CN113447944A - Three-dimensional laser scanner frame station height measurement system - Google Patents

Abstract

The invention discloses a stand height measurement system of a three-dimensional laser scanner, which relates to the technical field of laser scanning equipment. The scanner main body is provided with a laser emitting unit, a laser receiving unit, a centering laser unit, a first reflecting mirror and a rotatable mirror. The second reflecting mirror, a hollow through hole is opened inside the main body of the scanner, and a dichroic mirror is arranged in the through hole. When measuring the height of the scanner stand, the dichroic mirror transmits the laser light emitted by the laser emitting unit, For the reflection of the laser emitted by the centering laser unit, the visible color laser emitted by the centering laser unit shoots vertically downward through the through hole and locates a known point, and adjusts the pulse ranging laser emitted by the laser emission unit to coincide with the visible color laser. The invention eliminates manual measurement steps, has high measurement efficiency, does not have any influence on the measurement performance of the scanner, reduces measurement errors caused by uneven ground, and ensures the accuracy of the height measurement of the stand.

Description

A three-dimensional laser scanner stand height measurement system

technical field

The invention relates to the technical field of laser scanning equipment, in particular to a stand height measurement system of a three-dimensional laser scanner.

Background technique

The ground-based 3D laser scanner needs to be installed on a tripod and other brackets before the operation. During the operation, multi-station measurements will be performed, and the multi-station scan data will be fused and spliced together through post-processing to form a set of point cloud data. .

When the 3D laser scanner is erected, the ground point of the stand uses RTK and other measuring equipment to accurately record the position coordinates, which provides the accurate stand position for the subsequent point cloud fusion and splicing, and calculates the scanning mirror laser of the scanner according to the coordinates of the ground stand. The coordinates of the output position; with the coordinates of the laser output position, in the process of point cloud fusion and splicing, the data of each station can be accurately positioned, making it easier for the data of adjacent stations to be fused and spliced.

Since the height of the 3D laser scanner is not fixed, only the coordinates of the ground station can not calculate the coordinates of the 3D laser scanner.

For the stand height of the 3D laser scanner, the common measurement method is to measure the length of two sides by means of a right-angled triangle, and calculate the length of the other side, which is the stand height, so as to calculate the coordinates of the laser scanner. Usually a meter ruler is used for manual measurement, but due to the uneven ground, it is difficult to ensure that the measured sides form a right-angled triangle, the measurement error is large, and the measurement efficiency is low. The stand coordinates of the position where the mirror exits the laser. The scanning mirror of some scanners cannot be directly measured inside the fuselage, or direct measurement will cause the scanning mirror to be polluted and affect the measurement performance of the scanner.

There is also a method of adding an auxiliary altimeter sheet, which is to fix the altimeter sheet at the bottom of the instrument and stretch out a section, directly measure the height from the altimeter sheet to the ground, and according to the known height from the altimeter sheet to the laser scanning mirror to emit laser light However, in this case, the measurement error caused by the uneven ground cannot be avoided, and the measurement accuracy cannot be guaranteed.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects in the prior art, the present invention provides a three-dimensional laser scanner stand height measurement system, which can not only accurately measure the stand height by using the measurement function of the three-dimensional laser scanner itself, but also avoid the errors existing in manual measurement. It can also achieve fast and convenient measurement and simplify the tedious operation steps.

The technical scheme adopted by the present invention to solve its technical problems is:

A three-dimensional laser scanner stand height measurement system, comprising a scanner body, the scanner body is provided with a laser emitting unit, a laser receiving unit, a centering laser unit, a first reflecting mirror and a second reflecting mirror, the The second reflection mirror is rotatable, the first reflection mirror is arranged on the downstream optical path of the outgoing optical path of the laser emitting unit, the second reflection mirror is arranged on the downstream optical path of the reflection optical path of the first reflection mirror, the laser The receiving unit is used to receive the laser signal reflected on the object to be measured;

A hollow through hole is opened inside the scanner body, and a dichroic mirror is arranged in the through hole. In the downstream optical path of the emitting optical path, the visible color laser light emitted by the centering laser unit is reflected by the dichroic mirror, and the pulse ranging laser reflected by the second mirror is transmitted through the dichroic mirror. Further, the reflective surface of the first reflecting mirror is at 45 degrees, and the reflecting surface of the second reflecting mirror is at 45 degrees.

