CN114684388A - Method for realizing on-satellite autonomous mission planning based on orbital system sun vector - Google Patents
Method for realizing on-satellite autonomous mission planning based on orbital system sun vector Download PDFInfo
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- CN114684388A CN114684388A CN202210251098.2A CN202210251098A CN114684388A CN 114684388 A CN114684388 A CN 114684388A CN 202210251098 A CN202210251098 A CN 202210251098A CN 114684388 A CN114684388 A CN 114684388A
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Abstract
The invention discloses a method for realizing on-satellite autonomous task planning based on orbital system solar vectors.A ground task planning system plans tasks and determines solar altitude angle information at the task observation time; the operation control system plans an instruction sequence according to information provided by a ground task planning system, wherein the instruction sequence comprises task mode words, load parameter configuration and a solar altitude angle modification instruction at an observation moment, and the instruction sequence does not comprise a guidance law of a platform and a rotary table and a load on-off instruction; when the satellite enters the border, the instruction sequence is annotated; the satellite software enters a corresponding task according to the task mode words, calculates key points of the start time and the end time of the task, and autonomously executes the observation task; and transmitting the observation data to a ground mission planning system through data transmission. The method can reduce the number of instructions in the instruction sequence of the ground injection, reduce the operation burden of ground personnel, reduce the observation error caused by the time delay of the ground injection and reduce the error probability.
Description
Technical Field
The invention belongs to the field of satellite autonomous mission planning, and provides a method for autonomous mission planning of a sun synchronous near-circular orbit satellite, in particular to a method for realizing on-satellite autonomous mission planning according to an orbital system sun vector.
Background
The satellite task planning belongs to a part of resource management from the perspective of systematic application, currently, the execution of the satellite in-orbit task is mainly based on the information of the satellite in-orbit energy condition, attitude information, load stand-alone health state, orbit and the like received by a ground measurement, operation and control system, through negotiation between ground operators and satellite users, the observation target and the observation time are selected, and the observation target and the observation time are realized through the form of injecting an instruction sequence on the ground measurement, operation and control system, wherein the instruction sequence is an instruction set, and the included instructions generally comprise an instruction for controlling the task execution time sequence, a load stand-alone switch instruction, a load stand-alone parameter configuration instruction and the like. In order to observe the precision and fully utilize space resources, more and more loads are carried by a single satellite, task observation is realized through the cooperation of various loads, and if the task observation is realized by totally depending on a ground injection instruction sequence form, the instructions needing ground injection are more and more complex. The instruction sequence is time consuming, labor intensive and prone to error. If the instruction sequence cannot be timely injected due to short satellite entry time, the observation task cannot be timely completed or the observation time is reduced.
At present, the processor performance of the on-board integrated electronic system reaches more than 200MHz, the screened industrial processor can reach 1GHz, and the on-board integrated electronic system has the capability of transferring partial functions of ground task planning to on-board processing by combining with larger memory capacity.
Object of the Invention
The invention provides a method for planning a task by a sun synchronous near-circular orbit satellite according to an orbital system sun vector, aiming at the problems that the ground operation is complex and the error is easy to occur and the like caused by the fact that the satellite observation task mainly depends on a ground injection instruction sequence to control a satellite load single machine to carry out observation at present.
The technical scheme of the invention is as follows: a method for realizing on-satellite autonomous mission planning based on orbital system sun vectors comprises the following specific steps:
firstly, a ground task planning system plans a task and determines sun altitude angle information at the task observation time;
secondly, planning an instruction sequence by the operation control system according to information provided by a ground task planning system, wherein the instruction sequence comprises task mode words, load parameter configuration and a sun altitude modification instruction at an observation moment, and the instruction sequence does not comprise a guidance law of a platform and a rotary table and a load startup and shutdown instruction;
step three, when the satellite enters the field, the instruction sequence is injected;
step four, the satellite software enters corresponding tasks according to the task mode words, calculates key points of the start time and the end time of the tasks, and autonomously executes observation tasks;
and fifthly, downloading the observation data to a ground task planning system through data transmission.
