Extensible semi-physical simulation platform for large remote sensing satellite

Abstract

The invention relates to an extensible semi-physical simulation platform for a large remote sensing satellite, and the platform is characterized in that a time reference module is used for providing a unified time reference to drive the simulation platform and an on-satellite equivalent service simulator, and achieves the time alignment of the on-satellite equivalent service simulator; the comprehensive expansion and interface unit module is used for providing CAN (Controller Area Network) and SpaceWire bus interface board cards; the simulation main control unit sends a remote control instruction to the CAN bus interface board card, the CAN bus interface board card sends the remote control instruction to the on-satellite equivalent service simulator through instruction format conversion, and the on-satellite equivalent service simulator sends telemetry information to the simulation main control unit through the CAN bus interface board card after receiving the instruction; and receiving the on-satellite equivalent service simulator service data transmitted by the SpaceWire bus board card, and realizing state monitoring and service data precision analysis of the on-satellite equivalent service simulator. The ground simulation task closed-loop test and on-orbit task deduction of the remote sensing satellite are completed, various on-satellite problems are found and solved in advance, and the development efficiency of the whole satellite is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of remote sensing satellite semi-physical system simulation, and relates to an expandable semi-physical simulation platform for large remote sensing satellites. Background Art

[0002] At present, remote sensing satellites face problems such as high pressure in the design stage and tight development cycle. Some problems in the satellite design and development stages need to be identified in advance and accurately. Therefore, it is necessary to adopt the method of whole-satellite ground semi-physical simulation verification to conduct mission simulations on satellites in advance and effectively identify remote sensing satellite risks.

[0003] The existing semi-physical simulation basic platforms are mostly focused on micro-satellites, which have a single function and relatively simple data flow compared to large satellites. Therefore, the designed semi-physical simulation basic platforms are not suitable for large remote sensing satellites with complex mission flows. At present, the semi-physical simulation equipment used by most satellite development units is developed for a specific type of satellite, and the development objects are mostly micro-satellites, which lack a certain degree of versatility; some satellite development units use software simulation on PCs for simulation, which cannot reflect the actual status of the satellite; and some satellite development units use relatively expensive hardware platforms, which are costly.

[0004] In view of the characteristics of existing large-scale remote sensing satellites with short development cycle, large number and great functional differences, in order to save costs and shorten the development cycle, it is urgent to design and invent a basic simulation platform suitable for ground-based scalable semi-physical simulation of large remote sensing satellite constellations, which can be used to realize satellite service communications, remote control and telemetry transmission and other functions, and cooperate with other on-board equivalent business simulators to achieve signal-level mission closed-loop simulation. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose an expandable semi-physical simulation platform for large remote sensing satellites, to provide a signal-level software and hardware verification environment for ground semi-physical simulation and deduction of large remote sensing satellites, and to support the completion of self-closed-loop and task collaborative simulation verification of satellite key missions.

[0006] The technical solution of the present invention is: an expandable semi-physical simulation platform for large remote sensing satellites, including a time reference module, a comprehensive expansion and interface unit module, a simulation main control unit, a SpaceWire switch and a large-capacity server;

[0007] A time reference module, used to provide a unified time reference to drive the simulation platform and the on-board equivalent service simulator, so as to achieve time alignment of multiple on-board equivalent service simulators;

[0008] Comprehensive expansion and interface unit module, providing CAN bus interface board, SpaceWire bus interface board and corresponding board drivers;

[0009] The simulation main control unit sends remote control commands to the CAN bus interface board in the integrated expansion and interface unit module. The CAN bus interface board converts the command format and sends it to the onboard equivalent business simulator. After receiving the command, the onboard equivalent business simulator sends telemetry information to the simulation main control unit via the CAN bus interface board; receives the business data of the onboard equivalent business simulator transmitted via the SpaceWire bus board, and realizes the status monitoring of the onboard equivalent business simulator and the accuracy analysis of business data;

[0010] SpaceWire switch, which realizes the exchange and transmission of business data between equivalent business simulators, simulation main control units, integrated expansion and interface unit modules on each satellite;

[0011] A large-capacity server is used as the front-end display interface of the simulation main control unit and realizes the remote control function of the simulation main control unit.

[0012] Furthermore, various boards of the integrated expansion and interface unit and the simulation main control unit are all carried by the PXI-E bus chassis.