Further, a vertical motor is included, and the output end of the vertical motor is connected to the second reflector through a rotating shaft.

Further, it includes a control unit and a power supply for supplying power to the scanner body, the control unit includes a motor controller, a processor for judging the rotation angle of the vertical motor, and a processor for controlling the vertical motor Rotation angle of the drive.

Further, the scanner main body includes a left cavity, a right cavity and a reflection cavity located between the left cavity and the right cavity, the laser emitting unit, the laser receiving unit, the The centering laser unit and the first reflection mirror are arranged in the left cavity, and the through hole and the second reflection mirror are arranged in the reflection cavity.

Further, the dichroic mirror is inclined in the through hole.

Further, the bottom end of the main body of the scanner is provided with a bracket, and the bracket is provided with an opening that communicates with the through hole.

Further, the pulse ranging laser is transmitted on the dichroic mirror, and the visible color laser is reflected on the dichroic mirror.

Further, a calibration device for adjusting the levelness of the scanner body is included.

Further, the laser emitting unit includes a laser, a collimator and an optical fiber, the laser outputs the pulse ranging laser through the optical fiber, and the pulse ranging laser is collimated by the collimator and then shoots toward the first laser. a reflector.

Compared with the prior art, the beneficial effects of the present invention are:

In the present invention, a laser emitting unit, a laser receiving unit, a centering laser unit, a first reflecting mirror and a rotatable second reflecting mirror are arranged in the main body of the scanner, and a hollow through hole is opened inside the main body of the scanner, and the through hole is A dichroic mirror is provided, according to the characteristics of the dichroic mirror, the laser light emitted by the laser emitting unit is transmitted, and the laser light emitted by the centering laser unit is reflected;

When measuring the height of the scanner stand, the visible color laser emitted by the centering laser unit shoots down the through hole vertically and locates a known point, adjust the pulse ranging laser emitted by the laser emission unit to coincide with the visible color laser, and the laser emission unit The measurement function is run for many times, the average value is obtained, and the accurate stand height is finally obtained. The present invention realizes the accurate measurement of the stand height by using its own height measuring function while ensuring the height measuring function of the three-dimensional laser scanner, eliminating the need for manual measurement. The measurement efficiency is high, the reflection mirror or the scanning mirror will not be polluted, the measurement performance of the scanner will not be affected, the measurement error caused by the uneven ground is reduced, and the accuracy of the height measurement of the stand is guaranteed.

Description of drawings

Fig. 1 is the structural representation of embodiment 1;

Fig. 2 is the structural representation of embodiment 2;

In the picture:

1. Scanner body; 101, Left cavity; 102, Right cavity; 103, Reflective cavity; 2, Laser emission unit; 201, Laser; 202, Collimator; 203, Optical fiber; 204, Pulse ranging laser ; 3, laser receiving unit; 4, first mirror; 5, second mirror; 6, vertical motor; 7, rotating shaft; 8, power supply; 9, motor controller; 10, processor; 11, known point; 12, bracket; 13, centering laser unit; 1301, visible color laser; 14, through hole; 15, dichroic mirror; 16, encoder; 17, photoelectric conversion circuit.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects solved by the invention clearer, the invention will be further described below with reference to the accompanying drawings and embodiments. The present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

Example 1

As shown in FIG. 1 , this embodiment provides a three-dimensional laser scanner, including a scanner main body 1, and the scanner main body 1 is provided with a laser emitting unit 2, a laser receiving unit 3, a first reflecting mirror 4 and a second reflecting mirror 5. The first reflection mirror 4 is arranged on the downstream optical path of the outgoing optical path of the laser emitting unit 2, the second reflection mirror 5 is arranged on the downstream optical path of the reflection optical path of the first reflection mirror 4, and the laser receiving unit 3 is used to receive the reflection on the object to be measured. laser signal, the second mirror 5 is driven to rotate by the vertical motor 6, and the second mirror 5 and the vertical motor 6 are connected by the rotating shaft 7. The reflection surface of the mirror 5 is at 45 degrees.

