CN114157339A - Star affair computer and satellite system - Google Patents

Abstract

The invention relates to a satellite computer and a satellite system, which comprise a host, wherein the host comprises a power supply conversion module, a main control module and an interface module; the power supply conversion module is used for power supply protection and power supply conversion so as to stably supply power to the main control module and the interface module; the main control module comprises a main control chip; the interface module comprises a JTAG enhanced driving unit; the JTAG enhanced driving unit is connected with a JTAG interface of the main control chip and is used for enhancing the signal intensity of JTAG signals. By arranging the JTAG enhancement driving unit, the invention can weaken the influence of ground static electricity, on-satellite radiation and single ions on the JTAG interface of the main control chip, simultaneously improve the stability of JTAG signal transmission, improve the reliability of a satellite system and improve the product competitiveness.

Description

A satellite computer and satellite system

technical field

The invention relates to the technical field of satellites, in particular to a satellite service computer and a satellite system.

Background technique

The commercialization of spaceflight is showing an explosive development trend all over the world. A large number of commercial satellites have been developed and launched, most of which are microsatellites under 100 kilograms, covering communication, remote sensing, technology testing and other fields. The development cycle of microsatellites is short. In the full-cycle development process of satellite products, the quality and reliability requirements of microsatellites are much looser than those of traditional satellites. The design life of microsatellites is usually 1 year under the condition of irradiated by the space environment.

As the brain of satellite communication control, the satellite computer is the core part of the satellite electronic system. The satellite computer mainly completes the management tasks of each sub-system and each single machine on the satellite. Due to the limitations of weight, size and power consumption, the satellite computer needs to be highly integrated, simplify the hardware system, and need to have high reliability and flexibility. It is an important support for realizing platform functions and completing satellite payload tasks.

The ground test interface of the traditional star service computer will use the 422 bus or other communication bus methods to reserve the remote control telemetry function of the information on the satellite, and the JTAG debugging function of the star service computer main control. But it only leads to its own single machine. Once the entire satellite is synthesized and capped, if the software of each single unit in the satellite still needs to be updated, the satellite needs to be removed, resulting in rework, and a heavy price will be paid in terms of progress and quality. The applicant found that although some low-orbit commercial satellites choose to directly lead the ground test interface to the star catalog, they are still limited by the reliability of the interface and the signal integrity problems caused by the ultra-long cables in the satellite. For example, the key signals such as JTAG include TMS, TCK, TDO, TDI, NTRST, VCC and GND at least 6 TTL or CMOS single-ended signals. First, after long-distance transmission through 4-10m cables in the satellite, the signal will be serious Distortion, the JTAG function cannot be enabled; the second is that due to the inconsistent level of different JTAG interfaces, if the JTAG downloader with mismatched levels is misused, there is a risk of burning the single-machine main control chip.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a satellite service computer and satellite system, which can improve the stability of JTAG signal transmission while weakening the influence of ground static electricity, on-board radiation and single ion on the JTAG interface of the main control chip, Improve the reliability of satellite systems and enhance product competitiveness.

In order to achieve the above object, an embodiment of the present invention provides a star service computer. As an implementation manner, the star service computer includes a host computer, and the host computer includes a power conversion module, a main control module, and an interface module; wherein,

The power conversion module is used for power protection and power conversion to stably supply power to the main control module and the interface module;

The main control module includes a main control chip;

The interface module includes a JTAG enhanced drive unit;

Wherein, the JTAG enhancement driving unit is connected with the JTAG interface of the main control chip for enhancing the signal strength of the JTAG signal.

As one of the implementation manners, the JTAG enhanced driving unit further includes a power supply selection circuit, and the power supply selection circuit is used to select and adapt the level of the external JTAG downloader.

As an implementation manner, the satellite service computer further includes a first shielded connector, the first shielded connector is connected with the JTAG enhanced driving unit, and is used for shielding the internal wiring of the satellite system when transmitting the JTAG signal. interfere with the signal.

As one of the implementation manners, the JTAG enhanced driving unit is also used for transparently transmitting the remote control signal and telemetry signal of the satellite service computer.

As one embodiment, the power conversion module includes: an electronic fuse circuit, an EMI filter and a DC/DC switch circuit, and the electronic fuse circuit is connected to the DC/DC switch circuit through the EMI filter ;in,

The electronic fuse circuit is used for power protection;

the EMI filter for signal filtering;

The DC/DC switch circuit is used for power conversion.

