Capacitive displacement sensor, electronic equipment and displacement measurement method

Abstract

The invention discloses a capacitive displacement sensor, electronic equipment and a displacement measurement method. The capacitive displacement sensor comprises a control device, a first flexible film and a second flexible film, the first flexible thin film comprises a first insulating layer substrate and an exciting electrode; the second flexible film comprises a second insulating layer substrate, a reference electrode and a measuring electrode. Displacement measurement is achieved through the reference electrode and the measuring electrode, the influence of temperature, humidity, electromagnetic interference and other environmental factors on the measurement result can be eliminated, the measurement precision is improved, high-voltage signal excitation is adopted, the signal intensity and the detection sensitivity can be enhanced, and the measurement accuracy is improved. In addition, the high-voltage signal can also enable the two polar plates to have large adsorption force, so that the distance between the two polar plates is always kept at a relatively fixed size, errors caused by external interference can be reduced, and the precision of a measurement result is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of displacement sensors, and in particular to a capacitive displacement sensor, electronic equipment and a displacement measurement method. Background Art

[0002] Displacement sensors are one of the important components for achieving precise measurement and control in modern industry, and are widely used in robotics, precision machining, automatic control and other fields. Capacitive displacement sensors have gradually gained attention due to their high sensitivity, high resolution and non-contact measurement capabilities. Its basic principle is to infer displacement by measuring the change in capacitance based on the functional relationship between the change in capacitance and parameters such as the distance between electrodes and dielectric properties. However, traditional capacitive sensors have shortcomings such as complex design, high manufacturing cost and weak anti-interference ability under complex working conditions, which restricts their further development.

[0003] In the prior art, common capacitive displacement sensors include single parallel plate capacitor structure, multi-electrode array structure, differential capacitor structure and intelligent capacitance measurement method based on ASIC chip. Although the performance of existing capacitive displacement sensors has made certain progress, the existing capacitive displacement sensors are sensitive to external environment such as temperature, humidity and electromagnetic interference, resulting in reduced measurement accuracy.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a capacitive displacement sensor, an electronic device and a displacement measurement method to solve the problem of reduced measurement accuracy caused by the existing capacitive displacement sensors being more sensitive to the external environment.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a capacitive displacement sensor, which includes: a control device, a first flexible film and a second flexible film; the first flexible film includes a first insulating layer substrate and an excitation electrode; the second flexible film includes a second insulating layer substrate, a reference electrode and a measuring electrode;

[0008] The first flexible film and the second flexible film are arranged opposite to each other;

[0009] The reference electrode is arranged opposite to the excitation electrode, and the measuring electrode is arranged opposite to the excitation electrode;

[0010] When the second flexible film slides relative to the first flexible film, the overlapping area between the measuring electrode and the excitation electrode changes as the second flexible film slides relative to the first flexible film, and the overlapping area between the reference electrode and the excitation electrode does not change as the second flexible film slides relative to the first flexible film;

[0011] The control device is respectively connected to the excitation electrode, the reference electrode and the measuring electrode, and is used to provide a high-voltage signal to the excitation electrode, and to detect a first induced voltage generated between the reference electrode and the excitation electrode and a second induced voltage generated between the measuring electrode and the excitation electrode, and obtain a first discharge time and a second discharge time for the first induced voltage and the second induced voltage to discharge to a preset voltage threshold, so as to obtain a displacement change according to the first discharge time and the second discharge time.

[0012] According to a further configuration of the present invention, in an initial state, the area of ​​the reference electrode is smaller than the area of ​​the excitation electrode, and the area of ​​the reference electrode completely overlaps with the area of ​​the excitation electrode; and the area of ​​the measuring electrode at least partially overlaps with the area of ​​the excitation electrode.

[0013] In a further configuration of the present invention, the first flexible film is a polyimide film or a polyethylene terephthalate film; and the second flexible film is a polyimide film or a polyethylene terephthalate film.

[0014] According to a further configuration of the present invention, the excitation electrode is a copper film, a gold film or an aluminum film.

[0015] According to a further configuration of the present invention, the reference electrode is a copper film, a gold film or an aluminum film; and the measuring electrode is a copper film, a gold film or an aluminum film.

[0016] According to a further configuration of the present invention, the high voltage signal includes a high voltage square wave signal, a high voltage sine wave signal or a high voltage pulse signal.

