Design method of digital satellite measurement and control system function level simulation model

Abstract

The invention discloses a design method of a digital satellite measurement and control system function level simulation model, which comprises the following steps: S1, simulation task demand analysis: simulation model function demand analysis, simulation model context environment establishment, simulation task case analysis, typical case scene refinement, and simulation function capture and decomposition realization; s2, simulation model system summary design, including simulation model context environment detailed analysis, simulation model function analysis, simulation model system architecture design, and simulation function refinement and distribution realization; s3, detailed design of a simulation model system, including state machine behavior design of simulation model composition modules, simulation model internal composition design, key sub-function and key sub-model design, and realization of assembly of simulation function modules; and S4, verifying a key algorithm of the simulation model.

Description

Technical Field

[0001] The present invention relates to the field of digital satellite component model construction in the field of aerospace electronic communications, and in particular to a design method for a functional level simulation model of a digital satellite measurement and control system. Background Art

[0002] In recent years, satellite systems are developing towards satellite constellation systems. Satellite measurement, control and communication systems are important components of satellite platforms. Faced with the large-scale and functionally diverse development requirements brought about by high-density constellations, in order to achieve high-integration, low-cost, and high-efficiency product design and iterative optimization, and quickly provide the optimal system-level solution, it is necessary to carry out digital design based on MBSE. On the other hand, in the constellation development process, more emphasis is placed on systematically carrying out simulation verification work such as constellation mission collaborative planning and information flow joint testing in the early stages of development. For a single satellite, simulation requirements are proposed for information flow, control flow, task flow, etc. Therefore, there is an urgent need for the simultaneous delivery of actual products and digital simulation models for satellite subsystems and subsystems.

[0003] MBSE has been applied to satellite communication systems, subsystem modeling and simulation verification, and digital development of measurement and control systems. However, there is still little research on the modeling application of MBSE in digital satellite simulation models. Faced with the large demand for the delivery of digital satellite simulation models, scientific, systematic, and standardized modeling methods and processes are urgently needed as guidance. Summary of the invention

[0004] In order to realize the standardized construction of a digital satellite measurement and control subsystem model, the present invention provides a design method for a functional level simulation model of a digital satellite measurement and control system.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted to solve the technical problem is as follows: A method for designing a functional level simulation model of a digital satellite measurement and control system comprises the following steps: Step S1: Simulation task requirement analysis, including simulation model function requirement analysis, simulation model context environment establishment and simulation task use case analysis, and typical use case scenario refinement; wherein, the model structure design includes the analysis of the simulation model external environment and external interface, and the model function design realizes the capture and decomposition of the simulation model function; Step S2: Simulation model system outline design, including detailed analysis of the simulation model context, simulation model function analysis, and simulation model system architecture design; wherein the model structure design realizes the identification of model composition and internal interfaces; the model function design realizes the refinement and allocation of functions; Step S3: Detailed design of the simulation model system, including the state machine behavior design of the simulation model component modules, the internal component design of the simulation model, and the design of key sub-functions and key sub-models; wherein the structural design of the model realizes the internal logic sub-modules and interconnection of the simulation model modules, and the functional design of the model realizes the switching and assembly of functions; Step S4: Verification of key algorithms of the simulation model.

[0006] Furthermore, the sub-steps of step S1 are further refined as follows: Step S11: Simulation requirement analysis, further summarizing the measurement and control system simulation task requirements into six requirements: measurement and control link status and performance simulation, measurement and control system and single machine business status simulation, remote control command analysis and response simulation, telemetry data simulation and output simulation, simulation model status control, simulation log and status output; Step S12: Establishing the simulation model context and analyzing the simulation task use cases, capturing the "users" of the simulation business in the context, and clarifying the expected goals and implementation methods of the measurement and control system simulation model through use case analysis; Step S13: Refinement of typical use case scenarios. According to the characteristics of the measurement and control system business, the general basic use case "S non-coherent measurement and control communication mode and remote control and telemetry" is refined using a timing diagram. The timing diagram contains loop nodes that describe the behavior within each simulation step after the model is initialized.

[0007] Furthermore, the step S12 specifically includes the following contents: First, all external environmental factors of the measurement and control system should be captured without duplication or omission through simulation context analysis. According to the simulation business requirements, the "users" who need the measurement and control system simulation model to provide corresponding "services" in the environmental context factors should be further captured. Independent, non-related, mutually exclusive and "user-oriented" basic use cases should be formed. In the specific use cases, the "services" provided by the measurement and control system simulation model for specific "users" or the "services" required to be provided by specific "users" should be described. The external environmental factors of the measurement and control system simulation model generally include: ground station model, constellation base model, relay satellite model, digital satellite control module, digital satellite integrated electronic model, digital satellite power supply and distribution model, digital satellite attitude and orbit control model, digital satellite thermal control model, and digital satellite structure model; The “users” of the measurement and control system simulation model for functional level simulation include: ground station model, relay satellite model, digital satellite integrated electronic model, digital satellite control module, digital satellite power supply and distribution model, digital satellite attitude and orbit control model; The general basic use cases of the measurement and control system simulation model are: S non-coherent measurement and control communication mode and remote control and telemetry; its general basic use cases include: telemetry data generation and output, power consumption and heat consumption calculation, remote control command parsing and response; the derived use cases of the basic use cases include: S non-coherent measurement and control communication mode and remote control and telemetry for relays, Ka measurement and control communication mode and remote control and telemetry for ground, and S spread-hop measurement and control communication mode and remote control and telemetry for ground.

[0008] Furthermore, in step S13, the implementation process of the specific functional logic of the timing diagram is as follows: After the simulation starts, the simulation model of the measurement and control system responds to the "initialization" information of the overall model and returns the configuration result status, which is abbreviated as message response item 1; At each simulation step: 1) Receive the "integrated power remote control command" information from the digital satellite model, parse and respond to the command, and update the working status of the simulation model, which is abbreviated as message response item 2; 2) Receive the "uplink remote control" information from the ground station model, and after determining that the link establishment conditions are met, forward the uplink remote control data to the digital satellite integrated power module, which is abbreviated as message response item 3; 3) Receive the "downlink telemetry" information from the digital satellite model, and after determining that the link establishment conditions are met, forward the entire satellite telemetry data to the ground station model, which is abbreviated as message response item 4; 4) Receive the "telemetry request" information from the digital satellite model, form the telemetry data of the measurement and control system, and output it to the integrated power model in a certain format, which is simply recorded as message response item 5; 5) Organize the important business data and main events within the simulation step to form the simulation status and simulation log output, which is abbreviated as message response item 6.

