CN103411544B - The method of the relative displacement of a kind of photodiode code-disc and measurement object thereof - Google Patents

Abstract

The present invention relates to the method for the relative displacement of a kind of photodiode code-disc and measurement object thereof, belong to field of measuring technique.The present invention includes laser pick-off plate and send out laser aid, it is characterized in that: laser pick-off plate is made up of diode code-disc one and diode code-disc two, one end of diode code-disc one and diode code-disc two is vertically fixed mutually, the size structure function of diode code-disc one and diode code-disc two is consistent, and the photodiode array that diode code-disc one is arranged by the capable n of n forms; Often row arranges n photodiode, often row n photodiode is set, n be greater than 1 positive odd number; Often row and often the photodiode that arranges all to be on same straight line and each row and column are parallel to each other, often row and the straight line of photodiode composition that often arranges mutually vertical, often row and often arrange be spaced apart m millimeter, m is greater than 0; Send out laser aid to be made up of two laser heads, one end of two laser heads is vertically arranged mutually.

Description

The method of the relative displacement of a kind of photodiode code-disc and measurement object thereof

Technical field

The present invention relates to the method for the relative displacement of a kind of photodiode code-disc and measurement object thereof, belong to field of measuring technique.

Background technology

Along with bridge occupies the status become more and more important in communications and transportation, Bridge Design continuous progress that is theoretical and operating technique makes bridge span constantly have new breakthrough, and version is also increasingly sophisticated.Be not only traditional railway bridge, domestic high ferro is also in building on a large scale.Bridge in use can be subject to the increase of external environment such as volume of transport, environmental load, reinforcement corrosion, freeze thawing damage, alkali, fatigue effect, damage accumulation, the factor such as corrosion effect and material aging, inevitably make stability reduction, structural-load-carrying capacity decline, degradation resistance, permanance reduction etc. the problem be connected between each component of bridge, these sum up the change getting up can be expressed as relative position between each component.So the safety monitoring of the heavy constructions such as bridge should come into one's own gradually.

What existing detection method adopted mostly is manually carry out regular visit, and drawback one to ensure the real-time measurement to measured object, cannot provide continuous print data; Drawback two is, manual inspection cannot record the accumulation of relative position change.Therefore, we are in the urgent need to a kind of easy, monitoring method of accurately, not needing manual intervention.

Summary of the invention

The present invention is directed to the proposition of above problem, and develop the method for the relative displacement of a kind of photodiode code-disc and measurement object thereof.The present invention proposes a kind of simply and accurately to the method for the heavy construction safety monitorings such as bridge.Not only can realize the monitoring of real-time on-site, and the accumulation of the relative position change between each component can be carried out record.Data simultaneously by collecting also can carry out suitable early warning analysis and maintenance work.

Technological means of the present invention is as follows:

A kind of photodiode code-disc, comprises laser pick-off plate and sends out laser aid; Laser pick-off plate is made up of diode code-disc one and diode code-disc two, one end of diode code-disc one and diode code-disc two is vertically fixed mutually, the size structure function of diode code-disc one and diode code-disc two is consistent, and the photodiode array that diode code-disc one is arranged by the capable n of n forms; Often row arranges n photodiode, often row n photodiode is set, n be greater than 1 positive odd number; Often row and often the photodiode that arranges all to be on same straight line and each row and column are parallel to each other, often row and the straight line of photodiode composition that often arranges mutually vertical, often row and often arrange be spaced apart m millimeter, m is greater than 0; Send out laser aid to be made up of two laser heads, one end of two laser heads is vertically arranged mutually; Laser pick-off plate and a laser aid are arranged on different stiff ends; Diode code-disc one and diode code-disc two external power supply; The position of laser pick-off plate and a laser aid is arranged on different positions; Laser pick-off plate is arranged on the object of the position change wanting tested; Send out laser aid and be arranged on static position, the laser beam vertical irradiation that original state two laser heads send is on diode code-disc one and (n+1)/2 row of diode code-disc two (2) and the photodiode of (n+1)/2 row; Laser pick-off plate connects computing module.

