Displacement measurement device, displacement measurement method, and computer program product

Abstract

The invention relates to the technical field of displacement measurement, and particularly provides a displacement measurement device, a displacement measurement method and a computer program product. The device comprises a transmitting unit and a detecting unit, the transmitting unit comprises a laser source and a first collimator which are connected based on a first optical fiber; the detection unit comprises a second collimator and a detector which are connected based on a second optical fiber; the laser source, the first collimator, the second collimator and the detector are located on the same optical axis. According to the device, a laser beam transmitted by a first optical fiber is converted into first collimated light based on a first collimator, the first collimated light is converted into second collimated light through a displacement unit to be measured, the second collimated light is coupled into a second optical fiber based on a second collimator, and the second collimated light transmitted by the second optical fiber and light energy of the second collimated light are detected based on a detector. The horizontal displacement amount of the displacement unit to be measured on a plane perpendicular to the optical axis direction can be obtained based on the light energy of the second collimated light, and displacement measurement is achieved.

Description

Technical Field

[0001] The present application relates to the field of displacement measurement technology, and in particular, to a displacement measurement device, a displacement measurement method, and a computer program product. Background Art

[0002] Precision displacement measurement technology is a technology that obtains deformation information of an object by measuring its tiny displacement. It is mainly used in engineering design and material research, and provides strong support for related fields by measuring the deformation, deflection, and deformation of an object. With the emergence and development of industries such as precision manufacturing, optoelectronics, and biomedicine, precision displacement measurement technology is given higher requirements.

[0003] Currently, precision measurements are mostly achieved by laser interferometry technology, such as laser interferometers, which can achieve sub-nanometer or even sub-wavelength precision measurements. However, such measurement devices are relatively complex. Summary of the invention

[0004] In view of this, an object of the embodiments of the present application is to provide a displacement measurement device, a displacement measurement method and a computer program product to solve the relatively complex technical problems of existing precision displacement measurement devices.

[0005] In a first aspect, an embodiment of the present application provides a displacement measurement device based on optical mode decomposition, the device comprising: a transmitting unit and a detecting unit;

[0006] The transmitting unit includes a laser source and a first collimator connected based on a first optical fiber; the detecting unit includes a second collimator and a detector connected based on a second optical fiber; the laser source, the first collimator, the second collimator and the detector are on the same optical axis;

[0007] The emitting unit emits a laser beam based on the laser source, and converts the laser beam transmitted by the first optical fiber into a first collimated light based on the first collimator;

[0008] The displacement unit to be measured is configured between the first collimator and the second collimator, and the first collimated light is converted into the second collimated light after passing through the displacement unit to be measured;

[0009] The detection unit couples the second collimated light into the second optical fiber based on the second collimator, and detects the second collimated light and its light energy transmitted by the second optical fiber based on the detector;

[0010] The light energy of the second collimated light can represent the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction.

[0011] In the above implementation process, the displacement measurement device based on optical mode decomposition includes a transmitting unit and a detecting unit. The transmitting unit includes a laser source and a first collimator connected based on a first optical fiber; the detecting unit includes a second collimator and a detector connected based on a second optical fiber; the laser source, the first collimator, the second collimator and the detector are on the same optical axis; the transmitting unit emits a laser beam based on the laser source, and converts the laser beam transmitted by the first optical fiber into a first collimated light based on the first collimator; the first collimated light is converted into a second collimated light after passing through the displacement unit to be measured; the detecting unit couples the second collimated light into the second optical fiber based on the second collimator, and detects the second collimated light and its light energy transmitted by the second optical fiber based on the detector. The displacement measurement device based on optical mode decomposition can obtain the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction according to the light energy of the second collimated light detected by the detector, so as to realize the displacement measurement of the displacement unit to be measured; and the structure of the displacement measurement device based on optical mode decomposition is simpler, which solves the relatively complex technical problems of the existing precision displacement measurement device.

[0012] Optionally, in an embodiment of the present application, the device further includes: an offset unit, the offset unit being located between the transmitting unit and the detecting unit; the offset unit being used to at least provide a horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction.

[0013] In the above implementation process, the offset unit can provide the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction, thereby reducing the displacement measurement difficulty of the displacement measurement device based on optical mode decomposition.

[0014] Optionally, in an embodiment of the present application, the device also includes: a signal processing unit, which is connected to the detector; the signal processing unit is used to receive the light energy of the second collimated light detected by the detector, and calculate the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light.

