A large-range precision scanning device and its topography reconstruction method

Abstract

The present invention discloses a large-range precision scanning device and a method for topography reconstruction thereof. The present invention includes a laser ranging system, a motion servo system, a user interaction system, an intermediate-frequency vibration sensing and adaptive measurement system, and a power supply system. A light spot is emitted to a measurement point by an improved laser phase method ranging system; after the light spot of the specific wavelength is reflected by the ground, it sequentially passes through the fixed mirror group, the zoom lens group unit, the adapter mirror group, and finally enters the detector; the detector acquires the reflected image of the ground light spot collected and obtains the distance offset value of the corresponding measurement point. Based on the device disclosed in the present invention, the use of a dual-sensing ranging scheme can achieve measurement within a range of 30 m for the construction pouring surface of high-reflectivity concrete, realize intermediate-frequency vibration sensing and adaptive measurement at the construction site, improve the efficiency of differential frequency phase method laser ranging, and realize large-range topography reconstruction.

Description

Technical Field

[0001] The present invention relates to precision detection technology, and particularly to a large-range precision scanning device and a method for topography reconstruction thereof. The present invention provides two working modes of single-point ranging and elevation measurement, and can achieve high-precision measurements such as distance measurement, elevation measurement, and topography reconstruction. Background Art

[0002] Total stations use a technology called Phase Measurement to measure distances. This technology uses a light beam emitted by a light source such as a laser or infrared ray, which is irradiated onto a reflecting prism or object on the target, and then the light beam is reflected back to the total station. The ranging device inside the total station is usually a laser rangefinder that measures the round-trip time of the light beam, and then calculates the distance between the target object and the instrument based on the speed of light and time.

[0003] At present, there are already mature commercial products of total stations. The main foreign manufacturers include Leica, TOPCON, etc., and the main domestic manufacturers include South Surveying & Mapping, Suzhou Yiguang, etc. A wide variety of total stations have been developed according to different measurement requirements, and the highest resolution can reach the millimeter level.

[0004] Concrete construction has multiple processes such as spreading, leveling, troweling, etc. It is of great significance to measure and analyze the parameters such as surface elevation and height difference in real time, efficiently and accurately during the construction process to ensure and improve the construction quality. The pouring surface has various forms, and there are huge differences in characteristics such as surface strength, moisture content, and reflectivity. During the construction process, the reflectivity of the pouring surface is high, and often no data can be obtained for ranging; the construction site environment of the pouring surface is complex, and background vibration is inevitable, seriously affecting the measurement accuracy. Existing measurement methods mostly use a laser emitter and a calibration rod system for manual measurement, with an error greater than 3 mm, which cannot meet the construction accuracy requirements, and has poor timeliness, consumes a large amount of labor costs, and will damage the completed surface.

[0005] To solve the above problems, the present invention discloses a large-range precision scanning device and a method for topography reconstruction thereof. Based on a dual-sensing ranging scheme, a triangulation ranging system and an improved heterodyne phase method laser ranging system are invented to achieve precise imaging of the projected light spot at a large tilt angle. A motion servo system is invented to read the absolute position to ensure the measurement accuracy. A medium-frequency vibration perception and adaptive measurement technology for the construction site is proposed, and a method for topography reconstruction is proposed. Summary of the Invention

[0006] The object of the present invention is to propose a large-range precision scanning device and a method for topography reconstruction thereof to measure the problem that traditional ranging methods cannot achieve efficient measurement due to the huge differences in characteristics such as surface strength, moisture content, and reflectivity during the concrete construction process.

[0007] To achieve the above object, the present invention adopts the following technical solutions to solve the problem:

[0008] A large-range precision scanning device includes a laser ranging system, a motion servo system, a user interaction system, an intermediate-frequency vibration sensing and adaptive measurement system, and a power supply system; the laser ranging system provides position and distance data, and the motion servo system adjusts the movement path of the device; the intermediate-frequency vibration sensing system monitors vibrations in real time and optimizes measurement data; the user interaction system feeds back the device status to the user and at the same time receives user instructions, and the industrial control computer in the user interaction system directly controls the operation of the motion servo system and the laser ranging system; the power supply system is used to supply power to the laser ranging system, the motion servo system, the user interaction system, and the intermediate-frequency vibration sensing and adaptive measurement system, and monitors the power status in real time to ensure the normal operation of the system.

