A lunar activity mission modeling method and system based on MBSE

Abstract

A method and system for modeling lunar surface activity tasks based on MBSE, the invention relates to the field of system engineering technology. The invention is to solve the problem of high complexity of lunar surface activities and difficulty in task modeling. The invention includes modeling lunar surface activity tasks of "task-subtask-metatask" based on the binary relationship of "function-requirement" of lunar surface activity tasks; formulating lunar surface activity event standards oriented to deduction, taking lunar surface personnel equipment entities or entity sets as behavioral subjects, discrete time and space domains as index dimensions, and entity behaviors or state changes as basic events, to construct a spatiotemporal event sequence model that characterizes the dynamic process of entity sets; treating lunar surface activity tasks as systems, adopting a top-down approach, starting from requirements, and establishing a lunar surface activity model based on MBSE. The invention is used for modeling lunar surface activity tasks.

Description

Technical Field

[0001] The present invention relates to the technical field of system engineering, and in particular to a lunar surface activity task modeling method and system based on MBSE. Background Art

[0002] MBSE (Model-Based Systems Engineering) originates from a deep understanding of the needs of complex system development and the challenge of coping with them. With the rapid development of science and technology, especially in the fields of aerospace, automobiles, medical equipment, software development and energy, the complexity and integration of systems are constantly increasing, and traditional system engineering methods can no longer meet the needs of modern system development.

[0003] MBSE, as an emerging system engineering method, aims to guide the full life cycle management of complex systems by establishing system models. It emphasizes that in the system design and development process, all stages, from requirements analysis, architecture design, simulation verification to final delivery and maintenance, should be based on a unified system model. This model-based approach not only improves the efficiency and quality of system design, but also reduces the risk and cost of system development.

[0004] The lunar surface activity mission involves knowledge and technology from multiple disciplines, such as aerospace technology, robotics, communication technology, environmental science, etc. It is a relatively complex mission system. MBSE can clearly express and present each link, element and relationship in the lunar surface activity mission through the system modeling method. Therefore, a lunar surface activity mission modeling method and system based on MBSE is provided to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of high complexity of lunar activities and difficulty in task modeling, and further provide a method and system for lunar activity task modeling based on MBSE. The present invention gives full play to the management ability of MBSE for the entire life cycle of complex systems, so it is suitable for task modeling of complex lunar activities.

[0006] The technical solution adopted by the present invention to solve the above problems is: a lunar activity task modeling method based on MBSE, comprising:

[0007] The first step is to model the lunar surface activity tasks based on the binary relationship of "function-requirement" of lunar surface activity tasks, i.e. "task-subtask-meta-task";

[0008] The second step is to formulate the lunar surface activity event standards for deduction, taking lunar surface personnel and equipment entities or entity sets as the behavior subjects, discrete time and space domains as the index dimensions, and the behavior or state changes of the entities as the basic events, to build a spatiotemporal event sequence model that characterizes the dynamic process of the entity set;

[0009] The third step is to regard the lunar surface activity mission as a system, adopt a top-down approach, and establish a lunar surface activity model based on MBSE based on demand.

[0010] Preferably, the first step is to model the lunar surface activity task of "task-subtask-meta-task" based on the binary relationship of "function-requirement" of the lunar surface activity task, and the specific steps include:

[0011] S1. First, a formal description of lunar surface activity tasks is given;

[0012] S2. Next, the tasks are decomposed based on the functional requirements.

[0013] Preferably, in S1, the lunar surface activity mission is formally described, and the specific steps also include:

[0014] Determine the components of lunar surface activity missions based on expected goals;

[0015] Analyze the relationship between the lunar surface activity subtasks vertically and determine the task hierarchy of lunar surface activity tasks;

[0016] Horizontally analyze the temporal relationship between lunar surface activity meta-tasks;

[0017] Consider the granularity of task decomposition, that is, the description of how finely the task is decomposed.

[0018] Preferably, in S2, task decomposition based on functional requirement relationships is performed, and the specific steps further include:

[0019] The lunar surface activity mission acquires the subtasks and metatasks it focuses on by performing the functions required by the mission;

[0020] The hierarchical structure model is used as the result of the layer-by-layer correspondence between subtasks and metatasks to achieve the decomposition of lunar surface activity tasks;

[0021] The lunar surface activity mission organizes subtasks and meta-task sets hierarchically through functional requirements, maps the requirement relationship into the task hierarchy generation process, and enables the task hierarchy model to formally describe the lunar surface activity mission.

[0022] Preferably, the second step is to formulate the lunar activity event standard for deduction, taking the lunar personnel and equipment entity or entity set as the behavior subject, the discrete time and space domain as the index dimension, and the behavior or state change of the entity as the basic event, and constructing the spatiotemporal event sequence model that characterizes the dynamic process of the entity set. The specific steps include:

[0023] S1. First, construct the "event" model in the lunar surface activity mission;

[0024] S2. Then construct a spatiotemporal event sequence.

[0025] Preferably, the specific steps of constructing the "event" model in the lunar surface activity mission in S1 also include:

[0026] The lunar surface entity set with similar or collaborative capabilities and oriented to the same tasks is abstracted into a class. The attributes of the class correspond to the common capabilities and states of the entity set, the methods of the class correspond to the common behaviors of the entity set, and the relationship between the classes is reflected in the association, collaboration, dependency and other relationships between the entities in the task realization process. The instance of the class is the individual or collection of individuals in the entity set.

[0027] Time is abstracted into three types: moment, period, and duration. A moment expresses instantaneous time, that is, a point on the timeline; a period expresses continuous time, that is, a section on the timeline; and duration expresses an attribute, a measure of the continuity of a behavior or state expressed by only a numerical value.

[0028] Spatial abstraction is divided into three types: position, area and shape. Position is a discrete point or set of points in space. Area is a continuous block in space, which can be closed or non-closed. The most common one is a rectangular area. Shape is the spatial occupancy property of an entity, which is generally approximated by polygons. It has nothing to do with the specific spatial position and only reflects the form of the entity itself.

