Angle sensor based on hyperbolic lens and its measurement method

Abstract

The present invention provides an angle sensor based on a hyperbolic lens and a measurement method thereof, wherein the angle sensor comprises a photodetector 1 and a photodetector 2, a hyperbolic lens 1 and a hyperbolic lens 2, wherein the hyperbolic lens 1 is arranged between the photodetector 1 and the transmission component, and during the measurement process in which a light beam is transmitted from a light-transmitting hole to the same photodetector, the light beam emitted from the light-transmitting hole is incident on the hyperbolic lens 1, and after being transmitted by the hyperbolic lens 1, is incident on the photodetector 1; a processing system processes and obtains the rotation angle value of the measured object according to the incident position change value of the light beam received on the photodetector 1 and / or the photodetector 2. The novel angle sensor can not only realize continuous angle measurement, but also has high precision and fast calculation speed.

Description

Technical Field

[0001] The present invention relates to the field of precision testing technology, and in particular to an angle sensor based on a hyperbolic lens and a measuring method thereof. Background Art

[0002] Angle sensor is a commonly used geometric sensor, which is widely used in many fields such as aerospace, industrial production, mechanical manufacturing and military science. Figure 1 As shown in the figure, the Chinese patent with the patent number of 201510276409.0 and the name of "a continuous incremental optical arm amplification type high-precision angle sensor" discloses an angle sensor with a simple structure, suitable for measuring the continuous incremental changes in the angle of the object being measured, reliable measurement, and easy to achieve batch production. According to the basic principle of optical arm amplification type continuous angle measurement, the calculation process of the angle sensor is complex and time-consuming, and there are nonlinear errors in the system, resulting in limited measurement accuracy. Summary of the invention

[0003] The object of the present invention is to provide an angle sensor based on a hyperbolic lens and a measurement method thereof, which can further improve the measurement accuracy and calculation speed.

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

[0005] An angle sensor based on a hyperbolic lens, comprising:

[0006] a light source for emitting a light beam;

[0007] A transmission component, the transmission component is used to connect with the object to be measured, the transmission component is rotatable and has a plurality of light-transmitting holes along the circumferential direction, the transmission component has a hollow part, the light source is located in the hollow part and at the center of the transmission component, and the position is fixed, and the light beam emitted by the light source is transmitted through the light-transmitting holes;

[0008] Photodetector 1 and photodetector 2, hyperbolic lens 1 and hyperbolic lens 2,

[0009] The hyperbolic lens 1 is arranged between the photodetector 1 and the transmission component. In the measurement process of the light beam being transmitted from the light-transmitting hole to the same photodetector, the light beam emitted from the light-transmitting hole is incident on the hyperbolic lens 1, and is incident on the photodetector 1 after being transmitted through the hyperbolic lens 1.

[0010] The second hyperbolic lens is disposed between the second photodetector and the transmission component. During the measurement process in which the light beam is transmitted from the light-transmitting hole to the same photodetector, the light beam emitted from the light-transmitting hole is incident on the second hyperbolic lens, and is incident on the second photodetector after being transmitted by the second hyperbolic lens.

[0011] The photodetector 1 and the photodetector 2 receive the light beams transmitted from the hyperbolic lens 1 and the hyperbolic lens 2 respectively, and display the incident positions thereof, and during the measurement process, at least one of the photodetector 1 and the photodetector 2 can receive the light beam;

[0012] In the above scheme, by arranging a hyperbolic lens between the photodetector and the transmission component, a linear relationship between the rotation angle of the transmission component and the position of the light spot can be achieved, thereby eliminating nonlinear errors and improving the measurement accuracy of the angle sensor.

[0013] In a further optimized solution, the transmission component includes an integrally formed transmission part and a positioning part, the transmission part is provided with the plurality of light-transmitting holes along the circumferential direction, and the object to be measured is fixed to the positioning part. By setting the transmission component as a component in which the transmission part and the positioning part are integrally formed, the positioning part can be operated (for example, clamped) during assembly to achieve positioning between the transmission component and components such as the photodetector and the light source, and the object to be measured and the light source are respectively located at different positions of the transmission component, and mutual influence between the object to be measured and the light source can also be avoided.

[0014] In a further optimized solution, the positioning portion is a regular polygonal column or a cylinder. The regular polygonal column structure itself has a strong positioning effect, which can better realize the positioning between the emitting component and the photoelectric detector, light source and other components.

[0015] In a further optimized solution, the hollow portion is formed by a cylindrical through hole arranged along the axial direction of the transmission portion. Such an arrangement allows the light-transmitting holes to be distributed along the cylindrical hole wall, thereby achieving better angle measurement.