[0009] Further, the laser ranging system consists of a ranging system using an improved laser phase method and a laser triangulation ranging system with a variable working distance.

[0010] Further, the ranging system using the improved laser phase method includes a DAC module, a laser driving module, a photodiode amplification module, a photodetector, a pre-amplification circuit, a signal conditioning module, a data acquisition and processing module, and a laser; the signal conditioning module includes an AGC circuit, a mixing circuit, and a filtering circuit;

[0011] The DAC module: generates a modulation signal and a local oscillator signal, where the local oscillator signal is stored in the DAC module, and the modulation signal is sent to the photodiode amplification module;

[0012] The photodiode amplification module: amplifies the modulation signal to generate a modulation voltage signal and sends it to the laser driving module;

[0013] The laser driving module: converts the modulation voltage signal into a modulation current signal and generates a DC bias current to jointly drive the laser, maintaining the laser at the required operating point to ensure that the laser can work in a stable state;

[0014] The laser emits laser light that passes through a mirror, and the optical path is divided into two. The first path passes through an optical fiber coupler, and the other path passes through a telescope lens group and is reflected back from a reflecting surface. Finally, both optical signals pass through the photodetector;

[0015] The photodetector converts the two received optical signals into two weak current signals respectively. The current signals are converted into voltage signals after passing through the pre-amplification circuit and are input to the signal conditioning module;

[0016] The AGC circuit included in the signal conditioning module receives two voltage signals, and then the mixing circuit and the filtering circuit adjust the signal amplitudes of the two voltage signals, reduce the high-frequency signals to the low-frequency band, filter out the high-frequency signals, and output low-frequency signals;

[0017] The data acquisition and processing module: includes a data acquisition unit and a data processing unit. The data acquisition unit is used to acquire the low-frequency signals output by the signal conditioning module, and the data processing unit processes the acquired low-frequency signals. The data processing unit obtains the phase difference of the signals and the ranging data D' of the object to be measured;

[0018]

[0019] where λ represents the wavelength of light.

[0020] Furthermore, the laser triangulation ranging system with variable working distance includes a fixed lens group, a zoom lens group unit, a relay lens group, and a detector; a light spot is emitted to the measuring point by the improved laser phase ranging system. After the light spot with a specific wavelength is reflected by the ground, it passes through the fixed lens group, the zoom lens group unit, and the relay lens group in sequence, and finally enters the detector; the detector acquires the reflected image of the ground light spot collected and obtains the distance offset value of the corresponding measuring point; the zoom lens group unit can achieve continuous zooming from 15m to 30m.

[0021] Furthermore, the fixed lens group and the zoom lens group unit in the laser triangulation ranging system with variable working distance are built in the way of positive lens group + negative lens group. The positive lens group is used to converge light, and the negative lens group is used to shorten the total length of the system. By changing the distance between the negative lens group and the positive lens group, the focal length of the lens group is changed to achieve focusing on object points at different distances;

[0022] The focal length f of the laser triangulation ranging system with variable working distance is:

[0023]

[0024] where f1, f2, and f are the focal lengths of the positive lens group, the negative lens group, and the combined system respectively; d is the focal length between the positive lens group and the negative lens group.

[0025] Furthermore, the motion servo system consists of a laser ranging precision pitching rotating shaft, a triangulation ranging precision pitching rotating shaft, a horizontal precision rotating shaft, and a triangulation automatic precision focusing system;

[0026] The precision pitching rotation axis for laser ranging is driven by a two-stage transmission of helical gears and worm gears, and a high-precision absolute circular grating is installed on the axis to accurately obtain the absolute position during laser ranging. The precision pitching rotation axis for triangulation ranging is also driven by a two-stage transmission of helical gears and worm gears, and the position of the triangulation ranging system is obtained through the absolute circular grating. The horizontal precision rotation axis also has an absolute circular grating and can obtain the absolute position during the scanning process. The automatic precision focusing system for triangulation is equipped with an absolute magnetic ring encoder and can achieve automatic focusing after obtaining the current absolute angular position.

