CN218380868U

CN218380868U - Optical displacement detection system

Info

Publication number: CN218380868U
Application number: CN202222869364.6U
Authority: CN
Inventors: 刘瑞军; 陈宝锋
Original assignee: Shenzhen Leiying Photoelectric Technology Co ltd
Current assignee: Shenzhen Leiying Photoelectric Technology Co ltd
Priority date: 2022-10-27
Filing date: 2022-10-27
Publication date: 2023-01-24
Anticipated expiration: 2032-10-27

Abstract

The utility model discloses an optical displacement detecting system, including first fixed grating, the fixed grating of second, activity grating and signal processor, first fixed grating and the fixed grating of second set gradually in same one side of activity grating along measuring direction, one side that the activity grating was kept away from to first fixed grating is equipped with first light source, one side that the activity grating was kept away from to the fixed grating of second is equipped with the second light source, the opposite side of activity grating is equipped with first light signal receiver and the second light signal receiver that is used for receiving the light that first light source and second light source sent respectively, and first light signal receiver and second light signal receiver are connected with signal processor respectively. By adopting two paths of light sources to detect the displacement, the movable grating can be flexibly connected with components of the lens, so that the flexibility of structural design is increased; when the displacement sensor is used, the movable grating can be directly connected with the displacement component, so that the displacement of the displacement component can be directly detected, and measurement errors can be avoided.

Description

Optical displacement detection system

Technical Field

The utility model relates to a displacement detection technical field, concretely relates to optics displacement detecting system.

Background

At present, the displacement of the movable part is mainly detected by a coaxial encoder or a magnetic encoder. However, in practical use, both the coaxial encoder and the magnetic encoder have specific requirements on installation, occupy large space and solidify design mode, are not favorable for being used in products with smaller structural space, have limited precision of common coaxial encoders and magnetic encoders, and have great disadvantages in displacement detection requiring short-distance high precision.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the disappearance that prior art exists, provide an optics displacement detecting system, its flexibility ratio that can increase displacement detecting system structural design improves the detection precision simultaneously, better avoiding measuring error.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides an optical displacement detecting system, includes first fixed grating, the fixed grating of second, activity grating and signal processor, first fixed grating and the fixed grating of second set gradually in same one side of activity grating along measuring direction, one side that the activity grating was kept away from to first fixed grating is equipped with first light source, one side that the activity grating was kept away from to the fixed grating of second is equipped with the second light source, the opposite side of activity grating is equipped with first light signal receiver and the second light signal receiver who is used for receiving the light that first light source and second light source sent respectively, and first light signal receiver and second light signal receiver are connected with signal processor respectively.

As a preferred technical scheme, first fixed grating is equipped with a plurality of the same first light-transmitting grooves that distribute along measuring direction, the fixed grating of second is equipped with a plurality of the same second light-transmitting grooves that distribute along measuring direction, the activity grating is equipped with a plurality of the same third light-transmitting grooves that distribute along measuring direction, first light-transmitting groove, second light-transmitting groove and third light-transmitting groove are distributed the interval homogeneous phase the same.

As a preferable technical solution, the first light-transmitting grooves and the second light-transmitting grooves have the same number, and the third light-transmitting grooves have a number greater than the number of the first light-transmitting grooves and the second light-transmitting grooves.

As a preferable technical solution, the widths of the first light-transmitting groove, the second light-transmitting groove and the third light-transmitting groove are the same.

As a preferred technical solution, the phase difference between the intensity of the optical signal received by the first optical signal receiver and the intensity of the optical signal received by the second optical signal receiver is 90 degrees.

As a preferred technical solution, the distances between the first fixed grating and the movable grating are the same as the distances between the second fixed grating and the movable grating.

As a preferred technical solution, the first fixed grating and the second fixed grating are integrally connected.

As a preferred technical solution, the first light source and the second light source have different light intensities and do not interfere with each other.

As a preferred technical scheme, the signal processor is an MCU.

As a preferred technical solution, the first optical signal receiver and the second optical signal receiver are both photosensitive devices.

Compared with the prior art, the utility model has obvious advantages and beneficial effects, specifically speaking, the displacement detection can be realized by adopting two paths of light sources, the energy consumption is low, the occupied space is small, the movable grating can be flexibly connected with components of the lens, different connection methods can be designed according to different spaces, and the length of the movable grating can be designed according to the moving range of the movable components, so that the space is saved, and compared with the traditional fixed installation mode, the flexibility of the structural design is greatly increased; when the displacement sensor is used, the movable grating can be directly connected with the displacement component, so that the displacement of the displacement component can be directly detected, and compared with a motor end connected with a coaxial encoder and a magnetic encoder, the displacement sensor can better avoid measurement errors and improve the measurement precision.

