in the lunar sampling mission, according to the nominal parameters, the six orbit numbers of the orbit in the first lunar orbit descent control phase and the orbit entry time, the first lunar orbit descent control phase is jointly planned with the second lunar orbit descent and powered descent control phases in the lunar sampling mission to obtain the landing longitude deviation;

[0026] Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angles of the two lunar descending orbits.

[0027] Optionally, according to the nominal parameters, the six orbital numbers, and the orbital entry time, jointly planning the first control phase with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and iterating the first deviation according to a first variable, including:

[0028] For the second lunar orbit descent control phase in the lunar sampling mission, the second lunar orbit descent control phase is jointly planned with the powered descent control phase in the lunar sampling mission according to the nominal parameters, the six orbital numbers of the orbit in the second lunar orbit descent control phase, and the orbit entry time, to obtain the landing longitude deviation;

[0029] Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angle of the second descent orbit around the moon.

[0030] In a second aspect, an embodiment of the present invention provides a device for planning a lunar sampling timing, fixed point, landing and timing takeoff, including:

[0031] An acquisition module is used to determine, for the first control phase of the lunar sampling mission, six orbital numbers and orbit entry time of the orbit in which the first control phase is located, as well as nominal parameters for timed, point-fixed landing and timed takeoff in the lunar sampling mission. The six orbital numbers are parameters required to describe the movement of the satellite in the Keplerian orbit, and the nominal parameters include nominal landing time, nominal landing point and nominal takeoff time;

[0032] a processing module, configured to jointly plan the first control phase with a subsequent control phase in the lunar sampling mission according to the nominal parameters, the six orbital numbers, and the orbital entry time, obtain a first deviation, and iterate the first deviation according to a first variable; the first deviation is a deviation between the satellite and the nominal parameters when landing and taking off on the moon, and the first variable is a variable related to time and / or orbital plane in the first control phase and the subsequent control phase in the lunar sampling mission;

[0033] When the first deviation is less than the convergence threshold, the target variable of the first control stage is determined so that the satellite can achieve the timing, point, and take-off based on the target variables of each control stage.

[0034] Optionally, the control phase of the lunar sampling mission includes: mid-course correction, first near-moon braking, second near-moon braking, third near-moon braking, first circumlunar orbit descent, second circumlunar orbit descent, phase adjustment of the orbit-return assembly, powered descent, and lunar takeoff.

[0035] Optionally, the processing module is specifically used for:

[0036] For the mid-course correction control phase in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the mid-course correction control phase is located and the orbit entry time, the mid-course correction control phase is jointly planned with the first near-moon braking, the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control phases in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the take-off longitude deviation;

[0037] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the orbital inclination after mid-course correction, the yaw angle of three near-moon brakings and the semi-major axis of the target orbit after the third near-moon braking.

[0038] Optionally, the processing module is specifically used for:

[0039] For the first near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the first near-moon braking control stage is located and the orbit entry time, the first near-moon braking control stage is jointly planned with the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation;

[0040] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the first near-moon braking, the yaw angles of the second and third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

[0041] Optionally, the processing module is specifically used for:

[0042] For the second near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the second near-moon braking control stage is located, and the orbit entry time, the second near-moon braking control stage is jointly planned with the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent, and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation, and the takeoff longitude deviation;

[0043] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the second near-moon braking, the yaw angle of the third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

[0044] Optionally, the processing module is specifically used for:

[0045] For the third near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the third near-moon braking control stage is located and the orbit entry time, the third near-moon braking control stage is jointly planned with the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation;

[0046] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the third near-moon braking, the yaw angles of the two circumlunar descent orbits and the semi-major axis of the target orbit after the third near-moon braking.

[0047] Optionally, the processing module is specifically used for:

[0048] For the first lunar orbit descent control phase in the lunar sampling mission, according to the nominal parameters, the six orbit numbers of the orbit in the first lunar orbit descent control phase and the orbit entry time, the first lunar orbit descent control phase is jointly planned with the second lunar orbit descent and powered descent control phases in the lunar sampling mission to obtain the landing longitude deviation;

[0049] Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angles of the two lunar descending orbits.

[0050] Optionally, the processing module is specifically used for:

[0051] For the second lunar orbit descent control phase in the lunar sampling mission, the second lunar orbit descent control phase is jointly planned with the powered descent control phase in the lunar sampling mission according to the nominal parameters, the six orbital numbers of the orbit in the second lunar orbit descent control phase, and the orbit entry time, to obtain the landing longitude deviation;

[0052] Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angle of the second descent orbit around the moon.

[0053] In a third aspect, an embodiment of the present invention further provides a computer device, including:

[0054] A memory for storing program instructions;

[0055] The processor is used to call the program instructions stored in the memory and execute the above-mentioned method for planning lunar sampling, timing, fixed-point landing and timing takeoff according to the obtained program.

[0056] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the above-mentioned method for planning lunar sampling, timing, point, landing and takeoff.

[0057] In a fifth aspect, an embodiment of the present invention further provides a computer program product, which includes an executable program, and the executable program is executed by a processor to implement the above-mentioned method for planning lunar sampling, timing, fixed-point landing and timing takeoff. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 A schematic diagram of a detector architecture provided by an embodiment of the present invention;

[0060] Figure 2 A schematic diagram of a type of lunar sample return mission provided by an embodiment of the present invention;

[0061] Figure 3 A schematic diagram of a prograde orbit lunar northern hemisphere sampling landing and takeoff provided by an embodiment of the present invention;

[0062] Figure 4 A schematic diagram of a prograde orbit lunar southern hemisphere sampling landing and takeoff provided by an embodiment of the present invention;

[0063] Figure 5 A schematic diagram of a retrograde orbit lunar northern hemisphere sampling landing and takeoff provided by an embodiment of the present invention;

[0064] Figure 6 A schematic diagram of a retrograde orbit lunar southern hemisphere sampling landing and takeoff provided by an embodiment of the present invention;

[0065] Figure 7 A schematic diagram of a system architecture provided by an embodiment of the present invention;

[0066] Figure 8 A flow chart of a method for planning a lunar sampling timing, fixed-point, landing, and timing takeoff provided by an embodiment of the present invention;

[0067] Fig. 9 A schematic diagram of the structure of a device for planning lunar sampling, timing, point, landing and takeoff provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0068] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] The application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions protected by the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. It is known to those of ordinary skill in the art that with the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems. The terms "first" and "second" in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0070] Before introducing a method for planning lunar sampling, timing, point-to-point landing and timing takeoff provided in an embodiment of the present application, in order to facilitate understanding, the following terms and background technologies involved in the embodiment of the present application are first introduced.

