A real-time closed-loop navigation signal simulation method, device, equipment and medium

Abstract

The application discloses a real-time closed-loop navigation signal simulation method, device, equipment and medium, the method comprises the steps that S1, initialization system configuration, including configuration network connection mode, clock synchronization card and the like; S2, real-time data synchronization mechanism is established, installs reflection memory card on track simulation machine and real-time closed-loop navigation signal source, and automatically establishes data synchronization function, and realizes real-time transmission of data through PCI bus and optical fiber; S3, creates navigation signal simulation task, and simultaneously configures four addresses and a track cycle list in navigation signal simulation software reflection memory card; S4, navigation signal simulation is executed, reads track data and calculates the required parameters of navigation signal simulation, generates navigation signal through SGC signal generation card, and compares reference track and track positioned by receiver in real time to carry out closed-loop test and verification of navigation signal. The application realizes high-precision, high-dynamic performance navigation signal simulation.

Description

Technical Field

[0001] This application relates to the field of navigation simulation technology, and in particular, to a real-time closed-loop navigation signal simulation method, apparatus, device, and medium. Background Technology

[0002] With the rapid development of satellite navigation technology, satellite navigation signal simulators are widely used in the development, testing, and maintenance of various radio frequency electronic systems. Traditional satellite navigation signal simulation methods typically employ a host computer + DSP + FPGA architecture or a host computer + FPGA architecture, resulting in large size, high cost, and limited real-time performance. While ZYNQ-based satellite navigation signal simulators are integrated and miniaturized, they have limited functionality and a limited number of channels, making them unable to simulate multiple systems and users. Currently, navigation signal simulators need to simulate various navigation signals from four major and two minor navigation systems, including dozens of mainstream navigation signal frequencies and hundreds of satellites in parallel simulation. This results in a massive amount of simulation data, placing high demands on the simulator's computational capabilities. Furthermore, in some special application scenarios, such as indoors, tunnels, and underground parking garages, traditional satellite navigation signal power is too low or there is no satellite navigation signal at all, requiring reliance on indoor satellite navigation technology for positioning. However, existing navigation signal simulation methods have many problems. First, the transmission of trajectory data from the simulator to the industrial control computer's numerical simulation model and signal generation simulator typically involves multiple stages, such as trajectory network transmission, intermediate data network forwarding, and PCI forwarding. This results in numerous data transmission stages from trajectory to analog signal, each with its own jitter, leading to high data transmission latency and making it difficult to meet the requirements of strong real-time performance and high sampling rates. Second, the low trajectory sampling rate, limited by data transmission and processing speed, makes it difficult to simulate navigation signals in some highly dynamic and ultra-high dynamic scenarios. Third, issues with trajectory data transmission and reception, as well as the trajectory model itself, can cause discontinuities in the final trajectory used for navigation signal simulation calculations. Finally, the simulation signal accuracy is insufficient. Due to the latency and jitter of the trajectory data, the simulated navigation signal deviates significantly from the real scene, affecting the accuracy of testing and verification. These problems severely restrict the application and development of satellite navigation signal simulation technology. Summary of the Invention

[0003] This application provides a real-time closed-loop navigation signal simulation method to solve the technical problems in the prior art, such as high data transmission delay, large jitter, inability to detect and correct trajectory anomalies, and low sampling rate of trajectory and navigation mathematical simulation calculations leading to insufficient simulation accuracy during satellite navigation signal simulation.

[0004] This application is achieved through the following solution:

[0005] A real-time closed-loop navigation signal simulation method includes the following steps:

[0006] S1. Initialize system configuration, including installing the real-time operating system, configuring the network connection method and clock synchronization card to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory transmission program;

[0007] S2. Establish a real-time data synchronization mechanism. Install reflective memory cards on both the trajectory simulator and the real-time closed-loop navigation signal source to automatically establish data synchronization function and realize real-time data transmission through PCI bus and optical fiber.

[0008] S3. Create a navigation signal simulation task, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation settings. At the same time, configure the reflective memory card with four addresses and a circular list of trajectories in the navigation signal simulation software. The four addresses include the start command address, the user trajectory address, the initialization completion address, and the trajectory completion address.

[0009] S4. Perform navigation signal simulation, read trajectory data to calculate the parameters required for navigation signal simulation, generate navigation signals through the SGC signal generation card, and compare the reference trajectory and the trajectory located by the receiver in real time to perform closed-loop test verification of the navigation signal; when reading trajectory data, perform trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detect whether the continuity of the current frame trajectory is abnormal with the previous few frame trajectories, and continuously receive and process according to the beat.

[0010] Further, step S1 specifically includes the following steps:

[0011] S11. Install Linux / RTX real-time operating system on the industrial control computer and trajectory simulator on the real-time closed-loop navigation signal source;

[0012] S12. Set the network connection method of the industrial control computer on the real-time closed-loop navigation signal source, and set the network connection type to private network;

[0013] S13. Configure a clock synchronization card in the trajectory simulator to support 10M input, install the driver and provide an SDK development package with high real-time interrupt capability, and realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory sending program.

[0014] Furthermore, step S2 specifically includes the following steps:

[0015] S21. Configure a PCI interface reflective memory card on the trajectory simulator and the real-time closed-loop signal source, and connect them using optical fiber.

[0016] S22, The reflective memory card driver automatically establishes a data synchronization function to achieve real-time data transmission.

[0017] Furthermore, step S3 specifically includes the following steps:

[0018] S31. Create a navigation signal simulation task, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation. In the navigation signal simulation software, configure a circular list of four addresses and one trajectory. The four addresses include the start command address StartAddr, the user trajectory address TrackAddr, the initialization completion address initedAddr, and the trajectory completion address TrackfinishAddr. The size of the circular list is circleBufferSize.

[0019] S32. Configure trajectory data generation to run in the Linux / RTX environment of the trajectory simulator;

[0020] S33. Configure the trajectory data receiving task to run in a Linux real-time environment and use the reflected memory card interrupt to send and receive the trajectory.

[0021] S34. Set the signal parameter calculation task to run in a Linux real-time environment;

[0022] S35. Configure the signal generation task to run on the SGC signal generation card.

[0023] Furthermore, step S4 specifically includes the following steps:

[0024] S41. Real-time transmission of trajectory and reception of external trajectory data. When reading trajectory data, the trajectory data to be written to the buffer is subjected to trajectory continuity anomaly detection and processing. The continuity between the current frame trajectory and the previous few frame trajectories is detected as abnormal, and reception processing is performed continuously according to the beat.

