CN113126113B - Non-contact surface roughness measuring device and method - Google Patents

Non-contact surface roughness measuring device and method Download PDF

Info

Publication number
CN113126113B
CN113126113B CN202110421735.1A CN202110421735A CN113126113B CN 113126113 B CN113126113 B CN 113126113B CN 202110421735 A CN202110421735 A CN 202110421735A CN 113126113 B CN113126113 B CN 113126113B
Authority
CN
China
Prior art keywords
stepping motor
data
laser radar
height
encoder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110421735.1A
Other languages
Chinese (zh)
Other versions
CN113126113A (en
Inventor
刘立超
毕全鹏
陈黎卿
陈状
毕大伟
王韦韦
张春岭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Anhui Agricultural University AHAU
Original Assignee
Anhui Agricultural University AHAU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Anhui Agricultural University AHAU filed Critical Anhui Agricultural University AHAU
Priority to CN202110421735.1A priority Critical patent/CN113126113B/en
Publication of CN113126113A publication Critical patent/CN113126113A/en
Application granted granted Critical
Publication of CN113126113B publication Critical patent/CN113126113B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/006—Theoretical aspects
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/4802—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Electromagnetism (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

The invention discloses a non-contact surface roughness measuring device and method, and belongs to the technical field of surface micro-landform measurement. The non-contact surface roughness measuring device is matched with a measuring method, and the method comprises the following steps: s1, adjusting the height of a lower support; s2, initializing the device; s3, the driving controller controls the stepping motor B to accurately rotate according to a set program, the laser radar samples the soil to be detected in a line scanning mode, and data are transmitted to the portable computer; s4, the driving controller controls the stepping motor A to rotate accurately according to a set program; s5, repeating the working step of the S3; s6, performing trend removing processing on the data to obtain complete three-dimensional elevation data which is more in line with evaluation of the earth surface micro landform; and S7, evaluating the surface micro landform. The invention solves the problems that the existing measuring method has low measuring efficiency and the three-dimensional data obtained by post-processing the data has low coincidence degree with the actual micro-landforms with different scales formed after cultivation.