[0015] In the above implementation process, the signal processing unit can receive the light energy of the second collimated light detected by the detector, and calculate the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction based on the light energy of the second collimated light, thereby realizing the displacement measurement of the displacement unit to be measured.

[0016] Optionally, in an embodiment of the present application, the laser beam emitted by the laser source is a Gaussian beam.

[0017] In the above implementation process, by setting the laser beam emitted by the laser source to be a Gaussian beam, the calculation difficulty of "calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light" can be reduced.

[0018] Optionally, in an embodiment of the present application, the first optical fiber and the second optical fiber are single-mode optical fibers.

[0019] In the above implementation process, based on the single-mode optical fiber, it can be ensured that the optical signal propagates in the optical fiber in a single path, thereby reducing signal distortion and improving the accuracy of the displacement measurement result.

[0020] Optionally, in an embodiment of the present application, the offset unit includes an electrically controlled translation stage.

[0021] In the above implementation process, the resolution of the electric-controlled translation stage can reach the nanometer level. Based on the electric-controlled translation stage, precise positioning and movement can be achieved, and precise control and measurement of tiny displacements can be achieved in conjunction with the transmitting unit and the detecting unit.

[0022] In a second aspect, an embodiment of the present application provides a displacement measurement method, which is implemented based on the displacement measurement device as described in any one of the first aspects above;

[0023] The method comprises:

[0024] Placing the displacement unit to be measured between the first collimator and the second collimator of the displacement measuring device;

[0025] Based on the light energy of the second collimated light detected by the detector of the displacement measuring device, the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction is calculated.

[0026] In the above implementation process, by placing the displacement unit to be measured between the first collimator and the second collimator of the displacement measuring device, and calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light detected by the detector, the displacement measurement of the displacement unit to be measured can be achieved.

[0027] Optionally, in an embodiment of the present application, the calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light detected by the detector of the displacement measuring device includes: obtaining the initial light energy of the second collimated light detected by the detector when the displacement unit to be measured is located at an initial measurement position; obtaining the termination light energy of the second collimated light detected by the detector when the displacement unit to be measured is located at a termination measurement position; and calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the initial measurement position, the termination measurement position, the initial light energy, the termination light energy, and the current light energy detected by the detector.

[0028] In the above implementation process, since the signal equation finally received by the detector is positively correlated with the displacement; therefore, based on the initial measurement position, the ending measurement position, the initial light energy, the ending light energy and the current light energy detected by the detector, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction can be quickly calculated.

[0029] Optionally, in an embodiment of the present application, the calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the initial measurement position, the termination measurement position, the initial light energy, the termination light energy and the current light energy detected by the detector includes: obtaining a plurality of intermediate light energies of the second collimated light detected by the detector when the displacement unit to be measured is located at a plurality of different intermediate measurement positions; inputting the initial light energy, the termination light energy and the plurality of intermediate light energies into a displacement calculation model to be trained respectively, and obtaining a displacement calculation result output by the displacement calculation model to be trained according to the light energy; optimizing the internal parameters of the displacement calculation model to be trained according to the initial measurement position, the termination measurement position, a plurality of different intermediate measurement positions and the displacement calculation result, and obtaining a trained displacement calculation model; inputting the current light energy detected by the detector into the trained displacement calculation model, and determining the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the output result of the trained displacement calculation model.

[0030] In the above implementation process, by training the displacement calculation model and inputting the current light energy detected by the detector into the trained displacement calculation model, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction can be more accurately determined according to the output results of the model.

[0031] In a third aspect, an embodiment of the present application provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the method described in any one of the second aspects above.

[0032] The beneficial effects of the present application include at least: the displacement measurement device based on optical mode decomposition can obtain the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction according to the light energy of the second collimated light detected by the detector, thereby realizing the displacement measurement of the displacement unit to be measured; and the structure of the displacement measurement device based on optical mode decomposition is simpler, which solves the relatively complex technical problems of existing precision displacement measurement devices.

[0033] In addition, the displacement measurement device based on optical mode decomposition provided by the present application is to reversely solve the change in light energy that can be detected by the second collimator to obtain the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis, which can theoretically achieve nanometer-level accuracy. Based on quantum analysis, it breaks through the diffraction limit and realizes precise measurement under non-interference conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic structural diagram of a displacement measurement device based on optical mode decomposition provided in an embodiment of the present application;

[0036] Figure 2 A schematic diagram of light energy trend provided in an embodiment of the present application;

[0037] Figure 3 A schematic structural diagram of another displacement measurement device based on optical mode decomposition provided in an embodiment of the present application;

[0038] Figure 4 A schematic diagram of light energy trends at different rotation angles provided in an embodiment of the present application;

[0039] Figure 5 A flow chart of a displacement measurement method provided in an embodiment of the present application.

