Basic circuit device of measurement and control time service all-in-one machine of cubesat

Abstract

The invention relates to a basic circuit device of a measurement, control and time service all-in-one machine of a cubesat. A 400MHz radio frequency module, a 8400MHz fixed radio frequency module, a full-system full-frequency-point navigation satellite system module, a radio frequency antenna, a hardware watchdog, a DC / DC conversion module, a radio frequency power supply module, a current and voltage detection module, a driving circuit and other circuit modules are integrated into an integrated basic circuit. A basic peripheral circuit integrating a satellite positioning navigation system, a time service system, load telemetering, remote control and data transmission can be provided through the modules integrated on the basic circuit, a standard integrated, lightweight and multifunctional hardware platform is provided for the cubesat, and the problem of pain points of the current cubesat in practical application is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of cubic satellite circuit design, and relates to a basic circuit device of a measurement, control and timing integrated machine of a cubic satellite. Background Art

[0002] CubeSats are characterized by their light weight and small size. They have the most basic satellite system functional units such as navigation, remote sensing, telemetry, communication positioning and timing. At present, they have become an international micro-satellite standard. A remote sensing satellite basically has the functions of "positioning", "navigation", "remote sensing" and "communication", and can achieve interconnection with the ground, achieve deep coupling of the "ground network" and "sky network" links, and meet the communication needs of the majority of users to send data, information and status to the user terminal. The user terminal can set the satellite's in-orbit communication mode and payload operation tasks according to the mission requirements.

[0003] With the massive increase in satellite payloads and radio equipment, frequency conflicts have increased, mutual interference has become increasingly serious, and crosstalk between electrical signals has occurred, which will lead to abnormal communication between radio equipment or payloads, or even failures. With the development of commercial satellites, the coverage of satellite demand for space-based information has expanded from regional to global; in terms of response speed, the response speed for acquisition, transmission, and processing of space information tends to be real-time. As for the current traditional satellite system basic circuits such as communications, navigation, and remote sensing, their isolated design methods are difficult to meet the actual application needs of cubic satellite standardization, marketization, and commercialization. Therefore, how to provide basic peripheral circuits that integrate satellite positioning and navigation systems, timing systems, payload telemetry, remote control, and data transmission has become a technical problem that needs to be solved in the actual application of cubic satellites. Summary of the invention

[0004] In view of the problems existing in the above-mentioned traditional technologies, the present invention proposes a basic circuit device for a cubic satellite's measurement, control and timing integrated machine, which can provide the cubic satellite with a basic peripheral circuit integrating satellite positioning and navigation system, timing system, payload telemetry, remote control and data transmission.

[0005] In order to achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: Provided is a basic circuit device of a measurement, control and timing integrated machine for a cubic satellite, comprising a main control chip, a 900MHz&400MHz radio frequency module, an 8400MHz fixed radio frequency module, a full-system full-frequency navigation satellite system module, a radio frequency antenna, a hardware watchdog, a DC / DC conversion module, a radio frequency power supply module, a current and voltage detection module and a drive circuit; The main control chip is respectively connected to the 900MHz&400MHz RF module, the 8400MHz fixed RF module, the full-system full-frequency navigation satellite system module, the hardware watchdog, the RF power module, the current and voltage detection module and the drive circuit; the 900MHz&400MHz RF module, the 8400MHz fixed RF module and the full-system full-frequency navigation satellite system module are respectively connected to the RF antenna; the current and voltage detection module is respectively connected to the DC / DC conversion module and the RF power module; the RF power module is respectively connected to the 900MHz&400MHz RF module, the 8400MHz fixed RF module and the full-system full-frequency navigation satellite system module; The driving circuit includes an OC instruction driving control circuit, a PPS differential driving circuit, a dual-channel CAN driving circuit, an RSS422 / RS485 driving circuit and an Ethernet port driving circuit.