[0016] In a further optimized solution, the transmission part and the positioning part are regular polygonal columns or cylinders of the same shape. Such a configuration is convenient for production, that is, the transmission component is an integral structure, and only the column needs to be divided into two parts along the axial direction, and each side of the upper part is provided with a light-transmitting hole, so as to form the transmission part.

[0017] In a further optimized solution, the transmission component is provided with a mounting hole for easy connection with the object to be measured, and the mounting hole is located at the positioning portion.

[0018] In a further optimized solution, a light absorbing material layer is provided in the non-light-transmitting hole area of ​​the inner wall of the transmission component. By providing the light absorbing material layer, the light beam that is not transmitted out can be absorbed to prevent the light beam from being reflected back to the light source.

[0019] On the other hand, the present invention also provides a measurement method of the above-mentioned angle sensor based on the hyperbolic lens, comprising the following steps:

[0020] Connecting the transmission component to the object to be measured so that the transmission component can rotate with the rotation of the object to be measured;

[0021] Adjust the positional relationship between the light beam, the reflective component, the photodetector 1, the photodetector 2, the hyperbolic lens 1 and the hyperbolic lens 2, so that the light beam emitted from a light transmission hole is incident on the hyperbolic lens 1, is transmitted through the hyperbolic lens 1 and is incident on the photodetector 1, and / or the light beam emitted from a light transmission hole is incident on the hyperbolic lens 2, is transmitted through the hyperbolic lens 2 and is incident on the photodetector 2;

[0022] Emits a light beam, the light beam is transmitted through one or more light-transmitting holes of the reflective component, and the photodetector 1 and / or the photodetector 2 detects an initial position of the light beam emitted from one of the light-transmitting holes;

[0023] The object to be measured rotates, and during the rotation process, the photodetector 1 and / or the photodetector 2 detects a change in the incident position of the light beam emitted from one of the light-transmitting holes on the respective detectors until the object to be measured stops rotating;

[0024] The processing system obtains the rotation angle value of the object to be measured by processing the incident position change value of the laser beam 1 received on the photoelectric detector 1 and / or the incident position change value of the laser beam 2 received on the photoelectric detector 2.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] By setting the light source at the center of the transmission component and providing a number of light-transmitting holes on the transmission component, the light beam emitted by the light source can be directly transmitted out and received by the photodetector. Compared with the reflection method, the calculation process is simplified, the calculation speed is improved, and the structure of the entire device is also simplified.

[0027] By setting the hyperbolic lens 1 and the hyperbolic lens 2, it is possible to achieve a linear relationship between the rotation angle of the transmission component and the position of the light spot, thereby eliminating nonlinear errors and improving the measurement accuracy of the angle sensor.

[0028] By mounting the measured object on the transmission component, the transmission component rotates together with the measured object when the measured object rotates. By measuring the changes in the incident position points of the light beams transmitted from different light-transmitting holes on the transmission component during the rotation process and located on the photodetector 1 and the photodetector 2 respectively, the processing system can calculate the change value of the rotation angle of the measured object according to the changes in the incident position of the light beams on the two photodetectors. The sensor has a simple structure, is suitable for measuring the continuous incremental changes in the angle of the measured object, has reliable measurement, and is easy to achieve batch production.

[0029] Two critical points are set on both photodetector 1 and photodetector 2 to detect the rotation angle of the corresponding light-transmitting hole. The cooperation of the two photodetectors can always detect the position of one of the light beams transmitted by the light-transmitting hole of the transmission component to the corresponding photodetector; for example, when the light beam is emitted from one light-transmitting hole and exceeds the detection range of the two critical points on photodetector 1, the light beam is emitted from the other light-transmitting hole and enters the detection range of the two critical points on photodetector 2. The processing system can switch its detection results to calculate the rotation angle of the object being measured, and the calculation is simpler and more convenient. 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 relevant drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 The present invention is a schematic diagram of measuring the rotation angle of an object by using a continuous incremental optical arm amplification type angle sensor in the prior art.

[0032] Figure 2 Schematic diagram of the angle sensor provided in the embodiment.

[0033] Figure 3 It is a schematic diagram of the structure of the transmission component.

[0034] Figure 4 Schematic diagram of the light path of a light beam emitted by the same light source after passing through different positions of a hyperbolic lens.

[0035] Figure 5 Schematic diagram of the positional relationship between the light source and the photodetector.