The intersection point arranged (n+1)/2 row (n+1)/2 of n capable n row diode code-disc one is set to initial point and sets up two-dimensional coordinate system, and (n+1)/2 row is set to coordinate system x-axis, and (n+1)/2 row are set to coordinate system y-axis; Position setting is carried out to the photodiode of the capable n row of the n of diode code-disc one (1), from first photodiode in the lower left corner, number consecutively is that 1 to n represents line number from top to bottom, from left to right number consecutively 1 to n represent row number, n be greater than 1 positive odd number; The photodiode positions of (n+1)/2 row (n+1)/2 row is setting coordinate (0,0) photodiode positions that, (n+1)/2 row ((n+1)/2)+1 arranges is (m, 0), the photodiode positions that (n+1)/2 row ((n+1)/2)-1 arranges is (-m, 0); With the diode location of each photoelectricity of this rule settings, namely the diode location of the photoelectricity of the capable k row of s is ((k-(n+1)/2) m, (s-(n+1)/2) m), s, k are less than or equal to n; The change in location of laser pick-off plate can be driven when laser pick-off plate stationary device position changes, the position of the initial reception laser beam of such diode code-disc one can change thereupon, receives the change that laser beam position change can be embodied in the diode of the photoelectricity receiving laser; With should laser pick-off plate stationary device position change time, the position of the initial reception laser beam of diode code-disc two can change thereupon, and diode code-disc two receives the change of diode that laser beam position change can be embodied in the photoelectricity receiving laser; The relative position that can be obtained measured object by the algorithm of computing module is changed.

The algorithm realization of computing module is as follows:

Suppose that diode code-disc one in use procedure at n reception to the photodiode coordinate of laser spots is

B′ _n＝(x′ _n,y′ _n)，（1）

(x ' _n, y ' _n) represent the photodiode of photodiode at the capable kth row of the position coordinates i.e. s of diode code-disc one, (x ' _s, y ' _k)=(k-(n+1)/2) m, (s-(n+1)/2) m);

N+1 reception to the photodiode coordinate of the point of laser is

B′ _n+1＝(x′ _n+1,y′ _n+1)，（2）

(x ' _n+1, y ' _n+1) represent the position coordinates i.e. photodiode positions of the s ' row kth ' row of photodiode at diode code-disc one,

(x′ _s,y′ _k)=((k′－(n+1)/2)m,(s′－(n+1)/2)m)，

Diode code-disc one (1) plane receives the vector of the point of laser

$\stackrel{\→}{d_x}=\stackrel{\→}{B_n^{\′}{B}_{n+1}^{\′}}=[(x_{n+1}^{\′}-x_n^{\′}),(y_{n+1}^{\′}-y_n^{\′})],---\left(3\right)$

With formula (1) (2) (3) in like manner, diode code-disc two at n reception to the photodiode coordinate of laser spots is

B′′ _n＝(y′′ _n,z′′ _n)，

(y ' ' _n, z ' ' _n) represent the photodiode positions of photodiode at the capable kth row of the position coordinates i.e. s of diode code-disc two,

(y′′ _n,z′′ _n)=((k－(n+1)/2)m,(s－(n+1)/2)m)，

N+1 reception to the photodiode coordinate of laser spots is

B′′ _n+1＝(y′′ _n+1,z′′ _n+1)，

(y ' ' _n+1, z ' ' _n+1) represent photodiode and at the position coordinates i.e. photodiode coordinate of the s ' row kth ' row of diode code-disc two be,

(y′′ _n+1,z′′ _n+1)=((k′－(n+1)/2)m,(s′－(n+1)/2)m)，

Diode code-disc two plane receives the vector of the point of laser

$\stackrel{\→}{d_y}=\stackrel{\→}{B_n^{\′\′}{B}_{n+1}^{\′\′}}=[(y_{n+1}^{\′\′}-y_n^{\′\′}),(z_{n+1}^{\′\′}-z_n^{\′\′})],$

