Life cycle time management and maintenance approach for fully autonomous flight spacecraft

Abstract

A kind of full life cycle time management and maintenance method suitable for full autonomous flight spacecraft, comprising: 1) satellite full life cycle time management and maintenance is divided into two cases of normal in-orbit and abnormal in-orbit time management and maintenance, satellite normal in-orbit work is transferred to step 2), satellite abnormal in-orbit work is transferred to step 5);2) according to satellite orbit and setting, satellite time management and maintenance is carried out in two cases of satellite charged launch and satellite uncharged launch;3) starboard data management computer distributes time to all devices of satellite through bus;4) attitude and orbit control computer completes satellite time management and maintenance according to the time distributed by starboard data management computer;5) according to the fault type during in-orbit, satellite time management and maintenance are completed.The present application ensures that the system can be independently managed and maintained after initialization in the case of failure, and ensures the safe and normal operation of the satellite.

Description

Technical Field

[0001] This invention relates to a method for time management and maintenance throughout the entire lifecycle of fully autonomous spacecraft, applicable to the time management and maintenance of fully autonomous spacecraft throughout their entire lifecycle. Background Technology

[0002] With the widespread application of all-electric propulsion spacecraft, due to their low thrust, long orbital insertion times (lasting several months), and long invisible arcs from the ground, spacecraft must possess fully autonomous flight capabilities. Satellite time management and maintenance play a crucial role in the normal operation and application of fully autonomous satellites. The clocks of all satellite systems need to be unified to a single time standard to ensure that satellite systems complete their corresponding flight tasks in sequence. The formation of downlink telemetry information and the execution of onboard commands depend on time management. Furthermore, functions such as attitude and orbit control, orbit extrapolation, sensor protection, and satellite data fusion all rely on a unified and managed onboard time. Therefore, satellites are required to autonomously complete orbit and time generation, maintenance, and management. During the satellite's on-orbit operation, it is also required to possess full lifecycle time management and maintenance capabilities.

[0003] Currently, traditional time management and maintenance of spacecraft during their on-orbit operation suffer from the following problems:

[0004] 1) Traditional spacecraft only consider time management and maintenance of equipment and GNSS under normal conditions during their on-orbit operation. They do not have time management and maintenance plans for the entire life cycle of the spacecraft and the coupling of different equipment states, which makes it impossible to autonomously handle different time management conditions on-orbit.

[0005] 2) Traditional spacecraft do not consider system failures. For example, if the system experiences a reset or power failure, the autonomous time maintenance and management scheme requires ground intervention to confirm the completion of time synchronization management, which affects the spacecraft's autonomous operation efficiency. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a time management and maintenance method for the entire life cycle of a fully autonomous spacecraft. This method addresses the time management and maintenance of the satellite throughout its entire life cycle under all operating conditions, both normal and abnormal, ensuring that the system can autonomously manage and maintain time after initialization in case of a fault, thus guaranteeing the safety and normal operation of the satellite.

[0007] The technical solution of this invention is: a method for time management and maintenance of fully autonomous flight spacecraft throughout their entire lifecycle, comprising:

[0008] 1) Satellite lifecycle time management and maintenance are divided into two situations: normal on-orbit operation and abnormal on-orbit time management and maintenance. When the satellite is working normally on-orbit, proceed to step 2); when the satellite is working abnormally on-orbit, proceed to step 5.

[0009] 2) Based on the satellite orbit and settings, satellite time management and maintenance are performed under both powered and unpowered launch conditions;

[0010] 3) The onboard data management computer distributes time information to all satellite devices via a bus;

[0011] 4) The attitude and orbit control computer performs satellite time management and maintenance based on the time distributed by the onboard data management computer;

[0012] 5) Perform satellite time management and maintenance based on the types of faults encountered during the on-orbit period.

