An on-orbit autonomous save method for electric propulsion in a failure state
By setting up a data storage area before and after a fault in the electric propulsion system and autonomously transmitting the data, the problem of difficulty in obtaining telemetry data when the electric propulsion system of an ultra-low orbit satellite experiences a fault in the non-tracking arc segment has been solved. This enables the storage of telemetry data at a high sampling rate, ensuring timely fault location and safeguarding satellite safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING INST OF CONTROL ENG
- Filing Date
- 2026-02-26
- Publication Date
- 2026-06-26
AI Technical Summary
In existing technologies, when a fault occurs in the electric propulsion system of an ultra-low orbit satellite during the non-telemetry and control segment, it is impossible to obtain high-speed telemetry data in a timely manner, which makes fault location difficult and affects satellite safety.
Two data storage areas are set up in the electric propulsion system, which are used to store telemetry data before and after a fault, and can be autonomously transmitted according to ground commands within the telemetry and control arc, so as to realize on-board autonomous storage and high-speed sampling of telemetry data.
It enables the high-sampling-rate storage of telemetry data before and after electric propulsion system failures on the satellite, ensuring timely and accurate fault location, safeguarding satellite safety, and supporting fault analysis and location throughout the entire life cycle.
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Figure CN122276178A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to spacecraft electric propulsion system technology, and more particularly to a method for autonomously saving and transmitting on-orbit fault states of electric propulsion, applicable to on-orbit applications of spacecraft electric propulsion systems. Background Technology
[0002] Very low Earth orbit (VLEO) satellites, with their low orbits and high atmospheric drag, are constrained by their weight. Traditional chemical propulsion systems cannot meet the total impulse requirements throughout their operational lifespan, necessitating the use of high-specific-impulse ion electric propulsion systems. To compensate for atmospheric drag, the electric propulsion system of VLEO satellites is essentially constantly firing. However, due to their low orbits, the telemetry and control (TT&C) arc is very short, typically 3-5 minutes. Therefore, most of the TT&C time for the electric propulsion system occurs outside the TT&C arc. When a fault occurs outside the TT&C arc, without crucial telemetry data before and after the fault, on-orbit fault location is extremely difficult, hindering timely fault localization and handling. Considering the high drag of VLEO satellites, if the electric propulsion system cannot promptly resume ignition, orbital decay will accelerate, severely impacting satellite safety. Prior to this invention, electric propulsion systems could only perform fault location analysis through whole-satellite telemetry after an on-orbit failure. Due to the limited resources of whole-satellite telemetry, it was impossible to provide high-speed telemetry data to the electric propulsion subsystem. The telemetry cycle was generally only 500ms to 1s. Especially for low-Earth orbit satellites, telemetry outside the telemetry and control arc was delayed, and the telemetry cycle was generally more than 30s. Summary of the Invention
[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for autonomously saving and transmitting on-orbit fault status of electric propulsion, so as to realize the high-speed autonomous saving and timely transmission of important telemetry data before and after the electric propulsion system fails.
[0004] The solution of this invention is: an on-board autonomous storage and downlink method for electric propulsion on-orbit fault status. After the electric propulsion system is ignited, the following steps are executed in each control cycle: Based on the fault codes of the electric propulsion system, fault diagnosis is performed to determine whether a fault has occurred in the electric propulsion system. Before a failure occurs in the electric propulsion system, the telemetry data of the electric propulsion system is cyclically stored in the first data storage area on the storage unit of the electric propulsion control unit; After a failure occurs in the electric propulsion system, the telemetry data of the electric propulsion system is stored in the second data storage area on the storage unit of the electric propulsion control unit until the second data storage area is full. During the most recent entry of the satellite into the telemetry and control arc after the malfunction, it will transmit the telemetry data of the electric propulsion system before and after the malfunction according to the ground remote control command.
[0005] Preferably, a fault word of 0 indicates that the electric propulsion system has not malfunctioned, while a fault word of non-zero indicates that the electric propulsion system has malfunctioned.
[0006] Preferably, before the electric propulsion system is ignited, the fault word is set to 0 by default, the contents of the first data storage area and the second data storage area are cleared, the sequence number of the telemetry data frame before and after the fault is cleared, the telemetry data storage pointer before the fault points to the first address of the first data storage area, and the telemetry data storage pointer after the fault points to the first address of the second data storage area; after the electric propulsion system is ignited, once a fault occurs in the electric propulsion system, the fault word becomes non-zero.
[0007] Preferably, the above-mentioned method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite further includes the following steps: After transmitting the telemetry data before and after the fault, if a "clear electric propulsion system fault word command" is received from the ground, the fault word of the electric propulsion system will be cleared, and the contents of the first and second data storage areas will be cleared. The sequence numbers of the telemetry data frames before and after the fault will be cleared. Before the fault, the telemetry data storage pointer will point to the first address of the first data storage area; after the fault, the telemetry data storage pointer will point to the first address of the second data storage area.
[0008] Preferably, during the most recent satellite entry into the telemetry and control arc after the fault, if the received ground remote control command is a "data transmission command before the fault", the telemetry data before the fault stored in the first data storage area will be transmitted sequentially; if the received ground remote control command is a "data transmission command after the fault", the telemetry data after the fault stored in the second data storage area will be transmitted sequentially.
