High-precision non-contact micro-displacement measurement system based on photoelectric conversion and use method of high-precision non-contact micro-displacement measurement system

Abstract

The invention discloses a high-precision non-contact micro-displacement measurement system based on photoelectric conversion and a use method, realizes high-precision non-contact displacement detection by detecting the change of reflected light intensity on the surface of a measured object, and belongs to the technical field of instrument measurement. According to the system, the reflection type optical fiber displacement sensing technology is adopted, the optical fiber probe is used for receiving light intensity changes of reflected light on the surface of a measured object, weak light signals are converted into measurable voltage signals in combination with the trans-impedance amplifier circuit, the measurement precision of 10 micrometers is achieved within the range of 0-2 mm, and linear response is good. The photoelectric conversion high-precision non-contact micro displacement measuring instrument has the advantages of high precision, simple structure, low cost, strong environmental adaptability and no mechanical damage, and breaks through triangular bottlenecks of precision, cost and environmental adaptability in the field of micro measurement at present. The method has a huge application prospect in the field of precision measurement related to scientific research, industrial scenes and the like.

Description

Technical Field

[0001] This invention belongs to the field of instrument measurement technology, specifically relating to a high-precision non-contact micro-displacement measurement system based on photoelectric conversion and its usage method. Background Technology

[0002] With the rapid iteration of modern industrial technology towards high precision and miniaturization, micro-displacement measurement has become a core link restricting the performance improvement of high-end equipment and breakthroughs in key processes, and is widely permeated in strategic fields such as industrial manufacturing, environmental monitoring, and transportation engineering. In industrial manufacturing, core processes such as lithography mask alignment, electron microscope sample stage positioning, and precision machine tool spindle calibration place stringent requirements on displacement control accuracy at the micrometer to nanometer level. In the field of environmental monitoring, scenarios such as earthquake precursor crustal deformation capture, landslide early warning, and glacier movement monitoring require the accurate identification of millimeter-level micro-displacement changes to avoid disaster risks. In transportation engineering, high-precision displacement data is relied upon to ensure the safe operation of infrastructure, including high-speed rail track thermal expansion and contraction monitoring, long-span bridge structural health diagnosis, and tunnel settlement detection. Therefore, the development of micro-displacement measurement systems with both high precision and high stability has become an urgent need to promote the upgrading of precision manufacturing, ensure public safety, and break through the technological bottlenecks of high-end equipment.

[0003] Currently, there are various existing methods for measuring micro-displacement, including Michelson interferometry, eddy current sensing, capacitive grating sensing, and laser triangulation. Among these, Michelson interferometry, based on the principle of light interference, achieves nanometer-level accuracy and is a classic solution for high-precision displacement measurement, widely used in laboratory-level precision testing scenarios. Eddy current sensors, with their non-contact measurement characteristics, fast response speed, and strong anti-contamination capabilities, are commonly used in displacement monitoring of metal components. Capacitive grating sensors, based on the principle of capacitance change, have a simple structure and moderate cost, suitable for medium-to-low precision displacement measurement scenarios. Laser triangulation utilizes the principle of laser reflection imaging, combining non-contact measurement with high precision, and has been initially promoted in industrial settings. These methods have all achieved certain measurement results in specific scenarios, laying the foundation for technological development in the field of micro-displacement measurement. However, many technical bottlenecks and application limitations still exist, making it difficult to meet the practical needs of multi-scenario, high-precision, and low-cost measurement.

[0004] While the Michelson interferometry method offers high accuracy, it is extremely sensitive to environmental vibrations and temperature fluctuations, requiring stringent temperature-controlled vibration isolation equipment, thus limiting its applicability. Eddy current sensors are only suitable for conductive metallic materials and cannot measure the displacement of non-metallic components, and their measurement range is relatively short. Capacitive grating sensors are mostly contact-based, easily abrading fragile samples or the measured components, and their measurement accuracy is significantly affected by contact pressure. Laser triangulation is susceptible to the reflectivity of the measured object's surface, resulting in insufficient measurement stability. Furthermore, there is a bottleneck in the "accuracy-cost-environmental adaptability" triangle: high-precision solutions often involve bulky equipment, high costs, and complex operation, requiring specialized technicians for debugging and maintenance, leading to high maintenance costs; low-cost solutions, on the other hand, suffer from insufficient accuracy and poor stability, making them unsuitable for high-end applications. In addition, existing systems lack integration in specific scenarios, such as deformation monitoring of MEMS devices in industrial settings, micro-displacement detection of non-metallic materials, and unmanned, long-distance monitoring of landslide hazard areas in geological monitoring, all of which cannot be effectively met. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a high-precision non-contact micro-displacement measurement system and its usage method based on photoelectric conversion, so as to solve the technical problems of low accuracy, complex operation, great susceptibility to environmental influence, high maintenance cost and large equipment size of the existing micro-displacement measurement system.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a high-precision non-contact micro-displacement measurement system based on photoelectric conversion, comprising: a light source module for emitting light signals; The transmission module is used to transmit optical signals; The displacement generating module is used to support and move the object under test to generate displacement; The conversion module is used to receive the optical signal reflected from the surface of the object being measured on the displacement generating module and transmitted back via the transmission module, and convert the optical signal into an electrical signal. The amplification module is used to amplify the electrical signal output from the conversion module; The display module is used to receive and display the electrical signal amplified by the amplification module.

