CN1280607C - Laser dam safety monitoring method - Google Patents

Abstract

The present invention discloses a novel laser large dam safety monitoring method. In the method, collimated laser is arranged at a base point of a dam shoulder of a large dam and irradiates every dam section of the large dam. A set of sealed pipeline type controllable detecting systems which are fixed to the dam section into an integral body are arranged at every dam section. At the time of measurement, light spot offsets from the center of ground glass in a detecting system to show that offset occurs in every dam section. Through mathematic model operation, the deformation quantity of the large dam can be measured, and for a longer large dam, the influence of the light spot size of laser on measurement precision and range is considered. The system can be used by sectioning, and the whole system can also realize the self-check of laser collimation to ensure the requirement of the high precision of the automated monitoring of the deformation of the large dam. The method has the advantages of simple structure and high performance-price ratio, and by fixing imaging object distance, batch production can be realized through the ground glass, and production cost is maximumly reduced. Under the precondition that monitoring precision is ensured, technological problems of long-distance monitoring, particularly the monitoring of the large dam of which the length is 800m to 1000m are solved.

Description

A kind of method of laser dam safety monitoring

Technical field

The invention belongs to the measurement monitoring method, relate to a kind of deformation monitoring of dam, particularly a kind of new pattern laser dam safety monitoring method.

Background technology

What use was more in the laser dam safety monitoring method is laser wave band plate imaging method, also claim 3 collimations, it is mainly by the laser instrument collimated light source, zone plate and receiving target three parts are formed, laser instrument and receiving target are placed in respectively on the fixing basic point of two ends dam abutment, zone plate is placed in respectively on each monolith, the laser beam of sending from laser instrument is through the zone plate focussing force, on receiving target, form a bright round dot, on receiving target, measure the deviation value of bright spot to the center, this value is exactly the deformation values of measured monolith, when utilizing laser wave band plate imaging method to carry out the dam deformation measurement, because the distance of the relative basic point of each monolith is different thereby require the focal length of each zone plate to have nothing in common with each other, so each zone plate is all different, can not form batch process like this, the cost of manufacture height, for long distance monitoring, it particularly is the above dam monitoring of 800m～1000m, because there is certain limitation in the collimation of laser, can make the imaging of laser in the optical detection system not reach the expection requirement, thereby limit the measurement dynamic range.

Summary of the invention

Defective or deficiency at above-mentioned prior art exists the objective of the invention is to, and a kind of new pattern laser dam safety monitoring method is provided.This method can make laser-optical imagery measuring system realize producing in batches, greatly reduce production cost, measurement range, measuring accuracy and resolution have been improved greatly, and under the prerequisite that guarantees monitoring accuracy, solved the technical barrier of the above dam monitoring of long distance monitoring, particularly 800m～1000m.

To achieve these goals, the technical solution adopted in the present invention is: a kind of new pattern laser dam safety monitoring method, it is characterized in that, and comprise the following steps:

1) dam is numbered into the n section, n=0,1, i-1, i, i+1, i+2, n, wherein i is a natural number, laser instrument is installed on the fixing basic point of dam dam abutment, and one laser collimation system is housed at the Laser emission end, at each monolith one cover detection system is housed respectively, constitutes optical imaging system, the detection system in the described optical imaging system is by frosted glass plate, image-forming objective lens, photoelectric device, circuit board and communication system are formed, frosted glass plate is set, image-forming objective lens, photoelectric device three's center and laser beam axis are in same axis, the laser instrument of optical imaging system, the triangular relative distance of laser collimation system and detection system immobilize and and monolith be fixed into one, laser radiation is subjected to displacement to the distortion with dam of the hot spot of frosted glass, reflects the distortion of dam by the skew of Laser Measurement imaging point on photoelectric device behind frosted glass and image-forming objective lens;

2) light that sends of laser forms hot spot thereon behind frosted glass, behind image-forming objective lens, image in the target surface center of photoelectric device again, when dam body does not deform, be imaged on the target surface center, as reference point, when dam body deformed, said detecting system was moved with this monolith, the picture point relative photoelectric device target surface center of laser this moment after by optical imaging system is offset, and this variable quantity can be measured dam horizontal displacement Δ X and sedimentation Δ Z by the mathematical model computing;

3) every cover detection system, is only measured in the detection system immigration light path with the i section when needs are measured the distortion of i section dam body by Electric Machine Control, and all the other monolith detection systems are all left light path system, pass through so that light is smooth and easy;

4) for long especially dam body, at k section dam body one laser instrument and laser collimation system are set again, with as LASER Light Source and the laser collimation system of k+1 to n monolith deformation detection, k is a natural number, i+2＜k＜n, and come the collimation of calibration of laser with the basic point of dam abutment, and adopt basic point progressively to transmit, the horizontal displacement that known Laser Measuring with dam end group point place gets k section dam body is Δ X _k, settling amount is Δ Z _k, that is the displacement of k section laser instrument, the horizontal displacement that records k+1 section dam body with k section laser instrument and laser collimation system thereof again is Δ x based on this _K+1, settling amount is Δ z _K+1, then the practical distortion of k+1 section dam body can be expressed as: horizontal displacement: Δ X _K+1=Δ X _k+ Δ x _K+1, vertical sedimentation amount: Δ Z _K+1=Δ Z _k+ Δ z _K+1, wherein each displacement is vector, and the rest may be inferred can detect the displacement of n monolith.