[0027] Furthermore, the intermediate-frequency vibration sensing and adaptive measurement system senses environmental vibrations through inertial accelerometers placed on the ground, calculates the tilt angles of the horizontal and vertical axes, analyzes its own vibrations using the data of the biaxial compensator, compensates the measurement results according to the angles, analyzes the intensity-time curve of the vibration signal, and realizes the zero-crossing sampling of the vibration for the ranging data.

[0028] Furthermore, a method for realizing a large-range precision scanning device establishes a measurement space coordinate system with reference to the mechanical structure of the large-range precision scanning device; takes the vertical direction as the z direction of the measurement space coordinate system; takes the ground as the zero plane in the z direction of the measurement space coordinate system, and the specific wavelength is preferably 650 nm;

[0029] The straight line perpendicular to the vertical direction on the plane where the laser ranging axis and the triangulation ranging optical path are located is taken as the x direction of the measurement space coordinate system, and the direction perpendicular to both the z axis and the x direction is taken as the y direction of the measurement space coordinate system; the geometric center of the leveling base of the large-range precision scanning device is taken as the geometric zero point of the measurement space coordinate system, and the vertically upward direction is the positive direction of the z axis; the measurement point is denoted as point A', the center of the rotation axis of the triangulation ranging system is point D, the center of the rotation axis of the laser ranging is point C, the offset of the measurement point obtained by the triangulation ranging system is Δx, the height data of the measurement point relative to the measuring device is Δh, and the range reference point A is set at the intersection of the receiving optical axis and the transmitting optical axis to minimize the off-axis aberration of the range center point. The formulas are as follows:

[0030] l o tan(α - β) = l i tan(90° - θ1)

[0031]

[0032] b = l o sin(α - β)

[0033]

[0034] Δh = Δz·cosα

[0035]

[0036] Among them, Δz is the distance between the position A' of the object to be measured and the reference position A, Δx is the distance between the imaging spot B' on the photodetector and the reference position B, f1, f2, and f are the focal lengths of the positive and negative lens groups and the combined system respectively; d is the focal length between the lens groups, θ1 is the angle between the image plane and the normal direction of the triangulation lens group, and θ2 is the angle between the reference position and the line connecting the measured position and the focus of the lens group; l i 、l o are the object distance and image distance at the reference point respectively, α is the angle between the outgoing optical axis and the optical axis of the receiving lens, and β is the angle between the image plane and the receiving optical axis.

[0037] The beneficial effects of the present invention compared with the prior art are as follows:

[0038] First, the present invention uses a dual-sensing ranging scheme to achieve measurement within a range of 30 m on the construction pouring surface of high-reflectivity concrete; second, the present invention measures the on-site ground vibration based on an inertial acceleration sensor, analyzes its own vibration using a biaxial compensator, and realizes medium-frequency vibration perception and adaptive measurement at the construction site; third, the present invention uses a high-frequency DAC to generate transmitted data with variable frequency and arbitrary phase offset, improves the efficiency of differential frequency phase method laser ranging, and realizes large-range topography reconstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of the composition of a large-range precision scanning device according to an embodiment of the present invention.

[0040] Figure 2 is a schematic diagram of the principle and composition of laser phase ranging according to an embodiment of the present invention.

[0041] Figure 3 is a schematic diagram of the principle of a triangulation ranging system according to an embodiment of the present invention.

[0042] Figure 4 is a simplified diagram of a triangulation ranging zoom system according to an embodiment of the present invention.

[0043] Figure 5 is a schematic diagram of the principle of the device measurement method according to an embodiment of the present invention.

[0044] Figure 6 is a schematic diagram of the composition of a frequency vibration perception and adaptive measurement system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following specifically describes the present invention with reference to the drawings and embodiments.

[0046] The embodiments of the present invention relate to a large-range precision scanning device and a topography reconstruction method thereof, which can be used for precise measurement of geometric quantities.