[0040] Figure numerals: 01 - displacement measuring device; 10 - transmitting unit; 101 - laser source; 102 - first collimator; 20 - detection unit; 201 - second collimator; 202 - detector; 30 - offset unit; 40 - signal processing unit. DETAILED DESCRIPTION

[0041] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0043] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0044] See also Figure 1 The schematic diagram of the structure of a displacement measurement device 01 based on optical mode decomposition provided in an embodiment of the present application is shown. The displacement measurement device 01 based on optical mode decomposition includes: a transmitting unit 10 and a detecting unit 20;

[0045] The transmitting unit 10 includes a laser source 101 and a first collimator 102 connected based on a first optical fiber; the detecting unit 20 includes a second collimator 201 and a detector 202 connected based on a second optical fiber; the laser source 101, the first collimator 102, the second collimator 201 and the detector 202 are on the same optical axis;

[0046] The emitting unit 10 emits a laser beam based on the laser source 101, and the first collimator 102 converts the laser beam transmitted by the first optical fiber into a first collimated light;

[0047] The displacement unit to be measured is arranged between the first collimator 102 and the second collimator 201, and the first collimated light is converted into the second collimated light after passing through the displacement unit to be measured;

[0048] The detection unit 20 couples the second collimated light into the second optical fiber based on the second collimator 201, and detects the second collimated light and its light energy transmitted by the second optical fiber based on the detector 202;

[0049] The light energy of the second collimated light can represent the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction.

[0050] Among them, the laser source 101 can be an electric light source that uses excited state particles to emit light under stimulated radiation. The first optical fiber / the second optical fiber can be implemented by quartz optical fiber or glass optical fiber, and the length of the first optical fiber / the second optical fiber can be adjusted according to the actual application scenario. The first collimator 102 / the second collimator 201 can convert the divergent light transmitted by the optical fiber into parallel light (Gaussian beam) through a front-mounted convex lens. The distance between the first collimator 102 and the second collimator 201 can also be adjusted according to the actual application scenario, and this application does not make specific restrictions on this.

[0051] Since the first collimator 102 can output a Gaussian beam, that is, the photons output by the first collimator 102 have a Gaussian distribution in space, the TEM00 equation can be used to approximate it:

[0052] The complex field of the Gaussian beam output by the first collimator 102 is described. Wherein, the z-axis is in the same direction as the optical axis, and E 00 (x, y, z) represents the photon energy of the Gaussian beam output by the first collimator 102 at the position (x, y, z), E 0 represents the beam amplitude, w 0 represents the beam waist, w(z) represents the spot size of the beam (which changes with the change of z), H 0 represents the Hermitian polynomial, e represents the natural constant, j represents the imaginary part, k represents the wave number, λ represents the wavelength of light. Usually, the divergence of the output Gaussian beam after collimation is small. In this case, it can be considered that w(z) = w 0 In addition, when the first optical fiber / the second optical fiber is implemented by a single-mode optical fiber, the first optical fiber / the second optical fiber can only pass the fundamental mode, so the photons whose quantum states are not converted in the Gaussian beam output by the first collimator 102 can be filtered based on the second collimator 201. Therefore, the Gaussian beam output by the first collimator 102 is converted into the EEM10 mode after passing through the displacement unit to be measured, which can be used: Describe the complex field of the light beam received by the second collimator 201, E 00 (x, y, 0) represents the photon energy of the light beam received by the second collimator 201 at the position (x, y, 0).

[0053] Please refer to Figure 2 , Figure 2 A schematic diagram of light energy trend provided in an embodiment of the present application. Figure 2Specifically shown is a schematic diagram of the change of the light energy received by the second collimator 201 with the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction. Figure 2 The middle abscissa represents the value of the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis (unit: mm); Figure 2 The ordinate represents the normalized value of the light energy received by the second collimator 201, that is, the ratio between the light energy received by the second collimator 201 and the standard light energy. The standard light energy refers to the light energy received by the second collimator 201 when no displacement unit to be measured is placed between the first collimator 102 and the second collimator 201.

