Distributed simulation system and device based on DDS

Abstract

The invention provides a distributed simulation system and device based on a DDS (Direct Digital Synthesizer), which can meet the requirements of the accuracy of a human-in-loop semi-physical simulation process of an aircraft, the data publishing / subscribing real-time performance of each component, the compatibility of development software of each professional subsystem, the interactivity of third-party data and simulation data and the reusability and expansibility of a model. A distributed simulation system operation framework is utilized, access of a heterogeneous system is supported, and finally confrontation between a human-in-loop semi-physical simulation system and an illusion party generated by a computer is achieved. An HLA distributed simulation architecture thought is adopted, simulation system data can be interacted through a real-time network through DDS middleware, and interaction content comprises flight simulation data, control panel data, visual head-up display data and MFD data.

Description

Technical Field

[0001] The present invention relates to the field of distributed computing and simulation technology, and in particular to a distributed simulation system and device based on DDS. Background Art

[0002] The semi-physical real-time simulation system of aircraft "man-in-the-loop" is often composed of a complex network environment with multiple platforms and subsystems. The amount of interactive data is also growing exponentially, presenting a complex many-to-many relationship between data sources and data requirements, as well as the actual situation of cross-cutting in time, space and data flow control. It is urgent to solve the problems of interconnection, intercommunication, functional expansion, data synchronization, interaction, expansion, bridging and centralized solution between simulation systems in the distributed heterogeneous environment of software systems, realize the integration of various subsystems of semi-physical real-time simulation of aircraft "man-in-the-loop", support the integrated interconnection of internal subsystems of each simulation system and other heterogeneous systems, and data interaction during joint simulation experiments, have functions such as data communication middleware, interface development and interface adaptation, provide efficient data interaction services and access services, and provide interfaces for future remote networking. These are urgent needs for the architecture design and application of the semi-physical real-time simulation system of aircraft "man-in-the-loop". Summary of the invention

[0003] In view of the defects in the prior art, the object of the present invention is to provide a distributed simulation system and device based on DDS.

[0004] The DDS-based distributed simulation system provided by the present invention comprises:

[0005] Front-end UI management subsystem: performs human-computer interaction and realizes interconnection and interoperability among subsystems based on DDS data communication middleware;

[0006] Hardware resource control subsystem: Centrally control the platform hardware components and provide underlying support for the simulation business layer;

[0007] Simulation platform business control subsystem: manages and controls the simulation business carried by the simulation platform;

[0008] Simulation data recording and playback subsystem: stores and manages the simulation interaction data generated during the simulation process, and provides a visual analysis interface and data playback interface;

[0009] Simulation system timing synchronization subsystem: performs platform software timing synchronization, takes the system time of a server or computer as the reference point, and regularly uses the DDS network to publish time information to all nodes in the simulation system. After receiving the time information, each node obtains its own system time and calculates the difference, so that all nodes in the entire simulation system can achieve time synchronization;

[0010] Third-party bridging subsystem: obtain third-party system data as required, convert and inject into the simulation platform; obtain simulation platform data as required and inject into the third-party system;

[0011] The front-end UI management subsystem, hardware resource management subsystem, simulation platform business management subsystem and simulation data recording and playback subsystem are connected to the master control node; the simulation system timing synchronization subsystem is connected to the system server through DDS; the third-party bridging subsystem connects the third-party system and the master control node.

[0012] Preferably, the front-end UI management subsystem includes: database configuration and network service configuration of the main control system;

[0013] Database system configuration includes hypothetical database configuration and physical database configuration;

[0014] The network service system configuration includes the master control network service configuration, the three-dimensional situation network service configuration and the DDS network configuration;

[0015] The master control network service configuration items and the three-dimensional situation network service configuration items have the service IP address and port number, and the DDS network configuration items have the network type and domain ID; the master control network service is used to provide services to simulation nodes; the three-dimensional situation network service provides services to the three-dimensional environment visualization monitoring system and provides simulation data for its entities; the DDS network provides real-time data communication support for distributed simulation systems. All simulation nodes on the DDS network transmit data through the publish and subscribe mechanism, providing a topic-based data publish / subscribe model. By configuring the publish / subscribe relationship between each subsystem, plug-and-play discovery of each node is achieved and data interaction is completed.

[0016] Preferably, the hardware resource management and control subsystem includes a server and a client;

[0017] The server is used to collect and display information about each node on the platform and the working status of each model process in the scene, provide basic control commands for the simulation platform, and support the display of network topology;

[0018] The client is used to receive files and commands / scripts sent by the server, collect node local information and system-related model process information, and report to the server.

[0019] Preferably, the server includes:

[0020] UI: Displays the information of each platform node and the working status of each model;

[0021] Command / file control module: including initialization, start, pause, stop commands, files and scripts;

[0022] Data transmission module: receives data collected by the client in the form of messages or TCP / IP, UDP, or DDS communication protocols;

[0023] Data sorting module: Integrate the received node information and model information for UI display.