[0007] Preferably, the optical path receiving end of the transmission module and the light source module are positioned on the same horizontal line; The displacement generating module is located in front of the other end of the transmission module, in front of the output end. The optical receiver of the conversion module is connected to the reflected optical receiver of the transmission module; The amplification module and the conversion module are electrically connected; The display module and the amplification module are electrically connected; The transmission module is a Y-shaped optical fiber or two independent optical fibers, with its receiving end and transmitting end aligned together with the measurement area of ​​the displacement generation module.

[0008] Preferably, the light source module is a red laser generator, and the wavelength of the emitted light signal is 630-760nm.

[0009] Preferably, the conversion module is an avalanche photodiode.

[0010] Preferably, the displacement generating module is an x-axis displacement platform with a range of 0-6mm and a scale accuracy of 0.01mm.

[0011] Preferably, the amplification module is a photoelectric IV conversion amplifier module or a transimpedance amplifier module.

[0012] Preferably, it further includes: a power supply module for supplying power to the system; A voltage regulator module is used to provide a stable operating voltage; The bias module is used to provide bias voltage to the conversion module; The power conversion module is used to provide both positive and negative power supplies to the amplification module.

[0013] More preferably, the voltage regulator module is connected to the power supply module, the amplification module, and the display module; The bias module is connected to the power supply module and the conversion module; The power conversion module is connected to the amplification module.

[0014] This invention also discloses a method for using the above-mentioned high-precision non-contact micro-displacement measurement system based on photoelectric conversion, comprising the following steps: 1) Start the light source module, conversion module, amplification module, and display module; 2) Place the object to be measured on the displacement generating module, and the displacement generating module will cause the object to be measured to move. 3) The light signal emitted by the light source module is transmitted through the transmission module and illuminates the surface of the object under test. The reflected light signal is collected by the transmission module and transmitted to the conversion module. 4) The conversion module converts the received reflected light signal into an electrical signal; 5) The amplification module amplifies the electrical signal and then transmits it to the display module; 6) The display module displays the electrical signal value corresponding to the displacement magnitude.

[0015] Preferably, power is supplied to the system before startup, and the appropriate operating voltage is provided to each module through voltage regulation, biasing and power conversion. The displacement of the object under test is calculated and obtained from the displayed electrical signal value based on the pre-calibrated voltage-displacement relationship. The measurement system has a range of 0-2 mm and a measurement accuracy of 10 μm.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a high-precision non-contact micro-displacement measurement system based on photoelectric conversion. Since different objects have different reflectivities, the intensity of light reflected back from their reflective surfaces varies. Therefore, a fixed light source provides the system with an optical signal. The transmission module receives the reflected optical signal and converts it into an electrical signal for transmission. The amplification module amplifies the electrical signal and transmits it to a voltage regulator module. The voltage regulator module processes the signal and displays it through a display module, recording the displacement magnitude and corresponding voltage. By measuring the voltages corresponding to multiple known displacements of the same reflective surface, a voltage-displacement relationship is obtained. Based on this relationship, when determining the displacement of the same object, the light source module and the transmission module are fixed to the side of the casing at the same horizontal plane, ensuring that the laser emitted by the light source module passes through the transmission module. The object to be measured is placed on the displacement generating module at one end of the transmission module, and the other end of the transmission module is placed close to the reflective surface. Light emitted from the light source module shines onto the reflective surface via the transmission fiber. The reflected light signal is then received and collected by the conversion module and converted into an electrical signal. This signal then enters the amplification module, which amplifies the signal and transmits it to the voltage regulation module. The voltage regulation module adjusts the voltage to a suitable level, and the displacement magnitude is calculated based on the voltage-displacement relationship and displayed by the display module. Red laser emitters are less expensive than red diodes, and systems using red laser emitters have a faster response time, can display displacement information in real time, and can monitor the displacement magnitude.

[0017] Furthermore, this red light-based non-contact micro-displacement measuring instrument is inexpensive and compact, effectively solving the problems of high cost and inconvenience of existing high-precision instruments such as laser interferometers and spectral confocal sensors. It enables real-time observation of displacement changes when minute displacements occur.

[0018] Furthermore, this invention selects a stable light source with a suitable wavelength as the laser module of the system, responsible for providing the optical signal, and selects a sensitive optical signal receiving device to detect subtle changes in illuminance. Since illuminance is to be measured, the selected light source should be a single wavelength source within the visible light range. Avalanche photodiodes are more sensitive to wavelengths in the 600-900 nm range, and red light with wavelengths of 650-750 nm falls within its high-response range, matching the operating characteristics of avalanche photodiodes. This results in a stronger detection capability for weak reflected light signals, higher photoelectric conversion efficiency, and a more pronounced avalanche gain effect, thereby improving the sensitivity and accuracy of displacement measurement.

[0019] Furthermore, the displacement generating module is an x-axis displacement platform with a total length of 0-6mm and a scale of 0.01mm. Its bottom surface is fixed to the side of the outer shell, which can generate minute displacements and improve the accuracy of measurement.

[0020] Furthermore, the STM32 development board was selected as the display module because it can display data stably and quickly, and is also inexpensive.

