A sysml-based helicopter multi-level model integration method

Abstract

The application belongs to the technical field of system engineering, and discloses a helicopter multi-level model integration method based on SysML. The method comprises the following steps: S1, developing a helicopter level model; S2, developing a subsystem level model; S3, developing a sub-system level model; S4, developing a device level model; each level model development comprises the corresponding level of SysML module definition, interaction relationship definition, black box function and performance analysis, SysML module interface modeling and analysis, architecture modeling and analysis, white box analysis, and model traceability relationship definition; each level model development except the helicopter level model development comprises integration verification with all the previous level models.

Description

Technical Field

[0001] This invention belongs to the field of systems engineering technology and discloses a method for integrating multi-level helicopter models based on SysML. Background Technology

[0002] With the development of technology and the increasing complexity of equipment systems, traditional document-based systems engineering methods can no longer meet the development needs of new products. Model-based systems engineering (MBSE) has emerged in this context. MBSE emphasizes using models as the authoritative source of truth for product development, ensuring that the same model is used at all stages of product development. This effectively solves the problems of poor consistency, low communication efficiency, and inconsistent data sources inherent in document-based systems engineering, thus significantly shortening the product development cycle and improving system development efficiency. With the rapid development of computer technology, MBSE has become an important technical means for the development of complex systems, and has been widely applied and achieved significant results in fields such as aerospace, automotive, nuclear industry, and medical.

[0003] Systems engineering methods emphasize top-down analysis and bottom-up verification. To better organize system requirements, functions, and metrics, the system is typically divided into multiple levels. In the helicopter field, helicopters are usually divided into 3-5 levels. Modeling and analysis are performed at each level using the MBSE method. Requirements, functions, metrics, and interfaces are decomposed, allocated, and transferred from top to bottom, and integrated and verified from bottom to top across different levels. Considering the complexity of helicopter equipment, the types and number of models involved at each level are substantial, and the model size grows exponentially as the analysis deepens, posing a significant challenge to the integration of SysML models across different levels. Currently, mainstream international MBSE methodologies include MagicGrid, HarmonySE, OPM, and OOSEM, among which HarmonySE and MagicGrid are more widely used in the domestic aerospace field. The HarmonySE methodology, proposed by IBM, was introduced to China and widely adopted at the same time as its SysML modeling tool, Rhapsody. While suitable for beginners, HarmonySE employs a uniform analysis process, making it less applicable to the aerospace field. It also lacks detailed guidance on integrating models across different levels, and its tutorial examples are simplistic and lack practical reference value. In contrast, the MagicGrid methodology, based on extensive MBSE engineering application experience and tailored to the specific characteristics of various industrial sectors (defense, automotive, aerospace, medical, etc.), offers practical significance for MBSE work in the helicopter field. However, it also lacks detailed methods and case studies on integrating models across different levels. Methodologies such as OPM and OOSEM are more general but lack practical guidance for helicopter MBSE work.

[0004] In summary, the mainstream international methodologies currently only analyze the integration of models at different levels at the theoretical level, without providing clear methods and case guidance at the practical level. However, helicopter MBSE work is characterized by cross-level and cross-professional operations. The integration of MBSE models at different levels or between different professions at the same level is a crucial link in helicopter MBSE work, and it is of great significance for model consistency analysis and early requirements and model verification in design and development activities. Summary of the Invention

[0005] Purpose of the invention: This invention proposes a SysML-based multi-level helicopter model integration method, which provides process and methodological guidance for the top-down decomposition, allocation and transfer of SysML models for helicopters and the bottom-up SysML model integration verification. It can ensure the consistency of SysML models between different levels or different disciplines at the same level, and ensure that different levels and different disciplines carry out modeling and analysis work based on a unique source of truth.

[0006] Technical solution

[0007] A SysML-based method for ensemble multi-level helicopter models includes the following steps:

[0008] S1: Develop helicopter-level models;

[0009] S2: Develop subsystem-level models;

[0010] S3: Develop subsystem-level models;

[0011] S4: Develop device-level models;

[0012] Each level of model development includes the following layers: SysML module definition, interaction relationship definition, black-box functional and performance analysis, SysML module interface modeling and analysis, architecture modeling and analysis, white-box analysis, and model traceability relationship definition.

[0013] Each level of model development, except for the helicopter-level model development, includes integration and validation with all preceding levels of models.

[0014] Furthermore, in S1, the specific process is as follows:

[0015] 1.1 Define the helicopter SysML module and typical helicopter indicators, and define the constraint formulas for the typical helicopter indicators; the typical helicopter indicators include cruise speed, maximum takeoff weight, empty weight, flight time, and range; the internal components of the helicopter SysML module include attributes, ports, behaviors, and structures.

[0016] 1.2. Use SysML module definition diagram to define the SysML modules corresponding to the external interactive systems / organizations that have interaction relationships with the helicopter. The external interactive systems / organizations include communication satellites, ground support systems, airports, air traffic control systems, ground support personnel, pilots, and atmospheric environment.

[0017] 1.3 Treat the helicopter as a whole, without focusing on its internal components, and conduct black-box functional and performance analysis of the helicopter;

[0018] 1.4 Helicopter SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the analysis results of helicopter functional logic and functional interaction in 1.3, the helicopter functional architecture and functional interfaces are formed.

[0019] 1.5 Helicopter architecture modeling and analysis: Based on the helicopter functional architecture and functional interface diagram, taking into account historical development experience, technological advancement and production process factors, identify solutions to realize the key functions of the helicopter, and define no less than two candidate logical architectures for the helicopter.

[0020] Taking into account customer constraints, helicopter performance characteristics, and development costs, the evaluation criteria for candidate helicopter logical architectures are determined, and the optimal solution is selected based on these evaluation criteria. A typical helicopter logical architecture includes airframe structure, avionics system, flight control system, fuel system, hydraulic system, power system, transmission system, electrical system, and rotor system.

[0021] 1.6 Helicopter white-box analysis: The internal structure of the helicopter is opened up, and based on the opened helicopter's various logical subsystems, SysML language is used to carry out further functional and performance refinement analysis. The helicopter function, functional interface, and performance index model obtained from the analysis in 1.3 is further decomposed until the corresponding model elements can be assigned to the helicopter's various logical subsystems.

[0022] For the helicopter white-box functional interface developed based on SysML, the interface modules and ports corresponding to each logical subsystem of the helicopter are established using method 1.4. Generalization is used to establish the inheritance relationship between helicopter-level interface modules and subsystem-level interface modules, representing the decomposition and allocation relationship between higher-level interfaces and lower-level interfaces. The performance indicators decomposed during the helicopter white-box development process are modeled, and the constraint relationship between different levels of performance indicators is established. For example, a top-level helicopter indicator (such as range) can be decomposed into multiple indicators such as available fuel, engine unit fuel consumption rate, rotor power required, and flight speed. SysML parametric graphs should be used to establish the constraint formula between the top-level helicopter indicator and each decomposed indicator.

[0023] 1.7 Define model traceability relationships. Establish dependencies between SysML modules, black-box and white-box functions, function interfaces, performance indicators, port model elements, and between each model element and requirements, all built using the SysML language.

[0024] Furthermore, in S2, the specific process is as follows:

[0025] 2.1 Define the SysML module for the subsystem. The power subsystem is selected as an example. The model development process for other subsystems is similar. Define the SysML module for the power subsystem and its typical indicators and constraint formulas. The typical indicators of the power subsystem include weight, power and fuel consumption rate.

[0026] 2.2 Establish the inheritance relationship with the helicopter logical subsystem. Using the SysML module definition diagram, the inheritance relationship between the power subsystem SysML module and the helicopter logical power subsystem defined in 1.5 is established through the generalization of the SysML language. This allows the power subsystem to fully inherit the white-box analysis results of the helicopter level and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels.

[0027] 2.3 Conduct black-box functional and performance analysis of the subsystems. Treat the power subsystem as a whole, without focusing on its internal components, and carry out functional logic, functional interaction and performance analysis between the power subsystem and the interaction system. The interaction system of the power system includes other helicopter subsystems and the external interaction system / organization defined in 1.2.

[0028] 2.4. Subsystem SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the functional logic and functional interaction analysis results of the power subsystem in 2.3, the functional architecture and functional interfaces of the power subsystem are formed. Based on the functional interface interaction items and directions obtained from the analysis in 2.3, the corresponding power subsystem interface modules and flow attributes are defined, where flow attributes are used to define the interaction items and directions of the functional interfaces. The ports of the power subsystem SysML modules are defined, and the port type is set to the corresponding interface module. The ports of the interaction system SysML modules are also defined. The interfaces of the SysML modules are represented using ports. Using the SysML internal module diagram, the corresponding ports of the power subsystem SysML module instances and the interaction system SysML module instances are connected through Connectors.

