Wide-range electric field measurement methods, devices, equipment, and media for liquid metal probes

Abstract

This application discloses a wide-range electric field measurement method, device, equipment, and medium for a liquid metal probe, relating to the field of electric field measurement technology. The method includes: acquiring the real-time differential capacitance signal output by a differential capacitance detection electrode; obtaining the real-time displacement and offset direction of the liquid metal droplet relative to its initial equilibrium position based on a pre-calibrated capacitance-displacement correspondence; obtaining the real-time displacement change rate along the current offset direction by combining continuous sampling of the real-time displacement; when the absolute value of the real-time displacement reaches a preset displacement threshold, or the expected contact time is not greater than a preset time threshold, determining the application method of the compensation electrode and the DC control bias voltage based on a bias compensation relationship; applying the voltage and acquiring the controlled residual differential capacitance; and finally calculating the measured electric field strength value along the sensitive axis. This application can suppress liquid metal droplet contact saturation under a strong electric field and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe.

Description

Technical Field

[0001] This application relates to the field of electric field measurement technology, and in particular to wide-range electric field measurement methods, devices, equipment and media using liquid metal probes. Background Technology

[0002] Electric field strength measurement is widely used in high-voltage equipment condition monitoring, electrostatic protection, space electric field sensing, weak electric field detection, and complex electromagnetic environment assessment. Liquid metal probes, due to the excellent conductivity, deformability, and interface response characteristics of liquid metal droplets, can produce detectable displacement or morphological changes under the influence of an external electric field. They can also convert electric field signals through differential capacitance and other methods, making them suitable for flexible, miniaturized, and highly sensitive electric field measurements.

[0003] Existing liquid metal electric field probes typically encapsulate a liquid metal droplet within an elastic cavity, with capacitive sensing electrodes positioned on either side or circumferentially around the droplet. When an external electric field is applied to the probe, the liquid metal droplet deviates from its initial equilibrium position under the combined influence of electric field force, interfacial force, and elastic restoring force. The sensing electrodes output a differential capacitance signal based on the capacitance change caused by the droplet displacement, and the external electric field strength is then calculated using a pre-calibrated capacitance-electric field correspondence. To improve the measurement capability of strong electric fields, common methods include increasing the length of the elastic cavity, expanding the allowable displacement range of the droplet, reducing structural sensitivity, or employing range-based calibration.

[0004] However, the movable space of liquid metal droplets is limited by the size of the elastic cavity. Under the influence of a strong electric field, they are prone to rapid displacement to the vicinity of the cavity wall, and may even experience wall contact, stagnation, or nonlinear saturation. This causes the differential capacitance signal to lose its stable correspondence with the external electric field, affecting the accuracy and repeatability of the measurement. Simply increasing the size of the elastic cavity can increase the droplet displacement margin, but it will reduce the miniaturization of the probe and may reduce the displacement response sensitivity under weak electric fields. On the other hand, simply reducing the probe sensitivity will weaken the ability to detect weak electric fields, making it difficult to simultaneously achieve sensitive measurement in weak electric fields and wide-range measurement in strong electric fields. Therefore, how to suppress wall contact saturation of liquid metal droplets under strong electric fields and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe has become an urgent problem to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a wide-range electric field measurement method, device, equipment and medium for liquid metal probes, aiming to solve the technical problem of how to suppress the saturation of liquid metal droplets at the wall under strong electric fields and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe.

[0006] To achieve the above objectives, this application proposes a wide-range electric field measurement method for a liquid metal probe. The method is used for electric field measurement based on a liquid metal probe, which includes an elastic cavity, a liquid metal droplet disposed within the elastic cavity, a differential capacitance detection electrode for detecting the displacement of the liquid metal droplet, and a compensation electrode for applying a compensating electric field force to the liquid metal droplet. A dielectric isolation structure is provided between the compensation electrode and the liquid metal droplet. The method includes: Obtain the real-time differential capacitance signal output by the differential capacitance detection electrode; Based on the pre-calibrated capacitance-displacement correspondence, the real-time displacement and offset direction of the liquid metal droplet relative to its initial equilibrium position are determined; Based on the real-time displacement obtained from continuous sampling, the real-time displacement change rate of the liquid metal droplet along the current offset direction is determined; When the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or when the estimated contact time determined based on the real-time displacement and the rate of change of the real-time displacement is less than or equal to a preset time threshold, the application method of the compensation electrode and the DC control bias voltage are determined based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship. The DC control bias voltage is applied to the compensation electrode according to the application method described above, and the corresponding controlled residual differential capacitance is obtained. Based on the controlled residual differential capacitance, the DC control bias voltage, and the application method of the compensation electrode, the measured value of the electric field strength of the external electric field under test along the sensitive axis of the liquid metal probe is calculated.

[0007] Furthermore, to achieve the above objectives, this application also proposes a wide-range electric field measurement device for a liquid metal probe, the device comprising: The signal acquisition module is used to acquire the real-time differential capacitance signal output by the differential capacitance detection electrode. The displacement calculation module is used to determine the real-time displacement and offset direction of the liquid metal droplet relative to the initial equilibrium position based on the pre-calibrated capacitance-displacement correspondence. A rate determination module is used to determine the real-time displacement change rate of the liquid metal droplet along the current offset direction based on the real-time displacement obtained by continuous sampling. The bias determination module is used to determine the application method of the compensation electrode and the DC control bias voltage based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship when the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or when the estimated wall contact time determined based on the real-time displacement and the real-time displacement change rate is less than or equal to a preset time threshold. The compensation reading module is used to apply the DC control bias voltage to the compensation electrode according to the application method, and to obtain the corresponding controlled residual differential capacitance; The field strength calculation module is used to calculate the measured value of the electric field strength of the external electric field under test along the sensitive axis of the liquid metal probe, based on the controlled residual differential capacitor, the DC control bias voltage, and the application method of the compensation electrode.

[0008] Furthermore, to achieve the above objectives, this application also proposes a wide-range electric field measurement device for a liquid metal probe, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the wide-range electric field measurement method for the liquid metal probe as described above.

[0009] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the steps of the wide-range electric field measurement method of the liquid metal probe as described above.

[0010] One or more technical solutions proposed in this application have at least the following technical effects: First, the real-time differential capacitance signal output by the differential capacitance detection electrode is acquired. This signal reflects the position response of the liquid metal droplet under the action of the external electric field to be measured, providing input for subsequent displacement calculation. Then, based on the pre-calibrated capacitance-displacement correspondence, the real-time displacement and offset direction of the liquid metal droplet relative to the initial equilibrium position are determined, converting the capacitance change into droplet displacement with directional information, which facilitates the determination of which side of the cavity wall the droplet moves towards. Next, based on the real-time displacement obtained by continuous sampling, the real-time displacement change rate of the liquid metal droplet along the current offset direction is determined, thereby obtaining the current movement trend of the droplet and providing a basis for whether compensation is needed. When the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or the expected contact time determined based on the real-time displacement and the real-time displacement change rate is less than or equal to a preset value, the calculation is performed as follows: When the threshold value is reached, it indicates that the droplet has approached the safe boundary of the cavity wall, or that there is a risk of contact with the wall based on the current movement trend. At this point, based on the real-time displacement, offset direction, and pre-calibrated bias compensation relationship, the application method of the compensation electrode and the DC control bias voltage are determined, so that the compensation electrode and bias voltage correspond to the current offset state of the droplet. Subsequently, the DC control bias voltage is applied to the compensation electrode according to the application method, and the corresponding controlled residual differential capacitance is obtained, so that the droplet can still obtain residual displacement information through differential capacitance detection after the bias compensation intervention. Finally, based on the controlled residual differential capacitance, DC control bias voltage, and application method of the compensation electrode, the electric field strength measurement value of the external electric field to be measured along the sensitive axis of the liquid metal probe is calculated, so that the electric field calculation simultaneously utilizes the droplet residual response and the applied compensation amount. Through the above steps, this application can suppress the saturation of liquid metal droplets contacting the wall under a strong electric field and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe. Attached Figure Description

[0011] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart illustrating an embodiment of the wide-range electric field measurement method for liquid metal probes in this application. Figure 2 This is a flowchart illustrating Embodiment 2 of the wide-range electric field measurement method for liquid metal probes in this application. Figure 3This is a simplified flowchart illustrating the wide-range electric field measurement method using a liquid metal probe provided in Embodiment 2 of this application. Figure 4 This is a schematic diagram of the module structure of the wide-range electric field measurement device for liquid metal probes according to an embodiment of this application; Figure 5 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the wide-range electric field measurement method of the liquid metal probe in the embodiments of this application.

[0014] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0015] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0016] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0017] It should be noted that the executing entity of this application embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device or electric field measurement system capable of realizing the above functions. The following uses an electric field measurement system as an example to describe this embodiment and the following embodiments.

[0018] Based on this, embodiments of this application provide a wide-range electric field measurement method for a liquid metal probe, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the wide-range electric field measurement method using a liquid metal probe according to this application.