Other characteristics of above-mentioned measuring method are, the frosted glass in the described detection system is the fixture distance to the distance at image-forming objective lens center, and frosted glass makes divergence of beam form a hot spot, is convenient to imaging, weakens light intensity simultaneously, prevents that photoelectric device from reaching capacity; Enlarging or reducing by this system in the photoelectric device imaging, measure with the dam deformation that adapts in various degree to realize the different measuring scope; Measurement result satisfies the code requirement of dam safety monitoring; Described photoelectric device is ccd video camera, CMOS camera and PSD sensor; Adopt centroid algorithm, extract the positional information of imaging facula, improved resolution and precision; Also adopt laser self checking technology to come compensating measurement errors to improve measuring accuracy.Whole optical imaging system can also be realized the self checking of laser alignment, guarantee dam deformation automatic monitoring high-precision requirement, the method is simple in structure, cost performance is high, and can realize producing in batches to be fixed into the picture object distance by frosted glass, greatly reduces production costs; And under the prerequisite that guarantees monitoring accuracy, solved the technical barrier of the above dam monitoring of long distance monitoring, particularly 800m～1000m.

Description of drawings

Fig. 1 is the laser dam safety monitoring method structural principle synoptic diagram of invention;

Fig. 2 is hot spot barycentric coordinates figure.

The present invention is described in further detail according to embodiment that technical scheme of the present invention is finished below in conjunction with accompanying drawing and inventor.

Embodiment

New pattern laser dam safety monitoring method structural principle signal of the present invention is shown in Figure 1: the concrete implementation step of this example is as follows:

1) dam is numbered into plurality of sections, every section 10-25 rice is long, helium-neon laser is installed on the fixing basic point of dam dam abutment, and one laser collimation system is housed at the Laser emission end, at each monolith one detection system is housed respectively, constitute optical imaging system, detection system is by frosted glass plate, image-forming objective lens, photoelectric device and circuit board communication system are formed, frosted glass plate is set, image-forming objective lens, photoelectric device three's center and laser beam axis are in same axis, the laser instrument of optical imaging system, the triangular relative distance of laser collimation system and detection system immobilizes also and monolith is fixed into one, laser radiation is subjected to displacement to the distortion with dam of the hot spot of frosted glass, reflects the distortion of dam by the skew of Laser Measurement imaging point on photoelectric device behind frosted glass and lens;

2) light that sends of laser forms hot spot thereon behind frosted glass, behind image-forming objective lens, image in the target surface center of photoelectric device again, when dam body does not deform, be imaged on the target surface center, as reference point, when dam body deformed, said detecting system was moved with this monolith, the picture point relative photoelectric device target surface center of laser this moment after by optical imaging system is offset, and this variable quantity can be measured dam horizontal displacement Δ X and sedimentation Δ Z by the mathematical model computing.

3) every group of detection system, only measured in the detection system immigration light path with the i section when needs are measured the distortion of i section dam body by its displacement of Electric Machine Control, and all the other monolith detection systems are all left light path system, pass through so that light is smooth and easy.

Imaging facula is adopted centroid algorithm, extract the positional information of imaging facula, the hot spot barycentric coordinates are referring to Fig. 2, and its algorithm is as follows:

$x=\frac{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{i=0}{\overset{i=N}{\mathrm{\Σ}}}(H(i,j)\×i)}{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{I=0}{\overset{i=N}{\mathrm{\Σ}}}H(i,j)},y=\frac{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{j=0}{\overset{i=N}{\mathrm{\Σ}}}(H(i,j)\×j)}{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{i=0}{\overset{i=N}{\mathrm{\Σ}}}H(i,j)}$

Wherein: i, the coordinate of j remarked pixel, i is capable, the j row;

H (i, j) expression i is capable, the gray-scale value of the pixel of j row;

M, N are respectively the width and the height of image;

4) when dam body is long especially, because there is certain limitation in the collimation of laser, can make the imaging of laser in the optical detection system not reach the expection requirement, thereby limited the measurement dynamic range, can be provided with a laser instrument and laser collimation system again this moment at k section dam body, with as LASER Light Source and the laser collimation system of k+1 to n monolith deformation detection, and come the collimation of calibration of laser with the basic point of dam abutment, adopt basic point progressively to transmit, the horizontal displacement that known Laser Measuring with dam end group point place gets k section dam body is Δ X _k, settling amount is Δ Z _k, that is the displacement of k section laser instrument, the horizontal displacement that records k+1 section dam body with k section laser instrument and colimated light system thereof again is Δ x based on this _K+1, settling amount is Δ z _K+1, then the practical distortion of k+1 section dam body can be expressed as: horizontal displacement: Δ X _K+1=Δ X _k+ Δ x _K+1, vertical sedimentation amount: Δ Z _K+1=Δ Zx+ Δ z _K+1, wherein each displacement is vector, and the rest may be inferred can detect the displacement of n monolith.

