A dynamics-based charge management performance simulation method and system

Abstract

This application belongs to the field of precision measurement and specifically discloses a dynamics-based charge management performance simulation method and system. Through this application, the simulation system covers the six-degree-of-freedom control loop of the test mass and the charge management loop. The mutual coupling of the two loops makes the charge management process closer to the on-orbit situation. After the system simulation is completed, the test mass charge measurement value, the actual test mass charge value and the acceleration time series are output. The output data is post-processed to evaluate the charge management performance, which can realize dynamic simulation of the charge management process and directly reflect the complex interaction between charge accumulation, electric field and environmental factors.

Description

Technical Field

[0001] The present application belongs to the field of precision measurement, and more specifically, to a dynamics-based charge management performance simulation method and system. Background Art

[0002] Space-based gravitational wave detection is a critical frontier in precision measurement. Due to cosmic radiation, the test mass of a space-based gravitational wave detector accumulates charge over long periods of operation. This interaction with the surrounding electromagnetic field introduces unwanted acceleration interference, significantly impacting the accuracy of gravitational wave detection. Therefore, charge management systems are crucial in space-based gravitational wave detection missions and directly impact the overall performance of the detector.

[0003] The current mainstream charge management solution is to measure the mass charge value through force modulation method, and then use appropriate ultraviolet light to generate photocurrent based on the measured charge to control the charge below the required value.

[0004] To avoid interference with gravitational wave detection, the core indicator of charge management performance is to verify that the acceleration noise caused by mass charge is better than Existing evaluation methods rely on this acceleration noise metric to calculate a corresponding charge threshold based on an electrostatic force model. The charge management performance is then determined by measuring the charge of the test mass to determine whether it is below this threshold. However, this approach carries certain risks because the electrostatic force model it relies on is calculated based on static, independent, and linear assumptions, ignoring the dynamic process and complexity of charge management, particularly the coupling between the test mass dynamics and the charge management process. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the purpose of this application is to provide a dynamics-based charge management performance simulation method and system, aiming to solve the problem that the electrostatic force model relied on by the existing technology is based on static, independent and linear assumptions for calculation, and its limitations lead to high risks in charge management performance evaluation.

[0006] A first aspect of the present application relates to a dynamics-based charge management performance simulation system, comprising: a proof mass six-degree-of-freedom control loop and a charge management loop; the proof mass six-degree-of-freedom loop comprises: a sensitive probe module, a capacitive displacement sensing circuit module, a PID control module, an AC amplitude calculation module, and an electrostatic actuator module; the charge management loop comprises: a charge measurement module, an ultraviolet discharge module, and a charge accumulation module;

[0007] The sensitive probe module is configured to respectively calculate the capacitance between each control plate and the inspection mass when the inspection mass deviates from the center position, respectively calculate the capacitance difference of the six-degree-of-freedom control plates and output it to the capacitive displacement sensing circuit module; calculate the potential of the inspection mass according to the charge value on the inspection mass output by the charge accumulation module and the six-degree-of-freedom AC feedback voltage output by the electrostatic actuator module; calculate the potential of the twelve control plates according to the six-degree-of-freedom AC feedback voltage output by the electrostatic actuator module; calculate the electrostatic force that causes the inspection mass to produce a reverse offset by combining the potential of the inspection mass, the potential of the twelve control plates and the potential of the injection plate, so as to return the inspection mass to the center position, and output all the potentials to the ultraviolet discharge module;

[0008] A capacitive displacement sensing circuit module is configured to convert capacitance differences in six degrees of freedom into corresponding voltage signals;

[0009] A PID control module is configured to convert the voltage signals of the six degrees of freedom into corresponding force signals respectively;

[0010] an AC amplitude calculation module configured to calculate an amplitude combination of an AC feedback voltage applied to a sensitive probe required to generate a six-degree-of-freedom force signal;

[0011] The electrostatic actuator module is configured to combine the amplitude combination and the carrier combination of the feedback voltage to form a complete six-degree-of-freedom AC feedback voltage, and output it to the sensitive probe module;

[0012] a charge measurement module configured to generate a modulation voltage combination and apply it to four control plates with the same degree of freedom, thereby causing the proof mass to produce a corresponding modulated motion; perform orthogonal demodulation on the measured displacement of the modulated motion of the proof mass to obtain the modulation motion amplitude; calculate the charge measurement value based on the modulation motion amplitude and output it to the ultraviolet discharge module;

[0013] The UV discharge module is configured to model the LEDs used for quality inspection and the LEDs used to illuminate the plate and frame, based on an actual UV discharge device. The on / off state of each LED is controlled by a charge management method and the charge measurement value output by the charge measurement module. The UV light power and charge measurement value are combined to calculate the on-time of the turned-on LEDs. The light power, on-time of the turned-on LEDs, and the potential of each region output by the sensitive probe module are used as inputs to the photocurrent model to determine the actual UV discharge rate and output it to the charge accumulation module.

