Electrostatic driving system for space inertial sensor and voltage reference noise suppression method in electrostatic driving system

Abstract

The invention discloses an electrostatic driving system for a space inertial sensor and a voltage reference noise suppression method in the electrostatic driving system, and belongs to the technical field of space inertial sensor inspection quality low-noise control. According to the method, the problem that the inherent noise, the temperature drift noise and the load regulation noise of the voltage reference cannot be comprehensively suppressed by the existing method is solved. According to the invention, the inherent noise of the voltage references is suppressed by using a parallel structure of the plurality of voltage references, and on the basis of the parallel structure of the plurality of voltage references, the temperature coefficient algebraic sum of the plurality of voltage references connected in parallel is as small as possible, so that the sensitivity of the voltage references to the ambient temperature is reduced, and the purpose of suppressing the noise caused by temperature drift is achieved. And meanwhile, a differential buffer isolation structure is designed to suppress load regulation noise caused by variable output of the DAC module, so that voltage reference output fluctuation caused by load impedance change is weakened. The method can be applied to noise suppression of the voltage reference in an electrostatic driving system of a space inertial sensor.

Description

Technical Field

[0001] This invention belongs to the field of low-noise control technology for testing quality of space inertial sensors, specifically relating to an electrostatic drive system for space inertial sensors and a method for suppressing voltage reference noise in the electrostatic drive system. Background Technology

[0002] The space inertial sensor is one of the core payloads of the space gravitational wave detection satellite. The test mass (TM), as a key component, serves as the reflector of the high-precision inter-satellite laser interferometer, providing an inertial reference for laser interferometry-based gravitational wave detection. When a gravitational wave arrives, it causes a minute displacement between the test masses, resulting in a subtle change in the optical path of the laser interferometer, which can then be used to detect the gravitational wave. Based on this principle, the test mass needs to remain relatively stationary with respect to the spacecraft and be in an ideal free-fall state free from external non-conservative forces. Due to various interferences in the space environment and within the spacecraft, a drag-free control of the test mass is required via an electrostatic drive system to maintain relative stationary position between the test mass and the spacecraft.

[0003] The electrostatic drive system of a space inertial sensor mainly includes a voltage reference (REF), an FPGA controller, a DAC module, a digital-to-analog converter (DVA), and a low-pass filter (LPF). The voltage reference, as the primary source of noise in the drive circuit, significantly affects the stability of the actuator's drive circuit output voltage after its output noise is propagated through the digital-to-analog converter (DAC) and drive voltage amplifier (DVA), thereby reducing the accuracy of space inertial sensor measurements and the accuracy of quality control. Furthermore, the target of space gravitational wave detection is concentrated in the millihertz frequency band, and electrical noise in the low-frequency range of the electrostatic drive system at the millihertz level will have a significant negative impact on the detection results. Therefore, to ensure the reliability of the electrostatic control system, suppressing the voltage noise of the voltage reference output in the millihertz frequency band is particularly important.

[0004] The literature (Halloin H, Prat P, Brossard J. Long term characterization of voltage references[J]. arXiv preprint arXiv:1312.5101, 2013.) tested the point noise characteristics of some voltage reference chips in the millihertz-level operating frequency band of space inertial sensors. However, the literature only tested the output noise and did not provide a method for suppressing voltage reference noise in the millihertz-level operating frequency band.

[0005] Patent application (CN207198708U) discloses a voltage reference source with noise suppression capability. The voltage reference source includes n voltage references, an adder, and an output unit. The output terminals of the n voltage references are connected to the input terminals of the adder, and the adder is used to sum the voltages of the n voltage references. The output of the adder is connected to the input of the output unit, and the output unit performs voltage division and filtering on the voltage summation result to improve the signal-to-noise ratio of the voltage references. However, it still cannot comprehensively suppress the inherent noise, temperature drift noise, and load regulation noise of the voltage references, resulting in a relatively limited noise reduction effect, and it lacks analysis of the noise reduction mechanism.