Description

Non-contact surface roughness measuring device and method
Technical Field
The invention relates to the technical field of surface micro-landform measurement, in particular to a non-contact surface roughness measuring device and method.
Background
The surface soil roughness reflects small-scale changes of the soil surface elevation, and is an important factor influencing the surface hydrology and the erosion process. At present, the roughness of the ground surface after cultivation is mostly limited to contact measurement, and although the measuring method has a simple structure, the measuring precision is low, and the original ground surface is easy to damage. The camera shooting technology is mostly used in the environment with uniform illumination and no shadow, the measurement precision is higher, but the precision is lower and the application is less in the environment with large elevation change of furrows. The laser ranging method is widely applied to non-contact measurement, can realize millimeter-level or submillimeter-level measurement accuracy, but is time-consuming and low in efficiency.
The soil roughness is divided into two types, one is directional roughness caused by the inclined surface of a furrow, and the other is random roughness reflecting the real landform of the land. In the existing data post-processing method, the influence of the directional roughness is not always considered, and when the earth surface micro-landform parameters are evaluated, the calculation result is inconsistent with the actual micro-landform, and the precision is reduced.
In order to solve the problems, the measuring efficiency is further improved, and the degree of coincidence between three-dimensional data obtained by data post-processing and actual micro-landforms with different scales formed after cultivation is further improved, the invention provides a non-contact type surface roughness measuring device and method.
Disclosure of Invention
The invention aims to provide a non-contact surface roughness measuring device and a non-contact surface roughness measuring method, which aim to solve the problems in the background technology:
the existing measuring method has the problems of low measuring efficiency and low coincidence degree of three-dimensional data obtained by data post-processing and actual micro landforms with different scales formed after cultivation.
In order to achieve the purpose, the invention adopts the following technical scheme:
a non-contact surface roughness measuring device comprises a telescopic lower support and an upper support, wherein the telescopic lower support comprises a bottom rod and a telescopic rod, the telescopic rod is telescopically connected to the bottom rod, a scale is arranged on the telescopic rod, an adjustable device is fixedly arranged at the joint of the telescopic rod and the bottom rod, a stepping motor A is fixedly connected to the top end of the telescopic rod, an encoder A is integrally arranged on the stepping motor A, a flat key is fixedly arranged on an output shaft of the stepping motor A, the upper support is fixedly connected with the stepping motor A through the flat key, a laser detection device is arranged on the upper support,
preferably, the laser detection device comprises a protective shell, a laser radar, a stepping motor B, an encoder B, a connecting shaft and a bearing, wherein the protective shell is fixedly connected with the upper bracket through a connecting bolt, the stepping motor B is fixedly connected inside the protective shell, the encoder B is integrally installed on the stepping motor B, a fixed plate is fixedly connected to an output shaft of the stepping motor B, one end of the connecting shaft is fixedly connected with one side, away from the stepping motor B, of the fixed plate, the other end of the connecting shaft is fixedly connected with the bearing, the connecting shaft is rotatably connected with the protective shell through the bearing, and the laser radar is fixedly installed on the fixed plate through the bolt; the inside still fixed mounting of protective housing has the power, power and step motor A, step motor B, encoder A and encoder B electric connection.
A method of non-contact surface roughness measurement comprising the steps of:
s1, adjusting the height of a lower support to reach an ideal height H of measurement data;
s2, starting a power supply, and initializing the device;
s3, the drive controller acquires a signal of the encoder B, the stepping motor B is controlled to rotate accurately according to a set program, the laser radar samples the soil to be detected in a line scanning mode, and data are transmitted to the portable computer;
s4, the drive controller acquires a signal of the encoder A and controls the stepping motor A to rotate accurately according to a set program;
s5, repeating the working step of the S3;
s6, processing data, namely converting, splicing and trend-removing the data by using a portable computer to obtain complete three-dimensional elevation data which is more in line with evaluation of the micro landform of the earth surface;
and S7, taking a complete area, and evaluating the surface micro-landform.
Preferably, the adjusting the lower rack height mentioned in S1 specifically includes the following operations:
a1, moving the position of a telescopic rod on a bottom rod of a lower support, and reading out specific reading by using a graduated scale on the telescopic rod so as to directly measure the height H of a laser radar from the surface of soil to be measured;
and A2, fixing the telescopic rod at a required height by using an adjustable device at the joint of the telescopic rod and the bottom rod.