[0014] The charge accumulation module is configured to add the ultraviolet discharge rate output by the ultraviolet discharge module and the ambient charging rate to obtain a net charging rate, perform time integration on the net charging rate to obtain a charge accumulation value, superimpose the initial charge value and the charge fluctuation value on the test mass caused by charging and discharging, obtain the test mass charge value and output it to the sensitive probe module.

[0015] In some embodiments, the electrostatic force on the proof mass The calculation formula is as follows:

[0016]

[0017] in, is the direction of freedom, For the plate The capacitance between the test mass and The gradient of the direction, For the plate and the capacitance between the proof mass, To test the capacitance between the mass and the frame, For the plate The electric potential on To test the mass potential, is the plate number, taking values ​​of 1, 2, ..., 18;

[0018] The proof mass potential The calculation formula is as follows:

[0019]

[0020] in, is the total capacitance of the inertial sensor, is the charge value on the test mass.

[0021] In some embodiments, the actual ultraviolet discharge rate Calculation formula:

[0022]

[0023] in,

[0024]

[0025]

[0026] in, The number of areas divided for inspection quality, is the number of regions divided into by the plate frame, The unit photon flux is from the inspection mass The number of photoelectrons flowing out of the region, To check the quality and plate frame The potential difference between the regions, For photonics from the inspection quality The flow from one area to the other toward the plate frame The migration probability function of a region, The unit photon flux is from the plate frame The number of photoelectrons flowing into the test mass in the region, For the plate frame The potential difference between the region and the proof mass, For photoelectrons to pass from the plate frame The relative inspection quality of the flow to each area The migration probability function of a region, To check the quality The quantum yield of the region, To check the quality The ratio of ultraviolet light absorbed by each region; For the plate frame The quantum yield of the region, For the plate frame The ratio of ultraviolet light absorbed by each region, is the UV light power, is Planck's constant, is the frequency of ultraviolet light.

[0027] In some embodiments, the on / off of each LED is controlled by a charge management method and a charge measurement value output by a charge measurement module, specifically:

[0028] If the charge management mode is fast discharge or continuous discharge, it is determined based on the charge measurement value. If the charge measurement value is positive, the LED that illuminates the plate and frame is turned on. Otherwise, the LED that illuminates the quality inspection is turned on.

[0029] If the charge management mode is pulse self-discharge, the specified LED is turned on in pulse form.

[0030] In some embodiments, the duration of the LED being turned on is The calculation formula is as follows:

[0031]

[0032] in,

[0033]

[0034]

[0035]

[0036] in, is the charge measurement, is the theoretical UV discharge rate, is the gain of the charge measurement, To test the amplitude of the modulated motion of the mass at the modulation frequency, To check the quality, is the total capacitance of the inertial sensor, is the modulation voltage frequency, is the capacitance between the control plate and the proof mass in the x-direction, is the capacitance gradient in the x-direction between the control plate and the proof mass, is the modulation voltage amplitude, is the coefficient of the discharge rate from the UV light power to the test mass, and its size is related to the LED being turned on. is the UV light power.

[0037] A second aspect of the present application relates to a dynamics-based charge management performance simulation method, wherein the dynamics-based charge management performance simulation method is based on a dynamics-based charge management performance simulation system according to any embodiment of the present application, and the method comprises:

[0038] receiving a designation of charge management parameter values ​​and a charge management mode, wherein the charge management parameters include at least: a modulation voltage amplitude, a modulation voltage frequency domain, and a measurement time for a charge measurement module, and ultraviolet light power, a charge control time, a total simulation run time, and a sampling rate for ultraviolet discharge, and the charge management mode is rapid discharge, continuous discharge, or pulse self-discharge;

[0039] Perform simulation according to the specified charge management parameter values ​​and charge management method;

[0040] After the simulation is completed, the test mass charge measurement value, the test mass actual charge value and the acceleration time series are output.

[0041] In some embodiments, if the charge management mode is rapid discharge, during the simulation process, the charge measurement module operates for a corresponding period of time according to the measurement time, the ultraviolet discharge module does not operate during this stage, and other modules operate normally; after the charge measurement module is completed, the measurement average value of the last few measurement cycles is transmitted to the ultraviolet discharge module, and the ultraviolet discharge module operates for a corresponding period of time according to the charge control time. During this stage, the charge measurement module does not operate, and other modules operate normally. During the operation of the ultraviolet discharge module, the LED is turned on for a corresponding period of time according to the turn-on duration during the operation period; from the end of ultraviolet discharge until the start of rapid discharge in the next cycle, the charge measurement module and the ultraviolet discharge module do not operate; after one cycle ends, the above operation is repeated for periodic operation;

[0042] If the charge management mode is continuous discharge, all modules of the simulation system run simultaneously during the simulation process, and the charge measurement module transmits the real-time measured charge value to the UV discharge module;

[0043] If the charge management method is pulse self-discharge, during the simulation process, the charge measurement link of the simulation system does not run, other modules run normally, and the ultraviolet discharge module continues to run; the selected LED will be turned on in a pulse form and last for the entire running time. Any LED can be selected to turn on, the specified light power is a pulse signal with the same frequency as the injected potential, and the phase difference between the light pulse signal and the injected potential is specified.