[0021] Furthermore, the outer shell is made of corrosion-resistant transparent acrylic sheet, which is cut and spliced ​​to form a strong integrated structure with good sealing performance. The upper part has a semi-open design, which facilitates operation while maintaining the stability of the measurement environment and improving the durability of the instrument.

[0022] The method of using the high-precision non-contact micro-displacement measurement system based on photoelectric conversion disclosed in this invention reflects the magnitude of displacement through changes in light signals, achieving a non-contact measurement method and avoiding the contamination and errors that may be introduced in traditional methods. Through a stable light source, non-contact measurement method, automated data recording, and intuitive reading display, it achieves efficient, accurate, and convenient micro-displacement measurement. The method of use is simple; the user only needs to place the sample to be measured on the displacement platform to quickly obtain the displacement result. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the principle of a high-precision non-contact micro-displacement measurement system based on photoelectric conversion disclosed in this invention; Figure 2 This is a schematic diagram of a high-precision non-contact micro-displacement measurement system based on photoelectric conversion disclosed in this invention.

[0024] The components include: 1. Light source module; 2. Transmission module; 3. Displacement generation module; 4. Conversion module; 5. Amplification module; 6. Display module; 7. Power supply module; 8. Voltage regulator module; 9. Bias module; 10. Power conversion module; 11. Housing. a. Red laser pointer; b. Single-mode fiber optic cable; c. Avalanche photodiode; d. Opto-IV converter amplifier module; e. DC bias module; f. Single-supply boost to positive / negative dual-supply module; g. STM32 development board; h. Lithium battery pack; i. Regulated power supply module; j. Displacement platform. Detailed Implementation

[0025] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] This invention discloses a high-precision non-contact micro-displacement measurement system based on photoelectric conversion, comprising: The light source module 1, the transmission module 2 which is set on the same horizontal line as the light source module 1, the displacement generating module 3 which is set at one end of the transmission module 2, the conversion module 4 which is set at the other end of the transmission module 2, the amplification module 5 which is connected to the conversion module 4, the display module 6 which is connected to the amplification module 5, the power supply module 7 which is connected to the display module 6 and the voltage regulator module 8, the voltage regulator module 8 which is connected to the amplification module 5, the bias module 9 which is connected to the amplification module 5 and the display module 6, the power conversion module 10 which is connected to the voltage regulator module 8 and the bias module 9, and the outer shell 11 covering the outside of the transmission module 2, the conversion module 4, the amplification module 5, the display module 6, the power supply module 7, the voltage regulator module 8, the bias module 9, and the power conversion module 10; Light source module 1 is a red laser generator used to emit light signals; Transmission module 2 is a Y-shaped optical fiber formed by fusing two optical fibers at one end, used for transmitting optical signals; The displacement generating module 3, consisting of the displacement platform j and the object being measured, is used to generate minute displacements. Conversion module 4 is an avalanche photodiode, used to convert optical signals into electrical signals; Amplification module 5 is an opto-IV amplifier module used to amplify electrical signals; Display module 6 is an STM32 development board g, used to display the output voltage; The power module 7 is a lithium battery pack h, which is used to power the conversion module 4, the amplification module 5 and the display module 6. The voltage regulator module 8 is a voltage regulator module i, used to stabilize the voltage output from the power supply module 7 to the amplifier module 5 and the display module 6; The bias module 9 is a DC bias module, used to provide the voltage output by the power conversion module 7 to the conversion module 4; The power conversion module 10 is a single-power boost to positive and negative dual-power module f, used to provide a compatible positive and negative dual power supply for the amplification module 5.

[0032] It also includes a power supply module 7, which is connected to the voltage regulator module 8 and the bias module 9 respectively, and is used to provide the working voltage.

[0033] The light source module 1 is connected to an external 110-220V AC power supply.

[0034] The light source module 1 is installed on the outside of the housing 11; the wavelength of the red laser generator is 630-760nm.

[0035] The displacement generating module 3 is an x-axis displacement platform with a total length of 0-6mm and a scale of 0.01mm, and its bottom surface is fixed to the side of the outer shell 11.

[0036] Display module 6 is an STM32 development board g, fixed to the side of the outer casing 11.

[0037] The outer shell 11 is made of transparent acrylic sheet, which is cut and glued into shape, with the upper part being a semi-open structure.

[0038] This invention discloses a method for using a high-precision non-contact micro-displacement measurement system based on photoelectric conversion. The method, employing the aforementioned high-precision non-contact micro-displacement measurement system based on photoelectric conversion, includes the following steps: 1) When the power is turned on, the conversion module 4, amplification module 5, display module 6, voltage regulator module 8, bias module 9, and power conversion module 10 will start automatically; 2) Connect the power supply to the light source module 1 and turn it on. After the light source module 1 has finished preheating, adjust the displacement generating module 3 to make the object under test move slightly. The laser emitted by the light source module 1 shines on the reflective surface of the object under test on the displacement generating module 3 through the transmission module 2, and enters the transmission module 2 again after reflection. The conversion module 4 converts the light signal into an electrical signal, and the amplification module 5 amplifies the electrical signal and transmits it to the display module 6. 3) Observe the reading on display module 6. After the reading stabilizes, obtain the magnitude of the displacement of the measured object. The light source module 1, transmission module 2, and displacement generation module 3 are placed on the same horizontal line.