[0071] Landing and takeoff control is one of the risks and technical challenges faced by extraterrestrial exploration missions, and has always been a hot topic for domestic and foreign scholars and engineers. The flight practice of the later period of the "Apollo" project showed that the probe could accurately land at the predetermined position on the lunar surface and achieve a fixed-point landing. Under the guidance of the three-step strategy of "orbiting", "landing" and "returning" of the lunar exploration project, China has conducted early research on fixed-point landing control and the content is relatively comprehensive. The commonly used orbit change strategies to achieve fixed-point landing include circle adjustment, phase adjustment orbit and orbital plane adjustment. Chang'e-4 proposed the mission goal of soft landing on the back of the moon for the first time. Compared with the Chang'e-3 mission, the landing area has been greatly reduced. In addition, the measurement and control constraints under the occlusion of the back of the moon make the flight program arrangement more compact, which has led to the mission requirements of timing and fixed-point landing control. For this problem, scholars proposed a semi-analytical solution method for timed and fixed-point landing control based on the evolution characteristics of orbital deviation with perturbation and the advantages of analytical and numerical methods, realizing the rapid and accurate solution of lunar landing control parameters; and proposed a full-course orbit control design method, which carried out segmented design and joint planning for the full-course orbital control of Earth-Moon transfer, near-moon braking, circumlunar orbit descent and powered descent, ensuring the timed and fixed-point lunar landing under the condition of orbital deviation. As the final battle of the third phase of lunar exploration, Chang'e 5 must achieve the goal of "return". As one of the most complex and difficult tasks in China's aerospace at that time, the requirements for timed and fixed-point landing were more stringent due to the limitations of the sampling area range and sampling time. In addition, in order to save the fuel consumption of orbital correction during the long-range guidance of the ascender to the greatest extent, the task requirements of timed coplanar takeoff were proposed for the first time. In response to this problem, scholars established an analytical model for calculating the takeoff azimuth and the initial value of the takeoff time, derived the mapping relationship between the orbital plane deviation of the long-range guidance terminal and the orbital parameter deviation of the entry point, and established an iterative solution model to achieve a "virtual" coplanar takeoff.

[0072] Chang'e-6, which has developed into the fourth phase of lunar exploration, has upgraded its mission goal to the first return of samples from the far side of the moon, and the scope of the sampling area has been greatly reduced compared to Chang'e-5. Due to the obstruction of the far side of the moon, the mission introduced the Queqiao-2 relay satellite operating in the frozen orbit of the moon to work together. The Queqiao-2 relay satellite provided measurement and control support during the key stages of power descent, lunar surface sampling and lunar surface takeoff. The restriction of the sampling area and the addition of relay satellites have put forward higher requirements for the control of scheduled, fixed-point, and scheduled landing and takeoff. In addition, the change in the location of the sampling area and the first use of the lunar retrograde orbit around the moon have led to changes in the geometric relationships such as power descent and lunar surface takeoff, which determines that the scheduled, fixed-point, and scheduled landing and takeoff control algorithms cannot simply inherit Chang'e-5, and need to be re-derived and designed.

[0073] The probe of the lunar sampling return mission based on lunar orbit rendezvous and docking generally includes an orbiter, a lander, an ascender and a returner, such as Figure 1Among them, the orbiter is used for maneuvering control during Earth-Moon transfer, near-Moon braking, waiting in the lunar circle, lunar-Earth impact, and Moon-Earth transfer. The lander is used for powered descent and lunar orbit control before powered descent. The ascender is used for takeoff from the lunar surface and rendezvous and docking with the orbiter-returner assembly. The returner is used to carry lunar samples and return to the ground.

[0074] Taking the Chang'e-5 mission as an example, the return flight process based on the lunar orbit rendezvous and docking can generally be divided into 11 stages, namely the launch stage, Earth-Moon transfer stage, near-Moon braking stage, lunar circumlunar flight stage, powered descent stage, lunar surface work stage, lunar surface takeoff stage, rendezvous and docking stage, lunar circumlunar waiting stage, lunar-Earth transfer stage and reentry recovery stage. The following introduces some of these stages and the controls they contain.

[0075] The Earth-Moon transfer phase starts from the separation of the probe and the launch vehicle until it reaches the perigee, and the transfer time is about 5 days. Three mid-course correction controls are generally reserved during the Earth-Moon transfer process. The control timing is determined according to the measurement and control constraints, and the strategies of the three controls are the same. The planning variable X includes the three-directional velocity increment components [Δv xi ,Δv yi ,Δv zi ], where i is the number of mid-course corrections. The target variable Y includes [T p-1 ,i p-1 ,h p-1 ], where T p-1 is the time of first arrival at the perigee, i p-1 is the orbital inclination, h p-1 is the perigee height.

[0076] The near-moon braking phase starts from the deceleration and braking of the probe at the perigee until it enters the circumlunar orbit. After the probe reaches the perigee, it brakes several times (taking 3 brakings as an example) and finally enters the circumlunar orbit at an altitude of about 200 km. The near-moon braking control is mainly in-plane control, but the orbital plane can be corrected by setting the yaw angle. The planning variables X include [Δv T-LOI-i ], where Δv T-LOI-i is the tangential component of the braking speed increment in the recent month, and i is the number of braking times in the recent month. The target variable Y includes [a T-i ], where a T-i is the target semi-major axis after the i-th near-moon braking control.

[0077] The circumlunar flight phase starts from the time when the probe enters the circumlunar circular orbit and ends before the powered descent. In this stage, the probe will choose to separate into the orbit-return assembly and the landing assembly. The former will be parked in the circumlunar orbit and will implement phase adjustment control at an appropriate time (see the literature for details, which will not be described in detail here) to create target orbit conditions for the takeoff and rendezvous of the ascender; the latter will implement circumlunar orbit reduction control to create entry conditions for powered descent. Circumlunar orbit reduction is generally implemented in two times. The first time is to optimize the pitch angle at a fixed time and fixed startup time to minimize the perigee height; the second time is to target the powered descent point parameters, that is, the perigee amplitude angle and height of the powered descent circle. The two orbit reductions are mainly controlled within the orbital plane, but the orbital plane can be corrected by setting the yaw angle. The first circumlunar orbit reduction control is mainly used for the test injection of the powered descent engine. No planning is performed, and the second circumlunar orbit reduction is mainly planned. The planning variables X include [Δv t-DM-2 ,Δv r-DM-2 ], where Δv t-DM-2 is the tangential component of the velocity increment of the second lunar descent, Δv r-DM-2 is the radial component of the velocity increment of the second lunar orbit descent. The target variable Y includes [h p-d ,ω p-d ], where h p-d is the perigee height corresponding to the dynamic descent point, ω p-d is the perigee angle corresponding to the dynamic descent point.

[0078] The powered descent phase starts from the perigee of the powered descent circle to the landing on the lunar surface. The powered descent control is implemented autonomously by the landing assembly, mainly for on-plane control, and an analytical geometric relationship is established through the powered descent point, range and landing point.

[0079] The lunar surface work phase starts with the landing of the lander assembly on the lunar surface and ends with the completion of sample sampling and packaging, and the ascent vehicle's preparation for takeoff.

