Arrayed erosion rate spatiotemporal distribution diagnostic method, device and electronic equipment

Abstract

The application provides an array type erosion rate space-time distribution diagnosis method and device and electronic equipment, and relates to the field of plasma erosion rate diagnosis. The method comprises the following steps: measuring the currents of a plurality of unrelated branches through a current sampling device; taking the currents of the unrelated branches as known quantities to obtain the current on each branch in the meshed circuit by solving a Kirchhoff current law equation group, and obtaining the resistance value corresponding to each erosion sensor unit according to the node voltage of each node measured by a voltage sampling device through Ohm's law; monitoring the probe temperature of the erosion sensor probe through a thermocouple, determining the erosion rate perpendicular to the surface of the insulating base body through the erosion sensor probe according to the resistance value and the probe temperature, calculating the change of the erosion rate with time by using an interpolation method according to the erosion rates corresponding to the erosion sensor units in the space range, and obtaining the erosion rate space-time distribution diagnosis result.

Description

Technical Field

[0001] This application relates to the field of plasma erosion rate diagnostic technology, and in particular to an array-type erosion rate spatiotemporal distribution diagnostic method, device, and electronic device. Background Technology

[0002] Currently, space electric propulsion technology, due to its high specific impulse and low fuel consumption, has been widely applied in missions such as deep space exploration and satellite orbit maintenance. With the rapid development of commercial spaceflight, the construction of low-Earth orbit (LEO) constellations has become a key focus in the aerospace field. The Starlink constellation (over 7,000 satellites) has already achieved large-scale on-orbit application of electric propulsion technology. The construction of related LEO constellations has significantly increased the number of electric propulsion applications in the aerospace field, making research on the impact of electric propulsion on spacecraft increasingly important.

[0003] Hall thrusters and ion thrusters account for over 90% of space electric propulsion applications. Both types of electric propulsion work by ionizing the working fluid to form charged particles (ions and electrons), which are then confined and accelerated by an electromagnetic field and ejected to generate thrust. The ions ejected by electric propulsion can reach energies of hundreds of electron volts (eV). A small fraction of these high-energy particles return to the spacecraft surface at relatively high energies (tens of eV) due to collisions or electromagnetic field effects. These high-energy particles bombard the surface material, causing it to erode. High-energy particle erosion can lead to surface damage, material degradation, and deterioration, potentially affecting the long-term stable operation of the spacecraft. Existing on-orbit studies on the erosion rate of space electric thruster plumes include erosion / sputtering product diagnosis based on high-cost quartz crystal microbalances, and erosion sensor diagnosis based on lower-cost methods. Ground-based erosion studies also include erosion rate diagnosis based on long-term (>100h) tests and material surface morphology analysis, and diagnosis based on laser-induced fluorescence measurement of sputtering products.

[0004] However, existing electric propulsion erosion rate diagnostic equipment is unable to obtain spatiotemporal distribution data of erosion rate within the same time period, resulting in insufficient spatial resolution and an inability to accurately reflect the erosion distribution gradient of the thruster plume on the spacecraft surface. Consequently, the spatiotemporal accuracy of the currently diagnosed thruster plume erosion data on the spacecraft surface is low. Summary of the Invention

[0005] The purpose of this invention is to provide an array-based method, apparatus, and electronic device for diagnosing the spatiotemporal distribution of erosion rate, in order to solve the technical problem of low spatiotemporal accuracy of the erosion data of thruster plumes on spacecraft surfaces currently diagnosed.

[0006] In a first aspect, this application provides an array-based method for diagnosing the spatiotemporal distribution of erosion rates, applied to a system for diagnosing the spatiotemporal distribution of erosion rates. The system includes multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices, and diagnostic circuit components. The erosion sensor units are arranged in an array on the surface of a spacecraft relative to the outlet of an electric thruster and connected to a power source in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate and an erosion sensor probe. The surface of the insulating substrate is coated with the erosion sensor probe. The thermocouple is positioned on the back side of the insulating substrate via a groove. Multiple nodes of the mesh circuit are equipped with voltage sampling devices, and multiple branches of the mesh circuit are equipped with current sampling devices. The method includes:

[0007] The current sampling device measures the current of multiple unrelated branches, which are determined by solving a set of non-linearly related branch currents based on Kirchhoff's current law equation for multiple branches in the mesh circuit.

[0008] The current in each branch of the mesh circuit is obtained by solving Kirchhoff's current law equations, using the current in the unrelated branches as known quantities. The resistance value of each erosion sensor unit is obtained by Ohm's law based on the current in each branch and the node voltage measured by the voltage sampling device.

[0009] The temperature of the erosion sensor probe is monitored by the thermocouple. Based on the resistance value and the probe temperature, the erosion rate of the surface perpendicular to the insulating substrate is determined by the erosion sensor probe. The change of the erosion rate over time is calculated using interpolation based on the erosion rate corresponding to each erosion sensor unit in the spatial range, and the spatiotemporal distribution diagnosis result of the erosion rate is obtained.

[0010] In one possible implementation, an electrical connection structure is fabricated on the insulating substrate to connect to the erosion sensor probe and the wires. The exposed conductor in the electrical connection structure used to connect the erosion sensor probe is covered with an insulating material after coating to prevent direct contact with the plasma environment. The erosion sensor probe is a conductor coating deposited onto the insulating substrate by magnetron sputtering. Determining the erosion rate perpendicular to the surface of the insulating substrate based on the resistance value and the probe temperature using the erosion sensor probe includes:

[0011] The erosion thickness of the conductor coating is calculated based on the change in resistance value and the probe temperature, and the erosion rate of the erosion sensor probe on the surface perpendicular to the insulating substrate is determined based on the erosion thickness of the conductor coating.

