Satellite electric propulsion autonomous task planning method and system based on energy surplus prediction

Abstract

The invention relates to the technical field of spacecraft on-orbit energy autonomous management and intelligent control, in particular to a satellite electric propulsion autonomous task planning method and system based on energy surplus prediction, and the method comprises the steps: obtaining data, calculating future illumination angle information, and dynamically predicting the average power generation power through combining the temperature of a solar cell array and a photovoltaic characteristic model; the charge state of a storage battery and satellite load priority configuration are obtained, and the energy surplus value of the future period is calculated; performing task arbitration according to the charge state and the energy surplus value, and generating an opportunity dimension orbit instruction when the condition is met; the attitude control system adjusts the satellite attitude to point to the orbit maintaining direction, and the intelligent power distribution system is connected with the electric propulsion power supply and dynamically adjusts the consumed power according to the real-time energy surplus value. According to the invention, the conversion from surplus electric energy to orbit maintenance power is realized, and the energy utilization efficiency and autonomous operation capability of the satellite are improved.

Description

Technical Field

[0001] This invention relates to the field of autonomous energy management and intelligent control technology for spacecraft in orbit, and in particular to a method and system for autonomous mission planning of satellite electric propulsion based on energy surplus prediction. Background Technology

[0002] In the application scenario of on-orbit autonomous operation technology for multi-payload high-power missions of micro and nano satellites, energy surplus prediction estimates the portion of the satellite's energy supply that exceeds its consumption in the future by analyzing the dynamics of solar power generation and changes in payload power consumption; satellite electric propulsion uses electrical energy to convert into thrust to achieve precise orbit adjustment or attitude control; autonomous mission planning dynamically optimizes the execution sequence of multi-payload missions and the timing of electric propulsion operations based on energy prediction results in order to maintain energy balance and support continuous mission execution.

[0003] Existing satellite energy management and mission planning technologies suffer from the following technical challenges: Due to the complexity of the space environment, such as fluctuations in solar panel temperature and albedo, there is a discrepancy between ground-based power generation predictions based on orbital parameters and theoretical illumination conditions and the actual on-orbit power generation of the satellite. Ground-based planning employs conservative strategies to ensure satellite safety; however, when the satellite operates in well-lit areas, actual power generation may exceed predictions, resulting in surplus energy. Existing power systems dissipate this surplus energy as heat via shunts, rather than utilizing it effectively, leading to energy waste. For example, microsatellites carrying high-power payloads such as high-resolution cameras and onboard AI computing modules experience significantly increased power generation when the solar panels are in a low-temperature, high-efficiency zone. However, ground commands cannot respond to this change in real time, preventing the surplus energy from being dynamically allocated to the electric propulsion system for orbit maintenance, thus wasting energy that could have been converted into satellite orbital potential energy. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a satellite electric propulsion autonomous mission planning method and system based on energy surplus prediction. This invention solves the technical problem of wasted surplus energy during the on-orbit operation of micro and nano satellites due to the prediction deviation of power generation caused by the complexity of the space environment.

[0005] To solve the above-mentioned technical problems, the specific contents of the present invention are as follows:

[0006] In a first aspect, the present invention provides a satellite electric propulsion autonomous mission planning method based on energy surplus prediction, comprising: Step 1: The onboard computer acquires the satellite's real-time orbital parameters and uses these parameters to calculate the illumination angle information for the future planning period. Step 2: The onboard computer dynamically predicts the average power generation within the future planning period based on the illumination angle information, the real-time temperature of the solar cell array, and the pre-stored photovoltaic output characteristic model. Step 3: The onboard computer obtains the current state of charge of the battery pack and reads the priority configuration and task queue information of the onboard load from the satellite management database. The priority configuration divides the load into primary loads that must be guaranteed, core secondary loads that are executed according to the task queue, and electric propulsion system as a flexible power consumption load. Step 4: The onboard computer calculates the energy surplus value within the future planning period based on the average power generation, the power consumption of the primary load, and the priority configuration. Step 5: The onboard computer performs mission arbitration based on the current state of charge and the energy surplus value. When the arbitration result is that the current state of charge is higher than the high charge threshold and the energy surplus value is greater than the minimum start-up power of the electric propulsion system, it generates and issues an instruction to enter the opportunity orbit maintenance mode. Step 6: In response to the command to enter the opportunity orbit maintenance mode, the attitude control system adjusts the satellite attitude so that the thrust vector points to the orbit maintenance direction, and the intelligent power distribution system connects the power supply of the electric propulsion system. Step 7: The intelligent power distribution system dynamically adjusts the power consumption of the electric propulsion system based on the real-time changing energy surplus value.

[0007] Furthermore, the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention, wherein the dynamic prediction of the average power generation within the future planning period includes: The onboard computer retrieves the temperature decay coefficient corresponding to the solar cell array model from the photovoltaic output characteristic model. Based on the temperature decay coefficient and the real-time temperature, the correction amount of the photoelectric conversion efficiency relative to the standard test conditions is calculated; The correction amount is applied to the standard photoelectric conversion efficiency to obtain the actual photoelectric conversion efficiency; The average power generation is calculated using the actual photoelectric conversion efficiency and the illumination angle information.

