A method for autonomous downlink of delayed telemetry from small GEO satellites

Abstract

The present invention discloses a method for autonomous downlinking of delayed telemetry of a small GEO satellite, the method comprising the following steps: step one: creating a delayed telemetry downlink task queue; step two: maintaining and managing the delayed telemetry downlink task queue in step one; step three: selecting a delayed telemetry downlink mode; step four: uploading delayed telemetry data according to the delayed telemetry downlink task queue and the delayed telemetry downlink mode after maintenance and management. The present invention enables a small GEO satellite to store satellite delayed telemetry when it is in an invisible measurement and control arc segment, and autonomously downlinks delayed telemetry of concern to the ground in a visible measurement and control arc segment based on information such as the length of the visible arc segment, satellite fault conditions, and the execution of important measurement and control events, so that the satellite health status can be quickly judged based on the delayed telemetry information, and an emergency response strategy can be formulated to ensure the satellite's in-orbit flight safety.

Description

Technical Field

[0001] The invention belongs to the technical field of small GEO satellites, and in particular relates to a method for autonomous downlink of delayed telemetry of a small GEO satellite. Background Art

[0002] At present, due to market uncertainty and economic pressures brought by the price decline of traditional services, satellite operators prefer to build small GEO satellites to achieve the minimum total investment to develop new services. Small GEO satellites are generally developed with low-cost ideas, and are used with low-cost launch vehicles currently in service for low-orbit launches to improve the satellite platform load ratio.

[0003] Since the separation orbit between the satellite and the launch vehicle is relatively low, the launch vehicle only sends the satellite into the LEO orbit, and the satellite usually needs to use an upper stage or an independent propulsion module to increase its orbit. On the other hand, in order to further improve the carrying ratio of the satellite platform, small GEO satellites usually use all-electric propulsion to change orbits to enter the geostationary synchronous orbit, which causes the satellite to operate in the transfer orbit for 4 to 8 months. During this period, the satellite has a long period of invisible measurement and control. During the all-electric propulsion orbit change of small GEO satellites, it is impossible to accurately grasp the working status of the satellite in the unobservable arc segment. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a method for autonomous downlinking of delayed telemetry of a small GEO satellite, to realize that the small GEO satellite stores the delayed telemetry of the satellite when it is in an invisible tracking and control arc, and to autonomously downlink the delayed telemetry of concern to the ground in the visible tracking and control arc of the satellite based on the duration of the visible arc, satellite fault conditions, execution conditions of important tracking and control events and other information, so that the health status of the satellite can be quickly judged based on the delayed telemetry information, and an emergency response strategy can be formulated to ensure the safety of the satellite's in-orbit flight.

[0005] The object of the present invention is achieved through the following technical scheme: a method for autonomous downlink of delayed telemetry of a small GEO satellite, the method comprising the following steps: step one: creating a delayed telemetry downlink task queue; step two: maintaining and managing the delayed telemetry downlink task queue in step one; step three: selecting a delayed telemetry downlink mode; step four: uploading delayed telemetry data according to the delayed telemetry downlink task queue and the delayed telemetry downlink mode after maintenance and management.

[0006] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, in step one, creating a delayed telemetry downlink task queue includes the following steps: taking the end of the last delayed telemetry downlink to the start of this delayed telemetry downlink as a cycle, sending instructions from the ground or triggering the onboard computer software to store the delayed telemetry through the interface enabled by delayed telemetry storage by the autonomous task management software, and creating a downlink task queue.

[0007] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, in step 2, the onboard computer software dynamically maintains the delayed telemetry downlink task queue, and a new downlink task is directly placed in the downlink task queue; if the downlink task queue is full, first check whether there is a downlink task that has been executed in the current downlink task queue (execution status == 1), and if so, delete the downlink task with the earliest completed execution time; otherwise, compare the priority of the new downlink task with the downlink task in the downlink task queue, if the priority of the new downlink task is low or the priority of the new downlink task is the same as that of the downlink task in the downlink task queue, discard the new downlink task, and set the telemetry downlink queue task column storage status to 1 (1 indicates that the delayed telemetry queue storage fails. The default is 0: the delayed telemetry queue is stored correctly); if the priority of the new downlink task is high, delete the downlink task with the lowest priority in the current downlink task queue.

