Displacement measurement system and displacement measurement method

Abstract

The application provides a displacement measurement system and a displacement measurement method. The displacement measurement system comprises a grating ruler and a detection module. The grating ruler comprises a plurality of grating electrodes arranged periodically; the grating electrodes are configured to receive scanning signals with different phases; the detection module comprises a detection electrode and a processing unit; during the displacement measurement process, the detection electrode is relatively displaced with the grating ruler and outputs a coupling voltage; and the processing unit performs fitting according to a preset resolution and the coupling voltage and determines a displacement amount. By making the phases of the scanning signals of the grating electrodes unique and performing data fitting on the coupling voltages corresponding to adjacent grating electrode pairs, a micrometer-level displacement is decomposed into a nanometer-level resolution, thereby meeting the demand for high precision in the field of precision manufacturing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of displacement measurement, in particular to a displacement measurement system and a displacement measurement method. BACKGROUND

[0002] In the field of precision machining, precision displacement (angle) sensors are an indispensable important component, which are compared to the ruler of intelligent manufacturing, and the accuracy thereof directly determines the leading degree of the machining and manufacturing link.

[0003] Grating rulers are widely used as core precision displacement sensors. The principle thereof relies on optical signal conversion (transmission / reflection of light), and the optical sensor converts the optical signal into an electrical signal to realize displacement counting. However, the prior art has significant defects: (1) optical detection equipment leads to high cost; (2) the precision is generally limited to the micron level, and it is difficult to meet the nanometer measurement requirement. SUMMARY

[0004] The technical problem solved by the present application is to provide a displacement measurement system and a displacement measurement method, and to solve the problem that the prior art precision displacement sensor cannot meet the higher precision measurement requirement.

[0005] To solve the above technical problem, the first technical solution provided by the present application is to provide a displacement measurement system, which comprises:

[0006] A grating ruler comprising a plurality of grating electrodes arranged periodically; the grating electrodes are configured to receive scanning signals with different phases;

[0007] A detection module comprising a detection electrode and a processing unit; in the displacement measurement process, the detection electrode is relatively displaced with the grating ruler and outputs a coupling voltage; the processing unit performs fitting according to a preset resolution and the coupling voltage, and determines a displacement amount.

[0008] In some embodiments, the preset resolution is any one of a reference resolution set, and the reference resolution set comprises at least one resolution;

[0009] The detection module further comprises a storage unit, which is used to store at least a path point-voltage mapping relationship of the detection electrode on a preset path;

[0010] The processing unit further performs fitting according to the path point-voltage mapping relationship and the preset resolution, and establishes a displacement amount-voltage mapping relationship, and is further used to obtain the corresponding displacement amount by real-time coupling voltage query in the displacement measurement process.

[0011] In some embodiments, the gate electrodes are equidistantly arranged along a measurement direction; in the measurement direction, the width of the detection electrode is equal to the width of the gate electrodes, and the width of each gate electrode is equal to the distance between adjacent gate electrodes.

[0012] The detection electrode is one, and the preset path is a displacement path of the detection electrode relative to at least one of the gate electrodes; or,

[0013] The detection electrode is multiple, and the preset path is a static path formed by the positions of the detection electrodes, and in the static path, the orthogonal projection of at least one of the multiple detection electrodes on the grating ruler is arranged to coincide with the corresponding gate electrode.

[0014] In some embodiments, the displacement measurement system further comprises a cascade shift register configured to sequentially output the scan signals to each of the gate electrodes, and the delay time between adjacent scan signals is constant.

[0015] To solve the above technical problems, the second technical scheme provided by the present application is to provide a displacement measurement method, which comprises:

[0016] Determine the preset resolution;

[0017] Output the scan signals to each of the gate electrodes; wherein the gate electrodes are configured to receive the scan signals with different phases;

[0018] Make the detection electrode and the grating ruler relatively displace and output the coupling voltage;

[0019] Determine the displacement according to the preset resolution and the coupling voltage.

[0020] In some embodiments, the outputting of the scan signals to each of the gate electrodes comprises:

[0021] Using a cascade shift register to sequentially output the scan signals to each of the gate electrodes, and the delay time between adjacent scan signals is constant.