[0024] Preferably, the client comprises:

[0025] Command / file receiving module: receives commands, files, and scripts sent by the server;

[0026] Data collection module: collects local node information, including CPU model, CPU usage, memory size, memory usage, and system-related model information;

[0027] Data sorting module: sort and merge the collected data in a fixed format;

[0028] Data transmission module: reports the collected data to the server in the form of messages or TCP / IP, UDP, or DDS communication protocols.

[0029] Preferably, the simulation platform business management and control subsystem includes:

[0030] Simulation model operating environment generation module: responsible for assembling the models required for this simulation into simulation units;

[0031] Simulation scenario configuration module: organizes the assumption information of each aircraft equipment set by the user through the UI interface, generates all assumption information, and pushes it to each subsystem in the distributed simulation system;

[0032] Simulation platform monitoring module: During the simulation process, real-time observation of the two teams’ mission execution in the airspace is carried out, and the simulation process is observed through two-dimensional maps and three-dimensional situation observation;

[0033] Simulation platform model control module: during the simulation process, it can perform control operations including initialization, running, pausing / resuming and stopping of a simulation game at any time;

[0034] Simulation model deployment module: Model deployment and integration of the simulation platform, configuration component class function management of all configuration information related to flight experiment design and configuration management system, including configuration of the system, communication configuration of external systems, connection database configuration, assumption format configuration and resource allocation configuration of distributed systems;

[0035] Simulation model management module: responsible for external model checking, uploading new models to the system, deleting existing models in the system, creating model objects, modifying model objects, deleting model objects, model list display, and model object list display.

[0036] Preferably, the simulation system timing synchronization subsystem includes:

[0037] Provide time management server tools to obtain the physical time and logical time of the time server, publish time information to each subsystem node through the time synchronization service of the distributed data interaction middleware, and enable each node to complete time calibration and synchronization;

[0038] Apply network time synchronization technology, that is, build an NTP server in the local area network to achieve automatic time synchronization.

[0039] Preferably, the simulation system timing synchronization subsystem includes:

[0040] Management submodule: responsible for starting, executing and stopping the simulation timing service;

[0041] Timing service submodule: responsible for timing services, including timer processing, publishing system physical time to DDS middleware, and obtaining simulation system physical time;

[0042] The management submodule is responsible for starting and stopping the service of the timing service submodule. After the service is started, the timer is started to calculate and obtain the system physical reference time of the simulation system timing synchronization subsystem and publish it to the DDS network;

[0043] The subsystems of each simulation system obtain the reference time data and simulation data through DDS data subscription, and then synchronize the reference time to the subsystems of each simulation system.

[0044] Preferably, the third-party bridging subsystem includes: a software bridging module and a physical device bridging module, which separates abstraction from implementation and replaces inheritance relationship with composition relationship, thereby reducing the coupling degree of the two variable dimensions of abstraction and implementation. It has interface adaptation function, and is based on middleware. It completes data mapping with other heterogeneous system transmission protocols through a bridging gateway, and realizes the access, conversion and transmission of third-party system data and simulation platform data. It supports time synchronization, communication protocol conversion, data interface conversion, DR processing, data acquisition, data transmission and reception management functions between various aircraft simulation systems to realize data interaction.

[0045] The DDS-based distributed simulation device provided according to the present invention includes the DDS-based distributed simulation system.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) Using a centralized server for internal data interaction can reduce system pressure caused by large amounts of data;

[0048] (2) The third-party bridging subsystem is adopted, which can access the third-party system through interface data injection and has good scalability;

[0049] (3) The system architecture adopts a data synchronization mechanism, that is, after each node completes a frame, it will return a completion mark to the system framework. After receiving the completion marks of all nodes, the system framework will advance to the next frame, thus ensuring the synchronization of system operation;

[0050] (4) The subsystem functions were integrated, and the front-end UI management subsystem, hardware resource management subsystem, simulation business management subsystem, and simulation data recording and playback subsystem were integrated into a set of master control systems, which makes it more convenient for simulation operators to conduct simulation experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0052] Figure 1 This is the overall system architecture diagram;

[0053] Figure 2 It is the system hardware deployment diagram;

[0054] Figure 3 It is the interaction relationship diagram between each module;

[0055] Figure 4 This is the composition diagram of the console front-end UI subsystem;

[0056] Figure 5 Set up graphs for distributed simulation systems;

[0057] Figure 6 It is the system structure diagram;

[0058] Figure 7 This is the server structure diagram;

[0059] Figure 8 This is the client structure diagram;

[0060] Fig. 9 Manage business process diagrams for models;

[0061] Fig.10 Design diagrams for classes;

[0062] Fig.11 Design diagrams for classes;

[0063] Fig.12 It is the system structure diagram;

[0064] Fig.13 This is the system architecture diagram;

[0065] Fig.14 Publish timing diagrams for timing;

[0066] Fig.15 Subscribe timing diagram for simulation nodes;

[0067] Fig.16 This is a schematic diagram of the management module;

[0068] Fig.17 For timing service diagram;

[0069] Fig.18 It is the system flow chart;

[0070] Fig.19 This is a schematic diagram of interface format conversion;