[0009] The beneficial effects of this invention compared to the prior art are: (1) The present invention proposes an autonomous storage and downlink method for on-orbit fault status of electric propulsion for ultra-low orbit satellites, similar to the black box of an aircraft. Through the design of this method, important telemetry data before and after the electric propulsion system fails can be autonomously stored on the satellite. (2) The data sampling period stored on the satellite in this invention is configurable, generally 16~64ms, which is higher than the conventional fast frame telemetry data sampling rate (500ms~1s) of the satellite. The higher the telemetry data sampling rate before and after the fault occurs, the more conducive it is to the analysis and location of the fault in orbit. (3) When the present invention enters the ground telemetry and control arc again after a fault, it completes the downlink of data before and after the fault according to the ground remote control command, which provides an important guarantee for the ground to conduct fault diagnosis and location and fault handling, and ensures the safety of the satellite in orbit; (4) After the telemetry data before and after the fault is transmitted, the fault word of the electric propulsion system is cleared according to the ground remote control command. Before the next ignition, the first and second data storage areas are automatically cleared, so that the on-orbit fault status can continue to be automatically saved, providing a guarantee for fault analysis and location throughout the satellite's life cycle. Attached Figure Description
[0010] Figure 1 This invention relates to an embodiment of a method for autonomously saving and transmitting on-orbit fault status of electric propulsion. Detailed Implementation
[0011] The present invention will be further described below with reference to the embodiments.
[0012] This invention provides a method for autonomously saving and transmitting on-orbit fault status of an electric propulsion system. The method involves executing the following steps in each control cycle: Based on the fault codes of the electric propulsion system, fault diagnosis is performed to determine whether a fault has occurred in the electric propulsion system. Before a failure occurs in the electric propulsion system, the telemetry data of the electric propulsion system is cyclically stored in the first data storage area on the storage unit of the electric propulsion control unit; After a failure occurs in the electric propulsion system, the telemetry data of the electric propulsion system is stored in the second data storage area on the storage unit of the electric propulsion control unit until the second data storage area is full. During the most recent entry of the satellite into the telemetry and control arc after the malfunction, it will transmit the telemetry data of the electric propulsion system before and after the malfunction according to the ground remote control command.
[0013] A fault word of 0 indicates that the electric propulsion system is not malfunctioning, while a fault word of non-zero indicates that the electric propulsion system has malfunctioned. Before the electric propulsion system ignites, the fault word defaults to 0, the contents of the first and second data storage areas are cleared, the sequence numbers of telemetry data frames before and after the fault are cleared, the telemetry data storage pointer before the fault points to the starting address of the first data storage area, and the telemetry data storage pointer after the fault points to the starting address of the second data storage area; after the electric propulsion system ignites, if a fault occurs in the electric propulsion system, the fault word becomes non-zero.
[0014] After transmitting the telemetry data before and after the fault, if a "clear electric propulsion system fault word command" is received from the ground, the fault word of the electric propulsion system will be cleared, and the contents of the first and second data storage areas will be cleared. The sequence numbers of the telemetry data frames before and after the fault will be cleared. Before the fault, the telemetry data storage pointer will point to the first address of the first data storage area; after the fault, the telemetry data storage pointer will point to the first address of the second data storage area.
[0015] Preferably, the storage unit of the electric propulsion control unit is FLASH. Preferably, the control cycle is 16ms to 64ms, which is configurable.
[0016] Preferably, during the most recent satellite entry into the telemetry and control arc after the fault, if the received ground remote control command is a "fault-pre-fault data transmission command", the fault-pre-fault data stored in the first data storage area will be transmitted sequentially; if the received ground remote control command is a "fault-post-fault data transmission command", the fault-post-fault data stored in the second data storage area will be transmitted sequentially.
[0017] Preferably, the control cycle stores one frame of telemetry data for each control cycle T, and the size of the telemetry data frame is MByte. M takes the value of 16~1024. Preferably, the telemetry data frame includes a frame sequence number, a feature code, and telemetry data. Preferably, the telemetry data includes the voltage, current, pressure, and temperature during the operation of the electric propulsion system.
[0018] Example 1 The ignition control of the electric propulsion subsystem is driven and controlled by the electric propulsion control unit. The application software also runs on the electric propulsion control unit, which has a processor and memory, typically including SRAM and FLASH.
[0019] Two important data storage areas are set up on the FLASH memory of the electric propulsion control unit. One area stores data before the electric propulsion subsystem failure (N1). T seconds), data after 1 storage failure (N2) Before a fault occurs, important data is stored cyclically every control cycle T (16ms ~ 64ms). After a fault occurs, data is stored every control cycle T (16ms ~ 64ms). Storage stops when the data is full. The specific process is as follows: Each control cycle T stores a data frame of M bytes in size, with the following format: Table 1. Data frame format before the fault
[0020] Table 2. Data frame storage format before the fault.