[0029] 2.5 Subsystem architecture modeling and analysis: Based on the functional architecture and functional interface diagram of the power subsystem, and taking into account historical development experience, technological advancement and manufacturing process factors, identify solutions to realize the key functions of the power subsystem, and define no less than two candidate logical architectures for the power subsystem.

[0030] Taking into account customer constraints, power subsystem performance characteristics and development costs, the evaluation criteria for candidate power subsystem logical architectures are determined, and the optimal solution is selected based on these evaluation criteria. A typical power subsystem logical architecture includes one engine, two engines, and an auxiliary power unit.

[0031] 2.6 Subsystem white-box analysis: The internal structure of the power subsystem is opened up, and further functional and performance refinement analysis is carried out based on the opened power subsystem's logical subsystems. The power subsystem's function, functional interface, and performance index model obtained from the analysis in 2.3 is further decomposed until the corresponding model elements can be assigned to the power subsystem's logical subsystems.

[0032] 2.7 Define model traceability relationships. Establish dependency relationships between SysML modules of the power subsystem and logic subsystem, black-box and white-box functions of the power subsystem, function interfaces, performance indicators, port model elements, and between each model element and requirements, including satisfaction relationships, traceability relationships, and refinement relationships.

[0033] 2.8 Subsystem → Helicopter Model Integration and Verification: A new IBD diagram is created using the helicopter SysML module as the background environment. This diagram establishes the interface connections between the power subsystem and other helicopter subsystems that interact with it, as well as the interface connections between the power subsystem and external interactive systems / organizations. All ports between the power subsystem and external interactive systems / organizations are connected through the helicopter's ports. The IBD diagram between the helicopter and external interactive systems / organizations is updated to show the interface connections between internal helicopter subsystems and between internal helicopter subsystems and the helicopter itself. The parameter diagram of the helicopter SysML module is updated, supplementing the connection relationships between helicopter-level indicators and power subsystem indicators. Helicopter-level indicators are then concretized into subsystem indicators. Model integration and verification are conducted between the power subsystem and the helicopter, and between the power subsystem and the interactive systems, including verification of behavioral and parameter models.

[0034] Furthermore, in S3, the specific process is as follows:

[0035] 3.1 Define the SysML module of the subsystem, taking the auxiliary power unit subsystem of the power subsystem as an example; define the SysML module of the auxiliary power unit subsystem and its typical indicators and constraint formulas. The typical indicators of the auxiliary power unit subsystem include weight, power, output shaft speed and fuel consumption rate.

[0036] 3.2 Establish the inheritance relationship between the logical subsystems of the subsystem and the subsystem. Use the SysML module definition diagram to establish the inheritance relationship between the SysML module of the auxiliary power unit subsystem and the logical subsystem of the auxiliary power unit defined in 2.5 through the generalization of the SysML language. This allows the auxiliary power unit subsystem to fully inherit the white-box analysis results of the power subsystem and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels.

[0037] 3.3 Subsystem black-box functional and performance analysis;

[0038] 3.4 Subsystem SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the functional logic and functional interaction analysis results of the auxiliary power unit subsystem in 3.3, the functional architecture and functional interfaces of the auxiliary power unit subsystem are formed. Based on the functional interface interaction items and directions obtained from the analysis in 3.3, the corresponding auxiliary power unit subsystem interface modules and flow attributes are defined, where the flow attributes are used to define the interaction items and directions of the functional interfaces. The ports of the SysML modules of the auxiliary power unit subsystem are defined, and the port type is set to the corresponding interface module. The ports of the interactive system SysML modules are updated and improved. The interfaces of the SysML modules are represented using ports. Using the SysML internal module diagram, the corresponding ports of the auxiliary power unit SysML module instances and the interactive system SysML module instances are connected through Connectors.

[0039] 3.5 Subsystem architecture modeling and analysis: Taking into account historical development experience, performance characteristics of auxiliary power units, development costs, technological advancement, and production process factors, based on the functional architecture of the auxiliary power unit subsystem, identify and determine solutions to realize the key functions of the auxiliary power unit subsystem. A typical auxiliary power unit subsystem includes the auxiliary power unit and the auxiliary power unit electronic controller.

[0040] 3.6 Subsystem white-box analysis: The internal structure of the auxiliary power unit subsystem is opened up, and further functional and performance refinement analysis is carried out based on the opened auxiliary power unit subsystem's logical components. The functional, functional interface, and performance index models of the auxiliary power unit subsystem obtained from the analysis in 3.3 are further decomposed until the corresponding model elements can be assigned to the logical components of the auxiliary power unit subsystem.

[0041] 3.7 Define model traceability relationships. For the auxiliary power unit subsystem and logical component equipment SysML modules established by SysML language, the black box and white box functions, function interfaces, performance indicators, and port model elements of the auxiliary power unit subsystem, the model elements of this layer and the model elements of the upper layer, and the model elements of this layer and the requirements, establish dependency relationships, including satisfaction relationships, traceability relationships, and refinement relationships.

[0042] 3.8 Subsystem → Subsystem → Helicopter Model Integration Verification: A new IBD diagram is created using the SysML module of the power subsystem as the background environment. This diagram is used to establish the interface connections between the auxiliary power unit subsystem and other subsystems of the power subsystem that interact with it. It also establishes the interface connections between the auxiliary power unit subsystem and other logical subsystems of the helicopter, as well as between the auxiliary power unit subsystem and external interactive systems / organizations. The connections between the auxiliary power unit subsystem and other logical subsystems of the helicopter, and between the auxiliary power unit subsystem and external interactive systems / organizations, are all through the ports of the power subsystem. Simultaneously, the connection relationships between the affected interface model elements in the IBD diagrams of the power subsystem and other logical subsystems of the helicopter under the SysML module, and the connection relationships between the affected interface model elements in the IBD diagram of the helicopter and external interactive systems / organizations are updated sequentially.

[0043] The parameter diagrams of the power subsystem SysML module and the helicopter SysML module are updated sequentially. The connection relationship between helicopter-level indicators and power subsystem indicators is supplemented. The more abstract helicopter-level indicators are concretized into measurable indicators of the subsystem, and the indicators of the subsystem are concretized into indicators of the subsystem.

[0044] Conduct layer-by-layer integrated verification of the models between the auxiliary power unit subsystem, the power subsystem, and the helicopter, considering three aspects: structure, behavior, and parameters.

[0045] Furthermore, in S4, the specific process is as follows:

[0046] 4.1 Define the equipment SysML module, and select the equipment - electronic controller of the auxiliary power unit subsystem as an example;

[0047] 4.2 Establish the inheritance relationship between the logical components of the subsystem and the auxiliary power unit electronic controller. Use the SysML module definition diagram and establish the inheritance relationship between the SysML module of the auxiliary power unit electronic controller and the logical components of the auxiliary power unit subsystem defined in 3.5 through the generalization of the SysML language. This will enable the auxiliary power unit electronic controller to fully inherit the white-box analysis results of the auxiliary power unit subsystem and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels.

[0048] 4.3 Equipment Function and Performance Analysis: Based on the normal use scenarios and typical fault scenarios of the auxiliary power unit electronic controller, SysML activity diagrams, timing diagrams and state machine diagrams are used in combination to conduct functional logic and functional interaction analysis between the auxiliary power unit electronic controller and the interactive system. SysML parametric diagrams are used simultaneously to model the performance index constraints of the auxiliary power unit electronic controller.

[0049] 4.4. Equipment SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the functional logic and functional interaction analysis results of the auxiliary power unit electronic controller in 4.3, the functional architecture and functional interfaces of the auxiliary power unit electronic controller are formed; based on the functional interface interaction items and directions obtained from the analysis in 4.3, the corresponding interface modules and flow attributes of the auxiliary power unit electronic controller are defined, where the flow attributes are used to define the interaction items and directions of the functional interfaces; the ports of the auxiliary power unit electronic controller SysML module are defined, and the port type is set to the corresponding interface module; the ports of the interaction system SysML module are updated and improved, where the interfaces of the SysML module are represented using ports;

[0050] Using the SysML internal module diagram, the corresponding ports of the auxiliary power unit electronic controller SysML module instance and the interactive system SysML module instance are connected through the Connector.

