Satellite electric propulsion system TT&C unit

Abstract

A satellite electric propulsion system measurement and control unit mainly consists of a main control and radio frequency power processing unit control module, a direct current power supply processing unit control module, a storage supply unit control module and a power module. The main control and radio frequency power processing unit control module is designed based on an anti-radiation reconfigurable computing platform, realizes functions such as multi-channel telemetry signal acquisition and processing, data storage and the like, and realizes communication and control with a satellite computer and a radio frequency power processing unit based on a double-redundancy CAN bus. The direct current power supply processing unit control module mainly outputs double-redundancy OC instructions, is used for realizing enable control of positive and negative high-voltage modules and a heating ignition module in the direct current power supply processing unit and current and voltage regulation, and simultaneously collects real-time current and voltage values for satellite working process judgment. The storage supply unit control module mainly realizes control of an electromagnetic valve and a high / low pressure self-locking valve, and regulates and controls gas flow. The power module provides a power supply required by the measurement and control unit and provides a current for a load.

Description

Technical Field

[0001] The present invention relates to the field of spacecraft electric propulsion technology, and in particular to a design of a measurement and control unit for a satellite electric propulsion system, and is particularly applicable to a radio frequency ion electric propulsion system. Background Art

[0002] With the continuous development of radio frequency ion and Hall electric propulsion technologies, electric propulsion systems, with their advantages of high power, high specific impulse, and long life, are becoming the most important technological direction in the future field of spacecraft propulsion. For many future deep space exploration missions and various microsatellites, high-performance and highly reliable electric propulsion technology can effectively improve spacecraft maneuverability, control accuracy, and on-orbit time, making it an essential supporting technology for completing various missions. Compared with advanced international standards, my country's engineering applications are still in the early stages, and it is crucial to further strengthen and accelerate technological development to achieve significant economic and technical benefits.

[0003] Electric propulsion systems primarily consist of thrusters, a propulsion unit (PPU), a propellant storage and supply system, and a digital control interface unit (DCIU). Ensuring high-reliability operation of electric propulsion systems remains a significant technical challenge. Spacecraft propulsion systems, particularly those with the most complex structures, such as radio frequency ion propulsion technology, place high demands on reliability, low cost, high integration, and high precision across all components. The measurement and control unit (TCU), a key control device within the electric propulsion system, centrally controls all components within the system, acquires system telemetry data, manages and ensures the normal operation of the entire system, and performs fault diagnosis and functional reconfiguration, playing a crucial role in the efficient operation of the electric propulsion system. Currently, most domestic research institutions focus on improving and resolving key issues related to thruster performance, while no research institution has dedicated itself to the development of electric propulsion TCUs. With the rapid advancement of electronic information technology and aerospace microelectronics, a growing number of high-performance, high-reliability, and high-dose radiation-resistant aerospace-grade integrated circuits and design methods are being applied to various spacecraft, providing significant support for the future development of electric propulsion systems. Summary of the Invention

[0004] The purpose of the present invention is to address the problems of low reliability, single function and disability in the existing technology, and to provide a radiation-resistant, miniaturized, highly integrated, intelligent and reconfigurable satellite electric propulsion system measurement and control unit, which realizes functional control and data telemetry of the electric propulsion system based on a high-performance intelligent reconfigurable computing control platform.

[0005] The technical solution of the present invention is: a satellite electric propulsion system measurement and control unit, which is used to control the radio frequency power processing unit, direct current power processing unit and storage and supply unit in the satellite electric propulsion system, thereby realizing satellite orbit change and attitude control, and includes a main control and radio frequency power processing unit control module, a direct current power processing unit control module, a storage and supply unit control module and a power supply module;

[0006] The main control and RF power processing unit control module is used to receive instructions from the satellite service computer, feedback the electric propulsion system status telemetry data for satellite workflow judgment, and store the status data according to the satellite service instructions. At the same time, it sets the incident power and reflected power of the RF power processing unit and collects its frequency parameters.

[0007] The DC power processing unit control module is used to control the DC power processing unit, enable and adjust the positive and negative high-voltage outputs, enable and adjust the heating, enable and adjust the ignition, and collect the voltage and current values ​​output by the DC power processing unit through the ADC;

[0008] The storage and supply unit control module collects the feedback value of the storage and supply unit pressure sensor through the ADC, and outputs the flow adjustment control signal through closed-loop feedback to achieve autonomous control of the propellant gas flow;

[0009] The power supply module is used to provide power input for each module of the measurement and control unit, and to provide voltage and current for each valve load in the storage and supply unit, and to provide an enable signal for the self-locking valve in the storage and supply unit according to external input instructions.