[0008] Furthermore, in the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention, the onboard computer reads the priority configuration of onboard payloads from the satellite service management database, including: The onboard computer reads the load configuration table from the satellite service management database, which records the functional attributes of different loads; The onboard computer analyzes the functional attributes and classifies the control, thermal control, and telemetry receivers that maintain the basic operation of the platform as the primary load. High-resolution cameras, infrared cameras, and onboard artificial intelligence processing units that perform specific tasks are classified as the core secondary payloads; The electric propulsion system is classified separately as the elastic power consumption load triggered by the energy surplus.

[0009] Furthermore, in the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention, the execution of mission arbitration includes: The current state of charge is compared with a preset safety threshold. When the comparison result indicates that the current state of charge is lower than the safety threshold, a safety mode instruction is generated; The safety mode command is used to trigger the following actions: disconnect the power supply link between the core secondary load and the electric propulsion system, and generate attitude control commands to keep the satellite solar panels continuously aligned with the sun.

[0010] Furthermore, the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention, wherein the execution of mission arbitration further includes: Determine whether there are any core secondary load tasks to be executed in the task queue; If it exists, query the peak power consumption requirement of the core secondary load task; The energy surplus value is added to the maximum allowable discharge power of the battery to obtain the total available power; Compare the total available power with the peak power consumption requirement; When the total available power is greater than or equal to the peak power consumption requirement, a task execution instruction is generated, and a latching signal is generated simultaneously to prevent the electric propulsion system from starting during the execution of the core secondary load task.

[0011] Furthermore, in the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention, the dynamic adjustment of the power consumption of the electric propulsion system includes: After the intelligent power distribution system connects to the power supply of the electric propulsion system, a power distribution coefficient is set, wherein the value of the power distribution coefficient is greater than 0 and not greater than 1. The energy surplus value is monitored in real time, and the energy surplus value is multiplied by the power allocation coefficient to obtain the target power value; Control the power regulator of the electric propulsion system so that the instantaneous input power of the electric propulsion system tracks the target power value.

[0012] Furthermore, in the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention, in the opportunity-based orbit maintenance mode, the attitude control system adjusts the satellite attitude, including: The onboard computer calculates the optimal thrust vector to offset orbital decay or increase orbital altitude based on the real-time orbital parameters, and determines the direction of the optimal thrust vector in the satellite body coordinate system. The onboard computer sends an attitude pointing command, including the pointing information, to the attitude control system. After receiving the attitude pointing command, the attitude control system calculates the attitude pointing command and drives the satellite attitude mechanism to align the nozzle of the electric thruster with the direction of the optimal thrust vector. After completing the attitude adjustment, the attitude control system sends an attitude ready signal to the onboard computer.

[0013] Furthermore, the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention also includes an exit mechanism; The onboard computer continuously monitors three judgment conditions in parallel: whether there is a high-priority command at the ground command receiving port, whether the current state of charge of the battery pack is lower than the high power threshold, and whether the predicted energy surplus value at the next moment is less than or equal to zero. When any of the aforementioned judgment conditions are detected, the onboard computer immediately interrupts the current mission arbitration logic and generates an exit instruction including an emergency shutdown code for the electric propulsion system. The exit command is sent to the intelligent power distribution system via the intra-satellite communication bus. Upon receiving the exit command, the intelligent power distribution system parses the exit command and immediately cuts off the power output to the electric propulsion system.

[0014] Furthermore, the satellite electric propulsion autonomous mission planning method based on energy surplus prediction described in this invention also includes: The onboard computer parses the task data of the core secondary load to obtain the planned execution time and power consumption level of the core secondary load; Compare the planned execution time with the future planning cycle; When calculating the energy surplus value, the estimated power consumption of the core secondary load that overlaps with the future planning period in time is deducted; The onboard computer uses this energy surplus value, after deducting the estimated power consumption, as the basis for dynamically adjusting the power consumption of the electric propulsion system.

