Method and system for real-time scheduling of short message resources during overseas orbit control

Abstract

The invention belongs to the technical field of satellite measurement and control, and provides an overseas orbit control time short message resource real-time scheduling method and system, and the method comprises the steps: building a short message frame library through satellite service software, and pre-configuring a normal frame with a fixed frame length and an orbit control special frame; the attitude and orbit control software monitors the orbit control state in real time, the satellite service software identifies an orbit control ignition instruction and an orbit control stage mark, and a double-queue parallel sending mechanism is started; performing link configuration on the relay satellites according to a double-queue parallel sending mechanism, and implementing frequency division multiplexing downloading; and entering a transition period after monitoring that the orbit control is finished, and performing periodic attenuation control on the orbit control special frame. According to the method, the problem that real-time state monitoring of the geosynchronous orbit satellite in the overseas orbit control period fails is solved, the orbit control anomaly recognition rate is increased to 99% or above, monitoring real-time performance is broken through, and overseas orbit control safety and controllability are remarkably improved; the resource utilization rate is optimized, the adaptive capacity is enhanced, and second-level on-demand downloading of key parameters and dynamic optimization of channel resources are realized.

Description

Technical Field

[0001] The present invention belongs to the field of satellite measurement and control technology, and specifically relates to a method and system for real-time scheduling of short message resources during overseas orbit control. In particular, it relates to a method for dynamically scheduling and real-time downlinking of short message resources through relay satellites when a satellite implements orbit control overseas. Background Art

[0002] Satellite orbit control refers to the critical operation of adjusting satellite orbital parameters using onboard thrusters. Out-of-bounds orbit control specifically refers to the process performed when the satellite is out of the visual range of ground tracking and control stations. This operation relies on relay satellites for status monitoring, requiring real-time transmission of critical data such as thruster operating conditions, attitude deviations, and orbital parameter increments to ensure control accuracy and safety.

[0003] Traditional satellite short message systems (such as Beidou) use a fixed frame structure and static scheduling mechanism for telemetry downlink. Their frame format is rigid and limited in length (Beidou civilian frames are ≤78 bytes). The pre-set fields contain only general parameters such as power supply and temperature, and cannot dynamically embed key parameters such as thrust vector angle deviation and cathode current required for orbit control. The downlink cycle is rigidly set to the minute level (typically 60 seconds / frame), and transmission must wait for channel allocation to complete before transmission, with no ability to increase the frequency on demand. Resource allocation utilizes a single-queue serial mode, requiring orbit control data to queue and wait for normal frame transmission to complete, lacking the ability to preempt service priorities.

[0004] The above mechanism will expose serious flaws in overseas orbit control scenarios, including: Format rigidity leads to missing parameters: The fixed frame structure cannot accommodate orbit control-specific parameters. Abnormal operating conditions such as cathode voltage drops have no dedicated fields to be transmitted, making it impossible for the ground system to diagnose faults in real time. Cycle hysteresis causes control blind spots: The minute-level downlink cycle is much slower than the second-level monitoring requirements of orbit control. Due to the downlink delay, faults cannot be handled in time, resulting in increased fuel consumption. Failure of resource preemption causes data backlog: The single-channel serial transmission mode causes the orbit control data queue blocking rate to reach as high as 73%, which cannot meet the minimum frame interval required by the relay satellite system and forms a monitoring blind spot.

[0005] The root cause of these deficiencies is that static frame libraries cannot adapt to dynamic service demands, fixed cycles cannot meet real-time requirements, and single-channel resources cannot support multiple services concurrently. The patent document "Method and System for Implementing Onboard Integrated Electronic Short Messages" (CN120301479A) discloses a method for optimizing short message transmission by constructing an onboard integrated electronic short message framework and an autonomous ground station selection algorithm. This method solves the real-time communication difficulties of ground telemetry systems in short arc segments and improves satellite application efficiency and emergency response capabilities. However, this method lacks the ability to adapt to changes in orbital control states and cannot adapt to dynamic service demands.

[0006] The patent document "Dynamic Scheduling Method for Relay Satellite Space-Time-Frequency Domain Resources for Multiple Users" (CN106507366A) discloses a dynamic scheduling method for relay satellite space-time-frequency domain resources for multiple users. This method optimizes resource allocation by combining latency and packet loss rate, solving the problems of low spectrum utilization and unmet service needs in multi-user scenarios, achieving efficient resource utilization and improved economic benefits. However, the core issue lies in the relay satellite resource scheduling method's lack of adaptability to the downlink of telemetry data from different orbital control states.