As an implementation manner, the model of the main control chip is the SOC of the Smartfusion2 series; the main control module further includes a storage unit, a clock unit and a watchdog unit, the storage unit, the clock unit and the watchdog unit. The watchdog unit is respectively connected with the main control chip; wherein,

The storage unit includes FLASH, SRAM and DDR.

As one of the implementation manners, the interface module further includes an interface level conversion unit and an interface unit, and the interface level conversion unit is connected with the interface unit; wherein,

The interface unit includes an RS422 transceiver interface, an OC command output interface, and a CAN interface, and each interface adopts an active-standby double insurance design.

As one embodiment, the star service computer further includes at least one backup machine, the structure of the backup machine is the same as that of the main machine, and a multi-mode redundant design is formed.

Based on the same inventive concept, an embodiment of the present invention further provides a satellite system, where the satellite system includes the satellite service computer described in any of the foregoing embodiments.

As one of the implementation manners, the satellite system further includes a second shielded connector, which is connected to the satellite service computer for shielding interference signals outside the satellite system when transmitting JTAG signals .

To sum up, the satellite service computer and satellite system provided by the embodiments of the present invention include a host, and the host includes a power conversion module, a main control module, and an interface module; wherein, the power conversion module is used for power protection and power conversion, and is used for the main control The module and the interface module provide stable power supply; the main control module includes a main control chip; the interface module includes a JTAG enhanced drive unit; wherein, the JTAG enhanced drive unit is connected to the JTAG interface of the main control chip for enhancing the signal strength of the JTAG signal. The invention can improve the stability of JTAG signal transmission, improve the reliability of the satellite system, and improve product competition while weakening the influence of ground static electricity, on-board radiation and single ions on the JTAG interface of the main control chip by setting the JTAG enhanced driving unit. force.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

FIG. 1 is a structural block diagram of a star service computer according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a JTAG enhanced driver unit according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a specific structure of a star service computer according to an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a GNSS module provided by an embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a satellite system according to an embodiment of the present invention.

Detailed ways

In order for those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first", "second" and the like in the description, claims and the above drawings of the present invention are used to distinguish similar objects, but are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed steps or units, but may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Herein, one element, port, component or part is "connected" or "connected" with another element, port, component or part, it can be understood as a direct electrical connection, or it can also be understood as an indirect electrical connection with intermediate elements . Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

Please refer to FIG. 1 . FIG. 1 is a structural block diagram of a star service computer according to an embodiment of the present invention. As shown in FIG. 1, the star service computer includes a host computer 10, and the host computer 10 includes a power conversion module 11, a main control module 12 and an interface module 13; the power conversion module 11 is used for power protection and power conversion, and is used for the main control module 12 and The interface module 13 provides stable power supply; the main control module 12 includes a main control chip 120; the interface module 13 includes a JTAG enhanced drive unit 130; wherein the JTAG enhanced drive unit 130 is connected to the JTAG interface of the main control chip 120 for enhancing the JTAG signal signal strength.

Specifically, the power conversion module 11 converts the voltage required by the main control module 12 and the interface module 13 by receiving the primary power bus voltage input by the satellite energy board, such as 1.2V, 1.8V, 2.5V, 3.3V, 5V. The main control module 12 is the core of the satellite computer, and is responsible for processing and arranging all the commands on the satellite system. The interface module 13 provides various interface types to realize communication and data interaction with various subsystems and loads on the satellite. The main control module 12 includes a main control chip 120, and the interface module 13 includes a JTAG enhanced drive unit 130, which is connected to the JTAG interface of the main control chip 120 for enhancing the signal strength of the JTAG signal input to the JTAG interface. When the JTAG interface of the main control chip 120 is brought out to the star catalog (ie, the surface of the satellite system) to facilitate the realization of the JTAG debugging function after synthesizing and capping the entire satellite, the super-long cable in the satellite will cause signal integrity problems. For example, the key signals such as JTAG include TMS, TCK, TDO, TDI, NTRST, VCC and GND at least 6 TTL or CMOS single-ended signals. After long-distance transmission through the 4-10m cable in the satellite, the signal will be seriously distorted. The JTAG function could not be enabled. In this embodiment, by adding a first-level driving unit, the stability of the JTAG signal can be improved, and after the JTAG enhanced driving unit 130 is added, the JTAG interface of the main control chip 120 of the satellite internal affairs computer is not directly exposed, and the ground is also weakened. The effects of static electricity, on-star radiation, and single ions on it.

Please refer to FIG. 2 , which is a schematic structural diagram of a JTAG enhanced driving unit 130 according to an embodiment of the present invention. As shown in FIG. 2 , the JTAG enhanced driving unit 130 further includes a power supply selection circuit, and the power supply selection circuit is used to select and adapt the level of the external JTAG downloader.

