GNSS simulator control and management system

Abstract

The invention provides a GNSS (Global Navigation Satellite System) simulator control and management system, which is characterized by comprising a non-real-time module, a weak real-time module and a strong real-time module for data interaction, the non-real-time module comprises a database module, a model management module, a test design module and a model and data preprocessing module; the non-real-time module is used for storing models, data, parameters, test design schemes, corresponding document data, simulation evaluation result data and reports; the weak real-time module comprises a simulation management control program module and a visual program module. The simulation management program module carries out evaluation subsystem interface, operation control system interface, simulation management, data recording and online interaction. The visual program module is used for carrying out visual display; the strong real-time module comprises a simulation management program module and a mathematical model module, and the strong real-time module realizes real-time calculation of the models and realizes real-time data transmission between the models according to a signal incidence relation set by a test.

Description

Technical Field

[0001] The invention belongs to the field of control and management, and in particular relates to a GNSS simulator control and management system. Background Art

[0002] At present, the global satellite navigation system (GNSS) has the remarkable characteristics of all-weather, high precision, automation, and high efficiency. It is widely used in various sectors of the national economy, such as autonomous driving, smart cities, smart ports, precision agriculture, geological monitoring, emergency rescue, personnel dispatching, and telemedicine, and has gradually penetrated into people's daily lives. Generally speaking, the application of GNSS can be roughly divided into two parts: static positioning and dynamic positioning. The main application areas of static positioning are mapping, measurement, and self-positioning; dynamic positioning is mainly used for moving objects on the mobile targets to be monitored, autonomous navigation, etc., and is functionally divided into dispatching command and security and anti-theft systems.

[0003] Whether in the field of static surveying and mapping or dynamic navigation, ground GNSS receivers are required to receive satellite navigation signals. High-dynamic satellite navigation receivers are generally used in many aspects, such as monitoring stations and base stations in the field of satellite monitoring, moving carriers such as missile aircraft, rockets and spacecraft in the field of aerospace, and timing receivers of 4G and 5G base stations in the field of ground communications. Regardless of any type of GNSS receiver, a large amount of experimental environment verification and testing is required before actual application, because the establishment of its experimental conditions and environment is subject to factors such as cost and cycle.

[0004] The multi-channel satellite navigation signal simulator is mainly used to simulate and generate satellite navigation signals in various actual environments, and can provide a simulated real satellite experimental environment for GNSS terminal products such as GNSS receivers. The simulator needs to generate satellite navigation signals received by the satellite navigation receiver on the carrier according to the dynamic environment of the carrier, fully simulate the various complex environments encountered by the satellite navigation receiver during the movement of the carrier, and provide realistic simulation signals for the satellite navigation receiver. It can be used for functional testing of satellite navigation receivers, measurement accuracy identification, and target motion feature simulation, etc.

[0005] As the core of the GNSS simulator test system, the control and management system is similar to the human brain and the CPU of a computer, and plays a decisive role in decision-making management, operation and maintenance control in the entire system. Compared with foreign countries, my country's simulator research is relatively late, especially the implementation of the control and management system, which is one of the problems that need to be solved urgently in actual deployment. Summary of the invention

[0006] The purpose of the present invention is to provide a GNSS simulator control and management system, which adopts a modular design and divides the real-time differences of the entire system into three parts: a non-real-time module, a weak real-time module, and a strong real-time module, thereby ensuring the efficient operation of the GNSS simulator control and management to the greatest extent.

[0007] The technical solution of the present invention is implemented as follows: a GNSS simulator control and management system, characterized in that data interaction is performed between non-real-time modules, weak real-time modules, and strong real-time modules; the non-real-time module includes a database module, a model management module, an experimental design module, and a model and data preprocessing module; the non-real-time module is used to store models, data, parameters, experimental design plans and corresponding document data, as well as simulation evaluation result data and reports; the weak real-time module includes a simulation management control program module and a visualization program module, and the simulation management program module performs evaluation system interface, operation control system interface, simulation management, data recording and online interaction; the visualization program module performs visual display; the strong real-time module includes a simulation management program module and a mathematical model module, and the strong real-time module realizes real-time calculation of the model, and realizes real-time data transmission between models according to the signal correlation relationship set in the experiment.