[0013] Furthermore, the time reference module includes an NTP time calibration server, a frequency reference source, and a time control board;

[0014] The frequency reference source provides the reference working clock, TTL level and 1PPS signal to the NTP time synchronization server and the time control board;

[0015] The NTP time synchronization server receives external GPS navigation signals, and starts to calibrate the time after receiving the GPS navigation signals and the reference working clock sent by the frequency reference source, and sends the NTP network time to the simulation main control unit through the large-capacity server;

[0016] The timing control board receives the TTL level, reference working clock and 1PPS signal provided by the frequency reference source, generates the frequency reference required by the on-board equivalent service simulator through the on-board waveform shaping circuit and frequency division circuit, and converts the 1PPS signal generated by the frequency reference source into the 1PPS signal required by each on-board equivalent service simulator through the power divider.

[0017] Furthermore, the NTP time synchronization server adopts a redundant architecture design, and the high-precision clock is directly derived from the atomic clocks of various satellites in the Beidou and GPS systems. The local clock source is tamed through signal analysis to achieve the function of accurately maintaining the local clock after the satellite signal is lost.

[0018] Furthermore, the frequency reference source uses a rubidium atomic clock or a high-stability crystal oscillator disciplined by the GNSS system to provide a reference working clock and a 1PPS signal to the NTP time synchronization server and the time control board.

[0019] Furthermore, the working modes of the SpaceWire bus interface board include interface mode and router mode; in router mode, the board can route data packets between SpaceWire ports and between SpaceWire ports and PCI buses; in interface mode, the board allows data packets to be sent and received independently on each SpaceWire link without path or logical addressing.

[0020] Furthermore, the integrated expansion and interface unit module also includes a data storage board for storing business data and telemetry data from an onboard equivalent business simulator.

[0021] Furthermore, the integrated expansion and interface unit module reserves an LVDS interface and has the expansion capability of performing LVDS data interaction with an onboard equivalent service simulator.

[0022] Furthermore, the simulation main control unit includes a driving module, a business data interaction control module, and a human-computer interaction module;

[0023] The driver module configures and drives the boards in the integrated expansion and interface unit modules based on the PXI-E bus architecture, including setting and processing board parameters, and sending and receiving board data;

[0024] Business data interaction control module, which realizes the functions of remote control command reception, telemetry data packaging and distribution, and time synchronization;

[0025] The human-computer interaction module generates control instructions to the back-end driver module or business data interaction control module based on the user's operations on the interface.

[0026] The beneficial effects of the present invention compared with the prior art are:

[0027] (1) The scalable semi-physical simulation platform for large remote sensing satellites provided in this application builds a unified hardware and software simulation test framework structure, simulates the satellite's intra-satellite information interaction process through standardized processing boards, integrates core functional components, and supports access to on-board equivalent business simulators, provides a unified time-frequency reference and simulation drive environment, has control and data management functions, and supports pure physical simulation, physical + digital combination and other types of simulation test working modes; using this platform and the on-board equivalent business simulator to support the completion of the ground simulation mission closed-loop test and on-orbit mission deduction of the remote sensing satellite, discover and solve various on-board problems in advance, and effectively improve the development efficiency of the entire satellite;

[0028] (2) The present invention provides semi-physical simulation control and interface driver, and utilizes universal bus boards such as Spacewire bus and CAN bus to connect multiple satellite equivalent business simulators, etc., to realize functions such as remote control and telemetry data transmission, time reference transmission, and business data interaction; the semi-physical simulation system is connected through a 10G optical fiber network to realize simulation control and data interaction, and an LVDS interface is reserved, which has the expansion capability of LVDS data interaction with the satellite equivalent business simulator, and can cover the interface requirements of large remote sensing satellites, and adopts a PXI-E bus chassis to configure interface boards and function boards, thereby ensuring the versatility and scalability of the semi-physical simulation basic platform;

[0029] (3) The present invention provides the time reference required by the simulation system through the time reference module. The time reference module provides accurate time reference to the equivalent business simulator on the semi-physical simulation platform through the NTP time synchronization server, frequency reference source, and time control board, including CAN bus time information, 1PPS synchronization signal, etc.; the network time information is transmitted to various simulators through the NTP time synchronization server, ensuring the data transmission accuracy and rate, and realizing the local clock accurate maintenance function after the satellite signal is lost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a schematic diagram of an expandable semi-physical simulation platform for large remote sensing satellites. DETAILED DESCRIPTION