[0013] Based on time management and maintenance equipment, on-orbit malfunctions are categorized into three types: onboard data management computer malfunctions, attitude and orbit control computer malfunctions, and overall satellite power failures. Therefore, satellite time management and maintenance include:

[0014] 5.1) Perform satellite time management and maintenance in the event of a reset or switchover of the onboard data management computer;

[0015] 5.2) Perform satellite time management and maintenance in the event of a reset or switchover of the attitude and orbit control computer;

[0016] 5.3) Perform satellite time management and maintenance in the event of a complete satellite power failure.

[0017] The satellite time management and maintenance in the event of a reset or switchover of the onboard data management computer includes:

[0018] The onboard data management computer recovers important data from the lower-level machine;

[0019] The onboard data management computer performs time synchronization based on the satellite time in important data.

[0020] Set the satellite time attribute to "SRAM time";

[0021] The attitude and orbit control computer receives satellite time from the onboard data management computer, maintains its own satellite time unchanged, and does not synchronize its time according to the satellite data management computer's satellite time.

[0022] The attitude and orbit control computer performs satellite time management and maintenance based on the onboard GNSS's operational status.

[0023] The satellite time management and maintenance in the event of a reset or switchover of the attitude and orbit control computer includes:

[0024] (521) The attitude and orbit control computer recovers important data from the onboard data management computer and performs time synchronization based on the satellite time in the important data as the starting point;

[0025] (522) Determine whether the attitude and orbit control computer has been successfully restored. If successful, proceed to step (523); otherwise, proceed to step (524).

[0026] (523) The attitude and orbit control computer receives the satellite time and satellite time attribute information sent by the satellite data management computer, and uses the satellite data management computer’s satellite time to complete the time synchronization, and then proceeds to step (525).

[0027] (524) The attitude and orbit control computer does not perform any operation to trigger FDIR for processing, and returns to step (522) after processing is completed.

[0028] (525) The attitude and orbit control computer completes satellite time management and maintenance based on the working status of the onboard GNSS.

[0029] The satellite time management and maintenance in the event of a complete satellite power failure includes:

[0030] The onboard data management computer recovers important data from the FLASH memory and starts timing from the satellite time in the important data.

[0031] Set the satellite time attribute to "FLASH time";

[0032] The attitude and orbit control computer receives satellite time from the onboard data management computer, maintains its own satellite time, and does not synchronize its time with the satellite time of the onboard data management computer.

[0033] The attitude and orbit control computer performs satellite time management and maintenance based on the onboard GNSS's operational status.

[0034] In the case of satellite launch while powered on, satellite time management and maintenance are performed, including:

[0035] (211) Determine if the satellite is working properly. If it is, proceed to step 212); otherwise, proceed to step 5.3.

[0036] (212) Determine whether the onboard data management computer is working properly. If it is, proceed to step (213); otherwise, proceed to step 5.1.

[0037] (213) Before launch, the onboard data management computer is compared via ground commands;

[0038] (214) Set the satellite time attribute to "ground time" and proceed to step 3).

[0039] Satellite time management and maintenance are performed when the satellite is launched without power, including:

[0040] (221) Determine if the satellite is working properly. If it is, proceed to step 222); otherwise, proceed to step 5.3.

[0041] (222) After the satellite takes off and separates from the rocket, the onboard data management computer is powered on to determine whether the onboard data management computer is working properly. If it is working properly, proceed to step (223); otherwise, proceed to step 5.1.

[0042] (223) The onboard data management computer performs calibration based on the satellite time set before launch;

[0043] (224) Set the satellite time attribute to "default time" and proceed to step 3).

[0044] The attitude and orbit control computer performs satellite time management and maintenance based on the time distributed by the onboard data management computer, including:

[0045] (41) Determine whether the attitude control computer is working properly. If it is, proceed to step (42); otherwise, proceed to step 5.2.

[0046] (42) The attitude and orbit control computer completes time synchronization based on the satellite time sent by the onboard data management computer;

[0047] (43) Based on the working status of the onboard GNSS, complete the satellite time management and maintenance.

