A displacement sensor based on time-space transformation

Abstract

The present invention provides a novel displacement sensor based on time-space transformation. This time-difference displacement sensor includes: a first reflector for receiving a laser beam reflected by a first reflective surface of a triangular wave reflector and causing the laser beam to be reflected along the same path to the second reflective surface of the triangular wave reflector during measurement; a first laser shifter for uniformly shifting the laser beam reflected by the second reflective surface of the triangular wave reflector within a set range; a first photodetector and a second photodetector for receiving the laser beam translated by the first laser shifter twice within one translation cycle of the first laser shifter; and a processing system for calculating the displacement change of the measured object based on the time difference between the laser beams received by the first and second photodetectors and the translation speed of the first laser shifter. This invention can improve the measurement accuracy of the displacement sensor.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to a displacement sensor based on time-space transformation. Background Art

[0002] The new displacement measurement principle based on the optical triangulation amplification method is achieved by combining triangular wave optical devices with high-precision PSDs (Position Sensitive Devices, also known as photodetectors) on the basis of the optical triangulation amplification method. The Chinese patent No. 2018207451284 provides a tracking displacement sensor that uses a laser translator to drive the photodetector to move, so that the position of the reflected laser beam from the triangular wave reflector incident on the photodetector remains unchanged, thereby improving the measurement accuracy of the time difference-based displacement sensor and increasing its amplification factor. However, all movement has inertia, and the movement inertia of the laser translator will slow the response speed of the photodetector, which in turn affects the measurement accuracy. The Chinese patent No. 2021105615727 provides a time difference-based displacement sensor and its measurement method. Displacement measurement is achieved through the time field constructed by laser deflection. High-precision displacement measurement can be achieved through high-precision time measurement, and displacement measurement is converted into time measurement. However, the laser deflection angle is affected by the device and has a limited angle range. In addition, the incident angle of the photodetector changes continuously during the deflection process, which inevitably has a certain impact. Summary of the Invention

[0003] The object of the present invention is to provide a displacement sensor based on time-space transformation that can improve measurement accuracy.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A displacement sensor based on time-space transformation includes: a triangular wave reflector including a first reflective surface and a second reflective surface;

[0006] Laser beam 1 is incident on the first reflecting surface of the triangle wave reflector;

[0007] a first reflector for receiving the laser beam reflected by the first reflective surface of the triangular wave reflector and causing the laser beam to be reflected along the same path to the second reflective surface of the triangular wave reflector during a measurement process in which the laser beam is incident on the same first reflective surface;

[0008] Laser shifter 1, used to shift the laser beam reflected by the second reflecting surface of the triangular wave reflector at a uniform speed within a set range;

[0009] Photodetector 1 and photodetector 2, for receiving the laser beam translated by laser translator 1;

[0010] The processing system is used to calculate the displacement change value of the object being measured based on the time difference between the first photoelectric detector and the second photoelectric detector receiving the laser beam and the translation speed of the first laser translator.

[0011] As an implementation method, the first and second reflection surfaces of the triangular wave reflector respectively have an angle of 150 degrees with the horizontal plane, the incident angle of the laser beam 1 to the first reflection surface is 30 degrees, and the reflector 1 is parallel to the first reflection surface.

[0012] Preferably, the above-mentioned displacement sensor based on time-space transformation further includes:

[0013] The second laser beam is incident on the first reflecting surface of the triangular wave reflector, and the initial incident points of the first laser beam and the second laser beam on the first reflecting surface are different;

[0014] a second reflector, for receiving the second laser beam reflected by the first reflective surface of the triangular wave reflector, and causing the second laser beam to be reflected along the same path to the second reflective surface of the triangular wave reflector during a measurement process in which the second laser beam is incident on the same first reflective surface;

[0015] The second laser shifter is used to shift the laser beam reflected by the second reflecting surface of the triangular wave reflector at a uniform speed within a set range;

[0016] Photodetector 3 and photodetector 4 are used to receive the laser beam translated by laser translator 2;

