Intercept and Docking Planning and Guidance Method and Device Based on Dynamic Double Anchor Points

Abstract

The present invention provides a rendezvous and docking planning and guidance method and device based on dynamic double anchor points, which relates to the technical field of spacecraft control. The method includes: obtaining a normal rendezvous and docking planning scheme based on a near anchor point and an emergency rendezvous and docking planning scheme based on a far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point; starting the rendezvous and docking process according to the normal rendezvous and docking planning scheme, and predicting the rendezvous error at the end of the long-distance guidance section in real time; determining whether the accuracy requirement is met based on the rendezvous error predicted in real time. If so, continue the rendezvous and docking process according to the normal rendezvous and docking planning scheme. If not, interrupt the rendezvous and docking process of the normal rendezvous and docking planning scheme and switch to the emergency rendezvous and docking planning scheme for the subsequent rendezvous and docking process. The present invention can improve the rapidity and safety of rendezvous and docking.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of spacecraft control, and particularly to a rendezvous and docking planning and guidance method and device based on dynamic double anchor points. Background Art

[0002] The lunar orbit rendezvous and docking technology is a key technology for manned lunar exploration missions. The space environment in the lunar orbit is complex, the autonomous orbit determination accuracy is limited and significantly affected by the illumination conditions and relative distances, while the manned lunar landing and takeoff rendezvous and docking missions have high requirements for rapidity and safety. How to ensure the rapidity of rendezvous and docking on the premise of safety has become an urgent problem to be solved. Summary of the Invention

[0003] The embodiments of the present invention provide a rendezvous and docking planning and guidance method and device based on dynamic double anchor points, which can improve the rapidity and safety of rendezvous and docking.

[0004] In a first aspect, the embodiments of the present invention provide a rendezvous and docking planning and guidance method based on dynamic double anchor points, which is applied to a landing and ascent vehicle as an active spacecraft. The method includes:

[0005] Obtaining a normal rendezvous and docking planning scheme based on a near anchor point and an emergency rendezvous and docking planning scheme based on a far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point;

[0006] Starting the rendezvous and docking process according to the normal rendezvous and docking planning scheme, and predicting the rendezvous error at the end of the long-distance guidance section in real time;

[0007] Determining whether the accuracy requirement is met based on the rendezvous error obtained by real-time prediction. If so, continue the rendezvous and docking process according to the normal rendezvous and docking planning scheme. If not, interrupt the rendezvous and docking process of the normal rendezvous and docking planning scheme and switch to the emergency rendezvous and docking planning scheme for the subsequent rendezvous and docking process.

[0008] In a second aspect, the embodiments of the present invention further provide a rendezvous and docking planning and guidance device based on dynamic double anchor points, which is applied to a landing and ascent vehicle as an active spacecraft. The device includes:

[0009] An obtaining unit, configured to obtain a normal rendezvous and docking planning scheme based on a near anchor point and an emergency rendezvous and docking planning scheme based on a far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point;

[0010] A predicting unit, configured to predict the rendezvous error at the end of the long-distance guidance section in real time when starting the rendezvous and docking process according to the normal rendezvous and docking planning scheme;

[0011] A scheme switching processing unit is configured to determine whether the accuracy requirement is met based on the rendezvous error obtained by real-time prediction. If so, the rendezvous and docking process continues according to the normal rendezvous and docking planning scheme. If not, the rendezvous and docking process of the normal rendezvous and docking planning scheme is interrupted, and the emergency rendezvous and docking planning scheme is switched to for the subsequent rendezvous and docking process.

[0012] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0013] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed on a computer, the computer is made to execute the method described in any embodiment of this specification.

[0014] The embodiment of the present invention provides a rendezvous and docking planning guidance method and device based on dynamic double anchor points. By designing two rendezvous and docking planning schemes, one is a normal rendezvous and docking planning scheme based on a near anchor point, and the other is an emergency rendezvous and docking planning scheme based on a far anchor point. In the long-distance guidance section, the near anchor point is used as the aiming point, and the rendezvous and docking process is carried out according to the normal rendezvous and docking planning scheme, and the rendezvous error at the end of the long-distance guidance section is predicted in real time. When it is determined that the rendezvous error does not meet the accuracy requirement, the emergency rendezvous and docking planning scheme is switched to for the subsequent rendezvous and docking process, so as to achieve a safe rendezvous and docking process. It can be seen that this solution adopts a dynamic selection method of double anchor points to adapt to the change of the rendezvous error at the end of the long-distance guidance section caused by the autonomous orbit determination error, thereby improving the safety during the rapid rendezvous and docking process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 is a flowchart of a rendezvous and docking planning guidance method based on dynamic double anchor points provided by an embodiment of the present invention;

