Displacement measurement system and displacement measurement method

Abstract

The invention provides a displacement measurement system and a displacement measurement method. The displacement measurement system comprises a grating ruler and a detection module. The grid ruler comprises a plurality of grid electrodes which are periodically arranged; the gate electrode is configured to receive scanning signals of different phases; the detection module comprises a detection electrode and a processing unit; in the displacement measurement process, the detection electrode and the grating ruler generate relative displacement and output coupling voltage; and the processing unit performs fitting according to the preset resolution and the coupling voltage and determines the displacement. By enabling the phase of the scanning signal of each gate electrode to have uniqueness and performing data fitting on the coupling voltage corresponding to the adjacent gate electrodes, micron-scale displacement is decomposed into nano-scale resolution, and the requirement of the precision manufacturing field for high precision is met.

Description

Technical Field

[0001] This application relates to the field of displacement measurement, and in particular to a displacement measurement system and a displacement measurement method. Background Technology

[0002] In the field of precision machining, precision displacement (angle) sensors are an indispensable and important component, often referred to as the ruler of intelligent manufacturing. Their accuracy directly determines the leading position of the processing and manufacturing process.

[0003] Optical grating rulers are widely used as core precision displacement sensors. Their principle relies on optical signal conversion (transmitted / reflected light), using an optical sensor to convert light signals into electrical signals to achieve displacement counting. However, existing technologies have significant drawbacks: (1) optical detection equipment leads to high costs; (2) the accuracy is generally limited to the micrometer level, making it difficult to meet the needs of nanometer-level measurement. Summary of the Invention

[0004] The main technical problem addressed by this application is to provide a displacement measurement system and a displacement measurement method, thereby solving the problem that existing precision displacement sensors cannot meet the requirements for higher precision measurement.

[0005] To address the aforementioned technical problems, the first technical solution provided in this application is: a displacement measurement system, comprising: A grating ruler includes a plurality of grating electrodes arranged periodically; the grating electrodes are configured to receive scan signals with different phases. The detection module includes a detection electrode and a processing unit; during displacement measurement, the detection electrode and the grating scale undergo relative displacement and output a coupling voltage; the processing unit fits the data according to a preset resolution and the coupling voltage, and determines the displacement amount.

[0006] In some embodiments, the preset resolution is any one of a set of reference resolutions, and the set of reference resolutions includes at least one resolution; The detection module further includes a storage unit, which is used to store at least the path point-voltage mapping relationship of the detection electrode on a preset path; The processing unit also fits the path point-voltage mapping relationship and the preset resolution, and establishes a displacement-voltage mapping relationship. It is also used to obtain the corresponding displacement amount by real-time coupling voltage query during displacement measurement.

[0007] In some embodiments, the gate electrodes are arranged at equal intervals along the measurement direction; in the measurement direction, the width of the detection electrode is equal to the width of the gate electrode, and the width of each gate electrode is equal to the spacing between adjacent gate electrodes; Wherein, there is one detection electrode, and the preset path is the displacement path traversed by the detection electrode relative to at least one of the gate electrodes; or, The detection electrodes are multiple, and the preset path is a static path formed by the positions of each detection electrode. In the static path, at least one of the multiple detection electrodes has its orthographic projection on the grid ruler coincide with the corresponding grid electrode.

[0008] In some embodiments, the displacement measurement system further includes a cascaded shift register configured to sequentially output the scan signal to each of the gate electrodes, wherein the delay time between adjacent scan signals is constant.

[0009] To solve the above-mentioned technical problems, the second technical solution provided in this application is: to provide a displacement measurement method, wherein, it includes: Determine the preset resolution; A scan signal is output to each gate electrode; wherein the gate electrode is configured to receive the scan signals with different phases. This causes a relative displacement between the detection electrode and the grating ruler, and outputs a coupling voltage. The displacement is determined based on the preset resolution and the coupling voltage.

[0010] In some embodiments, outputting scan signals to each gate electrode includes: The scan signal is sequentially output to each of the gate electrodes using a cascaded shift register, and the delay time between adjacent scan signals is constant.

[0011] In some embodiments, determining the displacement based on the preset resolution and the coupling voltage includes: Obtain the path point-voltage mapping relationship of the detection electrode on the preset path; The path point-voltage mapping relationship is fitted and the preset resolution is used to establish the displacement-voltage mapping relationship; The real-time coupling voltage of the detection electrode is obtained, and the corresponding displacement is obtained by querying.

[0012] In some embodiments, the preset path is a displacement path traversed by the detection electrode relative to at least one of the gate electrodes; The step of obtaining the path point-voltage mapping relationship of the detection electrode on the preset path includes: The detection electrode and the gate electrode are aligned at each of the path points using an optical alignment device, and the coupling voltage of the detection electrode at each of the path points is obtained to obtain the path point-voltage mapping relationship.

