Spacecraft task time sequence arrangement test system and test method thereof

Abstract

The spacecraft task time sequence arrangement test system comprises an instruction layer state machine, a task layer state machine and an orbit layer state machine, the starting time and the task duration of a task are determined in an instruction layer, and constraint on a single task is completed; then, in a task layer, according to whether the task has a precondition or a postcondition, arranging the time sequence of the task so as to form a task group formed by sorting and combining a plurality of tasks; and finally, arranging the task group on an orbit layer according to whether the orbit is required or not, so as to complete the task time sequence arrangement of the spacecraft in the on-orbit application scene. The multi-layer state machine is simple in structure and high in interpretability, multi-task arrangement of the satellite in the geosynchronous orbit and the sun-synchronous orbit can be met at the same time, and the efficiency of satellite mode test design is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the field of mission planning, and in particular relates to a spacecraft mission timing arrangement test system and a test method thereof. Background Art

[0002] The task scheduling of spacecraft application scenarios is the process of designing spacecraft missions based on predetermined mission objectives, spacecraft capabilities, resource overhead and other conditions. During the execution of the mission, each subsystem needs to execute the corresponding instructions in order according to the decomposed mission requirements. In this process, various types of constraints are inevitably involved. In response to these constraints, the existing space mission planning mainly focuses on determining the satellite's observation actions and data transmission actions based on user observation requirements and satellite constraints. The main idea is to abstract the planning problem to establish a mathematical model and accurately solve it. However, the current related research mainly focuses on single-task level planning, and it is difficult to establish an accurate mathematical model, and it is impossible to plan the timing scheduling of multiple tasks in actual application scenarios, and it cannot be used for test design. In addition, some scholars have proposed a combination of classic machine learning algorithms such as support vector machines and artificial neural networks to build a high-precision schedulability prediction model for mission planning. This type of method shows outstanding advantages in intelligent decision-making, but because it is highly dependent on the quality and scale of training data and has very limited interpretability, it has great disadvantages in the credibility of the calculation results. Summary of the invention

[0003] In view of the problems existing in the task timing arrangement in the current spacecraft application scenario test, the present invention adopts a multi-layer state machine to plan the tasks in layers. The multi-layer state machine is divided into an instruction layer state machine, a task layer state machine and an orbit layer state machine from top to bottom. First, at the instruction layer, the start time and task duration of the task are determined to complete the constraints on the single task; then at the task layer, the task timing is arranged according to whether the task has preconditions or postconditions, thereby forming a task group composed of multiple task sorting combinations; finally, the task group can be arranged at the orbit layer according to whether there are requirements for the orbit, thereby completing the arrangement of the task timing for the spacecraft in the on-orbit application scenario. The multi-layer state machine has a simple structure and strong interpretability. It can simultaneously meet the multi-task arrangement of satellites in geosynchronous orbits and sun-synchronous orbits. The satellite task timing arranged by this method can be used in the satellite's sky test, which effectively improves the efficiency of satellite mode test design.

[0004] The above-mentioned purpose of the present invention is mainly achieved through the following technical solutions:

[0005] A spacecraft mission timing arrangement test method comprises the following steps:

[0006] (1) Inject the task into the instruction layer state machine, and obtain the time attribute T of the task according to the start time and task duration of the task. If the time attribute T has requirements on the task duration or start time, mark the time attribute of the task in the task group, and place the task at the specified position of the task group time sequence according to the requirements; if the time attribute T has no requirements on the task duration or start time, sort the tasks according to the initial generation order to obtain sorted tasks;

[0007] (2) Inject the sorted tasks obtained in step (1) into the task layer state machine and classify them into unconstrained task groups and constrained task groups according to whether the task execution is constrained by other tasks;

[0008] (3) Analyze the tasks in the constrained task group obtained in step (2), select the predecessor or successor tasks of the task, form a small task group, and then analyze the small task group again. Repeat the above operation until the small task group is not constrained by other tasks, and classify the small task group into an unconstrained task group;

[0009] (4) Repeat step (3) to analyze the tasks until all tasks are injected into the unconstrained task group, execute the tasks according to the timing of the unconstrained task group, complete the timing arrangement of the task layer, and obtain the spacecraft mission that completes the task timing arrangement.