[0047] [1] First Embodiment

[0048] The following describes the first embodiment proposed according to the present invention with reference to the accompanying drawings.

[0049] As Figure 1 shown, according to an embodiment proposed by the present invention, a large - range precision scanning device includes a laser ranging system 100, a motion servo system 200, a user interaction system 300, an intermediate - frequency vibration sensing and adaptive measurement system 400, and a power supply system 500. The laser ranging system 100 provides position and distance data, and the motion servo system 200 adjusts the movement path of the device; the intermediate - frequency vibration sensing system 400 monitors vibrations in real - time and optimizes measurement data to improve the accuracy of the data; the user interaction system 300 feeds back the device status to the user and at the same time receives user instructions; the power supply system 500 provides stable power for all other systems and monitors the power status in real - time to ensure the normal operation of the system.

[0050] As Figure 1 shown, in this embodiment, the laser ranging system 100 consists of a group of ranging systems 102 that improve the laser phase method and a group of laser triangulation ranging systems 101 with variable working distances.

[0051] The motion servo system 200 consists of a laser ranging precision pitching shaft 203, a triangulation ranging precision pitching shaft 202, a horizontal precision slewing shaft 204, and a triangulation automatic precision focusing system 201.

[0052] The laser ranging precision pitching shaft 203 is driven by a two - stage transmission of helical gears and worm gears, and a high - precision absolute circular grating is installed on the shaft, which can accurately obtain the absolute position during laser ranging; the triangulation ranging precision pitching shaft 202 is also driven by a two - stage transmission of helical gears and worm gears, and the position of the triangulation ranging system is obtained through an absolute circular grating; the horizontal precision slewing shaft 204 also has an absolute circular grating and can obtain the absolute position during the scanning process; the triangulation automatic precision focusing system 201 is equipped with an absolute magnetic ring encoder and can achieve automatic focusing after obtaining the current absolute angular position.

[0053] The laser ranging precision pitching shaft 203, the triangulation ranging precision pitching shaft 202, the horizontal precision slewing shaft 204, and the triangulation automatic precision focusing system 201 can all obtain the current absolute position through high - precision absolute angular encoders and absolute magnetic ring encoders, improving the accuracy of ranging.

[0054] As Figure 2As shown, in this embodiment, the ranging system 102 using the improved laser phase method includes a DAC module 102-1, a laser driving module 102-2, a photodiode amplification module 102-3, a photodetector 102-4, a pre-amplification circuit 102-5, a signal conditioning module 102-6, a data acquisition and processing module 102-8, and a laser 102-9. The signal conditioning module 102-6 includes an AGC circuit 102-7, a mixing circuit, and a filtering circuit, which are used to adjust the signal amplitude, reduce the high-frequency signal to the low-frequency band, filter out the high-frequency signal, and output a low-frequency signal.

[0055] The DAC module 102-1 generates a dual-frequency modulation signal. There is no integer multiple relationship between the two frequencies. By using two different phase detectors, the phase difference data is finally obtained.

[0056] The DAC module 102-1: generates a modulation signal and a local oscillator signal. The local oscillator signal is stored in the DAC module 102-1, and the modulation signal is sent to the photodiode amplification module 102-3.

[0057] The photodiode amplification module 102-3: amplifies the modulation signal, generates a modulation voltage signal, and sends it to the laser driving module 102-2.

[0058] The laser driving module 102-2: converts the modulation voltage signal into a modulation current signal and generates a DC bias current to jointly drive the laser 102-9, maintaining the laser 102-9 at the required operating point to ensure that the laser 102-9 can operate in a stable state.

[0059] The laser 102-9 emits laser light that passes through a mirror 102-10. The optical path is divided into two. The first path passes through an optical fiber coupler 102-11, and the other path passes through a telescope lens group 102-12 and is reflected back from a reflecting surface. Finally, both optical signals pass through the photodetector 102-4;

[0060] The photodetector 102-4 converts the two received optical signals into two weak current signals respectively. The current signals are converted into voltage signals after passing through the pre-amplification circuit 102-5 and are input to the signal conditioning module 102-6;

[0061] The AGC circuit 102-7 included in the signal conditioning module 102-6 receives the two voltage signals, and then the mixing circuit and the filtering circuit adjust the signal amplitude of the two voltage signals, reduce the high-frequency signal to the low-frequency band, filter out the high-frequency signal, and output a low-frequency signal.