[0071] Fig. 20 This is the structural diagram of the connection between XSim and the system;

[0072] Fig.21 This is the structural diagram of the overall control system. DETAILED DESCRIPTION

[0073] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0074] Example

[0075] The present invention provides a method for designing a distributed aircraft "man-in-the-loop" semi-physical real-time simulation system framework based on the DDS specification, which can meet the accuracy of the aircraft "man-in-the-loop" semi-physical simulation process, the real-time publication / subscription of each component data, the compatibility of various professional subsystem development software, the interactivity of third-party data and simulation data, and the reusability and extensibility requirements of the model. It uses a distributed simulation system operation framework to support the access of heterogeneous systems, and ultimately realizes the confrontation between the "man-in-the-loop" semi-physical simulation system and the computer-generated phantom party. The design method adopts the HLA distributed simulation architecture idea. Through the DDS middleware, the simulation system data can be interacted through the real-time network. The interactive content includes flight simulation data, control panel data, visual head-up display data, and MFD data. The overall system architecture is as follows: Figure 1 shown.

[0076] DDS can generate corresponding framework codes according to the files specified by idl. Users can develop interface programs for interconnection between simulation systems by developing idl interfaces.

[0077] The system framework supports Windows and Linux systems, and supports domestic operating systems and domestic chips. The overall system adopts "centralized-distributed", that is, the deployment is centralized and the architecture is distributed. The system uses DDS to realize data interaction between nodes through subscription and publishing. Due to the large amount of data and its continuous expansion, the system currently uses two topics: Topic1 and Topic2. Topic1 is the basic data, mainly physical, electromagnetic and key event data, which interacts through Ethernet and is mainly used for third-party interaction or distributed deployment; Topic2 is system data, including most of the data generated by the simulation system, which interacts through shared memory and is used for data interaction within the simulator. It has interface adaptation function, can complete data mapping with other heterogeneous system transmission protocols based on middleware through bridging gateway, and realize the access, conversion and transmission of third-party system data and simulation platform data, support the provision of time synchronization, communication protocol conversion, data interface conversion, DR processing, data acquisition, data transmission and reception management and other functions between various aircraft simulation systems, and realize data interaction. This design method can comprehensively improve the computing power of the "man-in-the-loop" semi-physical real-time simulation of aircraft, and lay the foundation for providing more accurate "man-in-the-loop" semi-physical aircraft simulation training.

[0078] The simulation operation framework includes a total of six subsystems: the simulation system front-end UI subsystem, the simulation platform hardware resource management and control subsystem, the simulation platform business management and control subsystem, the simulation data recording and playback subsystem, the simulation system timing synchronization subsystem, and the third-party data bridging subsystem. The six subsystems interact with data through DDS. The simulation system front-end UI subsystem is responsible for human-computer interaction, such as scenario editing; the simulation platform hardware resource management and control subsystem is responsible for hardware monitoring, and the simulation platform business management and control subsystem is responsible for the simulation process, such as simulation initialization, start, and stop; the simulation data recording and playback subsystem is responsible for data recording and playback; the simulation system timing synchronization subsystem is responsible for system synchronization; and the third-party data bridging subsystem is responsible for the access of heterogeneous systems. In terms of hardware deployment, a centralized computing approach is adopted. The deployment of the six subsystems is as follows: Figure 2 shown.

[0079] The system server is responsible for the operation and solution of the entire simulation system. The flight simulation models are all run in the server. The interaction between the flight simulation system display and control equipment (mainly including MFD, vision, HUD, etc.) is completed through the flight simulator terminal interaction node.

[0080] Among the six subsystems of the simulation framework, the front-end UI management subsystem, hardware resource management subsystem, simulation business management subsystem, and simulation data recording and playback subsystem are implemented through the master control node. The simulation system timing synchronization subsystem and the third-party bridge subsystem are both implemented with separate computers.

[0081] (1) Console front-end UI subsystem

[0082] The console front-end UI subsystem mainly completes the human-computer interaction function, and the DDS-based data communication middleware completes the interconnection and interoperability between various subsystems. The middleware adopts standard middleware technical specifications, provides data interaction capabilities between nodes in the distributed system, provides a graphical human-computer interface for the simulation platform comprehensive management and control subsystem, supports human-computer interaction between users and the simulation model management module, simulation model operating environment generation module, simulation business control module, and simulation data recording and playback subsystem, and supports dynamic screen display of the simulation business monitoring module. The user operates the interaction relationship between the console front-end UI subsystem and each module, such as Figure 3 shown.

[0083] The console front-end UI subsystem is mainly divided into the main page, simulation model management page, simulation model operating environment generation page, simulation business control page, simulation data recording and playback page, simulation business monitoring page, hardware resource management page, and system settings page. Figure 4 shown.

[0084] The system settings mainly include the database configuration and network service configuration of the main control system, such as Figure 5 shown.

[0085] Database system configuration includes assumption database configuration and entity database configuration (including configuration information of plug-in entity, model entity and entity assembly);

[0086] The network service system configuration includes the master control network service configuration, three-dimensional situation network service configuration and DDS network configuration.