[0009] Furthermore, the sub-steps of step S2 are further refined as follows: Step S21: Detailed analysis of the simulation model context environment, combined with the analysis of the simulation context environment and the timing diagram, to determine the input and output interfaces of the measurement and control system simulation model and the information flow of the interfaces; Step S22: Simulation model function analysis, performing white box function analysis of the simulation model, and decomposing the functions into the logical components of the measurement and control system simulation model: simulation control module and simulation business module; Step S23: Design of the system architecture of the simulation model. The system architecture of the measurement and control system simulation model is designed through the BDD diagram. The measurement and control system simulation model mainly includes two parts: a measurement and control system simulation control module and a measurement and control system business model.

[0010] Furthermore, the step S21 specifically includes the following contents: There is an uplink / downlink data communication interface between the measurement and control system simulation model and the ground station model; there is a forward / return communication interface with the relay satellite model; there are simulation control input and simulation status output interfaces with the digital satellite control module; there are measurement and control subsystem telemetry / remote control and whole satellite remote control / telemetry PCM code interfaces with the digital satellite integrated electrical model.

[0011] Furthermore, in step S22, the "service" requirements for the measurement and control subsystem simulation model in the timing diagram are decomposed and refined one by one, and 14 activity functions and their detailed explanations are formed by carrying out the functional analysis of the "S non-coherent measurement and control communication mode and remote control and telemetry" scenario as follows: Function 1: Initialize the subsystem simulation model, read the input initialization data, and complete the initialization configuration of parameters and status; Function 2: Input interface query and traversal, traversal query all external input interface function calls; Function 3: Subsystem remote control command acquisition and forwarding. When the remote control command interface function has information input, the input information is forwarded to the corresponding unit of the simulation business module; Function 4: Uplink remote control data acquisition and link status judgment. When the uplink remote control data interface function has information input, the current measurement and control link status is calculated. When the value of "ground uplink link establishment" is TRUE, the input information is transferred to the corresponding unit of the measurement and control subsystem business module. Function 5: Acquisition of downlink telemetry PCM code and determination of link status. When there is information input to the downlink telemetry PCM code interface function, the data is transferred to the corresponding unit of the business module, the current measurement and control link status is calculated, and the value of "ground downlink link establishment" is set to TRUE or FALSE. Function 6: Remote control command analysis and working mode switching. The business unit analyzes and responds to remote control commands, and performs power on / off, working mode and configuration settings and switching of single-machine models within the subsystem. Function 7: Frame processing and forwarding of uplink remote control data, receiving uplink remote control data from the simulation control module, and forming uplink remote control PCM code according to the status of the single-machine model on the internal measurement and control link of the subsystem and forwarding it to the PCM output interface of the transponder model; Function 8: forwarding of frame processing of downlink telemetry PCM code, receiving downlink telemetry PCM code from simulation control module, forming downlink telemetry frame data; forwarding downlink telemetry frame to ground antenna output interface according to the status of single machine on measurement and control link; Function 9: Update the parameters and status of a single machine and group telemetry, update the parameters and status of the single machine model in the subsystem, and form the actual telemetry data format; Function 10: Encapsulation of business data: encapsulate the business output data of the business model and the telemetry data of each stand-alone model into interface functions according to the format of internal data interaction of the digital satellite. Function 11: Downlink telemetry frame forwarding to the external interface. When the value of "ground downlink link establishment" is TRUE, the downlink telemetry frame data is written to the downlink telemetry output interface of the digital satellite. Function 12: Request external call and output uplink remote control PCM code, request external call to the uplink remote control PCM code output interface function of the measurement and control system simulation model, write and output the uplink remote control PCM code to the integrated power model, Function 13: Request external call and output of telemetry data of measurement and control subsystem, request external call of subsystem telemetry output interface function of subsystem simulation model, write and output subsystem telemetry data to integrated power model, Function 14: Simulation log and status output, organize the simulation status, simulation log, simulation log data output, Among them, functions 1 to 5, functions 10 to 14 are allocated to the simulation control module, and functions 6 to 9 are allocated to the simulation business module; Through function 1, message response item 1 in the timing analysis of the use case analysis scenario is implemented, that is, the processing of "initialization" information; functions 2, 3, and 6 are used to implement message response item 2, that is, the processing of "integrated power remote control command" information; functions 2, 4, 7, and 12 are used to implement message response item 3, that is, the processing of "uplink remote control" information; functions 2, 5, 8, and 13 are used to implement message response item 4, that is, the processing of "downlink telemetry" information; functions 2, 6, 9, and 13 are used to implement message response item 5, that is, the processing of "telemetry request" information; functions 6 to 14 are used to implement the processing of message response item 6.

[0012] Furthermore, the step S23 specifically includes the following contents: The simulation control module of the measurement and control system encapsulates and calls business functions and external interfaces. The business model of the measurement and control system inherits from the physical model of the measurement and control system, and abstracts specific classes and class parameter attributes and functions according to the single-machine composition and simulation requirements of the actual physical system to realize the simulation and emulation of each single-machine function and performance in the subsystem.

[0013] Furthermore, the sub-steps of step S3 are further refined as follows: Step S31: design of the state machine behavior of the simulation model component modules. The behavior of the simulation model throughout its life cycle is implemented by the state machine models of the component modules, including the simulation model business module state machine, the simulation model control module state machine, and the information interaction between the state machines; Step S32: design the internal composition of the simulation model, design the internal composition of the business module and the control module in the measurement and control system simulation model through the IBD diagram, as well as the interface and information flow relationship between the modules; Step S33: Design of key sub-functions and key sub-models, design of key sub-models: visibility and uplink link establishment judgment model, key sub-functions: S measurement and control link uplink simulation process.

[0014] Furthermore, the step S31 specifically includes the following contents: The business module state machine has the following states: standby, waiting for control instructions, time-jumping operation mode, double-speed operation mode, and normal operation mode; Each state in the normal operation mode can cover the four functions of the simulation model business module captured in the outline design, namely function 6 to function 9. For complex functions, they will be further decomposed into several sub-functions for implementation; "Function 6: Remote control command analysis and working mode switching" realizes the "remote control response simulation" state in the state machine; "Function 7: Frame processing and forwarding of uplink remote control data" can be further decomposed into two sub-functions: "S non-coherent spread spectrum remote control uplink" and "S spread hop remote control uplink"; respectively realize the two states of "S non-coherent uplink measurement and control service simulation" and "S spread hop uplink measurement and control service simulation" in the state machine; "Function 8: forwarding of frame processing of downlink telemetry PCM code" can be further decomposed into: S non-coherent spread spectrum telemetry downlink, S spread hop telemetry downlink; respectively realize: "S non-coherent downlink measurement and control service simulation", "S spread hop downlink measurement and control service simulation" two states; "Function 9: Single machine parameter status update and group telemetry" implements the "telemetry acquisition simulation" state in the state machine.