[0006] In summary, in order to address the problem that existing voltage reference noise suppression methods cannot comprehensively suppress the inherent noise, temperature drift noise, and load regulation noise of the voltage reference, a new voltage reference noise suppression method is proposed, which is an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this invention is to address the problem that existing methods cannot comprehensively suppress the inherent noise, temperature drift noise, and load regulation noise of a voltage reference. Therefore, this invention proposes an electrostatic drive system for space inertial sensors and a method for suppressing voltage reference noise in the electrostatic drive system, so as to achieve comprehensive noise suppression of the output of the electrostatic drive circuit in the millihertz frequency band.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0009] According to one aspect of the present invention, an electrostatic drive system for a space inertial sensor is provided, the electrostatic drive system comprising an external voltage source, a first voltage reference to an nth voltage reference, a buffer, a digital-to-analog converter, and a drive module; wherein:

[0010] The output terminal of the external voltage source is connected to the input terminals of the first voltage reference to the nth voltage reference, respectively;

[0011] The output terminals of the first voltage reference to the nth voltage reference are all connected to the input terminal of the buffer;

[0012] The output of the buffer is connected to the input of the digital-to-analog converter;

[0013] The output of the digital-to-analog converter is connected to the input of the driver module.

[0014] According to another aspect of the present invention, a method for suppressing voltage reference noise in an electrostatic drive system, the method specifically includes the following steps:

[0015] Step 1: Use the output signal of the external voltage source as the input of the voltage reference parallel structure, which is composed of the first voltage reference to the nth voltage reference connected in parallel;

[0016] Step 2: Use the output signal of the parallel voltage reference structure as the input of the buffer, where the buffer is an amplifier;

[0017] Step 3: Use the output signal of the buffer as the input of the driver module, and then use the output signal of the driver module as the drive signal output.

[0018] The beneficial effects of this invention are:

[0019] This invention suppresses the inherent noise of voltage references in electrostatic drive systems by designing a parallel structure of multiple voltage references. Based on this parallel topology, the algebraic sum of the temperature coefficients of the multiple parallel voltage references is minimized. This ensures that the parallel structure formed by the multiple voltage references is a compensating structure with complementary positive and negative temperature coefficients, reducing the voltage references' sensitivity to ambient temperature and thus suppressing noise caused by temperature drift. Simultaneously, a differential buffer isolation structure is designed to suppress load regulation noise caused by the variable output of the DAC module and weaken voltage reference output fluctuations caused by load impedance changes. Compared with existing methods, this invention achieves comprehensive suppression of inherent noise, temperature drift noise, and load regulation noise, significantly improving noise reduction performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the equivalent model circuit for the voltage reference.

[0021] Figure 2 This is a block diagram of the voltage reference noise suppression method.

[0022] In the figure, the first curve corresponding to the yellow dot represents temperature remaining constant over time; the second and third curves corresponding to the yellow dot represent voltage changes at two points over time; and the fourth curve corresponding to the yellow dot represents the output voltage of the parallel structure over time. It can be seen that the output voltage fluctuation of the parallel structure is significantly smaller than that of a single voltage reference, indicating that the parallel structure can suppress inherent noise. The first curve corresponding to the blue dot represents temperature changing linearly over time; the second and third curves corresponding to the blue dot represent voltage changes at two points over time; and the fourth curve corresponding to the blue dot represents the output voltage of the parallel structure over time. It can be seen that the output voltage of the parallel structure is unaffected by temperature changes, and temperature coefficient compensation can suppress noise caused by temperature drift. The two curves corresponding to the orange dot represent the output voltage changes over time with and without a buffer, respectively. It can be seen that after adding a buffer, the output voltage fluctuation is significantly reduced.

[0023] Figure 3 This is a schematic diagram of the equivalent model of two voltage references in parallel;

[0024] In the figure, (a) is the parallel topology of the voltage reference, and (b) is the equivalent circuit of (a).