[0044] In some implementations, the method further includes post-processing the output data to obtain charge measurement accuracy, charge control accuracy, and acceleration noise at each stage of charge management, and using these as indicators to determine charge management performance.

[0045] In some embodiments, the output data is post-processed to obtain the charge measurement accuracy, charge control accuracy, and acceleration noise at each stage of charge management, specifically:

[0046] Take the data for a period of time after the charge measurement value stabilizes, calculate the standard deviation of the data in this period of time, and use it as the charge measurement accuracy;

[0047] The magnitude of the mass charge value after stopping the discharge is used as the charge control accuracy;

[0048] The acceleration time series before, after and during charge management are taken and Fourier transformed to obtain the acceleration noise caused by the test mass charge in the corresponding stage.

[0049] In some embodiments, acceleration noise under different charge management methods and charge management parameters is obtained, and by comparison, it is determined that the acceleration noise of the entire charge management process meets the charge management method and charge management parameters required by the budget, thereby achieving uninterrupted gravitational wave detection during the charge management process.

[0050] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0051] (1) This application proposes a dynamics-based charge management performance simulation system, which covers the six-degree-of-freedom control loop of the test mass and the charge management loop. The mutual coupling of the two loops makes the charge management process closer to the on-orbit situation. Specifically, on the one hand, the charge management loop comprehensively simulates the entire process of inertial sensor charge management, including environmental charging, charge measurement and ultraviolet discharge processes; the six-degree-of-freedom control loop of the test mass is used to simulate the dynamic state of the test mass in the inertial sensor probe; on the other hand, the electric field of the sensitive probe module in the six-degree-of-freedom control loop of the test mass provides the corresponding on-orbit environment for the ultraviolet discharge module in the charge management loop. At the same time, the charge accumulation module in the charge management provides the sensitive probe module in the six-degree-of-freedom control loop of the test mass with the actual on-orbit test mass potential change, realizing the on-orbit process of the two dynamically coupled.

[0052] (2) This application proposes a dynamics-based charge management performance simulation method. After the system simulation is completed, the test mass charge measurement value, the test mass actual charge value and the acceleration time series are output. The output data are post-processed to evaluate the charge management performance. This can realize dynamic simulation of the charge management process and directly reflect the complex interaction between charge accumulation, electric field and environmental factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the geometric structure of the inertial sensor sensitive probe provided by this application.

[0054] Figure 2 This is a structural diagram of a dynamics-based charge management performance simulation system provided by this application.

[0055] Figure 3 This is a flow chart of a dynamics-based charge management performance simulation method provided in this application.

[0056] Figure 4 This is a result diagram of two charge measurements in two cycles during the rapid discharge process provided by an embodiment of the present application.

[0057] Figure 5 This is the change in the mass charge value during two cycles of the rapid discharge process provided by the embodiment of the present application.

[0058] Figure 6 This is the acceleration noise situation at each stage in two cycles during the rapid discharge process provided by the embodiment of the present application.

[0059] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0060] 1-12 are control plates; 13-18 are injection plates; 19 is the inspection mass; 20 is the plate frame. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0062] The term "and / or" as used herein describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. The symbol " / " as used herein indicates that the related objects are in an "or" relationship, for example, A / B means either A or B.

[0063] The terms "first" and "second" in this specification and claims are used to distinguish different objects rather than to describe a specific order of objects. For example, "first response message" and "second response message" are used to distinguish different response messages rather than to describe a specific order of response messages.

[0064] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0065] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more, for example, multiple processing units means two or more processing units, etc.; multiple elements means two or more elements, etc.

[0066] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0067] like Figure 1 As shown, the inertial sensor sensitive probe includes 1 proof mass and 18 plates, among which No. 1-12 corresponds to 12 control plates, which are used to monitor the displacement of the proof mass and control the proof mass to be located at the center position; No. 13-18 corresponds to 6 injection plates, which are used to apply the AC modulated signal for the capacitive displacement sensing circuit, that is, the injection voltage, to the proof mass.

[0068] First, a simulation system is built based on the process of inertial sensor charge management. In one embodiment, the simulation system is built using SIMULINK based on the theoretical model, but is not limited to this simulation software. This application provides a dynamics-based charge management performance simulation system, such as Figure 2As shown, it includes a six-degree-of-freedom control loop and a charge management loop. The six-degree-of-freedom loop includes a sensitive probe module, a capacitive displacement sensing circuit module, a PID control module, an AC amplitude calculation module, and an electrostatic actuator module; the charge management loop includes a charge measurement module, a UV discharge module, and a charge accumulation module.