[0051] 4.5 Integrate supplier equipment models. Based on the white-box analysis results of the auxiliary power unit subsystem, the aircraft design unit integrates the SysML models submitted by relevant equipment manufacturers of the auxiliary power unit subsystem at the equipment level to ensure that the interface relationships, functions, and performance of each device conform to the upper-level definition.

[0052] 4.6 Define model traceability relationships. Establish dependency relationships between auxiliary power unit electronic controllers, auxiliary power unit electronic controller functions, function interfaces, performance indicators, and port model elements established through SysML language, between model elements in this layer and upper-layer model elements, and between model elements in this layer and requirements. These relationships include satisfaction relationships, traceability relationships, and refinement relationships.

[0053] 4.7 Equipment → Subsystem → Subsystem → Helicopter Model Integration and Verification: A new IBD diagram is created using the SysML module of the auxiliary power unit subsystem as the background environment. This diagram establishes the interface connections between the auxiliary power unit electronic controller and other interacting devices, as well as between the auxiliary power unit electronic controller and other logical subsystems of the helicopter, and between the auxiliary power unit electronic controller and external interactive systems / organizations. All connections between the auxiliary power unit electronic controller and other logical subsystems of the helicopter, and between the auxiliary power unit electronic controller and external interactive systems / organizations, are made through the ports of the auxiliary power unit subsystem. Simultaneously, the connection relationships between affected interface model elements in the IBD diagram under the SysML module of the power subsystem, the connection relationships between affected interface model elements in the IBD diagram between the power subsystem and other logical subsystems of the helicopter under the SysML module of the helicopter, and the connection relationships between affected interface model elements in the IBD diagram between the helicopter and external interactive systems / organizations are updated sequentially.

[0054] The parameter diagrams of the auxiliary power unit subsystem SysML module, the power subsystem SysML module, and the helicopter SysML module are updated sequentially to supplement the connection relationship between helicopter-level indicators and power subsystem indicators. That is, the more abstract helicopter-level indicators are concretized into measurable indicators of the subsystem, and the indicators of the subsystem are concretized into indicators of the subsystem.

[0055] The model is integrated and verified layer by layer between the auxiliary power unit electronic controller, the auxiliary power unit subsystem, the auxiliary power unit subsystem, the power subsystem, and the helicopter, mainly considering three aspects: structure, behavior, and parameters.

[0056] In summary, the beneficial effects of the present invention are as follows:

[0057] It can improve the integration efficiency of SysML models at different levels. When defining models at different levels, by establishing the inheritance relationship between subclasses and parent classes, it not only ensures that subclasses inherit the model elements such as functions, architecture, and interfaces of the parent class, but also gives subclasses enough flexible design space.

[0058] To achieve seamless integration and simulation of SysML models across levels and disciplines, the working logic of each system can be simulated as early as possible to identify design defects in a timely manner.

[0059] To achieve the integration and simulation analysis of SysML interface models across levels and disciplines, and to identify problems in the interface design process in a timely manner in the early stages of development.

[0060] Implement cross-level and cross-professional SysML functional model integration and simulation analysis to verify the feasibility, rationality, and consistency with the upper-level definition of functional logic and functional interaction.

[0061] To achieve the integration and simulation analysis of cross-level and cross-professional indicator models, to verify and simulate the top-down decomposition, allocation, and transmission of indicator parameters and the bottom-up integration, and to identify problems in the definition and analysis of indicator models as early as possible. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of a typical abstract hierarchical division of a helicopter.

[0063] Figure 2 This is a schematic diagram of a Vee helicopter model.

[0064] Figure 3 A schematic diagram defining the multi-level model relationships of the system.

[0065] Figure 4 This is a schematic diagram of the SysML module and index definition for helicopters.

[0066] Figure 5A diagram illustrating the helicopter use case definition.

[0067] Figure 6 This is a schematic diagram illustrating the black-box and white-box functional analysis of a helicopter.

[0068] Figure 7 A schematic diagram defining the multi-level SysML module for helicopters.

[0069] Figure 8 A schematic diagram defining the multi-level interface module for helicopters.

[0070] Figure 9 A schematic diagram defining the functional interface and the helicopter SysML module interface.

[0071] Figure 10 This is a schematic diagram of the integration of the subsystem and the helicopter indicator model.

[0072] Figure 11 This is a schematic diagram of the integration of indicator models for subsystems and sub-systems.

[0073] Figure 12 This is a schematic diagram illustrating the integration of indicator models for equipment and subsystems.

[0074] Figure 13 This is a schematic diagram illustrating the definition and update of the IBD diagram for the subsystem -> helicopter integration.

[0075] Figure 14 This is a schematic diagram of the multi-level interface model integration for helicopters.

[0076] Figure 15 This diagram illustrates the integration and data communication of a multi-level SysML model for a helicopter.

[0077] Figure 16 This is a flowchart of a SysML-based method for integrating multi-level helicopter models. Detailed Implementation

[0078] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0079] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0080] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0081] This invention proposes a SysML-based multi-level helicopter model integration method, enabling bottom-up integration of SysML models across levels and disciplines. It ensures that modeling and analysis at different levels are based on a single source of truth, providing methodological guidance for the integration and data exchange of cross-level and cross-discipline SysML models in design and development activities. This method is applicable to all stages of the helicopter's entire lifecycle. Figure 1 , Figure 2 .

[0082] This invention is applicable to multi-level SysML model integration in the design process of complex systems such as aviation, aerospace, automotive, and medical. It covers the integration of SysML model elements across levels and between different disciplines at the same level. It can assist in the verification of the consistency and accuracy of SysML models at each level, ensuring that modeling and analysis work at different levels is based on a unique source of truth.

[0083] This invention fully follows the principle of hierarchical MBSE work in complex systems, considers different types of model elements and related views such as architecture, function, performance, and interface, solves the compatibility problem between model elements at different levels, and ensures the independence and reusability of each level of model.

[0084] This invention takes into account both the SysML language specification and the practical application of MBSE in complex systems. It fully utilizes the nine types of views proposed by SysML to represent different aspects of system design (function, behavior, structure, parameters), and proposes how to flexibly use various types of views to integrate multi-level and multi-disciplinary models.

[0085] This invention uses a Module Definition Diagram (BDD diagram) to define system modules, the compositional relationships between modules, the hierarchical relationships of products, interface modules and inheritance relationships, module port definitions, constraint modules, and custom value types, etc. For example... Figure 7 , Figure 8 .

[0086] This invention uses an Internal Module Diagram (IBD) to define the system and the interface relationships between its components, including the direction of interface elements and the connection relationships between interfaces. Ports at different levels have different abstraction levels, ensuring the independence and ordered inheritance of ports at each level. Figure 13 , Figure 14 .

[0087] This invention uses parametric diagrams to define the constraint relationships between performance indicator models, supporting the top-down decomposition, allocation, and transmission of indicator parameters, as well as the bottom-up integration. These constraint relationships are continuously updated as the design analysis activities progress, ensuring consistency and uniqueness among indicator parameters at different levels. For example... Figure 10 , Figure 11 , Figure 12 .

[0088] This invention uses state machine diagrams (and) or activity diagrams to establish state-based and / or scenario-based behavior analysis. By combining it with internal module diagrams, it enables data interaction between different levels or different modules within the same level. For example... Figure 14 , Figure 15 .

[0089] This invention uses generalization to establish dependencies between modules (Blocks) at different levels, which can simultaneously ensure the inheritance of analysis results from upper-level modules by lower-level modules and the relative independence of lower-level modules, providing methodological guidance for the development of SysML modules at different levels.

[0090] This invention uses generalization to establish dependencies between interface blocks at different levels, ensuring compatibility between different levels and providing support for the integration of multi-level SysML models. For example... Figure 7 , Figure 8 .

[0091] Considering the iterative and incremental development characteristics of MBSE work in complex systems, the multi-level SysML model integration work in this invention also typically requires multiple iterations. It mainly employs a model fusion approach to simultaneously achieve the inheritance of analysis results and the updating of model content between different versions of the model, thereby ensuring the continuity of analysis work at different stages. For example... Figure 2 , Figure 3.

[0092] The main flowchart of this invention is as follows: Figure 16 As shown below. The following is a detailed description of this flowchart.