[0017] Figure 2 is a hardware architecture diagram of an electronic device provided by an embodiment of the present invention;

[0018] Figure 3It is a structural diagram of a rendezvous and docking planning and guidance device based on dynamic double anchor points provided by an embodiment of the present invention. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] Please refer to Figure 1 , an embodiment of the present invention provides a rendezvous and docking planning and guidance method based on dynamic double anchor points, which is applied to a landing and ascent vehicle as an active spacecraft. The method includes:

[0021] Step 100, obtaining a normal rendezvous and docking planning scheme based on a near anchor point and an emergency rendezvous and docking planning scheme based on a far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point;

[0022] Step 102, starting the rendezvous and docking process according to the normal rendezvous and docking planning scheme, and predicting the rendezvous error at the end of the long-distance guidance section in real time;

[0023] Step 104, determining whether the accuracy requirement is met based on the rendezvous error predicted in real time. If so, continue the rendezvous and docking process according to the normal rendezvous and docking planning scheme. If not, interrupt the rendezvous and docking process of the normal rendezvous and docking planning scheme and switch to the emergency rendezvous and docking planning scheme for the subsequent rendezvous and docking process.

[0024] In the embodiment of the present invention, by designing two rendezvous and docking planning schemes, one is a normal rendezvous and docking planning scheme based on a near anchor point, and the other is an emergency rendezvous and docking planning scheme based on a far anchor point. In the long-distance guidance section, the near anchor point is used as the aiming point, and the rendezvous and docking process is carried out according to the normal rendezvous and docking planning scheme, and the rendezvous error at the end of the long-distance guidance section is predicted in real time. When it is determined that the rendezvous error does not meet the accuracy requirement, it is switched to the emergency rendezvous and docking planning scheme to carry out the subsequent rendezvous and docking process, so as to achieve a safe rendezvous and docking process. It can be seen that this solution adopts a dynamic selection method of double anchor points to adapt to the change of the rendezvous error at the end of the long-distance guidance section caused by the autonomous orbit determination error, thereby improving the safety in the fast rendezvous and docking process.

[0025] The execution manners of the following described Figure 1 steps are described.

[0026] First, for step 100, obtain a normal rendezvous and docking planning scheme based on a near anchor point and an emergency rendezvous and docking planning scheme based on a far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point.

[0027] The process of the lunar lander and the spacecraft performing a manned lunar takeoff and rapid rendezvous and docking is divided into a lunar ascent stage, a long-distance guidance stage, and a short-distance guidance stage. The lunar lander acts as the active spacecraft to complete the rendezvous mission. After ascending from the lunar surface and entering the lunar orbit, through guidance in the long-distance guidance stage, the lunar lander (active spacecraft) reaches the anchor point behind the spacecraft (target spacecraft) within the specified time and meets the initial orbit requirements for entering the short-distance guidance stage.

[0028] Since the manned lunar takeoff and rendezvous and docking mission has very high requirements for both rapidity and safety, therefore, in addition to designing a normal rendezvous and docking planning scheme based on a near anchor point, an emergency rendezvous and docking planning scheme based on a far anchor point can also be designed so that when a failure occurs in the long-distance guidance stage and the normal rendezvous and docking process based on the near anchor point cannot be achieved, the emergency rendezvous and docking planning scheme can be switched to.

[0029] Among them, a typical failure in the long-distance guidance stage is that the autonomous orbit determination error causes the rendezvous error at the end of the long-distance guidance stage, which cannot meet the initial orbit requirements of the short-distance guidance stage.

[0030] In the embodiment of the present invention, the normal rendezvous and docking planning scheme based on a near anchor point and the emergency rendezvous and docking planning scheme based on a far anchor point are pre-designed and are respectively:

[0031] The normal rendezvous and docking planning scheme is:

[0032] In the lunar ascent stage, take off from the lunar surface and ascend to orbit, and then enter the long-distance guidance stage;

[0033] In the long-distance guidance stage, start flying from the orbit entry point to the near anchor point, and then enter the short-distance guidance stage;

[0034] In the short-distance guidance stage, start from the near anchor point, capture the target parking point behind the target spacecraft, perform position holding at the target parking point for the first set duration, then enter the approach stage and finally complete the docking with the target spacecraft.

