CN112455724B - Space passive object transfer method based on throwing, striking and receiving - Google Patents

Space passive object transfer method based on throwing, striking and receiving Download PDF

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CN112455724B
CN112455724B CN202011334556.6A CN202011334556A CN112455724B CN 112455724 B CN112455724 B CN 112455724B CN 202011334556 A CN202011334556 A CN 202011334556A CN 112455724 B CN112455724 B CN 112455724B
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satellite
throwing
satellites
passive object
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CN112455724A (en
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郑子轩
李晨
朱战霞
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Northwestern Polytechnical University
Shenzhen Institute of Northwestern Polytechnical University
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Shenzhen Institute of Northwestern Polytechnical University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/242—Orbits and trajectories
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

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Abstract

The invention discloses a space passive object transfer method based on throwing, striking and receiving, which comprises the following steps: step 1: determining a throwing scheme according to the shielding condition between the current position and the target position of the passive object; step 2: selecting service satellites participating in the task and a hitting point range according to current positions of all service satellites, task energy and time constraints; and step 3: optimizing to obtain a hitting point position and a reference track of each service satellite based on the selected service satellite; and 4, step 4: generating an expanded reference track based on the reference track obtained by optimization; and 5: and (4) executing the throwing scheme determined in the step (1), tracking the extended reference track, and realizing the transfer of the passive object. The passive object is moved by moving different service satellites, so that the service satellites do not need to move for a long time and the overall energy consumption of the system can be reduced.