[0025] Figure 4 This is a schematic diagram of the voltage reference buffer circuit connection;

[0026] Figure 5 This is a schematic diagram illustrating the measured noise suppression effect when multiple voltage references are connected in parallel compared to a single voltage reference.

[0027] Figure 6 This is a schematic diagram of the measured noise suppression effect after positive and negative temperature coefficient compensation.

[0028] Figure 7 This is a schematic diagram illustrating the measured noise suppression effect after applying the differential buffer isolation structure.

[0029] Figure 8 This is a schematic diagram illustrating the noise suppression effect of the noise suppression method of the present invention on the output of the driving circuit. Detailed Implementation

[0030] Specific implementation method one: Combining Figure 2 This embodiment describes an electrostatic drive system for a space inertial sensor. The electrostatic drive system includes an external voltage source, a first voltage reference to an nth voltage reference, a buffer, a digital-to-analog converter (DAC), and a drive module; wherein:

[0031] The output terminal of the external voltage source is connected to the input terminals of the first voltage reference to the nth voltage reference, respectively;

[0032] The output terminals of the first voltage reference to the nth voltage reference are all connected to the input terminal of the buffer;

[0033] The output of the buffer is connected to the input of the digital-to-analog converter;

[0034] The output of the digital-to-analog converter is connected to the input of the driver module.

[0035] This embodiment eliminates the inherent noise of the voltage references by connecting n voltage references in parallel. The drive module includes an amplifier circuit (DVA) and a low-pass filter (LPF). The output of the digital-to-analog converter is connected to the input of the amplifier circuit, and the output of the amplifier circuit is connected to the input of the low-pass filter. Furthermore, to address the issue of load regulation noise caused by the variable output of the DAC module in the electrostatic drive system of a space inertial sensor, this invention designs a differential buffer isolation structure to reduce voltage reference output fluctuations caused by changes in load impedance.

[0036] Specific Implementation Method Two: This implementation method further defines Specific Implementation Method One. After the first voltage reference to the nth voltage reference are connected in parallel, the voltage output by the parallel voltage reference is:

[0037]

[0038] in, express The voltage output by the parallel voltage reference at any given time;

[0039] This represents the nominal output voltage of each voltage reference;

[0040] Indicates the total number of voltage references;

[0041] express Time of the first The random noise component of the actual output of a voltage reference.

[0042] The other steps and parameters are the same as in Specific Implementation Method 1.

[0043] In this invention, the typical output amplitude of the voltage reference is 5V or 10V.

[0044] Specific Implementation Method 3: This implementation method further defines Specific Implementation Method 2. After the first voltage reference to the nth voltage reference are connected in parallel, the power noise density spectrum of the output voltage noise of the parallel voltage references is... for:

[0045]

[0046] in, The power noise density spectrum represents the output voltage noise of a single voltage reference.

[0047] The other steps and parameters are the same as in Specific Implementation Method Two.

[0048] Specific Implementation Method Four: This implementation method further defines Specific Implementation Method Three, wherein the temperature coefficients of the first voltage reference to the nth voltage reference satisfy:

[0049]

[0050] in, Indicates the first Temperature coefficient of a voltage reference .

[0051] The other steps and parameters are the same as in Specific Implementation Method 3.

[0052] Based on the topology of multiple voltage references in parallel, this implementation further limits the number of voltage references to be connected in parallel, requiring the use of n voltage references with the smallest possible algebraic sum of temperature coefficients. Ideally, the algebraic sum of the temperature coefficients of the n voltage references in parallel should be 0. That is, through the compensation structure with complementary positive and negative temperature coefficients, noise caused by temperature drift can be suppressed, thereby reducing the sensitivity of the voltage references to ambient temperature.

[0053] Specific Implementation Method Five: This implementation method is a further limitation of Specific Implementation Method Four, wherein the first... Temperature coefficient of voltage reference The method of obtaining it is as follows:

[0054] Step 1, put the first A voltage reference is heated to a set temperature. (The specific temperature value here can be set based on experience), and record the temperature as follows. At that time, the first Output voltage of each voltage reference ;

[0055] Step 2: During the natural cooling process of the voltage reference, a set of temperature and output voltage data is collected at fixed intervals.