[0010] The tasks with completed time sequence obtained in step (4) are injected into the orbital layer state machine to check whether the tasks or task groups have requirements for the specified orbits. The tasks or task groups are rearranged to the corresponding time points as needed. Unrelated tasks or task groups are output according to the time arrangement made by the task layer state machine, and finally the spacecraft tasks with completed task time sequence are obtained.

[0011] In the step (1), if the time attribute T has requirements on the task duration or start time, the time attribute of the task is marked in the task group, and the task is placed at a specified position in the task group time sequence as required; if the time attribute T has no requirements on the task duration or start time, the tasks are sorted in random order to obtain sorted tasks.

[0012] A spacecraft mission timing arrangement test system for application scenarios includes a command layer state machine, a mission layer state machine and an orbit layer state machine, wherein:

[0013] The instruction layer state machine is used to mark the tasks that have requirements on the task duration or start time among the injected tasks, and place the tasks at the specified position of the task group time sequence according to the requirements, sort the tasks that have no requirements on the task duration or start time according to the initial generation order, and inject the sorted tasks into the task layer state machine;

[0014] The task layer state machine is used to receive the tasks injected by the instruction layer state machine, analyze the tasks constrained by other tasks, select the predecessor or successor tasks of the tasks, form a small task group, and then analyze the small task group again. The above operation is repeated until the small task group is not constrained by other tasks, and the timing arrangement is completed according to the obtained unconstrained individual tasks and small task groups.

[0015] It also includes an orbital layer state machine. After the task layer state machine completes the timing arrangement, the sorted tasks are injected into the orbital layer state machine. The orbital layer state machine is used to check whether the task or task group has requirements for the specified orbit after receiving the task injected by the task layer state machine, and reschedule the task or task group to the corresponding time point as needed. Unrelated tasks or task groups are output according to the time arrangement made by the task layer state machine to obtain the spacecraft mission that completes the task timing arrangement.

[0016] In the instruction layer state machine, tasks that have no requirements on task duration or start time are sorted in random order.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] (1) The structure of the multi-layer state machine of the present invention is simple, the process of autonomous task scheduling is clear, and the interpretability is strong;

[0019] (2) The state machine of the present invention contains many states and can meet the needs of multiple autonomous task scheduling for both low and high orbits;

[0020] (3) The method of the present invention has strong scalability and can be applied not only to the ground testing phase of the satellite, but also to the autonomous task scheduling during the satellite in-orbit testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the flow chart of instruction layer state machine;

[0022] Figure 2 It is the task layer state machine flow chart;

[0023] Figure 3 This is the flow chart of the track layer state machine. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] Before scheduling the task sequence, you first need to clarify the attributes of the task, so that you can clarify the constraints of the task itself and before the task during the task test. Taking the remote sensing satellite as an example, the main attributes of the task are shown in the following table:

[0026]

[0027] It should be noted that the division of task attributes here is only effective when arranging tasks, and has nothing to do with the rationality of task design, that is, all tasks involved in task arrangement can be executed correctly. Figure 1 As shown in the figure, after injecting the task, we first need to consider the constraints of the task's time attribute T on the execution of instructions within the task. For example, some tasks need to start at a specified time point, and some tasks need to be executed for a sufficient length of time to take effect. Therefore, in the instruction layer state machine, the time attribute T of the task is judged. If there is a requirement for the task duration (t2=y) or the start time (t1=x), the time attribute of the task is marked in the task group, and it is placed in the specified position of the task group time sequence according to the requirement. Other tasks are not required and can be executed normally according to the initial generation order, or randomly sorted and executed to avoid local optimal solutions.

[0028] After the instruction layer state machine is sorted, the task layer state machine can be used on this basis, such as Figure 2 As shown, multiple tasks are sorted according to task type constraints. First, they can be classified according to whether the task execution is constrained by other tasks. After being divided into unconstrained task groups and constrained task groups, the tasks are analyzed. If they have predecessors or tasks, their predecessors or successors are selected to form small task groups. Then the small task groups are analyzed again until their task groups are not constrained by other tasks. This is the case. The small task group is an unconstrained task group and can be classified as an unconstrained task group. Continuously running the state machine until all tasks are injected will form an unconstrained task group that contains all tasks but can be divided into single tasks and small task groups. After that, the tasks can be executed according to the timing of the unconstrained task group to complete the timing arrangement of the task layer.

