Satellite data transmission method, system and computer readable storage medium

Abstract

The application provides a satellite data transmission method and system, which keeps a satellite operation computer PPS and a GNSS receiver PPS synchronized; adopts satellite operation software to divide a clock scheduling 1 second of the satellite operation computer into four periods, which respectively correspond to sending time of a UTC time broadcast data packet, a payload demand information data packet, a payload remote control instruction data packet and a satellite platform key data packet, and sets sending time control strategies of the four data packets; adopts GNSS receiver FPGA software to control sending time of a GNSS receiver B type positioning data packet according to an overall sending time sequence diagram; adopts satellite operation computer FPGA software to set storage and forwarding strategies of the GNSS receiver B type positioning data packet; and according to the sending time control strategies and the storage and forwarding strategies, sends all kinds of data packets of the satellite operation computer to a payload manager through an asynchronous RS422 communication interface to realize satellite data transmission.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite data transmission, in particular to a satellite data transmission method and system based on satellite software and FPGA software and a computer readable storage medium. BACKGROUND

[0002] An artificial satellite is mainly composed of a comprehensive electronic system, a power supply system, a measurement and control system, an attitude and orbit control system, a load manager and related load units. A satellite computer and a load manager are designed to have an asynchronous RS422 communication interface, which is the only channel for the satellite platform to send load instructions and obtain load state data. The exchanged data packet information between the two is as shown in the table. Figure 1 The length and transmission cycle requirements of various data packets sent by the satellite computer to the load manager are shown in Table 1.

[0003] Table 1: Data information table of the satellite computer sending end

[0004]

[0005] In the process of sending various data packets from the satellite computer to the load manager, in order to ensure reliable transmission, the number of transmission channels is usually designed to be increased to achieve this. Such a design not only increases the hardware design cost, but also makes the communication interface and external connection line more complex, and also increases the software design difficulty and system running burden. SUMMARY

[0006] The present application provides a satellite data transmission method and system based on satellite software and FPGA software and a computer readable storage medium to solve the above problems in the prior art.

[0007] The present application is achieved by the following technical solutions.

[0008] According to one aspect of the present application, a satellite data transmission method is provided, which controls the transmission timing of various data packets of a satellite computer at the sending end of an asynchronous RS422 communication interface, comprising:

[0009] The PPS signal of the satellite computer is kept synchronized with the PPS signal of the GNSS receiver;

[0010] The clock scheduling of the satellite computer is divided into four periods by the satellite software;

[0011] The four periods are respectively corresponding to the transmission timing of UTC time broadcast data packets, load demand information data packets, load remote control instruction data packets and satellite platform key data packets, and the transmission timing control strategy of the four kinds of data packets is set;

[0012] The FPGA software of the GNSS receiver is used to control the sending time of the GNSS receiver B-type positioning data packet according to the set sending time sequence diagram;

[0013] The FPGA software of the star computer is used to set the storage and forwarding strategy of the GNSS receiver B-type positioning data packet;

[0014] According to the sending time control strategy of the four kinds of data packets and the storage and forwarding strategy of the GNSS receiver B-type positioning data packet, the star computer sends various data packets to the payload manager through the asynchronous RS422 communication interface, so as to realize satellite data transmission.

[0015] Preferably, the sending time control strategy of the four kinds of data packets comprises:

[0016] The sending time T1 is the sending time of the UTC time broadcast data packet, which is within the set time a after the PPS signal;

[0017] The sending time T2 is the sending frequency of the payload demand information data packet, which is b Hz, i.e. b times per second; wherein, in each second, the first sending time is within the set time range c after the PPS signal; the second sending time is within the set time range e after the set time d after T0, wherein T0 is the whole second time corresponding to the PPS signal; the third sending time is within the set time range g after the set time f after T0; and the fourth sending time is within the set time range i after the set time h after T0;

[0018] The sending time T3 is the sending time of the payload remote control instruction data packet, which is within the set time j after the PPS signal in the first cycle of T0;

[0019] The sending time T5 is the sending time of the satellite platform key data packet, which is within the set time l after the set time k after T0 after the PPS signal.