[0093] 1. Helicopter-level model development

[0094] 1.1 Define the Helicopter SysML Module (Block)

[0095] definition Figure 1 The corresponding helicopter SysML module (Block) for level 1 and typical helicopter indicators (defined through the SysML module's property, i.e., ValueProperty) define the constraint formulas for these typical indicators (defined using the ConstraintBlock module). Typical helicopter indicators include cruise speed, maximum takeoff weight, empty weight, flight time, and range. For example... Figure 4 .

[0096] The helicopter SysML module defined here serves as the context for helicopter-level model development. All subsequent helicopter-level model development and analysis activities will be carried out within this SysML module. The internal components of the helicopter SysML module include attributes, ports, behaviors, and structures.

[0097] 1.2 Define the SysML module (Block) for the external interaction system / organization

[0098] Using the SysML Module Definition Graph (BDD Graph), define the SysML modules corresponding to the external interactive systems / organizations that interact with the helicopter. These external interactive systems / organizations typically include communication satellites, ground support systems, airports, air traffic control systems, ground support personnel, pilots, and the atmospheric environment.

[0099] 1.3 Analysis of Helicopter Black Box Functions and Performance

[0100] Treat the helicopter as a whole, without focusing on its internal components, and conduct black-box functional and performance analysis of the helicopter.

[0101] Define helicopter use cases, use case contexts, and actors (users). Use cases at this level primarily describe the functional aspects of the helicopter and should be defined from the perspective of the helicopter user, characterizing how the helicopter is used by the user to achieve predetermined goals. Helicopter-level use cases typically contain multiple levels, with connections established between different levels using inclusion and extension. A typical helicopter level 1 use case usually includes passenger and cargo transport, communication, flight to the destination, energy generation and management, and supporting helicopter operations. Define the runtime context and actors (users) for each use case, where the actors are one or more of the external interactive systems / organizations defined in section 1.2. For example... Figure 5 .

[0102] Based on normal helicopter usage scenarios and typical abnormal usage scenarios (including single-engine failure, fuel transmission failure, landing gear retraction / extension failure, lubricating oil pressure failure, etc.), this study analyzes the functional logic of the helicopter in various usage scenarios for each low-level use case related to helicopter use. This analysis combines SysML activity diagrams, sequence diagrams, and state machine diagrams. It includes analysis of the functional execution flow between the helicopter and external interaction systems / organizations, the preconditions for functional execution, performance constraints, and emergency operation procedures under abnormal scenarios, capturing the functional and performance constraints related to helicopter use. Functional interaction analysis between the helicopter and external interaction systems / organizations is also conducted, focusing on the input and output types and directions of various helicopter functions, capturing the helicopter's functional interfaces and interaction items. Functional interfaces are primarily represented by the InputPin and OutputPin angles of Activity model elements. Figure 9 .

[0103] Based on typical helicopter support and maintenance scenarios, including fuel filling / draining, ground power supply, and towing and transportation, this study combines SysML activity diagrams, sequence diagrams, and state machine diagrams to conduct functional logic and interaction analysis between helicopters and external systems / organizations in various typical support and maintenance scenarios. This analysis mainly includes functional execution flow, functional execution preconditions, and functional input / output analysis, and analyzes which functions and interfaces the helicopter should provide to support helicopter support and maintenance work.

[0104] Simultaneously use SysML parametric graphs to model the performance index constraints obtained from the above steps.

[0105] 1.4 Modeling and Analysis of Helicopter SysML Module Interface

[0106] Using the SysML Module Definition Diagram (BDD diagram), based on the analysis results of helicopter functional logic and functional interaction in section 1.3, the helicopter functional architecture and functional interfaces are formed.

[0107] Based on the functional interface interaction items and directions derived from the analysis in section 1.3, corresponding helicopter interface modules (InterfaceBlock) and flow properties (FlowProperty) are defined. The flow properties define the interaction items and directions of the functional interfaces. Ports for the helicopter SysML modules are defined, with the port type set to the corresponding interface module. Ports for external interaction systems / organization SysML modules are also defined. The interfaces of SysML modules are represented through ports. For example... Figure 4 .

[0108] Using the SysML Internal Module Diagram (IBD), the corresponding ports of the helicopter SysML module instance and the external interactive system / organization SysML module instance are connected using the Connector model element. The model element corresponding to the SysML module instance is a Part, and the Part type is set to the corresponding SysML module.

[0109] Note: In BDD diagrams, the Block representation system is used; in IBD diagrams, the Part, i.e., the instance representation system of SysML modules, is used.

[0110] 1.5 Helicopter Architecture Modeling and Analysis

[0111] Based on helicopter functional architecture and functional interface N 2 The figure comprehensively considers factors such as historical development experience, technological advancement and production process to identify solutions for realizing the key functions of helicopters and define no less than two candidate logical architectures for helicopters.

[0112] Taking into account customer constraints, helicopter performance characteristics, and development costs, evaluation criteria for candidate helicopter logical architectures are determined, and the optimal solution is selected based on these evaluation criteria. A typical helicopter logical architecture includes airframe structure, avionics system, flight control system, fuel system, hydraulic system, power system, transmission system, electrical system, and rotor system.

[0113] 1.6 Helicopter White-box Analysis

[0114] The internal structure of the helicopter is opened up, and based on the opened helicopter's various logical subsystems, SysML language is used to carry out further functional and performance refinement analysis. The helicopter function, functional interface, and performance index model obtained from the analysis in 1.3 are further decomposed until the corresponding model elements can be assigned to the helicopter's various logical subsystems.

[0115] For the helicopter white-box functional interfaces developed using SysML, method 1.4 is used to establish interface blocks and ports corresponding to each logical subsystem of the helicopter. Generalization is used to establish the inheritance relationship between helicopter-level interface blocks and subsystem-level interface blocks, representing the decomposition and allocation relationship between higher-level and lower-level interfaces. Performance indicators decomposed during the helicopter white-box development process are modeled, and constraint relationships between different levels of performance indicators are established. For example, a top-level helicopter indicator (such as range) can be decomposed into multiple indicators such as available fuel, engine unit fuel consumption rate, rotor power requirement, and flight speed. SysML parametric graphs should be used to establish constraint formulas between the top-level helicopter indicator and each decomposed indicator.

[0116] The diagrams illustrating the black-box and white-box functional analysis processes are as follows: Figure 6 The analysis process and principles for black-box and white-box interfaces and performance indicators are roughly similar.

[0117] 1.7 Define the model traceability relationship

[0118] For helicopters and logical subsystems built using the SysML language, establish dependencies (including fulfillment relationships, traceability relationships, refinement relationships, and verification relationships) between SysML modules (Blocks), helicopter black-box and white-box functions (Activities), function interfaces (InputPin / OutputPin), performance metrics (ValueProperty), ports, and other model elements, as well as between each model element and requirements.

[0119] 2. System-level model development

[0120] 2.1 Define the SysML module (Block) of the subsystem

[0121] definition Figure 1 The SysML module (Block) corresponding to the middle level 2 subsystem takes the power subsystem as an example, and the model development process for other subsystems is similar.

[0122] Define the SysML module of the powertrain subsystem and its typical indicators, as well as the constraint formulas for these typical indicators. Typical indicators of the powertrain subsystem include weight, power, and fuel consumption rate.

[0123] 2.2 Establish inheritance relationship with helicopter logic subsystem

[0124] Using the SysML Module Definition Graph (BDD), the inheritance relationship between the SysML module of the power subsystem and the helicopter logical power subsystem defined in 1.5 is established through the generalization of the SysML language. This allows the power subsystem to fully inherit the white-box analysis results of the helicopter level and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels.

[0125] 2.3 Subsystem Black-Box Function and Performance Analysis

[0126] Treating the power subsystem as a whole, without focusing on its internal components, we conduct functional logic, functional interaction, and performance analysis between the power subsystem and the interaction system. The interaction system of the power system includes other helicopter subsystems and the external interaction system / organization defined in 1.2.

[0127] Based on normal operating scenarios and typical fault scenarios of the powertrain system (such as single-engine failure, low engine oil pressure, and high engine oil temperature), this study combines SysML activity diagrams, timing diagrams, and state machine diagrams to analyze the functional execution flow, preconditions, performance constraints, and emergency operation procedures under abnormal scenarios of the powertrain system and its interaction system. This analysis captures the functional and performance constraints of the powertrain subsystem in terms of usage. Furthermore, it conducts functional interaction analysis between the powertrain subsystem and the interaction system, focusing on the input and output types and directions of various functions of the powertrain subsystem, and capturing the functional interfaces and interaction items of the powertrain subsystem.

