A line laser emission device and a high-precision elevation measurement method

Abstract

The present invention discloses a line laser emission device and a high-precision elevation measurement method, which include a housing and a rotation drive mechanism, an optical conversion module, and a laser source installed inside the housing; the optical conversion module includes a prism bracket, a cube beam splitter prism, a Powell prism, a driving gear II, a driven gear II, and a motor II; the prism bracket is driven to rotate by the rotation drive mechanism; the bottom of the prism bracket is provided with an opening, the middle part is provided with a clamping groove directly above the opening, and one side is provided with a bearing. The driven gear II is nested at the left end of the Powell prism, the right end of the Powell prism is installed in the bearing, and the cube beam splitter prism is fixed in the clamping groove; the driving gear II is installed on the output shaft of the motor II and meshes with the driven gear II. The present invention can achieve high-precision measurement at a lower cost, while increasing the data acquisition frequency and accuracy, thereby improving the usability and efficiency of the device, especially in a working environment with high-frequency vibration.

Description

Technical Field

[0001] The present invention relates to a line laser emission device and a high-precision elevation measurement method, belonging to the technical field of intelligent construction of subgrade and pavement. Background Art

[0002] In the current measurement technology field, laser measurement devices are widely used due to their high precision and fast response. Especially with the assistance of the Global Positioning System (GPS) and other satellite navigation systems, laser measurement technology has become a key tool in the field of intelligent construction of transportation civil engineering.

[0003] However, although the existing laser measurement devices have made remarkable progress in terms of accuracy and reliability, there are still some limitations. The first is the working performance in high-frequency vibration working scenarios. Laser measurement devices are usually affected by high-frequency vibration noise from rollers during road construction operations, with the vibration frequency around 50 Hz. During measurement, the data accuracy can be effectively improved by increasing the data acquisition frequency and setting anti-vibration measures for the hardware. Increasing the rotation frequency of the rotating laser can effectively increase the amount of data per unit time, but the increase in the rotation frequency will pose challenges to the stability and power consumption of the device;

[0004] The publicly disclosed invention patent (publication number: CN117630998A) mentions an improved laser signal receiving device that uses a hierarchical array arrangement of laser sensors. Although it can increase the data sampling frequency, it doubles the manufacturing cost. Existing high-precision laser measurement devices are often expensive and do not consider the data error problem caused by high-frequency vibration, which limits their application in environments with limited resources or small-scale projects. Summary of the Invention

[0005] The present invention solves the technical problems existing in the prior art by providing a line laser emission device and a high-precision elevation measurement method; the present invention can achieve high-precision measurement at a lower cost, while increasing the data acquisition frequency and accuracy, thereby improving the usability and efficiency of the device, especially in a high-frequency vibration working environment.

[0006] The technical solution provided by the present invention to solve the above technical problems is: a line laser emission device, including a housing and a rotation drive mechanism, an optical conversion module, and a laser source installed in the housing;

[0007] The optical conversion module includes a prism bracket, a cube beam splitter prism, a Powell prism, a driving gear II, a driven gear II, and a motor II. The prism bracket is fixed on the rotation driving mechanism and is driven by the rotation driving mechanism to rotate. An opening is provided at the bottom of the prism bracket, a clamping groove is provided in the middle directly above the opening, and a bearing is provided on one side. The driven gear II is nested at the left end of the Powell prism, and the right end of the Powell prism is installed in the bearing. The cube beam splitter prism is fixed in the clamping groove. The driving gear II is installed on the output shaft of the motor II and meshes with the driven gear II.

[0008] A notch facing the Powell prism is provided on the housing. The laser source is located directly below the cube beam splitter prism.

[0009] A further technical solution is that the rotation driving mechanism includes a driving gear I, a driven gear I, a motor I, and a vertical shaft. The driven gear I is rotatably installed on the vertical shaft. The driving gear I is installed on the output shaft of the motor I and meshes with the driven gear I. The prism bracket is fixed on the driven gear I. A through hole is axially provided on the vertical shaft directly below the opening, and the laser source is located directly below the through hole.