[0029] For high-orbit and most low-orbit satellites, the tasks arranged at this time have met all constraints. However, when the satellite is in the return orbit, some tasks may be related to the orbit. At this time, it is necessary to analyze whether there are orbital constraints after completing the task group arrangement, such as Figure 3 As shown, if there is a demand for a specified track, the task group needs to be rescheduled to the corresponding time point, while unrelated task groups can be executed normally according to the time arrangement made by the task layer state machine.

[0030] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0031] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A spacecraft mission timing arrangement test method, characterized in that: The following steps are involved: (1) Inject the task into the instruction layer state machine, and obtain the time attribute T of the task according to the start time and task duration of the task. If the time attribute T has requirements on the task duration or start time, mark the time attribute of the task in the task group, and place the task at the specified position of the task group time sequence according to the requirements; if the time attribute T has no requirements on the task duration or start time, sort the tasks according to the initial generation order to obtain sorted tasks; (2) Inject the sorted tasks obtained in step (1) into the task layer state machine and classify them into unconstrained task groups and constrained task groups according to whether the task execution is constrained by other tasks; (3) Analyze the tasks in the constrained task group obtained in step (2), select the predecessor or successor tasks of the task, form a small task group, and then analyze the small task group again. Repeat the above operation until the small task group is not constrained by other tasks, and classify the small task group into an unconstrained task group; (4) Repeat step (3) to analyze the tasks until all tasks are injected into the unconstrained task group, execute the tasks according to the timing of the unconstrained task group, complete the timing arrangement of the task layer, and obtain the spacecraft mission that completes the task timing arrangement.

2. A spacecraft mission timing arrangement test method according to claim 1, characterized in that: The tasks with completed time sequence obtained in step (4) are injected into the orbital layer state machine to check whether the tasks or task groups have requirements for the specified orbits. The tasks or task groups are rearranged to the corresponding time points as needed. Unrelated tasks or task groups are output according to the time arrangement made by the task layer state machine, and finally the spacecraft tasks with completed task time sequence are obtained.

3. A spacecraft mission timing arrangement test method according to claim 1, characterized in that: In the step (1), if the time attribute T has requirements on the task duration or start time, the time attribute of the task is marked in the task group, and the task is placed at a specified position in the task group time sequence as required; if the time attribute T has no requirements on the task duration or start time, the tasks are sorted in random order to obtain sorted tasks.

4. A spacecraft mission timing arrangement test system for application scenarios, characterized by: It includes the instruction layer state machine, the task layer state machine and the track layer state machine, among which: The instruction layer state machine is used to mark the tasks that have requirements on the task duration or start time among the injected tasks, and place the tasks at the specified position of the task group time sequence according to the requirements, sort the tasks that have no requirements on the task duration or start time according to the initial generation order, and inject the sorted tasks into the task layer state machine; The task layer state machine is used to receive the tasks injected by the instruction layer state machine, analyze the tasks constrained by other tasks, select the predecessor or successor tasks of the tasks, form a small task group, and then analyze the small task group again. The above operation is repeated until the small task group is not constrained by other tasks, and the timing arrangement is completed according to the obtained unconstrained individual tasks and small task groups.

5. The spacecraft mission timing arrangement test system for application scenarios according to claim 4 is characterized in that: It also includes an orbital layer state machine. After the task layer state machine completes the timing arrangement, the sorted tasks are injected into the orbital layer state machine. The orbital layer state machine is used to check whether the task or task group has requirements for the specified orbit after receiving the task injected by the task layer state machine, and reschedule the task or task group to the corresponding time point as needed. Unrelated tasks or task groups are output according to the time arrangement made by the task layer state machine to obtain the spacecraft mission that completes the task timing arrangement.

6. The spacecraft mission timing arrangement test system for application scenarios according to claim 4 is characterized in that: In the instruction layer state machine, tasks that have no requirements on task duration or start time are sorted in random order.

7. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method of claim 1.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to claim 1 are implemented.

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