[0128] Based on the powertrain subsystem maintenance scenario, we capture and analyze the functions and interfaces related to powertrain subsystem maintenance to determine which functions and interfaces the powertrain subsystem should provide to support the maintenance work.

[0129] Simultaneously use SysML parametric graphs to model the performance index constraints obtained from the above steps.

[0130] 2.4 SysML Module Interface Modeling and Analysis of Subsystem

[0131] Using the SysML Module Definition Diagram (BDD diagram), based on the functional logic and functional interaction analysis results of the power subsystem in section 2.3, the functional architecture and functional interfaces of the power subsystem are formed.

[0132] Based on the functional interface interaction items and directions derived from the analysis in section 2.3, corresponding power subsystem interface modules (InterfaceBlock) and flow properties (FlowProperty) are defined. The flow properties are used to define the interaction items and directions of the functional interfaces. Ports for the power subsystem SysML modules are defined, with the port type set to the corresponding interface module. Ports for the interaction system SysML modules are also defined. The interfaces of the SysML modules are represented using ports.

[0133] Using the SysML Internal Module Diagram (IBD), the corresponding ports of the power subsystem SysML module instances and the interaction system SysML module instances are connected through a Connector.

[0134] 2.5 points System architecture modeling and analysis

[0135] Functional architecture and functional interfaces based on the power subsystem N 2 The figure comprehensively considers factors such as historical development experience, technological advancement and production process to identify solutions for realizing the key functions of the power subsystem and defines no less than two candidate logical architectures for the power subsystem.

[0136] Taking into account customer constraints, power subsystem performance characteristics, and development costs, the evaluation criteria for candidate logical architectures of the power subsystem are determined, and the optimal solution is selected based on these evaluation criteria. A typical power subsystem (dual-engine) logical architecture (logical subsystem) includes engine 1, engine 2, and auxiliary power unit (APU).

[0137] 2.6 Subsystem White-box Analysis

[0138] The internal structure of the power subsystem is opened up, and further functional and performance refinement analysis is carried out based on the opened power subsystem's logical subsystems. The functional, functional interface, and performance index models of the power subsystem obtained from the analysis in 2.3 are further decomposed until the corresponding model elements can be assigned to the logical subsystems of the power subsystem.

[0139] 2.7 Define the model traceability relationship

[0140] This involves establishing dependencies (including fulfillment relationships, traceability relationships, and refinement relationships) between model elements such as SysML modules (Blocks), black-box and white-box functions (Activities), function interfaces (InputPin / OutputPin), performance indicators (ValueProperty), and ports, as well as between each model element and requirements, all built using the SysML language.

[0141] 2.8 Subsystem → Helicopter Model Integration Verification

[0142] Create a new IBD diagram using the helicopter SysML module as the background environment. This diagram establishes the interface connections between the power subsystem and other helicopter subsystems that interact with it, as well as the interface connections between the power subsystem and external interactive systems / organizations. All ports between the power subsystem and external interactive systems / organizations are connected through the helicopter's ports. Simultaneously, update the IBD diagram between the helicopter and external interactive systems / organizations to display the interface connections between internal helicopter systems and between internal helicopter systems and the helicopter itself. For example... Figure 13 .

[0143] Update the parameter diagram of the helicopter SysML module to supplement the connection relationship between helicopter-level indicators and power subsystem indicators, that is, to concretize the helicopter-level indicators into subsystem indicators.

[0144] Conduct model integration and verification between the power subsystem and the helicopter, and between the power subsystem and the interaction system, including the verification of behavioral models and parameter models.

[0145] 3 Subsystem-level Model Development

[0146] 3.1 Define the SysML subsystem (Block)

[0147] definition Figure 1 The SysML module corresponding to the middle level 3 subsystem uses the Auxiliary Power Unit (APU) subsystem of the power subsystem as an example. The model development process for other subsystems is similar.

[0148] Define the SysML module and typical indicators of the Auxiliary Power Unit (APU) subsystem, as well as the constraint formulas for the typical indicators. The typical indicators of the APU subsystem include weight, power, output shaft speed, fuel consumption rate, etc.

[0149] 3.2 Establish the inheritance relationship between the logical subsystems of the subsystem and the main system.

[0150] Using the SysML Module Definition Diagram (BDD), the inheritance relationship between the SysML module of the Auxiliary Power Unit (APU) subsystem and the logical subsystem APU defined in 2.5 is established through the generalization of the SysML language. This allows the APU subsystem to fully inherit the white-box analysis results of the power subsystem and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels.

[0151] 3.3 Subsystem Black-Box Function and Performance Analysis

[0152] The Auxiliary Power Unit (APU) subsystem is treated as a whole, without focusing on its internal components. Functional logic, functional interaction, and performance analysis are conducted between the APU subsystem and the interaction system. The interaction system of the APU subsystem includes other logical subsystems of the power subsystem defined in 2.6, other helicopter subsystems defined in 1.6, and external interaction systems / organizations defined in 1.2.

[0153] Based on the normal operating scenarios and typical failure scenarios (APU oil supply failure, APU lubricating oil blockage) of the Auxiliary Power Unit (APU) subsystem, this study combines SysML activity diagrams, timing diagrams, and state machine diagrams to analyze the functional execution flow, preconditions, performance constraints, and emergency operation procedures under abnormal scenarios of the APU subsystem and its interaction system. This analysis captures the functional and performance constraints of the APU subsystem in terms of usage. Furthermore, the study analyzes the functional interactions between the APU subsystem and its interaction system, focusing on the input and output types and directions of various functions of the APU subsystem, and capturing its functional interfaces and interaction items.

[0154] Based on the ground maintenance scenario of the Auxiliary Power Unit (APU) subsystem, we conducted function capture and interface analysis related to the ground maintenance of the APU subsystem to determine which functions and interfaces the APU subsystem should provide to support engine maintenance work.

[0155] Simultaneously use SysML parametric graphs to model the performance index constraints obtained from the above steps.

[0156] 3.4 Subsystem SysML Module Interface Modeling and Analysis

[0157] Using the SysML Module Definition Diagram (BDD diagram), based on the functional logic and functional interaction analysis results of the Auxiliary Power Unit (APU) subsystem in section 3.3, the functional architecture and functional interfaces of the APU subsystem are formed.

[0158] Based on the functional interface interaction items and directions derived from the analysis in section 3.3, corresponding auxiliary power unit (APU) subsystem interface modules (InterfaceBlock) and flow properties (FlowProperty) are defined. The flow properties are used to define the interaction items and directions of the functional interfaces. The ports of the SysML module in the APU subsystem are defined, with the port type set to the corresponding interface module. The ports of the interactive system SysML module are updated and improved. The interfaces of the SysML module are represented using ports.

[0159] Using the SysML Internal Module Diagram (IBD), the corresponding ports of the Auxiliary Power Unit (APU) SysML module instance and the Interaction System SysML module instance are connected through the Connector.

[0160] 3.5 Subsystem Architecture Modeling and Analysis

[0161] Taking into account factors such as historical development experience, Auxiliary Power Unit (APU) performance characteristics, development costs, technological advancement, and manufacturing processes, solutions for realizing the key functions of the APU subsystem are identified and determined based on the functional architecture of the APU subsystem. A typical APU subsystem includes the APU and the APU electronic controller.

[0162] 3.6 Subsystem White-box Analysis

[0163] The internal structure of the Auxiliary Power Unit (APU) subsystem is opened up, and further functional and performance refinement analysis is carried out based on the opened APU subsystem's logical components. The functional, functional interface, and performance index models of the APU subsystem obtained from the analysis in 3.3 are further decomposed until the corresponding model elements can be assigned to the logical components of the APU subsystem.

[0164] 3.7 Define the model traceability relationship

[0165] For the Auxiliary Power Unit (APU) subsystem and its logical components built using the SysML language, establish dependencies (including fulfillment relationships, traceability relationships, and refinement relationships) between SysML modules (Blocks), black-box and white-box functions (Activities), function interfaces (InputPin / OutputPin), performance indicators (ValueProperty), ports, and other model elements, as well as between the current layer model elements and the upper layer model elements, and between the current layer model elements and requirements.

[0166] 3.8 Subsystem → Sub-system → Helicopter Model Integration Verification

[0167] Create a new IBD diagram with the power subsystem SysML module as the background environment. This diagram is used to establish the interface connections between the Auxiliary Power Unit (APU) subsystem and other power subsystems that interact with it. It also establishes the interface connections between the APU subsystem and other logical subsystems of the helicopter, as well as between the APU subsystem and external interactive systems / organizations. The connections between the APU subsystem and other logical subsystems of the helicopter, as well as between the APU subsystem and external interactive systems / organizations, are all through the ports of the power subsystem. At the same time, the connection relationships between the affected interface model elements in the power subsystem and other logical subsystems of the helicopter IBD diagram under the helicopter SysML module, as well as the connection relationships between the affected interface model elements in the helicopter and external interactive systems / organizations IBD diagram, are updated sequentially.