[0010] A further technical solution is that the prism bracket is fixed on the driven gear I by bolts.

[0011] A further technical solution is that the prism bracket is made of aluminum alloy.

[0012] A further technical solution is that the housing is made of ABS engineering plastic material.

[0013] A further technical solution is that a high-transmission quartz glass is provided in the notch to protect the Powell prism from the influence of the external environment.

[0014] A high-precision elevation measurement method specifically includes the following steps:

[0015] Step 1: Place the line laser emitting device at the reference point. After centering and leveling, start the line laser emitting device. The line laser emitting device emits a rotating line laser in space, and at the same time, the line laser deflects in space.

[0016] Step 2: Place the line laser receiving device at the measurement point to be measured and adjust the direction of its received laser to face the line laser emitting device.

[0017] Step 3: Record the corresponding data of the line laser during the acquisition time and substitute it into the elevation calculation formula to calculate the final relative elevation value between the center of the line laser receiving device and the center of the line laser emitting device.

[0018] Step 4: Calculate the absolute elevation of the center of the line laser receiving device based on the final relative elevation value.

[0019] A further technical solution is that the specific process of the line laser deflecting in space in step 1 is as follows: The motor II drives the driving gear II, and drives the driven gear II and the Powell prism to rotate. First, the driving gear II rotates clockwise α degrees, then rotates the driving gear II counterclockwise by 2 α degrees, and finally rotates the driving gear II clockwise by α degrees to reset, where α ranges from 15° to 35°.

[0020] A further technical solution is that the elevation calculation formula includes:

[0021]

[0022]

[0023] In the formula: Δ H is the final relative elevation value between the center of the line laser receiving device and the center of the line laser emitting device; Δ H i is the calculated relative elevation value between the center of the line laser receiving device and the center of the line laser emitting device for the i -th calculation; n is the number of calculation values, with a size of ; p is the data ratio to be excluded, with a value range of 0 to 0.5; p × n represents the floor value of excluding the p × n observed values at both ends of the data set; h 0 is the vertical distance between the upper sensor and the lower sensor in the line laser receiving device, a is the vertical distance correction coefficient, with a value range of 0.5 to 1.5, ω is the rotation speed of the line laser emitting device, f 1 is the sine function in trigonometric functions, f 2 is the tangent function in trigonometric functions, t i1 、 t i2 、 t i3 are the time data of the three responses of the upper sensor of the line laser receiving device arranged from small to large, t j1 、 t j2 、 t j3They are the time data arranged from small to large of the three responses of the lower sensor of the line laser receiving device.

[0024] A further technical solution is that the calculation formula in step 4 is:

[0025]

[0026] In the formula: H A is the absolute elevation of the center of the line laser receiving device, H B is the absolute elevation of the center of the line laser transmitting device, and Δ H is the final value of the relative elevation between the center of the line laser receiving device and the center of the line laser transmitting device.

[0027] The beneficial effects of the present invention are:

[0028] 1. Optimize the structure of the laser emission end, especially the beam splitting prism component. Only one beam splitting prism and one Powell prism component are used. By adjusting the angle change of the Powell prism through the rotation mechanism, the rotation of line lasers with different shapes in space is realized;

[0029] 2. A high-precision ranging algorithm is proposed. When the laser rotates 10 circles in 1 second, 10 data can be obtained. Using three of these data and substituting them into the calculation formula, a height calculation value can be obtained. Taking 3 out of 10, that is = 120 kinds, and the data update frequency is 120Hz. In road construction, the vibration compaction frequency of the road roller is about 50Hz. Since 120 > 50, this algorithm can effectively avoid the influence brought by the vibration noise of the road roller. Description of the Drawings

[0030] Figure 1 is the overall structural schematic diagram of a line laser transmitting device of the present invention;

[0031] Figure 2 is the schematic diagram of the Powell prism converting the line laser of the present invention;

[0032] Figure 3 is the schematic diagram of the line laser deflection range;

[0033] Figure 4 is the schematic diagram of the line laser transmitting device emitting the line laser;

[0034] Figure 5 is the installation schematic diagram of the line laser transmitting device and the line laser receiving device in the high-precision elevation measurement method of the present invention.