[0008] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, in step three, the delayed telemetry downlink mode includes a sampling delayed telemetry frame downlink mode, a specific time period delayed telemetry frame telemetry data downlink mode, a specified time period delayed telemetry package data downlink mode, and a fault delayed telemetry package telemetry data downlink mode.

[0009] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, the sampling delayed telemetry frame downlink mode is: all delayed telemetry frame data in the visible arc are quickly downlinked in area 1. If the amount of downlinked data exceeds the total amount of data downlinked in the visible arc, the satellite needs to autonomously determine the downlink sampling rate to ensure that the satellite can downlink sufficiently long invisible arc telemetry data in the visible arc.

[0010] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, the downlink mode of delayed telemetry frame telemetry data in a specific period of time is: downlink the delayed telemetry frame data in the visible arc fast downlink area 1 in a specific period of time, and the ground specifies the information of the downlink start time and the downlink end time through instructions, and the satellite autonomously generates and executes the downlink task sequence.

[0011] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, the downlink mode of delayed telemetry package data in a specified time period is: downlink the delayed telemetry package data in the visible arc fast downlink area 2 in a specific period of time, and the ground specifies the information of the downlink start time and the downlink end time through instructions, and the satellite autonomously generates and executes the downlink task sequence.

[0012] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, the telemetry data downlink mode of the fault delayed telemetry package is as follows: according to the available time for delayed telemetry downlink of the visible arc segment, the delayed telemetry package data within the visible arc fast downlink area 2 is sampled and downlinked, and the package delayed telemetry data downlink task is autonomously created and executed; the satellite determines the time period when the fault alarm occurs according to the FDIR fault alarm identifier, and autonomously generates and executes the fault event package telemetry downlink task sequence on board.

[0013] In the above-mentioned method for autonomous downlink of delayed telemetry of small GEO satellites, in step 4, the onboard computer software starts to sequentially downlink the delayed telemetry data according to the time of the delayed telemetry downlink task. If the data downlink is completed within a visible arc segment, the task execution status is set to 1 (indicating that the downlink has been successfully completed); if a delayed telemetry downlink prohibition instruction is received, the task execution status is set to 0, and the task is re-downloaded in the next visible arc segment.

[0014] In the above-mentioned method for autonomous downlink of delayed telemetry of a small GEO satellite, if the storage status of the telemetry downlink queue task queue is 1, it means that the delayed telemetry queue storage fails.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The present invention can realize autonomous downlink of delayed telemetry. In each downlink cycle, the satellite autonomous mission flight software autonomously calculates the start time, end time, and sampling rate of delayed telemetry transmission in this cycle based on orbit information and available ground station locations, and selects different downlink modes to send to the onboard computer, which then autonomously creates a downlink task queue;

[0017] (2) The present invention can realize autonomous task maintenance of delayed telemetry downlink tasks. The onboard computer can dynamically maintain the delayed telemetry downlink task queue, and new downlink tasks can be directly placed in the downlink task queue. If the downlink task queue is full, compare the priority of the new task with that in the task list. If the priority of the new task is low, discard the task and do not process it. If the priority of the new task is high, delete the task with the lowest priority and the latest time in the existing queue. If the priority of the new task is the same as that of the queue task, delete the task with the latest time in the existing queue and add the new task;

[0018] (3) The present invention can sample and transmit the delayed telemetry packet data according to the available time for delayed telemetry transmission in the visible arc segment, and autonomously create and execute the packet delayed telemetry data transmission task. The satellite determines the time period when the fault alarm occurs according to the FDIR fault alarm identifier, and autonomously generates and executes the fault event packet telemetry transmission task sequence on the satellite. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0020] Figure 1 It is a flow chart of a method for autonomous downlink of delayed telemetry of a small GEO satellite provided by an embodiment of the present invention;

[0021] Figure 2 It is a flowchart of the delayed telemetry autonomous downlink task queue processing provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] Figure 1 1 is a flow chart of a method for autonomous downlink of delayed telemetry of a small GEO satellite provided by an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0024] Step 1: Delayed telemetry downlink task queue creation. The time from the end of the last delayed telemetry downlink to the start of this delayed telemetry downlink is a cycle. The ground sends a command or the autonomous task management software triggers the onboard computer software to store delayed telemetry through the "delayed telemetry storage enable" interface and create a downlink task queue.

