Strong-robustness layered and distributed fusion method for remote sensing satellites

Abstract

The invention discloses a strong-robustness layered and distributed fusion method for remote sensing satellites, and the method comprises the steps: determining a satellite cluster layered management organization structure, and carrying out the role division of satellites; the responsibility of the platform is determined based on role configuration, and the task execution node, the local fusion center node and the system fusion center node process data step by step and synchronize the data to the backup node. Through multi-satellite data backup, role automatic switching and task autonomous migration, tasks of failure nodes can be automatically migrated to backup nodes, and the purpose that failure of partial nodes of a fusion system does not affect the overall function of the system is achieved.

Description

Technical Field

[0001] This invention belongs to the field of remote sensing satellite data processing technology, and in particular relates to a robust hierarchical distributed fusion method for multi-source information from remote sensing satellites. Background Technology

[0002] With the development of science and technology and the increasing application demands in fields such as military, industry, environmental protection, and disaster reduction, the field of remote sensing satellites has developed rapidly. The number of remote sensing satellites launched is increasing, their orbital altitudes are getting higher, and their swath width, resolution, and other indicators are getting stronger. The payloads they carry cover visible light, infrared, and microwave, and the types of payloads include photoelectric, radar, SAR, and laser spectral ranges. The number of spectral bands ranges from a few to thousands. They face serious problems of large data volume and information overload. How to effectively utilize the massive amount of remote sensing data from multiple sources has become a hot issue.

[0003] Data fusion systems can fuse remote sensing data from different sensors to achieve complementary integration of multi-sensor information. By reducing redundancy among measurements from multi-source remote sensing data, the system's generation capabilities are enhanced; by utilizing overlapping coverage areas, spatial and temporal coverage is expanded; and by employing collaborative observation, the reliability of the results is improved.

[0004] Common fusion system architectures include centralized and distributed types. Centralized fusion architectures transmit raw remote sensing data from all satellites to a central fusion center for processing and fusion. While this results in optimal fusion because the fusion center utilizes raw measurement data from all satellite platforms without information loss, the large volume of raw measurement data, limited onboard bandwidth, and long data transmission time lead to poor timeliness. Distributed fusion architectures, on the other hand, have each satellite platform with its own processor to preprocess the raw data before transmitting the intermediate results to the central node for fusion. This method has low channel capacity requirements, strong system vitality, and is widely used in engineering. However, if the central node is damaged, the fusion system faces the risk of reduced performance or even failure. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned shortcomings and provide a robust hierarchical distributed fusion method for remote sensing satellites. This solves the technical problem that traditional distributed fusion systems face performance degradation or even failure once the fusion center is damaged. This invention proposes a highly robust hierarchical distributed fusion method for remote sensing satellites. Through multi-satellite data backup, automatic role switching, and autonomous task migration, the tasks of failed nodes are automatically migrated to backup nodes, achieving the goal that the failure of some nodes in the fusion system does not affect the overall system function.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A robust hierarchical distributed fusion method for remote sensing satellites includes: S1 defines the hierarchical management structure of the satellite constellation and assigns roles to the satellites. This hierarchical structure includes a system fusion center layer, a local fusion center layer, and a sensor layer. Roles are categorized into system fusion center layer roles, local fusion center layer roles, and sensor layer roles. System fusion center layer roles include system fusion center nodes and system fusion center backup nodes; local fusion center layer roles include local fusion center nodes and local fusion center backup nodes; and sensor layer roles include task execution nodes. The S2 task execution node processes the sensor-acquired data and transmits the processing results to the local fusion center node. The local fusion center node receives the processing results from multiple task execution nodes and synchronizes them to the local fusion center backup node; The local fusion center node merges the processing results of multiple task execution nodes and transmits the processing results to the system fusion center node; The system fusion center node receives the processing results from the local fusion center node and synchronizes them to the system fusion center backup node; The system fusion center node fuses the processing results of the local fusion center nodes to obtain the target information; When a local fusion center node or a system fusion center node fails, the local fusion center node or the system fusion center node will be switched to a local fusion center backup node or a system fusion center backup node, respectively.

[0007] Furthermore, after the satellites are assigned roles, the role configuration list is managed uniformly by the system fusion center node and distributed to lower-level nodes in the form of event triggering. When the role configuration list changes, the system fusion center node distributes the changed role information to the subordinate local fusion center nodes, local fusion center backup nodes, and task execution nodes. The role configuration list also includes the affiliation relationships of roles at different levels. The task execution node transmits data to the local fusion center node specified by the affiliation relationship in the role configuration list, and the local fusion center node transmits data to the system fusion center node specified by the affiliation relationship in the role configuration list.