[0035] The emergency rendezvous and docking planning scheme is:

[0036] In the long-distance guidance stage, first capture the far anchor point, and then enter the short-distance guidance stage;

[0037] In the close-range guidance section, starting from the far anchor point, first capture the transfer parking point located behind the target spacecraft, and perform position holding at the transfer parking point for a second set duration. Then, fly from the transfer parking point to the target parking point, and perform position holding at the target parking point for a third set duration. Then, enter the approach section and finally complete docking with the target spacecraft.

[0038] Thus, it can be seen that the emergency rendezvous and docking planning scheme, compared with the normal rendezvous and docking planning scheme, first captures the transfer parking point from the far anchor point for position holding, and then captures the target parking point to gradually approach the target spacecraft and achieve the final rendezvous and docking.

[0039] In the embodiments of the present invention, the total rendezvous and docking duration of the normal rendezvous and docking planning scheme is less than that of the emergency rendezvous and docking planning scheme.

[0040] In the above two rendezvous and docking planning schemes, the six-degree-of-freedom closed-loop control method is adopted in the approach section to complete docking with the target spacecraft. And after switching to the emergency rendezvous and docking planning scheme, the method of capturing the far anchor point is the LAMBERT guidance method or the CW guidance method.

[0041] In the embodiments of the present invention, the determination methods of the normal rendezvous and docking planning scheme, the emergency rendezvous and docking planning scheme, the near anchor point, and the far anchor point are determined based on the space-time folding method. Among them, the anchor point is a characteristic point that can affect the rendezvous and docking mission and meets the set conditions.

[0042] Taking an anchor point as an example below, the value of the anchor point and the determination method of the corresponding rendezvous and docking planning scheme are described. The near anchor point and the far anchor point are both determined according to this method (S1~S4).

[0043] S1. Determine the flight interval obtained after the anchor point divides the rendezvous and docking flight trajectory of the active spacecraft; the number of the anchor points is one; the anchor point is a characteristic point that can constrain the rendezvous and docking flight trajectory and meets the set conditions;

[0044] In the embodiments of the present invention, according to the actual mission, analyze the characteristic points that affect the rendezvous and docking mission, and define the characteristic points that can affect the flight trajectory and meet the set conditions as anchor points. This anchor point can be used as the aiming point in the long-distance guidance section. When the active spacecraft located behind conducts rendezvous and docking with the target spacecraft located in front, the active spacecraft takes the anchor point as the aiming point in the long-distance guidance section. When it is determined that the anchor point is reached, the subsequent stage of rendezvous and docking is started. This anchor point can be the relative velocity between the active spacecraft and the target spacecraft.

[0045] For the rendezvous and docking mission, both the active spacecraft and the target spacecraft fly on their respective orbits to gradually reduce the relative distance and then complete the docking. Since the orbit is an approximately circular orbit, the set conditions satisfied by the anchor point are as follows:

[0046] Vx = -1.5ωTZ, and Z = 4X / 3π;

[0047] Where, Vx is the relative velocity in the track direction between the active spacecraft and the target spacecraft, ω is the orbital angular velocity of the target spacecraft, T is the orbital period, X is the coordinate value in the track direction, and Z is the coordinate value in the direction pointing to the center of the earth.

[0048] S2. Based on the set values of the anchor point, construct the target requirements and constraint conditions for each flight interval;

[0049] For the existing rendezvous and docking mission planning problems, generally, the flight trajectory planning problem is studied. By giving a clear target requirement, satisfying certain constraint conditions, and using optimization algorithms such as genetic algorithms, convex optimization, and neural networks, an optimized flight trajectory is found.

[0050] In the embodiments of the present invention, the mission implementation and trajectory optimization are combined, and the rendezvous and docking mission planning problem is described as multiple objective optimization problems. The optimization objectives and constraint conditions of this problem are shown in Table 1:

[0051] Table 1:

[0052] Optimization objective Constraint condition 1. Time (shortest) Sensitive device measurement range (distance, field of view) 2. Fuel (most economical) Sensitive device measurement error 3. Phase adaptation ability (maximum) Guidance and control accuracy 4. Reach the forward, backward, and radial docking interfaces Trajectory safety 5. …… Safety zone 6. Docking corridor 7. TT&C coverage constraint 8. Lighting condition (sunlight suppression angle) 9. Energy requirement 10. ……

[0053] For the above optimization objectives and constraint conditions, the optimization objectives required by different mission scenarios are different, and the constraint conditions may also be different. The optimization objectives and constraint conditions are specifically determined according to the actual mission scenario.