[0168] The parameter diagrams of the power subsystem SysML module and the helicopter SysML module are updated sequentially to supplement the connection relationship between helicopter-level indicators and power subsystem indicators. That is, the more abstract helicopter-level indicators are concretized into measurable indicators of the subsystem, and the indicators of the subsystem are concretized into indicators of the subsystem.

[0169] The model is integrated and verified layer by layer from the Auxiliary Power Unit (APU) subsystem to the power subsystem, and from the power subsystem to the helicopter, mainly considering three aspects: structure, behavior, and parameters.

[0170] 4. Device-level model development

[0171] 4.1 Define the device SysML module

[0172] definition Figure 1 The SysML module corresponding to the middle level 4 device takes the electronic controller of the Auxiliary Power Unit (APU) subsystem as an example. The model development process for other devices is similar.

[0173] 4.2 Establish inheritance relationships with the logical components of the subsystem.

[0174] Using the SysML Module Definition Diagram (BDD), the inheritance relationship between the SysML module of the auxiliary power unit electronic controller and the logical components of the auxiliary power unit (APU) subsystem defined in 3.5 is established through the generalization of the SysML language. This allows the auxiliary power unit electronic controller to fully inherit the white-box analysis results of the auxiliary power unit (APU) subsystem and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels.

[0175] 4.3 Equipment Function and Performance Analysis

[0176] Based on the normal use scenarios and typical fault scenarios (such as power supply failure of the auxiliary power unit electronic controller), we combine SysML activity diagrams, timing diagrams and state machine diagrams to conduct functional logic and functional interaction analysis between the auxiliary power unit electronic controller and the interactive system. At the same time, we use SysML parametric diagrams to model the performance index constraints of the auxiliary power unit electronic controller.

[0177] 4.4 Equipment SysML Module Interface Modeling and Analysis

[0178] Using the SysML Module Definition Diagram (BDD diagram), based on the functional logic and functional interaction analysis results of the auxiliary power unit electronic controller in section 4.3, the functional architecture and functional interfaces of the auxiliary power unit electronic controller are formed.

[0179] Based on the functional interface interaction items and directions derived from the analysis in section 4.3, the corresponding interface module (InterfaceBlock) and flow property (FlowProperty) of the auxiliary power unit electronic controller are defined. The flow property is used to define the interaction items and directions of the functional interface. The ports of the auxiliary power unit electronic controller SysML module are defined, and the port type is set to the corresponding interface module. The ports of the interaction system SysML module are updated and improved. The interfaces of the SysML module are represented using ports.

[0180] Using the SysML Internal Module Diagram (IBD), the corresponding ports of the auxiliary power unit electronic controller SysML module instance and the interactive system SysML module instance are connected through the Connector.

[0181] 4.5 Integrated Supplier Equipment Model

[0182] Based on the white-box analysis results of the Auxiliary Power Unit (APU) subsystem, the aircraft design unit performs equipment-level integration on the SysML models submitted by the relevant equipment manufacturers of the APU subsystem to ensure that the interface relationships, functions, and performance of each device conform to the upper-level definition.

[0183] 4.6 Define the model traceability relationship

[0184] For the auxiliary power unit electronic controller, the auxiliary power unit electronic controller's functions (Activity), function interfaces (InputPin / OutputPin), performance indicators (ValueProperty), ports, etc., established through the SysML language, the dependency relationships (including satisfaction relationships, traceability relationships, and refinement relationships) are established between the model elements of the auxiliary power unit electronic controller, ...

[0185] 4.7 Equipment → Subsystem → Sub-system → Helicopter Model Integration and Verification

[0186] Create a new IBD diagram using the SysML module of the Auxiliary Power Unit (APU) subsystem as the background environment. This diagram is used to establish the interface connections between the APU electronic controller and other devices that interact with it, as well as the interface connections between the APU electronic controller and other logical subsystems of the helicopter, and between the APU electronic controller and external interactive systems / organizations. The connections between the APU electronic controller and other logical subsystems of the helicopter, and between the APU electronic controller and external interactive systems / organizations, are all established through the ports of the APU subsystem. Simultaneously, update the connection relationships between the affected interface model elements in the IBD diagram under the SysML module of the power subsystem, the connection relationships between the affected interface model elements in the IBD diagram of the power subsystem and other logical subsystems of the helicopter under the SysML module of the helicopter, and the connection relationships between the affected interface model elements in the IBD diagram of the helicopter and external interactive systems / organizations.

[0187] The parameter diagrams of the Auxiliary Power Unit (APU) subsystem SysML module, the power subsystem SysML module, and the helicopter SysML module are updated sequentially to supplement the connection relationship between helicopter-level indicators and power subsystem indicators. That is, the more abstract helicopter-level indicators are concretized into measurable indicators of the subsystem, and the indicators of the subsystem are concretized into indicators of the subsystem.

[0188] The model is integrated and verified layer by layer between the auxiliary power unit electronic controller, the auxiliary power unit (APU) subsystem, the APU subsystem, the power subsystem, and the helicopter, mainly considering three aspects: structure, behavior, and parameters.

[0189] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A SysML-based method for integrating multi-level helicopter models, characterized in that: Includes the following steps: S1: Develop helicopter-level models; S2: Develop subsystem-level models; S3: Develop subsystem-level models; S4: Develop device-level models; Each level of model development includes the following layers: SysML module definition, interaction relationship definition, black-box functional and performance analysis, SysML module interface modeling and analysis, architecture modeling and analysis, white-box analysis, and model traceability relationship definition. Each level of model development, except for the helicopter-level model development, includes integration and validation with all preceding levels of models.

2. The method according to claim 1, characterized in that: In S1, the specific process is as follows: 1.1 Define the helicopter SysML module and typical helicopter indicators, and define the constraint formulas for the typical helicopter indicators; the typical helicopter indicators include cruise speed, maximum takeoff weight, empty weight, flight time, and range; the internal components of the helicopter SysML module include attributes, ports, behaviors, and structures. 1.

2. Use SysML module definition diagram to define the SysML modules corresponding to the external interactive systems / organizations that have interaction relationships with the helicopter. The external interactive systems / organizations include communication satellites, ground support systems, airports, air traffic control systems, ground support personnel, pilots, and atmospheric environment. 1.3 Treat the helicopter as a whole, without focusing on its internal components, and conduct black-box functional and performance analysis of the helicopter; 1.4 Helicopter SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the analysis results of helicopter functional logic and functional interaction in 1.3, the helicopter functional architecture and functional interfaces are formed. Based on the functional interface interaction items and directions derived from the analysis in 1.3, the corresponding helicopter interface modules and flow attributes are defined, where the flow attributes are used to define the interaction items and directions of the functional interfaces; the ports of the helicopter SysML modules are defined, and the port type is set to the corresponding interface module; the ports of the external interaction system / organization SysML modules are defined. The interface of the SysML module is represented by ports; Using the internal module diagram of SysML, the corresponding ports of the helicopter SysML module instance and the external interactive system / organization SysML module instance are connected using the Connector model element. The model element corresponding to the SysML module instance is a Part, and the Part type is set to the corresponding SysML module. 1.5 Helicopter architecture modeling and analysis: Based on the helicopter functional architecture and functional interface diagram, taking into account historical development experience, technological advancement and production process factors, identify solutions to realize the key functions of the helicopter, and define no less than two candidate logical architectures for the helicopter. Taking into account customer constraints, helicopter performance characteristics, and development costs, the evaluation criteria for candidate helicopter logical architectures are determined, and the optimal solution is selected based on these evaluation criteria. A typical helicopter logical architecture includes airframe structure, avionics system, flight control system, fuel system, hydraulic system, power system, transmission system, electrical system, and rotor system. 1.6 Helicopter white-box analysis: The internal structure of the helicopter is opened up, and based on the opened helicopter's various logical subsystems, SysML language is used to carry out further functional and performance refinement analysis. The helicopter function, functional interface, and performance index model obtained from the analysis in 1.3 is further decomposed until the corresponding model elements can be assigned to the helicopter's various logical subsystems. For the helicopter white-box functional interface developed based on SysML language, the interface modules and ports corresponding to each logical subsystem of the helicopter are established using method 1.