[0080] The lunar takeoff phase starts from the time when the ascender takes off from the lunar surface and ends when it enters orbit. The lunar takeoff control is carried out autonomously by the ascender, and an analytical geometric relationship is established with the orbit entry point through the constraints of the launch direction, takeoff point and range.

[0081] The rendezvous and docking phase is from the time the ascender enters orbit to the completion of rendezvous and docking. This phase includes several remote control operations of the ascender, which will not be described in detail here.

[0082] The other stages are not closely related to the algorithm in this paper and will not be described in detail here. For details, please refer to the literature. The following table summarizes the control strategies for different stages of the lunar return mission.

[0083] Table 1 Planning strategies for control at different stages

[0084] Serial number control Planning variables Target variable 1 TCM-1 / 2 / 3 <![CDATA[Δv x ,Δv y ,Δv z ]]> <![CDATA[T p_1 ,i p_1 ,h p_1 ]]> 2 LOI-1 <![CDATA[Δv T_LOI-1 ]]> <![CDATA[a T-1 ]]> 3 LOI-2 <![CDATA[Δv T_LOI-2 ]]> <![CDATA[a T-2 ]]> 4 LOI-3 <![CDATA[Δv T_LOI-3 ]]> <![CDATA[a T-3 ]]> 5 HYXZ <![CDATA[Δv T_hyxz ]]> <![CDATA[a T-hyxz ]]> 6 DM-1 / 2 <![CDATA[Δv t_DM-2 ,Δv r_DM-2 ]]> <![CDATA[h p_d ,oh p_d ]]>

[0085] Since the moon rotates from west to east, in order to ensure that the powered descent is in the same plane as the lunar takeoff and other flight processes, the instantaneous landing point under the lunar solid system is located to the west of the takeoff point. According to the type of lunar orbit and the distribution of landing points, the lunar sampling return based on lunar orbit rendezvous and docking can be divided into four types: prograde orbit lunar northern hemisphere sampling, prograde orbit lunar southern hemisphere sampling, retrograde orbit lunar northern hemisphere sampling and retrograde orbit lunar southern hemisphere sampling. Figure 2 As shown, four types of schematic diagrams are given. In the figure, point D is the landing point, point L is the take-off point, and the longitude difference between point D and point L is determined by the working time on the lunar surface.

[0086] The lunar sampling return based on the lunar orbit rendezvous and docking requires that the lunar orbit passes through the landing point at the landing time and the take-off time. Taking the sampling of the northern hemisphere of the moon in the prograde orbit as an example, a schematic diagram of the timing, fixed-point landing and timing take-off of the lunar center instantaneous equatorial inertial system is given, as shown in Figure 3 As shown in the figure, it is a two-dimensional subsatellite point trajectory on the lunar surface, D is the landing point at the time of landing, L is the landing point at the time of take-off, G is the ascending node, H is the descending node, arc GH is the subsatellite point trajectory of the probe on the lunar surface, arc NE is the meridian passing the landing point, arc NF is the meridian passing the take-off point, and i is the inclination of the lunar orbit. Point A is the powered descent point, point N is the North Pole, and point S is the South Pole.

[0087] From spherical trigonometry, we know that the longitude λ of the landing point at the target landing time is d and the target landing point longitude λ at takeoff time l The following relationships exist:

[0088]

[0089] In the formula, Ω m is the longitude of the orbital ascending node at the time of power descent, i is the orbital inclination at the time of power descent, is the latitude of the landing point.

[0090] Since the target landing point is at time T d , take-off time T l , and the longitude and latitude of the target landing point are all fixed values. The longitude difference between the landing point and the target at the landing time and take-off time is as follows:

[0091]

[0092] Schematic diagram of the lunar southern hemisphere sampling landing and takeoff in the prograde orbit, such as Figure 4 As shown. For the sampling of the lunar southern hemisphere in the prograde orbit, The difference in longitude between the landing point and the target at the landing time and take-off time is as follows:

[0093]

[0094] Schematic diagram of the lunar northern hemisphere sampling landing and takeoff in the retrograde orbit, such as Figure 5 For the sampling of the lunar northern hemisphere in retrograde orbit, The difference in longitude between the landing point and the target at the time of landing and take-off is:

[0095]

[0096] Schematic diagram of the lunar southern hemisphere sampling landing and takeoff in the retrograde orbit, such as Figure 6 For the sampling of the lunar southern hemisphere in retrograde orbit, The difference in longitude between the landing point and the target at the time of landing and take-off is:

[0097]

[0098] Timed, fixed-point landing and timed takeoff refer to controlling the upper assembly to descend at the predetermined time and land at the predetermined landing point, and controlling the ascender to take off at the predetermined time and be "virtually" coplanar with the orbit of the return assembly. Combined with the above analysis, the control objectives of timed, fixed-point landing and timed takeoff can be expressed as:

[0099]

[0100] In the formula, ΔT d is the deviation between the moon-setting time and the nominal moon-setting time, Δλ d is the deviation between the actual longitude and the nominal longitude, Δλ l To account for the “virtual” coplanarity, the deviation between the orbiter sub-satellite point longitude and the landing point longitude at the nominal take-off time is calculated.

[0101] Figure 7 A system architecture applicable to an embodiment of the present invention is exemplarily shown. The system architecture includes a server 700 . The server 700 may include a processor 710 , a communication interface 720 , and a memory 730 .

[0102] The communication interface 720 is used to transmit data with the satellite.

[0103] The processor 710 is the control center of the server 700, and uses various interfaces and routes to connect various parts of the entire server 700, and executes various functions and processes data of the server 700 by running or executing software programs and / or modules stored in the memory 730, and calling data stored in the memory 730. Optionally, the processor 710 may include one or more processing units.

[0104] The memory 730 can be used to store software programs and modules. The processor 710 executes various functional applications and data processing by running the software programs and modules stored in the memory 730. The memory 730 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function, etc.; the data storage area can store data created according to business processing, etc. In addition, the memory 730 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0105] It should be noted that the above Figure 7 The structure shown is only an example and is not limited to this embodiment of the present invention.

[0106] Based on the above description, Figure 8 A flow chart of a method for planning a lunar sampling timing, fixed-point landing and timing takeoff provided by an embodiment of the present invention is exemplarily shown. The flow chart can be executed by a device for planning a lunar sampling timing, fixed-point landing and timing takeoff.

[0107] like Figure 8 As shown in the figure, the process specifically includes:

[0108] Step 810, for the first control phase of the lunar sampling mission, determine the six orbital numbers and orbital entry time of the orbit in which the first control phase is located, as well as the nominal parameters of the timed, point-located landing and take-off in the lunar sampling mission. The six orbital numbers are the parameters required to describe the movement of the satellite in the Keplerian orbit, and the nominal parameters include the nominal landing time, the nominal landing point and the nominal take-off time.

