Non-contact component displacement test circuit

Abstract

The application provides a non-contact component displacement test circuit, which comprises a charging circuit, an integration circuit, a discharging circuit, a switching circuit and a gain adjusting circuit; the input end of the charging circuit is connected with a test electrode plate; the charging circuit is connected with a reference source; the reference source is used for providing a reference signal for the charging circuit; the output end of the charging circuit is connected with the input end of the integration circuit; the output end of the integration circuit outputs a voltage signal through the gain adjusting circuit; and the charging circuit is further connected with the switching circuit and the discharging circuit respectively. The non-contact component displacement test circuit provided by the application can accurately test the linear displacement between two components without the relative movement of the two components contacting the test sensor, without exerting external force on the test moving component, without considering the installation space and fixing mode of the displacement test sensing part, and without being limited by whether the test component movement track is a straight line or a multi-directional space relative movement.

Description

Technical Field

[0001] This application belongs to the field of electronic circuit technology, and in particular relates to a non-contact component displacement testing circuit. Background Technology

[0002] Displacement is a physical quantity that must be measured in the control of internal combustion engines. The commonly used measurement method is to use a displacement sensor. The sensor has a fixed part and a movable part installed on two relatively moving parts. When the parts move, they move the movable part of the displacement sensor, thus measuring the displacement of the parts. This method can directly obtain the displacement measurement value. However, because it requires the addition of a displacement sensor for testing, it is limited by the test space and installation method, and cannot complete the displacement measurement in some specific situations. Summary of the Invention

[0003] In view of this, this application aims to propose a non-contact component displacement testing circuit to solve the problem that displacement measurement cannot be completed in certain situations due to limitations in testing space and installation methods.

[0004] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0005] This application provides a non-contact component displacement testing circuit, including:

[0006] Charging circuit, integrating circuit, discharging circuit, switching circuit and gain adjustment circuit;

[0007] The input terminal of the charging circuit is connected to the test plate, the charging circuit is connected to the reference source, the reference source is used to provide a reference signal to the charging circuit, the output terminal of the charging circuit is connected to the input terminal of the integrating circuit, and the output terminal of the integrating circuit outputs a voltage signal through the gain adjustment circuit.

[0008] The charging circuit is also connected to the switching circuit and the discharging circuit, respectively.

[0009] Furthermore, the test plate is composed of test plate 1 and test plate 2;

[0010] The charging circuit includes a first main control chip, the thirteenth pin of the first main control chip is connected to the test plate 1, its third pin is connected to the test plate 2, its fourteenth pin is connected to the reference source, its twelfth pin is connected to the integration circuit, and its tenth pin is connected to the switching circuit and the discharge circuit respectively.

[0011] The twelfth pin of the first main control chip is also grounded through the second capacitor;

[0012] The first main control chip has sixteen pins connected to the power supply VCC, and its fifth, sixth and ninth pins are grounded.

[0013] Furthermore, the integrating circuit includes a fifth operational amplifier, the third pin of the fifth operational amplifier is connected to the twelfth pin of the first main control chip, the second pin of the fifth operational amplifier is connected to the first pin of the first main control chip, and the sixth pin of the fifth operational amplifier is connected to the gain adjustment circuit through a third resistor, with the end of the third resistor closest to the gain adjustment circuit grounded through a third capacitor.

[0014] The second pin of the fifth operational amplifier is connected to its sixth pin.

[0015] Furthermore, the gain adjustment circuit includes a sixth operational amplifier, the third pin of which is connected to a third resistor, and the sixth pin of which is connected to a voltage output terminal through a fourth resistor to output a voltage signal.

[0016] The second pin of the sixth operational amplifier is connected to a potentiometer via a ninth resistor, grounded via a fifth resistor, and connected to a fourth resistor via an eighth resistor. The end of the fifth resistor closest to ground is connected to the potentiometer via a seventh resistor, and the potentiometer is connected to the power supply VCC via a sixth resistor.

[0017] Furthermore, the switching circuit includes a third main control chip, the seventh pin of the third main control chip is connected to the tenth pin of the first main control chip, the tenth pin of the third main control chip is connected to a first resistor, the ninth pin of the third main control chip is connected to a first capacitor, the eleventh pin of the third main control chip is connected to a second resistor, and the common terminal of the first resistor, the first capacitor and the second resistor are connected together.