Preferably, the device initialization mentioned in S2 specifically includes the following operations:
b1, controlling the stepping motor A to rotate, enabling a measuring curve S of the laser radar to be parallel to gully, and finishing initialization work of the stepping motor A;
and B2, controlling the stepping motor B to rotate, enabling the central line of the laser radar to be perpendicular to the upper bracket, and finishing initialization work of the stepping motor B.
Preferably, the programmed precise rotation and the sampling of the lidar mentioned in S3 specifically include the following operations:
c1, a driving controller obtains a signal of the encoder B, and controls the stepping motor B to rotate clockwise by a stepping angle theta, wherein the formula of the stepping angle theta is as follows:
Figure BDA0003028089260000041
in the formula, n is the sampling frequency, l is the sampling interval of the laser radar on the soil to be detected, and H is the height of the laser radar from the ground to be detected;
c2, after the laser radar rotates a step angle theta along with the stepping motor B, the laser radar samples the soil to be detected in a line scanning mode, and meanwhile, data are returned to the portable computer in a polar coordinate mode;
c3, after the data is transmitted back to the portable computer, judging the relationship between sigma theta and the angle alpha, wherein the sigma theta is the sum of the stepping angles of the stepping motor from the initial position to the current position, and the formula of the angle alpha is as follows:
Figure BDA0003028089260000042
in the formula, H is the height of the laser radar from the ground to be measured, and L is the horizontal distance of the laser radar from the lower support;
c4, when the sigma theta is less than or equal to alpha, sequentially repeating the operation steps in the C1-C3;
c5, when the sigma theta is larger than or equal to alpha, the driving controller controls the stepping motor B to rotate anticlockwise to an initialization position;
and C6, controlling the stepping motor B by the driving controller to sequentially repeat the operation steps C1-C5 in the opposite direction.
Preferably, the rotation of the stepping motor a mentioned in S4 specifically includes the following operations:
d1, receiving a signal of the encoder A by the driving controller;
and D2, controlling the stepping motor A to rotate 180 degrees.
Preferably, the data processing mentioned in S6 specifically includes the following operations:
e1, transmitting data of each measuring point back to the portable computer in a polar coordinate mode by using a laser radar;
e2, the portable computer obtains complete three-dimensional elevation data of the earth surface through coordinate transformation;
e3, importing the three-dimensional elevation data of the ground surface into MATLAB, and completing missing areas caused by the influence of the width of the lower support through interpolation processing;
and E4, performing trend removing processing on the acquired data.
Preferably, the de-trending process specifically includes the following steps:
preferably, according to the method for processing the three-dimensional elevation data of the earth surface mentioned in the step E3, a program is written by using a function in MATLAB, and a datum plane of the three-dimensional elevation data of the earth surface is extracted; (ii) a
And F2, subtracting the datum plane by utilizing the original three-dimensional elevation data of the earth surface to obtain a random height component reflecting the real micro landform of the earth surface.
Preferably, the surface micro-relief evaluation parameters mentioned in S7 are specifically:
and further evaluating the quality of cultivation by reflecting the degree of the deviation of the surface micro-landform from the average height through the root-mean-square height, wherein the root-mean-square formula is as follows:
Figure BDA0003028089260000051
wherein M is the number of columns of the sampling region, N is the number of rows of the sampling region, M is the column number, N is the row number, and z (x) m ,y n ) The height of the sampling point corresponding to the m-th column and the n-th row,
Figure BDA0003028089260000052
is the average height of all sample points.
Compared with the prior art, the invention provides a non-contact surface roughness measuring device and method, which have the following beneficial effects:
(1) The invention provides a non-contact surface roughness measuring device, which changes the existing soil roughness measuring method, realizes the left-right swing by driving a laser radar through a stepping motor, samples data at each interval of the rotation of the stepping motor, improves the acquisition area and the measuring efficiency by utilizing the rotation of the stepping motor, and solves the problem that the existing measuring method is lower in the measuring efficiency.
(2) The invention also provides a non-contact surface roughness measuring method matched with the non-contact surface roughness measuring device, the method removes the reference surface of the soil surface by the interpolation processing and the detrending processing of MATLAB of the acquired data, and obtains a random height component of a relatively complete real micro-landform of the surface; the three-dimensional data of the ground surface processed by the method is more consistent with the real landform environment, and has an important data support effect on the evaluation of the farming quality of the ground surface; the method effectively solves the problem that the three-dimensional data obtained by data post-processing is low in coincidence degree with the actual micro landforms with different scales formed after cultivation, provides accurate data for later sowing, and improves economic benefits.