Specifically, the JTAG enhanced drive unit 130 includes a JTAG drive circuit and a power supply selection circuit. The JTAG drive circuit is used to enhance the signal strength of the JTAG signal input to the JTAG interface, and the power supply selection circuit of the JTAG enhanced drive unit 130 is the external interface VCC power supply selection circuit. The terminal can be fully adapted to different levels of the external JTAG downloader, such as 1.8V, 2.5V, and 3.3V, to eliminate the risk of damage to the main control chip 120 caused by selecting the wrong JTAG downloader with different voltages.

In one embodiment, the JTAG enhanced driving unit 130 is also used to transparently transmit the remote control signal and telemetry signal of the star service computer.

Please refer to FIG. 3 , which is a schematic diagram of a specific structure of a star service computer according to an embodiment of the present invention. As shown in FIG. 3 , in one embodiment, the power conversion module 11 includes: an electronic fuse circuit, an EMI filter and a DC/DC switch circuit, and the electronic fuse circuit is connected to the DC/DC switch circuit through the EMI filter. Among them, the electronic fuse circuit is used for power protection, the EMI filter is used for signal filtering, and the DC/DC switch circuit is used for power conversion.

Specifically, the power conversion module 11 of this embodiment selects an integrated electronic fuse circuit for power protection. For example, using the integrated electronic fuse chip TPS25944, the device body area is only 4mm × 3mm. The peripheral circuit built with the TPS25944 chip has functions such as overcurrent fuse, current limit, current monitoring, overvoltage protection, undervoltage protection, and output voltage slow start. The power conversion module 11 converts the voltage required by the main control module 12 and the interface module 13 to the voltage required by the main control module 12 and the interface module 13 through the switching power supply DC/DC after passing through current limiting, surge suppression, and EMI filter by receiving the primary power bus voltage input by the satellite energy board. For example 1.2V, 1.8V, 2.5V, 3.3V, 5V. It is also possible to supply the required voltage to the analog section through a linear power supply LDO. The electronic fuse circuit is used in the power conversion module 11 of this embodiment, which can set the thresholds for undervoltage, overvoltage, overcurrent, dVo/Dt slow start slope, power supply normal and inrush current protection, and also provide accurate current Monitor output functions. A first-level EMI filter is added between EFUSE (electronic fuse circuit) and DC/DC, which can effectively filter the interference of the satellite bus voltage to each sub-system, and also prevent the power supply interference on each sub-system from adversely affecting the satellite bus voltage. . And considering the area of the hardware PCB printed board, compared with the traditional satellite system design, the traditional satellite system achieves the same functions as above, and the PCB area is about 60mm×20mm. After using the electronic fuse circuit, the area is reduced by more than 90%, and the cost is also greatly reduced.

In one embodiment, the model of the main control chip 120 is the SOC of the Smartfusion2 series; the main control module 12 also includes a storage unit, a clock unit and a watchdog unit, and the storage unit, the clock unit and the watchdog unit are respectively connected with the main control chip 120. connection; wherein, the storage unit includes FLASH, SRAM and DDR.

Specifically, in this embodiment, the main control chip 120 of the star service computer is an industrial-grade Microsemi Smartfusion2 series SOC. Smartfusion2 series SOC has the characteristics of low power consumption, high performance, rich logic resources, etc., and the price is relatively low and easy to obtain. The chip integrates a system-level FPGA, a 166MHz ARM Cortex-M3 processor, security processing accelerator, DSP module, SRAM, eNVM and high-performance communication interface. On the basis of common peripherals such as SRAM and PLL, it integrates a high-speed multiplier , with peripheral interfaces such as DDR2/3, CAN, USB, and Gigabit Ethernet, which can meet the needs of comprehensive electronic external interfaces. As an industrial-grade device, it has a single-ion locking index SEL≥22.5MeV-cm2/mg, which can effectively cope with the complex irradiation environment in the aerospace environment. And as a FLASH type SOC, it has a certain immunity to the radiation of the aerospace environment. In order to achieve a more reliable design goal, a watchdog unit is additionally designed to monitor the running status of the main control chip 120 of the star service computer. For example, MAX706 military temperature grade chip is selected. If the unit cannot receive the dog feeding signal sent by the main control chip 120, the watchdog unit will have "dog bite", and automatically reset and reload the program of the main control unit of the star service computer in time.