[0010] Preferably, the main control and RF power processing unit control modules, the DC power processing unit control module, the storage and supply unit control module, and the power supply module are sequentially connected in a stacked manner from top to bottom.

[0011] Preferably, each of the control modules is designed based on aerospace-grade radiation-resistant devices, and the total radiation dose can reach 100KRad (Si).

[0012] Preferably, the main control and RF power processing unit control module adopts a reconfigurable processor as the control core, with an embedded soft core and a dual-redundant satellite service CAN bus, which is used to receive control instructions from the satellite service computer and send control signals to each unit, process and upload various telemetry data of the satellite electric propulsion system; the soft core program storage and refresh are realized through the radiation-resistant PROM memory and refresh circuit; the SPI FLASH memory is used to meet the storage and reading of telemetry data, and the frequency and power reference voltage of the RF power processing unit are set by sending messages through a dual-redundant RF CAN bus, and the output power and reflected power of the RF power processing unit are read by receiving messages.

[0013] Preferably, the DC power processing unit control module is composed of a dual-redundant optocoupler switch circuit and an ADC acquisition circuit, and is controlled by the output instructions of the main control and RF power processing unit control modules. The optocoupler switch circuit is used to control the on / off of the positive / negative high-voltage module, heating module, and ignition module in the DC power processing unit, and to perform regulation and control of different voltages and currents; the ADC acquisition circuit collects voltage and current values ​​in real time, and feeds them back to the satellite service computer via the main control and RF power processing unit control modules.

[0014] Preferably, the regulation and control of voltage and current is achieved by setting OC instructions, and the control instructions are composed of different binary numbers, which correspond to different voltage and current outputs required in the DC power supply processing unit.

[0015] Preferably, the ADC acquisition circuit collects voltage and current feedback values ​​in real time, and after median filtering and fitting, sends the obtained voltage and current telemetry data to the satellite service computer.

[0016] Preferably, the storage and supply unit control module includes a DC / DC conversion circuit, two switch circuits, a temperature acquisition A / D chip, and a pressure acquisition A / D chip;

[0017] The DC / DC conversion circuit performs secondary power conversion on the voltage input by the power module to provide the voltage and current required for the valves in the storage and supply unit to be turned on and off;

[0018] One of the two switching circuits is composed of an optocoupler and a MOS tube, and is used to control the Bang-Bang solenoid valve; the other switching circuit is composed of a triode and is controlled by an adjustable PWM signal output by the main control and RF power processing unit control module to adjust the opening of the propellant flow; the adjustable PWM signal is output by the main control and RF power processing unit control module based on the pressure sensor value collected in real time by the pressure acquisition A / D chip, after linear conversion and judgment. The PWM signal duty cycle is linearly related to the flow rate, and a pressure control threshold is set at the same time to form a closed-loop feedback to maintain the stability of the thruster gas flow output by the storage and supply unit;

[0019] The temperature acquisition A / D chip collects the voltage value across the thermistor inside the storage and supply unit in real time, converts it into the storage and supply unit temperature value through median filtering fitting, and sends it to the main control and RF power processing unit control module.

[0020] Preferably, the switching circuit composed of an optocoupler and a MOS tube outputs a high-level control signal of a preset duration to control the opening of the Bang-Bang solenoid valve. After opening, it outputs a maintaining voltage to keep the solenoid valve in the open state, and outputs a low level to close the Bang-Bang solenoid valve.

[0021] Preferably, the power supply module provides power input for each module of the measurement and control unit; the opening and closing of the high-pressure self-locking valve and the low-pressure self-locking valve in the storage and supply unit are controlled by a switching circuit composed of an optocoupler and a MOS tube. The switching circuit outputs a high-level signal of a preset duration to open the high / low-pressure self-locking valve, and then outputs a high-level signal of the same duration to close the high / low-pressure self-locking valve.