This embodiment also includes a control unit and a power supply 8 for supplying power to the scanner body 1 , the control unit includes a motor controller 9 , a processor 10 for judging the rotation angle of the vertical motor 6 , and a processor 10 for controlling the rotation of the vertical motor 6 Angle drive.

Specifically, the scanner main body 1 includes a left cavity 101, a right cavity 102 and a reflection cavity 103 located between the left cavity 101 and the right cavity 102, a processor 10, a laser emitting unit 2, a laser receiving unit 3 and The first reflection mirror 4 is arranged in the left cavity 101, the laser receiving unit 3 is arranged above the laser emitting unit 2, the second reflection mirror 5 is arranged in the reflection cavity 103, the power supply 8, the control unit, the driver and the vertical motor 6 is provided in the right cavity 102.

The bottom end of the scanner main body 1 is provided with a bracket 12, and the bracket 12 is preferably a tripod with strong stability. The pulse ranging laser 204 emitted by the laser emitting unit 2 can be any pulse laser used for ranging, pulse ranging laser The wavelengths of 204 include, but are not limited to, 1550 nm, 1545 nm, 1064 nm, 940 nm, 905 nm, 850 nm, and 785 nm.

This embodiment also includes a calibration device for adjusting the level of the scanner main body 1. The calibration device can be a level bubble or a level bead, or other devices with calibration functions. The laser emitting unit 2 includes a laser 201, a collimator The laser 201 outputs a pulse ranging laser 204 through the optical fiber 203 , and the pulse ranging laser 204 is collimated by the collimator 202 and then directed to the first mirror 4 .

How the altimetry function works:

The laser 201 outputs the pulse ranging laser 204 through the optical fiber 203, and the pulse ranging laser 204 is collimated by the collimator 202 and then directed to the first mirror 4, then reflected to the second mirror 5, and finally emitted to the object to be measured , the pulse ranging laser 204 is started to start distance measurement, and the average value is obtained by multiple measurements. The second mirror 5 is connected to the rotor of the vertical motor 6 through the rotating shaft 7, and the output direction of the laser is controlled by the rotation of the vertical motor 6. The laser Both the incident angle and the reflection angle on the first mirror 4 are 45 degrees.

Example 2

As shown in FIG. 2 , this embodiment provides a three-dimensional laser scanner stand height measurement system, including a scanner main body 1, and the scanner main body 1 is provided with a laser emitting unit 2, a laser receiving unit 3, and a centering laser unit 13. , a first reflecting mirror 4 and a rotatable second reflecting mirror 5, the first reflecting mirror 4 is arranged on the downstream optical path of the outgoing light path of the laser emitting unit 2, and the second reflecting mirror 5 is arranged at the downstream of the reflecting optical path of the first reflecting mirror 4 Optical path, the laser receiving unit 3 is used to receive the laser signal reflected on the object to be measured, the scanner main body 1 is provided with a hollow through hole 14, the through hole 14 is provided with a dichroic mirror 15, and the dichroic mirror 15 is in the The through hole 14 is inclined and arranged, and the dichroic mirror 15 is arranged on the reflection light path of the second mirror 5 and the downstream light path of the output light path of the centering laser unit 13. The dichroic mirror 15 is also called a dichroic mirror. The light of the other wavelengths is completely transmitted, and the light of other wavelengths is completely reflected. In this embodiment, the pulse ranging laser 204 and the visible color laser 1301 are transmitted or reflected by the characteristics of the above-mentioned dichroic mirror 15.

The visible color laser 1301 emitted by the centering laser unit 13 strikes the dichroic mirror 15, is reflected by the dichroic mirror 15, passes through the through hole 14 and is vertically emitted below the scanner body 1; when the second mirror 5 When rotated to a specific angle, the pulse ranging laser 204 emitted by the laser emitting unit 2 strikes the first reflecting mirror 4, is reflected by the first reflecting mirror 4 to the second reflecting mirror 5, and is then reflected downward by the second reflecting mirror 5, Then, it passes through the through hole 14 and the dichroic mirror 15 and exits the scanner body 1 vertically.