[0069] The sensitive probe module is partly responsible for the capacitance signal caused by the displacement of the test mass. This is explained using the four X-axis plates 1 to 4 as an example. The principle is a parallel plate capacitor. Therefore, when the test mass deviates from the center position, the capacitance between the four control plates and the test mass is:

[0070]

[0071]

[0072]

[0073]

[0074] in, is the dielectric constant of vacuum, To control the area of ​​the plates facing the test mass, the four plates are identical. To check the distance between the mass and the control plate when it is in the center, To test the offset distance of the mass relative to the center position in the X direction, is the distance between the centers of the two plates on the same side of the X axis, It is the rotation angle of the test mass relative to the center position around the Z axis.

[0075] The other part of the sensitive probe module is the dynamic model of the test mass. According to the basic structure of the inertial sensor sensitive probe, the electrostatic force on the test mass is determined as:

[0076]

[0077] in, is the direction of freedom, For the plate The capacitance between the test mass and The gradient of the direction, For the plate and the capacitance between the proof mass, To test the capacitance between the mass and the frame, For the plate The electric potential on To test the mass potential, is the plate number, which can be 1, 2, ..., 18.

[0078] Among them, the plate potential is mainly divided into two parts. The potential of control plates 1 to 12 is:

[0079]

[0080] The injection plate potentials of No. 13~18 are:

[0081]

[0082] in, It is the AC feedback voltage, which is generally a 100 Hz sinusoidal voltage and comes from the electrostatic actuator module; is a high frequency carrier, is the amplitude of the high-frequency carrier, is the frequency of the high-frequency carrier, usually 100kHz, For time.

[0083] The proof mass potential is:

[0084]

[0085] in, is the total capacitance of the inertial sensor, To verify the charge value on the mass, it comes from the charge accumulation module.

[0086] The capacitance displacement sensing circuit module is responsible for converting the output capacitance signal into a voltage signal. Specifically, the conversion is obtained by directly multiplying the capacitance difference by the capacitance displacement sensing gain. The specific gain size can be set according to the circuit used and is not unique.

[0087] The PID control module is responsible for converting the voltage signals of the six degrees of freedom into corresponding force signals. In an embodiment shown, the PID toolbox of SIMULINK is directly sampled and the PID parameters are directly set using the toolbox.

[0088] The AC amplitude calculation module is responsible for generating the force signal and needs to apply feedback voltage to the sensitive probe. The specific calculation method is not unique and can be calculated based on actual conditions.

[0089] The electrostatic actuator module combines the amplitude of the AC feedback voltage determined by the AC amplitude calculation module and then combines the carrier of the AC feedback voltage to form a complete AC feedback voltage, which is then transmitted to the sensitive probe module.

[0090] In one embodiment shown, the carrier wave is controlled by frequency division, that is, different degrees of freedom are controlled by sine waves of different frequencies. The generated AC feedback voltage is input to the sensitive probe. The generation method of this AC feedback voltage is not unique and can be combined with actual generation. The corresponding electrostatic force is calculated according to the above formula inside the sensitive probe. The acceleration is obtained based on Newton's law inside the sensitive probe module. The acceleration is integrated twice with time to obtain the displacement. This is superimposed with the displacement at the previous moment to obtain the displacement of the current test mass again. The corresponding capacitance signal is generated at this displacement to control the repetition of the above process, thereby controlling the test mass to the center position.

[0091] The charge measurement module includes a modulation voltage module and a solution module. The modulation voltage module is responsible for applying a sinusoidal modulation voltage to each of the four control plates with the same degree of freedom of the sensitive probe. In one illustrated embodiment, the four control plates applied to the X-axis produce a corresponding modulation motion of the proof mass in the X-direction. The modulation voltage pattern is shown below; the principles for other directions are similar:

[0092]

[0093] in, is the modulation voltage amplitude, is the modulation voltage frequency, For time, For the plate The magnitude of the voltage fluctuation introduced by the applied modulation voltage is limited by the performance of the electrostatic actuator. The power spectrum density of the voltage noise applied in this embodiment is:

[0094]

[0095] The method to obtain the corresponding time series based on the power spectrum density is to first construct the complex frequency based on the power spectrum density and consider the random phase, and then perform inverse Fourier transform on it to obtain the corresponding time series. The complex spectrum is:

[0096]

[0097] in, represents the imaginary part, is the power spectral density, For the phase at each frequency, the phase is randomly generated during the construction process, and then the inverse Fourier transform is performed on it, and the time domain change of the voltage fluctuation can be obtained as follows:

[0098]

[0099] in, is the inverse Fourier transform.

[0100] The power spectrum density of the modulated voltage noise is obtained by referring to the above ideas. First, the complex frequency is constructed based on the power spectrum density and the random phase is considered. Then, the inverse Fourier transform is performed on it to obtain the time series fluctuation of the voltage. .

[0101] The form of the charge measurement application direction is not unique and is not limited to this embodiment.

[0102] When the voltage is applied, the test mass will move. Considering that a laser interferometer will be used to measure it in practice, its measurement accuracy is limited, and there is a certain deviation in the measured displacement. , whose size is limited by the size of the interferometer used. The actual displacement obtained is:

[0103]

[0104] in, To verify the actual displacement of the mass, is the displacement measured by the laser interferometer.