[0025] S42. Calculate the parameters required for navigation signal simulation based on the received trajectory data;

[0026] S43. Generate navigation signals using the SGC signal generation card;

[0027] S44. Real-time comparison of the reference trajectory and the trajectory located by the receiver;

[0028] S45. Based on the comparison results, dynamically adjust the trajectory or adjust the relevant functions of the receiver to achieve closed-loop test verification of the navigation signal.

[0029] Further, step S41 specifically includes:

[0030] S411. The trajectory simulator is configured with a clock synchronization card trigger frequency, and the calculation frequency is set to be consistent with the trajectory data sampling frequency. A trajectory storage buffer is established, and the delay period is set to control the initial number of trajectories retained in the trajectory buffer in the pipeline. The trajectory storage buffer is used to meet simulation requirements of different accuracy. The trajectory interval supports: 0.5ms, 1ms, 2ms, 2.5ms, 5ms, and 10ms. The trajectory data format is as follows: the coordinate system used for the trajectory is the Earth-centered Earth-Fixed (ECEF) coordinate system, and the pitch, roll, and yaw attitudes adopt the relative northeast-sky (ENU) coordinate system.

[0031] S412: Read trajectory data directly from the reflective memory card via the PCI interface;

[0032] S413. Read the trajectory data of the existing memory location according to the clock system's time stamp, perform anomaly detection and processing on the trajectory data, store it in the trajectory buffer, and continuously receive and process it according to the beat.

[0033] S414. After reading the first trajectory data and the start simulation marker, the simulation calculation thread is triggered to start the navigation simulation initialization process. During the initialization process, the trajectory data received at the corresponding time is stored in the trajectory buffer.

[0034] Further, in step S411, a trajectory storage address algorithm is designed. Assuming the number of users in the simulation is N, the size of each trajectory block is 60 + 25 × 8 × N. The calculation process for the position of the trajectory data read each time is as follows:

[0035] The value of the address where the trajectory reading is completed is denoted as SaveIndex;

[0036] Create a variable CurReadIndex, initialize it to 0 each time the simulation starts and stops, and record how many times it is read. This is used to compare with SaveIndex to determine how many times the trajectory should be read this time. Under normal circumstances, SaveIndex and CurReadIndex are equal to 1. When there is jitter in the receiver for more than one tick cycle and no jitter in the transmitter, it will be greater than 1. When there is jitter in the transmitter for more than one tick cycle and no jitter in the receiver, it will be equal to 0.

[0037] Calculate the starting address of the memory for the current trajectory data being read:

[0038] CurReadAddr=TrackAddr+(60+25×8×N) ×(( CurReadIndex+1)%circleBufferSize);

[0039] Based on the calculated starting address, the trajectory data of the corresponding memory block location is read and stored in the buffer.

[0040] Further, in step S413, anomaly detection and processing are performed on the trajectory data, and the data is stored in the trajectory buffer. This specifically includes the following steps:

[0041] By analyzing the interrelationships between trajectory data of time, acceleration, velocity, and position, we can detect whether there are any abnormalities in the continuity between the trajectory data of the current frame and the trajectory data of the previous frames.

[0042] When an anomaly is detected in the continuity of trajectory data, the error type of the trajectory data is determined based on the anomaly, and the data is processed according to the error type. The error types include trajectory loss and data jump.

[0043] The processed trajectory data is stored in the trajectory buffer.

[0044] Furthermore, by analyzing the interrelationships between trajectory data related to time, acceleration, velocity, and position, the continuity between the current trajectory data and previous trajectory data is checked for anomalies. This includes the following steps:

[0045] Check whether the time is continuous, including three situations: normal situation, track loss, and track duplication;

[0046] The position derivative is compared with the velocity in the trajectory data, and the velocity derivative is compared with the acceleration. When the error exceeds the corresponding set threshold, it is judged as an abnormality in trajectory continuity. The abnormality includes one or more of the following: position abnormality, velocity abnormality, and acceleration abnormality.

[0047] Furthermore, the errors are categorized and processed accordingly, specifically including the following steps:

[0048] When the error type is "track loss", the handling strategies include:

[0049] Segmentation strategy: For single-point missing cases, linear interpolation is used to supplement trajectory data; for continuous point missing cases (≤3), third-order spline curve interpolation is used to supplement trajectory data; for long-term point missing cases (≥3), the rigid body motion equation model is switched to calculate trajectory data to supplement trajectory data.

[0050] Data parameter priority mechanism: position takes precedence over velocity, velocity takes precedence over acceleration, ensuring the continuity of key navigation signal parameters;

[0051] When the error type is data jump, the handling strategies include:

[0052] An adaptive Kalman filter system is established using a filtering and smoothing method. During the simulation, the trajectory parameters are used to train the process noise parameters. When trajectory jumps or abnormalities occur, the moving average of the filter system is used to replace the abnormal data to correct the jump anomalies.

[0053] Further, step S42 specifically includes the following steps:

[0054] S421. Use the current navigation signal simulation time to obtain the trajectory data corresponding to the time from the trajectory buffer. If the trajectory is continuously obtained, when obtaining the trajectory in the second frame after the start of the simulation, calculate the jump time length by subtracting the time to be obtained this time from the current received trajectory time and the reserved delay T number × interval, and record it as jumpTimes. After this frame, add JumpTimes to the time of obtaining the trajectory each time.

[0055] S422. Calculate navigation signal parameters using trajectory data;

[0056] S423 transmits navigation signal parameters to the SGC signal generation card via the PCI bus.

[0057] Further, step S43 specifically includes the following steps:

[0058] S431 and SGC signal generation cards receive navigation signal parameters;

[0059] S432. The navigation signal is generated from the navigation signal parameters through the FPGA logic circuit. When modulating the signal, the code phase accumulated by the dynamic parameter conversion is detected. When a transition occurs, the code phase accumulation is reset once according to the current simulation time to ensure that the signal modulation is continuous after the transition.

[0060] S433. Filter, up-convert, and amplify the generated navigation signal;

[0061] S434 outputs the filtered, up-converted, and amplified navigation signal to the signal interface.

[0062] Further, step S44 specifically includes the following steps:

[0063] S441. Collect navigation, positioning, and speed measurement results from the receiver under test;

[0064] S442. Calculate the positioning and velocity measurement error index between the receiver positioning and velocity measurement results and the simulated trajectory;

[0065] S443. Determine whether the simulation accuracy meets the requirements based on the error index.

[0066] Further, step S45 specifically includes the following steps:

[0067] S451. If the simulation accuracy does not meet the requirements, adjust the trajectory simulation parameters, sampling rate, and receiver algorithm.

[0068] S452. Dynamically adjust the trajectory simulation parameters according to the current simulation scenario;

[0069] S453. Update the sampling rate calculated by the simulation reception of the navigation signal according to the sampling rate of the simulation trajectory;

[0070] S454, return to the steps of real-time trajectory transmission and external trajectory data reception to continue the next round of simulation. After multiple rounds of testing, a suitable trajectory sampling rate for the simulation trajectory is found.

