Low earth orbit satellite integrity information resolving system and modeling method thereof

Abstract

The invention belongs to the technical field of satellite information resolving, and discloses a low-earth-orbit satellite integrity information resolving system and a modeling method thereof, and the method comprises the steps: building a low-earth-orbit satellite integrity resolving demand; the low-orbit satellite integrity resolving requirements comprise a function requirement, a performance requirement, an interface requirement and a reliability requirement; based on functional requirements, creating a use case graph of low earth orbit satellite user distance measurement precision calculation; based on the use case graph, creating an activity graph of low earth orbit satellite user distance measurement precision calculation; creating a framework design drawing according to the use case drawing; creating an internal interface graph according to interface requirements; based on the performance requirements, creating a performance analysis graph of low-earth-orbit satellite integrity resolving, and creating a block definition graph of low-earth-orbit satellite integrity resolving performance index analysis; creating a fault mode influence analysis table based on the reliability requirement; according to the method, documents are replaced by the models, the method has the advantages of simple design process, simple iteration mode, quick demand change response, high maintainability and the like, and the development cycle can be effectively shortened.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite information calculation, and in particular relates to a low-orbit satellite integrity information calculation system and a modeling method thereof. Background Art

[0002] Low Earth Orbit Satellite (LEO) refers to a satellite with an orbital altitude between 500 and 2000 kilometers from the ground. LEO satellites play a key role in many fields such as communications, earth observation, scientific research and national security. With the rapid construction of low-orbit satellite navigation constellations, they will become an important means of navigation and positioning in production and life in the future because of their integrated communication, navigation, positioning and timing service functions. The integrity monitoring of low-orbit satellites mainly monitors the reliability of observation data and navigation ephemeris broadcast by low-orbit satellites, and provides warning information to users through navigation messages in a timely manner when service is unavailable. In the construction of low-orbit satellite navigation systems, the integrity information solution of low-orbit satellites is an important technical guidance document for system development. How to design a suitable integrity information solution for low-orbit satellites according to the integrity monitoring needs of low-orbit satellite navigation systems is an urgent problem to be solved.

[0003] At present, the traditional low-orbit satellite integrity information solution method is generally based on document model design. However, since it requires the use of a large number of design documents, it is difficult to directly express user needs and the design process is complicated. At the same time, there is cumbersome demand tracing and a lot of iterative work when the requirements change. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a low-orbit satellite integrity information solution system and a modeling method thereof, so as to solve the technical problems that the traditional low-orbit satellite integrity information solution method is generally based on document-based model design, which makes it difficult to directly express user needs and the design process is complicated. At the same time, there are technical problems such as cumbersome demand tracing and a large amount of iterative work when the demand changes.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a modeling method for a low-orbit satellite integrity information solution system, which constructs a low-orbit satellite integrity information solution system based on a pre-created MBSE model; specifically, it includes: According to the requirements of low-orbit satellite integrity monitoring, the requirements of low-orbit satellite integrity solution are established; the requirements of low-orbit satellite integrity solution include functional requirements, performance requirements, interface requirements and reliability requirements; Based on the functional requirements, create a use case diagram for low-orbit satellite user ranging accuracy solution; based on the use case diagram for low-orbit satellite user ranging accuracy solution, create an activity diagram for low-orbit satellite user ranging accuracy solution; Create an architecture design diagram based on the use case diagram of low-orbit satellite user ranging accuracy solution; create an internal interface diagram based on the interface requirements; Based on the performance requirements, create a performance analysis diagram of low-orbit satellite integrity solution, and create a block definition diagram of low-orbit satellite integrity solution performance indicator analysis; Based on reliability requirements, a failure mode impact analysis table is created; thus, a low-orbit satellite integrity information solution system is obtained.

[0006] Furthermore, the functional requirements are requirements for calculating ranging accuracy of low-orbit satellite users, the performance requirements include integrity processing timeliness and the number of low-orbit satellites that can be processed, the interface requirements are interfaces for data transmission, and the reliability requirements are fault response methods when solving ranging accuracy of low-orbit satellite users.