[0054] In the embodiments of the present invention, after the set values of the anchor point are determined, the target requirements and constraint conditions for each flight interval can be constructed based on the set values of the anchor point. Specifically:

[0055] Construct the target requirement G of the i-th optimization objective in the j-th flight interval according to the following formula j,i :

[0056] G j,i = F i (t j , p)

[0057] Where, F i (t j , p) is a function of the i-th objective function value, the time t of the j-th flight interval j and the anchor point p, where, t jThe value range of is from the initial time to the end time of the j-th flight interval; when the number of anchor points p = 1, two flight intervals are obtained, that is, j = 1, 2;

[0058] Construct the objective requirement G of all optimization objectives in the j-th flight interval according to the following formula j :

[0059]

[0060] where n is the total number of optimization objectives, and k i is the weight coefficient of the i-th optimization objective;

[0061] Construct the constraint conditions of the j-th flight interval according to the following formula:

[0062] σ m (t) < c m (t j )

[0063] σ m (t) = T m (t j , p, t)

[0064] where σ m (t) is the set of constraint conditions such as lighting conditions, TT&C conditions, trajectory safety conditions, relative states, etc. during the flight process, c m (t j ) is the upper bound of the constraint conditions corresponding to the j-th flight interval, and T m (t j , p, t) is the function of the constraint condition value and the time t of the j-th flight interval j and the anchor point p.

[0065] The purpose of setting the anchor point is to decouple multiple strong constraints and make multiple optimization objectives achievable, so as to cope with normal / fault and other situations.

[0066] S3. According to the objective requirements and constraint conditions of each flight interval, combined with the existing flight phase division method and the guidance law adopted in the flight phase, iteratively solve the planning scheme of each flight interval;

[0067] The rendezvous and docking mission planning is closely related to the division of each stage of the rendezvous and docking mission. The existing division methods of flight stages are as follows: the launch stage from the launch point to the orbital insertion point, the long-range guidance stage from the orbital insertion point to the initial aiming point, the close-range guidance stage from the initial aiming point to the contact point, the docking stage from the contact point to the docking point, and the combined body stage from the docking point to the separation point. Among them, the close-range guidance stage can be further divided into the homing stage, the approach stage, and the translation and approach stage. Among them, the guidance laws for the long-range guidance stage, the homing stage, the approach stage, and the translation and approach stage are multi-variable coordinated guidance, CW guidance, line-of-sight guidance, and golden section phase plane control respectively.

[0068] Correspondingly, each flight stage corresponds to a set of time and space, which are described by flight time and relative distance. If the flight time is zero and the relative distance is also zero, it can be understood that this period of time and space is folded; if the flight time is not zero, using the corresponding guidance law, a certain relative distance approach can be achieved. These have solutions in theory and successful experiences in engineering. Therefore, the flight mission planning can be quickly realized by using the time and space folding method.

[0069] Through the setting of anchor points and time and space folding, the optimization problem of complex multi-task objectives is degraded and decomposed into simple and easy-to-solve optimization problems, thus becoming an optimization problem that is feasible and easy to implement in engineering. The process of rendezvous and docking is from far to near, and the control is from rough to precise. After introducing the anchor points, the original complex rendezvous and docking optimization problem is degraded into the optimization problem from the orbital insertion point to the anchor point and then from the anchor point to the docking point. There are prior optimization methods for the optimization problem from the orbital insertion point to the anchor point, and there is also prior knowledge for the optimization from the anchor point to the docking point, that is, the optimization through the anchor point is definitely solvable. The introduction of anchor points enables the rendezvous and docking process to converge from the rough error control at the orbital insertion point to the error range allowed by the anchor point, and then converge from the error range control of the anchor point to meet the final docking accuracy requirements, thereby also grading and decomposing the difficulty of the optimization problem. The setting of anchor points depends on the main bottleneck constraints and is finally determined through optimization iteration.

[0070] Specifically, the planning scheme of each flight interval is iteratively solved in the following way:

[0071] Step A1: Set an initial value for the set value of the anchor point based on the set conditions;

[0072] Step A2: Based on the current set value of the anchor point, optimize the planning scheme of each flight interval by using the time and space folding method;

[0073] Step A3: Determine whether the optimized planning scheme meets the end condition. If it meets the end condition, use the current set value of the anchor point as the aiming point of the rendezvous and docking flight trajectory; if it does not meet the end condition, adjust the set value of the anchor point, reconstruct the target requirements and constraint conditions for each flight interval based on the set value of the anchor point, and return to Step A2.