[0071] This application also provides a real-time closed-loop navigation signal simulation device, comprising:

[0072] The initialization configuration module is used to initialize the system configuration, including installing the real-time operating system, configuring the network connection method, and using the clock synchronization card to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory transmission program;

[0073] The data synchronization module is used to establish a real-time data synchronization mechanism. Reflective memory cards are installed on both the trajectory simulator and the real-time closed-loop navigation signal source to automatically establish data synchronization function and realize real-time data transmission.

[0074] The simulation task creation module is used to create navigation signal simulation tasks, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation settings. At the same time, it configures a loop list of four addresses and one trajectory in the navigation signal simulation software. The four addresses include the start command address, the user trajectory address, the initialization completion address, and the trajectory completion address.

[0075] The navigation signal simulation module is used to perform navigation signal simulation, read trajectory data to calculate the parameters required for navigation signal simulation, generate navigation signals through the SGC signal generation card, and compare the reference trajectory and the trajectory located by the receiver in real time to perform closed-loop test verification of the navigation signal. When reading trajectory data, the module performs trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detects whether the continuity between the current frame trajectory and the previous few frame trajectories is abnormal, and continuously receives and processes the data according to the beat.

[0076] This application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of the real-time closed-loop navigation signal simulation method.

[0077] This application also provides a storage medium including a stored program that, when the program is executed, controls the device where the storage medium is located to perform the steps of the real-time closed-loop navigation signal simulation method.

[0078] Compared with the prior art, this application has the following beneficial effects:

[0079] 1. This application utilizes a reflective memory card to achieve real-time data synchronization between a trajectory simulator and a navigation signal simulation computer, ensuring efficient and low-latency transmission of trajectory data, effectively reducing data transmission jitter, and controlling time jitter within 50µs, thus solving the jitter problem caused by network transmission uncertainty in the prior art;

[0080] 2. This application enables data transmission between the navigation signal simulation computer, the reflection memory card, and the navigation signal generation card via the PCI bus. Trajectory data is directly accessed from the reflection memory card to the navigation signal simulation computer, bypassing traditional network transmission and protocol processing steps, significantly reducing data transmission latency. This meets the requirements of strong real-time performance and high sampling rate, and overcomes the latency and jitter problems caused by multiple steps in traditional methods.

[0081] 3. This application optimizes the data transmission and simulation calculation process, increasing the trajectory sampling rate to 2000Hz and shortening the navigation signal simulation calculation interval to once every 0.5ms. Simultaneously, the minimum number of delay cycles can be reduced to two cycles, achieving 1ms real-time performance. This significantly improves performance parameters and enables the simulation of navigation signals in ultra-high dynamic scenarios. It overcomes the problems of low trajectory sampling rates and large navigation simulation calculation intervals in traditional methods, making it difficult to simulate high-dynamic and ultra-high-dynamic scenarios, and substantially enhances the original dynamic range.

[0082] 4. This application runs a real-time operating system on the trajectory simulator and the navigation signal source industrial control computer, and provides strict time determinism and high-precision clock synchronization through the clock board, ensuring the real-time performance of the numerical simulation calculation, improving the overall real-time performance of the system, and overcoming the problem of insufficient RTSS support in the real-time subsystem environment in the prior art;

[0083] 5. This application achieves closed-loop control and accurate simulation of navigation signals by dynamically adjusting trajectory parameters through real-time comparison of simulation signals and reference signals, which significantly improves the matching degree between simulation signals and real scenes and solves the problem of large deviation between simulation signals and actual scenes in traditional methods;

[0084] 6. This application, through the design of an in-memory data structure, supports an easily scalable number of users for trajectory transmission, addressing the needs of different user numbers;

[0085] 7. This application uses the memory of the reflective memory card to solve the problems of repeated reading of the same moment, loss of beat, and data being read and written in half when the data is being written by cyclically reading and writing multiple memory blocks according to the size of the trajectory parameters.

[0086] 8. This application incorporates a pseudorange jump function in the signal generation design, enabling trajectory transmission between the trajectory generation system and the reversing signal simulation system without requiring a controllable interaction process. From the moment the first trajectory is sent, it is only necessary to continuously send the trajectory according to the beat, simplifying the interaction process.

[0087] 9. This application supports the detection and correction of trajectory anomalies, reducing the requirements for trajectory models and improving the robustness of the entire system.

[0088] In addition to the purposes, features, and advantages described above, this application has other purposes, features, and advantages. A further detailed description of this application will be provided below with reference to the figures. Attached Figure Description

[0089] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0090] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0091] Figure 1 This is a schematic diagram of the overall architecture of the real-time closed-loop navigation signal simulation device that implements the functions of this application;

[0092] Figure 2 This is a flowchart illustrating a preferred embodiment of the real-time closed-loop navigation signal simulation method of this application;

[0093] Figure 3 This is a data flow diagram of a real-time closed-loop navigation signal simulation device;

[0094] Figure 4 This is a flowchart of the trajectory anomaly detection processing according to a preferred embodiment of this application.

[0095] Figure 5 This is a schematic diagram of a real-time closed-loop navigation signal simulation device module according to a preferred embodiment of this application;

[0096] Figure 6 This is a schematic block diagram of an electronic device according to a preferred embodiment of this application;

[0097] Figure 7 This is an internal structural diagram of a computer device according to a preferred embodiment of this application. Detailed Implementation

[0098] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0099] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0100] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or a real-time closed-loop navigation signal simulation device capable of performing the above functions. The following example uses a real-time closed-loop navigation signal simulation device (see...). Figure 1 Taking the execution subject as an example, this embodiment and the following embodiments will be described.

[0101] like Figure 2 and Figure 3 As shown, a preferred embodiment of this application provides a real-time closed-loop navigation signal simulation method, including the following steps:

[0102] S1. Initialize system configuration, including installing the real-time operating system, configuring the network connection method and clock synchronization card to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory transmission program;

[0103] S2. Establish a real-time data synchronization mechanism. Install reflective memory cards on both the trajectory simulator and the real-time closed-loop navigation signal source to automatically establish data synchronization function and realize real-time data transmission through PCI bus and optical fiber.

[0104] S3. Create a navigation signal simulation task, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation settings. At the same time, configure the reflective memory card with four addresses and a circular list of trajectories in the navigation signal simulation software. The four addresses include the start command address, the user trajectory address, the initialization completion address, and the trajectory completion address.