Furthermore, in the fourth step, the on-board software enters the corresponding task according to the task mode word, calculates key points at the start time and the end time of the task, and autonomously executes the observation task; the method comprises the following specific steps:
for a sun-synchronous circular orbit satellite, defining a Z axis of a satellite mass center orbit coordinate system as a connecting line from the satellite to the earth mass center and pointing to the earth mass center; the directions of negative normals of Y-axis orbit planes of the satellite mass center orbit coordinate system are consistent; the X axis and the Y, Z axis of the satellite mass center orbit coordinate system form a right-hand orthogonal system and point to the advancing direction in the orbit plane; the satellite centroid orbit coordinate system is a VVLH coordinate system;
the satellite attitude control module deduces a normalized orbital system solar vector mu so according to the solar ephemeris model and the orbit data; the respective angles of the solar vector μ so under the VVLH system are defined as follows: the phi angle is an included angle between the projection of the sun vector mu so on the orbital plane and the z axis, and is positive around the Y axis; the angle alpha is an included angle between a sun vector mu so and the projection of the sun vector mu so on the xoy plane, namely a sun altitude angle, and is negative towards the Z axis; the beta angle is an included angle between the sun vector mu so and the projection of the sun vector mu so on the orbital plane, namely an orbital sun angle, and is negative towards the Y axis; the angle theta is an included angle between the projection of the sun vector mu so and the x axis, and is positive around the Z axis;
the relationship between the sun vector and each included angle is deduced as follows:
the calculation formula of the values of alpha, beta, theta and phi can be obtained from the formula (1):
α＝-asin(μso(3)) (3)
β＝asin(μso(2)) (4)
θ＝atan2(μso(2)，μso(1)) (5)
according to the characteristics of the track, in the same track observation, the phi angle is linearly changed in [ -pi, pi ], the beta angle is almost unchanged, and the relation between the phi angle and the alpha and beta angles is shown in formulas (6) and (7);
sun raising stage:
sun falling stage:
the formula for calculating α from φ and β is as follows:
the calculation formula of the angle theta and the angles alpha and beta is as follows:
sun rising section:
sun landing section:
if the value of the solar altitude angle alpha at the task observation time designed by the ground task planning system is known, the value phi at the observation time can be calculated by alpha and beta, and the on-board time t _ flag (i) (i is 1,2,3 …) observed at the start and the end of the task can be deduced because the value phi is linearly changed, and as shown in a formula (11), the on-board software calculates t _ flag (i) at intervals to eliminate errors; when the satellite time is equal to t _ flag (i), the autonomous task management module of the satellite-borne software outputs corresponding instructions according to the current satellite energy condition, the satellite attitude information, the orbit information and the health state of the load single machine, executes related operations and starts or ends task observation;
wherein: t _ flag (i) is a time point on the start-stop satellite observed by the task;
t _ sat is the current time on the satellite;
and omega is the orbital angular velocity of the aircraft and is given by the orbital module.
Furthermore, a right-hand orthogonal system is defined by the X axis and the Y, Z axis of the satellite centroid orbit coordinate system, the satellite centroid orbit coordinate system points to the advancing direction in the orbit plane, and if the satellite centroid orbit coordinate system is a circular orbit, the satellite centroid orbit coordinate system is consistent with the speed direction.
The invention has the beneficial effects that: different from the traditional satellite task planning, instructions such as guidance law of a planning platform and a rotary table, load startup and shutdown and the like are not needed in an instruction sequence, the number of instructions for upper injection is effectively reduced, and the success rate of upper injection is improved.
According to the method for planning the satellite task by utilizing the solar vector of the orbital system, the relative position and the angle between the satellite and the sun are calculated through the solar vector, the execution time sequence of the satellite task is planned according to the moment when the satellite reaches the specified angle, the visible observation time window can be discretized, different observation tasks are executed in different time periods, the mutual exclusion and the autonomous execution of the task are realized, and the method has the advantages of saving measurement and control channel resources, reducing manual intervention, improving the utilization efficiency of on-satellite resources and the like.