[0015] Furthermore, the step S32 specifically includes the following contents: The simulation model control module can be further divided into a simulation process control module, a simulation state data control module, and a business interface encapsulation module; the simulation process control module responds to the control instructions of the start, end, and pause of the digital satellite model, realizes the management and control of the measurement and control system business model, and realizes the call of the business function; the simulation state control data module realizes the output of the simulation business state and model state; the business interface encapsulation module realizes the interface function encapsulation of the external output data of the business module; The measurement and control system simulation business module can be divided into the following components according to the specific functional implementation: visibility and link calculation model, transponder model, measurement and control fixed model, and antenna system model. The visibility and link calculation model includes satellite ground station visibility judgment, ground-to-earth uplink / downlink calculation, satellite-relay satellite visibility judgment, and relay link calculation module. The internal unit of the measurement and control system simulation business module has a data input and output interface consistent with the actual single machine.

[0016] Furthermore, the step S33 specifically includes the following contents: The specific implementation process of the visibility and uplink chain building judgment model algorithm is as follows: The first step is to read orbital parameters and ground station related parameters; The second step is to input the real-time pointing angle of the measurement and control antenna and determine the visibility based on the relative position relationship between the satellite and the ground station and the antenna pointing information; Step 3: If the satellite is visible, calculate the distance between the satellite and the ground station; Step 4: Calculate free space loss and ground-to-space link loss; Step 5: Calculate the input power and SNR of the measurement and control antenna to determine whether a link can be established; Step 6: If the chain is successfully established, Tiandi Uplink Chain Establishment = true; The uplink simulation process of the S measurement and control link is implemented by the S antenna model and the transponder model, in which the functions allocated to the S antenna model and the transponder model are designed as follows: Simulation task flow of the S antenna model: In the first step, the S-antenna model calculates the pointing angle and outputs it; In the second step, the S-antenna model calculates the antenna system loss; The third step is to determine whether the link margin within the subsystem is met; Step 4: If the power is sufficient, the S antenna model forwards the uplink data to the transponder model; The simulation task flow of the transponder model: The first step is to determine whether the transponder model is powered and turned on; Step 2: Calculate the transponder model input power and SNR; Step 3: Determine whether the frequency band code group matches; Step 4: Input the uplink data from the antenna model and judge it as uplink continuous remote control by data length or frame header; Step 5: The transponder model recovers the remote control PCM signal and forwards it.

[0017] Furthermore, in step S4, the input of satellite orbit information required for link calculation of the simulation model is obtained based on STK, and closed-loop verification of the algorithm is realized; In the SysML model, the block objects of "satellite orbit attitude information" and "ground station parameter information" are established to define the satellite orbit and attitude information, the latitude and longitude information of the ground station, the gain and EIRP parameters of the antenna as the scene input parameters of the STK simulation; STK is started through Magic Draw software, and the simulation of the satellite orbit and the satellite-to-ground link is run within the set time to generate the satellite-to-ground link AER data at different times; The real-time satellite orbit information output by STK is used as the input of the visibility and uplink link establishment judgment algorithm to calculate the link margin and signal-to-noise ratio parameters to determine whether the link is successfully established. The C / N0 parameters calculated by STK are compared with the C / N0 calculated by the simulation model to verify the simulation model algorithm.

[0018] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: 1. The present invention proposes a function-structure design method for a model-based complex product operation simulation model. From the perspective of the model providing external message response services, the forward design of the simulation model function decomposition and refinement is carried out, and the design of the model architecture and operation state machine is realized through the assembly of functions.

[0019] 2. The present invention proposes a modeling method for a digital satellite subsystem simulation model based on the Magic Grid methodology of cutting, which is used to guide the development of the simulation model code of the measurement and control subsystem operation. This method can not only be used to guide the development of other subsystem models of digital satellites, but is also suitable for the development of digital simulation models of complex electronic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 An overview diagram of a method for designing a functional level simulation model of a measurement and control system according to an embodiment of the present invention; Figure 2 A functional level simulation model requirement diagram of a measurement and control system according to an embodiment of the present invention; Figure 3 A context analysis IBD diagram for a simulation model according to an embodiment of the present invention; Figure 4 A simulation model scenario analysis use case diagram of an embodiment of the present invention; Figure 5 A timing diagram of a simulation model scene refinement according to an embodiment of the present invention; Figure 6 An activity diagram for functional analysis of a simulation model according to an embodiment of the present invention; Figure 7 A BDD diagram is defined for a simulation model architecture according to an embodiment of the present invention; Figure 8 An IBD diagram of the internal composition of a simulation model according to an embodiment of the present invention; Fig. 9 A state machine diagram of a simulation model business module according to an embodiment of the present invention; Fig.10 A space-ground link calculation activity diagram according to an embodiment of the present invention; Fig.11 An activity diagram for performing S incoherent uplink remote control for a simulation model according to an embodiment of the present invention; Fig.12 The simulation model of an embodiment of the present invention is based on the STK verification framework. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0022] The present invention carries out simulation task requirement analysis, simulation model outline design, simulation model system detailed design and other design activities for the digital satellite measurement and control system simulation model modeling task, and verifies the key algorithms of the simulation model. Figure 1 As shown, this embodiment discloses a design method for a functional level simulation model of a digital satellite measurement and control system, which is divided into four steps. Each of the first three steps specifically includes two aspects: structural design and functional design of the simulation model, as shown below: Step S1: Simulation task requirement analysis, including simulation model function requirement analysis, simulation model context environment establishment and simulation task use case analysis, and typical use case scenario refinement; wherein, the model structure design includes the analysis of the simulation model external environment and external interface, and the model function design realizes the capture and decomposition of the simulation model function; Specifically, the sub-steps of step S1 are further refined as follows: Step S11: Simulation requirements analysis, further summarizing the simulation task requirements of the measurement and control system into: The simulation task requirements of the measurement and control system are: to establish a simulation model of the digital satellite measurement and control system, which can truly reflect the functions, performance and workflow of the measurement and control system; to simulate the influence of remote control commands and injection numbers on the subsystem state change process; to simulate the subsystem to generate telemetry data, which can change dynamically according to the remote control commands. Combined with the characteristics of the simulation task, the subsystem simulation model task book is analyzed and decomposed, such as Figure 2 As shown in the figure, the six requirements of the simulation model of the measurement and control system are captured: (1) Simulate the working status and performance of different measurement and control links of the measurement and control system - measurement and control link status and performance simulation; (2) Simulate different stand-alone services and working states within the measurement and control system - simulation of the measurement and control system and stand-alone service states; (3) Simulation of the measurement and control system’s response to actual remote control commands and notes – remote control command analysis and response simulation; (4) Simulate the measurement and control system to output real-time telemetry status - telemetry data simulation and output simulation; (5) Control the operation and parameters of the simulation model of the measurement and control system - state control of the simulation model; (6) Simulation business and status output of the measurement and control system simulation model - simulation log and status output.