[0020] Preferably, it further comprises any one or any multiple of the following:

[0021] The value of a is 1 ms;

[0022] The value of b is 4;

[0023] The value of c is 2-10 ms;

[0024] The value of d is 250 ms;

[0025] The value of e is 2-10 ms;

[0026] The value of f is 500 ms;

[0027] The value of g is 2-10 ms;

[0028] said h is 750 ms,

[0029] said i is 2-10 ms;

[0030] said j is 60-150 ms;

[0031] said k is 850 ms;

[0032] said l is 12.2 ms.

[0033] Preferably, the sending timing chart requirement setting comprises:

[0034] setting the sending time control strategy of the UTC time broadcast data packet, the payload demand information data packet, the payload remote control instruction data packet, the satellite platform key data packet, and the GNSS receiver B-type positioning data packet respectively;

[0035] According to the sending time control strategy of each data packet, the overall sending timing is constructed, so that the star software, the star computer FPGA software and the GNSS receiver FPGA software cooperate with each other to complete the setting of the sending timing chart requirement.

[0036] Preferably, the sending time control strategy of the GNSS receiver B-type positioning data packet comprises:

[0037] Sending time T4: the GNSS receiver B-type positioning data packet is sent by the GNSS receiver at a set time m after its PPS signal, a total of n packets of data are sent, and the longest time required for sending is p.

[0038] Preferably, it further comprises any one or any multiple of the following:

[0039] said m is 300 ms;

[0040] said n is 10;

[0041] said p is 146.1 ms.

[0042] Preferably, the setting of the storage and forwarding strategy of the GNSS receiver B-type positioning data packet comprises:

[0043] Setting the sending priority of the star software sending and the star computer FPGA sending; wherein: the star software sending comprises: the UTC time broadcast data packet, the payload demand information data packet, the payload remote control instruction data packet, and the satellite platform key data packet; the star computer FPGA software sending comprises: the GNSS receiver B-type positioning data; the priority of the star software sending is higher than the priority of the star computer FPGA software sending;

[0044] The sending control switch of the asynchronous RS422 communication interface is controlled by the star service software, when the sending is prohibited, the star service computer FPGA software caches the current sending package, and the sending is suspended; when the sending is allowed, all the cached data is re-sent from the cached interrupt package.

[0045] Preferably, further comprising:

[0046] The header and tail check information is set for each type of data package of the star service computer.

[0047] The payload manager FPGA software checks the received data package according to the header and tail check information, and receives and processes the data package when the check is correct.

[0048] Preferably, further comprising:

[0049] The interrupt sending GNSS receiver B type positioning data package will be discarded due to the check failure.

[0050] According to another aspect of the present application, a satellite data transmission system is provided, characterized in that the system is used for controlling the sending time sequence of each type of data package of the star service computer at the sending end of the asynchronous RS422 communication interface, comprising:

[0051] The PPS signal synchronization module is used for keeping the star service computer PPS signal and the GNSS receiver PPS signal in synchronization.

[0052] The star service software sending time control strategy module is used for dividing the clock scheduling 1 second of the star service computer into four periods; the four divided periods are respectively corresponding to the sending time of the UTC time broadcast data package, the payload demand information data package, the payload remote control instruction data package and the satellite platform key data package, and the sending time control strategy of the four types of data packages is set.

[0053] The FPGA software sending time control strategy module is used for controlling the sending time of the GNSS receiver B type positioning data package to the star service computer according to the set sending time sequence diagram requirement by using the GNSS receiver FPGA software, and setting the storage and forwarding strategy of the GNSS receiver B type positioning data package by using the star service computer FPGA software.

[0054] The satellite data transmission module is used for sending each type of data package of the star service computer to the payload manager through the asynchronous RS422 communication interface according to the sending time control strategy of the four types of data packages and the storage and forwarding strategy of the GNSS receiver B type positioning data package, so as to realize the satellite data transmission.

[0055] According to a third aspect of the present application, there is provided a computer readable storage medium having stored thereon a computer program which, when executed by a processor, is adapted to perform the method of any one of the preceding claims.