[0006] The basic circuit device of the measurement, control and timing integrated machine of the above-mentioned cubic satellite integrates the main control chip, 900MHz&400MHz RF module, 8400MHz fixed RF module, full-system full-frequency navigation satellite system module, RF antenna, hardware watchdog, DC / DC conversion module, RF power module, current and voltage detection module and drive circuit and other circuit modules into an integrated basic circuit. When the basic circuit is applied to the cubic satellite, the basic peripheral circuit integrating satellite positioning and navigation system, timing system, payload telemetry, remote control and data transmission can be provided through the modules integrated on the basic circuit, providing a standard integrated, lightweight and multi-functional hardware platform for the cubic satellite, solving the pain points of the current cubic satellite in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0008] Figure 1 It is a basic circuit block diagram of a basic circuit device of a measurement, control and timing integrated machine of a cubic satellite in one embodiment; Figure 2 It is a block diagram of a management circuit of a 900MHz&400MHz radio frequency module in one embodiment; Figure 3 A block diagram of a management circuit of an 840MHz radio frequency module in one embodiment; Figure 4 is a block diagram of a management circuit of a GNSS radio frequency module in one embodiment; Figure 5A circuit diagram of an MP2148GQD-33 chip in one embodiment; Figure 6 A circuit diagram of a MAX706TEST chip module in one embodiment; Figure 7 A circuit diagram of a MAX4172 chip in one embodiment; Figure 8 A circuit diagram of an IRF7240TRPBF power distribution switch in one embodiment; Fig. 9 is a circuit diagram of an OC instruction drive control circuit in one embodiment; Fig.10 A circuit diagram of a LAN8720A chip in one embodiment; Fig.11 A circuit diagram of a SN65HVD230 chip in one embodiment; Fig.12 FIG. 4 is a circuit diagram of a MAX3485E8 serial port driver chip in one embodiment. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0010] It should be noted that the reference to "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The presentation of this phrase at various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It will be appreciated by those skilled in the art that the embodiments described herein may be combined with other embodiments. The term "and / or" used in the specification of the present invention and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0011] The following will describe the implementation of the present invention in detail with reference to the accompanying drawings in the embodiment diagram of the present invention.

[0012] In one embodiment, Figure 1As shown, a basic circuit device 100 of a measurement, control and timing integrated machine for a cubic satellite is provided, including a main control chip, a 900MHz & 400MHz radio frequency module, an 8400MHz fixed radio frequency module, a full-system full-frequency navigation satellite system module, a radio frequency antenna, a hardware watchdog, a DC / DC conversion module, a radio frequency power supply module, a current and voltage detection module and a driving circuit. The main control chip is respectively connected to the 900MHz & 400MHz radio frequency module, the 8400MHz fixed radio frequency module, the full-system full-frequency navigation satellite system module, the hardware watchdog, the radio frequency power supply module, the current and voltage detection module and the driving circuit, and the 900MHz & 400MHz radio frequency module, the 8400MHz fixed radio frequency module and the full-system full-frequency navigation satellite system module are respectively connected to the radio frequency antenna. The current and voltage detection module is respectively connected to the DC / DC conversion module and the radio frequency power supply module, and the radio frequency power supply module is respectively connected to the 900MHz & 400MHz radio frequency module, the 8400MHz fixed radio frequency module and the full-system full-frequency navigation satellite system module. The driving circuit includes an OC instruction driving control circuit, a PPS differential driving circuit, a dual-channel CAN driving circuit, an RSS422 / RS485 driving circuit and an Ethernet port driving circuit.

[0013] It can be understood that this embodiment provides a basic circuit design integrating a satellite positioning navigation system, a timing system, a payload telemetry, a remote control and a data transmission, including circuit modules such as a 900MHz&400MHz RF module, an 8400MHz fixed RF module and a full-system full-frequency navigation satellite system module, such as Figure 1 As shown. Among them, the main control chip can use the STM32 embedded single-chip microcomputer as the minimum system control unit of the basic circuit. The main control chip can be connected to the 900MHz&400MHz RF module, the 8400MHz fixed RF module, and the full-system full-frequency navigation satellite system module through the internal electronic logic latch control and level conversion module. The 900MHz&400MHz RF module has the functions of power-off restart, parameter setting and mode switching, and uses the self-management function of monitoring and automatic reset by the hardware watchdog. The IO port control of the RF power module can control the 900MHz&400MHz RF module power on / off restart function (i.e. signal control isolation design).

[0014] The current and voltage detection module is used to collect the power supply voltage and current of the 900MHz&400MHz RF module, the 8400MHz fixed RF module and the full-system full-frequency navigation satellite system module in real time, as well as the ambient temperature near the main control chip and each module in real time. The OC command drive control circuit can provide 8-way OC (Operand Constant, an indirect command) / direct command hardware control output to meet the direct power or state control of multiple stand-alone machines. The dual-channel CAN drive circuit can receive and forward uplink remote (sensing / measuring) commands, receive the spread spectrum remote (sensing / measuring) command signal sent by the ground station, convert it into a digital signal after existing despreading and demodulation, and provide a link to the satellite computer through the CAN bus. The 900MHz&400MHz RF module receives the data generated by the payload on the cubic satellite (such as the data of the monitoring camera payload) and the satellite telemetry information received by the CAN bus through its own data interface, and transmits the satellite telemetry information and the payload interface data to the ground link through the telemetry antenna in the RF antenna after framing, packaging, coding modulation and amplification.