Drawings
FIG. 1 is a schematic diagram of a non-contact surface roughness measuring device according to the present invention;
FIG. 2 is a schematic structural diagram of a laser detection device of a non-contact surface roughness measurement device according to the present invention;
FIG. 3 is a cross-sectional view of a laser detection device of a non-contact surface roughness measurement device according to the present invention
Fig. 4 is a schematic structural diagram of a stepping motor a and an upper bracket of a non-contact surface roughness measuring device according to the present invention;
FIG. 5 is a schematic flow chart of a non-contact surface roughness measurement method according to the present invention;
FIG. 6 is a schematic diagram of an original three-dimensional topography used for data processing in a non-contact surface roughness measurement method according to the present invention;
FIG. 7 is a schematic diagram of a wavelet reference surface extracted by a de-trending process in a non-contact surface roughness measurement method according to the present invention;
fig. 8 is a schematic diagram of a three-dimensional landform after detrending processing in a non-contact surface roughness measurement method according to the present invention.
Description of the figure numbers:
1. a lower bracket; 2. an adjustable device; 3. an encoder A; 4. a stepping motor A; 5. a laser detection device; 6. an upper bracket; 7. a flat bond; 8. a protective shell; 9. a bearing; 10. a connecting shaft; 11. a laser radar; 12. a power source; 13. a stepping motor B; 14. an encoder B; 15. and (5) fixing the plate.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, are used in the orientations and positional relationships indicated in the drawings, which are based on the orientations and positional relationships indicated in the drawings, and are used for convenience of description and simplicity of description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
Example 1:
referring to fig. 1-4, a non-contact surface roughness measuring device comprises a telescopic lower support 1 and an upper support 6, wherein the telescopic lower support 1 comprises a bottom rod and a telescopic rod, the telescopic rod is telescopically connected to the bottom rod, a scale is arranged on the telescopic rod, an adjustable device 2 is fixedly arranged at the joint of the telescopic rod and the bottom rod, a stepping motor A4 is fixedly connected to the top end of the telescopic rod, an encoder A3 is integrally arranged on the stepping motor A4, a flat key 7 is fixedly arranged on an output shaft of the stepping motor A4, the upper support 6 is fixedly connected with the stepping motor A4 through the flat key 7, a laser detection device 5 is arranged on the upper support 6,
the laser detection device 5 comprises a protective shell 8, a laser radar 11, a stepping motor B13, an encoder B14, a connecting shaft 10 and a bearing 9, the protective shell 8 is fixedly connected with the upper bracket 6 through a connecting bolt, the stepping motor B13 is fixedly connected inside the protective shell 8, the encoder B14 is integrally installed on the stepping motor B13, a fixing plate 15 is fixedly connected onto an output shaft of the stepping motor B13, one end of the connecting shaft 10 is fixedly connected with one side, far away from the stepping motor B13, of the fixing plate 15, the other end of the connecting shaft is fixedly connected with the bearing 9, the connecting shaft 10 is rotatably connected with the protective shell 8 through the bearing 9, and the laser radar 11 is fixedly installed on the fixing plate 15 through a bolt; the inside of protective housing 8 still fixed mounting has power 12, and power 12 and step motor A4, step motor B13, encoder A3 and encoder B14 electric connection.
The invention provides a non-contact surface roughness measuring device, which changes the existing soil roughness measuring method, realizes the left-right swing by driving a laser radar through a stepping motor, samples data at each interval of the rotation of the stepping motor, improves the acquisition area and the measuring efficiency by utilizing the rotation of the stepping motor, and solves the problem that the existing measuring method is lower in the measuring efficiency.
Example 2:
referring to fig. 5, there is a difference in the embodiment 1;
a method of non-contact surface roughness measurement comprising the steps of:
s1, adjusting the height of a lower support 1 to reach an ideal height H of measured data;
the adjustment of the height of the lower bracket 1 specifically comprises the following operations:
a1, moving the position of a telescopic rod on a bottom rod of a lower support 1, reading out specific reading by using a graduated scale on the telescopic rod, and further directly measuring the height H of a laser radar 11 from the surface of soil to be measured;
a2, fixing the telescopic rod at a required height by using an adjustable device 2 at the joint of the telescopic rod and the bottom rod.
S2, starting a power supply 12, and initializing the device;
the device initialization specifically includes the following operations:
b1, controlling a stepping motor A4 to rotate, so that a measuring curve S of the laser radar 11 is parallel to gully, and finishing initialization work of the stepping motor A4;
and B2, controlling the stepping motor B13 to rotate, enabling the central line of the laser radar 11 to be perpendicular to the upper support 6, and finishing initialization work of the stepping motor B13.