[0023] Step S12: Establishing the simulation model context environment and analyzing the simulation task use cases, capturing the "users" of the simulation business in the context environment, establishing the simulation task use cases of the measurement and control system simulation model based on the task analysis of the measurement and control system simulation model, and clarifying the expected goals and implementation methods of the measurement and control system simulation model through the use case analysis; Furthermore, the step S12 specifically includes the following contents: First, all external environmental factors of the measurement and control system should be captured without duplication or omission through simulation context analysis. According to the simulation business requirements, the "users" who need the measurement and control system simulation model to provide corresponding "services" in the environmental context factors should be further captured. The basic use cases that are independent, non-related, mutually exclusive and "user-oriented" should be split and merged to form independent, non-related, mutually exclusive and "user-oriented" basic use cases. In the specific use cases, the "services" provided by the measurement and control system simulation model for specific "users" or the "services" required to be provided by specific "users" should be described. To this end, we first sorted out all the stakeholders of the measurement and control system simulation model in the execution of digital satellite simulation tasks, split and simplified the overall model of the digital satellite according to the actual business, and captured the external environment elements that interacted with the measurement and control system simulation model, such as Figure 3 shown.

[0024] As can be seen in the figure, the external environmental factors of the measurement and control system simulation model generally include eight parts: ground station model, constellation base model, relay satellite model, digital satellite control module, digital satellite integrated electronic model, digital satellite power supply and distribution model, digital satellite attitude and orbit control model, digital satellite thermal control model, and digital satellite structure model. Figure 4 The system model use case diagram shown.

[0025] In the figure, the "users" of the measurement and control system simulation model for functional level simulation include: ground station model, relay satellite model, digital satellite integrated electronic model, digital satellite control module, digital satellite power supply and distribution model, digital satellite attitude and orbit control model; In particular, the basic use case can include the general basic use case through the "include" relationship, and extend the general basic use case through the "Generalization" relationship. The general basic use cases of the measurement and control system simulation model are: S non-coherent measurement and control communication mode and remote control telemetry, simulation control and status output; the basic use cases of the basic use case "S non-coherent measurement and control communication mode and remote control telemetry" "include" include: telemetry data generation and output, power consumption and heat consumption calculation, remote control command analysis and response; the derived use cases of the basic use case include: S non-coherent measurement and control communication mode and remote control telemetry for relay, Ka measurement and control communication mode and remote control telemetry for ground, S expansion jump measurement and control communication mode and remote control telemetry for ground.

[0026] In the simulation, the measurement and control system model needs to have complex information interaction with multiple parties (digital satellite integrated electronic model, ground station model, relay satellite model). Figure 5 As shown in the figure, combined with the actual business of the measurement and control system and the realization of simulation functions, a timing diagram is used to describe the basic use case scenario "S non-coherent measurement and control communication mode and remote control and telemetry" in detail.

[0027] Step S13: Refinement of typical use case scenarios. According to the characteristics of the measurement and control system business, the general basic use case "S non-coherent measurement and control communication mode and remote control and telemetry" is refined using a timing diagram. The timing diagram contains loop nodes that describe the behavior within each simulation step after the model is initialized.

[0028] In order to describe the information interaction process clearly, the overall model of the digital satellite is divided into the digital satellite control module and the digital satellite business (integrated electronics) module in the timing diagram, and the measurement and control system model is divided into the simulation control module and the business model. Figure 5 As shown, after the simulation starts, the simulation control module of the measurement and control system responds to the initialization information of the digital satellite control module to initialize the relevant parameters of the business model.

[0029] Furthermore, in step S13, the implementation process of the specific functional logic of the timing diagram is as follows: After the simulation starts, the simulation model of the measurement and control system responds to the "initialization" information of the overall model and returns the configuration result status, which is abbreviated as message response item 1; At each simulation step: 1) Receive the "integrated power remote control command" information from the digital satellite model, parse and respond to the command, and update the working status of the simulation model, which is abbreviated as message response item 2; 2) Receive the "uplink remote control" information from the ground station model, and after determining that the link establishment conditions are met, forward the uplink remote control data to the digital satellite integrated power module, which is abbreviated as message response item 3; 3) Receive the "downlink telemetry" information from the digital satellite model, and after determining that the link establishment conditions are met, forward the entire satellite telemetry data to the ground station model, which is abbreviated as message response item 4; 4) Receive the "telemetry request" information from the digital satellite model, form the telemetry data of the measurement and control system, and output it to the integrated power model in a certain format, which is simply recorded as message response item 5; 5) Organize the important business data and main events within the simulation step to form the simulation status and simulation log output, which is abbreviated as message response item 6.

[0030] In particular, the use of timing diagrams to refine the scenarios actually clarifies the message response services provided by the measurement and control system simulation model to the outside world. In order to respond to each "call behavior information", the measurement and control system simulation model is required to implement the corresponding functions.

[0031] Step S2: Simulation model system outline design, including detailed analysis of the simulation model context environment, simulation model function analysis, and simulation model system architecture design; among which, the model's structural design realizes the identification of the model's composition and internal interfaces; the model's functional design realizes the refinement and allocation of functions.

[0032] Specifically, the sub-steps of step S2 are further refined as follows: Step S21: Detailed analysis of the simulation model context environment, combined with the analysis of the simulation context environment and the timing diagram, to determine the input and output interfaces of the measurement and control system simulation model and the information flow of the interfaces; Furthermore, the step S21 specifically includes the following contents: Combined with the analysis of the timing diagram, the simulation model system solution design is carried out. The information exchange and parameter dependency between the various elements in the simulation model task context can be further obtained, so as to sort out and determine the external input and output interfaces and information flow items of the measurement and control system simulation model, such as Figure 4 As shown. Figure 4It can be seen that there is an uplink / downlink data communication interface between the measurement and control system simulation model and the ground station model, and the relevant parameters of the ground station transmitting antenna are obtained; there is a forward / reverse communication interface between the measurement and control system simulation model and the relay satellite model; the measurement and control system simulation model and the digital satellite control module transmit simulation control information and simulation status through the corresponding interface; consistent with the actual satellite, the measurement and control system simulation model exchanges information with the digital satellite integrated electrical model through the specified subsystem telemetry / remote control and whole satellite remote control / telemetry PCM interfaces.