[0105] S4. Perform navigation signal simulation, read trajectory data to calculate the parameters required for navigation signal simulation, generate navigation signals through the SGC signal generation card, and compare the reference trajectory and the trajectory located by the receiver in real time to perform closed-loop test verification of the navigation signal; when reading trajectory data, perform trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detect whether the continuity of the current frame trajectory is abnormal with the previous few frame trajectories, and continuously receive and process according to the beat.

[0106] Compared with the prior art, this embodiment has the following beneficial effects:

[0107] 1. This embodiment utilizes a reflective memory card to achieve real-time data synchronization between the trajectory simulator and the navigation signal simulation computer, ensuring efficient and low-latency transmission of trajectory data, effectively reducing data transmission jitter, and controlling time jitter within 50µs, thus solving the jitter problem caused by network transmission uncertainty in the prior art;

[0108] 2. This embodiment uses the PCI bus to connect the navigation signal simulation computer, the reflection memory card, and the navigation signal generation card for data transmission. The trajectory data is directly accessed from the reflection memory card to the navigation signal simulation computer, bypassing the traditional network transmission and protocol processing links, which significantly reduces the data transmission latency. This meets the requirements of strong real-time performance and high sampling rate, and overcomes the latency and jitter problems caused by multiple links in the traditional method.

[0109] 3. This embodiment optimizes the data transmission and simulation calculation process, increasing the trajectory sampling rate to 2000Hz and shortening the navigation signal simulation calculation interval to once every 0.5ms. Simultaneously, the minimum number of delay cycles can be reduced to two cycles, achieving 1ms real-time performance. This significantly improves performance parameters and enables the simulation of navigation signals in ultra-high dynamic scenarios. It overcomes the problems of low trajectory sampling rates and large navigation simulation calculation intervals in traditional methods, making it difficult to simulate high-dynamic and ultra-high-dynamic scenarios. The dynamic range is significantly improved, as in the original scheme:

[0110] Speed ​​range: ≥ ±80000 m / s;

[0111] Acceleration range: ≥ ±8000 m / s 2 ;

[0112] jerk range: ≥ ±8000 m / s 3 ;

[0113] The solution in this embodiment has been tested and found to be as follows:

[0114] Speed ​​range: ±295000m / s;

[0115] Acceleration range: ±590000m / s 2 ;

[0116] jerk range: ±590000m / s 3 ;

[0117] 4. In this embodiment, a real-time operating system runs on the trajectory simulator and the navigation signal source industrial control computer, and provides strict time determinism and high-precision clock synchronization through the clock board, ensuring the real-time performance of the numerical simulation calculation, improving the overall real-time performance of the system, and overcoming the problem of insufficient RTSS support in the real-time subsystem environment in the prior art;

[0118] 5. This embodiment achieves closed-loop control and accurate simulation of navigation signals by dynamically adjusting trajectory parameters through real-time comparison of simulation signals and reference signals. This significantly improves the matching degree between simulation signals and real scenes and solves the problem of large deviations between simulation signals and actual scenes in traditional methods.

[0119] 6. This embodiment, through the design of a memory data structure, supports an easily scalable number of users for trajectory transmission, addressing the needs of different numbers of users;

[0120] 7. In this embodiment, the memory of the reflective memory card is read and written in a loop using multiple memory blocks according to the size of the trajectory parameters to solve the problems of repeated reading at the same moment, loss of beat, and data being read and written halfway through the trajectory transmission process.

[0121] 8. This embodiment, combined with the designed signal generation, supports pseudorange jump functionality, allowing trajectory transmission between the trajectory generation system and the reversing signal simulation system without requiring a controllable interaction process. From the moment the first trajectory is sent, it is only necessary to continuously send the trajectory according to the beat, simplifying the interaction process.

[0122] 9. This embodiment supports the detection and correction of trajectory anomalies, reducing the requirements for the trajectory model and improving the robustness of the entire system.

[0123] Preferably, step S1 specifically includes the following steps:

[0124] S11. Install a Linux / RTX real-time operating system, such as Linux kernel 5.4.0-103.el8.x86_64, on the industrial control computer and trajectory simulator on the real-time closed-loop navigation signal source;

[0125] S12. Configure the network connection method of the industrial control computer on the real-time closed-loop navigation signal source. Set the network connection type to private network and use static IP address allocation. For example, configure the IP address of the industrial control computer of the real-time closed-loop navigation signal source to 192.168.2.1 and the IP address of the simulator to 192.168.2.2.

[0126] S13. Configure a clock synchronization card in the trajectory simulator, model TIME1000, with a PCI interface, supporting 10M input. Install the driver and provide an SDK development package for high real-time interrupts. Its main function is to provide high real-time interrupts to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator's trajectory sending program. Connect the 10M output of the real-time closed-loop navigation signal source to the 10M input port of the clock board of the trajectory simulator.

[0127] Preferably, step S2 specifically includes the following steps:

[0128] S21. Configure PCI interface reflective memory cards (such as PMC5565 reflective memory cards) on the trajectory simulator and real-time closed-loop signal source, and connect them using optical fibers. For example, establish an optical fiber reflective memory network connection between reflective memory cards, using SFP28 optical fiber cable with a transmission rate of 2.5Gbps.

[0129] S22, The reflective memory card driver automatically establishes a data synchronization function to achieve real-time data transmission.

[0130] The advantages of this embodiment include: low latency in trajectory data transmission, small jitter range, automatic data synchronization, and simplified software control logic structure.

[0131] Preferably, step S3 specifically includes the following steps:

[0132] S31. Create a navigation signal simulation task, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation. In the navigation signal simulation software, configure a circular list of four addresses and one trajectory. The four addresses include the start command address StartAddr, the user trajectory address TrackAddr, the initialization completion address initedAddr, and the trajectory completion address TrackfinishAddr. The size of the circular list is circleBufferSize.

[0133] S32. Configure trajectory data generation to run in the Linux / RTX environment of the trajectory simulator;

[0134] S33. Configure the trajectory data receiving task to run in a Linux real-time environment and use the reflected memory card interrupt to send and receive the trajectory.

[0135] S34. Set the signal parameter calculation task to run in a Linux real-time environment, such as using an Intel i7-12700k processor.

[0136] S35. Configure the signal generation task to run on the SGC signal generation card, model SGC_V320.

[0137] The advantages of this embodiment include: configurable reflective memory card address, stable and efficient interrupt transmission trajectory method, high real-time stability of real-time Linux system under high-frequency CPU, low price of general-purpose computer, and high real-time signal generation.

[0138] Preferably, step S4 specifically includes the following steps:

[0139] S41. Real-time transmission of trajectory and reception of external trajectory data. When reading trajectory data, the trajectory data to be written to the buffer is subjected to trajectory continuity anomaly detection and processing. The continuity between the current frame trajectory and the previous few frame trajectories is detected as abnormal, and reception processing is performed continuously according to the beat.

