Satellite service dynamic replacement method and system oriented to satellite group scene

Abstract

The invention provides a satellite service dynamic replacement method and system oriented to a satellite group scene, and the method comprises the steps: building a function description model and a resource description model, carrying out the formalized description of the service function and resource load of a satellite, maintaining the task, resource and state information of the satellite through a service maintenance module, and carrying out the troubleshooting service, once a fault service is found, a single satellite service, a group of satellite services executed in parallel or a group of satellite services executed in sequence can be screened out by calling multiple replacement algorithms in the service replacement module to dynamically replace the fault service; and according to the evaluation model, each group of feasible solutions or suboptimal solutions strictly meeting function and resource demand constraints or constraint relaxation are evaluated and sorted, and a reliable basis is provided for generating a final replacement scheme.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a method and system for dynamically replacing satellite services in a star cluster scenario. Background Art

[0002] As the space industry continues to advance, private and public operators are planning or have already deployed large-scale low-Earth orbit (LEO) satellite constellations. These satellite constellations, using multiple orbits, provide extensive coverage of the Earth, marking a new era in global satellite communications.

[0003] However, once any of the satellites fails, it is difficult to inspect and repair the fault. If the mission is terminated or fails as a result, it will cause huge losses. Even if the fault can be successfully eliminated, the satellite will not be able to continue the mission during the fault time, which will seriously affect the normal implementation of the mission and reduce the overall reliability of the system. However, with the advancement of satellite manufacturing and operation technology, some satellites are able to manage tasks autonomously without relying on real-time telemetry and control from ground stations. These satellites integrate dedicated and general payloads, abstracting the underlying technical details, making it possible to perform complex space operations by calling and combining satellite services. Dynamic service replacement technology can reallocate tasks from failed satellites to other satellites in the constellation, thereby maximizing mission completion rate and system reliability in dynamic topology changes.

[0004] However, only a few studies have focused on transferring interrupted missions from faulty satellites to other satellites, which greatly limits the reliability of satellite mission execution. As service functions become increasingly rich, it is often impossible to match a single replaceable service to a crashed service. However, current research on service composition mainly focuses on finding the optimal solution, and rarely explores feasible suboptimal replacement solutions.

[0005] Therefore, the present invention abstracts the satellite mission in the space information scenario as a service, proposes a set of service maintenance and replacement methods, effectively records and maintains the available services in real time, and promptly searches for a single or a group of satellite services on the crashed satellite for replacement. A reasonable evaluation model is proposed to evaluate and rank the replacement plans to provide effective support for decision-making and ensure the reliability and success rate of space-based missions. Summary of the invention

[0006] In view of the defects in the prior art, an object of the present invention is to provide a method and system for dynamically replacing satellite services in a constellation scenario.

[0007] A satellite service dynamic replacement system for a constellation scenario provided by the present invention includes: a service maintenance module and a service replacement module;

[0008] The service maintenance module is used to register satellite services and record basic information of the satellite services, and to troubleshoot faulty services based on the basic information and trigger the service replacement module;

[0009] The service replacement module uses a variety of service replacement algorithms to select a single or a group of satellite services to replace the faulty service; the service replacement algorithms include a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution of services, and a combined replacement algorithm for sequential execution of services.

[0010] Preferably, the service maintenance module includes a service registration center and a service pool;

[0011] The service registration center is used to receive a registration request sent by an unregistered satellite to record basic information of the satellite;

[0012] The service pool is used to receive heartbeat packets regularly sent to the service pool by registered satellites, update real-time status records according to the heartbeat packets, and automatically clear overdue records when no updates are received.

[0013] Preferably, the service pool will also periodically check the overdue records, and if any satellite is found to be faulty, the service replacement module will be activated to replace the faulty satellite service;

[0014] The heartbeat packet includes the current workload, timestamp, remaining energy and energy acquisition rate.