[0007] Therefore, it is necessary to break through the technical bottlenecks of on-demand adaptation of frame content and dynamic allocation of channels, and provide a real-time scheduling method for overseas orbit control short message resources with strong adaptability that can optimize resource utilization and improve real-time performance. Summary of the Invention

[0008] In view of the defects in the prior art, the purpose of the present invention is to provide a real-time scheduling method and system for short message resources of overseas orbit control.

[0009] According to the present invention, a real-time scheduling method for short-duration message resources of an external orbit control system is provided, comprising: Step S1: The satellite service software builds a short message frame library and pre-configures normal frames with fixed frame lengths and orbit control-specific frames; Step S2: The attitude and orbit control software monitors the orbit control status in real time, and the satellite service software identifies the orbit control ignition command and orbit control phase flag, and starts the dual-queue parallel sending mechanism; Step S3: configuring the link for the relay satellite according to the dual-queue parallel transmission mechanism, and implementing frequency division multiplexing downlink; Step S4: After the attitude and orbit control software monitors the orbit control, it enters a transition period and performs periodic attenuation control on the orbit control dedicated frame.

[0010] Preferably, in step S1, the short message module of the satellite service software constructs a short message frame library in the non-volatile memory of the satellite service computer, and presets two types of short message frame structures with fixed lengths, including normal monitoring frames and orbit control special frames.

[0011] The normal monitoring frame is fixed at 128 bytes in length, includes conventional telemetry parameters of power supply voltage, temperature sensor data and / or star-sensing attitude angle, and is sent according to a preset period.

[0012] The track control dedicated frame length is fixed at 128 bytes, and the field combination is automatically switched according to the three stages of track control.

[0013] Preferably, the three stages include an ignition stage short message frame library, a steady-state stage short message frame library and a transition stage short message frame library.

[0014] During the ignition phase, the short message frame library switches the orbit control-specific frame content to a combination of thrust vector angle deviation, cathode voltage, and tank pressure fields. In the steady-state phase, the short message frame library switches the orbit control-specific frame content to a combination of orbit semi-major axis change rate and three-axis angular velocity fields; During the transition phase, the short message frame library switches the orbit control-specific frame content to a combination of pitch angle error and orbit inclination deviation fields.

[0015] Preferably, in step S2, the spacecraft service software continuously monitors the orbit control trigger instruction code. When it detects that the instruction code data field sent by the attitude and orbit control software to the electric propulsion controller is 0xA5A5, it is determined to be an orbit control ignition instruction, the dynamic scheduling module is immediately activated, and the orbit control phase is marked as the ignition phase. The scheduling module activates a dual-queue parallel sending mechanism, including a high-priority queue and a low-priority queue. The high-priority queue dynamically adjusts the sending frequency, dynamically compresses the orbit control-specific frames to the shortest allowed value during orbit control, and extends the normal monitoring frame period. The satellite service software injects configurable parameters through the ground measurement and control station to set the parameters of the relay satellite.

[0016] In step S3, dual-carrier frequency division multiplexing technology is used to allocate track control dedicated frames to the carrier of the high priority queue, and normal monitoring frames to the carrier of the low priority queue. The center frequency and modulation mode are determined according to the carrier type, and the field combination is switched.

[0017] Preferably, the high priority queue adopts a hardware interrupt preemption sending right mechanism, which immediately triggers the MCU interrupt when the track control dedicated frame is generated, forcibly suspends the normal detection frame sending process, and starts the track control dedicated frame sending within 10 milliseconds after successful preemption.

[0018] For the low priority queue, the orbit control period is automatically extended to three times the original period.

[0019] The configurable parameters include the bandwidth allocation ratio of the carrier of the high priority queue, which is stored in the non-volatile memory.

[0020] The shortest allowed value is dynamically calculated based on the timing characteristics of the relay satellite link and is not less than the minimum frame interval of 10 seconds required by the relay satellite.

[0021] Preferably, the carrier of the high priority queue is the high priority carrier f1, the center frequency range is 2200.0MHz to 2299.9MHz, the modulation mode is QPSK, the bandwidth allocation ratio is the preset parameter Q, stored in the on-board non-volatile memory, the transmission content is the orbit control dedicated frame, and the period is compressed to the shortest allowable value T min .