[0008] The system adopts a modular design. By dividing the real-time differences of the entire system into three parts: non-real-time module, weak real-time module, and strong real-time module, the efficient operation of GNSS simulator control and management is determined to the greatest extent. The database module is the core of test task preparation, including models, data, parameters, test design plans and related documents, as well as simulation evaluation result data and reports.

[0009] As a preferred implementation method, the database module in the non-real-time module uses SQL Server 2000 database as a platform, and provides association settings between data tables through distributed access support. The database implementation uses SQL Server 2000 database as a platform, which is a mature commercial database system with a moderate scale. Relatively speaking, Access database can only provide simple operations based on tables, while Oracle system is too large and complex. SQL Server already has the functions of a database system, can perform data management based on relational tables, and provide distributed access support, provide association settings between data tables, and also provide stored procedure technology to speed up database operations. It can support integration with applications under the support of ADO standard interfaces, and also provides enterprise database management tools to directly operate and maintain the database. SQL Server databases are used in a large number of distributed real-time simulation systems, and practice has verified that the database can meet simulation requirements.

[0010] As a preferred implementation, the model management module includes model code and model description, wherein the model code adopts standard interface conventions and is standardly encapsulated in C code; the model description describes the external characteristics of the model, and performs characteristic browsing and model integration. Model resource design is divided into two parts: model code and model description. The model code is the specific implementation of the model. Although there are no specific requirements for modeling, a standard interface convention is proposed for the implementation form of the model, and the model implementation is standardly encapsulated in C code; the model description describes the external characteristics of the model, thereby facilitating the characteristic browsing and integration of the model. The external characteristics of the model mainly include model parameters, model input and model output descriptions. These description information are stored in the database in a standard format, thereby providing basic data for simulation test design.

[0011] As a preferred implementation, the test design module designs a matching test scheme for the test task of the ground operation and control system, and the test design module has built-in satellite constellation, orbit model, ionosphere model, troposphere model, multipath model, user machine motion model selection and parameter setting, and also includes the selection of simulation computer and model allocation. The test design module designs a matching test scheme for the test task of the ground operation and control system, including the selection of satellite constellation, orbit model, ionosphere model, troposphere model, multipath model, user machine motion model selection and parameter setting; and also includes the selection of simulation computer and model allocation.

[0012] The system provides object-oriented standard test settings, and provides three-level management settings functions of project~scheme~test. Projects are determined for specific test tasks, such as positioning test, orbit determination test, clock error test, integrity test, etc.; different test object compositions and parameter settings are determined for the projects to form test schemes, such as satellite composition and configuration, number and type of users, etc.; finally, the specific composition of each test is determined as a subset of the scheme according to the test scheme. The test selects models of different accuracy from the model library, and allocates models according to real-time requirements, while setting model operation parameters and test system parameters.

[0013] As a preferred embodiment, the model and data preprocessing module assists in modeling and analysis, and establishes and verifies the model data in the fields of satellite orbits, space environment and signal coding. The verified model is packaged according to the standard model interface, and then the model information is classified and recorded in the database module. The model and data preprocessing module provides a platform for auxiliary modeling and analysis for different fields, such as satellite orbits, space environment, signal coding, etc., which is used for model establishment and verification, as well as preprocessing of some model data. The verified model is packaged according to the standard model interface, and then the model information is classified and recorded in the database.

[0014] For specific ground system test tasks and simulation test settings, some models and data with large computational load are preprocessed to obtain simplified models and streamlined data, which are used as replaceable models to replace or cooperate with the calculation of highly complex models in real-time simulation. Mainly satellite orbit models and space environment models (ionosphere).