[0105] The solution module is responsible for measuring the displacement of the inspection mass , perform quadrature demodulation to obtain the modulated motion amplitude , according to the relationship between charge value and motion amplitude, multiply by the gain to get the charge measurement value. The gain of modulating motion amplitude to charge measurement value is:

[0106]

[0107] in, To check the quality, is the total capacitance of the inertial sensor.

[0108] The charge measurement value is then solved as:

[0109]

[0110] The UV discharge module is based on an actual UV discharge device. In one illustrated embodiment, the LEDs used for quality inspection and for illuminating the plates and frame of a Tianqin inertial sensor are used. Different UV discharge device placements can affect the light distribution ratio, and other situations can be reflected through the light distribution ratio.

[0111] The fast discharge and continuous discharge modes judge the positive and negative charge values ​​measured by the input charge measurement module and turn on the corresponding LED. If the charge measurement value is positive, the LED that illuminates the plate and frame is turned on. Otherwise, the LED that illuminates the quality inspection is turned on. At the same time, input the UV light power , based on the optical power and charge measurements of the turned-on LED, the duration of the LED being turned on is determined.

[0112] The duration of the on-state will take into account the relationship between the discharge rate and the optical power, which is approximately linear:

[0113]

[0114] in, is the coefficient of light power to discharge rate. Its specific value will be determined by simplifying the photocurrent model formula. The simplified idea temporarily does not consider the influence of the electric field. The photocurrent model will be described in detail below and will not be elaborated here.

[0115] Based on the above relationship and the charge measurement, the LED on-time can be calculated:

[0116]

[0117] Pulse self-discharge, since no charge measurement is performed, will turn on the specified LED in a pulsed manner and continue for the entire operating time.

[0118] After determining the LEDs that are turned on, the optical power, and the on-time, the UV discharge rate can be determined based on the photocurrent model, taking into account the actual electric field inside the inertial sensor.

[0119] The ultraviolet discharge module takes the light power, the LED on-time and the electric field of the sensitive probe module as inputs and determines the ultraviolet discharge rate according to the photocurrent model.

[0120] The photocurrent model first divides the potential of the plates and frame into 14 regions based on the inertial sensor structure. These regions are: 12 control plates with different potentials, designated as regions 1-12; 6 injection plates with the same potential, designated as region 13; and the plate frame is grounded, designated as region 14. Similarly, the proof mass surfaces corresponding to these regions are numbered identically.

[0121] The optical power entering the inertial sensor is , the corresponding photon flux is:

[0122]

[0123] in, is Planck's constant, is the frequency of ultraviolet light.

[0124] The photon flux entering the inertial sensor will be reflected and absorbed multiple times inside the sensor. Indicates inspection quality The ratio of photon flux absorbed by a region. After this region absorbs the photon flux, corresponding photoelectrons will be generated due to the photoelectric effect. The conversion effect is expressed by quantum yield. The generated photoelectrons can only affect the discharge when they flow out of the test mass and reach the plate and frame. Whether this can be achieved is also related to the electric field in which they are located. The electric field comes from the sensitive probe module of the six-degree-of-freedom control loop. The influence of the electric field is expressed by the migration probability function So the number of photoelectrons flowing out of the test mass is:

[0125]

[0126] in, To check the quality and plate frame The potential difference between the regions, To check the quality The quantum yield of the surface, To check the quality The proportion of UV light absorbed by a surface.

[0127] The corresponding number of photoelectrons flowing into the test mass is:

[0128]

[0129] in, is the potential difference between the 𝑖th region of the plate frame and the proof mass, For the plate frame The quantum yield of the surface, For the plate frame The proportion of UV light absorbed by a surface.

[0130] The outflow of photoelectrons from the test mass is defined as a positive discharge rate, and the inflow of photoelectrons into the test mass is defined as a negative discharge rate. Therefore, by summing the number of photoelectrons in all regions, the discharge rate can be obtained as:

[0131]

[0132] in, The area divided for inspection quality is 14 here. The area divided by the plate frame is 14 in size, where the potential difference comes from the sensitive probe module of the six-degree-of-freedom control loop.

[0133] The event rate of ultraviolet discharge at this time for:

[0134]

[0135] In one embodiment, the ambient charging rate is 45 e / s when considering the solar minimum, and the event rate of ambient charging is It is 2064 / s.

[0136] The charge accumulation module takes as input the UV discharge rate and the ambient charge rate, then adds them together to obtain the net charge rate. By integrating the net charge rate over time, the accumulated charge value is obtained. The initial charge value and the charge and discharge fluctuation values ​​are then added to obtain the test quality charge value, thereby establishing a charge management loop. The specific expression of the above module is:

[0137]

[0138] in, is the ambient charging rate, is the UV discharge rate, Indicates time, It is the time series of charge fluctuation caused by charging and discharging, is the initial charge on the test mass. The corresponding power spectral density is:

[0139]

[0140] in, The power spectrum density of charge fluctuations caused by ambient charging and UV discharge, is the charge of a single electron, The rate of events that charge the environment, is the event rate of UV discharge, is the frequency.