[0029] Preferably, the specific step of constructing the spatiotemporal event sequence in S2 further includes:

[0030] The model is expressed as SES = {Mission, Time, Space, Eventi}, where Mission is the lunar activity mission of SES, Time is the effective period corresponding to the mission, Space is the spatial area corresponding to the mission, and Eventi is the event sequence. The event sequence is an ordered set of events corresponding to the meta-task division and organized according to the time and task implementation logic.

[0031] Preferably, the spatiotemporal event sequence model includes a spatiotemporal event sequence model for astronauts' cabin activities and a spatiotemporal event sequence model for astronauts' cabin activities:

[0032] The spatiotemporal event sequence model of astronauts entering the cabin is constructed as follows: “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is normal) – astronauts open the hatches on both sides – astronauts enter the mobile laboratory”. / “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is abnormal) – laboratory status check (laboratory failure is not serious) – astronauts report problems – astronauts repair (laboratory returns to normal) – astronauts enter the mobile laboratory”. / “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is abnormal) – laboratory status check (laboratory failure is serious) – astronauts report problems – ground command center gives maintenance plan – astronauts evacuate”;

[0033] Construct a spatiotemporal event sequence model for astronauts’ extravehicular activities: “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is no abnormality in the extravehicular space suit function) – astronauts put on extravehicular space suits – cabin depressurization – astronauts open the cabin door and walk out of the cabin” / “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is abnormality in the extravehicular space suit function) – check the status of the extravehicular space suit (the fault of the extravehicular space suit is not serious) – astronauts report problems – astronauts repair (the extravehicular space suit returns to normal) – astronauts put on extravehicular space suits – cabin depressurization – astronauts open the cabin door and walk out of the cabin” / “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is abnormality in the extravehicular space suit function) – check the status of the extravehicular space suit (the fault of the extravehicular space suit is serious) – astronauts report problems – the ground command center gives a repair plan – the astronauts terminate the extravehicular activities”.

[0034] Preferably, in the third step, the lunar surface activity task is regarded as a system, and a top-down approach is adopted to establish a lunar surface activity model based on MBSE based on the requirements. The specific steps include:

[0035] Use the requirement diagram in MBSE to implement requirement analysis;

[0036] Use the module definition diagram in MBSE to implement task system structure analysis;

[0037] Use the module definition diagram and activity diagram in MBSE to build the task model;

[0038] Use sequence diagrams in MBSE to analyze time logic relationships;

[0039] Use state machine diagram to show the dynamic process of tasks.

[0040] Another technical solution adopted by the present invention to solve the above problem is: a lunar activity task modeling system based on MBSE, comprising:

[0041] The lunar surface activity task module is configured to perform lunar surface activity task modeling of "task-subtask-metatask" based on the "function-requirement" binary relationship of the lunar surface activity task;

[0042] A space-time event sequence establishment module is configured to develop a deduction-oriented lunar surface activity event standard, taking lunar surface personnel and equipment entities or entity sets as the behavior subjects, discrete time and space domains as the index dimensions, and the behavior or state changes of the entities as the basic events, to build a space-time event sequence model that characterizes the dynamic process of the entity set;

[0043] The lunar surface activity establishment module is configured to regard the lunar surface activity task as a system, adopt a top-down approach, and establish an MBSE-based lunar surface activity model based on requirements.

[0044] The present invention has the following beneficial technical effects:

[0045] The present invention decomposes and abstracts the lunar surface activity mission system, converts complex system problems into a series of relatively simple sub-problems for processing, can intuitively grasp the overall structure, functions and performance requirements of the mission, and helps to improve design efficiency.

[0046] The present invention uses the universal modeling language SysML, which can enable technicians in different disciplines to communicate and cooperate using the same method at the same time, and is suitable for lunar surface activity tasks involving multi-disciplinary knowledge and technology.

[0047] The MBSE of the present invention supports comprehensive simulation and verification of the system, simulation and verification of the entire process of lunar surface activity missions, simulation of actual working environment and conditions, and comprehensive testing and evaluation of the system. The present invention gives full play to the management ability of MBSE for the entire life cycle of complex systems, and is thus suitable for mission modeling of complex lunar surface activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flow chart of a method for modeling lunar surface activity tasks based on MBSE of the present invention;

[0049] Figure 2 It is a demand analysis diagram of manned lunar surface activities of the present invention;

[0050] Figure 3 This is a lunar surface activity operation process and executor module definition diagram of the present invention

[0051] Figure 4 This is a diagram of a lunar surface activity mission system of the present invention;

[0052] Figure 5 It is a flowchart for astronauts entering a cabin described by an activity diagram of the present invention;

[0053] Figure 6 It is an astronaut exit flow chart described by an internal flow chart of the present invention;

[0054] Figure 7 It is a task decomposition model of the lunar surface activity task based on the functional requirement relationship of the present invention;

[0055] Figure 8 It is a lunar mission event-related model;

[0056] Fig. 9 It is a “white box” model of events oriented to deduction;

[0057] Fig.10 It is a three-dimensional structural model of the lunar surface activity mission workflow. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0059] Specific implementation method 1: Combination Figures 1 to 10 To illustrate this embodiment, the present invention provides a lunar activity task modeling method based on MBSE, comprising:

[0060] The first step is to model the lunar surface activity tasks based on the binary relationship of "function-requirement" of lunar surface activity tasks, i.e. "task-subtask-meta-task";

[0061] The second step is to formulate the lunar surface activity event standards for deduction, taking lunar surface personnel and equipment entities or entity sets as the behavior subjects, discrete time and space domains as the index dimensions, and the behavior or state changes of the entities as the basic events, to build a spatiotemporal event sequence model that characterizes the dynamic process of the entity set;

[0062] The third step is to regard the lunar surface activity mission as a system, adopt a top-down approach, and establish a lunar surface activity model based on MBSE based on demand.