This embodiment includes a vertical motor 6, the second reflecting mirror 5 is driven to rotate by the vertical motor 6, and the second reflecting mirror 5 and the vertical motor 6 are connected by a rotating shaft 7. Preferably, the reflecting surface of the first reflecting mirror 4 is in the shape of a rotating shaft 7. 45 degrees, the reflection surface of the second mirror 5 is 45 degrees.

This embodiment also includes a control unit and a power supply 8 for supplying power to the scanner body 1 . The control unit includes a motor controller 9 , a processor 10 for judging the rotation angle of the vertical motor 6 , and a processor 10 for controlling the rotation of the vertical motor 6 . The angle driver and the photoelectric conversion circuit 17, this embodiment also includes the encoder 16, the processor 10 judges the motor rotation angle through the encoder 16, the processor 10 controls the motor to rotate to the set angle through the driver, the encoder 16 adopts 8000 Linear incremental encoder 16, with an angular resolution of 162 arc seconds, meets the requirements of motor control. In this embodiment, the processor 10 is respectively connected with the laser emitting unit 2 , the centering laser unit 13 , the power supply 8 , the motor controller 9 and the photoelectric conversion circuit 17 , and the photoelectric conversion circuit 17 is located between the processor 10 and the laser receiving unit 3 . between.

Specifically, the scanner main body 1 includes a left cavity 101, a right cavity 102 and a reflection cavity 103 located between the left cavity 101 and the right cavity 102, a processor 10, a laser emitting unit 2, a laser receiving unit 3 and The first reflection mirror 4 is arranged in the left cavity 101 , the power supply 8 , the control unit, the driver and the vertical motor 6 are arranged in the right cavity 102 , and the second reflection mirror 5 is arranged in the reflection cavity 103 .

Specifically, the first reflecting mirror 4 is disposed above the laser emitting unit 2, the laser receiving unit 3 is disposed on one side of the first reflecting mirror 4, and the second reflecting mirror 5 is disposed on the other side of the first reflecting mirror 4. A rotatable second mirror 5 is arranged above the hole 14, the centering laser unit 13 is arranged on one side of the dichroic mirror 15, the laser receiving unit 3 is arranged above the laser emitting unit 2, and the centering laser unit 13 is arranged on the side of the dichroic mirror 15. Below the laser emitting unit 2. It should be noted that the above setting is only a preferred way of this embodiment. Under the condition of ensuring the normal operation of this embodiment, each unit and component in the scanner main body 1 can be adjusted in position according to actual needs.

The bottom end of the scanner main body 1 is provided with a bracket 12, and the bracket 12 is provided with an opening that communicates with the through hole 14. The bracket 12 is preferably a tripod with strong stability, and the pulse ranging laser 204 emitted by the laser emitting unit 2 can be Any pulsed laser used for ranging, the wavelength of the pulsed ranging laser 204 includes but is not limited to 1550 nm, 1545 nm, 1064 nm, 940 nm, 905 nm, 850 nm and 785 nm. The visible-color laser 1301 emitted by the centering laser unit 13 may be any continuous laser visible to the human eye, such as visible red light, visible green light, and visible blue light. The pulsed ranging laser light 204 is transmitted on the dichroic mirror 15 , and the visible color laser light 1301 is reflected on the dichroic mirror 15 .

This embodiment also includes a calibration device for adjusting the level of the scanner main body 1. The calibration device can be a level bubble or a level bead, or other devices with calibration functions. The laser emitting unit 2 includes a laser 201, a collimator The laser 201 outputs a pulse ranging laser 204 through the optical fiber 203 , and the pulse ranging laser 204 is collimated by the collimator 202 and then directed to the first mirror 4 .