[0025] Step 2: Maintenance and management of delayed telemetry downlink tasks. The onboard computer software dynamically maintains the delayed telemetry downlink task queue, and new downlink tasks are directly placed in the downlink task queue. If the downlink task queue is full, first check whether there is a queue in the current queue that has been executed (execution status == 1), and if so, delete the oldest completed queue. Otherwise, compare the priority of the new task with that of the task list. If the priority of the new task is low or the priority of the new task is the same as that of the queue task, discard the task and set the telemetry queue storage status to 1 (1 means that the delayed telemetry queue storage failed. The default is 0: the delayed telemetry queue is stored correctly). If the priority of the new task is high, delete the lowest priority task in the existing queue.

[0026] Step 3: Delayed telemetry download mode selection. According to the autonomous download requirements of delayed telemetry, four delayed telemetry autonomous download modes are established. The onboard computer software can autonomously select the delayed telemetry download mode according to the mission requirements. The specific download modes are as follows:

[0027] (a) Sampling delayed telemetry frame downlink mode (mode 1): All delayed telemetry frame data in area 1 in the visible arc are quickly downlinked. If the amount of downlinked data exceeds the total amount of data downlinked in the visible arc, the satellite needs to autonomously determine the downlink sampling rate to ensure that the satellite can downlink sufficiently long invisible arc telemetry data in the visible arc.

[0028] (b) Delayed telemetry frame telemetry data downlink mode for a specific period of time (mode 2): The delayed telemetry frame data in area 1 for a specific period of time is downlinked. The ground specifies the downlink start time, downlink end time and other information through instructions, and the satellite autonomously generates and executes the downlink task sequence.

[0029] (c) Delayed telemetry package data downlink mode for specified time period (mode 3): The delayed telemetry package data in area 2 in a specific time period is downlinked. The ground specifies the downlink start time, downlink end time and other information through instructions, and the satellite autonomously generates and executes the downlink task sequence.

[0030] (d) Fault delay telemetry packet telemetry data downlink mode (mode 4): According to the available time for delayed telemetry downlink in the visible arc segment, the delayed telemetry packet data in area 2 is sampled and downlinked, and the packet delay telemetry data downlink task is autonomously created and executed. The satellite determines the time period when the fault alarm occurs based on the FDIR fault alarm mark, and autonomously generates and executes the fault event packet telemetry downlink task sequence on board.

[0031] Step 4: Autonomous downlink of delayed telemetry. The onboard computer software starts to sequentially downlink delayed telemetry data according to the downlink task time of delayed telemetry. If the data downlink is completed within a visible arc segment, the task execution status is set to 1 (indicating that the downlink has been successfully completed). If a delayed telemetry downlink prohibition instruction is received, the task execution status is set to 0, and the task is re-downloaded in the next visible arc segment.

[0032] The present invention provides a method for autonomous downlinking of delayed telemetry of a small GEO satellite, which is used for storing satellite delayed telemetry when the small GEO satellite is in an invisible measurement and control arc segment, and autonomously downlinking delayed telemetry of concern to the ground based on information such as the visible arc segment duration, satellite fault conditions, and execution conditions of important measurement and control events in the satellite visible measurement and control arc segment, so that the satellite health status can be quickly judged based on the delayed telemetry information, and an emergency response strategy can be formulated to ensure the satellite's in-orbit flight safety.

[0033] The delayed telemetry in the present invention is a method of satellite telemetry in which the collected telemetry data is stored in an onboard storage device and sent when the satellite flies through the action range (observable arc) of the ground tracking and control station.

[0034] In the present invention, for small GEO satellites, the requirements for the delayed telemetry autonomous downlink function are as follows:

[0035] a. The onboard computer needs to establish and maintain the delayed telemetry downlink task queue according to the ground delayed telemetry task creation instructions, the calculation results of the invisible / visible arc segment by the autonomous task software or the FDIR event trigger;

[0036] b. Delayed telemetry supports the following four downloading methods:

[0037] 1) Delayed telemetry can be transmitted frame by frame;

[0038] 2) Delayed telemetry can be sampled and transmitted;

[0039] 3) Delayed telemetry can be downloaded in packets;

[0040] 4) Delayed telemetry can be transmitted based on the time when a specific event occurs (important satellite measurement and control events, before and after satellite failures, ground-specified telemetry during a specific period of time, etc.).