[0015] As a preferred implementation, the simulation management control program module in the weak real-time module provides simulation data management functions, and provides models, data and test preparation for the simulation test system by using a database management system for model management, simulation test project management and test project management. The weak real-time module is mainly composed of a simulation management control program module and a visualization program module. The simulation management program realizes the measurement subsystem interface, operation control system interface, simulation management, data recording and online interaction functions; the visualization program realizes the visualization function;

[0016] After determining the test items, the control and management system sends a query to other subsystems indicating that the simulation parameter settings have been completed. If other subsystems have completed the parameter settings, a simulation initialization command is sent; otherwise, it waits. After the simulation initialization is completed, other subsystems send initialization completion information to the control and management system. After collecting the initialization completion information of all subsystems, the control and management system sends time synchronization information to complete system time synchronization. After the local clock reaches the simulation start time, the simulation starts. At the same time, the time synchronization response information returned by other subsystems is monitored. If there are still subsystems that have not completed the time synchronization operation after 30 seconds, the simulation ends. During the simulation, the simulation control (simulation stop) can be performed through the user interface of the control and management system. After receiving the stop command, the control and management system sends the corresponding control command to other subsystems and ends the simulation.

[0017] The simulation management and control module also provides simulation data management functions. With the database management system as the core, it realizes model management, simulation test project management and test project management, and provides models, data and test preparation for the entire simulation test system.

[0018] The test evaluation subsystem sends the "set test project" use case (code) to the control management subsystem, which automatically loads the simulation test stored in the database according to the code index.

[0019] During the real-time simulation process, the test and evaluation subsystem can set model parameters through network commands, including port power parameter settings, satellite power parameter settings, satellite multipath parameter settings and special script parameter settings.

[0020] The system operator uses the "Set Simulation Test Parameters" use case to modify and add simulation test parameters (time, step size) stored in the database, thereby completing the setting of the simulation test project of the simulation test system.

[0021] The system operator uses the "Set Simulation Model" use case to modify the mathematical simulation model parameters stored in the database and notify the mathematical simulation subsystem. The system operator uses the "Set Simulation Model" use case to add a new mathematical simulation model based on the model description provided by the mathematical simulation subsystem.

[0022] System operators use the "Database Operations" use case to query, modify, back up, and restore the database.

[0023] As a preferred embodiment, the visualization module of the weak real-time module is developed by two-dimensional and three-dimensional display through STK software, and the connect module or PL module is used to implement the program interface, and the satellite orbit and user receiver status information on the Ethernet are received in real time and displayed on the STK interface. The visualization module is developed by two-dimensional and three-dimensional display through STK software, and the connect module or PL module is used to implement the program interface, and the satellite orbit and user receiver status information on the Ethernet are received in real time and displayed on the STK interface. At the same time, operations such as visibility analysis can be performed with the help of the calculation function of STK. In addition, a visual display in the form of a table is provided on the simulation management platform for system monitoring.

[0024] As a preferred implementation mode, the operation and control system interface of the weak real-time module realizes the data interface with the ground operation and control system, sends simulation test control commands and signal simulation data of simulation calculation to the ground operation and control system according to the simulation test task, receives the satellite injection data output by the ground operation and control system, and forwards it to the corresponding simulation model at the same time. The operation and control system interface module realizes the data interface with the ground operation and control system, sends simulation test control commands and signal simulation data of simulation calculation to the ground operation and control system according to the specific simulation test task, receives the satellite injection data output by the ground operation and control system, and forwards it to the corresponding simulation model at the same time. The original design of this interface module was to interact with the ground operation and control through the test and communication subsystem, and then changed to directly exchange data with the ground operation and control related subsystems, that is, to share the multicast address with the ground operation and control related subsystems.