[0141] Similarly, according to the idea of ​​converting power spectrum density into time series, according to power spectrum density Considering the random phase to construct the complex frequency, and performing the inverse Fourier transform on it, we can get the charge fluctuation caused by charging and discharging .

[0142] The coupling between the above two loops includes: the inspection mass potential in the sensitive probe module of the six-degree-of-freedom control loop is closely related to the charge management loop, and the electric field of the sensitive probe module also affects the charge management loop, and there is mutual coupling between the two.

[0143] like Figure 2 As shown, the present application provides a dynamics-based charge management performance simulation method, the dynamics-based charge management performance simulation method is based on the dynamics-based charge management performance simulation system of any embodiment of the present application, the method comprising:

[0144] receiving a designation of charge management parameter values ​​and a charge management mode, wherein the charge management parameters include at least: a modulation voltage amplitude, a modulation voltage frequency domain, and a measurement time for a charge measurement module, and ultraviolet light power, a charge control time, a total simulation run time, and a sampling rate for ultraviolet discharge, and the charge management mode is rapid discharge, continuous discharge, or pulse self-discharge;

[0145] Perform simulation according to the specified charge management parameter values ​​and charge management method;

[0146] After the simulation is completed, the test mass charge measurement value, the test mass actual charge value and the acceleration time series are output.

[0147] In some embodiments, if the charge management mode is rapid discharge, during the simulation process, the charge measurement module operates for a corresponding period of time according to the measurement time, the ultraviolet discharge module does not operate during this stage, and other modules operate normally; after the charge measurement module is completed, the measurement average value of the last few measurement cycles is transmitted to the ultraviolet discharge module, and the ultraviolet discharge module operates for a corresponding period of time according to the charge control time. During this stage, the charge measurement module does not operate, and other modules operate normally. During the operation of the ultraviolet discharge module, the LED is turned on for a corresponding period of time according to the turn-on duration during the operation period; from the end of ultraviolet discharge until the start of rapid discharge in the next cycle, the charge measurement module and the ultraviolet discharge module do not operate; after one cycle ends, the above operation is repeated for periodic operation;

[0148] If the charge management mode is continuous discharge, all modules of the simulation system run simultaneously during the simulation process, and the charge measurement module transmits the measured charge value to the UV discharge module;

[0149] If the charge management method is pulse self-discharge, during the simulation process, the charge measurement link of the simulation system does not run, other modules run normally, and the ultraviolet discharge module continues to run; the selected LED will be turned on in a pulse form and last for the entire running time. The LED selected to be turned on can be arbitrarily, the specified optical power is a pulse signal with the same frequency as the injected potential, and the phase difference between the optical pulse signal and the injected potential is specified.

[0150] In some implementations, the method further includes post-processing the output data to obtain charge measurement accuracy, charge control accuracy, and acceleration noise at each stage of charge management, and using these as indicators to determine charge management performance.

[0151] In some embodiments, the output data is post-processed to obtain the charge measurement accuracy, charge control accuracy, and acceleration noise at each stage of charge management, specifically:

[0152] Take the data for a period of time after the charge measurement value stabilizes, calculate the standard deviation of the data in this period of time, and use it as the charge measurement accuracy;

[0153] The magnitude of the mass charge value after stopping the discharge is used as the charge control accuracy;

[0154] The acceleration time series before, after and during charge management are taken and Fourier transformed to obtain the acceleration noise caused by the test mass charge in the corresponding stage.

[0155] In some embodiments, acceleration noise under different charge management methods and charge management parameters is obtained, and by comparison, it is determined that the acceleration noise of the entire charge management process meets the charge management method and charge management parameters required by the budget, thereby achieving uninterrupted gravitational wave detection during the charge management process.

[0156] In an illustrated embodiment, after the simulation system is built, appropriate charge management parameters are input to simulate the entire charge link. After the simulation is completed, the charge measurement value, actual charge value and X-axis acceleration are output.

[0157] In an embodiment shown, the selected charge management mode is fast discharge, and the input charge management parameters include: modulation voltage amplitude is 1V, is 10mHz, the optical power is 10 μW, and the initial charge value is 10 6 e. The charge measurement time is 3000s, the charge control time is 200s, and the discharge interval is 5000s. The charge management simulation is performed within two cycles of 10000s and the corresponding results are output.

[0158] The charge measurement value output from the charge measurement solver module is as follows Figure 4 As shown. Take a period of time after it stabilizes and calculate its standard deviation as the measurement accuracy. The calculation principle of the standard deviation is:

[0159]

[0160] The charge value output from the charge accumulation module is as follows Figure 5 As shown, the proof mass charge value after discharge is used as the charge control accuracy.