[0035] As shown in the figure: 1 - housing; 2 - laser source; 3 - through hole; 4 - vertical axis; 5 - driven gear I; 6 - Powell prism; 7 - driven gear II; 8 - driving gear II; 9 - motor II; 10 - cube beam splitter prism; 11 - prism bracket; 12 - high - transmission quartz glass; 13 - opening; 14 - driving gear I; 15 - through hole. Detailed implementation manners

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] As Figure 1 shown, a line - laser emission device provided by the present invention includes a housing 1 and a rotation drive mechanism, an optical conversion module, and a laser source 2 installed in the housing 1;

[0041] The laser source 2 emits dot - shaped laser from bottom to top, with a laser wavelength of 635 nm, a laser power of 2 mW, and the working mode of the laser source being continuous - wave mode. It is fixedly connected to the inner wall of the housing 1;

[0042] The optical conversion module includes a prism bracket 11 (made of aluminum alloy), a cube beam splitter prism 10, a Powell prism 6, a driving gear II 8, a driven gear II 7, and a motor II 9; the prism bracket 11 is fixed on the rotation driving mechanism, and the prism bracket 11 is driven by the rotation driving mechanism to rotate clockwise at a rotation speed of 600 rpm (600 revolutions per minute, 10 revolutions per second); an opening 13 with a diameter of 20 mm is provided at the bottom of the prism bracket 11, a clamping groove (with a length of 20 mm and a width of 20 mm) is provided in the middle directly above the opening 13, a bearing hole with a diameter of 25 mm is provided on the side wall, and a bearing (with an inner diameter of 20 mm and an outer diameter of 25 mm, used to bear radial loads and achieve precise rotational movement) is horizontally provided in the bearing hole. The cube beam splitter prism 10 is fixed in the clamping groove by UV glue. The driven gear II 7 is nested at the left end of the Powell prism 6, the right end of the Powell prism 6 is horizontally installed in the bearing, and its right end extends into the prism bracket 11 and faces the left side of the cube beam splitter prism 10; the driving gear II 8 is installed on the output shaft of the motor II 9 and meshes with the driven gear II 7;

[0043] The cube beam splitter prism 10 is used to change the propagation path of the dot laser, convert the dot laser propagating from bottom to top into a horizontally propagating laser, with dimensions of 20 mm×20 mm×20 mm, a working wavelength range of 400~700 nm, and a beam splitting ratio of 70R / 30T; the transmission ratio of the driven gear II 7 to the driving gear II 8 is 1;

[0044] The Powell prism 6 is used to convert the dot laser into a line laser (as shown in Figure 2 ), with a diameter of 20 mm and a divergence angle of 30°;

[0045] A notch facing the Powell prism 6 is provided on the housing 1; the laser source 2 is located directly below the cube beam splitter prism 10.

[0046] The motor II 9 drives the driven gear II 7 through the driving gear II 8 to deflect according to the deflection rule, so as to realize the deflection of the line laser in space. The rotation speed of the driving gear II 8 is 50 rpm. Initially, the angle between the line laser and the plumb line is 0°. The deflection rule is that first the driving gear II 8 rotates clockwise by α degrees, then the driving gear II 8 rotates counterclockwise by 2 α degrees, and finally the driving gear II 8 rotates clockwise by α degrees to reset. The range of α is 15°~35°; (as shown in Figure 3 )

[0047] In this embodiment, a specific implementation of the rotation drive mechanism includes a driving gear I 14, a driven gear I 5, a motor I 15, and a vertical shaft 4, which is used to drive the prism bracket 11 to rotate clockwise at a rotation speed of 600 rpm (600 revolutions per minute, 10 revolutions per second); the driven gear I is rotatably installed on the vertical shaft, the driving gear I is installed on the output shaft of the motor I and meshes with the driven gear I; the prism bracket 11 is fixed to the driven gear I 5 by bolts, a through hole 3 is axially provided on the vertical shaft 4 directly below the opening 13, and the laser source is located directly below the through hole 3; in this way, the dot laser emitted upward from the laser source 2 passes through the through hole 3 and the opening 13 in sequence, enters the cube beam splitter prism 10, then enters the Powell prism 6 through the cube beam splitter prism 10, and the Powell prism 6 converts the dot laser into a line laser and emits it out of the housing 1 (as Figure 4 shown).