S3, the drive controller acquires a signal of the encoder B14, controls the stepping motor B13 to accurately rotate according to a set program, samples the soil to be detected in a line scanning mode by the laser radar 11, and transmits data to the portable computer;
the accurate rotation according to the program and the sampling of the laser radar 11 specifically include the following operations:
c1, the driving controller obtains a signal of the encoder B14, and controls the stepping motor B to rotate clockwise by a stepping angle theta, wherein the formula of the stepping angle theta is as follows:
Figure BDA0003028089260000101
in the formula, n is the sampling frequency, l is the sampling interval of the laser radar 11 on the soil to be detected, and H is the height of the laser radar 11 from the ground to be detected;
c2, after the laser radar 11 rotates by a step angle theta along with the stepping motor B13, the laser radar 11 samples the soil to be detected in a line scanning mode, and returns data to the portable computer in a polar coordinate mode;
c3, after the data is transmitted back to the portable computer, judging the relationship between sigma theta and the angle alpha, wherein the sigma theta is the sum of the stepping angles of the stepping motor from the initial position to the current position, and the formula of the angle alpha is as follows:
Figure BDA0003028089260000102
in the formula, H is the height of the laser radar 11 from the ground to be measured, and L is the horizontal distance of the laser radar 11 from the lower support 1;
c4, when the sigma theta is less than or equal to alpha, sequentially repeating the operation steps in the C1-C3;
c5, when the sigma theta is larger than or equal to alpha, the driving controller controls the stepping motor B13 to rotate anticlockwise to an initialization position;
and C6, controlling the stepping motor B13 by the drive controller to sequentially repeat the operation steps in C1-C5 in the opposite direction.
S4, the drive controller acquires a signal of the encoder A3 and controls the stepping motor A4 to rotate accurately according to a set program;
the rotation of the stepping motor A4 specifically includes the following operations:
d1, receiving a signal of the encoder A3 by the driving controller;
d2, controlling the stepping motor A4 to rotate 180 degrees.
S5, repeating the working step of the S3;
s6, processing data, namely converting, splicing and trend-removing the data by using a portable computer to obtain complete three-dimensional elevation data which is more in line with evaluation of the micro landform of the earth surface;
the data processing specifically comprises the following operations:
e1, transmitting data of each measuring point back to the portable computer in a polar coordinate mode by using a laser radar 11;
e2, the portable computer obtains complete three-dimensional elevation data of the earth surface through coordinate transformation;
e3, importing the three-dimensional elevation data of the ground surface into MATLAB, and completing the missing region caused by the influence of the width of the lower support 1 through interpolation processing;
and E4, performing trend removing processing on the acquired data.
The trend removing treatment specifically comprises the following steps:
f1, according to the earth surface three-dimensional elevation data processing method mentioned in the E3, writing a program by using a function in the MA TLAB, and extracting a datum plane of the earth surface three-dimensional elevation data;
and F2, subtracting the datum plane by utilizing the original three-dimensional elevation data of the earth surface to obtain a random height component reflecting the real micro landform of the earth surface.
S7, taking a complete area, and evaluating the micro landform of the earth surface;
the evaluation parameters of the surface micro-landform are as follows:
the root mean square height reflects the degree of the deviation of the surface micro-landform from the average height, and the quality of cultivation is further evaluated, wherein the root mean square formula is as follows:
Figure BDA0003028089260000121
wherein M is the number of columns of the sampling region, N is the number of rows of the sampling region, M is the column number, N is the row number, and z (x) m ,y n ) The height of the sampling point corresponding to the mth column and the nth row,
Figure BDA0003028089260000122
is the average height of all sample points.
The invention also provides a non-contact surface roughness measuring method matched with the non-contact surface roughness measuring device, the method removes the datum plane of the soil surface through interpolation processing and detrending processing of MATLAB of the acquired data, and obtains a random height component of a relatively complete real micro landform of the surface; the three-dimensional data of the ground surface processed by the method is more consistent with the real landform environment, and has an important data support effect on the evaluation of the farming quality of the ground surface; the method effectively solves the problem that the three-dimensional data obtained by data post-processing is low in coincidence degree with the actual micro landforms of different scales formed after cultivation, provides accurate data for later sowing, and improves economic benefits.
Example 3:
the difference is based on the embodiments 1-2;