[0008] Furthermore, the task execution node processes the sensor-acquired data, including: The task execution node preprocesses the sensor-acquired data to obtain standard remote sensing images; then it extracts target information from the standard remote sensing images; the target information includes imaging time, target location, target category or motion state information; The task execution node transmits data to the local fusion center node according to time-triggered rules.

[0009] Furthermore, the local fusion center node performs fusion processing on the processing results of multiple task execution nodes, including: the local fusion center node receives target information from multiple affiliated task execution nodes, performs spatial and temporal registration on the target information, associates the same target acquired by different satellites at different times, and obtains the locally optimal target identity and status information through the optimal estimation algorithm.

[0010] Furthermore, the system fusion center node performs fusion processing on the processing results of the local fusion center nodes, including: the system fusion center node receives the processing results transmitted by its local fusion center nodes, the processing results including locally optimal target identity and status information; based on the locally optimal target identity and status information, track association matching is performed, the locally estimated identical target information is associated together, and then estimation fusion is performed to obtain globally optimal target identity and status information.

[0011] Furthermore, when the local fusion center node synchronizes the processing results to the local fusion center backup node, or when the system fusion center node synchronizes the processing results of the local fusion center node to the system fusion center backup node, the data synchronization adopts a time-triggered strategy and uses a unique identifier, timestamp, and version number to track the evolution history of the data.

[0012] Furthermore, the health status of nodes is monitored using the following methods: The task execution node, the local fusion center node, the local fusion center backup node, and the system fusion center backup node send heartbeat information containing health status to the corresponding system fusion center node; the system fusion center node monitors the health status of all its subordinate nodes, while the system fusion center backup node receives the heartbeat information of the system fusion center node and monitors the health status of the system fusion center node. When a task execution node fails, the task is executed by a new task execution node. When a local fusion center node fails, it will automatically switch to the local fusion center backup node as the local fusion center node. When the system fusion center node fails, it will automatically switch over to the system fusion center backup node as the system fusion center node; If the backup node of the system fusion center or the local fusion center fails, select a new backup node.

[0013] Furthermore, if the health status of the task execution node received by the system fusion center node is abnormal, or if no task execution node heartbeat information is received within a timeout, the task execution node is considered to have failed. When a new task execution node executes a task, it updates the global role configuration list and sends it to all nodes. After receiving the global role configuration list, the new task execution node executes the task according to the role rules and sends the target information to the superior local fusion center node.

[0014] Furthermore, if the health status of the system fusion center node is abnormal when it receives the heartbeat information from the local fusion center node, or if it does not receive the heartbeat information from the local fusion center node within a timeout period, the local fusion center node is considered to have failed. When the system fusion center node autonomously switches from a local fusion center backup node to a local fusion center node, the system fusion center node modifies the global role configuration list maintained by this node, changes the original local fusion center node's role to offline and abnormal, changes the original local fusion center backup node's role to local fusion center node, selects a new local fusion center backup node, and distributes the global role configuration list to all nodes. After receiving the new role configuration list, the original local fusion center backup node modifies the role information in its role configuration file to local fusion center node and performs operations according to the local fusion center node rules. After receiving the global role configuration list, the task execution node sends the processing results to the new local fusion center node. The new local fusion center node receives the target information from the task execution node, performs fusion processing, and sends the processing results to the system fusion center node.

[0015] Furthermore, if the system fusion backup center node detects an abnormal health status of the system fusion center node, it is considered that the system fusion center node has failed. When switching from a system fusion center backup node to a system fusion center node, the role configuration list managed by this node is modified. The original system fusion center node role is changed to offline, and the original system fusion center backup node role is changed to system fusion center node. A new system fusion center backup node is selected, and the global role configuration list is distributed to all nodes. The local fusion center node, local fusion center backup node, and task execution node receive the distributed global role configuration list and send heartbeat information to the new system fusion center node. The new system fusion center backup node receives the global role configuration list and performs operations according to the role rules.