[0015] Secondly, the satellite electric propulsion autonomous mission planning system based on energy surplus prediction provided by the present invention is applied to the aforementioned satellite electric propulsion autonomous mission planning method based on energy surplus prediction, including: The orbital environment perception section is used to acquire the satellite's real-time orbital parameters and use these parameters to calculate the illumination angle information for future planning cycles. The power generation prediction section is connected to the orbital environment sensing section and is used to dynamically predict the average power generation within the future planning period based on the illumination angle information, the real-time temperature of the solar cell array, and the pre-stored photovoltaic output characteristic model. The status assessment section is used to obtain the current state of charge of the battery pack and read the priority configuration and task queue information of the on-board loads from the space service management database. The priority configuration divides the loads into primary loads that must be guaranteed, core secondary loads that are executed according to the task queue, and electric propulsion systems as flexible power consumption loads. The energy surplus calculation section connects the power generation prediction section and the state assessment section, and is used to calculate the energy surplus value in the future planning period based on the average power generation, the power consumption of the first-level load, and the priority configuration. The mission arbitration section connects the state assessment section and the energy surplus calculation section. It is used to perform mission arbitration based on the current state of charge and the energy surplus value. When the arbitration result is that the current state of charge is higher than the high charge threshold and the energy surplus value is greater than the minimum start-up power of the electric propulsion system, it generates and issues an instruction to enter the opportunity orbit maintenance mode. The execution control section, connected to the mission arbitration section, is used to respond to the command to enter the opportunity orbit maintenance mode, control the attitude control system to adjust the satellite attitude so that the thrust vector points to the orbit maintenance direction, and control the intelligent power distribution system to connect the power supply of the electric propulsion system. The power regulation section, connected to the energy surplus calculation section and the execution control section, is used to dynamically adjust the power consumption of the electric propulsion system based on the real-time changing energy surplus value through the intelligent power distribution system.

[0016] Beneficial effects of this invention: This invention establishes a dynamic and accurate energy surplus calculation model through real-time monitoring and prediction of satellite orbital parameters, solar array temperature, and load status by an onboard computer. This enables the electric propulsion system to adaptively adjust power consumption based on real-time changes in energy supply, converting excess electrical energy dissipated as heat in the existing power system into effective orbit-maintaining thrust, significantly improving satellite energy utilization efficiency. The system employs a multi-level mission arbitration mechanism and a parallel monitoring rapid exit mechanism, ensuring the reliable execution of high-priority payload missions while guaranteeing the safety of electric propulsion operations, enhancing the satellite's autonomous operation capability and system reliability in complex space environments. By organically integrating energy prediction, load management, and electric propulsion control, closed-loop optimized scheduling of onboard energy is achieved, providing an effective energy autonomous management solution for the long-life on-orbit operation of micro- and nano-satellites. Attached Figure Description

[0017] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0018] Figure 1 The flowchart shows the satellite electric propulsion autonomous mission planning method based on energy surplus prediction provided by this invention. Detailed Implementation

[0019] To make the technical solution of the present invention clearer, the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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. The present invention provided by various embodiments will be described in detail below with reference to the accompanying drawings. To better understand the purpose of the present invention, the present invention will be described in further detail below.

[0020] Firstly, please refer to Figure 1 The present invention provides a satellite electric propulsion autonomous mission planning method based on energy surplus prediction, comprising: Step 1: The onboard computer acquires the satellite's real-time orbital parameters and uses these parameters to calculate the illumination angle information for the future planning period. Step 2: The onboard computer dynamically predicts the average power generation within the future planning period based on the illumination angle information, the real-time temperature of the solar cell array, and the pre-stored photovoltaic output characteristic model. Step 3: The onboard computer obtains the current state of charge of the battery pack and reads the priority configuration and task queue information of the onboard load from the satellite management database. The priority configuration divides the load into primary loads that must be guaranteed, core secondary loads that are executed according to the task queue, and electric propulsion system as a flexible power consumption load. Step 4: The onboard computer calculates the energy surplus value within the future planning period based on the average power generation, the power consumption of the primary load, and the priority configuration. Step 5: The onboard computer performs mission arbitration based on the current state of charge and the energy surplus value. When the arbitration result is that the current state of charge is higher than the high charge threshold and the energy surplus value is greater than the minimum start-up power of the electric propulsion system, it generates and issues an instruction to enter the opportunity orbit maintenance mode. Step 6: In response to the command to enter the opportunity orbit maintenance mode, the attitude control system adjusts the satellite attitude so that the thrust vector points to the orbit maintenance direction, and the intelligent power distribution system connects the power supply of the electric propulsion system. Step 7: The intelligent power distribution system dynamically adjusts the power consumption of the electric propulsion system based on the real-time changing energy surplus value.

[0021] The onboard computer obtains the satellite's real-time position and velocity vector in the inertial coordinate system by analyzing signals from the Global Navigation Satellite System or by running orbital recursion algorithms. Based on the orbital dynamics model, the computer calculates the satellite's azimuth change relative to the sun over the next few tens of minutes, and then accurately calculates the incident angle of sunlight on the solar panel surface and the time window for entering and exiting the Earth's shadow. This step provides a spatiotemporal reference for energy forecasting.

[0022] After obtaining the time-series data of the illumination angle, the system combines real-time acquired telemetry data of the solar array temperature with a photovoltaic characteristic curve library stored in the onboard memory. By querying the temperature decay coefficient corresponding to the current solar array model, the computer performs temperature compensation correction on the photoelectric conversion efficiency under standard test conditions, generating a predicted power generation value that conforms to actual on-orbit operating conditions. This dynamic prediction method effectively overcomes the interference of space environment temperature fluctuations on power generation estimation.