[0036] Figure 6 Schematic diagram of the relationship between the angle of a line laser and the receiving angles of photodetector 1 and photodetector 2.

[0037] Description of the numbers in the figure:

[0038] 1-light source, 2-light beam 2, 3-hyperbolic lens 1, 4-hyperbolic lens 2, 5-transmission component, 6-light transmission hole, 7-photodetector 1, 8-photodetector 2, 9-hollow part, transmission part 51, positioning part 52. DETAILED DESCRIPTION

[0039] 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.

[0040] like Figure 2 As shown, this embodiment provides an angle sensor based on a hyperbolic lens, including a light source 1, a hyperbolic lens 1 3, a hyperbolic lens 2 4, a transmission component 5, a photodetector 1 7, a photodetector 2 8 and a processing system.

[0041] Among them, the transmission component 5 is used to connect with the object to be measured. The transmission component 5 can rotate and then rotate with the object to be measured. The transmission component 5 is provided with a plurality of light-transmitting holes 6 along the circumferential direction. The transmission component 5 is provided with a hollow part 9. The light source 1 can be a point light source or a line light source, which is located in the hollow part 9 and at the center of the transmission component 5, and the position is fixed. The light beam 2 emitted by the light source 1 is transmitted out through the light-transmitting hole 6.

[0042] Among them, a hyperbolic lens 13 is arranged between the photodetector 17 and the transmission component 5, so that in the measurement process of the light beam 2 being transmitted from the light-transmitting hole 6 to the same photodetector, the light beam 2 emitted from the light-transmitting hole 6 is incident on the hyperbolic lens 13, and is incident on the photodetector 17 after being transmitted through the hyperbolic lens 13; a hyperbolic lens 24 is arranged between the photodetector 28 and the transmission component 55, so that in the measurement process of the light beam 2 being transmitted from the light-transmitting hole 6 to the same photodetector, the light beam 2 emitted from the light-transmitting hole 6 is incident on the hyperbolic lens 24, and is incident on the photodetector 28 after being transmitted through the hyperbolic lens 24.

[0043] Among them, photodetector 1 7 and photodetector 2 8 are used to respectively receive the light beams 2 emitted from different light holes 6 and display their incident positions during the measurement process in which the light beam 2 is emitted from the light hole 6 to the same photodetector. During the measurement process, at least one of the photodetector 1 7 and the photodetector 2 8 can receive the light beam 2 to achieve continuous measurement.

[0044] The processing system processes the incident position change value of the light beam 2 received by the photodetector 1 7 and / or the photodetector 2 8 to obtain the rotation angle value of the object being measured. The processing system can be any module, chip or device with mathematical computing capability, such as a single chip microcomputer, FPGA, or computer.

[0045] like Figure 4As shown, it is only used as an example of an implementable embodiment. The center thickness of the hyperbolic lens is 4cm, the focal length is 7cm, the material is PMMA, the refractive index is 1.495@532nm, the distance between the starting point of the light (i.e., light source 1) and the center of the front surface of the hyperbolic lens is 5cm, and the hyperbolic lens can transform the light at an angle of ±30°. The hyperbolic lens has a refractive effect, and the refraction angles of the light incident on different positions of the hyperbolic lens are different. Through the setting of the hyperbolic lens, it is possible to achieve a linear relationship between the incident position change measured by the photoelectric detector and the rotation angle of the transmission component 5 (i.e., the object to be measured), thereby eliminating the nonlinear error of the angle sensor in Example 1, and further improving the measurement accuracy.

[0046] like Figure 3 As shown, in this embodiment, the transmission component 5 includes an integrally formed transmission portion 51 and a positioning portion 52, and both the transmission portion 51 and the positioning portion 52 are regular polygonal columns. Figure 3 As shown, the shape of the positioning portion 52 is the same as that of the transmission portion 51. The hollow portion 9 is provided in the transmission portion 51, and is formed by a cylindrical through hole provided along the axial direction of the transmission portion 51. A plurality of light-transmitting holes 6 are distributed along the circumference of the transmission portion 51, penetrating the entire wall thickness of the transmission portion 51, so as to allow the light beam 2 emitted by the light source 1 to pass through and be incident on the photodetector. The positioning portion 52 is provided with a mounting hole, and the object to be measured is connected to the positioning portion 52 through the mounting hole. The transmission portion 51 and / or the positioning portion 52 may also be a cylinder, or other structures. The purpose of using a polygonal column is to facilitate the clamping of the positioning portion 52 for easy installation and positioning.