[0016] Compared with the prior art, the present invention has at least one of the following advantages: (1) This invention creatively proposes a robust hierarchical distributed fusion method for remote sensing satellites. Through multi-satellite data backup, automatic role switching and autonomous task migration, the tasks of the failed nodes will be automatically migrated to the backup nodes, so as to achieve the goal of not affecting the overall function of the system if some nodes of the fusion system fail. (2) This invention provides a method for hierarchical management organization structure and role division of clusters, with clear tasks for each node, which can effectively improve efficiency and reliability; (3) This invention can further improve the accuracy of target status and identity estimation by associating and fusing local tracks of different targets through the system fusion center node; (4) This invention enables autonomous business migration and improves system robustness by autonomously detecting the health status and switching the backup node to the primary node. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the overall implementation steps of the highly robust hierarchical distributed fusion method for remote sensing satellites according to the present invention. Figure 2 This is a schematic diagram of the robust layered distributed fusion system (example) architecture involved in the implementation example scheme of the present invention; Figure 3 This is a schematic diagram illustrating data processing at a task execution node, as executor of this invention. Figure 4 This is a schematic diagram illustrating the local fusion center node data processing in an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the data processing of the fusion center node in an example system of this invention. Figure 6 This is a schematic diagram illustrating the health status of all nodes within the integrated central node monitoring system used in the implementation example system. Figure 7 A diagram illustrating the reallocation of a new task execution node after the previous task execution node fails. Figure 8 A schematic diagram illustrating the autonomous switching of the local fusion center backup node to the local fusion center node after the failure of the local fusion center node; Figure 9 A schematic diagram illustrating the autonomous selection of new backup nodes after the failure of backup nodes in the system fusion center and local fusion center; Figure 10 This diagram illustrates how the system can automatically switch from a backup node to the original system fusion center node after the original node fails. Detailed Implementation

[0018] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0019] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0020] This invention discloses a robust hierarchical distributed fusion method for remote sensing satellites, the specific steps of which are as follows: Step 1: Confirm the hierarchical management structure of the cluster and complete the role assignment; 1) Determine the hierarchical management organizational structure of the cluster: The cluster organization adopts a layered architecture with three layers: the system fusion center layer, the local fusion center layer, and the sensor layer. The sensor layer nodes are responsible for processing data from individual nodes and sensors. Through preprocessing such as radiometric correction and geometric positioning, they generate standard remote sensing image products, and then extract target information of interest through target detection and recognition. The local fusion center layer receives the processing results from the sensor layer, performs spatiotemporal registration and correlation matching on the processing results from different sensors, and fuses data for the same target to improve the accuracy of target state and identity estimation. The system fusion center layer receives the processing results from the local fusion center layer and obtains globally optimal target state and identity information through filtering, correlation, and ensemble processing.

[0021] 2) Complete the role assignment: Based on the network status, storage, and processing capabilities of the remote sensing satellite platform, all satellites within the fusion system are assigned roles through parameter configuration. The role configuration list is centrally managed by the system fusion center node and distributed to lower-level nodes via event triggering. That is, when the role configuration list changes, the system fusion center node distributes the changed role information to its subordinate local fusion center nodes, local fusion center backup nodes, and task execution nodes. The fusion system of this invention has five roles: system fusion center layer roles include system fusion center nodes and system fusion center backup nodes; local fusion center layer roles include local fusion center nodes and local fusion center backup nodes; and sensor layer roles include task execution nodes. The role configuration list also includes the affiliation relationships between different levels of roles; that is, task execution nodes transmit data to the local fusion center nodes specified in the role configuration list, and local fusion center nodes transmit data to the system fusion center nodes specified in the role configuration list.

[0022] Step 2: Based on role configuration, determine the platform's responsibilities. The task execution node, local fusion center node, and system fusion center node process the data step by step and synchronize it to the backup node.

[0023] 1) The task execution node processes the sensor-acquired data: Based on the sensor type of the task execution node, the sensor-collected data is preprocessed to generate a standard product. Using a target detection and recognition algorithm, information about the target of interest is extracted, including imaging time, target location, target category, and motion state information. This target information is then sent to the local fusion center node. The task execution node transmits data to the local fusion center node according to a time-triggered rule; that is, each time the task execution node generates new target information, it sends the data to the local fusion center node. 2) The local fusion central node receives the processing results from multiple task execution nodes and synchronizes the data to the local fusion backup node: The local fusion center node receives target information from multiple task execution nodes. Based on the current node role configuration, it synchronizes the processing results of the task execution nodes to the local fusion center backup node for backup. Data synchronization adopts a time-triggered strategy and uses unique identifiers, timestamps, and version numbers to track the evolution history of data, reducing the risk of conflicts caused by data modifications.

[0024] 3) The local fusion center node performs fusion processing on the processing results of the task execution nodes: The local fusion center node receives target information from multiple task execution nodes, performs spatial and temporal registration of the targets, associates the same targets acquired by different satellites at different times, and obtains the locally optimal target identity and status information through the optimal estimation algorithm.