[0017] The processing system is specifically used to calculate the displacement change value of the object under test based on the time difference between photodetector 1 and photodetector 2 when they respectively receive the laser beam and the translation speed of laser translator 1; or to calculate the displacement change value of the object under test based on the time difference between photodetector 3 and photodetector 4 when they respectively receive the laser beam and the translation speed of laser translator 2.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This displacement sensor, based on time-space transformation, utilizes a laser translator to translate a reflected laser beam. Within half a translation period, the reflected laser beam is received by two photodetectors, generating a time difference. The distance between the two photodetectors is calculated based on the translation speed of the laser translator. The difference between this distance and the theoretical distance is the displacement measured by the displacement sensor. The laser translator's characteristic of parallelizing the emitted laser light ensures that the incident angle on the photodetectors remains consistent throughout the measurement process, further improving the accuracy of displacement measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 The figure shows a schematic diagram of the measurement principle of a displacement sensor based on time-space transformation provided in a structure of Example 1.

[0022] Figure 2 Shown is a schematic diagram of the principle of displacement measurement of the photoelectric detector before and after displacement.

[0023] Figure 3 The figure shows a schematic diagram of the measurement principle of a displacement sensor based on time-space transformation of another structure provided in Example 2.

[0024] Figure 4 Shown is a schematic diagram of the structural principle of a laser translator with edge detection function.

[0025] Description of the numbers in the figure:

[0026] Laser source 1, laser source 2, laser beam 1, laser beam 2, triangular wave reflector 5, housing 6, photodetector 1, photodetector 2, 8, reflector 1, laser shifter 1, laser shifter 2, 12, photodetector 3, photodetector 3, photodetector 3; photodetector 4, 14; edge photodetector 15; first reflective surface 51, second reflective surface 52; fixed reflector 1, 101; movable reflector 1, 102; fixed reflector 2, 121; movable reflector 2, 122. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] See also Figure 1In this embodiment, a displacement sensor based on time-space transformation is provided, including a laser source 1, a triangular wave reflector 5, a reflector 9, a photodetector 7 and a photodetector 2 8, wherein the triangular wave reflector 5 includes multiple reflective surfaces. For ease of understanding, the reflective surface for receiving the laser beam emitted by the laser source 1 (or 2) is defined as the first reflective surface, and the reflective surface for receiving the laser beam reflected by the reflector 1 (or 2) is defined as the second reflective surface.

[0030] In the displacement sensor based on time-space transformation described in this embodiment:

[0031] The laser source 1 is used to emit a laser beam 3 toward the first reflecting surface 51 of the triangular wave reflector 5;

[0032] Reflector 1-9 is used to receive the laser beam 1-3 reflected by the first reflection surface 51 of the triangular wave reflector 5, and to reflect the laser beam along the same path to the second reflection surface 52 of the triangular wave reflector 5 during the measurement process in which the laser beam 1-3 is incident on the same first reflection surface 51;

[0033] The laser shifter 10 is used to shift the laser reflected by the second reflection surface 52 of the triangular wave reflector 5 at a uniform speed within a set range;

[0034] Photodetector 1 7 and photodetector 2 8 are used to receive the laser beam translated by laser shifter 10 twice within one translation cycle of laser shifter 10; that is, photodetector 1 7 and photodetector 2 8 are both within the set range of laser shifter 10, thereby ensuring that the laser beam translated by laser shifter 10 can be received.

[0035] The processing system is used to calculate the displacement change value of the object being measured based on the time difference between the photoelectric detector 1 7 and the photoelectric detector 2 8 receiving the laser beam respectively, and the translation speed of the laser translator 10.

[0036] The processing system can be an arithmetic circuit composed of components, and has different circuit structures based on different implementation methods. However, those skilled in the art can easily implement the arithmetic circuit based on the calculation process of the processing system, so a specific arithmetic circuit diagram is not provided here. The processing system can also be a processor with an integrated arithmetic circuit, such as an STM32 single-chip microcomputer.

[0037] The purpose of the laser shifter 10 is to translate the incident laser beam. The simplest implementation involves constructing two parallel mirrors, one of which is mounted on a displacement actuator, such as a piezoelectric ceramic displacement platform, to adjust the distance between the two parallel mirrors. In this embodiment, a fixed mirror 101 and a movable mirror 102 form the laser shifter. The translation range of the laser shifter 10 is less than the length of one reflective surface of the triangular wave mirror.