[0109] In an embodiment of the present invention, the lunar sampling mission includes multiple control stages. For the first control stage, it is first necessary to determine the six orbital numbers and the orbit entry time of the orbit in which the first control stage is located. Among them, the six orbital numbers are the parameters required to describe the movement of the satellite on the Kepler orbit, including: semi-major axis, eccentricity, orbital inclination, ascending node ecliptic longitude, perigee argument, and true anomaly. Specifically, the semi-major axis is half of the major axis of the elliptical orbit, which can sometimes be regarded as the average orbital radius; the eccentricity is a measure of the degree of flatness of the ellipse, and is defined as the ratio of the distance between the two foci of the ellipse to the length of the major axis; the orbital inclination is the angle between the orbital plane and the equatorial plane; the ascending node ecliptic longitude is the point where the satellite crosses the equator when it moves from the southern hemisphere to the northern hemisphere, and the angle between the ascending node and the vernal equinox to the center of the earth is called the ascending node right ascension; the perigee argument is the angle measured counterclockwise from the ascending node along the planetary motion orbit to the perigee; the true anomaly is the angle between the orbital perigee and the satellite position vector at a certain moment. The above parameters can be used to express the specific position and speed of the object through trigonometric calculations.

[0110] Then, after determining the six orbital numbers and the time of orbital entry, it is also necessary to determine the nominal parameters for the scheduled landing and takeoff in the lunar sampling mission. The nominal parameters include the nominal landing time, the nominal landing point and the nominal takeoff time.

[0111] Step 820, based on the nominal parameters, the six orbital numbers and the orbital entry time, jointly plan the first control stage with the subsequent control stage in the lunar sampling mission to obtain a first deviation, and iterate the first deviation based on a first variable; the first deviation is the deviation between the satellite and the nominal parameters when landing and taking off on the moon, and the first variable is a variable related to time and / or orbital plane in the first control stage and the subsequent control stage in the lunar sampling mission.

[0112] In an embodiment of the present invention, after determining the six orbital numbers and the orbital entry time of the orbit in which the first control stage is located, the first control stage and its subsequent control stage in the lunar sampling mission are jointly planned according to the nominal parameters, the six orbital numbers and the orbital entry time to obtain the first deviation. Among them, the first deviation can be the deviation between the satellite and the nominal parameters when landing and taking off on the moon. The nominal parameters include the planned landing time, landing site, and take-off site. Therefore, the first deviation can include landing time deviation, landing site deviation, and take-off site deviation. It can be understood that since the latitude of the landing site and the take-off site is the same, the landing site deviation and the take-off site deviation can also be called landing longitude deviation and take-off longitude deviation.

[0113] Then, the first deviation is iterated according to the first variable. Among them, the landing time deviation in the first deviation is related to the orbital time, and the landing site deviation and the take-off site deviation are related to the orbital surface. Therefore, the first variable is a variable related to time and / or orbital surface in the first control phase and the subsequent control phase in the lunar sampling mission. Exemplarily, the variables related to the orbital surface may include orbital inclination and yaw angle, and the variables related to time may include the semi-major axis. Specifically, the first deviation can be iterated according to the first variable based on the differential correction algorithm, or it can be iterated according to the first variable based on the sequential quadratic programming algorithm. The algorithm for iteration is not specifically limited here. Among them, the computational efficiency of the sequential quadratic programming algorithm is lower than that of the differential correction algorithm. Therefore, the differential correction algorithm is taken as an example in the present invention.

[0114] Exemplarily, the iteration based on the differential correction algorithm includes: taking the first variable as a constraint variable and the first deviation as a control variable,

[0115] Assume that the constraint variable is an m-dimensional vector Q and the control variable is an n-dimensional vector P. There is a functional relationship between the two, as shown in the following formula: Q = f(P) (1)

[0116] If the initial value of the control variable is P0, the corresponding constraint variable value is Q0, and the Taylor expansion of equation (1) at P0 is performed and the first-order term is taken, the following equation is obtained:

[0117] Where M is the Jacobian matrix, which reflects the sensitivity of the constraint variables to small changes in the control variables.

[0118] Given the current constraint variable Q0 and the target constraint variable Q s There is a certain deviation Q S -Q0, then using formula (2), the corrected Q can be iteratively calculated S -Q0 The required control variable improvement ΔP is as follows:

[0119] ΔP=M -1 ΔQ (3)

[0120] If m≠n, the minimum norm generalized inverse can be used to calculate ΔP, as follows: ΔP=M T (M.M T ) -1 ΔQ(4)

[0121] And so on, iterative calculation is performed until the target constraint variable converges.

[0122] Step 830: When the first deviation is less than the convergence threshold, the target variable of the first control stage is determined so that the satellite can achieve the timing, point, landing and take-off based on the target variables of each control stage.

[0123] In the embodiment of the present invention, based on the differential correction algorithm, the first deviation is iterated according to the first variable. Finally, when the first deviation is less than the convergence threshold, the target variable of the first control stage is determined. The convergence threshold can be a value set according to experience, such as the convergence threshold of the landing time deviation is 1s, and the convergence threshold of the landing point deviation and the take-off point deviation is 0.001 degrees. The convergence threshold is not specifically limited here.

[0124] When the above process is executed in each control stage, the target variables of each control stage are obtained, and the timing, fixed-point, and timing takeoff can be achieved based on the target variables of each control stage.

[0125] In the embodiment of the present invention, the control phases in the lunar sampling mission include: mid-course correction, first near-moon braking, second near-moon braking, third near-moon braking, first orbit around the moon, second orbit around the moon, orbit return assembly phase adjustment, powered descent, and lunar takeoff. Therefore, it is necessary to execute the above process multiple times to obtain the target variables of each control phase. Specifically:

[0126] For the mid-course correction control phase of the lunar sampling mission, determine the six orbital numbers and orbital entry time of the current orbit, as well as the nominal parameters of the timed, fixed-point, and timed landing and takeoff in the lunar sampling mission. For example, taking the retrograde orbit southern hemisphere sampling return as an example, the probe orbit entry time is 03May 202410:04:26.870UTCG, and the six orbital numbers are shown in Table 2; the nominal landing time is 01Jun 2024 22:09:03UTCG; the nominal take-off time is 03Jun 2024 23:44:10UTCG; the longitude and latitude of the landing point are (154.47°W, 41.6°S).

[0127] Table 2 Six numbers of orbital tracks

[0128]

[0129] Then, according to the nominal parameters, the six orbital numbers of the orbit in the mid-course correction control stage and the orbit entry time, the mid-course correction control stage is jointly planned with the first near-moon braking, the second near-moon braking, the third near-moon braking, the first orbit around the moon, the second orbit around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stage in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the take-off longitude deviation. Based on the differential correction algorithm, according to the orbital inclination after the mid-course correction, the yaw angle of the three near-moon brakings and the semi-major axis of the target orbit after the third near-moon braking, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated. Until the landing time deviation, the landing longitude deviation and the take-off longitude deviation are less than the convergence threshold, the target variables of the mid-course correction control stage are determined.

