Angle measurement sensor and calibration method and measurement method thereof

Abstract

The present invention relates to an angle measurement sensor and a calibration method and a measurement method thereof. The angle measurement sensor comprises: a laser for emitting a laser beam; a reflector that can rotate synchronously with the object to be measured, for receiving the laser beam emitted by the laser and reflecting the laser beam to a refractor; the refractor is used to refract the laser beam reflected by the reflector and emit it; a photoelectric detector for receiving the laser beam refracted from the refractor and measuring its incident position; a processing system for calculating the rotation angle of the object to be measured according to the incident position change of the laser beam received by the photoelectric detector. The sensor refracts the reflected laser beam through the refractor to amplify the change of the reflection angle before and after the rotation, and finally calculates the rotation angle of the object to be measured through the change of the incident position of the laser on the photoelectric detector.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to an angle measurement sensor and a calibration method and a measurement method thereof. Background Art

[0002] At present, in the field of high-precision measurement of small angles, optical methods are widely used for measurement, such as optical dividing head method, polyhedron method, diffraction method, autocollimation method, fiber optic method, acousto-optic modulation method, optical internal reflection method, laser interferometry method, ring laser method, etc. However, such methods have a small measurement range, high cost, and relatively complex structure. Summary of the invention

[0003] The purpose of the present invention is to improve the deficiencies in the prior art and provide an angle measurement sensor.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] An angle measurement sensor, comprising:

[0006] A laser for emitting a laser beam;

[0007] A reflector that can rotate synchronously with the object to be measured, and is used to receive the laser beam emitted by the laser and reflect the laser beam to the refraction mirror;

[0008] The refractor is used to refract the laser beam reflected by the reflector and emit it;

[0009] a photoelectric detector, used for receiving the laser beam refracted from the refractor and measuring its incident position;

[0010] The processing system is used to calculate the rotation angle of the object to be measured according to the change in the incident position of the laser beam received by the photoelectric detector.

[0011] In a further solution, the reflector is mounted on the object to be measured, ensuring that the rotation angles of the reflector and the object to be measured are consistent.

[0012] In a further solution, the laser beam is incident on the rotation midpoint of the reflector, ensuring that the laser beam is incident on the same point on the reflector, and preventing the laser beam from incident on different points on the reflector under the same optical path, thereby causing deviation in angle measurement.

[0013] In a further embodiment, the refractor is a prism.

[0014] In a further embodiment, the prism includes prism surface one and prism surface two, the laser beam is incident on prism surface one and refracted; prism surface two receives the laser beam refracted by prism surface one, causes the laser beam to be refracted again, and causes the laser beam to be emitted from prism surface two.

[0015] In a further embodiment, the prism surface one is connected to the prism surface two, and the angle between the prism surface one and the prism surface two is an acute angle.

[0016] In a further solution, the angle at which the laser beam is incident on the first prism surface is an acute angle, so as to ensure that the laser beam is refracted twice in the prism with a non-zero refraction angle, thereby amplifying the position change twice.

[0017] On the other hand, the present invention also proposes a method for calibrating the position change and rotation angle of the above-mentioned angle measurement sensor, the steps of which are as follows:

[0018] Step 1:

[0019] A reflector is arranged on the object to be measured so that the reflector can run synchronously with the object to be measured;

[0020] Step 2:

[0021] Adjust the positional relationship between the laser, the reflector, the refractor and the photoelectric detector, so that the laser beam emitted by the laser is incident on the reflector, reflected by the reflector, incident on the refractor, and refracted by the refractor to be received by the photoelectric detector, while ensuring that the laser incident point is at the same position during the rotation of the reflector;

[0022] Step 3:

[0023] Given the rotation angles α1, α2, α3…αn, the position change of the photodetector at the corresponding rotation angle is recorded, and the formula of the rotation angle and the position change of the photodetector is obtained by nonlinear fitting.

[0024] On the other hand, the present invention also provides a measurement method of the above angle measurement sensor, comprising the following steps:

[0025] A reflector is arranged on the object to be measured so that the reflector can run synchronously with the object to be measured;

[0026] Adjust the positional relationship between the laser, the reflector, the refractor and the photoelectric detector, so that the laser beam emitted by the laser is incident on the reflector, reflected by the reflector, incident on the refractor, and received by the photoelectric detector after being transmitted by the refractor, while ensuring that the laser incident point is at the same position during the rotation of the reflector;

[0027] The object to be measured rotates, and during the rotation, the laser beam emitted by the laser is transmitted along the same optical path to the same position of the reflector, and is reflected by the reflector to the prism;

[0028] The rotation angle of the object being measured is calculated according to the position change of the incident light received by the photoelectric detector during operation.