[0038] In order to ensure the amplification performance of the displacement sensor based on time-space transformation, the number of reflections of the laser incident on the laser translator 10 between the two parallel mirrors is greater than 10.

[0039] like Figure 1 As shown, the photodetector 7 uses a photosensitive diode. The laser beam 3 before displacement is represented by a solid line, and the laser beam 3 after displacement is represented by a dotted line. The transmission path of the laser beam 3 is as follows:

[0040] Before displacement, laser source 1 emits laser beam 13 to the first reflection surface 51 of the triangular wave reflector 5. The first reflection surface 51 of the triangular wave reflector 5 reflects laser beam 13 to reflector 19. Reflector 19 reflects the laser beam reflected by the first reflection surface 51 to the second reflection surface 52. The second reflection surface 52 then reflects the incident laser beam to laser shifter 10.

[0041] In half a translation cycle, the laser shifter 10 reflects the incident laser beam to the photodetector 7 (here it is assumed that the photodetector 7 receives the laser beam first). The moment when the photodetector 7 receives the laser beam is recorded as t1. As the laser shifter 10 translates at a uniform speed, the laser beam incident to the laser shifter 10 is reflected to the photodetector 8 after a certain period of time. The moment when the photodetector 8 receives the laser beam is recorded as t2.

[0042] After displacement ( Figure 1 It is shown as shifting to the left. During the shift, the laser source 1, the reflector 9, the laser shifter 10, the photodetector 7, and the photodetector 28 are synchronously shifted to the left. The laser source 1 emits a laser beam 3 to the first reflective surface 51 of the triangular wave reflector 5 (compared to another position point of the same reflective surface before the shift). The first reflective surface 51 of the triangular wave reflector 5 reflects the laser beam 3 to the reflector 9. The reflector 9 reflects the laser reflected by the first reflective surface 51 along the same path before the shift to the second reflective surface 52. The second reflective surface 52 then reflects the incident laser beam along the same path before the shift to the laser shifter 10.

[0043] Assuming that the theoretical distance between photodetector 1 7 and photodetector 2 8 is L, and the laser moving speed of laser translator 10 is V, the displacement measured by laser translator 10 is L'=V×(t2-t1), and the displacement of the object being measured is L'-L.

[0044] In order to ensure that the laser beam reflected by the reflector 9 is reflected along the same path to the second reflective surface 52 of the triangular wave reflector 5 before and after displacement, it can be achieved, for example, in the following manner: the reflector 1 is parallel to the first reflective surface and the second reflective surface, and the acute angle between the laser beam 1 and the first reflective surface is equal to twice the angle between the first reflective surface and the horizontal plane.

[0045] For example, in a preferred embodiment, the first and second reflecting surfaces 51, 52 of the triangular wave reflector 5 each form an angle of 150 degrees with the horizontal plane (assuming the positive direction is horizontal to the right and rotates counterclockwise). The incident angle of laser beam 3 emitted by laser source 1 on first reflecting surface 51 is 30 degrees, and reflector 9 is parallel to first reflecting surface 51. While ensuring that reflector 9 ensures that laser beam 3 emitted by laser source 1 is incident on the same first reflecting surface during measurement, the emitted laser beam 3 is reflected along the same path to the second reflecting surface 52 of the triangular wave reflector 5. Other different configurations are also possible.

[0046] A triangular wave does not necessarily need to be an isosceles triangle wave. That is, the acute angles between the two reflecting surfaces forming the triangular wave and the horizontal plane can be equal or unequal. In the displacement sensor based on time-space transformation provided in this embodiment, the specific structure of the triangular wave reflector 5 is not limited, as long as the first reflecting surface 51 is parallel to the second reflecting surface 52. In other words, there is no restriction on the angle between the two reflecting surfaces forming the triangular wave.