[0140] S42. Calculate the parameters required for navigation signal simulation based on the received trajectory data;

[0141] S43. Generate navigation signals using the SGC signal generation card;

[0142] S44. Real-time comparison of the reference trajectory and the trajectory located by the receiver;

[0143] S45. Based on the comparison results, dynamically adjust the trajectory or adjust the relevant functions of the receiver to achieve closed-loop test verification of the navigation signal.

[0144] The advantages of this embodiment include: real-time detection and correction of trajectory anomalies, real-time dynamic comparison of the error between the simulated trajectory and the received trajectory, and high real-time visualization of positioning and trajectory deviation.

[0145] Preferably, step S41 specifically includes:

[0146] S411. The trajectory simulator is configured with a clock synchronization card trigger frequency, and the calculation frequency is set to be consistent with the trajectory data sampling frequency. A trajectory storage buffer is established, and the delay period is set to control the initial number of trajectories retained in the trajectory buffer in the pipeline. The trajectory storage buffer is used to meet simulation requirements of different accuracy. The trajectory interval supports: 0.5ms, 1ms, 2ms, 2.5ms, 5ms, and 10ms. The trajectory data format is as follows: the coordinate system used for the trajectory is the Earth-centered Earth-Fixed (ECEF) coordinate system, and the pitch, roll, and yaw attitudes adopt the relative northeast-sky (ENU) coordinate system.

[0147] S412: Read trajectory data directly from the reflective memory card via the PCI interface;

[0148] S413. Read the trajectory data of the existing memory location according to the clock system's time stamp, perform anomaly detection and processing on the trajectory data, store it in the trajectory buffer, and continuously receive and process it according to the beat.

[0149] S414. After reading the first trajectory data and the start simulation marker, the simulation calculation thread is triggered to begin the navigation simulation initialization process. During the initialization process, the trajectory data received at the corresponding time is stored in the trajectory buffer (see...). Figure 4 ).

[0150] The advantages of this embodiment include: easy configuration of time intervals, anomaly detection and repair processes to ensure correct execution of the process, and direction of trajectory issues.

[0151] Preferably, in step S411, a trajectory storage address algorithm is designed. Assuming the number of users in the simulation is N, the size of each trajectory block is 60 + 25 × 8 × N. The calculation process for the position of the trajectory data read each time is as follows:

[0152] S4111. Read the value of the trajectory completion address, denoted as SaveIndex;

[0153] S4112. Create a variable CurReadIndex, initialize it to 0 each time the simulation starts and stops, and record how many times it is read. It is used to compare with SaveIndex to determine how many times the trajectory should be read this time. Under normal circumstances, SaveIndex and CurReadIndex are equal to 1. When there is jitter in the receiver for more than one tick cycle and no jitter in the transmitter, it will be greater than 1. When there is jitter in the transmitter for more than one tick cycle and no jitter in the receiver, it will be equal to 0.

[0154] S4113. Calculate the starting address of the memory for the current trajectory data being read:

[0155] CurReadAddr=TrackAddr+(60+25×8×N) ×(( CurReadIndex+1)%circleBufferSize);

[0156] S4114. Based on the calculated starting address, read the trajectory data of the corresponding memory block location and store it in the buffer.

[0157] The advantages of this embodiment include: ensuring that each frame of the trajectory can be written and read correctly.

[0158] Preferably, in step S413, anomaly detection and processing are performed on the trajectory data, and the data is stored in the trajectory buffer. This specifically includes the following steps:

[0159] S4131. By using the interrelationship between trajectory data of time, acceleration, velocity, and position, detect whether the continuity between the trajectory data of the current frame and the trajectory data of the previous frames is abnormal;

[0160] S4132. When an anomaly is detected in the continuity of trajectory data, the error type of the trajectory data is determined based on the anomaly, and the data is processed according to the error type classification. The error types include trajectory loss and data jump.

[0161] S4133. Store the processed trajectory data in the trajectory buffer.

[0162] The advantages of this embodiment include: efficient anomaly detection indicating the direction of trajectory problems, and trajectory processing ensuring the correct execution of the process.

[0163] Preferably, the correlation between trajectory data of time, acceleration, velocity, and position is used to detect whether the continuity between the current trajectory data and the previous few trajectory data is abnormal, specifically including the following steps:

[0164] S41311. Check whether the time is continuous, including three situations: normal situation, track loss, and track duplication;

[0165] S41312. The position derivative is compared with the velocity in the trajectory data. The velocity derivative is compared with the acceleration. When the error exceeds the corresponding set threshold, it is judged as an abnormality in trajectory continuity. The abnormality includes one or more of the following: position abnormality, velocity abnormality, and acceleration abnormality.

[0166] The advantages of this embodiment include: efficient anomaly detection indicating the direction of trajectory problems.

[0167] Preferably, the processing is categorized according to error type, specifically including the following steps:

[0168] When the error type is "track loss", the handling strategies include:

[0169] Segmentation strategy: For single-point missing cases, linear interpolation is used to supplement trajectory data; for continuous point missing cases (≤3), third-order spline curve interpolation is used to supplement trajectory data; for long-term point missing cases (≥3), the rigid body motion equation model is switched to calculate trajectory data to supplement trajectory data.

[0170] Data parameter priority mechanism: position takes precedence over velocity, velocity takes precedence over acceleration, ensuring the continuity of key navigation signal parameters;

[0171] When the error type is data jump, the handling strategies include:

[0172] An adaptive Kalman filter system is established using a filtering and smoothing method. During the simulation, the trajectory parameters are used to train the process noise parameters. When trajectory jumps or abnormalities occur, the moving average of the filter system is used to replace the abnormal data to correct the jump anomalies.

[0173] The advantages of this embodiment include: selecting the appropriate solution based on different problems, and processing trajectories efficiently and stably.

[0174] Preferably, step S42 specifically includes the following steps:

[0175] S421. Use the current navigation signal simulation time to obtain the trajectory data corresponding to the time from the trajectory buffer. If the trajectory is continuously obtained, when obtaining the trajectory in the second frame after the start of the simulation, calculate the jump time length by subtracting the time to be obtained this time from the current received trajectory time and the reserved delay T number × interval, and record it as jumpTimes. After this frame, add JumpTimes to the time of obtaining the trajectory each time.

[0176] S422. Calculate navigation signal parameters using trajectory data;

[0177] S423 transmits navigation signal parameters to the SGC signal generation card via the PCI bus.

[0178] The advantages of this embodiment include: the trajectory simulator sends the trajectory without interaction, and there is no need for interaction or waiting from the start of sending until the end of the test.

