A satellite positioning accuracy parameter modeling and calculation method based on SysML

Abstract

The present application provides a satellite positioning accuracy parameter modeling and calculation method based on SysML, including: determining the input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification of the satellite positioning accuracy parameter calculation model according to the influencing components of the satellite positioning accuracy parameters; creating a system composition diagram of the positioning accuracy parameter calculation model according to the input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification; generating a constraint block of the positioning accuracy parameter calculation model; building a parameter diagram of the positioning accuracy parameter calculation model; creating a positioning accuracy parameter calculation instance; performing parameter simulation on the positioning accuracy parameter calculation model to obtain a simulation result of the positioning accuracy parameter. The present invention can solve the problem that the original document-based system engineering can no longer meet the requirements as the complexity of satellite products increases, and is helpful to form a spacecraft indicator system analysis model based on the SysML language.

Description

Technical Field

[0001] The present invention relates to a satellite positioning accuracy parameter modeling and calculation method based on SysML, belongs to the field of satellite system engineering, and is suitable for modeling and calculating satellite positioning accuracy parameters during satellite solution design indicator budgeting and on-orbit indicator closed-loop verification. Background Art

[0002] Satellite engineering involves the work of multiple large systems such as carriers, ground systems, and launch sites. At the same time, the satellite itself contains multiple subsystems such as power supply, information, communication, and payload. Its composition is complex and its working conditions are numerous. It is a typical product that combines complex machinery, electricity, heat, network, and software. The development of satellite systems is a typical system engineering. In the process of satellite development, the indicator budget in the satellite scheme design phase and the closed-loop verification of indicators in the on-orbit phase are both important links in satellite development and are the key basis for whether the satellite can successfully complete the user's mission indicators and achieve mission success. At the same time, the satellite positioning accuracy parameter is the core indicator parameter of the satellite. Whether this indicator can meet the requirements is the key to whether the satellite can successfully complete its mission in orbit.

[0003] In recent years, with the increasing complexity of satellite products, the importance of system design has become increasingly prominent. The original document-based system engineering can no longer meet the requirements, and model-based system engineering is becoming the mainstream design method. In order to adapt to the development of more complex system engineering in the future, China's aerospace industry also urgently needs to transform decades of successful experience in aerospace system engineering into model-based system engineering, and realize the transformation from text-based and empirical to model-based and digital. MBSE-based methods are gradually being applied and developed in the aerospace field as an emerging field.

[0004] With the in-depth application of MBSE methods based on SysML language in spacecraft system engineering, the use of SysML language to carry out modeling of spacecraft products is helpful to form an index system analysis model for spacecraft. For the emerging field and modeling method of MBSE, it is difficult for beginners and users to use this tool efficiently to quickly and conveniently carry out satellite-related analysis work. The present invention aims at the key core indicator positioning accuracy parameters of satellites. Based on SysML language, a modeling and calculation method of satellite positioning accuracy parameters is invented, the modeling process and implementation method are clarified, and a set of unified satellite positioning accuracy parameter analysis models are proposed, which makes the calculation clearer and more specific, and can be quickly learned and put into practical application for beginners and users, thereby improving the practicality of the model method. Summary of the invention

[0005] The technical problem solved by the present invention is that for the emerging field of MBSE and modeling methods, it is difficult for beginners and users to efficiently use this tool to quickly and conveniently carry out satellite-related analysis work. A satellite positioning accuracy parameter modeling and calculation method based on SysML is proposed.

[0006] The present invention provides a satellite positioning accuracy parameter modeling and calculation method based on SysML, comprising:

[0007] S1: Determine the input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification of the satellite positioning accuracy parameter calculation model based on the influencing components of the satellite positioning accuracy parameters;

[0008] S2: Create a system composition diagram of the positioning accuracy parameter calculation model based on input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification;

[0009] S3: Generate constraint blocks for the positioning accuracy parameter calculation model;

[0010] S4: construct parameter diagram of positioning accuracy parameter calculation model;

[0011] S5: Create a positioning accuracy parameter calculation instance;

[0012] S6: Perform parameter simulation on the positioning accuracy parameter calculation model to obtain simulation results of the positioning accuracy parameters.