[0063] In a preferred embodiment, the first step is to model the lunar surface activity task of "task-subtask-meta-task" based on the binary relationship of "function-requirement" of the lunar surface activity task, and the specific steps include:

[0064] S1. First, a formal description of lunar surface activity tasks is given;

[0065] S2. Next, the tasks are decomposed based on the functional requirements.

[0066] In a preferred embodiment, the lunar surface activity mission is formally described in S1, and the specific steps also include:

[0067] Determine the components of lunar surface activity missions based on expected goals;

[0068] Analyze the relationship between the lunar surface activity subtasks vertically and determine the task hierarchy of lunar surface activity tasks;

[0069] Horizontally analyze the temporal relationship between lunar surface activity meta-tasks;

[0070] Consider the granularity of task decomposition, that is, the description of how finely the task is decomposed.

[0071] In a preferred embodiment, in S2, task decomposition based on functional requirement relationships is performed, and the specific steps further include:

[0072] The lunar surface activity mission acquires the subtasks and metatasks it focuses on by performing the functions required by the mission;

[0073] The hierarchical structure model is used as the result of the layer-by-layer correspondence between subtasks and metatasks to achieve the decomposition of lunar surface activity tasks;

[0074] The lunar surface activity mission organizes subtasks and meta-task sets hierarchically through functional requirements, maps the requirement relationship into the task hierarchy generation process, and enables the task hierarchy model to formally describe the lunar surface activity mission.

[0075] In a preferred embodiment, the second step is to formulate a deduction-oriented lunar activity event standard, with lunar personnel and equipment entities or entity sets as the behavior subjects, discrete time and space domains as index dimensions, and entity behaviors or state changes as basic events. The specific steps of constructing a spatiotemporal event sequence model that characterizes the dynamic process of entity sets include:

[0076] S1. First, construct the "event" model in the lunar surface activity mission;

[0077] S2. Then construct a spatiotemporal event sequence.

[0078] In a preferred embodiment, the specific steps of constructing the "event" model in the lunar activity mission in S1 also include:

[0079] The lunar surface entity set with similar or collaborative capabilities and oriented to the same tasks is abstracted into a class. The attributes of the class correspond to the common capabilities and states of the entity set, the methods of the class correspond to the common behaviors of the entity set, and the relationship between the classes is reflected in the association, collaboration, dependency and other relationships between the entities in the task realization process. The instance of the class is the individual or collection of individuals in the entity set.

[0080] Time is abstracted into three types: moment, period, and duration. A moment expresses instantaneous time, that is, a point on the timeline; a period expresses continuous time, that is, a section on the timeline; and duration expresses an attribute, a measure of the continuity of a behavior or state expressed by only a numerical value.

[0081] Spatial abstraction is divided into three types: position, area and shape. Position is a discrete point or set of points in space. Area is a continuous block in space, which can be closed or non-closed. The most common one is a rectangular area. Shape is the spatial occupancy property of an entity, which is generally approximated by polygons. It has nothing to do with the specific spatial position and only reflects the form of the entity itself.

[0082] In a preferred embodiment, the specific step of constructing the spatiotemporal event sequence in S2 further includes:

[0083] The model is expressed as SES = {Mission, Time, Space, Eventi}, where Mission is the lunar activity mission of SES, Time is the effective period corresponding to the mission, Space is the spatial area corresponding to the mission, and Eventi is the event sequence. The event sequence is an ordered set of events corresponding to the meta-task division and organized according to the time and task implementation logic.

[0084] In a preferred embodiment, the spatiotemporal event sequence model includes a spatiotemporal event sequence model for astronauts' cabin entry activities and a spatiotemporal event sequence model for astronauts' cabin exit activities:

[0085] The spatiotemporal event sequence model of astronauts entering the cabin is constructed as follows: “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is normal) – astronauts open the hatches on both sides – astronauts enter the mobile laboratory”. / “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is abnormal) – laboratory status check (laboratory failure is not serious) – astronauts report problems – astronauts repair (laboratory returns to normal) – astronauts enter the mobile laboratory”. / “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is abnormal) – laboratory status check (laboratory failure is serious) – astronauts report problems – ground command center gives maintenance plan – astronauts evacuate”;

[0086] Construct a spatiotemporal event sequence model for astronauts’ extravehicular activities: “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is no abnormality in the extravehicular space suit function) – astronauts put on extravehicular space suits – cabin depressurization – astronauts open the cabin door and walk out of the cabin” / “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is abnormality in the extravehicular space suit function) – check the status of the extravehicular space suit (the fault of the extravehicular space suit is not serious) – astronauts report problems – astronauts repair (the extravehicular space suit returns to normal) – astronauts put on extravehicular space suits – cabin depressurization – astronauts open the cabin door and walk out of the cabin” / “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is abnormality in the extravehicular space suit function) – check the status of the extravehicular space suit (the fault of the extravehicular space suit is serious) – astronauts report problems – the ground command center gives a repair plan – the astronauts terminate the extravehicular activities”.

[0087] In a preferred embodiment, the third step regards the lunar surface activity task as a system, adopts a top-down approach, and establishes a lunar surface activity model based on MBSE based on requirements. The specific steps include:

[0088] Use the requirement diagram in MBSE to implement requirement analysis;

[0089] Use the module definition diagram in MBSE to implement task system structure analysis;

[0090] Use the module definition diagram and activity diagram in MBSE to build the task model;

[0091] Use sequence diagrams in MBSE to analyze time logic relationships;

[0092] Use state machine diagram to show the dynamic process of tasks.

[0093] In a preferred embodiment, the lunar surface activity mission is formally described

[0094] Lunar surface activity missions often involve multiple disciplines. It is a process of determining the mission structure and function and making mission decisions using knowledge reasoning methods. It can be represented by a three-dimensional model similar to the Hall three-dimensional structure, namely the knowledge dimension, event dimension and process dimension, such as Fig.10 shown.