[0022] In some embodiments, the determining of the displacement according to the preset resolution and the coupling voltage comprises:

[0023] Obtain the path point-voltage mapping relationship of the detection electrode on the preset path;

[0024] According to the path point-voltage mapping relationship and the preset resolution, fitting is performed to establish a displacement-voltage mapping relationship;

[0025] Obtain the real-time coupling voltage of the detection electrode, and query to obtain the corresponding displacement.

[0026] In some embodiments, the preset path is a displacement path of the detection electrode relative to at least one of the gate electrodes;

[0027] The obtaining of the path point-voltage mapping relationship of the detection electrode on the preset path comprises:

[0028] The alignment of each path point of the detection electrode and the gate electrode is performed under an optical alignment device, and a coupling voltage corresponding to each path point of the detection electrode is obtained, thereby obtaining the path point-voltage mapping relationship.

[0029] In some embodiments, the preset path is a static path constituted by positions of each detection electrode;

[0030] The obtaining of the path point-voltage mapping relationship of the detection electrode on the preset path comprises:

[0031] The coupling voltage of each detection electrode is obtained, and the path point-voltage mapping relationship is obtained; wherein, the position of each detection electrode is the path point.

[0032] In some embodiments, the fitting according to the path point-voltage mapping relationship and the preset resolution, and the establishment of the displacement amount-voltage mapping relationship comprises:

[0033] The first coupling voltage corresponding to a first path point on the preset path and the second coupling voltage corresponding to a second path point are obtained; wherein, the first path point and the second path point are any two adjacent path points on the preset path;

[0034] The number of state positions in the interval of the adjacent two path points is obtained according to the preset resolution;

[0035] The state position-voltage corresponding relationship in the interval from the first path point to the second path point is fitted and generated with the first coupling voltage and the second coupling voltage as reference points;

[0036] The displacement amount-voltage mapping relationship is established according to the state position-voltage corresponding relationship.

[0037] The beneficial effects of the present application: different from the prior art, the present application provides a displacement measurement system and a displacement measurement method, the displacement measurement system comprises a grating ruler and a detection module. The grating ruler comprises a plurality of grid electrodes arranged periodically; the grid electrodes are configured to receive scanning signals with different phases; the detection module comprises a detection electrode and a processing unit; during the displacement measurement process, the detection electrode is relatively displaced with the grating ruler and outputs a coupling voltage; the processing unit performs fitting according to a preset resolution and the coupling voltage, and determines the displacement amount. By making the phases of the scanning signals of the grid electrodes unique, and performing data fitting on the coupling voltages corresponding to adjacent grid electrode pairs, the micron-level displacement is decomposed into nanometer-level resolution, meeting the demand for high precision in the field of precision manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative labor.

[0039] Figure 1 is a structural schematic diagram of a first embodiment of the displacement measurement system provided by the embodiments of the present application;

[0040] Figure 2 is a structural schematic diagram of a second embodiment of the displacement measurement system provided by the embodiments of the present application;

[0041] Figure 3 is a timing diagram of an embodiment of the scanning signal corresponding to the grid electrode provided by the embodiments of the present application;

[0042] Figure 4 is a schematic diagram of the detection electrode at the starting point of a preset path provided by the embodiments of the present application;

[0043] Figure 5 is a schematic diagram of the detection electrode at the midpoint of a preset path provided by the embodiments of the present application;

[0044] Figure 6 is a schematic diagram of the detection electrode at the end point of a preset path provided by the embodiments of the present application;

[0045] Figure 7 is a schematic diagram of the detection electrode at a part of the path points of a preset path provided by the present application;

[0046] Figure 8a is Figure 7 is a simulated color diagram of the coupling voltage corresponding to each path point in

[0047] Figure 8b isFigure 7 Coupling voltage simulation schematic gray scale diagram corresponding to each path point in the middle;

[0048] Figure 9 is Figure 8a Local amplification simulation schematic color diagram of coupling voltage corresponding to the first intermediate path point in the middle;

[0049] Figure 10 is Figure 8a Comparison diagram of coupling voltage corresponding to the first intermediate path point and the second intermediate path point in the middle;

[0050] Figure 11 is a structural schematic diagram of a third embodiment of a displacement measurement system provided by the embodiments of the present application;

[0051] Figure 12 is Figure 11 Amplification structure schematic diagram at M in the middle;

[0052] Figure 13 is a structural schematic diagram of a fourth embodiment of a displacement measurement system provided by the embodiments of the present application;

[0053] Figure 14 is a flowchart of an embodiment of a displacement measurement method provided by the embodiments of the present application;

[0054] Figure 15 is Figure 14 Flowchart of an embodiment of step S4 in the middle;

[0055] Figure 16 is Figure 15 Flowchart of an embodiment of step S42 in the middle.