[0033] Step S22: In the simulation model function analysis, an activity diagram is used to perform white box function analysis on the simulation model. The function analysis activity diagram of the measurement and control model system is as follows: Figure 6 As shown in the figure, the simulation scenario is aimed at the simulation of the satellite after it is stable in orbit. And the functions are decomposed into the logical components of the measurement and control system simulation model: simulation control module, simulation business module; Furthermore, in step S22, the "service" requirements for the measurement and control subsystem simulation model in the timing diagram are decomposed and refined one by one, and the simulation scenario is oriented to the measurement and control subsystem function and information flow simulation after the satellite is stable in orbit. By carrying out the functional analysis of the "S non-coherent measurement and control communication mode and remote control and telemetry" scenario, 14 activity functions and their detailed explanations are formed as follows: Function 1: Initialize the subsystem simulation model, read the input initialization data, and complete the initialization configuration of parameters and status; The following simulation functions are implemented in each simulation step: (1) The functions and detailed implementation of the simulation control module of the measurement and control system simulation model are as follows: Function 2: Input interface query and traversal. Traverse and query all external input interface function calls; Function 3: Subsystem remote control command acquisition and forwarding. When the remote control command interface function has information input, the input information is forwarded to the corresponding unit of the simulation business module; Function 4: Uplink remote control data acquisition and link status judgment. When the uplink remote control data interface function has information input, the current measurement and control link status is calculated. When the value of "ground uplink link establishment" is TRUE, the input information is transferred to the corresponding unit of the measurement and control subsystem business module; Function 5: Acquisition of downlink telemetry PCM code and determination of link status. When the downlink telemetry PCM code interface function has information input, the data is transferred to the corresponding unit of the business module, the current measurement and control link status is calculated, and the value of "ground downlink link establishment" is set to TRUE or FALSE; (2) The functions and detailed implementation of the simulation business module of the measurement and control system simulation model are as follows: Function 6: Remote control command analysis and working mode switching. The business unit analyzes and responds to remote control commands, and performs power on / off, working mode and configuration settings and switching of single-machine models within the subsystem; Function 7: Frame processing and forwarding of uplink remote control data. Receive uplink remote control data from the simulation control module, and form uplink remote control PCM code according to the status of the single-machine model on the subsystem internal measurement and control link and forward it to the transponder model PCM output interface; Function 8: Forwarding of frame processing of downlink telemetry PCM code. Receive downlink telemetry PCM code from the simulation control module to form downlink telemetry frame data; forward the downlink telemetry frame to the ground antenna output interface according to the status of the single machine on the measurement and control link; Function 9: Update the parameters and status of a single machine and group telemetry. Update the parameters and status of the single machine model in the subsystem to form the actual telemetry data format; (3) The simulation control module of the measurement and control system simulation model further realizes the business output and simulation status output functions of the model. The detailed implementation of the functions is as follows: Function 10: Encapsulation of business data. The business output data of the business model and the telemetry data of each stand-alone model are encapsulated in the interface function according to the format of internal data interaction of the digital satellite. Function 11: forward downlink telemetry frames to external interface. When the value of “ground downlink link establishment” is TRUE, downlink telemetry frame data is written to the downlink telemetry output interface of the digital satellite. Function 12: Request external call and output uplink remote control PCM code. Request external call to the uplink remote control PCM code output interface function of the measurement and control system simulation model, write the uplink remote control PCM code and output it to the integrated power model. Function 13: Request external call and output telemetry data of the measurement and control subsystem. Request external call to the subsystem telemetry output interface function of the subsystem simulation model, write and output the subsystem telemetry data to the integrated power model, Function 14: Simulation log and status output. Organize the simulation status, simulation log, and simulation log data output. To this end, the processing of the message response items of the timing analysis of the S13 use case scenario is realized through functional decomposition. Specifically, through function 1, the message response item 1 in the timing analysis of the use case analysis scenario, that is, the processing of the "initialization" information, is realized; functions 2, 3, and 6 are used to realize the message response item 2, that is, the processing of the "integrated power remote control command" information; functions 2, 4, 7, and 12 are used to realize the message response item 3, that is, the processing of the "uplink remote control" information; functions 2, 5, 8, and 13 are used to realize the message response item 4, that is, the processing of the "downlink telemetry" information; functions 2, 6, 9, and 13 are used to realize the message response item 5, that is, the processing of the "telemetry request" information; functions 6-14 are used to realize the message response item 6, that is, the processing of the "output of the simulation state".

[0034] At the same time, functions 1 to 5, functions 10 to 14 are allocated to the simulation control module, and functions 6 to 9 are allocated to the simulation business module.

[0035] Step S23: Design of simulation model system architecture. Design the system architecture of the measurement and control system simulation model through the BDD diagram. Based on the interface signal flow and material flow transfer process in the task context analysis, combined with the use case diagram and interaction diagram in the demand analysis, the overall architecture of the digital satellite simulation model is comprehensively considered to form the system architecture of the measurement and control system simulation model. Use the module definition diagram (BDD diagram) in the SysML system to model and describe the system architecture. Figure 7 As shown in the figure, the simulation model of the digital satellite measurement and control system mainly consists of two parts: the measurement and control system simulation control module and the measurement and control system business model. Among them, the measurement and control system simulation control module manages the entire life cycle of the measurement and control system business model according to requirements, and encapsulates and calls business functions and external interfaces. The measurement and control system business model inherits from the measurement and control system physical model, and abstracts specific classes and class attributes, functions, etc. according to the single-machine composition and simulation requirements of the actual physical system, so as to realize the management of each single-machine sub-model in the subsystem.

[0036] Based on the simulation model system architecture, combined with the information flow of context analysis, the detailed design of the measurement and control system simulation model is carried out. The internal composition and interface information flow of the simulation model, the behavior of the simulation model throughout its life cycle, and the key internal modules are designed. The internal interface IBD diagram of the measurement and control system simulation model is established to describe the signal and material transmission relationship between the components of the simulation model, such as Figure 8 The simulation control module of the measurement and control system in the simulation model of the measurement and control system realizes the interconnection between the simulation business model and the external interface, and further needs to realize the following functions: model initialization, simulation control, simulation status and log output, etc.

[0037] Furthermore, the step S23 specifically includes the following contents: The simulation control module of the measurement and control system encapsulates and calls business functions and external interfaces. The business model of the measurement and control system inherits from the physical model of the measurement and control system, and abstracts specific classes and class parameter attributes and functions according to the single-machine composition and simulation requirements of the actual physical system to realize the simulation and emulation of each single-machine function and performance in the subsystem.

[0038] Step S3: Detailed design of the simulation model system, including the state machine behavior design of the simulation model component modules, the internal component design of the simulation model, and the design of key sub-functions and key sub-models; wherein the structural design of the model realizes the internal logic sub-modules and interconnection of the simulation model modules, and the functional design of the model realizes the switching and assembly of functions; Specifically, the sub-steps of step S3 are further refined as follows: Step S31: design of the state machine behavior of the simulation model component modules. The behavior of the simulation model throughout its life cycle is implemented by the state machine models of the component modules, including the simulation model business module state machine, the simulation model control module state machine, and the information interaction between the state machines; Furthermore, the step S31 specifically includes the following contents: Combining the simulation requirements with the actual business of the measurement and control system, the state machine diagram of the simulation model business module is obtained as follows: Fig. 9 As shown in the figure, the business module state machine has the following five states: standby, waiting for control instructions, time-jumping operation mode, double-speed operation mode, and normal operation mode; Each state in the normal operation mode can cover the four functions of the simulation model business module captured in the outline design, namely function 6 to function 9. For complex functions, they will be further decomposed into several sub-functions for implementation; "Function 6: Remote control command analysis and working mode switching" realizes the "remote control response simulation" state in the state machine; "Function 7: Frame processing and forwarding of uplink remote control data" can be further decomposed into two sub-functions: "S non-coherent spread spectrum remote control uplink" and "S spread hop remote control uplink"; respectively realize the two states of "S non-coherent uplink measurement and control service simulation" and "S spread hop uplink measurement and control service simulation" in the state machine; "Function 8: forwarding of frame processing of downlink telemetry PCM code" can be further decomposed into: S non-coherent spread spectrum telemetry downlink, S spread hop telemetry downlink; respectively realize: "S non-coherent downlink measurement and control service simulation", "S spread hop downlink measurement and control service simulation" two states; "Function 9: Single machine parameter status update and group telemetry" implements the "telemetry acquisition simulation" state in the state machine.