[0012] In a possible implementation, a "field" - shaped mesh structure circuit formed by connecting 2m*n - m - n of the erosion sensor units into m*n nodes;

[0013] The m*n nodes correspond to m*n equations in the Kirchhoff's current law equations. There are 2m*n - m - n + 1 branches between the "field" - shaped mesh structure circuit and the circuit of the power supply. The 2m*n - m - n + 1 branches correspond to 2m*n - m - n + 1 unknowns, and the number of irrelevant branches is m*n - m - n + 1;

[0014] The step of obtaining the current on each branch of the mesh circuit by taking the current of the irrelevant branches as known quantities and solving the Kirchhoff's current law equations includes:

[0015] Taking the currents of the m*n - m - n + 1 irrelevant branches measured by the current sampling device as known quantities, substituting them into the Kirchhoff's current law equations, and solving the equations to obtain the current on each branch of the mesh circuit.

[0016] In a possible implementation, the voltage sampling device includes a first operational amplifier, a first analog multiplexer, a tiny precision resistor, a differential amplifier, an analog - to - digital conversion chip, and a first micro - control chip; the sampling points of the voltage sampling device are connected to m*n - 2 target nodes other than the two connection nodes at both ends of the power supply; before obtaining the resistance value corresponding to each erosion sensor unit according to the current on each branch and the node voltage measured by the voltage sampling device through Ohm's law, it further includes:

[0017] Controlling the first analog multiplexer by the first micro - control chip to detect the node voltages of all the target nodes; among them, there is a function of matching and amplifying the signal of the first operational amplifier according to the power supply and the resistance value between the first analog multiplexer and the analog - to - digital conversion pin of the first micro - control chip.

[0018] In a possible implementation, the current sampling device includes a sampling resistor, a second operational amplifier, a second analog multiplexer, and a second micro - control chip. The resistance value of the sampling resistor has high accuracy, low temperature drift, and is less than or equal to the minimum resistance value of the erosion sensor unit; the step of measuring the currents of multiple irrelevant branches by the current sampling device includes:

[0019] Measuring the currents of the m*n - m - n + 1 irrelevant branches by the sampling resistor, the second operational amplifier, the second analog multiplexer, and the second micro - control chip.

[0020] In one possible implementation, each branch of the mesh circuit is connected to an erosion sensor corresponding to one of the erosion sensor units, the erosion sensor acting as a resistor, and all the erosion sensors are uniformly arranged within the spatial range of the electric propulsion plume erosion rate to be diagnosed.

[0021] In one possible implementation, the diagnostic circuit assembly includes the power supply and multiple wires fixed to the mounting surface and connected to the interface of the erosion sensor unit to form the mesh circuit; the power supply is a low-voltage regulated power supply, and the output of the low-voltage regulated power supply is connected to two nodes of the mesh circuit, wherein the low-potential node of the two nodes serves as a reference ground.

[0022] Secondly, this application provides an array-type spatiotemporal distribution diagnostic device for erosion rate, applied to a spatiotemporal distribution diagnostic system for erosion rate. The spatiotemporal distribution diagnostic system for erosion rate includes multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices, and diagnostic circuit components. The erosion sensor units are arranged in an array on the surface of a spacecraft relative to the outlet of an electric thruster and connected to a power source in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate and an erosion sensor probe. The surface of the insulating substrate is coated with the erosion sensor probe. The position of the erosion sensor probe corresponds to the position of the thermocouple, which is disposed via a groove on the back side of the insulating substrate. Multiple nodes of the mesh circuit are provided with the voltage sampling devices, and multiple branches of the mesh circuit are provided with the current sampling devices. The system includes:

[0023] The measurement module is used to measure the current of multiple unrelated branches through the current sampling device. The unrelated branches are determined by solving a set of non-linearly related branch currents based on Kirchhoff's current law equation for multiple branches in the mesh circuit. The measurement module is also used to measure the gating voltage connected to m*n-2 nodes through the voltage sampling device.

[0024] The solution module is used to obtain the current in each branch of the mesh circuit by solving the Kirchhoff current law equations, taking the current in the unrelated branches as a known quantity, and to obtain the resistance value corresponding to each erosion sensor unit by Ohm's law based on the current in each branch and the node voltage measured by the voltage sampling device.

[0025] The calculation module is used to monitor the probe temperature of the erosion sensor probe through the thermocouple, determine the erosion rate of the surface perpendicular to the insulating substrate through the erosion sensor probe based on the resistance value and the probe temperature, and calculate the change of the erosion rate over time using interpolation based on the erosion rate corresponding to each erosion sensor in the spatial range, so as to obtain the spatiotemporal distribution diagnosis result of the erosion rate.

[0026] Thirdly, this application also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program that can run on the processor, and the processor executes the computer program to implement the method described in the first aspect above.

[0027] Fourthly, this application also provides a computer-readable storage medium storing computer-executable instructions that, when invoked and executed by a processor, cause the processor to perform the method described in the first aspect above.