[0022] The carrier of the low priority queue is the low priority carrier f2, the center frequency range is 2200.00 MHz to 2299.99 MHz, the modulation mode is BPSK, the bandwidth is allocated to the remaining bandwidth, and the transmission content is a normal monitoring frame.

[0023] In step S3, the short message module determines whether the orbit control state is in the ignition stage according to the orbit control stage flag. If so, the ignition stage short message frame library is called; if not, the steady-state stage short message frame library is called to determine whether it is in the transition stage. If not, it is determined again whether it is in the ignition stage. If so, the transition stage short message frame library is called and step S4 is executed.

[0024] Preferably, step S4 includes: Step S4.1, set the initial period to 10 seconds; Step S4.2: linearly and gradually attenuate the orbit control dedicated frame transmission period over time, and call the transition phase short message frame library; Step S4.3: Determine whether the orbit semi-major axis deviation is less than or equal to the set value θ. If so, stop sending the orbit control dedicated frame. If not, execute step S4.2. Step S4.4: Determine whether the track control dedicated frame transmission period has returned to a normal value. If so, stop attenuating. If not, execute step S4.2.

[0025] Preferably, the method further includes an exception handling step: The exception type is determined based on the exception handling mechanism. If the exception type is a relay link interruption, the system switches to store-and-forward mode and resends the packets in batches after the link is reestablished. If the abnormality type is orbit control timeout, the safety mode is triggered and the fault code is transmitted, and the ground command is reset; When the exception type is data verification failure, the error frame is discarded and logged, and automatically resent in the next sending cycle.

[0026] According to the present invention, a real-time dispatch system for short message resources of an outbound orbit control system is provided, comprising: an electric propulsion controller, a satellite affairs computer and a CAN bus; The satellite service computer includes non-volatile memory, attitude and orbit control software, and satellite service software; The satellite service software includes short message module and dynamic scheduling module; The electric propulsion controller and the satellite computer communicate via the CAN bus, and the short message module builds a short message frame library in the non-volatile memory; The satellite service software continuously monitors the CAN bus, captures and identifies orbit control ignition commands and orbit control phase flags in real time, and activates the dual-queue parallel sending mechanism; The dynamic scheduling module configures the link for the relay satellite based on the dual-queue parallel transmission mechanism and implements frequency division multiplexing downlink; After the attitude and orbit control software monitors the orbit control, it enters the transition period and performs periodic attenuation control on the orbit control-specific frames.

[0027] Preferably, the star service computer determines the exception type according to the exception handling mechanism, takes corresponding handling measures, and determines the recovery conditions: When the exception type is relay link interruption, it switches to store-and-forward mode and resends in batches after the link is reestablished; If the abnormality type is orbit control timeout, the safety mode is triggered and the fault code is transmitted, and the ground command is reset; When the exception type is data verification failure, the error frame is discarded and logged, and automatically resent in the next sending cycle.

[0028] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention solves the problem of real-time status monitoring failure caused by the fixed short message format and long downlink cycle during the period of outbound orbit control of geosynchronous orbit satellites, and realizes the on-demand downlink of key parameters in seconds and dynamic optimization of channel resources.

[0029] 2. This invention increases the frequency of sending short message frames of track control status, and shortens the downlink delay of key track control parameters from hours (>60 minutes) to seconds (≤5 seconds), breaking through the real-time monitoring and significantly improving the safety and controllability of overseas track control.

[0030] 3. The present invention supports on-demand switching of track control fields throughout the entire cycle and dynamic bandwidth allocation, with enhanced adaptive capabilities, enabling better positioning of anomalies. The track control anomaly recognition rate is increased to over 99%, significantly improving safety.

[0031] 4. The present invention implements frequency division multiplexing downlink through the multi-carrier channel of the relay satellite, allocates configurable carriers with a high bandwidth ratio to the orbit control frame, optimizes resource utilization, and the relay satellite channel utilization rate reaches 91.7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings: Figure 1 This is a flow chart of the real-time scheduling method for short message resources of overseas orbit control. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0034] According to the present invention, a real-time scheduling method for short message resources during outbound orbit control is provided. This method addresses the blind spot problem of orbit control status monitoring caused by the fixed format and long cycle of the existing short message system. It solves the problem of failure of real-time status monitoring of geosynchronous orbit satellites during outbound orbit control due to the fixed format of short messages and long downlink cycle, and achieves on-demand downlink of key parameters in seconds and dynamic optimization of channel resources. Figure 1 For example, including: Step S1, system initialization configuration: executed through the short message module of the satellite service software, pre-configuring normal frames with fixed frame lengths and orbit control special frames.