[0015] When the entire satellite program is required to be uploaded, the main control chip links the 900MHz & 400MHz RF module to have measurement and control functions at the same time. Injection and remote control can be automatically switched according to the data type (such as integer and floating point). When the satellite computer is offline, the 900MHz & 400MHz RF module supports beacon mode to provide beacon function. The receiver serial port control signal of the 900MHz & 400MHz RF module is converted into 2-way CAN bus signal to realize the function of communicating with the satellite computer; the design of RSS422 / RS485 drive circuit and Ethernet port drive circuit provides a variety of peripheral interfaces (serial port and network port) and payload communication data downlink direct transmission capabilities, such as Figure 2 As shown in FIG. 1 , it is a block diagram of the management circuit of the 900MHz & 400MHz radio frequency module, in which each module circuit can be integrated and implemented by selecting the existing corresponding functional module circuit. Figure 3 As shown in the figure, it is a block diagram of the management circuit of the 840MHz RF module, in which each module circuit can be integrated with the existing corresponding functional module circuit. The basic circuits of the 840MHz RF module and the 900MHz&400MHz RF module are basically similar except that the parameter settings and mode switching functions are slightly different.

[0016] like Figure 4The figure shows the management circuit block diagram of the full-system full-frequency navigation satellite system module. Each module circuit can be integrated with the existing corresponding functional module circuit. The full-system full-frequency navigation satellite system module adopts the GNSS (Global Navigation Satellite System) RF module, which can realize the GNSS PPS (pulse per second) signal reception function. The PPS single-ended TTL (Transistor-Transistor Logic) level signal is converted into a differential level signal (pulse per second signal) through the PPS differential drive circuit for timing of the satellite computer. The full-system full-frequency navigation satellite system module can also realize the function of converting the GNSS receiver serial port control signal into a 2-way CAN signal to realize the communication function with the satellite computer. Similarly, the full-system full-frequency navigation satellite system module can use the hardware watchdog to monitor and automatically reset the self-management function, and also has the module power IO port control, which can control the GNSS RF module to realize the power-on / off restart function (i.e. signal control isolation design) and RF module parameter setting.

[0017] The above modules can be integrated after selecting various types of existing circuit modules with the required functions according to the design index requirements of the basic circuit. Each module is designed with its own unique functions. For the energy control problem of the cubic satellite, when one or more modules are required to work together, the module currently needed will be automatically turned on (while other modules that are not currently needed will remain closed by default). The backup mechanism of commercial cubic satellites is deeply considered in the circuit design. Therefore, the integration of multiple modules can ensure that when one of the modules fails, other modules can be indirectly replaced or not affected by the failed module, and avoid the problem of weak computing power or real-time operation of the integrated core module.

[0018] The above-mentioned basic circuit device 100 of the measurement, control and timing integrated machine of the cubic satellite integrates circuit modules such as the main control chip, 900MHz&400MHz RF module, 8400MHz fixed RF module, full-system full-frequency navigation satellite system module, RF antenna, hardware watchdog, DC / DC conversion module, RF power supply module, current and voltage detection module and drive circuit into an integrated basic circuit. When the basic circuit is applied to the cubic satellite, the modules integrated on the basic circuit can provide a basic peripheral circuit integrating satellite positioning and navigation system, timing system, payload telemetry, remote control and data transmission, so as to provide a standard integrated, lightweight and multi-functional hardware platform for the cubic satellite, and solve the pain points of the current cubic satellite in practical applications.

[0019] In one embodiment, Figure 5As shown, the RF power module uses the step-down MP2148GQD-33 chip, which has a low quiescent current, output voltage ripple and spike pulse less than 50mV, and the maximum output current maxI is 1A. The selection of this module can well meet the power distribution needs of each module. The peripheral circuits are all existing circuits required to ensure the normal operation of this chip. You can refer to the configuration requirements of this chip and understand it in the same way. The other module chips in the following text can be similar.

[0020] In one embodiment, Figure 6 As shown, the hardware watchdog uses the MAX706TEST chip module. It can be understood that in order to monitor the power supply voltage and prevent the program in the main control chip from running away and the program from entering an abnormal dead loop, the MAX706TEST chip module is used as a hardware watchdog. When the DC-3V3 voltage of the MAX706TEST chip module is lower than 1V, the WDI interface outputs a low level. During the rise of the DC-3V3 voltage, the reset signal RESET maintains a low level until the power supply voltage rises above the reset threshold value. After exceeding the reset threshold for about 200ms, the reset signal RESET is released to a high level to ensure that the STM32 main control chip works after the power supply is started normally. The WDI interface is the input pulse pin of the hardware watchdog. If the pin does not flip the level within the set period, the reset (RST) pin will output a 200ms low level to reset the STM32 main control chip.

[0021] In one embodiment, Figure 7 As shown, the current and voltage detection module uses the MAX4172 chip, which is an integrated current detection and amplification chip. The selection of its current measuring resistor and voltage output adjustment resistor can be referred to as follows: The selection of the current measuring resistor needs to consider several factors (including voltage loss, accuracy, efficiency and power loss). The adjustment of the voltage output adjustment resistor determines the full-scale output voltage range, and the full-scale output voltage is less than the power supply voltage of the main control chip 1.2V.