[0130] Exemplarily, planning starts from the first mid-course correction, and the mid-course correction is jointly planned with the first near-moon braking, the second near-moon braking, the third near-moon braking, the first lunar orbit reduction, the second lunar orbit reduction, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stage, and the initial value of the planning variable is set to the nominal parameter. The landing time deviation corresponding to the nominal parameters is 101s, the landing longitude deviation is 3.543°, and the longitude deviation at the take-off time is 4.537°. Iteration is performed based on the differential correction algorithm until the landing time deviation, the landing longitude deviation and the take-off longitude deviation are less than the convergence threshold. The iteration process is shown in Table 3. Finally, the mid-course correction aiming value of the lunar inclination is 146.830°, the yaw angle of the three near-moon braking is -0.966°, and the semi-major axis of the lunar orbit aimed at the third near-moon braking is 1938.360km. The target variable of the mid-course correction control stage is determined: the lunar inclination value is 146.830°.

[0131] Table 3 Calculation process of mid-course correction of scheduled landing and takeoff

[0132] Iterations <![CDATA[i p_1 / °]]> <![CDATA[Ψ LOI-123 / °]]> <![CDATA[a T-3 / °]]> <![CDATA[ΔT d / s]]> <![CDATA[Δλ d / °]]> <![CDATA[Δλ l / °]]> 1 146.827 -1.072 1938.231 100.698 3.543 4.537 2 146.833 -1.072 1938.231 102.622 4.804 5.678 3 146.827 -1.066 1938.231 100.354 3.335 4.266 4 146.827 -1.072 1938.241 93.241 3.516 4.530 5 146.830 -0.965 1938.359 0.323 0.040 0.027 6 146.830 -0.966 1938.360 -0.004 -0.001 -0.001

[0133] Then, for the first near-moon braking control phase of the lunar sampling mission, determine the six orbital numbers and orbit entry time of the current orbit, as well as the nominal parameters of the timed, fixed-point, and timed takeoff landing in the lunar sampling mission. For example, continuing with the above example, take the orbit after the first mid-course correction control, apply a control error of 0.05m / s, and determine the six orbital numbers of the current orbit.

[0134] According to the nominal parameters, the six orbital numbers of the orbit in the first near-moon braking control stage and the orbit entry time, the first near-moon braking control stage is jointly planned with the second near-moon braking, the third near-moon braking, the first orbit around the moon, the second orbit around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stage in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation. Based on the differential correction algorithm, according to the yaw angle of the first near-moon braking, the yaw angles of the second and third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking, the landing time deviation, the landing longitude deviation and the takeoff longitude deviation are iterated. Until the landing time deviation, the landing longitude deviation and the takeoff longitude deviation are less than the convergence threshold, the target variables of the first near-moon braking control stage are determined.

[0135] Exemplarily, planning starts from the first near-moon braking, and the first near-moon braking is jointly planned with the second near-moon braking, the third near-moon braking, the first lunar orbit descent, the second lunar orbit descent, the phase adjustment of the orbit-return assembly, the powered descent, and the lunar surface takeoff control stage, and the initial value of the planning variable is set to the nominal parameter. Iteration is performed based on the differential correction algorithm until the landing time deviation, the landing longitude deviation, and the takeoff longitude deviation are less than the convergence threshold. The iteration process is shown in Table 4. Finally, the yaw angle of the first near-moon braking is -0.89°, the yaw angle of the second and third near-moon braking is -1.020°, and the third near-moon braking aims at the semi-major axis of the lunar orbit of 1938.356km. The target variable of the first near-moon braking control stage is determined: the yaw angle is -0.89°.

[0136] Table 4 Calculation process of the first near-month braking, fixed-point landing and timed takeoff

[0137] Iterations <![CDATA[Ψ LOI-1 / °]]> <![CDATA[a T-3 / °]]> <![CDATA[Ψ LOI-23 / °]]> <![CDATA[ΔT d / s]]> <![CDATA[Δλ d / °]]> <![CDATA[Δλ l / °]]> 1 -0.966 1938.361 1.000 -56.873 -2.112 -2.991 2 -0.960 1938.361 1.000 -56.951 -2.116 -2.997 3 -0.966 1938.371 1.000 -64.338 -2.114 -2.992 4 -0.966 1938.361 1.007 -57.014 -2.119 -3.002 5 -3.380 1938.352 0.532 1.900 0.083 0.081 6 -2.221 1938.354 -0.189 1.014 0.041 0.040 7 -0.890 1938.356 -1.020 0.030 0.001 0.001

[0138] Then, for the second near-moon braking control phase in the lunar sampling mission, determine the six orbital numbers and orbit entry time of the current orbit, as well as the nominal parameters of the timed, fixed-point, and timed takeoff landing in the lunar sampling mission. For example, continuing with the above example, take the orbit after the first near-moon braking control, apply a control error of 1.5m / s, and determine the six orbital numbers of the current orbit.

[0139] According to the nominal parameters, the six orbital numbers of the orbit in the second near-moon braking control phase and the orbit entry time, the second near-moon braking control phase is jointly planned with the third near-moon braking, the first orbit around the moon, the second orbit around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control phases in the lunar sampling mission to obtain the landing time deviation, landing longitude deviation and takeoff longitude deviation. Based on the differential correction algorithm, according to the yaw angle of the second near-moon braking, the yaw angle of the third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking, the landing time deviation, landing longitude deviation and takeoff longitude deviation are iterated. Until the landing time deviation, landing longitude deviation and takeoff longitude deviation are less than the convergence threshold, the target variables of the second near-moon braking control phase are determined.

[0140] Exemplarily, planning starts from the second near-moon braking, and the second near-moon braking is jointly planned with the third near-moon braking, the first lunar orbit reduction, the second lunar orbit reduction, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stage, and the initial value of the planning variable is set to the nominal parameter. Iteration is performed based on the differential correction algorithm until the landing time deviation, the landing longitude deviation and the takeoff longitude deviation are less than the convergence threshold. The iteration process is shown in Table 5. Finally, the yaw angle of the second near-moon braking is 1.147°, the yaw angle of the third near-moon braking is -0.245°, and the semi-major axis of the lunar orbit aimed at by the third near-moon braking is 1938.484km. The target variable of the second near-moon braking control stage is determined: the yaw angle is 1.147°.