[0028] This application brings the following beneficial effects:

[0029] This application provides an array-based method, apparatus, and electronic device for diagnosing the spatiotemporal distribution of erosion rate. The erosion rate spatiotemporal distribution diagnostic system includes multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices, and diagnostic circuit components. The erosion sensor units are arranged in an array on the spacecraft surface relative to the electric thruster outlet and connected to the power supply in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate and an erosion sensor probe. The surface of the insulating substrate is coated with the erosion sensor probe, and the thermocouple is positioned on the back side of the insulating substrate via a groove. Voltage sampling devices are installed at multiple nodes of the mesh circuit, and current sampling devices are installed on multiple branches of the mesh circuit. The method can measure the current of multiple unrelated branches using the current sampling devices. The unrelated branches are determined by solving a set of non-linearly related branch currents based on Kirchhoff's current law equations. Using the current of the unrelated branches as known quantities, the current in each branch of the mesh circuit is obtained by solving the Kirchhoff current law equations, and then... The node voltage measured by the current and voltage sampling devices on each branch is used to obtain the resistance value corresponding to each erosion sensor unit through Ohm's law. The probe temperature of the erosion sensor probe is monitored by thermocouples. Based on the resistance value and probe temperature, the erosion rate of the surface perpendicular to the insulating substrate is determined by the erosion sensor probe. The change of erosion rate over time is calculated using interpolation based on the erosion rate corresponding to each erosion sensor unit in the spatial range, and the spatiotemporal distribution diagnosis result of erosion rate is obtained. In this scheme, multiple sensors are connected by a mesh circuit connection structure of array-type erosion sensor units. Then, Kirchhoff's current law is used to reduce the number of necessary sampling points. This not only improves the efficiency of spatiotemporal distribution diagnosis of erosion rate, but also realizes synchronous multi-point measurement of erosion rate at multiple locations and real-time monitoring of the spatiotemporal distribution of erosion rate. By synchronous sampling of multiple erosion sensors and interpolation algorithms, the erosion rate at multiple surface points in the spatial range is obtained, and its continuous spatiotemporal distribution is obtained. This overcomes the limitation of spatial resolution capability of single-point measurement, achieves high spatiotemporal resolution, improves data accuracy, and solves the technical problem of low spatiotemporal accuracy of the erosion data of thruster plumes on spacecraft surfaces currently diagnosed.

[0030] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 A schematic flowchart illustrating the array-based spatiotemporal distribution diagnostic method for erosion rate provided in this application embodiment;

[0033] Figure 2 A front view of the probe mounting orientation when measuring the erosion rate of a Hall thruster plume at the sensor probe position using the erosion rate spatiotemporal distribution diagnostic system provided in this application embodiment;

[0034] Figure 3 A circuit diagram of the erosion rate spatiotemporal distribution diagnostic system provided in this application embodiment;

[0035] Figure 4 This is a schematic diagram illustrating the principle of erosion rate measurement provided in an embodiment of this application.

[0036] Figure 5 This is a schematic diagram illustrating the yield of metallic silver sputtered by Xe+ ion bombardment, provided in an embodiment of this application.

[0037] Figure 6 This is a schematic diagram of the spatiotemporal distribution interpolation results of the erosion rate provided in the embodiments of this application;

[0038] Figure 7 A schematic diagram of the structure of an array-type erosion rate spatiotemporal distribution diagnostic device provided in an embodiment of this application;

[0039] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.

[0040] Icons: 100 - Erosion sensor unit; 200 - Flat panel Hall thruster; 300 - Multiple wires; 400 - Power supply; 500 - Voltage measuring device; 600 - Current measuring device. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] The terms "comprising" and "having," and any variations thereof, used in the embodiments of this application, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0043] Currently, existing equipment for studying electric propulsion erosion rates is either single-point diagnostic or uses a single probe. This single-point diagnostic method can only measure the erosion rate at a single location, making it difficult to obtain spatiotemporal distribution data of the erosion rate over a given time period. Furthermore, it requires lengthy testing, resulting in high time costs and low temporal resolution. The sensor's distance from the thruster outlet also makes it difficult to capture localized erosion hotspots. Moreover, while existing technologies indirectly estimate the erosion rate through resistance changes, which is cheaper than quartz crystal microbalances, its single-point measurement characteristics and limited spatial resolution are insufficient to meet the precise diagnostic requirements of next-generation electric propulsion systems for the spatiotemporal distribution characteristics of plume erosion. Therefore, the accuracy of currently diagnosed thruster plume erosion data on spacecraft surfaces is relatively low.

[0044] Based on this, embodiments of this application provide an array-based method, apparatus, and electronic device for diagnosing the spatiotemporal distribution of erosion rate. This method can solve the technical problem of low accuracy in the erosion data of thruster plumes on spacecraft surfaces currently diagnosed.

[0045] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0046] Figure 1 This is a flowchart illustrating an array-based spatiotemporal distribution diagnostic method for erosion rates, provided in an embodiment of this application. The method is applied to an erosion rate spatiotemporal distribution diagnostic system, which includes multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices, and diagnostic circuit components. The erosion sensor units are arranged in an array on the spacecraft surface relative to the electric thruster outlet and connected to a power supply in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate (such as a PCB or ceramic) and an erosion sensor probe (such as a silver plating). The surface of the insulating substrate is coated with the erosion sensor probe, and the thermocouple is positioned on the back side of the insulating substrate via a groove. Voltage sampling devices are installed at multiple nodes of the mesh circuit, and current sampling devices are installed on multiple branches of the mesh circuit. Figure 1 As shown, the method includes:

[0047] Step S110: Measure the current of multiple unrelated branches using a current sampling device.