[0025] The strong real-time module is implemented by a simulation management program and a mathematical model, and specifically includes real-time simulation, data injection, time synchronization and data forwarding functions;

[0026] This module realizes the real-time calculation of the model and the real-time data transmission between models according to the signal correlation relationship set in the experiment. A unified simulation engine is designed and implemented, and compiled into a simulation program together with the pre-prepared model library. The program is encapsulated into three levels and two-level interfaces. The three levels are: simulation engine, simulation model, and simulation data, and the three levels are independent of each other; the two-level interface is the interface between the engine and the model, and the interface between the model and the data. In this way, a standard node simulation program is obtained, and the configurability and data-driven of the model are realized without recompiling the code. Driven by the unified simulation engine and time synchronization module, the simulation module can realize the real-time distributed operation of the simulation model (satellite orbit, target user, space environment, and test evaluation).

[0027] As a preferred embodiment, the strong real-time module includes real-time simulation, data injection, time synchronization and data forwarding functions, and the real-time control of the real-time simulation module model operation is directly controlled by memory address mapping. The real-time control of the real-time simulation module model operation is directly controlled by memory address mapping. Due to the complexity of the simulation test system and the large amount of data, in order to save address space, the initialization and real-time simulation shared address mode is adopted. Initialization is used for loading. Once the model initialization is completed, it enters the real-time simulation stage, that is, it is converted to the real-time operation control mode.

[0028] As a preferred implementation, the time synchronization synchronizes the simulation test system time with the assistance of the RNSS time and frequency module, and synchronizes with the operation and control system time with the support of the operation and control time and frequency module.

[0029] After adopting the above technical solution, the beneficial effects of the present invention are:

[0030] 1. A GNSS simulator control and management system provided by the present invention adopts a modular design. By dividing the real-time differences of the entire system into three parts: a non-real-time module, a weak real-time module, and a strong real-time module, the efficient operation of the GNSS simulator control and management is ensured to the greatest extent.

[0031] 2. A GNSS simulator control and management system provided by the present invention takes the database completed by the task preparation subsystem as input, coordinates and manages the operation of the mathematical simulation system, radio frequency simulation system, test evaluation subsystem and test environment subsystem of the GNSS simulator, and completes the recording, display and online interactive control of simulation data. The management and control subsystem runs along with the simulation test process and has typical time characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 This is a control and management system architecture diagram in an embodiment of the present invention;

[0034] Figure 2 This is a diagram of the external interface architecture of the control and management system in an embodiment of the present invention;

[0035] Figure 3 This is a structural diagram of preprocessing implementation in an embodiment of the present invention;

[0036] Figure 4 1 is a diagram of the operation control interface structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example:

[0039] like Figure 1 As shown, the present invention provides a GNSS simulator control and management system, which adopts a modular design and is mainly composed of three parts: a non-real-time module, a weak real-time module, and a strong real-time module.

[0040] In the embodiment of the present application, the function of the non-real-time module is implemented by a simulation design program, which specifically includes a database module, a model management module, an experimental design module, and a model and data preprocessing module.

[0041] In the embodiment of the present application, the database module is the core of the test task preparation, including models, data, parameters, test design schemes and related documents, as well as simulation evaluation result data and reports. The database implementation adopts SQL Server 2000 database as the platform, which is a mature commercial database system with moderate scale. Relatively speaking, Access database can only provide simple operations based on tables, while Oracle system is too large and complex. SQL Server already has the functions of a database system, can manage data based on relational tables, provide distributed access support, provide association settings between data tables, and also provide stored procedure technology to speed up the operation of the database. It can support integration with applications under the support of ADO standard interface, and also provide enterprise database management tools to directly operate and maintain the database. SQL Server database is used in a large number of distributed real-time simulation systems, and practice has verified that the database can meet the simulation requirements. The user authorization management, security maintenance, data backup and general query statistics of the database can be directly implemented by borrowing the functional modules provided by the database system itself.