Description

Space passive object transfer method based on throwing, striking and receiving
Technical Field
The invention belongs to the technical field of space target transfer, and particularly relates to a space passive object transfer method based on throwing, hitting and receiving.
Background
Along with the continuous extension of the function of space station, the volume of space station is constantly increased, and in some out-of-station maintenance assembly work, the distance between the part bin and the working surface exceeds the working space of the mechanical arm of the space station.
The existing solutions are of two types, one is that a track is arranged on the outer surface of the space station for the mechanical arm to move, and the other is that an object is dragged to a working surface by using a flying service satellite. The first method is difficult to apply because the space station is formed by splicing cabin sections with different specifications at different periods. The second method requires the service satellite to move repeatedly, increasing energy consumption.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a space passive object transfer method based on throwing, striking and receiving, and solves the problems that a service satellite needs to move repeatedly during the transfer of a part bin in the outside-station maintenance and assembly work of a space station at present, and the energy consumption is large.
In order to achieve the purpose, the invention provides the following technical scheme: a space passive object transfer method based on throwing, hitting and accessing comprises the following steps:
step 1: determining a throwing scheme according to the shielding condition between the current position and the target position of the passive object;
step 2: selecting service satellites participating in the task and a hitting point range according to current positions of all service satellites, task energy and time constraints;
and 3, step 3: optimizing to obtain a hitting point position and a reference track of each service satellite based on the selected service satellite;
and 4, step 4: generating an expanded reference track based on the reference track obtained by optimization;
and 5: and (4) executing the throwing scheme determined in the step (1), tracking the extended reference track, and realizing the transfer of the passive object.
Further, the specific steps of step 1 are as follows:
when no shielding object exists between the current position and the target position of the driven object or the shielding object between the current position and the target position of the driven object can be adjusted and avoided through the positions of the throwing satellite and the receiving satellite, the beating satellite does not need to be moved to beat; otherwise, the hitting satellite needs to be moved to carry out relay hitting.
Further, the number of hit satellites is several.
Further, the number of the hit satellites is determined according to task energy, time constraint, the condition of the sheltered object on the throwing path and the distribution condition of the service satellites.
Further, the specific steps of step 2 are as follows:
selecting service satellites participating in the task according to the current positions of all the service satellites, task energy and time constraints, and respectively selecting a first service satellite and a second service satellite nearby from the service satellites participating in the task according to the current positions and the target positions of the passive objects;
when the remaining momentum direction of the first service satellite after grabbing the target can avoid the shielding object or the path from the second service satellite to the target position can avoid the shielding object, the first service satellite is selected as a throwing satellite and the second service satellite is selected as an access satellite, otherwise, a plurality of hitting satellites are required to be selected nearby.
Further, the reference trajectory and the hit point position of each service satellite are calculated by a direct method trajectory optimization method based on the collision system in the step 3.
Further, the reference trajectory in step 4 is a segmented continuous system composed of a plurality of segments divided by the calculated collision time, the segments are discontinuous, and forward expansion and reverse expansion are performed on each segment to obtain virtual motion trajectories of the collision system before and after the collision time, which are used as expanded reference trajectories.
Further, in the step 5, a current segment of the extended reference trajectory is tracked according to the state quantity of the service satellite and the state quantity of the passive object, and a next segment of the extended reference trajectory is tracked after jumping when a real collision is detected.
Compared with the prior art, the invention has at least the following beneficial effects:
the invention provides a space passive object transfer method based on throwing, striking and receiving, aiming at the transfer of space passive objects, a service spacecraft is not required to move repeatedly, the energy required by a single service spacecraft is reduced, when no shielding object exists between the current position and the target position of the passive object or the shielding object between the current position and the target position of the passive object can be adjusted and avoided through the positions of a throwing satellite and a receiving satellite, the passive object is directly thrown out through one service satellite without moving the throwing satellite to strike, the other service satellite is directly received at a receiving point, the service satellite only needs to move in a short distance and throw the passive object to require energy, and when the shielding object between the current position and the target position of the passive object is difficult to strike through the throwing satellite and the receiving satellite to change the path of the passive object, the passive object is moved by moving different service satellites, so that the service satellites do not need to move for a long time and the overall energy consumption of the system can be reduced.
Furthermore, the service satellite participating in the task is selected in the step 2, so that the whole optimization result is not the global optimal solution, the calculation amount of the global optimal solution is large, the calculation amount can be greatly reduced by selecting the task satellite in advance, the local optimal solution can be quickly obtained, and the optimization speed is accelerated.
Drawings
FIG. 1 is a schematic diagram of a space passive object transfer task based on throwing, hitting and picking according to the present invention;
FIG. 2 is a schematic diagram of an extended reference trajectory according to the present invention;
in the drawings: 1-space station, 2-service satellite, 3-passive object, 4-first target position, 5-hitting position, 6-motion track of passive object, 7-second target position, 8-throwing position avoiding shielding, 9-third target position, 10-reference track, 11-actual track, 12-reverse extension section of reference track, 13-forward extension section of reference track, 14-jumping time of reference track, and 15-jumping time of actual track.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
As shown in fig. 1, the invention provides a space passive object transfer method based on throwing, striking and receiving, which performs task design according to the constraint of transfer tasks and the distribution situation of service satellites flying around a space station 1, and designs a reference track 10 for each service satellite; the reference trajectory 10 is expanded offline, and tracking control is performed with the expanded trajectory as a final reference trajectory. The method comprises the following specific steps:
step 1: determining a throwing scheme according to the shielding condition between the current position and the target position of the passive object 3 to be transferred; if the shielding object does not exist or can be eliminated through the adjustment of the position of the throwing satellite, the service satellite 2 is not moved to strike; if the shielding object cannot be avoided, one service satellite 2 is transferred to carry out striking, the striking satellites can not be limited to one time, striking points are determined according to the throwing scheme and the distribution situation of the service satellites in the step 1, and the number of the striking satellites is determined according to task energy, time constraint, the situation of the shielded object on the throwing path and the distribution situation of the service satellites; the motion trajectory 6 of the passive object is shown in fig. 1.