[0039] This invention discloses a high-precision non-contact micro-displacement measurement system based on photoelectric conversion, comprising: Light source module 1 is responsible for emitting light signals. Light source module 1 is used to emit red light with a wavelength of 700nm. The use of red light with a wavelength of 700nm is matched with the characteristics of avalanche photodiode c, which makes the detection capability of weak reflected light signals stronger, the photoelectric conversion efficiency higher, and the avalanche gain effect more obvious, thereby improving the sensitivity and accuracy of displacement measurement.

[0040] Transmission module 2, positioned at the same horizontal level as the light source, is used to acquire the light signal emitted by light source module 1. Displacement generation module 3 is located between light source module 1 and transmission module 2. Conversion module 4, connected to transmission module 2, converts optical signals into electrical signals. Amplification module 5, connected to conversion module 4, is used to amplify the converted electrical signal. Display module 6, connected to amplification module 5, is used to display the voltage magnitude obtained after processing by amplification module 5. Power module 7, connected to voltage regulator module 8 and bias module 9, provides voltage to the operating module. The voltage regulator module 8, connected to the amplifier module 5 and the display module 6, is used to stabilize the voltage output by the voltage module 7. The bias module 9, connected to the amplification module 5, is used to convert the voltage output from the voltage module 7 into a voltage suitable for the amplification module 5. The power conversion module 10, connected to the amplification module 5, is used to provide a compatible positive and negative dual power supply to the amplification module 5. The outer casing 11 covers the transmission module 2, conversion module 4, amplification module 5, display module 6, voltage regulator module 8, bias module 9, and power conversion module 10. The outer casing 11 is made of transparent acrylic sheet, cut and glued together. The upper part has a semi-open structure to facilitate operation while maintaining the stability of the measurement environment. The outer casing 11, made of transparent acrylic sheet, not only provides a stable measurement environment but also improves the durability of the instrument.

[0041] This instrument is easy to use. Users simply place the sample to be tested on displacement generating module 3 to quickly obtain voltage, and then determine the magnitude of the displacement based on the voltage-displacement relationship. This instrument is inexpensive and compact, effectively solving the problems of high cost and inconvenience of existing spectrometers. This instrument can achieve real-time observation of concentration changes when the displacement changes.

[0042] See Figure 1 This is a schematic diagram of the principle of the high-precision non-contact micro-displacement measurement system based on photoelectric conversion disclosed in this invention. As can be seen from the figure, the high-precision non-contact micro-displacement measurement system based on photoelectric conversion includes: a light source module 1; a transmission module 2; a displacement generation module 3; a conversion module 4; an amplification module 5; a display module 6; a power supply module 7; a voltage stabilization module 8; a bias module 9; a power conversion module 10; and a housing 11. The light source module 1 and the displacement generation module 3, located on the same horizontal straight line, are located at opposite ends of the transmission module 2. The light signal emitted by the light source module 1 passes through the transmission module 2 and illuminates the surface of the object being measured on the displacement generation module 3. The conversion module 4 converts the light signal into an electrical signal, which then enters the amplification module 5 for amplification and transmission. Finally, based on the voltage-displacement relationship, the displacement of the object being measured is calculated and displayed through the display module 6. Transmission module 2, conversion module 4, amplification module 5, display module 6, power module 7, voltage regulator module 8, bias module 9, and power conversion module 10 are all housed inside the outer casing 11 to ensure that the instrument is not affected by external interference. Conversion module 4, amplification module 5, display module 6, battery module 7, voltage regulator module 8, bias module 9, and power conversion module 10 are connected to ensure the overall operation of the instrument.

[0043] See Figure 2This is a schematic diagram of a high-precision non-contact micro-displacement measurement system based on photoelectric conversion disclosed in this invention. As shown in the diagram, the system includes: a red laser pointer (a); a single-mode fiber (b); an avalanche photodiode (c); a photoelectric IV-to-electrical amplifier module (d); a DC bias module (e); a single-power boost converter to dual-power supply module (f); an STM32 development board (g); a lithium battery pack (h); a regulated power supply module (i); and a displacement platform (j). The red laser pointer (a) and the displacement platform (j), located on the same horizontal line, are at opposite ends of the single-mode fiber (b). The light signal emitted by the red laser pointer (a) passes through the single-mode fiber (b) and illuminates the surface of the object being measured on the displacement platform (j). The reflected light signal re-enters another single-mode fiber (b) and is converted into an electrical signal by the avalanche photodiode (c). This electrical signal then enters the photoelectric IV-to-electrical amplifier module (d) for amplification and transmission. Finally, based on the voltage-displacement relationship, the displacement of the object is calculated and displayed on the STM32 development board (g). The avalanche photodiode c, photoelectric IV conversion amplifier module d, STM32 development board g, lithium battery pack h, regulated power supply module i, DC bias module e, regulated power supply module i and single power supply boost to positive and negative dual power supply module f are connected to ensure the overall operation of the instrument.