[0015] The service registration center includes a function description model and a resource description model; the function description model is used to record the functions and corresponding parameters of the services carried by the satellite; the resource description model is used to formally describe the types of resources carried by the satellite and the corresponding attribute information.

[0016] Preferably, the functional description model uses the RDF resource description framework to describe the access URL and parameters of the service. The information contained in the access URL includes the satellite number, the service operation method and the functional type of the current service, and the parameter part describes the data type and semantics of the service input parameters and output parameters respectively.

[0017] A satellite service dynamic replacement method for a constellation scenario provided by the present invention includes:

[0018] Service maintenance steps: registering satellite services and recording basic information of the satellite services, and troubleshooting faulty services based on the basic information;

[0019] Service replacement step: using a variety of service replacement algorithms to select a single satellite service or a group of satellite services to replace the faulty service.

[0020] Preferably, the service replacement algorithm includes a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution of services, and a combined replacement algorithm for sequential execution of services;

[0021] The priorities of the service replacement algorithms are, from high to low, a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution of services, and a combined replacement algorithm for sequential execution of services.

[0022] Preferably, the service replacement step includes:

[0023] Step S2.1: calling a one-to-one service direct replacement algorithm to find a single satellite service for replacement;

[0024] Step S2.2: calling the combined replacement algorithm of the parallel execution service to process the satellites that meet the functional requirements selected in the one-to-one service direct replacement algorithm, and the same type of resources on different satellites will be superimposed to perform the task;

[0025] Step S2.3: Call the combination replacement algorithm for sequentially executing services to replace the service combination of multiple satellites.

[0026] Preferably, the step S2.1 comprises:

[0027] Step S2.1.1: Determine whether the single satellite service meets the functional requirements of the target service. If yes, execute step S2.1.2; if no, call the combined replacement algorithm for sequentially executing services;

[0028] Step S2.1.2: Determine whether the single satellite service meets the resource requirements of the target service. If not, obtain a solution set with relaxed resource constraints, call the second evaluation model to evaluate and sort the solution set, and then call the combined replacement algorithm for parallel execution of services; if so, obtain a solution set that strictly meets the demand constraints, call the first evaluation model to evaluate and sort the solution set, and then obtain the sorted replacement solutions that strictly meet the demand constraints for manual decision-making.

[0029] Preferably, the step S2.2 includes: determining whether the resources on multiple satellites that meet the functional requirements screened out in the one-to-one service direct replacement algorithm can meet the resource requirements of the target service after superposition; if so, obtaining a solution set that strictly meets the demand constraints, calling the first evaluation model to evaluate and sort the solution set, and outputting the sorted replacement solutions that strictly meet the demand constraints obtained by the first evaluation model for manual decision-making; if not, obtaining a solution set with relaxed resource constraints, calling the third evaluation model to evaluate and sort the solution set, and then executing step S2.3.

[0030] Preferably, the step S2.3 comprises:

[0031] Step S2.3.1: Determine whether the current service combination of multiple satellites can meet the functional requirements of the target service. If so, execute step S2.3.2; if not, relax the constraints of the functional requirements to obtain candidate satellites, and execute step S2.3.3;

[0032] Step S2.3.2: Determine whether the service combination of the multiple satellites can meet the resource demand of the target service. If so, obtain a solution set that strictly meets the demand constraint, and call the first evaluation model to evaluate and sort the solution set; if not, obtain a solution set with relaxed resource constraints, and call the third evaluation model to evaluate and sort the solution set;

[0033] Step S2.3.3: Determine whether the combination of resources on the candidate satellites can meet the resource requirements of the target service. If so, obtain a solution set with relaxed functional constraints, and call the fourth evaluation model to evaluate and rank the solution set; if not, obtain a solution set with relaxed functional and resource constraints, and call the fifth evaluation model to evaluate and rank the solution set;

