A multi-mode supply air-breathing electric propulsion orbit autonomous regulation system and method based on space weather forecast

Abstract

The application is a multi-mode supply air-breathing electric propulsion orbit autonomous regulation system and method based on space weather prediction. The application relates to the technical field of ultra-low-orbit air-breathing electric propulsion satellite orbit maintenance and autonomous orbit transfer. When the prediction result shows that the thrust gap disappears in a short time, the system keeps the satellite in the current ultra-low-orbit task orbit, and compensates for the short-term resistance gap by using a small amount of xenon gas. When the prediction result shows that the thrust gap will continue to be large for a long time in the future, the system determines the target orbit height that meets the task constraints and the working medium consumption constraints by using a neural network, reinforcement learning, dynamic programming, heuristic optimization or deterministic mathematical optimization algorithm, and controls the xenon electric propulsion to perform orbit raising. The scheme can improve the autonomous survival ability, xenon use efficiency and orbit task continuity of the ultra-low-orbit satellite when the solar activity and geomagnetic disturbance cause the atmospheric density anomaly.

Description

Technical Field

[0001] This invention relates to the field of orbit maintenance and autonomous orbit change technology for ultra-low Earth orbit air-breathing electric propulsion satellites, and is a multi-mode supply air-breathing electric propulsion orbit autonomous control system and method based on space weather forecasting. Background Technology

[0002] Very low Earth orbit (VLEO) satellites offer significant advantages such as high imaging resolution, low communication latency, and low cost of orbit insertion. However, as the orbital altitude decreases, the residual atmospheric density increases significantly, making aerodynamic drag a major factor limiting the satellite's on-orbit lifespan. Internationally, preliminary explorations have been conducted at VLEO altitudes of 100-300 km. For example, ESA's GOCE satellite validated the imaging resolution advantages of VLEO satellites, while JAXA's SLATS satellite at an altitude of approximately 167 km demonstrated the severe challenge that increased atmospheric drag poses to the on-orbit lifespan of traditional xenon electric propulsion satellites. Air-breathing electric propulsion, by collecting the thin atmosphere of VLEO as a propellant, can theoretically reduce or eliminate the lifespan limitation imposed by the propellant, and is therefore considered an important technological direction for long-term VLEO deployment.

[0003] However, atmospheric density in ultra-low Earth orbit (ULE) is significantly affected by solar activity and geomagnetic disturbances. The solar 10.7 cm radio current (F10.7) reflects the level of solar extreme ultraviolet radiation and affects thermospheric heating, while the geomagnetic activity index (Ap) reflects the intensity of geomagnetic disturbances and affects thermospheric density expansion. When F10.7 or Ap changes significantly, atmospheric density at the same orbital altitude and latitude / longitude can change by orders of magnitude or a significant proportion within a short period, leading to simultaneous changes in satellite aerodynamic drag, air intake flow for air-breathing electric propulsion, discharge pressure, and available thrust. For example, at an altitude of 200 km, atmospheric density can differ by more than three times during periods of strong geomagnetic storms (Ap≥100) compared to periods of calm (Ap<10); similarly, atmospheric density can differ by several times between years of peak solar activity (F10.7>200) and years of solar troughs (F10.7<80). Such drastic changes pose a fundamental threat to the orbital maintenance capabilities of air-breathing electric propulsion satellites.

[0004] For air-breathing electric propulsion satellites that rely solely on atmospheric propellant, excessively low atmospheric density can lead to insufficient airflow, insufficient discharge pressure, and insufficient thrust; conversely, excessively high atmospheric density can result in excessive drag, increased power demand, and increased thermal control pressure. Most existing research, both domestically and internationally, focuses on analyzing air-breathing electric propulsion missions at specific orbital altitudes and average atmospheric densities, lacking sufficient consideration of the time-varying and predictive control of atmospheric density. Existing multi-propellant air-breathing electric propulsion systems can compensate for thrust shortfalls or assist ignition using xenon propellant. However, adjusting xenon flow solely based on the current instantaneous state can lead to two problems: first, misjudging short-term density anomalies as long-term risks and excessively raising the orbit, affecting ultra-low Earth orbit mission performance; second, failing to raise the orbit in advance before long-term density anomalies occur, resulting in excessive xenon consumption or insufficient thrust to cover drag over a prolonged period.

[0005] Advances in space weather forecasting technology have provided new solutions to these problems. Organizations such as the National Oceanic and Atmospheric Administration (NOAA), the European Space Agency (ESA), and the Space Environment Research and Forecasting Center (SEPC) of the Chinese Academy of Sciences can now provide Ap and F10.7 forecasts for the next 24 hours to several days, with forecast accuracy sufficient for orbit maintenance decisions. Combining space weather forecasting with thermospheric models allows for the prediction of future atmospheric density trends several hours to several days in advance, thus providing forward-looking orbit control data for air-breathing electric propulsion satellites.

[0006] Therefore, an autonomous control method is needed that combines space weather forecasting, atmospheric density calculation, air-breathing electric propulsion mission model, thrust gap prediction, and orbital altitude optimization. This method would enable the satellite to distinguish between short-term atmospheric density variations and long-term unsustainable conditions, and to make a reasonable choice between on-orbit xenon compensation and xenon electric propulsion for orbit raising. This would maximize xenon utilization efficiency and mission continuity while ensuring mission performance. Summary of the Invention

[0007] This invention addresses the problems of existing technologies by disclosing a multi-mode supply air-breathing electric propulsion orbit autonomous control system and method based on space weather forecasting. This invention enables satellites employing multi-mode supply air-breathing electric propulsion to estimate atmospheric density at their current and future orbital positions based on space weather forecast parameters such as Ap and F10.7, calculate the feasible region and thrust gap for the air-breathing electric propulsion orbit, and choose between on-orbit xenon compensation or orbital ascent to avoid danger based on the persistence and severity of the thrust gap.