vertically inserting a measuring device into soil to be measured, opening an adjustable device, adjusting the height of a lower support to enable the scale value to be H =1.3m, screwing the adjustable device, and fixing the height of the support, wherein the height H of the device is the distance between a scanning center of a laser radar and the ground; after the height is adjusted, a power supply of the device is started, the device is initialized, the driving controller controls the stepping motor A to rotate, so that the measuring curve S of the laser radar is parallel to the gully, the driving controller controls the stepping motor B to rotate, the center line of the laser radar is perpendicular to the upper support, and the initialization of the device is completed.
The driving controller obtains a signal of the encoder B, the stepping motor B is controlled to rotate clockwise by a step angle theta, l is a sampling interval of the laser radar on the soil to be detected and is set to be l =0.01m, and then
Figure BDA0003028089260000131
n is the sampling frequency, after the laser radar rotates a step angle theta along with the stepping motor B, the laser radar samples the soil to be detected in a line scanning mode, and simultaneously returns data to the portable computer in a polar coordinate mode; after receiving data, the portable computer judges the size relationship between sigma theta and an angle alpha, wherein sigma theta is the sum of the step angles of the stepping motor from the initial position to the current position, and the horizontal distance from the central scanning line of the laser radar to the lower bracket is L =0.5m, and the angle alpha is represented by the following formula:
Figure BDA0003028089260000132
when the sigma theta is less than or equal to alpha, all the operation steps in the paragraph are sequentially repeated;
when the sigma theta is larger than or equal to alpha, the driving controller controls the stepping motor B to rotate anticlockwise to the initial position, and then controls the stepping motor B to repeat all the operation steps in the opposite direction in the above paragraph.
After sampling is finished, the driving controller controls the stepping motor A to rotate 180 degrees, and whether the degree of rotation is smaller than 360 degrees is judged;
if yes, repeating all the operation steps in the paragraphs 2, 3 and 4;
if not, finishing sampling, and carrying out coordinate transformation on the data by the portable computer, and completing missing partial areas through interpolation processing in MATLAB to obtain complete three-dimensional elevation data of the earth surface;
and performing detrending processing on the acquired data, writing a program by using a function in MATLAB, extracting a datum plane of the three-dimensional elevation data of the earth surface, and subtracting the datum plane by using the original three-dimensional elevation data of the earth surface to obtain a random height component reflecting the real micro landform of the earth surface.
After the data processing is finished, the flatness of the earth surface micro landform can be evaluated by using the data, the cultivation quality is more accurately evaluated, and the specific evaluation formula is as follows:
Figure BDA0003028089260000141
wherein M is the number of columns of the sampling region, N is the number of rows of the sampling region, M is the column number, N is the row number, and z (x) m ,y n ) The height of the sampling point corresponding to the m-th column and the n-th row,
Figure BDA0003028089260000142
is the average height of all sample points.
Example 4:
referring to FIGS. 6 to 8, the embodiments 1 to 3 are different from each other in that;
data processing in a non-contact surface roughness measurement method comprises the following steps of intercepting an evaluation surface and performing de-trending:
and the portable computer acquires data transmitted back by the laser radar, performs coordinate conversion on the data and converts the data into visual earth surface three-dimensional elevation data. When the laser radar acquires data by a set method, because the lower support has a certain width, the earth surface information at the position cannot be acquired, and the MATLAB is used for carrying out interpolation processing on the data to completely supplement the vacancy at the position. And randomly intercepting a surface to be evaluated on the complete three-dimensional elevation data of the earth surface, as shown in fig. 6, for later evaluation of the flatness of the earth surface.
For the extraction of the wavelet reference surface, many wavelet functions can be selected. Different wavelet functions are suitable for different surfaces to be measured, and the selection standard of the wavelet function is generally selected by experience. Meanwhile, the selection of the wavelet decomposition times has important influence on improving the extraction precision of the wavelet reference surface. By using dbN wavelet function and the optimal decomposition number 6 obtained by calculation on the randomly intercepted surface to be evaluated, the wavelet reference surface of the surface to be evaluated can be extracted through the parameters, as shown in fig. 7.
The wavelet reference surface can well reflect the fluctuation trend of the soil furrow. The influence of the lodging tendency on the flatness evaluation can be eliminated by subtracting the wavelet reference surface from the original elevation data, and the three-dimensional elevation of the soil obtained after the trend removing treatment is more consistent with the real soil roughness, as shown in fig. 8.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the equivalent alternatives or modifications according to the technical solution and the inventive concept of the present invention within the technical scope of the present invention.