[0161] The acceleration in the X-axis direction is output from the sensitive probe mode, and the acceleration time series corresponding to each stage is selected for Fourier transform to obtain the acceleration noise, such as Figure 6 The charge management performance is evaluated by comparing the acceleration noise at each stage. If the acceleration noise at each stage meets the budget requirements, gravitational wave detection can continue.

[0162] In summary, the present application offers the following advantages over existing technologies: This application uses comprehensive charge measurement accuracy, charge control accuracy, and acceleration noise at each stage of charge management as indicators to determine charge management performance. This method utilizes a comprehensive simulation system that combines dynamic simulation with real-time coupling. The simulation system outputs charge measurement values ​​from the charge measurement module, test mass charge values ​​from the charge accumulation module, and, most importantly, the dynamic state of the test mass from the sensitive probe module. This allows for continuous monitoring of acceleration noise changes in complex space environments, thereby more comprehensively and accurately reflecting the performance of the charge management system.

[0163] It is understandable that the detailed functional implementation of each of the above units / modules can be found in the introduction of the aforementioned method embodiment, and will not be repeated here.

[0164] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method and will not be repeated here.

[0165] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0166] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0167] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0168] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC.

[0169] The above embodiments can be implemented in whole or in part using software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions. When loaded and executed on a computer, the computer program instructions fully or partially produce the processes or functions described in the embodiments of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted via the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive (SSD)).

[0170] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0171] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A dynamics-based charge management performance simulation system, characterized in that: include: Verify mass six-degree-of-freedom control loop and charge management loop; The six-degree-of-freedom loop of the inspection mass includes: a sensitive probe module, a capacitive displacement sensing circuit module, a PID control module, an AC amplitude calculation module and an electrostatic actuator module; the charge management loop includes: a charge measurement module, a UV discharge module and a charge accumulation module; The sensitive probe module is configured to respectively calculate the capacitance between each control plate and the inspection mass when the inspection mass deviates from the center position, respectively calculate the capacitance difference of the six-degree-of-freedom control plates and output it to the capacitive displacement sensing circuit module; calculate the potential of the inspection mass according to the charge value on the inspection mass output by the charge accumulation module and the six-degree-of-freedom AC feedback voltage output by the electrostatic actuator module; calculate the potential of the twelve control plates according to the six-degree-of-freedom AC feedback voltage output by the electrostatic actuator module; calculate the electrostatic force that causes the inspection mass to produce a reverse offset by combining the potential of the inspection mass, the potential of the twelve control plates and the potential of the injection plate, so as to return the inspection mass to the center position, and output all the potentials to the ultraviolet discharge module; A capacitive displacement sensing circuit module is configured to convert capacitance differences in six degrees of freedom into corresponding voltage signals; A PID control module is configured to convert the voltage signals of the six degrees of freedom into corresponding force signals respectively; an AC amplitude calculation module configured to calculate an amplitude combination of an AC feedback voltage applied to a sensitive probe required to generate a six-degree-of-freedom force signal; The electrostatic actuator module is configured to combine the amplitude combination and the carrier combination of the feedback voltage to form a complete six-degree-of-freedom AC feedback voltage, and output it to the sensitive probe module; a charge measurement module configured to generate a modulation voltage combination and apply it to four control plates with the same degree of freedom, thereby causing the proof mass to produce a corresponding modulated motion; perform orthogonal demodulation on the measured displacement of the modulated motion of the proof mass to obtain the modulation motion amplitude; calculate the charge measurement value based on the modulation motion amplitude and output it to the ultraviolet discharge module; The UV discharge module is configured to model the LEDs used for quality inspection and the LEDs used to illuminate the plate and frame, based on an actual UV discharge device. The on / off state of each LED is controlled by a charge management method and the charge measurement value output by the charge measurement module. The UV light power and charge measurement value are combined to calculate the on-time of the turned-on LEDs. The light power, on-time of the turned-on LEDs, and the potential of each region output by the sensitive probe module are used as inputs to the photocurrent model to determine the actual UV discharge rate and output it to the charge accumulation module. The charge accumulation module is configured to add the ultraviolet discharge rate output by the ultraviolet discharge module and the ambient charging rate to obtain a net charging rate, perform time integration on the net charging rate to obtain a charge accumulation value, superimpose the initial charge value and the charge fluctuation value on the test mass caused by charging and discharging, obtain the test mass charge value and output it to the sensitive probe module.

2. The simulation system according to claim 1, wherein: The electrostatic force on the proof mass The calculation formula is as follows: in, is the direction of freedom, For the plate The capacitance between the test mass and The gradient of the direction, For the plate and the capacitance between the proof mass, To test the capacitance between the mass and the frame, For the plate The electric potential on To test the mass potential, is the plate number, taking values ​​of 1, 2, ..., 18; The proof mass potential The calculation formula is as follows: in, is the total capacitance of the inertial sensor, is the charge value on the test mass.