[0056] It should be noted that this invention uses a multimeter with an accuracy of 8.5 digits or higher to acquire the output voltage value of the voltage reference.

[0057] Step 3: Process each set of data collected in Step 2. The processing method is as follows:

[0058] For any set of data collected in step 2, compare the temperature with the temperature range in that set of data. Subtract the output voltage from the set of data and compare it with the voltage. Differences are used to create a set of processed data;

[0059] Similarly, each set of data collected in step 2 is processed separately;

[0060] Step 4: Based on the least squares method, use the processed data from each group to analyze the... The relationship between the temperature disturbance of the voltage reference and the output voltage fluctuation is fitted:

[0061]

[0062] in, , Indicates temperature difference. This represents the output voltage difference of the voltage reference.

[0063] The other steps and parameters are the same as in Specific Implementation Method Four.

[0064] Substitute the temperature difference from each group of data processed in step 3 into... Substitute the output voltage difference from each group of data processed in step 3 into... The corresponding time is determined based on the collection time of each set of data. By fitting the processed data sets, the temperature coefficient can be obtained. .

[0065] Specific Implementation Method Six: Combination Figure 2 This embodiment describes a method for suppressing voltage reference noise in an electrostatic drive system. The method specifically includes the following steps:

[0066] Step 1: Use the output signal of the external voltage source as the input of the voltage reference parallel structure, which is composed of the first voltage reference to the nth voltage reference connected in parallel;

[0067] Step 2: Use the output signal of the parallel voltage reference structure as the input of the buffer, where the buffer is an amplifier;

[0068] Step 3: Use the output signal of the buffer as the input of the driver module, and then use the output signal of the driver module as the drive signal output.

[0069] Specific Implementation Method Seven: This implementation method further defines Specific Implementation Method Six. The voltage output by the parallel voltage reference structure is:

[0070]

[0071] in, express The voltage output of the parallel structure of the voltage reference at any given time;

[0072] This represents the nominal output voltage of each voltage reference;

[0073] Indicates the total number of voltage references;

[0074] express Time of the first The random noise component of the actual output of a voltage reference.

[0075] The other steps and parameters are the same as in Specific Implementation Method Six.

[0076] Specific Implementation Method Eight: This implementation method further defines Specific Implementation Method Seven. After the first voltage reference to the nth voltage reference are connected in parallel, the power noise density spectrum of the voltage noise output by the parallel voltage reference structure is... for:

[0077]

[0078] in, The power noise density spectrum represents the output voltage noise of a single voltage reference.

[0079] The other steps and parameters are the same as in Specific Implementation Method Seven.

[0080] Specific Implementation Method Nine: This implementation method further defines Specific Implementation Method Eight, wherein the temperature coefficients of the first voltage reference to the nth voltage reference satisfy:

[0081]

[0082] in, Indicates the first Temperature coefficient of a voltage reference .

[0083] The other steps and parameters are the same as in Specific Implementation Method 8.

[0084] Specific Implementation Method Ten: This implementation method is a further limitation of Specific Implementation Method Nine, wherein the first... Temperature coefficient of voltage reference The method of obtaining it is as follows:

[0085] Step 1, put the first A voltage reference is heated to a set temperature. (The specific temperature value here can be set based on experience), and record the temperature as follows. At that time, the first Output voltage of each voltage reference ;

[0086] Step 2: During the natural cooling process of the voltage reference, a set of temperature and output voltage data is collected at fixed intervals.

[0087] It should be noted that this invention uses a multimeter with an accuracy of 8.5 digits or higher to acquire the output voltage value of the voltage reference.

