A time-sensitive network-based analog flight data deterministic communication demonstration system

Abstract

The application discloses a kind of simulation flight data determinacy communication demonstration system based on time sensitive network, including by end system and switch form airborne network, demonstration manager and network tester.Demonstration manager is used to set the simulation parameter of end system and switch.Simulation end system has flight simulation application module, interface service module and network driver module;It is the interaction of simulating the flight data stream of real end system in time sensitive network;Through simulating periodic flight data, the flight state synchronization interaction of application layer is simulated, the data frame of data link layer is configured and encapsulated guarantee, and the communication function of simulation end system is simulated.Simulation switch has switching module and TSN protocol configuration module;It is according to scheduling or forwarding logic processing data frame.

Description

Technical Field

[0001] This invention relates to the field of avionics communication network technology, and more particularly, to a deterministic communication demonstration system for simulated flight data implemented using Time-Sensitive Network (TSN) with protocol improvements. Background Technology

[0002] To standardize the development of industrial Ethernet and overcome issues such as low bandwidth in bus-type networks and poor compatibility with existing industrial Ethernet standards, IEEE 802.1 initiated the Time-Sensitive Networking (TSN) working group in November 2012. This group is responsible for extending the standard Ethernet 802.3 to support real-time and deterministic data transmission for industrial control. Deterministic transmission technology in Time-Sensitive Networking refers to technologies that guarantee the quality of service (QoS) related to end-to-end transmission latency (such as latency upper bounds and jitter). The core problem it addresses is how to meet the requirements of service flows for end-to-end transmission latency and jitter in uncertain network environments. As a product of the convergence of operation technology (OT) and information technology (IT) networks, TSN can meet the real-time and deterministic requirements of industrial control while being compatible with Ethernet, enabling the mixed transmission of industrial control data and Ethernet data. Therefore, TSN data transmission has the following three characteristics.

[0003] Real-time performance: The end-to-end delay of control messages is bounded. The upper limit of the delay is usually given by the specific requirements of industrial control. The end-to-end delay of a message is the time from when the first bit of the starting node is sent on the link to when the first bit reaches the terminal node.

[0004] Determinism: The jitter of end-to-end delay in control messages is usually very small, such as on the order of microseconds.

[0005] Compatibility: Control messages can be transmitted in combination with other Ethernet messages.

[0006] Real-time performance and determinism are prerequisites and key requirements; compatibility reflects the integration of time-sensitive networking and Ethernet.

[0007] As the carrier of modern aircraft intelligence, avionics networks face increasingly stringent requirements for bandwidth, real-time performance, and determinism in data transmission due to rising mission complexity. While flight simulation technology is a crucial means of design verification and training, current mainstream demonstration systems are still based on traditional Ethernet architectures. Because traditional Ethernet employs a "best-effort" transmission mechanism, it struggles to provide a deterministic upper bound on latency when handling high loads or bursts of traffic. This can easily lead to severe latency jitter, out-of-order delivery, or even packet loss in critical data such as flight control commands and attitude feedback, seriously hindering the synchronization accuracy and quality of service in flight simulations. To address these challenges, Time-Sensitive Networking (TSN) based on the IEEE 802.1 standard family offers an ideal solution for building deterministic networks, thanks to its microsecond-level clock synchronization, traffic shaping, and frame duplication elimination mechanisms. It has already been widely applied in industrial and automotive fields. However, in the field of aviation simulation, how to meet the characteristics of UDP (User Datagram Protocol) encapsulation and high dynamic interaction of simulated flight data, solve the problem of deep integration between upper-layer aviation application interfaces and lower-layer TSN deterministic flow control mechanisms, and build a performance verification platform with intuitive visualization capabilities remains a key technical challenge that urgently needs to be solved.

[0008] Therefore, this invention aims to deeply modify the existing simulated flight communication architecture to construct a functional demonstration system capable of collaboratively running a TSN deterministic protocol stack. By mapping simulated flight data services to TSN scheduling strategies, the system verifies the TSN technology's ability to safeguard critical flight data in a real physical topology, intuitively demonstrating its advantages in improving system real-time performance and reliability. This provides an efficient experimental environment and technical support for the research of next-generation avionics network communication mechanisms. Summary of the Invention

[0009] The purpose of this invention is to provide a flight simulator modification and implementation scheme based on TSN technology, aiming to build a flight simulator demonstration platform with low latency and high reliability through a deterministic transmission mechanism. This flight simulator demonstration platform deeply integrates link-layer raw frame construction and direct stream injection technology with the TSN standard protocol suite (covering IEEE 802.1AS, Qav, Qbv, CB, Qci, and Qbu / br), achieving low-level deterministic transmission of UDP packets encapsulating flight attitude, position, and control commands, and establishing an end-system model based on TSN protocol mapping. By pre-setting high-precision clock synchronization, gated list (GCL) periodic scheduling, and credit shaping parameters at the two-layer switching nodes, it possesses fine-grained conflict avoidance and bandwidth reservation capabilities for multi-priority traffic, establishing a switching node model supporting deterministic forwarding of time-sensitive flows. The deterministic interactive demonstration system for simulated flight data built based on the above model can realize the real-time visualization and synchronization of key parameters among multiple simulators. The intermediate system uses XPC tools to collect POSI, DREF and CTRL messages at preset intervals and execute deterministic flow injection. The switching nodes work together to run time-aware shaping, flow filtering and frame duplication and elimination mechanisms to ensure low-latency forwarding and seamless redundancy of key data under extreme interference, while maintaining good compatibility with traditional Ethernet.

[0010] This invention proposes a demonstration system for deterministic interaction of simulated flight data based on Time-Sensitive Networking (TSN), comprising three parts: an airborne network formed by end systems and switches, a demonstration manager, and a network tester. This demonstration system deeply integrates TSN technology, binding link-layer raw frame construction and direct injection technology to the TSN hardware driver at the underlying level, ensuring that the demonstration system strictly meets the requirements of deterministic scheduling and traffic shaping mechanisms throughout the entire message transmission and reception process. The demonstration system can format simulated flight data, enabling the modified simulation end system nodes to access the TSN architecture and achieving deterministic transmission of aviation-grade real-time data. The demonstration manager is used to set the simulation parameters of the end systems and switches in the airborne network, making them simulated end systems (end nodes) and simulated switches (switching nodes).

