CN113190951A - Avionics system function decomposition method irrelevant to implementation - Google Patents

Abstract

The invention relates to the field of model-based avionics system architecture design and implementation, in particular to an avionics system function decomposition method irrelevant to implementation. The method comprises the following steps: layering the top layer functions of the avionics system downwards until the divided functional modules only have one unique atomic function and cannot be decomposed downwards; meanwhile, the functional modules of all layers are defined in a standardized way according to the data dependence of the functional modules and are described according to a functional description template; carrying out generalized abstraction on the atomic function modules with similar functions, and generalizing to obtain a generalized atomic function module; organizing the generalized functional modules, including establishing parent-child hierarchical relationships among the functional modules and refining names of the functional modules; and performing function description on the organized function modules, and examining and unifying data dependence related to each function module.

Description

Avionics system function decomposition method irrelevant to implementation

Technical Field

The invention relates to the field of model-based avionics system architecture design and implementation, in particular to an avionics system function decomposition method irrelevant to implementation.

Technical Field

The model-based system engineering method is widely applied to the avionics system architecture design process, in order to realize rapid architecture design and system integration oriented to an avionics system family, technologies such as modular design and software product line are maturely applied to the avionics system architecture design and realization field, and a field sharing library is constructed and formed so as to hope for reuse of design assets such as models and software, thereby improving the design efficiency and reducing the overall cost to the maximum extent. The avionics system field shared library takes the model as a main object, and realizes the management and planning of the functional model in the avionics field, so that the model can be reused in the design of various avionics products.

Disclosure of Invention

The purpose of the invention is as follows:

in order to realize the multiplexing of an avionic system function model, construct an avionic system shared function library and apply the function model to more extensive system architecture model design, the invention provides an avionic system function decomposition method irrelevant to specific implementation, aiming at decomposing the top-level function of an avionic system into a low-level atomic-level function, supporting the design of the avionic system function model shared library and helping the system function to construct a reference architecture model.

Technical scheme

The invention provides a method for decomposing avionics system functions irrelevant to implementation, which comprises the following steps:

layering the top layer functions of the avionics system downwards until the divided functional modules only have one unique atomic function and cannot be decomposed downwards; meanwhile, the functional modules of all layers are defined in a standardized way according to the data dependence of the functional modules and are described according to a functional description template;

carrying out generalized abstraction on the atomic function modules with similar functions, and generalizing to obtain a generalized atomic function module;

organizing the generalized functional modules, including establishing parent-child hierarchical relationships among the functional modules and refining names of the functional modules;

and performing function description on the organized function modules, and examining and unifying data dependence related to each function module.

Further, before layering top-level functions of the avionics system downwards, the method further comprises:

identifying the engineering field, the top task, the task stage and the possible resident platform type of the avionic system;

identifying and reviewing relevant document material;

an initial primary data element list of the avionics system and a vocabulary describing the data of the avionics system are created.

Further, layering top-level functions of the avionics system downwards until the layered function modules only have one unique atomic function and cannot be layered downwards, and the method comprises the following steps:

selecting the jth functional module at the ith layer in a task stage to perform decomposition analysis on the jth functional module at the ith layer to obtain a functional module at the next layer, wherein the functional module at the next layer is used for further performing decomposition and refinement on the ith functional module;

when n functional modules with atomic functions exist in the next layer of functional modules, the remaining functional modules need to be decomposed and analyzed continuously;

labeling the applicable platform type attribute, labeling the task stage attribute, creating description and identifying data dependence for each lower layer functional module;

wherein, the function module of the layer 1 is the top function module which is analyzed by decomposition.

Further, generalization and promotion can be performed on functional modules with similar atomic functions under the same top-level function, and can also be performed on functional modules with similar atomic functions under the same top-level purpose.

Further, for a target function module with atomic function, the generalization and abstraction of the function module with similar atomic function to obtain the generalized function module includes:

the method comprises the following steps of carrying out upper generalization on target function modules from a specific task stage or from a specific implementation;

and adjusting the attribute, description and data dependence according to the generalized target function module.