[0095] Fig.10 In the figure, the knowledge dimension represents the knowledge resources needed for reasoning about lunar surface activity tasks. It is the information flow throughout the entire task simulation process, including low-level multi-source heterogeneous data, intermediate-level situation understanding knowledge, and high-level situation prediction knowledge. The function dimension represents that the lunar surface activity task is an abstract overall task. The tasks can be modularized according to their functions and decomposed into different subtasks. The mapping between the lunar surface entities and the subtasks is completed by the functional requirements. The process dimension represents the temporal relationship between each task. According to the priority principle and causal relationship, the execution order of the tasks is determined.

[0096] When formally describing the lunar surface activity mission, it is necessary to formally describe the concept of the lunar surface activity mission, starting from the expected goal, determine the components of the lunar surface activity mission; then vertically analyze the relationship between the lunar surface activity subtasks to determine the task hierarchy of the lunar surface activity mission; finally, horizontally analyze the temporal relationship between the lunar surface activity metatasks. Formal description is the process of realizing the lunar surface activity mission from abstraction to instantiation. The steps of the formal description process of the lunar surface activity mission are as follows.

[0097] Step 1: Formalize the concept and purpose of lunar surface activity missions;

[0098] Step 2: Decompose the lunar surface activity task to obtain the subtask space set of the lunar surface activity task;

[0099] Step 3: According to the granularity of the research problem, determine whether the lunar surface activity subtasks have been decomposed. If so, proceed to step 4; otherwise, go to step 2.

[0100] Step 4: Determine the meta-tasks of lunar activities based on the logical demand relationship between tasks and behaviors, and analyze the temporal relationship between meta-tasks;

[0101] Step 5: According to the task pruning rules, the hierarchical structure of lunar surface activity tasks is unified and the hierarchical relationship of lunar surface activity tasks is adjusted;

[0102] Step 6: Assign the lunar surface activity meta-tasks to the corresponding task units, and establish a mapping relationship between the meta-tasks and task units based on the capability requirements.

[0103] Task decomposition is the core of the formal description of lunar surface activity tasks. It is the process of decomposing lunar surface activity tasks into several lunar surface activities according to the overall mission objectives. The decomposition of lunar surface activity tasks is to decompose the given lunar surface activity tasks into several sub-tasks with appropriate granularity, which have no direct connection within the same level and are executed in parallel as much as possible.

[0104] 1) Decomposition ideas

[0105] The goal of lunar surface activity task decomposition is to achieve a fast and efficient solution to the space mission according to certain rules, and the decomposition method is in line with human cognition. Since the lunar surface activity task is a situation-level event, the idea of ​​hierarchical decomposition of the lunar surface activity task is to decompose the lunar surface activity task into many independent subtasks with clear structural hierarchies and at the same level with a dominant role in the task structure hierarchy.

[0106] 2) Decomposition level

[0107] The lunar surface activity task hierarchy is a refinement and concretization of the abstract concept of tasks. It has a tree-like hierarchical structure and consists of subtasks and meta-tasks. The relevant task concepts are defined below.

[0108] (1) Task: It is a series of orderly spatial activities carried out by the entity unit to complete the mission it undertakes under a certain spatial environment and space-time constraints.

[0109] (2) Sub-Task. The lunar surface activity task is modularized according to the functional requirements required to complete the task and the decision points that users are concerned about in command decision-making. Each module unit needs to have the function set required to perform the lunar surface activity task, and these function sets need to be supported and completed by the corresponding lunar surface activity sub-task set. A large function is realized by multiple sub-tasks, and each sub-task corresponds to a functional capability. Therefore, the module unit and the task can be matched according to the functional requirements to obtain the lunar surface activity sub-task set.

[0110] (3) Meta-Task. Meta-task is a task that can be completed directly by entity units. Meta-tasks are independent of each other and are at the lowest end of the lunar surface activity task hierarchy and cannot be divided any further. It consists of an action sequence and can be solved based on the logical relationship between the meta-task and the situation factor requirements and completed by the task execution entity unit.

[0111] 1) Functional requirements for lunar surface activities

[0112] The execution of lunar surface activity missions revolves around various functions, and functions are the specific embodiment of missions. The overall function of the lunar surface mission is a complex system function, which can be decomposed into a series of sub-functions and implemented by different mission module unit groups. Therefore, it is logical to analyze the space mission based on the functional requirement relationship, which can clarify the structural hierarchy of the lunar surface activity mission. The functional requirements of the lunar surface activity mission are defined based on the binary relationship between "function-task".

[0113] The functional requirement relationship of lunar surface activity tasks plays an important role in the decomposition process of space missions. The binary requirement relationship of "function-task" can constrain the hierarchical structure generation process of lunar surface activity tasks, that is, after the total lunar surface activity task determines the function set it contains through formal description, the functional requirement relationship is used to determine the subtask set that completes different functions, and then the hierarchical structure of lunar surface activity tasks is obtained. Functional background construction can make space commanders clear what tasks are needed to complete each function, so as to decompose the lunar surface activity tasks accordingly.

[0114] Let F be the function set, T be the task set, and I be the binary relationship between F and T, indicating that there is a demand relationship between tasks and functions, that is, Then K = (F, T, I) is called the functional background of the space mission.

[0115] The lunar surface activity task decomposition framework based on functional requirements relationship is as follows: Figure 7 As shown in the figure. The lunar surface activity task obtains the subtasks and metatasks of interest by executing the functions required by the task, and then uses the hierarchical model as the result of the layer-by-layer correspondence between subtasks and metatasks to achieve the decomposition of the lunar surface activity task. The lunar surface activity task hierarchically organizes the subtask and metatask set through functional requirements, maps the requirement relationship to the task hierarchy generation process, and enables the task hierarchy model to formally describe the lunar surface activity task.