[0013] In some embodiments, the preset path is a static path formed by the positions of each of the detection electrodes; The step of obtaining the path point-voltage mapping relationship of the detection electrode on the preset path includes: The coupling voltage of each of the detection electrodes is obtained, and the path point-voltage mapping relationship is obtained; wherein, the location of each of the detection electrodes is the path point.

[0014] In some embodiments, the step of fitting the path point-voltage mapping relationship and the preset resolution to establish a displacement-voltage mapping relationship includes: Obtain the first coupling voltage corresponding to the first path point and the second coupling voltage corresponding to the second path point on the preset path; wherein the first path point and the second path point are any two adjacent path points on the preset path. The number of state positions within the interval between two adjacent path points is obtained according to the preset resolution. Using the first coupling voltage and the second coupling voltage as reference points, a state position-voltage correspondence is fitted and generated within the interval from the first path point to the second path point. Based on the state position-voltage correspondence, the displacement-voltage mapping relationship is established.

[0015] The beneficial effects of this application are as follows: Unlike existing technologies, this application provides a displacement measurement system and a displacement measurement method. The displacement measurement system includes a grating and a detection module. The grating includes multiple grating electrodes arranged periodically; the grating electrodes are configured to receive scanning signals with different phases. The detection module includes detection electrodes and a processing unit. During displacement measurement, the detection electrodes and the grating undergo relative displacement and output a coupling voltage. The processing unit fits the data according to a preset resolution and the coupling voltage to determine the displacement. By ensuring the uniqueness of the phase of the scanning signal of each grating electrode and by performing data fitting on the coupling voltages corresponding to adjacent grating electrodes, micron-level displacement is decomposed into nanometer-level resolution, meeting the high-precision requirements of the precision manufacturing field. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the first embodiment of the displacement measurement system provided in this application; Figure 2This is a schematic diagram of the structure of the second embodiment of the displacement measurement system provided in this application; Figure 3 This is a timing diagram of an embodiment of the scanning signal corresponding to the gate electrode provided in this application. Figure 4 This is a schematic diagram of the starting point of a preset path for the detection electrode provided in the embodiments of this application; Figure 5 This is a schematic diagram of the midpoint of the detection electrode in a preset path provided in the embodiments of this application; Figure 6 This is a schematic diagram of the detection electrode provided in the embodiments of this application at the end of a preset path; Figure 7 This is a schematic diagram of a portion of the path points of the detection electrode provided in this application along a preset path; Figure 8a yes Figure 7 Color illustrations showing the coupling voltage simulation at each path point in the middle; Figure 8b yes Figure 7 Grayscale image showing the simulation of coupling voltage at each path point; Figure 9 yes Figure 8a A color illustration of a locally magnified simulation of the coupling voltage corresponding to the first intermediate path point in the middle. Figure 10 yes Figure 8a A schematic diagram comparing the coupling voltages corresponding to the first and second intermediate path points in the middle; Figure 11 This is a schematic diagram of the third embodiment of the displacement measurement system provided in this application. Figure 12 yes Figure 11 Enlarged structural diagram at point M; Figure 13 This is a schematic diagram of the fourth embodiment of the displacement measurement system provided in this application. Figure 14 This is a flowchart illustrating one embodiment of the displacement measurement method provided in this application; Figure 15 yes Figure 14 A flowchart illustrating the implementation method of step S4 in the middle section; Figure 16 yes Figure 15 A flowchart illustrating an implementation method for step S42.

[0018] Explanation of icon numbers: 100. Displacement measurement system; 1. Grating scale; 11. Glass substrate; 12. Signal line; 2. Detection module; 21. Processing unit; 22. Storage unit; 23. Cascaded shift register; 231. Shift register; 24. Timing controller; T3. Rising edge timing. Detailed Implementation

[0019] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0020] In the following description, specific details such as particular system architectures, interfaces, and technologies are presented for illustrative purposes rather than for limiting purposes, in order to provide a thorough understanding of this application.

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] Please see Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the displacement measurement system provided in this application. Figure 2 This is a schematic diagram of the structure of the second embodiment of the displacement measurement system provided in this application. Figure 3 This is a timing diagram of an embodiment of the scanning signal corresponding to the gate electrode provided in this application.

[0025] This application provides a displacement measurement system 100. The displacement measurement system 100 includes a grating scale 1 and a detection module 2. The grating scale 1 includes a plurality of grating electrodes S arranged periodically; the grating electrodes S are configured to receive scanning signals with different phases; the detection module 2 includes a detection electrode P and a processing unit 21; during the displacement measurement process, the detection electrode P and the grating scale 1 undergo relative displacement and output a coupling voltage; the processing unit 21 performs fitting based on a preset resolution and the coupling voltage, and determines the displacement amount.

[0026] By making the phase of the scanning signal of each gate electrode S unique and by fitting the data of the coupling voltage corresponding to adjacent gate electrodes S, the micron-level displacement is decomposed into nanometer-level resolution, meeting the high precision requirements of the precision manufacturing field.