[0087] The configuration items of the master control network service and the three-dimensional situation network service include the IP address and port number of the service. The DDS network configuration items include the type of network and the domain ID. The master control network service is mainly used to provide services to the simulation node subsystem and the flight resource management subsystem (optional). The three-dimensional situation network service mainly provides services to the three-dimensional environment visualization monitoring system and provides simulation data for its entities. The DDS network mainly provides real-time and efficient data communication support for distributed simulation systems. All simulation nodes on the network transmit data through a publish and subscribe mechanism, providing a topic-based data publish / subscribe model. By configuring the publish / subscribe relationship between each subsystem, plug-and-play discovery of each node can be achieved and data interaction can be completed.

[0088] (2) Hardware Resource Management Subsystem

[0089] The hardware resource control subsystem completes the centralized control of the platform hardware components and provides underlying support for the simulation business layer. The hardware platform control system consists of two parts: the server and the client. The server is mainly used to collect and display the information of each node on the platform, the working status information of each model process in the scene, provide basic control commands for the simulation basic platform, and support the display of the network topology structure; the client is mainly used to receive files and commands / scripts issued by the server, collect node local information, system-related model process information, and report to the server.

[0090] The hardware system structure is as follows Figure 6 As shown. It has a variety of service quality management (QoS) strategies, such as reliable transmission, best effort transmission, data periodicity, node existence, etc. Different subsystem nodes can meet different needs for data interaction and transmission by configuring QoS strategies. It has a relay-based data forwarding function to ensure that there is only one data link for data communication between subsystems across network segments or across LANs, which is forwarded through relays to reduce data traffic across network segments and across LANs.

[0091] UI: Displays information of each node on the platform and working status of each model;

[0092] Server: collects information about each platform node, working status information of each model process in the scene, and provides basic control commands for the simulation basic platform;

[0093] Client: Receives files / scripts sent by the server, receives commands sent by the server, collects local node information (CPU model, CPU usage, memory size, memory usage), collects system-related model information, and uploads the collected information to the server.

[0094] The server structure diagram is as follows Figure 7 shown.

[0095] Command / file control module: includes initialization, start, pause, stop and other commands, files and scripts.

[0096] Data transmission module: Receives data collected by the client in the form of messages or communication protocols such as TCP / IP, UDP, and DDS.

[0097] Data sorting module: Integrate the received node information and model information for UI display.

[0098] The client structure is as follows Figure 8 shown.

[0099] The client structure includes:

[0100] Command / file receiving module: receiving commands, files, scripts, etc. sent by the server;

[0101] Data collection module: collects node local information (CPU model, CPU usage, memory size, memory usage), and collects system-related model information;

[0102] Data sorting module: sort and merge the collected data into a fixed format;

[0103] Data transmission module: reports the collected data to the server in the form of messages or communication protocols such as TCP / IP, UDP, DDS, etc.

[0104] (3) Simulation platform business control subsystem

[0105] The simulation platform business management and control subsystem is mainly responsible for the management and control of the simulation business carried by the system simulation platform, as well as business-related auxiliary functions. It is specifically divided into the following six modules: simulation model management module, simulation model operating environment generation module, simulation scenario configuration module, simulation platform monitoring module, simulation platform model control module and simulation model deployment module.

[0106] The simulation model management module is responsible for external model checking, uploading new models to the system, deleting existing models in the system, creating model objects, modifying model objects, deleting model objects, displaying model lists, and displaying model object lists.

[0107] The simulation model operating environment generation module is responsible for assembling the models required for this simulation into simulation units, for example, assembling flight, radar, electronic warfare, weapon and other models into an aircraft entity as a simulation unit.

[0108] Model management business process such as Fig. 9 shown.

[0109] The simulation scenario configuration module mainly includes the scenario management module, the two-dimensional map management module, the flight unit ID design and the class design. In addition to the flight object, a simulation exercise also requires the setting of flight-related scenario information, such as: setting the flight grouping information of both parties, how many task units each group has, the initial position (GPS coordinates) of each task unit entering the airspace, flight altitude, flight direction, fuel, pilot ID, flight unit ID and other information.

[0110] Organize the assumption information of each aircraft equipment set by the user through the UI interface, generate all assumption information, and push it to each subsystem in the distributed system through the network communication module.

[0111] Class design such as Fig.10 shown.

[0112] The interface design program logic is as follows:

[0113] [void getLoadPlanDestDir()]

[0114] Read the mount scheme copy generation path and write to dir

[0115] [void getTypesInfoDestDir()]

[0116] Read type definition copy generation path, write to dir

[0117] [bool readScenarioInitInf()]

[0118] Select to read the scenario plan file in the specified path, or create a new empty scenario plan

[0119] [bool readImagUIInfo()]

[0120] Read scenario interface configuration information

[0121] [bool saveXML()]

[0122] Save the current scenario plan as an XML file

[0123] [void readSendXML()]

[0124] Read the currently edited scenario plan content

[0125] [bool sendXML()]

[0126] Push the edited scenario plan

[0127] [void clearAllInfo()]

[0128] Clear the currently edited scenario plan content

[0129] Simulation platform monitoring module: During the simulation process, users can observe the process of both teams performing tasks in the airspace in real time, and users can observe the simulation process more intuitively through two-dimensional maps and three-dimensional situation. The functions of this module include: two-dimensional map simulation function, three-dimensional situation simulation function, key event display function, flight unit list display function, and flight unit detailed information display function.