[0054] In the case where the displacement unit to be measured is horizontally displaced on a plane perpendicular to the optical axis, assuming that the displacement amount is a, after the displacement unit to be measured is horizontally displaced, the photon energy E of the light beam received by the second collimator 201 at the position (x, y, 0) is 00 (x,y,0) can be expressed as: Usually, the aperture of the lens is much larger than the diameter of the light beam received by the second collimator 201. In this case, the phase change function of the lens can be expressed as: Wherein, t(x, y) represents the transmission coefficient, and f represents the focus of the lens. Further, the complex field of the light beam received by the second collimator 201 after passing through the lens in the second collimator 201 can be expressed as: U ′ ′ =E 00 (x,y)*t(x,y). Here, the Fresnel diffraction at z=f (the focal length of the lens) is calculated, and (u,v) is used to represent the coordinates of the image on the focal plane, which gives: Combined with the above U l ′ The expression of can be obtained: Among them, Considered as E 00 The Fourier transform of (x,y).

[0055] Furthermore, according to the time-shift property of Fourier transform, we can get: in, And the formula is further equivalent to: Secondly, the receiving coupling efficiency must also be considered. A simplified mathematical model can be used to consider the coupling of single-mode optical fibers. In this model, the receiving coupling efficiency is close to Gaussian distribution and can be expressed as: Among them, E 1 =U f (u,v), Therefore, the expression of receiving coupling efficiency can be equivalently replaced by: That is: Furthermore, we can get: That is: Wherein, g(v) represents a function related to v, and g(v) and B can be obtained by integrating the expression of the above receiving coupling efficiency. And the theoretical detection accuracy r of the displacement measurement device 01 based on optical mode decomposition can be obtained based on the formula Calculated; where P min represents the minimum power that can be measured by the detector 202, K max It represents the maximum value (absolute value) of the slope of the curve of the light energy measured by the detector 202 changing with the displacement a.

[0056] Therefore, based on the above analysis, it can be known that the signal equation finally received by the detector 202 is positively correlated with the displacement a. That is, based on the displacement measuring device 01 based on optical mode decomposition provided by the present application, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction can be obtained according to the light energy of the second collimated light detected by the detector, so as to realize the displacement measurement of the displacement unit to be measured. And the structure of the displacement measuring device 01 based on optical mode decomposition is simpler, which solves the more complex technical problems of the existing precision displacement measuring devices. In addition, the displacement measuring device 01 based on optical mode decomposition provided by the present application is solved by reversely solving the light energy change that can be detected by the second collimator 201, and realizes nanometer-level displacement measurement without relying on laser interferometry technology.

[0057] Please refer to Figure 3 , Figure 3 A schematic structural diagram of another displacement measurement device 01 based on optical mode decomposition provided in an embodiment of the present application.

[0058] In some optional embodiments, the displacement measurement device 01 based on optical mode decomposition also includes: an offset unit 30, which is located between the transmitting unit 10 and the detecting unit 20; the offset unit 30 is used to at least provide the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction.

[0059] Among them, the offset unit 30 can be implemented by a high-precision translation stage, such as an electrically controlled translation stage. Based on the offset unit 30, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis can be provided, which reduces the displacement measurement difficulty of the displacement measurement device 01 based on optical mode decomposition. The offset unit 30 can also provide the rotation angle of the displacement unit to be measured in the direction perpendicular to the optical axis. In addition, based on the offset unit 30, the rotation angle of the displacement unit to be measured in the direction perpendicular to the optical axis can be adjusted, and the horizontal displacement on the plane perpendicular to the optical axis can be provided for the displacement unit to be measured at the target rotation angle. By obtaining the light energy of the second collimated light transmitted by the second optical fiber when the offset unit 30 is at different rotation angles, the detector 202 can detect the change of the "horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis", and select a suitable rotation angle according to the actual displacement measurement accuracy requirements. Please refer to Figure 4 , Figure 4 A schematic diagram of light energy trends at different rotation angles provided in an embodiment of the present application. Figure 4 Specifically shown is a schematic diagram of the change of the light energy received by the second collimator 201 with the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction when the offset unit 30 is at the first rotation angle and the second rotation angle respectively. Figure 4 The solid line in represents the curve of the light energy received by the second collimator 201 changing with the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction when the offset unit 30 is at the first rotation angle; Figure 4 The dotted line in shows a curve of the light energy received by the second collimator 201 changing with the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis when the offset unit 30 is at the second rotation angle. Figure 4 The middle abscissa represents the value of the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis (unit: mm); Figure 4 The ordinate represents the light energy received by the second collimator 201 (unit: mW). Since the theoretical detection accuracy r of the displacement measurement device 01 based on optical mode decomposition can be based on the formula Calculated, that is, the theoretical detection accuracy of the displacement measuring device 01 and K maxThere is an inverse proportional relationship between them. Therefore, when the offset unit 30 is at the first rotation angle, the displacement measuring device 01 has a higher measurement accuracy for the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis (relative to the case where the offset unit 30 is at the second rotation angle). When the displacement measurement accuracy is required to be high, the offset unit 30 can be rotated to the first rotation angle; and when the offset unit 30 is at the first rotation angle, based on the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis provided by the offset unit 30, the displacement measuring device 01 can achieve a higher precision measurement of the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis.