[0034] Step S2.3.4: Output the sorted replacement plans with relaxed demand constraints obtained by the second evaluation model, the third evaluation model, the fourth evaluation model and the fifth evaluation model respectively, and the sorted replacement plans that strictly meet the demand constraints obtained by the first evaluation model for manual decision-making.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention establishes a function description model and a resource description model to formally describe the service function and resource load of the satellite, adopts a service maintenance module to maintain the satellite's tasks, resources and status information and troubleshoot faulty services, and once a faulty service is found, multiple replacement algorithms in a service replacement module are called to screen out a single satellite service, a group of satellite services executed in parallel or a group of satellite services executed sequentially to dynamically replace the faulty service, and evaluates and ranks each group of feasible solutions that strictly meet the function and resource requirement constraints or suboptimal solutions with relaxed constraints according to the evaluation model, thereby providing a reliable basis for generating a final replacement plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0038] Figure 1 It is a schematic diagram of the system architecture of the present invention;

[0039] Figure 2 This is a schematic diagram of the service replacement process in the present invention;

[0040] Figure 3 This is an example diagram of a one-to-one service direct replacement algorithm in the present invention;

[0041] Figure 4 An example diagram of a combined replacement algorithm for parallel execution services in the present invention;

[0042] Figure 5 This is an example diagram of the combined replacement algorithm for sequentially executing services in the present invention. DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0044] The present invention involves real-time task dynamic replacement, service-oriented computing and space edge computing. It proposes corresponding formal models for the satellite's service functions and resource loads, which are used to maintain the satellite's task and resource information. The service maintenance module is used to regularly update and check the satellite's status records and troubleshoot faulty services.

[0045] Embodiment 1

[0046] According to the present invention, a satellite service dynamic replacement system for a constellation scenario is provided. Figure 1 As shown, it includes: a service maintenance module and a service replacement module. The service maintenance module is used to register satellite services and record the basic information of the satellite services, and to troubleshoot faulty services based on the basic information, triggering the service replacement module. The service replacement module uses a variety of service replacement algorithms to screen out a single or a group of satellite services to replace the faulty services. The service replacement algorithms include a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution services, and a combined replacement algorithm for sequential execution services. Each algorithm will try to find a feasible solution that strictly meets the functional requirements and resource requirements constraints. If such a solution does not exist, a suboptimal solution with relaxed constraints is given, and subsequent algorithms are called to continue to find such a feasible solution. For the feasible solutions and suboptimal solutions given by each algorithm, the present invention provides a reasonable evaluation model for evaluation, thereby providing a reliable basis for the final replacement solution.

[0047] The service maintenance module includes a service registration center and a service pool. An unregistered satellite will send a registration request to the service registration center to record the basic information of the satellite. Accurate matching can be achieved by formally describing space missions and satellite services using functional description models and resource description models. The satellite will periodically send a heartbeat packet to the service pool, and the heartbeat packet includes the current workload, timestamp, remaining energy, and energy acquisition rate. After receiving each heartbeat packet, the service pool will update the real-time status record and automatically clear the overdue record when no update is received. The service pool will also check these records regularly, and if any satellite is found to be faulty, the service replacement module will be activated to replace the faulty satellite service.

[0048] The functional description model adopts the RDF resource description framework to describe the access URL and parameters of the service. The information contained in the access URL includes the satellite number, the service operation method and the function type of the current service, and the parameter part describes the data type (rule) and semantics (semantic) of the service input parameter (input) and output parameter (output), wherein the data type adopts the eight data types in Java: byte, short, int, long, double, float, boolean and String, and the semantics are described using noun phrases and verb phrases in natural language.

[0049] Considering the complexity and diversity of many resources, in order to facilitate management and planning, the present invention divides many resource loads into five different resource domains according to their functional uses: navigation, computing, communication, remote sensing and science, such as

[0050] As shown in Table 1:

[0051]

[0052] Each resource load also has one or more different attributes to describe it from various dimensions. At the same time, the present invention also defines the matching and combination methods of various satellite resources, as shown in Table 2:

[0053]

[0054] The service replacement module generates service replacement solutions by calling the one-to-one direct service replacement algorithm, the combined replacement algorithm for parallel execution of services, and the combined replacement algorithm for sequential execution of services in sequence. When any algorithm successfully finds a feasible solution set that strictly meets the requirements of the target service, the search process terminates. Otherwise, a suboptimal solution set with relaxed constraints will be provided, and subsequent algorithms will be called to continue to find feasible solutions that strictly meet the constraints. Finally, various solutions will be evaluated and ranked through appropriate evaluation models for manual decision-making.