[0011] The simulation terminal system uses a general-purpose computing platform combined with an FPGA-based TSN network card to simulate the terminal system functions in an avionics environment. Through periodic acquisition of simulated flight data such as aircraft position data, flight control data, and data reference extension information, it customizes and simulates the behavior of the Xplane Connect (XPC) interaction interface at the network application layer, maps and configures time-sensitive flows at the data link layer to ensure latency, and encapsulates and parses them according to the UDP packet format to simulate the deterministic communication function of the terminal system. The simulation terminal system includes a flight simulation application module (105), an interface service module (106), and a network driver module (107).

[0012] The simulated switching node uses a TSN gigabit switch and performs two-layer deterministic forwarding processing on data frames entering the switching node according to the preset gating list (GCL), credit shaping parameters, and filtering control rules. The simulated switching node is divided into a switching module (201) and a TSN protocol configuration module (202).

[0013] In this invention, a time-sensitive networking-based deterministic interaction demonstration system for simulated flight data directly constructs raw Ethernet frames containing MAC layer headers during message transmission and reception by calling a send function, and embeds a VLAN priority identifier (PCP) in the frame header to achieve encapsulation and direct transmission of simulated flight data at the Ethernet data link layer; by configuring a gating list, switching nodes perform message forwarding processing according to fixed time slices identified by mechanisms such as Time-Aware Shaping (TAS); and by networking the peer system and switches, such as... Figure 1 As shown, a complete deterministic interactive mapping is implemented, simulating the entire communication process of flight data based on a time-sensitive network: simulated flight data acquisition, raw frame construction, hardware stream injection, switching node scheduling, and terminal parsing and reproduction.

[0014] Specifically, the present invention provides a deterministic communication demonstration system for simulated flight data based on time-sensitive networks, comprising:

[0015] The airborne network is formed by networking end systems and switches, and the airborne network is used to generate flight data streams;

[0016] The network tester is used to generate background interference traffic for the airborne network;

[0017] Its distinguishing feature is that it also includes a demonstration manager for receiving flight data streams and background interference traffic;

[0018] The demonstration manager sets up a simulation terminal system and a simulation switch; and the simulation terminal system and the simulation switch are connected by a physical link (101) to form a deterministic interaction path for simulated flight data;

[0019] The simulation terminal system includes a flight simulation application module (105), an interface service module (106), and a network driver module (107).

[0020] The simulated switch is equipped with a switching module (201) and a TSN protocol configuration module (202).

[0021] The flight simulation application module (105) is used to define the flight data stream;

[0022] The interface service module (106) is used to directly construct the original link layer frame and complete the bidirectional protocol encapsulation / parsing logic;

[0023] The network driver module (107) is based on the physical transceiver, VLAN ID extraction and PCP priority mapping features of the Linux underlying architecture;

[0024] The switching module (201) performs actual forwarding processing of simulated flight data according to the configured fixed MAC address table;

[0025] The TSN protocol configuration module (202) is used for the coordinated scheduling of the TSN protocol suite of TAS, CBS, PSFP, and FRER.

[0026] The advantages of the time-sensitive network-based deterministic interactive function demonstration system for simulated flight data of this invention are as follows:

[0027] 1. This invention modifies the protocol of ordinary Ethernet by introducing TSN technology, constructing a demonstration manager for flight simulation scenarios. By realizing real-time mapping between aircraft simulated flight data and deterministic communication mechanisms, the demonstration system of this invention significantly enhances the simulation environment's fidelity, simulating the deterministic communication process of flight data streams in a time-sensitive environment. It provides a highly efficient TSN testing and verification environment for studying communication modes and real-time reliability assurance mechanisms in deterministic networks.

[0028] 2. The design of the demonstration system of this invention is based on the Linux platform. By constructing raw Ethernet data frames and sending them by calling the pcap_sendpacket function, the TSN technology of traditional flight simulation data is transformed. The XPC interaction interface is optimized to support the custom configuration of aviation data in the form of DataRef extended information and to allow the construction of different aviation data queues mapped to corresponding priorities, thereby realizing the interactive guarantee of simulated flight data and facilitating the quantitative analysis of communication behavior under time-sensitive network constraints.

[0029] 3. The demonstration system of this invention strictly follows the IEEE 802.3 and IEEE 802.1Q series standards, and has excellent protocol interoperability. The demonstration manager is built on the physical end system and switches in the airborne network. The transmitted data frames can achieve seamless networking and data interaction with existing commercial Ethernet devices. It supports the replacement or integration of some nodes in a real physical network environment to complete the flexible deployment of the flight simulation interactive network.

[0030] 4. The demonstration system of this invention provides rich TSN communication parameter configuration and real-time monitoring functions. By modifying parameters such as gating list, shaping algorithm and preemption sequence on the demonstration manager, the impact of communication parameters on flight synchronization service quality (QoS) can be intuitively observed, realizing time-sensitive network comparison experiments in simulated flight scenarios. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a network architecture for connecting end systems and switches.

[0032] Figure 2 This is a schematic diagram of the deterministic demonstration system for simulated flight data based on time-sensitive networks according to the present invention.

[0033] Figure 3 This is a design diagram of the deterministic interactive function module for simulated flight data based on time-sensitive networking in the demonstration manager of this invention.

[0034] Figure 4 This is a block diagram of the system implementation structure of the setting terminal in the demonstration manager of this invention.

[0035] Figure 5 This is a block diagram illustrating the implementation structure of setting up exchange nodes in the demonstration manager of this invention.

[0036] Figure 6 This is the experimental topology for verifying the real-time performance characteristics of time-sensitive networks according to the present invention.