[0027] The coupling voltage output by the detection electrode P is a voltage signal that varies with position and is generated on the detection electrode P through capacitive coupling when the detection electrode P and the grid ruler 1 undergo relative displacement.

[0028] In some embodiments, the displacement measurement system 100 is an angular displacement measurement device.

[0029] In other implementations, the displacement measurement system 100 is a linear displacement measurement device.

[0030] The following description mainly uses the displacement measurement system 100 as a linear displacement measurement device.

[0031] During the measurement process, the detection module 2 is positioned opposite to the grid ruler 1 in the vertical direction of the grid ruler 1, and the detection electrode P and the grid electrode S are aligned along the measurement direction in the direction of the grid ruler 1.

[0032] For example, the effective level of the scan signal for each gate electrode S is a preset logic level, which is either high or low. That is, the effective level of the scan signal for each gate electrode S is either high or low.

[0033] In this embodiment, the effective level of the scanning signal for each gate electrode S is high.

[0034] For example, the effective level duration of the scan signal of each gate electrode S varies periodically to facilitate subsequent data fitting.

[0035] For example, the effective level duration of the scan signal of each gate electrode S is the same, which can simplify the subsequent fitting process.

[0036] In some embodiments, the preset resolution is any one of the reference resolution set, and the reference resolution set includes at least one resolution; the detection module 2 further includes a storage unit 22, which is used to store at least the path point-voltage mapping relationship of the detection electrode P on the preset path; the processing unit 21 also fits the path point-voltage mapping relationship and the preset resolution, and establishes the displacement-voltage mapping relationship, and is also used to obtain the corresponding displacement by real-time coupling voltage query during the displacement measurement process.

[0037] The preset resolution is used to determine the accuracy level of displacement measurement, and it can be any value in the reference resolution set.

[0038] When the reference resolution set contains only one resolution, the default resolution is a fixed default value.

[0039] When the reference resolution set includes multiple resolutions, the preset resolution is adjustable, and the resolution can be selected according to usage requirements. This can be understood as the measurement accuracy of the displacement measurement system 100 being adjustable.

[0040] The path points on the preset path can be regarded as the relative positions of the detection electrode P with respect to the grating ruler 1 during the simulation measurement process.

[0041] The displacement-voltage mapping relationship is set to correspond one-to-one with the resolution.

[0042] In other embodiments, the storage unit 22 is also used to store the displacement-voltage mapping relationship, and the processing unit 21 also determines the corresponding displacement-voltage mapping relationship according to the preset resolution, and obtains the corresponding displacement through real-time coupling voltage query during the displacement measurement process.

[0043] It can be understood that the displacement-voltage mapping relationship in this embodiment can be directly stored in the storage unit 22, or it can be generated in real time according to the preset resolution during the displacement measurement process.

[0044] In other embodiments, the displacement-voltage mapping relationship can also be generated by an external processing unit based on the path point-voltage mapping relationship and a preset resolution. Furthermore, the path point-voltage mapping relationship of the detection electrode P on the preset path can also be generated by an external processing unit.

[0045] In some embodiments, the gate electrodes S are arranged at equal intervals along the measurement direction; in the measurement direction, the width of the detection electrode P is equal to the width of the gate electrode S, and the width of each gate electrode S is equal to the spacing between adjacent gate electrodes S; wherein, there is one detection electrode P, and the preset path is the displacement path through which the detection electrode P passes relative to at least one gate electrode S; or, there are multiple detection electrodes P, and the preset path is a static path formed by the positions of each detection electrode P, and in the static path, the orthographic projection of at least one of the multiple detection electrodes P on the grid ruler 1 coincides with the corresponding gate electrode S.

[0046] By equidistantly arranging the gate electrodes S, the scanning signals of the gate electrodes S are ensured to form a periodic distribution in space, resulting in differentiated capacitive coupling between the detection electrode P and different gate electrodes S during movement. That is, through the equal-width design of the gate electrodes S and the detection electrode P, the capacitive coupling strength between them exhibits a regular difference with position. Combined with the uniqueness of the scanning signal of the gate electrodes S, the phase and voltage characteristics of the coupling voltage of the detection electrode P at different positions can be accurately captured. This structural characteristic allows the system to determine the direction of movement without relying on directional judgment.

[0047] In other embodiments, the width of each gate electrode S and the spacing between adjacent gate electrodes S may not be equal in the measurement direction, and can be selected according to actual needs.

[0048] In the direction of the plate surface of the grating ruler 1, the grating electrode S and the detection electrode P have the same shape and size, which makes the voltage coupling change more regular and is conducive to improving the subdivision accuracy in the subsequent fitting process; at the same time, it can maintain the maximum constant coupling area during relative displacement, which is convenient for outputting a coupling voltage with stable amplitude.

[0049] For example, in the plate direction of the grid ruler 1, both the grid electrode S and the detection electrode P are rectangular.