[0035] Specifically, the construction of a configurable short message frame library is completed, and two types of fixed-length short message frame structures are preset in the non-volatile memory of the satellite service computer, including normal monitoring frames and orbit control-specific frames.

[0036] Normal monitoring frame: The length is fixed at 128 bytes. It contains common telemetry parameters such as power supply voltage, temperature sensor data, and star sensor attitude angle. It is sent at a preset period (60 seconds by default).

[0037] Track control dedicated frame: supports three-stage dynamic field configuration, with the same length of 128 bytes. Its field content automatically switches field combinations according to the track control stage, including key telemetry fields during track control; During the different stages of orbit control (ignition, steady-state, and transition), the telemetry within the short message frame is configured to monitor key parameters. The ignition phase includes information such as thrust vector angle and cathode electrical parameters, while the transition phase switches to attitude and orbit parameters, which automatically cease with periodic decay. During the ignition phase, the key telemetry monitored is the anode current to prevent short circuits caused by electrical sparks; during the steady-state phase, the focus is on observing thruster status; and during the transition phase, the focus is on observing orbit information to determine whether orbit control is in place.

[0038] Specifically, the contents of the track control dedicated frame fields include: Ignition stage: thrust vector angle deviation (4 bytes), cathode voltage (2 bytes), tank pressure (2 bytes); Steady-state stage: orbit semi-major axis change rate (4 bytes), three-axis angular velocity (6 bytes); Transition stage: attitude stability, namely pitch angle error (2 bytes) and orbit inclination deviation (4 bytes).

[0039] According to the field combination settings in different orbit control stages, the downlink of key orbit control status telemetry is guaranteed at different stages of orbit control, instead of transmitting some traditional, fixed platform health status telemetry at a fixed frequency.

[0040] Step S2: orbit control real-time processing flow, monitoring orbit control status, and the satellite service software identifies the orbit control instructions.

[0041] Specifically, the electric propulsion controller and the satellite service computer communicate using the CAN (Controller Area Network) bus, and the attitude and orbit control software and satellite service software run on the satellite service computer processor.

[0042] The satellite service software continuously monitors the orbit control trigger instruction code on the CAN bus. When it detects that the instruction code data field sent to the electric propulsion controller is 0xA5A5, it is determined to be an orbit control ignition instruction, immediately activates the dynamic scheduling module, and marks the orbit control stage as the ignition period.

[0043] After capturing the orbit control engine ignition command (satellite bus command code) and orbit control phase flag in real time, the scheduling module starts the dual-queue parallel management strategy, in which the high-priority queue uses hardware interrupts to preempt high priority, dynamically compresses the orbit control dedicated frame to the shortest allowed period (i.e., the predetermined shortest period), and at the same time extends the normal monitoring frame period.

[0044] The satellite service software sets the parameters of the relay satellite and injects configurable parameters through the ground measurement and control station, shortening the downlink delay of key orbit control parameters from hours to seconds, significantly improving the safety and controllability of overseas orbit control.

[0045] In more preferred embodiments, the dynamic scheduling algorithm is activated. When a track control instruction is detected, the scheduling module starts a dynamic scheduling mechanism of dual queues and parallel transmission. The priority of the track control dedicated frame queue is higher than that of the normal monitoring frame. The transmission frequency is dynamically adjusted. During the track control period, the track control dedicated frame period is compressed to the predetermined minimum period, and the normal monitoring frame period is extended. Specifically, The high-priority queue, dedicated to orbit control frames, uses a hardware interrupt preemption mechanism. When an orbit control frame is generated, it immediately triggers an MCU (microcontroller unit) interrupt (priority 7), forcibly suspending the normal frame transmission process. After successful preemption, orbit control frame transmission is restarted within 10 milliseconds. By increasing the frequency of short orbit control status message frames, the real-time nature of orbit control status acquisition on the ground is further improved.

[0046] For low-priority queues: manage normal monitoring frames, and the orbit control period is automatically extended to three times the original period (i.e. 180 seconds).

[0047] Step S3: Allocate channel resources, implement frequency division multiplexing downlink, and configure the link for the relay satellite.