The displacement be located in diode code-disc one is D _x,

$D_x=\left|\stackrel{\→}{B_n^{\′}{B}_{(n+1)}^{\′}}\right|=\sqrt{{(x_{(n+1)}^{\′}-x_n^{\′})}^2+{(y_{(n+1)}^{\′}-y_n^{\′})}^2}$

$=\sqrt{((k^{\′}-(n+1)/2)m-(k-(n+1)/2)m{)}^2-{((s^{\′}-(n+1)/2)m-(s-(n+1)/2)m)}^2,}$

Be D in the displacement of diode code-disc (2) _y

$D_y=\left|\stackrel{\→}{B_n^{\′\′}+B_{n+1}^{\′\′}}\right|=\sqrt{{(y_{n+1}^{\′\′}-y_n^{\′\′})}^2+{(z_{n+1}^{\′\′}-z_n^{\′\′})}^2},$

$=\sqrt{((k^{\′}-(n+1)/2)m-(k-(n+1)/2)m{)}^2-{((s^{\′}-(n+1)/2)m-(s-(n+1)/2)m)}^2}.$

Ultimate principle of the present invention and beneficial effect:

Laser pick-off plate is made up of diode code-disc one and diode code-disc two, one end of diode code-disc one and diode code-disc two is vertically fixed mutually, the size structure function of diode code-disc one and diode code-disc two is consistent, and the photodiode array that diode code-disc one is arranged by the capable n of n forms; Often row arranges n photodiode, often row n photodiode is set, n be greater than 1 positive odd number; Often row and often the photodiode that arranges all to be on same straight line and each row and column are parallel to each other, often row and the straight line of photodiode composition that often arranges mutually vertical, often row and often arrange be spaced apart m millimeter, m is greater than 0; M is measuring error, and m can carry out adjustment size according to actual needs.

When observing the buildings such as bridge, because their each components are generally within same tectonic plates.

If observe the change conditions of two interface components A and the B built, just need the spatial reference point O of an absolute rest.As Fig. 1, suppose that O point is an absolute reference point in space, A, B be respectively on measured object two components each a bit.With O point for initial point sets up space spheric coordinate system, if the coordinate of you n moment A, B is followed successively by (n+1) A, B respective coordinates is the moment

N moment and (n+1) moment be followed successively by

Order

$\stackrel{\→}{D}=\stackrel{\→}{{\mathrm{AB}}_{n+1}}-{\stackrel{\→}{\mathrm{AB}}}_n,---\left(5\right)$

If illustrate that relative motion does not occur A and B.Otherwise there is relative motion in A and B.

The use of absolute reference point can the analytical calculation of simplified measurement process and data, the method one that absolute reference point is chosen is place absolute reference point O being chosen at distance measured object infinite distance, even L → ∞, but the size of L is inversely proportional to measuring accuracy, distance precision far away is poorer, causes measuring error excessive.Second method be by absolute reference point O and measured object from very close to, but so just cannot ensure property independent of one another therebetween, one shakes in a dynamic process, and by force, the independence between each component is beyond expression of words, causes measurement data inaccurate for correlativity.Therefore in engineering construction, choosing of absolute reference point is a kind of perfect condition.

Therefore, how to design a kind of in real time not only simple but also can ensure that the monitoring scheme of precision of data just becomes a difficult problem.

The present invention is based on photodiode code-disc to carry out the reception of signal, change into the relative shift of measured object thus Real-Time Monitoring is carried out to the health status of each component that bridge and various large scale structureization are built.Simplify the method for measurement, and solve inaccuracy and the non real-time nature of data measured by traditional manual inspection.