[0088] Step 3: Process each set of data collected in Step 2. The processing method is as follows:

[0089] For any set of data, compare the temperature and temperature in that set of data. Subtract the output voltage from the set of data and compare it with the voltage. Differences are used to create a set of processed data;

[0090] Similarly, each set of data collected in step 2 is processed separately;

[0091] Step 4: Based on the least squares method, use the processed data from each group to analyze the... The relationship between the temperature disturbance of the voltage reference and the output voltage fluctuation is fitted:

[0092]

[0093] in, , Indicates temperature difference. This represents the output voltage difference of the voltage reference.

[0094] The other steps and parameters are the same as in Specific Implementation Method Nine.

[0095] The noise reduction mechanism of this invention is analyzed below:

[0096] Since voltage references are multi-port active devices, their equivalent modeling must consider active characteristics and cannot simply use passive equivalent approximations. Considering that the focus is on suppressing low-frequency noise, the effects of internal parasitic capacitance and inductance are ignored, retaining only the main resistive characteristics. The equivalent circuit of a single voltage reference is as follows: Figure 1 As shown, the area within the dashed box is a simplified equivalent model of the voltage reference;

[0097] Among them, R ieq and R oeq These are the input and output resistances of the voltage reference, respectively, V i V is the input voltage. out For the output voltage, R loadFor external load resistance, V s A controlled voltage source, which is influenced by factors such as output current and input voltage, can be further expressed as:

[0098] (1)

[0099] in, e represents the proportionality coefficient between the output voltage and the input voltage. in This represents the inherent noise within the voltage reference, V. ed This indicates voltage fluctuations caused by two types of external disturbances: temperature drift and load regulation.

[0100] By modeling the equivalent circuit of the voltage reference and analyzing the millihertz frequency band of interest to space inertial sensors, it was found that the inherent noise of the voltage reference in this frequency region mainly includes thermal noise, shot noise, and flicker noise. Thermal noise and shot noise are white noise, and their noise power is roughly uniform across the frequency range. However, the noise power of flicker noise increases with decreasing frequency, exhibiting... Features, among which, The value is generally between 0.8 and 1.3. For external disturbance noise other than the inherent noise of the voltage reference, the temperature drift noise and load regulation noise with the most significant noise amplitude are selected.

[0101] To address inherent noise, temperature drift noise, and load regulation noise, this invention proposes three noise suppression methods: parallel connection of multiple voltage references, temperature coefficient compensation, and buffer isolation. The overall scheme block diagram is shown below. Figure 2 As shown.

[0102] (1) Inherent noise suppression:

[0103] If the nominal output voltage of the voltage reference is V nom If the actual output random noise component is e(t), then the output voltage can be expressed as:

[0104] (2)

[0105] The noise level in the millihertz band is quantized using the power noise spectral density (NSD) output from a voltage reference; the noise is numerically equal to the square root of the noise power spectral density. According to the Wiener-Khinchin theorem, its power spectral density... It can be represented as:

[0106] (3)

[0107] The autocorrelation function representing voltage noise. It is the imaginary unit. Since it is an unbiased estimation function, the noise power spectral density and the variance of the noise components satisfy the following relationship:

[0108] (4)

[0109] As can be seen from formula (4), the larger the variance of the output voltage noise, the higher the overall noise power. Therefore, from a probabilistic and statistical perspective, variance can be used to measure noise intensity, which provides a theoretical basis for subsequent quantization noise reduction strategies.

[0110] In practical applications, it is assumed that the noise processes of each voltage reference are independent when multiple reference sources are connected in parallel. When n identical and independent voltage references are connected in parallel, according to formula (2), the output of each voltage reference can be expressed as:

[0111] (5)

[0112] In formula (5) As an independent random noise process, and in formula (2) They have the same statistical properties.