[0130] Simulation platform model control module: During the simulation process, users can initialize, run, pause / resume, stop, and other control operations on a simulation game at any time. Interactive users who use TCP for instructions can pause or stop the simulation process at any time during the simulation process.

[0131] Simulation model deployment module: model deployment and integration of simulation platform. Configuration component class functions manage all configuration information related to flight experiment design and configuration management system, including configuration of this system, communication configuration of external system, connection database configuration, assumption format configuration and resource allocation configuration of distributed system.

[0132] Class design such as Fig.11 shown.

[0133] The interface design program logic is as follows:

[0134] [void setDBConfig()]

[0135] Set database connection configuration

[0136] [void setNetConfig()]

[0137] Setting network connection configuration

[0138] [void setResourceConfig()]

[0139] Set system resource configuration

[0140] [void setXMLFormat()]

[0141] Set XML configuration format information

[0142] [void setSimConfig()]

[0143] Set up common simulation configuration

[0144] (4) Simulation data recording and playback subsystem

[0145] The simulation platform data recording and playback subsystem is used to store and manage the simulation interaction data generated during the simulation process, and provides a visual analysis interface and data playback interface to facilitate the review and analysis of the simulation process.

[0146] (5) Simulation system timing synchronization subsystem

[0147] It mainly completes the timing synchronization of the platform software. Using the system time of a server or computer as a reference point, the DDS network is used to regularly publish time information to all nodes in the simulation system. After receiving the time information, each node obtains its own system time and calculates the difference, so that all nodes in the entire simulation system can achieve time synchronization.

[0148] The simulation system timing synchronization subsystem needs to provide a time management server tool that can obtain the physical time and logical time of the time server, publish time information to each subsystem node through the time synchronization service of the distributed data interaction middleware, and enable each node to complete time calibration and synchronization.

[0149] Architecture such as Fig.12 shown.

[0150] The timing synchronization subsystem can be used as the time source for the entire distributed simulation system. This subsystem can act as a time server to provide reference time to all simulation nodes, and can also act as a simulation cycle booster for the entire simulation system.

[0151] After obtaining the system time source from the time server, the time data is periodically published through the DDS communication middleware on the network. Each node of the simulation system also obtains the base time of the system by subscribing to the time data of the DDS communication middleware in the same domain on the network.

[0152] Unifying the above mechanisms ensures time synchronization of the entire distributed simulation system.

[0153] The big data generation and processing system is a cluster of various computing devices. The computing devices use unified and synchronized standard time to record the timing of various events, such as E-MAIL information, log information, file creation and access time, database processing time, etc.

[0154] The control, calculation, processing, application and other data or operations between different computing devices in the big data system are all time-series. If the computer time is not synchronized, these applications or operations may not be able to proceed normally.

[0155] Big data systems are time-sensitive computing and processing systems. Time synchronization is the basic guarantee for big data to be processed correctly and is the technical support for big data to play its role.

[0156] In the era of big data, big data communications within the entire processing and computing system are carried out through the network.

[0157] The same is true for time synchronization, which uses the Internet of big data to transmit standard time information and achieve time synchronization within the big data system.

[0158] In order to ensure the accuracy of the physical time of the timing synchronization subsystem, network time synchronization technology can be applied, that is, to build an NTP server in the local area network to achieve automatic timing.

[0159] The Network Time Protocol (NTP) is the technical basis of time synchronization.

[0160] In the same LAN, we can build our own NTP time synchronization server. The timing synchronization subsystem sends time synchronization request instructions to the fixed IP and port of the NTP time server regularly or on demand through the TCP / IP network protocol. After receiving the request, the server returns the reference time to the timing synchronization subsystem.

[0161] After the timing synchronization subsystem receives the reference time returned by the NTP time synchronization server, it can publish the reference time data to the DDS communication middleware.

[0162] For all simulation system nodes that have subscribed to the topic data from the DDS communication middleware and registered callbacks, once the timing synchronization subsystem publishes the time data, they will immediately receive the data it publishes. After receiving the time data, each simulation node will synchronize its simulation node time.

[0163] The simulation timing synchronization subsystem only needs to be synchronized once through the NTP service, and it needs to be based on user needs. If the user needs to manually synchronize the simulation timing synchronization subsystem time, there is no need to set up an NTP server.

[0164] System architecture Fig.13 shown.

[0165] The distributed simulation system consists of a simulation control subsystem (including front-end UI control), a timing synchronization subsystem, a simulation node subsystem, and other subsystems (hardware resource management and control, simulation data recording and playback, and three-party data bridging).