[0048] Among them, the uncorrelated branches are determined by solving a set of branch currents that are not linearly correlated through Kirchhoff's current law equations for multiple branches in a mesh circuit.

[0049] As a possible implementation manner, the above diagnostic circuit component includes a power supply and multiple wires. The wires are fixed on the mounting surface and connected to the interfaces of the erosion sensor units to form a mesh circuit; the power supply is a low-voltage regulated power supply, and the output of the low-voltage regulated power supply is connected to two nodes of the mesh circuit. Among them, the low-potential node of the two nodes is grounded, and the low-potential node serves as a reference ground. Exemplarily, as Figure 2 and Figure 3 shown, the erosion rate spatio-temporal distribution diagnostic system includes: multiple erosion sensor units 100, multiple wires 300, a power supply 400, multiple voltage measuring devices 500, and multiple current measuring devices 600.

[0050] In an optional implementation manner, an erosion sensor corresponding to an erosion sensor unit is connected in each branch of the above mesh circuit. The erosion sensor serves as a resistor, and all erosion sensors are evenly arranged in the spatial range of the plume erosion rate to be diagnosed for an electric propulsion.

[0051] Exemplarily, the above mesh circuit is: a "field" - shaped mesh structure circuit formed by connecting 2m*n - m - n of the above erosion sensor units into m*n nodes; the m*n nodes correspond to m*n equations in the Kirchhoff's current law equations set, and there are 2m*n - m - n + 1 branches between the "field" - shaped mesh structure circuit and the circuit of the power supply. The 2m*n - m - n + 1 branches correspond to 2m*n - m - n + 1 unknowns, and the number of uncorrelated branches is m*n - m - n + 1.

[0052] In practical applications, the erosion sensor units are connected into a "field" - shaped mesh circuit, which has m*n nodes and 2m*n - m - n + 1 branches. There are n(m - 1)+m(n - 1)=2m*n - m - n erosion sensor units. The power supply (such as a low - voltage regulated power supply) is connected to two nodes of the circuit, with one end grounded. The voltage sampling device measures the voltages of all nodes (except the power supply node) through an analog multiplexer. The number of uncorrelated branches is the number of unknowns (2m*n - m - n + 1)-the number of equations (m*n)=m*n - m - n + 1. Therefore, the current sampling device measures the currents of m*n - m - n + 1 uncorrelated branches through precision sampling resistors and differential amplifiers. The sampled data is processed by a micro - control chip and output to a computer through USB.

[0053] For example, as Figure 2As shown, 12 erosion sensor probes are arranged in an array, with every 4*n sensors forming a circle from the inside out. The positions of each erosion sensor in the spatio-temporal resolution erosion rate measurement device can be arranged arbitrarily, and finally the erosion rate distribution in the whole space and its change over time are obtained by an interpolation algorithm. Obviously, the more sensors, the closer the relative distance, and the higher the measurement frequency, the higher the measurement accuracy. In this embodiment, as Figure 2 and Figure 3 shown, the circuits connected to the 12 erosion sensors are arranged in a "field" shape. The flat-type Hall thruster 200 is located in the center, and the sensors are located at the center of each short side, with the placement direction perpendicular to the line connecting the sensor center and the thruster center. Then the position coordinates of each sensor are (taking the intersection of the central axis of the thruster and the plane where the sensor probe is located as the origin, unit: mm): (150, 300), (-150, 3百), (300, 150), (0, 150), (-300, 150), (150, 0), (-150, 0), (300, -150), (0, -150), (-300, -150), (150, -300), (-150, -300).

[0054] In an optional implementation manner, the voltage sampling device includes a first operational amplifier, a first analog multiplexer, a tiny precision resistor, a differential amplifier, an analog-to-digital conversion chip, and a first micro-control chip; the sampling points of the voltage sampling device are connected to m*n - 2 target nodes other than the two connection nodes at both ends of the power supply; before the step of obtaining the resistance value corresponding to each erosion sensor unit according to Ohm's law based on the current in each branch and the node voltage measured by the voltage sampling device below, the method may further include the following steps:

[0055] Controlling the first analog multiplexer by the first micro-control chip to detect the node voltages of all target nodes; wherein, between the first analog multiplexer and the analog-to-digital conversion pin of the first micro-control chip, there is a function of amplifying the signal by selecting the first operational amplifier according to the power supply and the resistance value.

[0056] As an example, the current sampling device includes a sampling resistor, a second operational amplifier, a second analog multiplexer, and a second micro-control chip. The resistance value of the sampling resistor is less than or equal to the minimum resistance value of the erosion sensor unit, and the resistance value of the sampling resistor has high accuracy and low temperature drift; measuring the currents of multiple uncorrelated branches by the current sampling device may specifically include the following steps: measuring the currents of m*n - m - n + 1 uncorrelated branches by the sampling resistor, the second operational amplifier, the second analog multiplexer, and the second micro-control chip.

[0057] It should be noted that the measuring device provided in this application embodiment is suitable for measuring the erosion rate distribution over an arbitrary curved surface / spatial range over a period of time after any number of erosion sensors are connected in any way as a loop. Figure 3 Only one example of the connection configuration of the measuring device is shown.