[0008] This invention provides the following technical solutions: A multi-mode supply-driven air-breathing electric propulsion orbit autonomous control system based on space weather forecasting, the system comprising a space weather forecast receiving module, an orbit state acquisition module, an atmospheric density calculation module, a thrust and feasible domain assessment module, a thrust gap prediction module, a multi-mode orbit decision-making module, and a propulsion module; The space weather forecast receiving module acquires the geomagnetic activity index Ap and the solar 10.7cm radio current F10.7 for the current and future periods; The orbital status acquisition module acquires the longitude, latitude, and orbital altitude of the air-breathing electric propulsion satellite for the current and future periods; The atmospheric density calculation module calculates the atmospheric density at the satellite's location based on the geomagnetic activity index Ap, solar radio flux F10.7, longitude, latitude, and orbital altitude. The thrust and feasible region assessment module calculates aerodynamic drag, available thrust for air-breathing electric propulsion, power constraints, discharge pressure constraints, and orbital feasible region based on atmospheric density. The thrust gap prediction module calculates the magnitude, duration, and cumulative impulse of the thrust gap within the prediction time window; The multi-mode orbit decision module determines whether to execute the orbit retention xenon compensation mode or the xenon electric propulsion orbit lifting mode based on the thrust gap. The propulsion execution module adjusts the xenon gas flow rate, electric propulsion power, and orbital maneuvering program according to the instructions output by the multi-mode orbit decision module.

[0009] Preferably, the geomagnetic activity index Ap acquired by the space weather forecast receiving module includes at least one of the current geomagnetic activity index, the three-hour segmented Ap prediction value, and the daily average Ap prediction value, and F10.7 includes at least one of the current F10.7, the daily average F10.7, the 27-day average F10.7, or their prediction values, and the Ap and F10.7 are interpolated to a time step consistent with the satellite orbit forecast.

[0010] Preferably, the atmospheric density calculation module uses NRLMSISE-00, JB2008, DTM, or a thermospheric atmospheric model corrected from on-orbit data.

[0011] Calculate the atmospheric density at each moment within the prediction time window. Where h is the orbital altitude, lat is the latitude, lon is the longitude, and UT is the Universal Time.

[0012] Preferably, the drag and feasible region evaluation module calculates the orbital velocity using the following formula:

[0013] The mass flow rate drawn in by the atmospheric working fluid collection device is read from the data returned by the spaceborne sensors:

[0014] in, It refers to the collection efficiency of an atmospheric working fluid collection device, obtained through ground testing or simulation. It is the cross-sectional area of ​​the inlet of the atmospheric working fluid collection device; The mass flow rate used for ionization acceleration is read from the data returned by the onboard plasma diagnostic equipment, or calculated according to the following formula:

[0015] in, The characteristic operating condition dataset generated from the thruster ground test was obtained through table lookup or interpolation methods; The equivalent aerodynamic drag experienced by the satellite is read from data returned by onboard sensors:

[0016] in, It is the equivalent drag coefficient obtained from satellite modeling and simulation. It is the equivalent cross-sectional area obtained from satellite modeling and simulation; The thrust of air-breathing electric propulsion relying solely on atmospheric propellant can be read from data returned by onboard sensors:

[0017] Where u is the equivalent ion jet velocity, which is obtained from the characteristic operating condition dataset formed by the thruster ground test through table lookup or interpolation methods.

[0018] Preferably, the orbital feasible region includes a power feasible constraint and a discharge pressure feasible constraint, wherein the power feasible constraint is the jet power used for drag compensation. No greater than the power available for propulsion by the solar array Subtract attitude control and platform power Power margin after t; The feasible constraint for the discharge gas pressure is the working gas pressure after collection and compression. Not less than the minimum stable discharge pressure of the thruster When the same orbital height simultaneously satisfies the power feasibility constraint and the discharge pressure feasibility constraint, the orbital height is determined to belong to the feasible domain of air-breathing electric propulsion orbits.

[0019] Preferably, the thrust gap prediction module calculates the thrust gap relying solely on atmospheric working fluid according to the following formula:

[0020] And calculate the duration of the continuous gap. Gap peak Cumulative spurt gap and the amount of xenon required to maintain the current orbit .

[0021] Preferably, the multi-mode orbit decision module includes a short-term anomaly detection unit and a long-term anomaly detection unit; when Less than the first duration threshold and When the xenon consumption is less than the first xenon consumption threshold, the short-term anomaly detection unit outputs a track-keeping xenon compensation mode; when Greater than the second duration threshold Greater than the cumulative impulse gap threshold, or When the xenon consumption exceeds the second xenon consumption threshold, the long-term anomaly detection unit outputs the xenon electric propulsion orbit lifting mode.

[0022] Preferably, the on-orbit xenon compensation mode includes: maintaining the satellite's current ultra-low orbit mission altitude unchanged, prioritizing the use of inhaled atmospheric working fluid to generate drag compensation thrust, and controlling the xenon storage and supply module to provide a small flow rate of xenon to compensate. This continues until the predicted or measured atmospheric density anomaly ends, the thrust gap falls below the set threshold, or the air-breathing electric propulsion system regains thrust-drag balance.

[0023] A method for autonomous control of a multi-mode supply-driven air-breathing electric propulsion orbit based on space weather forecasting, the method comprising the following steps: Step S1: Obtain Ap and F10.7 from the space weather forecast, and obtain the longitude, latitude, and orbital altitude of the satellite's current and future predicted trajectories; Step S2: Calculate the atmospheric density sequence for the current and future prediction time windows based on Ap, F10.7, longitude, latitude, and orbital altitude; Step S3: Calculate the intake mass flow rate, aerodynamic drag, available thrust, power constraint, discharge pressure constraint, and orbital feasible region of the air-breathing electric propulsion system based on the atmospheric density sequence. The orbital feasible region is obtained by scanning multiple candidate orbital altitudes. For each candidate orbital altitude, the minimum jet velocity, jet power, minimum discharge pressure, and xenon compensation requirements required to achieve thrust-drag balance at the corresponding atmospheric density are calculated, and these requirements are then satisfied. and The set of candidate orbital heights is denoted as the feasible region; Step S4: Calculate the thrust gap of the current orbit within the prediction time window; Step S5: Determine whether the atmospheric density anomaly is a short-term or long-term anomaly based on the duration, peak value, and cumulative impulse gap of the thrust gap. Step S6: When a short-term anomaly is determined, execute the track-stayed xenon compensation mode; Step S7: When a long-term anomaly is determined, the target orbital altitude is determined by an artificial intelligence model or mathematical optimization algorithm, and xenon electric propulsion is used to lift the orbit. When determining the target orbital altitude, in

