Displacement sensor capable of improving magnification and measurement method thereof
Through multiple laser beam reflections and multiple reading head-set displacement sensors, the problem of limited amplification in the prior art is solved, and high-precision displacement measurement is achieved, ensuring continuous and effective measurement.
Patent Information
- Application Number
- CN201810736602.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2018-07-06
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2038-07-06
AI Technical Summary
The limited magnification of existing displacement sensors leads to limited measurement accuracy and the inability to achieve high-precision displacement measurements in a small range.
Multiple mirror groups and photodetectors are used to achieve multi-magnification through multiple laser beam reflections. Combined with the settings of multiple reading heads, it ensures that the position change of the laser beam can always be read during the displacement process, ensuring continuous displacement. Measurement.
The magnification and measurement accuracy are significantly improved, ensuring that effective measurement can always be achieved during the displacement process, and achieving high-precision displacement sensing.
Smart Images
Figure CN108534688B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of measurement technology, and in particular to a displacement sensor capable of improving magnification and a measurement method thereof. Background Art
[0002] The new displacement measurement principle based on the optical triangulation amplification method is realized on the basis of the optical triangulation amplification method, combining the triangular wave optical device and the high-precision PSD (Position Sensitive Device). The triangular wave optical device subdivides the linear displacement into equal intervals, which reduces the processing accuracy and size requirements of the optical device, while reducing the size requirements of the high-precision PSD, and realizes high-precision displacement measurement in a small range. The displacement measurement principle based on the optical triangulation amplification method is that after the relative displacement between the reading head and the triangular wave optical reflective component occurs, the small horizontal displacement t is amplified to T on the photoelectric detector (PSD) through optical triangulation amplification, which can greatly improve the accuracy of length measurement. However, the displacement sensor in the prior art, for example, the displacement sensor provided in the application number 201810481645.X and the invention name "Displacement sensor with improved amplification factor and its measurement method", still has a limited amplification factor, which in turn leads to limited measurement accuracy. Summary of the invention
[0003] The object of the present invention is to provide a displacement sensor capable of improving measurement accuracy and magnification, and a method for displacement measurement using the displacement sensor.
[0004] In order to achieve the above object, the present invention provides the following technical solutions:
[0005] A displacement sensor capable of improving magnification, comprising:
[0006] A triangular wave reflector, comprising at least three reflective surfaces, wherein the at least three reflective surfaces are sequentially distributed along the moving direction;
[0007] A laser source, used for emitting a laser beam, wherein the laser beam is incident on a reflecting surface of the triangular wave reflector;
[0008] A reflector group, comprising at least two reflectors, wherein the at least two reflectors are sequentially distributed along a moving direction;
[0009] Each of the reflectors corresponds to at least one of the reflective surfaces, and the reflector is used to receive the laser beam reflected by the corresponding reflective surface and reflect the received laser beam again;
[0010] The reflecting surface is used to receive the laser beam emitted by the laser source or the laser beam reflected by the reflecting mirror, and to reflect the received laser beam again;
[0011] A photoelectric detector, used for receiving the laser beam reflected by the reflection surface and no longer received by the reflection mirror group, and measuring its incident position;
[0012] The processing system is used to calculate the displacement change value of the object to be measured according to the incident position change of the laser beam received by the photoelectric detector.
[0013] As an implementation method, the at least two reflectors are parallel to each other, and every two reflectors are connected by a transition portion, forming a sawtooth structure as a whole.
[0014] As an implementable embodiment, the at least two reflectors are directly connected to form a straight-line structure as a whole.
[0015] As a possible implementation method, the reflector is parallel to the reflective surface, and the acute angle formed by the laser beam emitted by the laser source and the reflective surface is equal to twice the angle between the reflective surface and the horizontal plane.
[0016] As an implementable embodiment, it also includes a shell, and the laser source, the reflector group and the photoelectric detector are all fixedly arranged in the shell to form a reading head.