4. Generalization is used to establish the inheritance relationship between helicopter-level interface modules and subsystem-level interface modules, representing the decomposition and allocation relationship between higher-level interfaces and lower-level interfaces. The performance indicators decomposed during the helicopter white-box development process are modeled, and the constraint relationship between different levels of performance indicators is established. 1.7 Define model traceability relationships. Establish dependencies between SysML modules, black-box and white-box functions, function interfaces, performance indicators, port model elements, and between each model element and requirements, all built using the SysML language.

3. The method according to claim 2, characterized in that: In step 1.3, the specific process of analyzing the helicopter's black box functions and performance is as follows: Define helicopter use cases, use case contexts, and actors; use cases at this level describe the functional aspects of the helicopter, defined from the perspective of the helicopter user, and characterize how the helicopter is used by the user to achieve the predetermined goal. Helicopter-level use cases contain multiple levels, and use cases at different levels are connected using inclusion and extension. Based on both normal helicopter usage scenarios and typical abnormal usage scenarios (including single-engine failure, fuel transmission failure, landing gear retraction / extension failure, and lubricating oil pressure failure), this study analyzes the functional logic of the helicopter in each usage scenario using SysML activity diagrams, sequence diagrams, and state machine diagrams for each low-level use case related to helicopter use. This includes analyzing the functional execution flow between the helicopter and external interaction systems / organizations, the preconditions for functional execution, performance constraints, and emergency operation procedures under abnormal scenarios, capturing the functional and performance constraints related to helicopter use. Furthermore, it analyzes the functional interactions between the helicopter and external interaction systems / organizations, focusing on the input and output types and directions of various helicopter functions, capturing the helicopter's functional interfaces and interaction items. Functional interfaces are represented using the InputPin and OutputPin angles of the activity model elements. Based on typical helicopter support and maintenance scenarios, including oil filling / draining, ground power supply, and towing and transportation, this study combines SysML activity diagrams, sequence diagrams, and state machine diagrams to conduct functional logic and functional interaction analysis between helicopters and external systems / organizations in various typical support and maintenance scenarios. This includes functional execution flow, functional execution preconditions, and functional input / output analysis. The analysis also examines which functions and interfaces the helicopter should provide to support helicopter support and maintenance work. Simultaneously use SysML parametric graphs to model the performance index constraints obtained from the above steps.

4. The method according to claim 3, characterized in that: In S2, the specific process is as follows: 2.1 Define the SysML module for the subsystem. The power subsystem is selected as an example. The model development process for other subsystems is similar. Define the SysML module for the power subsystem and its typical indicators and constraint formulas. The typical indicators of the power subsystem include weight, power and fuel consumption rate. 2.2 Establish the inheritance relationship with the helicopter logical subsystem. Using the SysML module definition diagram, the inheritance relationship between the power subsystem SysML module and the helicopter logical power subsystem defined in 1.5 is established through the generalization of the SysML language. This allows the power subsystem to fully inherit the white-box analysis results of the helicopter level and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels. 2.3 Conduct black-box functional and performance analysis of the subsystems. Treat the power subsystem as a whole, without focusing on its internal components, and carry out functional logic, functional interaction and performance analysis between the power subsystem and the interaction system. The interaction system of the power system includes other helicopter subsystems and the external interaction system / organization defined in 1.

2. 2.

4. Subsystem SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the functional logic and functional interaction analysis results of the power subsystem in 2.3, the functional architecture and functional interfaces of the power subsystem are formed. Based on the functional interface interaction items and directions obtained from the analysis in 2.3, the corresponding power subsystem interface modules and flow attributes are defined, where flow attributes are used to define the interaction items and directions of the functional interfaces. The ports of the power subsystem SysML modules are defined, and the port type is set to the corresponding interface module. The ports of the interaction system SysML modules are also defined. The interfaces of the SysML modules are represented using ports. Using the SysML internal module diagram, the corresponding ports of the power subsystem SysML module instances and the interaction system SysML module instances are connected through Connectors. 2.5 Subsystem architecture modeling and analysis: Based on the functional architecture and functional interface diagram of the power subsystem, and taking into account historical development experience, technological advancement and manufacturing process factors, identify solutions to realize the key functions of the power subsystem, and define no less than two candidate logical architectures for the power subsystem. Taking into account customer constraints, power subsystem performance characteristics and development costs, the evaluation criteria for candidate power subsystem logical architectures are determined, and the optimal solution is selected based on these evaluation criteria. A typical power subsystem logical architecture includes one engine, two engines, and an auxiliary power unit. 2.6 Subsystem white-box analysis: The internal structure of the power subsystem is opened up, and further functional and performance refinement analysis is carried out based on the opened power subsystem's logical subsystems. The power subsystem's function, functional interface, and performance index model obtained from the analysis in 2.3 is further decomposed until the corresponding model elements can be assigned to the power subsystem's logical subsystems. 2.7 Define model traceability relationships. Establish dependency relationships between SysML modules of the power subsystem and logic subsystem, black-box and white-box functions of the power subsystem, function interfaces, performance indicators, port model elements, and between each model element and requirements, including satisfaction relationships, traceability relationships, and refinement relationships. 2.8 Subsystem → Helicopter Model Integration and Verification: A new IBD diagram is created using the helicopter SysML module as the background environment. This diagram establishes the interface connections between the power subsystem and other helicopter subsystems that interact with it, as well as the interface connections between the power subsystem and external interactive systems / organizations. All ports between the power subsystem and external interactive systems / organizations are connected through the helicopter's ports. The IBD diagram between the helicopter and external interactive systems / organizations is updated to show the interface connections between internal helicopter subsystems and between internal helicopter subsystems and the helicopter itself. The parameter diagram of the helicopter SysML module is updated, supplementing the connection relationships between helicopter-level indicators and power subsystem indicators. Helicopter-level indicators are then concretized into subsystem indicators. Model integration and verification are conducted between the power subsystem and the helicopter, and between the power subsystem and the interactive systems, including verification of behavioral and parameter models.

5. The method according to claim 4, characterized in that: In section 2.3, the specific process of subsystem black-box function and performance analysis is as follows: Based on the normal use scenarios and typical fault scenarios of the power system, such as single-engine failure, low engine oil pressure, and high engine oil temperature, SysML activity diagrams, timing diagrams, and state machine diagrams are used in combination to analyze the functional execution flow, functional execution preconditions, performance index constraints, and emergency operation procedures under abnormal scenarios of the power system and the interaction system, capturing the functional and performance index constraints of the power subsystem in terms of use; functional interaction analysis between the power subsystem and the interaction system is carried out, focusing on the input, output types and directions of various functions of the power subsystem, capturing the functional interfaces and functional interaction items of the power subsystem; Based on the powertrain subsystem maintenance scenario, we will capture the functions and analyze the functional interfaces related to powertrain subsystem maintenance, and analyze which functions and functional interfaces the powertrain subsystem should provide to support the powertrain subsystem maintenance work. Simultaneously use SysML parametric graphs to model the performance index constraints obtained from the above steps.