[0019] In this embodiment, the wide-range electric field measurement method of the liquid metal probe is applied to electric field measurement based on the liquid metal probe. The liquid metal probe includes an elastic cavity, a liquid metal droplet disposed in the elastic cavity, a differential capacitance detection electrode for detecting the displacement of the liquid metal droplet, and a compensation electrode for applying a compensation electric field force to the liquid metal droplet. A dielectric isolation structure is provided between the compensation electrode and the liquid metal droplet. The method includes steps S10~S60: Step S10: Obtain the real-time differential capacitance signal output by the differential capacitance detection electrode; It should be noted that, in this embodiment, the liquid metal probe includes an elastic cavity, a liquid metal droplet, a differential capacitance detection electrode, and a compensation electrode. The elastic cavity refers to a flexible or elastic insulating cavity used to contain the liquid metal droplet and allow the droplet to generate a displacement response under the action of an external electric field to be measured. The liquid metal droplet can be gallium-based liquid metal, gallium-indium alloy, or other metal droplets that remain liquid at the operating temperature and are conductive. The liquid metal droplet is located within the elastic cavity, and the differential capacitance detection electrode is positioned on both sides or opposite to the liquid metal droplet in its direction of movement to sense the capacitance change caused by the droplet's position change. The compensation electrode is isolated from the liquid metal droplet by the elastic cavity wall, dielectric layer, or insulating layer, and applies a compensation electric field force to the liquid metal droplet through a non-contact electric field. The differential capacitance detection electrode is an electrode structure positioned on both sides or opposite to the liquid metal droplet in its direction of movement to form a differential capacitance detection channel. When the liquid metal droplet's position changes, the capacitance value corresponding to the differential capacitance detection electrode changes. A compensation electrode is an electrode structure used to receive DC control bias voltage and generate a compensation electric field. The compensation electrode can be connected to the drive terminal or reference terminal in different application methods. A dielectric isolation structure is an insulating structure located between the compensation electrode and the liquid metal droplet, used to prevent direct conduction between the two while allowing the compensation electric field to act on the liquid metal droplet. It can be an elastic cavity wall, a dielectric layer, or an insulating layer. A real-time differential capacitance signal is the capacitance difference signal output by the differential capacitance detection electrode at the current sampling time. This signal can be obtained by subtracting the capacitance values ​​of the two detection electrodes, or it can be directly output by the differential capacitance detection circuit.

[0020] Understandably, the electric field measurement system can acquire the output signal of the differential capacitance detection electrode according to a preset sampling period. The preset sampling period can be set based on the droplet response speed, detection circuit bandwidth, and compensation control response time, for example, to a millisecond or sub-millisecond sampling period. Before acquisition, the detection channel can be zero-point calibrated to obtain the zero-position capacitance signal corresponding to the initial equilibrium position. This step, by acquiring the droplet position change signal differentially, can reduce the effects of common-mode interference, temperature drift, and some parasitic capacitance, providing stable input data for subsequent displacement calculation.

[0021] Step S20: Determine the real-time displacement and offset direction of the liquid metal droplet relative to the initial equilibrium position based on the pre-calibrated capacitance-displacement correspondence. It should be noted that the capacitance-displacement correspondence refers to the calibration relationship between the differential capacitance signal and the displacement of the liquid metal droplet. This relationship can be a lookup table interpolation relationship, a piecewise linear relationship, or a polynomial fitting relationship. The initial equilibrium position refers to the position of the liquid metal droplet when it is in equilibrium within the elastic cavity under conditions where there is no external electric field to be measured or a reference electric field. The real-time displacement refers to the current displacement of the liquid metal droplet relative to the initial equilibrium position. The offset direction refers to the direction in which the liquid metal droplet moves relative to the initial equilibrium position toward the first or second side cavity wall. The first and second side cavity walls refer to the cavity wall regions distributed on both sides of the initial equilibrium position along the sensitive axis of the liquid metal probe.

[0022] In practice, the electric field measurement system first acquires the capacitance values ​​corresponding to the first and second detection electrodes, and then obtains the real-time differential capacitance value. The real-time differential capacitance value is compared with the zero-position differential capacitance value to obtain the differential capacitance offset. Subsequently, using a pre-calibrated capacitance-displacement correspondence, the differential capacitance offset is converted into a real-time displacement. A positive or negative differential capacitance offset corresponds to the droplet's displacement towards different cavity wall directions. In this example, the capacitance-displacement correspondence can be obtained during the factory calibration stage. During calibration, the liquid metal droplet is positioned at multiple known displacement locations, and the corresponding differential capacitance values ​​are recorded to form lookup table data or a fitting curve. If temperature changes affect the elastic cavity size or electrode spacing, the current temperature value can be used as a correction parameter to correct the zero-position differential capacitance value or calibration coefficient. This step converts the capacitance signal into a displacement with directional information, providing a clear basis for subsequent selection of compensation electrodes and determination of compensation voltage, reducing the directional uncertainty caused by relying solely on capacitance amplitude.

[0023] Step S30: Based on the real-time displacement obtained by continuous sampling, determine the real-time displacement change rate of the liquid metal droplet along the current offset direction; It should be noted that the real-time displacement change rate refers to the rate at which the displacement of the liquid metal droplet changes over time, reflecting the current motion trend of the droplet. The real-time displacement change rate along the current offset direction refers to the velocity component corresponding to the droplet moving closer to the cavity wall on the current offset side.

[0024] Understandably, the electric field measurement system continuously acquires real-time displacements at multiple sampling times. To reduce the impact of single-point noise, multiple real-time displacements can be processed using moving averages, median filtering, or low-pass filtering. The displacement change rate is then determined based on the displacement difference between adjacent sampling times or at intervals of several sampling periods. When the real-time displacement change rate indicates that the droplet is approaching the cavity wall, this rate is used as the displacement change rate in the direction of approaching the cavity wall; when the real-time displacement change rate indicates that the droplet is moving away from the cavity wall, the displacement change rate in the direction of approaching the cavity wall can be taken as zero. This step not only obtains the droplet's current position but also its movement trend, thus allowing for the identification of saturation risks before the droplet reaches the cavity wall, providing a basis for applying compensation voltage in advance.

[0025] Step S40: When the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or when the estimated contact time determined based on the real-time displacement and the rate of change of the real-time displacement is less than or equal to a preset time threshold, the application method of the compensation electrode and the DC control bias voltage are determined based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship. It should be noted that the preset displacement threshold refers to the droplet displacement boundary value used to trigger compensation. This threshold can be set according to the cavity wall's ultimate displacement, for example, taking 60% to 95% of the cavity wall's ultimate displacement amplitude. A value that is too small will cause compensation to intervene too early, while a value that is too large may result in insufficient compensation space after the droplet approaches the cavity wall. The estimated contact time refers to the remaining motion time estimated based on the droplet's current position and the rate of change of displacement in the direction approaching the cavity wall. The preset time threshold refers to the time boundary value used to trigger compensation, which can be determined based on the sampling period, droplet damping response time, and DC control bias voltage establishment time, for example, taking the time corresponding to several sampling periods, or not less than the time required for the bias voltage to stabilize. The bias compensation relationship refers to the calibration relationship between the compensation requirement and the DC control bias voltage under different compensation electrode application methods. This relationship can be a lookup table relationship, a piecewise fitting relationship, or a conversion relationship obtained based on an equivalent electric field force model. The compensation electrode application method refers to the connection method in which the compensation electrodes participate in the drive, which can include the target compensation electrode group, the wiring status of the drive end and the reference end, and the direction markings. The driving terminal refers to the electrode that receives the DC control bias voltage, while the reference terminal refers to the electrode that serves as a voltage reference. Direction markings are used to distinguish whether the compensating electric field force acts in the first or second direction.

[0026] Understandably, when the absolute value of the real-time displacement reaches a preset displacement threshold, or the expected contact time with the wall is not greater than a preset time threshold, the electric field measurement system selects the corresponding compensation electrode group based on the offset direction. Subsequently, the compensation requirement is determined based on the real-time displacement, the rate of change of displacement in the direction approaching the cavity wall, and the preset target displacement. The preset target displacement can be set near the initial equilibrium position or within the linear response range of the cavity. Finally, the amplitude of the DC control bias voltage is obtained through the bias compensation relationship, and the output port and wiring status are determined in conjunction with the compensation electrode application method. Compensation triggering depends not only on the magnitude of the displacement but also on the droplet's motion trend; for droplets rapidly approaching the wall, early intervention is possible, while unnecessary compensation is avoided for droplets slowly offsetting or returning to the center, thereby improving the targeting and stability of the compensation control.

[0027] In practice, the preset displacement threshold can be determined based on the limiting displacement amplitude of the cavity wall corresponding to the current offset direction of the liquid metal droplet, and satisfies the following relationship: In the formula, To preset the displacement threshold, This represents the limiting displacement amplitude of the cavity wall corresponding to the current offset direction of the liquid metal droplet. It is a preset proportional coefficient that is greater than 0 and less than 1.

[0028] The preset time threshold is determined based on at least one of the sampling period of the differential capacitance detection electrode, the damping response time of the liquid metal droplet in the elastic cavity, and the establishment time of the DC control bias voltage.

[0029] Step S50: Apply the DC control bias voltage to the compensation electrode according to the application method, and obtain the corresponding controlled residual differential capacitance; It should be noted that the DC control bias voltage refers to the DC drive voltage applied to the compensation electrode to generate the compensation electric field force. The controlled residual differential capacitance refers to the residual capacitance signal output by the differential capacitance detection electrode after the DC control bias voltage is applied and after necessary correction.

[0030] Understandably, the electric field measurement system outputs a DC control bias voltage to the compensation electrode according to a defined application method. To avoid droplet overshoot caused by voltage abrupt changes, the output voltage can be limited and its rate of change constrained. The voltage limit can be set based on the dielectric breakdown voltage, the distance between the compensation electrodes, and the rated output capability of the drive circuit. The rate of change constraint can be set based on the droplet damping response time and sampling period. During the application of the DC control bias voltage, the differential capacitance detection electrode is still used to detect the droplet position. The detection method can employ AC detection signal superposition, frequency selection, or synchronous demodulation to reduce the impact of the DC bias on the capacitance detection channel. If the compensation voltage causes parasitic capacitance shift, the differential capacitance detection value under bias can be corrected using a pre-calibrated bias parasitic capacitance correction relationship to obtain the controlled residual differential capacitance. This step can still obtain the capacitance signal corresponding to the droplet residual displacement after the compensation electric field force is introduced, ensuring that the measurement in strong electric field scenarios does not only rely on the compensation voltage but also retains the actual droplet response information.

[0031] Step S60: Calculate the measured value of the electric field strength of the external electric field under test along the sensitive axis of the liquid metal probe, based on the controlled residual differential capacitor, the DC control bias voltage, and the application method of the compensation electrode.

[0032] It should be noted that the sensitive axis direction refers to the measurement direction in which the liquid metal probe is most sensitive to changes in the external electric field, which is usually consistent with the main displacement direction of the liquid metal droplet. The electric field component corresponding to the residual displacement refers to the residual response of the external electric field calculated based on the controlled residual differential capacitance. The active compensation electric field component refers to the compensation amount calculated based on the DC control bias voltage and the application method of the compensation electrode.