[0062] The data acquisition and processing module 102-8: It includes a data acquisition unit and a data processing unit. The data acquisition unit is used to acquire the low-frequency signals output by the signal conditioning module 102-6, and the data processing unit processes the acquired low-frequency signals, and the data processing unit obtains the phase difference of the signals and the ranging data D' of the object to be measured.

[0063]

[0064] Among them, λ represents the wavelength of light.

[0065] As Figure 3 shown, it is a laser triangulation ranging system 101 with a variable working distance; adding a laser triangulation ranging system 101 with a variable working distance can capture the projected shape of the light spot, improve the overall measurement accuracy of the system by using multi-sensor fusion, and through innovative optical zoom design, achieve precise imaging of the projected light spot with a large tilt angle, analyze the light spot shape to compensate the ranging accuracy, optimize the imaging quality of the light detection system in depth, and the spot size received by the target surface of the detector 101-4 is perfectly within the diffraction limit, with high light energy utilization rate and good spatial resolution. The laser triangulation ranging system 101 with a variable working distance is composed of a fixed lens group 101-1, a zoom lens group unit 101-2, an adapter lens group 101-3, and a detector 101-4, where the zoom lens group unit 101-2 can achieve continuous zoom from 15m to 30m.

[0066] As Figure 1 and 3 shown, in this embodiment, a light spot is emitted from the improved laser phase method ranging system 102 to the measuring point; after the light spot with a specific wavelength is reflected by the ground, it passes through the fixed lens group 101-1, the zoom lens group unit 101-2, and the adapter lens group 101-3 in sequence, and finally enters the detector 101-4; the detector 101-4 acquires the reflected image of the ground light spot collected and obtains the distance offset value of the corresponding measuring point.

[0067] As Figure 4 shown, in this embodiment, the fixed lens group 101-1 and the zoom lens group unit 101-2 of the laser triangulation ranging system 101 with a variable working distance are built in the way of a positive lens group + a negative lens group. The positive lens group is used to converge light, and the negative lens group is used to shorten the total length of the system. By changing the distance between the negative lens group and the positive lens group, the focal length of the lens group is changed to achieve focusing on object points at different distances.

[0068] As Figure 4As shown, in this embodiment, f1, f2, and f are the focal lengths of the positive lens group, negative lens group, and combined system, respectively; H1, H2, and H are the principal planes of the positive lens group, negative lens group, and combined system, respectively; d is the distance between the positive lens group and the negative lens group; and K is the total system length. The focal length of the laser triangulation ranging system 101 is:

[0069]

[0070] As Figure 6 shown, in this embodiment, the intermediate-frequency vibration sensing and adaptive measurement system 400 senses environmental vibrations through the ground-mounted inertial accelerometer 401, calculates the tilt angles of the horizontal and vertical axes, analyzes its own vibrations using the biaxial compensator data analysis, compensates the measurement results according to the angles, and analyzes the intensity-time curve of the vibration signal to achieve vibration zero-crossing sampling of the ranging data.

[0071] As Figure 5 shown, in this embodiment, for the large-range precision scanning device, a measurement space coordinate system is established with reference to the mechanical structure of the large-range precision scanning device; the vertical direction is taken as the z direction of the measurement space coordinate system; the ground is taken as the zero plane in the z direction of the measurement space coordinate system, and the specific wavelength is preferably 650 nm;

[0072] The straight line on the plane where the laser ranging axis and the triangulation ranging optical path are located and perpendicular to the vertical direction is taken as the x direction of the measurement space coordinate system, and the direction perpendicular to both the z axis and the x direction is taken as the y direction of the measurement space coordinate system; the geometric center of the leveling base of the large-range precision scanning device is the geometric zero point of the measurement space coordinate system, and the vertically upward direction is the positive direction of the z axis;

[0073] The measurement point is denoted as point A', the rotation axis center of the triangulation ranging system is point D, the rotation axis center of the laser ranging is point C, the offset of the measurement point obtained by the triangulation ranging system is Δx, the height difference between the measurement point and the measurement device is Δh, and the range reference point A is set at the intersection of the receiving optical axis and the transmitting optical axis to minimize the off-axis aberration at the range center point. l i 、l o are the object distance and image distance at the reference point, respectively, α is the angle between the outgoing optical axis and the receiving lens optical axis, and β is the angle between the image plane and the receiving optical axis.