[0056] Thanks to the technical scheme, the present application has at least one of the following beneficial effects:

[0057] The satellite data transmission method provided by the present application solves the problem of timing control of multiple data transmission sequences on one data transmission channel based on star software and FPGA software, and only through the software strategy of cooperation between the star software and the FPGA software, the requirement of reliable transmission of multiple data on one data channel is met.

[0058] The satellite data transmission method provided by the present application fully utilizes the synchronization characteristics of the PPS clock signal of the GNSS receiver and the PPS clock signal of the star computer, and realizes the function of forwarding various data by using the star software and the FPGA software without increasing external interfaces, and simultaneously realizes the transmission of multiple data on the asynchronous RS422 interface for communication between the star computer and the load manager.

[0059] The satellite data transmission method provided by the present application considers the possibility of transmission conflict between the star software transmission and the FPGA software forwarding according to the high reliability requirement of aerospace, designs a transmission switch of the port, defines a transmission priority, guarantees the timeliness of critical instructions and data, and detects incorrect data through data CRC check to guarantee the integrity of the data.

[0060] The satellite data transmission method provided by the present application realizes reliable transmission of multiple data on a transmission channel with limited hardware resources, and has reference value. BRIEF DESCRIPTION OF DRAWINGS

[0061] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:

[0062] Figure 1 The figure is a data information diagram between the star computer and the load manager.

[0063] Figure 2 The figure is a work flow diagram of the satellite data transmission method in a preferred embodiment of the present application.

[0064] Figure 3 The figure is a data packet transmission timing diagram between the star computer and the load manager in a preferred embodiment of the present application.

[0065] Figure 4 The figure is a schematic diagram of the composition module of the satellite data transmission system in a preferred embodiment of the present application. DETAILED DESCRIPTION

[0066] The embodiments of the present application are described in detail below: the embodiments are implemented on the premise of the technical solutions of the present application, and detailed implementation manners and specific operation processes are given. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application.

[0067] An embodiment of the present application provides a satellite data transmission method, which is based on satellite software and FPGA software, and realizes multiple data transmission between a satellite computer and a load manager and simultaneous storage of large-capacity data on one transmission channel, avoids conflicts, and realizes reliable data transmission in a satellite engineering application.

[0068] In the embodiment, the following interface modules of the asynchronous RS422 interface are mainly involved:

[0069] (1) a sending interface of the satellite software for sending data packet numbers 1, 2, 4 and 5;

[0070] (2) a sending interface of a GNSS receiver B-type positioning data packet of GNSS receiver FPGA software;

[0071] (3) a storage and forwarding interface of the satellite computer FPGA software for GNSS receiver B-type positioning data packets.

[0072] As shown in the figure, the satellite data transmission method based on the satellite software and the FPGA software controls the sending time sequence of various data packets of the satellite computer at the sending end of the asynchronous RS422 communication interface, including: Figure 2 S1, keeping the satellite computer PPS signal and the GNSS receiver PPS signal in synchronization;

[0073] S2, dividing a 1-second clock schedule of the satellite computer into four periods by using the satellite software;

[0074] S3, setting the sending time control strategy of the four data packets according to the sending time of the UTC time broadcast data packet, the load demand information data packet, the load remote control instruction data packet and the satellite platform key data packet;

[0075] S4, controlling the sending time of the GNSS receiver B-type positioning data packet (the sending control of the GNSS receiver to the satellite computer) according to the set sending time sequence diagram by using the GNSS receiver FPGA software;

[0076] S5, setting the sending time control strategy of the four data packets according to the sending time of the UTC time broadcast data packet, the load demand information data packet, the load remote control instruction data packet and the satellite platform key data packet;

[0077] S5, using the star computer FPGA software, setting the storage and forwarding strategy of the GNSS receiver B type positioning data packet;

[0078] S6, according to the sending time control strategy of the four kinds of data packets and the storage and forwarding strategy of the GNSS receiver B type positioning data packet, the star computer sends various data packets to the payload manager through the asynchronous RS422 communication interface, and realizes satellite data transmission.