[0023] The satellite management database pre-stores a load characteristic configuration table, clearly recording the power level and functional classification of each electrical device. After reading this configuration table, the onboard computer classifies basic platform service loads such as attitude control computers, thermal control heaters, and telemetry and remote control transceivers as primary loads; intermittent high-power task loads such as high-resolution cameras and onboard intelligent computing units as secondary loads; and the electric propulsion system as an adjustable tertiary load. Simultaneously, the computer extracts the timing planning information for tasks to be executed from the task queue.

[0024] Based on the above data, the computer performs energy budget calculations: subtracting the fixed power consumption of primary loads and the power required to maintain the floating charge state of batteries from the predicted power generation, the net energy surplus for the planning period is obtained. This calculation process comprehensively considers the dynamic characteristics of both the supply and demand sides of the power system.

[0025] The mission arbitration module combines the energy surplus value with the current state of charge of the battery as a joint criterion. When the battery charge is higher than the safety threshold and the energy surplus continues to exceed the minimum start-up threshold of the electric propulsion system, the computer generates an opportunistic orbit maintenance command. This command is synchronously sent to the attitude control system and the intelligent power distribution system via the intra-satellite bus.

[0026] Based on orbital mechanics principles, the attitude control system calculates the optimal thrust direction to counteract atmospheric drag or increase orbital altitude. Upon receiving an opportunity-based orbital maintenance command, the system drives the reaction wheel or thruster to adjust the satellite's attitude, aligning the electric thruster nozzles axially with the predetermined thrust vector. Simultaneously, the intelligent power distribution system closes the power supply circuit for the electric propulsion system.

[0027] After the electric propulsion system enters standby mode, the power regulator uses a maximum power point tracking algorithm to sample the real-time energy surplus value at a frequency of seconds. By adjusting the gate voltage or the working fluid flow rate, the actual power consumption of the thruster dynamically follows the changes in surplus power. This closed-loop control transforms excess electrical energy that might otherwise be diverted and dissipated into continuous orbital control force.

[0028] This invention achieves coordinated optimization of energy scheduling and orbit control by periodically updating orbital parameters and payload status. For example, when a satellite enters a high-light-intensity orbital segment, the system automatically converts surplus electrical energy into orbital sustaining power; and when a remote sensing imaging mission is initiated, priority is given to powering the payload and propulsion system operations are suspended. This autonomous decision-making mechanism significantly improves the energy utilization efficiency of microsatellites in complex orbital environments.

[0029] The process of dynamically predicting average power generation requires a deep understanding of the physical characteristics of photovoltaic devices. The onboard computer first indexes the temperature decay parameters corresponding to the current solar array model from a photovoltaic characteristic model library. These parameters are typically obtained through ground-based vacuum thermal tests. The difference between the real-time telemetry temperature and the 25-degree Celsius baseline value specified in the standard test conditions is multiplied by a temperature decay coefficient to obtain a correction for the photoelectric conversion efficiency. The corrected actual efficiency value, along with the illumination angle information, is input into the power generation calculation model. This model considers the cosine relationship between the angle between sunlight and the solar panel normal, ultimately outputting a predicted average power generation value that takes into account temperature and geometric factors. This prediction method can adapt to the drastic temperature changes of the solar panel from tens of degrees below zero to nearly one hundred degrees above zero during the satellite's on-orbit operation.

[0030] Regarding the priority configuration mechanism, the load configuration table in the satellite management database uses an XML structured storage format. Each load entry includes attribute fields such as equipment identification code, rated power, and operating mode set. When the onboard computer parses the functional attributes, systems that maintain the basic operation of the satellite, such as attitude control, thermal management, and telemetry and remote control, are classified as Level 1 loads. These loads have a rigid requirement for continuous power supply. Mission payloads such as high-resolution cameras are marked as Level 2 loads, and their operating periods are dynamically allocated by the mission planning module. The electric propulsion system, as a Level 3 load, has unique interruptibility characteristics, and its operating state is directly modulated by the energy surplus value. This classification method reflects the differentiated treatment of load characteristics in the power management strategy.

[0031] The generation logic for the safety mode command is based on the power system's safety boundaries. The onboard computer continuously monitors the battery pack's state of charge (SCC). When the value falls below a preset safety threshold, it indicates that the satellite faces a power shortage risk. At this point, the computer generates a safety mode command package, which includes a load-down sequence code and attitude adjustment parameters. After the command is executed, the satellite maintains only the most basic platform load operation while controlling its attitude to align the solar panels with the sun at maximum extent, restoring battery power as quickly as possible. This design ensures the satellite's autonomous survivability under extreme conditions.

[0032] For the extended logic of mission arbitration, when the onboard computer detects a secondary load task to be executed in the mission queue, it initiates a power coordination judgment process. The computer first queries the nominal peak power demand of the task, and then calculates the total available power of the system by combining the current energy surplus value with the maximum safe discharge power that the battery can provide. When the total available power covers the peak demand of the task, the computer sends a hardware latch signal to the electric propulsion system power manager at the same time as issuing the task execution command. This dual-signal mechanism prevents the bus voltage drop that may be caused by the simultaneous operation of high-power loads and the electric propulsion system.