[0044] Example 1 A high-precision non-contact micro-displacement measurement system based on photoelectric conversion includes: The system comprises a light source module 1, a transmission module 2 positioned on the same horizontal line as the light source module 1, a displacement generating module 3 located at one end of the transmission module 2, a conversion module 4 located at the other end of the transmission module 2, an amplification module 5 connected to the conversion module 4, a display module 6 connected to the amplification module 5, a power supply module 7 connected to the voltage regulator module 8 and the bias module 9, a voltage regulator module 8 connected to the amplification module 5 and the display module 6, a bias module 9 connected to the conversion module 4, and a housing 11 covering the outside of the transmission module 2, the conversion module 4, the amplification module 5, the display module 6, the power supply module 7, the voltage regulator module 8, the bias module 9, and the power conversion module 10; the light source module 1 is a red laser generator used to emit light signals; the transmission module 2 is used to transmit light signals; the displacement generating module 3 is used to place the object to be displaced; the light signal emitted by the light source module 1 is irradiated onto the surface of the displacement generating module 3 by the transmission module, and is received by the transmission module 2 after reflection. The conversion module 4 is used to convert optical signals into electrical signals; the amplification module 5 is used to amplify electrical signals; the display module 6 is used to display the processed voltage; the power supply module 7 is used to supply power to the working components; the voltage regulator module 8 is used to stabilize the voltage output by the power supply module 7; the bias module 9 is used to convert the voltage output by the voltage module 7 into a voltage suitable for the amplification module 5; and the power conversion module 10 is used to provide a suitable positive and negative dual power supply for the amplification module 5.

[0045] Example 2 A method for using a high-precision non-contact micro-displacement measurement system based on photoelectric conversion includes the following steps: The precision component to be tested is placed on the displacement generating module 3. The displacement generating module 3 is designed to precisely control the minute movements of the component, achieved through a precision linear slide. Subsequently, the light source module 1 is activated, emitting a stable light signal. This light signal is guided to the surface of the component via the transmission module 2. The transmission module 2 ensures that the light signal accurately illuminates the specific measurement area of ​​the component. When the light signal illuminates the component surface, a portion of the light is reflected. The reflected light signal is collected again by the transmission module 2 and guided to the conversion module 4. Upon receiving the reflected light signal, the conversion module 4 converts it into a corresponding electrical signal based on its intensity. The intensity of the reflected light signal changes with minute variations in the distance between the component and the transmission module 2; therefore, the amplitude of the electrical signal output by the conversion module 4 also changes accordingly, reflecting the component's displacement information. Since the electrical signal output by the conversion module 4 may be too weak for direct, precise display, it is transmitted to the amplification module 5. The amplification module 5 appropriately amplifies the electrical signal to a level that can be clearly recognized by the display module 6, while maintaining signal integrity and accuracy. The electrical signal processed by amplification module 5 is transmitted to display module 6. Display module 6 receives and displays the value of the electrical signal in real time. By observing the electrical signal value on display module 6 and combining it with a pre-established "electrical signal value-displacement" calibration curve, the operator can accurately calculate the real-time minute displacement of the precision component under test. This achieves non-contact minute displacement measurement of non-metallic components, avoiding potential damage from traditional contact measurements. Furthermore, photoelectric conversion and signal amplification ensure measurement accuracy and provide an intuitive display method, effectively addressing the technical need for high-precision, non-contact minute displacement measurement of precision components in industrial settings.

[0046] Compared to the Michelson interferometry method, this system, by employing photoelectric conversion, reduces its sensitivity to environmental vibrations and temperature fluctuations, eliminating the need for stringent temperature-controlled vibration isolation equipment and thus broadening its application scenarios. Compared to eddy current sensors, this system can measure displacement in non-metallic materials, overcoming the limitation of eddy current sensors being restricted to conductive metallic materials. The non-contact measurement method avoids the wear or damage that contact measurement methods such as capacitive grating sensors may cause to the surface of the measured object, making it particularly suitable for measuring fragile or precision components. Addressing the issue of laser triangulation being susceptible to the reflectivity of the measured object's surface, this system improves measurement stability by optimizing the transmission and reception mechanism of the optical signal. The light source module 1 emits an optical signal, which is guided by the transmission module 2 and received by the conversion module 4, forming a relatively closed and stable optical path, reducing interference from the external environment on the reflected light signal.

[0047] Through modular design, the goal of high-precision, non-contact micro-displacement measurement is achieved, while striking a balance between cost, size, and operational complexity. The collaborative work of the light source module 1, transmission module 2, displacement generation module 3, conversion module 4, amplification module 5, and display module 6 forms an efficient and reliable measurement chain. This integrated solution effectively addresses the "accuracy-cost-environmental adaptability" bottleneck commonly found in existing technologies, providing a more practical and universally applicable micro-displacement measurement tool for fields such as industrial manufacturing and environmental monitoring.

[0048] Example 3 A high-precision non-contact micro-displacement measurement system based on photoelectric conversion includes: a light source module 1 for emitting light signals; a transmission module 2 for transmitting light signals; a displacement generation module 3 for carrying and moving the object under test to generate displacement; a conversion module 4 for receiving the light signals reflected from the surface of the object under test on the displacement generation module 3 and transmitted back via the transmission module 2, and converting the light signals into electrical signals; an amplification module 5 for amplifying the electrical signals output by the conversion module 4; and a display module 6 for receiving and displaying the electrical signals amplified by the amplification module 5.