[0041] c. The onboard computer has the ability to dynamically maintain and manage the task list under delayed telemetry, and can transmit delayed telemetry data according to task priority;

[0042] The four delayed telemetry autonomous downlink modes in the present invention are defined as follows:

[0043] a. Sampling delayed telemetry frame downlink mode (mode 1): quickly downlink all delayed telemetry frame data in the visible arc. If the amount of data downlinked exceeds the total amount of data downlinked in the visible arc, the satellite needs to autonomously determine the downlink sampling rate to ensure that the satellite can downlink sufficiently long invisible arc telemetry data in the visible arc.

[0044] b. Delayed telemetry frame telemetry data downlink mode for a specific period of time (mode 2): The delayed telemetry frame data for a specific period of time is downlinked, and the ground specifies the downlink start time, downlink end time and other information through instructions. The satellite autonomously generates and executes the downlink task sequence.

[0045] c. Delayed telemetry package data downlink mode for specified time period (mode 3): Delayed telemetry package data for a specific time period is downlinked. The ground specifies the downlink start time, downlink end time and other information through instructions. The satellite autonomously generates and executes the downlink task sequence.

[0046] d. Fault delay telemetry package telemetry data downlink mode (mode 4): According to the available time for delayed telemetry downlink in the visible arc segment, the delayed telemetry package data is sampled and downlinked, and the package delay telemetry data downlink task is autonomously created and executed. The satellite determines the time period when the fault alarm occurs based on the FDIR fault alarm mark, and autonomously generates and executes the fault event package telemetry downlink task sequence on board.

[0047] like Figure 1 As shown in the figure, the autonomous downlink process of delayed telemetry is as follows: the onboard computer creates and manages the delayed telemetry downlink task queue, with the end of the last delayed telemetry downlink to the start of this delayed telemetry downlink as a cycle, selects the downlink mode according to the downlink task requirements, reads the data in the delayed telemetry storage area in the onboard computer, and marks the delayed telemetry mark in the telemetry package format mark field, and then executes the delayed telemetry downlink task according to the priority. After the downlink task is completed, delete the current task in the delayed telemetry downlink list.

[0048] like Figure 2 As shown, in the present invention, the onboard computer is responsible for the creation and maintenance of the delayed telemetry downlink task queue. The time from the end of the last delayed telemetry downlink to the start of this delayed telemetry downlink is a cycle. The onboard computer software stores the delayed telemetry and creates a downlink task queue, triggered by a command sent from the ground or by the autonomous task management software through the "delayed telemetry storage enable" interface.

[0049] In the present invention, the onboard computer software dynamically maintains the delayed telemetry downlink task queue, and new downlink tasks are directly placed in the downlink task queue. If the downlink task queue is full, first check whether there is a queue that has been executed in the current queue (execution status == 1), and if so, delete the earliest completed queue. Otherwise, compare the priority of the new task with the task list. If the priority of the new task is low or the priority of the new task is the same as the queue task, discard the task and set the telemetry queue storage status to 1 (1 indicates that the delayed telemetry queue storage failed. The default is 0: the delayed telemetry queue is stored correctly). If the priority of the new task is high, delete the lowest priority task in the existing queue.

[0050] The onboard computer software starts to sequentially download the delayed telemetry data according to the delayed telemetry download task time. If the data download is completed within a visible arc segment, the task execution status is set to 1 (indicating that the download has been successfully completed). If a delayed telemetry download prohibition instruction is received, the task execution status is set to 0, and the task is re-downloaded in the next visible arc segment.

[0051] The present invention can realize the autonomous downlink of delayed telemetry. In each downlink cycle, the satellite autonomous mission flight software autonomously calculates the start time, end time and sampling rate of delayed telemetry transmission in this cycle according to orbit information and available ground station positions, and selects different downlink modes to send to the onboard computer, which autonomously creates a downlink task queue.