[0033] Understandably, the electric field measurement system first obtains the electric field component corresponding to the residual displacement based on the controlled residual differential capacitance and the residual capacitance-electric field correspondence. Then, it obtains the active compensation electric field component based on the DC control bias voltage, the application method of the compensation electrodes, and the bias voltage-compensation electric field correspondence. The application method of the compensation electrodes provides a directional indicator to determine the positive or negative relationship of the active compensation electric field component along the sensitive axis. Subsequently, the electric field component corresponding to the residual displacement is combined with the active compensation electric field component with directional information to obtain the measured electric field strength value of the external electric field to be measured along the sensitive axis. The electric field strength calculation utilizes both the droplet residual displacement information and the applied compensation voltage information, allowing the droplet to reflect a strong external electric field through the compensation voltage even when confined to a small displacement range, thereby expanding the effective measurement range.

[0034] Furthermore, when the absolute value of the real-time displacement is less than the preset displacement threshold and the expected contact time is greater than the preset time threshold, the electric field strength measurement value of the external electric field to be measured along the sensitive axis of the liquid metal probe is calculated based on the real-time differential capacitance signal and the pre-calibrated capacitance-electric field correspondence.

[0035] When the absolute value of the real-time displacement is less than the preset displacement threshold and the expected contact time is greater than the preset time threshold, it indicates that the liquid metal droplet has not yet approached the cavity wall and will not contact the wall in a short time according to the current movement trend. At this time, the electric field measurement system can directly calculate the electric field strength measurement value of the external electric field along the sensitive axis of the liquid metal probe without applying a DC control bias voltage to the compensation electrode.

[0036] The absolute value of real-time displacement refers to the magnitude of the liquid metal droplet's offset from its initial equilibrium position, characterizing the degree to which the droplet deviates from its initial equilibrium position. The preset displacement threshold is the displacement boundary used to determine whether to enter the compensation measurement mode; it can be set based on the limit displacement of the elastic cavity wall, the droplet's linear response range, and a safety margin. The estimated wall contact time is the remaining motion time estimated based on the droplet's current position and the rate of change of displacement in the direction approaching the cavity wall. The preset time threshold is the time boundary used to determine whether early compensation intervention is needed; it can be set based on the sampling period, the droplet's damping response time, and the DC control bias voltage establishment time. The capacitance-electric field correspondence refers to the pre-calibrated relationship between the real-time differential capacitance signal and the external electric field strength to be measured. This relationship can be a lookup table interpolation relationship, a piecewise linear relationship, or a fitted curve, used to convert the differential capacitance signal into an external electric field strength when no DC control bias voltage is applied.

[0037] In practice, the electric field measurement system first determines whether the absolute value of the real-time displacement is less than a preset displacement threshold and whether the expected contact time is greater than a preset time threshold. If both conditions are met, the compensation electrode remains in an undriven or reference-biased state, and the real-time differential capacitance signal output by the differential capacitance detection electrode is read. Subsequently, based on the pre-calibrated capacitance-electric field correspondence, the real-time differential capacitance signal is converted into a measured value of the electric field strength along the sensitive axis of the external electric field to be measured. When the droplet is within the safe displacement range, the electric field strength is directly calculated using the differential capacitance signal, reducing the parasitic effects and driving interference caused by the intervention of the compensation voltage. When the droplet approaches the risk of saturation, the system switches to the compensation measurement process, which can balance the sensitivity of weak electric field measurement and the measurement range of strong electric field measurement.

[0038] This embodiment detects the displacement of liquid metal droplets using differential capacitance and applies a DC-controlled bias voltage when the droplet approaches the cavity wall or faces a risk of wall-tethering. The external electric field strength is then calculated by combining the controlled residual differential capacitance and the DC-controlled bias voltage, forming a measurement process that integrates detection, prediction, compensation, and calculation. This process reduces the possibility of droplet saturation under strong electric fields without increasing the size of the elastic cavity, while retaining the sensitive response of droplet displacement detection under weak electric fields. This improves the measurement continuity and applicability of the liquid metal probe across different electric field strength ranges.

[0039] As an example, the real-time differential capacitance signal includes a first capacitance value corresponding to the first differential capacitance detection electrode and a second capacitance value corresponding to the second differential capacitance detection electrode; determining the real-time displacement and offset direction of the liquid metal droplet relative to the initial equilibrium position according to a pre-calibrated capacitance-displacement correspondence includes: calculating the difference between the first capacitance value and the second capacitance value to obtain a real-time differential capacitance value; comparing the real-time differential capacitance value with the temperature-corrected zero-position differential capacitance value to obtain a differential capacitance offset; determining the real-time displacement of the liquid metal droplet relative to the initial equilibrium position according to the differential capacitance offset and the pre-calibrated capacitance-displacement correspondence; and determining the offset direction of the liquid metal droplet relative to the initial equilibrium position according to the sign of the differential capacitance offset; wherein the capacitance-displacement correspondence is a lookup table interpolation relationship, a piecewise linear relationship, or a polynomial fitting relationship.

[0040] It should be noted that the first capacitance value refers to the current capacitance value formed between the first differential capacitance detection electrode and the liquid metal droplet, and the second capacitance value refers to the current capacitance value formed between the second differential capacitance detection electrode and the liquid metal droplet; the real-time differential capacitance value refers to the difference between the first capacitance value and the second capacitance value; the zero-position differential capacitance value refers to the differential capacitance reference value corresponding to the liquid metal droplet at its initial equilibrium position; the temperature-corrected zero-position differential capacitance value refers to the reference value obtained after compensating the zero-position differential capacitance value according to the current temperature value; the differential capacitance offset refers to the offset of the real-time differential capacitance value relative to the temperature-corrected zero-position differential capacitance value; the capacitance-displacement correspondence can be a lookup table interpolation relationship, a piecewise linear relationship, or a polynomial fitting relationship, used to represent the correspondence between the differential capacitance offset and the liquid metal droplet displacement.

[0041] Understandably, the electric field measurement system first acquires the first capacitance value corresponding to the first differential capacitance detection electrode and the second capacitance value corresponding to the second differential capacitance detection electrode. The first and second differential capacitance detection electrodes can be arranged on opposite sides of the liquid metal droplet's direction of movement, so that when the droplet shifts to one side, the capacitance value on one side increases and the capacitance value on the other side decreases, thereby forming a differential detection signal.

[0042] Then, the electric field measurement system obtains the real-time differential capacitance value based on the first and second capacitance values. The real-time differential capacitance value can retain its sign; the sign indicates the direction of the droplet's offset relative to its initial equilibrium position, and the magnitude indicates the degree of droplet offset. To reduce the influence of zero-point drift in the detection circuit, the zero-point differential capacitance value corresponding to the initial equilibrium position can be recorded when the liquid metal probe is in a condition without an external electric field to be measured or a reference electric field.

[0043] Based on this, the electric field measurement system acquires the current temperature value and corrects the zero-point differential capacitance value according to pre-calibrated temperature compensation data. The temperature compensation data can be derived from zero-point calibration results under different temperature conditions. For example, zero-point differential capacitance values ​​can be recorded at multiple temperature points, and then the zero-point differential capacitance value corresponding to the current temperature value can be obtained through table lookup interpolation or piecewise linear relationships. The current temperature value can be obtained from a temperature sensor located near the probe, and the temperature correction range can be determined based on the operating environment of the liquid metal probe.

[0044] Next, the electric field measurement system compares the real-time differential capacitance value with the temperature-corrected zero-point differential capacitance value to obtain the differential capacitance offset. A positive differential capacitance offset indicates that the liquid metal droplet has shifted towards the first side cavity wall; a negative differential capacitance offset indicates that the liquid metal droplet has shifted towards the second side cavity wall. The correspondence between the first and second side cavity walls can be determined during the probe calibration stage and should be consistent with the wiring direction of the detection electrodes.

[0045] Furthermore, the electric field measurement system determines the real-time displacement of the liquid metal droplet relative to its initial equilibrium position based on the differential capacitance offset and the capacitance-displacement correspondence. If a lookup table interpolation relationship is used, the two calibration points adjacent to the differential capacitance offset can be found in the calibration table, and the real-time displacement can be obtained through interpolation. If a piecewise linear relationship is used, the corresponding linear coefficient can be called based on the interval containing the differential capacitance offset. If a polynomial fitting relationship is used, the differential capacitance offset can be substituted into the fitting relationship to obtain the real-time displacement.

[0046] In this example, the polynomial fitting relationship can be expressed as: In the formula, For real-time displacement, This is the differential capacitor offset. This is the current temperature value. to A pre-calibrated coefficient related to the current temperature value. This represents the order of the polynomial fitting relationship. The polynomial order can be determined based on the calibration error and computational complexity. For example, when a low-order fitting can meet the error requirements, a first-order or second-order fitting relationship is preferred.

[0047] After completing the real-time displacement calculation, the electric field measurement system determines the offset direction based on the sign of the differential capacitance offset and outputs both the real-time displacement and the offset direction to the subsequent compensation and judgment process. If the differential capacitance offset is close to zero, the offset direction can be maintained as the previous valid direction, or the droplet state can be recorded as close to the equilibrium position to avoid frequent direction switching near the zero point.

[0048] This example uses a first capacitance value and a second capacitance value to form a differential capacitance signal, which can reduce the impact of common-mode interference and some parasitic capacitance changes on displacement detection. The differential capacitance offset is calculated using the temperature-corrected zero-point differential capacitance value, reducing zero-point drift caused by temperature changes. Real-time displacement is calculated by interpolation through table lookup, piecewise linear relationship, or polynomial fitting relationship, so that the capacitance signal can be converted into a droplet displacement with directional information, providing basic data for subsequent wall contact time determination, compensation electrode selection, and DC control bias voltage determination.