[0021] Table 3 Data frame format after fault
[0022] Table 4 Data frame storage format after a fault
[0023] During the ignition process of the electric propulsion system, the automatic saving of electric propulsion telemetry data is initiated. The specific saving process is as follows: S1. In each control cycle T, the fault word of the electric propulsion system is judged. If the fault word of this cycle is 0, proceed to S2; if the fault word of this cycle is non-zero, proceed to S4. S2. If the fault word in the previous cycle is non-zero, then: after the fault, the content of the storage area is cleared to 0, the frame sequence number is set to 0, and the data storage location pointer after the fault points to AfterFaultAddr0; before the fault, the content of the storage area is cleared to 0, the frame sequence number is set to 0, and the data storage location pointer before the fault points to BeforeFaultAddr0; jump to S1. If the fault word in the previous cycle was 0, then: the pointer to the address in the first data storage area before the fault occurred points to the next address; jump to S3; S3. Determine whether the data storage pointer before the fault was pointing to the last address of the first memory area. If not, jump to S1; if so, move the pointer to the first address of the first memory area and jump to S1. S4. After the fault, the data is stored in the second data storage area. The pointer points to the address, and then the pointer points to the next address; jump to S5; S5. Determine whether the data storage pointer after the fault points to the last address of the second storage area. If not, jump to S1; if yes, end the storage and exit the electric propulsion fault data saving process. The fault data download process is as follows: After entering ground control, the electric propulsion system fault word is sent to the ground as telemetry data. When the ground detects that the electric propulsion system fault word is non-zero, it sends ground remote control commands "data transmission command before fault" and "data transmission command after fault". Otherwise, no ground remote control commands are sent.
[0024] If the remote control command received by the satellite from the ground is "data transmission command before failure", then the stored telemetry data before failure will be transmitted to the ground in sequence; if the remote control command received by the satellite from the ground is "data transmission command after failure", then the stored telemetry data after failure will be transmitted in sequence.
[0025] After transmitting the telemetry data before and after the fault, if a "clear electric propulsion system fault word command" is received from the ground, the fault word of the electric propulsion system will be cleared, and the contents of the first and second data storage areas will be cleared. The sequence numbers of the telemetry data frames before and after the fault will be cleared. Before the fault, the telemetry data storage pointer will point to the first address of the first data storage area; after the fault, the telemetry data storage pointer will point to the first address of the second data storage area.
[0026] All contents not described in detail in this specification are within the protection scope of the technical solution of this invention.
Claims
1. A method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite, characterized in that... After the electric propulsion system ignites, the following steps are executed in each control cycle: Based on the fault codes of the electric propulsion system, fault diagnosis is performed to determine whether a fault has occurred in the electric propulsion system. Before a failure occurs in the electric propulsion system, the telemetry data of the electric propulsion system is cyclically stored in the first data storage area on the storage unit of the electric propulsion control unit; After a failure occurs in the electric propulsion system, the telemetry data of the electric propulsion system is stored in the second data storage area on the storage unit of the electric propulsion control unit until the second data storage area is full. During the most recent entry of the satellite into the telemetry and control arc after the malfunction, it will transmit the telemetry data of the electric propulsion system before and after the malfunction according to the ground remote control command.
2. The method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 1, characterized in that, A fault word of 0 indicates that the electric propulsion system has not malfunctioned, while a fault word of non-zero indicates that the electric propulsion system has malfunctioned.
3. The method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 2, characterized in that, Before the electric propulsion system is ignited, the fault word is set to 0 by default, the contents of the first and second data storage areas are cleared, the sequence numbers of telemetry data frames before and after the fault are cleared, and the telemetry data storage pointer before the fault points to the first address of the first data storage area. After a fault occurs, the telemetry data storage pointer points to the first address of the second data storage area; after the electric propulsion system is ignited, if a fault occurs in the electric propulsion system, the fault word becomes non-zero.
4. The method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 2, characterized in that, It also includes the following steps: After transmitting the telemetry data before and after the fault, if a "clear electric propulsion system fault word command" is received from the ground, the fault word of the electric propulsion system will be cleared, and the contents of the first and second data storage areas will be cleared. The sequence numbers of the telemetry data frames before and after the fault will be cleared. The telemetry data storage pointer before the fault will point to the first address of the first data storage area, and the telemetry data storage pointer after the fault will point to the first address of the second data storage area.
5. The method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 1, characterized in that, The storage unit of the electric propulsion control unit is FLASH.
6. The method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 1, characterized in that, The control cycle is 16~64ms.
7. A method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 1, characterized in that, If the received ground remote control command is "data transmission command before failure" during the most recent satellite entry into the telemetry and control arc after the failure, the telemetry data before failure stored in the first data storage area will be transmitted sequentially; if the received ground remote control command is "data transmission command after failure", the telemetry data after failure stored in the second data storage area will be transmitted sequentially.
8. A method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 1, characterized in that, One telemetry data frame is saved for each control cycle T.
9. A method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 8, characterized in that, The telemetry data frame includes a frame number, a feature code, and telemetry data.
10. A method for autonomously saving and transmitting on-orbit fault status of electric propulsion satellite according to claim 9, characterized in that, The telemetry data includes the voltage, current, pressure, and temperature of the electric propulsion system during operation.