Further, the functional description of the organized functional modules, the examination and the unification of the data dependency of the functional modules include:

performing description analysis on all the functional modules;

capturing the traceability of each functional module to relevant document data;

updating the description of the corresponding functional module according to the traced document data;

reviewing and unifying data dependency on the data element table according to the description of the functional module;

when unified, updating the main data element list;

examining the preambles and the successors of all the functional modules;

capturing the subsequent preorders of the functional modules with the subsequent preorders;

establishing an initial function for a functional module without a preamble successor, and capturing a missing preamble successor;

when the data dependencies of all functional modules are completely defined, the vocabulary is examined according to the data dependencies,

further, the method further comprises:

if there is a problem with the decomposition of the function block having the atomic function, it is necessary to decompose again from the layer where the problem occurs.

The invention provides a computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out any of the methods.

The invention provides a system function decomposition method which is independent of implementation, completes the definition of an avionics system function module, develops a systematization process, decomposes, plans and organizes the top-level avionics function from the task capability of the avionics system, ensures that the decomposed function is independent of the specific implementation, finally realizes the atomic decomposition and hierarchical organization of the avionics system function, and provides a function model library for constructing an avionics system function reference architecture model.

Effects of the invention

The invention constructs a method for decomposing the avionics system function, decomposes the avionics top-level function into atomic functions irrelevant to specific implementation, supports the construction of an avionics system shared function model library, and provides a basis for designing a system function reference architecture model.

Drawings

Fig. 1 is a schematic diagram of the definition and constituent elements of a function.

Fig. 2 is a development function exploded view.

Fig. 3 is a process diagram of an identification function.

FIG. 4 is a diagram of a functional generalization process.

Fig. 5 is a functional organization process diagram.

Fig. 6 is a functional description process diagram.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings in which:

in order to solve the problems of consistency and reusability of function blocks and coverage of top-level functions in the function decomposition process, the invention develops a function decomposition method and process for avionics system function analysis. The method provides the precise semantics and syntax required for functional decomposition and defines procedural terms to reduce ambiguity in functional recognition.

The functional decomposition process described herein describes in detail what is needed, how is, and the details of the steps performed, by means of explicit steps, as referred to in the decomposition process. The process adopts an iterative mode to ensure that when the function is split from different perspectives in the function splitting process, the completed splitting result can be reviewed to ensure that the function splitting requirement is met and modification and updating are supported, for example, when a new function is identified or the current function splitting result and the completed result are in contradiction.

The functional decomposition process designed by the invention forces the decomposition function to be examined and tracked from different perspectives. The perspective introduced by the process includes decomposed blocks, task phases and platform types, which are described as attributes of the function.

1) And (5) decomposing the block.

The decompose block describes the basic behavior of the current function using well-defined verbs in the function name. Templates for these actions or low-level functions are built by consistent terminology specification definitions. For example, in the case of decomposing the functions of the unmanned aerial vehicle system, verbs such as "transfer", "determine", "generate", "execute", and "transmit command state" are used as behavior "templates" that occur repeatedly. The standardized decomposed block template provides a guide to assist the hierarchical function decomposition process, and when a particular function at a high level is decomposed into its subfunctions, one or more decomposed blocks are generated. Typical decomposition blocks suitable for the avionics system functional decomposition process include:

receiving: data or information is collected from another function or from an external source.

Determining: the data is transformed to obtain a usable and targeted result.

Generating: the strategic objective is translated into a tactical instruction.

Perform: instructing a change in the configuration of the aircraft.

2) And (5) a task phase.

The task phase is a "one state" that describes the system's operational phase from a task perspective. The task phase adopts a state-based method, the system behavior is examined within the function decomposition range, and many functions are presented in a plurality of task phases. An aircraft needs to be properly configured for all phases, depending on the current phase and circumstances. An aircraft may have the following mission phases in operation:

start/shut down/coast

Landing

Climbing up

Cruise

Descent and approach

3) The platform type.

The platform type is the system class, or the specific technology that is intended to be covered in the functional decomposition. To apply the decomposed clusters of functions to a wider range of system solutions, the platform type is used to help identify those functions that need to be generalized. Low-level aircraft functionality, such as that obtained through functional decomposition, is applicable to fixed-wing aircraft, rotorcraft, and vertical/short takeoff and landing aircraft. Those low-level functions that are only applicable to a particular platform should explicitly describe the platform type in their functional attributes, making it clear that the function is only applicable to a certain type of platform and not to other types of platforms.