[0037] Figure 7 This is the experimental topology for verifying the reliability characteristics of time-sensitive networks according to the present invention. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The examples of the parameters listed are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0039] This invention, based on Time-Sensitive Networking (TSN) technology, achieves deep integration between flight simulator end nodes and the TSN deterministic transmission mechanism by directly constructing raw Ethernet frames conforming to the 802.1Q standard at the link layer and implementing low-level flow injection through hardware and software collaboration. During data interaction, the demonstration manager formats and encapsulates the simulated flight data and embeds a VLAN Priority Pointer (PCP) in the frame header, ensuring it meets the deterministic scheduling and traffic shaping constraints within the network. By cooperating with the time-sensitive network gating scheduling strategy of the switching nodes, this invention's demonstration system for deterministic interaction of simulated flight data based on time-sensitive network fully realizes the interactive mapping process of "simulated flight data acquisition – raw frame construction – hardware flow injection – switching node scheduling – terminal parsing and reproduction," simulating a fully closed-loop deterministic communication process of flight data in a time-sensitive environment.

[0040] In one embodiment of the present invention, the end system and the switch are networked, such as... Figure 1 As shown, the network architecture includes four end systems and one switch. A demonstration system for deterministic interaction of simulated flight data based on time-sensitive networking is presented. Figure 2 The system comprises three parts: an airborne network formed by end systems and switches, a demonstration manager, and a network tester. The information transmitted in the airborne network formed by the end systems and switches is collectively referred to as simulated flight data in the demonstration manager. This simulated flight data includes, but is not limited to, aircraft position data, flight control data, and extended data reference information. The extended data reference information includes, but is not limited to, real-time flight status parameters in multiple dimensions, such as angle of attack, heading relative to the ground, sideslip angle, ground speed, true airspeed, roll angle, pitch angle, and yaw angle.

[0041] End system: When end system A acts as the transmitting end system, it is marked as 10A; when end system B acts as the first receiving end system, it is marked as 10B; when end system C acts as the configuration management end system, it is marked as 10C. When end system D acts as the second receiving end system, it is marked as 10D.

[0042] Switches: including a first TSN switching node 20A, a second TSN switching node 20B, and an Ethernet switching node 20C.

[0043] Network Tester 30A: The network tester is used to provide definable background interference traffic. By customizing the frame format of the interference traffic, including configuring parameters such as source and destination MAC addresses and VLAN tags, it simulates the contention and interference process of nondeterministic services on time-sensitive traffic.

[0044] Demonstration Manager: Used to configure the simulation parameters of end systems and switches in the airborne network, making them simulate end systems (end nodes) and switches (switching nodes).

[0045] Presentation Manager

[0046] The presentation manager can be a computer configured with Linux 5.10.0 or later, at least 16GB of RAM, and at least 50GB of hard drive space; it should come pre-installed with the integrated development environment Visual Studio Code 1.108.1, the iproute2 toolset, and the net-tools network toolkit. The configured monitor should have a refresh rate of 60Hz or higher.

[0047] The simulation end systems set in the demonstration manager are also simulation parameter settings for the end systems in the airborne network. The simulation end systems (10A, 10B, 10C, and 10D) use general computing technology to simulate the flight data interaction function of the airborne network's end systems. By simulating the generation cycle of real-time flight simulation data, customizing and simulating the synchronous interaction of flight status at the application layer, configuring and directly encapsulating the Ethernet frame encapsulation format and VLAN priority identifier at the data link layer, and directly framing according to the Ethernet link layer protocol, they simulate the communication function of the airborne network's end systems. Each simulation end system consists of three parts: a flight simulation application module 105, an interface service module 106, and a network driver module 107. The simulation switches (20A, 20B, and 20C) simulate commercial switches that support Time-Sensitive Networking Protocol (TSN) or standard Ethernet protocols. The simulation switches consist of two parts: a switching module 201 and a TSN protocol configuration module 202, which process data frames entering the switching node according to a preset scheduling mechanism or standard forwarding logic.

[0048] In one embodiment of the present invention, Figure 3 A demonstration management system based on Time-Sensitive Networking (TSN) is presented, comprising four simulation terminal systems (10A, 10B, 10C, and 10D), three simulation switching nodes (20A, 20B, and 20C), and one network tester (30A) within the demonstration manager. Each simulation terminal system is connected to the switching network via network interface 102. Figure 4 As shown, the end system and the switching node are connected via physical link 101; the switching node accesses the switching network through port 103, and the switching nodes are cascaded together via physical link 104, thus forming a multi-hop switching network topology. Figure 3 , Figure 4In this setup, the transmitting system 10A, the configuration management system 10C, and the network tester 30A are all connected to the first TSN switching node 20A, thus constructing two parallel transmission paths with comparative dimensions: the first is a TSN deterministic communication path, which uses pre-configured scheduling mechanisms such as Credit-Based Shaping (CBS), Time-Aware Shaping (TAS), and Per-Flow Filtering and Judgment (PSFP) at the switching node. The first TSN switching node 20A is cascaded to the second TSN switching node 20B and ultimately connected to the first receiving system 10B. The second is a standard Ethernet comparative path, following the traditional Ethernet "best-effort" transmission logic. The first TSN switching node 20A is cascaded to the Ethernet switching node 20C and connected to the second receiving system 10D. Background interference traffic is injected into the first TSN switching node 20A through the network tester 30A. The demonstration manager allows for direct observation and quantitative verification of the deterministic guarantee effect of TSN technology on simulated flight data in terms of end-to-end latency, latency jitter, and other Quality of Service (QoS) indicators. During the specific implementation of the demonstration manager, adjustments can be made based on the demonstration scale. Figure 3 The topology shown can be flexibly expanded, and its system expansion scale depends only on the physical number of the simulation end system and switching nodes, as well as the port capacity of a single switching node.