[0042] The database is constructed from three sub-databases: simulation model library, simulation design solution library, and simulation experiment library. Specifically, the implementation of each database font is as follows:

[0043] (1) Simulation model library

[0044] The simulation design model library is used to store various model information needed for simulation projects. This information specifically includes the common information of the model class to which the model belongs, as well as the characteristic information of the model itself. For simulation, the common information of the model class that needs to be used mainly includes the description information, parameter information, input signal information and output signal information of the model class. The information of the model needed for simulation includes the description information of the model, the simulation step of the model, etc.

[0045] The simulation design model library specifically includes the following:

[0046] Model class table: records the relevant information of a model class;

[0047] Model class parameter table: records the parameter information of the specified model class;

[0048] Model class input signal table: records the information of various input signals of the specified model class;

[0049] Model class output signal table: records the information of various output signals of the specified model class;

[0050] Model table: records information about different models of a specified model class.

[0051] (2) Simulation Design Solution Library

[0052] The simulation design program library stores the template information required for a type of simulation experiment, including the model class, model configuration parameters, and signal encoding required for this type of experiment. The specific contents are as follows:

[0053] Project table: records various information of the specified project;

[0054] Design plan table: record the information of various plans under the specified project;

[0055] Scheme composition table: records the model composition information of the specified scheme;

[0056] Scheme parameter table: records the information of various parameters of each model under the specified scheme;

[0057] Signal coding table: records the information of various output signals of each model under the specified scheme;

[0058] (3) Simulation test library

[0059] The simulation test is a subset of the design scheme. The simulation test library is a specific implementation of the design scheme. It stores the test composition under this type of design scheme, including model selection, model setting parameters, computer composition and configuration, and data association between models. The specific contents are as follows:

[0060] Simulation test table: record various information of the specified project and specified test under the specified scheme;

[0061] Test node table: records the codes and names of each simulation node used in a test;

[0062] Simulation node table: records the network address and hardware configuration information of each simulation node in the project hardware environment;

[0063] Test model table: records the information of each model in the specified test;

[0064] Test parameter table: record the information of each parameter of each model of the specified test;

[0065] Test input signal table: records the input and output correlation information of each model of the specified test;

[0066] In the embodiment of the present application, the model management module is a solution that focuses on providing standard interfaces and unified management for models in response to the simulation test system that does not provide a special environment and requirements for simulation modeling. The model resource design is divided into two parts: model code and model description. The model code is the specific implementation of the model. Although there are no specific requirements for modeling, a standard interface convention is proposed for the implementation form of the model. The model implementation is standardly encapsulated in C code; the model description describes the external characteristics of the model, which facilitates the model's feature browsing and model integration. The external characteristics of the model mainly include model parameters, model input and model output descriptions. These description information are stored in the database in a standard format, thereby providing basic data for simulation test design.

[0067] Specifically, the functional implementation steps of the model management module are as follows:

[0068] 1) Each model is encapsulated into three functions: initialization, real-time calculation, and post-processing. The function prototypes are defined as follows:

[0069] int model_init(struct SimParam*pSimParam,float*pPar,float*pInput,float*pOutput,float*g_pUser);

[0070] int model_output(struct SimParam*pSimParam,float*pPar,float*pInput,float*pOutput,float*g_pUser);

[0071] int model_end(struct SimParam*pSimParam, float*pPar, float*pInput, float*pOutput, float*g_pUser);

[0072] 2) All input parameters are floating-point pointers, and the memory is allocated and released by the main control function;

[0073] 3) pSimParam is the system parameter, including simulation time, frame count and other system information;

[0074] 4) pPar, pInput, and pOutput are parameter, input signal, and output signal arrays respectively; pUser is used to exchange data within the model, and is tentatively set to 1024 bytes;

[0075] 5) The model reads data from the pPar and pInput arrays and outputs the results to the pOutput array;

[0076] 6) The order and number of initial parameters, initial input, parameters, input signals, and output signals must match the records in the database;

[0077] 7) Each model is assigned a unique model code, which must match the model code in the database.