[0074] Optimize the planning scheme for each flight interval by using the space-time folding method. Specifically, the space-time folding method is as follows: fold the flight phase with a flight time of 0; and / or fold the flight phase with both the relative velocity and relative distance being 0; and / or add flight phases based on mission requirements.

[0075] It should be noted that the space-time folding method can incorporate human experience to achieve free addition, deletion, and planning of flight phases to meet different mission requirements.

[0076] In the embodiment of the present invention, the end condition is as follows:

[0077] Condition 1: Each flight interval meets the target requirements of the corresponding flight interval; and,

[0078] Condition 2: Among two adjacent flight intervals, the end state of the previous flight interval is completely covered by the initial conditions of the next flight interval.

[0079] Condition 1 is used to ensure that each flight interval can meet the corresponding target requirements, that is, under the corresponding constraint conditions, the planning scheme can meet the corresponding target requirements. Condition 2 is used to ensure the reasonable connection between two adjacent flight intervals. Neither of them can be missing.

[0080] Taking the example of dividing the flight trajectory into two flight intervals by an anchor point, in step A1, assume the initial value is V0. Thus, the complex multi-strong-constraint multi-objective optimization problem is transformed into an optimization problem from the orbit insertion point to V0 and from V0 to the docking point. According to the foregoing description, there is a prior optimization method for the optimization problem from the orbit insertion point to the anchor point, and there is also prior knowledge for the optimization from the anchor point to the docking point, that is, the optimization through the anchor point is determined to have a feasible solution. Therefore, in step A2, the optimized planning schemes for the two flight intervals can be obtained. In step A3, after the interval optimization is completed, overall coordination is still required. It is necessary to ensure that the planning scheme for each flight interval meets the end condition. If it is satisfied, the V0 point is recorded as the determined Vd; if not, the set value of the anchor point is adjusted to V1. Since the set value of the anchor point has changed, the constraint conditions and target requirements for each flight interval need to be adjusted accordingly, and then return to step A2 to re-obtain the planning scheme for each flight interval under this set value. Assume that V1, V2,... Vn are iterated until Vn meets the end condition, then the Vn point is recorded as the determined Vd. After Vd is determined, the corresponding planning scheme is also determined. The planning scheme includes the flight time, relative distance, guidance strategy, and flight orbit of each flight stage, and Vd is determined as the aiming point or parking point on the flight trajectory.

[0081] It should be noted that the adjustment principle of the set value of the anchor point needs to be determined according to specific tasks in combination with manual experience. According to the setting conditions of the anchor point, the relative distance is adjusted, and then the orbital height difference is adjusted accordingly.

[0082] In addition, it should also be noted that the space-time folding method can occur before the iteration or during the iteration.

[0083] S4. Output the planning scheme of the rendezvous and docking mission based on the solution results.

[0084] Since the planning scheme for each flight interval has been determined, it indicates that the planning scheme for the entire rendezvous and docking mission has been determined. After the planning scheme of the rendezvous and docking mission is output, parameter configuration can be performed based on the flight time and relative distance of each flight stage in the output planning scheme, so as to complete the design of the planning scheme of the rendezvous and docking mission by using the configured parameters.

[0085] That is to say, using the above scheme, a normal rendezvous and docking planning scheme based on the near anchor point and an emergency rendezvous and docking planning scheme based on the far anchor point can be obtained.

[0086] Then, for step 102, start the rendezvous and docking process according to the normal rendezvous and docking planning scheme, and predict the rendezvous error at the end of the long-distance guidance section in real time.

[0087] The emergency rendezvous and docking planning scheme is an emergency scheme that will only be used when the rendezvous error at the end of the long-distance guidance section does not meet the accuracy requirements during the long-distance guidance section. Therefore, during the lunar ascent section and the long-distance guidance section, the near anchor point is used as the aiming point. That is to say, the relative distance between the two spacecraft gradually decreases. When it is determined that the relative distance to the target spacecraft has decreased to the relative distance corresponding to the near anchor point, that is, the near anchor point is captured, the close-range guidance section begins.

[0088] In order to ensure that the rendezvous error at the end of the long-distance guidance section can meet the accuracy requirements, it is necessary to continuously correct the orbit deviation synchronously during the long-distance guidance section. The orbit deviation includes but is not limited to: orbit phase difference, orbit plane deviation, and orbit apsidal line deviation. And during the long-distance guidance section, the rendezvous error at the end of the long-distance guidance section is predicted in real time. Specifically, the prediction method is realized by combining the orbit determination data provided by the autonomous navigation system with the orbit extrapolation model.