[0049] As an example, determining the application method of the compensation electrode and the DC control bias voltage based on the real-time displacement, the offset direction, and a pre-calibrated bias compensation relationship includes: determining a target compensation electrode group among at least two groups of compensation electrodes based on the offset direction; determining the application method of the compensation electrode based on the target compensation electrode group and the offset direction, the application method including the target compensation electrode group, the wiring state of the driving end and the reference end, and a direction indicator determined by the wiring state; determining a target compensation force amplitude based on the real-time displacement, a preset target displacement, and the displacement change rate of the liquid metal droplet along the direction approaching the cavity wall; determining the amplitude of the DC control bias voltage based on the target compensation force amplitude and the pre-calibrated bias compensation relationship; and determining the DC control bias voltage based on the amplitude of the DC control bias voltage and the application method of the compensation electrode.

[0050] It should be noted that the target compensation electrode group refers to a group of compensation electrodes that participate in applying the compensation electric field force under the current offset direction of the liquid metal droplet; the compensation electrode application method refers to the combination of the target compensation electrode group, the wiring status of the driving end and the reference end, and the direction marking; the direction marking can be a symbol used to distinguish the first side compensation direction and the second side compensation direction; the target compensation force amplitude refers to the magnitude of the compensation force that needs to be applied to suppress the liquid metal droplet from continuing to approach the cavity wall; the preset target displacement refers to the displacement amplitude that the droplet is expected to maintain after compensation intervention, which can be located near the initial equilibrium position or within the linear response range; the bias compensation relationship refers to the pre-calibrated correspondence between the target compensation force amplitude and the DC control bias voltage amplitude.

[0051] Understandably, the first step is to select the target compensation electrode group based on the offset direction of the liquid metal droplet. If the offset direction points towards the first side cavity wall, a compensation electrode group capable of generating the second side compensation direction is selected; if the offset direction points towards the second side cavity wall, a compensation electrode group capable of generating the first side compensation direction is selected. The compensation electrodes consist of at least two groups, each corresponding to the compensation requirements under two opposite offset directions of the droplet.

[0052] Then, the method of applying the compensation electrodes is determined based on the target set of compensation electrodes and the offset direction. The method of applying the compensation electrodes may include: which set of compensation electrodes serves as the driving end, which set serves as the reference end, and the direction indicator corresponding to this wiring state. The direction indicator can be +1 or -1, used to distinguish the direction of the compensation component in subsequent electric field strength calculations.

[0053] Next, the target compensation force amplitude is determined based on the real-time displacement, the preset target displacement, and the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall. In this example, the target compensation force amplitude can be expressed as: In the formula, The target compensation force amplitude is non-negative, and the direction of the target compensation force is determined by the method of applying the compensation electrode. The equivalent displacement compensation coefficient is pre-calibrated, and its unit can be Newtons per meter. For real-time displacement, To preset the target displacement amplitude, The equivalent damping compensation coefficient is pre-calibrated and can be expressed in Newton-seconds per meter. Let be the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall. In this formula, the dimensions of the displacement deviation term and the velocity damping term are both force.

[0054] The preset target displacement amplitude can be set according to the droplet's linear response range, and is usually less than the preset displacement threshold. If the real-time displacement amplitude does not exceed the preset target displacement amplitude, the displacement deviation term is zero; if the droplet is moving away from the cavity wall, the displacement change rate in the direction approaching the cavity wall is zero. This reduces the frequent intervention of the compensation voltage within the safe displacement range.

[0055] Furthermore, the DC control bias voltage amplitude is determined based on the target compensation force amplitude and the bias compensation relationship. The bias compensation relationship can be obtained through calibration: under different compensation electrode application methods, record the DC control bias voltage amplitudes corresponding to multiple compensation force amplitudes, and form a lookup table relationship or a piecewise fitting relationship. In use, select the corresponding calibration data according to the current compensation electrode application method, and then obtain the DC control bias voltage amplitude from the target compensation force amplitude.

[0056] Based on this, the DC control bias voltage amplitude is combined with the compensation electrode application method to obtain the DC control bias voltage to be applied. The magnitude of the DC control bias voltage is determined by the bias compensation relationship, and the application port, reference port, and direction indicator are determined by the compensation electrode application method. The amplitude of the DC control bias voltage can be limited by the dielectric breakdown voltage, the compensation electrode spacing, and the rated output range of the drive circuit.

[0057] This example selects the compensation electrode set based on the droplet's offset direction and determines the target compensation force amplitude by combining real-time displacement and wall-to-wall movement trends, ensuring that the compensation voltage matches the droplet's current state. Simultaneously, a pre-calibrated bias compensation relationship is used to determine the DC control bias voltage, reducing reliance on the assumption of an ideal electrode structure. Therefore, the compensation electrode application method and the DC control bias voltage can correspond to the droplet's offset direction, displacement amplitude, and movement trend, reducing the risk of the droplet continuing to wall-to-wall under a strong electric field and providing stable conditions for subsequent controlled residual differential capacitance readings and electric field strength calculations.

[0058] As an example, the pre-calibrated bias compensation relationship includes multiple compensation mapping relationships, each compensation mapping relationship corresponds to a compensation electrode application method, and each compensation mapping relationship is used to represent the correspondence between the target compensation force amplitude and the DC control bias voltage amplitude under the corresponding application method; the compensation mapping relationship is a lookup table relationship, a piecewise fitting relationship, or an equivalent parallel plate voltage inverse calculation relationship; the direction identifier of the DC control bias voltage is determined by the application method of the compensation electrode.

[0059] It should be noted that, in this example, the compensation mapping relationship refers to the calibrated correspondence between the target compensation force amplitude, current temperature value, real-time displacement, and DC control bias voltage amplitude under a certain compensation electrode application method; the compensation electrode application method number refers to the number used to distinguish different compensation electrode groups and wiring states; the equivalent parallel plate voltage inverse calculation relationship refers to the calculation relationship of determining the DC control bias voltage amplitude in reverse based on the target compensation force amplitude under the equivalent parallel plate capacitor structure; the equivalent parallel plate capacitor structure refers to approximating the compensation electrode, dielectric isolation structure, cavity medium, and liquid metal droplet as a capacitor structure with equivalent spacing, equivalent effective area, and equivalent dielectric constant; the equivalent dielectric constant refers to the dielectric parameter calculated under the combined action of the medium participating in the formation of the compensation electric field, the electrode edge field, and the droplet position, with the unit being farads per meter. The equivalent spacing can be calculated based on the dielectric isolation thickness between the compensation electrode and the liquid metal droplet, the cavity medium thickness, and the current position of the droplet; the equivalent effective area can be calculated based on the effective coverage area of ​​the compensation electrode and the area of ​​the liquid metal droplet subjected to the electric field; the edge field correction coefficient can be obtained through calibration.

[0060] Understandably, firstly, the electric field measurement system is numbered according to the already determined method of applying the compensation electrodes. The corresponding compensation mapping relationship is invoked. Different application methods correspond to different electrode groups, drive terminals, and reference terminals. Therefore, even if the target compensation force amplitude is the same, the required DC control bias voltage amplitude may be different. Each compensation mapping relationship can be calibrated and stored separately to reduce the impact of electrode layout differences on voltage conversion.

[0061] In this example, the magnitude of the DC control bias voltage can be expressed as: In the formula, The magnitude of the DC control bias voltage. The target compensation force amplitude, This is the current temperature value. The real-time displacement is... The application method of the compensation electrode is numbered. This is a compensation mapping relationship corresponding to the application method; Either a lookup table relationship or a piecewise fitting relationship can be used. The lookup table relationship is suitable for situations with many calibration points and significant structural nonlinearity, while the piecewise fitting relationship is suitable for situations where the compensation force and voltage have different slopes in different intervals.

[0062] The compensation mapping relationship can be obtained through calibration. During calibration, at the... Under various application methods, the DC control bias voltage amplitudes corresponding to multiple target compensation force amplitudes are recorded, and these records are repeated at different temperature points and different droplet displacement positions; subsequently, a system containing... , , and The calibration table can be used, or piecewise fitting coefficients can be obtained within different intervals. Temperature points can be set according to the probe's operating temperature range, for example, covering normal temperature, low temperature, and high temperature conditions; displacement points can cover the interval from the initial equilibrium position to near the preset displacement threshold.

[0063] When using the equivalent parallel plate voltage inverse calculation relationship, the first... The compensating electric field effect under this compensation electrode application method is approximately equivalent to the force relationship of a parallel plate. The amplitude of the compensating electric field force and the amplitude of the DC control bias voltage satisfy the following: The result can be obtained by reverse calculation from the above formula: In the formula, For the first The equivalent spacing of the compensation electrodes under various compensation electrode application methods, in meters; For the first The edge field correction coefficient under the compensation electrode application method is used to correct the deviation caused by the edge field and structural approximation. It is a positive number and can be obtained through calibration. For the first The equivalent dielectric constant under various compensation electrode application methods, expressed in farads per meter; For the first The equivalent area of ​​the compensation electrode under various application methods is expressed in square meters. This relationship is used for scenarios where the compensation electrode approximately satisfies the force relationship of a parallel plate. If the cavity structure, electrode edge field, or droplet shape leads to large deviations, a lookup table relationship or a piecewise fitting relationship can be used preferentially.

[0064] Furthermore, the electric field measurement system is based on After obtaining the DC control bias voltage amplitude, the voltage output port and reference port are determined by combining this with the application method of the compensation electrodes. The direction indication of the DC control bias voltage is determined by the application method, not solely by the voltage amplitude. This allows for separate processing of voltage magnitude and compensation direction, avoiding unclear direction information due to the voltage amplitude being a non-negative value.

[0065] The DC control bias voltage amplitude can also be limited by a safe voltage range. The safe voltage range can be set based on the compensation electrode spacing, the cavity dielectric withstand voltage, and the rated output capability of the drive circuit; when calculated... When the voltage exceeds the safe voltage range, the output amplitude can be limited to the safe voltage range, and the corresponding state can be recorded as the limiting state for subsequent measurement result correction or status indication.

[0066] This example establishes compensation mapping relationships for different compensation electrode application methods, enabling the DC control bias voltage to be converted according to changes in the target compensation force amplitude, temperature, and droplet position. This reduces the impact of a single voltage relationship being difficult to adapt to various electrode wiring states. By separating the voltage amplitude calculation and direction identification, the compensation direction is more clearly defined. The voltage amplitude is determined through table lookup relationships, piecewise fitting relationships, or equivalent parallel plate voltage inverse calculation relationships, giving the DC control bias voltage a calibrable correspondence with the compensation requirements. This provides a stable input for droplet compensation under strong electric fields and subsequent electric field strength calculations.