[0166] The timing synchronization subsystem is mainly composed of a management submodule and a timing service submodule, and is started and stopped by the simulation control subsystem through the management submodule.

[0167] The management submodule is responsible for starting, executing and stopping the simulation timing service.

[0168] The timing service submodule is responsible for timing services, including timer processing, publishing system physical time to the DDS middleware, and executing to obtain the physical time of the simulation system.

[0169] The management submodule is responsible for starting and stopping the timing service submodule. After the service is started, the timer is turned on, and the system physical reference time of the timing synchronization subsystem is calculated and obtained regularly. The data publishing submodule is responsible for publishing the reference time data to the DDS network.

[0170] The simulation node subsystem can obtain the reference time data and simulation data through DDS data subscription. After successfully obtaining the reference time data, the reference time can be synchronized to each simulation node subsystem.

[0171] DDS (Data Distribution Service) communication middleware is the basis of all data communications in this subsystem. It is a new generation of distributed real-time communication middleware protocol, adopts a publish / subscribe architecture, emphasizes data-centricity, and provides a rich QoS service quality strategy to ensure real-time, efficient, and flexible data distribution, which can meet the needs of various distributed real-time communication applications. Therefore, using this middleware as the basis for data communication can meet the real-time, accurate, and efficient synchronization of the system time of the simulation system subnodes.

[0172] The "Time Management Service" is used to synchronize the clocks of each simulation subsystem unit node in the distributed system. During the simulation deduction process of the "Simulation Platform", since different simulation subsystems may be deployed on different PC terminals, the system time of different PC terminals may be different, so the time recorded in the logs generated during the simulation deduction process is different, which will cause trouble for subsequent processing and log-related business logic. Therefore, before the "Simulation Platform" performs simulation deduction, the current system time of the "Simulation Platform" server must first be synchronized to the PC terminals of each flight simulation subsystem. The client program of the terminal records the system time of the server, and uses the server system time as a benchmark to calculate the difference with the local system time. The time used when storing logs in the subsequent deduction process is the calculated time, so as to ensure that the data time in the log is consistent with the system time of the server.

[0173] System timing Fig.14 shown.

[0174] The simulation node subscription sequence is as follows Fig.15 shown.

[0175] Management modules such as Fig.16 shown.

[0176] The main methods of the management module are as follows:

[0177] (1)ReqStart()

[0178] The simulation control calls this interface to start the simulation authorization service

[0179] (2)ReqStop()

[0180] The simulation control calls this interface to stop the simulation timing service.

[0181] (3)startTimeSyncService()

[0182] Used to execute and start simulation timing service

[0183] (4)CTimeSyncManage()

[0184] Constructor

[0185] (5)CTimeSyncManage()

[0186] Destructor

[0187] Timing service submodules such as Fig.17 shown.

[0188] The main methods of timing service are as follows:

[0189] (1)StartTimer()

[0190] Start timer

[0191] (2)StopTimer()

[0192] Stop Timer

[0193] (3)timerProc()

[0194] Timer processing function

[0195] (4)timeout()

[0196] Timeout processing function

[0197] (5)publishSysTime()

[0198] Publish system physical time to DDS middleware

[0199] (6)getSysTime()

[0200] Execute to obtain the physical time of the simulation system

[0201] Main attributes of timing service:

[0202] (1)m_cur_systime

[0203] Save the current simulation system physical time

[0204] (2)m_timer_event_id

[0205] Timer ID

[0206] (6) Third-party data bridging subsystem

[0207] The third-party data bridging subsystem includes a software bridging module and a physical device bridging module. Its main functions are: obtaining third-party system data as required, converting and injecting it into the simulation platform, and obtaining simulation platform data as required and injecting it into the third-party system.

[0208] System design: The third-party data bridging subsystem is mainly composed of software bridging modules and physical device bridging modules. Its function is to separate abstraction from implementation so that they can change independently. It is implemented by replacing inheritance relationships with composition relationships, thereby reducing the coupling degree of the two variable dimensions of abstraction and implementation. It has interface adaptation functions and can complete data mapping with other heterogeneous system transmission protocols through bridging gateways based on middleware, and realize the access, conversion and transmission of third-party system data and simulation platform data. It supports time synchronization, communication protocol conversion, data interface conversion, DR processing, data acquisition, data transmission and reception management and other functions between various aircraft simulation systems to realize data interaction.

[0209] Design and implementation: The main function of the third-party data bridging subsystem is to obtain third-party system data, convert it and inject it into the simulation platform, obtain simulation platform data as required, and inject it into the third-party system simulation. It is suitable for using the bridging mode. The system process is as follows: Fig.18 shown.

[0210] Get data: Implement the role and get data from third-party systems.

[0211] Conversion injection: concretely implement the role, give the concrete implementation of the implementation role interface, and do not convert and inject the data obtained from the third-party system.

[0212] Get simulation data: process the data from the third-party system and get the simulation platform data.

[0213] Data transfer: inject the acquired simulation platform data into a third-party system.

