CN106168461A - A kind of novel telemeasurement calibration instrument - Google Patents

Abstract

A kind of novel telemeasurement calibration instrument, belongs to fields of measurement, particularly relates to the calibrating method of remote non-cpntact measurement.The problem that present invention mainly solves the calibration of telemeasurement, it is provided that one is remote to be detected contactless calibrating method and is embodied as approach.The present invention is made up of in isoplanar two laser pens that angle is the least, a laser range finder and two angular transducers (rotary angle transmitter in a horizontal plane, the pitch reference in a vertical guide).Calculate the centre-to-centre spacing of taken a picture upper two laser spots according to the horizontal angle of capture apparatus, the angle of pitch and the data such as distance to tested surface during detection, and then obtain the size of each pixel on photo, thus realize the scaling function in remote detection.It is mainly used in inaccessible detected target is carried out calibration during remote image detection so that testing result with quantitative analysis and comparison, can improve the digitized of detection, test result more science.

Description

A kind of novel telemeasurement calibration instrument

[technical field]

The present invention relates toMeasureField, particularly relates toThe calibrating method of remote non-cpntact measurement and realization。

[background technology]

The key factor of remote detection by quantitative is that dimension is measured, and will complete accurately on the digital photograph of long distance shooting Measure it may first have to demarcating the developed width representated by a pixel in the size of each pixel, i.e. image, its unit is mm/pix.Referred to as " calibration ", the precision of calibration is directly connected to the precision measured to this process.

Tradition calibration common practices is when photographic subjects thing, and the scale of known physical length and area is placed on object Side, includes scale during shooting, it is desirable to scale color is the most single, it is simple to rapid extraction.Such as it is ingested at needs The black paper slip of crack other patch one full-length.Gather after image through processing, black paper slip can be extracted in image in length Pixel number on direction, the full-length of paper slip i.e. obtains the width representated by a pixel divided by pixel number^[1]。 If the length of paper slip is 100mm, actually measured pixel number is 1000.Developed width representated by so one pixel= 100/1000=0.1mm/pix.

The advantage of this method is that length of the scale is fixed and pressed close to and measures target, and calibration error is little, and conversion method is the easiest In realization.But its major defect is people to be allowed for place scale close to target, be not suitable for calibrating at a distance and surveying If amount testing staff has way to place scale close to target, contact New Instrument for Crack Width i.e. be can be used directly and meter ruler is surveyed The amount width in crack and length, at all without going again to carry out to calibrate → measure → a series of loaded down with trivial details work such as conversion.

[summary of the invention]

[to solve the technical problem that (goal of the invention)] the present invention is to solveThe calibration of telemeasurementProblem, it is provided that A kind ofThe contactless calibrating method of remote detection and realization。

[technical scheme] detection calibration instrument at a distance is by isoplanar two laser pens that angle α is the least, a Laser Measuring Distance meter and two angular transducer (rotary angle transmitter in a horizontal plane, the pitch reference in a vertical guide) groups Become.The two bundle laser penetrated by laser pen, form two hot spots, its centre distance on the objective plane vertical with observed direction Distance S to objective plane that d and diastimeter record₁Linear relationship is there is between (directly being recorded by laser range finder)^[2] (as shown in Figure 1):

$d=2tan\left(\frac{\mathrm{\α}}{2}\right)\·(S_1+S_0)---\left(1\right)$

In above formula, S₀It is the intersection point distance to diastimeter range finding starting point plane of two laser pen reverse extendings, with two Together as the initial parameter of calibration instrument, there is deviation owing to instrument assembles in the angle α of laser pen, every instrument is both needed to individually mark Fixed, it is also required to re-start demarcation and correction, to ensure the accuracy that detection is measured after maintenance or before formal detection work every time.

By (1) formula computer result out it is when diastimeter is just to tested plane, between two calibration laser spots Distance.Under normal circumstances, diastimeter not can just to tested surface, but with just be there is horizontal sextant angle β in tested surface direction With vertical angle θ (being recorded by level angle sensor and pitch reference respectively), as shown in Figure 2.Figure midplane OCBD is Tested surface, AO direction is just to tested surface direction, AB a length of S (=S₁+S₀), distance between two laser spots on photo^[1], i.e. scheme 2 middle conductor EF length are calibration length d needing to obtain.