[0024] Minimize the objective function, where, This is the current orbital altitude. From Ascend to candidate altitude Required speed increment Xenon consumption This is a penalty for violating constraints such as power balance, minimum discharge pressure, satellite thermal control, and orbital safety. , , and These are the weighting coefficients; Step S8: During the orbit retention or orbit raising process, continuously update Ap, F10.7, atmospheric density and thrust gap, and adjust xenon supply and orbital maneuver commands based on the update results; In-orbit closed-loop correction: The atmospheric density calculation results and thrust gap prediction results are corrected using satellite accelerometers, orbit determination residuals, electric thruster telemetry parameters, and xenon storage and supply pressure; when the prediction error exceeds the error threshold for multiple consecutive time steps, the atmospheric density correction coefficient is re-estimated or a conservative threshold control strategy is switched to.

[0025] A computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement a method for autonomous control of a multi-mode supply-breathing electric propulsion orbit based on space weather forecasting.

[0026] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement a multi-mode supply-breathing electric propulsion orbit autonomous control method based on space weather forecasting.

[0027] The present invention has the following beneficial effects: This invention provides a multi-mode supply system and method for autonomous orbit control of air-breathing electric propulsion satellites based on space weather forecasting. This system tightly couples space weather forecasting data, atmospheric models, and air-breathing electric propulsion mission models, achieving end-to-end autonomous control from space environment forecasting to orbit decision-making, propellant supply, and maneuver commands. Compared to existing multi-propellant supply schemes that adjust xenon flow solely based on instantaneous atmospheric density, this invention can predict atmospheric density trends hours to days in advance, enabling air-breathing electric propulsion satellites to make reasonable decisions regarding orbit maintenance or orbit elevation before atmospheric density anomalies occur.

[0028] This invention distinguishes between short-term and long-term density anomalies, employing a xenon-based orbital compensation mode and a xenon-electric propulsion orbit-raising mode respectively. This avoids excessive orbit-raising and loss of mission altitude during short-term geomagnetic storms, and also prevents continuous and excessive consumption of xenon or even instability during long-term density rises. This multi-mode decision-making mechanism achieves a reasonable balance between xenon consumption, mission altitude retention rate, and aerodynamic drag compensation capability.

[0029] The orbital feasibility domain assessment method proposed in this invention incorporates the power constraints, discharge pressure constraints, and time-varying atmospheric density characteristics of air-breathing electric propulsion into a unified feasible domain determination, and searches for the target orbital altitude within this feasible domain. This avoids selecting orbital points that, while reducing drag, exceed the working capacity of electric propulsion or the satellite power envelope, thus making the orbital ascent decision physically reasonable and engineering feasible.

[0030] This invention introduces long-term indicators such as cumulative impulse gap and xenon consumption as decision-making criteria. Compared with the criteria of using only instantaneous thrust gap or instantaneous density threshold, it can better reflect the overall sustainability of the mission within the prediction time window and avoid being falsely triggered by short-term density spikes or missed by slow drift.

[0031] This invention introduces intelligent optimization methods such as neural networks, genetic algorithms, particle swarm optimization, and Bayesian optimization into the orbital ascent decision-making process. With the cumulative impulse gap, orbital ascent velocity increment, xenon consumption, and power margin as joint optimization objectives, it can provide an approximate optimal solution in the multi-constraint, strongly coupled target orbital altitude selection problem, and can be completed under the limited computing power of onboard computers.

[0032] The orbital autonomous control method of this invention includes an on-orbit closed-loop correction stage, which uses on-orbit measured data such as accelerometers, orbit determination residuals, electric thruster telemetry, and xenon storage and supply pressure to correct atmospheric density calculation results and thrust gap prediction results. This enables the system to adaptively cope with inherent biases of thermosphere models and space weather forecast errors, thereby improving the robustness and long-term applicability of autonomous decision-making.

[0033] The proposed solution is compatible with existing multi-propellant supply air-breathing electric propulsion systems (such as multi-propellant supply mode air-breathing field-cutting electric propulsion systems) and can be directly used as its upper-level mission planning and trajectory decision-making module without redesigning the thruster structure and air path structure, which facilitates engineering applications. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 The diagram shows the overall structure of the multi-mode supply air-breathing electric propulsion orbit autonomous control system based on space weather forecasting of the present invention. Figure 2 The diagram shows the overall process flow of the autonomous orbit control method of the present invention. Figure 3This diagram illustrates the changes over time in atmospheric density, aerodynamic drag, available thrust, thrust gap, and xenon flow rate during orbital xenon compensation under short-term geomagnetic storm disturbances. Figure 4 This is a schematic diagram showing the objective function curves of candidate orbital altitude search and target orbital altitude J(h) in xenon electric propulsion orbit lifting under long-term density rise during a period of strong solar activity. Figure 5 This diagram illustrates how satellite orbital altitude, Ap index, F10.7 index, and xenon consumption rate change over time.

[0036] Among them, 101-space weather forecast receiving module, 102-orbit status acquisition module, 103-atmospheric density calculation module, 104-thrust and feasible domain assessment module, 105-thrust gap prediction module, 106-multi-mode orbit decision module, 107-propulsion execution module, 108-xenon storage and supply module, 109-air-breathing electric thruster, and 110-atmospheric working fluid collection device; Detailed Implementation The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The present invention will be described in detail below with reference to specific embodiments. Specific Implementation Example 1: according to Figures 1 to 5 As shown, the specific optimized technical solution adopted by the present invention to solve the above-mentioned technical problems is: The present invention relates to a multi-mode supply air-breathing electric propulsion orbit autonomous control system and method based on space weather forecasting.