(1) three dimensions variation analysis

The performance of vibration has two kinds, a kind of be shake in space a kind of be translation in plane.Hypothesis space has A, B 2 point, if with A be reference point to describe the motion conditions of B, in conjunction with above formula (1) (2) (3) (4), we can pass through change reflect the displacement of B.As shown in Figure 2, if under three dimensions spherical coordinate system, A point coordinate is (0,0,0), B point coordinate is then θ is the subpoint B ' of B point in xoy plane and the angle of X-axis, for the angle of L and Z axis.Then

Can find out thus: the variables L under three-dimensional coordinate system, θ, all can by two-dimensional coordinate x, y, z represent.

(2) two-dimensional space variation record

Known by formula formula (6), for each change in displacement of measured object, we can be decomposed into it changes in coordinates and x ' o ' y ' plane, x ' o ' z ' plane and y ' o ' z ' plane of three planes.The change in location of measured object accurately can be expressed by wherein any two planes.

In two-dimensional space, we utilize photodiode code-disc to carry out the record of relative position.Two orthogonal code-discs 1,2 difference corresponding vertical placement laser instrument 1 and laser instrument 2 is with it installed below bridge floor.Two code-discs represent plane x ' o ' y ' and y ' o ' z ' successively.So just, the motion vector in three dimensions has been resolved into the kinematic variables on two two dimensional surfaces.

By moments of vibration from three dimensions, be decomposed into the Displacement Analysis on two two dimensional surfaces, that is: B is projected as B ' on x ' o ' y ', and y ' o ' z ' plane is projected as B ' '.Displacement on x ' o ' y ' horizontal plane is displacement on y ' o ' z ' vertical plane is then can use with represent with A to be the change in location of reference point B.

(3) code-disc receives the corresponding relation between data and two-dimensional space amount

The code-disc that apparatus of the present invention use is a photodiode array, is embedded with code translator, divides and has horizontal stroke, ordinate.By the coded system of single-chip microcomputer matrix keyboard, each photodiode is positioned.As shown in Figure 3, suppose that use procedure at n reception to the coordinate of the point of laser is on the code-disc (code-disc of x ' o ' y ' plane represents diode code-disc 1) of x ' o ' y ' plane

B′ _n＝(x′ _n,y′ _n)（7）

The n+1 moment

B′ _n+1＝(x′ _n+1,y _′n+1)（8）

Displacement in x ' o ' y ' plane

${\stackrel{\→}{d}}_x=\stackrel{\→}{B_n^{\′}{B}_{n+1}^{\′}}=[(x_{n+1}^{\′}-x_n^{\′}),(y_{n+1}^{\′}-y_n^{\′})]---\left(9\right)$

With formula (7) (8) (9) in like manner, the code-disc (code-disc of y ' o ' z ' plane represents diode code-disc two (2)) of y ' o ' z ' plane has

B′′ _n＝(y′′ _n,z′′ _n)（10）

B′′ _n+1＝(y′′ _n+1,z′′ _n+1)（11）

$\stackrel{\→}{d_y}=\stackrel{\→}{B_n^{\′\′}{B}_{n+1}^{\′\′}}=[(y_{n+1}^{\′\′}-y_n^{\′\′}),(z_{n+1}^{\′\′}-z_n^{\′\′})]---\left(12\right)$

The displacement be located in x ' o ' y ' plane is Dx

$D_x=\left|\stackrel{\→}{B_n^{\′}{B}_{(n+1)}^{\′}}\right|=\sqrt{{(x_{(n+1)}^{\′}-x_n^{\′})}^2+{(y_{(n+1)}^{\′}-y_n^{\′})}^2}---\left(13\right)$

Displacement in y ' o ' z ' plane is Dy

$D_y=\left|\stackrel{\→}{B_n^{\′\′}{B}_{(n+1)}^{\′\′}}\right|=\sqrt{{(y_{(n+1)}^{\′\′}-y_n^{\′\′})}^2+{(z_{(n+1)}^{\′\′}-z_n^{\′\′})}^2}---\left(14\right)$

(3) discrete analysis that represents of code-disc and precision discussion

On code-disc, any time a bit has double discrete sense, one be heavily spatially discrete one be heavily in time discrete.