[0018] Furthermore, the discharge circuit includes a second main control chip, and the fourteenth pin of the second main control chip is connected to the twelfth pin of the first main control chip.

[0019] Compared with the prior art, the non-contact component displacement testing circuit described in this application has the following advantages:

[0020] The non-contact component displacement testing circuit described in this application uses two test plates to sense the displacement. The testing circuit includes a reference source, a charging circuit, a sampling capacitor, an integrating circuit, a switching circuit, a discharging circuit, and a gain adjustment circuit. It uses two relatively moving metal objects as the sensing part of the testing circuit. The testing method of this circuit ensures that the two relatively moving components do not come into contact through the test sensor, does not apply external force to the moving components, does not need to consider the installation space or fixing method of the displacement testing sensing part, and is not limited by whether the movement trajectory of the test components is linear or multi-directional relative spatial movement. It can accurately test the linear displacement between the two components. Furthermore, through coordinate determination and numerical calibration, it can separately test the displacement of the two components on the X-axis, Y-axis, and Z-axis. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a circuit diagram of a non-contact component displacement test according to an embodiment of this application;

[0023] Figure 2 This is a voltage signal waveform diagram as described in the embodiments of this application;

[0024] Figure 3 This is a displacement test diagram of the component described in the embodiment of this application in terms of its spatial position. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0026] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] Please see Figure 1 As shown, this embodiment provides a non-contact component displacement testing circuit that uses test plates (composed of test plate 1 and test plate 2) to sense the displacement. The testing circuit includes: a reference source, a charging circuit, a sampling capacitor, an integrating circuit, a switching circuit, a discharging circuit, and a gain adjustment circuit.

[0028] The test circuit described in this embodiment uses two test plates to sense the displacement. The test circuit includes a reference source, a charging circuit, a sampling capacitor, an integrating circuit, a switching circuit, a discharging circuit, and a gain adjustment circuit. It uses two relatively moving metal objects as the sensing part of the test circuit. The test method of this test circuit ensures that the two relatively moving parts do not come into contact through the test sensor, does not apply external force to the test moving parts, does not need to consider the installation space or fixing method of the displacement test sensing part, and is not limited by whether the movement trajectory of the test parts is linear or multi-directional relative spatial movement. It can accurately test the linear displacement between the two parts. Furthermore, through coordinate determination and numerical calibration, it can separately test the displacement of the two parts on the X-axis, Y-axis, and Z-axis.

[0029] Among them, pin 1 Vin of the reference source input is connected to the power supply VCC, pin 2 GND is connected to the power ground GND, and pin 3 Vout outputs the reference signal to provide a signal to the charging circuit, which is connected to channel X1 of pin 14 of U1 in the charging circuit.

[0030] In the charging circuit, pin 13 (common terminal X) of U1 is connected to test plate 1, and pin 3 (common terminal Y) of U1 is connected to test plate 2; pin 5 (channel Y1), pin 6 (control signal INH), and pin 9 (channel selection signal B) of U1 are connected to ground GND; channel selection signal A is connected to pin 7 (output terminal Q4) of U3 in the switching circuit; pin 12 (channel X0) and pin 1 (channel Y0) of U1 are connected to pin 3 (positive input terminal) and pin 2 (negative input terminal) of U5 in the integrating circuit; pin 12 (channel X0) of U1 is also connected to one end of integrating capacitor C2 and pin 14 (channel X1) of U2 in the discharging circuit; the other end of integrating capacitor C2 is connected to GND; VCC, GND, and VEE of U1 are connected to the power supply VCC, ground GND, and negative power supply VEE, respectively.

[0031] In the integrating circuit, the negative input pin 2 and output pin 6 of U5 are connected to form a follower. The output pin 6 is connected to one end of the filter resistor R3. The signal is filtered by R3 and C3. The output signal V3 is connected to the positive input pin 3 of U6 in the gain adjustment circuit. Pins 7 and 4 of U5 are connected to the power supply VCC and the negative power supply VEE, respectively.

[0032] In the discharge circuit, pin 13 (common terminal X) of U2 is connected to ground signal GND, pin 6 (control signal INH) and pin 9 (channel selection signal B) are connected to grounded GND, and channel selection signal A is connected to pin 7 (output terminal Q4) of U3 in the switching circuit; VCC, GND, and VEE of U2 are connected to the power supply VCC, ground GND, and negative power supply VEE, respectively.