[0025] 4) The system fusion center node receives the processing results from the local fusion nodes and synchronizes them to the system fusion backup nodes: The system fusion center node receives intermediate processing results from multiple affiliated local fusion center nodes. Based on the current node role configuration, it synchronizes the processing results of the local fusion center nodes to the system fusion center backup node for backup. Data synchronization adopts a time-triggered strategy and uses unique identifiers, timestamps, and version numbers to track the evolution history of data, reducing the risk of conflicts caused by data modifications.

[0026] 5) The system fusion center node performs fusion processing on the received local fusion node processing results: The system fusion center node receives the processing results transmitted by its local fusion center nodes. Based on the received local optimal target identity and status information, it achieves track association matching through steps such as spatiotemporal alignment and correlation calculation, and associates the locally estimated same target information together. Since the system fusion center obtains richer data information, it can further improve the accuracy of target status and identity estimation.

[0027] Step 3: The platform autonomously detects its health status, quickly identifies faulty satellite platforms, and enables autonomous business migration by switching backup nodes to primary nodes, thereby improving system robustness. 1) The system's central node receives heartbeat information from all its affiliated nodes and monitors the health status of the nodes: The task execution node, local fusion center node, local fusion center backup node, and system fusion center backup node send heartbeat information containing health status to the corresponding system fusion center node at a certain frequency. The system fusion center node monitors the health status of all its subordinate nodes. At the same time, the system fusion center backup node receives the heartbeat information from the system fusion center node and monitors the health status of the system fusion center node.

[0028] 2) If a task execution node fails, the task will be reassigned and executed by a new task execution node; If the system fusion center node receives a heartbeat message from a task execution node indicating an abnormal health status, or fails to receive a heartbeat message from a task execution node within a timeout period, it considers the task execution node abnormal. The task is then reassigned to a new task execution node, the global role configuration list is updated, and this information is sent to all nodes within the system. The new task execution node receives the global role configuration list, executes the task according to the role rules, and sends the target information to the superior local fusion center node.

[0029] 3) If a local fusion center node fails, the system will automatically switch over to the backup local fusion center node: If the system fusion center node receives a heartbeat message from a local fusion center node indicating an abnormal health status, or fails to receive a heartbeat message from a local fusion center node within a timeout period, it triggers the primary / backup switchover process. The system fusion center node modifies its global role configuration list, changing the original local fusion center node's role to offline / abnormal, and the original local fusion center backup node's role to local fusion center node. It then selects a new local fusion center backup node and distributes the global role configuration list to all its affiliated satellite platforms. Upon receiving the new role configuration list, the original local fusion center backup node modifies its role configuration file to local fusion center node and executes operations according to the local fusion center node rules. The task execution node, upon receiving the global role configuration list, sends the processing results to the new local fusion center node. The new local fusion center node receives the task execution node's target information, performs fusion processing, and sends the processing results to the system fusion center node.

[0030] 4) If the system fusion center backup node or a local fusion center backup node fails, select a new backup node: If the system fusion center node receives heartbeat information from both the local fusion center backup node and the system fusion center backup node and finds their health status abnormal, or fails to receive heartbeat information within a timeout period, it determines that either the local fusion center backup node or the system fusion center backup node is offline and abnormal. The system fusion center node modifies the global role configuration list maintained by this node, changing the roles of the original local fusion center backup node and the system fusion center backup node to offline and abnormal. It then selects a new local fusion center backup node or the system fusion center backup node and distributes the global role configuration list to all its associated satellite platforms. The new local fusion center backup node or the system fusion center backup node receives the global role configuration list distributed by the system fusion center and performs operations according to the backup node rules. After receiving the new role configuration list, the local fusion center node backs up its data to the new local fusion center backup node. The system fusion center node then backs up its data to the new system fusion center backup node.

[0031] 5) If the system fusion center node fails, the system will automatically switch over to the backup system fusion center node as the new system fusion center node: The system fusion center node continuously sends its health status to the system fusion center backup node via heartbeats. Once the system fusion backup center node detects an abnormal health status in a system fusion center node, it modifies the role configuration list managed by this node, changing the original system fusion center node's role to offline and the original system fusion center backup node's role to system fusion center node. It then selects a new system fusion center backup node and distributes the global role configuration list to all its affiliated satellite platforms. The local fusion center node, local fusion center backup node, and task execution node receive the distributed global role configuration list and send heartbeat information to the new system fusion center node. The new system fusion center backup node receives the global role configuration list and executes operations according to the role rules.