[0050] In other embodiments, the grid electrode S and the detection electrode P can also be in the shape of a parallelogram or the like in the direction of the grid ruler 1.

[0051] For example, the gate electrode S can be fabricated on the glass substrate 11 using a photolithography process. The application of photolithography gives the gate ruler 1 the advantages of high dimensional accuracy and low cost. Here, there are no excessive restrictions on the width of the gate electrode S and the spacing between the gate electrodes S, which can be selected according to actual needs.

[0052] The position of the detection electrode P at each path point can be aligned using an optical alignment device to facilitate displacement calibration at each path point.

[0053] For example, a microscope is used to align the detection electrode P.

[0054] The following explanation will primarily take the example of a 5-micrometer width of the gate electrode S and a 5-micrometer spacing between the gate electrodes S in the measurement direction.

[0055] In some specific embodiments, there is one detection electrode P, and the preset path is the displacement path through which the detection electrode P passes relative to at least one gate electrode S.

[0056] The preset path is a straight path, and the length of the preset path is greater than or equal to the width of the gate electrode S.

[0057] Please see Figures 1 to 10 , Figure 4 This is a schematic diagram of the detection electrode provided in this application embodiment at the starting point of a preset path. Figure 5 This is a schematic diagram of the midpoint of the detection electrode in a preset path provided in the embodiments of this application. Figure 6 This is a schematic diagram of the detection electrode provided in the embodiments of this application at the end of a preset path. Figure 7 This is a schematic diagram of a portion of the path points of the detection electrode provided in this application along a preset path. Figure 8a yes Figure 7 Color illustrations showing the coupling voltage simulation at each path point. Figure 8b yes Figure 7 Grayscale image illustrating the coupling voltage simulation at each path point. Figure 9 yes Figure 8a A color illustration of a locally magnified simulation of the coupling voltage corresponding to the first intermediate path point. Figure 10 yes Figure 8a A schematic diagram comparing the coupling voltages corresponding to the first and second intermediate path points.

[0058] The coupling of a detection electrode P to a grid electrode S arranged in a continuous manner is illustrated by an example.

[0059] The six gate electrodes S arranged in a continuous sequence are referred to as gate electrode S1 to gate electrode S6.

[0060] like Figure 4 As shown, at the starting point of the preset path, the orthographic projection of the detection electrode P on the grid ruler 1 coincides with that of the grid electrode S3; as Figure 5 As shown, at the midpoint of the preset path, in the direction of the plate surface of the grating ruler 1, the detection electrode P is located between the grating electrode S3 and the grating electrode S4; as Figure 6 As shown, at the end of the preset path, in the direction of the plate surface of the grid ruler 1, the orthogonal projection of the detection electrode P on the grid ruler 1 coincides with the grid electrode S4.

[0061] like Figure 7As shown, the preset path includes four intermediate path points between the path start point and the path midpoint. All path points in the preset path are equally spaced. That is, the preset path includes six path points within the interval between the path start point and the path midpoint, with each path point spaced 1 micrometer apart.

[0062] like Figure 9 As shown, coupling voltages A to F represent the coupling voltages of gate electrodes S1 to S6 to the detection electrode P, respectively. The coupling voltage of gate electrode S to the detection electrode P refers to the voltage signal induced on the detection electrode P by the gate electrode S through capacitive coupling under the drive of the scan signal.

[0063] The highest coupling voltage C is the coupling voltage between the nearest gate electrode S and the detection electrode P. Since the scan signal of each gate electrode S is unique, the location of the nearest gate electrode S can be determined by the rising (or falling) edge of the coupling voltage C. Further, the specific position of the detection electrode P is determined based on the magnitudes of the coupling voltages B and D. If the coupling voltage D is greater than the coupling voltage B, it indicates that the detection electrode P is offset to the right relative to the nearest gate electrode S in the displacement direction; if the coupling voltage D is less than the coupling voltage B, it indicates that the detection electrode P is offset to the left relative to the nearest gate electrode S in the displacement direction; if the coupling voltage D is equal to the coupling voltage B, it indicates that the detection electrode P is aligned with the nearest gate electrode S in the displacement direction. The displacement direction here is the measurement direction from the start to the end of the preset path.

[0064] For example, such as Figure 7 and Figure 9 As shown, taking the first intermediate path point of the preset path in the measurement direction as an example, the rising edge timing of the coupling voltage C is the same as the rising edge timing T3 of the gate electrode S3, that is, the gate electrode S3 is the gate electrode S closest to the detection electrode P, the coupling voltage D is greater than the coupling voltage B, and the detection electrode P is offset to the right relative to the gate electrode S3 in the displacement direction.

[0065] In some embodiments, the path point-voltage mapping relationship on the preset path can be obtained by repeating the above steps to obtain the coupling voltage of the detected voltage at each path point during the movement from the midpoint of the path to the end point of the path. The path point-voltage mapping relationship obtained in this way has higher accuracy.