[0067] As an example, applying the DC control bias voltage to the compensation electrode according to the application method and obtaining the corresponding controlled residual differential capacitance includes: applying the DC control bias voltage to the compensation electrode according to the application method; applying an AC detection signal to the differential capacitance detection electrode during the application of the DC control bias voltage; performing frequency selection or synchronous demodulation on the detection signal output by the differential capacitance detection electrode to obtain the differential capacitance detection value under bias; correcting the differential capacitance detection value under bias according to a pre-calibrated bias parasitic capacitance correction relationship to obtain the controlled residual differential capacitance; determining the electric field component corresponding to the residual displacement according to the controlled residual differential capacitance and the pre-calibrated residual capacitance-electric field correspondence; determining the active compensation electric field component according to the DC control bias voltage, the application method of the compensation electrode, and the pre-calibrated bias voltage-compensation electric field correspondence; and calculating the electric field strength measurement value of the external electric field to be measured along the sensitive axis of the liquid metal probe according to the electric field component corresponding to the residual displacement and the active compensation electric field component.

[0068] It should be noted that, in this example, the differential capacitance detection value under biased conditions refers to the differential capacitance value collected by the differential capacitance detection electrode during the application of DC control bias voltage by the compensation electrode; the bias parasitic capacitance correction relationship refers to the calibration correspondence between DC control bias voltage, current temperature value, compensation electrode application method, and differential parasitic capacitance offset; the controlled residual differential capacitance refers to the capacitance obtained by subtracting the differential parasitic capacitance offset from the differential capacitance detection value under biased conditions; the residual capacitance-electric field correspondence refers to the calibration relationship between the controlled residual differential capacitance and the electric field component corresponding to the residual displacement; the bias voltage-compensation electric field correspondence refers to the calibration relationship between the amplitude of DC control bias voltage and the amplitude of the active compensation electric field component.

[0069] Understandably, the electric field measurement system first applies a DC control bias voltage to the corresponding compensation electrodes according to the predetermined compensation electrode application method. The compensation electrode application method includes the compensation electrode group, the drive terminal, the reference terminal, and the direction indicator. The amplitude of the DC control bias voltage is derived from the bias compensation relationship, and the direction information is determined by the compensation electrode application method.

[0070] During the application of the DC control bias voltage, the electric field measurement system applies an AC detection signal to the differential capacitance detection electrodes. The frequency of the AC detection signal can be set according to the bandwidth of the capacitance detection circuit, the response frequency of the compensation drive circuit, and the ambient noise frequency band, while the amplitude can be set to a detection amplitude that does not cause significant additional displacement of the liquid metal droplets. In this way, the DC bias is used for compensation drive, and the AC detection signal is used for capacitance reading, and the two can be distinguished in signal processing.

[0071] Then, the detection signal output from the differential capacitance detection electrode is frequency-selectively or synchronously demodulated to obtain the differential capacitance detection value under bias conditions. Frequency selection can retain the corresponding frequency band of the AC detection signal and suppress the effects of DC bias and low-frequency drift; synchronous demodulation can extract the capacitance change based on the reference frequency of the AC detection signal. The differential capacitance detection value under bias conditions is denoted as... .

[0072] Based on this, the bias parasitic capacitance correction relationship is used to... After correction, the controlled residual differential capacitance is obtained. The bias parasitic capacitance correction relationship can be obtained during the calibration stage: under different compensation electrode application methods, different DC control bias voltage amplitudes, and different temperature conditions, the parasitic offset of the differential capacitance detection channel is recorded to form a lookup table relationship or a piecewise fitting relationship. The controlled residual differential capacitance can be expressed as: In the formula, The controlled residual differential capacitor This refers to the differential capacitance detection value under the biased state. For the first The differential parasitic capacitance offset related to the DC control bias voltage and the current temperature value under the various compensation electrode application methods. The application method of the compensation electrode is numbered. The magnitude of the DC control bias voltage. The current temperature value.

[0073] Next, based on the controlled residual differential capacitance and the residual capacitance-electric field correspondence, the electric field components corresponding to the residual displacement are determined. The residual capacitance-electric field correspondence can be obtained through calibration, for example, by recording the known external electric field residual responses corresponding to different residual differential capacitance values ​​under controlled conditions after compensation intervention, forming a lookup table relationship or a piecewise fitting relationship.

[0074] Furthermore, based on the DC control bias voltage, the application method of the compensation electrodes, and the correspondence between the bias voltage and the compensation electric field, the active compensation electric field component is determined. The correspondence between the bias voltage and the compensation electric field can be calibrated separately for different application methods of the compensation electrodes. The direction of the active compensation electric field component is determined by the direction indicator, and the amplitude is determined by the amplitude of the DC control bias voltage.

[0075] Finally, the electric field component corresponding to the residual displacement and the actively compensated electric field component with direction information are combined to obtain the measured electric field strength value of the external electric field under test along the sensitive axis of the liquid metal probe. The measured electric field strength value can be expressed as: In the formula, The measured value of the electric field strength is... The electric field component corresponding to the residual displacement is determined based on the controlled residual differential capacitance and the current temperature value. The amplitude of the active compensation electric field component is determined based on the DC control bias voltage and the current temperature value. For the first The direction indicator is determined by the method of applying the compensation electrode, and The value can be +1 or -1.

[0076] Furthermore, the residual capacitance-electric field correspondence and the bias voltage-compensation electric field correspondence are obtained through calibration; wherein, the residual capacitance-electric field correspondence is used to represent the relationship between the controlled residual differential capacitance and the electric field component corresponding to the residual displacement, and the bias voltage-compensation electric field correspondence is used to represent the relationship between the DC control bias voltage and the amplitude of the active compensation electric field component.

[0077] In this example, during the application of a DC control bias voltage, the differential capacitance detection value is obtained through AC detection signal and frequency selection or synchronous demodulation, reducing the impact of DC bias on capacitance reading; the controlled residual differential capacitance is obtained through the bias parasitic capacitance correction relationship, reducing the parasitic offset introduced by compensation voltage and temperature changes; the electric field strength measurement value is calculated by jointly using the electric field component corresponding to the residual displacement and the active compensation electric field component, so that the liquid metal droplet can still participate in the electric field calculation under controlled conditions, improving the continuity and stability of strong electric field measurement.

[0078] As an example, applying the DC control bias voltage to the compensation electrode according to the application method includes: generating the output voltage of the current sampling period based on the output voltage of the previous sampling period and the DC control bias voltage determined in the current sampling period; performing amplitude limiting and rate-of-change constraint processing on the output voltage of the current sampling period; and applying the processed output voltage to the compensation electrode.

[0079] It should be noted that the target bias voltage refers to the DC control bias voltage obtained according to the bias compensation relationship, before it has undergone amplitude limiting and rate of change constraint processing; the output voltage of the current sampling period refers to the actual voltage value applied to the compensation electrode; amplitude limiting processing refers to limiting the output voltage within a preset safe voltage range; and rate of change constraint processing refers to limiting the amount of output voltage change between adjacent sampling periods.

[0080] Understandably, the electric field measurement system first acquires the actual output voltage to the compensation electrode from the previous sampling period, and then acquires the target bias voltage determined for the current sampling period. If the current sampling period is the first sampling period after compensation begins, the output voltage from the previous sampling period can be zero voltage, or it can be the reference bias voltage when the compensation electrode is in the reference state.

[0081] Then, the target bias voltage is limited according to a preset voltage limit. The preset voltage limit can be set to not exceed the safe range corresponding to the cavity dielectric breakdown voltage, or it can be less than the upper limit of the allowable output voltage of the drive circuit. After the limiting process, the output voltage amplitude of the current sampling period does not exceed the preset voltage limit.

[0082] Next, based on the output voltage of the previous sampling period, the output voltage of the current sampling period is subject to a rate-of-change constraint. When the difference between the target bias voltage and the output voltage of the previous sampling period exceeds the preset maximum voltage change, the voltage change of the current sampling period is limited to the preset maximum voltage change; when the difference does not exceed the preset maximum voltage change, the limited target bias voltage can be directly used as the output voltage of the current sampling period.

[0083] In this example, the amplitude limiting and rate of change constraint processes satisfy the following: In the formula, The output voltage for the current sampling period. The output voltage of the previous sampling period. For preset voltage limits, This represents the preset maximum voltage change between adjacent sampling periods. The preset voltage limit can be determined based on the spacing between the compensation electrodes, the withstand voltage of the cavity medium, and the rated output range of the drive circuit; the preset maximum voltage change can be determined based on the sampling period, the damping response time of the liquid metal droplet, and the response capability of the drive circuit.

[0084] After obtaining the output voltage for the current sampling period, the electric field measurement system applies the processed output voltage to the corresponding compensation electrode according to the compensation electrode application method. The compensation electrode application method determines the driving terminal, reference terminal, and direction indicator, and the output voltage amplitude is determined by the result of amplitude limiting processing and rate of change constraint processing.

[0085] Preset voltage limits and preset maximum voltage variations can be programmed into the electric field measurement system during probe calibration or factory configuration. If the liquid metal probe is used in different electric field ranges or different temperature environments, different parameter groups can be set according to the medium's withstand pressure margin, droplet response time, and drive circuit specifications.

[0086] This example uses amplitude limiting to confine the voltage applied to the compensation electrode within a safe range, reducing the risk of dielectric breakdown and drive circuit overload. Through rate-of-change constraint, voltage changes between adjacent sampling periods are smoother, reducing droplet overshoot and oscillations caused by voltage spikes. This implementation makes the application of the DC control bias voltage more stable, providing a more stable operating state for subsequent controlled residual differential capacitance readings and electric field strength calculations.

[0087] As an example, the pre-calibrated bias compensation relationship is obtained as follows: under multiple known external electric field intensities, the displacement, capacitance response, and corresponding DC control bias voltage of the liquid metal droplet are acquired; the application method of the compensation electrode, the target compensation force amplitude, and the DC control bias voltage amplitude are recorded when the liquid metal droplet is in different displacement ranges; based on the recorded results, a compensation mapping relationship between the target compensation force amplitude and the DC control bias voltage amplitude under different compensation electrode application methods is established.