[0007] Furthermore, the use case diagram of the low-orbit satellite user ranging accuracy solution shows the traceability relationship of the functional requirements; the activity diagram of the low-orbit satellite user ranging accuracy solution is used to control the operations that need to be performed in the low-orbit satellite integrity solution process.

[0008] Furthermore, the architecture design diagram is designed according to the signal system type of the low-orbit satellite.

[0009] Furthermore, the internal interface diagram displays the interactive information input or output via TCP or FS.

[0010] Furthermore, performance evaluation parameters are added to the performance analysis diagram of the low-orbit satellite integrity solution.

[0011] Furthermore, the performance evaluation parameters include an integrity information processing data sampling interval and an integrity information processing timeliness.

[0012] Furthermore, based on reliability requirements, the process of creating a failure mode impact analysis table is as follows: Creating a fault response rule for low-orbit satellite integrity solution based on the reliability requirements; A failure mode impact analysis table is created based on the reliability requirements and the fault response rules of the low-orbit satellite integrity solution; wherein the failure mode impact analysis table is used to analyze the causes and impacts of each type of low-orbit satellite integrity solution failure mode.

[0013] Furthermore, the fault response rules of the low-orbit satellite integrity solution include failure modes, failure causes, failure impacts and failure control measures of the low-orbit satellite integrity solution.

[0014] The present invention also provides a low-orbit satellite integrity information solution system, and the low-orbit satellite integrity information solution system is obtained by adopting the modeling method of the low-orbit satellite integrity information solution system.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The modeling method of the low-orbit satellite integrity information solution system provided by the present invention adopts a top-down modeling method for model-based system engineering. First, according to the low-orbit satellite integrity monitoring requirements, the system requirements of the low-orbit satellite integrity solution are collected. Secondly, based on the functional requirements of the low-orbit satellite integrity solution, a use case diagram and an activity diagram are created. Then, based on the use case diagram, an architecture design diagram of the low-orbit satellite integrity solution is created. Then, based on the performance requirements, a performance analysis diagram of the low-orbit satellite integrity solution is created. Then, based on the reliability requirements, a failure mode impact analysis table is created, so as to obtain a final scheme design model as the low-orbit satellite integrity information solution system. The present invention replaces documents with models, has the advantages of a concise design process, a simple iteration method, a fast response to demand changes, high maintainability, and the like, and can effectively shorten the development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention provides a flow chart of a modeling method for a low-orbit satellite integrity information solution system. DETAILED DESCRIPTION

[0017] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The present invention provides a modeling method for a low-orbit satellite integrity information solution system, and constructs a low-orbit satellite integrity information solution system based on a pre-created MBSE (Model Based Systems Engineering) model; as shown in the attached Figure 1 As shown, the modeling method of the low-orbit satellite integrity information solution system includes the following steps: Step 1: According to the requirements of low-orbit satellite integrity detection, the requirements of low-orbit satellite integrity solution are established in the pre-created MBSE model. The requirements of low-orbit satellite integrity solution include functional requirements, performance requirements, interface requirements and reliability requirements.

[0019] Specifically, the functional requirement is the ranging accuracy calculation requirement for low-orbit satellite users; among them, the ranging accuracy calculation requirement for low-orbit satellite users refers to the ability to accurately calculate users in the low-orbit satellite system, such as ground terminals, mobile devices or other satellites and the distance between satellites. The calculation requirement needs to meet the preset accuracy requirements, which is the key to ensuring that satellite navigation systems, earth observation systems and communication systems can operate normally and provide high-quality services.

[0020] The performance requirements include integrity processing time and the number of low-orbit satellites that can be processed to ensure that the system can operate efficiently under specified conditions.

[0021] The interface requirement is an interface for data transmission to define a data exchange format, protocol or interface specification; preferably, the data transmission interface includes TCP input / output or FS input / output.