[0013] According to at least one embodiment of the present invention, step S1 includes:

[0014] S11: Determine the influencing components of satellite positioning accuracy parameters;

[0015] S12: Determine all input variables and output variables of the calculation model according to each influencing component;

[0016] S13: Determine all constraint formulas from input to output based on the input variables and output variables of the calculation model;

[0017] S14: Determine all intermediate variables according to the constraint formula, wherein the intermediate variables and output variables are constraint attributes of the total system in the system composition diagram in the subsequent steps;

[0018] S15: Classify all input variables and determine the variable subsystem classification.

[0019] According to at least one embodiment of the present invention, the influencing components of the positioning accuracy parameters include GPS orbit determination accuracy, star-sensing attitude determination accuracy, synchronization time accuracy, calibration residuals, and ground processing errors.

[0020] According to at least one embodiment of the present invention, step S15 includes: determining to which subsystem each input variable belongs.

[0021] According to at least one embodiment of the present invention, step S2 includes:

[0022] S21: a module definition diagram of a system composition diagram for establishing a positioning accuracy parameter calculation model;

[0023] S22: the overall system block defining the positioning accuracy parameter calculation model;

[0024] S23: defining some component attributes of the total system block of the positioning accuracy parameter calculation model to define each subsystem block used;

[0025] S24: define all input variables and define the value types of the input variables. If a value type that is not previously in the value type library appears, add the new value type to the library. When defining the input variables, define the input variables under the subsystem to which they belong as value attributes of the subsystem block.

[0026] S25: Define the constraint attributes and value attributes of the overall system block, wherein the output variables and the intermediate variables serve as the constraint attributes of the overall system block.

[0027] According to at least one embodiment of the present invention, the generation of the constraint block in step S3 includes defining variable parameters and variable types and constraint formulas corresponding to the constraint block, and step S3 includes the following process:

[0028] S31: creating a new variable parameter in the parameter attribute of the positioning accuracy parameter calculation model constraint block, and defining the variable type;

[0029] S32: inputting the language used by the constraint formula and the content of the constraint formula in the constraint attribute of the constraint block;

[0030] S33: Complete the definition of all constraint blocks of the positioning accuracy parameter calculation model.

[0031] According to at least one embodiment of the present invention, step S4 includes:

[0032] S41: creating a parameter map in a total system block of a positioning accuracy parameter calculation model;

[0033] S42: associating input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classifications related to the calculation parameters to be created in a parameter diagram of the positioning accuracy parameter calculation model;

[0034] S43: Connect the variables of the constraint block and the variables in the subsystem box accordingly to complete the establishment of the parameter diagram;

[0035] S44: establishing corresponding parameter diagrams for all defined constraint blocks;

[0036] S45: Create a positioning accuracy parameter total calculation model, and include all previous parameter graphs as sub-graphs into the positioning accuracy parameter total calculation model.

[0037] According to at least one embodiment of the present invention, step S5 includes:

[0038] S51: creating a module definition diagram, and creating a positioning accuracy parameter calculation model instance diagram in the module definition diagram;

[0039] S52: Determine the structure to which the positioning accuracy parameter calculation model instance diagram belongs;

[0040] S53: Determine the subordinate relationship between each instance graph of the positioning accuracy parameter calculation model;

[0041] S54: defining and assigning values ​​to the attributes of the corresponding input variables in the slot attributes of the instance graph;

[0042] S55: Complete the attribute definition and assignment of all input variables of the positioning accuracy parameter calculation model.

[0043] According to at least one embodiment of the present invention, step S6 includes:

[0044] S61: Check the logic and compilation of the positioning accuracy parameter calculation model;

[0045] S62: Use the simulation function to perform parameter simulation on the positioning accuracy parameter calculation model to obtain simulation results of the positioning accuracy parameters.

[0046] According to at least one embodiment of the present invention, both the modeling instance and the simulation establishment have a reuse function, and simulation under different satellite models and comparison of simulation results under different conditions are achieved by modifying the assignment parameters.