[0047] See Figure 1 The above-mentioned time-difference-based displacement sensor may further include a housing 6. Laser source 1, reflector 9, laser translator 10, photodetector 7, and photodetector 2 8 are all fixedly disposed within housing 6, forming a probe. Both the laser beam 3 emitted by laser source 1 and its reflected beam can pass through the transceiver end face of the probe. The laser source 1, reflector 9, laser translator 10, photodetector 7, and photodetector 2 8 are all fixedly disposed within housing 6, maintaining their relative positions and ensuring synchronized displacement.

[0048] During measurement, depending on the actual application, the triangular wave reflector 5 can be fixed to the object being measured, and the stylus can remain stationary. When the object is displaced, the triangular wave reflector 5 and the stylus can move relative to each other, and the stylus can measure the displacement of the triangular wave reflector 5, that is, the object being measured. As another embodiment, the stylus can also be fixed to the object being measured, with the triangular wave reflector 5 remaining stationary. When the object is displaced, the stylus moves, and the stylus and triangular wave reflector 5 are displaced relative to each other. The stylus can measure the relative displacement between the stylus and triangular wave reflector 5, and thus obtain the displacement of the object being measured.

[0049] The measurement selects the triangular wave reflector 5 or the probe to be fixed on the object to be measured, which improves the measurement convenience.

[0050] When the displacement sensor based on time-space transformation is used to measure displacement, the steps are as follows:

[0051] Step 1: Fix the object to be measured on a triangular wave reflector or a measuring head;

[0052] Step 2: Adjust the positional relationship between laser beam 1 (i.e., laser source 1), triangular wave reflector, reflector 1, laser shifter 1, photodetector 1, and photodetector 2, so that reflector 1 receives the laser beam reflected by the first reflective surface of the triangular wave reflector, and the laser beam is reflected along the same path to the second reflective surface of the triangular wave reflector during the measurement process in which laser beam 1 is incident on the same first reflective surface, and photodetector 1 and photodetector 2 are within the translation range of laser shifter 1, that is, during the movement of laser shifter 1, they can receive the laser beam reflected by the second reflective surface of the triangular wave reflector;

[0053] Step 3: Start the laser translator 1 to translate at a constant speed and emit the laser beam 1. After the laser beam 1 passes through the first reflective surface of the triangular wave reflector, the reflector 1, and the second reflective surface of the triangular wave reflector, it is detected by the photodetector 1 and the photodetector 2 respectively within half a translation period, and the time of detection of the laser beam is recorded;

[0054] Step 4: The object to be measured moves. During the displacement process, the time when the photoelectric detector 1 and the photoelectric detector 2 detect the laser beam are recorded respectively;

[0055] Step 5: The processing system calculates the displacement value of the object to be measured based on the time difference between the first photodetector and the second photodetector receiving the laser beam, and the translation speed of the first laser translator.

[0056] Example 2

[0057] See Figure 3Compared with the displacement sensor based on time-space transformation described in Example 1, the displacement sensor based on time-space transformation provided in this embodiment further includes a laser beam 4 incident on another first reflection surface 51 of the triangular wave reflector 5; and the following components:

[0058] The second reflecting mirror 11 is used to receive the laser beam 24 reflected by the other first reflecting surface 51 of the triangular wave reflecting mirror 5, and to reflect the laser beam along the same path to the other second reflecting surface 52 of the triangular wave reflecting mirror 5 during the measurement process in which the laser beam 24 is incident on the same other first reflecting surface 51;

[0059] The second laser shifter 12 is used to shift the laser beam reflected by the second reflecting surface 52 of the triangular wave reflector 5 at a uniform speed within a set range;

[0060] The photodetector 3 13 and the photodetector 4 14 are used to receive the laser beam translated by the laser shifter 2 twice within one translation cycle of the laser shifter 2;

[0061] In the displacement sensor based on time-space transformation described in this embodiment, the processing system calculates the displacement change value of the object to be measured based on the time difference between the photodetector 1 7 and the photodetector 2 8 when they respectively receive the laser beam and the translation speed of the laser translator 10; or, calculates the displacement change value of the object to be measured based on the time difference between the photodetector 3 13 and the photodetector 4 14 when they respectively receive the laser beam and the translation speed of the laser translator 2 12.