[0022] The reliability requirement is a fault response mode during ranging accuracy calculation of low-orbit satellite users.

[0023] Step 2: In the pre-created MBSE model, a use case diagram (User Case Diagram) of low-orbit satellite user ranging accuracy solution is created according to the functional requirements; wherein the use case diagram of low-orbit satellite user ranging accuracy calculation displays the traceability relationship of the functional requirements; based on the use case diagram of low-orbit satellite user ranging accuracy solution, an activity diagram (Activity Diagram) of low-orbit satellite user ranging accuracy solution is created; wherein the activity diagram of low-orbit satellite user ranging accuracy solution is used to control the operations required in the low-orbit satellite integrity solution process.

[0024] It should be noted that the process of creating a use case diagram for low-orbit satellite user ranging accuracy solution is as follows: Determine an external entity that directly interacts with the low-orbit satellite user ranging accuracy calculation function; wherein the external entity that directly interacts with the low-orbit satellite user ranging accuracy calculation function includes a ground control center operator or a satellite user device; preferably, the satellite user device is such as a smart phone, a smart car or a GPS receiver.

[0025] According to the functional requirements, specific use cases are identified; among them, specific use cases, for example: requesting ranging accuracy calculation, receiving ranging results, or calibrating ranging data.

[0026] Use association lines to connect participants and use cases to indicate the interaction between participants and use cases; use include or extend relationships to show the dependency or extension relationship between use cases.

[0027] Clarify the traceability relationship between each use case and functional requirement through annotations or specific marking methods; preferably, use color coding, labels or annotation text to indicate the traceability relationship between each use case and functional requirement to ensure consistency between the use case diagram and the functional requirements.

[0028] It should also be noted that the activity diagram of low-orbit satellite user ranging accuracy solution is a graphical representation used to describe the activity flow in the system, which is used to show in detail a series of operations, decisions and actions that the system needs to perform in order to achieve a certain goal or complete a certain use case; taking a simplified activity diagram of low-orbit satellite user ranging accuracy solution as an example, in the example activity diagram, start and end / wait for next ranging request represent the starting point and end point of the activity or the loop waiting point respectively; the ground control center sends a ranging request, which is the trigger event of the activity, initiated by the operator or automation system of the ground control center; the satellite receives the ranging request, processes the ranging request, and sends the ranging request to the user. Summarizing and sending ranging results to the ground control center describes the processing flow of the satellite after receiving the request; the ground control center receives and verifies the ranging results is the process of the ground control center receiving and verifying the ranging results returned by the satellite; whether the accuracy requirements are met is a decision point, and whether further calibration is needed is determined based on the comparison between the accuracy of the ranging results and the expected value or the set threshold; the ground control center sends calibration instructions and the satellite receives calibration instructions and adjusts parameters is the process in which when the ranging results do not meet the accuracy requirements, the ground control center sends calibration instructions to the satellite, and the satellite adjusts parameters according to the instructions to improve the ranging accuracy.

[0029] Step 3. Based on the use case diagram of low-orbit satellite user ranging accuracy solution, create an architecture design diagram in the pre-created MBSE model; wherein the architecture design diagram is designed according to the low-orbit satellite signal system type, and the architecture design diagram is used for low-orbit satellite integrity information processing; an internal interface diagram is created according to the interface requirements, and the internal interface diagram displays the interactive information input or output through TCP or FS.

[0030] In the present invention, the process of creating an architecture design diagram in a pre-created MBSE model is as follows: According to the signal system type, the corresponding satellite signal receiving and processing components are identified; the integrity information processing components are identified, which are used to monitor and evaluate the integrity of satellite signals; and the user equipment components are identified, which are used to receive satellite signals and perform preliminary processing.

[0031] Define the relationship between components; specifically, use data flows or communication links to represent information exchange between components; and mark the direction and type of data flows.

[0032] In the graphical tool, the satellite signal reception and processing components, integrity information processing components, and user equipment components are laid out according to logical or physical relationships, and annotations are added to each component and data flow to explain its function and interface to obtain an architectural design diagram.