[0079] In a preferred embodiment of S3, the sending time control strategy of the four kinds of data packets is set, including:

[0080] Sending time T1: the sending time of UTC time broadcast data packet is within a set time a after PPS signal;

[0081] Sending time T2: the sending frequency of payload demand information data packet is b Hz, that is, b times per second; wherein, in each second, the first sending time is within a set time range c after PPS signal; the second sending time is within a set time range e after T0+ set time d, wherein T0 is the whole second time corresponding to PPS signal; the third sending time is within a set time range g after T0+ set time f; the fourth sending time is within a set time range i after T0+ set time h;

[0082] Sending time T3: the payload remote control command data packet runs in the first cycle of T0, and the sending time is within a set time j after PPS signal;

[0083] Sending time T5: the sending time of satellite platform key data packet is within a set time l after T0+ set time k after PPS signal.

[0084] In a specific application example of S3, the sending time control strategy of the four kinds of data packets is set, including:

[0085] Sending time T1: the sending time of UTC time broadcast data packet is within 1 ms after PPS signal;

[0086] Sending time T2: the sending frequency of payload demand information data packet is 4 Hz, that is, 4 times per second; wherein, in each second, the first sending time is within 2 ms to 10 ms after PPS signal; the second sending time is within 2 ms to 10 ms after T0+ 250 ms, wherein T0 is the whole second time corresponding to PPS signal; the third sending time is within 2 ms to 10 ms after T0+ 500 ms; the fourth sending time is within 2 ms to 10 ms after T0+ 750 ms;

[0087] Sending time T3: the payload remote control command data packet runs in the first cycle of T0, and the sending time is within 60 ms to 150 ms after PPS signal;

[0088] Sending time T5: the sending time of the satellite platform key data packet is within 12.2 ms after T0+850 ms after the PPS signal.

[0089] In a preferred embodiment of S4, the set sending timing diagram requirements include:

[0090] The sending time control strategy of the UTC time broadcast data packet, the payload demand information data packet, the payload remote control instruction data packet, the satellite platform key data packet, and the GNSS receiver B-class positioning data packet is set respectively;

[0091] According to the sending time control strategy of each data packet, the overall sending timing is constructed, so that the star software, the star computer FPGA software and the GNSS receiver FPGA software cooperate with each other to complete the setting of the sending timing diagram requirements.

[0092] In a preferred embodiment of S4, the sending time control strategy of the GNSS receiver B-class positioning data packet includes:

[0093] Sending time T4: the GNSS receiver B-class positioning data packet is sent by the GNSS receiver at a set time m after its PPS signal, a total of n packets of data are sent, and the longest time required for sending is p.

[0094] In a specific application example of S4, the sending time control strategy of the GNSS receiver B-class positioning data packet includes:

[0095] Sending time T4: the GNSS receiver B-class positioning data packet is sent by the GNSS receiver at 300 ms after its PPS signal, a total of 10 packets of data are sent, and the longest time required for sending is 146.1 ms (this time is obtained by calculation: 255*11 / 230400*10).

[0096] In a preferred embodiment of S5, the storage and forwarding strategy for the GNSS receiver B-class positioning data packet is set, including:

[0097] The sending priority of the star software sending and the star computer FPGA software sending is set; wherein: the star software sending includes: the UTC time broadcast data packet, the payload demand information data packet, the payload remote control instruction data packet, and the satellite platform key data packet; the star computer FPGA software sending includes: the GNSS receiver B-class positioning data; the priority of the star software sending is higher than the priority of the star computer FPGA software sending;

[0098] The sending control switch of the asynchronous RS422 communication interface is set, and the sending control switch is controlled by the star service software; when the sending is prohibited, the star service computer FPGA software caches the current sending package, and the sending is suspended; when the sending is allowed, all the cached data is re-sent from the cached interrupt package.

[0099] In a preferred embodiment of S6, further comprising:

[0100] The header and tail check information of each type of data package of the star service computer is set.

[0101] The payload manager FPGA software checks the received data package according to the header and tail check information, and receives and processes the data package when the check is correct.