[0049] One end of the optical path receiving end of the transmission module 2 is positioned on the same horizontal line as the light source module 1, ensuring that the optical signal emitted by the light source module 1 can be efficiently and stably coupled into the transmission module 2. "Same horizontal line" can refer to physical collinear alignment or alignment within the same plane, reducing optical signal loss during coupling. This can be achieved through a precision mechanical structure for fixation, positioning using fiber optic clamps or V-grooves, or fine alignment using an adjustable fine-tuning platform. The displacement generating module 3 is positioned in front of the other end of the transmission module 2's output end, allowing the optical signal emitted from the transmission module 2 to directly illuminate the surface of the object being measured on the displacement generating module 3, thus achieving non-contact measurement. This can be achieved by mounting the displacement generating module 3 on an optical platform and allowing its movement range to cover the output light spot area of ​​the transmission module 2, or by fixing the displacement generating module 3 at an appropriate working distance in front of the output end of the transmission module 2 using a bracket. The optical receiving end of the conversion module 4 is connected to the reflected light receiving end of the transmission module 2, ensuring that the optical signal reflected from the surface of the object being measured and collected by the transmission module 2 is accurately introduced into the conversion module 4 for photoelectric conversion. The reflected light receiver of transmission module 2 is physically connected to the light receiver of conversion module 4 via fiber optic connectors (such as FC / PC, SMA, etc.), or via free-space optical coupling, i.e., focusing coupling is achieved by setting a lens group between the two. Amplification module 5 is electrically connected to conversion module 4. This electrical connection allows the weak electrical signal output from conversion module 4 to be directly sent to amplification module 5 for amplification, providing a sufficiently strong signal for subsequent display and analysis. The electrical connection can be achieved through wires, coaxial cables, or traces on a printed circuit board, ensuring signal transmission integrity and low noise. Display module 6 is electrically connected to amplification module 5. This electrical connection allows the amplified electrical signal from amplification module 5 to be transmitted to display module 6 in real time for easy observation and recording of measurement results. The electrical connection can be achieved through wires, ribbon cables, or connections on integrated circuit boards, ensuring accurate signal transmission. Transmission module 2 is a Y-shaped fiber or two independent fibers. Its receiver and transmitter are aligned with the measurement area of ​​displacement generation module 3. The specific form of transmission module 2 (Y-shaped fiber or two independent fibers) is crucial for achieving optical signal transmission and reflected light signal collection. Y-type optical fibers have one common end and two branch ends, one for transmission and the other for reception; two independent fibers are used for transmission and reception respectively. Both structures enable optical path integration and compactness. The receiving and transmitting ends are aligned with the measurement area of ​​displacement generation module 3, aiming to ensure a high degree of spatial overlap between the emitted light spot and the reflected light collection area, thereby maximizing the collection efficiency of the reflected light signal and improving measurement sensitivity and accuracy.

[0050] The light source module 1 can be a red laser diode with a collimating lens, whose emitted beam is connected to the transmitting branch of the transmission module 2 via an FC / PC fiber optic connector. The transmission module 2 can be a Y-type fiber optic coupler, with its common end serving as a shared port for both transmission and reception, aligned with the measurement area of ​​the displacement generation module 3. The displacement generation module 3 can be a precision motorized displacement stage with a reflective mirror, on which the object being measured is fixed. The receiving branch of the Y-type fiber optic cable is connected to the input of the avalanche photodiode (APD) of the conversion module 4 via another FC / PC fiber optic connector. The electrical signal output of the conversion module 4 is connected to the input of the transimpedance amplifier of the amplification module 5 via a shielded cable. The output of the amplification module 5 is then connected to the input of the digital voltmeter or oscilloscope of the display module 6 via a ribbon cable.

[0051] Light source module 1 uses a semiconductor laser diode module with an output power of 5mW and a wavelength of 650nm. This module typically integrates a laser diode chip, a driving circuit, and a lens group for beam collimation, enabling it to directly output a collimated red laser beam. A laser diode of model HL6501MG is selected, along with a corresponding constant current driving circuit and optical collimation components, to ensure the stability of the laser output power and beam quality. This laser diode exhibits excellent output characteristics at a wavelength of 650nm, and the red light it emits has low transmission loss in air, making it easily and efficiently received by silicon-based photodetectors.

[0052] Conversion module 4 employs a silicon avalanche photodiode, model C30902E. This avalanche photodiode is configured in a constant-temperature environment to ensure performance stability. Its light-receiving surface is precisely aligned with the output end of transmission module 2 to maximize the reception of reflected light signals. To activate the avalanche multiplication effect, a high reverse bias voltage of 200V is applied to the avalanche photodiode, which can be provided by bias module 9. When the reflected light signal is incident on the avalanche photodiode, a current proportional to the light intensity is generated internally and amplified through avalanche multiplication. This amplified current signal is then sent to amplification module 5, where it is converted into a voltage signal and further amplified, ultimately displayed by display module 6.

[0053] The displacement generation module 3 employs an x-axis displacement platform driven by a precision ball screw and a high-resolution stepper motor. This platform precisely controls the rotation of the ball screw via the stepper motor, thereby driving the slider carrying the measured object to move linearly along the x-axis. To achieve a measurement range of 0-6mm, a ball screw with a suitable pitch can be selected, and the movement range can be limited by setting electronic or mechanical limits. A scale accuracy of 0.01mm can be achieved by using a stepper motor with high microstepping drive, combined with a high-precision ball screw and precision guide rails. Using a stepper motor with a step angle of 1.8 degrees and a microstepping drive of 1 / 16, combined with a ball screw with a lead of 1mm, a smaller step resolution can be achieved, and a scale accuracy of 0.01mm can be ensured through software control. Furthermore, the platform can also integrate a high-precision grating ruler as a position feedback sensor to further calibrate and ensure the accuracy of the displacement.