Specifically, the method comprises the following steps: as shown in fig. 1: if the current position is not blocked from the target position, such as the situation between the current position and the first target position 4, calling one accompanying service satellite 2 to throw the passive object 3, and calling another service satellite to access the object near the first target position 4; if the shielding angle is small, namely the condition between the current position and the second target position 7, the movement amount of the throwing satellite or the receiving satellite can be accepted, namely the energy required by the movement amount of the service satellite 2 can meet the requirement that the service satellite 2 completes movement, the passive object 1 moves to the throwing position where shielding is avoided, the throwing point of the throwing satellite also moves to the throwing position where shielding is avoided 8 or the passive object is not moved, the receiving point of the receiving satellite moves to 4, only two service satellites are required to be moved to complete throwing and receiving, and extra service satellites are not required to be moved to perform relay striking. If the shielding object can not avoid the third target position 9, for example, an additional service satellite needs to be moved to hit at the hitting position 5, so that the passive object bypasses the shielding object and reaches the third target position 9.
Under general conditions, the target position can be reached without out-of-plane transfer, and only two service satellites are needed to be used as a throwing satellite and a receiving satellite; if out-of-plane transfer is required, a service satellite is additionally called to hit the satellite.
Step 2: according to the current positions of all the service satellites 2 and the task energy or time constraints, selecting the service satellites 2 participating in the task and the range of a hitting point from all the service satellites 2, and preferably considering the service satellite 2 closest to the hitting point by the hitting satellite; the task energy mainly refers to energy consumed by the movement of the center of mass and the posture adjustment of the service satellite 2 and the movement of the mechanical arm. In one task, possible energy constraints include: the total energy consumption of all the service satellites or the energy remaining after all the service satellites complete the mission is as average as possible. The time constraint is the time it takes for the passive object to eventually reach the target position from the start of the task.
Specifically, the method comprises the following steps: suppose a space station has a large number of satellite services available for invocation. The track optimization problem considering collision is a strong nonlinear problem, a global optimal solution cannot be obtained, the calculated amount is large, the calculated amount can be greatly reduced by selecting the service satellite participating in the task in advance, and a local optimal solution can be quickly obtained; the throwing satellite and the receiving satellite are generally selected nearby according to the position of a passive object; if the remaining momentum direction of one service satellite after grabbing the target can avoid the shielding or the path from one service satellite to the target position can avoid the shielding, the two service satellites are selected as a throwing satellite and a receiving satellite. And (4) selecting a hitting point according to the throwing scheme and the service satellite distribution in the step (1).
And 3, aiming at the selected service satellite, calculating a reference track by adopting a direct method track optimization method based on a collision system.
The specific calculation steps are as follows: the kinetic equation for a mission satellite or passive object is as follows:
Figure BDA0002796802100000051
in the formula: m is a mass matrix of the satellite or the passive object; q is the position in the state quantity, the angle quantity;
Figure BDA0002796802100000052
the speed in the state quantity, the angular velocity quantity (first derivative of q),
Figure BDA0002796802100000053
the acceleration in the state quantity, the angular acceleration amount (second derivative of q), C is a nonlinear term, τ is the driving force, J is the jacobian matrix, and f is the external force, which is referred to herein as the collision force.
Collisions are modeled based on complementary constraints, which are typically as follows:
Figure BDA0002796802100000054
complementary constraints describe two mutually exclusive constraints z ≧ 0 and g (z) ≧ 0. At least one constraint is 0 to satisfy z · g (z) 0. The complementary constraint can be described compactly as 0 ≦ z ≦ g (z) ≧ 0.
Similarly, the collision is described as
0≤φn(q)⊥fn≥0
Figure BDA0002796802100000061
Figure BDA0002796802100000062
Wherein phinNormal distance, f, representing potential contact pointsnIndicating the normal force of the collision. f. oftThe tangential direction of the collision is represented, here broken down into d directions for ease of calculation. γ is an auxiliary parameter and ψ (q, q.) is the tangential velocity.
The direct method disperses the track into N nodes, optimizes the state quantity and the control quantity of the whole track, and describes the dynamics of the system in a constraint mode. The method does not need to carry out forward dynamic simulation in the optimization process, and avoids numerical difficulties in the forward method. In the general form of
Figure BDA0002796802100000063
In the formula: gfIs the terminal objective function; q. q.sNIs the terminal state quantity; h is a time step length; g is a process objective function; q. q.skThe state at the moment k; u. ofkIs the control input at time k; lambda [ alpha ]kIs a collision force; u is the value range of the control quantity; q is the value range of the state quantity.
In this form, the constraint structure of the direct method considering collisions is as follows for the (k + 1) th node
Figure BDA0002796802100000064
Figure BDA0002796802100000065
0≤φn(qk+1)⊥fn,k+1≥0
Figure BDA0002796802100000066
Figure BDA0002796802100000067
The constraints of all the state quantities and the control quantities on all the nodes jointly form the constraint of the optimization problem. By solving the optimization problem, the state quantity, the control quantity, the collision force and the like of the service satellite and the passive object at each time node can be obtained. And interpolating the state quantity and the control quantity to obtain a reference track and a reference control input. The optimization problem has high dimensionality, but is sparse and can be solved by using the existing solver.
Step 4, performing forward and reverse expansion on each segment of the generated reference track to generate an expanded reference track; the expanded reference track is segmented into calculated collision points calculated by optimization, and the forward and reverse expansion is the motion track of the system on the assumption that collision constraint does not exist.
As shown in fig. 2, the actual trajectory 11 and the reference trajectory 10 are biased, and since the collision system is typically a discontinuous system, in the trajectory tracking problem we describe it as a hybrid system. The hybrid system consists of reference tracks 10 and jump moments 14 of the reference tracks connecting the reference tracks, as shown in fig. 2. For a collision system, the collision time is the jump time. In general, due to errors, the transition time 14 of the reference trajectory does not coincide with the transition time 15 of the actual trajectory, and the control system tends to diverge before and after the transition time. To solve this problem, we introduce an extended reference trajectory. For each segment, the segment is expanded in the forward direction and the reverse direction into a reverse expansion segment 13 of the reference track and a forward expansion segment 12 of the reference track, respectively, as shown in fig. 2, and during tracking, the expanded reference track is switched only after a jump time 15 of the actual track occurs.
Step 5, executing a task, tracking the extended reference track, and realizing the transfer of the passive object; and tracking the current segment of the extended reference track by the state quantity of the service satellite and the state quantity of the passive object until a real collision is detected and switching to the next segment, wherein the state quantity of the service satellite and the state quantity of the passive object respectively comprise the mass center position, the speed, the acceleration, the attitude angle, the angular velocity, the angular acceleration, the angle of a mechanical arm joint of the service satellite, the angular velocity and the angular acceleration of the service satellite.
Specifically, the method comprises the following steps: after the extended track is obtained through off-line calculation, the tracking control can be completed according to a general tracking control method:
Figure BDA0002796802100000071
。