According to Fig. 2 intermediate cam relation, can be in the hope of:

$d=h\·\left(tan\right(\mathrm{\γ}+\frac{\mathrm{\α}}{2})-tan(\mathrm{\γ}+\frac{\mathrm{\α}}{2}\left)\right)---\left(2\right)$

In formula: $h=\frac{S_1+S_0}{\sqrt{1+{\tan }^2\mathrm{\θ}+{\tan }^2\mathrm{\β}}}$

$\mathrm{\γ}={\tan }^{-1}\sqrt{{\tan }^2\mathrm{\θ}+{\tan }^2\mathrm{\β}}$

Initial parameter α of calibration instrument and S₀Demarcation, can use just to test plane method, measure one group of S₁With d value, With method of least square, data measured is carried out best straight line matching again^[2], recommend here to utilize LINEST function in Excel, permissible Quickly obtain required parameter^[3].It is shown in Table 1 if any calibration instrument initial testing data:

S surveyed by table 1₁-d nominal data (unit: rice)

S1	d	d/2
			6.128	0.35	0.175
8.672	0.485	0.2425
			10.893	0.605	0.3025
13.269	0.725	0.3625
			15.793	0.865	0.4325
18.079	0.985	0.4925
			19.762	1.07	0.535
21.822	1.18	0.59

Then can obtain table 2 with LINEST function:

Table 2 LINEST function partial results

K=0.0264458186

B=0.01332779

R=0.999940564

By r value it can be seen that d-S₁Linear dependence or reasonable, this just establishes for high-precision remote calibration Basis.Can obtain:

S₀=b/k=0.5039659

α=2 Atan (k)=0.0528793

This two-value is the initiation parameter of this instrument, substitutes into (2) formula, in conjunction with the S preserved in real time that takes pictures₁, β and θ, Calculate d value, then record in correspondence image the pixel count n between two optical spot centre, i.e. can obtain scaled values f=d/ of this picture N, its unit is: rice/pixel (m/Pix), thus realizes remote calibration.

[beneficial effect] compared with prior art, the beneficial effects of the present invention is: carries for the calibration of remote detection by quantitative Supply a kind of feasible solution, given detailed demonstration and derivation, obtain the calibration formula of practicality.Hardware is implemented to press Make autonomous device shown in Fig. 3 dashed box, but be in most cases to be applied on particular detection instrument according to real needs.One As together with image capture device, in conjunction with special-purpose software, complete under computer to take pictures, parameter (distance, angle etc.) record, The work such as auto-scaling and follow-up measurement, data analysis.Fig. 4 is i.e. to apply the present invention to detect in a remote bridge appearance On instrument, compensate for the deficiency that traditional axle inspection exists, it is possible to solve the inspection of artificial bridge well or utilize bridge-checking vehicle to carry out bridge inspection people Member's safety, suitable inspection bridge type, on problems such as the impacts of traffic and environment, it is possible to search and gather bridge quickly and accurately sick Evil information, improves testing staff's work efficiency, solves a great problem of long distance bridge defect detection.Its two, apply this Bright bridge inspection instrument, compared with traditional artificial conjugative bridge inspection car detection mode, considers personnel's spending, rents bridge-checking vehicle, combustion Oil take, each side factor such as toll, utilize bridge examine instrument carry out the expense of bridge inspection only just correspond to utilize bridge-checking vehicle ten/ 1/1 to eight, concrete Data Comparison is as shown in table 3.

Table 3 utilizes bridge-checking vehicle to carry out bridge inspection working unit day testing cost contrast table with bridge inspection instrument

[accompanying drawing explanation]

Fig. 1 is the calibration principle schematic of the present invention；

In figure: 1-laser pen 2-laser range finder 3-angular transducer

Fig. 2 is the general calibration schematic diagram of the present invention；

In figure: θ-pitching angle beta-level angle S-distance (=S₀+S₁)

Fig. 3 is the hardware architecture diagram of the present invention；

In figure: 1-level angle sensor 2-pitch reference 3-laser range finder 4-calibrates laser pen

5-single-chip microcomputer main control unit 6-RS232 interface 7-high-definition camera 8-high definition object lens 9-notebook computer

Fig. 4 is the application example schematic diagram of the present invention.