When measuring the coordinates of the stand, the specific operation steps are as follows:

S1: Turn on the centering laser unit 13, and align the centering laser unit 13 with the dichroic mirror 15. After being reflected by the dichroic mirror 15, it is aimed at the known point 11 on the ground where the coordinates have been measured. Calibration devices, such as level bubbles, to adjust the level of the instrument;

S2: Start the altimetry function of the instrument, the processor 10 controls the vertical motor 6 to drive the second mirror 5 to rotate, and adjusts the reflection direction of the pulse ranging laser 204 to align with the position of the through hole 14 on the scanner body 1, and lock;

At this time, the pulse ranging laser 204 transmits the dichroic mirror 15 , the incident angle and the reflection angle of the pulse ranging laser 204 on the first mirror 4 are both 45 degrees, and the pulse ranging laser 204 is on the second mirror 5 The incident angle and reflection angle are both 45 degrees, and the pulse ranging laser 204 is emitted vertically downward;

S3: Start the pulse ranging laser 204 to start distance measurement, calculate the average value of multiple measurements, and measure the precise height from the laser exit point to the ground stand site;

S4: Calculate the frame station coordinates of the scanner according to the coordinates of the known frame station on the ground, or input the coordinates of the known frame station on the ground into the 3D laser scanner, and the instrument automatically calculates its own frame station coordinates.

While ensuring the height measurement function of the ground-type three-dimensional laser scanner, the invention adds the function of measuring the height of the stand by using its own height measurement function, eliminating manual measurement steps, high measurement efficiency, and no reflection mirror or scanning mirror. The phenomenon of pollution does not have any effect on the measurement performance of the scanner, reduces the measurement error caused by the uneven ground, and ensures the accuracy of the height measurement of the stand.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall fall within the protection scope of the present invention. within.

Claims (10)

1. A three-dimensional laser scanner frame station height measuring system is characterized by comprising a scanner body, wherein a laser emitting unit, a laser receiving unit, a centering laser unit, a first reflecting mirror and a second reflecting mirror are arranged in the scanner body, the second reflecting mirror can rotate, the first reflecting mirror is arranged on a downstream light path of an emergent light path of the laser emitting unit, the second reflecting mirror is arranged on a downstream light path of a reflected light path of the first reflecting mirror, and the laser receiving unit is used for receiving laser signals reflected on an object to be measured;

the scanner comprises a scanner body and is characterized in that a hollow through hole is formed in the scanner body, a dichroic mirror is arranged in the through hole, the dichroic mirror is arranged on a second reflecting mirror reflection light path and a downstream light path of a centering laser unit emergent light path, visible laser emitted by a centering laser unit is reflected through the dichroic mirror, and pulse ranging laser reflected by the second reflecting mirror is transmitted through the dichroic mirror.

2. The three-dimensional laser scanner gantry station height measurement system of claim 1, wherein the first mirror has a 45 degree reflective surface and the second mirror has a 45 degree reflective surface.

3. The three-dimensional laser scanner gantry station height measurement system of claim 1, comprising a vertical motor, an output of which is coupled to the second mirror via a rotating shaft.

4. The three-dimensional laser scanner gantry height measurement system of claim 3, comprising a control unit and a power supply for supplying power to the scanner body, the control unit comprising a motor controller, a processor for determining the vertical motor rotation angle, and a driver for controlling the vertical motor rotation angle.

5. The three-dimensional laser scanner gantry height measuring system of claim 1, wherein the scanner body comprises a left cavity, a right cavity, and a reflective cavity between the left cavity and the right cavity, the laser emitting unit, the laser receiving unit, the centering laser unit, and the first reflecting mirror are disposed within the left cavity, and the through hole and the second reflecting mirror are disposed within the reflective cavity.

6. The three-dimensional laser scanner gantry height measurement system of claim 1, wherein the dichroic mirror is obliquely disposed within the through hole.

7. The three-dimensional laser scanner erecting station height measuring system as recited in claim 1, wherein a support is provided at a bottom end of said scanner body, said support being provided with an opening communicating with said through hole.

8. The three-dimensional laser scanner gantry height measurement system of claim 1, wherein the pulsed ranging laser is transmitted through the dichroic mirror and the visible color laser is reflected off the dichroic mirror.

9. The three-dimensional laser scanner gantry height measurement system of claim 1, comprising a calibration device for adjusting the level of the scanner body.

10. The three-dimensional laser scanner gantry station height measuring system of any one of claims 1-9, wherein the laser emitting unit comprises a laser, a collimator, and an optical fiber, the laser outputs the pulsed distance measuring laser through the optical fiber, and the pulsed distance measuring laser is collimated by the collimator and then directed to the first reflecting mirror.

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