[0088] It should be noted that, in this example, the known external electric field strength refers to the reference electric field strength generated by a standard electric field generator or a calibrated electrode structure; the capacitance response refers to the capacitance signal output by the differential capacitance detection electrode under the corresponding electric field and droplet displacement state; the displacement range can be multiple ranges divided according to the displacement amplitude of the liquid metal droplet relative to the initial equilibrium position; the compensation mapping relationship refers to the calibrated correspondence between the target compensation force amplitude and the DC control bias voltage amplitude under a compensation electrode application method.

[0089] Understandably, multiple known external electric field intensities are first set in the calibration environment. These multiple known external electric field intensities can cover the weak electric field measurement range, the medium electric field measurement range, and the strong electric field measurement range near compensation triggering of the liquid metal probe. The interval between adjacent electric field intensities can be set according to the degree of nonlinearity of the droplet displacement response, using a smaller interval in the range where the droplet displacement changes rapidly and a larger interval in the range where the droplet response is relatively smooth.

[0090] Then, under each known external electric field strength, the real-time displacement and capacitance response of the liquid metal droplet are acquired. The real-time displacement can be obtained from the differential capacitance signal and the capacitance-displacement correspondence, while the capacitance response can include the real-time differential capacitance value, differential capacitance offset, or differential capacitance detection value under bias conditions. During acquisition, data can be recorded after the droplet response reaches a steady state, or dynamic data can be recorded during the droplet's approach to the cavity wall to cover compensation requirements under different displacement ranges.

[0091] Next, when the liquid metal droplet is in different displacement ranges, the compensation electrode application method is selected according to the offset direction. The displacement range can include the range near the initial equilibrium position, the linear response range, and the range close to the preset displacement threshold. For each displacement range, the wiring status and direction markings of the corresponding compensation electrode group, drive end, and reference end are recorded, so that the calibration results under the same application method can be retrieved later according to the offset direction.

[0092] Based on this, the corresponding target compensation force amplitude is determined. The target compensation force amplitude can be obtained from the real-time displacement, the preset target displacement, and the displacement change rate in the direction approaching the cavity wall, or it can be obtained from the real-time displacement and the preset target displacement in a static calibration scenario. For the same compensation electrode application method, the DC control bias voltage amplitude corresponding to multiple target compensation force amplitudes can be recorded.

[0093] Furthermore, for each target compensation force amplitude, the DC control bias voltage amplitude is adjusted, and the voltage amplitude that brings the liquid metal droplet to the vicinity of a preset target displacement or within a preset controlled displacement range is recorded. The preset target displacement can be set to a displacement amplitude less than a preset displacement threshold, and the preset controlled displacement range can be determined based on the droplet's linear response range and allowable measurement error. If multiple available voltage records correspond to the same target compensation force amplitude, the average value or the voltage record with better stability can be used as calibration data.

[0094] Then, the application method of the compensation electrode, the target compensation force amplitude, and the DC control bias voltage amplitude are stored accordingly. For the same compensation electrode application method, one set of compensation mapping relationships can be formed; for different compensation electrode application methods, multiple sets of compensation mapping relationships can be formed separately. The compensation mapping relationships can be obtained by using a lookup table or by using a piecewise fitting relationship between adjacent calibration points.

[0095] When temperature changes significantly affect the droplet response, electrode spacing, or dielectric parameters, calibration can be repeated at different temperature points. These temperature points can be set according to the operating environment of the liquid metal probe, covering low-temperature, room-temperature, and high-temperature conditions. The resulting compensation mapping relationship can include a temperature index, allowing the electric field measurement system to retrieve corresponding calibration data or perform interpolation at the current temperature value.

[0096] Furthermore, the target compensation force amplitude is also corrected according to the droplet interface force correction term, and the target compensation force amplitude is expressed as: In the formula, This is a droplet interfacial force correction term related to the real-time displacement, the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall, and the current temperature value.

[0097] This example establishes a compensation mapping relationship under multiple known external electric field intensities, multiple displacement ranges, and different compensation electrode application methods. The DC control bias voltage amplitude no longer depends solely on the ideal electrode model, but rather combines the liquid metal droplet displacement state, electrode application method, and actual calibration results. This method improves the consistency between the bias compensation relationship and the actual structure of the liquid metal probe, reduces conversion errors caused by electrode edge field, temperature changes, and droplet position variations, and provides a stable basis for subsequent compensation voltage determination and wide-range electric field measurement.

[0098] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 2 , Figure 2 This is a flowchart illustrating the second embodiment of the wide-range electric field measurement method for the liquid metal probe of this application. Step S30 of the wide-range electric field measurement method for the liquid metal probe includes steps S31 to S34: Step S31: Continuously acquire multiple real-time displacements according to a preset sampling period; Step S32: Perform moving average, median filtering, or low-pass filtering on the multiple real-time displacements to obtain a filtered displacement sequence; Step S33: Determine the real-time displacement change rate based on two filtered displacements separated by a preset sampling interval in the filtered displacement sequence; Step S34: Determine the displacement rate of the liquid metal droplet along the direction approaching the cavity wall based on the sign of the real-time displacement and the real-time displacement change rate.

[0099] It should be noted that the preset sampling period refers to the time interval between two adjacent displacement samples, which can be set according to the bandwidth of the differential capacitance detection circuit, the response time of the liquid metal droplet, and the establishment time of the compensation voltage; the filtered displacement sequence refers to the displacement data sequence obtained after performing a moving average, median filtering, or low-pass filtering on multiple consecutive real-time displacements; the preset sampling interval refers to the sampling point interval used to calculate the displacement change rate, which can be 1 to 5 sampling periods.

[0100] Understandably, the electric field measurement system continuously acquires multiple real-time displacements according to a preset sampling period. The preset sampling period can be set according to the response speed of the liquid metal probe; for example, a shorter sampling period is used when the droplet response is fast, and a longer sampling period is used when the droplet response is slow. In one embodiment, the preset sampling period can be set to 0.1 milliseconds to 10 milliseconds. The continuously acquired real-time displacements can be stored in a buffer in chronological order of sampling time. The length of the buffer can be determined based on the required data volume calculated according to the filtering window and the displacement change rate.

[0101] Then, multiple real-time displacements are filtered to obtain a filtered displacement sequence. If there are occasional spikes in the detected signal, median filtering can be used; if the displacement data is mainly affected by random noise, moving average can be used; if high-frequency noise needs to be suppressed, low-pass filtering can be used. The window length for moving average or median filtering can be 3 to 9 sampling points. If the window is too short, noise suppression is limited; if the window is too long, it will increase response hysteresis.

[0102] Based on this, the real-time displacement change rate is determined according to two filtered displacements separated by a preset sampling interval in the filtered displacement sequence. The real-time displacement change rate can be expressed as: In the formula, This represents the real-time displacement change rate corresponding to the current sampling period. This is the filter shift for the current sampling period. To be separated Filter shift per sampling period, For the preset sampling interval, The preset sampling period is used. This calculation method uses the displacement difference between interval sampling points to obtain the droplet motion trend, avoiding excessive sensitivity to noise when only two adjacent sampling points are used.

[0103] Next, the direction indicator is determined based on the sign or offset direction of the real-time displacement. When the real-time displacement amplitude is greater than the zero dead zone, it can be determined by the sign of the real-time displacement. When the real-time displacement is within the zero-position dead zone, the previous valid direction indicator can be used, or the direction indicator can be determined by the differential capacitance offset sign. The zero-position dead zone can be set according to the differential capacitance detection noise and displacement calculation resolution to avoid frequent switching of the direction indicator when the droplet approaches the equilibrium position.

[0104] Furthermore, based on the direction indicator and the real-time displacement rate of change, the displacement rate of the liquid metal droplet along the direction approaching the cavity wall is determined. In this example, the displacement rate of the liquid metal droplet along the direction approaching the cavity wall can be expressed as: In the formula, Let be the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall. The direction identifier is determined by the offset direction. The real-time displacement change rate is given when the offset direction points towards the first side cavity wall. When the offset direction points towards the second side cavity wall, .like A value greater than 0 indicates that the droplet is moving closer to the currently offset sidewall; if A value less than or equal to 0 indicates that the droplet has not continued to approach the cavity wall, and the rate of change of displacement in the direction of approaching the cavity wall is taken as 0.

[0105] This embodiment reduces the impact of single displacement sampling noise on motion trend judgment through continuous sampling and filtering; it can reflect the wall-approaching motion state of liquid metal droplets by calculating the real-time displacement change rate through interval sampling points; and it avoids the problem of unclear direction caused by judging motion risk solely based on the magnitude of the displacement change rate by determining the displacement change rate in the direction of approaching the cavity wall through directional identification, thus providing a more stable data foundation for subsequent calculation of estimated wall contact time and compensation triggering.

[0106] As an example, the estimated contact time is determined as follows: based on the offset direction, the limiting displacement amplitude of the cavity wall corresponding to the offset direction of the liquid metal droplet is determined; based on the limiting displacement amplitude of the cavity wall and the absolute value of the real-time displacement, the remaining displacement margin of the liquid metal droplet along the offset direction is determined; when the displacement change rate of the liquid metal droplet along the direction approaching the cavity wall is greater than 0, the estimated contact time is determined based on the remaining displacement margin and the displacement change rate along the direction approaching the cavity wall; when the displacement change rate of the liquid metal droplet along the direction approaching the cavity wall is equal to 0, the estimated contact time is set to a preset maximum time value.

[0107] It should be noted that the cavity wall limit displacement amplitude refers to the displacement amplitude corresponding to the liquid metal droplet moving to the cavity wall safety boundary along the current offset direction, which can be calibrated based on the internal cavity size of the elastic cavity, the initial position of the droplet, and the safety gap; the remaining displacement margin refers to the remaining distance between the current position of the liquid metal droplet and the current offset side cavity wall safety boundary; the expected contact time refers to the time estimated based on the remaining displacement margin and the displacement change rate in the direction of approaching the cavity wall; the preset maximum time value refers to the upper limit value of the expected contact time when the droplet does not continue to approach the cavity wall, which can be set to a value greater than the preset time threshold.