Please refer to FIG. 3 and FIG. 4 in combination. FIG. 4 is a schematic structural diagram of a GNSS module provided by an embodiment of the present invention. As shown in FIG. 3 and FIG. 4 , the main control module 12 further includes a GNSS module, which is connected to the main control chip 120. The GNSS module includes a radio frequency input interface RF_IN, a power input interface VCC, serial communication interfaces TXD and RXD (TXD1, RXD1 , TXD2, RXD2), reset signal interface RESET, and pulse-per-second signal interface PPS.

Specifically, the GNSS module includes a pre-RF processing unit, a baseband platform, a temperature-compensated crystal oscillator unit, and a power supply unit. The power supply unit supplies power to the pre-RF processing unit, the baseband platform, and the temperature-compensated crystal oscillator unit. The crystal oscillator unit is connected with the baseband platform. The GNSS module only has the RF input interface RF_IN, the power input interface VCC, the serial communication interfaces TXD and RXD (TXD1, RXD1, TXD2, RXD2, the serial communication interface backup design), the reset signal interface RESET, and the second pulse signal interface PPS. The GNSS module in this embodiment is an ASIC chip module, which is designed for general industrial use. The pin to pin can be replaced by a module with the same frequency point and similar function in situ, so as to ensure the convenient maintenance of the GNSS module to the greatest extent. Using this GNSS module, the RF input interface RF_IN can be directly connected to the satellite navigation antenna, the module can complete signal down-conversion, AGC, VGA, AD conversion and other processing, as well as 12-channel GPS L1CA code navigation signal, 12-channel BD B1C code Real-time capture, tracking and positioning calculation of navigation signals, and finally output data positioning data and time information through the serial port, and output 1PPS time synchronization signal. Using this GNSS module not only reduces the area and weight to a great extent.

In one embodiment, the interface module 13 further includes an interface level conversion unit and an interface unit, and the interface level conversion unit is connected with the interface unit; wherein, the interface unit includes: an RS422 transceiver interface, an OC command output interface and a CAN interface. Interfaces are designed with active and standby dual insurance.

Specifically, the main control chip 120 performs interface management, and the interface level conversion unit is used to perform interface level conversion. The interface unit includes an RS422 transceiver interface (RS422TX RS422RX), an OC command output interface, a CAN interface, etc., all of which are connected in terms of topology. Designed for hot and cold backup. For example, when there is a problem with the primary CAN interface of the host 10 , the system will automatically switch to the backup CAN interface of the host 10 .

In one embodiment, the star service computer further includes at least one backup machine 20, and the structure of the backup machine 20 is the same as that of the host computer 10, and forms a multi-mode redundant design.

Please refer to FIG. 3 , in one embodiment, the satellite computer further includes a first shielded connector 30 , and the first shielded connector 30 is connected to the JTAG enhanced drive unit 130 for shielding the interior of the satellite system when transmitting JTAG signals interference signal.

Specifically, in order to ensure high reliability requirements, the present embodiment implements a primary-backup multi-mode redundancy design at the hardware level of the star service computer. The hardware is divided into a main machine 10 and a backup machine 20 with identical functions. In a normal working state, only the main machine 10 works. The ground monitoring and control station will monitor the status of the satellite service computer in real time. Once the satellite service computer program runs abnormally and the watchdog unit cannot achieve the reset condition, the ground station will send a machine cutting command to switch the satellite service computer to the standby machine 20, and continue to complete. Various functions of the star computer. The main and standby design of the interface and the design of the host 10 and the standby machine 20 can better ensure the stability of the star service computer. For example, when there is a problem with the main CAN interface of the host 10, the system will automatically switch to the backup CAN of the host 10. interface. If and only if both CAN interfaces of the host 10 fail, the system cannot complete the communication with each load. If the satellite ground telemetry station cannot receive the command, it will actively upload the command of the main and backup machine 20 of the satellite service computer to switch to the backup machine 20. The backup machine 20 has exactly the same software and hardware architecture as the host machine 10, and continues to use the main CAN interface of the backup machine 20 for communication, and switches to the backup CAN interface after failure. The 422 interface is the same as the OC output interface, both of which are designed with double insurance to ensure the stability of the star service platform.

In one embodiment, the star service computer adopts a standard board-card stacking design, and adopts a partial shielding cavity isolation design.

Specifically, in this embodiment, the hardware circuit of the star service computer adopts a standard board-card stacking design, and the sensitive circuit on the single board adopts a partial shielding cavity isolation design, which ensures the mechanical requirements of the microsatellite and also ensures that the microsatellite is high EMC indicator.