Drawings
FIG. 1 is an angle diagram of a sun vector in an orbital coordinate system;
FIG. 2 is a schematic diagram showing the corresponding relationship between the solar altitude and the observation interval;
fig. 3 is a schematic flow chart of autonomous mission in satellite.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
For a sun-synchronous circular orbit satellite, defining a Z axis of a satellite centroid orbit coordinate system (VVLH coordinate system) as a connecting line from the satellite to the earth centroid, and pointing to the earth centroid; the Y-axis track plane is aligned with the negative normal direction, and the X-axis and the Y, Z-axis form a right-hand orthogonal system, pointing to the advancing direction (aligned with the speed direction if the track plane is a circular track). The satellite attitude control module derives a normalized orbital system solar vector mu so according to the solar ephemeris model and the orbit data. Then the respective angles of the sun vector μ so under the VVLH system are defined as shown in fig. 1: wherein the phi angle is an included angle between the projection of the sun vector mu so on the orbital plane and the z axis, and is positive around the Y axis; the angle alpha is the included angle (namely the solar altitude angle) between the sun vector mu so and the projection of the sun vector mu so on the xoy plane, and is negative towards the Z axis; the angle beta is an included angle (namely an orbital solar angle) between a sun vector mu so and the projection of the sun vector mu so on the orbital plane, and is negative towards the Y axis; the angle theta is the included angle between the projection of the sun vector mu so and the x axis, and is positive around the Z axis.
The relationship between the sun vector and each included angle is deduced as follows:
the calculation formulas of the alpha, beta, theta and phi values can be obtained by the formula (1).
α＝-asin(μso(3)) (3)
β＝asin(μso(2)) (4)
θ＝atan2(μso(2)，μso(1)) (5)
According to the characteristics of the track, in the same track observation, the phi angle is linearly changed within [ -pi, pi ], the beta angle is almost unchanged, and the relation between the phi angle and the alpha and beta angles is shown as formulas (6) and (7).
Sun raising stage:
sun falling stage:
the formula for calculating α from φ and β is as follows:
the calculation formula of the angle theta and the angles alpha and beta is as follows:
sun rising section:
sun landing section:
if the value of the solar altitude angle alpha at the task observation time designed by the ground task planning system is known (which can be modified by instruction remark), the value of phi at the observation time can be calculated from alpha and beta, and as the value of phi is linearly changed, the on-board time t _ flag (i) (i is 1,2,3 …) of the start and the end of the task observation can be deduced, as shown in formula (11), the on-board software calculates t _ flag (i) at intervals, and the error is eliminated. When the satellite time is equal to t _ flag (i), the autonomous task management module of the satellite-borne software outputs corresponding instructions according to the current satellite energy condition, the satellite attitude, the orbit information, the health state of the load single machine and other information, executes related operations, and starts or ends task observation.
Wherein: t _ flag (i) is a time point on the start-stop satellite observed by the task;
t _ sat is the current time on the satellite;
and omega is the angular velocity of the orbit of the aircraft and is given by an orbit module.
The whole satellite task observation execution process comprises the following steps:
The operation is different from the traditional satellite task planning in that instructions such as guidance law of a planning platform and a rotary table, load startup and shutdown and the like are not needed in an instruction sequence, the number of instructions for upper injection is effectively reduced, and the success rate of the upper injection is improved.
At present, the satellite carries more and more loads, the tasks are more and more complex, the limitation is caused by space resources and environment, the adjustment of the satellite attitude and the on-off operation of a load single machine are required to be carried out according to an observation task, and aiming at the characteristics of a low-orbit solar synchronous near-circular orbit satellite, the invention provides a satellite autonomous task planning method based on an orbit system solar vector. The following embodiments of the present invention are described with reference to examples:
a ground user designs an observation solar altitude angle in advance and plans a task observation starting moment, and the planned solar altitude angle sequence in the embodiment of the invention is sun rising-17 degrees, sun rising-13 degrees, sun rising-5 degrees, sun rising 20 degrees or so for 75 seconds, the maximum value alpha max of the solar altitude angle is about 75 seconds, sun falling 20 degrees or so for 75 seconds, sun falling 5 degrees, sun falling-13 degrees and sun falling-17 degrees. For a total of 14 points.
The start time of the ground-based annotation task is recorded as t0, the on-satellite time when the observation angle is in place is calculated after the on-satellite receives the start of the task and recorded as t1-t 14, and the corresponding relation between the solar altitude and the observation interval is shown in fig. 2.