[0078] The managed model categories include orbit calculation model, user trajectory calculation model, satellite clock error calculation model, visibility analysis model, observation value generation model, ionospheric delay calculation model, tropospheric delay calculation model, multipath effect calculation model, relativistic error calculation model, integrity error calculation model, phase offset error calculation model, navigation time calculation program model, navigation ephemeris fitting program model, etc.

[0079] In the embodiment of the present application, the test design module designs a matching test scheme for the test task of the ground operation and control system, including the selection and parameter setting of satellite constellations, orbit models, ionosphere models, troposphere models, multipath models, and user machine motion models; and also includes the selection of simulation computers and model allocation. The system provides object-oriented standard test settings, and provides a three-layer management setting function of project-scheme-test, and determines projects for specific test tasks, such as positioning tests, orbit determination tests, clock error tests, integrity tests, etc.; then determines different test object compositions and parameter settings for the projects to form test schemes, such as satellite composition and configuration, number and type of users, etc.; finally, determines the specific composition of each test as a subset of the scheme for the test scheme, and the test selects models of different precision from the model library, and allocates models according to real-time requirements, and sets model operation parameters and test system parameters at the same time.

[0080] Specifically, the detailed operation functions of the test design module include the following aspects:

[0081] Solution configuration management includes management functions at two levels: project and solution, including: creating new projects, creating new solutions, deleting solutions, viewing solution trees, copying solutions, setting solution model parameters, signal coding, parameter coding, adding model nodes, deleting model nodes, etc.

[0082] The test configuration includes two functions: test management and model management, including: selecting a project, selecting a design scheme, creating a new test, opening a test, copying a test, saving a test, deleting a test, setting test parameters, selecting monitoring signals, displaying model nodes, displaying models, specifying replacement models, setting models, adding models, deleting models, displaying model class information, automatically assigning addresses, setting model initial parameters, setting model initial inputs, setting model parameters, setting model output signals, setting model input signals, and model self-checking.

[0083] To support the object-oriented operation of the model, the model algorithm is encapsulated, the signal data exchange between models is unified to the test design layer for association, and the address is automatically allocated. The simulation engine then completes the extraction and forwarding of signal data between models.

[0084] The results of the test design can be saved in the database, allowing the management and control subsystem to browse, modify and copy the test, and can be extracted and loaded online to drive the system operation. To simplify the application of the system, the system provides a series of typical test settings for specific test tasks and stores them in the database, allowing users to directly load these tests.

[0085] In the embodiment of the present application, the model and data preprocessing module provides an auxiliary modeling and analysis platform for different fields, such as satellite orbits, space environment, signal coding, etc., which is used for model establishment and verification, as well as preprocessing of some model data. The verified model is packaged according to the standard model interface, and then the model information is classified and recorded in the database. For specific ground system test tasks and simulation test settings, some models and data with large computational workloads are preprocessed to obtain simplified models and streamlined data, which are used as replaceable models in real-time simulation to replace or cooperate with the calculation of highly complex models. Mainly satellite orbit models and space environment models (ionosphere).

[0086] In the embodiment of the present application, the weak real-time module is mainly composed of a simulation management control program module and a visualization program module. The simulation management program realizes the test subsystem interface, the operation control system interface, the simulation management, the data recording and the online interaction functions; the visualization program realizes the visualization function. After determining the test item, the control and management system sends a query to other subsystems that the simulation parameter setting is completed. If other subsystems have completed the parameter setting work, a simulation initialization command is sent; otherwise, it waits. After the simulation initialization is completed, other subsystems send initialization completion information to the control and management system. After collecting the initialization completion information of all subsystems, the control and management system sends time synchronization information to complete the system time synchronization. After the local clock reaches the simulation start time, the simulation starts, and at the same time, the time synchronization response information returned by other subsystems is listened. If there are still subsystems that have not completed the time synchronization operation after 30 seconds, the simulation ends. During the simulation process, the simulation control (simulation stop) can be performed through the user interface of the control and management system. After receiving the stop command, the control and management system sends the corresponding control command to other subsystems and ends the simulation.