[0062] The displacement sensor based on time-space transformation described in this embodiment can realize continuous displacement measurement. Specifically, one of the two laser beams can be selected for measurement. When the reflection point of one laser beam is located at certain positions of the reflective surface, such as the top of the reflective surface, the intersection position of the two reflective surfaces, etc., the length of the corresponding photodetector is limited, and therefore it may not be reflected to the corresponding photodetector. The reflection point of the other laser beam is located at other positions of the other reflective surface and can be reflected to the corresponding photodetector. It can be realized that at every moment when the object being measured moves, at least one of the laser beams reflected by each second reflective surface 52 on the triangular wave reflector 5 can be reflected to the corresponding photodetector. At this time, the processing system can switch back and forth to calculate the time difference between the two groups of photodetectors, and perform superposition and accumulation to realize the measurement of a one-time change or a continuous incremental displacement change of the object being measured. The measurement method is simple, reliable, easy to operate, and can improve measurement accuracy.

[0063] like Figure 3 As shown, laser beam 1 3 and laser beam 2 4 are emitted by laser source 1 1 and laser source 2 2 respectively.

[0064] The two measurement systems can be both arranged in a housing to form a probe, or the two measurement systems can be respectively arranged in a housing to form two probes. Specifically, laser source 1, laser source 2, reflector 1, reflector 2, laser shifter 1, laser shifter 2, photodetector 1, photodetector 2, photodetector 3, and photodetector 4 are all fixedly arranged in the housing to form a probe. Alternatively, laser source 1, reflector 1, laser shifter 1, photodetector 1, and photodetector 2 are all fixedly arranged in a housing to form a probe; and laser source 2, reflector 2, laser shifter 2, photodetector 3, and photodetector 4 are all fixedly arranged in another housing to form another probe.

[0065] It is easy to understand that in this embodiment, the purpose of setting the laser source 1 and the laser source 2 is to avoid that when one set of photoelectric detectors cannot receive the laser beam, the laser beam can be received by the other set of photoelectric detectors to achieve displacement measurement. Therefore, in addition to the following Figure 3 In addition to the arrangement shown, other arrangements can be made, as long as laser source one and laser source two are staggered so that the initial incident points of laser beam one and laser beam two on the first reflection surface are different. For example, laser beam two can also be incident on another first reflection surface on the same side of the first reflection surface on which laser beam one is incident, or can be incident on the same reflection surface as laser beam one, but with different incident point positions.

[0066] The photodetectors (one to four) may be photodiodes, photocells or phototransistors.

[0067] When the displacement sensor based on time-space transformation in this embodiment is used to perform displacement measurement, the steps are as follows:

[0068] Step 1: Fix the object to be measured on a triangular wave reflector or a measuring head;

[0069] Step 2: Adjust the positional relationship between laser beam 1, triangular wave reflector, reflector 1, laser shifter 1, photodetector 1, and photodetector 2, so that reflector 1 receives the laser beam reflected by laser beam 1 from the first reflective surface of the triangular wave reflector, and the laser beam is reflected along the same path to the second reflective surface of the triangular wave reflector during the measurement process in which laser beam 1 is incident on the same first reflective surface, and photodetector 1 and photodetector 2 are within the translation range of laser shifter 1; adjust the positional relationship between laser beam 2, triangular wave reflector, reflector 2, laser shifter 2, photodetector 3, and photodetector 4, so that reflector 2 receives the laser beam reflected by laser beam 2 from the first reflective surface of the triangular wave reflector, and the laser beam is reflected along the same path to the second reflective surface of the triangular wave reflector during the measurement process in which laser beam 2 is incident on the same first reflective surface, and photodetector 3 and photodetector 4 are within the translation range of laser shifter 2;

[0070] Step 3: Start the laser shifter 1 for uniform translation and emit laser beam 1. After the laser beam 1 passes through the first reflective surface of the triangular wave reflector, the first reflector, and the second reflective surface of the triangular wave reflector, within half a translation period, the laser beam is detected by the first photodetector and the second photodetector, and the time when the laser beam is detected is recorded; or start the laser shifter 2 for uniform translation and emit laser beam 2. After the laser beam 2 passes through the first reflective surface of the triangular wave reflector, the second reflective surface of the triangular wave reflector, and the second reflective surface of the triangular wave reflector, within half a translation period, the laser beam is detected by the third photodetector and the fourth photodetector, and the time when the laser beam is detected is recorded;