[0039] Step S32: design the internal composition of the simulation model, design the internal composition of the business module and the control module in the measurement and control system simulation model through the IBD diagram, as well as the interface and information flow relationship between the modules; Furthermore, the step S32 specifically includes the following contents: The simulation model control module can be further divided into a simulation process control module, a simulation state data control module, and a business interface encapsulation module; the simulation process control module responds to the start, end, pause and other control instructions of the digital satellite model, realizes the management and control of the measurement and control system business model, and realizes the call of business functions; the simulation state control data module realizes the output of simulation business status and model status; the business interface encapsulation module realizes the interface function encapsulation of the external output data of the business module; The business model of the measurement and control system simulation model mainly realizes the following functions: remote control command analysis and processing, business process processing, telemetry acquisition and output, performance parameter simulation, etc. According to the specific functional implementation, the measurement and control system simulation business module can be divided into the following components: visibility and link calculation model, transponder model, measurement and control fixed release model, antenna system model, etc. The visibility and link calculation model includes modules such as satellite ground station visibility judgment, earth-to-ground uplink / downlink calculation, satellite-relay satellite visibility judgment, and relay link calculation; the internal unit of the measurement and control system simulation business module has a data input and output interface consistent with the actual single machine.

[0040] Step S33: Design of key sub-functions and key sub-models, design of key sub-models: visibility and uplink link establishment judgment model, key sub-functions: S measurement and control link uplink simulation process.

[0041] Furthermore, in the detailed design of the simulation model of the measurement and control system, visibility and link calculation are very important functions in the simulation model of the measurement and control system. The simulation of the measurement and control business process requires link connectivity as a prerequisite. The overall link simulation calculation mainly considers two factors: external environmental factors and the internal working status of the subsystem. The "visibility and uplink link establishment judgment algorithm" and the operation algorithm of different links within the subsystem are designed separately. The step S33 specifically includes the following contents: like Fig.10 As shown, the specific implementation process of the visibility and uplink chain building judgment model algorithm is as follows: The first step is to read orbital parameters and ground station related parameters; The second step is to input the real-time pointing angle of the measurement and control antenna and determine the visibility based on the relative position relationship between the satellite and the ground station and the antenna pointing information; Step 3: If the satellite is visible, calculate the distance between the satellite and the ground station; Step 4: Calculate free space loss and ground-to-space link loss; Step 5: Calculate the input power and SNR of the measurement and control antenna to determine whether a link can be established; Step 6: If the chain is successfully established, Tiandi Uplink Chain Establishment = true; In the detailed design of the simulation model, the uplink simulation process of the S measurement and control link is realized by the S antenna model and the transponder model. The specific process is realized by the activity diagram, in which the function design allocated to the S antenna model and the transponder model is as follows: like Fig.11 As shown in the figure, the simulation task flow of the S antenna model is: In the first step, the S-antenna model calculates the pointing angle and outputs it; In the second step, the S-antenna model calculates the antenna system loss; The third step is to determine whether the link margin within the subsystem is met; Step 4: If the power is sufficient, the S antenna model forwards the uplink data to the transponder model; like Fig.11 As shown in the figure, the simulation task flow of the transponder model is: The first step is to determine whether the transponder model is powered and turned on; Step 2: Calculate the transponder model input power and SNR; Step 3: Determine whether the frequency band code group matches; Step 4: Input the uplink data from the antenna model and judge it as uplink continuous remote control by data length or frame header; Step 5: The transponder model recovers the remote control PCM signal and forwards it.

[0042] Step S4: Verification of key algorithms of the simulation model.

[0043] It is worth noting that visibility and link calculations require parameters such as the relative positional relationship between the satellite and the ground station, and environmental factors of the satellite-to-ground link as input. In the model design phase, the relevant parameters originally derived from the overall digital satellite model cannot be directly obtained. Therefore, in the design method of the functional-level simulation model of the measurement and control system, the input of the satellite orbit information required for the link calculation of the simulation model was designed based on STK, and the closed-loop verification of the algorithm was realized; like Fig.12 As shown in the figure, in the SysML model, block objects such as "satellite orbit attitude information" and "ground station parameter information" are established to define the satellite orbit and attitude information, the latitude and longitude information of the ground station, the antenna gain and EIRP and other parameters as the scene input parameters of the STK simulation; start STK through Magic Draw software, run the simulation of the satellite orbit and the satellite-to-ground link within the set time, and generate the satellite-to-ground link AER (Azimuth, Elevation, Range) data at different times; The real-time satellite orbit information output by STK is used as the input of the visibility and uplink link establishment judgment algorithm to calculate parameters such as link margin and signal-to-noise ratio to determine whether the link is successfully established. The C / N0 parameters calculated by STK are compared with the C / N0 calculated by the simulation model to verify the simulation model algorithm.

[0044] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A design method for a functional level simulation model of a digital satellite measurement and control system, characterized in that: The following steps are involved: Step S1: Simulation task requirement analysis, including simulation model function requirement analysis, simulation model context environment establishment and simulation task use case analysis, and typical use case scenario refinement; wherein, the model structure design includes the analysis of the simulation model external environment and external interface, and the model function design realizes the capture and decomposition of the simulation model function; Step S2: Simulation model system outline design, including detailed analysis of the simulation model context, simulation model function analysis, and simulation model system architecture design; wherein the model structure design realizes the identification of model composition and internal interfaces; the model function design realizes the refinement and allocation of functions; Step S3: Detailed design of the simulation model system, including the state machine behavior design of the simulation model component modules, the internal component design of the simulation model, and the design of key sub-functions and key sub-models; wherein the structural design of the model realizes the internal logic sub-modules and interconnection of the simulation model modules, and the functional design of the model realizes the switching and assembly of functions; Step S4: Verification of key algorithms of the simulation model.

2. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 1, characterized in that: The sub-steps of step S1 are further refined as follows: Step S11: Simulation requirement analysis, further summarizing the simulation task requirements of the measurement and control system into six requirements: measurement and control link status and performance simulation, measurement and control system and single machine business status simulation, remote control command analysis and response simulation, telemetry data simulation and output simulation, simulation model status control, simulation log and status output; Step S12: Establish the simulation model context and analyze the simulation task use cases, capture the "users" of the simulation business in the context, and clarify the expected goals and implementation methods of the measurement and control system simulation model through use case analysis; Step S13: Refinement of typical use case scenarios. According to the characteristics of the measurement and control system business, the general basic use case "S non-coherent measurement and control communication mode and remote control and telemetry" is refined using a timing diagram. The timing diagram contains loop nodes that describe the behavior within each simulation step after the model is initialized.

3. The design method of a digital satellite measurement and control system functional level simulation model according to claim 2 is characterized in that: The step S12 specifically includes the following contents: First, all external environmental factors of the measurement and control system should be captured without duplication or omission through simulation context analysis. According to the simulation business requirements, the "users" who need the measurement and control system simulation model to provide corresponding "services" in the environmental context factors should be further captured. Independent, non-related, mutually exclusive and "user-oriented" basic use cases should be formed. In the specific use cases, the "services" provided by the measurement and control system simulation model for specific "users" or the "services" required to be provided by specific "users" should be described. The external environmental factors of the measurement and control system simulation model generally include: ground station model, constellation base model, relay satellite model, digital satellite control module, digital satellite integrated electronic model, digital satellite power supply and distribution model, digital satellite attitude and orbit control model, digital satellite thermal control model, and digital satellite structure model; The "users" of the measurement and control system simulation model for functional level simulation include: ground station model, relay satellite model, digital satellite integrated electronic model, digital satellite control module, digital satellite power supply and distribution model, digital satellite attitude and orbit control model; The general basic use cases of the measurement and control system simulation model are: S non-coherent measurement and control communication mode and remote control and telemetry; its general basic use cases include: telemetry data generation and output, power consumption and heat consumption calculation, remote control command parsing and response; the derived use cases of the basic use cases include: S non-coherent measurement and control communication mode and remote control and telemetry for relays, Ka measurement and control communication mode and remote control and telemetry for ground, and S spread-hop measurement and control communication mode and remote control and telemetry for ground.

4. The design method of a digital satellite measurement and control system functional level simulation model according to claim 2 is characterized in that: In step S13, the implementation process of the specific functional logic of the timing diagram is as follows: After the simulation starts, the simulation model of the measurement and control system responds to the "initialization" information of the overall model and returns the configuration result status, which is abbreviated as message response item 1; At each simulation step: 1) Receive the "integrated power remote control command" information from the digital satellite model, parse and respond to the command, and update the working status of the simulation model, which is abbreviated as message response item 2; 2) Receive the "uplink remote control" information from the ground station model, and after determining that the link establishment conditions are met, forward the uplink remote control data to the digital satellite integrated power module, which is abbreviated as message response item 3; 3) Receive the "downlink telemetry" information from the digital satellite model, and after determining that the link establishment conditions are met, forward the entire satellite telemetry data to the ground station model, which is abbreviated as message response item 4; 4) Receive the "telemetry request" information from the digital satellite model, form the telemetry data of the measurement and control system, and output it to the integrated power model in a certain format, which is simply recorded as message response item 5; 5) Organize the important business data and main events within the simulation step to form the simulation status and simulation log output, which is abbreviated as message response item 6.

5. The design method of a digital satellite measurement and control system functional level simulation model according to claim 1 is characterized in that: The sub-steps of step S2 are further refined as follows: Step S21: Detailed analysis of the simulation model context environment, combined with the analysis of the simulation context environment and the timing diagram, to determine the input and output interfaces of the measurement and control system simulation model and the information flow of the interfaces; Step S22: Simulation model function analysis, performing white box function analysis of the simulation model, and decomposing the functions into the logical components of the measurement and control system simulation model: simulation control module and simulation business module; Step S23: Design of the system architecture of the simulation model. The system architecture of the measurement and control system simulation model is designed through the BDD diagram. The measurement and control system simulation model mainly includes two parts: a measurement and control system simulation control module and a measurement and control system business model.

6. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 5, characterized in that: The step S21 specifically includes the following contents: There is an uplink / downlink data communication interface between the measurement and control system simulation model and the ground station model; There is a forward / return communication interface with the relay satellite model; There are simulation control input and simulation status output interfaces with the digital satellite control module; there are telemetry / remote control of the measurement and control subsystem and PCM code interfaces of the whole satellite remote control / telemetry with the digital satellite integrated electrical model.

7. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 5, characterized in that: In step S22, the "service" requirements for the measurement and control subsystem simulation model in the timing diagram are decomposed and refined one by one, and 14 activity functions and their detailed explanations are formed by carrying out the functional analysis of the "S non-coherent measurement and control communication mode and remote control and telemetry" scenario as follows: Function 1: Initialize the subsystem simulation model, read the input initialization data, and complete the initialization configuration of parameters and status; Function 2: Input interface query and traversal, traversal query all external input interface function calls; Function 3: Subsystem remote control command acquisition and forwarding. When the remote control command interface function has information input, the input information is forwarded to the corresponding unit of the simulation business module; Function 4: Uplink remote control data acquisition and link status judgment. When the uplink remote control data interface function has information input, the current measurement and control link status is calculated. When the value of "ground uplink link establishment" is TRUE, the input information is transferred to the corresponding unit of the measurement and control subsystem business module. Function 5: Acquisition of downlink telemetry PCM code and determination of link status. When there is information input to the downlink telemetry PCM code interface function, the data is transferred to the corresponding unit of the business module, the current measurement and control link status is calculated, and the value of "ground downlink link establishment" is set to TRUE or FALSE. Function 6: Remote control command analysis and working mode switching. The business unit analyzes and responds to remote control commands, and performs power on / off, working mode and configuration settings and switching of single-machine models within the subsystem. Function 7: Frame processing and forwarding of uplink remote control data, receiving uplink remote control data from the simulation control module, and forming uplink remote control PCM code according to the status of the single-machine model on the internal measurement and control link of the subsystem and forwarding it to the PCM output interface of the transponder model; Function 8: forwarding of frame processing of downlink telemetry PCM code, receiving downlink telemetry PCM code from simulation control module, forming downlink telemetry frame data; forwarding downlink telemetry frame to ground antenna output interface according to the status of single machine on measurement and control link; Function 9: Update the parameters and status of a single machine and group telemetry, update the parameters and status of the single machine model in the subsystem, and form the actual telemetry data format; Function 10: Encapsulation of business data: encapsulate the business output data of the business model and the telemetry data of each stand-alone model into interface functions according to the format of internal data interaction of the digital satellite. Function 11: Downlink telemetry frame forwarding to the external interface. When the value of "ground downlink link establishment" is TRUE, the downlink telemetry frame data is written to the downlink telemetry output interface of the digital satellite. Function 12: Request external call and output uplink remote control PCM code, request external call to the uplink remote control PCM code output interface function of the measurement and control system simulation model, write and output the uplink remote control PCM code to the integrated power model, Function 13: Request external call and output of telemetry data of measurement and control subsystem, request external call of subsystem telemetry output interface function of subsystem simulation model, write and output subsystem telemetry data to integrated power model, Function 14: Simulation log and status output, organize the simulation status, simulation log, simulation log data output, Among them, functions 1 to 5, functions 10 to 14 are allocated to the simulation control module, and functions 6 to 9 are allocated to the simulation business module; Through function 1, message response item 1 in the timing analysis of the use case analysis scenario is implemented, that is, the processing of "initialization" information; functions 2, 3, and 6 are used to implement message response item 2, that is, the processing of "integrated power remote control command" information; functions 2, 4, 7, and 12 are used to implement message response item 3, that is, the processing of "uplink remote control" information; functions 2, 5, 8, and 13 are used to implement message response item 4, that is, the processing of "downlink telemetry" information; functions 2, 6, 9, and 13 are used to implement message response item 5, that is, the processing of "telemetry request" information; functions 6 to 14 are used to implement the processing of message response item 6.

8. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 5, characterized in that: The step S23 specifically includes the following contents: The simulation control module of the measurement and control system encapsulates and calls business functions and external interfaces. The business model of the measurement and control system inherits from the physical model of the measurement and control system, and abstracts specific classes and class parameter attributes and functions according to the single-machine composition and simulation requirements of the actual physical system to realize the simulation and emulation of each single-machine function and performance in the subsystem.

9. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 1, characterized in that: The sub-steps of step S3 are further refined as follows: Step S31: design of the state machine behavior of the simulation model component modules. The behavior of the simulation model throughout its life cycle is implemented by the state machine models of the component modules, including the simulation model business module state machine, the simulation model control module state machine, and the information interaction between the state machines; Step S32: design the internal composition of the simulation model, design the internal composition of the business module and the control module in the measurement and control system simulation model through the IBD diagram, as well as the interface and information flow relationship between the modules; Step S33: Design of key sub-functions and key sub-models, design of key sub-models: visibility and uplink link establishment judgment model, key sub-functions: S measurement and control link uplink simulation process.

10. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 9, characterized in that: The step S31 specifically includes the following contents: The business module state machine has the following states: standby, waiting for control instructions, time-jumping operation mode, double-speed operation mode, and normal operation mode; Each state in the normal operation mode can cover the four functions of the simulation model business module captured in the outline design, namely function 6 to function 9. For complex functions, they will be further decomposed into several sub-functions: "Function 6: Remote control command analysis and working mode switching" realizes the "remote control response simulation" state in the state machine; "Function 7: Frame processing and forwarding of uplink remote control data" can be further decomposed into two sub-functions: "S non-coherent spread spectrum remote control uplink" and "S spread hop remote control uplink"; respectively realize the two states of "S non-coherent uplink measurement and control service simulation" and "S spread hop uplink measurement and control service simulation" in the state machine; "Function 8: forwarding of frame processing of downlink telemetry PCM code" can be further decomposed into: S non-coherent spread spectrum telemetry downlink and S spread hop telemetry downlink; respectively realize: "S non-coherent downlink measurement and control service simulation" and "S spread hop downlink measurement and control service simulation" two states; "Function 9: Single machine parameter status update and group telemetry" implements the "telemetry acquisition simulation" state in the state machine.

11. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 9, characterized in that: The step S32 specifically includes the following contents: The simulation model control module can be further divided into a simulation process control module, a simulation state data control module, and a business interface encapsulation module; the simulation process control module responds to the control instructions of the start, end, and pause of the digital satellite model, realizes the management and control of the measurement and control system business model, and realizes the call of the business function; the simulation state control data module realizes the output of the simulation business state and model state; the business interface encapsulation module realizes the interface function encapsulation of the external output data of the business module; The measurement and control system simulation business module can be divided into the following components according to the specific functional implementation: visibility and link calculation model, transponder model, measurement and control fixed model, and antenna system model. The visibility and link calculation model includes satellite ground station visibility judgment, ground-to-earth uplink / downlink calculation, satellite-relay satellite visibility judgment, and relay link calculation module. The internal unit of the measurement and control system simulation business module has a data input and output interface consistent with the actual single machine.

12. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 9, characterized in that: The step S33 specifically includes the following contents: The specific implementation process of the visibility and uplink chain building judgment model algorithm is as follows: The first step is to read orbital parameters and ground station related parameters; The second step is to input the real-time pointing angle of the measurement and control antenna and determine the visibility based on the relative position relationship between the satellite and the ground station and the antenna pointing information; Step 3: If the satellite is visible, calculate the distance between the satellite and the ground station; Step 4: Calculate free space loss and ground-to-space link loss; Step 5: Calculate the input power and SNR of the measurement and control antenna to determine whether a link can be established; Step 6: If the chain is successfully established, Tiandi Uplink Chain Establishment = true; The uplink simulation process of the S measurement and control link is implemented by the S antenna model and the transponder model, in which the functions allocated to the S antenna model and the transponder model are designed as follows: Simulation task flow of the S antenna model: In the first step, the S-antenna model calculates the pointing angle and outputs it; In the second step, the S-antenna model calculates the antenna system loss; The third step is to determine whether the link margin within the subsystem is met; Step 4: If the power is sufficient, the S antenna model forwards the uplink data to the transponder model; The simulation task flow of the transponder model: The first step is to determine whether the transponder model is powered and turned on; Step 2: Calculate the transponder model input power and SNR; Step 3: Determine whether the frequency band code group matches; Step 4: Input the uplink data from the antenna model and judge it as uplink continuous remote control by data length or frame header; Step 5: The transponder model recovers the remote control PCM signal and forwards it.

13. The method for designing a functional level simulation model of a digital satellite measurement and control system according to claim 1, characterized in that: In the step S4, the input of satellite orbit information required for link calculation of the simulation model is obtained based on STK, and closed-loop verification of the algorithm is realized; In the SysML model, create the block objects of "Satellite orbit attitude information" and "Ground station parameter information", respectively define the satellite orbit and attitude information, the longitude and latitude information of the ground station, the gain and EIRP parameters of the antenna, as the scene input parameters of the STK simulation; Start STK through Magic Draw software, run the simulation of satellite orbit and satellite-to-ground link within the set time, and generate satellite-to-ground link AER data at different times; The real-time satellite orbit information output by STK is used as the input of the visibility and uplink link establishment judgment algorithm to calculate the link margin and signal-to-noise ratio parameters to determine whether the link is successfully established. The C / N0 parameters calculated by STK are compared with the C / N0 calculated by the simulation model to verify the simulation model algorithm.

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