[0089] Finally, for step 104, it is determined whether the accuracy requirements are met based on the rendezvous error obtained by real-time prediction. If so, the rendezvous and docking process continues according to the normal rendezvous and docking planning scheme. If not, the rendezvous and docking process of the normal rendezvous and docking planning scheme is interrupted, and the emergency rendezvous and docking planning scheme is switched to for the subsequent rendezvous and docking process.

[0090] In the embodiment of the present invention, the subsequent rendezvous and docking process switched to the emergency rendezvous and docking planning scheme is as follows:

[0091] During the long-distance guidance section, first capture the far anchor point, and then enter the close-range guidance section;

[0092] During the close-range guidance section, starting from the far anchor point, first capture the transition parking point located behind the target spacecraft, and after maintaining the position at the transition parking point for a second set duration, fly from the transition parking point to the target parking point, and after maintaining the position at the target parking point for a third set duration, enter the approaching section and finally complete the docking with the target spacecraft.

[0093] It can be seen that the aiming point is switched from the near anchor point to the far anchor point. After capturing the far anchor point, it is necessary to first capture a relatively far transition parking point, and then fly from the transition parking point to the target parking point, and complete the docking after entering the approaching section.

[0094] In one embodiment of the present invention, the switching of the rendezvous and docking planning scheme is based on the long-distance guidance section. During the rendezvous and docking process according to the normal rendezvous and docking planning scheme, when it is determined that the relative distance to the target spacecraft reaches the relative distance corresponding to the far anchor point, the process of real-time predicting the rendezvous error at the end of the long-distance guidance section is stopped. Subsequently, the rendezvous and docking process continues according to the normal rendezvous and docking planning scheme. This is because after the relative distance reaches the relative distance corresponding to the far anchor point, the relative distance will gradually decrease, so it is impossible to switch to the emergency rendezvous and docking planning scheme of the far anchor point.

[0095] The above-mentioned rendezvous and docking process will be described below with a simulation example.

[0096] It is set that the latitude and longitude of the landing position in the lunar fixed coordinate system are 20° and 10° respectively; the spacecraft (target spacecraft) is located in a near-circular lunar orbit with an orbital altitude of 110 km; described in the spacecraft orbit coordinate system (the origin is the center of mass of the spacecraft, the Z-axis points to the center of the moon, the Y-axis points to the opposite direction of the orbital angular velocity, and the X-axis conforms to the right-hand rule), and the far anchor point is set as X Far = [-22 0 10.0], and the near anchor point is X Near = [-7 0 3.0]; the initial mass of the landing ascent vehicle (active spacecraft) is 10,000 kg; a 40,000 N engine is used during the powered ascent process; the perigee / apogee altitude of the target injection orbit of the landing ascent vehicle is 15×80 km.

[0097] Among them, Table 2 gives the orbital parameters of the landing ascent vehicle after entering the orbit (UTC time is 2026.12.10:0:0.0).

[0098] Table 2:

[0099]

[0100] The simulation starts from the lunar surface ascent. The long-distance guidance section guidance is aimed at the near anchor point. After the 3rd guidance execution is completed, it is determined that the rendezvous error at the end of the long-distance guidance section does not meet the accuracy requirements. It is selected to re-aim at the far anchor point, and the normal rendezvous process is transferred to the emergency rendezvous process. The LAMBERT guidance strategy is used to capture the far anchor point, and then the 2 km transition parking point is captured, and finally the 200 m target parking point is captured.

[0101] Table 3 gives the relative states at the key points of capturing the far anchor point, capturing the transition parking point, and capturing the target parking point. x, y, z are the relative positions, and vx, vy, vz are the relative velocities.

[0102] Table 3:

[0103] <![CDATA[x (m) > y z <![CDATA[vx (m / s) > vy vz Capture the far anchor point 21998.957 63.599 10190.038 -13.495 -0.027 -0.363 Capture the 2 km transition parking point 1976.179 -0.221 19.248 -0.092 0.011 -0.074 Capture the 200 target parking point 207.908 1.396 29.978 -0.208 -0.037 -0.419

[0104] Among them, the capture far-anchoring point position error is less than 200 m, the capture transition parking point position error is less than 30 m, and the capture target parking point position error is less than 30 m. It can ensure that the entire lunar takeoff and rendezvous and docking process is completed within 6 hours.