[0071] Step 4: The object to be measured moves. During the displacement process, the time when the photoelectric detector 1 and the photoelectric detector 2 detect the laser beam is recorded respectively, or the time when the photoelectric detector 3 and the photoelectric detector 4 14 detect the laser beam is recorded respectively;

[0072] In step five, the processing system calculates the displacement value of the object to be measured based on the time difference between when photodetector one and photodetector two respectively receive the laser beam, and the translation speed of laser translator one; or calculates the displacement value of the object to be measured based on the time difference between when photodetector three and photodetector four respectively receive the laser beam, and the translation speed of laser translator two.

[0073] Example 3

[0074] See Figure 4Unlike Example 1, the displacement sensor based on time-space transformation provided in this embodiment further includes an edge photodetector 15. Specifically, an edge photodetector 15 is provided at each end of the fixed reflector 101 and the movable reflector 102. The edge photodetector 15 has the same structure as the photodetector 1 (or 2, 3, or 4), and is also a photodetector.

[0075] The laser translation speed V is equal to the product of the moving speed V' of the moving reflective mirror of the laser translator in the laser translation direction and the number of reflections N of the laser in the laser translator.

[0076] The edge photodetector 15 is used to detect whether the incident laser and the outgoing laser of the laser translator enter the edge. When the edge photodetector 15 in the incident direction detects the incident laser, the position of the laser translator needs to be adjusted so that the incident laser does not enter the edge photodetector 15 during the measurement process. Once the incident laser reaches the edge photodetector 15, it will inevitably affect the intensity of the incident laser, and the laser incident on the edge photodetector 15 will cause a large amount of stray light in the reflected laser, affecting the measurement accuracy. When the edge photodetector 15 in the outgoing direction detects the laser, the time is counted as t'. If the moving reflector 102 moves away from the fixed reflector 101, the number of reflections N is reduced by 1, otherwise the number of reflections N is increased by 1.

[0077] The translation distance L' is calculated based on the laser translator's uniform motion during the time difference. The theoretical distance between photodetector 1 7 and photodetector 2 8 is L, and the laser movement speed of laser translator 10 is V. The displacement measured by laser translator 10 is L' = V' × N1 × (t2 - t') + V' × N2 × (t1 - t'). The displacement of the measured object is L' - L. N1 is the number of laser reflections within the laser translator from t' to t2, and N2 is the number of laser reflections within the laser translator from t1 to t'.

[0078] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, and they should be covered by the protection scope of the present invention.

Claims

1. A displacement sensor based on time-space transformation, characterized in that: include: A triangular wave reflector comprising a first reflecting surface and a second reflecting surface; Laser beam 1 is incident on the first reflecting surface of the triangle wave reflector; a first reflector for receiving the laser beam reflected by the first reflective surface of the triangular wave reflector and causing the laser beam to be reflected along the same path to the second reflective surface of the triangular wave reflector during a measurement process in which the laser beam is incident on the same first reflective surface; Laser shifter 1, used to shift the laser beam reflected by the second reflecting surface of the triangular wave reflector at a uniform speed within a set range; Photodetector 1 and photodetector 2 are used to receive the laser beam translated by laser shifter 1 twice in one translation cycle of laser shifter 1, wherein photodetector 1 receives the laser beam translated by laser shifter 1 for the first time and photodetector 2 receives the laser beam translated by laser shifter 1 for the second time; A processing system for calculating a displacement change value of the object under test based on a time difference between when the first photodetector and the second photodetector receive the laser beams and a translation speed of the first laser translator; The laser moving speed of laser translator 1 is V, and the displacement measured by laser translator 1 is , the displacement change of the measured object is , where L is the distance between photodetector 1 and photodetector 2, the moment when photodetector 1 receives the laser beam is t1, and the moment when photodetector 2 receives the laser beam is t2; the laser translation speed V is equal to the product of the moving speed V' of the moving reflector of the laser translator in the laser translation direction and the number of reflections N of the laser in the laser translator.