[0056] Explanation of reference numerals:

[0057] 100, displacement measurement system; 1, grating ruler; 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 DESCRIPTION

[0058] The schemes of the embodiments of the present application will be described in detail below in conjunction with the drawings of the specification.

[0059] In the following description, specific details such as specific system structures, interfaces, techniques, etc. are presented in order to thoroughly understand the present application, but are not intended to limit the present application.

[0060] With reference to the drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0061] The terms "first", "second", "third" in the present application are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0062] In this document, reference to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is explicitly contemplated that embodiments described herein can be combined with each other.

[0063] Please refer to Figures 1 to 3 , Figure 1 is a structural schematic diagram of a first embodiment of a displacement measurement system provided by the embodiments of the present application, Figure 2 is a structural schematic diagram of a second embodiment of a displacement measurement system provided by the embodiments of the present application, Figure 3 is a timing diagram of an embodiment of a scanning signal corresponding to a grid electrode provided by the embodiments of the present application.

[0064] The application provides a displacement measurement system 100. The displacement measurement system 100 comprises a grating ruler 1 and a detection module 2. The grating ruler 1 comprises 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 comprises a detection electrode P and a processing unit 21; during the displacement measurement, the detection electrode P is relatively displaced with the grating ruler 1 and outputs a coupling voltage; the processing unit 21 performs fitting according to a preset resolution and the coupling voltage, and determines a displacement amount.

[0065] By making the phases of the scanning signals of the grating electrodes S unique and performing data fitting on the coupling voltages corresponding to adjacent grating electrodes S, the micron-level displacement is decomposed into nanometer-level resolution, thereby meeting the demand for high precision in the field of precision manufacturing.

[0066] The coupling voltage output by the detection electrode P is a voltage signal varying with position generated on the detection electrode P through capacitive coupling when the detection electrode P is relatively displaced with the grating ruler 1.

[0067] In some embodiments, the displacement measurement system 100 is an angular displacement measurement device.

[0068] In some other embodiments, the displacement measurement system 100 is a linear displacement measurement device.

[0069] Hereinafter, the displacement measurement system 100 is taken as a linear displacement measurement device for illustration.

[0070] During the measurement, the detection module 2 is arranged opposite to the grating ruler 1 in the vertical direction of the plate surface of the grating ruler 1, and the detection electrode P is arranged in alignment with the grating electrodes S in the plate surface direction of the grating ruler 1 along the measurement direction.

[0071] Exemplarily, the effective voltage level of the scanning signal of each grating electrode S is a preset logic level, which is a high level or a low level. That is, the effective voltage level of the scanning signal of each grating electrode S is a high level, or the effective voltage level of the scanning signal of each grating electrode S is a low level.

[0072] In this embodiment, the effective voltage level of the scanning signal of each grating electrode S is a high level.

[0073] Exemplarily, the effective voltage level of the scanning signal of each grating electrode S is periodically changed, so as to facilitate subsequent data fitting.

[0074] Exemplarily, the effective voltage level of the scanning signal of each grating electrode S is the same, which can simplify the subsequent fitting process.

[0075] 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, the storage unit 22 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 further performs fitting according to the path point-voltage mapping relationship and the preset resolution, and establishes the displacement amount-voltage mapping relationship, and is further used to obtain the corresponding displacement amount by real-time coupling voltage query in the displacement measurement process.

[0076] The preset resolution is used to determine the accuracy level of displacement measurement, which can be any one of the reference resolution set.

[0077] When the reference resolution set contains one resolution, the preset resolution is a preset fixed value.

[0078] When the reference resolution set contains multiple resolutions, the preset resolution is an adjustable value, which can be selected according to the use requirement. It can be understood that the measurement accuracy of the displacement measurement system 100 is adjustable.

[0079] The path point on the preset path can be regarded as the relative position of the detection electrode P relative to the grating ruler 1 in the simulation measurement process.