To more clearly illustrate the structural features and technical means of the present invention and the specific objects and functions achieved thereby, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments:

drawings

Fig. 1 is a schematic diagram of the detection principle of the embodiment of the present invention;

fig. 2 is a signal graph of an embodiment of the present invention;

fig. 3 is a schematic diagram of the offset value segment ordering according to an embodiment of the present invention.

The attached drawings indicate the following:

10. a first fixed grating 11, a first light-transmitting groove 20, and a second fixed grating

21. A second light-transmitting groove 30, an active grating 31 and a third light-transmitting groove

40. First light source 50, second light source 60, first optical signal receiver

70. A second optical signal receiver.

Detailed Description

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the indicated position or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.

As shown in fig. 1, the utility model provides an optical displacement detection system, including first fixed grating 10, the fixed grating 20 of second, movable grating 30 and signal processor (not shown), first fixed grating 10 and the fixed grating 20 of second set gradually in the same one side of movable grating 30 along measuring direction, one side that movable grating 30 was kept away from to first fixed grating 10 is equipped with first light source 40, one side that movable grating 30 was kept away from to the fixed grating 20 of second is equipped with second light source 50, the opposite side of movable grating 30 is equipped with first light signal receiver 60 and the second light signal receiver 70 that are used for receiving the light that first light source 40 and second light source 50 sent respectively, and first light signal receiver 60 and second light signal receiver 70 are connected with signal processor respectively, the phase difference of the light signal intensity that first light signal receiver 60 received and the light signal intensity that second light signal receiver 70 received is 90 degrees. The utility model discloses in, signal processor is MCU, first light signal receiver 60 and second light signal receiver 70 are photosensitive components and parts. The light intensity signals received by the first optical signal receiver 60 and the second optical signal receiver 70 are processed by a signal processor with a certain algorithm, so as to achieve the purpose of detecting displacement.

Specifically, first fixed grating 10 is equipped with a plurality of the same first light transmission grooves 11 that distribute along the measuring direction, the fixed grating 20 of second is equipped with a plurality of the same second light transmission grooves 21 that distribute along the measuring direction, movable grating 30 is equipped with a plurality of the same third light transmission grooves 31 that distribute along the measuring direction, first light transmission grooves 11, second light transmission grooves 21 and third light transmission grooves 31 distribute the interval homogeneous phase the same. The number of the first light-transmitting grooves 11 and the second light-transmitting grooves 21 is the same, and the number of the third light-transmitting grooves 31 is greater than the number of the first light-transmitting grooves 11 and the second light-transmitting grooves 21. The widths of the first, second and third light-transmitting

grooves

11, 21 and 31 are the same. The first and second fixed

gratings

10 and 20 are the same distance from the movable grating 30. In this embodiment, the first fixed grating 10 and the second fixed grating 20 are integrally connected for convenience of installation and use, and it should be understood that the first fixed grating 10 and the second fixed grating 20 may be separately provided in actual use. The width of first light transmission groove 11, second light transmission groove 21 and third light transmission groove 31 is 0.1mm, the interval of first light transmission groove 11, second light transmission groove 21 and third light transmission groove 31 is 0.1mm, the distance between the fixed grating 20 of first fixed grating 10 and second and activity grating 30 is 0.15mm, the thickness of the fixed grating 20 of first fixed grating 10, second and activity grating 30 is 0.175mm.

In order to facilitate the conversion of the optical signal and improve the detection accuracy, the first light source 40 and the second light source 50 have different light intensities and do not interfere with each other.

The utility model discloses the process of carrying out displacement detection as follows:

(1) The first light source 40 and the second light source 50 are enabled to emit light rays with constant intensity, the movable grating 30 is enabled to move relative to the first fixed grating 10 and the second fixed grating 20 along the measuring direction, the first optical signal receiver 60 receives the light rays of the first light source 40 which pass through the first fixed grating 10 and the movable grating 30, and the second optical signal receiver 70 receives the light rays of the second light source 50 which pass through the second fixed grating 20 and the movable grating 30;

(2) Converting the light intensity signals of the light received by the first optical signal receiver 60 and the second optical signal receiver 70 into electrical signals y1 (x) and y2 (x) which change periodically, respectively, wherein the phase difference between the electrical signals y1 (x) and y2 (x) is 90 degrees;

(3) Writing a Triangle _ atan2 function by referring to an atan2 function, firstly, dividing electrical signals y1 (x) and y2 (x) in a single period into four parts, recording the part as a first part if y1 (x) is less than or equal to zero and y2 (x) is less than 0, recording the part as a second part if y1 (x) is less than or equal to zero and y2 (x) is greater than or equal to 0, recording the part as a third part if y1 (x) is greater than zero and y2 (x) is greater than or equal to 0, and not recording the part as a fourth part if y1 (x) is greater than zero and y2 (x) is less than 0, and then carrying out different operations on each part:

a first part: y = ((2 × y2 (x) min-y2 (x) + y1 (x)) + y2 (x) min).

A second part: y = (y 2 (x) + y1 (x) + y2 (x) min).