[0214] Third-party data interface adaptation: The interface adaptation function is to realize the data conversion between the interface of the third-party system data and the middleware standard interface. The internal data in the simulation platform can interact directly through the communication protocol because all functions have been considered when designing each subsystem, and a complete interface control file has been formulated. The design of the interface control file of the heterogeneous system must be different from the simulation platform, and even the programming language may be different. Through the interface adapter submodule, the interface configuration files compiled in different compilation languages ​​can be converted and compiled to make them conform to the interface standard of the platform and use the communication protocol in the platform for data transmission. The interface adaptation method of the interface adapter submodule to interact with the third-party system adopts the message interaction method, and the data interaction message is divided into three parts: the message header, the message body and the message tail. For example, the frame identifier, source address code, destination address code, information category code, information length, information exchange time symbol and other data bits in the data are defined as the message header, the information field of all simulation interactions in the middle is defined as the message body, and the check field data bits at the tail are defined as the message tail. After defining the communication data interface of heterogeneous systems, heterogeneous system data can be input, transmitted and output in the multicast network. Fig.19 shown.

[0215] The data interface in the simulation platform includes the assumption configuration, equipment model and environment model. The specific interface contents are as follows:

[0216] The scenario configuration interface defines the relevant data information involved in the initial scenario, including scenario name, scenario time, scenario label, minimum simulation step, maximum simulation step, longitude and latitude of the airspace starting point, longitude and latitude of the airspace ending point, longitude and latitude of the starting point of both sides' key targets, longitude and latitude of the ending point of both sides, and equipment initialization information involved in the scenario.

[0217] The equipment model interaction interface defines the simulation interfaces related to the equipment model simulation operation and related functional performance. Taking the aircraft model as an example, it includes the flight control model interaction related input and output, sensor model interaction related input and output, mission model interaction related input and output, etc.

[0218] The simulation environment model interaction interface defines airspace-related environment simulation interface information, including meteorology, hydrology, electromagnetics, infrared, etc.

[0219] Third-party data communication protocol adaptation: When exchanging data with third-party systems, the third-party systems may use different communication protocols, such as shared memory, multicast, DDS, UDP, etc. This makes it impossible for heterogeneous systems to interact with the platform. Through the communication protocol adapter module, the heterogeneous system API interface is compiled, and the communication protocol used by the heterogeneous system is converted into a multicast communication protocol that meets the platform communication standards, so that data can be interacted with the platform.

[0220] The reason for building a multicast network to interact with heterogeneous systems is to take advantage of the wide application range of multicast communication protocols, which can adapt to more types of heterogeneous systems. The communication protocol only needs to convert the interface and compile the corresponding code to convert it into a multicast protocol that meets the platform interaction standards and interact with the simulation platform.

[0221] XSim system interconnection:

[0222] According to the current state of technology, the XSim system is different from other third-party systems. It has richer functions and can be connected with the distributed simulation operation framework through its specially developed overall control system. On the one hand, it is necessary to control the operation of the entire distributed simulation system, on the other hand, it is necessary to complete the push of the test scenario file; on the other hand, it is necessary to complete the initialization construction of the XSim distributed simulation environment.

[0223] The data interaction between the XSim system and the distributed simulation running framework is realized through DDS Topic3. The connection method is as follows Fig. 20 shown.

[0224] As the control center of the distributed simulation system, the XSim overall control system mainly includes three modules: distributed simulation environment initialization, scenario push, and distributed simulation system operation control. Fig.21 shown.

[0225] Distributed environment initialization mainly starts the distributed simulation server and simulation engine before the distributed simulation starts. Scenario file push mainly selects the specified scenario file and sends it to other systems through the data bus. Operation control mainly sends process control instructions (start, pause, end) during the distributed simulation process to control the operation status of the entire system.

[0226] The interaction relationship with the control interface of XSim is shown in Table 1.

[0227] Table 1 Overall control system interface relationship description table

[0228]

[0229] Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

[0230] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A distributed simulation system based on DDS, characterized in that: include: Front-end UI management subsystem: performs human-computer interaction and realizes interconnection and interoperability among subsystems based on DDS data communication middleware; Hardware resource control subsystem: Centrally control the platform hardware components and provide underlying support for the simulation business layer; Simulation platform business control subsystem: manages and controls the simulation business carried by the simulation platform; Simulation data recording and playback subsystem: stores and manages the simulation interaction data generated during the simulation process, and provides a visual analysis interface and data playback interface; Simulation system timing synchronization subsystem: performs platform software timing synchronization, takes the system time of a server or computer as the reference point, and regularly uses the DDS network to publish time information to all nodes in the simulation system. After receiving the time information, each node obtains its own system time and calculates the difference, so that all nodes in the entire simulation system can achieve time synchronization; Third-party bridging subsystem: obtain third-party system data as required, convert and inject into the simulation platform; obtain simulation platform data as required and inject into the third-party system; The front-end UI management subsystem, hardware resource control subsystem, simulation platform business control subsystem and simulation data recording and playback subsystem are connected to the master control node; The simulation system timing synchronization subsystem is connected to the system server via DDS; The third-party bridging subsystem connects the third-party system and the master control node.