[0017] According to a further configuration of the present invention, the control device comprises: a processor, a high voltage signal generator, a comparator and a clamping circuit; wherein,

[0018] The high-voltage signal generator is connected to the excitation electrode and is used to generate a high-voltage signal;

[0019] The clamping circuit is connected to the reference electrode and the measuring electrode respectively, and is used to clamp the first induced voltage and the second induced voltage at a positive voltage;

[0020] The comparator is connected to the clamping circuit, and is used to output a high level when the first induced voltage and the second induced voltage are higher than a preset voltage threshold, and output a low level when the voltage is lower than the preset voltage threshold, so as to obtain a first digital signal and a second digital signal, or to output a low level when the first induced voltage and the second induced voltage are higher than a preset voltage threshold, and output a high level when the voltage is lower than the preset voltage threshold, so as to obtain a first digital signal and a second digital signal;

[0021] The processor is connected to the high-voltage signal generator and the comparator, respectively, and is used to control the high-voltage signal generator to generate a high-voltage signal, and is used to obtain the first discharge time and the second discharge time according to the first digital signal and the second digital signal, and obtain the displacement change according to the first discharge time and the second discharge time.

[0022] A further configuration of the present invention further includes a filter, wherein the filter is connected between the clamping circuit and the comparator and is used for filtering the first induced voltage and the second induced voltage.

[0023] In a second aspect, the present invention further provides an electronic device, which includes the capacitive displacement sensor as described above.

[0024] In a third aspect, the present invention further provides a displacement measurement method based on the above-mentioned capacitive displacement sensor, which comprises the steps of:

[0025] The control device outputs a high voltage signal to the excitation electrode, so that the excitation electrode generates a periodic high voltage signal;

[0026] detecting a first induced voltage generated between the reference electrode and the excitation electrode and a second induced voltage generated between the measuring electrode and the excitation electrode;

[0027] Obtaining a first digital signal according to the first induced voltage, and obtaining a second digital signal according to the second induced voltage;

[0028] Obtaining a first discharge time according to the first digital signal, and obtaining a second discharge time according to the second digital signal;

[0029] A capacitance change of the sensor is obtained according to the first discharge time and the second discharge time, and a displacement change of the sensor is obtained according to the capacitance change.

[0030] The present invention provides a capacitive displacement sensor, an electronic device and a displacement measurement method, wherein the capacitive displacement sensor comprises: a control device, a first flexible film and a second flexible film; the first flexible film comprises a first insulating layer substrate and an excitation electrode; the second flexible film comprises a second insulating layer substrate, a reference electrode and a measuring electrode. The control device outputs a high-voltage signal to the excitation electrode so that the excitation electrode generates a periodic high-voltage signal, and detects a first induced voltage generated between the reference electrode and the excitation electrode and a second induced voltage generated between the measuring electrode and the excitation electrode, and obtains a first discharge time and a second discharge time for the first induced voltage and the second induced voltage to discharge to a preset voltage threshold, so as to obtain a displacement change according to the first discharge time and the second discharge time. The present invention realizes displacement measurement through a reference electrode and a measuring electrode, which can eliminate the influence of environmental factors such as temperature, humidity and electromagnetic interference on the measurement result, and improves the measurement accuracy. The high-voltage signal excitation can not only enhance the signal strength and detection sensitivity, but also enable the two plates to have a larger adsorption force, so that the distance between the two plates is always kept at a relatively fixed size, thereby reducing the error caused by external interference and improving the accuracy of the measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary personnel in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0032] Figure 1 It is a structural schematic diagram of the capacitive displacement sensor in the present invention.

[0033] Figure 2 It is a structural schematic diagram of the capacitive displacement sensor in the present invention from another angle.

[0034] Figure 3 1 is a circuit schematic diagram of a capacitive displacement sensor in one embodiment of the present invention.

[0035] Figure 4 4 is a circuit schematic diagram of a capacitive displacement sensor in another embodiment of the present invention.

[0036] Figure 5 It is a schematic structural diagram of a capacitive displacement sensor using a multi-layer thin film structure in one embodiment of the present invention.

[0037] Figure 6 It is a flow chart of a displacement measurement method of a capacitive displacement sensor in one embodiment of the present invention.