[0049] Simulation system settings

[0050] The simulation terminal system, namely flight simulation application module 105 in 10A, 10B, 10C, and 10D, is responsible for constructing a realistic avionics operating environment and managing data interaction specifications. This module interacts with a high-precision flight and environmental dynamics model in real time, acquiring raw flight dynamic data, including aircraft position, attitude, speed, and environmental parameters, as its data source. Following preset flight mission plans and communication parameters, it simulates the generation and processing of flight status data in a real avionics environment. Operators can configure flight mission attributes, message transmission cycles, and Time-Sensitive Network (TSN) attributes in the demonstration system through a human-machine interface. For periodic messages such as track data and aircraft attitude data, further configuration is required, including: message ID, message name, transmission cycle, message source IP, message destination IP, message source UDP, message destination UDP, VLAN priority identifier, and message length. For each planned virtual link, the required configuration includes: virtual link ID, virtual link interface, virtual link IP, and the message list mapping relationship carried by that virtual link. Furthermore, in order to quantitatively describe the usage of communication link resources by simulated flight data, the communication parameter configuration unit 304 is based on... The bandwidth load rate of single-channel simulated flight data is calculated. Indicates the first The bandwidth duty cycle (i.e., bandwidth load rate) of simulated flight data. The length of the application layer message payload representing the simulated flight data, in bytes. This indicates the combination of additional overhead generated by protocol stack encapsulation, including the number of bytes in the UDP, IP, and Ethernet MAC layer headers with VLAN tags; Indicates the message sending period, in microseconds (μs); This represents the rated transmission rate of the current physical link, measured in Mbps. By calculating the bandwidth load rate of a single simulated flight data stream, the simulation system can predict and assess the link load security under the current network topology configuration.

[0051] After completing the configuration of the simulation terminal system, the simulation function of the flight simulation application module 105 is started. This module sends the configured service port information and traffic characteristic parameters to the interface service module 106. The flight simulation application module 105 generates a business data stream by combining the real-time acquired current flight dynamic data with the maintained message configuration information, and responds to the received message events returned by the interface service module 106. It also performs real-time parsing and visualization of the flight status data frames received by the simulation terminal system.

[0052] The simulation terminal system, namely the interface service module 106 in 10A, 10B, 10C, and 10D, is responsible for performing format conversion, encapsulation, and parsing between simulated flight data and Ethernet link layer frames. It also performs deterministic priority mapping to the network driver module 107 based on traffic type identifiers to ensure a deterministic transmission mechanism and low latency characteristics for simulated flight data interaction. The interface service module 106 includes two functional groups: a sending functional group and a receiving functional group. For the sending functional group, the traditional UDP / IP protocol stack packet processing is bypassed, and a link layer frame containing an Ethernet MAC layer header and VLAN tag is directly constructed. Upon receiving real-time simulated flight data from the flight simulation application module 105, the corresponding UDP header is added according to the traffic type identifier and service port configuration, and the source and destination ports are set. Then, an IP header is constructed, and the IP identifier, fragmentation offset, and IP header checksum are configured. A MAC layer header is further added, and a VLAN tag and corresponding PCP priority identifier are inserted into the frame header. The encapsulated Ethernet frame is then sent to the network driver module 107. For the receiving function group set, after receiving a data frame from the network driver module 107, the operating system kernel completes the frame format parsing and 802.1Q data frame processing operations, and performs TCP / IP protocol stack processing. The receiving function group will determine the virtual link ID number and device number of the data frame, perform VLAN virtual interface mapping, complete IP verification, decrypt the IP packet header, determine whether the data frame is a packet type, complete packet reassembly operations, perform UDP verification, decrypt the UDP packet header, extract the original flight simulation message, and submit it to the flight simulation application module 105 in real time for display and status reproduction processing.

[0053] The network driver module 107 in the simulation end system, namely 10A, 10B, 10C, and 10D, implements the actual transmission control of messages to be sent to network interface 102 and receives data packets from network interface 102, performing distribution and delivery processing of the communication protocol stack. Based on the underlying network driver architecture of the Linux platform, network driver module 107 captures data from the physical port, removes the Ethernet MAC header and VLAN tag from the captured data frames, extracts the VLAN ID into the receive descriptor, and submits it to the interface service module 106 in the end system for processing. Data packets with VLAN tags, PCP priority identifiers, and encapsulated according to a specific frame format, received from interface service module 106, are directly handed over by network driver module 107 to network interface 102 for transmission, thus completing the physical transmission processing of simulated flight data frames.

[0054] Figure 4A block diagram of the simulation terminal system of this invention is provided. The simulation terminal system consists of three parts: a flight simulation application module 105, an interface service module 106, and a network driver module 107. The transmitting terminal system 10A interacts with the operator through a demonstration manager. The operator can input communication parameter configurations and operation control commands to the terminal system through the demonstration manager (referred to as control / configuration 302). At the same time, the terminal system provides the operator with a visual result of the flight status through the demonstration manager (referred to as result display 303). The transmitting terminal system 10A connects to the switching network 30 through the network interface 102 using a TSN network card. When the second terminal system 10D receives the simulated flight data frame, the network interface 102 connects to the switching network 30 using a regular Ethernet card.

[0055] The flight simulation application module 105 provides communication parameter configuration, external model interaction, flight state simulation, and application-layer-based send / receive functions. The flight simulation application module generates, sends, and receives flight state data according to the message parameters configured by the operator. The communication parameter configuration function is executed in the communication parameter configuration unit 304; the external model interaction function is executed in the external model interface 305; the flight state simulation and calculation function is executed in the flight simulation program 306; the application-layer-based message sending function is executed in the message generator 307; and the application-layer-based message receiving function is executed in the message receiver 308. Configuration information input by the operator is sent to the communication parameter configuration unit 304 to configure communication parameters; program control information input by the operator is sent to the external model interface 305; and flight attitude control information input by the operator is directly sent to the flight simulation program 306 to control the entire flight simulation process. The communication parameters configured by the operator are issued by the communication parameter configuration unit 304, thereby customizing the message sending and receiving logic of the message generator 307 and the message receiver 308. The flight simulator 306 runs according to control commands and transmits the real-time calculated flight simulator data to the message generator 307 through the external model interface 305 and sends it to the interface service module 106. The flight simulator data received by the message receiver 308 is transmitted to the flight simulator 306 through the external model interface 305 to reproduce the flight state. At the same time, the flight simulator 306 feeds back the visualization results to the human-machine interface for display in real time.