[0116] 3) Lunar surface activity task decomposition process

[0117] Step 1: Constructing the list of functional requirements for lunar surface activity tasks. According to the formal description of lunar surface activity tasks and the mission objectives of the decomposition and research mission, determine the set of functional requirements for executing lunar surface activity tasks, and construct the list of functions required for executing lunar surface activity tasks;

[0118] Step 2: Obtaining the task space set. According to the temporal relationship and functional relationship, the lunar surface activity tasks are preliminarily decomposed according to the logical demand relationship between "task-function" to obtain a series of independent main predefined subtasks to form the task space set;

[0119] Step 3: Based on the functional principle and the lunar surface activity task structure, the lunar surface activity predefined subtasks are decomposed into a series of mutually independent secondary predefined subtasks and predefined meta-tasks of different granularities, forming the lunar surface activity task subtask set and meta-task set, and constructing a task list;

[0120] Step 4: Determine whether the task has been decomposed. If so, go to Step 5; otherwise, go to Step 3;

[0121] Step 5: Build a functional background list and a task background list to determine the degree of coverage between the decomposed tasks and the functions required by the tasks;

[0122] Step 6: Obtain the decomposed lunar activity task hierarchy model.

[0123] In simulation, it is important to emphasize the spatiotemporal properties of events. Similar events may differ greatly when they occur at different times and in different spaces. For example, in the case of the same "astronaut manual surface sampling" event, there is a big difference between the duration of the event and the state transition of the astronaut when the astronaut takes a sample on the flat ground after a rest and when the astronaut takes a sample on the slope after a long period of continuous work. Therefore, it is necessary to develop a lunar activity event class with a standard interface to support the normal operation of the simulation algorithm.

[0124] The materialization result of the mission is ultimately manifested as a set of entity units and their behavior states. In order to facilitate the effective description and deduction of the result, the concept of spatiotemporal event series is proposed. Spatiotemporal event series (SES) is a serialization model that uses lunar surface personnel and equipment entities or entity sets as behavioral subjects, discrete time and space domains as index dimensions, and entity behavior or state changes as basic events to express the dynamic process of entity sets.

[0125] Events in SES refer to the behaviors or states of entity objects (Entity) that are closely related to lunar surface activity tasks in specific time slices (Time Slice) and space regions (Space Region). In lunar surface activity applications, various types of entity units are uniformly abstracted as targets, which are the core elements that determine the current status and development trends of lunar surface activities. In the complex lunar surface environment, targets are generally represented as vector point objects (including movement trends), their activity paths (trajectories) are represented as line elements, and their detection and activity ranges are represented as surface elements. Therefore, the geographical expression of events in the lunar surface environment is reflected in the limited point objects and their attached line and surface elements in a specific time and space domain, as well as the logical relationships between points, lines, and surfaces. This structure has great similarities with objects in program design, so modeling events based on object-oriented thinking is undoubtedly the most adaptable.

[0126] The "event" in the lunar surface activity mission is a discrete image of the behavior or state of the target entity in the spatiotemporal domain. The construction idea of ​​its object model is as follows: the lunar surface entity set with similar or collaborative capabilities and facing the same type of tasks is abstracted into a class. The attributes of the class correspond to the common capabilities and states of the entity set, and the methods of the class correspond to the common behaviors of the entity set. The relationship of the class is reflected in the association, collaboration, dependency and other relationships between the entities in the task implementation process. The instance of the class is the individual or individual set in the entity set. Time is abstracted into three types: moment, period and duration. The moment expresses instantaneous time, that is, a point on the time axis; the period expresses continuous time, that is, a section on the time axis; the duration expresses an attribute, which is a measure of the continuity of behavior or state expressed by only one numerical value. The time relationship is manifested in 7 types: lead (<), lag (>), simultaneous (=), quasi-simultaneous (≈), not earlier than (≥), not later than (≤), and between (<>). In the lunar surface activity mission, "space" is abstracted into three types: position, area and shape. Position is a discrete point or point set in space. Area is a continuous block in space, which can be closed or non-closed. The most common is a rectangular area. Shape is the spatial occupancy property of an entity, which is generally approximated by polygons. It has nothing to do with the specific spatial position and only reflects the entity's own form. Spatial relationships are expressed in 6 types: Disjoint, Touch, Overlap, Equal, Contain, and Within. The event-related model definition is as follows: Figure 8 shown.

[0127] The spatiotemporal event sequence is a set of events for the realization of tasks in a specific time and space. Its model can be expressed as SES = {Mission, Time, Space, Eventi}, where Mission is the lunar activity mission facing SES, Time is the effective period corresponding to the mission, and Space is the spatial area corresponding to the mission. The event sequence is reflected as an ordered set of events corresponding to the meta-task division and organized according to the time and task realization logic.

[0128] Fig. 9 The event description method shown is a black box model, which does not give the specific dynamic process inside the event and cannot realize dynamic simulation deduction. Therefore, it is necessary to establish a "white box" model of the event when performing single event dynamic deduction simulation.

[0129] The "white box" model of events needs to further decompose the events into a series of basic actions of the entity (other events can also be called as basic actions), call the required entity models, algorithms and rules from the simulation support library, and calculate the state transition of the entity in executing these actions according to the set time step.

[0130] Specific implementation method 2: Combination Figures 1 to 10 To illustrate this embodiment, the present invention further provides a lunar activity task modeling system based on MBSE, comprising:

[0131] The lunar surface activity task module is configured to perform lunar surface activity task modeling of "task-subtask-metatask" based on the "function-requirement" binary relationship of the lunar surface activity task;

[0132] A space-time event sequence establishment module is configured to develop a deduction-oriented lunar surface activity event standard, taking lunar surface personnel and equipment entities or entity sets as the behavior subjects, discrete time and space domains as the index dimensions, and the behavior or state changes of the entities as the basic events, to build a space-time event sequence model that characterizes the dynamic process of the entity set;

[0133] The lunar surface activity establishment module is configured to regard the lunar surface activity task as a system, adopt a top-down approach, and establish an MBSE-based lunar surface activity model based on requirements.

[0134] Specific implementation method three: Combination Figures 1 to 10 To illustrate this embodiment, the present invention provides a method for modeling lunar surface activity tasks based on MBSE. The flowchart of the present invention is as follows: Figure 1 As shown, the specific steps are as follows:

[0135] Step 1: Based on the binary relationship of "function-requirement" of lunar surface activity tasks, form a lunar surface activity task system of "task-subtask-meta-task".