[0060] In some optional embodiments, the displacement measurement device 01 based on optical mode decomposition also includes: a signal processing unit 40, which is connected to the detector 202; the signal processing unit 40 is used to receive the light energy of the second collimated light detected by the detector 202, and calculate the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light.

[0061] The signal processing unit 40 can be implemented by a microprocessor, a single chip computer or a programmable logic controller, etc. The signal processing unit 40 can receive the light energy of the second collimated light detected by the detector 202, and calculate the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light, thereby realizing the displacement measurement of the displacement unit to be measured.

[0062] In some optional embodiments, the laser beam emitted by the laser source 101 is a Gaussian beam.

[0063] The Gaussian beam refers to a beam whose amplitude distribution in the cross section complies with a Gaussian function. By setting the laser beam emitted by the laser source 101 to be a Gaussian beam, the difficulty of calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light can be reduced.

[0064] In some optional embodiments, the first optical fiber and the second optical fiber are single-mode optical fibers.

[0065] Among them, single-mode fiber refers to an optical fiber with only one transmission mode. Based on single-mode fiber, it can ensure that the optical signal propagates in a single path in the optical fiber, reduce signal distortion, and improve the accuracy of displacement measurement results.

[0066] In some optional embodiments, the displacement unit 30 includes an electrically controlled translation stage.

[0067] The electric-controlled displacement stage is a precision device that realizes displacement control through electric drive. The resolution of the electric-controlled displacement stage can reach the nanometer level. Based on the electric-controlled displacement stage, precise positioning and movement can be achieved, and precise control and measurement of micro displacement can be achieved in conjunction with the transmitting unit 10 and the detecting unit 20.

[0068] Please refer to Figure 5 , Figure 5 A flow chart of a displacement measurement method provided in an embodiment of the present application. The displacement measurement method is implemented based on the displacement measurement device as described in any one of the first aspects above, and may include the following steps:

[0069] S101, placing a displacement unit to be measured between a first collimator and a second collimator of the displacement measuring device;

[0070] S102: Calculate the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light detected by the detector of the displacement measuring device.

[0071] The specific implementation of step S101 and step S102 in the displacement measurement method can refer to the relevant description of the “displacement measurement device based on optical mode decomposition” above. To avoid repetition, the detailed description is appropriately omitted here.

[0072] In some optional embodiments, S102, based on the light energy of the second collimated light detected by the detector of the displacement measuring device, calculating the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction, including: obtaining the initial light energy of the second collimated light detected by the detector when the displacement unit to be measured is at the initial measurement position; obtaining the termination light energy of the second collimated light detected by the detector when the displacement unit to be measured is at the termination measurement position; based on the initial measurement position, the termination measurement position, the initial light energy, the termination light energy and the current light energy detected by the detector, calculating the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction.

[0073] Among them, the initial measurement position can be the position when the displacement unit to be measured or the electric-controlled displacement stage mentioned above is in the same optical axis as the optical device in the transmitting unit and the detection unit. The termination measurement position can be adjusted according to the actual application scenario; specifically, it can be adjusted according to the farthest moving distance of the displacement unit to be measured or the displacement range of the electric-controlled displacement stage mentioned above. Since the signal equation finally received by the detector 202 is positively correlated with the displacement a. Therefore, based on the initial measurement position, the termination measurement position, the initial light energy, the termination light energy and the current light energy detected by the detector, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction can be quickly calculated.

[0074] In some optional embodiments, the calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the initial measurement position, the termination measurement position, the initial light energy, the termination light energy and the current light energy detected by the detector includes: obtaining a plurality of intermediate light energies of the second collimated light detected by the detector when the displacement unit to be measured is located at a plurality of different intermediate measurement positions; inputting the initial light energy, the termination light energy and the plurality of intermediate light energies into a displacement calculation model to be trained respectively, and obtaining a displacement calculation result output by the displacement calculation model to be trained according to the light energy; optimizing the internal parameters of the displacement calculation model to be trained according to the initial measurement position, the termination measurement position, a plurality of different intermediate measurement positions and the displacement calculation result, and obtaining a trained displacement calculation model; inputting the current light energy detected by the detector into the trained displacement calculation model, and determining the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the output result of the trained displacement calculation model.