[0058] like Figure 3 As shown, the erosion rate spatiotemporal distribution measurement device includes 12 erosion sensor units; a current and voltage sampling device (sampling the voltage of 7 nodes and the current of 4 branches); and a power supply. The sensor probes are silver-plated with a thickness of 10mm × 0.1mm × 0.002mm and are placed on a plane offset inwards by 20cm from the outlet plane of the Hall thruster. The power supply is a 0.2V low-voltage regulated power supply. The current and voltage sampling device includes an operational amplifier, an analog multiplexer, a miniature precision resistor, a differential amplifier, an analog-to-digital converter chip, and a microcontroller chip.

[0059] In step S120, the current in each branch of the mesh circuit is obtained by solving the Kirchhoff current law equations, using the current in the unrelated branches as known quantities. The resistance value of each erosion sensor unit is obtained by using Ohm's law based on the current and voltage of each branch and the node voltage measured by the sampling device.

[0060] For example, during operation, the current sampling device and the voltage sampling device poll and sample the voltage of each node and the current of each branch at a frequency of 100 kHz, and perform a measurement every 0.1 s to obtain the function of the resistance of each erosion sensor of the array-type erosion rate spatiotemporal distribution measurement device changing with time during the experiment.

[0061] In one optional implementation, the current in each branch of the mesh circuit is obtained by solving the Kirchhoff current law equations, using the current in unrelated branches as known quantities. Specifically, this may include the following steps: substituting the current in m*nm-n+1 unrelated branches measured by the current sampling device as known quantities into the Kirchhoff current law equations and solving the equations to obtain the current in each branch of the mesh circuit.

[0062] By using the multiplexing method of the voltage and current sampling devices and the Kirchhoff's law solution method, the resistance value can be solved by using the analog multiplexer to poll and sample the node voltage and unrelated branch current, thereby reducing hardware complexity and ensuring accuracy.

[0063] Step S130: Monitor the probe temperature of the erosion sensor probe using a thermocouple. Determine the erosion rate of the surface perpendicular to the insulating substrate based on the resistance value and probe temperature using the erosion sensor probe. Calculate the change in erosion rate over time using interpolation based on the erosion rate corresponding to each erosion sensor unit in the spatial range, and obtain the spatiotemporal distribution diagnosis result of the erosion rate.

[0064] As an optional implementation, an electrical connection structure is fabricated on the insulating substrate to connect with the erosion sensor probe and wires. The exposed conductor in the electrical connection structure used to connect the erosion sensor probe is covered with insulating material after coating to prevent the exposed conductor from directly contacting the plasma environment. The erosion sensor probe is a conductor coating deposited onto the insulating substrate by magnetron sputtering. The erosion rate on the surface perpendicular to the insulating substrate is determined by the erosion sensor probe based on the resistance value and probe temperature. Specifically, this may include the following steps: calculating the erosion thickness of the conductor coating based on the change in resistance value and probe temperature, and determining the erosion rate on the surface perpendicular to the insulating substrate at the location of the erosion sensor probe based on the erosion thickness of the conductor coating.

[0065] For the process of measuring the erosion rate using a single erosion sensor, for example, on a cross-section of a silver plating layer on a plane, incident high-energy particles can bombard silver atoms away from the plating layer, causing the plating layer to thin. This is similar to the Xe content commonly found in space electric propulsion plumes and backflows. + Taking ions as an example, the specified sputtering rate can be obtained based on their incident energy (eV) and incident angle, that is, the statistically obtained sputtering rate for each incident Xe + The number of silver atoms sputtered / etched away by ions. The total erosion rate of a surface can be obtained by integrating the energy and incident angle of all particles incident on that surface at a given location. .in For erosion rate, The atomic mass of the probe coating material. The density of the probe coating material. The relative spatial orientation angle of the eroded section (e.g.) Figure 4 As shown, with one side of the substrate as 0° and the other side as 180°, The energy of the incident particle, The angular number density of various incident particles (the number of incident particles per unit time per unit area at a given incident angle). Let be the particle energy distribution function. The material sputtering yield is a function of incident energy and incident angle. i (representing different particle types), Σ represents the sum of the erosion rates for different types of incident particles. In this embodiment, the thruster backflow is mainly Xe. + The sensor probe material is silver, which is affected by Xe. +The sputtering yield of particle erosion is related to the incident ion energy and ion angle as follows: Figure 5 As shown.

[0066] Because the sensor probe is small in scale relative to the thruster structure / plume (~1cm <<~40cm), such as Figure 4 As shown, the location measured by the erosion probe can be considered a single point, where the erosion rate is constant. Furthermore, since the probe cross-section can be approximated as a cuboid, and the probe height is much smaller than its width, it can be assumed that only the upper surface of the probe is affected by erosion; therefore, erosion only leads to a reduction in probe thickness. For measuring the erosion rate distribution on the spacecraft surface caused by electric thrusters, the probe material can be selected from high-energy Xe... + Materials with high sputtering rates under ion bombardment (such as silver used in this embodiment) are used to complete the erosion rate measurement on a suitable time scale.

[0067] In this embodiment, the curve of probe thickness changing over time can be calculated based on probe resistance and thermocouple data. , ,in The measured probe resistance, For time, The resistivity of the probe. The temperature is obtained from the thermocouple signal; the signal is a function of temperature. ,in For temperature, (This is the thermocouple voltage signal). The probe length is 10mm. This is the cross-sectional area of ​​the probe. The probe width is 0.1mm. The probe height is 2μm. From the above formula, we can obtain... And thus (Generally speaking, the erosion rate at a specified location is constant when the thruster is operating stably, i.e.) The probe thickness change rate (a function of change with time) obtained is the erosion rate of the silver at the sensor position on the space surface caused by the thruster backflow erosion as a function of time.