[0074] l o tan(α - β) = l i tan(90° - θ1)

[0075]

[0076] b = l o sin(α - β)

[0077]

[0078] Δh = Δz·cosα

[0079]

[0080] Wherein, O is the origin of the coordinate system, Δz is the distance between the position A' of the object to be measured and the reference position A, Δx is the distance between the imaging spot B' on the photodetector and the reference position B, f1, f2, and f are the focal lengths of the positive and negative lens groups and the combined system respectively; d is the focal length between the lens groups; θ1 is the angle between the image plane and the normal direction of the triangulation lens group, and θ2 is the angle between the reference position and the line connecting the position to be measured and the focus of the lens group.

[0081] An efficient and accurate measurement method for the concrete construction process depends on the large-range precision scanning device described in this embodiment. Through dual-sensor ranging and accurate height measurement, the ranging method includes the following steps:

[0082] Step 1: Control the motion servo system 200 to project the laser onto the measurement point A' using the laser phase ranging system 102 and obtain the ranging data D'.

[0083] Step 2: Calculate the β angle, and control the motion servo system 200 to align the triangulation ranging system 101 with the measurement point A'.

[0084] Step 3: Calculate the focal length f, control the motion servo system 200 to make the detector 101-4 receive a clear light spot, and use the laser ranging correction algorithm based on the light spot distribution, including edge detection, Gaussian fitting centroid method, and Gaussian filtering, etc., to correct the ranging data D' obtained by the phase method ranging.

[0085] A topography reconstruction method depends on the large-range precision scanning device that can detect the unevenness of a large-range plane. The ranging method includes the following steps:

[0086] Step 1: Obtain the height data Δh at a single point according to the large-range precision scanning device.

[0087] Step 2: Move outward along the x-axis of the measurement space coordinate system and measure the height data Δh of each point on a single x-axis line.

[0088] Step 3: Rotate around the z-axis and measure the height data Δh of each point within a large-angle range in the plane.

[0089] Step 4: Reconstruct the topography of the ground according to the height data Δh of each point to obtain the unevenness information of the large-range ground.

[0090] Such as Figure 1As shown, in this embodiment, for the user interaction system 300 and the power supply system 500 described above, the user interaction system includes an interactive control screen and a wireless ad hoc network system, and the industrial control computer directly controls the operation of the motion servo system 200 and the laser ranging system 100; the power supply system 500 is mainly used to supply power to the laser ranging system 100, the motion servo system 200, the user interaction system 300, and the intermediate frequency vibration perception and adaptive measurement system 400, and includes a power supply, a switch, a charging slot. The power supply ensures the long-term battery life of the measurement system during on-site measurement, and the housing protects the industrial control computer and the power circuit safety, and has the functions of waterproof and sunscreen.