[0048] Dual-carrier frequency division multiplexing technology is adopted to implement frequency division multiplexing downlink through the multi-carrier channel of the relay satellite, allocating configurable carriers with a high bandwidth ratio to the orbit control frames, optimizing resource utilization, and the relay satellite channel utilization rate reaches 91.7%.

[0049] Specifically, dedicated orbit control frames are allocated to high-priority carrier frequencies, and normal frames are allocated to low-priority carrier frequencies. The center frequency and modulation mode are determined according to the carrier type. This supports on-demand switching of orbit control full-cycle fields and dynamic bandwidth allocation, with enhanced adaptability, including: High-priority carrier f1: The center frequency range is 2200.0 MHz to 2299.9 MHz, the modulation method is QPSK (Quadrature Phase Shift Keying), and the bandwidth allocation ratio is the preset parameter Q (a configuration parameter that can be modified by injection), which is stored in the onboard non-volatile memory; The transmission content is track control dedicated frame (10 seconds / frame), and the period is compressed to the shortest allowed value T min (e.g. ≥10 seconds); High-priority carrier bandwidth ratio: The default value is 75% and can be adjusted within the range of 65% to 80%.

[0050] The minimum permissible value is dynamically calculated based on the timing characteristics of the relay satellite link and must not be less than the minimum frame interval required by the relay satellite. Minimum frame interval: fixed at 10 seconds, which complies with international relay satellite system specifications.

[0051] Low-priority carrier f2: Center frequency range is 2200.00 MHz to 2299.99 MHz, modulation is BPSK (Binary Phase Shift Keying), bandwidth is allocated to the remaining portion, and transmission content is normal monitoring frames (180 seconds / frame). The specific center frequency is not specified.

[0052] According to the current orbit control stage, select the field combination in the preset short message frame library: Ignition stage: Thrust vector angle, cathode voltage, and tank pressure data are read from sensors in real time and filled into predefined fields.

[0053] Steady-state stage: replace the cathode voltage field with the orbit semi-major axis change rate, and retain the three-axis angular velocity fields.

[0054] Transition phase: Delete all propulsion parameters and add attitude stability and orbit deviation parameters.

[0055] Step S4: Transition period control strategy requires periodic attenuation control.

[0056] After the orbit control is completed, the system enters the transition period, gradually reducing the orbit control dedicated frame sending period to the normal period, and dynamically replacing the frame content with attitude and orbit monitoring parameters. When the orbit parameters converge to within the threshold range, the sending of orbit control dedicated frames is stopped.

[0057] The field combination is implemented through an on-board mapping table, which may contain a variety of predefined field configuration templates.

[0058] Specifically, after orbit control is completed, the linear decay algorithm is started, including: Step S4.1: The initial cycle is maintained for 10 seconds.

[0059] Step S4.2: The orbit control frame period increases linearly over time to a normal value, and the frame content dynamically migrates to the attitude / orbit monitoring parameters; In a preferred embodiment, 5 second periods are added every minute (the slope is configurable).

[0060] Step S4.3: Stop decaying when the period returns to a normal value of 60 seconds.

[0061] The rules for frame content migration follow the presets of the short message frame library: perform field replacement in the transition phase; delete fields related to thruster working conditions; add attitude stability (roll angle / pitch angle standard deviation) and add orbit semi-major axis deviation.

[0062] The termination condition is that when the orbit semi-major axis deviation is less than or equal to the set value θ, the sending of orbit control dedicated frames is stopped. θ is preferably 10m.

[0063] In more preferred embodiments, an exception handling step is also included.

[0064] Exception handling steps: determine the exception type based on the exception handling mechanism, take corresponding handling measures, and determine the recovery conditions. The track control exception recognition rate has been increased to over 99%.

[0065] Due to the limited length and fixed content of traditional short messages, it is impossible to locate the causes of possible anomalies during orbit control. However, by building a short message frame library, anomalies can be better located.

[0066] When the exception type is relay link interruption and no ACK (acknowledgement message) is received for three consecutive frames, the system switches to store-and-forward mode and retransmits packets in batches after the link is reestablished. When the abnormality type is orbit control timeout, and the orbit control strategy continues for 300 seconds after the set end time, the safety mode is triggered and the fault code is transmitted, and the ground command is reset; When the exception type is data verification failure, the error frame is discarded and logged, and it is automatically resent in the next cycle.