[0056] In the communication parameter configuration unit 304 of the flight simulation application module 105, the communication parameters that operators can configure mainly include: virtual link and network protocol parameters, and time synchronization parameters. The configuration results are then distributed to various functional subunits to customize their operational logic. For virtual link and network protocol parameters, the communication parameter configuration unit 304 provides specific settings for VL information and UDP / IP information, supporting the definition of network interface names, virtual link IDs, virtual link IPs, message source / destination IP addresses, and UDP port numbers. These addressing and link characteristic parameters are then sent to the message generator 307 and message receiver 308 to customize the encapsulation format during message generation and the port listening and filtering rules during message reception. For time synchronization parameters, the communication parameter configuration unit 304 allows setting the synchronization period and interval of simulated flight data and sends this synchronization control strategy to the external model interface 305 to establish the data acquisition frequency and interaction rhythm when communicating with the simulated flight program. Furthermore, the communication parameter configuration unit 304 provides an attribute configuration dialog box to add, modify, and delete the aforementioned communication parameters, and provides a list view for visual viewing and management of the currently configured parameters.

[0057] The external model interface 305 in the flight simulation application module 105 enables data acquisition and injection with the flight simulation program 306 (e.g., mature commercial flight simulation software). Based on a common flight simulation communication protocol interface, this module's interactive functions mainly include: network communication link establishment, customized assembly of service message sequences, and real-time acquisition and synchronization of simulated flight data. For network communication link establishment, the external model interface 305 initializes the parameters already configured by the communication parameter configuration module 304, such as the physical network interface, source and destination MAC addresses, IP addresses, and VLAN identifiers. It then establishes a UDP data channel with the flight simulation program 306 based on the common flight simulation communication protocol and performs connection verification. For customized assembly of service message sequences, the external model interface 305 performs differentiated priority mapping based on the different real-time requirements of the simulated flight data. Aircraft position information and flight control information are defined as high-priority services, while data reference extension information is defined as medium-priority services, thus providing a classification and labeling basis for subsequent deterministic transmission at the link layer. In addition to basic position and control data, this module also has scalability. Through the data referencing function interface, operators can customize more types of simulated flight data acquisition sequences (such as engine parameters, weather radar data, etc.). This module allows for the configuration of different transmission queues and loop intervals through the program, enabling on-demand acquisition and orderly transmission of multi-source heterogeneous simulated flight data, thereby supporting full-element simulation verification in complex flight scenarios. For real-time acquisition and synchronization of simulated flight data, the external model interface 305 maintains data interaction with the simulated flight program 306 through the main loop program, acquiring latitude, longitude, altitude, attitude angle, and speed parameters in real time according to the preset synchronization cycle, and transmitting the acquired raw simulated flight data to the message generator 307 in real time to complete the construction and transmission of business messages; at the same time, the external model interface 305 receives parsed data or control commands from the message receiver 308 and synchronously writes them into the simulated flight program 306, thereby realizing the transmission, reception, and reproduction of multi-source heterogeneous simulated flight data.

[0058] For the message generator 307 in the flight simulation application module 105, based on the configuration parameters issued by the communication parameter configuration unit 304 and combined with the real-time simulated flight data transmitted by the external model interface 305, it realizes the periodic construction and transmission of messages based on multi-level message queues. The message generator 307 establishes mutually independent message sending queues according to the service type of the simulated flight data, and maps and injects the real-time collected data into the corresponding queues respectively. Driven by a unified clock source, this module traverses each message queue according to a preset synchronization period, extracts the payload in the queue to generate a service data stream containing priority characteristics, and submits it to the interface service module 106, thereby ensuring that different types of simulated flight data can enter the transmission link in an orderly manner according to the predetermined period.

[0059] The message receiver 308 in the flight simulation application module 105 receives parsed messages from the interface service module 106 according to the receiving strategy issued by the communication parameter configuration unit 304. The message receiver 308 performs legality verification and classification on the received data, and transmits the extracted flight control commands or environmental parameters to the external model interface 305 in real time to drive the flight simulation program 306 to reproduce the state.

[0060] In the interface service module 106 of the end system, the bidirectional conversion and processing between simulated flight data and underlying Ethernet frames is performed according to the Time-Sensitive Networking (TSN) protocol specification. This module encapsulates application layer messages step-by-step in the sending direction, implements PCP-based priority mapping, and submits the data frames to be sent to the network driver module 107. Simultaneously, the interface service module 106 obtains link layer data frames from the network driver module 107, performs protocol parsing and payload extraction, and delivers the messages to the application layer. The interface service module 106 is logically divided into two main functional groups: a sending function group and a receiving function group. These two functional groups share a data path. When a sending message is received from the flight simulation application module 105, the sending function group is activated; when the interface service module 106 receives data frame information from a specific VLAN interface from the network driver module 107, the receiving function group is activated.

[0061] The sending function group set in the interface service module 106 mainly includes three functional units: UDP encapsulation unit 309, IP encapsulation unit 310, and MAC layer encapsulation unit 311. In the UDP encapsulation unit 309, a UDP header is added to the simulated flight data according to the configured communication parameters, the source and destination ports are set, and the UDP checksum is calculated. In the IP encapsulation unit 310, an IP datagram header is constructed, the source and destination IP addresses are configured, and IP checksum calculation and necessary fragmentation identification processing are completed. In the MAC layer encapsulation unit 311, a link layer encapsulation operation is performed, an Ethernet MAC header is added, and according to the priority policy issued by the communication parameter configuration unit, a VLAN tag is inserted into the frame header, the corresponding PCP priority identifier is embedded, and finally, a data frame conforming to the 802.1Q standard is generated and submitted to the network driver module 107.

[0062] The receiving function group set in the interface service module 106 mainly includes three parts: a frame format parsing unit 314, an 802.1Q frame processing unit 313, and a TCP / IP protocol stack. Relying on the network protocol stack processing mechanism of the Linux kernel layer, when a data frame is transmitted from the network driver module 107, it first enters the frame format parsing unit 314. This unit distinguishes and identifies the data frame type based on the characteristics of the Ethernet frame header. For 802.1Q data frames determined to carry VLAN tags, this unit directs them to the 802.1Q frame processing unit 313 for processing. The kernel network subsystem performs the physical VLAN tag stripping operation, and the restored data packet is then handed over to the system's TCP / IP protocol stack 312. For ordinary Ethernet data frames determined to be untagged, the frame format parsing unit 314 directly forwards them to the TCP / IP protocol stack 312. Finally, the service message processed by the standard protocol stack process is submitted to the flight simulation application module 105, thus completing the message reception processing.