[0048] When the onboard GNSS is functioning normally, satellite time management and maintenance include:

[0049] (4311) The attitude and orbit control computer uses GNSS time to calibrate its own clock;

[0050] (4312) The attitude and orbit control computer feeds back the clock difference to the onboard data management computer according to the onboard telemetry transmission frequency;

[0051] (4313) The onboard data management computer determines whether the clock error is less than the set threshold; if it is less than the threshold, proceed to (4314); otherwise, proceed to step (4316).

[0052] (4314) The onboard data management computer performs time synchronization based on the clock difference;

[0053] (4315) Update the satellite time attribute to "GNSS time" and return to step 3.

[0054] (4316) The onboard data management computer keeps the satellite time unchanged and returns to step 3).

[0055] When the onboard GNSS malfunctions, satellite time management and maintenance include:

[0056] (4321) The attitude and orbit control computer completes calibration based on the onboard data management computer time;

[0057] (4322) Determine if the GNSS is unavailable for an extended period of time while in orbit; if it is unavailable for an extended period of time, proceed to step (4323); otherwise, return to step 4.

[0058] (4323) Alarm, when the ground sends a command to the onboard data management computer to compare, proceed to step (4321);

[0059] (4324) Set the satellite time attribute to "Ground time" and return to step 3).

[0060] The advantages of this invention compared to the prior art are:

[0061] This invention provides solutions for satellite time management and maintenance under various conditions, including powered-on launch, unpowered launch, and multiple time management devices working together under normal on-orbit conditions, as well as management and maintenance under different on-orbit anomalies. Through full lifecycle time maintenance and management, it provides a unified, accurate, and precise on-board time for satellite functionality and mission execution, ensuring normal satellite operation. Furthermore, the time management and maintenance methods provided for on-orbit anomalies ensure seamless time maintenance and management without affecting autonomous flight, significantly improving overall satellite application efficiency and reducing ground operation and management costs. This has significant reference value for the improvement and development of future spacecraft's full lifecycle autonomous flight time management and maintenance capabilities. Attached Figure Description

[0062] Figure 1 A flowchart illustrating the time-based maintenance and management methods for the entire satellite lifecycle.

[0063] Figure 2 Flowchart for the maintenance and management method of resetting / switching time for onboard data management computer.

[0064] Figure 3 Flowchart for the maintenance management method of resetting / switching time for attitude and track control computer.

[0065] Figure 4 Flowchart for satellite power outage maintenance and management methods. Detailed Implementation

[0066] The fully autonomous spacecraft satellite adopts a distributed architecture. The onboard data management computer serves as the host computer, while the lower-level computers consist of a power management computer, a battery management unit, and an attitude and orbit control computer, forming a distributed network system via a bus. In the event of a system cutoff or power failure in orbit, to prevent the loss of information (including time information), the satellite is designed with a critical data storage function. Important data is stored in the onboard data management computer's FLASH memory and the lower-level computers' static random access memory (SRAM). Satellite time management is jointly implemented by the onboard data management computer and the attitude and orbit control computer, with each device maintaining a specific time.

[0067] like Figure 1 As shown, the present invention provides a method for time management and maintenance throughout the entire lifecycle of a fully autonomous spacecraft, which mainly includes time management and maintenance for satellite powered-on launch, time management and maintenance for satellite unpowered launch, time management and maintenance for onboard data management computer, time management and maintenance for on-orbit GNSS unavailability, time management and maintenance for attitude and orbit control computer, time management and maintenance for on-orbit GNSS (including GNSS available time management and maintenance and GNSS unavailability time management and maintenance), and time management and maintenance during satellite or abnormal equipment failures (abnormalities mainly consider time management and maintenance during onboard data management computer reset / switching, time management and maintenance during attitude and orbit control computer reset / switching, and time management and maintenance during satellite power failure).

[0068] The implementation steps of this invention are as follows:

[0069] 1) Satellite lifecycle time management and maintenance is divided into two situations: normal on-orbit operation and abnormal on-orbit operation. When the satellite is working normally on-orbit, proceed to step 2); when the satellite is working abnormally on-orbit, proceed to step 9.