[0179] Preferably, step S43 specifically includes the following steps:

[0180] S431 and SGC signal generation cards receive navigation signal parameters;

[0181] S432. Navigation signal parameters are generated using FPGA logic circuits, and then the navigation signal parameters are modulated into a navigation baseband signal using a DSP in conjunction with the FPGA. During signal modulation, the accumulated code phase of the dynamic parameter conversion is detected. When a transition occurs, the accumulated code phase is reset once according to the current simulation time to ensure continuous signal modulation after the transition. For signals with different modulation forms, the carrier phase reset method varies slightly due to differences in code length and message length. Therefore, each different form needs to be developed and debugged separately when implementing the function.

[0182] S433: The generated navigation signal is filtered, up-converted, and amplified using a bandpass filter, RF module, and power amplifier.

[0183] S434 outputs the filtered, up-converted, and amplified navigation signal to the signal interface.

[0184] The advantages of this embodiment include: each stage is designed independently, which simplifies the structure and control logic of the entire system.

[0185] Preferably, step S44 specifically includes the following steps:

[0186] S441. Collect navigation, positioning, and speed measurement results from the receiver under test;

[0187] S442. Calculate the positioning and velocity measurement error index between the receiver positioning and velocity measurement results and the simulated trajectory, including three-dimensional position error and velocity measurement error;

[0188] S443. Determine whether the simulation accuracy meets the requirements based on the error indicators. The accuracy requirements are: three-dimensional position error less than 10m and velocity measurement error less than 0.2m / s.

[0189] The advantages of this embodiment include: it facilitates visual viewing of the current simulation status and results, and is beneficial for demonstrating and observing problems.

[0190] Preferably, step S45 specifically includes the following steps:

[0191] S451. If the simulation accuracy does not meet the requirements, adjust the trajectory simulation parameters, sampling rate, receiver algorithm, etc. For example, if the positioning effect is not ideal in the high dynamic part, the sampling rate can be increased and the test can be repeated.

[0192] S452. Dynamically adjust the trajectory simulation parameters according to the current simulation scenario;

[0193] S453. Update the sampling rate calculated by the simulation reception of the navigation signal according to the sampling rate of the simulation trajectory;

[0194] S454, Return to the steps of real-time trajectory transmission and external trajectory data reception (S41) to continue the next round of simulation. After multiple rounds of testing, a suitable trajectory sampling rate for the simulation trajectory is found.

[0195] The advantages of this embodiment include: iterative optimization of the trajectory model and adjustment of model parameters, facilitating iterative adjustments.

[0196] like Figure 5 As shown, another preferred embodiment of this application also provides a real-time closed-loop navigation signal simulation device, comprising:

[0197] The initialization configuration module is used to initialize the system configuration, including installing the real-time operating system, configuring the network connection method, and using the clock synchronization card to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory transmission program;

[0198] The data synchronization module is used to establish a real-time data synchronization mechanism. Reflective memory cards are installed on both the trajectory simulator and the real-time closed-loop navigation signal source to automatically establish data synchronization function and realize real-time data transmission.

[0199] The simulation task creation module is used to create navigation signal simulation tasks, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation settings. At the same time, it configures a loop list of four addresses and one trajectory in the navigation signal simulation software. The four addresses include the start command address, the user trajectory address, the initialization completion address, and the trajectory completion address.

[0200] The navigation signal simulation module is used to perform navigation signal simulation, read trajectory data to calculate the parameters required for navigation signal simulation, generate navigation signals through the SGC signal generation card, and compare the reference trajectory and the trajectory located by the receiver in real time to perform closed-loop test verification of the navigation signal. When reading trajectory data, the module performs trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detects whether the continuity between the current frame trajectory and the previous few frame trajectories is abnormal, and continuously receives and processes the data according to the beat.

[0201] The real-time closed-loop navigation signal simulation device provided in this embodiment employs the real-time closed-loop navigation signal simulation method described in the above embodiments, solving the technical problems in the prior art such as high data transmission delay, large jitter, inability to detect and correct trajectory anomalies, and insufficient simulation accuracy due to low sampling rates in trajectory and navigation mathematical simulation calculations during satellite navigation signal simulation. Compared with the prior art, the beneficial effects of the real-time closed-loop navigation signal simulation device provided in this application are the same as those of the real-time closed-loop navigation signal simulation method provided in the above embodiments, and other technical features in the real-time closed-loop navigation signal simulation device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0202] like Figure 6 As shown, a preferred embodiment of this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the real-time closed-loop navigation signal simulation method in the above embodiments.

[0203] This application provides an electronic device that employs the real-time closed-loop navigation signal simulation method described in the above embodiments, addressing the problem that existing experimental testing methods and numerical simulation methods cannot quickly, accurately, and comprehensively assess whether the flow field of the test section meets the requirements of aero-engine icing tests. Compared with the prior art, the beneficial effects of the electronic device provided in this application are the same as those of the real-time closed-loop navigation signal simulation method provided in the above embodiments, and other technical features of the electronic device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0204] like Figure 7 As shown, a preferred embodiment of this application also provides a computer device, which may be a terminal or a liveness detection server, and its internal structure diagram may be as follows. Figure 7As shown, the computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The network interface is used to communicate with other external computer devices via a network connection. When the computer program is executed by the processor, it implements the steps of the aforementioned real-time closed-loop navigation signal simulation method.

[0205] Those skilled in the art will understand that Figure 7 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0206] The computer equipment provided in this application employs the real-time closed-loop navigation signal simulation method described in the above embodiments, addressing the problem that existing experimental testing methods and numerical simulation methods cannot quickly, accurately, and comprehensively assess whether the flow field of the test section meets the requirements of aero-engine icing tests. Compared with the prior art, the beneficial effects of the computer equipment provided in this application are the same as those of the real-time closed-loop navigation signal simulation method provided in the above embodiments, and other technical features in the electronic equipment are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0207] A preferred embodiment of this application also provides a storage medium including a stored program that, when the program is executed, controls the device where the storage medium is located to perform the steps of the real-time closed-loop navigation signal simulation method in the above embodiments.

[0208] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0209] If the functions described in this embodiment are implemented as software functional units and sold or used as independent products, they can be stored in one or more computing device-readable storage media. Based on this understanding, the parts of this application's embodiments that contribute to the prior art or the technical solutions can be embodied in the form of software products. These software products are stored in a storage medium and include several instructions to cause a computing device (which may be a personal computer, server, mobile computing device, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage media include: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and various other media capable of storing program code.

[0210] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language C++ and the embedded programming language C.

[0211] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0212] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0213] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0214] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the real-time closed-loop navigation signal simulation method described above.

[0215] The computer program product provided in this application solves the problem that existing experimental testing methods and numerical simulation methods cannot quickly, accurately, and comprehensively evaluate whether the flow field of the test section meets the requirements of aero-engine icing tests. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the real-time closed-loop navigation signal simulation method provided in the above embodiments, and will not be repeated here.