[0055] After the service maintenance module finds out the faulty service, the service replacement module uses a variety of service replacement algorithms, including a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution services, and a combined replacement algorithm for sequential execution services, to select a single or a group of satellite services to replace the faulty service. Each algorithm will try to find a feasible solution that strictly meets the functional requirements and resource requirements. If such a solution does not exist, a suboptimal solution with relaxed constraints is given, and subsequent algorithms are called to continue to find such a feasible solution. For the feasible solutions and suboptimal solutions given by each algorithm, the present invention provides a reasonable evaluation model for evaluation, thereby providing a reliable basis for the final replacement plan.

[0056] Embodiment 2

[0057] The method for dynamically replacing satellite services in a constellation scenario provided by the present invention includes:

[0058] Service maintenance steps: register satellite services and record basic information of the satellite services, and troubleshoot faulty services based on the basic information.

[0059] Service replacement step: Use multiple service replacement algorithms to select a single or a group of satellite services to replace the faulty service. The service replacement algorithms include a one-to-one service direct replacement algorithm, a combination replacement algorithm for parallel execution services, and a combination replacement algorithm for sequential execution services. The priorities of the service replacement algorithms are, from high to low, one-to-one service direct replacement algorithm, a combination replacement algorithm for parallel execution services, and a combination replacement algorithm for sequential execution services. The service replacement process steps include:

[0060] Step S2.1: Calling a one-to-one service direct replacement algorithm to find a single satellite service for replacement. Step S2.1 includes:

[0061] Step S2.1.1: Determine whether the single satellite service meets the functional requirements of the target service. If so, execute step S2.1.2; if not, call the combined replacement algorithm for sequentially executing services.

[0062] Step S2.1.2: Determine whether the single satellite service meets the resource requirements of the target service. If not, obtain a solution set with relaxed resource constraints, call the second evaluation model to evaluate and sort the solution set, and then call the combined replacement algorithm for parallel execution of services; if so, obtain a solution set that strictly meets the demand constraints, call the first evaluation model to evaluate and sort the solution set, and then obtain the sorted replacement solutions that strictly meet the demand constraints for manual decision-making.

[0063] Step S2.2: Call the combined replacement algorithm for parallel execution of services, process the satellites that meet the functional requirements selected in the one-to-one service direct replacement algorithm, and the same type of resources on different satellites will be superimposed to perform the task. The step S2.2 includes: determining whether the resources on multiple satellites that meet the functional requirements selected in the one-to-one service direct replacement algorithm can meet the resource requirements of the target service after superposition. If so, obtain a solution set that strictly meets the demand constraints, call the first evaluation model to evaluate and sort the solution set, and output the replacement solution that strictly meets the demand constraints after sorting obtained by the first evaluation model for manual decision-making; if not, obtain a solution set with relaxed resource constraints, call the third evaluation model to evaluate and sort the solution set, and then execute step S2.3.

[0064] Step S2.3: Calling a combination replacement algorithm for sequentially executing services to replace the service combination of multiple satellites. Step S2.3 includes:

[0065] Step S2.3.1: Determine whether the current service combination of multiple satellites can meet the functional requirements of the target service. If so, execute step S2.3.2; if not, relax the constraints of the functional requirements to obtain candidate satellites, and execute step S2.3.3.

[0066] Step S2.3.2: Determine whether the service combination of the multiple satellites can meet the resource requirements of the target service. If so, obtain a solution set that strictly meets the demand constraints, and call the first evaluation model to evaluate and sort the solution set; if not, obtain a solution set with relaxed resource constraints, and call the third evaluation model to evaluate and sort the solution set.