[0066] In other embodiments, the coupling voltage waveform of the detection electrode P during the movement from the midpoint to the end point of the path is symmetrically set along the displacement direction to the coupling voltage waveform of the detection electrode P during the movement from the starting point to the midpoint of the path. This means that the path point-voltage mapping relationship from the midpoint to the end point can be symmetrically obtained based on the path point-voltage mapping relationship within the interval from the starting point to the midpoint, thus obtaining the path point-voltage mapping relationship on the preset path. This method can reduce the alignment process of path points.

[0067] Furthermore, such as Figure 10 As shown, the coupling voltage waveforms of the detection electrode P at the first intermediate path point and the second intermediate path point are compared. The coupling voltage AF is different at different positions. Therefore, the coupling voltage waveforms of the detection electrode P at the six path points on the preset path can be fitted to calculate the coupling voltage of the detection electrode P at the positions between adjacent path points.

[0068] Simulation results show that the coupling voltage difference between any two adjacent path points is on the order of V, while current voltage measurement calculations can easily reach the mV level. Therefore, thousands of points can be fitted between adjacent path points, and the resolution of the processing unit 21 is satisfied. At this time, the position inferred by identifying the coupling voltages B, C, and D is such that, taking the example that 1,000 points can be fitted between adjacent path points, the accuracy can reach 1µm / 1000=1nm, that is, the accuracy can reach the nanometer level.

[0069] The number of fitted point locations between adjacent path points is related to the preset resolution.

[0070] In the measurement direction, the ratio of the spacing between adjacent path points to the number of fitted point locations between adjacent path points is the preset resolution.

[0071] In other embodiments, the spacing between each path point can be different. Here, there are no excessive restrictions on the spacing between each path point or the number of path points; the selection is made according to actual needs.

[0072] Please see Figures 11 to 13 , Figure 11 This is a schematic diagram of the third embodiment of the displacement measurement system provided in this application. Figure 12 yes Figure 11 A magnified structural diagram at point M. Figure 13 This is a schematic diagram of the fourth embodiment of the displacement measurement system provided in this application.

[0073] In other embodiments, such as Figure 11As shown, there are multiple detection electrodes P, and the preset path is a static path formed by the positions of each detection electrode P. On the static path, the orthographic projection of at least one of the multiple detection electrodes P on the grid ruler 1 coincides with the corresponding grid electrode S.

[0074] For example, there are 11 detection electrodes P, which are equally spaced apart. In the measurement direction, the spacing between adjacent detection electrodes P is greater than the spacing between adjacent gate electrodes S.

[0075] In one specific embodiment, the spacing between adjacent detection electrodes P is 6 micrometers in the measurement direction.

[0076] The 11 detection electrodes P are named detection electrode P1 to detection electrode P11 respectively.

[0077] Taking the example where the orthographic projection of detection electrode P1 on grid ruler 1 coincides with the corresponding grid electrode S, and the orthographic projection of detection electrode P11 on grid ruler 1 coincides with the corresponding grid electrode S, and in the direction of the grid ruler 1, detection electrode P6 is located between two adjacent grid electrodes S. By obtaining the coupling voltage of each detection electrode P, the path point-voltage mapping relationship of the preset path can be obtained.

[0078] This can be understood as follows: the displacement of the positions of detection electrodes P1 to P6 relative to the corresponding gate electrode S is equivalent to the displacement of the six equally spaced path points within the path start point to path midpoint interval in the above embodiment relative to the corresponding gate electrode S; the displacement of the positions of detection electrodes P6 to P11 relative to the corresponding gate electrode S is equivalent to the displacement of the six equally spaced path points within the path midpoint to path end point interval in the above embodiment relative to the corresponding gate electrode S.

[0079] In other embodiments, the number of detection electrodes P can be other than the number of detection electrodes P, and the detection electrodes P can be arranged without spacing. There are no great restrictions here, and the selection can be made according to actual needs.

[0080] The arrangement of multiple detection electrodes P reduces calibration complexity. For example, during calibration, only one detection electrode P needs to be aligned with a specific grid electrode S to complete the overall data calibration. Simultaneously, the configuration of multiple detection electrodes P simplifies the calibration process and reduces reliance on microscope positioning.

[0081] In some embodiments, the displacement measurement system 100 further includes a cascaded shift register 23, which is configured to sequentially output scan signals to each gate electrode S, and the delay time between adjacent scan signals is constant.

[0082] The cascaded shift register 23 includes multiple cascaded shift registers 231, each of which is configured to correspond one-to-one with the gate electrode S and is used to provide a scan signal to the gate electrode S.

[0083] The gate electrodes S are arranged in a periodic manner, with each gate electrode S corresponding to an independent shift register 241. The timing controller 24 provides control signals to the shift register 241 through signal line 12.

[0084] For example, a shift register 231 may be constructed using thin-film transistor (TFT) technology.