[0022] The advantages of the present invention over the prior art are: the present invention is based on the design of an intelligent reconfigurable computing platform, and at the same time, highly reliable aerospace-grade components are selected. Compared with general satellite-borne electrical components, the performance and reliability are greatly improved. The radiation-resistant reconfigurable processor selected by the present invention has sufficient interfaces and logic units for centralized control of functions, and can reconstruct functions through software programming, eliminating parts of the processor chip damaged by single-particle radiation, thereby avoiding the common problems of insufficient resources and failure to work in processors such as ARM and DSP. The present invention uses aerospace-grade diodes, triodes, and VDOMS tubes to design switch control circuits, which have fast response speeds and high reliability, and can provide support for the accurate operation of the electric propulsion system to achieve precise orbit changes. Thanks to the high-performance aerospace-grade integrated circuits, the present invention is not only light in weight, but also has very low power consumption. It integrates different functions and releases limited space for satellite payloads. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the main control and radio frequency power processing unit control module of the present invention;

[0025] Figure 3 This is a schematic diagram of a DC power processing unit control module of the present invention;

[0026] Figure 4 This is a schematic diagram of the storage and supply unit control module of the present invention;

[0027] Figure 5 Schematic diagram of the power module of the present invention;

[0028] Figure 6 This is an overall block diagram of the present invention. DETAILED DESCRIPTION

[0029] A satellite electric propulsion system measurement and control unit is the core control component of the satellite radio frequency ion electric propulsion system. The satellite radio frequency ion electric propulsion system also includes a radio frequency power processing unit, a DC power processing unit and a storage and supply unit. The measurement and control unit is used to control other units to achieve satellite orbit change and attitude control. Figure 6As shown, it consists of a main control and RF power processing unit control module 1, a DC power processing unit control module 2, a storage and supply unit control module 3, and a power supply module 4. The main control and RF power processing unit control module plays a core control role. To meet the needs of upward communication and downward control, the control functions of each module are concentrated in the module, reducing the load of each unit of the satellite electric propulsion system and enabling stable operation in a cosmic particle radiation environment. The modules are connected in a stacked manner according to the control order. Figure 1 As shown, the main control and RF power processing unit control module 1, the DC power processing unit control module 2, the storage and supply unit control module 3, and the power supply module 4 are stacked in sequence from top to bottom and installed within a housing 12. Heat is dissipated between the circuit boards of the modules via heat dissipation bosses 14 and from the sides via heat dissipation grilles 13. Vibration dampers 5 are installed at the four corners of the housing structure's backplane, and each circuit board is fixed to a reinforcement rib 7 within the housing structure. The satellite service CAN bus and RF CAN bus interface 6, the DC power processing unit control interface 8, the DC power processing unit acquisition interface 9, the storage and supply unit control interface 10, and the power supply interface 11 are located on the same side of the housing. Each of these modules is designed based on space-grade radiation-resistant components, with a total radiation dose of up to 100 kRad(Si).

[0030] 1. Main control and RF power processing unit control module

[0031] It is mainly used to receive satellite computer instructions, feedback propulsion system status telemetry data, and judge the satellite workflow. It also stores status data according to satellite computer instructions, sets the incident power and reflected power of the radio frequency power processing unit, and collects its frequency parameters.

[0032] The main control and RF power processing unit control modules are designed based on an intelligent reconfigurable computing platform, with a radiation-resistant reconfigurable processor as the control core. They have a rich set of control interfaces and logic units, and can embed soft cores to achieve data transmission, analysis, and calculation. They can also be flexibly reconfigured through programming to implement functions such as program refresh and troubleshooting, meeting the system usage requirements in complex aerospace environments. A built-in dual-redundant satellite service CAN bus (the dual-redundant backup design greatly improves the reliability of the measurement and control unit) is used to receive control instructions from the satellite service computer and send control signals to each unit, process and upload various telemetry data of the satellite electric propulsion system, send messages via a dual-redundant RF CAN bus to set the frequency and power reference voltage of the RF power processing unit, and receive messages to read the output power and reflected power of the RF power processing unit. Program storage and refresh are achieved based on a 64Mbit radiation-resistant PROM memory and refresh circuit to ensure that the measurement and control unit is not affected by single-particle radiation; a 256Kbit SPI FLASH memory is used to store and read telemetry data.

[0033] The present invention provides a preferred embodiment, as Figure 2 The main control and RF power processing unit control module 1 is shown in Figure 1. The radiation-hardened reconfigurable processor uses the BQR5VSX95T chip, and communication and control are implemented using the Verilog language. The refresh circuit uses the BM501-003CBRH, which enables periodic program refreshes. The CAN bus controller uses the BSJ1000RH, the CAN bus transceiver uses the B1050RH, and the B54ACS164245SRH level conversion circuit implements 5V to 3.3V signal conversion. The dual-redundant satellite CAN bus connects to the satellite computer via the satellite CAN bus and RF CAN bus interface 6, receiving control commands and uploading telemetry data. The dual-redundant RF CAN bus connects to the RF power processing unit via the satellite CAN bus and RF CAN bus interface 6, transmitting the RF frequency and output power settings and receiving the reflected power analysis. The data memory uses the B28C256LVRH for storing and reading telemetry data.