[0113] When n identical and independent voltage references are connected in parallel, the total output voltage can be equivalent to the arithmetic mean of the output voltages of each branch. If the nominal output voltage of each voltage reference is V... nom Then the output voltage of n voltage references connected in parallel can be expressed as:

[0114] (6)

[0115] According to formula (6), the voltage noise after parallel connection can be expressed as:

[0116] (7)

[0117] because As independent random noise, based on the properties of the autocorrelation function and formulas (3) and (7), the power noise density spectrum (NSD) of the output voltage noise after parallel connection is:

[0118] (8)

[0119] The same voltage reference has the same noise NSD, denoted as Then the NSD of n voltage references connected in parallel can be expressed as:

[0120] (9)

[0121] According to formula (9), the output voltage noise NSD after n voltage references are connected in parallel can be reduced to 1 / n of that of a single voltage reference. Furthermore, according to formula (4), the variance is also reduced to 1 / n of that of a single voltage reference. Therefore, the voltage noise NSD is suppressed to its original value. .

[0122] In summary, the inherent noise of voltage references can be reduced by connecting multiple voltage references in parallel.

[0123] (2) Temperature drift noise

[0124] Thermal noise in a voltage reference is caused by ambient temperature fluctuations. The temperature coefficient (TC) of the voltage reference describes the sensitivity of the output voltage to temperature changes. If the voltage reference has a positive temperature coefficient, the output voltage increases with increasing temperature; conversely, if it has a negative temperature coefficient, the output voltage decreases with increasing temperature. The relationship between temperature disturbances in a single voltage reference and output voltage fluctuations is as follows:

[0125] (10)

[0126] in, This indicates the output voltage fluctuation caused by temperature drift, expressed in parts per million per degree Celsius (ppm / °C). This indicates the temperature disturbance amplitude of the reference chip. The temperature coefficient of the voltage reference.

[0127] According to formula (10), due to the output voltage For a fixed value, the typical operating scenario of the drive circuit The range is also defined, while the temperature coefficient... The value is taken within a certain range. Therefore, this invention starts with the temperature coefficient to reduce the noise caused by temperature drift.

[0128] like Figure 3 As shown, to illustrate the temperature drift noise suppression mechanism, a model is established as follows: Figure 3 The voltage reference parallel topology shown in (a) can, according to the parallel equivalence principle, be used to... Figure 3 The circuit in (a) is equivalent to: Figure 3 The circuit in (b) shows that when two voltage references are connected in parallel, the noise of the voltage references is decomposed into the inherent noise E. t1 and E t2 and changes in ambient temperature Reference voltage fluctuation at time and ;

[0129] Among them, E t1 and E t2 This represents two independent random noise sources, which are only related to their inherent internal noise. and Only related to temperature It is related to the temperature coefficient TC but independent of it.

[0130] Because it is equivalent to Figure 3 After the series connection in (b), the total output voltage is twice the single reference voltage. During observation, the output voltage should remain constant, and the total external resistance should also remain constant. Therefore, a value of R is used. Laod The resistor is divided into two values, R. Load A resistor of 2 / 3 is used for voltage division. Based on the equivalent circuit, the voltage fluctuation after parallel connection... for:

[0131] (11)

[0132] Extending this to a system with n voltage references connected in parallel, the output voltage fluctuation of the parallel system can be calculated. :

[0133] (12)

[0134] As can be seen from formula (12), when the output voltage of the voltage reference is the same, the smaller the algebraic sum of the temperature coefficients of the parallel chips, the smaller the temperature correlation of the parallel system, and the smaller the low-frequency noise caused by temperature. Theoretically, when the algebraic sum is zero, the parallel system will exhibit the characteristic that the output voltage is independent of temperature disturbance, thereby suppressing the temperature drift noise of the voltage reference and achieving the purpose of reducing temperature drift noise under temperature disturbance environment.