1. Standardized definition of functions

The system functions are building blocks in the functional decomposition, and the logic describes the "what the system does". A function is defined as "a task, behavioral action or activity that must be characterized by the performance of a task, behavioral action or activity to achieve a desired output result". To reduce ambiguity, maintain consistency, and promote reusability, a standard functional definition schema is developed based on these definitions during the functional decomposition process. By graphical depiction, the integrated definition of functional modeling gives an initial structured component that is used in developing a standard functional definition. As shown in fig. 1, the initial components of the standard functional definition are: function name, input, output, control and initiator (mechanism).

Other necessary functional element description components are also added in the present invention to support the functional decomposition process, including the annotation description, the reference to the parent function, the associated decomposition block, the available task phase, the available platform type, and the source document reference. The complete standard functional definition is summarized in table 1.

TABLE 1 Standard functional Definitions

2. Functional hierarchical Process description

The functional decomposition process can be decomposed into five key block diagrams, including 64 process steps. The functional decomposition overall process is shown in fig. 2, which contains an aggregation of four detailed sub-processes ("recognition function", "summarization function", "organization function", and "description function"). Each action and decision in the process is assigned a unique identifier and contains a detailed description of "What", "How", and "Why" and related examples. Following the entire functional decomposition process will produce a functional decomposition result that is robust, well organized, and implementation independent.

1) Functional decomposition of the overall process

First "identify project domain", determine the top level functional scope that needs to be decomposed by applying project knowledge or system run concepts. Determining the project domain constitutes all the work basis required for functional decomposition. Identifying and viewing the relevant technical material needs to be determined by searching academic journals, books, well-known websites and documents provided by the customers. The top level function can be identified by looking up the function and the data element (input, output, control or initiator). The top level function is a level one function in the functional organization hierarchy. The next several steps are determining the task phase, determining possible platform types, developing standardized functional decomposition blocks and determining functional description templates, which are related to domain-related attributes that provide more detailed information about the functions determined during the decomposition process. The data element lists (input and output) generated or used by the decomposed and identified functions are described by creating an initial master data element list. Developing a master data element list will facilitate activity modeling in functional decomposition and integration with various data models. This process will obtain and maintain a vocabulary of items and update (create vocabulary to capture terms) throughout the functional decomposition process. The detailed steps of the overall process of functional decomposition are shown in fig. 2.

The preceding steps complete the necessary work to initiate the functional decomposition process. The next step is to select a top level function and start decomposing the hierarchy of functions that make up it. The basic definition (the definition of the selected top-level function is established) needs to be established for all top-level functions before starting the decomposition. This is done by following an iterative process to identify, summarize, organize, and describe functions.

2) Function identification process

The function identification process is used to determine domain-specific attributes in the function decomposition process and to guide the generation of necessary functions. In the process, functions are developed mainly according to the decomposition block, the task stage and the platform type 3 basic visual angles, and attribute data corresponding to the basic visual angles are determined. After the steps of this process are completed, the functions will be appropriately labeled with the attribute data, a basic definition of the decomposed functions and some conceptual data dependencies are generated and ordered in a later process. The detailed steps of the function identification process are shown in fig. 3.

3) Functional generalization process

The functional generalization process inherits and uses the sub-level functions developed in the "recognition function" and generalizes them to make them more versatile and thus applicable to multiple task phases. For example, two airplane functions which are respectively operated in the takeoff phase and the landing phase of the airplane and the only difference is the state of the airplane, the two functions can be generalized and unified into one same function in the view of the mission phase. After generalization of the functions, all decomposed functions must be updated appropriately to reflect the new definitions, data dependencies or names.

Functional generalization allows for the labeling and identification of overly specific functions that are resolved. In order to adapt the decomposed functions to a wider application scenario, the decomposed functions should be implementation-independent, and function sub-blocks such as "how to complete a certain task" are avoided, so that a built-in check needs to be performed in the flow to ensure that all functions reach an appropriate atomic level. The detailed steps of the functional generalization are shown in fig. 4.

4) Functional organization process

The function organization process structures the list of functions developed earlier and assigns a hierarchy based on parent-child relationships with the goal of creating a functional grouping based on similar functional objectives. The end product should be a hierarchical functional structure consisting of sets of parent-child relationships. According to the hierarchy of parent-child functions, the parent function should include all the child functions grouped below it. Through the last function generalization step, some redundant and repeated functions can be deleted or merged, so that redundant functions need to be marked and audited. The detailed steps of the functional organization process are shown in fig. 5.