[0032] (3) The advantages of this invention compared with the prior art are: This invention addresses the problem of the failure of the fusion center of the remote sensing satellite on-orbit fusion system leading to a decrease in the efficiency of the entire fusion system. It proposes a strategy for the backup node of the fusion center. Through role configuration, data backup, health monitoring, and role switching, the task can be autonomously migrated to the backup node after the failure of the main node of the fusion center, thereby improving the robustness of the fusion system and having high practical application value.

[0033] Example: This invention proposes a robust hierarchical distributed fusion method for multi-source information from remote sensing satellites. Through strategies such as data backup, health monitoring, and autonomous role switching, it enables the system to autonomously switch backup nodes to become the fusion center after the failure of the system's fusion center or a local fusion center, thus avoiding performance degradation or failure of the fusion system. A satellite platform example of a hierarchical distributed fusion system deployment is provided to illustrate the specific implementation.

[0034] Reference Figure 1 , Figure 1 This is a flowchart illustrating the overall implementation steps of the highly robust hierarchical distributed fusion method for remote sensing satellites according to the present invention. Reference Figure 2 , Figure 2 This is a schematic diagram of the robust hierarchical distributed fusion system (example) architecture involved in the implementation example scheme of the present invention. The satellite platform deployed in this hierarchical distributed fusion system includes: high-orbit satellite 001, high-orbit satellite 002, high-orbit satellite 003, medium-orbit satellite 001, medium-orbit satellite 002, medium-orbit satellite 003, low-orbit satellite 001, low-orbit satellite 002, low-orbit satellite 003, low-orbit satellite 004, and low-orbit satellite 005.

[0035] The robust hierarchical distributed fusion method for remote sensing satellites proposed in this invention includes: Step 1: Confirm the hierarchical management structure of the cluster and complete the role assignment; 1) Determine the hierarchical management organizational structure of the cluster: Reference Figure 2 In the embodiments of the present invention, high-orbit satellites are the system fusion center layer, medium-orbit satellites are the local fusion center layer, and low-orbit satellites are the sensor layer.

[0036] 2) Complete the role assignment: Reference Figure 2 In this embodiment of the invention, high-orbit satellite 001 is the system fusion center node, and high-orbit satellite 002 is the system fusion center backup node; medium-orbit satellite 001 is the local fusion center node for low-orbit satellites 001 and 002, and also a backup node for medium-orbit satellite 002; medium-orbit satellite 002 is the local fusion center node for low-orbit satellites 003 and 004, and also a backup node for medium-orbit satellite 001; low-orbit satellites 001, 002, 003, and 004 are task execution nodes. High-orbit satellite 001 manages the global role configuration list and distributes the global role configuration list to all its affiliated nodes according to event-triggered rules. Low-orbit satellite 005, medium-orbit satellite 003, and high-orbit satellite 003 have no roles at this time.

[0037] Step 2: Based on role configuration, determine the platform's responsibilities. The task execution node, local fusion center node, and system fusion center node process the data step by step and synchronize it to the backup node.

[0038] 1) The task execution node processes the sensor-acquired data: Reference Figure 3 , Figure 3This is a schematic diagram illustrating data processing at the task execution node in an embodiment of the present invention. For the low-Earth orbit (LEO) satellites 001 and 002 at the task execution node, the acquired raw data is first processed to generate a standard product. Then, target detection and identification are performed on the standard product to extract information about targets of interest. Next, temporal correlation matching is performed on the extracted targets, associating identical targets acquired at different times together to generate target tracks and estimate target motion states. Finally, target information, including imaging time, satellite platform number and payload type, target number, target category, target location, and target motion state, is transmitted to the local fusion center node.

[0039] 2) The local fusion central node receives the processing results from multiple task execution nodes and synchronizes the data to the local fusion backup node: Reference Figure 2 After receiving the processing results from Low Earth Orbit (LEO) satellites 001 and 002, the medium-Earth orbit (MEO) satellite 001 simultaneously backs up the data to MEO satellite 002. Similarly, after receiving the processing results from LEO satellites 003 and 004, MEO satellite 002 simultaneously backs up the data to MEO satellite 001.