[0141] Table 5 The calculation process of the second near-month braking, fixed-point landing and timed takeoff

[0142] Iterations <![CDATA[Ψ LOI-2 / °]]> <![CDATA[a T-3 / °]]> <![CDATA[Ψ LOI-3 / °]]> <![CDATA[ΔT d / s]]> <![CDATA[Δλ d / °]]> <![CDATA[Δλ l / °]]> 1 0.366 1938.582 0.366 -76.037 0.044 0.000 2 0.372 1938.582 0.366 -76.036 0.041 -0.004 3 0.366 1938.592 0.366 -83.666 0.043 -0.001 4 0.366 1938.582 0.374 -76.051 0.040 -0.007 5 1.147 1938.484 -0.245 -0.005 0.000 0.000

[0143] Then, for the third near-moon braking control phase in the lunar sampling mission, determine the six orbital numbers and orbit entry time of the current orbit, as well as the nominal parameters of the timed, fixed-point, and timed takeoff landing in the lunar sampling mission. For example, continuing with the above example, take the orbit after the second near-moon braking control, apply a control error of 1.5m / s, and determine the six orbital numbers of the current orbit.

[0144] According to the nominal parameters, the six orbital numbers of the orbit in the third near-moon braking control phase and the orbit entry time, the third near-moon braking control phase is jointly planned with the first orbit around the moon, the second orbit around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control phases in the lunar sampling mission to obtain the landing time deviation, landing longitude deviation and takeoff longitude deviation. Based on the differential correction algorithm, according to the yaw angle of the third near-moon braking, the yaw angles of the two orbit around the moon and the semi-major axis of the target orbit after the third near-moon braking, the landing time deviation, landing longitude deviation and takeoff longitude deviation are iterated. Until the landing time deviation, landing longitude deviation and takeoff longitude deviation are less than the convergence threshold, the target variables of the third near-moon braking control phase are determined.

[0145] Exemplarily, planning starts from the third near-moon braking, and the third near-moon braking is jointly planned with the first lunar orbit reduction, the second lunar orbit reduction, the phase adjustment of the orbit-return assembly, the powered descent, and the lunar surface takeoff control stage, and the initial value of the planning variable is set to the nominal parameter. Iteration is performed based on the differential correction algorithm until the landing time deviation, the landing longitude deviation, and the takeoff longitude deviation are less than the convergence threshold. The iteration process is shown in Table 6. Finally, the yaw angle of the third near-moon braking is -0.95°, the yaw angle of the first and second lunar orbit reductions is -0.01°, and the third near-moon braking aims at the semi-major axis of the lunar orbit of 1937.73km. The target variables of the third near-moon braking control stage are determined: the yaw angle is -0.95° and the semi-major axis of the lunar orbit is 1937.73km.

[0146] Table 6 The calculation process of the third near-month braking, fixed-point landing and timed takeoff

[0147] Iterations <![CDATA[Ψ LOI-3 / °]]> <![CDATA[a T-3 / °]]> <![CDATA[Ψ DM-12 / °]]> <![CDATA[ΔT d / s]]> <![CDATA[Δλ d / °]]> <![CDATA[Δλ l / °]]> 1 -0.966 1938.361 0.001 -467.288 -0.084 -0.008 2 -0.960 1938.361 0.001 -467.422 -0.088 -0.013 3 -0.966 1938.371 0.001 -474.737 -0.085 -0.008 4 -0.966 1938.361 0.008 -467.298 -0.084 -0.008 5 -0.946 1937.733 -0.014 -0.954 -0.001 0.000

[0148] In one possible implementation, a circumlunar correction control may be reserved after the last near-moon braking to correct the near-moon braking residual and ensure the timely landing of the landing assembly. Therefore, it is also necessary to jointly plan the circumlunar correction control stage with the subsequent control stage. Specifically, for the circumlunar correction control stage in the lunar sampling mission, determine the six orbital numbers and orbit entry time of the current orbit, as well as the nominal parameters of the scheduled, fixed-point landing and scheduled takeoff in the lunar sampling mission. Exemplarily, continuing with the above example, take the orbit after the third near-moon braking control, apply a control error of 0.2m / s to implement the four-device separation, and determine the six orbital numbers of the current orbit.

[0149] According to the nominal parameters, the six orbital numbers of the orbit in the circumlunar correction control stage and the orbit entry time, the circumlunar correction control stage is jointly planned with the first circumlunar orbit descent, the second circumlunar orbit descent, and the powered descent control stage in the lunar sampling mission to obtain the landing time deviation and the landing longitude deviation. Based on the differential correction algorithm, the landing time deviation and the landing longitude deviation are iterated according to the semi-major axis of the target orbit of the circumlunar correction and the yaw angle of the two circumlunar orbits. Until the landing time deviation and the landing longitude deviation are less than the convergence threshold, the target variables of the circumlunar correction control stage are determined.

[0150] Exemplarily, planning starts with the lunar correction, and the lunar correction is jointly planned with the first lunar orbit reduction, the second lunar orbit reduction, and the powered descent control stage, and the initial value of the planning variable is set to the nominal parameter. Iteration is performed based on the differential correction algorithm until the landing time deviation and the landing longitude deviation are less than the convergence threshold. The iteration process is shown in Table 7. Finally, the lunar correction aims at the semi-major axis of the lunar orbit of 1939.85 km, and the yaw angle of the first and second lunar orbit reductions is -0.49°. The target variable of the lunar correction control stage is determined: the semi-major axis of the lunar orbit is 1939.85 km.

[0151] Table 7 Calculation process of lunar correction timing and fixed point landing

[0152] Iterations <![CDATA[a T-hyxz / °]]> <![CDATA[Ψ DM-12 / °]]> <![CDATA[ΔT d / s]]> <![CDATA[Δλ d / °]]> 1 1939.244 -0.715 9.362 0.051 2 1939.244 -0.708 9.361 0.051 3 1939.254 -0.715 9.208 0.051 4 1939.851 -0.481 -0.073 -0.001 5 1939.846 -0.490 0.002 0.000 6 1939.846 -0.490 0.000 0.000

[0153] Then, for the first lunar orbit descent control phase in the lunar sampling mission, during the first orbit descent, the probe has implemented the separation of the four devices, the orbiter orbital plane has been determined, and the lunar orbit descent will not be able to aim for a scheduled takeoff. In addition, the powered descent process is a landing at a specified latitude. Therefore, it is only necessary to aim for a fixed-point landing. Determine the six orbital numbers and orbit entry time of the current orbit, as well as the nominal parameters for scheduled, fixed-point landing and scheduled takeoff in the lunar sampling mission. Exemplarily, continuing with the above example, take the orbit after the lunar correction control, apply a control error of 0.2m / s, and determine the six orbital numbers of the current orbit.

[0154] According to the nominal parameters, the six orbital numbers of the orbit in the first lunar orbit reduction control phase and the orbit entry time, the first lunar orbit reduction control phase is jointly planned with the second lunar orbit reduction and powered descent control phase in the lunar sampling mission to obtain the landing longitude deviation. Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angles of the two lunar orbit reductions. Until the landing longitude deviation is less than the convergence threshold, the target variable of the first lunar orbit reduction control phase is determined.