In figure: 1-calibrates laser pen 2-level angle sensor 3-pitch reference 4-laser range finder

5-high-definition camera object lens 6-calibrates laser pen launch hole 7-high-capacity lithium battery

[detailed description of the invention]

The present invention is mainly by two laser pens, a laser range finder and two angular transducers (in a horizontal plane Pitch reference in rotary angle transmitter, a vertical guide) composition, complete remote under the control of a single-chip microcomputer main control unit Contactless calibration work in distance video images detection, thus quantitative measurement when solving the detection of long-distance video image is asked Topic.May be used on all long-distance video image detector devices, particular hardware is implemented can as shown in Figure 3, according to particular detection The real needs of instrument, together with image capture device, connect notebook computer, knot by RS232 serial ports and USB interface respectively Close special-purpose software, complete under computer to take pictures, parameter (distance, angle etc.) records, auto-scaling and follow-up measurement, data The work such as analysis.

Laser pen luminous power is determined, under usual illumination according to the required maximum distance of detection and working environment light condition The detecting distance of about 20m needs the laser pen of 20mW.The angle of two laser pens and the minimum distance of detection, maximum distance and Photo amplification all has relation, the least meeting to cause measuring relative error change greatly, then can limit photo amplification too greatly, need Debugging is to optimal as the case may be.Two light that two laser pens send necessarily be in same plane, on tested surface Two luminous point convergences as far as possible, regular and horizontal distribution.

Depending on the range of laser range finder and precision are according to the demand of detecting instrument, Multiple Type is had to be available for choosing on the market Select.Requirement can complete work of finding range under the control of single-chip microcomputer.

Pitch reference angular range 150 °, wherein depression angle 60 °, upward view angle 90 °.Level angle sensor angles model Enclose is 360 °, it is accordingly required in particular to be noted that level angle magnetic declination sensor, will when design and assembly detecting instrument Ensure its as far as possible away from camera lens because have for focusing in camera lens, zoom, the motor of adjustment aperture, its magnetic field pair The impact of magnetic declination sensor is the biggest！Also to ensure that it is always operating in horizontal plane.

Single-chip microcomputer main control unit internally controls the tune of laser pen, angular transducer, laser range finder and camera lens Jiao, zoom, aperture work and collect data message, are externally connected with notebook computer by RS232 interface, complete data stream and Control stream information exchange.Avoid range error for reducing interference, during laser range finder range finding, need Temporarily Closed laser pen.

The embodiment of the present invention, in addition to instrument examined by the bridge shown in Fig. 4, also will be used for the quick intelligent movable bridge researched and developed In the video detecting device of safety detecting system.As long as it can be said that at a distance video images detection instrument or equipment, The application present invention measures calibration.

Claims (5)

1. a remote detection calibration instrument, is characterized in that, this calibration instrument is by two laser pens, a laser range finder and two Angular transducer (rotary angle transmitter in a horizontal plane, the pitch reference in a vertical guide) forms.Two laser Must be positioned in same plane, be fixed on above remote detection equipment, and ensure there is a angle the least；Laser range finder Being placed in detection equipment side, during range finding, the light of injection should be put down with the primary optical axis of laser pen place plane and detection equipment camera lens OK；Pitch reference is arranged in detection equipment；Level angle sensor is then arranged on equipment supporter.

Remote detection calibration instrument the most according to claim 1, is characterized in that, described calibration instrument is commonly used at a distance On detection equipment, this equipment also includes single-chip microcomputer main control unit, optical image unit, video image interface and digital information control Interface.Main control unit controls the collaborative works such as laser pen, diastimeter, angular transducer, laser pen the two bundle laser penetrated, Forming two hot spots in observed object plane, detection is shot when gathering image and is protected together with data messages such as distance, angles Leave, try to achieve the centre distance of two hot spots according to space multistory geometrical relationship, in conjunction with the pixel count measured in shot image, To the size of each pixel of this image, thus realize telemeasurement calibration.

Remote detection calibration instrument the most according to claim 1, is characterized in that, level angle sensor to ensure in level Realizing 360 ° of rotations in face, equipment supporter needs horizontal adjustment scale.

Remote detection calibration instrument the most according to claim 2, is characterized in that, single-chip microcomputer main control unit is gone here and there by RS232 Row FPDP is connected with host computer (notebook computer), in order to the data message such as transmission range, angle the control that receives computer Signal processed.

Remote detection calibration instrument the most according to claim 2, is characterized in that, needs to close laser during diastimeter work Pen.