[0068] Once the erosion rate of the probe material by the plume plasma is determined, the spatiotemporal distribution of the plasma erosion rate on the spacecraft surface can be estimated based on the ratio (average) of the sputtering yield of the probe material to the spacecraft surface material. Furthermore, combining data from other plasma probes can further improve the reliability of the estimate. For example, for Xe... + In an ion-dominated electrically propelled plume plasma, all particles eroding the surface can be considered to be Xe. + Ions, if the ion current density at the sensor location is measured beforehand using a Faraday probe ( The sputtering yield can be calculated from the erosion rate, and then the average incident energy of the return ions can be obtained. Based on this incident energy and current density, the erosion rate of the return plasma on the spacecraft surface material can be estimated.

[0069] For the measurement process of the above-mentioned array-type erosion rate spatiotemporal distribution, for example, according to Kirchhoff's current law, the sum of the inflow and outflow currents at any node in the circuit is 0, that is... ,in For the current in the branches connected to the nodes, we can assume that the inflow current is positive and the outflow current is negative. In this embodiment of the resistor network, there are 9 nodes and 12 resistors. The circuit is divided into 13 branches by the nodes, corresponding to 13 branch currents. Therefore, Kirchhoff's current law equations have 13 unknowns. Since the potential of each node will be measured by a voltage sampling device (where the potential of the power supply node and ground node does not need to be measured since the power supply voltage is known), we only need to find the current in all branches to apply Ohm's law. The resistances of all erosion sensors were determined. It was found that nine equations (linearly independent) could be formulated, but there were 13 unknowns. Therefore, it was necessary to additionally measure the currents of four unrelated branches. Figure 3 As shown, in this embodiment, the currents of the power supply branch, the upper left branch, the upper right branch, and the lower right branch are selected for measurement, and the following set of equations can be established:

[0070] ;

[0071] The above system of equations is denoted as ,in The coefficient matrix marks which branches the current flows into and out of each node. Let be the current vector, where This refers to the current in the power supply branch. to These are the branch currents in the network, numbered in the order of "from left to right, from top to bottom". This is the zero vector based on Kirchhoff's current law. In this embodiment, , , , Since the given quantity is known, the current in all other branches can be calculated. Then, based on the sampled node voltage, the resistance of the erosion sensor on all branches can be calculated using the adjacent node voltage, branch current, and Ohm's law. Furthermore, the change rate of the sensor probe thickness can be calculated based on the resistance change rate of any sensor, as described above.

[0072] The change in erosion rate over time at each sensor location was calculated. Subsequently, an appropriate interpolation algorithm can be used to calculate the erosion rate distribution on the plane based on the measured data, according to the actual situation. In this embodiment, since the number of measuring points is relatively small and the known erosion rate should change continuously on the plane, and for the measurement of the erosion rate of an electric thruster, the erosion rate at a specified location when the thruster is operating stably can be considered a constant value that does not change with time. Therefore, the multiquadric kernel function interpolation of radial basis function interpolation (RBFInterpolation) is used to calculate the erosion rate distribution on the surface. The basic form of RBF interpolation is: given N sample points Construct a function , making ,in Let be the interpolation coefficients to be determined. The selected radial basis functions are determined by solving... Solve for all interpolation coefficients. The radial basis function used in this embodiment is the multiquadric kernel function, in the form of... ,in , c It is an adjustable shape parameter used to control the smoothness of a function, in this embodiment .

[0073] For example, assuming the erosion rate measurement result of all eight sensors in the outer ring is 1, and the measurement result of all four sensors in the inner ring is 2, the interpolation result is as follows: Figure 6 The image shows the spatial distribution of erosion rate at a single moment. Arranging the spatial distribution of erosion rate at different moments in a time series yields the spatiotemporal distribution of erosion rate.

[0074] The embodiments of this application can be used to study the interaction between electric propulsion plumes and spacecraft, the erosion of spacecraft surfaces, and can also be extended to diagnose the erosion rate distribution of various (low-temperature) plasma / high-energy particle environments.

[0075] By using a mesh circuit connection structure of array-type erosion sensor units, multiple sensors are connected through a mesh, and Kirchhoff's current law is used to reduce the number of necessary sampling points. This not only improves the efficiency of erosion rate spatiotemporal distribution diagnosis, but also enables simultaneous multi-point measurement of erosion rate at multiple locations and real-time monitoring of the spatiotemporal distribution of erosion rate. Through synchronous sampling of multiple erosion sensors and interpolation algorithms, the erosion rate at multiple surface points within the spatial range is obtained, and its continuous spatiotemporal distribution is then calculated. This overcomes the limitations of single-point measurement in terms of spatial resolution, achieves high spatiotemporal resolution, improves data accuracy, and solves the technical problem of low accuracy in diagnosing thruster plume erosion data on spacecraft surfaces.

[0076] The array-based spatiotemporal distribution diagnostic method for erosion rate provided in this application can serve as a low-cost, high-precision method for diagnosing the spatiotemporal distribution of erosion rate. The erosion rate spatiotemporal distribution diagnostic system provided in this application is adaptable to different numbers of sensors (2m*nmn), different installation orientations, different sensor materials (such as silver and copper), and interpolation algorithms, making it suitable for various research backgrounds (different plasma environments, spacecraft measurement ranges, etc.), thus exhibiting strong scalability.