[0155] Exemplarily, planning starts from the first lunar orbit reduction, and the first lunar orbit reduction is jointly planned with the second lunar orbit reduction and the powered descent control stage, and the initial value of the planning variable is set to the nominal parameter. Iteration is performed based on the differential correction algorithm until the landing longitude deviation is less than the convergence threshold. The iteration process is shown in Table 8, and finally the yaw angle of the first and second lunar orbit reduction is -0.263°. The target variable of the first lunar orbit reduction control stage is determined: the yaw angle is -0.263°.

[0156] Table 8 The calculation process of the first timed and fixed-point landing in the lunar orbit

[0157]

[0158] Then, for the second orbit-descent control phase of the lunar sampling mission, determine the six orbital numbers and orbit entry time of the current orbit, as well as the nominal parameters of the scheduled, fixed-point, and scheduled takeoff landing in the lunar sampling mission. For example, continuing with the above example, take the orbit after the first orbit-descent control, apply a control error of 0.2m / s, and determine the six orbital numbers of the current orbit.

[0159] According to the nominal parameters, the six orbital numbers of the orbit in the second lunar orbit reduction control phase and the orbit entry time, the second lunar orbit reduction control phase is jointly planned with the powered descent control phase in the lunar sampling mission to obtain the landing longitude deviation. Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angle of the second lunar orbit reduction. Until the landing longitude deviation is less than the convergence threshold, the target variable of the second lunar orbit reduction control phase is determined.

[0160] Exemplarily, planning starts from the second lunar orbit reduction, and the second lunar orbit reduction is jointly planned with the power descent control stage, and the initial value of the planning variable is set to the nominal parameter. Iteration is performed based on the differential correction algorithm until the landing longitude deviation is less than the convergence threshold. The iteration process is shown in Table 9, and finally the yaw angle of the second lunar orbit reduction is -0.428°. The target variable of the second lunar orbit reduction control stage is determined: the yaw angle is -0.428°.

[0161] Table 9 The calculation process of the second timed and fixed-point landing in the lunar orbit

[0162]

[0163] Actual flight data showed that although the first and second lunar orbits were no longer aimed at timed landing, the landing time deviation was less than 1 minute under the influence of normal orbit determination error and control error.

[0164] Finally, after obtaining the target variables of each control stage, the satellite can achieve scheduled landing, scheduled takeoff and fixed-point landing according to the target variables of each control stage.

[0165] In the embodiment of the present invention, the lunar sampling return mission is divided into four types, namely, prograde orbit lunar northern hemisphere sampling, prograde orbit lunar southern hemisphere sampling, retrograde orbit lunar northern hemisphere sampling, and retrograde orbit lunar southern hemisphere sampling, based on the type of lunar orbit and the distribution of the sampling area. Secondly, the stages of the sampling return mission and the control types contained therein are analyzed, and combined with the differentiated characteristics of the four types of sampling return missions, a mathematical model of timed fixed-point landing and timed takeoff and a dynamic real-time planning timed fixed-point landing and timed takeoff control method are established respectively, realizing that from the first mid-course correction of the Earth-Moon transfer stage to the last orbit reduction before landing, each control is dynamically jointly planned with the timed fixed-point landing and timed takeoff as the ultimate goal, which effectively improves the control reconstruction capability of the mission. The correctness and feasibility of the strategy are verified through simulation examples. It can be applied to the design of flight control strategies for subsequent (manned) lunar exploration missions in my country.

[0166] Based on the same technical concept, Fig. 9 The schematic diagram of the structure of a device for planning lunar sampling, fixed-point landing and scheduled takeoff provided by an embodiment of the present invention is exemplarily shown. The device can execute the process of the method for planning lunar sampling, fixed-point landing and scheduled takeoff.

[0167] like Fig. 9 As shown, the device specifically includes:

[0168] An acquisition module 910 is used to determine, for the first control phase of the lunar sampling mission, six orbital numbers and an orbit entry time of the orbit in which the first control phase is located, wherein the six orbital numbers are parameters required to describe the motion of the satellite on the Keplerian orbit;

[0169] The processing module 920 is used to jointly plan the first control stage with the subsequent control stage in the lunar sampling mission according to the six orbital numbers and the orbit entry time to obtain a first deviation, and iterate the first deviation according to a first variable based on a differential correction algorithm; the first deviation is a deviation between the satellite and the nominal parameters when landing and taking off on the moon, and the first variable is a variable related to time and / or orbital plane in the first control stage and the subsequent control stage in the lunar sampling mission;

[0170] When the first deviation is less than the convergence threshold, the target variable of the first control stage is determined so that the satellite can achieve the timing, point, and take-off based on the target variables of each control stage.

[0171] Optionally, the control phase of the lunar sampling mission includes: mid-course correction, first near-moon braking, second near-moon braking, third near-moon braking, first circumlunar orbit descent, second circumlunar orbit descent, phase adjustment of the orbit-return assembly, powered descent, and lunar takeoff.

[0172] Optionally, the processing module 920 is specifically used for:

[0173] For the mid-course correction control phase in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the mid-course correction control phase is located and the orbit entry time, the mid-course correction control phase is jointly planned with the first near-moon braking, the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control phases in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the take-off longitude deviation;

[0174] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the orbital inclination after mid-course correction, the yaw angle of three near-moon brakings and the semi-major axis of the target orbit after the third near-moon braking.

[0175] Optionally, the processing module 920 is specifically used for:

[0176] For the first near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the first near-moon braking control stage is located and the orbit entry time, the first near-moon braking control stage is jointly planned with the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation;

[0177] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the first near-moon braking, the yaw angles of the second and third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

[0178] Optionally, the processing module 920 is specifically used for:

[0179] For the second near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the second near-moon braking control stage is located, and the orbit entry time, the second near-moon braking control stage is jointly planned with the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent, and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation, and the takeoff longitude deviation;

[0180] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the second near-moon braking, the yaw angle of the third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

[0181] Optionally, the processing module 920 is specifically used for:

[0182] For the third near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the third near-moon braking control stage is located and the orbit entry time, the third near-moon braking control stage is jointly planned with the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation;

[0183] Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the third near-moon braking, the yaw angles of the two circumlunar descent orbits and the semi-major axis of the target orbit after the third near-moon braking.

[0184] Optionally, the processing module 920 is specifically used for:

[0185] For the first lunar orbit descent control phase in the lunar sampling mission, according to the nominal parameters, the six orbit numbers of the orbit in the first lunar orbit descent control phase and the orbit entry time, the first lunar orbit descent control phase is jointly planned with the second lunar orbit descent and powered descent control phases in the lunar sampling mission to obtain the landing longitude deviation;

[0186] Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angles of the two lunar descending orbits.

[0187] Optionally, the processing module 920 is specifically used for:

[0188] For the second lunar orbit descent control phase in the lunar sampling mission, the second lunar orbit descent control phase is jointly planned with the powered descent control phase in the lunar sampling mission according to the nominal parameters, the six orbital numbers of the orbit in the second lunar orbit descent control phase, and the orbit entry time, to obtain the landing longitude deviation;

[0189] Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angle of the second descent orbit around the moon.