[0102] In the above preferred embodiment, further comprising:

[0103] The interrupt sending GNSS receiver B type positioning data package will be discarded due to the check failure.

[0104] The working principle of the method provided by the above embodiments of the application is further described below. In some embodiments of the application:

[0105] Through the GNSS time calibration, the clock of the star service computer is consistent with the clock of the GNSS receiver, that is, the star service computer PPS signal is kept synchronous with the GNSS PPS signal.

[0106] The clock scheduling of the star service software is divided into 4 periods every 1 second, and each period is 250 milliseconds.

[0107] The star service software comprehensively considers the sending time of the five types of data packages and the length of the sending time, and the data package numbers 1, 2, 4 and 5 (see Table 1 for details) are reasonably sent by the star service software design timing, and the sending time control is performed according to the 4 periods divided by the star service software clock scheduling.

[0108] The GNSS receiver B-class positioning data packet is sent to the satellite computer through another RS422 interface, and the data amount is large. It needs to be forwarded to the payload manager storage through the satellite computer, and then downloaded to the ground through the data transmission channel. If the GNSS receiver B-class positioning data packet uses the method of storage and forwarding of the satellite software, it will occupy a lot of system resources. The time sequence control of the Tiangong-1 software task is very strict. Once disturbed, it can lead to task time sequence confusion, task exception and interruption, and the satellite platform does not need the GNSS single machine B-class positioning data for related processing. Therefore, the cost is the waste of system resources. After comprehensive consideration, the computer receives the asynchronous serial port data connected with the GNSS receiver B-class positioning data packet, and stores it. When the satellite software does not occupy the asynchronous RS422 communication interface of the computer and the payload manager, the GNSS receiver B-class positioning data packet is forwarded. The storage and forwarding strategy of the satellite computer FPGA software is adopted. The GNSS single machine FPGA software controls the sending of the GNSS receiver B-class positioning data packet according to the overall sending time sequence diagram, and avoids the sending conflict probability when the satellite software sends and the computer FPGA software forwards.

[0109] Through time sequence control, the possibility of sending conflict can be basically avoided, but from the software design reliability, the conflict situation still needs to be considered. For this reason, the satellite software sending and the computer FPGA software sending are designed with sending priority. The former has higher priority. The sending control switch of the asynchronous RS422 interface communication is designed. Only the satellite software can control the switch, which ensures that the satellite platform to the load instruction and data are not affected. Once the sending is prohibited, the computer FPGA software needs to buffer the current sending packet and suspend sending. When the sending is allowed, the buffered all data is re-sent from the interrupted packet.

[0110] The sending data are all with packet header and tail check information. The payload manager FPGA software needs to check the received data. Only the correct check can be received and processed. The GNSS receiver B-class positioning data packet interrupted in sending is discarded because of check failure.

[0111] As shown in Figure 3 , it is the sending time sequence diagram of various data packets. The sending time is specifically explained as follows:

[0112] Sending time T1: UTC time broadcast data packet sent by satellite software within 1ms after PPS.

[0113] Sending time T2: the frequency of the payload demand information data packet sent by the satellite service software is 4Hz (4 times per second). The first sending time in 1 second is within 2ms to 10ms after PPS; the second time is within 2ms to 10ms after T0+250ms (T0 is the whole second time corresponding to the PPS signal); the third time is within 2ms to 10ms after T0+500ms; and the fourth time is within 2ms to 10ms after T0+750ms.

[0114] Sending time T3: the payload remote control instruction packet is sent by the satellite service software in the remote control process, and is sent in the first cycle of T0. The satellite service software is sent within 60ms to 150ms after PPS.

[0115] Sending time T4: the GNSS receiver B-type positioning data packet is sent by the GNSS receiver at about 300ms after PPS. A total of 10 data packets are sent, and the longest time required for sending is 146.1ms.

[0116] Sending time T5: the satellite platform key packet is sent by the satellite service software at about T0+850ms after PPS, and is sent within 12.2ms.