[0067] Step S2.3.3: Determine whether the combination of resources on the candidate satellites can meet the resource requirements of the target service. If so, obtain a solution set with relaxed functional constraints, and call the fourth evaluation model to evaluate and rank the solution set; if not, obtain a solution set with relaxed functional and resource constraints, and call the fifth evaluation model to evaluate and rank the solution set.

[0068] Step S2.3.4: Output the sorted replacement plans with relaxed demand constraints obtained by the second evaluation model, the third evaluation model, the fourth evaluation model and the fifth evaluation model respectively, and the sorted replacement plans that strictly meet the demand constraints obtained by the first evaluation model for manual decision-making.

[0069] Further, the satellite service dynamic replacement method for the constellation scenario of the present invention is specifically described as follows in conjunction with the accompanying drawings:

[0070] like Figure 1As shown in the figure, the newly registered satellite will send a registration request to the service registration center to record the basic information of the satellite. In the space information scenario, the space-based mission provided by the satellite can be abstracted as a service. In order to achieve accurate matching of space-based missions and satellite resources, it is necessary to formally describe the functions and resources, which are referred to as the function description model and resource description model in this article. The former can record the functions and corresponding parameters of the services carried by the satellite, and the latter is used to formally describe the types of resources carried by the satellite and their attribute information.

[0071] The service pool mainly maintains the real-time changes of the mission load information on the satellite, which can be used to find available services and crashed services. Newly registered satellites will record their real-time status at the time of registration in the service pool; registered satellites will continuously update their real-time status records in the service pool through heartbeat packets sent at regular intervals. After receiving each heartbeat packet, the service pool will update the real-time status record and automatically clear expired records when no updates are received. The service pool will also check these records regularly. If any satellite is found to be faulty, the service replacement module will be activated to find candidate services for replacement.

[0072] When the service availability pool detects that a satellite has failed or crashed, the system will Figure 2 The process shown calls the one-to-one service direct replacement algorithm, the parallel execution service combination replacement algorithm, and the sequential execution service combination replacement algorithm for each service on it, trying to find one or more services provided by satellites to replace the service. If any algorithm successfully finds a feasible solution set that can strictly meet the target service demand constraints, the result is directly returned after evaluation and sorting; otherwise, a suboptimal solution set with relaxed constraints after evaluation and sorting is given, and then the subsequent algorithm is called to continue trying to find a feasible solution that strictly meets the constraints.

[0073] Since the computational overhead of finding a single satellite service for replacement is minimal and no communication overhead will be generated between multiple replacement satellites, it is preferred to try to use a one-to-one service direct replacement algorithm to find a single satellite service for replacement, which involves two parts: function and resource matching. In function matching, the present invention transforms the matching problem between two sets of parameters into a maximum matching problem in a bipartite graph, and each set of parameters constitutes a non-intersecting vertex set. In order to solve this maximum matching problem, a service parameter matching algorithm based on the Hopcroft-Karp algorithm (Hopcroft-Karp-BasedService Args Match, hereinafter referred to as HK-SAM) is proposed: if two parameters belonging to different sets match in data type and semantics, the two parameters are said to match, and the two vertices representing them can be connected. In data type matching, the present invention adopts a backward compatible method, that is, a parameter with a smaller data type value range can be matched by a parameter with a data type whose value range is not less than it. In particular, any parameter of a data type can be matched by a parameter of the String type. In semantic matching, the semantic description phrase is represented in the form of a word vector and compared using the cosine similarity method.

[0074] like Figure 3 As shown, the HK-SAM parameter matching algorithm is called to convert the input and output parameters of the target service on the faulty satellite C into C and Out C The input and output parameters In of the service S available on the candidate satellite S and Out S Match. If and Then service S can receive the same input parameters as the target service and provide the required output, thus satisfying the functional constraints. Figure 3 After performing resource matching according to the general matching criteria in , the satellite service that can meet the resource demand of the faulty satellite service is identified to ensure that it meets the requirements in terms of both functions and resources.