[0029] Compared with the prior art, the present invention has the following beneficial effects: the present invention uses different incident angles of the same laser beam on the same reflector to obtain different reflection angles, and refracts the reflected laser beam through a refracting mirror to amplify the change in the reflection angle before and after the rotation, and finally calculates the rotation angle of the object being measured through the change in the incident position of the laser on the photoelectric detector. The present invention has a simple measurement structure, low cost, and significantly improved measurement accuracy compared to traditional methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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 related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of the structure of an angle measurement sensor provided in Embodiment 1 of the present invention;

[0032] Figure 2 A schematic diagram of an angle measurement sensor provided in Embodiment 1 of the present invention;

[0033] Description of symbols in the figure

[0034] Laser 1, laser beam 2, reflecting mirror 3, refracting mirror 4, photodetector 5, prism surface 1 41, prism surface 2 42. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0036] See also Figure 1This embodiment schematically discloses an angle measurement sensor, including: a laser 1, a laser beam 2, a reflector 3, a refractor 4, and a photodetector 5. In this solution, the laser 1 is used to emit a laser beam 2; the reflector 3 that can rotate synchronously with the object to be measured is used to receive the laser beam 2 emitted by the laser 1 and reflect the laser beam 2 to the refractor 4; the refractor 4 is used to refract the laser beam 2 reflected by the reflector 3 and emit it; the photodetector 5 is used to receive the laser beam 2 refracted from the refractor 4 and measure its incident position. The processing system is used to calculate the rotation angle of the object to be measured according to the change in the incident position of the laser beam 2 received by the photodetector 5.

[0037] In a further embodiment, the refractor 4 is a prism.

[0038] Furthermore, the prism includes a prism surface 1 41 and a prism surface 2 42. The laser beam 2 enters the prism surface 1 41 of the refractor 4 and is refracted. When the refracted laser beam 2 enters the prism surface 2 42, the prism surface 2 42 causes the laser to be refracted again and the laser beam 2 is emitted from the prism surface 2 42.

[0039] Its principle is as follows Figure 2 As shown, the laser beam is refracted twice by a prism, so that the receiving position distance of the laser beam on the photoelectric detector is amplified, so that the rotation angle change of the measured object is amplified, and the measuring arm is reduced while improving the angle measurement accuracy.

[0040] like Figure 1 As shown, the arrow direction is the rotation direction of the measured object and the reflector. In addition, the photoelectric sensor uses PSD. The reflector and the laser beam before rotation are represented by solid lines, and the reflector and the laser beam after rotation are represented by dotted lines. The laser beam transmission path is as follows:

[0041] Before the rotation, the laser 1 emits a laser beam 2, which is reflected by the reflection surface 3 to the prism surface 1 41 of the refractor 4, and refracted, and incident on the prism surface 2 42. The prism surface 2 42 causes the laser beam 2 to be refracted again and incident on the photodetector 5. The photodetector 5 receives the laser beam 2 refracted and emitted by the prism surface 2 42, and measures its incident position, which is recorded as the first incident position at this time.

[0042] After the rotation, the laser 1 emits a laser beam 2, which is reflected by the reflection surface 3 to the prism surface 1 41 of the refractor 4, and refracted to be incident on the prism surface 2 42. The prism surface 2 42 causes the laser beam 2 to be refracted again and incident on the photodetector 5. The photodetector 5 receives the laser beam refracted and emitted by the prism surface 2 42, and measures its incident position, which is recorded as the second incident position.

[0043] The position change of the incident light can be obtained according to the first incident position and the second incident position, and the rotation angle of the measured object can be calculated.

[0044] Since the rotation angle and the position change amount are in a nonlinear relationship, the present invention also proposes a method for calibrating the position change amount and the rotation angle of the above-mentioned angle measurement sensor, and the steps are as follows:

[0045] Step 1:

[0046] A reflector is arranged on the object to be measured so that the reflector can run synchronously with the object to be measured;

[0047] Step 2:

[0048] Adjust the positional relationship between the laser, the reflector, the refractor and the photoelectric detector, and ensure that the laser incident point is at the same position during the rotation of the reflector, so that the laser beam emitted by the laser is incident on the reflector, reflected by the reflector, incident on the refractor, and received by the photoelectric detector after passing through the prism refractor;

[0049] Step 3:

[0050] Given the rotation angles α1, α2, α3…αn, the position change of the photodetector under the corresponding rotation angle is recorded, and the formula of the rotation angle and the position change of the photodetector is obtained by nonlinear fitting.

[0051] As a preferred implementation, the laser beam 2 is incident on the rotation midpoint of the reflector 3. This ensures that the laser beam 2 is incident on the same point on the reflector 3, preventing the laser beam 2 from incident on the reflector 3 at different points under the same optical path, thereby causing deviation in angle measurement.

[0052] As a preferred implementation, the reflector 3 is mounted on the object to be measured, and the rotation angles of the reflector 3 and the object to be measured are ensured to be consistent.

[0053] As a preferred embodiment, the prism surface 1 41 is connected to the prism surface 2 42, and the angle between the prism surface 1 41 and the prism surface 2 42 is an acute angle. Under the condition that the laser beam 2 is incident on the refractor 4, the refractor 4 refracts the laser beam 2, and after being emitted, the laser beam 2 can still be incident on the photodetector 5, the angle between the prism surface 1 41 and the prism surface 2 42 is not limited.

[0054] As a preferred embodiment, the angle at which the laser beam 2 is incident on the prism surface 1 41 is an acute angle. Thus, the position change is amplified twice. Under the condition that the laser beam 2 is refracted twice in the refraction mirror 4 at a non-zero refraction angle, the angle at which the laser beam 2 is incident on the prism surface 1 41 is not limited.

[0055] The angle measurement sensor provided in the above embodiment is implemented based on a refractor. The entire angle measurement sensor has a simple structure, low cost and high measurement accuracy.

[0056] Based on the above angle measurement sensor, the measurement method includes the following steps:

[0057] A reflector is arranged on the object to be measured so that the reflector can run synchronously with the object to be measured;

[0058] Adjust the positional relationship between the laser, the reflector, the refractor and the photoelectric detector, so that the laser beam emitted by the laser is incident on the reflector, reflected by the reflector, incident on the refractor, and received by the photoelectric detector after being transmitted by the refractor, while ensuring that the laser incident point is at the same position during the rotation of the reflector;

[0059] The object to be measured rotates, and during the rotation, the laser beam emitted by the laser is transmitted along the same optical path to the same position of the reflector, and is reflected by the reflector to the prism;

[0060] The rotation angle of the object being measured is calculated according to the position change of the incident light received by the photoelectric detector during operation.

[0061] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An angle measurement sensor, characterized in that: include: A laser for emitting a laser beam; A reflector that can rotate synchronously with the object to be measured, and is used to receive the laser beam emitted by the laser and reflect the laser beam to the refraction mirror; the laser beam is incident on the rotation midpoint of the reflector; The refractor is used to refract the laser beam reflected by the reflector and emit it; the refractor is a prism; the prism includes a prism surface 1 and a prism surface 2, the laser beam is incident on the prism surface 1 and refracted; the prism surface 2 receives the laser beam refracted by the prism surface 1, and refracts the laser beam again, and emits the laser beam from the prism surface 2; the prism surface 1 is connected to the prism surface 2, and the angle between the prism surface 1 and the prism surface 2 is an acute angle; the angle at which the laser beam is incident on the prism surface 1 is an acute angle; a photoelectric detector, used for receiving the laser beam refracted from the refractor and measuring its incident position; The processing system is used to calculate the rotation angle of the object to be measured according to the change in the incident position of the laser beam received by the photoelectric detector.

2. The angle measurement sensor according to claim 1, characterized in that: The reflector is installed on the object to be measured.

3. The method for calibrating the position change and rotation angle of an angle measurement sensor according to any one of claims 1-2, characterized in that: Here are the steps: Step 1: Arrange a reflector on the object to be measured so that the reflector can run synchronously with the object to be measured; Step 2: Adjust the positional relationship between the laser, the reflector, the refractor and the photoelectric detector, and ensure that the laser incident point is at the same position during the rotation of the reflector, so that the laser beam emitted by the laser is incident on the reflector, reflected by the reflector, incident on the refractor, and refracted by the refractor to be received by the photoelectric detector; Step 3: Given the rotation angles α1, α2, α3…αn, record the position change of the photodetector at the corresponding rotation angle, and obtain the formula of the rotation angle and the position change of the photodetector through nonlinear fitting.

4. The measuring method of the angle measuring sensor according to any one of claims 1 to 3, characterized in that: The following steps are involved: A reflector is arranged on the object to be measured so that the reflector can run synchronously with the object to be measured; Adjust the positional relationship between the laser, the reflector, the refractor and the photoelectric detector, so that the laser beam emitted by the laser is incident on the reflector, reflected by the reflector, incident on the refractor, and refracted by the refractor to be received by the photoelectric detector, while ensuring that the laser incident point is at the same position during the rotation of the reflector; The object to be measured rotates, and during the rotation, the laser beam emitted by the laser is transmitted along the same optical path to the same position of the reflector, and is reflected by the reflector to the refracting mirror; The rotation angle of the object being measured is calculated according to the position change of the incident light received by the photoelectric detector during operation.

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