[0087] In an embodiment of the present application, the simulation management control module also provides simulation data management functions, with the database management system as the core, to realize model management, simulation test project management and test project management, and provide models, data and test preparation for the entire simulation test system.

[0088] The test evaluation subsystem sends the "set test project" use case (code) to the control management subsystem, which automatically loads the simulation test stored in the database according to the code index.

[0089] During the real-time simulation process, the test and evaluation subsystem can set model parameters through network commands, including port power parameter settings, satellite power parameter settings, satellite multipath parameter settings and special script parameter settings.

[0090] The system operator uses the "Set Simulation Test Parameters" use case to modify and add simulation test parameters (time, step size) stored in the database, thereby completing the setting of the simulation test project of the simulation test system.

[0091] The system operator uses the "Set Simulation Model" use case to modify the mathematical simulation model parameters stored in the database and notify the mathematical simulation subsystem. The system operator uses the "Set Simulation Model" use case to add a new mathematical simulation model based on the model description provided by the mathematical simulation subsystem.

[0092] System operators use the "Database Operations" use case to query, modify, back up, and restore the database.

[0093] In the embodiment of the present application, the visualization module is developed by two-dimensional and three-dimensional display through STK software, and the connect module or PL module is used to realize the program interface, and the satellite orbit and user receiver status information on the Ethernet are received in real time and displayed on the STK interface. At the same time, the calculation function of STK can be used to perform operations such as inter-visibility analysis. In addition, a visualization display in the form of a table is provided on the simulation management platform for system monitoring.

[0094] In the embodiment of the present application, the operation and control system interface module realizes the data interface with the ground operation and control system, sends the simulation test control command and the signal simulation data of the simulation calculation to the ground operation and control system according to the specific simulation test task, receives the satellite injection data output by the ground operation and control system, and forwards it to the corresponding simulation model at the same time. The original design of this interface module is to interact with the ground operation and control through the test and communication subsystem, and then it is changed to directly exchange data with the ground operation and control related subsystem, that is, to share the multicast address with the ground operation and control related subsystem.

[0095] In the embodiment of the present application, the strong real-time module is implemented by a simulation management program and a mathematical model, specifically including real-time simulation, data injection, time synchronization and data forwarding functions. This module realizes the real-time calculation of the model and realizes real-time data transmission between models according to the signal association relationship set in the experiment. A unified simulation engine is designed and implemented, and compiled into a simulation program together with a pre-model library. The program is encapsulated into three levels and two-level interfaces. The three levels are: simulation engine, simulation model, and simulation data, and the three levels are independent of each other; the two-level interface is the interface between the engine and the model, and the interface between the model and the data. Thereby obtaining a standard node simulation program, realizing the configurability and data-driven of the model without recompiling the code, and driven by a unified simulation engine and a time synchronization module, the simulation module can realize the real-time distributed operation of the simulation model (satellite orbit, target user, space environment, and test evaluation).

[0096] In an embodiment of the present application, the real-time control of the real-time simulation module model operation is directly controlled by memory address mapping. Since the simulation test system is complex and the amount of data is large, in order to save address space, a shared address mode for initialization and real-time simulation is adopted. Initialization is used for loading. Once the model initialization is completed, it enters the real-time simulation stage, that is, it is converted to real-time operation control mode.

[0097] In the embodiment of the present application, the time synchronization module synchronizes the simulation test system time with the assistance of the RNSS time and frequency module; with the support of the operation and control time and frequency module, it synchronizes with the operation and control system time. After the module is initially timed by the operation and control timing client, it receives the clock 1PPS signal input by the RNSS through the clock board for period correction, and publishes clock information through the reflection memory to unify the time advancement of each node in the real-time simulation system, so that the management and control subsystem and the radio frequency simulation subsystem maintain a unified time advancement.