Precision analysis

Show by demarcation in the test: when dam body level or vertical direction move 1mm, 27 pixels (when certain focal length image-forming objective lens) are moved at the center of the imaging facula in the CMOS camera, the resolution of the known camera that adopts is 628 * 582, so the precision of measurement result can reach $\frac{1}{27}=0.037\left(\mathrm{mm}\right),$ Satisfy the code requirement of dam safety monitoring fully.

Claims (5)

1. a laser dam safety monitoring method is characterized in that, may further comprise the steps:

1) dam is numbered into the n section, n=0,1, i-1, i, i+1, i+2, n, wherein i is a natural number, laser instrument is installed on the fixing basic point of dam dam abutment, and one laser collimation system is housed at the Laser emission end, at each monolith one cover detection system is housed respectively, constitutes optical imaging system, the detection system in the described optical imaging system is by frosted glass plate, image-forming objective lens, photoelectric device, circuit board and communication system are formed, frosted glass plate is set, image-forming objective lens, photoelectric device three's center and laser beam axis are in same axis, the laser instrument of optical imaging system, the triangular relative distance of laser collimation system and detection system immobilize and and monolith be fixed into one, laser radiation is subjected to displacement to the distortion with dam of the hot spot of frosted glass, reflects the distortion of dam by the skew of Laser Measurement imaging point on photoelectric device behind frosted glass and image-forming objective lens;

2) light that sends of laser forms hot spot thereon behind frosted glass, behind image-forming objective lens, image in the target surface center of photoelectric device again, when dam body does not deform, be imaged on the target surface center, as reference point, when dam body deformed, said detecting system was moved with this monolith, the picture point relative photoelectric device target surface center of laser this moment after by optical imaging system is offset, and this variable quantity can be measured dam horizontal displacement Δ X and sedimentation Δ Z by the mathematical model computing;

3) every cover detection system, is only measured in the detection system immigration light path with the i section when needs are measured the distortion of i section dam body by Electric Machine Control, and all the other monolith detection systems are all left light path system, pass through so that light is smooth and easy;

4) for long especially dam body, at k section dam body one laser instrument and laser collimation system are set again, with as LASER Light Source and the laser collimation system of k+1 to n monolith deformation detection, k is a natural number, i+2＜k＜n, and come the collimation of calibration of laser with the basic point of dam abutment, and adopt basic point progressively to transmit, the horizontal displacement that known Laser Measuring with dam end group point place gets k section dam body is Δ X _k, settling amount is Δ Z _k, that is the displacement of k section laser instrument, the horizontal displacement that records k+1 section dam body with k section laser instrument and laser collimation system thereof again is Δ x based on this _K+1, settling amount is Δ z _K+1, then the practical distortion of k+1 section dam body can be expressed as: horizontal displacement: Δ X _K+1=Δ X _k+ Δ x _K+1, vertical sedimentation amount: Δ Z _K+1=Δ Z _k+ Δ z _K+1, wherein each displacement is vector, and the rest may be inferred can detect the displacement of n monolith.

2. the method for claim 1 is characterized in that, is the fixture distance with the frosted glass of described detection system to the distance at image-forming objective lens center, frosted glass makes divergence of beam form a hot spot, be convenient to imaging, weaken light intensity simultaneously, prevent that photoelectric device from reaching capacity.

3. the method for claim 1 is characterized in that, and is enlarging or reducing in the photoelectric device imaging by this optical imaging system.

4. the method for claim 1 is characterized in that, described photoelectric device is ccd video camera, CMOS camera and PSD sensor.

5. the method for claim 1 is characterized in that, adopts the imaging facula centroid algorithm, extracts the positional information of imaging facula, and the algorithm of hot spot barycentric coordinates is as follows:

$x=\frac{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{i=0}{\overset{i=N}{\mathrm{\Σ}}}(H(i,j)\×i)}{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{i=0}{\overset{i=N}{\mathrm{\Σ}}}H(i,j)},$

$y=\frac{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{i=0}{\overset{i=N}{\mathrm{\Σ}}}(H(i,j)\×j)}{\underset{j=0}{\overset{j=M}{\mathrm{\Σ}}}\underset{i=0}{\overset{i=N}{\mathrm{\Σ}}}H(i,j)}$

Wherein: i, the coordinate of j remarked pixel, i is capable, the j row;

H (i, j) expression i is capable, the gray-scale value of the pixel of j row;

M, N are respectively the width and the height of image.