[0091] The above-described embodiments are only a preferred solution of the present invention, but they are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can still make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A large-range precision scanning device, characterized in that, It includes a laser ranging system (100), a motion servo system (200), a user interaction system (300), an intermediate frequency vibration sensing and adaptive measurement system (400), and a power supply system (500); the laser ranging system (100) provides position and distance data, and the motion servo system (200) adjusts the device's motion path; the intermediate frequency vibration sensing system (400) monitors vibrations in real time and optimizes measurement data; the user interaction system (300) feeds back the device status to the user and at the same time receives user instructions. The industrial control computer in the user interaction system (300) directly controls the operation of the motion servo system (200) and the laser ranging system (100); the power supply system (500) is used to supply power to the laser ranging system (100), the motion servo system (200), the user interaction system (300), and the intermediate frequency vibration sensing and adaptive measurement system (400), and monitors the power status in real time to ensure the normal operation of the system; The laser ranging system (100) consists of a ranging system (102) that improves the laser phase method and a laser triangulation ranging system (101) with variable working distances; The ranging system (102) that improves the laser phase method includes a DAC module (102-1), a laser driver module (102-2), a photodiode amplification module (102-3), a photodetector (102-4), a preamplifier circuit (102-5), a signal conditioning module (102-6), a data acquisition and processing module (102-8), and a laser (102-9); among them, the signal conditioning module (102-6) includes an AGC circuit (102-7), a mixing circuit, and a filtering circuit; The DAC module (102-1): generates a modulation signal and a local oscillator signal, where the local oscillator signal is stored in the DAC module (102-1), and the modulation signal is sent to the photodiode amplification module (102-3); The photodiode amplification module (102-3): amplifies the modulation signal to generate a modulation voltage signal and sends it to the laser driver module (102-2); The laser driver module (102-2): converts the modulation voltage signal into a modulation current signal and generates a DC bias current to jointly drive the laser (102-9) and maintain the laser (102-9) at the required operating point to ensure that the laser (102-9) can work in a stable state; The laser (102-9) emits laser light that passes through a mirror (102-10), and the optical path is split into two. The first path passes through an optical fiber coupler (102-11), and the other path passes through a telescope lens group (102-12) and is reflected back from the reflecting surface. Finally, both optical signal paths pass through the photodetector (102-4); The photodetector (102-4) converts the two received optical signals into two weak current signals respectively. The current signals are converted into voltage signals after passing through the preamplifier circuit (102-5) and are input into the signal conditioning module (102-6); The AGC circuit (102-7) included in the signal conditioning module (102-6) receives two voltage signals, and then the mixing circuit and the filtering circuit adjust the signal amplitudes of the two voltage signals, reduce the high-frequency signals to the low-frequency band, filter out the high-frequency signals, and output low-frequency signals; The data acquisition and processing module (102-8): It includes a data acquisition unit and a data processing unit. The data acquisition unit is used to acquire the low-frequency signal output by the signal conditioning module (102-6), and the data processing unit processes the acquired low-frequency signal, and the data processing unit obtains the phase difference of the signal and the ranging data D' of the object to be measured; Where λ represents the wavelength of light.

2. The large-range precision scanning device according to claim 1, wherein The laser triangulation ranging system (101) with variable working distance includes a fixed lens group (101-1), a zoom lens group unit (101-2), a relay lens group (101-3), and a detector (101-4); a light spot is emitted to the measuring point by the improved laser phase ranging system (102), and after the light spot with a specific wavelength is reflected by the ground, it passes through the fixed lens group (101-1), the zoom lens group unit (101-2), and the relay lens group (101-3) in sequence, and finally enters the detector (101-4); the detector (101-4) acquires the reflected image of the ground light spot collected and obtains the distance offset value of the corresponding measuring point; among them, the zoom lens group unit (101-2) can achieve continuous zooming from 15m to 30m.

3. The large-range precision scanning device according to claim 2, characterized in that, The fixed lens group (101-1) and the zoom lens group unit (101-2) in the laser triangulation ranging system (101) with variable working distance are built in the way of a positive lens group + a negative lens group. The positive lens group is used to converge light, and the negative lens group is used to shorten the total length of the system. By changing the distance between the negative lens group and the positive lens group, the focal length of the lens group is changed to achieve focusing on object points at different distances; The focal length f of the laser triangulation ranging system (101) with variable working distance is: Where f1, f2, and f are the focal lengths of the positive lens group, the negative lens group, and the combined system respectively; d is the focal length between the positive lens group and the negative lens group.