[0117] The following takes the Tiangong-1 experimental satellite as an example to perform ground testing and on-orbit testing, and the performance of the method provided by the above embodiment of the application is verified as follows:

[0118] During the ground development stage of the Tiangong-1 satellite, the technical solution provided by the above embodiment of the application is applied to perform strict output transmission testing. The multiple testing results prove that the technical solution provided by the above embodiment of the application can meet the interface communication requirements between the satellite service computer and the payload manager, and the multiple data packets are normally sent, and the payload remote control instruction is executed correctly.

[0119] During the on-orbit task stage of the Tiangong-1 satellite after successful launching, the payload manager works normally, and the instruction is executed correctly. In the payload data transmitted by the data transmission channel, the ground analyzes the GNSS receiver B-type positioning data packet, and the data is correct and effective without abnormal error code.

[0120] Through the above testing, it is proved that the technical solution provided by the above embodiment of the application is successfully applied in the engineering practice of the Tiangong-1 satellite. During the ground development and on-orbit task of the Tiangong-1 satellite, the normal and correct transmission of data between the satellite service computer and the payload manager is realized. The timing control strategy of the method provided by the above embodiment of the application is correct and reliable, and is effective.

[0121] An embodiment of the application provides a satellite data transmission system.

[0122] As Figure 4As shown, the satellite data transmission system provided by the embodiment is used for controlling the sending timing of various data packets of the satellite computer at the sending end of the asynchronous RS422 communication interface, and comprises:

[0123] A PPS signal synchronization module, which is used for keeping the PPS signal of the satellite computer and the PPS signal of the GNSS receiver in synchronization;

[0124] A satellite software sending timing control strategy module, which is used for dividing the clock scheduling of the satellite computer into 4 periods, and setting the sending timing control strategy of the four kinds of data packets according to the sending timing of the UTC time broadcast data packet, the payload demand information data packet, the payload remote control instruction data packet and the satellite platform key data packet in the 4 periods respectively;

[0125] An FPGA software sending timing control strategy module, which is used for controlling the sending timing of the GNSS receiver B-type positioning data packet to the satellite computer according to the set sending timing diagram requirement by using the FPGA software of the GNSS receiver, and setting the storage and forwarding strategy of the GNSS receiver B-type positioning data packet by using the FPGA software of the satellite computer;

[0126] A satellite data transmission module, which is used for sending various data packets of the satellite computer to the payload manager through the asynchronous RS422 communication interface according to the sending timing control strategy of the four kinds of data packets and the storage and forwarding strategy of the GNSS receiver B-type positioning data packet, and realizing satellite data transmission.

[0127] It should be noted that the steps in the method provided by the present application can be realized by using corresponding modules, devices, units and the like in the system, and those skilled in the art can realize the composition of the system by referring to the technical scheme of the method, that is, the embodiments in the method can be understood as preferred examples of constructing the system, and will not be described here.

[0128] An embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor and can be used for executing the method in any one of the above-mentioned embodiments of the present application.

[0129] Optionally, the computer program, computer instruction and the like described above can be stored in one or more memories in a partitioned manner. And the computer program, computer instruction, data and the like described above can be called by the processor. Wherein:

[0130] The memory is used for storing programs; the memory can include volatile memory (English: volatile memory), such as random access memory (English: random-access memory, abbreviation: RAM), such as static random access memory (English: static random-access memory, abbreviation: SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviation: DDR SDRAM) and the like; the memory can also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory is used to store computer programs (such as application programs, functional modules and the like for implementing the above method), computer instructions and the like, and the above computer programs, computer instructions and the like can be stored in one or more memories. And the above computer program, computer instruction, data and the like can be called by the processor.

[0131] The processor is used for executing the computer program stored in the memory to realize each step in the method or each module of the system. For details, please refer to the related description in the above method and system embodiments.

[0132] The processor and the memory can be an independent structure, or an integrated structure. When the processor and the memory are independent structures, the memory and the processor can be coupled and connected through a bus.

[0133] Those skilled in the art know that, in addition to implementing the system and each device thereof provided by the present application in the form of pure computer readable program code, the system and each device thereof provided by the present application can also be realized in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps to achieve the same functions. Therefore, the system and each device thereof provided by the present application can be considered as a hardware component, and the devices included therein for realizing various functions can also be considered as structures within the hardware component; the devices for realizing various functions can also be considered as both software modules for realizing methods and structures within hardware components.