5) Function description procedure

The function description process will fully describe the decomposed functions, including traceability of related data, updated data dependency, updated narrative description, documentation of function input/output/control/startup data, and capture of the preamble and subsequent functions of each function. Capturing the predecessor and successor functions of the current function may heuristically identify the portion of the functional decomposition that has not been decomposed, i.e., the new function. These new functions can be iterated through the process, followed by a complete description of the functions performed in the same steps, and incorporated into the functional hierarchy. A final update and review of the master data element list and vocabulary is required. A detailed description of the functional description process is shown in fig. 6.

After all functions are described, if a new function needs to be determined, the whole function decomposition process is continuously triggered to iterate until all functions are identified, summarized, organized and described. After all top-level functions are processed, the function decomposition process is basically finished, the decomposed function hierarchy structure and related elements can be analyzed, and the function decomposition is updated and corrected according to the analysis result. The whole functional decomposition process will ensure that the decomposition result is complete, implementation independent and defines all relevant functions required by a specific domain.

Claims (8)

1. An avionics system function decomposition method irrelevant to implementation is oriented, and the method is characterized by comprising the following steps:

layering the top layer functions of the avionics system downwards until the divided functional modules only have one unique atomic function and cannot be decomposed downwards; meanwhile, the functional modules of all layers are defined in a standardized way according to the data dependence of the functional modules and are described according to a functional description template;

carrying out generalized abstraction on the atomic function modules with similar functions, and generalizing to obtain a generalized atomic function module;

organizing the generalized functional modules, including establishing parent-child hierarchical relationships among the functional modules and refining names of the functional modules;

and performing function description on the organized function modules, and examining and unifying data dependence related to each function module.

2. The method of claim 1, wherein prior to layering top-level functions of an avionics system down, the method further comprises:

identifying the engineering field, the top task, the task stage and the possible resident platform type of the avionic system;

identifying and reviewing relevant document material;

an initial primary data element list of the avionics system and a vocabulary describing the data of the avionics system are created.

3. The method of claim 2, wherein layering top-level functions of the avionics system down until the assigned functional module has only one atomic function and cannot be layered down, comprises:

selecting the jth functional module at the ith layer in a task stage to perform decomposition analysis on the jth functional module at the ith layer to obtain a functional module at the next layer, wherein the functional module at the next layer is used for further performing decomposition and refinement on the ith functional module;

when n functional modules with atomic functions exist in the next layer of functional modules, the remaining functional modules need to be decomposed and analyzed continuously;

labeling the applicable platform type attribute, labeling the task stage attribute, creating description and identifying data dependence for each lower layer functional module;

wherein, the function module of the layer 1 is the top function module which is analyzed by decomposition.

4. The method of claim 3, wherein generalizing the upland energy is performed for functional modules with similar atomic functions under the same top-level function and also for functional modules with similar atomic functions under the same top-level purpose.

5. The method of claim 4, wherein for a target function module with atomic functionality, said generalizing abstraction of function modules with similar atomic functionality to obtain a generalized function module comprises:

the method comprises the following steps of carrying out upper generalization on target function modules from a specific task stage or from a specific implementation;

and adjusting the attribute, description and data dependence according to the generalized target function module.

6. The method of claim 5, wherein describing the functions of the organized functional modules, and reviewing and unifying the data dependencies of the functional modules comprises:

performing description analysis on all the functional modules;

capturing the traceability of each functional module to relevant document data;

updating the description of the corresponding functional module according to the traced document data;

reviewing and unifying data dependency on the data element table according to the description of the functional module;

when unified, updating the main data element list;

examining the preambles and the successors of all the functional modules;

capturing the subsequent preorders of the functional modules with the subsequent preorders;

establishing an initial function for a functional module without a preamble successor, and capturing a missing preamble successor;

when the data dependencies of all functional modules are completely defined, the vocabulary is reviewed based on the data dependencies.

7. The method of claim 1, further comprising:

if there is a problem with the decomposition of the function block having the atomic function, it is necessary to decompose again from the layer where the problem occurs.

8. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the method according to any one of claims 1 to 7.

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