Comparing the interval between t1 and t0, because the load needs to be started up 600 seconds earlier, if (t1-t0) <600, the on-orbit task is abandoned, and the next time when the sun rises to the sun height is calculated to be-17 degrees. In order to reduce errors, the t1-t 14 are repeatedly calculated at certain time intervals on the satellite. The on-board software judges the current on-board time and the sizes of t1-t 14, and the following operations are carried out:
1, t1-600 s: and sending a load stand-alone 1 starting instruction.
T1-591 s: and configuring parameters of the load single machine 1 according to the single machine parameter table noted on the ground.
T1-240 s: and switching in a counterglow observation sub-mode, and sending a platform tracking guidance law.
T1-t 2: the load performs a daily observation task.
5, t 2: finishing the sun observation, sending a platform vertical ground guiding law, closing the load single machine 1, and switching in the sub-mode into the 0-degree observation task.
T3-120 s: and sending load single machines 2 and 3 starting instructions at an interval of 1 s.
T3-110 s: and configuring parameters of load single machines 2 and 3 according to the single machine parameter table annotated on the ground.
T3-63 s: and starting the turntable.
T3-60 s: and sending the starting instructions of the loads 4 and 5 according to time sequence.
T3-50 s: and configuring parameters of load single machines 4 and 5 according to the single machine parameter table annotated on the ground.
T3-40 s: the turntable is maneuvered to a predetermined position (determined by the angle theta) in preparation for observation.
12, t 3-t 4: and starting 0-degree task observation, moving the turntable to the next position after positioning and observing for 1s in the observation process, and circulating the steps until the observation is finished.
13, t 4: and (4) standing the platform, positioning the rotary table, finishing the observation at 0 degree, and setting the sub-mode characters to be observed at 20 degrees.
14, t4+2 s: the turntable is motorized to the next observation position.
T5-40 s: platform tracking, preparation for 20 ° observation.
16, t 5-t 6: platform tracking starts a 20-degree observation task.
17, t 6: finishing the observation of 20 degrees, erecting the platform, shutting down the turntable, closing the loads 2,3, 4 and 5 at the time sequence interval of 1s, and simultaneously setting an observation sub-mode character as alpha max observation.
18.t7-63 s: and starting the turntable.
T7-53 s: the turntable is motorized to a predetermined position.
20, t7-40 s: positioning by a rotary table, tracking by a platform and preparing for observation.
21, t 7-t 8: the alpha max observation task is started.
22, t 8: and finishing observation, erecting the platform, and powering off the machine after the turntable is mechanically returned.
23.……
24, t 14: and finishing the counterglow observation task, closing all the load single machines, erecting the platform and shutting down the turntable.
The steps only describe the autonomous execution process of the tasks in the solar lifting stage, the processes of the falling stage and the lifting stage are substantially the same, and the specific operation process also involves load communication, remote measurement and remote control processing and the like, and are not described again. The specific schematic diagram is shown in fig. 3.
According to the method for planning the satellite task by utilizing the solar vector of the orbital system, the relative position and the angle between the satellite and the sun are calculated through the solar vector, the execution time sequence of the satellite task is planned according to the moment when the satellite reaches the specified angle, the visible observation time window can be discretized, different observation tasks are executed in different time periods, the mutual exclusion and the autonomous execution of the task are realized, and the method has the advantages of saving measurement and control channel resources, reducing manual intervention, improving the utilization efficiency of on-satellite resources and the like.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (3)
1. A method for realizing on-satellite autonomous mission planning based on orbital system solar vectors is characterized by comprising the following steps: the method comprises the following specific steps:
firstly, a ground task planning system plans a task and determines sun altitude angle information at the task observation time;
secondly, planning an instruction sequence by the operation control system according to information provided by a ground task planning system, wherein the instruction sequence comprises task mode words, load parameter configuration and a sun altitude modification instruction at an observation moment, and the instruction sequence does not comprise a guidance law of a platform and a rotary table and a load startup and shutdown instruction;
step three, when the satellite enters the field, the instruction sequence is injected;
step four, the satellite software enters corresponding tasks according to the task mode words, calculates key points of the start time and the end time of the tasks, and autonomously executes observation tasks;
and fifthly, downloading the observation data to a ground task planning system through data transmission.