[0017] As an implementation method, there are at least two reading heads, and the positional relationship between the at least two reading heads satisfies: during the measurement process, at least one reading head can read the change in the incident position of the laser beam on the photodetector.
[0018] On the other hand, the present invention also provides a measurement method of the displacement sensor capable of improving the magnification, comprising the following steps:
[0019] Fix the object to be measured on the triangular wave reflector or reading head;
[0020] Adjust the positional relationship between the laser source, the triangular wave reflector, the photoelectric detector, and the reflector group so that the laser beam emitted by the laser source is incident on a reflective surface of the triangular wave reflector, and is incident on a corresponding reflector after being reflected by the reflective surface, the reflector receives the laser beam reflected by the corresponding reflective surface of the triangular wave reflector, and reflects the received laser beam to the next reflective surface of the triangular wave reflector, and the laser beam is finally incident on the photoelectric detector after being reflected multiple times between the reflector and the reflective surface of the triangular wave reflector;
[0021] A laser beam is emitted, and after the laser beam is reflected multiple times between the reflective mirror and the reflective surface of the triangular wave reflective mirror, its initial incident position is detected by a photoelectric detector;
[0022] The object being measured moves. During the movement, the photoelectric detector detects the change in the incident position of the laser beam until the object being measured stops moving.
[0023] The processing system calculates the displacement value of the object being measured through the change in the incident position of the laser beam detected by the photoelectric detector.
[0024] Compared with the prior art, the present invention has the following beneficial effects:
[0025] The displacement sensor with improved magnification of the present invention, compared with the displacement sensor with application number 201810481645.X, realizes multiple reflections through the setting of multiple reflectors, and then realizes multiple magnification, solves the problem of magnification limitation, thereby increasing the magnification and improving measurement accuracy.
[0026] By setting up multiple reading heads, during the measurement process, if a certain reading head cannot read the position change of the laser beam, it will switch to another reading head for measurement. Therefore, it can be guaranteed that effective measurement can be achieved during the displacement process and continuous displacement measurement can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show 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 creative work.
[0028] Figure 1 The figure shows a schematic diagram of the measuring principle of a displacement sensor with a structure capable of improving the magnification provided in Example 1.
[0029] Figure 2 The figure shows a schematic diagram of the incident angle of the laser beam of a displacement sensor with a structure that can improve the magnification provided in Example 1.
[0030] Figure 3 Shown is a schematic diagram of the displacement calculation formula principle.
[0031] Figure 4 The figure shows a schematic diagram of the measurement principle of a displacement sensor with a structure that can improve the amplification factor provided in Example 2.
[0032] Figure 5 The figure shows a schematic diagram of the measurement principle of a displacement sensor with a structure that can improve the amplification factor provided in Example 3.
[0033] Figure 6 The figure shows a schematic diagram of the measurement principle of another structure of a displacement sensor with improved amplification factor provided in Example 3.
[0034] Description of the numbers in the figure:
[0035] Laser source 1, laser beam 2, triangular wave reflector 3, reflective surface 31, reflector group 4, reflector 41, photodetector 5, housing 6. DETAILED DESCRIPTION
[0036] 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 used 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 belong to the protection scope of the present invention.
[0037] Example 1
[0038] See also Figure 1 In this embodiment, a displacement sensor with improved magnification is provided, including a laser source 1, a laser beam 2, a triangular wave reflector 3, the triangular wave reflector 3 including a reflecting surface 31, a reflector group 4, the reflector group 4 including a reflector 41, a photodetector 5, and a housing 6.