(1) spatially discrete: because the volume size of diode self be can not ignore, the code-disc that therefore photodiode is alternately formed anyhow is a discontinuous plane, causes dispersion error.But it is can be received that the displacement that this error and bridge vibration produce is compared.

(2) temporal discrete: to adopt the mode of sampling to take the data that code-disc receives, because the uncontinuity of sampling causes monitoring to be also discrete in time.The setting of sampling frequency formulates sampling frequency according to the natural vibration frequency of each bridge.Difference due to bridge material, structure causes the difference of natural frequency, therefore in engineering construction sampling frequency choose not identical yet.

Code-disc double discrete causes measurement and there is error.The method reducing error has two kinds: the first, and due to the given volume of photodiode, therefore we must use the photodiode of small volume to make code-disc and it to be arranged thick and fast; The second, under the prerequisite that bridge natural frequency is different, what should ensure sampling frequency chooses 8 times that are greater than bridge natural frequency, reduces the sample time discrete error caused with this.

Contrive equipment comprises laser beam emitting device and photodiode code-disc, occurs and receiving trap respectively as signal.Sender unit is generating laser, and it can produce linear light beam and low-power consumption, and high-effect luminous power exports, and stable performance, consistance is good, long service life.Signal receiving device is the receiving screen that diode laser matrix is formed, photodiode array receiving screen is the characteristic utilizing photodiode just conducting when there being illumination, convert light signal to electric signal when receiving screen receives the laser that emitter launches, make photodiode conducting thus can will receive the location presentation of the concrete photodiode of laser out.The advantages such as it has and is quick on the draw, low-power consumption, excellent performance, and the life-span is long.

In device use procedure, the data collected wholly on be divided into three kinds: i.e. transient data, average data and accumulation.Transient data is the vibration effect of a certain sampling time, is can regressor to a certain extent; Average accumulation is that record vibrates the total displacement variable that has an impact, is that one can not regressor; Average data is the mean value of whole vibration processes on the impact that measured object brings.

(4) alarm mode

According to the above-mentioned three kinds of data collected, following two kinds of alarm modes are taked in the early warning of this device:

(1) before device is installed, set the safe thresholding of code-disc according to the characteristic such as structure, amount of deflection of bridge, if receive the inswept discrete point of generating laser outside thresholding, then report to the police.Type of alarm is for installing some thumpers or light-emitting device is reminded to forbid that vehicle passes through bridge at end of the bridge.

(2) in device use procedure, real-time sampling analysis is carried out to measured object, by all data upload collected to administrative center, then carry out the related work such as field value set and bridge inspection and maintenance through control data corporation.

Beneficial effect of the present invention: the present invention utilizes real time health monitoring between generating laser and a set of each component being applicable to bridge and various large scale structureization building of photodiode code-disc design and the device of critical early warning.Monitoring method of the present invention is simple, device simple installation, and the energy that monitoring device consumes is few, normal work can be ensured for a long time, inaccurate and the non real-time nature of the artificial visually examine's method before avoiding, can meet monitoring requirements that is round-the-clock, real-time on-site, the data precision big error obtained is little.

Accompanying drawing explanation

Fig. 1 is its general principles key diagram.

Fig. 2 is three-dimensional spatial analysis of the present invention.

Fig. 3 is the present invention program's schematic diagram.

Fig. 4 (a) is scheme of installation of the present invention.

Fig. 4 (b) is that enlarged diagram is installed in Fig. 4 (a) of the present invention local.

Fig. 5 is that the present invention monitors process flow diagram.

Fig. 6 is the structure diagram of apparatus of the present invention.

Fig. 7 is diode code-disc one structure diagram of the present invention.