[0031] The present invention provides an extensible semi-physical simulation platform for large remote sensing satellites. The semi-physical simulation platform simulates the satellite intra-satellite information interaction process through a standardized processing board, integrates the core functional components, supports access to the on-board equivalent service simulator, provides a unified time and frequency reference and simulation drive environment, has control and data management functions, and supports pure physical simulation, physical + digital combination and other types of simulation test working modes. The semi-physical simulation basic platform includes a time control NTP time calibration server, a frequency reference source, a time control board, a large-capacity server, a simulation main control unit, a comprehensive expansion and interface unit, a SpaceWire switch, etc. Its main functions include the following three points:

[0032] (1) Provide various bus interface boards, data storage boards and other hardware devices as well as corresponding underlying drivers;

[0033] (2) Provide semi-physical simulation control and interface driver, use Spacewire bus, CAN bus and other general bus boards to connect multiple on-board equivalent business simulators, and realize remote control and telemetry data transmission, time reference transmission, business data interaction and other functions; connect the semi-physical simulation system through a 10G optical fiber network to realize simulation control and data interaction, and reserve an LVDS interface to have the expansion capability of LVDS data interaction with on-board equivalent business simulators;

[0034] (3) Provide the time reference required by the simulation system. The time reference subsystem provides accurate time reference to the equivalent business simulator on the semi-physical simulation platform through the NTP time server, frequency reference source, and time control board, including CAN bus time information, 1PPS synchronization signal, etc.; and transmits network time information to various simulators through the NTP time server.

[0035] like Figure 1 As shown, the present invention proposes an expandable semi-physical simulation platform for large remote sensing satellites, including a time reference module, a comprehensive expansion and interface unit module, a simulation main control unit, a SpaceWire switch, and a large-capacity server;

[0036] A time reference module, used to provide a unified time reference to drive the simulation platform and the on-board equivalent service simulator, so as to achieve time alignment of multiple on-board equivalent service simulators;

[0037] The time reference module includes NTP time server, frequency reference source and time control board;

[0038] The frequency reference source provides the reference working clock, TTL level and 1PPS signal to the NTP time synchronization server and the time control board;

[0039] The NTP time synchronization server receives external GPS navigation signals, and starts to calibrate the time after receiving the GPS navigation signals and the reference working clock sent by the frequency reference source, and sends the NTP network time to the simulation main control unit through the large-capacity server;

[0040] The timing control board receives the TTL level, reference working clock and 1PPS signal provided by the frequency reference source, generates the frequency reference required by the on-board equivalent service simulator through the on-board waveform shaping circuit and frequency division circuit, and converts the 1PPS signal generated by the frequency reference source into the 1PPS signal required by each on-board equivalent service simulator through the power divider.

[0041] Comprehensive expansion and interface unit module, providing CAN bus interface board, SpaceWire bus interface board and corresponding board drivers;

[0042] The simulation main control unit sends remote control commands to the CAN bus interface board in the integrated expansion and interface unit module. The CAN bus interface board converts the command format and sends it to the onboard equivalent business simulator. After receiving the command, the onboard equivalent business simulator sends telemetry information to the simulation main control unit via the CAN bus interface board; receives the business data of the onboard equivalent business simulator transmitted via the SpaceWire bus board, and realizes the status monitoring of the onboard equivalent business simulator and the accuracy analysis of business data;

[0043] The SpaceWire switch enables the exchange and transmission of business data between the equivalent business simulators, simulation main control units, integrated expansion and interface unit modules on each satellite.

[0044] A large-capacity server is used as the front-end display interface of the simulation main control unit and realizes the remote control function of the simulation main control unit.

[0045] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0046] Example 1

[0047] like Figure 1 The scalable semi-physical simulation platform for large remote sensing satellites of this embodiment mainly includes a time reference module, an integrated expansion and interface unit, a simulation main control unit, a SpaceWire switch and a large-capacity server; among them, various boards of the integrated expansion and interface unit and the simulation main control unit are all carried by a PXI-E bus chassis.

[0048] The main function of the time reference module is to provide a unified time reference driven simulation platform and on-board equivalent service simulator to achieve time alignment of multiple on-board equivalent service simulators, including NTP time synchronization server, time control card and frequency reference source.

[0049] The NTP time synchronization server uses the standard network time broadcast protocol to regularly send time synchronization information. The NTP time synchronization server uses the Beidou Bangtai company's T600-LBDRBP model NTP time synchronization server. The equipment adopts a redundant architecture design. The high-precision clock is directly derived from the atomic clock of each satellite in the Beidou and GPS systems. The local clock source is tamed through signal analysis to achieve the function of accurately maintaining the local clock after the satellite signal is lost.