[0034] 2. DC Power Processing Unit Control Module

[0035] It is used to control the positive and negative high-voltage modules, heating module and ignition module in the power processing unit of the electric propulsion system, to enable and adjust the positive and negative high-voltage outputs, to enable and adjust the heating, to enable and adjust the ignition, and to collect the voltage and current values ​​output by the DC power processing unit through the ADC.

[0036] The DC power processing unit control module consists of dual-redundant optocoupler switching circuits (also known as OC switching circuits) and ADC acquisition circuits. Controlled by command outputs from the main control and RF power processing unit control modules, it controls the on / off of the positive / negative high-voltage modules, heating module, and ignition module, and regulates various voltages and currents. Voltage and current regulation is achieved by programmed OC commands, which are centrally output via the optocoupler switching circuits. These commands set the on signal to "1" and the off signal to "0," forming the binary numbers 100, 010, and 001, respectively, regulating the DC power processing unit's outputs of 1050V, 1150V, and 1250V, and 2.5A, 3.5A, and 4.5A. Dual-redundant backup is also employed to ensure control reliability. The A / D chip takes the median value of every 10 samples, samples N points within the measurement range, and fits a linear equation. The resulting voltage and current telemetry data is then transmitted to the satellite control computer. In this example, an 8-channel 12-bit radiation-resistant A / D chip is used to collect voltage and current feedback values ​​in real time. After median filtering and fitting, the sampling accuracy can reach 0.2%.

[0037] The present invention provides a preferred embodiment, as Figure 3As shown, the basic components of the DC power processing unit control module 2 are connected to the DC power processing unit via the DC power processing unit control interface 8 and the DC power processing unit acquisition interface 9. The optocoupler is GH302-4R. One switch control signal is controlled by two control signals from the radiation-hardened reconfigurable processor, controlling the on / off of two optocouplers. This provides dual redundancy to enhance circuit reliability. The ADC acquisition circuit uses the radiation-hardened 12-bit 8-channel ADC B128S102RH as the voltage and current sampling chip, and the SW136AMTRH as the voltage reference chip. Furthermore, to meet isolation requirements, a signal isolation circuit, BUM1401 RH, is required between the ADC and the radiation-hardened reconfigurable processor. In summary, the module can output multiple OC commands, enabling control of various functional modules within the DC power processing unit. It can also collect voltage and current telemetry values ​​in real time and upload them to the satellite service computer.

[0038] 3. Storage and supply unit control module

[0039] The storage and supply unit control module is primarily responsible for precise control and regulation of gas flow, ensuring timely delivery of gas to the thrusters and neutralizers. It is responsible for remotely measuring temperature and pressure within the storage and supply unit and, through feedback, controls the on / off switching of the triode circuit in a closed loop, thereby regulating the propellant gas flow.

[0040] The storage and supply unit control module uses a switching circuit composed of an optocoupler and MOS transistor to control the bang-bang solenoid valve, thereby controlling the injection of a propellant gas. The main control and RF power processing unit control module outputs a 10ms high-level opening signal to control the bang-bang solenoid valve to open. A continuous 3.2V hold signal is then output to maintain the bang-bang solenoid valve open, and a low-level signal closes the bang-bang solenoid valve. These switching circuits all use a dual-redundancy backup design to ensure control reliability.

[0041] This module includes a DC / DC conversion circuit, which performs secondary power conversion on the input voltage of the power module to provide the voltage and current required for the valve to be turned on and off; the module also includes two temperature acquisition A / D chips (in this case, two single-channel 14-bit radiation-resistant A / D chips with a sampling range of 0.5V-4.5V). The median value is taken every 10 samples, N points are sampled within the measurement range, and a linear calculation formula is fitted (the sampling accuracy can reach 0.2% after processing by algorithms such as median filtering). The collected voltage value across the thermistor inside the storage and supply unit is converted into the storage and supply unit temperature value through the corresponding calculation formula, and uploaded to the satellite service computer by the main control and RF power processing unit control modules.