[0070] 2) Based on the satellite orbit and settings, the process is divided into powered satellite launch and unpowered satellite launch. For powered satellite launch, proceed to step 3); for unpowered satellite launch, proceed to step 4.

[0071] 3) When the satellite is launched while powered on, the satellite time management and maintenance process is as follows, proceeding to step 31):

[0072] (31) Determine if the satellite is working properly. If it is, proceed to step 32; otherwise, proceed to step 9.3.

[0073] (32) Determine whether the onboard data management computer is working properly. If it is, proceed to step (33); otherwise, proceed to step 9.1.

[0074] (33) Before launch, the onboard data management computer is compared via ground commands;

[0075] (34) Set the satellite time attribute to "Ground time" and proceed to step 5);

[0076] 4) When the satellite is launched without power, the satellite time management and maintenance process is as follows, proceeding to step (41):

[0077] (41) Determine if the satellite is working properly. If it is, proceed to step 42; otherwise, proceed to step 9.3.

[0078] (42) After the satellite takes off and separates from the rocket, the onboard data management computer is powered on to determine whether the onboard data management computer is working properly. If it is working properly, proceed to step (43); otherwise, proceed to step 9.1.

[0079] (43) The onboard data management computer performs calibration based on the satellite time set before the satellite launch;

[0080] (44) Set the satellite time attribute to "default time" and proceed to step 5);

[0081] 5) Satellite time management and maintenance are completed through the onboard data management computer. The onboard data management computer distributes time to all satellite devices through the bus, and then proceeds to step 6).

[0082] 6) Satellite time management and maintenance are completed through the attitude and orbit control computer. The process is as follows: Proceed to step (61):

[0083] (61) Determine whether the attitude control computer is working properly. If it is, proceed to step (62); otherwise, proceed to step 9.2.

[0084] (62) The attitude and orbit control computer completes time synchronization based on the satellite time sent by the onboard data management computer;

[0085] (63) The attitude and orbit control computer checks whether the on-board GNSS is working properly; if it is, proceed to step 7); if it is not, proceed to step 8.

[0086] 7) When the onboard GNSS is working normally, satellite time management and maintenance are performed through GNSS. The process is as follows, proceed to step (71):

[0087] (71) The attitude and orbit control computer uses GNSS time to calibrate its own clock;

[0088] (72) The attitude and orbit control computer feeds back the clock difference to the onboard data management computer according to the onboard telemetry transmission frequency;

[0089] (73) The onboard data management computer determines whether the clock error is less than the set threshold; if it is less than the threshold, proceed to (74); otherwise, proceed to (76).

[0090] (74) The onboard data management computer performs time synchronization based on the clock difference;

[0091] (75) Update the satellite time attribute to "GNSS time" and return to step 5.

[0092] (76) The onboard data management computer keeps the satellite time unchanged and returns to step 5);

[0093] 8) When the onboard GNSS malfunctions, the satellite time management and maintenance process is as follows, proceeding to step (81):

[0094] (81) The attitude and orbit control computer completes calibration based on the onboard data and computer time management.

[0095] (82) Determine if the GNSS is unavailable in orbit for an extended period; if it is unavailable for an extended period, proceed to step (83); otherwise, return to step 5.

[0096] (83) When an alarm is triggered and the ground sends a command to the onboard data management computer for comparison, proceed to step (84);

[0097] (84) Set the satellite time attribute to "Ground time" and return to step 5);

[0098] 9) During on-orbit operation, based on time management and equipment maintenance, faults are mainly classified into three categories: faults in the onboard data management computer are referred to step 9.1), faults in the attitude and orbit control computer are referred to step 9.2), and faults in the entire satellite power failure are referred to step 9.3. Figure 2-4 As shown, the details are as follows:

[0099] 9.1) In the event of a reset or switchover of the onboard data management computer, the satellite time management and maintenance process is as follows, proceeding to step (911):

[0100] (911) The onboard data management computer recovers important data from the lower-level machine;

[0101] (912) The onboard data management computer performs time synchronization based on the satellite time in the important data;

[0102] (913) Set the satellite time attribute to "SRAM time";

[0103] (914) The attitude and orbit control computer receives the satellite time from the onboard data management computer, maintains its own satellite time unchanged, and does not adjust its time according to the satellite time of the onboard data management computer.