[0077] Figure 7 A schematic diagram of an array-type spatiotemporal distribution diagnostic device for erosion rate is provided. This device can be applied to a spatiotemporal distribution diagnostic system for erosion rate, which includes multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices, and diagnostic circuit components. The erosion sensor units are arranged in an array on the spacecraft surface relative to the electric thruster outlet and connected to the power supply in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate and an erosion sensor probe. The surface of the insulating substrate is coated with the erosion sensor probe. The thermocouple is positioned on the back side of the insulating substrate via a groove. The voltage sampling devices are arranged at multiple nodes of the mesh circuit, and the current sampling devices are arranged on multiple branches of the mesh circuit. Figure 7 As shown, the array-type erosion rate spatiotemporal distribution diagnostic device 700 includes:

[0078] Measurement module 701 is used to measure the current of multiple unrelated branches through the current sampling device. The unrelated branches are determined by solving a set of non-linearly related branch currents based on Kirchhoff's current law equation for multiple branches in the mesh circuit. Measurement module 701 is also used to measure the gate voltage connected to m*n-2 nodes through the voltage sampling device.

[0079] The solution module 702 is used to obtain the current in each branch of the mesh circuit by solving the Kirchhoff current law equations, taking the current in the unrelated branch as a known quantity, and to obtain the resistance value corresponding to each erosion sensor unit by Ohm's law based on the current in each branch and the node voltage measured by the voltage sampling device.

[0080] The calculation module 703 is used to monitor the probe temperature of the erosion sensor probe through the thermocouple, determine the erosion rate of the surface perpendicular to the insulating substrate through the erosion sensor probe based on the resistance value and the probe temperature, and calculate the change of the erosion rate over time using interpolation based on the erosion rate corresponding to each erosion sensor in the spatial range, so as to obtain the spatiotemporal distribution diagnosis result of the erosion rate.

[0081] The array-type erosion rate spatiotemporal distribution diagnostic device provided in this application has the same technical features as the array-type erosion rate spatiotemporal distribution diagnostic method provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0082] An electronic device provided in this application embodiment, such as Figure 8 As shown, the electronic device 800 includes a processor 802 and a memory 801. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the steps of the method provided in the above embodiments.

[0083] See Figure 8 The electronic device also includes a bus 803 and a communication interface 804. The processor 802, the communication interface 804 and the memory 801 are connected through the bus 803. The processor 802 is used to execute executable modules, such as computer programs, stored in the memory 801.

[0084] The memory 801 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 804 (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network.

[0085] Bus 803 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 8 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0086] The memory 801 is used to store programs. After receiving an execution instruction, the processor 802 executes the program. The method executed by the apparatus defined by the process disclosed in any of the preceding embodiments of this application can be applied to the processor 802 or implemented by the processor 802.

[0087] The processor 802 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 802 or by instructions in software form. The processor 802 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 801, and processor 802 reads the information from memory 801 and, in conjunction with its hardware, completes the steps of the above method.

[0088] Corresponding to the above-described array-based spatiotemporal distribution diagnostic method for erosion rate, this application embodiment also provides a computer-readable storage medium storing computer-executable instructions. When the computer-executable instructions are invoked and executed by a processor, the computer-executable instructions cause the processor to perform the steps of the above-described array-based spatiotemporal distribution diagnostic method for erosion rate.

[0089] The array-type erosion rate spatiotemporal distribution diagnostic device provided in this application embodiment can be specific hardware on a device or software or firmware installed on the device. The implementation principle and technical effects of the device provided in this application embodiment are the same as those in the foregoing method embodiments. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the foregoing method embodiments. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can all be referred to the corresponding processes in the above method embodiments, and will not be repeated here.

[0090] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0091] For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0092] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0093] In addition, the functional units in the embodiments provided in this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0094] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the array-based erosion rate spatiotemporal distribution diagnostic method described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0095] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0096] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for diagnosing the spatiotemporal distribution of array-based erosion rates, characterized in that, Applied to the spatio-temporal distribution diagnosis system of erosion rate, the spatio-temporal distribution diagnosis system of erosion rate includes multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices and diagnostic circuit components. The erosion sensor units are arranged in an array form at the position of the spacecraft surface relative to the outlet of the electric thruster and are connected to the power supply in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate and an erosion sensor probe. The erosion sensor probe is plated on the surface of the insulating substrate. The thermocouple is arranged through a groove at the position corresponding to the back of the insulating substrate where the erosion sensor probe is located. The voltage sampling devices are arranged at multiple nodes of the mesh circuit and the current sampling devices are arranged on multiple branches of the mesh circuit; The method includes: Measuring the currents of multiple uncorrelated branches through the current sampling device, and the uncorrelated branches are determined by solving a set of branch currents that are not linearly correlated through Kirchhoff's current law equations based on multiple branches in the mesh circuit; Taking the currents of the uncorrelated branches as known quantities, obtaining the currents on each branch in the mesh circuit by solving the Kirchhoff's current law equations, and obtaining the resistance value corresponding to each erosion sensor unit according to the current on each branch and the node voltage measured by the voltage sampling device through Ohm's law; Monitoring the probe temperature of the erosion sensor probe through the thermocouple, determining the erosion rate perpendicular to the surface of the insulating substrate through the erosion sensor probe according to the resistance value and the probe temperature, and calculating the change of the erosion rate over time by using the interpolation method based on the erosion rates corresponding to each erosion sensor unit in the spatial range to obtain the spatio-temporal distribution diagnosis result of the erosion rate.