[0039] In the novel displacement sensor capable of increasing the magnification:
[0040] The laser source 1 emits a laser beam 2 and directs the laser beam 2 toward the first reflection surface 31 of the triangular wave reflector 3; the first reflector 41 of the reflector group 4 corresponding to the first reflection surface 31 is used to receive the laser beam 2 reflected by the first reflection surface 31 of the triangular wave reflector 3, and makes the laser beam reflect along the same path to the second reflection surface 31 of the triangular wave reflector 3 during the measurement process of the laser beam 2 incident on the first reflection surface 31; the second reflector 41 corresponding to the second reflection surface is used to receive the laser beam reflected by the second reflection surface 31 of the triangular wave reflector, and makes the laser beam reflect to the third reflection surface 31 of the triangular wave reflector 3; the photoelectric detector 5 is used to receive the laser beam 2 reflected by the second reflector to the third reflection surface 31 of the triangular wave reflector 3 and then reflected by the third reflection surface 31, and measure its incident position; the processing system is used to calculate the displacement change value of the object to be measured according to the incident position change of the laser beam 2 received by the photoelectric detector 5.
[0041] In order to ensure the amplification performance of the displacement sensor that can improve the amplification factor, the angle between the laser beam incident on the photodetector 5 and the photodetector 5 is preferably less than 45 degrees.
[0042] like Figure 1 As shown, the photodetector 5 adopts PSD, the laser beam 2 before displacement is represented by a solid line, the laser beam 2 after displacement is represented by a dotted line, and the transmission path of the laser beam 2 is as follows:
[0043] Before displacement, the laser source 1 emits a laser beam 2, and directs the laser beam 2 toward the first reflection surface 31 of the triangular wave reflector 3; the first reflector 41 of the reflector group 4 corresponding to the first reflection surface 31 is used to receive the laser beam 2 reflected by the first reflection surface 31 of the triangular wave reflector 3, and makes the laser beam be reflected along the same path to the second reflection surface 31 of the triangular wave reflector 3 during the measurement process of the laser beam 2 incident on the first reflection surface 31; the second reflector 41 corresponding to the second reflection surface is used to receive the laser beam reflected by the second reflection surface 31 of the triangular wave reflector, and makes the laser beam be reflected to the third reflection surface 31 of the triangular wave reflector 3; the photoelectric detector 5 is used to receive the laser beam 2 reflected by the second reflector to the third reflection surface 31 of the triangular wave reflector 3 and then reflected by the third reflection surface 31, and measure its incident position; this time is recorded as the first incident position.
[0044] After displacement ( Figure 1 , it is shown as shifting to the left, during which the laser source 1, the reflector group 4 and the photoelectric detector 5 are synchronously shifted), the laser source 1 emits a laser beam 2, and directs the laser beam 2 toward the first reflective surface 31 of the triangular wave reflector 3; the first reflector 41 of the reflector group 4 corresponding to the first reflective surface 31 is used to receive the laser beam 2 reflected by the first reflective surface 31 of the triangular wave reflector 3, and makes the laser beam be reflected along the same path to the second reflective surface 31 of the triangular wave reflector 3 during the measurement process of the laser beam 2 being incident on the first reflective surface 31; the second reflector 41 corresponding to the second reflective surface is used to receive the laser beam reflected by the second reflective surface 31 of the triangular wave reflector, and makes the laser beam be reflected to the third reflective surface 31 of the triangular wave reflector 3; the photoelectric detector 5 is used to receive the laser beam 2 reflected by the second reflector to the third reflective surface 31 of the triangular wave reflector 3 and then reflected by the third reflective surface 31, and measure its incident position; this is recorded as the second incident position. The displacement of the laser source 1, that is, the displacement of the object to be measured, can be calculated based on the first incident position and the second incident position. The calculation process can be obtained based on the trigonometric relationship, such as Figure 3 As shown, θ is the angle between the laser beam incident on the photodetector and the photodetector, and δ is the acute angle between the photodetector and the displacement direction of the object being measured.