[0033] In the present invention, the process of creating an internal interface diagram according to the interface requirements is as follows: According to the architecture design diagram, identify the internal interfaces that need to be displayed in detail; determine the interface type for the internal interfaces that need to be displayed in detail; define the interface protocol for the internal interfaces that need to be displayed in detail; for the TCP interface, define the message format, communication protocol and timing; for the FS interface, define the file path, read and write permissions and file format; use graphical tools to draw the interface diagram to show the connection and interaction between components, and mark the direction, type and protocol of the interface; then, add comments to each interface and interaction to explain its purpose and constraints to obtain the internal interface diagram.

[0034] Step 4: Based on the performance requirements, create a performance analysis diagram of low-orbit satellite integrity solution in a pre-created MBSE model; wherein, performance evaluation parameters are added to the performance analysis diagram of low-orbit satellite integrity solution, and the performance evaluation parameters are used for performance analysis during low-orbit satellite integrity solution; preferably, the performance evaluation parameters include integrity information processing data sampling interval and integrity information processing timeliness; and create a block definition diagram (Block Definition Diagram) for low-orbit satellite integrity solution performance indicator analysis in the pre-created MBSE model; wherein, the performance evaluation parameters are associated with the performance indicators, and the performance requirements are traced back to the functional requirements.

[0035] It should be noted that the performance analysis diagram of the LEO satellite integrity solution is used to show the key performance evaluation parameters in the LEO satellite integrity solution process and how the performance evaluation parameters affect the overall performance of the system; specifically, the creation process of the performance analysis diagram of the LEO satellite integrity solution is as follows: According to the performance requirements, the parameters that need to be evaluated are determined; the parameters that need to be evaluated include: the integrity information processing data sampling interval and the integrity information processing timeliness; a reasonable range or threshold is defined for each performance evaluation parameter to facilitate performance analysis; a performance curve is drawn using a graphical tool to show the relationship between the performance evaluation parameter and the system performance; preferably, different types of charts such as scatter plots, line graphs or bar graphs are used to display the data; finally, annotations are added to each performance evaluation parameter and performance curve to explain its meaning and impact on system performance, so as to obtain a performance analysis chart for the low-orbit satellite integrity solution.

[0036] The block definition diagram is used to define and associate performance evaluation parameters and performance indicators in the MBSE model, and trace performance requirements back to functional requirements. The creation process of the block definition diagram for the performance indicator analysis of the low-orbit satellite integrity solution is as follows: Create a new performance block to contain all performance evaluation parameters and performance indicators related to the integrity solution of low-orbit satellites; add previously identified performance evaluation parameters in the performance block, such as the integrity information processing data sampling interval and the integrity information processing timeliness; associate one or more performance indicators, such as accuracy, response time, throughput, etc., with each performance evaluation parameter; use lines or arrows to indicate the relationship between performance evaluation parameters and performance indicators; mark the traceability relationship between performance requirements and functional requirements in the BDD to ensure that the performance requirements can be accurately reflected in the functional design of the system; finally, add comments to each performance block, performance evaluation parameter, performance indicator, and traceability relationship to provide detailed instructions and explanations.

[0037] Step 5: Based on the reliability, a failure mode impact analysis table is created to obtain a modeling result of the low-orbit satellite integrity information solution system; specifically, the process of creating a failure mode impact analysis table based on the reliability is as follows: Step 51. Create a fault response rule for low-orbit satellite integrity solution according to the reliability requirement; wherein the fault response rule for low-orbit satellite integrity solution includes failure mode, failure cause, failure impact and failure control measures for low-orbit satellite integrity solution; specifically, the failure mode indicates failure of LEO satellite integrity information processing, the failure cause indicates errors in LEO satellite ephemeris or observation data and LEO data, the failure impact indicates reduced accuracy of integrity information solution and failure of integrity information solution, and the failure control measures indicate LEO observation data quality control and provision of alarm information.