[0039] A multi-mode supply-driven air-breathing electric propulsion orbit autonomous control system based on space weather forecasting is characterized by comprising a space weather forecast receiving module 101, an orbit state acquisition module 102, an atmospheric density calculation module 103, a thrust and feasible domain assessment module 104, a thrust gap prediction module 105, a multi-mode orbit decision module 106, and a propulsion module. The space weather forecast receiving module 101 is used to acquire the geomagnetic activity index Ap and the solar 10.7cm radio current F10.7 for the current and future periods. The orbital status acquisition module 102 is used to acquire the longitude, latitude and orbital altitude of the air-breathing electric propulsion satellite for the current and future periods; The atmospheric density calculation module 103 is used to calculate the atmospheric density at the satellite's location based on the Ap, F10.7, longitude, latitude, and orbital altitude. The thrust and feasible region evaluation module 104 is used to calculate aerodynamic drag, available thrust for air-breathing electric propulsion, power constraints, discharge pressure constraints and orbital feasible region based on the atmospheric density. The thrust gap prediction module 105 is used to calculate the magnitude, duration and cumulative impulse of the thrust gap within the prediction time window; The multi-mode orbit decision module 106 is used to determine whether to execute the orbit retention xenon compensation mode or the xenon electric propulsion orbit lifting mode based on the thrust gap. The propulsion execution module 107 is used to adjust the xenon gas flow rate, electric propulsion power, and orbital maneuvering program according to the instructions output by the multi-mode orbital decision module 106.

[0040] The space weather forecast receiving module 101 acquires at least one of the following: the current geomagnetic activity index, the three-hour segmented Ap forecast value, and the daily average Ap forecast value. The F10.7 includes at least one of the current F10.7, the daily average F10.7, the 27-day average F10.7, or their forecast values. The Ap and F10.7 are then interpolated to a time step consistent with the satellite orbit forecast.

[0041] The atmospheric density calculation module 103 uses NRLMSIESE-00, JB2008, DTM, or a thermosphere atmospheric model corrected from on-orbit data, according to...

[0042] Calculate the atmospheric density at each moment within the prediction time window. Where h is the orbital altitude, lat is the latitude, lon is the longitude, and UT is the Universal Time.

[0043] The resistance and feasible region evaluation module 104 is based on the formula...

[0044] Calculate the orbital velocity; The mass flow rate of the atmospheric working fluid collection device 110 is read from the data returned by the onboard sensors, or according to the formula.

[0045] The calculation yielded, where This refers to the collection efficiency of the atmospheric working fluid collection device 110, obtained from ground tests or simulations. It is the cross-sectional area of ​​the inlet of the atmospheric working fluid collection device 110; The mass flow rate used for ionization acceleration is read from the data returned by the onboard plasma diagnostic equipment, or according to the formula.

[0046] Calculation, where The characteristic operating condition dataset generated from the thruster ground test was obtained through table lookup or interpolation methods; The equivalent aerodynamic drag experienced by the satellite is read from data returned by onboard sensors, or calculated according to the formula.

[0047] The calculation yielded, where It is the equivalent drag coefficient obtained from satellite modeling and simulation. It is the equivalent cross-sectional area obtained from satellite modeling and simulation; Air-breathing electric propulsion relying solely on atmospheric working fluid can have its thrust read from data returned by onboard sensors, or according to the formula.

[0048] The calculation yields u, where u is the equivalent ion jet velocity, obtained from the characteristic operating condition dataset generated by the thruster ground test through table lookup or interpolation methods.

[0049] The orbital feasible region includes power feasibility constraints and discharge pressure feasibility constraints; the power feasibility constraint is the jet power used for drag compensation. No greater than the power available for propulsion by the solar array Subtract attitude control and platform power The power margin after t; the feasible constraint of the discharge gas pressure is the working gas pressure after collection and compression. Not less than the minimum stable discharge pressure of the thruster When the same orbital height simultaneously satisfies the power feasibility constraint and the discharge pressure feasibility constraint, the orbital height is determined to belong to the feasible domain of air-breathing electric propulsion orbits.

[0050] The thrust gap prediction module 105 according to

[0051] The thrust gap was calculated using only atmospheric working fluid, and the duration of the successive gaps was further calculated. Gap peak Cumulative spurt gap and the amount of xenon required to maintain the current orbit .

[0052] The multi-mode orbit decision module 106 includes a short-term anomaly detection unit and a long-term anomaly detection unit; when Less than the first duration threshold and When the xenon consumption is less than the first xenon consumption threshold, the short-term anomaly detection unit outputs a track-staying xenon compensation mode; when Greater than the second duration threshold Greater than the cumulative impulse gap threshold, or When the xenon consumption exceeds the second xenon consumption threshold, the long-term anomaly detection unit outputs the xenon electric propulsion orbit lifting mode.

[0053] The on-orbit xenon compensation mode includes: maintaining the satellite's current ultra-low orbit mission altitude unchanged, prioritizing the use of inhaled atmospheric working fluid to generate drag compensation thrust, and controlling the xenon storage and supply module 108 to provide a small flow rate of xenon to compensate. This continues until the predicted or measured atmospheric density anomaly ends, the thrust gap falls below the set threshold, or the air-breathing electric propulsion system regains thrust-drag balance.

[0054] The xenon electric propulsion orbit-lifting mode includes: searching or optimizing candidate target orbit altitudes within a prediction time window to determine the target orbit altitude. It controls the xenon electric propulsion to output the thrust required for orbital ascent, transferring the satellite from its ultra-low Earth orbit to the target orbit altitude; the... It must satisfy at least one of the following conditions during the future forecast period: reduced aerodynamic drag, reduced thrust gap, and reduced xenon consumption.

[0055] The target orbital height It is obtained through at least one intelligent optimization method such as neural network, genetic algorithm, particle swarm optimization, or Bayesian optimization; its optimization objective function includes at least two of the following: cumulative impulse gap, orbital speed increment, xenon consumption, and power margin.