2. A displacement sensor based on time-space transformation according to claim 1, characterized in that: The reflector 1 is parallel to the first reflective surface and the second reflective surface at the same time. The acute angle between the laser beam 1 and the first reflective surface is equal to twice the angle between the first reflective surface and the horizontal plane.

3. The displacement sensor based on time-space transformation according to claim 2, characterized in that: The angles between the first reflecting surface and the second reflecting surface of the triangular wave reflector and the horizontal plane are 150 degrees respectively, and the incident angle of the laser beam incident on the first reflecting surface is 30 degrees.

4. The displacement sensor based on time-space transformation according to claim 1, characterized in that: The device also includes a shell. The laser beam 1 is emitted by the laser source 1. The laser source 1, the reflector 1, the photoelectric detector 1 and the photoelectric detector 2 are all fixedly arranged in the shell to form a probe.

5. The displacement sensor based on time-space transformation according to claim 1, characterized in that: The laser translator includes a fixed plane reflector and a movable plane reflector driven by a displacement platform.

6. The displacement sensor based on time-space transformation according to any one of claims 1 to 5, characterized in that: Also includes: The second laser beam is incident on the first reflecting surface of the triangular wave reflector, and the initial incident points of the first laser beam and the second laser beam on the first reflecting surface are different; a second reflector for receiving the second laser beam reflected by the first reflective surface of the triangular wave reflector, and causing the second laser beam to be reflected along the same path to the second reflective surface of the triangular wave reflector during a measurement process in which the second laser beam is incident on the same first reflective surface; The second laser shifter is used to shift the laser beam reflected by the second reflecting surface of the triangular wave reflector at a uniform speed within a set range; Photodetector 3 and photodetector 4 are used to receive the laser beam translated by laser shifter 2 twice in one translation cycle of laser shifter 2, wherein photodetector 3 receives the laser beam translated by laser shifter 2 for the first time, and photodetector 4 receives the laser beam translated by laser shifter 2 for the second time. The processing system is specifically configured to calculate a displacement change value of the object under test based on a time difference between when the first photodetector and the second photodetector respectively receive the laser beam and a translation speed of the first laser translator; or to calculate a displacement change value of the object under test based on a time difference between when the third photodetector and the fourth photodetector respectively receive the laser beam and a translation speed of the second laser translator; The laser movement speed of laser translator 2 is V, then the displacement measured by laser translator 2 is L'=V×(t2-t1), and the displacement of the object being measured is L'-L, where L is the distance between photodetector 3 and photodetector 4; the laser translation speed V is equal to the product of the movement speed V' of the moving reflector of the laser translator in the laser translation direction and the number of reflections N of the laser in the laser translator.

7. The displacement sensor based on time-space transformation according to claim 6, characterized in that: The first laser beam and the second laser beam are respectively incident on two different first reflection surfaces of the triangular wave reflector.

8. The displacement sensor based on time-space transformation according to claim 6, characterized in that: The incident angle of the second laser beam incident on the first reflection surface is 30 degrees.

9. The displacement sensor based on time-space transformation according to claim 6, characterized in that: It also includes a shell, and the laser beam 1 and laser beam 2 are respectively emitted by laser source 1 and laser source 2. Laser source 1, laser source 2, reflector 1, reflector 2, laser shifter 1, laser shifter 2, photoelectric detector 1, photoelectric detector 2, photoelectric detector 3, and photoelectric detector 4 are all fixedly arranged in the shell to form a probe.

10. The displacement sensor based on time-space transformation according to claim 6, characterized in that: It also includes two shells, and the laser beam 1 and laser beam 2 are respectively emitted by laser source 1 and laser source 2. Laser source 1, reflector 1, laser translator 1, photoelectric detector 1 and photoelectric detector 2 are all fixedly arranged in one shell to form a probe, and laser source 2, reflector 2, laser translator 2, photoelectric detector 3 and photoelectric detector 4 are all fixedly arranged in another shell to form another probe.

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