[0067] The present invention also provides a real-time dispatching system for short message resources of out-of-bounds orbit control, comprising: an electric propulsion controller, a satellite affairs computer, and a CAN bus communication; The satellite service computer includes non-volatile memory, attitude and orbit control software, and satellite service software; The satellite service software includes a short message module and a dynamic scheduling module.

[0068] The electric propulsion controller and the satellite service computer communicate through CAN bus, and the short message module constructs a short message frame library in the non-volatile memory; The satellite service software continuously monitors the CAN bus, captures and identifies the orbit control ignition instruction and the orbit control stage mark in real time, starts the double queue parallel sending mechanism; The dynamic scheduling module configures the link of the relay satellite according to the double queue parallel sending mechanism, and implements frequency division multiplexing downlink; The attitude and orbit control software monitors the end of the orbit control, enters the transition period, and performs periodic attenuation control on the orbit control special frame.

[0069] In more preferred examples, the satellite service computer judges the exception type according to the exception processing mechanism, takes corresponding processing measures, and judges the recovery condition: When the exception type is the interruption of the relay link, the storage and forwarding mode is switched to, and the batch retransmission is performed after the link is reestablished; When the exception type is the orbit control timeout, the safety mode is triggered and the fault code is downloaded, and the ground command is reset; When the exception type is the data check failure, the error frame is discarded and the log is recorded, and the automatic reissue is performed in the next sending period.

[0070] The specific embodiments of the application are described above. It should be understood that the application is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the application. In the case of no conflict, the embodiments of the application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A real-time scheduling method for short message resources of overseas orbit control, characterized in that: include: Step S1: The satellite service software builds a short message frame library and pre-configures normal frames with fixed frame lengths and orbit control-specific frames; Step S2: The attitude and orbit control software monitors the orbit control status in real time, and the satellite service software identifies the orbit control ignition command and orbit control phase flag, and starts the dual-queue parallel sending mechanism; Step S3: configuring the link for the relay satellite according to the dual-queue parallel transmission mechanism, and implementing frequency division multiplexing downlink; Step S4: After the attitude and orbit control software monitors the orbit control, it enters a transition period and performs periodic attenuation control on the orbit control dedicated frame.

2. The real-time scheduling method for short-duration message resources of overseas orbit control according to claim 1 is characterized in that: In step S1, the short message module of the satellite service software builds a short message frame library in the non-volatile memory of the satellite service computer, presetting two types of short message frame structures with fixed lengths, including normal monitoring frames and orbit control special frames; The normal monitoring frame is fixed at 128 bytes in length and includes conventional telemetry parameters such as power supply voltage, temperature sensor data, and / or star-sensing attitude angle, and is sent at a preset period. The track control dedicated frame length is fixed at 128 bytes, and the field combination is automatically switched according to the three stages of track control.

3. The real-time scheduling method for short-duration messages of overseas orbit control according to claim 2 is characterized in that: The three stages include an ignition stage short message frame library, a steady-state stage short message frame library, and a transition stage short message frame library; During the ignition phase, the short message frame library switches the orbit control-specific frame content to a combination of thrust vector angle deviation, cathode voltage, and tank pressure fields. In the steady-state phase, the short message frame library switches the orbit control-specific frame content to a combination of orbit semi-major axis change rate and three-axis angular velocity fields; During the transition phase, the short message frame library switches the orbit control-specific frame content to a combination of pitch angle error and orbit inclination deviation fields.

4. The real-time scheduling method for short-duration messages of overseas orbit control according to claim 3 is characterized in that: In step S2, the onboard service software continuously monitors the orbit control trigger command code. When it detects that the command code data field sent by the attitude and orbit control software to the electric propulsion controller is 0xA5A5, it determines that it is an orbit control ignition command, immediately activates the dynamic scheduling module, and marks the orbit control phase as the ignition phase. The scheduling module activates a dual-queue parallel sending mechanism, including a high-priority queue and a low-priority queue. The high-priority queue dynamically adjusts the sending frequency, dynamically compresses the orbit control-specific frames to the shortest allowed value during orbit control, and extends the normal monitoring frame period. The satellite service software injects configurable parameters through the ground tracking and control station to set the parameters of the relay satellite; In step S3, dual-carrier frequency division multiplexing technology is used to allocate track control dedicated frames to the carrier of the high priority queue, and normal monitoring frames to the carrier of the low priority queue. The center frequency and modulation mode are determined according to the carrier type, and the field combination is switched.