[0135] Therefore, connecting a voltage reference with a positive temperature coefficient and a voltage reference with a negative temperature coefficient in parallel can reduce the coupling between the voltage output and the ambient temperature, while also reducing inherent noise. According to the principles of parallel connection, after the voltage references are connected in parallel, the total output noise power of the circuit equals the sum of the noise power of each voltage reference, and the internal resistance equals the original internal resistance in parallel. Therefore, the final output noise density... for:

[0136] (13)

[0137] in, This represents the temperature dependence factor; for voltage references with a positive temperature coefficient, For voltage references with negative temperature coefficients, Due to the equivalent internal resistance R of the voltage reference eq Much smaller than the equivalent resistance R Load Therefore, the above formula can be simplified to:

[0138] (14)

[0139] When the temperature is stable and It is zero because of the inherent internal noise E of the same voltage reference. t1 With E t2 They are approximately equal, therefore the final output voltage noise is:

[0140] (15)

[0141] Therefore, when a parallel reference chip with a TC algebraic sum of 0 is selected, temperature drift noise can theoretically be eliminated.

[0142] (3) Load regulation noise

[0143] Load regulation noise is caused by load variations in the voltage reference back-end circuitry, and the load regulation rate (LR) is a factor. I This reflects the coupling relationship between the voltage reference output voltage and the load current, which can be expressed as:

[0144] (16)

[0145] Among them, load regulation rate LR I For a given voltage reference, ∆E is a constant. I This indicates the magnitude of the output voltage fluctuation caused by the load. The change in load current due to the change in the DAC input impedance results in the following output voltage fluctuation:

[0146] (17)

[0147] in, Indicates the amplification factor of the DVA circuit. Indicates the number of bits in the DAC. This represents the DAC amplitude control word. According to formula (17), the input impedance of the DAC voltage reference pin fluctuates, which will lead to increased voltage noise. Therefore, it is necessary to optimize the voltage fluctuation caused by load disturbances to reduce the noise caused by complex regulation.

[0148] Load regulation noise suppression methods based on differential buffer isolation structures, such as... Figure 4 As shown, a precision operational amplifier with extremely low noise and bias current input is used as a buffer. Its high input impedance characteristic reduces the current consumption of the voltage reference. The stronger current carrying capacity of the operational amplifier provides a stronger driving capability for the DAC reference input pin, suppressing the current fluctuation of the voltage reference and achieving the purpose of suppressing the load regulation noise of the voltage reference.

[0149] Experimental Section

[0150] like Figure 5The figure shows the noise suppression effect of four voltage references in parallel versus a traditional single voltage reference. The voltage noise at 1 MHz is as follows: and The parallel scheme reduced the noise level by 33%.

[0151] like Figure 6 The figure shows a comparison of the noise suppression performance between a temperature-compensated dual-voltage-reference parallel system and a traditional single-voltage-reference system. The voltage noise levels at 1 MHz are respectively... and The parallel scheme reduced the noise level by 89%.

[0152] like Figure 7 The figure shows a comparison of the noise suppression effects of adding a buffer to a single voltage reference versus a traditional unbuffered single voltage reference. The voltage noise levels at 1 MHz are respectively... and The parallel scheme reduced the noise level by 37%.

[0153] like Figure 8 The figure shows a comparison between the voltage noise at 1 MHz and a traditional voltage reference without noise suppression, when 16 voltage references are connected in parallel with temperature compensation and buffering measures added. and The parallel scheme reduced the noise amplitude by 86%, demonstrating a significant noise suppression effect.

[0154] The above examples of the present invention are merely illustrative of the computational model and process of the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is impossible to exhaustively list all possible implementations here. Any obvious variations or modifications derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An electrostatic drive system for a space inertial sensor, characterized in that, The electrostatic drive system includes an external voltage source, a first voltage reference to an nth voltage reference, a buffer, a digital-to-analog converter, and a drive module; wherein: The output terminal of the external voltage source is connected to the input terminals of the first voltage reference to the nth voltage reference, respectively; The output terminals of the first voltage reference to the nth voltage reference are all connected to the input terminal of the buffer; The output of the buffer is connected to the input of the digital-to-analog converter; The output of the digital-to-analog converter is connected to the input of the driver module.

2. The electrostatic drive system for a space inertial sensor according to claim 1, characterized in that, After the first voltage reference to the nth voltage reference are connected in parallel, the voltage output by the parallel voltage reference is: in, express The voltage output by the parallel voltage reference at any given time; This represents the nominal output voltage of each voltage reference; Indicates the total number of voltage references; express Time of the first The random noise component of the actual output of a voltage reference.