[0136] First, the lunar surface activity tasks are formally described. 1) Starting from the expected goals, determine the components of the lunar surface activity tasks. 2) Vertically analyze the relationship between the lunar surface activity subtasks and determine the task hierarchy of the lunar surface activity tasks. 3) Horizontally analyze the temporal relationship between the lunar surface activity metatasks. 4) Consider the granularity of task decomposition, that is, the description of the degree of refinement of task decomposition.

[0137] Secondly, the task is decomposed based on the functional requirement relationship. 1) The lunar surface activity task obtains the subtasks and metatasks of its concern by executing the functions required by the task. 2) The hierarchical model is used as the result of the layer-by-layer correspondence between subtasks and metatasks to achieve the decomposition of the lunar surface activity task. 3) The lunar surface activity task organizes the subtask and metatask set hierarchically through functional requirements, maps the requirement relationship to the task hierarchy generation process, so that the task hierarchy model can formally describe the lunar surface activity task.

[0138] Step 2: Formulate a deduction-oriented lunar activity event standard, take lunar personnel and equipment entities or entity sets as the behavioral subjects, discrete time and space domains as index dimensions, and the behavior or state changes of entities as basic events, and build a spatiotemporal event series (SES) model that characterizes the dynamic process of the entity set.

[0139] First, the "event" model in the lunar surface activity mission is constructed. 1) The lunar surface entity set with similar or collaborative capabilities and facing the same type of tasks is abstracted into a class. The attributes of the class correspond to the common capabilities and states of the entity set, and the methods of the class correspond to the common behaviors of the entity set. The relationship between the class is reflected in the association, collaboration, dependency and other relationships between the entities in the task implementation process. The instance of the class is the individual or individual set in the entity set. 2) Time is abstracted into three types: moment, period and duration: moment expresses instantaneous time, that is, a point on the time axis; period expresses continuous time, that is, a section on the time axis; duration expresses an attribute, which is a measure of the continuity of behavior or state expressed by only one numerical value. 3) Space is abstracted into three types: position, area and shape: position is a discrete point or point set in space; area is a continuous block in space, which can be closed or non-closed, and the most common is a rectangular area; shape is the spatial occupancy attribute of the entity, generally approximated by polygons, which has nothing to do with the specific spatial position and only reflects the entity's own form.

[0140] Secondly, construct a spatiotemporal event sequence. Its model can be expressed as SES = {Mission, Time, Space, Eventi}, where Mission is the lunar activity mission for SES, Time is the effective period corresponding to the mission, Space is the spatial area corresponding to the mission, and Eventi is the event sequence. The event sequence is reflected as an ordered set of events corresponding to the meta-task division and logically organized according to time and task implementation.

[0141] Step 3: Treat the lunar surface activity mission as a system, adopt a top-down approach, and start from the requirements to implement the MBSE-based lunar surface activity model.

[0142] The specific implementation steps are as follows: 1) Use the requirement diagram in MBSE to implement requirement analysis. 2) Use the module definition diagram in MBSE to implement task system structure analysis. 3) Use the module definition diagram and activity diagram in MBSE to build the task model. 4) Use the sequence diagram in MBSE to analyze the time logic relationship. 5) Use the state machine diagram to display the dynamic process of the task.

[0143] Specific implementation method four: Combination Figures 1 to 10To illustrate this implementation method, execute step one: based on the binary relationship of "function-requirement" of lunar surface activity tasks, form a lunar surface activity task system of "task-subtask-meta-task".

[0144] First, the lunar surface activity tasks are formally described. The manned lunar surface activity scenarios based on the manned lunar mobile laboratory are decomposed into: astronauts entering the cabin, astronauts leaving the cabin; astronauts' in-cabin scientific experiments, astronauts' lunar-based astronomical observations, astronauts driving the mobile laboratory, and astronauts' in-cabin life; astronauts' extravehicular scientific experiments 1 (lunar earthquake experiments), astronauts' extravehicular scientific experiments 2 (electromagnetic experiments), astronauts' extravehicular scientific experiments 3 (low-temperature experiments), and astronauts' extravehicular scientific experiments 4 (vacuum experiments); astronauts' sample collection 1 (astronauts' manual surface collection), astronauts' sample collection 2 (robot deep drilling sampling); astronauts' topographic and geological detailed survey 1 (manned scientific research station site selection), astronauts' topographic and geological detailed survey 2 (resource development station site selection), astronauts' topographic and geological detailed survey 3 (lunar-based take-off and landing base site selection), and astronauts' topographic and geological detailed survey 4 (lunar surface road planning); astronauts' complex terrain detection 1 (lunar crater detection), and astronauts' complex terrain detection 2 (lunar lava pipeline detection).

[0145] Secondly, tasks are decomposed based on the functional requirements. The manned lunar activity requirements of the manned lunar mobile laboratory are decomposed into full-month arrival capability construction, astronaut lunar life support capability verification, human-machine collaborative operation mode exploration and capability construction, lunar scientific research requirements, lunar-based scientific experiment requirements, engineering construction requirements, and technical verification requirements.

[0146] The process from demand analysis to goal demonstration, plan formulation to the specific implementation of lunar surface activities and the corresponding executors are given, so as to establish the binary relationship between demand and function in each step. The executor of the manned lunar surface activity mission demand is the ground general design department; the executor of the manned lunar surface activity mission goal is the ground general design department; the executor of the manned lunar surface activity mission plan is the ground general design department, the ground model team, and the ground astronaut training center; the executors of the manned lunar surface activity mission event are the ground command center, the lunar manned lunar mobile laboratory, the lunar astronaut crew, the lunar lunar landing spacecraft, and the lunar unmanned lunar equipment.