[0080] The displacement amount-voltage mapping relationship is set one by one corresponding to the resolution.

[0081] In other embodiments, the storage unit 22 is further used to store the displacement amount-voltage mapping relationship, and the processing unit 21 further determines the corresponding displacement amount-voltage mapping relationship according to the preset resolution, and obtains the corresponding displacement amount by real-time coupling voltage query in the displacement measurement process.

[0082] It can be understood that the displacement amount-voltage mapping relationship in the embodiments of the application can be directly stored in the storage unit 22, or can be generated in real time according to the preset resolution in the displacement measurement process.

[0083] In other embodiments, the displacement amount-voltage mapping relationship can also be generated by an external processing unit according to the path point-voltage mapping relationship and the preset resolution. In addition, the path point-voltage mapping relationship of the detection electrode P on the preset path can also be generated by an external processing unit.

[0084] In some embodiments, the gate electrodes S are equidistantly arranged along the measurement direction; in the measurement direction, the width of the detection electrode P is equal to the width of the gate electrodes S, and the width of each gate electrode S is equal to the spacing between adjacent gate electrodes S; wherein the detection electrode P is one, and the preset path is the displacement path of the detection electrode P relative to at least one gate electrode S; or, the detection electrode P is multiple, and the preset path is the static path formed by the positions of the detection electrodes P, and in the static path, the orthographic projection of at least one of the multiple detection electrodes P on the grating ruler 1 is arranged to coincide with the corresponding gate electrode S.

[0085] The equidistant arrangement of the gate electrodes S ensures that the scanning signals of the gate electrodes S form a periodic distribution in space, so that the detection electrode P produces differential capacitive coupling with 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 presents regular differences with the change of position, and cooperates with the scanning signals of the gate electrodes S to have uniqueness, so that the phase and voltage characteristics of the coupled voltage of the detection electrode P at different positions can be accurately captured. This structural characteristic enables the system to determine the movement direction without relying on directionality judgment.

[0086] In other embodiments, in the measurement direction, the width of each gate electrode S can be different from the spacing between adjacent gate electrodes S, which can be selected according to actual needs.

[0087] In the plate surface direction of the grating ruler 1, the shapes and sizes of the gate electrodes S and the detection electrode P are the same, so that the change of voltage coupling is more regular, which is beneficial to improve the subdivision accuracy in the subsequent fitting process; at the same time, it can keep the maximum coupling area constant during relative displacement, which is convenient for outputting a coupling voltage with stable amplitude.

[0088] Exemplarily, in the plate surface direction of the grating ruler 1, the gate electrodes S and the detection electrode P are both rectangular.

[0089] In other embodiments, in the plate surface direction of the grating ruler 1, the gate electrodes S and the detection electrode P can also be parallelogram or other shapes.

[0090] Exemplarily, the gate electrodes S can be prepared on the glass substrate 11 by using a photolithography process, and the application of the photolithography process enables the grating ruler 1 to have the advantages of high size accuracy and low cost. The width of the gate electrodes S and the spacing between the gate electrodes S are not limited here, and can be selected according to actual needs.

[0091] The position of the detection electrode P at each path point can be aligned by using an optical alignment device, so as to facilitate displacement calibration of each path point.

[0092] Exemplarily, a microscope is used to perform alignment operation on the detection electrode P.

[0093] The following mainly takes the width of the gate electrode S in the measuring direction as 5 microns and the interval between the gate electrodes S as 5 microns as an example for illustration.

[0094] In some embodiments, the detection electrode P is one, and the preset path is a displacement path of the detection electrode P relative to the at least one gate electrode S.

[0095] 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.

[0096] Please refer to Figures 1 to 10 , Figure 4 is a schematic diagram of the detection electrode at the starting point of a preset path provided by the embodiments of the present application, Figure 5 is a schematic diagram of the detection electrode at the midpoint of a preset path provided by the embodiments of the present application, Figure 6 is a schematic diagram of the detection electrode at the ending point of a preset path provided by the embodiments of the present application, Figure 7 is a schematic diagram of the detection electrode at a partial path point of a preset path provided by the present application, Figure 8a is Figure 7 a simulation schematic color diagram of the coupling voltage corresponding to each path point in Figure 8b is Figure 7 a simulation schematic gray-scale diagram of the coupling voltage corresponding to each path point in Figure 9 is Figure 8a a simulation schematic color diagram of the coupling voltage of the first intermediate path point in Figure 10 is Figure 8a a comparison diagram of the coupling voltage of the first intermediate path point and the second intermediate path point in

[0097] The coupling of the detection electrode P by the six continuously arranged gate electrodes S is taken as an example for illustration.