[0056] This invention provides a method for autonomous control of a multi-mode supply-driven air-breathing electric propulsion orbit based on space weather forecasting, comprising the following steps: S1, obtain Ap and F10.7 from space weather forecasts, and obtain the longitude, latitude and orbital altitude of the satellite's current and future predicted trajectories; S2 calculates the atmospheric density sequence within the current and future prediction time windows based on Ap, F10.7, longitude, latitude, and orbital altitude; S3, calculate the intake mass flow rate, aerodynamic drag, available thrust, power constraint, discharge pressure constraint and orbital feasible region of the air-breathing electric propulsion system based on the atmospheric density sequence; S4, calculate the thrust gap at the current orbit within the prediction time window; S5. Based on the duration, peak value, and cumulative impulse gap of the thrust gap, determine whether the atmospheric density anomaly is a short-term or long-term anomaly. S6, when a short-term anomaly is detected, the track-stayed xenon compensation mode is executed; S7, when a long-term anomaly is determined, determines the target orbital altitude through an artificial intelligence model or mathematical optimization algorithm and executes xenon electric propulsion to lift the orbit; S8 continuously updates Ap, F10.7, atmospheric density, and thrust gap during orbital stay or ascent, and adjusts the xenon supply and orbital maneuver commands based on the update results.

[0057] The orbital feasible region in step S3 is obtained by scanning multiple candidate orbital altitudes; for each candidate orbital altitude, the minimum jet velocity, jet power, minimum discharge pressure, and xenon compensation requirements required to satisfy thrust-drag balance under the corresponding atmospheric density are calculated, and the requirements are then satisfied. and The set of candidate orbital heights is denoted as the feasible region.

[0058] When determining the target orbital altitude in step S7, using

[0059] Minimize the objective function, where This is the current orbital altitude. From Ascend to candidate altitude Required speed increment Xenon consumption This is a penalty for violating constraints such as power balance, minimum discharge pressure, satellite thermal control, and orbital safety. , , and These are the weighting coefficients.

[0060] Step S8 includes on-orbit closed-loop correction: using satellite accelerometers, orbit determination residuals, electric thruster telemetry parameters, and xenon storage and supply pressure to correct the atmospheric density calculation results and thrust gap prediction results; when the prediction error of multiple consecutive time steps exceeds the error threshold, the atmospheric density correction coefficient is re-estimated or a conservative threshold control strategy is switched to.

[0061] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement a multi-mode supply-driven air-breathing electric propulsion orbit autonomous control method based on space weather forecasting.

[0062] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a multi-mode supply-driven air-breathing electric propulsion orbit autonomous control method based on space weather forecasting.

[0063] This invention relates to the field of orbit maintenance and autonomous orbit change technology for ultra-low Earth orbit (ULE) air-breathing electric propulsion satellites, specifically to a multi-mode supply-based autonomous orbit control system and method for air-breathing electric propulsion based on space weather forecasts. The system acquires the geomagnetic activity index Ap and solar radio flux F10.7 from space weather forecasts, and combines this with the longitude, latitude, and orbital altitude of the satellite's current and predicted orbital positions. It then uses an atmospheric density calculation model to obtain the atmospheric density sequence for the satellite's current and future regions. Furthermore, it calculates the atmospheric propellant flow rate, aerodynamic drag, power constraints, discharge pressure constraints, orbital feasible region, and thrust gap obtainable by the air-breathing electric propulsion system. When the prediction indicates that the thrust gap will disappear in a short time, the system maintains the satellite in its current ULE mission orbit and uses a small amount of xenon to compensate for the short-term drag gap. When the prediction indicates that the thrust gap will remain large for a longer period, the system uses neural networks, reinforcement learning, dynamic programming, heuristic optimization, or deterministic mathematical optimization algorithms to determine the target orbital altitude that satisfies the mission constraints and propellant consumption constraints, and controls the xenon electric propulsion system to perform orbit ascent. This approach can improve the autonomous survivability, xenon utilization efficiency, and orbital mission continuity of ultra-low orbit satellites when solar activity and geomagnetic disturbances cause abnormal atmospheric density. Specific Implementation Example 2: The only difference between Embodiment 2 and Embodiment 1 of this application is that: like Figure 1 As shown, the multi-mode supply air-breathing electric propulsion orbit autonomous control system based on space weather forecasting provided by this invention includes a space weather forecast receiving module 101, an orbital state acquisition module 102, an atmospheric density calculation module 103, a thrust and feasible domain assessment module 104, a thrust gap prediction module 105, a multi-mode orbital decision-making module 106, and a propulsion execution module 107. The propulsion execution module 107 drives the xenon gas storage and supply module 108 and the air-breathing electric thruster 109 via commands. It also includes an atmospheric working fluid collection device 110.

[0065] The space weather forecast receiving module 101 receives Ap and F10.7 forecast data released by NOAA, ESA, SEPC and other organizations through a satellite-to-ground data link or pre-injection. The forecast data includes the current Ap and F10.7 values, three-hour segmented Ap forecast values, daily average Ap and daily average F10.7 forecast values, and 27-day average F10.7 values. The forecast values ​​are linearly interpolated or spline interpolated with a time step consistent with the satellite orbit forecast to form Ap(t) and F10.7(t) sequences that strictly correspond to the satellite orbit.

[0066] The orbital state acquisition module 102 acquires the current orbital elements of the satellite and the latitude lat(t), longitude lon(t), and orbital altitude h(t) within the prediction time window through GNSS receiver, on-board sensors, and orbital dynamics algorithms.

[0067] Atmospheric density calculation module 103 calls NRLMSISE-00, JB2008, or other thermospheric models to calculate the density at each time t within the prediction time window according to the formula.

[0068] Calculate atmospheric density and generate an atmospheric density sequence. .

[0069] The resistance and feasible region evaluation module 104 is in accordance with

[0070] Calculate the orbital velocity at each moment, according to

[0071] Calculate the inhalation mass flow rate according to

[0072] Calculate the mass flow rate used for ionization acceleration, according to

[0073] Calculate aerodynamic drag according to

[0074] The calculation relies solely on the available thrust of the atmospheric working fluid and is performed according to power constraints.

[0075] and discharge pressure constraint

[0076] Determine whether each orbital altitude belongs to the feasible orbital altitude region for an air-breathing electric propulsion mission.

[0077] Thrust gap prediction module 105 according to

[0078] Calculate the thrust gap timing sequence and extract the duration of continuous thrust gaps based on the timing sequence. Gap peak Cumulative spurt gap and the amount of xenon required to maintain the current orbit

[0079] The multi-mode orbit decision module 106 incorporates a short-term anomaly detection unit and a long-term anomaly detection unit. The short-term anomaly detection unit determines the short-term anomaly based on... and Conditions trigger the on-track xenon compensation mode; the long-term anomaly detection unit based on , or Any one of the conditions satisfies the triggering of the xenon electric propulsion orbit lifting mode.