2. The method according to claim 1, characterized in that, An electrical connection structure is processed on the insulating substrate and connected to the erosion sensor probe and the wire. The bare conductor used to connect the erosion sensor probe in the electrical connection structure is covered with an insulating material after coating, so that the bare conductor is not directly in contact with the plasma environment; The erosion sensor probe is a conductor coating sputtered onto the insulating substrate by magnetron; The determining the erosion rate perpendicular to the surface of the insulating substrate through the erosion sensor probe according to the resistance value and the probe temperature includes: Calculating the eroded thickness of the conductor coating according to the change of the resistance value and the probe temperature, and determining the erosion rate at the position where the erosion sensor probe is located on the surface perpendicular to the insulating substrate according to the eroded thickness of the conductor coating.

3. The method according to claim 1, characterized in that, The mesh circuit is a "field"-shaped mesh structure circuit formed by connecting 2m*n - m - n erosion sensor units into m*n nodes; The m*n nodes correspond to the m*n equations in the Kirchhoff's current law equations. There are 2m*n - m - n + 1 branches between the "field" - shaped mesh - structure circuit and the circuit of the power supply. The 2m*n - m - n + 1 branches correspond to 2m*n - m - n + 1 unknowns, and the number of uncorrelated branches is m*n - m - n + 1; The process of obtaining the current on each branch in the mesh circuit by taking the current of the uncorrelated branches as known quantities and solving the Kirchhoff's current law equations includes: Taking the current of the m*n - m - n + 1 uncorrelated branches measured by the current sampling device as known quantities and substituting them into the Kirchhoff's current law equations for solving the equations to obtain the current on each branch in the mesh circuit.

4. The method according to claim 3, characterized in that, The voltage sampling device includes a first operational amplifier, a first analog multiplexer, a tiny precision resistor, a differential amplifier, an analog - to - digital conversion chip, and a first micro - control chip. The sampling points of the voltage sampling device are connected to m*n - 2 target nodes except the two connection nodes at both ends of the power supply. Before obtaining the resistance value corresponding to each erosion sensor unit according to the current on each branch and the node voltage measured by the voltage sampling device through Ohm's law, it further includes: Controlling the first analog multiplexer by the first micro - control chip to detect the node voltages of all the target nodes; wherein, there is a function of matching and selecting the amplified signal of the first operational amplifier according to the power supply and the resistance value between the first analog multiplexer and the analog - to - digital conversion pin of the first micro - control chip.

5. The method according to claim 3, characterized in that, The current sampling device includes a sampling resistor, a second operational amplifier, a second analog multiplexer, and a second micro - control chip, and the resistance value of the sampling resistor is less than or equal to the minimum resistance value of the erosion sensor unit; The process of measuring the current of multiple uncorrelated branches by the current sampling device includes: Measuring the current of the m*n - m - n + 1 uncorrelated branches by the sampling resistor, the second operational amplifier, the second analog multiplexer, and the second micro - control chip.

6. The method according to claim 1, characterized in that, An erosion sensor corresponding to each erosion sensor unit is connected in each branch of the mesh circuit. The erosion sensor acts as a resistor, and all the erosion sensors are evenly arranged in the spatial range of the plume erosion rate of the to - be - diagnosed electric propulsion.

7. The method according to claim 1, characterized in that, The diagnostic circuit component includes the power supply and multiple wires. The wires are fixed on the installation surface and connected to the interfaces of the erosion sensor units to form the mesh circuit. The power supply is a low - voltage regulated power supply, and the output of the low - voltage regulated power supply is connected to two nodes of the mesh circuit. Among them, the node with lower electric potential of the two nodes is used as the reference ground.

8. An array-type erosion rate spatiotemporal distribution diagnostic device, characterized in that, An erosion rate spatiotemporal distribution diagnostic system is applied, comprising multiple erosion sensor units, thermocouples, voltage sampling devices, current sampling devices, and diagnostic circuit components. The erosion sensor units are arranged in an array on the spacecraft surface relative to the electric thruster outlet and connected to a power source in the diagnostic circuit components to form a mesh circuit. Each erosion sensor unit includes an insulating substrate and an erosion sensor probe. The surface of the insulating substrate is plated with the erosion sensor probe. The thermocouple is positioned on the back side of the insulating substrate via a groove. Multiple nodes of the mesh circuit are equipped with voltage sampling devices, and multiple branches of the mesh circuit are equipped with current sampling devices. The measurement module is used to measure the current of multiple unrelated branches through the current sampling device. The unrelated branches are determined by solving a set of non-linearly related branch currents based on the multiple branches in the mesh circuit using Kirchhoff's current law equation. The solution module is used to obtain the current in each branch of the mesh circuit by solving the Kirchhoff current law equations, taking the current in the unrelated branches as a known quantity, and to obtain the resistance value corresponding to each erosion sensor unit by Ohm's law based on the current in each branch and the node voltage measured by the voltage sampling device. The calculation module is used to monitor the probe temperature of the erosion sensor probe through the thermocouple, determine the erosion rate of the surface perpendicular to the insulating substrate through the erosion sensor probe based on the resistance value and the probe temperature, and calculate the change of the erosion rate over time using interpolation based on the erosion rate corresponding to each erosion sensor in the spatial range, so as to obtain the spatiotemporal distribution diagnosis result of the erosion rate.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions that, when invoked and executed by a processor, cause the processor to perform the method according to any one of claims 1 to 7.

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