[0098] The six continuously arranged gate electrodes S are respectively denoted as the gate electrode S1 to the gate electrode S6.

[0099] As shown in Figure 4 , at the starting point of the preset path, the orthographic projection of the detection electrode P on the ruler 1 is arranged to coincide with the gate electrode S3; as shown in Figure 5 , at the midpoint of the preset path, in the plate surface direction of the ruler 1, the detection electrode P is located between the gate electrode S3 and the gate electrode S4; as shown in Figure 6 , at the ending point of the preset path, in the plate surface direction of the ruler 1, the orthographic projection of the detection electrode P on the ruler 1 is arranged to coincide with the gate electrode S4.

[0100] As shown in Figure 7As shown, four intermediate path points are included between the path start point and the path midpoint of the preset path. The path points are equally spaced between each other in the preset path. That is, six path points are included in the interval between the path start point and the path midpoint of the preset path, and each path point is spaced by 1 micrometer.

[0101] As shown, the coupling voltages A to F represent the coupling voltages of the gate electrodes S1 to S6 to the detection electrode P, respectively. The coupling voltage of the gate electrode S to the detection electrode P refers to the voltage signal induced on the detection electrode P by the capacitive coupling of the gate electrode S under the driving of the scanning signal. Figure 9

[0102] The highest coupling voltage C is the coupling voltage of the gate electrode S closest to the detection electrode P to the detection electrode P. Since the scanning signal of each gate electrode S is unique, the gate electrode S closest to the detection electrode P can be determined by the rising edge position (or the falling edge position) of the coupling voltage C. Further, the specific position of the detection electrode P is determined according to 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 closest 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 closest gate electrode S in the displacement direction; and if the coupling voltage D is equal to the coupling voltage B, it indicates that the detection electrode P is coincidentally arranged relative to the closest gate electrode S in the displacement direction. The displacement direction here is the measurement direction of the preset path from the path start point to the path end point.

[0103] Exemplarily, as shown in FIGS. 5 and 6, 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 closest gate electrode S 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. Figure 7 Figure 9

[0104] In some embodiments, the coupling voltages of the detection voltages at the path points in the process of moving from the path midpoint to the path end point are obtained by repeating the above steps, and thus the path point-voltage mapping relationship on the preset path is obtained. The path point-voltage mapping relationship obtained in this way has higher accuracy.

[0105] ​​​In some embodiments, the coupling voltage waveform of the detection electrode P in the process of moving from the path midpoint to the path endpoint is symmetrically arranged with the coupling voltage waveform of the detection electrode P in the process of moving from the path starting point to the path midpoint along the displacement direction, i.e., the path point-voltage mapping relationship in the interval from the path midpoint to the path endpoint can be symmetrically obtained according to the path point-voltage mapping relationship in the interval from the path starting point to the path midpoint, so as to obtain the path point-voltage mapping relationship on the preset path. This way can reduce the alignment process of the path points.

[0106] Further, as shown in Figure 10 , the coupling voltage of the detection electrode P at the first intermediate path point is compared with the coupling voltage waveform at the second intermediate path point, and the coupling voltages A-F all have differences at different positions, so the coupling voltages of the detection electrode P at the corresponding 6 path points on the preset path can be fitted, and the coupling voltages of the detection electrode P at the positions between the adjacent path points can be calculated.

[0107] The simulation results show that the coupling voltage difference corresponding to any adjacent path point is of the order of V, and the current voltage measurement calculation can easily reach the level of mV, so 1000 point positions can be fitted between the adjacent path points, and the resolution of the processing unit 21 is met. At this time, the position inferred by identifying the coupling voltages B\C\D is taken as an example, the accuracy can reach 1um / 1000=1nm, i.e., the accuracy can reach nanometer-level measurement.

[0108] The number of fitted point positions between the adjacent path points is related to the preset resolution.

[0109] In the measurement direction, the ratio of the interval between the adjacent path points to the number of fitted point positions between the adjacent path points is the preset resolution.