[0054] Amplification module 5 employs an OPA656 high-speed, low-noise operational amplifier, combined with a precision feedback resistor and a small-capacity feedback capacitor to form a transimpedance amplifier circuit. The output current signal of conversion module 4 is connected to the inverting input of the OPA656, while the non-inverting input is grounded. The feedback resistor and capacitor are connected in parallel between the output and inverting input. This configuration converts weak photocurrent signals into voltage signals with good linearity and low noise. It provides high bandwidth and low input bias current, ensuring efficient and accurate processing of the weak current signal output from conversion module 4.

[0055] Power module 7 is a 12V DC switching power adapter used to convert 220V AC mains power to 12V DC power. Voltage regulator module 8 uses an LM7805 linear regulator chip to regulate the 12V DC power to 5V, providing a stable operating voltage for the digital control circuits and some analog circuits in the system. Bias module 9 can be a circuit based on a boost DC-DC converter, boosting and regulating the 12V input voltage to 50V, specifically used to provide reverse bias voltage for conversion module 4 (e.g., avalanche photodiodes). Power conversion module 10 is an integrated positive / negative power conversion chip that converts the 12V input voltage to a dual ±15V output voltage to meet the positive and negative power supply requirements of the operational amplifier in amplifier module 5.

[0056] Example 4 A method for using a high-precision non-contact micro-displacement measurement system based on photoelectric conversion, the method comprising the following steps: 1) Start the light source module 1, conversion module 4, amplification module 5, and display module 6. Activate the key functional modules in the system to put them into working condition and prepare them for subsequent measurement operations. Power and enable each module separately through independent power switches or control signals, and connect the power supply by sending commands through the microcontroller or by manually pressing a button.

[0057] 2) Place the object to be tested on the displacement generating module 3, which then moves the object to be tested. The object to be tested can be fixed on the bearing surface of the displacement generating module 3 using a clamp, suction cup, or adhesive. The displacement generating module 3 is driven by a stepper motor or piezoelectric ceramic to achieve precise displacement at the micron or even nanometer level.

[0058] 3) The light signal emitted by the light source module 1 is transmitted through the transmission module 2 and illuminates the surface of the object under test. The reflected light signal is collected by the transmission module 2 and transmitted to the conversion module 4. An optical path is established to realize the emission of the light signal, its interaction with the surface of the object under test (reflection), and the collection and guidance of the reflected light signal. The light source module 1 emits a collimated beam, which is guided to the surface of the object under test through the transmission module 2. When the beam illuminates the surface of the object under test, some light undergoes diffuse reflection or specular reflection. The receiving arm of the Y-shaped fiber in the transmission module 2 or a separate receiving fiber is responsible for collecting these reflected lights and efficiently transmitting them to the receiving end of the conversion module 4.

[0059] 4) Conversion module 4 converts the received reflected light signal into an electrical signal; the photosensitive element (such as a photodiode or avalanche photodiode) inside conversion module 4 generates a corresponding current or voltage signal according to the intensity of the light after receiving the light signal. The higher the intensity of the light, the stronger the generated electrical signal is usually.

[0060] 5) Amplification module 5 amplifies the electrical signal and transmits it to display module 6. It enhances the weak electrical signal output by conversion module 4, bringing it to a level that display module 6 can recognize and process, while simultaneously improving the signal-to-noise ratio to ensure the accuracy of the measurement results. Amplification module 5 can be a high-gain, low-noise analog amplifier circuit capable of amplifying signals at the microvolt or microampere level to the volt or milliampere level. Amplification module 5 may also include a filtering circuit to remove noise components from the signal, further improving signal quality.

[0061] 6) Display module 6 displays the electrical signal value corresponding to the displacement magnitude. It intuitively presents the processed electrical signals, showing the correspondence between these signals and the minute displacement of the object under test, thus enabling displacement measurement and reading. Display module 6 is a digital voltmeter or ammeter that directly displays the amplified electrical signal value. Alternatively, it can be a module with a microcontroller and an LCD screen. The microcontroller can convert the electrical signal value into the actual displacement based on a preset calibration curve and display it in digital or graphical form.

[0062] Before starting the high-precision non-contact micro-displacement measurement system based on photoelectric conversion, a 24V DC power adapter is used as power module 7 to provide initial power to the entire system. Voltage regulator module 8 uses an LM7812 linear regulator to stabilize the 24V DC voltage to 12V, supplying power to amplifier module 5 and display module 6. Bias module 9 is an adjustable high-voltage DC power supply that provides bias voltage to the avalanche photodiode (as conversion module 4) to ensure it operates near the avalanche breakdown region and achieves high gain. Power conversion module 10 is a DC-DC buck-boost converter that converts the 12V voltage to a ±5V dual power supply to meet the power requirements of the photoelectric IV conversion amplifier module (as amplifier module 5). After the system completes power configuration and stabilizes, displacement measurement is performed. When displacement generation module 3 moves the object under test, the light signal emitted by light source module 1 is transmitted to the surface of the object under test via transmission module 2. The reflected light is collected by transmission module 2 and sent to conversion module 4. The conversion module 4 converts the optical signal into an electrical signal, which is then amplified by the amplification module 5 and finally presented as a voltage value on the display module 6.