[0147] Execute step two: formulate deduction-oriented lunar activity event standards, take lunar personnel and equipment entities or entity sets as behavioral subjects, discrete time and space domains as index dimensions, and entity behaviors or state changes as basic events, and build a spatiotemporal event sequence model that characterizes the dynamic process of entity sets.

[0148] The spatiotemporal event sequence model of astronauts entering the cabin is constructed as follows: “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is normal) – astronauts open the hatches on both sides – astronauts enter the mobile laboratory”. / “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is abnormal) – laboratory status check (laboratory failure is not serious) – astronauts report problems – astronauts repair (laboratory returns to normal) – astronauts enter the mobile laboratory”. / “Mission site selection – mobile laboratory arrives at the designated location – lunar module lands – lunar module docks with laboratory – astronauts check the status of mobile laboratory (laboratory is abnormal) – laboratory status check (laboratory failure is serious) – astronauts report problems – ground command center gives maintenance plan – astronauts evacuate”;

[0149] Construct a spatiotemporal event sequence model for astronauts’ extravehicular activities: “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is no abnormality in the extravehicular space suit function) – astronauts put on extravehicular space suits – cabin depressurization – astronauts open the cabin door and walk out of the cabin” / “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is abnormality in the extravehicular space suit function) – check the status of the extravehicular space suit (the fault of the extravehicular space suit is not serious) – astronauts report problems – astronauts repair (the extravehicular space suit returns to normal) – astronauts put on extravehicular space suits – cabin depressurization – astronauts open the cabin door and walk out of the cabin” / “Selection of coordinates and start time for extravehicular activities – astronauts enter the extravehicular preparation area – astronauts check extravehicular service functions (there is abnormality in the extravehicular space suit function) – check the status of the extravehicular space suit (the fault of the extravehicular space suit is serious) – astronauts report problems – the ground command center gives a repair plan – the astronauts terminate the extravehicular activities”.

[0150] Execute step three: Taking the astronauts' lunar activity scenario based on the manned lunar mobile laboratory as an example, establish the MBSE model of lunar activity events.

[0151] 1) First, analyze the needs of the scenario as follows Figure 2 The demand analysis starts from strategic needs, scientific needs and engineering needs, and sorts out the needs of manned lunar activities based on the specific platform of the manned lunar mobile laboratory, which are divided into the needs of full-month arrival capability construction, the needs of astronaut lunar life support capability verification, the needs of human-machine collaborative operation mode exploration and capability construction, lunar scientific research needs, lunar-based scientific experiment needs, engineering construction needs, and technical verification needs.

[0152] The SysML modeling tool used in the present invention is MBSES developed by Zhirui Siwei. Figure 2 The cross circle in the figure represents an inclusion relationship. The manned lunar surface activity requirement of the manned lunar mobile laboratory is the first requirement, and the other requirements in the figure are sub-requirements of this requirement.

[0153] 2) Starting from the demand analysis, the module definition diagram is used to give the process from demand analysis to target demonstration, plan formulation and then to the specific implementation of lunar activities and the corresponding executors, so as to establish the binary relationship between the demand and function of each step, such as Figure 3 shown.

[0154] 3) Focus on Figure 3 In the lunar surface activity mission event, we can see that the executors involved in the lunar surface activity mission include the ground command center, astronaut crew, manned lunar mobile laboratory, lunar landing spacecraft, and various unmanned lunar surface equipment. On this basis, the module definition diagram is used to sort out the lunar surface activity mission system, such as Figure 4 shown. Figure 4 Each module in is a subtask in the lunar surface activity, which can be described using an activity diagram or an internal module diagram. For subtasks with judgment branch structures, such as astronauts entering the manned lunar surface mobile laboratory, use an activity diagram to describe it, such as Figure 5 For subtasks without branch structures, internal module diagrams can be used to connect actions in series to describe their processes, such as Figure 6 shown.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lunar activity mission modeling method based on MBSE, characterized in that: include: The first step is to model the lunar surface activity tasks based on the binary relationship of "function-requirement" of lunar surface activity tasks, i.e. "task-subtask-meta-task"; The second step is to formulate the lunar activity event standards for deduction. Taking lunar personnel and equipment entities or entity sets as the behavior subjects, discrete time and space domains as the index dimensions, and entity behavior or state changes as the basic events, a spatiotemporal event sequence model is constructed to characterize the dynamic process of the entity set. The specific steps include: S1. First, construct the "event" model in the lunar surface activity mission. The specific steps include: The lunar surface entity set with similar or collaborative capabilities and oriented to the same type of tasks is abstracted into a class. The attributes of the class correspond to the common capabilities and states of the entity set, the methods of the class correspond to the common behaviors of the entity set, and the relationship between the classes is reflected in the association, collaboration, and dependency between the entities in the task realization process. The instance of the class is the individual or collection of individuals in the entity set. Time is abstracted into three types: moment, period, and duration; Space is abstracted into three types: location, area, and shape; S2. Then construct a space-time event sequence, wherein the space-time event sequence model includes a space-time event sequence model for astronauts' cabin entry activities and a space-time event sequence model for astronauts' cabin exit activities; The third step is to regard the lunar surface activity mission as a system, adopt a top-down approach, and establish a lunar surface activity model based on MBSE based on demand.

2. The MBSE-based lunar activity task modeling method according to claim 1 is characterized by: The first step is to model the lunar surface activity task of "task-subtask-meta-task" based on the binary relationship of "function-requirement" of lunar surface activity tasks. The specific steps include: S1. First, a formal description of lunar surface activity tasks is given; S2. Next, the tasks are decomposed based on the functional requirements.

3. The MBSE-based lunar activity task modeling method according to claim 2 is characterized by: S1 formally describes the lunar surface activity mission, and the specific steps include: Determine the components of lunar surface activity missions based on expected goals; Analyze the relationship between the lunar surface activity subtasks vertically and determine the task hierarchy of lunar surface activity tasks; Horizontally analyze the temporal relationship between lunar surface activity meta-tasks; Consider the granularity of task decomposition, that is, the description of how finely the task is decomposed.