[0038] Step 52: Create a Failure Mode and Effects Analysis (FEMA) table in the pre-created MBSE model according to the fault response rules of the low-orbit satellite integrity solution and the reliability requirements; wherein the FEMA table is used to analyze the causes and effects of each type of failure mode to obtain all possible effects of each type of failure mode on the system.

[0039] It should be noted that failure mode impact analysis is a systematic method for identifying and analyzing potential failure modes in product design or processes, the impact of failure modes on the system, and evaluating their severity and probability of occurrence; preferably, the failure mode impact analysis table includes serial number, failure mode, failure cause, failure impact, severity level, probability level, risk priority number, and preventive measures or recommended improvement measures; wherein the serial number represents the unique identifier of the failure mode; the failure mode represents the description of the specific failure phenomenon or problem; the failure cause represents the analysis of the potential causes that may cause the failure; the failure impact represents the description of the impact of the failure on the system performance , safety, reliability and other aspects; severity level indicates the severity of the impact of the fault, usually expressed in high, medium and low levels; probability level indicates the possibility of fault occurrence, also expressed in high, medium and low levels; detectability level indicates the possibility of detecting the fault before or after it occurs, also expressed in high, medium and low levels; risk priority number indicates the product of severity level, probability level and detectability level, which is used to rank the risks of fault modes; preventive measures / suggested improvement measures indicate preventive measures or suggested improvement measures proposed for the fault mode to reduce the risk.

[0040] Step 6: Perform a matching analysis on the modeling results of the low-orbit satellite integrity information solution system in step 5 and the actual low-orbit satellite integrity solution requirements to obtain a matching analysis result; based on the matching analysis result, repeat steps 1-5 to optimize the newly added requirements or unresponded requirements and the parts that deviate from the actual requirements until the modeling results of the low-orbit satellite integrity information solution system fully match the actual requirements of the system, and output the low-orbit satellite integrity information solution system.

[0041] The specific process is as follows: Step 61: Compare the modeling results of the low-orbit satellite integrity information solution system with the actual low-orbit satellite integrity solution requirements item by item; use a requirement tracking matrix or similar tools to ensure that each requirement has a corresponding modeling element and that each modeling element meets the corresponding requirement.

[0042] Step 63: Mark the actual requirements that are not covered in the modeling results, that is, new requirements or unresponsive requirements; mark the parts where there are deviations between the modeling results and the actual requirements, including missing functions, substandard performance, interface mismatch and other issues.

[0043] Step 64: Analyze the impact of the differences in step 63 on the overall performance, safety and reliability of the system to obtain the results of the matching analysis.

[0044] Step 65: Repeat the previous steps 1 to 5 for newly added or unanswered requirements and those that deviate from the actual requirements; specifically, re-analyze requirements, design functions, analyze performance, and establish MBSE models to ensure that these parts are correctly modeled and met. It should be noted that after each iteration, the optimization effect is verified to ensure that the modified or newly added modeling elements match the actual requirements; use simulation, testing, or actual operation to verify whether the system's performance and functions meet the requirements; and repeat the above process until the modeling results of the low-orbit satellite integrity information solution system fully match the actual requirements of the system.

[0045] The modeling method of the low-orbit satellite integrity information solution system provided by the present invention first collects the system requirements of the low-orbit satellite integrity solution, then performs a requirements analysis on the functional requirements of the low-orbit satellite integrity solution to create a use case diagram and an activity diagram, and then creates an architecture design diagram of the low-orbit satellite integrity solution based on the use case diagram, and then creates a performance analysis diagram of the low-orbit satellite integrity solution based on the performance requirements, and then performs a reliability analysis based on the reliability requirements to generate a failure mode impact analysis table, and finally performs a matching analysis on the system requirements and the scheme design model, and iteratively optimizes the scheme design model to obtain the final scheme design model; the present invention can evaluate the correctness of the design scheme in the model, and directly iteratively verify the updated requirements, thereby avoiding the tediousness of repeatedly updating documents during requirement iteration, improving the efficiency and quality of the low-orbit satellite integrity information solution scheme design, and can promptly respond to changes in overall requirements.