[0075] Among them, parameters such as the number of intermediate measurement positions and the spacing between each measurement position can be adjusted according to the actual application situation. The number or degree of optimization of the displacement calculation model to be trained can be adjusted according to the actual displacement measurement accuracy requirements. By training the displacement calculation model and inputting the current light energy detected by the detector into the trained displacement calculation model, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction can be more accurately determined based on the output results of the model.

[0076] An embodiment of the present application further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the method as described in any one of the second aspects.

[0077] In several embodiments provided by the embodiments of the present application, it should be understood that the disclosed device / system and method can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to the multiple embodiments of the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and a part of the module, program segment or code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0078] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part.

[0079] The above description is only an optional implementation manner of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiments of the present application, which should be covered within the protection scope of the embodiments of the present application.

Claims

1. A displacement measurement device based on optical mode decomposition, characterized in that: The device comprises: a transmitting unit and a detecting unit; The transmitting unit includes a laser source and a first collimator connected based on a first optical fiber; the detecting unit includes a second collimator and a detector connected based on a second optical fiber; the laser source, the first collimator, the second collimator and the detector are on the same optical axis; The emitting unit emits a laser beam based on the laser source, and converts the laser beam transmitted by the first optical fiber into a first collimated light based on the first collimator; The displacement unit to be measured is configured between the first collimator and the second collimator, and the first collimated light is converted into the second collimated light after passing through the displacement unit to be measured; The detection unit couples the second collimated light into the second optical fiber based on the second collimator, and detects the second collimated light and its light energy transmitted by the second optical fiber based on the detector; The light energy of the second collimated light can represent the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction.

2. The device according to claim 1, characterized in that The device further comprises: an offset unit, the offset unit being located between the transmitting unit and the detecting unit; The offset unit is used to at least provide a horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction.

3. The device according to claim 1, characterized in that The device further comprises: a signal processing unit, the signal processing unit being connected to the detector; The signal processing unit is used to receive the light energy of the second collimated light detected by the detector, and calculate the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light.

4. The device according to any one of claims 1 to 3, characterized in that: in, The laser beam emitted by the laser source is a Gaussian beam.

5. The device according to claim 4, characterized in that in, The first optical fiber and the second optical fiber are single-mode optical fibers.

6. The device according to claim 2, characterized in that in, The displacement unit includes an electrically controlled translation stage.

7. A displacement measurement method, characterized in that: The displacement measurement method is implemented based on the displacement measurement device according to any one of claims 1 to 6; The method comprises: Placing the displacement unit to be measured between the first collimator and the second collimator of the displacement measuring device; Based on the light energy of the second collimated light detected by the detector of the displacement measuring device, the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction is calculated.

8. The method according to claim 7, characterized in that The calculating the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction based on the light energy of the second collimated light detected by the detector of the displacement measuring device comprises: Acquiring initial light energy of the second collimated light detected by the detector when the displacement unit to be measured is located at an initial measurement position; Acquiring the termination light energy of the second collimated light detected by the detector when the displacement unit to be measured is located at the termination measurement position; The horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction is calculated based on the initial measurement position, the final measurement position, the initial light energy, the final light energy and the current light energy detected by the detector.

9. The method according to claim 8, characterized in that The calculating, based on the initial measurement position, the termination measurement position, the initial light energy, the termination light energy, and the current light energy detected by the detector, the horizontal displacement of the displacement unit to be measured on a plane perpendicular to the optical axis direction comprises: Acquiring a plurality of intermediate light energies of the second collimated light detected by the detector when the displacement unit to be measured is located at a plurality of different intermediate measurement positions; Inputting the initial light energy, the final light energy, and the plurality of intermediate light energies into the displacement calculation model to be trained respectively, and obtaining the displacement calculation result output by the displacement calculation model to be trained according to the light energy; Optimizing internal parameters of the displacement calculation model to be trained according to the initial measurement position, the final measurement position, a plurality of different intermediate measurement positions, and the displacement calculation results to obtain a trained displacement calculation model; The current light energy detected by the detector is input into the trained displacement calculation model, and based on the output result of the trained displacement calculation model, the horizontal displacement of the displacement unit to be measured on the plane perpendicular to the optical axis direction is determined.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the method according to any one of claims 7 to 9 is implemented.

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