5. The real-time scheduling method for short-duration message resources of overseas orbit control according to claim 4 is characterized in that: The high-priority queue adopts a hardware interrupt preemption mechanism to trigger an MCU interrupt immediately when a dedicated track control frame is generated, forcibly suspending the normal detection frame sending process. After the preemption is successful, the dedicated track control frame sending is started within 10 milliseconds. For the low priority queue, the orbit control period is automatically extended to 3 times the original period; The configurable parameters include the bandwidth allocation ratio of the carrier of the high priority queue, which is stored in the non-volatile memory; The shortest allowed value is dynamically calculated based on the timing characteristics of the relay satellite link and is not less than the minimum frame interval of 10 seconds required by the relay satellite.

6. The real-time scheduling method for short-duration message resources of overseas orbit control according to claim 4 is characterized in that: The carrier of the high priority queue is the high priority carrier f1, with a center frequency range of 2200.0 MHz to 2299.9 MHz, a modulation mode of QPSK, a bandwidth allocation ratio of the preset parameter Q, stored in the onboard non-volatile memory, and a transmission content of a dedicated orbit control frame, with a period compressed to the shortest allowable value T min ; The carrier of the low priority queue is the low priority carrier f2, with a center frequency range of 2200.00 MHz to 2299.99 MHz, a modulation mode of BPSK, a bandwidth allocation of the remaining bandwidth, and a transmission content of a normal monitoring frame; In step S3, the short message module determines whether the orbit control state is in the ignition stage according to the orbit control stage flag. If so, the ignition stage short message frame library is called; if not, the steady-state stage short message frame library is called to determine whether it is in the transition stage. If not, it is determined again whether it is in the ignition stage. If so, the transition stage short message frame library is called and step S4 is executed.

7. The real-time scheduling method for short-duration message resources of overseas orbit control according to claim 3 is characterized in that: The step S4 comprises: Step S4.1, set the initial period to 10 seconds; Step S4.2: linearly and gradually attenuate the orbit control dedicated frame transmission period over time, and call the transition phase short message frame library; Step S4.3: Determine whether the orbit semi-major axis deviation is less than or equal to the set value θ. If so, stop sending the orbit control dedicated frame. If not, execute step S4.

2. Step S4.4: Determine whether the track control dedicated frame transmission period has returned to a normal value. If so, stop attenuating. If not, execute step S4.

2.

8. The real-time scheduling method for short-duration message resources of overseas orbit control according to claim 1 is characterized in that: It also includes exception handling steps: The exception type is determined based on the exception handling mechanism. If the exception type is a relay link interruption, the system switches to store-and-forward mode and resends the packets in batches after the link is reestablished. If the abnormality type is orbit control timeout, the safety mode is triggered and the fault code is transmitted, and the ground command is reset; When the exception type is data verification failure, the error frame is discarded and logged, and automatically resent in the next sending cycle.

9. A real-time dispatch system for short message resources of overseas orbit control, characterized in that: include: Electric propulsion controller, satellite computer and CAN bus; The satellite service computer includes non-volatile memory, attitude and orbit control software, and satellite service software; The satellite service software includes short message module and dynamic scheduling module; The electric propulsion controller and the satellite computer communicate via the CAN bus, and the short message module builds a short message frame library in the non-volatile memory; The satellite service software continuously monitors the CAN bus, captures and identifies orbit control ignition commands and orbit control phase flags in real time, and activates the dual-queue parallel sending mechanism; The dynamic scheduling module configures the link for the relay satellite based on the dual-queue parallel transmission mechanism and implements frequency division multiplexing downlink; After the attitude and orbit control software monitors the orbit control, it enters the transition period and performs periodic attenuation control on the orbit control-specific frames.

10. The real-time dispatching system for short message resources of overseas orbit control according to claim 9 is characterized in that: The satellite service computer determines the type of exception based on the exception handling mechanism, takes corresponding handling measures, and determines the recovery conditions: When the exception type is relay link interruption, it switches to store-and-forward mode and resends in batches after the link is reestablished; If the abnormality type is orbit control timeout, the safety mode is triggered and the fault code is transmitted, and the ground command is reset; When the exception type is data verification failure, the error frame is discarded and logged, and automatically resent in the next sending cycle.

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