[0033] The dynamic power adjustment process embodies the concept of closed-loop control. After the power supply circuit of the electric propulsion system is connected, the intelligent power distribution system typically sets the power allocation coefficient to a conservative value between 0.8 and 0.95 to provide a safety margin for the system. The system samples the real-time energy surplus value 10 times per second, multiplies it by the power allocation coefficient, and obtains the target power setpoint. The electric propulsion system power regulator uses a PID control algorithm to precisely control the output power by adjusting the gate voltage of the field-effect transistor, ensuring that the actual power consumption of the thruster smoothly tracks changes in the target value. This design ensures energy utilization efficiency while avoiding the impact of sudden power fluctuations on the power supply system.

[0034] During attitude adjustment, the onboard computer calculates the optimal thrust vector based on real-time orbital parameters, taking into account both the orbital perturbation model and the mission objective. The calculated thrust vector direction information is transmitted to the attitude control system via the 1553B data bus. Upon receiving the command, the attitude control computer first performs a command safety check, then converts it into rotational speed commands for the reaction wheels on each axis. When the attitude angle feedback from the star sensor deviates from the target value by less than 0.1 degrees, the system determines that the attitude adjustment is complete and sends a ready signal to the onboard computer. The accuracy of this process directly affects the efficiency of orbital control.

[0035] The exit mechanism employs a multi-path parallel monitoring architecture. The onboard computer monitors the ground command port via a dedicated hardware watchdog circuit, simultaneously acquiring battery voltage data through the ADC module to calculate the state of charge and maintaining data exchange with the energy prediction module. When any monitoring signal triggers a condition, the computer immediately interrupts the current task thread and generates a command packet including an emergency shutdown code. This command packet is sent to the intelligent power distribution system via a SpaceWire bus with redundancy checks. After parsing the command, the power manager cuts off power to the thrusters within 10 milliseconds. This rapid response mechanism ensures system safety.

[0036] The load power consumption estimation method embodies a forward-looking planning approach. When the onboard computer parses secondary load mission data, it extracts the mission plan execution timestamp and power consumption pattern identifier. After timing-matching the mission timeline with future planning cycles, the computer pre-deducts the estimated load power consumption during overlapping periods when calculating the energy surplus value. This time-window-based power budget management ensures that the final energy surplus value used for electric propulsion power regulation already takes into account the needs of subsequent missions, achieving time-series optimization of energy allocation.

[0037] Secondly, the satellite electric propulsion autonomous mission planning system based on energy surplus prediction provided by the present invention is applied to the aforementioned satellite electric propulsion autonomous mission planning method based on energy surplus prediction, including: The orbital environment perception section is used to acquire the satellite's real-time orbital parameters and use these parameters to calculate the illumination angle information for future planning cycles. The power generation prediction section is connected to the orbital environment sensing section and is used to dynamically predict the average power generation within the future planning period based on the illumination angle information, the real-time temperature of the solar cell array, and the pre-stored photovoltaic output characteristic model. The status assessment section is used to obtain the current state of charge of the battery pack and read the priority configuration and task queue information of the on-board loads from the space service management database. The priority configuration divides the loads into primary loads that must be guaranteed, core secondary loads that are executed according to the task queue, and electric propulsion systems as flexible power consumption loads. The energy surplus calculation section connects the power generation prediction section and the state assessment section, and is used to calculate the energy surplus value in the future planning period based on the average power generation, the power consumption of the first-level load, and the priority configuration. The mission arbitration section connects the state assessment section and the energy surplus calculation section. It is used to perform mission arbitration based on the current state of charge and the energy surplus value. When the arbitration result is that the current state of charge is higher than the high charge threshold and the energy surplus value is greater than the minimum start-up power of the electric propulsion system, it generates and issues an instruction to enter the opportunity orbit maintenance mode. The execution control part, connected to the task arbitration part, is used to control the attitude control system to adjust the satellite attitude so that the thrust vector points to the orbit maintenance direction in response to the instruction to enter the opportunity orbit maintenance mode, and control the intelligent power distribution system to turn on the power supply of the electric propulsion system. The power regulation part, connected to the energy surplus calculation part and the execution control part, is used to dynamically regulate the power consumption of the electric propulsion system according to the real-time changing energy surplus value through the intelligent power distribution system.

[0038] The on-board main control computer obtains the current and future position information of the satellite within a planning period (T_plan) according to the GNSS real-time orbit determination data or orbit recurrence model; calculates the time of entering and leaving the shadow, the illumination duration, and the incident angle of sunlight on the solar panel (beta angle) of the satellite in the future planning period according to the position information.

[0039] Combined with the real-time temperature of the solar cell array collected by satellite telemetry, the average power generation P_gen in the future planning period is predicted using a pre-set photovoltaic output characteristic model. The prediction formula corrects the influence of the temperature coefficient on the photoelectric conversion efficiency, ensuring that the predicted value is close to the actual on-orbit working conditions.