[0216] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0217] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A real-time closed loop navigation signal simulation method, characterized by, Including the following steps: S1. Initialize system configuration, including installing the real-time operating system, configuring the network connection method and clock synchronization card to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory transmission program; S2. Establish a real-time data synchronization mechanism. Install reflective memory cards on both the trajectory simulator and the real-time closed-loop navigation signal source to automatically establish data synchronization function and realize real-time data transmission through PCI bus and optical fiber. S3. Create a navigation signal simulation task, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation settings. At the same time, configure the reflective memory card with four addresses and a circular list of trajectories in the navigation signal simulation software. The four addresses include the start command address, the user trajectory address, the initialization completion address, and the trajectory completion address. S4. Perform navigation signal simulation, read trajectory data to calculate the parameters required for navigation signal simulation, generate navigation signals through the SGC signal generation card, and compare the reference trajectory and the trajectory located by the receiver in real time to perform closed-loop test verification of the navigation signal; when reading trajectory data, perform trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detect whether the continuity of the current frame trajectory is abnormal with the previous few frame trajectories, and continuously receive and process according to the beat; Step S4 specifically includes the following steps: S41. Real-time transmission and reception of external trajectory data. When reading trajectory data, the trajectory data to be written to the buffer undergoes trajectory continuity anomaly detection and processing. This involves detecting whether the continuity between the current frame's trajectory and the previous few frames' trajectories is abnormal, and continuously receiving and processing the data according to the beat. Specifically, this includes: S411. The trajectory simulator is configured with a clock synchronization card trigger frequency, and the calculation frequency is set to be consistent with the trajectory data sampling frequency. A trajectory storage buffer is established, and the delay period is set to control the initial number of trajectories retained in the trajectory buffer in the pipeline. The trajectory storage buffer is used to meet simulation requirements of different accuracy. The trajectory interval supports: 0.5ms, 1ms, 2ms, 2.5ms, 5ms, and 10ms. The trajectory data format is as follows: the coordinate system used for the trajectory is the geocentric coordinate system, and the pitch, roll, and yaw attitudes adopt the relative northeast-sky coordinate system. S412: Read trajectory data directly from the reflective memory card via the PCI interface; S413. Read the trajectory data of the existing memory location according to the clock system's time stamp, perform anomaly detection and processing on the trajectory data, store it in the trajectory buffer, and continuously receive and process it according to the beat. S414. After reading the first trajectory data and the start simulation marker, the simulation calculation thread is triggered to start the navigation simulation initialization process. During the initialization process, the trajectory data received at the corresponding time is stored in the trajectory buffer. S42. Calculate the parameters required for navigation signal simulation based on the received trajectory data; S43. Generate navigation signals using the SGC signal generation card; S44. Real-time comparison of the reference trajectory and the trajectory located by the receiver; S45. Based on the comparison results, dynamically adjust the trajectory or adjust the relevant functions of the receiver to achieve closed-loop test verification of the navigation signal.

2. The real-time closed-loop navigation signal simulation method of claim 1, wherein, Step S1 specifically includes the following steps: S11. Install Linux / RTX real-time operating system on the industrial control computer and trajectory simulator on the real-time closed-loop navigation signal source; S12. Configure the network connection method of the industrial control computer on the real-time closed-loop navigation signal source, and set the network connection type to private network; S13. Configure a clock synchronization card in the trajectory simulator to support 10M input, install the driver and provide an SDK development package with high real-time interrupt capability, and realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory sending program.

3. The real-time closed-loop navigation signal simulation method of claim 1, wherein, Step S2 specifically includes the following steps: S21. Configure a PCI interface reflective memory card on the trajectory simulator and the real-time closed-loop signal source, and connect them using optical fiber. S22, The reflective memory card driver automatically establishes a data synchronization function to achieve real-time data transmission.

4. The real-time closed-loop navigation signal simulation method of claim 1, wherein, Step S3 specifically includes the following steps: S31. Create a navigation signal simulation task, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation. In the navigation signal simulation software, configure a circular list of four addresses and one trajectory. The four addresses include the start command address StartAddr, the user trajectory address TrackAddr, the initialization completion address initedAddr, and the trajectory completion address TrackfinishAddr. The size of the circular list is circleBufferSize. S32. Configure trajectory data generation to run in the Linux / RTX environment of the trajectory simulator; S33. Configure the trajectory data receiving task to run in a Linux real-time environment and use the reflected memory card interrupt to send and receive the trajectory. S34. Set the signal parameter calculation task to run in a Linux real-time environment; S35. Configure the signal generation task to run on the SGC signal generation card.

5. The real-time closed-loop navigation signal simulation method of claim 1, wherein, In step S411, a trajectory storage address algorithm is designed. Assuming the number of users in the simulation is N, the size of each trajectory block is 60 + 25 * 8 * N. The calculation process for the position of the trajectory data read each time is as follows: The value of the address where the trajectory reading is completed is denoted as SaveIndex; Create a variable CurReadIndex, initialize it to 0 each time the simulation starts and stops, and record how many times it is read. This is used to compare with SaveIndex to determine how many times the trajectory should be read this time. Under normal circumstances, SaveIndex and CurReadIndex are equal to 1. When there is jitter in the receiver for more than one tick cycle and no jitter in the transmitter, it will be greater than 1. When there is jitter in the transmitter for more than one tick cycle and no jitter in the receiver, it will be equal to 0. Calculate the starting address of the memory for the current trajectory data being read: CurReadAddr=TrackAddr+(60+25*8*N)*(( CurReadIndex+1)%circleBufferSize); Based on the calculated starting address, the trajectory data of the corresponding memory block location is read and stored in the buffer.

6. The real-time closed-loop navigation signal simulation method of claim 1, wherein, In step S413, anomaly detection and processing are performed on the trajectory data, and the data is stored in the trajectory buffer. This specifically includes the following steps: By analyzing the interrelationships between trajectory data of time, acceleration, velocity, and position, we can detect whether there are any abnormalities in the continuity between the trajectory data of the current frame and the trajectory data of the previous frames. When an anomaly is detected in the continuity of trajectory data, the error type of the trajectory data is determined based on the anomaly, and the data is processed according to the error type. The error types include trajectory loss and data jump. The processed trajectory data is stored in the trajectory buffer.

7. The real-time closed-loop navigation signal simulation method according to claim 6, characterized in that, By analyzing the interrelationships between trajectory data related to time, acceleration, velocity, and position, the system detects whether there are anomalies in the continuity between the current trajectory data and the previous few data points. The specific steps include: Check whether the time is continuous, including three situations: normal situation, track loss, and track duplication; The position derivative is compared with the velocity in the trajectory data, and the velocity derivative is compared with the acceleration. When the error exceeds the corresponding set threshold, it is judged as an abnormality in trajectory continuity. The abnormality includes one or more of the following: position abnormality, velocity abnormality, and acceleration abnormality.