[0050] The frequency reference source uses a rubidium atomic clock or a high-stability crystal oscillator disciplined by the GNSS system to provide a reference working clock (10MHz clock) and a 1PPS signal to the hardware board of the semi-physical simulation platform.

[0051] Considering that the onboard equipment uses 1PPS mode for time synchronization and the time synchronization requirements under RS422 bus, the design uses the time control card PXI-ST08 to provide the 1PPS signal and time-frequency reference signal required by the onboard equivalent business simulator. The time control board receives the TTL level, 10MHz clock and 1PPS signal provided by the frequency reference source rubidium atomic clock, and generates the 1MHz high-precision clock required by the onboard equivalent business simulator through the on-board waveform shaping circuit and frequency division circuit, a total of 2 channels; the 1PPS signal generated by the rubidium atomic clock is converted into the 1PPS signal required by each onboard equivalent business simulator through the power divider, a total of 6 channels.

[0052] The comprehensive expansion and interface unit module mainly includes CAN bus interface board, SpaceWire bus interface board, data storage board and corresponding board drivers.

[0053] In view of the need to simulate the on-board CAN bus interface of the semi-physical basic simulation platform, the PXI-8512 / 2 board of NI under the PXI-E bus architecture is selected as the CAN bus interface board in this embodiment. The CAN bus interface board is configured as the host mode, and the cable network can be used to design the equivalent on-board CAN bus network. The PXI-8512 / 2 board has dual CAN bus ports and can simulate the dual bus characteristics of CAN / A and CAN / B. The board has a high-speed controller area network (CAN) interface with flexible data rate, and the application development work is completed through the NI-XNET driver.

[0054] The SpaceWire PXI board uses STAR-Dundee's highly efficient board software to support fast sending and receiving of SpaceWire packets directly to the board memory. The board supports high-speed data transmission, injection of various types of errors on demand, acting as a time code server, and highly optimized board software to meet the low latency transmission of SpaceWire packets directly to the board. The board has 4 SpaceWire interfaces and can operate in interface mode or router mode. In router mode, the board is able to route packets between SpaceWire ports and between SpaceWire ports and the PCI bus. In interface mode, the board allows packets to be sent and received independently on each SpaceWire link without routing or logical addressing.

[0055] The data storage board is used to store the original simulation data. Considering the storage expandability, it is equipped with a PXIe-8261 large-capacity data storage card. The board supports 4 drives, 4TB HDD high-speed data storage module, and 250MB / s continuous read and write speed.

[0056] The simulation main control unit contains three functional modules, including the driver module, the business data interaction control module, and the human-computer interaction module. The driver module is mainly based on the PXI-E bus architecture to configure and drive the boards in the integrated expansion and interface unit module, including setting and processing board parameters, sending and receiving board data, etc. The business data interaction control module is mainly used to realize the functions of remote control command reception, telemetry data packaging and distribution, time synchronization, etc. The human-computer interaction module is mainly based on the user's operation on the interface, and generates control instructions to the back-end driver module or business data interaction control module.

[0057] In order to build a SpaceWire network environment that is the same as that on the satellite, the SpaceWire switch in this embodiment uses the SpaceWire Router Mk2S switch. The Router Mk2S provides 8 SpaceWire interfaces, can be used as a time code controller, supports high-speed data transmission, can inject a variety of different types of errors according to usage requirements, and has highly optimized switch software that supports the switch to directly send and receive Spacewire data packets with low latency transmission.

[0058] The large-capacity server is used as the front-end display interface of the simulation main control unit and can realize the remote control function of the simulation main control unit.

[0059] The following uses a typical business scenario as an example to illustrate the business data flow:

[0060] 1. The NTP time synchronization server receives external GPS navigation signals, and the frequency reference source provides 10MHz clock and TTL level to the NTP time synchronization server and the time control board. The NTP time synchronization server starts to calibrate the time after receiving the navigation signal and clock signal, and sends the NTP network time to the simulation main control unit through the large-capacity server. The time control board provides 1MHz frequency reference and 1PPS to the equivalent business simulators on each satellite;

[0061] 2. The simulation main control unit sends remote control commands such as power on and off to the CAN bus interface board in the integrated expansion and interface unit module. The CAN bus interface board converts the command format and sends it to the onboard equivalent business simulator. After receiving the command, the onboard equivalent business simulator sends the telemetry information to the simulation main control unit via the CAN bus interface board;

[0062] 3. The service data between the on-board equivalent service simulators are exchanged and transmitted through the SpaceWire switch by means of logical addressing. At the same time, the service data is sent to the simulation main control unit through the SpaceWire bus card, the service data is parsed and analyzed for accuracy, and the service data and telemetry data are stored through the data storage card;

[0063] 4. The simulation main control unit displays the received telemetry data on the software loaded on the large-capacity server.