Please refer to FIG. 5 , which is a schematic structural diagram of a satellite system according to an embodiment of the present invention. As shown in FIG. 5 , based on the same inventive concept, an embodiment of the present invention further provides a satellite system, where the satellite system includes the satellite service computer of any of the foregoing embodiments.

Specifically, the satellite system includes the satellite service computer of any of the above-mentioned embodiments, and also includes an attitude control unit, a flyer measurement unit, and a payload unit. The satellite service computer communicates with each unit through the interface module 13 .

In one embodiment, the satellite system further includes a second shielded connector 40, which is connected to the satellite service computer for shielding interference signals outside the satellite system when transmitting JTAG signals.

Specifically, the second shielded connector 40 and the first shielded connector 30 lead out the JTAG interface of the main control chip 120 to the star catalog of the satellite system, and shield other signals outside the satellite system and inside the satellite system in the process of transmitting JTAG signals interference, and further improve the reliability of the satellite system.

To sum up, the satellite service computer and satellite system provided by the embodiments of the present invention include a host, and the host includes a power conversion module, a main control module, and an interface module; wherein, the power conversion module is used for power protection and power conversion, and is used for the main control The module and the interface module provide stable power supply; the main control module includes a main control chip; the interface module includes a JTAG enhanced drive unit; wherein, the JTAG enhanced drive unit is connected to the JTAG interface of the main control chip for enhancing the signal strength of the JTAG signal. The invention can improve the stability of JTAG signal transmission, improve the reliability of the satellite system, and improve product competition while weakening the influence of ground static electricity, on-board radiation and single ions on the JTAG interface of the main control chip by setting the JTAG enhanced driving unit. force.

In the description of this specification, description with reference to the terms "an embodiment", "an implementation", "example" or "specific example" etc. means the specific features, structures described in connection with the embodiment, the manner or the example , material or feature is included in at least one embodiment, implementation or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment, implementation or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in one or more embodiments. Furthermore, those skilled in the art may combine and combine the various embodiments, implementations or examples described in this specification.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

Claims (10)

1. a star service computer, is characterized in that, comprises host computer, and described host computer comprises power conversion module, main control module and interface module; Wherein, The power conversion module is used for power protection and power conversion to stably supply power to the main control module and the interface module; The main control module includes a main control chip; The interface module includes a JTAG enhanced drive unit; Wherein, the JTAG enhancement driving unit is connected with the JTAG interface of the main control chip for enhancing the signal strength of the JTAG signal. 2 . The star service computer according to claim 1 , wherein the JTAG enhanced driving unit further comprises a power supply selection circuit, and the power supply selection circuit is used to select and adapt the level of an external JTAG downloader. 3 . 3. The constellation computer according to claim 1, wherein the constellation computer further comprises a first shielded connector, the first shielded connector is connected with the JTAG enhanced drive unit for Shields interfering signals inside the satellite system when transmitting JTAG signals. 4 . The satellite service computer according to claim 1 , wherein the JTAG enhanced drive unit is also used to transparently transmit the remote control signals and telemetry signals of the satellite service computer. 5 . 5 . The star service computer according to claim 1 , wherein the power conversion module comprises: an electronic fuse circuit, an EMI filter and a DC/DC switch circuit, and the electronic fuse circuit filters the EMI through the electronic fuse circuit. 6 . The device is connected with the DC/DC switch circuit; wherein, The electronic fuse circuit is used for power protection; the EMI filter for signal filtering; The DC/DC switch circuit is used for power conversion. 6. Star service computer according to claim 1, is characterized in that, described main control chip model is the SOC of Smartfusion2 series; Described main control module also comprises storage unit and clock unit and watchdog unit, described storage unit, the clock unit and the watchdog unit are respectively connected with the main control chip; wherein, The storage unit includes FLASH, SRAM and DDR. 7. The star service computer according to claim 1, wherein the interface module further comprises an interface level conversion unit and an interface unit, and the interface level conversion unit is connected with the interface unit; wherein, The interface unit includes an RS422 transceiver interface, an OC command output interface, and a CAN interface, and each interface adopts an active-standby double insurance design. 8. The star service computer according to claim 1, wherein the star service computer further comprises at least one backup machine, and the structure of the backup machine is the same as that of the host computer, and forms a multi-mode redundant design . 9. A satellite system, characterized in that it comprises the satellite service computer according to any one of claims 1-8. 10 . The satellite system according to claim 9 , wherein the satellite system further comprises a second shielded connector, the second shielded connector is connected to the satellite service computer for transmitting JTAG Shields interfering signals from outside the satellite system when signalling.

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