[0108] Understandably, the limiting displacement amplitude of the cavity wall on the corresponding side is first determined based on the offset direction of the liquid metal droplet. If the offset direction points to the first cavity wall, the limiting displacement amplitude corresponding to the first cavity wall is used; if the offset direction points to the second cavity wall, the limiting displacement amplitude corresponding to the second cavity wall is used. The limiting displacement amplitudes of the first and second sides can be the same, or they can differ due to the cavity structure, electrode arrangement, or initial droplet position deviation.

[0109] The limiting displacement amplitude of the cavity wall can be obtained during the probe calibration stage. During calibration, the usable displacement range of the droplet is determined based on the internal length of the elastic cavity, the droplet size, and the reserved safety gap. The reserved safety gap can be set according to the droplet deformation range, manufacturing error, and detection error to avoid directly using the actual cavity wall position as the trigger boundary.

[0110] Then, the remaining displacement margin is determined based on the ultimate displacement amplitude of the cavity wall and the real-time displacement amplitude. In this example, the remaining displacement margin can be expressed as: In the formula, This refers to the remaining displacement margin. This represents the limiting displacement amplitude of the cavity wall corresponding to the current offset direction of the liquid metal droplet. This represents the real-time displacement. If the real-time displacement amplitude has reached or exceeded the cavity wall's limit displacement amplitude, the remaining displacement margin is set to zero.

[0111] Next, the estimated contact time is determined based on the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall. If the rate of change of displacement along the direction approaching the cavity wall is greater than 0, it indicates that the droplet is moving closer to the cavity wall on the current offset side. In this case, the estimated contact time is obtained based on the remaining displacement margin and the rate of change of displacement. If the rate of change of displacement along the direction approaching the cavity wall is equal to 0, it indicates that the droplet is not continuing to approach the cavity wall. In this case, the estimated contact time is set to the preset maximum time value.

[0112] In this example, the expected wall contact time can be expressed as: In the formula, The estimated wall contact time, This is the preset maximum time value. If the displacement change rate is less than 0 after filtering or numerical processing, it can be treated as 0 to keep the calculated estimated wall contact time consistent with the "approaching the cavity wall" state.

[0113] The preset maximum time value can be set according to the compensation triggering strategy, such as being greater than a preset time threshold, or taking the time corresponding to several sampling periods. In this way, when the droplet does not continue to approach the cavity wall, the expected contact time will not trigger the compensation condition; when the droplet approaches the cavity wall and the remaining displacement margin is small, the expected contact time will decrease as the movement speed increases.

[0114] Furthermore, the electric field measurement system can compare the expected contact time with a preset time threshold. The preset time threshold can be set according to the sampling period, the compensation voltage set-up time, and the droplet damping response time. If the expected contact time is less than or equal to the preset time threshold, it indicates that the droplet is at risk of contacting the wall, and the process of determining the compensation electrode application method and the DC control bias voltage can proceed.

[0115] This example determines the remaining displacement margin by using the cavity wall's ultimate displacement amplitude and the real-time displacement amplitude, reflecting the remaining space between the droplet and the cavity wall's safe boundary. The estimated contact time is determined by the remaining displacement margin and the rate of change of displacement towards the cavity wall, allowing for early identification of contact risk even before the droplet reaches the displacement threshold but at a high velocity. This implementation considers both the current position and the movement trend in the compensation triggering condition, reducing the hysteresis caused by relying solely on the displacement threshold and improving the stability of droplet compensation intervention under strong electric fields.

[0116] For example, to help understand the implementation flow of the wide-range electric field measurement method of the liquid metal probe obtained by combining this embodiment with the above embodiment one, please refer to... Figure 3 , Figure 3 A simplified flowchart of a wide-range electric field measurement method using a liquid metal probe is provided, specifically: First, the real-time differential capacitance signal is acquired, and the real-time displacement and offset direction of the liquid metal droplet are determined according to the pre-calibrated capacitance-displacement correspondence. Then, the real-time displacement change rate is determined based on the continuously sampled real-time displacement to reflect the current movement trend of the droplet. Next, it is determined whether the compensation trigger condition is met. If the droplet displacement does not meet the compensation trigger requirement, the electric field strength measurement value is directly calculated based on the real-time differential capacitance signal and the capacitance-electric field correspondence. If the droplet displacement or movement trend meets the compensation trigger condition, the compensation electrode application method and DC control bias voltage are determined, and the DC control bias voltage is applied to the compensation electrode while the controlled residual differential capacitance is acquired. Subsequently, the electric field strength measurement value is calculated by combining the controlled residual differential capacitance, the DC control bias voltage, and the compensation electrode application method, thus forming a corresponding processing path between conventional measurement and active compensation measurement.

[0117] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the wide-range electric field measurement method of the liquid metal probe of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0118] This application also provides a wide-range electric field measurement device for a liquid metal probe; please refer to [reference needed]. Figure 4 The wide-range electric field measurement device for the liquid metal probe includes: The signal acquisition module 10 is used to acquire the real-time differential capacitance signal output by the differential capacitance detection electrode; The displacement calculation module 20 is used to determine the real-time displacement and offset direction of the liquid metal droplet relative to the initial equilibrium position based on the pre-calibrated capacitance-displacement correspondence. The rate determination module 30 is used to determine the real-time displacement change rate of the liquid metal droplet along the current offset direction based on the real-time displacement obtained by continuous sampling. The bias determination module 40 is used to determine the application mode of the compensation electrode and the DC control bias voltage based on the real-time displacement, the offset direction and the pre-calibrated bias compensation relationship when the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or when the estimated wall contact time determined based on the real-time displacement and the real-time displacement change rate is less than or equal to a preset time threshold. The compensation reading module 50 is used to apply the DC control bias voltage to the compensation electrode according to the application method, and to obtain the corresponding controlled residual differential capacitance. The field strength calculation module 60 is used to calculate the measured value of the electric field strength of the external electric field to be measured along the sensitive axis of the liquid metal probe based on the controlled residual differential capacitor, the DC control bias voltage, and the application method of the compensation electrode.

[0119] The wide-range electric field measurement device for liquid metal probes provided in this application, employing the wide-range electric field measurement method for liquid metal probes described in the above embodiments, solves the technical problem of how to suppress the saturation of liquid metal droplets at the wall under a strong electric field and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe. Compared with the prior art, the beneficial effects of the wide-range electric field measurement device for liquid metal probes provided in this application are the same as those of the wide-range electric field measurement method for liquid metal probes provided in the above embodiments, and other technical features in the wide-range electric field measurement device for liquid metal probes are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0120] This application provides a wide-range electric field measurement device for a liquid metal probe. The wide-range electric field measurement device for a liquid metal probe includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the wide-range electric field measurement method for a liquid metal probe as described in Embodiment 1 above.

[0121] like Figure 5 As shown, the wide-range electric field measurement device for liquid metal probes may include a processing unit 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in ROM 1002 (Read Only Memory) or a program loaded from storage device 1003 into RAM 1004 (Random Access Memory). RAM 1004 also stores various programs and data required for the operation of the wide-range electric field measurement device for liquid metal probes. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. I / O interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, LCDs (Liquid Crystal Displays), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the wide-range electric field measurement device with liquid metal probes to communicate wirelessly or wiredly with other devices to exchange data. Although the figure shows a wide-range electric field measurement device with liquid metal probes having various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented alternatively.

[0122] The wide-range electric field measurement device for liquid metal probes provided in this application, employing the wide-range electric field measurement method for liquid metal probes described in the above embodiments, solves the technical problem of how to suppress the saturation of liquid metal droplets at the wall under a strong electric field and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe. Compared with the prior art, the beneficial effects of the wide-range electric field measurement device for liquid metal probes provided in this application are the same as those of the wide-range electric field measurement method for liquid metal probes provided in the above embodiments, and other technical features in this wide-range electric field measurement device for liquid metal probes are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0123] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0124] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the wide-range electric field measurement method of the liquid metal probe in the above embodiments.

[0125] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory or Flash Memory), optical fibers, CD-ROM (CD-Read Only Memory), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0126] The aforementioned computer-readable storage medium may be included in a wide-range electric field measurement device with a liquid metal probe; or it may exist independently and not assembled into a wide-range electric field measurement device with a liquid metal probe.

[0127] The aforementioned computer-readable storage medium carries one or more programs. When these programs are executed by the wide-range electric field measurement device of the liquid metal probe, the wide-range electric field measurement device of the liquid metal probe causes the following: it acquires the real-time differential capacitance signal output by the differential capacitance detection electrode; determines the real-time displacement and offset direction of the liquid metal droplet relative to its initial equilibrium position according to a pre-calibrated capacitance-displacement correspondence; determines the real-time displacement change rate of the liquid metal droplet along the current offset direction based on the continuously sampled real-time displacement; and when the absolute value of the real-time displacement is greater than or equal to a preset displacement... When the threshold, or the estimated contact time determined based on the real-time displacement and the rate of change of the real-time displacement, is less than or equal to a preset time threshold, the application method and DC control bias voltage of the compensation electrode are determined based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship; the DC control bias voltage is applied to the compensation electrode according to the application method, and the corresponding controlled residual differential capacitance is obtained; the electric field strength measurement value of the external electric field to be measured along the sensitive axis of the liquid metal probe is calculated based on the controlled residual differential capacitance, the DC control bias voltage, and the application method of the compensation electrode.

[0128] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0129] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the wide-range electric field measurement method of the liquid metal probe described above. This solves the technical problem of how to suppress the saturation of liquid metal droplets against the wall under a strong electric field and achieve wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the wide-range electric field measurement method of the liquid metal probe provided in the above embodiments, and will not be repeated here.