[0047] The method provided by the present invention is suitable for modeling and calculating the positioning accuracy parameters of satellites during the budget of satellite program design indicators and the closed-loop verification of on-orbit indicators. Based on the SysML language, a modeling and calculation method for satellite positioning accuracy parameters is invented, and a set of unified satellite positioning accuracy parameter analysis models are proposed, which makes the calculation clearer and more specific, and can be quickly learned and put into practical application for both beginners and users, thereby improving the practicality of the model method.

[0048] The method provided by the present invention can adapt to the development of more complex system engineering in the future, realize the transformation from text-based and empirical to model-based and digital, and conform to the mainstream design method of model-based system engineering. Compared with traditional methods, it can solve the problem that the original document-based system engineering can no longer meet the requirements as the complexity of satellite products increases, and help to form a spacecraft indicator system analysis model based on the SysML language. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The following will further explain the above characteristics, technical features, advantages and implementation methods of the present application in a clear and understandable manner through the description of the preferred embodiments and in combination with the accompanying drawings. The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application. Among them:

[0050] Figure 1 A flow chart of a modeling calculation method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0051] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described with reference to the accompanying drawings.

[0052] Based on the SysML language, this paper provides a modeling and calculation method for satellite positioning accuracy parameters, clarifies the modeling process, and proposes a unified satellite positioning accuracy parameter analysis model, which makes the calculation clearer and more specific. It can be quickly learned and put into practical application for both beginners and users, thus improving the practicality of the model method.

[0053] The SysML language related tools are shown in the following table:

[0054]

[0055]

[0056] like Figure 1 As shown, the specific process of the satellite positioning accuracy parameter modeling calculation method based on SysML provided in this application is as follows:

[0057] S1: Determine the input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification of the satellite positioning accuracy parameter calculation model based on the influencing components of the satellite positioning accuracy parameters;

[0058] Correctly and completely determining the input variables, output variables and constraint formulas of the positioning accuracy parameter calculation model will make the subsequent steps more efficient and reduce the occurrence of errors in the model method process. The specific steps for determining the input variables, output variables and constraint formulas related to the satellite positioning accuracy parameter calculation include:

[0059] S11: Determine the influencing components of satellite positioning accuracy parameters, including GPS orbit determination accuracy, star sensitivity attitude determination accuracy, synchronization time accuracy, calibration residuals, ground processing errors, etc.

[0060] S12: Determine all input variables and output variables of the calculation model according to each influencing component;

[0061] S13: Determine all constraint formulas from input to output based on the input variables and output variables of the calculation model;

[0062] S14: Determine all intermediate variables according to the constraint formula, wherein the intermediate variables and output variables are constraint attributes of the total system in the system composition diagram in the subsequent steps;

[0063] S15: Classify all input variables and determine the variable subsystem classification, that is, determine which subsystem each input variable belongs to, for example, the orbit height belongs to the orbit subsystem, and the attitude angle belongs to the attitude control subsystem.

[0064] S2: creating a system composition diagram of the positioning accuracy parameter calculation model based on the input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification determined in step S1;

[0065] Use the block definition diagram (BDD) to establish the system composition diagram, define the block and partial composition attributes of the total system, and define the variables as value attributes in the corresponding modules. Among them, the specific steps of creating the system composition diagram of the positioning accuracy parameter calculation model include:

[0066] S21: Establishing a module definition diagram (bdd) of a system composition diagram of a positioning accuracy parameter calculation model;

[0067] S22: define the overall system block of the positioning accuracy parameter calculation model;

[0068] S23: defining the partial properties of the total system block of the positioning accuracy parameter calculation model, that is, defining the blocks of each subsystem used;

[0069] S24: define all input variables and their value types. If a value type that is not previously in the value type library appears, this new value type needs to be added to the library. When defining an input variable, it needs to be defined under the subsystem to which it belongs as a value attribute of the subsystem block.

[0070] S25: Define the constraint attributes and value attributes of the overall system block. Output variables and intermediate variables need to be used as constraint attributes of the overall system block.