[0064] Based on the universal and modular design concept, the present invention designs a semi-physical simulation platform with multiple communication interfaces and expandability. By using this platform and the on-board equivalent business simulator, the closed-loop test of the ground simulation mission and the on-orbit mission simulation of the remote sensing satellite are completed, and various on-board problems are discovered and solved in advance, which effectively improves the development efficiency of the entire satellite.

[0065] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0066] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A scalable semi-physical simulation platform for large remote sensing satellites, characterized in that: It includes time reference module, integrated expansion and interface unit module, simulation main control unit, SpaceWire switch and large-capacity server; A time reference module, used to provide a unified time reference to drive the simulation platform and the on-board equivalent service simulator, so as to achieve time alignment of multiple on-board equivalent service simulators; Comprehensive expansion and interface unit module, providing CAN bus interface board, SpaceWire bus interface board and corresponding board drivers; The simulation main control unit sends remote control commands to the CAN bus interface board in the integrated expansion and interface unit module. The CAN bus interface board converts the command format and sends it to the onboard equivalent business simulator. After receiving the command, the onboard equivalent business simulator sends telemetry information to the simulation main control unit via the CAN bus interface board; receives the business data of the onboard equivalent business simulator transmitted via the SpaceWire bus board, and realizes the status monitoring of the onboard equivalent business simulator and the accuracy analysis of business data; SpaceWire switch, which realizes the exchange and transmission of business data between equivalent business simulators, simulation main control units, integrated expansion and interface unit modules on each satellite; A large-capacity server is used as the front-end display interface of the simulation main control unit and realizes the remote control function of the simulation main control unit.

2. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 1, characterized in that: The various boards of the comprehensive expansion and interface unit and the simulation main control unit are all based on the PXI-E bus chassis.

3. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 1, characterized in that: The time reference module includes an NTP time calibration server, a frequency reference source, and a time control board; The frequency reference source provides the reference working clock, TTL level and 1PPS signal to the NTP time synchronization server and the time control board; The NTP time synchronization server receives external GPS navigation signals, and starts to calibrate the time after receiving the GPS navigation signals and the reference working clock sent by the frequency reference source, and sends the NTP network time to the simulation main control unit through the large-capacity server; The timing control board receives the TTL level, reference working clock and 1PPS signal provided by the frequency reference source, generates the frequency reference required by the on-board equivalent service simulator through the on-board waveform shaping circuit and frequency division circuit, and converts the 1PPS signal generated by the frequency reference source into the 1PPS signal required by each on-board equivalent service simulator through the power divider.

4. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 3, characterized in that: The NTP time synchronization server adopts a redundant architecture design. The high-precision clock is directly derived from the atomic clocks of various satellites in the Beidou and GPS systems. The local clock source is tamed through signal analysis to achieve the function of accurately maintaining the local clock after the satellite signal is lost.

5. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 3, characterized in that: The frequency reference source uses a rubidium atomic clock or a high-stability crystal oscillator tamed by the GNSS system to provide a reference working clock and a 1PPS signal to the NTP time synchronization server and the time control board.

6. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 1, characterized in that: The working modes of the SpaceWire bus interface board include interface mode and router mode. In router mode, the board can route data packets between SpaceWire ports and between SpaceWire ports and PCI bus. In interface mode, the board allows data packets to be sent and received independently on each SpaceWire link without path or logical addressing.

7. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 1, characterized in that: The integrated expansion and interface unit module also includes a data storage board for storing business data and telemetry data from an onboard equivalent business simulator.

8. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 1, characterized in that: The comprehensive expansion and interface unit module reserves an LVDS interface and has the expansion capability of performing LVDS data interaction with an onboard equivalent service simulator.

9. The scalable semi-physical simulation platform for large remote sensing satellites according to claim 1, characterized in that: The simulation main control unit includes a driving module, a business data interaction control module, and a human-computer interaction module; The driver module configures and drives the boards in the integrated expansion and interface unit modules based on the PXI-E bus architecture, including setting and processing board parameters, and sending and receiving board data; Business data interaction control module, which realizes the functions of remote control command reception, telemetry data packaging and distribution, and time synchronization; The human-computer interaction module generates control instructions to the back-end driver module or business data interaction control module based on the user's operations on the interface.

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