[0130] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A wide-range electric field measurement method using a liquid metal probe, characterized in that, The method is used for electric field measurement based on a liquid metal probe. The liquid metal probe includes an elastic cavity, a liquid metal droplet disposed within the elastic cavity, a differential capacitance detection electrode for detecting the displacement of the liquid metal droplet, and a compensation electrode for applying a compensation electric field force to the liquid metal droplet. A dielectric isolation structure is provided between the compensation electrode and the liquid metal droplet. The method includes: Obtain the real-time differential capacitance signal output by the differential capacitance detection electrode; Based on the pre-calibrated capacitance-displacement correspondence, the real-time displacement and offset direction of the liquid metal droplet relative to its initial equilibrium position are determined; Based on the real-time displacement obtained from continuous sampling, the real-time displacement change rate of the liquid metal droplet along the current offset direction is determined; When the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or when the estimated contact time determined based on the real-time displacement and the rate of change of the real-time displacement is less than or equal to a preset time threshold, the application method of the compensation electrode and the DC control bias voltage are determined based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship. The DC control bias voltage is applied to the compensation electrode according to the application method described above, and the corresponding controlled residual differential capacitance is obtained. Based on the controlled residual differential capacitance, the DC control bias voltage, and the application method of the compensation electrode, the measured value of the electric field strength of the external electric field under test along the sensitive axis of the liquid metal probe is calculated.

2. The wide-range electric field measurement method for a liquid metal probe as described in claim 1, characterized in that, The real-time differential capacitance signal includes a first capacitance value corresponding to the first differential capacitance detection electrode and a second capacitance value corresponding to the second differential capacitance detection electrode. The step of determining the real-time displacement and offset direction of the liquid metal droplet relative to its initial equilibrium position based on a pre-calibrated capacitance-displacement correspondence includes: Calculate the difference between the first capacitance value and the second capacitance value to obtain the real-time differential capacitance value; The real-time differential capacitance value is compared with the temperature-corrected zero-position differential capacitance value to obtain the differential capacitance offset. Based on the differential capacitor offset and the pre-calibrated capacitance-displacement correspondence, the real-time displacement of the liquid metal droplet relative to the initial equilibrium position is determined. The offset direction of the liquid metal droplet relative to the initial equilibrium position is determined based on the sign of the differential capacitance offset. The capacitance-displacement correspondence can be a lookup table interpolation relationship, a piecewise linear relationship, or a polynomial fitting relationship, wherein the polynomial fitting relationship is expressed as follows: In the formula, The real-time displacement is... This refers to the differential capacitor offset. This is the current temperature value. to A pre-calibrated coefficient related to the current temperature value. Let be the order of the polynomial fitting relation.

3. The wide-range electric field measurement method for a liquid metal probe as described in claim 1, characterized in that, The step of determining the real-time displacement change rate of the liquid metal droplet along the current offset direction based on the real-time displacement obtained from continuous sampling includes: Multiple real-time displacements are continuously acquired according to a preset sampling period; The multiple real-time displacements are processed by moving average, median filtering, or low-pass filtering to obtain a filtered displacement sequence. The real-time displacement change rate is determined based on two filtered displacements that are separated by a preset sampling interval in the filtered displacement sequence; Based on the sign of the real-time displacement and the rate of change of the real-time displacement, the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall is determined; The displacement rate of the liquid metal droplet along the direction approaching the cavity wall is expressed as: In the formula, Let be the rate of change of displacement of the liquid metal droplet along the direction approaching the cavity wall. The direction identifier is determined by the offset direction. The real-time displacement change rate is given when the offset direction points towards the first side cavity wall. When the offset direction points towards the second side cavity wall, .

4. The wide-range electric field measurement method for a liquid metal probe as described in claim 3, characterized in that, The estimated contact time is determined as follows: Based on the offset direction, determine the cavity wall limit displacement amplitude corresponding to the offset direction of the liquid metal droplet; Based on the amplitude of the cavity wall's ultimate displacement and the absolute value of the real-time displacement, the remaining displacement margin of the liquid metal droplet along the offset direction is determined. When the displacement rate of the liquid metal droplet along the direction approaching the cavity wall is greater than 0, the estimated contact time is determined based on the remaining displacement margin and the displacement rate along the direction approaching the cavity wall. When the displacement rate of the liquid metal droplet along the direction approaching the cavity wall is equal to 0, the expected contact time is set to a preset maximum time value. Wherein, the remaining displacement margin and the expected wall contact time are respectively expressed as: In the formula, This refers to the remaining displacement margin. This represents the limiting displacement amplitude of the cavity wall corresponding to the current offset direction of the liquid metal droplet. The estimated wall contact time, This is the preset maximum time value.

5. The wide-range electric field measurement method for a liquid metal probe as described in claim 3, characterized in that, The step of determining the application method of the compensation electrode and the DC control bias voltage based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship includes: Based on the offset direction, a target compensation electrode group is determined from at least two groups of compensation electrodes; Based on the target compensation electrode group and the offset direction, the application method of the compensation electrode is determined. The application method includes the target compensation electrode group, the wiring status of the driving end and the reference end, and the direction indicator determined by the wiring status. The target compensation force amplitude is determined based on the real-time displacement, the preset target displacement, and the displacement change rate of the liquid metal droplet along the direction approaching the cavity wall. The amplitude of the DC control bias voltage is determined based on the target compensation force amplitude and the pre-calibrated bias compensation relationship. The DC control bias voltage is determined based on the amplitude of the DC control bias voltage and the application method of the compensation electrode; The target compensation force amplitude is expressed as: In the formula, The target compensation force amplitude, The equivalent displacement compensation coefficient is pre-calibrated. The real-time displacement is... To preset the target displacement amplitude, The pre-calibrated equivalent damping compensation coefficient, The displacement rate of the liquid metal droplet along the direction approaching the cavity wall is denoted as .

6. The wide-range electric field measurement method for a liquid metal probe as described in claim 5, characterized in that, The pre-calibrated bias compensation relationship includes multiple compensation mapping relationships. Each compensation mapping relationship corresponds to a compensation electrode application method, and each compensation mapping relationship is used to represent the correspondence between the target compensation force amplitude and the DC control bias voltage amplitude under the corresponding application method. The magnitude of the DC control bias voltage is expressed as follows: In the formula, The magnitude of the DC control bias voltage. The target compensation force amplitude, This is the current temperature value. The real-time displacement is... The application method of the compensation electrode is numbered. This is a compensation mapping relationship corresponding to the application method; The compensation mapping relationship is a lookup table relationship, a piecewise fitting relationship, or an equivalent parallel plate voltage inverse calculation relationship; wherein, the equivalent parallel plate voltage inverse calculation relationship is expressed as: In the formula, For the first The equivalent spacing of the compensation electrodes under various compensation electrode application methods For the first Edge field correction coefficient under various compensation electrode application methods. For the first Equivalent dielectric constant under various compensation electrode application methods For the first The equivalent area of ​​the compensation electrode under various application methods; The direction of the DC control bias voltage is determined by the way the compensation electrode is applied.

7. The wide-range electric field measurement method for a liquid metal probe as described in claim 1, characterized in that, The step of applying the DC control bias voltage to the compensation electrode according to the application method and obtaining the corresponding controlled residual differential capacitance includes: The DC control bias voltage is applied to the compensation electrode according to the application method described above; During the application of the DC control bias voltage, an AC detection signal is applied to the differential capacitor detection electrode; The detection signal output by the differential capacitance detection electrode is frequency-selected or synchronously demodulated to obtain the differential capacitance detection value under biased state. Based on the pre-calibrated bias parasitic capacitance correction relationship, the differential capacitance detection value under the biased state is corrected to obtain the controlled residual differential capacitance. Based on the controlled residual differential capacitance and the pre-calibrated residual capacitance-electric field correspondence, the electric field component corresponding to the residual displacement is determined; The active compensation electric field component is determined based on the DC control bias voltage, the application method of the compensation electrode, and the pre-calibrated bias voltage-compensation electric field correspondence. Based on the electric field component corresponding to the residual displacement and the active compensation electric field component, the measured value of the electric field intensity of the external electric field to be measured along the sensitive axis of the liquid metal probe is calculated. The controlled residual differential capacitance is represented as follows: In the formula, The controlled residual differential capacitor This refers to the differential capacitance detection value under the biased state. For the first The differential parasitic capacitance offset related to the DC control bias voltage and the current temperature value under the various compensation electrode application methods. The application method of the compensation electrode is numbered. The magnitude of the DC control bias voltage. The current temperature value; The measured value of the electric field strength is expressed as follows: In the formula, The measured value of the electric field strength is... The electric field component corresponding to the residual displacement is determined based on the controlled residual differential capacitance and the current temperature value. The amplitude of the active compensation electric field component is determined based on the DC control bias voltage and the current temperature value. For the first The direction indicator is determined by the method of applying the compensation electrode, and The value can be +1 or -1.

8. An electric field measuring device, characterized in that, The device employs the wide-range electric field measurement method using a liquid metal probe as described in any one of claims 1 to 7, and the device comprises: The signal acquisition module is used to acquire the real-time differential capacitance signal output by the differential capacitance detection electrode. The displacement calculation module is used to determine the real-time displacement and offset direction of the liquid metal droplet relative to the initial equilibrium position based on the pre-calibrated capacitance-displacement correspondence. A rate determination module is used to determine the real-time displacement change rate of the liquid metal droplet along the current offset direction based on the real-time displacement obtained by continuous sampling. The bias determination module is used to determine the application method of the compensation electrode and the DC control bias voltage based on the real-time displacement, the offset direction, and the pre-calibrated bias compensation relationship when the absolute value of the real-time displacement is greater than or equal to a preset displacement threshold, or when the estimated wall contact time determined based on the real-time displacement and the real-time displacement change rate is less than or equal to a preset time threshold. The compensation reading module is used to apply the DC control bias voltage to the compensation electrode according to the application method, and to obtain the corresponding controlled residual differential capacitance; The field strength calculation module is used to calculate the measured value of the electric field strength of the external electric field under test along the sensitive axis of the liquid metal probe, based on the controlled residual differential capacitor, the DC control bias voltage, and the application method of the compensation electrode.

9. A wide-range electric field measurement device using a liquid metal probe, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the wide-range electric field measurement method for the liquid metal probe as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the wide-range electric field measurement method of the liquid metal probe as described in any one of claims 1 to 7.

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