[0022] Among them, Figure 8 As shown, each module uses an IRF7240TRPBF power distribution switch to implement switch control of module power distribution.

[0023] In one embodiment, the OC instruction drive control circuit uses an OC direct instruction control module composed of a CD74AC273M chip and a ULN2803ADWR chip. The OC instruction drive is implemented using a Darlington transistor array. The maximum drive current of the integrated circuit can reach 500mA. The interface circuit is as follows: Fig. 9 As shown, at 200mA, the collector voltage when turned on is ≤1.5V; the absorption current capability is ≥200mA; and the pulse width is 160±10ms.

[0024] In one embodiment, Fig.10 As shown, the Ethernet port driver circuit uses the low-power LAN8720A chip. It can be understood that the Ethernet PHY layer chip uses the low-power LAN8720A chip, supports RMII interface and Ethernet MAX layer communication, has a built-in 10-BASE-T / 100BASE-TX full-duplex transmission module, supports 10Mbps and 100Mbps data signal rates, and can well meet the actual application requirements.

[0025] In one embodiment, Fig.11 As shown in the figure, the dual-channel CAN drive circuit uses the SN65HVD230 chip, which is a 3.3V CAN transceiver suitable for serial communication of the CAN bus with high communication rate, good anti-interference ability and high reliability. The SN65HVD230 chip has three different working modes: high speed, slope and waiting. Its working mode control can be achieved through the Rs control pin. Fig.11 The slope control method is adopted in the circuit. The SN65HVD230 chip has the characteristics of high speed and high anti-electromagnetic interference, and the electrical connection is very simple, so it has good practicality.

[0026] In one embodiment, Fig.12 As shown in the figure, the RSS422 / RS485 driver circuit uses the MAX3485E8 serial port driver chip. The MAX3485E serial port driver chip includes a driver and a receiver, both of which can be enabled and disabled independently. When both are disabled, the driver and receiver both output high impedance. The MAX3485 serial port driver chip has a 1 / 8 load, allowing 256 MAX3485E transceivers to be connected in parallel on the same communication bus, which can achieve error-free data transmission up to 10Mbps. The operating voltage range of the MAX3485E serial port driver chip is 3.0-5V, and it has fail-safe, over-temperature protection, current limiting protection, and over-voltage protection.

[0027] It should be noted that each of the above modules can adopt the existing chip circuit modules in the field and perform corresponding wiring and welding integration according to the functional pins of each chip circuit module itself, and then can be put into use after corresponding parameter configuration according to the chip working requirements and the design indicators of the cubic satellite.

[0028] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0029] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of protection of the invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A basic circuit device for a measurement, control and timing integrated device of a cubic satellite, characterized in that: Including main control chip, 900MHz&400MHz RF module, 8400MHz fixed RF module, full-system full-frequency navigation satellite system module, RF antenna, hardware watchdog, DC / DC conversion module, RF power module, current and voltage detection module and drive circuit; The main control chip is respectively connected to the 900MHz & 400MHz RF module, the 8400MHz fixed RF module, the full-system full-frequency navigation satellite system module, the hardware watchdog, the RF power supply module, the current and voltage detection module and the driving circuit; the 900MHz & 400MHz RF module, the 8400MHz fixed RF module and the full-system full-frequency navigation satellite system module are respectively connected to the RF antenna; the current and voltage detection module is respectively connected to the DC / DC conversion module and the RF power supply module; the RF power supply module is respectively connected to the 900MHz & 400MHz RF module, the 8400MHz fixed RF module and the full-system full-frequency navigation satellite system module; The driving circuit comprises an OC instruction driving control circuit, a PPS differential driving circuit, a dual-channel CAN driving circuit, an RSS422 / RS485 driving circuit and an Ethernet port driving circuit.

2. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1, characterized in that: The RF power module uses the step-down MP2148GQD-33 chip.

3. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1 or 2, characterized in that: The hardware watchdog uses the MAX706TEST chip module.

4. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1 or 2, characterized in that: The current and voltage detection module uses the MAX4172 core.

5. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1 or 2, characterized in that: The OC instruction drive control circuit adopts an OC direct instruction control module composed of CD74AC273M chip and ULN2803ADWR chip.

6. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1 or 2, characterized in that: The Ethernet port driver circuit uses the low-power LAN8720A chip.

7. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1 or 2, characterized in that: The dual-channel CAN driver circuit uses the SN65HVD230 chip.

8. The basic circuit device of the measurement, control and timing integrated machine of the cubic satellite according to claim 1 or 2, characterized in that: The RSS422 / RS485 driver circuit uses the MAX3485E8 serial port driver chip.

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