[0038] The marks in the accompanying drawings are: 100, control device; 110, processor; 120, high-voltage signal generator; 130, comparator; 140, clamping circuit; 150, filter; 200, first flexible film; 210, first insulating layer substrate; 220, excitation electrode; 300, second flexible film; 310, second insulating layer substrate; 320, reference electrode; 330, measuring electrode. DETAILED DESCRIPTION

[0039] The present invention provides a capacitive displacement sensor, an electronic device and a displacement measurement method. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] In the embodiments and the scope of the patent application, unless the text specifically defines the article, "a", "an", "the" and "the" may also include plural forms. If there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0041] It should be further understood that the wording "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when an element is said to be "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can also be an intermediate element. In addition, the "connection" or "coupling" used here can include wireless connection or wireless coupling. The wording "and / or" used here includes all or any unit and all combinations of one or more items listed in association.

[0042] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0043] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] The inventors have found that common capacitive displacement sensors include single parallel plate capacitor structure, multi-electrode array structure, differential capacitor structure and intelligent capacitance measurement method based on ASIC chip. The single parallel plate capacitor structure is simple in design, but is easily affected by environmental interference and has poor linearity; the multi-electrode array structure improves the measurement accuracy, but the manufacturing is complex and costly; the differential capacitor structure enhances the anti-interference ability, but has high requirements for circuit matching and is easily affected by processing errors; and the intelligent measurement method based on ASIC chip has the advantages of small size and high integration, but relies on expensive dedicated chips and has a long development cycle. Although the prior art has made certain progress in the performance of capacitive displacement sensors, there are still many shortcomings. First, it is difficult to balance sensitivity and linearity, and it is difficult to meet high precision and good linear characteristics at the same time; second, it is sensitive to external environment such as temperature, humidity and electromagnetic interference, resulting in reduced measurement accuracy; third, the production process of some high-precision sensors is complex and costly, which limits large-scale application; in addition, the existing design has poor adaptability, is mostly customized for specific scenarios, and is difficult to meet diverse needs; finally, the signal processing is highly complex, and the design of hardware circuits and algorithms increases R&D costs and power consumption.

[0045] In view of the above technical problems, the present invention provides a capacitive displacement sensor, an electronic device and a displacement measurement method, wherein the capacitive displacement sensor comprises: a control device, a first flexible film and a second flexible film; the first flexible film comprises a first insulating layer substrate and an excitation electrode; the second flexible film comprises a second insulating layer substrate, a reference electrode and a measuring electrode. The present invention realizes the measurement of displacement through the reference electrode and the measuring electrode, which can eliminate the influence of environmental factors such as temperature, humidity and electromagnetic interference on the measurement results, and improves the measurement accuracy; the use of high-voltage signal excitation can not only enhance the signal strength and detection sensitivity, but also enable the high-voltage signal to have a greater adsorption force between the two plates, so that the distance between the two plates is always maintained at a relatively fixed size, thereby reducing the error caused by external interference and improving the accuracy of the measurement results; the structure is simple, the production process is simplified, and the production cost is reduced; in addition, the combined design of the reference electrode and the measuring electrode improves the linearity and reliability of the measurement, has high adaptability, and is suitable for a variety of complex application scenarios; the signal processing is simple, and the cost and power consumption of the hardware circuit and algorithm are reduced.

[0046] Please also see Figures 1 to 5 , the present invention provides a preferred embodiment of a capacitive displacement sensor.

[0047] In some embodiments, Figures 1 to 3 As shown, the present invention provides a capacitive displacement sensor, which includes: a control device 100, a first flexible film 200 and a second flexible film 300; the first flexible film 200 includes a first insulating layer substrate 210 and an excitation electrode 220; the second flexible film 300 includes a second insulating layer substrate 310, a reference electrode 320 and a measuring electrode 330; the first flexible film 200 and the second flexible film 300 are arranged opposite to each other; the reference electrode 320 and the excitation electrode 220 are arranged opposite to each other, and the measuring electrode 330 and the excitation electrode 220 are arranged opposite to each other; wherein, when the second flexible film 300 slides relative to the first flexible film 200, the overlapping area between the measuring electrode 330 and the excitation electrode 220 increases as the second flexible film 300 and the first The flexible films 200 slide and change, and the overlapping area of ​​the reference electrode 320 and the excitation electrode 220 does not change as the second flexible film 300 slides and the first flexible film 200 slides; the control device 100 is respectively connected to the excitation electrode 220, the reference electrode 320 and the measuring electrode 330, and is used to provide a high-voltage signal to the excitation electrode 220, and is used to detect a first induced voltage generated between the reference electrode 320 and the excitation electrode 220 and a second induced voltage generated between the measuring electrode 330 and the excitation electrode 220, and obtain a first discharge time and a second discharge time when the first induced voltage and the second induced voltage are discharged to a preset voltage threshold, so as to obtain a displacement change according to the first discharge time and the second discharge time.

[0048] Specifically, the first flexible film 200 and the second flexible film 300 are used as two parallel plates, wherein the first flexible film 200 is provided with an excitation electrode 220, and the second flexible film 300 is provided with a reference electrode 320 and a measuring electrode 330, wherein the reference electrode 320 and the excitation electrode 220 form a parallel plate capacitor, and the measuring electrode 330 and the excitation electrode 220 form another parallel plate capacitor, and the first insulating layer substrate 210 and the second insulating layer substrate 310 serve as a supporting structure. In an initial state, the area of ​​the reference electrode 320 is smaller than the area of ​​the excitation electrode 220, and the area of ​​the reference electrode 320 completely overlaps with the area of ​​the excitation electrode 220; the area of ​​the measuring electrode 330 at least partially overlaps with the area of ​​the excitation electrode 220, and when the first flexible film 200 and the second flexible film 300 move relative to each other, the overlapping area of ​​the measuring electrode 330 and the excitation electrode 220 changes. During operation, one of the films is fixed to the fixed end of the device that needs to be tested for displacement, and the other film is fixed to the moving end of the device that needs to be tested for displacement. When the moving end of the device under test moves, it will drive the relative movement between the films, thereby achieving sliding.

[0049] The excitation electrode 220 can generate a periodic high-voltage signal after receiving a high-voltage signal. The capacitance formed by the reference electrode 320 and the excitation electrode 220 keeps the capacitance unchanged during the movement of the plate, and can provide a stable reference signal. The capacitance of the capacitance formed by the measuring electrode 330 and the excitation electrode 220 changes with the movement of the plate, which can reflect the actual displacement. By detecting the capacitance change of the measuring electrode 330 and taking the signal of the reference electrode 320 as a reference, displacement measurement is achieved. In specific implementation, the control device 100 outputs a high-voltage signal to the excitation electrode 220 so that the excitation electrode 220 generates a periodic high-voltage signal, and detects the first induced voltage generated between the reference electrode 320 and the excitation electrode 220 and the second induced voltage generated between the measuring electrode 330 and the excitation electrode 220, and obtains the first discharge time and the second discharge time of the first induced voltage and the second induced voltage to discharge to a preset voltage threshold. The first discharge time and the second discharge time can reflect the capacitance change of the sensor, so that the displacement change of the sensor can be further obtained, and high-precision displacement detection can be achieved.

[0050] In the above technical scheme, the present invention can eliminate the influence of environmental factors such as temperature, humidity and electromagnetic interference on the measurement results by detecting the capacitance change of the measuring electrode 330 and taking the signal of the reference electrode 320 as a reference, thereby improving the measurement accuracy; the use of high-voltage signal excitation can not only enhance the signal strength and detection sensitivity (the sensor changes the same distance, the absolute change of the high-voltage signal voltage is large, and it can be more sensitive), but the high-voltage signal can also make the two plates have a greater adsorption force, so that the distance between the two plates is always maintained at a relatively fixed size, thereby reducing the error caused by external interference and improving the accuracy of the measurement results; the structure is simple, and the high voltage can ensure the adsorption of the two films. No other mechanical structure is required to keep the distance stable. It only needs to limit the left deviation of the two films, which simplifies the production process and reduces the production cost; in addition, the combined design of the reference electrode 320 and the measuring electrode 330 improves the linearity and reliability of the measurement, has high adaptability, and is suitable for a variety of complex application scenarios; the signal processing is simple, which reduces the cost and power consumption of the hardware circuit and algorithm.

[0051] In some embodiments, the first flexible film 200 may be, but not limited to, a polyimide film or a polyethylene terephthalate film. The second flexible film 300 may be, but not limited to, a polyimide film or a polyethylene terephthalate film. In some embodiments, the present invention may also use a microstructured film or a highly elastic material instead of a common flexible film to optimize sliding properties and durability.

[0052] In some embodiments, the excitation electrode 220 is made of a conductive material, which may be, but is not limited to, a copper film, a gold film, an aluminum film, etc. In this embodiment, the excitation electrode 220 is a copper film.

[0053] In some embodiments, the reference electrode 320 is made of a conductive material, which may be, but is not limited to, a copper film, a gold film, an aluminum film, etc. In this embodiment, the reference electrode 320 is a copper film.

[0054] In some embodiments, the measuring electrode 330 may be, but is not limited to, a copper film, a gold film, an aluminum film, etc. In this embodiment, the measuring electrode 330 is a copper film.

[0055] In some embodiments, a rigid electrode may be used instead of a flexible electrode such as a copper film.

[0056] In some embodiments, the high voltage signal includes a high voltage square wave signal, a high voltage sine wave signal, or a high voltage pulse signal.

[0057] Specifically, a high voltage signal is used as the excitation voltage. Unlike the traditional low voltage or electrostatic excitation signal, the high voltage signal is less affected by external environmental factors, and can provide stronger anti-interference ability and achieve accurate position sensing. At the same time, the high voltage signal will make the two flexible films attract each other, thereby controlling the distance between the excitation electrode 220 and the measuring electrode 330 and the reference electrode 320 to be relatively constant, further improving the anti-interference ability of the sensor. In addition, the high voltage signal can not only be used as a position sensing signal, but also can control the attraction between the two flexible films by controlling the amplitude and duty cycle of the high voltage signal, thereby controlling the friction between the two flexible films, and realizing a function similar to an adjustable damper. The high voltage signal can be a high voltage square wave signal, a high voltage sine wave signal, a high voltage pulse signal, etc. In this embodiment, the high voltage signal is a high voltage square wave signal.

[0058] In some embodiments, an electrostatic adsorption electrode is provided between the excitation electrode 220 and the reference electrode 320 to increase the electrostatic adsorption force, and to improve the alignment accuracy by adding the electrostatic adsorption force during the sliding process of the sensor. The magnitude of the electrostatic adsorption force can be adjusted by independently regulating the voltage signal to further control the friction and sliding characteristics.

[0059] In some embodiments, the electrostatic adsorption capability of the first flexible film 200 and the second flexible film 300 may also be achieved by using a mechanical damping device.

[0060] In some embodiments, Figure 3 As shown, the control device 100 includes: a processor 110 , a high voltage signal generator 120 , a comparator 130 and a clamping circuit 140 . Among them, the high-voltage signal generator 120 is connected to the excitation electrode 220 for generating a high-voltage signal; the clamping circuit 140 is connected to the reference electrode 320 and the measuring electrode 330 respectively, for clamping the first induced voltage and the second induced voltage at a positive voltage; the comparator 130 is connected to the clamping circuit 140, for outputting a high level when the first induced voltage and the second induced voltage are higher than a preset voltage threshold, and outputting a low level when the voltage is lower than the preset voltage threshold, so as to obtain a first digital signal and a second digital signal, or, for outputting a low level when the first induced voltage and the second induced voltage are higher than a preset voltage threshold, and outputting a high level when the voltage is lower than the preset voltage threshold, so as to obtain a first digital signal and a second digital signal; the processor 110 is connected to the high-voltage signal generator 120 and the comparator 130 respectively, for controlling the high-voltage signal generator 120 to generate a high-voltage signal, and for obtaining the first discharge time and the second discharge time according to the first digital signal and the second digital signal, and obtaining the displacement change according to the first discharge time and the second discharge time.

[0061] Specifically, the control device 100 composed of the processor 110, the high-voltage signal generator 120, the comparator 130 and the clamping circuit 140 is used to realize the acquisition of the capacitance signal, wherein the high-voltage signal generator 120 includes a high-voltage square wave signal generator, a high-voltage sine wave signal generator and a high-voltage pulse signal generator, and this embodiment is described by taking the high-voltage square wave signal generator as an example. In this embodiment, the comparator 130 outputs a high level voltage when the first induced voltage and the second induced voltage are higher than the preset voltage threshold, and outputs a low level voltage when the voltage is lower than the preset voltage threshold, so as to obtain the first digital signal and the second digital signal. In specific implementation, the processor 110 receives a position signal (a discharge time signal of a voltage) and controls a high-voltage square wave signal generator to generate a high-voltage square wave signal. The excitation electrode 220 generates a periodic high-voltage square wave signal under the action of the high-voltage square wave signal. The reference electrode 320 and the measuring electrode 330 induce a first induced voltage and a second induced voltage under the action of the excitation electrode 220 (the reference electrode 320 and the measuring electrode 330 will generate induced charges). The first induced voltage and the second induced voltage are clamped at a positive voltage after being processed by the clamping circuit 140, and then the induced voltage is higher than a preset voltage through the comparator 130. The voltage above the preset voltage threshold is output at a high level, and the voltage below the preset threshold is output at a low level, thereby obtaining a first digital square wave signal and a second digital square wave signal. The processor 110 obtains a first discharge time t1 for the first induced voltage to discharge to the preset voltage threshold, i.e., the discharge time of the high level of the first digital square wave signal, and a second discharge time t2 for the second induced voltage to discharge to the preset voltage threshold, i.e., the discharge time of the high level of the second digital square wave signal, by measuring the proportion of the high level in one cycle. The first discharge time t1 and the second discharge time t2 can reflect the capacitance change of the sensor, thereby further obtaining the displacement change of the sensor.

[0062] In some embodiments, Figure 4 As shown, the capacitive displacement sensor also includes a filter 150, and the filter 150 is connected between the clamp circuit 140 and the comparator 130, and is used to filter the first induced voltage and the second induced voltage, so as to enhance the resistance to environmental interference. It should be noted that in some embodiments, a module with a dynamic threshold adjustment function can be added between the clamp circuit 140 and the comparator 130 to enhance the resistance to environmental interference.

[0063] In some embodiments, Figure 5As shown, the capacitive displacement sensor can also adopt a multi-layer film structure, that is, multiple sets of the first flexible film 200 and the second flexible film 300 can be used, multiple excitation electrodes 220 and multiple measurement electrode groups can be used to achieve multi-point displacement detection or higher resolution sensing. At the same time, the multi-layer structure can also realize multifunctional sensing applications, such as simultaneous measurement of displacement and force, through relative sliding control between different layers.

[0064] In some embodiments, the present invention further provides an electronic device, which includes the capacitive displacement sensor as described above. The details are as described in an embodiment of the capacitive displacement sensor, which will not be described in detail here.

[0065] In some embodiments, Figure 6 As shown, the present invention also provides a displacement measurement method based on the above-mentioned capacitive displacement sensor, which comprises the steps of:

[0066] S100, the control device outputs a high-voltage signal to the excitation electrode, so that the excitation electrode generates a periodic high-voltage signal; the details are as described in an embodiment of a capacitive displacement sensor, which will not be repeated here.

[0067] S200, detecting a first induced voltage generated between the reference electrode and the excitation electrode and a second induced voltage generated between the measuring electrode and the excitation electrode; the details are as described in an embodiment of a capacitive displacement sensor, which will not be described in detail here.

[0068] S300, obtaining a first digital signal according to the first induced voltage, and obtaining a second digital signal according to the second induced voltage; the details are as described in an embodiment of a capacitive displacement sensor, which will not be described in detail here.

[0069] S400, obtaining a first discharge time according to the first digital signal, and obtaining a second discharge time according to the second digital signal; the details are as described in an embodiment of a capacitive displacement sensor, which will not be described in detail herein.

[0070] S500: Obtain a capacitance change of the sensor according to the first discharge time and the second discharge time, and obtain a displacement change of the sensor according to the capacitance change. The details are as described in an embodiment of a capacitive displacement sensor, and will not be described in detail here.

[0071] In summary, the capacitive displacement sensor, electronic device and displacement measurement method provided by the present invention have the following beneficial effects:

[0072] By detecting the capacitance change of the measuring electrode and taking the signal of the reference electrode as the benchmark, the influence of environmental factors such as temperature, humidity and electromagnetic interference on the measurement results can be eliminated, thus improving the measurement accuracy.

[0073] The use of high-voltage signal excitation can not only enhance the signal strength and detection sensitivity, but also make the two plates have a greater adsorption force, so that the distance between the two plates is always kept at a relatively fixed size, thereby reducing the error caused by external interference, improving the accuracy of the measurement results, and further improving the anti-interference ability of the sensor;

[0074] The high-voltage signal can not only be used as a position sensing signal, but also can adjust the attraction between the two flexible films by controlling the amplitude of the high-voltage signal, thereby adjusting the friction between the two flexible films, thus realizing a function similar to that of an adjustable damper.

[0075] The structure is simple, which simplifies the production process and reduces the production cost;

[0076] The combined design of reference electrode and measuring electrode improves the linearity and reliability of measurement, has high adaptability, and is suitable for a variety of complex application scenarios;

[0077] The signal processing is simple, which reduces the cost and power consumption of hardware circuits and algorithms.

[0078] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A capacitive displacement sensor, characterized in that: include: A control device, a first flexible film and a second flexible film; The first flexible film includes a first insulating layer substrate and an excitation electrode; The second flexible film includes a second insulating layer substrate, a reference electrode and a measuring electrode; The first flexible film and the second flexible film are arranged opposite to each other; The reference electrode is arranged opposite to the excitation electrode, and the measuring electrode is arranged opposite to the excitation electrode; When the second flexible film slides relative to the first flexible film, the overlapping area between the measuring electrode and the excitation electrode changes as the second flexible film slides relative to the first flexible film, and the overlapping area between the reference electrode and the excitation electrode does not change as the second flexible film slides relative to the first flexible film; The control device is respectively connected to the excitation electrode, the reference electrode and the measuring electrode, and is used to provide a high-voltage signal to the excitation electrode, and to detect a first induced voltage generated between the reference electrode and the excitation electrode and a second induced voltage generated between the measuring electrode and the excitation electrode, and to obtain a first discharge time and a second discharge time for the first induced voltage and the second induced voltage to discharge to a preset voltage threshold, so as to obtain a displacement change according to the first discharge time and the second discharge time.

2. The capacitive displacement sensor according to claim 1, characterized in that: In the initial state, the area of ​​the reference electrode is smaller than the area of ​​the excitation electrode, and the area of ​​the reference electrode completely overlaps with the area of ​​the excitation electrode; the area of ​​the measuring electrode at least partially overlaps with the area of ​​the excitation electrode.

3. The capacitive displacement sensor according to claim 1, characterized in that: The first flexible film is a polyimide film or a polyethylene terephthalate film; the second flexible film is a polyimide film or a polyethylene terephthalate film.

4. The capacitive displacement sensor according to claim 1, characterized in that: The excitation electrode is a copper film, a gold film or an aluminum film.

5. The capacitive displacement sensor according to claim 1, characterized in that: The reference electrode is a copper film, a gold film or an aluminum film; the measuring electrode is a copper film, a gold film or an aluminum film.

6. The capacitive displacement sensor according to claim 1, characterized in that: The high voltage signal includes a high voltage square wave signal, a high voltage sine wave signal or a high voltage pulse signal.

7. The capacitive displacement sensor according to claim 1, characterized in that: The control device includes: a processor, a high voltage signal generator, a comparator and a clamping circuit; wherein, The high-voltage signal generator is connected to the excitation electrode and is used to generate a high-voltage signal; The clamping circuit is connected to the reference electrode and the measuring electrode respectively, and is used to clamp the first induced voltage and the second induced voltage at a positive voltage; The comparator is connected to the clamping circuit, and is used to output a high level when the first induced voltage and the second induced voltage are higher than a preset voltage threshold, and output a low level when the voltage is lower than the preset voltage threshold, so as to obtain a first digital signal and a second digital signal, or to output a low level when the first induced voltage and the second induced voltage are higher than a preset voltage threshold, and output a high level when the voltage is lower than the preset voltage threshold, so as to obtain a first digital signal and a second digital signal; The processor is connected to the high-voltage signal generator and the comparator, respectively, and is used to control the high-voltage signal generator to generate a high-voltage signal, and is used to obtain the first discharge time and the second discharge time according to the first digital signal and the second digital signal, and obtain the displacement change according to the first discharge time and the second discharge time.

8. The capacitive displacement sensor according to claim 7, characterized in that: A filter is also included, and the filter is connected between the clamping circuit and the comparator, and is used for filtering the first induced voltage and the second induced voltage.

9. An electronic device, characterized in that: It comprises a capacitive displacement sensor as described in any one of claims 1 to 8.

10. A displacement measurement method based on the capacitive displacement sensor according to any one of claims 1 to 8, characterized in that: Includes steps: The control device outputs a high voltage signal to the excitation electrode, so that the excitation electrode generates a periodic high voltage signal; detecting a first induced voltage generated between the reference electrode and the excitation electrode and a second induced voltage generated between the measuring electrode and the excitation electrode; Obtaining a first digital signal according to the first induced voltage, and obtaining a second digital signal according to the second induced voltage; Obtaining a first discharge time according to the first digital signal, and obtaining a second discharge time according to the second digital signal; A capacitance change of the sensor is obtained according to the first discharge time and the second discharge time, and a displacement change of the sensor is obtained according to the capacitance change.

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