And a third part: y = ((2 × y1 (x) max-y1 (x) + y2 (x)) + y2 (x) min).

The fourth part: y = ((2 × y1 (x) max-y1 (x) -y2 (x)) + y2 (x) min).

Here, y2 (x) min refers to the minimum value of y2 (x) and is equal to y1 (x) min, and y1 (x) max refers to the maximum value of y1 (x) and is equal to y2 (x) max. The four parts are combined to obtain an offset value y which is periodically changed along with the movement of the movable grating 30 about y1 (x) and y2 (x), and the offset value y in the same period is in a direct proportion relation with the movement distance of the movable grating 30;

(4) And (3) calculating the moving distance of the movable grating 30 relative to the origin according to a formula L = nd + ykd, where n is the period number of the offset value y, d is the moving distance of the movable grating 30 corresponding to one period of the offset value y, y is the offset value of the current period calculated in the step (3), and k is a proportionality coefficient between the offset value y and d.

Specifically, in step (4), the offset value in the same period calculated in step (3) is equally divided into a plurality of segments, and the segments are sorted by numbers, and the moving direction of the movable grating 30 is determined according to the changing order of the numbers.

As shown in fig. 2, in the present invention, the electrical signals y1 (x) and y2 (x), and the offset value y are all curves with the same period. Wherein y1 (x) and y2 (x) are triangular wave voltage signals with a phase difference of 90 degrees.

As shown in fig. 3, in this embodiment, the offset value in the same period is divided into three equal segments, and sequentially marked with 1, 2, and 3, and the offset line changes by 1, 2, and 3 or 3, 2, and 1 with the movement of the movable grating 30 during the detection process, so that it can be determined whether the movable grating 30 is far from the origin or close to the origin.

To sum up, the utility model can realize the displacement detection by adopting two paths of light sources, has low energy consumption and small occupied space, the movable grating can be flexibly connected with components of the lens, different connection methods can be designed according to different spaces, and the length of the movable grating can be designed according to the moving range of the movable components, thereby saving more space and greatly increasing the flexibility of structural design compared with the traditional fixed installation mode; the two paths of optical signals are converted into electric signals, and then the electric signals of the two paths of light sources are converted into offset values in direct proportion to displacement according to the atan2 function idea, so that the actual displacement can be quickly and accurately obtained, and the purpose of high-precision displacement detection can be achieved only by improving the sampling frequency as the sampling frequency is in direct proportion to the precision; when the displacement sensor is used, the movable grating can be directly connected with the displacement component, so that the displacement of the displacement component can be directly detected, and compared with a motor end connected with a coaxial encoder and a magnetic encoder, the displacement sensor can better avoid measurement errors and improve the measurement precision.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, so any modifications, equivalent replacements, improvements, etc. made to the above embodiments by the technology of the present invention are all within the scope of the technical solution of the present invention.

Claims

1. The utility model provides an optical displacement detecting system, its characterized in that includes first fixed grating, the fixed grating of second, activity grating and signal processor, the fixed grating of first fixed grating and second sets gradually in same one side of activity grating along measuring direction, one side that the activity grating was kept away from to first fixed grating is equipped with first light source, one side that the activity grating was kept away from to the fixed grating of second is equipped with the second light source, the opposite side of activity grating is equipped with first light signal receiver and the second light signal receiver that is used for receiving the light that first light source and second light source sent respectively, and first light signal receiver and second light signal receiver are connected with signal processor respectively.

2. The optical displacement sensing system of claim 1, wherein the first fixed grating has a plurality of identical first light-transmitting grooves extending along the measuring direction, the second fixed grating has a plurality of identical second light-transmitting grooves extending along the measuring direction, the movable grating has a plurality of identical third light-transmitting grooves extending along the measuring direction, and the first light-transmitting grooves, the second light-transmitting grooves and the third light-transmitting grooves have the same pitch.

3. The optical displacement sensing system of claim 2, wherein the first and second light-transmissive grooves are equal in number, and the third light-transmissive groove is greater in number than the first and second light-transmissive grooves.

4. The optical displacement sensing system of claim 2, wherein the first, second and third optically transparent slots are all the same width.

5. An optical displacement sensing system as claimed in claim 2, wherein the intensity of the optical signal received by the first optical signal receiver is 90 degrees out of phase with the intensity of the optical signal received by the second optical signal receiver.

6. An optical displacement sensing system according to claim 2 wherein the first and second fixed gratings are spaced the same distance from the movable grating.

7. An optical displacement sensing system according to claim 6 wherein the first and second fixed gratings are integrally connected.

8. An optical displacement sensing system according to claim 2, wherein the first and second light sources are of different intensities and do not interfere with each other.

9. An optical displacement sensing system according to claim 1 wherein the signal processor is an MCU.

10. The optical displacement sensing system of claim 1, wherein the first optical signal receiver and the second optical signal receiver are both photo-sensors.