[0040] 3) The local fusion center node performs fusion processing on the processing results of the task execution nodes: Reference Figure 4 , Figure 4 This is a schematic diagram illustrating the data processing at the local fusion center node, as executor of this invention. The local fusion center node, medium-Earth orbit satellite 001, receives target information from two mission execution nodes, low-Earth orbit satellite 001 and low-Earth orbit satellite 002. First, it performs target association matching, associating identical target information acquired by different platforms based on information such as target imaging time, target category, location, and motion state. Next, it performs fusion processing on the identical target information acquired by different platforms, including track synthesis and estimation fusion, to obtain locally optimal target identity and state information, which is then sent to the system fusion center node.

[0041] 4) The system fusion center node receives the processing results from the local fusion nodes and synchronizes them to the system fusion backup nodes: Reference Figure 2 After receiving the processing results from medium-orbit satellites 001 and 002, high-orbit satellite 001 simultaneously backs up the data to high-orbit satellite 002.

[0042] 5) The system fusion center node performs fusion processing on the received local fusion node processing results: Reference Figure 5 , Figure 5This is a schematic diagram of data processing at the system fusion center node in an embodiment of the present invention. The system fusion center node, high-orbit satellite 001, receives the locally optimal target trajectories from two local fusion center nodes, medium-orbit satellites 001 and 002. It performs spatiotemporal alignment of the target trajectories of the two satellites, performs track association matching based on target position, category, and other information, associates locally estimated information of the same target together, and then estimates and fuses them to obtain the optimal result based on global data, updating the target identity and status information.

[0043] Step 3: Autonomous monitoring of platform health status, rapid identification of faulty satellite platforms, and autonomous migration of services by switching backup nodes to primary nodes, thereby improving system robustness.

[0044] 1) The system's central node receives heartbeat information from all its affiliated nodes and monitors the health status of the nodes: Reference Figure 6 , Figure 6 This diagram illustrates the health status of all nodes within the example system fusion center node monitoring system. Task execution nodes (Low-Earth Orbit satellites 001, 002, 003, and 004), local fusion center node (Medium-Earth Orbit satellite 001 and local fusion center backup node (Medium-Earth Orbit satellite 002), and system fusion center backup node (High-Earth Orbit satellite 003) send heartbeat information containing health status data to system fusion center node (High-Earth Orbit satellite 001) at a certain frequency. System fusion center node (High-Earth Orbit satellite 001) monitors the health status of all its subordinate nodes. Simultaneously, system fusion center backup node (High-Earth Orbit satellite 002) receives the heartbeat information from system fusion center node (High-Earth Orbit satellite 001) and monitors the health status of system fusion center node (High-Earth Orbit satellite 001).

[0045] 2) If a task execution node fails, the task will be reassigned and executed by a new task execution node; Reference Figure 7 , Figure 7 This diagram illustrates the reassignment of a new task execution node after a previous one fails. If the system fusion center node (high-orbit satellite 001) receives a heartbeat message from low-orbit satellite 001 indicating an abnormal health status, or if it fails to receive a heartbeat message from low-orbit satellite 001 within a timeout period, it considers low-orbit satellite 001 to be abnormal. The task is then reassigned to a new low-orbit satellite 003, the global role configuration list is updated, and this information is sent to all nodes within the system. The new low-orbit satellite 003 receives the global role configuration list, executes the task according to the role rules, and sends the target information to the higher-level local fusion center node (medium-orbit satellite 001).

[0046] 3) If a local fusion center node fails, the system will automatically switch over to the backup local fusion center node: Reference Figure 8 , Figure 8 This diagram illustrates the autonomous switching of the local fusion center backup node to the local fusion center node after the failure of the local fusion center node. If the high-orbit satellite 001, the system fusion center node, receives a heartbeat message from the medium-orbit satellite 001, indicating an abnormal health status, or if it fails to receive a heartbeat message from the medium-orbit satellite 001 within a timeout period, it triggers the primary / backup switchover process. The high-orbit satellite 001 modifies and maintains the global role configuration list, changing the role status of the original medium-orbit satellite 001 to offline and abnormal, changing the role of the original medium-orbit satellite 002, the backup node, to the local fusion center node, and selecting a new backup node, medium-orbit satellite 003. The global role configuration list is then distributed to all affiliated satellite platforms. Upon receiving the new role configuration list, medium-orbit satellite 002 modifies its role information in its role configuration file to the local fusion center node and executes operations according to the local fusion center node rules. After receiving the global role configuration list, the low-Earth orbit satellites 001 and 002, the mission execution nodes, send the processing results to the new local fusion center node, medium-Earth orbit satellite 002. The new local fusion center node, medium-Earth orbit satellite 002, receives the target information from the low-Earth orbit satellites 001 and 002, performs fusion processing, and sends the processing results to the system fusion center node, high-Earth orbit satellite 001.