[0190] Based on the same technical concept, an embodiment of the present invention further provides a computer device, including:

[0191] A memory for storing program instructions;

[0192] The processor is used to call the program instructions stored in the memory and execute the above-mentioned method for planning lunar sampling, timing, fixed-point landing and timing takeoff according to the obtained program.

[0193] Based on the same technical concept, an embodiment of the present invention also provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the above-mentioned method for planning lunar sampling, timing, fixed-point landing and timing takeoff.

[0194] Based on the same technical concept, an embodiment of the present invention further provides a computer program product, characterized in that the computer program product includes an executable program, and the executable program is executed by a processor to implement the above-mentioned method for planning lunar sampling, timing, fixed-point landing and timing takeoff.

[0195] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0196] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0197] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0198] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0199] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for planning lunar sampling, fixed-point landing and fixed-point takeoff, characterized in that: include: For the first control phase of the lunar sampling mission, determine the six orbital numbers and orbit entry time of the orbit in which the first control phase is located, as well as the nominal parameters of the timed, point-fixed landing and timed takeoff in the lunar sampling mission. The six orbital numbers are the parameters required to describe the movement of the satellite in the Keplerian orbit, and the nominal parameters include the nominal landing time, the nominal landing point and the nominal takeoff time. According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control stage and the subsequent control stage in the lunar sampling mission are jointly planned to obtain a first deviation, and the first deviation is iterated according to a first variable; the first deviation is the deviation between the satellite and the nominal parameters when landing and taking off on the moon, and the first variable is a variable related to time and / or orbital plane in the first control stage and the subsequent control stage in the lunar sampling mission; When the first deviation is less than the convergence threshold, the target variable of the first control stage is determined so that the satellite can achieve the timing, point, and take-off based on the target variables of each control stage.

2. The method according to claim 1, characterized in that The control phases of the lunar sampling mission include: mid-course correction, the first near-moon braking, the second near-moon braking, the third near-moon braking, the first lunar orbit descent, the second lunar orbit descent, phase adjustment of the orbit-return assembly, powered descent, and lunar takeoff.

3. The method according to any one of claims 1 to 2, characterized in that: According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control phase is jointly planned with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and the first deviation is iterated according to a first variable, including: For the mid-course correction control phase in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the mid-course correction control phase is located and the orbit entry time, the mid-course correction control phase is jointly planned with the first near-moon braking, the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control phases in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the take-off longitude deviation; Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the orbital inclination after mid-course correction, the yaw angle of three near-moon brakings and the semi-major axis of the target orbit after the third near-moon braking.

4. The method according to any one of claims 1 to 2, characterized in that: According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control phase is jointly planned with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and the first deviation is iterated according to a first variable, including: For the first near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the first near-moon braking control stage is located and the orbit entry time, the first near-moon braking control stage is jointly planned with the second near-moon braking, the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation; Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the first near-moon braking, the yaw angles of the second and third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

5. The method according to any one of claims 1 to 2, characterized in that: According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control phase is jointly planned with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and the first deviation is iterated according to a first variable, including: For the second near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the second near-moon braking control stage is located, and the orbit entry time, the second near-moon braking control stage is jointly planned with the third near-moon braking, the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent, and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation, and the takeoff longitude deviation; Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the second near-moon braking, the yaw angle of the third near-moon braking and the semi-major axis of the target orbit after the third near-moon braking.

6. The method according to any one of claims 1 to 2, characterized in that: According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control phase is jointly planned with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and the first deviation is iterated according to a first variable, including: For the third near-moon braking control stage in the lunar sampling mission, according to the nominal parameters, the six orbital numbers of the orbit in which the third near-moon braking control stage is located and the orbit entry time, the third near-moon braking control stage is jointly planned with the first orbit descent around the moon, the second orbit descent around the moon, the phase adjustment of the orbit-return assembly, the powered descent and the lunar surface takeoff control stages in the lunar sampling mission to obtain the landing time deviation, the landing longitude deviation and the takeoff longitude deviation; Based on the differential correction algorithm, the landing time deviation, the landing longitude deviation and the take-off longitude deviation are iterated according to the yaw angle of the third near-moon braking, the yaw angles of the two circumlunar descent orbits and the semi-major axis of the target orbit after the third near-moon braking.

7. The method according to any one of claims 1 to 2, characterized in that: According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control phase is jointly planned with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and the first deviation is iterated according to a first variable, including: For the first lunar orbit descent control phase in the lunar sampling mission, according to the nominal parameters, the six orbit numbers of the orbit in the first lunar orbit descent control phase and the orbit entry time, the first lunar orbit descent control phase is jointly planned with the second lunar orbit descent and powered descent control phases in the lunar sampling mission to obtain the landing longitude deviation; Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angles of the two lunar descending orbits.

8. The method according to any one of claims 1 to 2, characterized in that: According to the nominal parameters, the six orbital numbers and the orbital entry time, the first control phase is jointly planned with a subsequent control phase in the lunar sampling mission to obtain a first deviation, and the first deviation is iterated according to a first variable, including: For the second lunar orbit descent control phase in the lunar sampling mission, the second lunar orbit descent control phase is jointly planned with the powered descent control phase in the lunar sampling mission according to the nominal parameters, the six orbital numbers of the orbit in the second lunar orbit descent control phase, and the orbit entry time, to obtain the landing longitude deviation; Based on the differential correction algorithm, the landing longitude deviation is iterated according to the yaw angle of the second descent orbit around the moon.

9. A device for planning lunar sampling, landing and takeoff at a fixed time and point, characterized in that: include: An acquisition module is used to determine, for the first control phase of the lunar sampling mission, six orbital numbers and orbit entry time of the orbit in which the first control phase is located, as well as nominal parameters for timed, point-fixed landing and timed takeoff in the lunar sampling mission. The six orbital numbers are parameters required to describe the movement of the satellite in the Keplerian orbit, and the nominal parameters include nominal landing time, nominal landing point and nominal takeoff time; a processing module, configured to jointly plan the first control phase with a subsequent control phase in the lunar sampling mission according to the nominal parameters, the six orbital numbers, and the orbital entry time, obtain a first deviation, and iterate the first deviation according to a first variable; the first deviation is a deviation between the satellite and the nominal parameters when landing and taking off on the moon, and the first variable is a variable related to time and / or orbital plane in the first control phase and the subsequent control phase in the lunar sampling mission; When the first deviation is less than the convergence threshold, the target variable of the first control stage is determined so that the satellite can achieve the timing, point, and take-off based on the target variables of each control stage.

10. A computer device, characterized in that: include: A memory for storing program instructions; A processor, configured to call the program instructions stored in the memory, and execute the method according to any one of claims 1 to 8 according to the obtained program.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the method according to any one of claims 1 to 8.

12. A computer program product, characterized in that The computer program product comprises an executable program, which is executed by a processor to implement the method according to any one of claims 1 to 8.

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