[0105] As Figure 2 , Figure 3 shown, based on the same concept as the above-mentioned rendezvous and docking planning guidance method based on dynamic double anchors, the embodiment of the present invention also provides a rendezvous and docking planning guidance device based on dynamic double anchors. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. In terms of the hardware level, as Figure 2 shown, it is a hardware architecture diagram of an electronic device where a rendezvous and docking planning guidance device based on dynamic double anchors provided by the embodiment of the present invention is located. In addition to Figure 2 the shown processor, memory, network interface, and non-volatile memory, the electronic device where the device is located in the embodiment usually may also include other hardware, such as a forwarding chip responsible for processing packets, etc. Taking software implementation as an example, as Figure 3 shown, as a logically meaningful device, it is formed by the CPU of its corresponding electronic device reading the corresponding computer program in the non-volatile memory into the memory and running. A rendezvous and docking planning guidance device based on dynamic double anchors provided by the present embodiment is applied to a landing and ascent vehicle as an active spacecraft. The device includes:

[0106] An acquisition unit 301, configured to acquire a normal rendezvous and docking planning scheme based on a near anchor point and an emergency rendezvous and docking planning scheme based on a far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point;

[0107] A prediction unit 302, configured to start a rendezvous and docking process according to the normal rendezvous and docking planning scheme, and predict the rendezvous error at the end of the long-distance guidance section in real time;

[0108] A scheme switching processing unit 303, configured to determine whether the accuracy requirement is met based on the rendezvous error predicted in real time. If so, continue the rendezvous and docking process according to the normal rendezvous and docking planning scheme. If not, interrupt the rendezvous and docking process of the normal rendezvous and docking planning scheme, and switch to the emergency rendezvous and docking planning scheme for the subsequent rendezvous and docking process.

[0109] In an embodiment of the present invention, during the rendezvous and docking process according to the normal rendezvous and docking planning scheme, when it is determined that the relative distance from the target spacecraft reaches the relative distance corresponding to the far anchor point, the process of predicting the rendezvous error at the end of the long-distance guidance section in real time is stopped.

[0110] It can be understood that the structure illustrated in the embodiments of the present invention does not constitute a specific limitation on a rendezvous and docking planning and guidance device based on dynamic double anchor points. In other embodiments of the present invention, a rendezvous and docking planning and guidance device based on dynamic double anchor points may include more or fewer components than those illustrated, or combine certain components, or split certain components, or have different component arrangements. The illustrated components can be implemented in hardware, software, or a combination of software and hardware.

[0111] Regarding the information interaction, execution process, etc. among the various modules within the above-mentioned device, since they are based on the same concept as the method embodiments of the present invention, the specific content can be referred to the descriptions in the method embodiments of the present invention, and will not be elaborated here.

[0112] The embodiments of the present invention further provide an electronic device, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, a rendezvous and docking planning and guidance method according to any one of the embodiments of the present invention is implemented.

[0113] The embodiments of the present invention further provide a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the processor is caused to execute a rendezvous and docking planning and guidance method according to any one of the embodiments of the present invention.

[0114] Specifically, a system or device equipped with a storage medium can be provided. Software program codes for implementing the functions of any one of the above-mentioned embodiments are stored on the storage medium, and the computer (or CPU or MPU) of the system or device is caused to read and execute the program codes stored on the storage medium.

[0115] In this case, the program code read from the storage medium itself can implement the functions of any one of the above-mentioned embodiments. Therefore, the program code and the storage medium storing the program code constitute a part of the present invention.

[0116] Embodiments of the storage medium for providing program codes include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Optionally, the program codes can be downloaded from a server computer via a communication network.

[0117] In addition, it should be clear that not only can the actual operations be completed in part or in whole by executing the program codes read by the computer, but also by means of instructions based on the program codes through an operating system operating on the computer, etc., so as to implement the functions of any one of the above-mentioned embodiments.

[0118] In addition, it can be understood that the program code read from the storage medium is written into the memory provided in the expansion board inserted into the computer or the memory provided in the expansion module connected to the computer. Subsequently, based on the instructions of the program code, the CPU or the like installed on the expansion board or the expansion module is made to execute part or all of the actual operations, thereby implementing the functions of any one of the above embodiments.