Claims (7)

1. a space passive object transfer method based on throwing, hitting and accessing is characterized by comprising the following steps:
step 1: determining a throwing scheme according to the shielding condition between the current position and the target position of the passive object (3);
and 2, step: selecting the service satellites (2) participating in the task and the range of the hitting point according to the current positions of all the service satellites (2), the task energy and the time constraint;
the specific steps of the step 2 are as follows:
selecting service satellites (2) participating in the task according to the current positions of all the service satellites (2), task energy and time constraints, and respectively selecting a first service satellite and a second service satellite nearby from the service satellites (2) participating in the task according to the current positions and the target positions of the passive objects (3);
when the remaining momentum direction of the first service satellite after grabbing the target can avoid an obstructing object or the path from the second service satellite to the target position can avoid the obstructing object, the first service satellite is selected as a throwing satellite and the second service satellite is selected as a receiving satellite, otherwise, a plurality of hitting satellites are required to be selected nearby;
and step 3: optimizing and obtaining the positions of the hit points and the reference tracks of the service satellites (2) based on the selected service satellites (2);
and 4, step 4: generating an expanded reference track based on the reference track obtained by optimization;
and 5: and (3) executing the throwing scheme determined in the step (1), tracking the extended reference track, and realizing the transfer of the passive object (3).
2. The method for transferring the space passive object based on the throwing striking and accessing as claimed in claim 1, wherein the specific steps of the step 1 are as follows:
when no shielding object exists between the current position of the driven object (3) and the target position or the shielding object between the current position of the driven object (3) and the target position can be adjusted and avoided through the positions of the throwing satellite and the receiving satellite, the beating satellite does not need to be moved to beat; otherwise, the beating satellite needs to be mobilized for relay beating.
3. The method for transferring the space passive object based on the throwing striking and accessing as claimed in claim 2, wherein the number of the striking satellites is several.
4. The method for transferring the space passive objects based on throwing and hitting access is characterized in that the number of hitting satellites depends on task energy, time constraints, the condition of the blocked objects on the throwing and hitting path and the distribution condition of service satellites.
5. The method for transferring the space passive object based on throwing, hitting and accessing as claimed in claim 1, wherein the reference trajectory and the hit point position of each service satellite are calculated by the direct method trajectory optimization method based on the collision system in the step 3.
6. The method for transferring the space passive object based on the throwing striking pick-up as claimed in claim 1, wherein the reference trajectory in step 4 is a segmented continuous system consisting of a plurality of segments divided by the calculated collision time, the segments are discontinuous, and forward expansion and reverse expansion are performed on each segment to obtain the virtual motion trajectory of the collision system before and after the collision time as the expanded reference trajectory.
7. The method for transferring the passive object in the space based on the throwing striking pick-up as claimed in claim 1, wherein in the step 5, the current segment of the extended reference track is tracked according to the state quantity of the service satellite and the state quantity of the passive object, and the next segment of the extended reference track is tracked after the jump when the real collision is detected.
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CN109591017A (en) * 2019-01-07 2019-04-09 西北工业大学 Robot for space captures the method for planning track after Tum bling Target

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US6843446B2 (en) * 1993-11-12 2005-01-18 David D. Scott Apparatus and methods for in-space satellite operations
WO2014111159A1 (en) * 2013-01-18 2014-07-24 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Determining a speed of a multidimensional motion in a global coordinate system

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Publication number Priority date Publication date Assignee Title
US6417798B1 (en) * 1999-10-18 2002-07-09 Astrium Gmbh Method and apparatus for position and attitude control of a satellite
JP2003081196A (en) * 2001-09-13 2003-03-19 Communication Research Laboratory Satellite orbit determining method
CN104520914A (en) * 2012-05-07 2015-04-15 罗伯特·布里斯克曼 Autonomous satellite orbital debris avoidance system and method
CN109591017A (en) * 2019-01-07 2019-04-09 西北工业大学 Robot for space captures the method for planning track after Tum bling Target

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