[0042] The module uses an 8-channel, 12-bit radiation-resistant A / D chip to collect real-time pressure sensor values ​​from four propellant gas pipelines within the storage and supply unit (the sampling voltage value corresponding to the pressure range of 0-206 kPa is 0.5V-4.5V, and the relationship is linear). A switching circuit composed of transistors is used to achieve gas flow regulation. The switching circuit is controlled by an adjustable PWM signal output by the main control and radio frequency power processing unit control module. The different duty cycles of the PWM signal determine the opening of the propellant regulation (in a linear relationship). At the same time, a pressure control threshold is set to form a closed-loop feedback with the real-time pressure collection value, which can dynamically adjust the propellant pipeline pressure value, thereby maintaining a stable gas supply.

[0043] The present invention provides a preferred embodiment, such as Figure 4 As shown, the basic components of the storage and supply unit control module 3 are connected to the storage and supply unit via the storage and supply unit control interface 10. This module can provide a 15V DC power supply to the storage and supply unit flow regulator and a 4-20mA current output control circuit. It collects the 0.5V-4.5V analog feedback signal from the flow regulation pressure sensor and uses a radiation-resistant NPN transistor 3DK3501 UB. A radiation-resistant reconfigurable processor outputs a PWM signal, which, through an RC filter circuit, generates an adjustable 0.7V-2V voltage signal for flow regulation. The module uses an optocoupler plus VDMOS design, adding a switching diode at both ends of the solenoid valve interface to provide a current storage circuit for the solenoid valve's inductor. The optocoupler uses the radiation-resistant GH302-4R, the switching diode uses the fast recovery diode 2CZ5806US, and the VDMOS uses the radiation-resistant field-effect transistor BCS7587U3RH. It also uses a dual-redundant backup design. The radiation-resistant reconfigurable processor outputs two 10ms high-level on signals, which then switch to output two continuous 3.2V low-level signals. The module uses the 12-bit 8-channel radiation-resistant ADC B128S102RH and the 14-bit single-channel radiation-resistant ADC B9243AMG to collect the voltage values ​​of the temperature sensor and pressure sensor in real time, and upload them to the satellite service computer after conversion through the radiation-resistant reconfigurable processor.

[0044] 4. Power Module

[0045] It is used to provide power input for each module of the measurement and control unit, and provide voltage and current for each valve load. It also has built-in enabling circuits for high-pressure self-latching valves and low-pressure self-latching valves.

[0046] The power module feeds the satellite bus power supply through an EMI filter into the radiation-resistant DC / DC circuit, providing the 28V DC power required by the measurement and control unit. The module also includes dual redundant switch control circuits for the high- and low-voltage latching valves. The radiation-resistant reconfigurable processor outputs a 100ms high-level (e.g., 24V) on- and 100ms high-level (e.g., 24V) off signals, providing the voltage and current required to open and close the high- and low-voltage latching valves in the storage and supply unit. This control controls the injection of a second propellant.

[0047] The present invention provides a preferred embodiment, as Figure 5 The figure shows the basic components of the power module 4, which is connected to the satellite bus power supply via the power interface 11 and supplies power to other modules via the stacking connector inside the measurement and control unit. The module uses a radiation-resistant LFH / (20-50)-461-75 EMI filter and a radiation-resistant power supply LDCD / (20-50)-28-65 / SP to convert the satellite bus's 42VDC to 28VDC, providing voltage and current for the measurement and control unit and load. The control circuit principles of the high-voltage and low-voltage self-latching valves are the same, using dual-redundant optocouplers and VDMOS transistors to achieve fast switching capabilities. The on and off signals are both controlled by a 100ms high-level signal generated by a radiation-resistant reconfigurable processor.

[0048] Parts of the present invention that are not described in detail belong to the common knowledge of those skilled in the art.

Claims

1. A satellite electric propulsion system measurement and control unit, used to control the radio frequency power processing unit, direct current power processing unit, and storage and supply unit in the satellite electric propulsion system, thereby achieving satellite orbit change and attitude control, characterized by: It includes main control and RF power processing unit control module, DC power processing unit control module, storage and supply unit control module and power supply module; The main control and RF power processing unit control module is used to receive instructions from the satellite service computer, feedback the electric propulsion system status telemetry data for satellite workflow judgment, and store the status data according to the satellite service instructions. At the same time, it sets the incident power and reflected power of the RF power processing unit and collects its frequency parameters. The DC power processing unit control module is used to control the DC power processing unit, enable and adjust the positive and negative high-voltage outputs, enable and adjust the heating, enable and adjust the ignition, and collect the voltage and current values ​​output by the DC power processing unit through the ADC; The storage and supply unit control module collects the feedback value of the storage and supply unit pressure sensor through the ADC, and outputs the flow adjustment control signal through closed-loop feedback to achieve autonomous control of the propellant gas flow; The power supply module is used to provide power input for each module of the measurement and control unit, and to provide voltage and current for each valve load in the storage and supply unit, and to provide an enable signal for the self-locking valve in the storage and supply unit according to external input instructions.