[0134] The satellite data transmission method, system, and computer-readable storage medium provided in the above embodiments of the present invention, based on satellite service software and FPGA software, fully utilize the synchronization characteristics of the GNSS receiver PPS clock signal and the satellite service computer PPS clock signal. Without adding external interfaces, various data forwarding functions are implemented using the satellite service software and FPGA software. Multiple data streams are simultaneously transmitted on the asynchronous RS422 interface between the satellite service computer and the payload manager. Considering the high reliability requirements of aerospace and the potential for transmission conflicts between the satellite service software's transmission and the FPGA's high-capacity forwarding, a port transmission switch is designed, and transmission priorities are defined to ensure the timeliness of critical instructions and data. Furthermore, incorrect data is detected through data CRC verification, ensuring data integrity. Reliable multi-channel data transmission is achieved on hardware-restricted transmission channels, providing valuable reference and guidance.

[0135] Any matters not covered in the above embodiments of the present invention are well-known in the art.

[0136] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A satellite data transmission method, characterized in that, Controlling the transmission timing of various data packets from the space station computer at the asynchronous RS422 communication interface transmitter, including: Keep the PPS signal of the satellite computer synchronized with the PPS signal of the GNSS receiver; Using satellite management software, the clock scheduling of the satellite management computer is divided into 4 cycles per second; The four cycles are divided into four periods, corresponding to the transmission timing of UTC time broadcast data packets, payload demand information data packets, payload remote control command data packets, and satellite platform critical data packets, respectively. Transmission timing control strategies for these four types of data packets are set. These strategies include: Transmission time T1: The transmission time of the UTC time broadcast data packet is within a set time 'a' after the PPS signal from the space agency computer; Transmission time T2: The payload demand information data packet transmission frequency is bHz, that is, b times per second; wherein, within each second, the first transmission time is within a set time range c after the PPS signal from the satellite computer; the second transmission time is within a set time range e after T0 + a set time d, where T0 is the whole second corresponding to the PPS signal from the satellite computer; the third transmission time is within a set time range g after T0 + a set time f; the fourth transmission time is within a set time range i after T0 + a set time h. Transmission time T3: The payload remote control command data packet runs in the first cycle of T0, and the transmission time is within the set time j after the PPS signal from the space station computer; Transmission time T5: The transmission time of the critical data packets of the satellite platform is within a set time l after the PPS signal from the satellite service computer (T0 + set time k). The timing of the transmission of Class B positioning data packets by the GNSS receiver is controlled by the FPGA software of the GNSS receiver according to the set transmission timing diagram requirements. The storage and forwarding strategy for Class B positioning data packets from the GNSS receiver was set using the FPGA software of the satellite computer. Based on the timing control strategy for sending the four types of data packets and the storage and forwarding strategy for the Class B positioning data packets of the GNSS receiver, the various data packets of the satellite computer are sent to the payload manager through the asynchronous RS422 communication interface to realize satellite data transmission.

2. The satellite data transmission method according to claim 1, characterized in that, It also includes any one or more of the following: The value of 'a' is 1ms. The value of b is 4; The value of c ranges from 2 to 10 ms; The value of d is 250ms; The value of e ranges from 2 to 10 ms; The value of f is 500ms; The value of g is 2 to 10 ms; The value of h is 750ms. The value of i ranges from 2 to 10 ms; The value of j ranges from 60 to 150 ms; The value of k is 850ms; The value of l is 12.2ms.

3. The satellite data transmission method according to claim 1, characterized in that, The settings for the transmission timing diagram include: Set transmission timing control strategies for UTC time broadcast data packets, payload requirement information data packets, payload remote control command data packets, satellite platform key data packets, and GNSS receiver Class B positioning data packets respectively; Based on the timing control strategy for sending each data packet, an overall transmission timing sequence is constructed, enabling the space service software, space service computer FPGA software, and GNSS receiver FPGA software to cooperate with each other and complete the setting of the transmission timing diagram requirements.