[0048] In this embodiment, the housing 1 is used to encapsulate and protect the internal electronic components, and is made of ABS engineering plastic material. The housing 1 has the characteristics of impact resistance, insulation and wear resistance, and is formed by an injection molding process, and its wall thickness is uniform to ensure mechanical strength and stability.

[0049] In this embodiment, in order to protect the Powell prism 6, a preferred implementation is that a high-transmission quartz glass 12 is provided at the notch on the upper side of the housing 1 to protect the Powell prism 6 from the influence of the external environment, such as dust, moisture, solvents and mechanical damage.

[0050] As Figure 5 shown, a high-precision elevation measurement method using the above embodiment specifically includes the following steps:

[0051] Step 1: Place the line laser emitting device at the reference point. After centering and leveling, start the line laser emitting device. The line laser emitting device emits a rotating line laser in space, and at the same time the line laser deflects in space according to the deflection rule;

[0052] The deflection rule is: the rotation speed of the driving gear II 8 is 50 rpm. Initially, the angle between the line laser and the plumb line is 0°. The deflection rule is that first the driving gear II 8 rotates clockwise by α degrees, then the driving gear II 8 rotates counterclockwise by 2 α degrees, and finally the driving gear II 8 rotates clockwise by α degrees to reset, α and the range of is 15° to 35°;

[0053] Step 2: Place the line laser receiving device at the measurement point to be measured, and adjust the direction of its received laser to face the line laser emitting device;

[0054] Step 3: Record the corresponding data of the line laser within the acquisition time t, and substitute it into the elevation calculation formula to calculate the final relative elevation value between the center of the line laser receiving device and the center of the line laser transmitting device;

[0055] Within the acquisition time t, the line laser receiving device has 10×t response data for the line laser emitted by the line laser transmitting device. Arbitrarily select three of the response data and substitute them into the elevation calculation formula for calculation. There are a total of ways of selection, and there are a total of times (subsequently replaced by n). The truncated mean algorithm (to reduce the influence of extreme values on the overall average) is used to calculate the final relative elevation value between the center of the line laser receiving device and the center of the line laser transmitting device. The calculation method is as follows:

[0056]

[0057]

[0058] In the formula: Δ H is the final relative elevation value between the center of the line laser receiving device and the center of the line laser transmitting device; Δ H i is the calculated relative elevation value between the center of the line laser receiving device and the center of the line laser transmitting device for the i th calculation; n is the number of calculated values, with a size of ; p is the data ratio to be excluded, with a value range of 0 to 0.5; p × n means rounding down the value of excluding p × n observed values at both ends of the data set; h 0 is the vertical distance between the upper sensor and the lower sensor in the line laser receiving device, a is the vertical distance correction coefficient, with a value range of 0.5 to 1.5, ω is the rotation speed of the line laser transmitting device, f 1 is the sine function in trigonometric functions, f 2 is the tangent function in trigonometric functions, t i1 、 t i2 、 t i3 are the time data of the three responses of the upper sensor of the line laser receiving device arranged from small to large, t j1 、 t j2 、 t j3They are the time data of the three responses of the lower sensor of the line laser receiving device arranged from small to large;

[0059] Step 4: Calculate the absolute elevation of the center of the line laser receiving device according to the final relative elevation value;

[0060]

[0061] In the formula: H A is the absolute elevation of the center of the line laser receiving device, H B is the absolute elevation of the center of the line laser transmitting device, and Δ H is the final relative elevation value between the center of the line laser receiving device and the center of the line laser transmitting device.