Embodiment

Monitor flow process as shown in Figure 5:

1. when bridge is in static time, system is once sampled every 1s, the photodiode now receiving laser should be initial point place (i.e. (n+1)/2 row (n+1)/2 row place), when bridge floor shakes, code-disc shakes with bridge floor, and the diode coordinate now receiving laser changes.

2., after detecting that the photodiode coordinate receiving laser changes, wake equipment set up, start working.

3. after equipment is waken up, increase sample frequency, (such as sample 100 times per second, concrete sample frequency will according to the project organization of whole bridge, intrinsic vibration frequency sets, because sampling cannot set synchronous with the vibrations of bridge floor by we, portray out more clearly to bridge be shaken process, we need moment bridge vibrations being arrived displacement maximum and minimum place to sample, sample frequency can be set to the octuple of the intrinsic vibration frequency of bridge to ten times by us, with the shock conditions enabling collected data comprehensively reflect bridge as far as possible.）

4. increase after sample frequency, the data at every turn collected recorded, carry out data calculating by module, calculating certain moment receives the photodiode of laser and the distance of true origin place photodiode.The safe distance (safe distance by after bridge construction, determine by the maximum vibration amplitude of the bridge that the physical property estimated when bridge security evaluation sets) of calculated distance and bridge is compared.

5. comparative result: if this distance is in safe distance scope, then only upload the data to control data corporation and preserve; If this distance exceeds safe range, then start warning device at once.(warning device can be install the equipment such as warning light at end of the bridge, reminds staff to stop vehicle to continue through bridge)

6. this process flow diagram is circulation process figure, will can proceed the work of data sampling while data upload.This project also has an advantage: bridge, in the process come into operation, some expendable displacements often can occur, such as due to situation that loosened screw etc. causes.(such as, in certain vibrations process, bridge floor there occurs the vibrations of 5cm on certain direction of level, but has only recovered 4cm when recovery, like this, just makes bridge floor position in static there occurs variation.The photodiode coordinate receiving laser in static is caused to be no longer (0,0).When this expendable displacement runs up to a certain degree time, be a severe test to the safety of bridge.) this device can make monitoring to the displacement accumulation of bridge.

As shown in Figure 6: a kind of photodiode code-disc, comprise laser pick-off plate and send out laser aid; Laser pick-off plate is made up of diode code-disc 1 and diode code-disc 22, one end of diode code-disc 1 and diode code-disc 22 is vertically fixed mutually, the size structure function of diode code-disc 1 and diode code-disc 22 is consistent, and the photodiode array that diode code-disc 1 is arranged by the capable n of n forms; Often row arranges n photodiode, often row n photodiode is set, n be greater than 1 positive odd number; Often row and often the photodiode that arranges all to be on same straight line and each row and column are parallel to each other, often row and the straight line of photodiode composition that often arranges mutually vertical, often row and often arrange be spaced apart m millimeter, m is greater than 0; Send out laser aid to be made up of two laser heads, one end of two laser heads is vertically arranged mutually; Laser pick-off plate and a laser aid are arranged on different stiff ends; Diode code-disc 1 and diode code-disc 22 external power supply; The position of laser pick-off plate and a laser aid is arranged on different positions; Laser pick-off plate is arranged on the object of the position change wanting tested; Send out laser aid and be arranged on static position, the laser beam vertical irradiation that original state two laser heads send is on diode code-disc 1 and (n+1)/2 row of diode code-disc 22 and the photodiode of (n+1)/2 row; Laser pick-off plate connects computing module.