[0075] Next, considering the workload rate W and the resource attribute redundancy rate R, the first evaluation model is used to evaluate and rank the candidate satellites for manual decision-making. The solution with a higher score is better. W and C R are workload penalty constant and resource redundancy penalty constant. Their initial default values ​​are both 0.5 and satisfy C W +C R =1. If C W Larger, users are more concerned about load balancing; if C R Larger, users are more concerned about resource utilization. The first evaluation model is as follows:

[0076]

[0077] If a candidate satellite meets the functional requirements but fails to meet the resource requirements, it is considered a suboptimal solution with relaxed resource requirements. For such a solution, considering that the number of resource attributes is n, the satisfaction rate of each resource attribute to the resource requirements is S j , use the second evaluation model to evaluate, and then call the combined replacement algorithm of the parallel execution service to find a solution that strictly meets the required constraints. The second evaluation model is as follows:

[0078]

[0079] In the combined replacement algorithm for parallel execution of services, the satellites that meet the functional requirements selected in the one-to-one service direct replacement algorithm are processed, and the same type of resources on different satellites will be superimposed to perform the task. Set the superposition effective constant C A , used to evaluate the overlay cost. C A Affected by factors such as resource type and environmental conditions. When n resources of the same type are superimposed, the attribute value of the jth resource is p j , the accumulated attribute value is p a , use the following formula to simulate this process:

[0080]

[0081] To find a set of candidate services that can execute in parallel and replace the failed satellite service, it is necessary to ensure that the functional and resource requirements of the services are covered. Figure 4 In the example, the target service C includes navigation, science, and computing functions. Candidate satellite X meets the navigation requirement, Y meets the science requirement, and both meet the computing requirement. X handles navigation, Y handles science, and X and Y jointly handle computing tasks.

[0082] When selecting satellite combinations to meet resource requirements, it is necessary to minimize resource waste. A greedy algorithm is used to select the local optimal result at each step to maximize the resource satisfaction rate until the optimal result is reached according to the Figure 3 After performing resource matching and finding that all resource requirements are met according to the parallel matching criteria in the paper, the first evaluation model mentioned earlier is used to rank the solution evaluations for manual decision making.

[0083] If a combination that strictly meets the resource requirements cannot be found, an attempt will be made to relax the constraints. For multiple satellites, a penalty value is introduced. Where num is the number of satellites. The satisfaction rates of all resource attributes are added up and averaged, and then multiplied by the penalty value P to obtain the evaluation score. This is the third evaluation model below. Then the sequentially executed combination replacement algorithm is called to find a solution that strictly meets the requirements. The third evaluation model is as follows:

[0084]

[0085] When using the combined replacement algorithm of sequentially executed services to find a set of sequentially executed candidate services to replace the target service, the key is to determine whether the input and output of these services can cover the input and output of the target service to ensure functional replacement. In addition, the satellite with the worst resource attributes in the candidate service combination must also meet the resource requirements of the faulty satellite service to ensure that when the part of the faulty service that uses this resource is scheduled to this satellite, it can complete the task.

[0086] like Figure 5 , the services of the candidate satellites constitute the nodes of the graph, and the input and output parameters of the services constitute the edges. The combined path is every path starting from the starting node S (excluding nodes S and T). The starting node S and the target node T are virtual nodes. S only has the service input parameters In on the faulty satellite C. C Equivalent output parameter Out S , and T only has the output parameter Out of the service on the faulty satellite C C Equivalent input parameters In T If a path eventually reaches the target node T, the set of service nodes on it represents the candidate satellite combination that can meet the target service function constraints.