2. The satellite electric propulsion system measurement and control unit according to claim 1, characterized in that: The main control and RF power processing unit control module, the DC power processing unit control module, the storage and supply unit control module, and the power supply module are connected in a stacked manner from top to bottom.

3. The satellite electric propulsion system measurement and control unit according to claim 1, characterized in that: Each of the control modules is designed based on aerospace-grade radiation-resistant devices, and the total radiation dose can reach 100KRad (Si).

4. The satellite electric propulsion system measurement and control unit according to claim 1, characterized in that: The main control and RF power processing unit control module uses a reconfigurable processor as the control core, with an embedded soft core and dual-redundant satellite service CAN bus, which is used to receive control instructions from the satellite service computer and send control signals to each unit, process and upload various telemetry data of the satellite electric propulsion system; the soft core program storage and refresh are realized through radiation-resistant PROM memory and refresh circuit; SPI FLASH memory is used to meet the storage and reading of telemetry data, and messages are sent through a dual-redundant RF CAN bus to set the frequency and power reference voltage of the RF power processing unit, and messages are received to read the output power and reflected power of the RF power processing unit.

5. The satellite electric propulsion system measurement and control unit according to claim 1, characterized in that: The DC power processing unit control module consists of a dual-redundant optocoupler switch circuit and an ADC acquisition circuit, and is controlled by the output instructions of the main control and RF power processing unit control modules. The optocoupler switch circuit is used to control the on / off of the positive / negative high-voltage module, heating module, and ignition module in the DC power processing unit, and to adjust and control different voltages and currents; the ADC acquisition circuit collects voltage and current values ​​in real time, and feeds them back to the satellite service computer through the main control and RF power processing unit control modules.

6. The satellite electric propulsion system measurement and control unit according to claim 5, characterized in that: The regulation and control of voltage and current are achieved by setting OC instructions. By setting different binary numbers to form control instructions, they correspond to the different voltage and current outputs required in the DC power processing unit.

7. The satellite electric propulsion system measurement and control unit according to claim 5, characterized in that: The ADC acquisition circuit collects voltage and current feedback values ​​in real time, and after median filtering and fitting, sends the obtained voltage and current telemetry data to the satellite service computer.

8. The satellite electric propulsion system measurement and control unit according to claim 1, characterized in that: The storage and supply unit control module includes a DC / DC conversion circuit, two switch circuits, a temperature acquisition A / D chip, and a pressure acquisition A / D chip; The DC / DC conversion circuit performs secondary power conversion on the voltage input by the power module to provide the voltage and current required for the valves in the storage and supply unit to be turned on and off; One of the two switching circuits is composed of an optocoupler and a MOS tube, and is used to control the Bang-Bang solenoid valve; the other switching circuit is composed of a triode and is controlled by an adjustable PWM signal output by the main control and RF power processing unit control module to adjust the opening of the propellant flow; the adjustable PWM signal is output by the main control and RF power processing unit control module based on the pressure sensor value collected in real time by the pressure acquisition A / D chip, after linear conversion and judgment. The PWM signal duty cycle is linearly related to the flow rate, and a pressure control threshold is set at the same time to form a closed-loop feedback to maintain the stability of the thruster gas flow output by the storage and supply unit; The temperature acquisition A / D chip collects the voltage value across the thermistor inside the storage and supply unit in real time, converts it into the storage and supply unit temperature value through median filtering fitting, and sends it to the main control and RF power processing unit control module.

9. The satellite electric propulsion system measurement and control unit according to claim 8, characterized in that The switching circuit composed of an optocoupler and a MOS tube outputs a high-level control signal with a preset duration to control the opening of the Bang-Bang solenoid valve. After opening, it outputs a maintaining voltage to keep the solenoid valve in the open state, and outputs a low level to close the Bang-Bang solenoid valve.

10. The satellite electric propulsion system measurement and control unit according to claim 1, characterized in that: The power supply module provides power input for each module of the measurement and control unit; the switching circuit composed of optocouplers and MOS tubes controls the opening and closing of the high-pressure self-locking valve and the low-pressure self-locking valve in the storage and supply unit. The switching circuit outputs a high-level signal of a preset duration to open the high / low-pressure self-locking valve, and then outputs a high-level signal of the same duration to close the high / low-pressure self-locking valve.

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