[0063] In the simulation terminal systems (10A, 10D), the network driver module 107 implements the specific transmission process of the encapsulated data frames to the network interface 102, and captures and transmits the received data frames from the network interface 102. The network driver module 107 internally comprises a data frame sending unit 315 and a data frame receiving unit 316, corresponding to the sending and receiving functions of the interface service module 106, respectively. For the sending process, the data frame sending unit 315 receives the complete Ethernet data frames encapsulated by the interface service module 106 and submits them to the network interface 102, which then transmits them to the switching network via the hardware network card. For the receiving process, the data frame receiving unit 316 is responsible for capturing the raw data bit stream from the physical link in real time from the network interface 102 and transmitting it to the interface service module 106.

[0064] Simulated switch settings

[0065] The simulated switching nodes, namely switching module 201 in 20A, 20B, and 20C, perform actual forwarding processing of simulated flight data based on the configured fixed MAC address table. This switching module 201 achieves fixed-route forwarding of data frames in the switched network by querying the configured fixed MAC address table and port mapping relationships.

[0066] The TSN protocol configuration module 202 in the simulated switching nodes, namely the first TSN switching node 20A and the second TSN switching node 20B, implements deterministic scheduling and shaping of traffic based on the Time-Sensitive Networking (TSN) protocol suite. The information to be configured includes: high-precision time synchronization parameters based on the IEEE 802.1AS standard, credit-based shaping (CBS) parameters, time-aware shaping (TAS) parameters, frame duplication and elimination (FRER) rules, and per-flow filtering and policing (PSFP) rules. Simultaneously, the TSN protocol configuration module 202, according to the scheduling policy issued by the configuration management system, performs queue mapping and time slot allocation based on VLAN PCP identifiers for data frames entering the switching module. By precisely controlling the opening and closing times of each priority queue gate, it ensures that critical simulated flight data is forwarded within protected time slices, thereby simulating the deterministic interaction and traffic shaping functions of avionics networks in a time-sensitive environment. Specifically, to ensure collision-free deterministic forwarding of simulated flight data at the exchange nodes, the TSN protocol configuration module 202 sets the duration for enabling the gated list (GCL) in the Time-Aware Shaping (TAS) mechanism. The constraint criteria are configured. , This indicates the gating window width (also known as duration) of the priority queue within the scheduling cycle. This indicates the number of service flows mapped in the priority queue; Indicates the first The maximum data frame length in the traffic flow; Indicates the forwarding rate of the switch port; This indicates the duration of the guard band reserved to prevent interference from non-time-sensitive traffic. The gating opening window width constraint criterion of this invention ensures that all critical simulated flight data can be queued and forwarded within a preset time window within a scheduling cycle.

[0067] Figure 5A block diagram of the switching node implementation structure of the present invention is provided. Switching node 20A comprises two parts: a TSN protocol configuration module 202 and a switching module 201. The TSN protocol configuration module 202 interacts with the operator through a demonstration manager. The operator can input switch configuration information to the TSN scheduling function module through the demonstration manager, and the configuration process and results of the TSN scheduling function module can also be displayed and fed back to the operator through the human-machine interface. Switching node 20A is connected to the switching network 30 through the physical port of switching module 201. The physical port of the switching node can be directly connected to the end system, and can also be connected to other switching nodes via optical fiber, thereby forming a multi-level switching network. The cascading method of the switching nodes is not limited to a single physical link; it also supports multi-link parallel connection through multiple physical ports, thereby expanding the data exchange capacity between switching nodes and forming a switching backbone network.

[0068] For the switching module 201, in the specific implementation of the first TSN switching node 20A, a commercial switch with TSN characteristics can be used. For example, a CS2018A-01 model TSN switch can be used as the switching module 201 in the switching node of this invention.

[0069] For the configuration communication link between the TSN protocol configuration module 202 and the switching module 201, a network management interface can be used for connection in the specific implementation. This communication link is used to implement the static routing configuration of the switching module 201 and the scheduling and control operations of the TSN core functions. The TSN protocol configuration module 202 is mainly responsible for implementing deterministic scheduling functions such as confidence-based traffic shaping (CBS), time-aware traffic shaping (TAS), frame copying and elimination (FRER), and per-flow filtering and policing (PSFP). By configuring the scheduling policy issued by the management system, the data frames entering the switching module are queued and allocated time slots based on VLAN PCP identifiers, thereby ensuring that critical simulated flight data is deterministically forwarded within the protected time slice.

[0070] Using the end system and switching nodes of this invention, a demonstration topology for Time-Sensitive Networking (TSN) simulated flight data interaction can be built, enabling the demonstration of multiple deterministic network functions. In the demonstration topology, the simulated end systems, namely 10A, 10B, 10C, and 10D, are connected to the simulated switching nodes, namely 20A, 20B, and 20C, via physical link 101. Simultaneously, the switching nodes can be cascaded using physical link 104 to expand the scale of the demonstration system. Simulated flight data sent from the end systems undergoes raw data acquisition, service message sequence customization, and encapsulation in a link-layer frame format based on VLAN tags and PCP priority identifiers. Finally, it is accessed into the switching network 30 via network interface 102. This bitstream data is introduced into the internal data forwarding structure of the switching nodes through the switch ports. Data exchange between ports is performed according to the configured fixed MAC forwarding table, and deterministic traffic shaping is performed based on configured scheduling strategies such as credit-based shaping, time-aware shaping, frame duplication and elimination, per-stream filtering, and policing. By dynamically adjusting cell information to smooth burst traffic, precisely controlling the opening and closing times of priority queue gates, performing bandwidth policing and illegal frame filtering for specific flows, and backing up and eliminating data frames across redundant paths, critical simulated flight data is ensured to be correctly routed and reliably delivered to the message destination system within the protected time slice. At the message receiving end, the 802.1Q identifier contained in the data frame is identified, and the data frame is parsed and decapsulated according to the protocol layer. Finally, the original flight simulation message is extracted, and the flight status is visualized and reproduced, thus completing the demonstration of deterministic communication processes in a time-sensitive network environment.