[0104] (915) The attitude and orbit control computer determines whether GNSS is available. If GNSS is available, return to step 7); if GNSS is unavailable, return to step 8.

[0105] 9.2) In the event of a reset or switchover of the attitude and orbit control computer, the satellite time management and maintenance process is as follows, proceeding to step (921):

[0106] (921) The attitude and orbit control computer recovers important data from the onboard data management computer and performs time synchronization based on the satellite time in the important data as the starting point;

[0107] (922) Determine whether the attitude and orbit control computer has been successfully restored. If successful, proceed to (923); otherwise, proceed to (924).

[0108] (923) The attitude and orbit control computer receives the satellite time and satellite time attribute information sent by the satellite data management computer, and uses the satellite time of the satellite data management computer to complete the time synchronization, and then proceeds to step (925).

[0109] (924) The attitude and orbit control computer does not perform any operation to trigger FDIR (Failure Detection, Isolation and Recovery) for processing, and returns to step (922) after processing is completed;

[0110] (925) The attitude and orbit control computer determines whether GNSS is available. If GNSS is available, return to step 7; if GNSS is unavailable, return to step 8.

[0111] 9.3) In the event of a complete satellite power failure, the satellite time management and maintenance process is as follows, proceeding to step (931):

[0112] (931) The onboard data management computer recovers important data from FLASH and starts timing from the star time in the important data;

[0113] (932) Set the satellite time attribute to "FLASH time";

[0114] (933) The attitude and orbit control computer receives the satellite time from the onboard data management computer, maintains its own satellite time, and does not adjust its time according to the satellite time of the onboard data management computer;

[0115] (934) The attitude and orbit control computer determines whether GNSS is available. If GNSS is available, return to step 7; if GNSS is unavailable, return to step 8.

[0116] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention based on the above-disclosed technical content 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 solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for full lifecycle time management and maintenance of fully autonomous flight spacecraft, characterized in that, include: 1) Satellite lifecycle time management and maintenance are divided into two situations: normal on-orbit operation and abnormal on-orbit operation. When the satellite is operating normally on-orbit, proceed to step 2); when the satellite is operating abnormally on-orbit, proceed to step 5). 2) Based on the satellite orbit and settings, satellite time management and maintenance are performed under both powered and unpowered launch conditions; 3) The onboard data management computer distributes time information to all satellite devices via a bus; 4) The attitude and orbit control computer manages and maintains the satellite time based on the time distributed by the onboard data management computer; 5) Perform satellite time management and maintenance based on the types of faults encountered during the on-orbit period; Based on time management and maintenance equipment, on-orbit malfunctions are categorized into three types: onboard data management computer malfunctions, attitude and orbit control computer malfunctions, and overall satellite power failures. Therefore, satellite time management and maintenance include: 5.1) Perform satellite time management and maintenance in the event of a reset or switchover of the onboard data management computer; 5.2) Perform satellite time management and maintenance in the event of a reset or switchover of the attitude and orbit control computer; 5.3) Perform satellite time management and maintenance in the event of a complete satellite power failure; The attitude and orbit control computer performs satellite time management and maintenance based on the time distributed by the onboard data management computer, including: (41) Determine if the attitude and orbit control computer is working properly. If it is, proceed to step (42); otherwise, proceed to step 5.