[0045] As a preferred implementation method, Figure 1As shown, the angle between the reflecting surface 31 of the triangular wave reflector 3 and the horizontal plane is 150 degrees (taking the horizontal right as the positive direction and rotating in the counterclockwise direction as an example). There can be other different settings while ensuring that the first reflector 41 of the reflector group 4 receives the laser beam 2 reflected by the first reflective surface 31 of the triangular wave reflector 3, and makes the laser beam be reflected along the same path to the second reflective surface of the triangular wave reflector 3 during the measurement process of the laser beam 2 incident on the same reflective surface 31; the reflector 41 corresponding to the second reflective surface receives the laser beam reflected by the second reflective surface of the triangular wave reflector, and makes the laser beam reflect to the third reflective surface of the triangular wave reflector.
[0046] For example, Figure 2 As shown, the following method can be used to realize that the first reflector 41 of the reflector group 4 is used to receive the laser beam 2 reflected by the first reflective surface 31 of the triangular wave reflector 3, and the laser beam is reflected along the same path to the second reflective surface of the triangular wave reflector 3 during the measurement process of the laser beam 2 incident on the same reflective surface 31; the reflector 41 corresponding to the second reflective surface is used to receive the laser beam reflected by the second reflective surface of the triangular wave reflector, and the laser beam is reflected to the third reflective surface of the triangular wave reflector: the reflector is parallel to the reflective surface, and the acute angle between the laser beam 2 and the first reflective surface 31 is equal to twice the angle between the reflective surface 31 and the horizontal plane, that is, Figure 2 The angle 1 indicated in the figure is equal to the angle 2.
[0047] like Figure 2 It can be seen that for the triangular wave reflector 3, as long as the reflecting surfaces are parallel to each other (that is, the angles with the horizontal plane are consistent), its specific structure is not limited, that is, there is no limit on the angle between the two reflecting surfaces forming the triangular wave, for example Figure 2 As shown in the figure, the angle between the two reflecting surfaces is 120 degrees; Figure 3 As shown in , the angle between the two reflection surfaces is 150 degrees, etc. Moreover, the triangular wave does not necessarily need to be an isosceles triangular wave, that is, the acute angles between the two reflection surfaces forming the triangular wave and the horizontal plane can be equal or unequal.
[0048] The displacement sensor capable of improving magnification may further include a housing 6, wherein the laser source 1, the reflector group 4 and the photodetector 5 are all fixedly disposed in the housing 6 to form a reading head, and the laser beam 2 emitted by the laser source 1 and its reflected beam may both pass through the transceiver end face of the reading head. The laser source 1, the reflector group 4 and the photodetector 5 are all fixedly disposed in the housing 6, and their positions may be kept fixed, and synchronous displacement of the three may also be ensured.
[0049] During measurement, according to the actual application situation, the triangular wave reflector 3 can be fixed on the object to be measured, and the reading head can be kept fixed. When the object to be measured is displaced, the triangular wave reflector 3 and the reading head move relative to each other, and the reading head can measure the displacement value of the triangular wave reflector 3, that is, the object to be measured; or, the reading head can be fixed on the object to be measured, the triangular wave reflector 3 can be kept fixed, the displacement of the object to be measured drives the reading head to move, and the reading head and the triangular wave reflector 3 are relatively displaced, and the reading head can measure the relative displacement between the reading head and the triangular wave reflector 3, and then obtain the displacement value of the object to be measured; during measurement, the triangular wave reflector 3 or the reading head is selected to be fixed on the object to be measured, which improves the convenience of measurement.
[0050] Based on the above displacement sensor capable of improving the magnification, the measurement method thereof comprises the following steps:
[0051] Fix the object to be measured on the triangular wave reflector or reading head;
[0052] Adjust the positional relationship between the laser beam, the triangular wave reflector, the photoelectric detector, and the reflector group, so that the first reflector in the reflector group receives the laser beam reflected by the corresponding 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 of the laser beam incident on the first reflective surface; the second reflector corresponding to the second reflective surface is used to receive the laser beam reflected by the second reflective surface of the triangular wave reflector, and the laser beam is reflected to the third reflective surface of the triangular wave reflector, and the photoelectric detector can receive the laser beam reflected by the second reflector to the third reflective surface of the triangular wave reflector and then reflected by the third reflective surface, and measure its incident position;
[0053] A laser beam is emitted, and after the laser beam is reflected multiple times between the reflective mirror and the reflective surface of the triangular wave reflective mirror, its initial incident position is detected by a photoelectric detector;
[0054] The object being measured moves. During the movement, the photoelectric detector detects the change in the incident position of the laser beam until the object being measured stops moving.