[0071] Network tester

[0072] The network tester 30A provides definable background interference traffic during system operation to simulate the contention and interference process of non-deterministic services on time-sensitive traffic in flight simulation. This module supports fine-grained customization of the interference traffic frame format, including independent configuration of parameters such as source MAC address, destination MAC address, VLAN tag identifier, and PCP priority. During comparative verification of simulated flight data interaction, the network tester 30A simultaneously injects two interference traffic streams with identical configuration parameters into the network: the first interference traffic stream has its destination address set to the first receiving system 10B, which is forwarded via the first TSN switching node 20A and the second TSN switching node 20B, and received by the network interface 102 of the receiving system 10B, used to generate link contention on a deterministic path guaranteed by time-sensitive network protocols; the second interference traffic stream has its destination address set to the second receiving system 10D, which is forwarded via the first TSN switching node 20A and the Ethernet switching node 20C, and received by the network interface 102 of the receiving system 10D, used to generate an equivalent link load on a standard Ethernet comparison path. Through this symmetrical traffic injection method, the system can observe and acquire service quality indicators such as end-to-end latency, latency jitter, and packet loss rate in real time during the flight state reproduction process of the first receiving system 10B and the second receiving system 10D under identical network congestion conditions. This allows for quantitative comparison and functional verification of the time-sensitive network deterministic mechanism in actual flight simulation application scenarios. Specifically, for end systems 10A, 10B, and 10C, network interface 102 is a TSN network card supporting the time-sensitive network protocol suite; for end system 10D, network interface 102 is a regular Ethernet card.

[0073] Example 1: Experimental Topology for Verifying the Real-Time Performance of Time-Sensitive Networks

[0074] To verify the real-time performance characteristics of Time-Sensitive Networks (TSNs), this embodiment constructs the following... Figure 6 The experimental topology shown is used to simulate deterministic transmission of simulated flight data under high-load interference conditions. The system includes a transmitting system 10A, two receiving systems 10B and 10D, two TSN switching nodes 20A and 20B supporting the TSN protocol, one Ethernet switching node 20C, and is connected to the interference traffic through a network tester. The traffic attributes are set as shown in Table 1 below.

[0075] Table 1. Flow attribute configuration parameters in Example 1

[0076]

[0077] In Example 1, the system includes two types of traffic: simulated flight data traffic and background interference traffic. The simulated flight data traffic is generated by end system 10A and sent to end systems 10B and 10D simultaneously. It includes three types of traffic: aircraft position data, flight control data, and data reference extension information. The background interference traffic is generated by the network tester and sent to end systems 10B and 10D simultaneously. The bandwidth utilization rate is set to 150% of the physical bandwidth of the link.

[0078] During the testing process, the background interference traffic transmission of the network tester was first disabled. Network packet capture was used to collect network service quality parameters when simulated flight data was sent from end system 10A to end system 10B. Subsequently, the background interference traffic transmission of the network tester was enabled. The time-sensitive network protocol's credit-based shaping mechanism, time-aware shaping mechanism, and per-flow filtering and policing mechanism were configured for TSN switching node 20A to optimize the communication link from end system 10A to end system 10B. The communication link from end system 10A to end system 10D was compared. Network packet capture was used on both end system 10B and end system 10D to collect reception data. At the same time, the flight status visualization in the flight simulation software was observed. The results are shown in Table 2 below.

[0079] Table 2 System service quality statistics and flight status statistics under various network configurations in Example 1

[0080]

[0081] Based on the comparison of test results, in the traditional Ethernet mode, due to the competition for buffer resources between background interference traffic and critical simulated flight data traffic within the switch, and the lack of a priority protection mechanism, the simulated flight data frames experience significant jitter and delay during the queuing process, resulting in severe stuttering of the flight screen at the receiving end. After enabling Time-Sensitive Network Scheduling (TSS), Credit-Based Shaping (CBS) effectively smooths out the suddenness of background interference traffic by setting the credit ramp-up and ramp-down slopes for different priority queues, preventing interference traffic from occupying bandwidth for a long time. Time-Aware Shaping (TAS) uses a gated list (GCL) to periodically enable or disable the output gating of specific queues, allocating dedicated protection time slices for critical simulated flight data traffic, achieving traffic isolation in the time domain and reducing its impact from interference traffic. Per-Flow Filtering and Policing (PSFP) plays a crucial role at the switch ingress. This mechanism monitors input traffic in real time based on the token bucket algorithm. When the rate of background interference traffic exceeds the preset Committed Information Rate (CIR), the excess traffic is marked as an illegal frame due to token exhaustion and is directly filtered and dropped at the ingress, thus preventing abnormal traffic from preempting switch buffer resources from the source and ensuring that compliant simulated flight data traffic can pass through without obstruction. Test results show that, compared with traditional Ethernet, the average end-to-end latency of traffic transmission was reduced by 55.4%, 70.6%, and 74.4% respectively when credit shaping, time-aware shaping, and per-flow filtering and policing mechanisms were applied, verifying the advantages of the above mechanisms in ensuring the real-time performance of avionics communications.

[0082] Example 2: Experimental Topology for Verifying the Reliability Characteristics of Time-Sensitive Networks

[0083] To verify the reliability characteristics of time-sensitive networks, this embodiment constructs the following... Figure 7 The experimental topology with redundant physical paths shown is used to verify the role of the Frame Replication and Deletion (FRER) mechanism in ensuring communication of critical services during link failures. The system includes a transmitting system 10A, a receiving system 10B, two TSN switching nodes 20A and 20B supporting the TSN protocol, and one Ethernet switching node 20C. The transmitting system ESA, through its TSN network card's frame replication mechanism, connects two different network interfaces to different ports of switch 20A, and then connects them to two different network interfaces of the receiving system 10B via TSN switching node 20B and Ethernet switching node 20C, respectively. The receiving system 10B is configured with the TSN network card's frame deletion mechanism, forming two independent physical paths, Path 1 and Path 2. The Frame Replication and Deletion mechanism adds a sequence number identifier to each frame of critical simulated flight data and copies it into two identical data frames, which are then synchronously transmitted to the receiving system 10B through the two paths. Duplicate frames are then removed at the receiving system 10B.