2. The DDS-based distributed simulation system according to claim 1, characterized in that: The front-end UI management subsystem includes: database configuration and network service configuration of the main control system; Database system configuration includes hypothetical database configuration and physical database configuration; The network service system configuration includes the master control network service configuration, the three-dimensional situation network service configuration and the DDS network configuration; The master control network service configuration items and the three-dimensional situation network service configuration items have the service IP address and port number, and the DDS network configuration items have the network type and domain ID; the master control network service is used to provide services to simulation nodes; the three-dimensional situation network service provides services to the three-dimensional environment visualization monitoring system and provides simulation data for its entities; the DDS network provides real-time data communication support for distributed simulation systems. All simulation nodes on the DDS network transmit data through the publish and subscribe mechanism, providing a topic-based data publish / subscribe model. By configuring the publish / subscribe relationship between each subsystem, plug-and-play discovery of each node is achieved and data interaction is completed.

3. The DDS-based distributed simulation system according to claim 1, characterized in that: The hardware resource management and control subsystem includes a server and a client; The server is used to collect and display information about each node on the platform and the working status of each model process in the scene, provide basic control commands for the simulation platform, and support the display of network topology; The client is used to receive files and commands / scripts sent by the server, collect node local information and system-related model process information, and report to the server.

4. The DDS-based distributed simulation system according to claim 3, characterized in that: The server includes: UI: Displays the information of each platform node and the working status of each model; Command / file control module: including initialization, start, pause, stop commands, files and scripts; Data transmission module: receives data collected by the client in the form of messages or TCP / IP, UDP, or DDS communication protocols; Data sorting module: Integrate the received node information and model information for UI display.

5. The DDS-based distributed simulation system according to claim 3, characterized in that: The client comprises: Command / file receiving module: receives commands, files, and scripts sent by the server; Data collection module: collects local node information, including CPU model, CPU usage, memory size, memory usage, and system-related model information; Data sorting module: sort and merge the collected data in a fixed format; Data transmission module: reports the collected data to the server in the form of messages or TCP / IP, UDP, or DDS communication protocols.

6. The DDS-based distributed simulation system according to claim 1, characterized in that: The simulation platform business management and control subsystem includes: Simulation model operating environment generation module: responsible for assembling the models required for this simulation into simulation units; Simulation scenario configuration module: organizes the assumption information of each aircraft equipment set by the user through the UI interface, generates all assumption information, and pushes it to each subsystem in the distributed simulation system; Simulation platform monitoring module: During the simulation process, real-time observation of the two teams’ mission execution in the airspace is carried out, and the simulation process is observed through two-dimensional maps and three-dimensional situation observation; Simulation platform model control module: during the simulation process, it can perform control operations including initialization, running, pausing / resuming and stopping of a simulation game at any time; Simulation model deployment module: Model deployment and integration of the simulation platform, configuration component class function management of all configuration information related to flight experiment design and configuration management system, including configuration of the system, communication configuration of external systems, connection database configuration, assumption format configuration and resource allocation configuration of distributed systems; Simulation model management module: responsible for external model checking, uploading new models to the system, deleting existing models in the system, creating model objects, modifying model objects, deleting model objects, model list display, and model object list display.

7. The DDS-based distributed simulation system according to claim 1, characterized in that: The simulation system timing synchronization subsystem comprises: Provide time management server tools to obtain the physical time and logical time of the time server, publish time information to each subsystem node through the time synchronization service of the distributed data interaction middleware, and enable each node to complete time calibration and synchronization; Apply network time synchronization technology, that is, build an NTP server in the local area network to achieve automatic time synchronization.

8. The DDS-based distributed simulation system according to claim 1, characterized in that: The simulation system timing synchronization subsystem comprises: Management submodule: responsible for starting, executing and stopping the simulation timing service; Timing service submodule: responsible for timing services, including timer processing, publishing system physical time to DDS middleware, and obtaining simulation system physical time; The management submodule is responsible for starting and stopping the service of the timing service submodule. After the service is started, the timer is started to calculate and obtain the system physical reference time of the simulation system timing synchronization subsystem and publish it to the DDS network; The subsystems of each simulation system obtain the reference time data and simulation data through DDS data subscription, and then synchronize the reference time to the subsystems of each simulation system.

9. The DDS-based distributed simulation system according to claim 1, characterized in that: The third-party bridging subsystem includes: a software bridging module and a physical device bridging module, which separates abstraction from implementation and replaces inheritance relationship with composition relationship, thereby reducing the coupling degree of the two variable dimensions of abstraction and implementation. It has interface adaptation function, and is based on middleware. It completes data mapping with other heterogeneous system transmission protocols through a bridging gateway, and realizes the access, conversion and transmission of third-party system data and simulation platform data. It supports time synchronization, communication protocol conversion, data interface conversion, DR processing, data collection, and data transmission and reception management functions between various aircraft simulation systems to realize data interaction.

10. A distributed simulation device based on DDS, characterized in that: A DDS-based distributed simulation system comprising any one of claims 1 to 9.

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