[0055] The processing system calculates the displacement value of the object being measured through the change in the incident position of the laser beam detected by the photoelectric detector.
[0056] Example 2
[0057] See also Figure 4 ,like Figure 4 As shown, the displacement sensor capable of improving the magnification in this embodiment is different from the displacement sensor capable of improving the magnification in Embodiment 1 in that: the multiple reflectors in this embodiment are directly connected to form a straight-line structure as a whole.
[0058] Example 3
[0059] See also Figure 5 The displacement sensor with improved magnification in this embodiment is different from the displacement sensor with improved magnification in Example 2 in that: the displacement sensor with improved magnification provided in this embodiment includes two reading heads, the two reading heads have the same structure and are symmetrically placed.
[0060] The displacement sensor with improved magnification 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 of the laser beams is located at certain positions of the reflection surface, such as the top of the reflection surface, the intersection position of the two reflection surfaces, etc., the length of the corresponding photodetector is limited, so it may not be reflected to the corresponding photodetector, and the photodetector cannot calculate its displacement value. The reflection point of the other laser beam is located at other positions of the other reflection surface, which can be reflected to the corresponding photodetector and can be converted and measured. It can be realized that at every moment when the measured object moves, at least one of the laser beams reflected by each reflection surface 31 on the triangular wave reflector 3 can be reflected to the corresponding photodetector. At this time, the processing system can switch back and forth to calculate the position change of the reflected laser beams of the two photodetectors, and perform superposition and accumulation to realize the measurement of the one-time change or continuous incremental displacement change of the measured object. The measurement method is simple, reliable, easy to operate, and can improve the measurement accuracy.
[0061] When the displacement sensor capable of improving the magnification described in this embodiment is used for measurement, the steps are as follows:
[0062] Fix the object to be measured on the triangular wave reflector or reading head;
[0063] Adjust the positional relationship between the laser beam, the triangular wave reflector, the photoelectric detector, and the reflector group, so that the first reflector in the reflector group receives the laser beam reflected by the corresponding reflective surface group 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 of the laser beam incident on the first reflective surface; the second reflector corresponding to the second reflective surface is used to receive the laser beam reflected by the second reflective surface of the triangular wave reflector, and the laser beam is reflected to the third reflective surface of the triangular wave reflector, and the photoelectric detector can receive the laser beam reflected by the second reflector to the third reflective surface of the triangular wave reflector and then reflected by the third reflective surface, and measure its incident position; when the photoelectric detector cannot receive the reflected laser beam, switch to another reading head and repeat the above operation process;
[0064] A laser beam is emitted, and after the laser beam is reflected multiple times between the reflective mirror and the reflective surface of the triangular wave reflective mirror, its initial incident position is detected by a photoelectric detector;
[0065] The object being measured moves. During the movement, the photoelectric detector detects the change in the incident position of the laser beam until the object being measured stops moving.
[0066] The processing system calculates the displacement value of the object being measured through the change in the incident position of the laser beam detected by the photoelectric detector.
[0067] It is easy to understand that in this embodiment, the purpose of setting two reading heads 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. Figure 5 In addition to the arrangement shown in the figure, there may be other arrangements, as long as the two reading heads are staggered so that the initial incident points of the laser beams in the two reading heads incident on the reflecting surface of the triangular wave reflector are at different positions, it is possible to achieve that when one group of photoelectric detectors cannot receive the laser beam, the laser beam can be received by the other group of photoelectric detectors.