[0098] Specifically, the time synchronization module needs to meet the following agreements:

[0099] 1) In any test, RNSS provides a 1PPS time pulse signal (TTL level, rising edge aligned with second pulse, preferably 1:1 square wave), which is responsible for synchronizing the signal with the signal of the main station when coordinating with the operation control system.

[0100] 2) The main station provides a network time synchronization program based on timer scheduling running on vxworks to align the simulation logic time with BDT. The time error is less than 10 milliseconds from the initialization of the simulation to the end of the simulation. Since only the initial synchronization is required, the signal synchronization is used directly afterwards. After the initialization is completed, the time synchronization timer is turned off.

[0101] 3) The management and control subsystem is responsible for synchronizing the simulation test system time, and transmits its corresponding BDT (a virtual BDT) once through the time synchronization management command before the arrival of the next second pulse of RNSS (at least 0.5 seconds in advance).

[0102] 4) The management and control subsystem updates the timestamp each time it transmits data through the reflective memory, and the radio frequency subsystem must read the data in a timely manner.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A GNSS simulator control and management system, characterized in that: Including data interaction between non-real-time modules, weak real-time modules, and strong real-time modules; The non-real-time module includes a database module, a model management module, an experimental design module and a model and data preprocessing module; The non-real-time module is used to store models, data, parameters, experimental design schemes and corresponding document data, as well as simulation evaluation result data and reports; The weak real-time module includes a simulation management control program module and a visualization program module. The simulation management program module performs measurement of the subsystem interface, the operation control system interface, simulation management, data recording and online interaction; the visualization program module performs visualization display; The strong real-time module includes a simulation management program module and a mathematical model module. The strong real-time module realizes real-time calculation of the model and realizes real-time data transmission between models according to the signal correlation relationship set in the experiment.

2. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The database module in the non-real-time module adopts SQL Server 2000 database as a platform and provides association settings between data tables through distributed access support.

3. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The model management module includes model code and model description, wherein the model code adopts standard interface conventions and is standardly encapsulated in C code; the model description describes the external characteristics of the model, performs characteristic browsing and model integration.

4. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The test design module designs a matching test plan for the test tasks of the ground operation and control system. The test design module has built-in selection and parameter settings of satellite constellations, orbit models, ionosphere models, troposphere models, multipath models, and user terminal motion models, and also includes the selection of simulation computers and model allocation.

5. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The model and data preprocessing module assists in modeling and analysis in the fields of star orbits, space environment and signal coding, and establishes and verifies, as well as preprocesses model data. The verified model is packaged according to the standard model interface, and then the model information is classified and recorded in the database module.

6. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The simulation management control program module in the weak real-time module provides simulation data management functions, and provides models, data and test preparation for the simulation test system by using a database management system to perform model management, simulation test project management and test project management.

7. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The visualization module of the weak real-time module is developed by two-dimensional and three-dimensional display through STK software, and the program interface is realized by using connect module or PL module, which receives satellite orbit and user receiver status information on Ethernet in real time and displays it on the STK interface.

8. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The operation and control system interface of the weak real-time module realizes the data interface with the ground operation and control system. According to the simulation test task, it sends simulation test control commands and simulation calculated signal simulation data to the ground operation and control system, receives satellite injection data output by the ground operation and control system, and forwards it to the corresponding simulation model at the same time.

9. A GNSS simulator control and management system as claimed in claim 1, characterized in that: The strong real-time module includes real-time simulation, data injection, time synchronization and data forwarding functions. The real-time control of the model operation of the real-time simulation module is directly controlled by memory address mapping.

10. A GNSS simulator control and management system as claimed in claim 9, characterized in that: The time synchronization synchronizes the simulation test system time with the assistance of the RNSS time and frequency module, and synchronizes with the operation and control system time with the support of the operation and control time and frequency module.

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