[0080] The propulsion execution module 107 adjusts the xenon flow rate of the xenon gas storage and supply module 108 and schedules the power of the air-breathing electric thruster 109 according to the mode instructions output by the multi-mode orbit decision module 106. In the orbit raising mode, the onboard computer generates an orbit maneuver program to control the satellite to complete the transfer from the ultra-low orbit mission orbit to the target orbit altitude.

[0081] like Figure 2 As shown, the orbit autonomous control method of the present invention includes steps S1 to S8. S1 acquires space weather forecasts and satellite predicted trajectories; S2 calculates the atmospheric density sequence within the predicted time window; S3 evaluates thrust parameters and the orbital feasible region; S4 calculates the thrust gap timing sequence; S5 determines short-term or long-term anomalies based on thrust gap characteristics; S6 executes the on-orbit xenon compensation mode; S7 executes the xenon electric propulsion orbit ascent mode, including target orbit altitude optimization; S8 performs on-orbit closed-loop correction of atmospheric density and thrust gap predictions. Specific implementation method three: This embodiment demonstrates the execution process of the on-orbit xenon compensation mode for a scenario involving atmospheric density rise lasting several hours to over ten hours caused by a short-term geomagnetic storm. An air-breathing electric propulsion satellite is assumed to be operating in a circular mission orbit with h0 = 200 km, equipped with a multi-propellant air-breathing electric propulsion system, with a rated power of 2 kW for each thruster, and a solar array providing propulsion power. = 2.5 kW, Xenon working fluid specific impulse = 2500 s, minimum stable discharge pressure of the thruster =0.1 Pa.

[0083] In the first step, the space weather forecast receiving module 101 receives the forecast for the next 24 hours at UT0: Ap will rise rapidly from the current 15 to 60 in the next 3 hours, and reach a peak of Ap = 80 at t = 6 h, then fall back to 25 at t = 12 h, and fall back to 20 at t = 24 h; F10.7 remains basically unchanged at around 120 during these 24 hours.

[0084] The second step involves the orbital status acquisition module 102 generating a predicted trajectory for the next 24 hours. The time step is 300 s.

[0085] The third step involves the atmospheric density calculation module 103 calling the NRLMSISE-00 model, according to...

[0086] The atmospheric density sequence was calculated. The results show that at t = 0 h... ≈ 2.6 × 10 -10 kg / m³; when Ap reaches its peak at t = 6 h It rose to approximately 6.2 × 10⁻⁶. -10 kg / m³ (approximately 2.4 times the initial value); after t = 24 h, ρ recovered to approximately 2.9 × 10⁻⁶. -10 kg / m³.

[0087] Step 4, the resistance and feasible region evaluation module 104 according to

[0088] The orbital velocity at 200 km is obtained as v ≈ 7784 m / s. Let the inlet cross-sectional area of ​​the atmospheric working fluid collection device 110 be... = 1 m², collection efficiency = 0.5, equivalent drag coefficient = 2.2, equivalent cross-sectional area = 1.0 m², ionization efficiency =0.4, equivalent ion jet velocity u=40000 m / s.

[0089] Near t = 0 h:

[0090]

[0091] Near the peak at t = 6 h:

[0092]

[0093] Both time periods satisfy P_jet ≤ 2.5 kW and p_in ≥ 0.1 Pa, and the 200 km orbit belongs to the feasible region Ω.

[0094] Step 5, the thrust gap prediction module 105 according to

[0095] The thrust gap sequence was calculated for the entire time window from t = 0 h to t = 24 h.

[0096] (Occurs at t ≈ 6 h)

[0097] Xenon consumption required to maintain the current orbit

[0098] Step 6: The multi-mode track decision module 106 queries the threshold table. In this embodiment, the threshold table is...

[0099]

[0100]

[0101]

[0102]

[0103] Due to the 24-hour time window , The short-term anomaly detection unit determines that it is a short-term anomaly and outputs the track-stayed xenon compensation mode.

[0104] In the seventh step, the propulsion execution module 107 controls the satellite to maintain a constant h = 200 km and prioritizes the use of the inhaled atmospheric working fluid to generate thrust. For the deficient parts The xenon gas flow rate output from the xenon gas storage and supply module 108 is adjusted in real time. In this example, the peak xenon gas flow rate is approximately 0.11 mg / s.

[0105] Step 8: During the roll from UT0 to UT0 + 24 h, rolling updates of S1~S5 are performed hourly. If the set threshold is still met, the orbital xenon compensation mode is maintained. After 24 hours, both forecasts and measurements show that Ap and atmospheric density have returned to normal, the thrust gap is lower than the set threshold, the air-breathing electric propulsion system regains thrust-drag balance, the system exits the orbital xenon compensation mode, and returns to a pure atmospheric propellant supply state. The total xenon consumption in this embodiment is approximately 0.006 kg, which is significantly lower than the method of raising the orbit to avoid the impact at t = 0 h, and the mission orbital altitude remains unchanged, ensuring the continuity of the ultra-low orbit imaging / mapping mission. Specific implementation method four: This embodiment demonstrates the execution process and target orbit altitude optimization of a xenon electric propulsion orbit-raising mode, targeting a scenario where atmospheric density rises over multiple days due to persistently high F10.7 levels during a period of strong solar activity. An air-breathing electric propulsion satellite operates in a circular mission orbit with h0 = 180 km, equipped with a multi-propellant air-breathing electric propulsion system. The candidate orbit altitude search range is [180 km, 260 km], with a search step size of 10 km, and the xenon propellant specific impulse is... = 2500 s, the solar cell array can provide propulsion power = 2.5 kW, minimum stable discharge pressure of the thruster = 0.1 Pa.

[0107] The first step is for the space weather forecast receiving module 101 to receive the forecast for the next 7 days: F10.7 will continue to rise from the current 130 to 210 and remain there for 5 days, the average Ap value will rise from 12 to 40, and there will be three moderate geomagnetic storms; the daily average F10.7 forecast and the 27-day average F10.7 are both at the peak level of the solar system.