[0047] like Figure 2 As shown, the solid line represents the beam 2 before rotation, and the dotted line represents the rotation The angled light beam 2, in the measurement process of light beam 2 being transmitted from light-transmitting hole 6 to the same photodetector, defines the incident point of light beam 2 on the photodetector before rotation as incident point 1, and the incident point of light beam 2 on the photodetector after rotation as incident point 2. The rotation angle can be calculated by the incident position change value measured on photodetector 1 7 or photodetector 2 8 (i.e., the distance between incident point 1 and incident point 2). For ease of description, define the projection of light source 1 (point) to photodetector (straight line) as the projection point, and the straight line where the distance between light source 1 and photodetector is located as the distance line. Specifically, we have s=s1±s2, where L is the distance between the light source 1 and the photodetector, s is the displacement change value measured by the photodetector (one or two), s1 is the distance between the incident point one and the projection point, s2 is the distance between the incident point two and the projection point, α is the angle between the light beam 2 and the distance line before rotation, and β is the angle between the light beam 2 and the distance line after rotation. It can be seen that the formula for calculating the rotation angle in this embodiment is simpler, so the calculation speed can be improved, and the overall structure of the angle sensor is also simpler and the cost is lower.

[0048] In order to ensure that the light beam 2 emitted by the light source 1 can be received by the photodetector 1 7 and / or the light source 1 2 after passing through the light-transmitting hole 6 to achieve continuous measurement, two critical points can be set for the photodetector 1 7 and the photodetector 2 8 respectively. The range of the rotation angle of each light-transmitting hole 6 of the transmission component 5 corresponding to the two critical points is the detection maximum value and the detection minimum value of the photodetector respectively. After the light beam 2 emitted by the light source 1 is emitted through the light-transmitting hole 6, at least one photodetector can receive it, that is, the light beam 2 is located in the detection area between the two critical points in the photodetector; the method for the processing system to switch detection calculation between the photodetector 1 7 and the photodetector 2 8 is that when one of the photodetector 1 7 and the photodetector 2 8 detects that the transmitted light beam 2 exceeds the area between the two critical points in the photodetector, the processing system automatically switches to using the detection value of the light beam 2 in the detection area of ​​the other photodetector for calculation.

[0049] It is easy to understand that in order to avoid interference, the photodetector 1 (or 2) can only receive the light beam 2 emitted from one light-transmitting hole 6 at the same time. Take the projection point of the light source 1 on the photodetector as the midpoint of the photodetector as an example. Figure 5 As shown, assuming that the length of the photodetector is H, the angle of the straight line laser emitted by the light source 1 is θ, and the distance between the light source 1 and the photodetector is L, the distribution angle range β of the light-transmitting hole 6 must meet the following conditions:

[0050] in

[0051] In order to ensure that there is always one photodetector between the photodetector 1 7 and the photodetector 2 8 that can receive the light beam 2, Figure 6 As shown, as an implementation, the positions of the photodetector 1 7 and the photodetector 2 8 can be set to satisfy the following relationship: the angle of the straight line laser emitted by the light source 1 is greater than the receiving angle δ of the photodetector 1 7 and the photodetector 2 8. When the rotation angle of the object to be measured is very small, the light beam 2 before and after the rotation may be emitted from the same light-transmitting hole 6 to the photodetector, and when the rotation angle is large, the light beam 2 before and after the rotation is emitted from different light-transmitting holes 6 to the same photodetector.

[0052] The angle sensor described in this embodiment not only has a simple structure and a fast operation speed, but also can realize a linear relationship between the incident position change of the photoelectric detector and the rotation angle of the measured object, thereby improving the measurement accuracy.

[0053] When using the above-mentioned hyperbolic lens-based angle sensor for measurement, the following operations are performed:

[0054] Connecting the transmission component to the object to be measured so that the transmission component can rotate with the rotation of the object to be measured;

[0055] Adjust the positional relationship between the light beam, the reflective component, the photodetector 1, the photodetector 2, the hyperbolic lens 1 and the hyperbolic lens 2, so that the light beam emitted from a light transmission hole is incident on the hyperbolic lens 1, is transmitted through the hyperbolic lens 1 and is incident on the photodetector 1, and / or the light beam emitted from a light transmission hole is incident on the hyperbolic lens 2, is transmitted through the hyperbolic lens 2 and is incident on the photodetector 2;

[0056] Emits a light beam, the light beam is transmitted through one or more light-transmitting holes of the reflective component, and the photodetector 1 and / or the photodetector 2 detects an initial position of the light beam emitted from one of the light-transmitting holes;

[0057] The object to be measured rotates, and during the rotation process, the photodetector 1 and / or the photodetector 2 detects a change in the incident position of the light beam emitted from one of the light-transmitting holes on the respective detectors until the object to be measured stops rotating;

[0058] The processing system obtains the rotation angle value of the object to be measured by processing the incident position change value of the laser beam 1 received on the photoelectric detector 1 and / or the incident position change value of the laser beam 2 received on the photoelectric detector 2.