[0047] 4) If the system fusion center backup node or a local fusion center backup node fails, select a new backup node: Reference Figure 9 , Figure 9This diagram illustrates the autonomous selection of new backup nodes after the failure of the system fusion center backup nodes and the local fusion center backup nodes. If the health status of the system fusion center backup node (high-orbit satellite 001) is abnormal when it receives heartbeat information from the local fusion center backup nodes (medium-orbit satellite 002 and high-orbit satellite 002), or if it fails to receive heartbeat information within a timeout period, then both local fusion center backup nodes (medium-orbit satellite 002 and high-orbit satellite 002) are determined to be offline and abnormal. The system fusion center backup node (high-orbit satellite 001) modifies the global role configuration list maintained by this node, changing the roles of medium-orbit satellite 002 and high-orbit satellite 002 to offline and abnormal. It then selects new local fusion center backup nodes (medium-orbit satellite 003 and high-orbit satellite 003) and distributes the global role configuration list to all affiliated satellite platforms. The new local fusion center backup nodes (medium-orbit satellite 003 and high-orbit satellite 003) receive the global role configuration list distributed by the system fusion center from high-orbit satellite 001 and execute operations according to the backup node rules. After receiving the new role configuration list, the local fusion center node, medium-orbit satellite 001, backs up the data to the new local fusion center backup node, medium-orbit satellite 003. The system fusion center node, high-orbit satellite 001, backs up the data to the new system fusion center backup node, high-orbit satellite 003.

[0048] 5) If the system fusion center node fails, the system will automatically switch over to the backup system fusion center node as the new system fusion center node: Reference Figure 10 , Figure 10 This diagram illustrates the autonomous switching of the system fusion center backup node to the system fusion center node after the system fusion center node fails. The system fusion center node, high-orbit satellite 001, continuously sends its health status to the system fusion center backup node, high-orbit satellite 003, via heartbeats. Once the system fusion backup node, high-orbit satellite 002, detects an abnormal health status of system fusion center node 001, it modifies the role configuration list managed by this node, changing the original role of system fusion center node 001 to offline, changing the original role of system fusion center backup node, high-orbit satellite 002, to system fusion center node, and selecting a new system fusion center backup node, high-orbit satellite 004. The global role configuration list is then distributed to all affiliated satellite platforms. The local fusion center node, medium-orbit satellites, the local fusion center backup node, and the task execution node receive the distributed global role configuration list and send heartbeat information to the new system fusion center node, high-orbit satellite 002. The new system fusion center backup node, high-orbit satellite 003, receives the global role configuration list and performs operations according to the role rules.

[0049] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0050] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A robust hierarchical distributed fusion method for remote sensing satellites, characterized in that, include: S1 defines the hierarchical management structure of the satellite constellation and assigns roles to the satellites; The satellite constellation's hierarchical management structure includes a system fusion center layer, a local fusion center layer, and a sensor layer; roles are categorized into system fusion center layer roles, local fusion center layer roles, and sensor layer roles. System fusion center layer roles include system fusion center nodes and system fusion center backup nodes; local fusion center layer roles include local fusion center nodes and local fusion center backup nodes; and sensor layer roles include task execution nodes. The S2 task execution node processes the sensor-acquired data and transmits the processing results to the local fusion center node. The local fusion center node receives the processing results from multiple task execution nodes and synchronizes them to the local fusion center backup node; The local fusion center node merges the processing results of multiple task execution nodes and transmits the processing results to the system fusion center node; The system fusion center node receives the processing results from the local fusion center node and synchronizes them to the system fusion center backup node; The system fusion center node fuses the processing results of the local fusion center nodes to obtain the target information; When a local fusion center node or a system fusion center node fails, the local fusion center node or the system fusion center node will be switched to a local fusion center backup node or a system fusion center backup node, respectively.

2. The robust hierarchical distributed fusion method for remote sensing satellites according to claim 1, characterized in that, After the satellites are assigned roles, the role configuration list is managed uniformly by the system fusion center node and distributed to lower-level nodes in the form of event triggering. When the role configuration list changes, the system fusion center node distributes the changed role information to the subordinate local fusion center nodes, local fusion center backup nodes, and task execution nodes. The role configuration list also includes the affiliation relationships of roles at different levels. The task execution node transmits data to the local fusion center node specified by the affiliation relationship in the role configuration list, and the local fusion center node transmits data to the system fusion center node specified by the affiliation relationship in the role configuration list.