4. The MBSE-based lunar activity task modeling method according to claim 2 is characterized by: In S2, tasks are decomposed based on functional requirements, and the specific steps include: The lunar surface activity mission acquires the subtasks and metatasks it focuses on by performing the functions required by the mission; The hierarchical structure model is used as the result of the layer-by-layer correspondence between subtasks and metatasks to achieve the decomposition of lunar surface activity tasks; The lunar surface activity mission organizes subtasks and meta-task sets hierarchically through functional requirements, maps the requirement relationship into the task hierarchy generation process, and enables the task hierarchy model to formally describe the lunar surface activity mission.

5. The MBSE-based lunar activity task modeling method according to claim 1 is characterized by: In S1, the moment expresses instantaneous time, i.e., a point on the time axis; the period expresses continuous time, i.e., a segment on the time axis; the duration expresses an attribute, a measure of the continuity of a behavior or state expressed by only one numerical value; The position is a discrete point or a set of points in space; the area is a continuous block in space, which can be closed or non-closed, and the most common is a rectangular area; the shape is the spatial occupancy property of the entity, which is approximated by polygons. It has nothing to do with the specific spatial position and only reflects the shape of the entity itself.

6. The MBSE-based lunar activity task modeling method according to claim 1 is characterized by: The specific steps of constructing the spatiotemporal event sequence in S2 also include: The model is expressed as SES={Mission, Time, Space, Eventi}, where Mission is the lunar activity mission of SES, Time is the effective period corresponding to the mission, Space is the spatial area corresponding to the mission, and Eventi is the event sequence. The event sequence is an ordered set of events corresponding to the meta-task division and organized according to the time and task implementation logic.

7. The MBSE-based lunar activity task modeling method according to claim 1 is characterized by: The spatiotemporal event sequence model of the astronauts' cabin entry activities is constructed as follows: "mission site selection - mobile laboratory arrives at the designated location - lunar module lands - lunar module docks with the laboratory - astronauts check the status of the mobile laboratory, and the inspection result shows that there is no abnormality in the laboratory - astronauts open the doors on both sides - astronauts enter the mobile laboratory"; Or "mission site selection - mobile laboratory arrives at designated site - lunar module lands - lunar module docks with laboratory - astronauts check mobile laboratory status, laboratory abnormality is detected - laboratory status check, laboratory failure is not serious - astronauts report problem - astronauts repair, laboratory returns to normal after repair - astronauts enter mobile laboratory"; Or "mission site selection - mobile laboratory arrives at designated site - lunar module lands - lunar module docks with laboratory - astronauts check mobile laboratory status, the result is abnormality - laboratory status check, the result is serious malfunction - astronauts report the problem - ground command center gives maintenance plan - astronauts evacuate"; Constructing the spatiotemporal event sequence model of the astronauts' extravehicular activities: "selection of the coordinates and start time of the extravehicular activities - the astronauts enter the extravehicular preparation area - the astronauts check the extravehicular space service functions, and the check results show that there is no abnormality in the extravehicular space suit functions - the astronauts put on the extravehicular space suits - the cabin depressurizes - the astronauts open the cabin door and walk out of the cabin"; Or "selection of EVA coordinates and start time - astronauts enter EVA preparation area - astronauts check EVA service functions, and the result shows that the EVA suit functions abnormally - EVA suit status check, and the result shows that the EVA suit malfunctions not seriously - astronauts report the problem - astronauts repair, and the EVA suit returns to normal after repair - astronauts put on EVA suits - cabin depressurization - astronauts open the cabin door and walk out"; Or "The coordinates and start time of the extravehicular activity are selected - the astronauts enter the extravehicular preparation area - the astronauts check the extravehicular space service functions, and the inspection results show that the extravehicular space suit functions abnormally - the extravehicular space suit status is checked, and the inspection results show that the extravehicular space suit has a serious malfunction - the astronauts report the problem - the ground command center gives a maintenance plan - the astronauts terminate the extravehicular activity." 8. The MBSE-based lunar activity task modeling method according to claim 1 is characterized by: The third step is to regard the lunar surface activity mission as a system, adopt a top-down approach, and establish a lunar surface activity model based on MBSE based on the needs. The specific steps include: Use the requirement diagram in MBSE to implement requirement analysis; Use the module definition diagram in MBSE to implement task system structure analysis; Use the module definition diagram and activity diagram in MBSE to build the task model; Use sequence diagrams in MBSE to analyze time logic relationships; Use state machine diagram to show the dynamic process of tasks.

9. A lunar activity mission modeling system based on MBSE, characterized in that: include: The lunar surface activity task module is configured to perform lunar surface activity task modeling of "task-subtask-metatask" based on the "function-requirement" binary relationship of the lunar surface activity task; The spatiotemporal event sequence establishment module is configured to formulate the lunar surface activity event standard for deduction, taking the lunar surface personnel and equipment entity or entity set as the behavior subject, the discrete time and space domain as the index dimension, and the entity's behavior or state change as the basic event, to build a spatiotemporal event sequence model that characterizes the dynamic process of the entity set: The space-time event sequence establishment module includes the "event" module in the lunar surface activity mission and the space-time event sequence module. The "event" module in the lunar surface activity mission is configured to abstract the lunar surface entity set with similar or collaborative capabilities and oriented to the same type of mission into a class. The attributes of the class correspond to the capabilities and states shared by the entity set, and the methods of the class correspond to the behaviors shared by the entity set. The relationship of the class is reflected in the association, collaboration, and dependency between the entities in the process of mission realization. The instance of the class is the individual or individual collection in the entity set; Time is abstracted into three types: moment, period, and duration; Space is abstracted into three types: location, area, and shape; A space-time event sequence module, which is configured such that the space-time event sequence model includes a space-time event sequence model for astronauts entering the cabin and a space-time event sequence model for astronauts leaving the cabin; The lunar surface activity establishment module is configured to regard the lunar surface activity task as a system, adopt a top-down approach, and establish an MBSE-based lunar surface activity model based on requirements.

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