[0062] As mentioned above, it is not any form of limitation to the present invention. Although the present invention has been disclosed by the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments with equivalent changes by using the disclosed technical content within the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A line laser emission device, characterized in that, It includes a housing and a rotary drive mechanism, an optical conversion module, and a laser source installed inside the housing; The optical conversion module includes a prism bracket, a cube beam splitter prism, a Powell prism, a driving gear II, a driven gear II, and a motor II; the prism bracket is fixed on the rotary drive mechanism and is driven by the rotary drive mechanism to rotate; the bottom of the prism bracket is provided with an opening, a clamping groove is provided in the middle directly above the opening, and a bearing is provided on one side. The driven gear II is nested at the left end of the Powell prism, and the right end of the Powell prism is installed in the bearing. The cube beam splitter prism is fixed in the clamping groove; the driving gear II is installed on the output shaft of the motor II and meshes with the driven gear II; A notch facing the Powell prism is provided on the housing; the laser source is located directly below the cube beam splitter prism. The rotary drive mechanism includes a driving gear I, a driven gear I, a motor I, and a vertical shaft; the driven gear I is rotatably installed on the vertical shaft. The driving gear I is installed on the output shaft of the motor I and meshes with the driven gear I; the prism bracket is fixed on the driven gear I. A through hole is axially provided on the vertical shaft directly below the opening, and the laser source is located directly below the through hole.

2. The line laser emitting device according to claim 1, characterized in that The prism bracket is fixed on the driven gear I by bolts.

3. A line laser emission device according to claim 1, wherein, The prism bracket is made of aluminum alloy.

4. A line laser emitting device according to claim 1, characterized in that, The housing is made of ABS engineering plastic material.

5. The line laser emitting device according to claim 1, characterized in that, A high-transmission quartz glass is provided in the notch to protect the Powell prism from the influence of the external environment.

6. A high-precision elevation measurement method, characterized in that, This method uses a line laser emission device according to any one of claims 1-5 for measurement, specifically including the following steps: Step 1: Place the line laser emission device at the reference point. After centering and leveling, start the line laser emission device. The line laser emission device emits a rotating line laser in space, and at the same time, the line laser deflects in space; Step 2: Place the line laser receiving device at the point to be measured and adjust the direction of its laser receiving surface to face the line laser emission device; Step 3: Record the corresponding data of the line laser during the acquisition time and substitute it into the elevation calculation formula to calculate the final relative elevation value between the center of the line laser receiving device and the center of the line laser emission device; Where: Δ H is the final relative elevation value between the center of the line laser receiving device and the center of the line laser emitting device; Δ H i is the relative elevation calculated value of the center of the line laser receiving device and the center of the line laser emitting device calculated for the i th time; n is the number of calculated values, with a size of ; p is the data ratio to be excluded, with a value range of 0 to 0.5; p × n represents the floor value of excluding the p × n observation values at both ends of the data set; h 0 is the vertical distance between the upper and lower sensors in the line laser receiving device, a is the vertical distance correction coefficient, with a value range of 0.5 to 1.5, ω is the rotation speed of the line laser emitting device, f 1 is the sine function in trigonometric functions, f 2 is the tangent function in trigonometric functions, t i1 、 t i2 、 t i3 are the time data of the three responses of the upper sensor of the line laser receiving device arranged from small to large, t j1 、 t j2 、 t j3 are the time data of the three responses of the lower sensor of the line laser receiving device arranged from small to large; Step 4: Calculate the absolute elevation of the center of the line laser receiving device according to the final relative elevation value.

7. A high-precision elevation measurement method according to claim 6, characterized in that, The specific process of the line laser deflecting in space in step 1 is as follows: The motor II drives the driving gear II, and drives the driven gear II and the Powell prism to rotate. First, the driving gear II rotates clockwise α degrees, then the driving gear II rotates counterclockwise by 2 α degrees, and finally the driving gear II rotates clockwise by α degrees to reset, where α ranges from 15° to 35°.

8. A high-precision elevation measurement method according to claim 6, characterized in that, The calculation formula in Step 4 is: In the formula: H A is the absolute elevation of the center of the line laser receiving device, H B is the absolute elevation of the center of the line laser transmitting device, Δ H is the final value of the relative elevation between the center of the line laser receiving device and the center of the line laser transmitting device.

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