[0084] During testing, the frame duplication and elimination mechanism of the end system was enabled. Simulated flight data was sent from the sending end system 10A to the receiving end system 10B. Upon receipt, the simulated flight data was simultaneously visualized by the flight simulation software. During system operation, one physical link was manually disconnected. When one link was disconnected, the receiving end 10B was able to seamlessly receive the backup frame and eliminate duplicate frames because a data frame with the same sequence number existed on the backup link. Experimental records showed that at the moment of link disconnection, the sequence number of the simulated flight data at the receiving end remained continuous, with no communication interruptions. This achieved redundant protection of critical data and improved the communication reliability of the avionics network during physical link failures.

Claims

1. A deterministic communication demonstration system for simulated flight data based on time-sensitive networking, comprising: The airborne network is formed by networking end systems and switches, and the airborne network is used to generate flight data streams; The network tester is used to generate background interference traffic for the airborne network; Its features are: It also includes a demo manager for receiving flight data streams and background interference traffic; The demonstration manager sets up a simulation terminal system and a simulation switch; and the simulation terminal system and the simulation switch are connected by a physical link (101) to form a deterministic interaction path for simulated flight data; The simulation terminal system includes a flight simulation application module (105), an interface service module (106), and a network driver module (107). The simulated switch is equipped with a switching module (201) and a TSN protocol configuration module (202). The flight simulation application module (105) is used to define the flight data stream; The interface service module (106) is used to directly construct the original link layer frame and complete the bidirectional protocol encapsulation / parsing logic; The network driver module (107) is based on the physical transceiver, VLAN ID extraction and PCP priority mapping features of the Linux underlying architecture; The switching module (201) performs actual forwarding processing of simulated flight data according to the configured fixed MAC address table; The TSN protocol configuration module (202) is used for the coordinated scheduling of the TSN protocol suite of TAS, CBS, PSFP, and FRER.

2. The time-sensitive network-based deterministic communication demonstration system for simulated flight data according to claim 1, characterized in that: The flight simulation application module (105) includes a communication parameter configuration unit (304), an external model interface (305), a flight simulation program (306), a message generator (307), and a message receiver (308). The communication parameter configuration unit (304) is used to calculate the bandwidth load rate of a single-channel simulated flight data. ; Indicates the first Bandwidth duty cycle of simulated flight data; This indicates the length of the application layer message payload representing the simulated flight data. This represents the combination of additional overheads incurred by protocol stack encapsulation; Indicates the rated transmission rate of the current physical link; The external model interface (305) is used to collect the current simulated flight data generated by the simulated flight program (306) in real time; the simulated flight data stream includes aircraft position data, flight control data and data reference extension information; The message generator (307) constructs and sends periodic messages based on multi-level message queues by combining the configuration parameters issued by the communication parameter configuration unit (304) with the real-time simulated flight data transmitted by the external model interface (305). Driven by a unified clock source, the message generator (307) traverses each message queue according to a preset synchronization period, extracts the payload in the queue to generate a service data stream containing priority features, and submits it to the interface service module (106), thereby ensuring that different types of simulated flight data can enter the transmission link in an orderly manner according to a predetermined period. The message receiver (308) receives the parsed message transmitted from the interface service module (106) according to the receiving strategy issued by the communication parameter configuration unit (304); the message receiver (308) performs legality verification and classification on the received data, and transmits the extracted flight control commands or environmental parameters to the external model interface (305) in real time to drive the flight simulation program (306) to reproduce the state.

3. The deterministic communication demonstration system for simulated flight data based on time-sensitive networking according to claim 1, characterized in that: The interface service module (106) includes a sending function group and a receiving function group; In the transmission direction, the transmission function group bypasses the standard UDP / IP protocol stack packet encapsulation process and directly constructs a link layer raw frame containing an Ethernet MAC layer header and a VLAN tag, and embeds a PCP priority identifier in the frame header; In the receiving direction, the receiving function group parses the 802.1Q data frame transmitted by the network driver module (107), extracts the original simulated flight message, and submits it to the flight simulation application module (105) for state reproduction.

4. The time-sensitive network-based deterministic communication demonstration system for simulated flight data according to claim 1, characterized in that: The network driver module (107) is implemented based on the underlying network driver architecture; The network driver module (107) captures data frames from the physical port, strips the MAC header and VLAN tag, and extracts the VLAN ID into the receive descriptor; at the same time, it delivers the encapsulated data packets transmitted by the interface service module (106) directly to the network interface (102) for physical transmission.

5. The time-sensitive network-based deterministic communication demonstration system for simulated flight data according to claim 1, characterized in that: The TSN protocol configuration module (202) performs deterministic scheduling of data frames entering the switching module (201) according to the TSN protocol suite; the scheduling mechanism includes Time-Aware Shaping (TAS), Credit-Based Shaping (CBS), Per-Stream Filtering and Surveillance (PSFP), and Frame Copying and Deletion (FRER); In the TSN protocol configuration module (202), queue mapping and time slot allocation based on VLAN PCP identifier are performed on the time-sensitive flow according to the preset scheduling policy.

6. The time-sensitive network-based deterministic communication demonstration system for simulated flight data according to claim 5, characterized in that: The TSN protocol configuration module (202) specifies the gating list opening duration constraint criteria in the TAS mechanism as follows: ; This indicates the width of the gating window for the priority queue during the scheduling period; This indicates the number of service flows mapped in the priority queue; Indicates the first The maximum data frame length in the traffic flow; Indicates the forwarding rate of the switch port; This indicates the duration of the protection band reserved to prevent interference from non-time-sensitive flow.

7. The time-sensitive network-based deterministic communication demonstration system for simulated flight data according to claim 1, characterized in that: The demo manager is configured with two parallel paths for real-time comparison; the first is a TSN deterministic communication path, consisting of at least two cascaded TSN switching nodes; the second is a standard Ethernet comparison path, consisting of at least one standard Ethernet switching node.

8. The deterministic communication demonstration system for simulated flight data based on time-sensitive networking according to claim 1, characterized in that: The communication demonstration system injects background interference traffic through a network tester and uses the demonstration manager to observe and quantify the end-to-end latency and latency jitter indicators of the simulation system under different paths in real time.

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