[0087] When constructing the composite service graph starting from the initial node S, the HK-SAM parameter matching algorithm is first used to match the input parameters of each candidate satellite service with the output parameters Out S If the match is successful, the candidate node is set as the successor node of S. Subsequently, in each round, the service node added in the previous round is used as the predecessor node, and its output parameters are evaluated with the input parameters In of the target node T. T If the match is successful, the combined path reaches the end point; otherwise, it will continue to explore by trying to match other candidate services to identify new successor nodes and advance the construction of the combined service graph.

[0088] After constructing the combined service graph, a depth-first search is used to filter paths starting from node S. Paths that cannot reach the target node T are initially eliminated, and the remaining paths represent candidate satellite combinations that are functionally equivalent to the target service. Next, these paths are evaluated according to the resource requirements of the target service, resource matching is performed according to the sequential matching criteria, combinations that do not meet the resource requirements are filtered out, and they are sorted according to the first evaluation model to obtain a set of candidate combinations that strictly meet the functional and resource constraints. If no feasible solution is found, the focus is on screening suboptimal solutions with relaxed resource constraints and sorting them according to the third evaluation model. The sequential matching criteria are shown in Table 2.

[0089] The path length has an upper limit, exceeding which means that no sequentially executed service composition can strictly satisfy the functional constraints. In this case, try to find a feasible suboptimal solution by relaxing the functional requirement constraints, that is, when reconstructing the composite service graph, replace the output parameter of the last node in the composite path with the input parameter of node T. T When matching, allow In T Arg R Arg may not be matched. R Initially 0, each time the composite service graph is rebuilt, Arg R Add one until In T All parameters in can be mismatched. For suboptimal solutions with relaxed functional requirements, a penalty value is introduced If the candidate service combination set meets the resource requirements, the fourth evaluation model is used to evaluate the solution set with the relaxed functional requirement constraints. The fourth evaluation model is as follows:

[0090]

[0091] If the candidate satellite combination set still cannot strictly meet the resource requirements of the service on the faulty satellite after the functional requirement constraints are relaxed, then it is regarded as a suboptimal solution set with both functional and resource requirement constraints relaxed, and is evaluated and ranked using the fifth evaluation model below. The formula is as follows:

[0092]

[0093] If after executing these three algorithms, only a suboptimal solution set with constraint relaxation can be obtained, the constraint relaxation scheme of each algorithm and its score will be given for manual decision-making.

[0094] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0095] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A satellite service dynamic replacement system for a constellation scenario, characterized in that: include: Service maintenance module and service replacement module; The service maintenance module is used to register satellite services and record basic information of the satellite services, and to troubleshoot faulty services based on the basic information and trigger the service replacement module; The service replacement module uses a variety of service replacement algorithms to select a single or a group of satellite services to replace the faulty service; the service replacement algorithms include a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution of services, and a combined replacement algorithm for sequential execution of services.

2. The satellite service dynamic replacement system for a constellation scenario according to claim 1, characterized in that: The service maintenance module includes a service registration center and a service pool; The service registration center is used to receive a registration request sent by an unregistered satellite to record basic information of the satellite; The service pool is used to receive heartbeat packets regularly sent to the service pool by registered satellites, update real-time status records according to the heartbeat packets, and automatically clear overdue records when no updates are received.

3. The satellite service dynamic replacement system for the constellation scenario according to claim 2, characterized in that: The service pool will also periodically check the overdue records, and if any satellite is found to be faulty, the service replacement module will be activated to replace the faulty satellite service; The heartbeat packet includes the current workload, timestamp, remaining energy and energy acquisition rate. The service registration center includes a function description model and a resource description model; the function description model is used to record the functions and corresponding parameters of the services carried by the satellite; the resource description model is used to formally describe the types of resources carried by the satellite and the corresponding attribute information.

4. The satellite service dynamic replacement system for the constellation scenario according to claim 3, characterized in that: The functional description model uses the RDF resource description framework to describe the access URL and parameters of the service. The access URL contains information such as the satellite number, the service operation method and the functional type of the current service, while the parameter part describes the data type and semantics of the service input parameters and output parameters respectively.