3. The simulation system according to claim 1, wherein: The actual ultraviolet discharge rate Calculation formula: in, in, The number of areas divided for inspection quality, is the number of regions divided into by the plate frame, The unit photon flux is from the inspection mass The number of photoelectrons flowing out of the region, To check the quality and plate frame The potential difference between the regions, For photonics from the inspection quality The flow from one area to the other toward the plate frame The migration probability function of a region, The unit photon flux is from the plate frame The number of photoelectrons flowing into the test mass in the region, For the plate frame The potential difference between the region and the proof mass, For photoelectrons to pass from the plate frame The relative inspection quality of the flow to each area The migration probability function of a region, To check the quality The quantum yield of the region, To check the quality The ratio of ultraviolet light absorbed by each region; For the plate frame The quantum yield of the region, For the plate frame The ratio of ultraviolet light absorbed by each region, is the UV light power, is Planck's constant, is the frequency of ultraviolet light.

4. The simulation system according to claim 1, wherein: The on / off of each LED is controlled by the charge management method and the charge measurement value output by the charge measurement module, specifically: If the charge management mode is fast discharge or continuous discharge, it is determined based on the charge measurement value. If the charge measurement value is positive, the LED that illuminates the plate and frame is turned on. Otherwise, the LED that illuminates the quality inspection is turned on. If the charge management mode is pulse self-discharge, the specified LED is turned on in pulse form.

5. The simulation system according to claim 1, wherein: The duration of the LED being turned on The calculation formula is as follows: in, in, is the charge measurement, is the theoretical UV discharge rate, To modulate the gain of motion amplitude to charge measurement, To test the amplitude of the modulated motion of the mass at the modulation frequency, To check the quality, is the total capacitance of the inertial sensor, is the modulation voltage frequency, is the capacitance between the control plate and the proof mass in the x-direction, is the capacitance gradient in the x-direction between the control plate and the proof mass, is the modulation voltage amplitude, is the coefficient of the discharge rate from the UV light power to the test mass, and its size is related to the LED being turned on. is the UV light power.

6. A dynamics-based charge management performance simulation method, characterized in that: The method is based on the simulation system according to any one of claims 1 to 5, and the method comprises: receiving a designation of charge management parameter values ​​and a charge management mode, wherein the charge management parameters include at least: a modulation voltage amplitude, a modulation voltage frequency domain, and a measurement time for a charge measurement module, and ultraviolet light power, a charge control time, a total simulation run time, and a sampling rate for ultraviolet discharge, and the charge management mode is rapid discharge, continuous discharge, or pulse self-discharge; Perform simulation according to the specified charge management parameter values ​​and charge management method; After the simulation is completed, the test mass charge measurement value, the test mass actual charge value and the acceleration time series are output.

7. The simulation method according to claim 6, wherein: If the charge management mode is rapid discharge, during the simulation process, the charge measurement module runs for a corresponding period of time according to the measurement time. During this stage, the ultraviolet discharge module does not run, and other modules run normally. After the charge measurement module runs, the measurement average value of the last few measurement cycles is transmitted to the ultraviolet discharge module. The ultraviolet discharge module runs for a corresponding period of time according to the charge control time. During this stage, the charge measurement module does not run, and other modules run normally. During the operation of the ultraviolet discharge module, the LED is turned on for a corresponding period of time according to the turn-on duration. From the end of ultraviolet discharge until the start of rapid discharge in the next cycle, neither the charge measurement module nor the ultraviolet discharge module runs. After one cycle ends, the above operation is repeated for periodic operation. If the charge management mode is continuous discharge, all modules of the simulation system run simultaneously during the simulation process, and the charge measurement module transmits the real-time measured charge value to the UV discharge module; If the charge management mode is pulse self-discharge, during the simulation process, the charge measurement link of the simulation system does not run, other modules run normally, and the ultraviolet discharge module continues to run; The selected LED will be turned on in a pulsed manner and will last for the entire operating time. You can choose to turn on any LED, specify the optical power as a pulse signal with the same frequency as the injection potential, and specify the phase difference between the optical pulse signal and the injection potential.

8. The simulation method according to claim 6, wherein: Also includes: The output data is post-processed to obtain the charge measurement accuracy, charge control accuracy and acceleration noise at each stage of charge management, which are used as indicators to determine the charge management performance.

9. The simulation method according to claim 8, wherein: The output data is post-processed to obtain the charge measurement accuracy, charge control accuracy and acceleration noise at each stage of charge management, specifically: Take the data for a period of time after the charge measurement value stabilizes, calculate the standard deviation of the data in this period of time, and use it as the charge measurement accuracy; The magnitude of the mass charge value after stopping the discharge is used as the charge control accuracy; The acceleration time series before, after and during charge management are taken and Fourier transformed to obtain the acceleration noise caused by the test mass charge in the corresponding stage.

10. The simulation method according to claim 9, wherein: The acceleration noise under different charge management methods and charge management parameters is obtained, and by comparison, it is determined that the acceleration noise of the entire charge management process meets the charge management method and charge management parameters required by the budget, thereby achieving uninterrupted gravitational wave detection during the charge management process.

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