[0040] Obtain the current state of charge (SOC) and bus voltage of the satellite battery pack. Divide the on-board loads into three priorities: Level 1 load (survival maintenance): including platform control, thermal control, and TT&C receiver; such loads must be guaranteed.

[0041] Level 2 load (core task): including high-resolution camera, infrared camera, and on-board AI processing unit; such loads are executed according to the task queue.

[0042] Level 3 load (energy regulation): including electric propulsion system; such loads are used as elastic power consumption units.

[0043] Calculate the energy surplus value P_surplus at the current moment and within the prediction period: P_surplus = P_gen - P_level1 - P_charge Where P_level1 is the power consumption of level 1 load, and P_charge is the charging power required to maintain the battery pack fully charged.

[0044] The task arbitration logic is as follows: If SOC < SOC_safe (safety threshold), enter the safety mode, cut off the level 2 and level 3 loads, and adjust the attitude to charge facing the sun.

[0045] If SOC ≥ SOC_task and there are secondary tasks to be executed, determine whether P_surplus + P_batt_discharge meets the peak power consumption of the task; if it meets, execute the secondary task and at the same time forcibly lock out the tertiary load to prevent instantaneous power from exceeding the limit.

[0046] If there are no secondary tasks, or the secondary tasks are completed, and SOC > SOC_high (high battery threshold, e.g., 90%), and P_surplus > P_EP_min (minimum starting power of electric propulsion), then enter the opportunistic orbit maintenance mode.

[0047] In the opportunistic orbit maintenance mode, the satellite attitude control system adjusts the satellite attitude so that the thrust vector points in a direction that can increase the orbit altitude or compensate for atmospheric drag; The intelligent power distribution unit (PDU) powers on the electric propulsion system and dynamically adjusts the working fluid flow rate or discharge voltage of the electric propulsion system according to the magnitude of the real-time P_surplus, so that the power consumption of the electric propulsion system fluctuates following P_surplus, and converts the surplus electric energy into thrust.

[0048] When any of the following situations is detected, immediately power off the electric propulsion system and exit the opportunistic orbit maintenance mode: Receiving a high-priority ground imaging command or an emergency measurement and control command; The SOC of the battery pack drops below SOC_high; It is predicted that entering the shadow area or the illumination angle deteriorates, resulting in P_surplus ≤ 0.

[0049] The control strategy of the electric propulsion system adopts the maximum power point tracking (MPPT) dissipation mode, that is, the electric propulsion power P_EP is set to: P_EP(t)=n P_surplus(t); Where n is the power distribution coefficient (0 < n ≤ 1), which ensures that the instantaneous output capacity of the photovoltaic array is maximally utilized without consuming the battery stock.

[0050] The on-board computer obtains the real-time position and velocity vector of the satellite in the inertial coordinate system by parsing the signals of the global navigation satellite system or running the orbit recurrence algorithm. Based on the orbit dynamics model, the computer calculates the azimuth change of the satellite relative to the sun in the next dozens of minutes, and then calculates the illumination incident angle on the surface of the solar panel and the time window for entering and exiting the earth's shadow. This step provides a spatio-temporal basis for energy prediction.

[0051] After obtaining the time-series data of the illumination angle, the system combines real-time acquired telemetry data of the solar array temperature with a photovoltaic characteristic curve library stored in the onboard memory. By querying the temperature decay coefficient corresponding to the current solar array model, the computer performs temperature compensation correction on the photoelectric conversion efficiency under standard test conditions, generating a predicted power generation value that conforms to actual on-orbit operating conditions. This dynamic prediction method effectively overcomes the interference of space environment temperature fluctuations on power generation estimation.

[0052] The satellite management database pre-stores a load characteristic configuration table, clearly recording the power level and functional classification of each electrical device. After reading the configuration table, the onboard computer classifies basic platform service loads such as attitude control computers, thermal control heaters, and telemetry and remote control transceivers as primary loads; intermittent high-power task loads such as high-resolution cameras and onboard intelligent computing units as secondary loads; and the electric propulsion system as an adjustable tertiary load. Simultaneously, the computer extracts the timing planning information for tasks to be executed from the task queue.

[0053] Based on the above data, the computer performs energy budget calculations: subtracting the fixed power consumption of primary loads and the power required to maintain the floating charge state of batteries from the predicted power generation, the net energy surplus for the planning period is obtained. The calculation process comprehensively considers the dynamic characteristics of both the supply and demand sides of the power system.

[0054] The mission arbitration module combines the energy surplus value with the current state of charge of the battery as a joint criterion. When the battery charge is higher than the safety threshold and the energy surplus continues to exceed the minimum start-up threshold of the electric propulsion system, the computer generates an opportunistic orbit maintenance command. The command is synchronously sent to the attitude control system and the intelligent power distribution system via the intra-satellite bus.