Claims (9)

1. A method for measuring by adopting a non-contact surface roughness measuring device is characterized in that the device comprises a telescopic lower support (1) and an upper support (6), the telescopic lower support (1) comprises a bottom rod and a telescopic rod, the telescopic rod is telescopically connected to the bottom rod, a scale is arranged on the telescopic rod, an adjustable device (2) is fixedly arranged at the joint of the telescopic rod and the bottom rod, a stepping motor A (4) is fixedly connected to the top end of the telescopic rod, an encoder A (3) is integrally arranged on the stepping motor A (4), a flat key (7) is fixedly arranged on an output shaft of the stepping motor A (4), the upper support (6) is fixedly connected with the stepping motor A (4) through the flat key (7), and a laser detection device (5) is arranged on the upper support (6);
the measurement method using the device is characterized by comprising the following steps:
s1, adjusting the height of a lower support (1) to reach an ideal height H of measured data;
s2, starting a power supply (12), and initializing the device;
s3, the driving controller obtains a signal of the encoder B (14), the stepping motor B (13) is controlled to rotate accurately according to a set program, the laser radar (11) samples soil to be detected in a line scanning mode, and data are transmitted to the portable computer;
s4, the drive controller acquires a signal of the encoder A (3) and controls the stepping motor A (4) to rotate accurately according to a set program;
s5, repeating the working step of the S3;
s6, processing data, namely converting, splicing and trend-removing the data by using a portable computer to obtain complete three-dimensional elevation data which is more in line with evaluation of the micro landform of the earth surface;
and S7, taking a complete area, and evaluating the earth surface micro landform.
2. The method according to claim 1, characterized in that the laser detection device (5) comprises a protective shell (8), a laser radar (11), a stepping motor B (13), an encoder B (14), a connecting shaft (10) and a bearing (9), wherein the protective shell (8) is fixedly connected with the upper bracket (6) through a connecting bolt, the stepping motor B (13) is fixedly connected inside the protective shell (8), the encoder B (14) is integrally installed on the stepping motor B (13), a fixing plate (15) is fixedly connected to an output shaft of the stepping motor B (13), one end of the connecting shaft (10) is fixedly connected with one side, away from the stepping motor B (13), of the fixing plate (15), the other end of the connecting shaft is fixedly connected with the bearing (9), the connecting shaft (10) is rotatably connected with the protective shell (8) through the bearing (9), and the laser radar (11) is fixedly installed on the fixing plate (15) through a bolt; the inside of protective housing (8) still fixed mounting have power (12), power (12) and step motor A (4), step motor B (13), encoder A (3) and encoder B (14) electric connection.
3. Method according to claim 1, characterized in that said adjustment of the height of the lower cradle (1) referred to in S1 comprises in particular the following operations:
a1, moving the position of a telescopic rod on a bottom rod of a lower support (1), reading a specific reading by using a graduated scale on the telescopic rod, and further directly measuring the height H of a laser radar (11) from the surface of soil to be measured;
a2, fixing the telescopic rod at a required height by using an adjustable device (2) at the joint of the telescopic rod and the bottom rod.
4. The method according to claim 1, wherein the device initialization mentioned in S2 specifically comprises the following operations:
b1, controlling the stepping motor A (4) to rotate, enabling a measuring curve S of the laser radar (11) to be parallel to gullies, and finishing initialization work of the stepping motor A (4);
and B2, controlling the stepping motor B (13) to rotate, so that the central line of the laser radar (11) is perpendicular to the upper bracket (6), and finishing initialization work of the stepping motor B (13).
5. Method according to claim 3, characterized in that said programmed precision rotation and sampling of the lidar (11) referred to in S3 comprises in particular the following operations:
c1, a driving controller obtains a signal of an encoder B (14) and controls a stepping motor B to rotate clockwise by a stepping angle theta, wherein the formula of the stepping angle theta is as follows:
Figure FDA0004053873290000031
in the formula, n is the sampling frequency, l is the sampling interval of the laser radar (11) on the soil to be detected, and H is the height of the laser radar (11) from the ground to be detected;
c2, after the laser radar (11) rotates by a step angle theta along with the stepping motor B (13), the laser radar (11) samples the soil to be detected in a line scanning mode, and returns data to the portable computer in a polar coordinate mode;
c3, after the data is transmitted back to the portable computer, judging the relationship between sigma theta and the angle alpha, wherein the sigma theta is the sum of the stepping angles of the stepping motor from the initial position to the current position, and the formula of the angle alpha is as follows:
Figure FDA0004053873290000032
in the formula, H is the height of the laser radar (11) from the ground to be measured, and L is the horizontal distance between the laser radar (11) and the lower support (1);
c4, when the sigma theta is less than or equal to alpha, sequentially repeating the operation steps in the C1-C3;
c5, when the sigma theta is larger than or equal to alpha, the driving controller controls the stepping motor B (13) to rotate anticlockwise to an initialization position;
c6, the driving controller controls the stepping motor B (13) to sequentially repeat the operation steps C1-C5 in the opposite direction.
6. Method according to claim 1, characterized in that the rotation of the stepper motor a (4) referred to in S4 comprises in particular the following operations:
d1, receiving a signal of the encoder A (3) by the driving controller;
d2, controlling the stepping motor A (4) to rotate 180 degrees.
7. The method according to claim 1, wherein the data processing mentioned in S6 specifically comprises the following operations:
e1, transmitting data of each measuring point back to the portable computer in a polar coordinate mode by using a laser radar (11);
e2, the portable computer obtains complete three-dimensional elevation data of the earth surface through coordinate transformation;
e3, importing the three-dimensional elevation data of the ground surface into MATLAB, and supplementing missing areas caused by the influence of the width of the lower support (1) through interpolation processing;
and E4, performing trend removing processing on the acquired data.
8. The method according to claim 7, wherein the de-trending process comprises the steps of:
f1, according to the ground surface three-dimensional elevation data processing method mentioned in the E3, writing a program by using a function in an MATLAB, and extracting a datum plane of the ground surface three-dimensional elevation data;
and F2, subtracting the datum plane by utilizing the original three-dimensional elevation data of the earth surface to obtain a random height component reflecting the real micro landform of the earth surface.
9. The method according to claim 1, wherein the surface micro-relief evaluation parameters mentioned in S7 are specifically:
and further evaluating the quality of cultivation by reflecting the degree of the deviation of the surface micro-landform from the average height through the root-mean-square height, wherein the root-mean-square formula is as follows:
Figure FDA0004053873290000051
wherein M is the number of columns of the sampling region, N is the number of rows of the sampling region, M is the column number, N is the row number, and z (x) m ,y n ) The height of the sampling point corresponding to the mth column and the nth row,
Figure FDA0004053873290000052
is the average height of all sample points. />
CN202110421735.1A 2021-04-20 2021-04-20 Non-contact surface roughness measuring device and method Active CN113126113B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110421735.1A CN113126113B (en) 2021-04-20 2021-04-20 Non-contact surface roughness measuring device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110421735.1A CN113126113B (en) 2021-04-20 2021-04-20 Non-contact surface roughness measuring device and method