[0110] In other embodiments, the intervals between the path points can be different, and the intervals between the path points and the number of path points are not limited too much here, and are selected according to actual needs.

[0111] Please refer to Figures 11 to 13 , Figure 11 is a structure schematic diagram of a third embodiment of the displacement measurement system provided by the embodiments of the present application, Figure 12 is Figure 11 an enlarged structure schematic diagram of M in Figure 13 is a structure schematic diagram of a fourth embodiment of the displacement measurement system provided by the embodiments of the present application.

[0112] In some embodiments, as shown in Figure 11As shown, the plurality of detection electrodes P are provided, and the preset path is a static path formed by positions of the detection electrodes P, and on the static path, a normal projection of at least one detection electrode P in the plurality of detection electrodes P on the grating ruler 1 is arranged to coincide with a corresponding grid electrode S.

[0113] Exemplarily, the plurality of detection electrodes P are 11, and the detection electrodes P are arranged at equal intervals. In the measurement direction, a spacing between adjacent detection electrodes P is greater than a spacing between adjacent grid electrodes S.

[0114] In an embodiment, in the measurement direction, the spacing between adjacent detection electrodes P is 6 microns.

[0115] The 11 detection electrodes P are respectively named as detection electrode P1 to detection electrode P11.

[0116] Taking the normal projection of the detection electrode P1 on the grating ruler 1 as an example, the normal projection of the detection electrode P11 on the grating ruler 1 coincides with a corresponding grid electrode S, and in the plate surface direction of the grating ruler 1, the detection electrode P6 is located between adjacent two grid electrodes S. The coupling voltage of each detection electrode P is obtained, and a path point-voltage mapping relationship of the preset path is obtained.

[0117] It can be understood that the displacement of the positions of the detection electrode P1 to the detection electrode P6 relative to the corresponding grid electrode S is equivalent to the displacement of the 6 equally spaced path points in the interval from the path starting point to the path midpoint relative to the corresponding grid electrode S in the above embodiment; and the displacement of the positions of the detection electrode P6 to the detection electrode P11 relative to the corresponding grid electrode S is equivalent to the displacement of the 6 equally spaced path points in the interval from the path midpoint to the path endpoint relative to the corresponding grid electrode S.

[0118] In other embodiments, the detection electrodes P can be other numbers, and the detection electrodes P can not be arranged at equal intervals, which is not limited herein, and can be selected according to actual needs.

[0119] The arrangement of the plurality of detection electrodes P can reduce the calibration complexity, for example, in the calibration process, only one detection electrode P needs to be aligned with a specific grid electrode S to complete the overall data calibration. At the same time, the configuration of the plurality of detection electrodes P simplifies the calibration process and reduces the dependence on the microscope positioning.

[0120] In some embodiments, the displacement measurement system 100 further comprises a cascade shift register 23, which is configured to sequentially output a scanning signal to each grid electrode S, and a delay time between adjacent scanning signals is constant.

[0121] The cascade shift register 23 comprises a plurality of cascaded shift registers 231, and the shift registers 231 are arranged one by one corresponding to the grid electrodes S, and are used to provide the scanning signal to the grid electrodes S.

[0122] 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.

[0123] For example, a shift register 231 may be constructed using thin-film transistor (TFT) technology.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] By employing a signal scanning method with a fixed delay time, the waveform output of each gate electrode S is ensured to have a unique temporal characteristic. 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 a unique waveform characteristic 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.

[0129] In some embodiments, the displacement measurement system 100 further comprises a timing controller 24, which is responsible for generating control signals to ensure that the shift register 231 operates in a predetermined timing, thereby coordinating the output of the scanning signals of the gate electrodes S.

[0130] The combination of the glass substrate 11 and the mature process of the shift register 231 not only ensures the precision of the structural size but also significantly reduces the manufacturing cost, achieving the synergistic optimization of high precision and low cost.

[0131] It should be understood that the timing controller 24 can be arranged in the displacement measurement system 100 or outside the displacement measurement system 100.