[0063] By stabilizing, biasing, and converting the power supply before system startup, the system ensures that key modules such as the light source module 1, conversion module 4, and amplification module 5 receive stable and compatible operating voltages. This significantly improves the stability of the photoelectric conversion process and the linearity of the electrical signal amplification, laying a solid foundation for subsequent accurate measurements. Simultaneously, by introducing a pre-calibrated voltage-displacement relationship and calculating the displacement of the object under test, the system can directly convert abstract electrical signal values ​​into physically meaningful displacement quantities, greatly enhancing the intuitiveness and practicality of the measurement. This method, combining precise power management and intelligent data processing, enables the entire measurement system to achieve a high level of measurement accuracy (10μm) within a specific range (0-2mm), effectively solving the problems of inaccurate measurement and operational inconvenience caused by unstable power supply and lack of direct displacement output in micro-displacement measurements.

[0064] In summary, this invention discloses a high-precision non-contact micro-displacement measurement system and its application method based on photoelectric conversion. It achieves high-precision non-contact displacement detection by detecting changes in the intensity of reflected light from the surface of the measured object, belonging to the field of instrument measurement technology. This system employs reflective fiber optic displacement sensing technology, utilizing a fiber optic probe to receive changes in the intensity of reflected light from the surface of the measured object. Combined with a transimpedance amplifier circuit, the weak light signal is converted into a measurable voltage signal, achieving a measurement accuracy of 10μm within a range of 0-2mm, with good linear response. This high-precision non-contact micro-displacement measurement system based on photoelectric conversion has advantages such as high precision, simple structure, low cost, strong environmental adaptability, and no mechanical damage. It overcomes the current "precision-cost-environmental adaptability" triangle bottleneck in the field of micro-measurement and has enormous application prospects in precision measurement fields such as scientific research and industrial applications.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0066] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A high-precision non-contact micro-displacement measurement system based on photoelectric conversion, characterized in that, It comprises: a light source module (1) for emitting light signals; a transmission module (2) for transmitting light signals; a displacement generation module (3) for carrying and moving the measured object to generate displacement; a conversion module (4) for receiving the light signals reflected by the surface of the measured object on the displacement generation module (3) and transmitted back through the transmission module (2), and converting the light signals into electrical signals; an amplification module (5) for amplifying the electrical signals output by the conversion module (4); a display module (6) for receiving and displaying the electrical signals amplified by the amplification module (5).

2. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 1, characterized in that, One end of the light path receiving end of the transmission module (2) is arranged on the same horizontal line as the light source module (1); The displacement generation module (3) is arranged in front of the other end of the transmission module (2); The light receiving end of the conversion module (4) is connected with the reflected light receiving end of the transmission module (2); The amplification module (5) is electrically connected with the conversion module (4); The display module (6) is electrically connected with the amplification module (5); The transmission module (2) is a Y-shaped optical fiber or two independent optical fibers, and the receiving end and the transmitting end are aligned with the measurement area of the displacement generation module (3).

3. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 1, characterized in that, The light source module (1) is a red light laser generator, and the wavelength of the emitted light signal is 630-760 nm.

4. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 1, characterized in that, The conversion module (4) is an avalanche photodiode (c).

5. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 1, characterized in that, The displacement generation module (3) is an x-axis displacement platform with a range of 0-6 mm and a scale accuracy of 0.01 mm.

6. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 1, characterized in that, The amplification module (5) is an optoelectronic IV conversion amplifier module or a transimpedance amplifier module.

7. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 1, characterized in that, It also comprises: a power module (7) for supplying power to the system; a voltage stabilizing module (8) for providing stable working voltage; a bias module (9) for providing bias voltage for the conversion module (4); a power conversion module (10) for providing positive and negative dual power supply for the amplification module (5).

8. The high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 7, characterized in that, The voltage stabilizing module (8) is connected with the power module (7), the amplification module (5) and the display module (6); The bias module (9) is connected with the power module (7) and the conversion module (4); The power conversion module (10) is connected with the amplification module (5).

9. The method of using the high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to any one of claims 1-8, characterized in that, It comprises the following steps: 1) Start the light source module (1), the conversion module (4), the amplification module (5) and the display module (6); 2) Place the measured object on the displacement generation module (3), and drive the measured object to generate displacement through the displacement generation module (3); 3) The light signal emitted by the light source module (1) is transmitted through the transmission module (2) and irradiated to the surface of the measured object, and the reflected light signal is collected through the transmission module (2) and then transmitted to the conversion module (4); 4) The conversion module (4) converts the received reflected light signal into an electrical signal; 5) The amplification module (5) amplifies the electrical signal and transmits it to the display module (6); 6) The display module (6) displays the electrical signal value corresponding to the displacement size.

10. The method of using a high-precision non-contact micro-displacement measurement system based on photoelectric conversion according to claim 9, wherein Before starting the system, provide power for the system, and through voltage stabilization, bias and power conversion processing, provide suitable working voltage for each module; According to the pre-calibrated voltage-displacement relationship, the displacement of the measured object is calculated and obtained according to the displayed electric signal value; The measuring system has a range of 0-2mm and a measuring accuracy of 10μm.

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