5. A method for dynamically replacing satellite services in a constellation scenario, characterized in that: include: Service maintenance steps: registering satellite services and recording basic information of the satellite services, and troubleshooting faulty services based on the basic information; Service replacement step: using multiple service replacement algorithms to select a single satellite service or a group of satellite services to replace the faulty service.

6. The method for dynamic satellite service replacement in a constellation scenario according to claim 5, characterized in that: The service replacement algorithm includes a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution of services, and a combined replacement algorithm for sequential execution of services; The priorities of the service replacement algorithms are, from high to low, a one-to-one service direct replacement algorithm, a combined replacement algorithm for parallel execution of services, and a combined replacement algorithm for sequential execution of services.

7. The method for dynamic satellite service replacement in a constellation scenario according to claim 5, characterized in that: The service replacement steps include: Step S2.1: calling a one-to-one service direct replacement algorithm to find a single satellite service for replacement; Step S2.2: calling the combined replacement algorithm of the parallel execution service to process the satellites that meet the functional requirements selected in the one-to-one service direct replacement algorithm, and the same type of resources on different satellites will be superimposed to perform the task; Step S2.3: Call the combination replacement algorithm for sequentially executing services to replace the service combination of multiple satellites.

8. The method for dynamic satellite service replacement in a constellation scenario according to claim 5, characterized in that: The step S2.1 comprises: Step S2.1.1: Determine whether the single satellite service meets the functional requirements of the target service. If yes, execute step S2.1.2; if no, call the combined replacement algorithm for sequentially executing services; Step S2.1.2: Determine whether the single satellite service meets the resource requirements of the target service. If not, obtain a solution set with relaxed resource constraints, call the second evaluation model to evaluate and sort the solution set, and then call the combined replacement algorithm for parallel execution of services; if so, obtain a solution set that strictly meets the demand constraints, call the first evaluation model to evaluate and sort the solution set, and then obtain the sorted replacement solutions that strictly meet the demand constraints for manual decision-making.

9. The method for dynamic satellite service replacement in a constellation scenario according to claim 5, characterized in that: The step S2.2 includes: determining whether the resources on multiple satellites that meet the functional requirements screened out in the one-to-one service direct replacement algorithm can meet the resource requirements of the target service after superposition; if so, obtaining a solution set that strictly meets the demand constraints, calling the first evaluation model to evaluate and sort the solution set, and outputting the sorted replacement plan that strictly meets the demand constraints obtained by the first evaluation model for manual decision-making; if not, obtaining a solution set with relaxed resource constraints, calling the third evaluation model to evaluate and sort the solution set, and then executing step S2.

3.

10. The satellite service dynamic replacement method in a constellation scenario according to claim 5, characterized in that: The step S2.3 comprises: Step S2.3.1: Determine whether the current service combination of multiple satellites can meet the functional requirements of the target service. If so, execute step S2.3.2; if not, relax the constraints of the functional requirements to obtain candidate satellites, and execute step S2.3.3; Step S2.3.2: Determine whether the service combination of the multiple satellites can meet the resource demand of the target service. If so, obtain a solution set that strictly meets the demand constraint, and call the first evaluation model to evaluate and sort the solution set; if not, obtain a solution set with relaxed resource constraints, and call the third evaluation model to evaluate and sort the solution set; Step S2.3.3: Determine whether the combination of resources on the candidate satellites can meet the resource requirements of the target service. If so, obtain a solution set with relaxed functional constraints, and call the fourth evaluation model to evaluate and rank the solution set; if not, obtain a solution set with relaxed functional and resource constraints, and call the fifth evaluation model to evaluate and rank the solution set; Step S2.3.4: Output the sorted replacement plans with relaxed demand constraints obtained by the second evaluation model, the third evaluation model, the fourth evaluation model and the fifth evaluation model respectively, and the sorted replacement plans that strictly meet the demand constraints obtained by the first evaluation model for manual decision-making.

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