[0119] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0120] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including the above method embodiments; and the foregoing storage medium includes various media such as ROM, RAM, magnetic disk or optical disc that can store program code.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rendezvous and docking planning guidance method based on dynamic double anchor points, characterized in that, it is applied to the landing and ascent vehicle as the active spacecraft, and the method includes: Obtaining a normal rendezvous and docking planning scheme based on the near anchor point and an emergency rendezvous and docking planning scheme based on the far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point; Starting the rendezvous and docking process according to the normal rendezvous and docking planning scheme, and predicting the rendezvous error at the end of the long-distance guidance section in real time; Determining whether the accuracy requirement is met based on the rendezvous error obtained by real-time prediction. If so, continue the rendezvous and docking process according to the normal rendezvous and docking planning scheme. If not, interrupt the rendezvous and docking process of the normal rendezvous and docking planning scheme and switch to the emergency rendezvous and docking planning scheme for the subsequent rendezvous and docking process; The rendezvous and docking process of the normal rendezvous and docking planning scheme is as follows: in the lunar ascent section, take off from the lunar surface and ascend to orbit, and then enter the long-distance guidance section; in the long-distance guidance section, start from the orbit entry point and fly to the near anchor point, and then enter the close-range guidance section; in the close-range guidance section, start from the near anchor point, capture the target parking point behind the target spacecraft, perform position holding at the target parking point for a first set duration, and then enter the approach section and finally complete docking with the target spacecraft; The subsequent rendezvous and docking process switched to the emergency rendezvous and docking planning scheme is as follows: in the long-distance guidance section, first capture the far anchor point, and then enter the close-range guidance section; in the close-range guidance section, start from the far anchor point, first capture the transition parking point located behind the target spacecraft, and perform position holding at the transition parking point for a second set duration, then fly from the transition parking point to the target parking point, and perform position holding at the target parking point for a third set duration, and then enter the approach section and finally complete docking with the target spacecraft.

2. The method according to claim 1, characterized in that, the total rendezvous and docking duration of the normal rendezvous and docking planning scheme is less than the total rendezvous and docking duration of the emergency rendezvous and docking planning scheme.

3. The method according to claim 1, characterized in that, it further includes: During the rendezvous and docking process according to the normal rendezvous and docking planning scheme, when it is determined that the relative distance from the target spacecraft reaches the relative distance corresponding to the far anchor point, stop the process of predicting the rendezvous error at the end of the long-distance guidance section in real time.

4. A rendezvous and docking planning guidance device based on dynamic double anchor points, characterized in that, it is applied to the landing and ascent vehicle as the active spacecraft, and the device includes: An acquisition unit for obtaining a normal rendezvous and docking planning scheme based on the near anchor point and an emergency rendezvous and docking planning scheme based on the far anchor point; the relative distance corresponding to the far anchor point is greater than the relative distance corresponding to the near anchor point; A prediction unit for predicting the rendezvous error at the end of the long-distance guidance section in real time during the rendezvous and docking process according to the normal rendezvous and docking planning scheme; A scheme switching processing unit, configured to determine whether the accuracy requirement is met based on the rendezvous error obtained by real-time prediction. If so, continue the rendezvous and docking process according to the normal rendezvous and docking planning scheme; if not, interrupt the rendezvous and docking process of the normal rendezvous and docking planning scheme, and switch to the emergency rendezvous and docking planning scheme for the subsequent rendezvous and docking process; The rendezvous and docking process of the normal rendezvous and docking planning scheme is as follows: In the lunar ascent stage, take off from the lunar surface and ascend to orbit, and then enter the far-range guidance stage; in the far-range guidance stage, fly from the orbit insertion point to the near anchor point, and then enter the close-range guidance stage; in the close-range guidance stage, start from the near anchor point, capture the target parking point behind the target spacecraft, perform position holding at the target parking point for a first set duration, then enter the approach stage and finally complete docking with the target spacecraft; The subsequent rendezvous and docking process after switching to the emergency rendezvous and docking planning scheme is as follows: In the far-range guidance stage, first capture the far anchor point, and then enter the close-range guidance stage; in the close-range guidance stage, start from the far anchor point, first capture the transition parking point located behind the target spacecraft, perform position holding at the transition parking point for a second set duration, then fly from the transition parking point to the target parking point, perform position holding at the target parking point for a third set duration, then enter the approach stage and finally complete docking with the target spacecraft.

5. The device according to claim 4, wherein, In the process of performing the rendezvous and docking process according to the normal rendezvous and docking planning scheme, when it is determined that the relative distance from the target spacecraft reaches the relative distance corresponding to the far anchor point, the process of real-time predicting the rendezvous error at the end of the far-range guidance stage is stopped.

6. An electronic device, comprising a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the method according to any one of claims 1-3 is implemented.

7. A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed in a computer, the computer is made to execute the method according to any one of claims 1-3.

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