8. The real-time closed-loop navigation signal simulation method of claim 6, wherein, The process involves classifying errors according to their types, and includes the following steps: When the error type is "track loss", the handling strategies include: Segmentation strategy: For single-point missing cases, linear interpolation is used to supplement trajectory data; for continuous point missing cases, third-order spline curve interpolation is used to supplement trajectory data; for long-term point missing cases, the rigid body motion equation model is switched to calculate trajectory data to supplement trajectory data. Data parameter priority mechanism: position takes precedence over velocity, velocity takes precedence over acceleration, ensuring the continuity of key navigation signal parameters; When the error type is data jump, the handling strategies include: An adaptive Kalman filter system is established using a filtering and smoothing method. During the simulation, the trajectory parameters are used to train the process noise parameters. When trajectory jumps or abnormalities occur, the moving average of the filter system is used to replace the abnormal data to correct the jump anomalies.

9. The real-time closed-loop navigation signal simulation method of claim 1, wherein, Step S42 specifically includes the following steps: S421. Use the current navigation signal simulation time to obtain the trajectory data corresponding to the time from the trajectory buffer. If the trajectory is continuously obtained, when obtaining the trajectory in the second frame after the simulation starts, calculate the jump time length by subtracting the time to be obtained this time from the current received trajectory time and the reserved delay T number * interval. This jump time is denoted as jumpTimes. After this frame, add JumpTimes to the time of obtaining the trajectory each time. S422. Calculate navigation signal parameters using trajectory data; S423 transmits navigation signal parameters to the SGC signal generation card via the PCI bus.

10. The real-time closed-loop navigation signal emulation method of claim 1, wherein, Step S43 specifically includes the following steps: S431 and SGC signal generation cards receive navigation signal parameters; S432. The navigation signal is generated from the navigation signal parameters through the FPGA logic circuit. When modulating the signal, the code phase accumulated by the dynamic parameter conversion is detected. When a transition occurs, the code phase accumulation is reset once according to the current simulation time to ensure that the signal modulation is continuous after the transition. S433. Filter, up-convert, and amplify the generated navigation signal; S434 outputs the filtered, up-converted, and amplified navigation signal to the signal interface.

11. The real-time closed-loop navigation signal emulation method of claim 1, wherein, Step S44 specifically includes the following steps: S441. Collect navigation, positioning, and speed measurement results from the receiver under test; S442. Calculate the positioning and velocity measurement error index between the receiver positioning and velocity measurement results and the simulated trajectory; S443. Determine whether the simulation accuracy meets the requirements based on the error index.

12. The real-time closed-loop navigation signal emulation method of claim 1, wherein, Step S45 specifically includes the following steps: S451. If the simulation accuracy does not meet the requirements, adjust the trajectory simulation parameters, sampling rate, and receiver algorithm. S452. Dynamically adjust the trajectory simulation parameters according to the current simulation scenario; S453. Update the sampling rate calculated by the simulation reception of the navigation signal according to the sampling rate of the simulation trajectory; S454, return to the steps of real-time trajectory transmission and external trajectory data reception to continue the next round of simulation. After multiple rounds of testing, a suitable trajectory sampling rate for the simulation trajectory is found.

13. A real-time closed loop navigation signal simulation apparatus, characterized by, include: The initialization configuration module is used to initialize the system configuration, including installing the real-time operating system, configuring the network connection method, and using the clock synchronization card to realize the clock synchronization function between the real-time closed-loop navigation signal source and the simulator trajectory transmission program; The data synchronization module is used to establish a real-time data synchronization mechanism. Reflective memory cards are installed on both the trajectory simulator and the real-time closed-loop navigation signal source to automatically establish data synchronization function and realize real-time data transmission. The simulation task creation module is used to create navigation signal simulation tasks, including trajectory data generation, trajectory data reception, signal parameter calculation, and signal generation settings. At the same time, it configures a loop list of four addresses and one trajectory in the navigation signal simulation software. The four addresses include the start command address, the user trajectory address, the initialization completion address, and the trajectory completion address. The navigation signal simulation module is used to perform navigation signal simulation, read trajectory data to calculate the parameters required for navigation signal simulation, generate navigation signals through the SGC signal generation card, and perform closed-loop testing and verification of the navigation signal by comparing the reference trajectory and the trajectory located by the receiver in real time. When reading trajectory data, it performs trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detecting whether the continuity of the current trajectory with the previous few trajectories is abnormal, and continuously receiving and processing according to the beat. Specifically, it is used for: real-time transmission of trajectory and reception of external trajectory data; when reading trajectory data, it performs trajectory continuity anomaly detection and processing on the trajectory data to be written to the buffer, detecting whether the continuity of the current trajectory with the previous few trajectories is abnormal, and continuously receiving and processing according to the beat, specifically including: The trajectory simulator is configured with a clock synchronization card trigger frequency, and the calculation frequency is set to match the trajectory data sampling frequency. A trajectory storage buffer is established, and the delay period is set to control the initial number of trajectories retained in the pipeline. The trajectory storage buffer is used to meet simulation requirements of different accuracy levels. The trajectory interval supports 0.5ms, 1ms, 2ms, 2.5ms, 5ms, and 10ms. The trajectory data format is as follows: the coordinate system used for the trajectory is the geocentric-ground-fixed coordinate system, and the pitch, roll, and yaw attitudes adopt the relative northeast-sky coordinate system. The trajectory data is read directly from the reflective memory card via the PCI interface. The trajectory data at the existing memory location is read according to the clock system's time stamp. Anomalies are detected and processed in the trajectory data, which is then stored in the trajectory buffer. The data is continuously received and processed according to the clock cycle. After reading the first frame of trajectory data and the start simulation marker, the simulation calculation thread is triggered to begin the navigation simulation initialization process. During initialization, the trajectory data received at the corresponding time is stored in the trajectory buffer. The parameters required for navigation signal simulation are calculated based on the received trajectory data. The navigation signal is generated through the SGC signal generation card. The reference trajectory and the trajectory located by the receiver are compared in real time. Based on the comparison results, the trajectory or related functions of the receiver are dynamically adjusted to achieve closed-loop testing and verification of the navigation signal.

14. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the real-time closed-loop navigation signal simulation method as described in any one of claims 1 to 12.

15. A storage medium, the storage medium comprising a stored program, characterized in that When the program is running, it controls the device containing the storage medium to perform the steps of the real-time closed-loop navigation signal simulation method as described in any one of claims 1 to 12.

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