[0071] S3: Generate constraint blocks for the positioning accuracy parameter calculation model;

[0072] The generation of constraint blocks includes defining variable parameters, variable types and constraint formulas corresponding to the constraint blocks.

[0073] S31: creating a new variable parameter in the parameter (Parameters) attribute of the positioning accuracy parameter calculation model constraint block, and defining the variable type;

[0074] S32: inputting the language used by the constraint formula and the content of the constraint formula in the constraint (Constraints) attribute of the constraint block;

[0075] S33: Complete the definition of all constraint blocks of the positioning accuracy parameter calculation model.

[0076] S4: Parameter map (par) of the positioning accuracy parameter calculation model is constructed;

[0077] The parameter diagram is a special kind of internal block diagram: it combines the engineering analysis model (such as performance model, reliability model) with other SysML models (such as behavioral model, structural model). The parameter diagram shows the constraints that must be satisfied between the system parameters on the design model, which helps to clarify the analysis of the system and the description of the architecture. The specific steps include:

[0078] S41: creating a par parameter map in the total system block of the positioning accuracy parameter calculation model;

[0079] S42: associating input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classifications related to the calculation parameters to be created in a parameter diagram of the positioning accuracy parameter calculation model;

[0080] S43: Connect the variables of the constraint block and the variables in the subsystem box accordingly to complete the establishment of this parameter diagram;

[0081] S44: establishing corresponding parameter diagrams for all defined constraint blocks;

[0082] S45: Create a positioning accuracy parameter total calculation model, and include all previous parameter graphs as sub-graphs into the positioning accuracy parameter total calculation model.

[0083] S5: Create a positioning accuracy parameter calculation instance;

[0084] According to the architectural relationship in the parameter diagram, the corresponding instance diagram is established and the architectural relationship is defined. The specific steps include:

[0085] S51: Create a module definition (bdd) diagram, and create a positioning accuracy parameter calculation model instance diagram in the bdd diagram;

[0086] S52: Determine the structure to which the Instance graph of the positioning accuracy parameter calculation model belongs;

[0087] S53: Determine the subordinate relationship between each instance graph of the positioning accuracy parameter calculation model Instance;

[0088] S54: In the Slots attribute of the Instance graph, define and assign the attributes of the corresponding input variables;

[0089] S55: Complete the attribute definition and assignment of all input variables of the positioning accuracy parameter calculation model.

[0090] S6: Parameter simulation of the positioning accuracy parameter calculation model to obtain simulation results of the positioning accuracy parameters.

[0091] The Simulation function in the SysML language is used for simulation calculation of instances. The specific steps include:

[0092] S61: Check the logic and compilation of the positioning accuracy parameter calculation model to ensure correct operation;

[0093] S62: Use the simulation function to perform parameter simulation on the positioning accuracy parameter calculation model to obtain simulation results of the positioning accuracy parameters.

[0094] Among them, the establishment of modeling instances and simulations has the function of reuse, and simulations under different satellite models can be realized by modifying the assigned parameters, as well as the comparison of simulation results under different conditions.

[0095] In the method provided in this application, correctly and completely determining the positioning accuracy parameter input variables, output variables and constraint formulas is an important step in the modeling process, which will make the subsequent steps more smoothly completed and can also reduce the occurrence of errors in the model method process.

[0096] In the method provided in this application, the constraint formula used in the positioning accuracy parameter model should try to use the engineering calculation formula listed in the standard specification, which is more suitable for engineering calculation and satellite indicator calculation review.

[0097] In the method provided in this application, there are multiple editing languages ​​and methods for defining constraint formulas, and you can choose a suitable editing language to write it according to your own needs.

[0098] In the method provided in the present application, during the creation process of the positioning accuracy parameter model instance, the architectural relationship of each Instance must be defined first, and then the variables are assigned. Without establishing the architectural relationship, the assignment cannot be achieved.