3. The robust hierarchical distributed fusion method for remote sensing satellites according to claim 1, characterized in that, The task execution node processes the sensor-acquired data, including: The task execution node preprocesses the sensor-acquired data to obtain standard remote sensing images; then it extracts target information from the standard remote sensing images; the target information includes imaging time, target location, target category or motion state information; The task execution node transmits data to the local fusion center node according to time-triggered rules.

4. The robust hierarchical distributed fusion method for remote sensing satellites according to claim 1, characterized in that, The local fusion center node performs fusion processing on the processing results of multiple task execution nodes, including: receiving target information from multiple task execution nodes, performing spatial and temporal registration on the target information, associating the same target acquired by different satellites at different times, and obtaining locally optimal target identity and status information through an optimal estimation algorithm.

5. A robust hierarchical distributed fusion method for remote sensing satellites according to claim 1, characterized in that, The system fusion center node performs fusion processing on the processing results of the local fusion center nodes, including: the system fusion center node receives the processing results transmitted by its local fusion center nodes, the processing results including locally optimal target identity and status information; based on the locally optimal target identity and status information, track association matching is performed, the locally estimated identical target information is associated together, and then estimation fusion is performed to obtain globally optimal target identity and status information.

6. The robust hierarchical distributed fusion method for remote sensing satellites according to claim 1, characterized in that, When a local fusion center node synchronizes its processing results to a local fusion center backup node, or when a system fusion center node synchronizes its processing results to a system fusion center backup node, data synchronization adopts a time-triggered strategy and uses a unique identifier, timestamp, and version number to track the evolution history of the data.

7. A robust hierarchical distributed fusion method for remote sensing satellites according to claim 1, characterized in that, Monitor node health status using the following methods: The task execution node, the local fusion center node, the local fusion center backup node, and the system fusion center backup node send heartbeat information containing health status to the corresponding system fusion center node; the system fusion center node monitors the health status of all its subordinate nodes, while the system fusion center backup node receives the heartbeat information of the system fusion center node and monitors the health status of the system fusion center node. When a task execution node fails, the task is executed by a new task execution node. When a local fusion center node fails, it will automatically switch to the local fusion center backup node as the local fusion center node. When the system fusion center node fails, it will automatically switch over to the system fusion center backup node as the system fusion center node; If the backup node of the system fusion center or the local fusion center fails, select a new backup node.

8. A robust hierarchical distributed fusion method for remote sensing satellites according to claim 7, characterized in that, If the health status of the task execution node is abnormal when the system fusion center node receives the task execution node's heartbeat information, or if it does not receive the task execution node's heartbeat information within a timeout period, the task execution node is considered to have failed. When a new task execution node executes a task, it updates the global role configuration list and sends it to all nodes. After receiving the global role configuration list, the new task execution node executes the task according to the role rules and sends the target information to the superior local fusion center node.

9. A robust hierarchical distributed fusion method for remote sensing satellites according to claim 7, characterized in that, If the health status of the local fusion center node is abnormal when it receives the heartbeat information from the local fusion center node, or if it does not receive the heartbeat information from the local fusion center node within a timeout period, the local fusion center node is considered to have failed. When the system fusion center node autonomously switches from a local fusion center backup node to a local fusion center node, the system fusion center node modifies the global role configuration list maintained by this node, changes the original local fusion center node's role to offline and abnormal, changes the original local fusion center backup node's role to local fusion center node, selects a new local fusion center backup node, and distributes the global role configuration list to all nodes. After receiving the new role configuration list, the original local fusion center backup node modifies the role information in its role configuration file to local fusion center node and performs operations according to the local fusion center node rules. After receiving the global role configuration list, the task execution node sends the processing results to the new local fusion center node. The new local fusion center node receives the target information from the task execution node, performs fusion processing, and sends the processing results to the system fusion center node.

10. A robust hierarchical distributed fusion method for remote sensing satellites according to claim 7, characterized in that, If the system fusion backup center node detects an abnormal health status of the system fusion center node, it is considered that the system fusion center node has failed. When switching from a system fusion center backup node to a system fusion center node, the role configuration list managed by this node is modified. The original system fusion center node role is changed to offline, and the original system fusion center backup node role is changed to system fusion center node. A new system fusion center backup node is selected, and the global role configuration list is distributed to all nodes. The local fusion center node, local fusion center backup node, and task execution node receive the distributed global role configuration list and send heartbeat information to the new system fusion center node. The new system fusion center backup node receives the global role configuration list and performs operations according to the role rules.

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