2. The method for realizing on-satellite autonomous mission planning based on the orbital solar vector as recited in claim 1, wherein: in the fourth step, the on-board software enters corresponding tasks according to the task mode words, calculates key points of the start time and the end time of the tasks, and autonomously executes observation tasks; the method comprises the following specific steps:
for a sun synchronization circular orbit satellite, defining a Z axis of a satellite mass center orbit coordinate system as a connecting line from the satellite to the earth mass center and pointing to the earth mass center; the directions of negative normals of Y-axis orbit planes of the satellite mass center orbit coordinate system are consistent; the X axis and the Y, Z axis of the satellite mass center orbit coordinate system form a right-hand orthogonal system and point to the advancing direction in the orbit plane; the satellite centroid orbit coordinate system is a VVLH coordinate system;
the satellite attitude control module deduces a normalized orbital system solar vector mu so according to the solar ephemeris model and the orbit data; the respective angles of the solar vector μ so under the VVLH system are defined as follows: the phi angle is an included angle between the projection of the sun vector mu so on the orbital plane and the z axis, and is positive around the Y axis; the angle alpha is an included angle between a sun vector mu so and the projection of the sun vector mu so on the xoy plane, namely a sun altitude angle, and is negative towards the Z axis; the beta angle is an included angle between the sun vector mu so and the projection of the sun vector mu so on the orbital plane, namely an orbital sun angle, and is negative towards the Y axis; the angle theta is an included angle between the projection of the sun vector mu so and the x axis, and is positive around the Z axis;
the relationship between the sun vector and each included angle is deduced as follows:
the calculation formula of the values of alpha, beta, theta and phi can be obtained from the formula (1):
α＝-asin(μso(3)) (3)
β＝asin(μso(2)) (4)
θ＝atan2(μso(2),μso(1)) (5)
according to the characteristics of the track, in the same track observation, the phi angle is linearly changed in [ -pi, pi ], the beta angle is almost unchanged, and the relation between the phi angle and the alpha and beta angles is shown as formulas (6) and (7);
sun raising stage:
sun falling stage:
the formula for calculating α from φ and β is as follows:
the calculation formula of the angle theta and the angles alpha and beta is as follows:
sun rising section:
sun landing section:
if the value of the solar altitude angle alpha at the task observation time designed by the ground task planning system is known, the value phi at the observation time can be calculated by alpha and beta, and the on-board time t _ flag (i) (i is 1,2,3 …) observed at the start and the end of the task can be deduced because the value phi is linearly changed, and as shown in a formula (11), the on-board software calculates t _ flag (i) at intervals to eliminate errors; when the satellite time is equal to t _ flag (i), the autonomous task management module of the satellite-borne software outputs corresponding instructions according to the current satellite energy condition, the satellite attitude information, the orbit information and the health state of the load single machine, executes related operations and starts or ends task observation;
wherein: t _ flag (i) is a time point on the start-stop satellite observed by the task;
t _ sat is the current time on the satellite;
and omega is the orbital angular velocity of the aircraft and is given by the orbital module.
3. The method for realizing on-satellite autonomous mission planning based on the orbital solar vector as recited in claim 2, wherein: and defining a right-hand orthogonal system formed by an X axis and an Y, Z axis of the satellite centroid orbit coordinate system, pointing to the advancing direction in the orbit plane, and if the orbit is a circular orbit, conforming to the speed direction.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116101514A (en) * | 2023-04-13 | 2023-05-12 | 中国科学院空天信息创新研究院 | Multi-star on-orbit autonomous cooperative system and autonomous task planning method thereof |
| WO2024021399A1 (en) * | 2022-07-28 | 2024-02-01 | 上海航天空间技术有限公司 | All-electric propulsion satellite orbit transfer method based on autonomous task planning |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2024021399A1 (en) * | 2022-07-28 | 2024-02-01 | 上海航天空间技术有限公司 | All-electric propulsion satellite orbit transfer method based on autonomous task planning |
| CN116101514A (en) * | 2023-04-13 | 2023-05-12 | 中国科学院空天信息创新研究院 | Multi-star on-orbit autonomous cooperative system and autonomous task planning method thereof |
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