Publications (2)

Publication Number Publication Date
CN113126113A CN113126113A (en) 2021-07-16
CN113126113B true CN113126113B (en) 2023-04-14

Family

ID=76778198

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110421735.1A Active CN113126113B (en) 2021-04-20 2021-04-20 Non-contact surface roughness measuring device and method

Country Status (1)

Country Link
CN (1) CN113126113B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114485460B (en) * 2021-12-28 2022-12-20 安徽农业大学 Laser radar-based surface three-dimensional topography measurement system and method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102135423A (en) * 2010-01-25 2011-07-27 中国科学院遥感应用研究所 Device and method for measuring roughness of earth surface

Also Published As

Publication number Publication date
CN113126113A (en) 2021-07-16

Similar Documents

Publication Publication Date Title
US20200103530A1 (en) Method for extracting elevation control point with assistance of satellite laser altimetry data
CN110390687B (en) Three-dimensional laser scanning-based river channel erosion and deposition measuring method
Holland et al. Practical use of video imagery in nearshore oceanographic field studies
CN107782240A (en) A kind of two dimensional laser scanning instrument scaling method, system and device
CN108303043B (en) Multi-sensor information fusion plant leaf area index detection method and system
CN105627948A (en) Large-scale complex curved surface measurement system and application thereof
CN108113700B (en) Position calibration method applied to three-dimensional ultrasonic imaging data acquisition
CN113126113B (en) Non-contact surface roughness measuring device and method
CN101922912A (en) Three-dimensional laser scanning measurement method and device
CN106989731A (en) A kind of close range photogrammetry method observed for roughness of ground surface
CN102353678B (en) Method for measuring cultural relic diseases
CN105388473B (en) A kind of near field RCS method for fast measuring based on high-resolution imaging
CN109814126A (en) A kind of Mobile plane laser radar phytomorph measuring device
CN110196031A (en) A kind of scaling method of three-dimensional point cloud acquisition system
CN111487621B (en) Sea surface flow field inversion method based on radar image and electronic equipment
CN103315770A (en) Target parameter processing method and system based on three-dimensional ultrasonic image
CN112361962A (en) Intelligent visual 3D information acquisition equipment of many every single move angles
CN114485460B (en) Laser radar-based surface three-dimensional topography measurement system and method
CN109282850B (en) Cultivation parameter measuring device and method and farm implement operation cultivation depth measuring method
CN108088389A (en) A kind of rotary double excitation contour measuring method, storage device and measuring device
CN205352322U (en) Large -scale complicated curved surface measurement system
CN204924273U (en) Three -dimensional laser sensor data calibrating device of panorama
Sellers et al. Ultrasonic cave mapping
CN105115443A (en) Horizontal full view angle high precision three-dimensional measuring method based on vision measurement technology
CN113160374A (en) Three-dimensional calculation method for volume change of gully based on terrain point cloud

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant