Industrial-grade multi-laser length measurement system collimation device

Abstract

The utility model relates to laser measurement technical field, concretely is a kind of collimating device of industrial grade multi-channel laser length measurement system. The technical problem of the device for measuring and adjusting laser length measurement system beam direction in situ on site is solved at present. A kind of collimating device of industrial grade multi-channel laser length measurement system, including pedestal, column installed on pedestal, workbench slidably installed on column and the right-angle coordinate target made of transparent or semi-transparent material and installed on workbench;The pedestal bottom is equipped with at least three adjusting screws, and the workbench includes fixed part connected with the column and rotating part rotatably installed on the fixed part;The right-angle coordinate target is installed on rotating part and right-angle coordinate target is inscribed with right-angle coordinate formula two-dimensional grid. The utility model is applicable to the collimation of long-range laser sensor light path of arrangement, alignment, measures laser beam offset error by the device and can be compensated, and the measurement precision is improved.

Description

Technical Field

[0001] This utility model relates to the field of laser measurement technology, specifically to a collimation device for an industrial-grade multi-channel laser length measurement system. Background Technology

[0002] In the context of smart manufacturing, various sensing devices are ubiquitous on industrial production lines. Among them, laser rangefinders and laser triangulation sensors are widely used for measuring the size parameters of dynamic objects due to their advantages such as high accuracy, fast response, and non-contact operation.

[0003] A laser rangefinder is an instrument that uses modulated laser pulses or phases to illuminate a target at a short to medium distance and receive the reflected light, thereby accurately measuring the distance between the object and itself.

[0004] A laser triangulation displacement sensor works by emitting a laser. When the laser shines on an object, the reflected light spot is received by an image acquisition device at certain distances and angles. Based on the laser and reflected light paths and the principle of similar triangles, the distance to the object is calculated. As the object moves, the light spot will be imaged at different positions on the image acquisition device, thus revealing the object's displacement.

[0005] When two laser rangefinders or laser triangulation sensors are arranged symmetrically opposite each other, the two rangefinders or sensors can detect their respective distances from the object as it passes by. By subtracting the detected distances on both sides from the fixed distance between the rangefinders or sensors, the thickness, width, and other length values ​​of the object can be obtained. For ease of description, this invention refers to such a rangefinder or sensor group as a laser length measurement system, and the laser rangefinder and laser triangulation sensor as laser emitters.

[0006] It can be seen that this type of laser length measurement system can only eliminate errors caused by optical path tilt when the object being measured is perpendicular to the laser beam emitted from the laser source. When the laser beams at both ends are aligned, the non-parallelism of the object's sides does not affect high-precision measurement. Therefore, in industrial applications, due to installation errors, mechanical deformation, or thermal drift, there may be errors such as the single-end sensor beam not being perpendicular to the surface of the object being measured, misalignment of the double-end opposing laser beams, or non-parallelism with the measurement axis of the object being measured. These errors, especially when measuring large dimensions, increase non-linearly. (See Appendix) Figure 1 .

[0007] Therefore, how to achieve on-site measurement and adjustment of the laser length measuring system beam direction, thereby improving the measurement accuracy of such systems, is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0008] This invention addresses the current lack of a device capable of on-site, in-situ measurement and adjustment of the beam direction of a laser length measurement system by providing a collimation device for an industrial-grade multi-channel laser length measurement system.

[0009] This utility model is achieved using the following technical solution: a collimation device for an industrial-grade multi-channel laser length measurement system, comprising a base, a column mounted on the base, a worktable slidably mounted on the column, and a rectangular coordinate target made of transparent or semi-transparent material mounted on the worktable; the base has at least three adjusting screws at its bottom, the worktable includes a fixed part connected to the column and a rotating part rotatably mounted on the fixed part; the rectangular coordinate target is mounted on the rotating part and has a rectangular coordinate two-dimensional grid engraved on it.

[0010] Furthermore, a linear guide rail is vertically mounted on the column, and the fixing part is slidably mounted on the linear guide rail and equipped with a sliding positioning device; the rotating part includes a plate for mounting a rectangular target and a rotating shaft extending from the plate and rotatably connected to the fixing part, the rotating shaft of the rotating part is horizontal and equipped with a rotation positioning device.

[0011] Furthermore, the base has threaded holes at each of the four corners at its bottom, and is equipped with at least three adjusting screws.

[0012] Furthermore, the rectangular coordinate target is made of translucent acrylic or frosted glass sheet, which is colorless or colored, and is engraved with a rectangular coordinate two-dimensional grid with a spacing of 1mm.

[0013] Furthermore, the base has a U-shaped outline, with the recessed part facing the worktable.

[0014] This utility model also discloses a collimation method for an industrial-grade multi-channel laser length measurement system, which is implemented using a collimation device for the industrial-grade multi-channel laser length measurement system, including the following steps: ① When the laser length measurement system is used for thickness measurement: First, adjust the adjusting screws on the base of the collimation device, and use a level to measure and adjust the base to be parallel to the roller conveyor or conveyor belt of the production line; Second, adjust the worktable to make the rectangular coordinate target horizontal and parallel to the direction of travel of the roller conveyor or conveyor belt, move the worktable up and down, observe the position change of the spot formed on the rectangular coordinate target by the laser beam emitted by one of the laser emitting ends of the laser length measurement system, and adjust the emission direction of the laser emitting end according to the position of the spot to achieve collimation of the laser beam emitted by the laser emitting end; ② When the laser length measuring system is used for width measurement: First, adjust the adjusting screws on the base of the collimation device, and use a level to measure and adjust the base to be parallel to the direction of the production line movement; Second, adjust the worktable so that the rectangular target is vertical and basically perpendicular to the direction of the roller or conveyor belt movement. Move the collimation device laterally from one side to the other along the roller or conveyor belt, observe the position change of the spot formed on the rectangular target by the laser beam emitted by one of the laser emitting ends of the laser length measuring system, and adjust the emission direction of the laser emitting end according to the position of the spot to achieve collimation of the laser beam emitted by the laser emitting end; ③ The bidirectional laser optical path alignment method is as follows: In the above adjustments ① and ②, the two laser beams emitted from the two laser emitters are clearly displayed on the same rectangular target, and the front or back laser beams can be clearly distinguished. Using the laser beams formed by the laser emitters that have been collimated in ① and ② as a reference, the rectangular target is moved up and down / left and right. The position difference between the laser beam formed by the other laser emitter and the reference laser beam on the rectangular target grid is observed. The emission direction of the other laser emitter is adjusted accordingly until the position difference is zero. At this time, the laser beams at both ends are collimated and aligned, and the laser beams are parallel or perpendicular to the roller or conveyor belt. ④ Adjustment of laser beams from vertical and horizontal orthogonal sources: When the laser length measurement system simultaneously measures width and thickness, the laser beams are arranged orthogonally in the vertical and horizontal directions. The laser beam collimation and alignment are adjusted according to the aforementioned ①, ②, and ③. Based on this, the worktable is adjusted in the laser orthogonal area so that the rectangular target and the base are placed at a 45° angle. At this time, the four laser beams illuminate the rectangular target, presenting four elliptical spots. After completing the bidirectional laser path alignment as described in ③, the laser emitter for measuring width or thickness is translated as a whole based on the position of the orthogonal spots, until the four elliptical spots converge at a single point, achieving the adjustment purpose.

[0015] This invention is applicable to the collimation and alignment of the optical path of large-range laser sensors arranged in opposite directions. The device measures the laser beam offset error and can be used for intuitive reference and compensation, which is convenient for installation or adjustment of the laser end pointing accuracy. By reducing the offset error of the opposing laser beam, this invention reduces the systematic error caused by the inaccurate pointing of the laser end and the influence of sampling point misalignment caused by the vibration of the measured object or the unevenness of the object surface, thereby improving the measurement accuracy of the width or thickness of continuously moving objects on industrial production lines. Attached Figure Description

[0016] Figure 1 Schematic diagram of dual laser beam collimation and alignment status (a excellent, b misaligned, c not collimated).

[0017] Figure 2This utility model describes a calibration device used for thickness measurement in a laser length measurement system.

[0018] Figure 3 A schematic diagram of the calibration device described in this utility model.

[0019] Figure 4 A schematic diagram of the light spot imaging on a Cartesian target.

[0020] Figure 5 This utility model describes a calibration device used for width measurement in a laser length measurement system.

[0021] 1-Base, 2-Column, 21-Linear guide rail, 3-Worktable, 4-Rectangular target, 5-Adjusting screw, 6-Laser triangular displacement sensor, 7-Laser emitter, 8-Laser beam, 9-Roller conveyor, 10-Object to be moved. Detailed Implementation

[0022] A collimation device for an industrial-grade multi-channel laser length measurement system includes a base 1, a column 2 mounted on the base 1, a worktable 3 slidably mounted on the column 2, and a rectangular coordinate target 4 made of transparent or semi-transparent material mounted on the worktable 3. The base 1 has at least three adjusting screws 5 at its bottom. The worktable 3 includes a fixed part connected to the column 2 and a rotating part rotatably mounted on the fixed part. The rectangular coordinate target 4 is mounted on the rotating part and has a rectangular coordinate two-dimensional grid engraved on it.

[0023] A linear guide rail 21 is vertically mounted on the column 2. The fixed part is slidably mounted on the linear guide rail 21 and is equipped with a sliding positioning device. The rotating part includes a plate for mounting the rectangular target 4 and a rotating shaft extending from the plate and rotatably connected to the fixed part. The rotating shaft of the rotating part is horizontal and is equipped with a rotation positioning device. The sliding positioning device generally uses a positioning screw on the fixed part. When the fixed part slides to a suitable position, the positioning screw can be adjusted to firmly fix the worktable 3 on the linear guide rail 21. The rotation positioning device generally uses a positioning screw on the fixed part. When the rotating part rotates to a suitable position, the positioning screw can be adjusted to secure it to the rotating shaft, preventing the rotating part from rotating. Of course, other existing technologies can also be used for the sliding positioning device and the rotation positioning device.

[0024] The base 1 has threaded holes at each of its four bottom corners and is equipped with at least three adjusting screws 5.

[0025] The rectangular target 4 is made of translucent acrylic or frosted glass sheet, and is colorless or colored, with a rectangular coordinate two-dimensional grid with a spacing of 1mm.

[0026] The base 1 has a concave shape, with the concave part facing the worktable 3, which allows the laser beam 8 of the laser emitter 7 to irradiate the rectangular target 4.

[0027] This utility model also discloses a collimation method for an industrial-grade multi-channel laser length measurement system, which is implemented using a collimation device for the industrial-grade multi-channel laser length measurement system, including the following steps: ① When the laser length measurement system is used for thickness measurement: First, adjust the adjusting screws 5 on the base 1 of the collimation device, and use a level to measure and adjust the base 1 to be parallel to the roller conveyor 9 or conveyor belt of the production line; Second, adjust the worktable 3 to make the rectangular target 4 horizontal and parallel to the direction of travel of the roller conveyor 9 or conveyor belt, move the worktable 3 up and down, observe the position change of the spot formed on the rectangular target 4 by the laser beam 8 emitted by one of the laser emitting ends 7 of the laser length measurement system, and adjust the emission direction of the laser emitting end 7 according to the position of the spot to achieve collimation of the laser beam 8 emitted by the laser emitting end 7; ② When the laser length measuring system is used for width measurement: First, adjust the adjusting screw 5 on the base 1 of the collimation device, and use a level to measure and adjust the base 1 to be parallel to the direction of the production line movement; Second, adjust the worktable 3 so that the rectangular target 4 is vertical and basically perpendicular to the direction of the roller 9 or conveyor belt. Move the collimation device laterally from one side to the other along the roller 9 or conveyor belt, observe the position change of the spot formed on the rectangular target by the laser beam 8 emitted by one of the laser emitting ends 7 of the laser length measuring system, and adjust the emission direction of the laser emitting end 7 according to the position of the spot to achieve collimation of the laser beam 8 emitted by the laser emitting end 7. ③ The bidirectional laser optical path alignment method is as follows: In the above adjustments ① and ②, the two light spots formed by the laser beams 8 emitted from the two laser emitters 7 are clearly presented on the same rectangular target 4, and the front or back laser light spots can be clearly distinguished. Taking the light spot formed by the laser emitter 7 after collimation in ① and ② as a reference, the rectangular target 4 is still moved up and down / left and right. The position difference between the light spot formed by the other laser emitter 7 and the reference light spot on the grid of the rectangular target 4 is observed, and the emission direction of the other laser emitter 7 is adjusted accordingly until the position difference is zero. At this time, the laser beams 8 at both ends are collimated and aligned, and the laser beams 8 are parallel or perpendicular to the roller 9 or conveyor belt. ④ Adjustment of laser beams from vertical and horizontal orthogonal sources: When the laser length measurement system simultaneously measures width and thickness, the vertical and horizontal laser beams 8 are orthogonally arranged. The collimation and alignment of the laser beams 8 are adjusted according to the aforementioned ①, ②, and ③. Based on this, the worktable 3 is adjusted in the laser orthogonal area so that the rectangular target 4 is placed at 45° with the base 1. At this time, the four laser beams 8 illuminate the rectangular target 4, presenting four elliptical light spots. Based on the bidirectional laser optical path alignment described in ③, the entire width or thickness laser emitting end 7 is translated as a whole according to the position of the orthogonal light spots, with the thickness or width measurement laser emitting end 7 as the reference, until the four elliptical light spots converge at one point, achieving the adjustment purpose.

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] like Figure 3 As shown, the base 1 has threaded holes at its four corners for 3 or 4 adjusting screws 5 to support the entire device; when the support surface is a plane, the 3 adjusting screws 5 adjust the position of the base 1; when the support surface is an arc surface, such as the surface of a roller, the 4 adjusting screws 5 adjust the position of the base 1.

[0030] The column 2 is vertically fixed to the base 1, and a linear guide rail 21 is installed on the column 2.