4. A large-range precision scanning device according to claim 3, characterized in that, The motion servo system (200) is composed of a laser ranging precision pitch rotating shaft (203), a triangulation ranging precision pitch rotating shaft (202), a horizontal precision rotating shaft (204), and a triangulation automatic precision focusing system (201); The laser ranging precision pitch rotating shaft (203) is driven by a helical gear and a worm and worm gear in two stages, and a high-precision absolute circular grating is installed on the shaft, which can accurately obtain the absolute position during laser ranging; the triangulation ranging precision pitch rotating shaft (202) is also driven by a helical gear and a worm and worm gear in two stages, and the position of the triangulation ranging system is obtained through the absolute circular grating; the horizontal precision rotating shaft (204) also has an absolute circular grating and can obtain the absolute position during the scanning process; the triangulation automatic precision focusing system (201) is equipped with an absolute magnetic ring encoder and can achieve automatic focusing after obtaining the current absolute angle position.

5. A wide-range precision scanning device according to claim 4, characterized in that, The intermediate frequency vibration sensing and adaptive measurement system (400) senses environmental vibrations through the inertial accelerometers (401) placed on the ground, calculates the tilt angles of the horizontal axis and the vertical axis, analyzes its own vibrations using the biaxial compensator data analysis, compensates the measurement results according to the angles, analyzes the intensity-time curve of the vibration signal, and realizes the zero-crossing sampling of the vibration of the ranging data.

6. The implementation method of a large-range precision scanning device according to claim 5, characterized in that, A measurement space coordinate system is established with reference to the mechanical structure of this large-range precision scanning device; The vertical direction is taken as the z - direction of the measurement space coordinate system; the ground is taken as the zero plane in the z - direction of the measurement space coordinate system, and the specific wavelength is 650 nm. The straight line perpendicular to the vertical direction in the plane where the laser ranging axis and the triangulation ranging optical path are located is taken as the x - direction of the measurement space coordinate system. The direction perpendicular to both the z - axis and the x - direction is taken as the y - direction of the measurement space coordinate system. The geometric center of the leveling base of the large - range precision scanning device is taken as the geometric zero point of the measurement space coordinate system, and the vertically upward direction is the positive direction of the z - axis. The measurement point is denoted as point A', the rotation center of the triangulation ranging system is point D, the rotation center of the laser ranging is point C. The triangulation ranging system obtains the measurement point offset as Δx, the height data of the measurement point relative to the measuring device is Δh, and the range reference point A is set at the intersection of the receiving optical axis and the transmitting optical axis to minimize the off - axis aberration of the range center point. The formula is as follows: l o tan(α - β) = l i tan(90° - θ1) b = l o sin(α - β) Δh = Δz·cosα Among them, Δz is the distance between the position A' of the object to be measured and the reference position A, Δx is the distance between the imaging spot B' on the photodetector and the reference position B, f1, f2, and f are the focal lengths of the positive and negative lens groups and the combined system respectively; d is the focal length between the lens groups, θ1 is the angle between the image plane and the normal direction of the triangulation lens group, and θ2 is the angle between the reference position and the line connecting the measured position and the focal point of the lens group; l i , l o are the object distance and image distance at the reference point respectively, α is the angle between the outgoing optical axis and the optical axis of the receiving lens, and β is the angle between the image plane and the receiving optical axis.

7. The implementation method of a large-range precision scanning device according to claim 6, characterized in that, Applying this method to the single - point elevation measurement in the concrete construction process specifically includes the following steps: Step 1: The motion servo system (200) uses the laser phase ranging system (102) to project the laser onto the measurement point A' and obtains the ranging data D'. Step 2: Calculate the β angle, and control the motion servo system (200) to align the triangulation ranging system (101) with the measurement point A'. Step 3: Calculate the focal length f, control the motion servo system (200) to make the detector (101 - 4) receive a clear light spot, and use the laser ranging correction algorithm based on the light spot distribution to correct the ranging data D' obtained by the phase - method ranging.

8. The implementation method of a large-range precision scanning device according to claim 6, characterized in that Applying this method to the shape reconstruction specifically includes the following steps: Step 1: According to the large - range precision scanning device, obtain the height data Δh at a single point. Step 2: Move outward along the x - axis of the measurement space coordinate system and measure the height data Δh of each point on a single x - axis line. Step 3: Rotate around the z - axis and measure the height data Δh of each point within a large - angle range in the plane. Step 4: According to the height data Δh of each point, perform shape reconstruction on the ground to obtain the unevenness information of the large - range ground.

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