3. The electrostatic drive system for a space inertial sensor according to claim 2, characterized in that, The power noise density spectrum of the output voltage noise of the parallel voltage references after the first voltage reference to the nth voltage reference are connected in parallel. for: in, The power noise density spectrum represents the output voltage noise of a single voltage reference.

4. The electrostatic drive system for a space inertial sensor according to claim 3, characterized in that, The temperature coefficients of the first voltage reference to the nth voltage reference satisfy: in, Indicates the first Temperature coefficient of a voltage reference .

5. An electrostatic drive system for a space inertial sensor according to claim 4, characterized in that, The first Temperature coefficient of voltage reference The method of obtaining it is as follows: Step 1, put the first A voltage reference is heated to a set temperature. And record the temperature as At that time, the first Output voltage of each voltage reference ; Step 2: During the natural cooling process of the voltage reference, a set of temperature and output voltage data is collected at fixed intervals. Step 3: Process each set of data collected in Step 2. The processing method is as follows: For any set of data collected in step 2, compare the temperature with the temperature range in that set of data. Subtract the output voltage from the set of data and compare it with the voltage. Differences are used to create a set of processed data; Similarly, each set of data collected in step 2 is processed separately; Step 4: Use the processed data from each group to analyze the first... The relationship between the temperature disturbance of the voltage reference and the output voltage fluctuation is fitted: in, , Indicates temperature difference. This represents the output voltage difference of the voltage reference.

6. A method for suppressing voltage reference noise in an electrostatic drive system of a space inertial sensor, characterized in that, The method specifically includes the following steps: Step 1: Use the output signal of the external voltage source as the input of the voltage reference parallel structure, which is composed of the first voltage reference to the nth voltage reference connected in parallel; Step 2: Use the output signal of the parallel voltage reference structure as the input of the buffer, where the buffer is an amplifier; Step 3: Use the output signal of the buffer as the input of the driver module, and then use the output signal of the driver module as the drive signal output.

7. The voltage reference noise suppression method in the electrostatic drive system of a space inertial sensor according to claim 6, characterized in that, The voltage output by the parallel voltage reference structure is: in, express The voltage output of the parallel structure of the voltage reference at any given time; This represents the nominal output voltage of each voltage reference; Indicates the total number of voltage references; express Time of the first The random noise component of the actual output of a voltage reference.

8. The voltage reference noise suppression method in the electrostatic drive system of a space inertial sensor according to claim 7, characterized in that, The power noise density spectrum of the voltage noise output by the parallel voltage reference structure after the first voltage reference to the nth voltage reference are connected in parallel. for: in, The power noise density spectrum represents the output voltage noise of a single voltage reference.

9. A method for suppressing voltage reference noise in an electrostatic drive system of a space inertial sensor according to claim 8, characterized in that, The temperature coefficients of the first voltage reference to the nth voltage reference satisfy: in, Indicates the first Temperature coefficient of a voltage reference .

10. A method for suppressing voltage reference noise in an electrostatic drive system of a space inertial sensor according to claim 9, characterized in that, The first Temperature coefficient of voltage reference The method of obtaining it is as follows: Step 1, put the first A voltage reference is heated to a set temperature. And record the temperature as At that time, the first Output voltage of each voltage reference ; Step 2: During the natural cooling process of the voltage reference, a set of temperature and output voltage data is collected at fixed intervals. Step 3: Process each set of data collected in Step 2. The processing method is as follows: For any set of data, compare the temperature and temperature in that set of data. Subtract the output voltage from the set of data and compare it with the voltage. Differences are used to create a set of processed data; Similarly, each set of data collected in step 2 is processed separately; Step 4: Use the processed data from each group to analyze the first... The relationship between the temperature disturbance of the voltage reference and the output voltage fluctuation is fitted: in, , Indicates temperature difference. This represents the output voltage difference of the voltage reference.

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