[0085] For example, the shift register 231 can be synchronously driven by multiple input sources to improve its driving capability and the uniformity of the scan signal output, thus avoiding measurement errors caused by waveform differences. For example, as Figure 13 As shown, the shift register 231 is driven synchronously by three input sources: front, middle, and rear. The number of input sources includes, but is not limited to, this, and can be selected according to the length of the grid ruler 1. Multiple input sources are suitable for medium to large-sized grid rulers 1.

[0086] The cascaded shift register 23 sequentially outputs scan signals, ensuring that the signal outputs of each gate electrode S exhibit a temporally ordered progressive relationship. A fixed time interval is maintained between adjacent scan signals.

[0087] For example, the effective level duration of the scan signal of each gate electrode S is the same, which can simplify the subsequent fitting process.

[0088] For example, such as Figure 3 As shown, the delay time between adjacent scan signals is the effective level duration of the scan signal, in order to further simplify the subsequent data fitting process.

[0089] By employing a signal scanning method with a fixed delay time, the waveform output of each gate electrode S is ensured to have unique temporal characteristics. This temporal uniqueness allows for predictable phase differences in the coupled voltage waveforms generated by the detection electrode P at different positions. This signal output method ensures that each gate electrode S generates unique waveform characteristics at a specific moment, providing a time reference for subsequent coupled waveform analysis. This characteristic allows for rapid location of the nearest gate electrode S by detecting the rising or falling edge of the coupled voltage waveform of the detection electrode P. Combined with a multi-point voltage fitting algorithm, the positioning accuracy can be improved to the nanometer level. The constant delay also simplifies signal timing control, reduces circuit complexity, and, in conjunction with the mature shift register 231 technology, can significantly reduce manufacturing costs. Simultaneously, this ordered scanning method avoids signal overlap interference, improving the stability and repeatability of the measurement process, making it particularly suitable for precision manufacturing scenarios requiring high-precision positioning.

[0090] In some embodiments, the displacement measurement system 100 further includes a timing controller 24, which is responsible for generating control signals to ensure that the shift register 231 operates according to a predetermined timing sequence, thereby coordinating the scan signal output of the gate electrode S.

[0091] The combination of mature technology of glass substrate 11 and shift register 231 not only ensures the accuracy of structural dimensions but also significantly reduces manufacturing costs, achieving synergistic optimization of high precision and low cost.

[0092] It should be understood that the timing controller 24 can be located in the displacement measurement system 100 or outside the displacement measurement system 100.

[0093] Please see Figures 14 to 16 , Figure 14 This is a flowchart illustrating one embodiment of the displacement measurement method provided in this application. Figure 15 yes Figure 14 A flowchart illustrating the implementation method of step S4. Figure 16 yes Figure 15 A flowchart illustrating an implementation method for step S42.

[0094] This application provides a displacement measurement method, which includes: Step S1: Determine the preset resolution; Step S2: Output scan signals to each gate electrode; wherein the gate electrode is configured to receive scan signals with different phases; Step S3: Displace the detection electrode relative to the grid ruler and output a coupling voltage; Step S4: Determine the displacement based on the preset resolution and coupling voltage.

[0095] By setting a specific resolution and outputting a scanning signal with a phase difference to drive the gate electrode, a unique coupling voltage characteristic is formed when the detection electrode and the gate ruler are relatively displaced.

[0096] The detection electrode and the gate electrode are aligned in the measurement direction, and their coupling voltage exhibits specific waveform characteristics as the displacement position changes.

[0097] In some implementations, step S2: outputting scan signals to each gate electrode includes: using a cascaded shift register to sequentially output scan signals to each gate electrode, and the delay time between adjacent scan signals is constant.

[0098] In some implementations, the displacement measurement method uses the displacement measurement system described above for measurement.

[0099] For example, a single input source can be used to drive the cascaded shift register, or two input sources can be used to drive the cascaded shift register, including but not limited to this.

[0100] Using a multi-input source driving method can improve the signal uniformity of cascaded shift registers.

[0101] By utilizing the periodic arrangement of the gate electrodes and the phase difference driven by the shift register, a unique coupling voltage characteristic is generated at each position. Combined with a preset resolution, nanometer-level displacement detection can be achieved. Coupled waveform analysis eliminates the need for direction determination and zero-point calibration, directly estimating the position from the voltage characteristics, thus improving measurement reliability and real-time performance.

[0102] In some implementations, step S4: determining the displacement based on a preset resolution and coupling voltage includes: Step S41: Obtain the path point-voltage mapping relationship of the detection electrode on the preset path; Step S42: Fit the path point-voltage mapping relationship and the preset resolution, and establish the displacement-voltage mapping relationship; Step S43: Obtain the real-time coupling voltage of the detection electrode and query the corresponding displacement.

[0103] When determining the displacement based on the preset resolution and coupling voltage, the path point-voltage mapping relationship is first established by collecting the coupling voltage data of the detection electrodes along the preset displacement path.