[0132] Please refer to Figures 14 to 16 , Figure 14 is a flowchart of an embodiment of the displacement measurement method provided by the present application, Figure 15 is Figure 14 a flowchart of an embodiment of step S4 in Figure 16 is Figure 15 a flowchart of an embodiment of step S42 in

[0133] The present application provides a displacement measurement method, which comprises:

[0134] Step S1: determining a preset resolution;

[0135] Step S2: outputting scanning signals to each gate electrode; wherein the gate electrodes are configured to receive scanning signals with different phases;

[0136] Step S3: causing the detection electrode to have a relative displacement with the grating ruler and output a coupling voltage;

[0137] Step S4: determining a displacement amount according to the preset resolution and the coupling voltage.

[0138] By setting a specific resolution and outputting scanning signals with different phases to drive the gate electrodes, a unique coupling voltage feature is formed when the detection electrode has a relative displacement with the grating ruler.

[0139] The detection electrode and the gate electrode are aligned in the measurement direction, and the coupling voltage thereof presents a specific waveform feature with the change of the displacement position.

[0140] In some embodiments, step S2: outputting scanning signals to each gate electrode, comprises: sequentially outputting scanning signals to each gate electrode by using a cascade shift register, and the delay time between adjacent scanning signals is constant.

[0141] In some embodiments, the displacement measurement method is measured by using the above-mentioned displacement measurement system.

[0142] Exemplarily, a single input source driving cascade shift register can be adopted, or two input source driving cascade shift registers can be adopted, including but not limited to the above.

[0143] The multi-input source driving mode can improve the signal uniformity of the cascade shift register.

[0144] By periodically arranging the gate electrodes and the phase difference between the shift register driving, a unique coupling voltage feature is generated at each position, and the nanoscale displacement detection can be realized by combining the preset resolution. The coupling waveform analysis does not need direction judgment and zero point calibration, and the position is directly calculated through the voltage feature, which improves the measurement reliability and real-time performance.

[0145] In some embodiments, the step S4 of determining the displacement according to the preset resolution and the coupling voltage comprises:

[0146] The step S41 of acquiring the path point-voltage mapping relationship of the detection electrode on the preset path comprises:

[0147] The step S42 of fitting according to the path point-voltage mapping relationship and the preset resolution, and establishing the displacement-voltage mapping relationship comprises:

[0148] The step S43 of acquiring the real-time coupling voltage of the detection electrode, and querying to obtain the corresponding displacement comprises:

[0149] When determining the displacement according to the preset resolution and the coupling voltage, the path point-voltage mapping relationship is first established by collecting the coupling voltage data of the detection electrode on the preset displacement path.

[0150] The preset path is a specific trajectory of the detection electrode relative to the gate electrode, and the discrete path point data is converted into a displacement-voltage relationship model by a mathematical fitting method. In actual measurement, after the coupling voltage of the detection electrode is acquired in real time, the corresponding displacement can be determined by reverse querying according to the model. In specific implementation, the voltage data can be processed by a polynomial fitting or an interpolation algorithm, or the matching and searching can be performed by a pre-calibrated database.

[0151] By establishing an accurate path point-voltage mapping relationship and performing mathematical fitting, the discrete coupling voltage measurement value can be converted into a continuous displacement calculation result, so that the measurement resolution is improved to the nanoscale. This positioning method based on voltage feature avoids the complex structure of the traditional grating ruler relying on optical interference, and reduces the system cost. The coupling voltage waveform fitting algorithm can improve the coupling voltage difference between adjacent states to the mV level, and realizes the nanoscale resolution by cooperating with high-precision voltage acquisition.

[0152] In some embodiments, the preset path is a displacement path through which the detection electrode passes relative to the at least one grid electrode. Step S41: obtaining a path point-voltage mapping relationship of the detection electrode on the preset path, comprising: performing alignment operation of each path point of the detection electrode and the grid electrode under the optical alignment device, and obtaining the coupling voltage of the detection electrode corresponding to each path point to obtain the path point-voltage mapping relationship.

[0153] The optical alignment device is used to perform precise alignment operation of the detection electrode and the grid electrode on the preset displacement path, and the coupling voltage data corresponding to each path point is obtained, so as to establish the mapping relationship between the path point and the voltage value. The optical alignment device can ensure the alignment accuracy of the detection electrode and the grid electrode at a specific position, and the complete voltage distribution model is formed by moving point by point and collecting the coupling voltage.