[0052] The present invention can realize autonomous task maintenance of delayed telemetry downlink tasks. The onboard computer can dynamically maintain the delayed telemetry downlink task queue, and new downlink tasks can be directly placed in the downlink task queue. If the downlink task queue is full, compare the priority of the new task with that in the task list. If the priority of the new task is low, discard the task and do not process it. If the priority of the new task is high, delete the task with the lowest priority and the latest time in the existing queue. If the priority of the new task is the same as that of the queue task, delete the task with the latest time in the existing queue and add the new task.

[0053] The present invention can sample and transmit the delayed telemetry package data according to the available time for delayed telemetry transmission in the visible arc segment, and autonomously create and execute the packet delayed telemetry data transmission task. The satellite determines the fault alarm occurrence period according to the FDIR fault alarm identifier, and autonomously generates and executes the fault event package telemetry transmission task sequence on the satellite.

[0054] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for autonomous downlink of delayed telemetry of a small GEO satellite, characterized in that: The method comprises the following steps: Step 1: Create a delayed telemetry download task queue; Step 2: Maintain and manage the delayed telemetry downlink task queue in step 1; Step 3: Select the delayed telemetry download mode; Step 4: Upload the delayed telemetry data according to the delayed telemetry download task queue and delayed telemetry download mode after maintenance management; In step 1, creating a delayed telemetry download task queue includes the following steps: The time from the end of the last delayed telemetry download to the start of the current delayed telemetry download is a cycle. The ground sends a command or the autonomous task management software triggers the onboard computer software to store the delayed telemetry through the interface enabled by the delayed telemetry storage, and creates a download task queue. In step 2, the onboard computer software dynamically maintains the delayed telemetry downlink task queue, and new downlink tasks are directly placed in the downlink task queue; If the downlink task queue is full, first check whether there is a completed downlink task in the current downlink task queue. If there is, delete the earliest completed downlink task; otherwise, compare the priority of the new downlink task with the downlink tasks in the downlink task queue. If the priority of the new downlink task is low or the priority of the new downlink task is the same as that of the downlink tasks in the downlink task queue, discard the new downlink task and set the storage status of the telemetry downlink team task column to 1; if the priority of the new downlink task is high, delete the downlink task with the lowest priority in the current downlink task queue; In step 3, the delayed telemetry transmission mode includes a sampling delayed telemetry frame transmission mode, a specific period delayed telemetry frame telemetry data transmission mode, a specified period delayed telemetry package data transmission mode, and a fault delayed telemetry package telemetry data transmission mode; The sampling delay telemetry frame transmission mode is: all the delayed telemetry frame data in the visible arc are quickly transmitted in area 1. If the amount of transmitted data exceeds the total amount of data transmitted in the visible arc, the satellite needs to autonomously determine the transmission sampling rate to ensure that the satellite can transmit long enough invisible arc telemetry data in the visible arc. The telemetry data downlink mode of delayed telemetry frames in a specific period is as follows: downlink the delayed telemetry frame data in the visible arc fast downlink area 1 in a specific period, and the ground specifies the downlink start time and downlink end time information through instructions, and the satellite autonomously generates and executes the downlink task sequence; The downlink mode of the delayed telemetry package data in the specified time period is as follows: downlink the delayed telemetry package data in the visible arc fast downlink area 2 in a specific period of time, and the ground specifies the downlink start time and downlink end time information through instructions, and the satellite autonomously generates and executes the downlink task sequence; The telemetry data transmission mode of the fault delay telemetry package is as follows: according to the available time for the delay telemetry transmission of the visible arc segment, the delay telemetry package data in the visible arc fast transmission area 2 is sampled and transmitted, and the package delay telemetry data transmission task is independently created and executed; The satellite determines the fault alarm occurrence period based on the FDIR fault alarm mark, and autonomously generates and executes the fault event package telemetry downlink task sequence on board; In step 4, the onboard computer software starts to sequentially download the delayed telemetry data according to the delayed telemetry download task expiration time. If the data download is completed within a visible arc segment, the task execution status is set to 1. If a delayed telemetry download prohibition instruction is received, the task execution status is set to 0, and the task is re-downloaded in the next visible arc segment.

2. The method for autonomous downlink of delayed telemetry of a small GEO satellite according to claim 1, characterized in that: The storage status of the telemetry downlink queue task column is 1, which means that the delayed telemetry queue storage failed.

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