[0031] The worktable 3 is used to support and mount relevant measuring components. The worktable 3 can move freely up and down along the linear guide 21. The worktable 3 is divided into two parts: a fixed part connected to the linear guide 21, and a rotating part that rotates along the fixed part via a shaft connection.

[0032] The rectangular target 4 is made of translucent acrylic or frosted glass sheet, and can be colorless or colored. It is engraved with a rectangular two-dimensional grid with a spacing of 1mm, and the grid lines are clearly distinguishable from the target background. It is connected to the rotating part of the worktable 3 by two screws.

[0033] Taking laser thickness measurement as an example, on the C-frame, adjust the base 1 of this device to be parallel to the roller conveyor 9. First, use a level to measure the horizontal angle of the roller conveyor 9, then place the level on the base 1 and adjust the three adjusting screws 5 of the base 1 to make the bottom surface parallel to the roller conveyor 9. Install a right-angle target 4 above the worktable 3, and move the worktable 3 up and down (e.g., Figure 2 As shown), the spot illuminated by laser beam 8 is positioned at a relevant location on the Cartesian target 4, as shown in the figure. Figure 4 Assuming that the upper laser spot moves from Q1 to Q2 and the lower laser spot moves from Q1' to Q2' initially, the emission directions of the upper and lower laser emitting ends 7 are adjusted respectively to make the spot displacement Lp approach zero. The laser beam 8 is then continuously observed on the rectangular target 4 until the spot displacement is within the allowable range. At this time, the laser beam 8 is in a collimated state.

[0034] Using the collimated upper laser emitter 7 as a reference, observe the offset between the lower laser emitter 7 and the upper laser emitter 7. Adjust the emission direction of the lower laser emitter 7 by overall translation until the two spots tend to coincide on the rectangular target 4. At this point, the laser beam 8 is aligned. The laser beam 8 passes through the gap between adjacent roller conveyors 9.

[0035] like Figure 5 As shown, the laser length measuring system is used to measure width. Adjust the adjusting screw 5 on the base 1 of the collimating device and use a level to measure and adjust the base 1 of the collimating device to be parallel to the direction of the production line movement; then adjust the worktable 3 so that the rectangular target 4 is vertical and basically perpendicular to the direction of travel of the roller conveyor 9. Move the collimating device along the roller conveyor 9 from one side to the other side, observe the position change of the spot formed by the laser beam 8 emitted by one of the laser emitting ends 7 of the laser length measuring system on the rectangular target 4, and adjust the emission direction of the laser emitting end 7 according to the position of the spot to achieve collimation of the laser beam 8 emitted by the laser emitting end 7; the emission direction of the other laser emitting end 7 is adjusted in the same way to achieve collimation of the laser beam 8.

[0036] Using the light spot formed by one of the laser emitters 7, which has been collimated, as a reference, the rectangular coordinate target 4 is moved left and right to observe the position difference between the light spot formed by the other laser emitter 7 and the reference light spot on the grid of the rectangular coordinate target 4. Based on this, the emission direction of the other laser emitter 7 is translated until the position difference is zero. At this time, the laser beams 8 at both ends are collimated and aligned, and the laser beams 8 are parallel to the roller conveyor 9.

Claims

1. A collimation device for an industrial-grade multi-channel laser length measurement system, characterized in that, It includes a base (1), a column (2) mounted on the base (1), a worktable (3) slidably mounted on the column (2), and a rectangular coordinate target (4) made of transparent or semi-transparent material mounted on the worktable (3); the base (1) has at least three adjusting screws (5) at its bottom, the worktable (3) includes a fixed part connected to the column (2) and a rotating part rotatably mounted on the fixed part; the rectangular coordinate target (4) is mounted on the rotating part and has a rectangular coordinate two-dimensional grid engraved on it.

2. The collimating device of the industrial-grade multi-laser length measurement system according to claim 1, wherein, A linear guide rail (21) is vertically mounted on the column (2), and the fixed part is slidably mounted on the linear guide rail (21) and equipped with a sliding positioning device; the rotating part includes a plate for mounting a rectangular target (4) and a rotating shaft extending from the plate and rotatably connected to the fixed part, and the rotating shaft of the rotating part is horizontal and equipped with a rotating positioning device.

3. The collimating device of the industrial-grade multi-laser length measurement system according to claim 2, wherein, The base (1) has threaded holes at all four corners of its bottom and is equipped with at least three adjusting screws (5).

4. The collimating device of the industrial-grade multi-laser length measurement system according to claim 3, wherein, The rectangular target (4) is made of translucent acrylic or frosted glass sheet, and is colorless or colored, with rectangular coordinate two-dimensional grids with a spacing of 1mm.

5. The collimating device of the industrial-grade multi-laser length measurement system according to claim 4, wherein, The base (1) has a concave shape, with the concave part facing the worktable (3).

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