[0033] In the switching circuit, pins 10, 9, and 11 of U3 are connected to one end of output resistor R1, charging capacitor C1, and input resistor R2, respectively. The other ends of R1, C1, and R2 are connected together to form an oscillation circuit. The reset pin RST of U3 is connected to GND. The output pin Q4 of U3 is connected to the channel selection signal A of U1 in the charging circuit and the channel selection signal A of U2 in the discharging circuit. The reset pin RST of U3 is connected to GND. VCC and GND of U3 are connected to the power supply VCC and ground GND, respectively.

[0034] The positive input terminal 3 of the gain adjustment circuit U6 is connected to the common terminal of the integrating circuit R3 and C3. The negative input terminal 2 and the output terminal 6 form a non-inverting amplifier circuit through the current limiting resistor R4, the feedback resistor R8, and the ground resistor R5. The voltage divider circuit is formed by the voltage divider resistor R6, the adjusting potentiometer W1, and the voltage divider resistor R7, and is connected to the negative input terminal 2 of the amplifier U6 through the input balancing resistor R9. The 7th and 4th terminals of U6 are connected to the power supply VCC and the negative power supply VEE, respectively.

[0035] like Figure 2 As shown, Q4 is the control waveform output by the switching circuit. t0~t1, t3~t4, and t6~t7 are the charging periods for the test plates; t1~t3, t4~t6, and t7~t9 are the sampling and holding periods for the sampling capacitor, where t1~t2, t4~t5, and t7~t8 are the sampling periods.

[0036] During the charging period t0 to t1, the channel selection signals B and A of the charging circuit are at levels 0 and 1, respectively. The common channels X and Y of U1 in the charging circuit are connected to the input channels X1 and Y1, respectively. Y is connected to signal ground, and X is connected to the reference source to charge the test plate. At time t01, the voltage V1 on the test plate reaches V11 and remains unchanged before t1. Simultaneously, during t0 to t1, the common channel X of U2 in the discharging circuit is connected to the input channel X1, and the charging capacitor C2 discharges to ground, completing the reset of signal V2 to zero, preparing for the next sampling. The dashed line represents the first state.

[0037] During the sampling and holding phase t1 to t3, the channel selection signals B and A of the charging circuit are at level 0 and 0, respectively. The common channels X and Y of U1 in the charging circuit are connected to the input channels X0 and Y0, respectively. Test plates 1 and 2 are connected to the positive and negative inputs of U5 in the integrating circuit, respectively. At the same time, the sampling capacitor C2 samples the signal on the plate.

[0038] The test plate capacitor and the sampling capacitor form a parallel capacitor, and the charge gradually balances out. At time t2, the charge reaches equilibrium, and the voltage signal on the test plate decreases from V11 to V12, while the signal on the sampling capacitor increases from 0 to V21. During the period t2 to t3, all signals are stable. The integrator circuit outputs signal V3 through the filter circuit, which stabilizes at V31. This stable voltage signal is proportional to the capacitance of the test plate, and the capacitance of the test plate is proportional to its relative position. Through data calibration and correction, the distance to the test plate can be calculated from the output signal V3 of the integrator circuit.

[0039] Similarly, after the next charging period t3~t4 and the sampling and holding period t4~t5, the voltage signal on the plates drops from V11 to V13, and the signal on the sampling capacitor rises from 0 to V22. During t5~t6, the integrator circuit outputs signal V3 through the filter circuit and stabilizes at V32; this stable voltage signal can also be used to calculate another distance between the test plates.

[0040] By using the two distance differences mentioned above, the relative displacement of the test plate, i.e. the relative displacement of the moving parts, can be calculated.

[0041] After the next charging period t6-t7 and the sampling and holding period t7-t9, the voltage signal on the plate decreases from V11 to V14, while the signal on the sampling capacitor increases from 0 to V23. During t8-t9, the integrator circuit outputs signal V3 through the filter circuit, which stabilizes at V33. This stable voltage signal represents a new distance of the test plate and can be used to calculate the relative displacement of the test plate.

[0042] Figure 2 In the diagram, t0~t1, t3~t4, and t6~t7 represent the different times it takes for the voltage to reach V11 during the charging period of the test plate, specifically t0~t01, t3~t34, and t6~t67 respectively. These durations are determined by the residual charge, i.e., the residual voltage, after the previous test of the test plate. Throughout the entire charging period, the charging parameters should be designed to ensure that the voltage on the test plate reaches V11. Simultaneously, this period must also ensure that the charge on the sampling capacitor is completely reset to zero through the discharge circuit.

[0043] The sampling times t1~t2, t4~t5, and t7~t8 are determined by the capacitance of the test plates, which is related to the relative position of the two test plates. The sampling and holding times t1~t3, t4~t6, and t7~t9 are designed to ensure that there is enough time to reach charge balance after the test plates and sampling capacitors are adjusted.

[0044] like Figure 3 As shown, in displacement testing, spatial coordinates of the X-axis, Y-axis, and Z-axis are established. By calibrating the data from X1 to X2, Y1 to Y2, and Z1 to Z2 in the three directions, the displacement of the object in the three directions can be tested.

[0045] The booster circuit processes the signal V3 output from the integrator circuit and the signal on the voltage divider potentiometer W1 into a subtractor signal. The voltage output signal can be adjusted to different voltage ranges, such as 0.5V to 4.5V, 1V to 8V, etc., according to the requirements of the subsequent interface circuit.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0047] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A non-contact component displacement testing circuit, characterized in that, include: Charging circuit, integrating circuit, discharging circuit, switching circuit and gain adjustment circuit; The input terminal of the charging circuit is connected to the test plate, which consists of test plate one and test plate two. The charging circuit is connected to a reference source, which provides a reference signal to the charging circuit. The output terminal of the charging circuit is connected to the input terminal of the integrating circuit, and the output terminal of the integrating circuit outputs a voltage signal through the gain adjustment circuit. The switching circuit is connected to the charging circuit and the discharging circuit respectively, and outputs a control signal to switch the test circuit between the charging phase and the sample-and-hold phase. During the charging phase, the charging circuit connects the first test plate to the reference source and grounds the second test plate, while the discharging circuit grounds the sampling capacitor to zero. During the sampling and holding phase, the charging circuit connects the first test plate and the second test plate to the positive and negative input terminals of the integrating circuit, respectively, so that the sampling capacitor and the test plates are charged and balanced. The integrating circuit follows and filters the balanced voltage signal. The gain adjustment circuit subtracts the voltage signal output by the integrating circuit from the voltage divider signal generated by the potentiometer and outputs an adjustable voltage signal.

2. The non-contact component displacement testing circuit according to claim 1, characterized in that: The charging circuit includes a first main control chip, the thirteenth pin of which is connected to the first test plate, the third pin of which is connected to the second test plate, the fourteenth pin of which is connected to the reference source, the twelfth pin of which is connected to the integrating circuit, and the tenth pin of which is connected to the switching circuit and the discharging circuit respectively. The twelfth pin of the first main control chip is also grounded through the second capacitor; The first main control chip has sixteen pins connected to the power supply VCC, and its fifth, sixth and ninth pins are grounded.

3. The non-contact component displacement testing circuit according to claim 2, characterized in that: The integrating circuit includes a fifth operational amplifier, the third pin of which is connected to the twelfth pin of the first main control chip, the second pin of which is connected to the first pin of the first main control chip, and the sixth pin of which is connected to the gain adjustment circuit through a third resistor. The end of the third resistor closest to the gain adjustment circuit is grounded through a third capacitor. The second pin of the fifth operational amplifier is connected to its sixth pin.

4. The non-contact component displacement testing circuit according to claim 3, characterized in that: The gain adjustment circuit includes a sixth operational amplifier, the third pin of which is connected to a third resistor, and the sixth pin of which is connected to a voltage output terminal through a fourth resistor to output a voltage signal. The second pin of the sixth operational amplifier is connected to a potentiometer via a ninth resistor, grounded via a fifth resistor, and connected to a fourth resistor via an eighth resistor. The end of the fifth resistor closest to ground is connected to the potentiometer via a seventh resistor. The potentiometer is connected to the power supply VCC via a sixth resistor.

5. The non-contact component displacement testing circuit according to claim 3, characterized in that: The switching circuit includes a third main control chip, the seventh pin of which is connected to the tenth pin of the first main control chip, the tenth pin of which is connected to a first resistor, the ninth pin of which is connected to a first capacitor, and the eleventh pin of which is connected to a second resistor. The common terminal of the first resistor, the first capacitor, and the second resistor is connected together.

6. The non-contact component displacement testing circuit according to claim 5, characterized in that: The discharge circuit includes a second main control chip, and the fourteenth pin of the second main control chip is connected to the twelfth pin of the first main control chip.

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