[0108] The second step is for the orbital state acquisition module 102 to generate a predicted trajectory for the next 7 days, with a time step of 600 s.

[0109] Thirdly, the atmospheric density calculation module 103 calls the NRLMSISE-00 model to calculate the density at each moment within the prediction time window according to...

[0110] Atmospheric density series were calculated. The results show that the average ρ at h = 180 km has increased from approximately 5.5 × 10⁻⁶. -10 kg / m³ increased to approximately 1.4 × 10 -9 kg / m³ (approximately 2.5 times); at h = 220 km, ρ increases by approximately 1.1 × 10⁻⁶. -10 kg / m³ increased to approximately 2.6 × 10 -10 kg / m³; at h = 250 km, ρ increases by approximately 5 × 10⁻⁶. -11 kg / m³ increased to approximately 1.2 × 10 -11 kg / m³.

[0111] Step 4, the resistance and feasible region evaluation module 104 according to

[0112] Calculate the orbital velocity at each candidate altitude, and set the same parameters as in Example 1, including the inlet cross-sectional area of ​​the atmospheric working fluid collection device 110. = 1 m², collection efficiency = 0.5, equivalent drag coefficient = 2.2, equivalent cross-sectional area = 1.0 m², ionization efficiency = 0.4, equivalent ion jet velocity u = 40000 m / s. Scan candidate orbital height set [180, 190, 200, …, 260] km. Where h = 180 km Approximately 93.7 mN, Demand exceeding 2.5 kW violates power constraints and is outside the feasible region; demand from h = 190 km to h = 260 km is simultaneously satisfied. and It belongs to the feasible region.

[0113] Fifth, the thrust gap prediction module 105 calculates the thrust gap for the next 7 days at each candidate altitude. , , At the current orbit h0 = 180 km , at h = 200 km , At h = 240 km , .

[0114] Step 6, Multi-mode Track Decision Module 106 makes the following judgment: , , If all three conditions are met, the long-term anomaly detection unit outputs the xenon electric propulsion orbit lifting mode.

[0115] Step 7: The execution module 107 calls the target function in step S7.

[0116] A search is performed over the feasible region [190, 200, …, 260] km, with weights set as follows: = 1.0、 = 100、 = 1×10³、 = 1×10 4 .

[0117] J(h) corresponding to each candidate height is calculated according to the parameters in this embodiment: h = 190 km: , , ,

[0118] h = 200 km: , , ,

[0119] h = 220 km: , , ,

[0120] h = 240 km: , , ,

[0121] h = 250 km: , , ,

[0122] h = 260 km: , , ,

[0123] J(h) reaches its minimum at h = 240 km. The target orbital altitude was selected. At this altitude, the duration of the thrust gap was significantly shortened throughout the entire 7-day prediction window, and the cumulative impulse gap and xenon consumption were both far below the threshold. At the same time, the total xenon consumption required for orbital ascent was approximately 0.135 kg, which is far less than the mass required to maintain the orbit at 180 km.

[0124] In the eighth step, the propulsion execution module 107 generates an orbit-raising command based on this, controlling the xenon gas storage and supply module to output xenon gas to the air-breathing electric thruster 109 to perform an acceleration maneuver, raising the satellite's orbital altitude from 180 km to 240 km. It also continuously predicts the optimal orbital altitude for the future.

[0125] Through the processing described in this embodiment, the satellite avoided the risk of prolonged high-power operation at 180 km or even xenon depletion during periods of strong solar activity. It completed its orbital ascent to 240 km at the cost of approximately 0.135 kg of xenon, awaiting the return of F10.7 before strategically lowering its orbit back to its mission orbit. This embodiment verifies the invention's ability to balance mission safety and efficient xenon utilization under prolonged density anomalies.

[0126] It should be noted that the orbital altitude, space weather forecast parameters, atmospheric model selection, thruster parameters, and thresholds T1, T2, I1, and M used in the embodiments of the present invention are as follows: Xe1 M Xe2 The objective function weights w1, w2, w3, and w4 are exemplary values. Specific values ​​need to be adjusted based on satellite sensor data, thruster parameters, and the actual space environment. Any adjustments to the parameters and algorithm implementation based on the system architecture and method steps proposed in this invention should be included within the scope of protection of this invention.

[0127] The above description is merely a preferred embodiment of a multi-mode supply-driven air-breathing electric propulsion orbit autonomous control system and method based on space weather forecasting. The scope of protection for such a system and method is not limited to the above embodiments; all technical solutions falling within this conceptual framework are within the scope of protection of this invention. It should be noted that for those skilled in the art, any improvements and variations made without departing from the principles of this invention should also be considered within the scope of protection of this invention.

Claims

1. A multi-mode supply-driven air-breathing electric propulsion orbit autonomous control system based on space weather forecasting, characterized in that: The system includes a space weather forecast receiving module, an orbital status acquisition module, an atmospheric density calculation module, a thrust and feasible region assessment module, a thrust gap prediction module, a multi-mode orbital decision-making module, and a propulsion module. The space weather forecast receiving module acquires the geomagnetic activity index Ap and the solar 10.7cm radio current F10.7 for the current and future periods; The orbital status acquisition module acquires the longitude, latitude, and orbital altitude of the air-breathing electric propulsion satellite for the current and future periods; The atmospheric density calculation module calculates the atmospheric density at the satellite's location based on the geomagnetic activity index Ap, solar radio flux F10.7, longitude, latitude, and orbital altitude. The thrust and feasible region assessment module calculates aerodynamic drag, available thrust for air-breathing electric propulsion, power constraints, discharge pressure constraints, and orbital feasible region based on atmospheric density. The thrust gap prediction module calculates the magnitude, duration, and cumulative impulse of the thrust gap within the prediction time window; The multi-mode orbit decision module determines whether to execute the orbit retention xenon compensation mode or the xenon electric propulsion orbit lifting mode based on the thrust gap. The propulsion execution module adjusts the xenon gas flow rate, electric propulsion power, and orbital maneuvering program according to the instructions output by the multi-mode orbit decision module.