[0104] The preset path is a specific trajectory of the detection electrode relative to the gate electrode. Discrete path point data is transformed into a displacement-voltage relationship model using mathematical fitting. In actual measurement, after acquiring the coupling voltage of the detection electrode in real time, the corresponding displacement can be determined by performing a reverse lookup based on this model. Specifically, polynomial fitting or interpolation algorithms can be used to process the voltage data, or a pre-calibrated database can be used for matching and searching.

[0105] By establishing a precise pathpoint-voltage mapping relationship and performing mathematical fitting, discrete coupled voltage measurements can be transformed into continuous displacement calculations, improving measurement resolution to the nanometer level. This voltage-characteristic-based positioning method avoids the complex structure of traditional grating rulers that rely on optical interference, reducing system costs. The coupled voltage waveform fitting algorithm can improve the difference between coupled voltages of adjacent states to the mV level, achieving nanometer-level resolution in conjunction with high-precision voltage acquisition.

[0106] In some embodiments, the preset path is the displacement path of the detection electrode relative to at least one gate electrode. Step S41: Obtain the path point-voltage mapping relationship of the detection electrode on the preset path, including: performing alignment operations on each path point of the detection electrode and the gate electrode under an optical alignment device, and obtaining the coupling voltage of the detection electrode at each path point to obtain the path point-voltage mapping relationship.

[0107] The detection electrode and the gate electrode are precisely aligned along a preset displacement path using an optical alignment device. This process acquires the coupling voltage data corresponding to each path point, thereby establishing a mapping relationship between the path points and voltage values. The optical alignment device ensures the alignment accuracy of the detection electrode and the gate electrode at specific positions. By moving the device point-by-point and collecting the coupling voltage, a complete voltage distribution model is formed.

[0108] For example, microscope-assisted alignment or automated positioning equipment can be used to achieve precise control of path points, while a mapping relationship can be constructed through multi-point acquisition and data fitting methods. In the implementation, the mapping accuracy can be improved by adjusting the path point density or optimizing the alignment algorithm. For example, in a gate electrode structure with a 5-micron line spacing, the path points can be divided into 6 or 11 subdivision positions for voltage acquisition.

[0109] The path-voltage mapping achieved through optical alignment significantly improves the accuracy and stability of displacement measurements. Precise alignment ensures that the coupled voltage data at each path point accurately reflects the actual physical location, and multi-point data fitting can improve the measurement resolution to the nanometer level. This mapping does not rely on complex optical systems or mechanical structures, reducing equipment costs and maintenance complexity. Furthermore, dense sampling of path points and voltage characteristic analysis effectively eliminate the effects of environmental interference and signal drift, ensuring high reliability of the system even in dynamic displacement scenarios.

[0110] In other embodiments, the preset path is a static path formed by the positions of each detection electrode. Step S41: Obtain the path point-voltage mapping relationship of the detection electrodes on the preset path, including: obtaining the coupling voltage of each detection electrode and obtaining the path point-voltage mapping relationship; wherein, the position of each detection electrode is a path point.

[0111] The detection electrodes are arranged in multiple configurations, with each electrode corresponding to a specific location as a path point. By collecting the coupling voltage data of each detection electrode, a correspondence between position and voltage is established.

[0112] In this implementation, the number of detection electrodes can be set according to the exposure accuracy of the grid electrode, and the data acquisition density can be improved by optimizing the spacing and layout of the detection electrodes.

[0113] The use of multiple detection electrodes enables the system to simultaneously acquire coupling voltage data from multiple points, and the combination of path point-voltage mapping significantly improves positioning accuracy. By acquiring coupling voltage characteristics at different locations in real time, and combining this with waveform processing algorithms, nanometer-level resolution can be achieved. The increased number of detection electrodes expands the data sample size, making voltage fitting calculations more accurate. This design simplifies the calibration process; overall calibration can be completed by aligning a single detection electrode with a specific gate electrode, reducing the need for manual intervention. Simultaneously, the multi-electrode layout enhances system robustness, maintaining measurement functionality even if some electrodes fail, thus improving overall measurement stability.

[0114] In some implementations, step S42: fitting the path point-voltage mapping relationship and a preset resolution, and establishing a displacement-voltage mapping relationship, includes: Step S421: Obtain the first coupling voltage corresponding to the first path point and the second coupling voltage corresponding to the second path point on the preset path; wherein, the first path point and the second path point are any two adjacent path points on the preset path; Step S422: Obtain the number of state positions within the interval between two adjacent path points according to the preset resolution; Step S423: Using the first coupling voltage and the second coupling voltage as reference points, fit and generate the state position-voltage correspondence within the interval from the first path point to the second path point; Step S424: Establish a displacement-voltage mapping relationship based on the state position-voltage correspondence.