[0068] At the same time, combined Figure 6 , Figure 6 Another structure provided in this embodiment is shown, which includes three reading heads. It is easy to understand that the number and placement of the reading heads are not limited as long as the photoelectric detectors of at least one group of reading heads receive the incident position of the laser beam.
[0069] Similarly, the displacement sensor described in Example 1 may also be provided with one or more measurement systems (reading heads) to achieve continuous measurement.
[0070] Although the displacement sensing devices with magnification provided in the above-mentioned embodiments have three reflective surfaces and two reflective mirrors, it is easy to understand that the number of reflective surfaces and reflective mirrors can be more. When there are more reflective mirrors and reflective surfaces, multiple reflective mirrors and reflective surfaces are arranged in sequence along the moving direction. Under the condition that the reflector corresponds to at least one reflective surface, the reflector is used to receive the laser beam reflected by the corresponding reflective surface and reflect the laser beam; the reflective surface is used to receive the laser beam emitted by the laser source or reflected by the reflector and reflect the laser beam, the number of reflective surfaces and reflective mirrors is not limited.
[0071] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A displacement sensor capable of increasing magnification, characterized in that: include: A triangular wave reflector, comprising at least three reflective surfaces, wherein the at least three reflective surfaces are sequentially distributed along the moving direction; A laser source, used for emitting a laser beam, wherein the laser beam is incident on a reflecting surface of the triangular wave reflector; A reflector group, comprising at least two reflectors, wherein the at least two reflectors are sequentially distributed along a moving direction; Each of the reflectors corresponds to at least one of the reflective surfaces, and the reflector is used to receive the laser beam reflected by the corresponding reflective surface and reflect the received laser beam again; The reflecting surface is used to receive the laser beam emitted by the laser source or the laser beam reflected by the reflecting mirror, and to reflect the received laser beam again; The reflector is parallel to the reflective surface, and the acute angle formed by the laser beam emitted by the laser source and the reflective surface is equal to twice the angle between the reflective surface and the horizontal plane; A photoelectric detector, used for receiving the laser beam reflected by the reflection surface and no longer received by the reflection mirror group, and measuring its incident position; A processing system, used to calculate the displacement change value of the object to be measured according to the incident position change amount of the laser beam received by the photoelectric detector; At least two reading heads, and the positional relationship between the two reading heads satisfies: during the measurement process, at least one reading head can read the change in the incident position of the laser beam on the photoelectric detector; The measuring method of the displacement sensor comprises the following steps: fixing the measured object on a triangular wave reflector or a reading head; adjusting the positional relationship of a laser source, a triangular wave reflector, a photoelectric detector and a reflector group, so that a laser beam emitted by the laser source is incident on a reflective surface of the triangular wave reflector, and is incident on a corresponding reflector after being reflected by the reflective surface, the reflector receives the laser beam reflected by the corresponding reflective surface of the triangular wave reflector, and reflects the received laser beam to the next reflective surface of the triangular wave reflector, and the laser beam is finally incident on the photoelectric detector after being reflected multiple times between the reflector and the reflective surface of the triangular wave reflector; emitting a laser beam, wherein the laser beam is reflected multiple times between the reflective mirror and the reflective surface of the triangular wave reflective mirror, and then its initial incident position is detected by a photoelectric detector; The object being measured moves. During the displacement process, the photoelectric detector detects the change in the incident position of the laser beam until the object being measured stops moving. The processing system calculates the displacement value of the object being measured through the change in the incident position of the laser beam detected by the photoelectric detector.
2. The displacement sensor with improved magnification according to claim 1, characterized in that: The at least two reflectors are parallel to each other, and every two reflectors are connected by a transition portion, forming a sawtooth structure as a whole.
3. The displacement sensor with improved magnification according to claim 1, characterized in that: The at least two reflectors are directly connected to form a straight-line structure as a whole.
4. The displacement sensor capable of improving magnification according to any one of claims 1 to 3, characterized in that: It also includes a shell, in which the laser source, the reflector group and the photoelectric detector are fixedly arranged to form a reading head.