2. The system according to claim 1, characterized in that: The geomagnetic activity index Ap acquired by the space weather forecast receiving module includes at least one of the current geomagnetic activity index, the three-hour segmented Ap forecast, and the daily average Ap forecast. F10.7 includes at least one of the current F10.7, the daily average F10.7, the 27-day average F10.7, or their forecasts. Ap and F10.7 are interpolated to a time step consistent with the satellite orbit forecast.

3. The system according to claim 2, characterized in that: The atmospheric density calculation module uses NRLMSISE-00, JB2008, DTM, or a thermospheric atmospheric model corrected from on-orbit data. Calculate the atmospheric density at each moment within the prediction time window. Where h is the orbital altitude, lat is the latitude, lon is the longitude, and UT is the Universal Time.

4. The system according to claim 3, characterized in that: The drag and feasible region evaluation module calculates the orbital velocity using the following formula: The mass flow rate drawn in by the atmospheric working fluid collection device is read from the data returned by the spaceborne sensors: in, It refers to the collection efficiency of an atmospheric working fluid collection device, obtained through ground testing or simulation. It is the cross-sectional area of ​​the inlet of the atmospheric working fluid collection device; The mass flow rate used for ionization acceleration is read from the data returned by the onboard plasma diagnostic equipment, or calculated according to the following formula: in, The characteristic operating condition dataset generated from the thruster ground test was obtained through table lookup or interpolation methods; The equivalent aerodynamic drag experienced by the satellite is read from data returned by onboard sensors: in, It is the equivalent drag coefficient obtained from satellite modeling and simulation. It is the equivalent cross-sectional area obtained from satellite modeling and simulation; The thrust of air-breathing electric propulsion relying solely on atmospheric propellant can be read from data returned by onboard sensors: Where u is the equivalent ion jet velocity, which is obtained from the characteristic operating condition dataset formed by the thruster ground test through table lookup or interpolation methods.

5. The system according to claim 4, characterized in that: The orbital feasible region includes power feasibility constraints and discharge pressure feasibility constraints. The power feasibility constraint is the jet power used for drag compensation. No greater than the power available for propulsion by the solar array Subtract attitude control and platform power Power margin after t; The feasible constraint for the discharge gas pressure is the working gas pressure after collection and compression. Not less than the minimum stable discharge pressure of the thruster When the same orbital height simultaneously satisfies the power feasibility constraint and the discharge pressure feasibility constraint, the orbital height is determined to belong to the feasible domain of air-breathing electric propulsion orbits.

6. The system according to claim 5, characterized in that: The thrust gap prediction module calculates the thrust gap relying solely on atmospheric working fluid using the following formula: And calculate the duration of the continuous gap. peak gap Cumulative spurt gap and the amount of xenon required to maintain the current orbit .

7. The system according to claim 6, characterized in that: The multi-mode orbit decision module includes a short-term anomaly detection unit and a long-term anomaly detection unit; when Less than the first duration threshold and When the xenon consumption is less than the first xenon consumption threshold, the short-term anomaly detection unit outputs a track-keeping xenon compensation mode; when Greater than the second duration threshold Greater than the cumulative impulse gap threshold, or When the xenon consumption exceeds the second xenon consumption threshold, the long-term anomaly detection unit outputs the xenon electric propulsion orbit lifting mode.

8. The system according to claim 7, characterized in that: The on-orbit xenon compensation mode includes: maintaining the satellite's current ultra-low orbit mission altitude, prioritizing the use of inhaled atmospheric propellant to generate drag compensation thrust, and controlling the xenon storage and supply module to provide a small flow of xenon to compensate. This continues until the predicted or measured atmospheric density anomaly ends, the thrust gap falls below the set threshold, or the air-breathing electric propulsion system regains thrust-drag balance.

9. A multi-mode supply-driven air-breathing electric propulsion orbit autonomous control method based on space weather forecasting, characterized by: The method includes the following steps: Step S1: Obtain Ap and F10.7 from the space weather forecast, and obtain the longitude, latitude, and orbital altitude of the satellite's current and future predicted trajectories; Step S2: Calculate the atmospheric density sequence for the current and future prediction time windows based on Ap, F10.7, longitude, latitude, and orbital altitude; Step S3: Calculate the intake mass flow rate, aerodynamic drag, available thrust, power constraint, discharge pressure constraint, and orbital feasible region of the air-breathing electric propulsion system based on the atmospheric density sequence. The orbital feasible region is obtained by scanning multiple candidate orbital altitudes. For each candidate orbital altitude, the minimum jet velocity, jet power, minimum discharge pressure, and xenon compensation requirements required to achieve thrust-drag balance at the corresponding atmospheric density are calculated, and these requirements are then satisfied. and The set of candidate orbital heights is denoted as the feasible region; Step S4: Calculate the thrust gap of the current orbit within the prediction time window; Step S5: Determine whether the atmospheric density anomaly is a short-term or long-term anomaly based on the duration, peak value, and cumulative impulse gap of the thrust gap. Step S6: When a short-term anomaly is determined, execute the track-stayed xenon compensation mode; Step S7: When a long-term anomaly is determined, the target orbital altitude is determined by an artificial intelligence model or mathematical optimization algorithm, and xenon electric propulsion is used to lift the orbit. When determining the target orbital altitude, in Minimize the objective function, where, This is the current orbital altitude. From Ascend to candidate altitude Required speed increment Xenon consumption Penalties for violating power balance, minimum discharge pressure, satellite thermal control, and orbital safety constraints. , , and These are the weighting coefficients; Step S8: During the orbit retention or orbit raising process, continuously update Ap, F10.7, atmospheric density and thrust gap, and adjust xenon supply and orbital maneuver commands based on the update results; In-orbit closed-loop correction: The atmospheric density calculation results and thrust gap prediction results are corrected using satellite accelerometers, orbit determination residuals, electric thruster telemetry parameters, and xenon storage and supply pressure; when the prediction error exceeds the error threshold for multiple consecutive time steps, the atmospheric density correction coefficient is re-estimated or a conservative threshold control strategy is switched to.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: The processor implements the method of claim 9 when executing the computer program.

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