2. (42) The attitude and orbit control computer completes time synchronization based on the satellite time sent by the onboard data management computer; (43) Perform satellite time management and maintenance based on the onboard GNSS's operational status; When the onboard GNSS is functioning normally, satellite time management and maintenance include: (4311) The attitude and orbit control computer uses GNSS time to calibrate its own clock; (4312) The attitude and orbit control computer feeds back the clock difference to the onboard data management computer according to the onboard telemetry transmission frequency; (4313) The onboard data management computer determines whether the clock error is less than the set threshold; if it is less than the threshold, proceed to (4314); otherwise, proceed to step (4316). (4314) The onboard data management computer performs time synchronization based on the clock difference; (4315) Update the satellite time attribute to "GNSS time", return to step 3) (4316) The onboard data management computer keeps the satellite time unchanged and returns to step 3). When the onboard GNSS malfunctions, satellite time management and maintenance include: (4321) The attitude and orbit control computer completes calibration based on the onboard data management computer time; (4322) Determine if the GNSS is unavailable in orbit for an extended period; if it is unavailable for an extended period, proceed to step (4323); otherwise, return to step 4. (4323) Alarm, when the ground sends a command to the onboard data management computer to compare, proceed to step (4321). (4324) Set the satellite time attribute to "Ground time" and return to step 3).

2. The method for full lifecycle time management and maintenance of a fully autonomous flight spacecraft according to claim 1, characterized in that, The satellite time management and maintenance in the event of a reset or switchover of the onboard data management computer includes: The onboard data management computer recovers important data from the lower-level machine; The onboard data management computer performs time synchronization based on the satellite time in important data. Set the satellite time attribute to "SRAM time"; The attitude and orbit control computer receives satellite time from the onboard data management computer, maintains its own satellite time unchanged, and does not synchronize its time according to the satellite data management computer's satellite time. The attitude and orbit control computer performs satellite time management and maintenance based on the onboard GNSS's operational status.

3. The method for full lifecycle time management and maintenance of a fully autonomous flight spacecraft according to claim 1, characterized in that, The satellite time management and maintenance in the event of a reset or switchover of the attitude and orbit control computer includes: (521) The attitude and orbit control computer recovers important data from the onboard data management computer and performs time synchronization based on the satellite time in the important data as the starting point; (522) Determine whether the attitude and orbit control computer has been successfully restored. If successful, proceed to step (523); otherwise, proceed to step (524). (523) The attitude and orbit control computer receives the satellite time and satellite time attribute information sent by the satellite data management computer, and uses the satellite time of the satellite data management computer to complete the time synchronization, and then proceeds to step (525). (524) The attitude and orbit control computer does not perform any operation to trigger FDIR for processing, and returns to step (522) after processing is completed. (525) The attitude and orbit control computer completes satellite time management and maintenance based on the working status of the onboard GNSS.

4. The method for full lifecycle time management and maintenance of a fully autonomous flight spacecraft according to claim 1, characterized in that, The satellite time management and maintenance in the event of a complete satellite power failure includes: The onboard data management computer recovers important data from the FLASH memory and starts timing from the satellite time in the important data. Set the satellite time attribute to "FLASH time"; The attitude and orbit control computer receives satellite time from the onboard data management computer, maintains its own satellite time, and does not synchronize its time with the satellite time of the onboard data management computer. The attitude and orbit control computer performs satellite time management and maintenance based on the onboard GNSS's operational status.

5. The method for full lifecycle time management and maintenance of a fully autonomous flight spacecraft according to claim 1, characterized in that, In the case of satellite launch while powered on, satellite time management and maintenance are performed, including: (211) Determine if the satellite is working properly; if so, proceed to step 212; otherwise, proceed to step 5.

3. (212) Determine if the onboard data management computer is working properly. If it is, proceed to step (213); otherwise, proceed to step 5.

1. (213) Before launch, the onboard data management computer is compared via ground commands; (214) Set the satellite time attribute to "ground time" and proceed to step 3).

6. The method for full lifecycle time management and maintenance of a fully autonomous flight spacecraft according to claim 1, characterized in that, Satellite time management and maintenance are performed when the satellite is launched without power, including: (221) Determine if the satellite is working properly; if so, proceed to step 222; otherwise, proceed to step 5.

3. (222) After the satellite takes off and separates from the launch vehicle, the onboard data management computer is powered on to determine whether it is working properly. If it is, proceed to step (223); otherwise, proceed to step 5.

1. (223) The onboard data management computer performs calibration based on the satellite time set before launch; (224) Set the satellite time attribute to "default time" and proceed to step 3.

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