[0055] Based on orbital mechanics principles, the attitude control system calculates the optimal thrust direction to counteract atmospheric drag or increase orbital altitude. Upon receiving an opportunity-based orbital maintenance command, the system drives the reaction wheel or thruster to adjust the satellite's attitude, aligning the electric thruster nozzles axially with the predetermined thrust vector. Simultaneously, the intelligent power distribution system closes the power supply circuit for the electric propulsion system.

[0056] After the electric propulsion system enters standby mode, the power regulator uses a maximum power point tracking algorithm to sample the real-time energy surplus value at a frequency of seconds. By adjusting the gate voltage or the working fluid flow rate, the actual power consumption of the thruster dynamically follows the changes in surplus power. This closed-loop control transforms excess electrical energy that might otherwise be diverted and dissipated into continuous orbital control force.

[0057] This invention achieves coordinated optimization of energy scheduling and orbit control by periodically updating orbital parameters and payload status. When the satellite enters a high-light-intensity orbital segment, the system automatically converts surplus electrical energy into orbital sustaining power; and when a remote sensing imaging mission is initiated, priority is given to powering the payload and propulsion system operations are suspended. This autonomous decision-making mechanism significantly improves the energy utilization efficiency of microsatellites in complex orbital environments.

[0058] For the load power consumption estimation method, when the onboard computer parses the secondary load mission data, it extracts the mission plan execution timestamp and power consumption mode identifier. After timing-matching the mission timeline with future planning cycles, the computer pre-deducts the estimated load power consumption during overlapping periods when calculating the energy surplus value. This time-window-based power budget management ensures that the final energy surplus value used for electric propulsion power regulation already takes into account the needs of subsequent missions, achieving time-series optimization of energy allocation.

[0059] The exit mechanism employs a multi-path parallel monitoring architecture. The onboard computer monitors the ground command port via a dedicated hardware watchdog circuit, simultaneously acquiring battery voltage data to calculate the state of charge (SOC) through an analog-to-digital converter and maintaining data exchange with the energy prediction module. When any monitoring signal triggers a condition, the computer immediately interrupts the current task thread and generates a command packet containing emergency shutdown code for the electric propulsion system. This command packet is sent to the intelligent power distribution system via an intra-satellite communication bus with redundancy checks. After parsing the command, the power manager cuts off power to the thrusters within milliseconds. This rapid response mechanism ensures system safety.

Claims

1. A satellite electric propulsion autonomous mission planning method based on energy surplus prediction, characterized in that, include; Step 1: The onboard computer acquires the satellite's real-time orbital parameters and uses these parameters to calculate the illumination angle information for the future planning period. Step 2: The onboard computer dynamically predicts the average power generation within the future planning period based on the illumination angle information, the real-time temperature of the solar cell array, and the pre-stored photovoltaic output characteristic model. Step 3: The onboard computer obtains the current state of charge of the battery pack and reads the priority configuration and task queue information of the onboard load from the satellite management database. The priority configuration divides the load into primary loads that must be guaranteed, core secondary loads that are executed according to the task queue, and electric propulsion system as a flexible power consumption load. Step 4: The onboard computer calculates the energy surplus value within the future planning period based on the average power generation, the power consumption of the primary load, and the priority configuration. Step 5: The onboard computer performs mission arbitration based on the current state of charge and the energy surplus value. When the arbitration result is that the current state of charge is higher than the high charge threshold and the energy surplus value is greater than the minimum start-up power of the electric propulsion system, it generates and issues an instruction to enter the opportunity orbit maintenance mode. Step 6: In response to the command to enter the opportunity orbit maintenance mode, the attitude control system adjusts the satellite attitude so that the thrust vector points to the orbit maintenance direction, and the intelligent power distribution system connects the power supply of the electric propulsion system. Step 7: The intelligent power distribution system dynamically adjusts the power consumption of the electric propulsion system based on the real-time changing energy surplus value.

2. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, The dynamic prediction of the average power generation during the future planning period includes: The onboard computer retrieves the temperature decay coefficient corresponding to the solar cell array model from the photovoltaic output characteristic model. Based on the temperature decay coefficient and the real-time temperature, the correction amount of the photoelectric conversion efficiency relative to the standard test conditions is calculated; The correction amount is applied to the standard photoelectric conversion efficiency to obtain the actual photoelectric conversion efficiency; The average power generation is calculated using the actual photoelectric conversion efficiency and the illumination angle information.

3. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, The onboard computer reads the priority configuration of the onboard load from the onboard service management database, including: The onboard computer reads the load configuration table from the satellite service management database, which records the functional attributes of different loads; The onboard computer analyzes the functional attributes and classifies the control, thermal control, and telemetry receivers that maintain the basic operation of the platform as the primary load. High-resolution cameras, infrared cameras, and onboard artificial intelligence processing units that perform specific tasks are classified as the core secondary payloads; The electric propulsion system is classified separately as the elastic power consumption load triggered by the energy surplus.

4. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, The arbitration of the execution task includes: The current state of charge is compared with a preset safety threshold. When the comparison result indicates that the current state of charge is lower than the safety threshold, a safety mode instruction is generated; The safety mode command is used to trigger the following actions: disconnect the power supply link between the core secondary load and the electric propulsion system, and generate attitude control commands to keep the satellite solar panels continuously aligned with the sun.

5. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, The arbitration for the execution of the task also includes: Determine whether there are any core secondary load tasks to be executed in the task queue; If it exists, query the peak power consumption requirement of the core secondary load task; The energy surplus value is added to the maximum allowable discharge power of the battery to obtain the total available power; Compare the total available power with the peak power consumption requirement; When the total available power is greater than or equal to the peak power consumption requirement, a task execution instruction is generated, and a latching signal is generated simultaneously to prevent the electric propulsion system from starting during the execution of the core secondary load task.

6. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, The dynamic adjustment of the power consumption of the electric propulsion system includes: After the intelligent power distribution system connects to the power supply of the electric propulsion system, a power distribution coefficient is set, wherein the value of the power distribution coefficient is greater than 0 and not greater than 1. The energy surplus value is monitored in real time, and the energy surplus value is multiplied by the power allocation coefficient to obtain the target power value; Control the power regulator of the electric propulsion system so that the instantaneous input power of the electric propulsion system tracks the target power value.

7. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, In the opportunity-based orbital maintenance mode, the attitude control system adjusts the satellite attitude, including: The onboard computer calculates the optimal thrust vector to offset orbital decay or increase orbital altitude based on the real-time orbital parameters, and determines the direction of the optimal thrust vector in the satellite body coordinate system. The onboard computer sends an attitude pointing command, including the pointing information, to the attitude control system. After receiving the attitude pointing command, the attitude control system calculates the attitude pointing command and drives the satellite attitude mechanism to align the nozzle of the electric thruster with the direction of the optimal thrust vector. After completing the attitude adjustment, the attitude control system sends an attitude ready signal to the onboard computer.

8. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, It also includes an exit mechanism; The onboard computer continuously monitors three judgment conditions in parallel: whether there is a high-priority command at the ground command receiving port, whether the current state of charge of the battery pack is lower than the high power threshold, and whether the predicted energy surplus value at the next moment is less than or equal to zero. When any of the aforementioned judgment conditions are detected, the onboard computer immediately interrupts the current mission arbitration logic and generates an exit instruction including an emergency shutdown code for the electric propulsion system. The exit command is sent to the intelligent power distribution system via the intra-satellite communication bus. Upon receiving the exit command, the intelligent power distribution system parses the exit command and immediately cuts off the power output to the electric propulsion system.

9. The satellite electric propulsion autonomous mission planning method based on energy surplus prediction according to claim 1, characterized in that, Also includes: The onboard computer parses the task data of the core secondary load to obtain the planned execution time and power consumption level of the core secondary load; Compare the planned execution time with the future planning cycle; When calculating the energy surplus value, the estimated power consumption of the core secondary load that overlaps with the future planning period in time is deducted; The onboard computer uses this energy surplus value, after deducting the estimated power consumption, as the basis for dynamically adjusting the power consumption of the electric propulsion system.

10. A satellite electric propulsion autonomous mission planning system based on energy surplus prediction, applied to the satellite electric propulsion autonomous mission planning method based on energy surplus prediction as described in any one of claims 1 to 9, characterized in that, include: The orbital environment perception section is used to acquire the satellite's real-time orbital parameters and use these parameters to calculate the illumination angle information for future planning cycles. The power generation prediction section is connected to the orbital environment sensing section and is used to dynamically predict the average power generation within the future planning period based on the illumination angle information, the real-time temperature of the solar cell array, and the pre-stored photovoltaic output characteristic model. The status assessment section is used to obtain the current state of charge of the battery pack and read the priority configuration and task queue information of the on-board loads from the space service management database. The priority configuration divides the loads into primary loads that must be guaranteed, core secondary loads that are executed according to the task queue, and electric propulsion systems as flexible power consumption loads. The energy surplus calculation section connects the power generation prediction section and the state assessment section, and is used to calculate the energy surplus value in the future planning period based on the average power generation, the power consumption of the first-level load, and the priority configuration. The mission arbitration section connects the state assessment section and the energy surplus calculation section. It is used to perform mission arbitration based on the current state of charge and the energy surplus value. When the arbitration result is that the current state of charge is higher than the high charge threshold and the energy surplus value is greater than the minimum start-up power of the electric propulsion system, it generates and issues an instruction to enter the opportunity orbit maintenance mode. The execution control section, connected to the mission arbitration section, is used to respond to the command to enter the opportunity orbit maintenance mode, control the attitude control system to adjust the satellite attitude so that the thrust vector points to the orbit maintenance direction, and control the intelligent power distribution system to connect the power supply of the electric propulsion system. The power regulation section, connected to the energy surplus calculation section and the execution control section, is used to dynamically adjust the power consumption of the electric propulsion system based on the real-time changing energy surplus value through the intelligent power distribution system.

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