[0154] Exemplarily, the precise control of the path point can be realized by using a microscope assisted alignment or an automatic positioning device, and the mapping relationship is constructed by using a multi-point collection and data fitting method. In the embodiments, the mapping accuracy can be improved by adjusting the path point density or optimizing the alignment algorithm, for example, in the grid electrode structure with a line distance of 5 microns, the path points are equally divided into 6 or 11 sub-positions for voltage collection.

[0155] The path point-voltage mapping relationship realized by the optical alignment device can significantly improve the accuracy and stability of the displacement measurement. The precise alignment operation ensures that the coupling voltage data of each path point accurately reflects the actual physical position, and the measurement resolution can be improved to the nanometer level by combining the multi-point data fitting. This mapping relationship does not need to rely on complex optical systems or mechanical structures, which reduces the equipment cost and maintenance difficulty. At the same time, through the dense sampling of the path point and the voltage characteristic analysis, the influence of environmental interference and signal drift can be effectively eliminated, so that the system still maintains high reliability in the dynamic displacement scene.

[0156] In other embodiments, the preset path is a static path constituted by positions of each detection electrode. Step S41: obtaining a path point-voltage mapping relationship of the detection electrode on the preset path, comprising: 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.

[0157] The detection electrode adopts a plurality of arrangement modes, and each detection electrode corresponds to a specific position as a path point. By collecting the coupling voltage data of each detection electrode, the corresponding relationship between the position and the voltage is established.

[0158] In the embodiments, the number of detection electrodes can be set according to the exposure accuracy of the grid electrode, and the data collection density is improved by optimizing the spacing and layout of the detection electrodes.

[0159] The arrangement of multiple detection electrodes enables the system to simultaneously collect multi-point coupling voltage data, and the path point-voltage mapping relationship can significantly improve the positioning accuracy. By real-time collection of coupling voltage characteristics at different positions, in combination with waveform processing algorithms, nanoscale resolution can be achieved. The increase in the number of detection electrodes increases the data sample size, making the voltage fitting calculation more accurate. This design simplifies the calibration process, and only a single detection electrode needs to be aligned with a certain gate electrode to complete the overall calibration, reducing the need for manual intervention. At the same time, the multi-electrode layout enhances the robustness of the system, and even if some electrodes fail, the measurement function can still be maintained, improving the overall measurement stability.

[0160] In some embodiments, step S42: fitting according to the path point-voltage mapping relationship and the preset resolution, and establishing a displacement-voltage mapping relationship, comprises:

[0161] Step S421: obtaining a first coupling voltage corresponding to a first path point and a second coupling voltage corresponding to a second path point on a preset path; wherein the first path point and the second path point are any two adjacent path points on the preset path;

[0162] Step S422: obtaining the number of state positions within the interval of the two adjacent path points according to the preset resolution;

[0163] Step S423: taking the first coupling voltage and the second coupling voltage as reference points, fitting to generate a state position-voltage correspondence relationship within the interval from the first path point to the second path point;

[0164] Step S424: establishing a displacement-voltage mapping relationship according to the state position-voltage correspondence relationship.

[0165] By obtaining the coupling voltages corresponding to the adjacent path points, the number of state positions within the path point interval is determined according to the preset resolution, and the correspondence relationship between the state positions and the voltages within the interval is generated based on the two voltage reference points, and finally the mapping model of the displacement and the voltage is established. A plurality of path points can be used as reference for segmented fitting, or the state position density can be controlled by adjusting the preset resolution. In a specific embodiment, the path points can be arranged at the overlapping or partially overlapping positions of the gate electrodes and the detection electrodes, or arranged tangentially, the coupling voltages can be collected in real time by the processing unit, and the fitting process can be realized by using polynomial fitting or interpolation algorithm. When the number of state positions within the path point interval increases appropriately, the fineness of the displacement-voltage mapping relationship can be improved.

[0166] The introduction of the preset resolution can dynamically adjust the state position density, ensuring nanoscale accuracy while avoiding data redundancy. This method does not rely on complex sensors, but only needs mathematical modeling of the voltage signal to achieve high-precision positioning, reducing system complexity and improving measurement stability.

[0167] In the above embodiments, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0168] The above is only the implementation of the present application, and does not limit the patent protection scope of the present application. Any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present 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. 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. 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.

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.

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; 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; Obtain the real-time coupling voltage of the detection electrode and query the corresponding displacement. 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.

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 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.

8. The displacement measurement method according to claim 5, 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.

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