[0059] 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. An angle sensor based on a hyperbolic lens, characterized in that: include: a light source for emitting a light beam; A transmission component, the transmission component is used to connect with the object to be measured, the transmission component is rotatable and has a plurality of light-transmitting holes along the circumferential direction, the transmission component has a hollow part, the light source is located in the hollow part and at the center of the transmission component, and the position is fixed, and the light beam emitted by the light source is transmitted through the light-transmitting holes; Photodetector 1 and photodetector 2, hyperbolic lens 1 and hyperbolic lens 2, The hyperbolic lens 1 is arranged between the photodetector 1 and the transmission component. In the measurement process of the light beam being transmitted from the light-transmitting hole to the same photodetector, the light beam emitted from the light-transmitting hole is incident on the hyperbolic lens 1, and is incident on the photodetector 1 after being transmitted through the hyperbolic lens 1. The second hyperbolic lens is disposed between the second photodetector and the transmission component. During the measurement process in which the light beam is transmitted from the light-transmitting hole to the same photodetector, the light beam emitted from the light-transmitting hole is incident on the second hyperbolic lens, and is incident on the second photodetector after being transmitted by the second hyperbolic lens. The photodetector 1 and the photodetector 2 receive the light beams transmitted from the hyperbolic lens 1 and the hyperbolic lens 2 respectively, and display the incident positions thereof, and during the measurement process, at least one of the photodetector 1 and the photodetector 2 can receive the light beam; A processing system, which processes the incident position change value of the light beam received by the photodetector 1 and / or the photodetector 2 to obtain the rotation angle value of the object to be measured; The transmission component includes an integrally formed transmission portion and a positioning portion, the hollow portion is disposed in the transmission portion, the transmission portion is provided with the plurality of light-transmitting holes along the circumferential direction, and the measured object is fixed to the positioning portion; The positioning portion is a regular polygonal column or a cylinder; The hollow portion is formed by a cylindrical through hole arranged along the axial direction of the transmission portion.

2. The angle sensor based on the hyperbolic lens according to claim 1, characterized in that: The transmission part and the positioning part are both regular polygonal columns or cylinders.

3. The angle sensor based on the hyperbolic lens according to claim 1, characterized in that: The transmission part and the positioning part are regular polygonal columns or cylinders with the same shape.

4. The angle sensor based on the hyperbolic lens according to claim 1, characterized in that: The transmission component is provided with a mounting hole for connecting with the object to be measured, and the mounting hole is located at the positioning part.

5. The angle sensor based on the hyperbolic lens according to claim 1, characterized in that: The light emitted by the light source is a line laser.

6. The angle sensor based on the hyperbolic lens according to claim 5, characterized in that: The angle of the line laser emitted by the light source is greater than the receiving angle of the photodetector 1 and the photodetector 2.

7. The method for measuring an angle sensor based on a hyperbolic lens according to any one of claims 1 to 6, characterized in that: The following steps are involved: Connecting the transmission component to the object to be measured so that the transmission component can rotate with the rotation of the object to be measured; Adjust the positional relationship between the light beam, the transmission component, the first photodetector, the second photodetector, the first hyperbolic lens, and the second hyperbolic lens, so that the light beam emitted from a light transmission hole is incident on the first hyperbolic lens, and is incident on the first photodetector after being transmitted through the first hyperbolic lens, and / or the light beam emitted from a light transmission hole is incident on the second hyperbolic lens, and is incident on the second photodetector after being transmitted through the second hyperbolic lens; Emits a light beam, the light beam is transmitted through one or more light-transmitting holes of the transmission component, and the photodetector 1 and / or the photodetector 2 detects an initial position of the light beam emitted from one of the light-transmitting holes; The object to be measured rotates, and during the rotation process, the photodetector 1 and / or the photodetector 2 detects a change in the incident position of the light beam emitted from one of the light-transmitting holes on the respective detectors until the object to be measured stops rotating; The processing system obtains the rotation angle value of the object to be measured by processing the incident position change value of the laser beam 1 received on the photoelectric detector 1 and / or the incident position change value of the laser beam 2 received on the photoelectric detector 2.

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