[0099] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0100] The above description is only an illustrative embodiment of the present application and is not intended to limit the scope of the present application. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. A satellite positioning accuracy parameter modeling and calculation method based on SysML, comprising: S1: Determine the input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification of the satellite positioning accuracy parameter calculation model based on the influencing components of the satellite positioning accuracy parameters; S2: Create a system composition diagram of the positioning accuracy parameter calculation model based on input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classification; S3: Generate constraint blocks for the positioning accuracy parameter calculation model; S4: construct parameter diagram of positioning accuracy parameter calculation model; S5: Create a positioning accuracy parameter calculation instance; S6: Perform parameter simulation on the positioning accuracy parameter calculation model to obtain simulation results of the positioning accuracy parameters.

2. The method according to claim 1, wherein: Step S1 includes: S11: Determine the influencing components of satellite positioning accuracy parameters; S12: Determine all input variables and output variables of the calculation model according to each influencing component; S13: Determine all constraint formulas from input to output based on the input variables and output variables of the calculation model; S14: Determine all intermediate variables according to the constraint formula, wherein the intermediate variables and output variables are constraint attributes of the total system in the system composition diagram in the subsequent steps; S15: Classify all input variables and determine the variable subsystem classification.

3. The method according to claim 2, wherein: The influencing components of positioning accuracy parameters include GPS orbit determination accuracy, star sensor attitude determination accuracy, synchronization time accuracy, calibration residuals, and ground processing errors.

4. The method according to claim 2, wherein: Step S15 includes: determining to which subsystem each input variable belongs.

5. The method according to claim 1, wherein: Step S2 includes: S21: a module definition diagram of a system composition diagram for establishing a positioning accuracy parameter calculation model; S22: the overall system block defining the positioning accuracy parameter calculation model; S23: defining some component attributes of the total system block of the positioning accuracy parameter calculation model to define each subsystem block used; S24: define all input variables and define the value types of the input variables. If a value type that is not previously in the value type library appears, add the new value type to the library. When defining the input variables, define the input variables under the subsystem to which they belong as value attributes of the subsystem block. S25: Define the constraint attributes and value attributes of the overall system block, wherein the output variables and the intermediate variables serve as the constraint attributes of the overall system block.

6. The method according to claim 1, wherein: The generation of the constraint block in step S3 includes defining the variable parameters and variable types and constraint formulas corresponding to the constraint block. Step S3 includes the following process: S31: creating a new variable parameter in the parameter attribute of the positioning accuracy parameter calculation model constraint block, and defining the variable type; S32: inputting the language used by the constraint formula and the content of the constraint formula in the constraint attribute of the constraint block; S33: Complete the definition of all constraint blocks of the positioning accuracy parameter calculation model.

7. The method according to claim 1, wherein: Step S4 includes: S41: creating a parameter map in a total system block of a positioning accuracy parameter calculation model; S42: associating input variables, output variables, constraint formulas, intermediate variables, and variable subsystem classifications related to the calculation parameters to be created in a parameter diagram of the positioning accuracy parameter calculation model; S43: Connect the variables of the constraint block and the variables in the subsystem box accordingly to complete the establishment of the parameter diagram; S44: establishing corresponding parameter diagrams for all defined constraint blocks; S45: Create a positioning accuracy parameter total calculation model, and include all previous parameter graphs as sub-graphs into the positioning accuracy parameter total calculation model.

8. The method according to claim 1, wherein: Step S5 includes: S51: creating a module definition diagram, and creating a positioning accuracy parameter calculation model instance diagram in the module definition diagram; S52: Determine the structure to which the positioning accuracy parameter calculation model instance diagram belongs; S53: Determine the subordinate relationship between each instance graph of the positioning accuracy parameter calculation model; S54: defining and assigning values ​​to the attributes of the corresponding input variables in the slot attributes of the instance graph; S55: Complete the attribute definition and assignment of all input variables of the positioning accuracy parameter calculation model.

9. The method according to claim 1, wherein: Step S6 includes: S61: Check the logic and compilation of the positioning accuracy parameter calculation model; S62: Use the simulation function to perform parameter simulation on the positioning accuracy parameter calculation model to obtain simulation results of the positioning accuracy parameters.

10. The method according to claim 9, wherein: The establishment of modeling instances and simulations are both reusable, and simulations under different satellite models can be realized by modifying the assigned parameters, as well as the comparison of simulation results under different conditions.

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