[0046] The present invention also provides a low-orbit satellite integrity information solution system, which is obtained by adopting the modeling method of the above-mentioned low-orbit satellite integrity information settlement system; the present invention does not specifically limit the specific structure of the low-orbit satellite integrity information solution system; it should be noted that the low-orbit satellite integrity information solution system can realize the digital model construction of the low-orbit user ranging accuracy solution solution.

[0047] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A modeling method for a low-orbit satellite integrity information solution system, characterized in that: Based on the pre-created MBSE model, a low-orbit satellite integrity information solution system is built; specifically, it includes: According to the requirements of low-orbit satellite integrity monitoring, the requirements of low-orbit satellite integrity solution are established; the requirements of low-orbit satellite integrity solution include functional requirements, performance requirements, interface requirements and reliability requirements; Based on the functional requirements, create a use case diagram for low-orbit satellite user ranging accuracy solution; based on the use case diagram for low-orbit satellite user ranging accuracy solution, create an activity diagram for low-orbit satellite user ranging accuracy solution; Create an architecture design diagram based on the use case diagram of low-orbit satellite user ranging accuracy solution; create an internal interface diagram based on the interface requirements; Based on the performance requirements, create a performance analysis diagram of low-orbit satellite integrity solution, and create a block definition diagram of low-orbit satellite integrity solution performance indicator analysis; Based on reliability requirements, a failure mode impact analysis table is created; thus, a low-orbit satellite integrity information solution system is obtained.

2. The modeling method of a low-orbit satellite integrity information solution system according to claim 1, characterized in that: The functional requirements are the requirements for calculating the ranging accuracy of low-orbit satellite users, the performance requirements include the integrity processing timeliness and the number of low-orbit satellites that can be processed, the interface requirements are the interfaces for data transmission, and the reliability requirements are the fault response methods when solving the ranging accuracy of low-orbit satellite users.

3. The modeling method of a low-orbit satellite integrity information solution system according to claim 1, characterized in that: The use case diagram of the low-orbit satellite user ranging accuracy solution shows the traceability relationship of the functional requirements; the activity diagram of the low-orbit satellite user ranging accuracy solution is used to control the operations that need to be performed in the low-orbit satellite integrity solution process.

4. The modeling method of a low-orbit satellite integrity information solution system according to claim 1, characterized in that: The architecture design diagram is designed according to the signal system type of the low-orbit satellite.

5. The modeling method of a low-orbit satellite integrity information solution system according to claim 1, characterized in that: The internal interface diagram displays the interactive information input or output via TCP or FS.

6. The modeling method of a low-orbit satellite integrity information solution system according to claim 1, characterized in that: The performance analysis diagram of the low-orbit satellite integrity solution has performance evaluation parameters added thereto.

7. The modeling method of a low-orbit satellite integrity information solution system according to claim 6, characterized in that: The performance evaluation parameters include integrity information processing data sampling interval and integrity information processing timeliness.

8. The modeling method of a low-orbit satellite integrity information solution system according to claim 1, characterized in that: Based on reliability requirements, the process of creating a failure mode impact analysis table is as follows: Creating a fault response rule for low-orbit satellite integrity solution based on the reliability requirements; A failure mode impact analysis table is created based on the reliability requirements and the fault response rules of the low-orbit satellite integrity solution; wherein the failure mode impact analysis table is used to analyze the causes and impacts of each type of low-orbit satellite integrity solution failure mode.

9. The modeling method of a low-orbit satellite integrity information solution system according to claim 8, characterized in that: The fault response rules for low-orbit satellite integrity solution include failure modes, failure causes, failure impacts and failure control measures for low-orbit satellite integrity solution.

10. A low-orbit satellite integrity information solution system, characterized in that: The low-orbit satellite integrity information solution system is obtained by adopting the modeling method of the low-orbit satellite integrity information solution system as described in any one of claims 1-9.

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