6. The method according to claim 5, characterized in that: In S3, the specific process is as follows: 3.1 Define the SysML module of the subsystem, taking the auxiliary power unit subsystem of the power subsystem as an example; define the SysML module of the auxiliary power unit subsystem and its typical indicators and constraint formulas. The typical indicators of the auxiliary power unit subsystem include weight, power, output shaft speed and fuel consumption rate. 3.2 Establish the inheritance relationship between the logical subsystems of the subsystem and the subsystem. Use the SysML module definition diagram to establish the inheritance relationship between the SysML module of the auxiliary power unit subsystem and the logical subsystem of the auxiliary power unit defined in 2.5 through the generalization of the SysML language. This allows the auxiliary power unit subsystem to fully inherit the white-box analysis results of the power subsystem and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels. 3.3 Subsystem black-box functional and performance analysis; 3.4 Subsystem SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the functional logic and functional interaction analysis results of the auxiliary power unit subsystem in 3.3, the functional architecture and functional interfaces of the auxiliary power unit subsystem are formed; based on the functional interface interaction items and directions obtained from the analysis in 3.3, the corresponding auxiliary power unit subsystem interface modules and flow attributes are defined, where the flow attributes are used to define the interaction items and directions of the functional interfaces; the ports of the SysML modules of the auxiliary power unit subsystem are defined, and the port type is set to the corresponding interface module; the ports of the interactive system SysML modules are updated and improved. The interfaces of the SysML modules are represented by ports. Using the internal module diagram of SysML, the corresponding ports of the auxiliary power unit SysML module instance and the interactive system SysML module instance are connected through the Connector. 3.5 Subsystem architecture modeling and analysis: Taking into account historical development experience, performance characteristics of auxiliary power units, development costs, technological advancement, and production process factors, based on the functional architecture of the auxiliary power unit subsystem, identify and determine solutions to realize the key functions of the auxiliary power unit subsystem. A typical auxiliary power unit subsystem includes the auxiliary power unit and the auxiliary power unit electronic controller. 3.6 Subsystem white-box analysis: The internal structure of the auxiliary power unit subsystem is opened up, and further functional and performance refinement analysis is carried out based on the opened auxiliary power unit subsystem's logical components. The functional, functional interface, and performance index models of the auxiliary power unit subsystem obtained from the analysis in 3.3 are further decomposed until the corresponding model elements can be assigned to the logical components of the auxiliary power unit subsystem. 3.7 Define model traceability relationships. For the auxiliary power unit subsystem and logical component equipment SysML modules established by SysML language, the black box and white box functions, function interfaces, performance indicators, and port model elements of the auxiliary power unit subsystem, the model elements of this layer and the model elements of the upper layer, and the model elements of this layer and the requirements, establish dependency relationships, including satisfaction relationships, traceability relationships, and refinement relationships. 3.8 Subsystem → Subsystem → Helicopter Model Integration Verification: A new IBD diagram is created using the SysML module of the power subsystem as the background environment. This diagram is used to establish the interface connections between the auxiliary power unit subsystem and other subsystems of the power subsystem that interact with it. It also establishes the interface connections between the auxiliary power unit subsystem and other logical subsystems of the helicopter, as well as between the auxiliary power unit subsystem and external interactive systems / organizations. The connections between the auxiliary power unit subsystem and other logical subsystems of the helicopter, and between the auxiliary power unit subsystem and external interactive systems / organizations, are all through the ports of the power subsystem. Simultaneously, the connection relationships between the affected interface model elements in the IBD diagrams of the power subsystem and other logical subsystems of the helicopter under the SysML module, and the connection relationships between the affected interface model elements in the IBD diagram of the helicopter and external interactive systems / organizations are updated sequentially. The parameter diagrams of the power subsystem SysML module and the helicopter SysML module are updated sequentially. The connection relationship between helicopter-level indicators and power subsystem indicators is supplemented. The more abstract helicopter-level indicators are concretized into measurable indicators of the subsystem, and the indicators of the subsystem are concretized into indicators of the subsystem. Conduct layer-by-layer integrated verification of the models between the auxiliary power unit subsystem, the power subsystem, and the helicopter, considering three aspects: structure, behavior, and parameters.

7. The method according to claim 6, characterized in that: In section 3.3, the subsystem black-box functional and performance analysis process is as follows: The auxiliary power unit subsystem is treated as a whole, without focusing on its internal components. The functional logic, functional interaction, and performance analysis between the auxiliary power unit subsystem and the interaction system are carried out. The interaction system of the auxiliary power unit subsystem includes other logical subsystems of the power subsystem defined in 2.6, other helicopter subsystems defined in 1.6, and external interaction systems / organizations defined in 1.

2. Based on the normal use scenarios and typical fault scenarios of the auxiliary power unit subsystem, such as APU oil supply failure and APU lubricating oil blockage, we combine SysML activity diagrams, timing diagrams and state machine diagrams to conduct functional execution flow, functional execution preconditions, performance index constraints and emergency operation procedures under abnormal scenarios between the auxiliary power unit subsystem and the interaction system. We capture the functional and performance index constraints of the auxiliary power unit subsystem in terms of use, and conduct functional interaction analysis between the auxiliary power unit subsystem and the interaction system. We focus on the input, output types and directions of various functions of the auxiliary power unit subsystem, and capture the functional interfaces and functional interaction items of the auxiliary power unit subsystem. Based on the ground maintenance scenario of the auxiliary power unit subsystem, we conduct function capture and interface analysis related to the ground maintenance of the auxiliary power unit subsystem to analyze which functions and interfaces the auxiliary power unit subsystem should provide to support the engine maintenance work; at the same time, we use SysML parametric diagrams to model the performance index constraints obtained from the above analysis.

8. The method according to claim 7, characterized in that: In S4, the specific process is as follows: 4.1 Define the equipment SysML module, and select the equipment - electronic controller of the auxiliary power unit subsystem as an example; 4.2 Establish the inheritance relationship between the logical components of the subsystem and the auxiliary power unit electronic controller. Use the SysML module definition diagram and establish the inheritance relationship between the SysML module of the auxiliary power unit electronic controller and the logical components of the auxiliary power unit subsystem defined in 3.5 through the generalization of the SysML language. This will enable the auxiliary power unit electronic controller to fully inherit the white-box analysis results of the auxiliary power unit subsystem and carry out further modeling and analysis on this basis, thereby ensuring the consistency of the model between different levels. 4.3 Equipment Function and Performance Analysis: Based on the normal use scenarios and typical fault scenarios of the auxiliary power unit electronic controller, SysML activity diagrams, timing diagrams and state machine diagrams are used in combination to conduct functional logic and functional interaction analysis between the auxiliary power unit electronic controller and the interactive system. SysML parametric diagrams are used simultaneously to model the performance index constraints of the auxiliary power unit electronic controller. 4.

4. Equipment SysML Module Interface Modeling and Analysis: Using the SysML module definition diagram, based on the functional logic and functional interaction analysis results of the auxiliary power unit electronic controller in 4.3, the functional architecture and functional interfaces of the auxiliary power unit electronic controller are formed; based on the functional interface interaction items and directions obtained from the analysis in 4.3, the corresponding interface modules and flow attributes of the auxiliary power unit electronic controller are defined, where the flow attributes are used to define the interaction items and directions of the functional interfaces; the ports of the auxiliary power unit electronic controller SysML module are defined, and the port type is set to the corresponding interface module; the ports of the interaction system SysML module are updated and improved, where the interfaces of the SysML module are represented using ports; Using the SysML internal module diagram, the corresponding ports of the auxiliary power unit electronic controller SysML module instance and the interactive system SysML module instance are connected through the Connector. 4.5 Integrate supplier equipment models. Based on the white-box analysis results of the auxiliary power unit subsystem, the aircraft design unit integrates the SysML models submitted by relevant equipment manufacturers of the auxiliary power unit subsystem at the equipment level to ensure that the interface relationships, functions, and performance of each device conform to the upper-level definition. 4.6 Define model traceability relationships. Establish dependency relationships between auxiliary power unit electronic controllers, auxiliary power unit electronic controller functions, function interfaces, performance indicators, and port model elements established through SysML language, between model elements in this layer and upper-layer model elements, and between model elements in this layer and requirements. These relationships include satisfaction relationships, traceability relationships, and refinement relationships. 4.7 Equipment → Subsystem → Subsystem → Helicopter Model Integration and Verification: A new IBD diagram is created using the SysML module of the auxiliary power unit subsystem as the background environment. This diagram establishes the interface connections between the auxiliary power unit electronic controller and other interacting devices, as well as between the auxiliary power unit electronic controller and other logical subsystems of the helicopter, and between the auxiliary power unit electronic controller and external interactive systems / organizations. All connections between the auxiliary power unit electronic controller and other logical subsystems of the helicopter, and between the auxiliary power unit electronic controller and external interactive systems / organizations, are made through the ports of the auxiliary power unit subsystem. Simultaneously, the connection relationships between affected interface model elements in the IBD diagram under the SysML module of the power subsystem, the connection relationships between affected interface model elements in the IBD diagram between the power subsystem and other logical subsystems of the helicopter under the SysML module of the helicopter, and the connection relationships between affected interface model elements in the IBD diagram between the helicopter and external interactive systems / organizations are updated sequentially. The parameter diagrams of the auxiliary power unit subsystem SysML module, the power subsystem SysML module, and the helicopter SysML module are updated sequentially to supplement the connection relationship between helicopter-level indicators and power subsystem indicators. That is, the more abstract helicopter-level indicators are concretized into measurable indicators of the subsystem, and the indicators of the subsystem are concretized into indicators of the subsystem. The model is integrated and verified layer by layer between the auxiliary power unit electronic controller, the auxiliary power unit subsystem, the auxiliary power unit subsystem, the power subsystem, and the helicopter, mainly considering three aspects: structure, behavior, and parameters.

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