4. The satellite data transmission method according to claim 3, characterized in that, The timing control strategy for transmitting Class B positioning data packets by the GNSS receiver includes: Transmission time T4: The GNSS receiver's Class B positioning data packets are transmitted by the GNSS receiver at a predetermined time m after its PPS signal. A total of n data packets are transmitted, and the maximum time required to complete the transmission is p.

5. The satellite data transmission method according to claim 4, characterized in that, It also includes any one or more of the following: The value of m is 300ms; The value of n is 10; The value of p is 146.1ms.

6. The satellite data transmission method according to claim 1, characterized in that, The setting of the storage and forwarding strategy for GNSS receiver Class B positioning data packets includes: The transmission priorities of the satellite service software and the satellite service computer FPGA software are set; wherein: the data packets transmitted by the satellite service software include: UTC time broadcast data packets, payload requirement information data packets, payload remote control command data packets, and satellite platform key data packets; the data packets transmitted by the satellite service computer FPGA software include: GNSS receiver Class B positioning data packets; the priority of the data packets transmitted by the satellite service software is higher than the priority of the data packets transmitted by the satellite service computer FPGA software; A transmit control switch for the asynchronous RS422 communication interface is configured. The transmit control switch is controlled by the space service software. When transmit is prohibited, the space service computer FPGA software buffers the current transmit packet and suspends transmit. When transmit is permitted, all buffered data is retransmitted starting from the buffered interrupt packet.

7. The satellite data transmission method according to any one of claims 1-6, characterized in that, Also includes: Set header and trailer checksum information for all types of data packets from the spaceborne computer; The load manager FPGA software verifies the received data packets based on the header and trailer verification information, and receives and processes the data packets when the verification is successful.

8. The satellite data transmission method according to claim 7, characterized in that, Also includes: GNSS receivers that interrupt transmission of Class B positioning data packets will discard them due to verification failure.

9. A satellite data transmission system, characterized in that, The system is used to control the transmission timing of various data packets from the space station computer at the asynchronous RS422 communication interface transmitter, including: The PPS signal synchronization module is used to keep the PPS signal of the satellite computer synchronized with the PPS signal of the GNSS receiver. The satellite operations software transmission timing control strategy module divides the satellite operations computer's clock scheduling from one second into four cycles. These four cycles correspond to the transmission timing of UTC time broadcast data packets, payload demand information data packets, payload remote control command data packets, and satellite platform critical data packets, respectively. The module sets transmission timing control strategies for these four types of data packets, including: Transmission time T1: The transmission time of the UTC time broadcast data packet is within a set time 'a' after the PPS signal from the space agency computer; Transmission time T2: The payload demand information data packet transmission frequency is bHz, that is, b times per second; wherein, within each second, the first transmission time is within a set time range c after the PPS signal from the satellite computer; the second transmission time is within a set time range e after T0 + a set time d, where T0 is the whole second corresponding to the PPS signal from the satellite computer; the third transmission time is within a set time range g after T0 + a set time f; the fourth transmission time is within a set time range i after T0 + a set time h. Transmission time T3: The payload remote control command data packet runs in the first cycle of T0, and the transmission time is within the set time j after the PPS signal from the space station computer; Transmission time T5: The transmission time of the critical data packets of the satellite platform is within a set time l after the PPS signal from the satellite service computer (T0 + set time k). The FPGA software transmission timing control strategy module uses the GNSS receiver FPGA software to control the transmission timing of GNSS receiver Class B positioning data packets to the satellite computer according to the set transmission timing diagram requirements; and uses the satellite computer FPGA software to set the storage and forwarding strategies for GNSS receiver Class B positioning data packets. The satellite data transmission module, based on the timing control strategy for sending the four types of data packets and the storage and forwarding strategy for the Class B positioning data packets of the GNSS receiver, sends various data packets from the satellite computer to the payload manager via an asynchronous RS422 communication interface, thereby realizing satellite data transmission.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, this program can be used to perform the method of any one of claims 1-8.

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