[0115] By acquiring the coupling voltages corresponding to adjacent path points, the number of state positions within a path point interval is determined with a preset resolution. Based on two voltage reference points, a correlation between state positions and voltages within the interval is generated through fitting, ultimately establishing a mapping model between displacement and voltage. Multiple path points can be used as references for piecewise fitting, or the density of state positions can be controlled by adjusting the preset resolution. In one specific embodiment, path points can be set at the overlapping or partially overlapping positions of the gate electrode and the detection electrode, or at tangential positions. The coupling voltage can be acquired in real time by the processing unit, and the fitting process can be implemented using polynomial fitting or interpolation algorithms. Increasing the number of state positions within a path point interval appropriately improves the precision of the displacement-voltage mapping relationship.

[0116] The introduction of preset resolution allows for dynamic adjustment of state position density, ensuring nanometer-level precision while avoiding data redundancy. This method does not rely on complex sensors and can achieve high-precision positioning solely through mathematical modeling of voltage signals, reducing system complexity and improving measurement stability.

[0117] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0118] The above are merely embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A displacement measurement system, characterized in that, include: A grating ruler includes a plurality of grating electrodes arranged periodically; the grating electrodes are configured to receive scan signals with different phases. The detection module includes detection electrodes and a processing unit; During displacement measurement, the detection electrode and the grating scale undergo relative displacement and output a coupling voltage; the processing unit fits the data according to the preset resolution and the coupling voltage, and determines the displacement amount.

2. The displacement measurement system according to claim 1, characterized in that, The preset resolution is any one of the reference resolution set, and the reference resolution set includes at least one resolution; The detection module further includes a storage unit, which is used to store at least the path point-voltage mapping relationship of the detection electrode on a preset path; The processing unit also fits the path point-voltage mapping relationship and the preset resolution, and establishes a displacement-voltage mapping relationship. It is also used to obtain the corresponding displacement amount by real-time coupling voltage query during displacement measurement.

3. The displacement measurement system according to claim 2, characterized in that, The gate electrodes are arranged at equal intervals along the measurement direction; in the measurement direction, the width of the detection electrode is equal to the width of the gate electrode, and the width of each gate electrode is equal to the spacing between adjacent gate electrodes; Wherein, there is one detection electrode, and the preset path is the displacement path traversed by the detection electrode relative to at least one of the gate electrodes; or, The detection electrodes are multiple, and the preset path is a static path formed by the positions of each detection electrode. In the static path, at least one of the multiple detection electrodes has its orthographic projection on the grid ruler coincide with the corresponding grid electrode.

4. The displacement measurement system according to claim 1, characterized in that, The displacement measurement system also includes a cascaded shift register, which is configured to sequentially output the scan signal to each of the gate electrodes, and the delay time between adjacent scan signals is constant.

5. A displacement measurement method, characterized in that, include: Determine the preset resolution; A scan signal is output to each gate electrode; wherein the gate electrode is configured to receive the scan signals with different phases. This causes a relative displacement between the detection electrode and the grating ruler, and outputs a coupling voltage. The displacement is determined based on the preset resolution and the coupling voltage.

6. The displacement measurement method according to claim 5, characterized in that, The step of outputting scan signals to each gate electrode includes: The scan signal is sequentially output to each of the gate electrodes using a cascaded shift register, and the delay time between adjacent scan signals is constant.

7. The displacement measurement method according to claim 5, characterized in that, The step of determining the displacement based on the preset resolution and the coupling voltage includes: Obtain the path point-voltage mapping relationship of the detection electrode on the preset path; The path point-voltage mapping relationship is fitted and the preset resolution is used to establish the displacement-voltage mapping relationship; The real-time coupling voltage of the detection electrode is obtained, and the corresponding displacement is obtained by querying.

8. The displacement measurement method according to claim 7, characterized in that, The preset path is the displacement path of the detection electrode relative to at least one of the gate electrodes; The step of obtaining the path point-voltage mapping relationship of the detection electrode on the preset path includes: The detection electrode and the gate electrode are aligned at each of the path points using an optical alignment device, and the coupling voltage of the detection electrode at each of the path points is obtained to obtain the path point-voltage mapping relationship.

9. The displacement measurement method according to claim 7, characterized in that, The preset path is a static path formed by the positions of each of the detection electrodes. The step of obtaining the path point-voltage mapping relationship of the detection electrode on the preset path includes: The coupling voltage of each of the detection electrodes is obtained, and the path point-voltage mapping relationship is obtained; wherein, the location of each of the detection electrodes is the path point.

10. The displacement measurement method according to claim 7, characterized in that, The step of fitting the path point-voltage mapping relationship and the preset resolution to establish a displacement-voltage mapping relationship includes: Obtain the first coupling voltage corresponding to the first path point and the second coupling voltage corresponding to the second path point on the preset path; wherein the first path point and the second path point are any two adjacent path points on the preset path. The number of state positions within the interval between two adjacent path points is obtained according to the preset resolution. Using the first coupling voltage and the second coupling voltage as reference points, a state position-voltage correspondence is fitted and generated within the interval from the first path point to the second path point. Based on the state position-voltage correspondence, the displacement-voltage mapping relationship is established.

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