A kind of photodiode code-disc realizes the method for the relative displacement of measuring object: as shown in Figure 7: the intersection point arranged (n+1)/2 row (n+1)/2 of n capable n row diode code-disc 1 is set to initial point and sets up two-dimensional coordinate system, (n+1)/2 row is set to coordinate system x-axis, and (n+1)/2 row are set to coordinate system y-axis; Carry out position setting to the photodiode of the n of diode code-disc 1 capable n row, from first photodiode in the lower left corner, number consecutively is that 1 to n represents line number from top to bottom, and from left to right number consecutively 1 to n represents row number, n be greater than 1 positive odd number; The photodiode positions of (n+1)/2 row (n+1)/2 row is setting coordinate (0,0) photodiode positions that, (n+1)/2 row ((n+1)/2)+1 arranges is (m, 0), the photodiode positions that (n+1)/2 row ((n+1)/2)-1 arranges is (-m, 0); With the diode location of each photoelectricity of this rule settings, namely the diode location of the photoelectricity of the capable k row of s is ((k-(n+1)/2) m, (s-(n+1)/2) m), s, k are less than or equal to n; The change in location of laser pick-off plate can be driven when laser pick-off plate stationary device position changes, the position of the initial reception laser beam of such diode code-disc 1 can change thereupon, receives the change that laser beam position change can be embodied in the diode of the photoelectricity receiving laser; With should laser pick-off plate stationary device position change time, the position of the initial reception laser beam of diode code-disc 22 can change thereupon, and diode code-disc 22 receives the change that laser beam position change can be embodied in the diode of the photoelectricity receiving laser; The relative position that can be obtained measured object by the algorithm of computing module is changed.

The algorithm realization of computing module is as follows:

Suppose that diode code-disc one (1) in use procedure at n reception to the photodiode coordinate of laser spots is

B′ _n＝(x′ _n,y′ _n)，（1）

(x ' _n, y ' _n) represent the photodiode of photodiode at the capable kth row of the position coordinates i.e. s of diode code-disc one (1), (x ' _s, y ' _k)=(k-(n+1)/2) m, (s-(n+1)/2) m);

N+1 reception to the photodiode coordinate of the point of laser is

B′ _n+1＝(x′ _n+1,y′ _n+1)，（2）

(x ' _n+1, y ' _n+1) represent the position coordinates i.e. photodiode positions of the s ' row kth ' row of photodiode at diode code-disc one (1),

(x′ _s,y′ _k)=((k′－(n+1)/2)m,(s′－(n+1)/2)m)，

Diode code-disc one (1) plane receives the vector of the point of laser

${\stackrel{\→}{d}}_x=\stackrel{\→}{B_n^{\′}{B}_{n+1}^{\′}}=[(x_{n+1}^{\′}-x_n^{\′}),(y_{n+1}^{\′}-y_n^{\′})]---\left(3\right)$

With formula (1) (2) (3) in like manner, diode code-disc two (2) at n reception to the photodiode coordinate of laser spots is

B′′ _n＝(y′′ _n,z′′ _n)，

(y ' ' _n, z ' ' _n) represent the photodiode positions of photodiode at the capable kth row of the position coordinates i.e. s of diode code-disc two (2),

(y′′ _n,z′′ _n)=((k－(n+1)/2)m,(s－(n+1)/2)m)，

N+1 reception to the photodiode coordinate of laser spots is

B′′ _n+1＝(y′′ _n+1,z′′ _n+1)，

(y ' ' _n+1, z ' ' _n+1) represent photodiode and at the position coordinates i.e. photodiode coordinate of the s ' row kth ' row of diode code-disc two (2) be,

(y′′ _n+1,z′′ _n+1)=((k′－(n+1)/2)m,(s′－(n+1)/2)m)，

Diode code-disc two (2) plane receives the vector of the point of laser

$d_y=\left|\stackrel{\→}{B_n^{\′\′}+B_{n+1}^{\′\′}}\right|=[(y_{n+1}^{\′\′}-y_n^{\′\′}),(z_{n+1}^{\′\′}-z_n^{\′\′})],$

The displacement be located in diode code-disc one (1) is D _x,

$D_x=\left|\stackrel{\→}{B_n^{\′}{B}_{(n+1)}^{\′}}\right|=\sqrt{{(x_{(n+1)}^{\′}-x_n^{\′})}^2+{(y_{(n+1)}^{\′}-y_n^{\′})}^2}$

$=\sqrt{((k^{\′}-(n+1)/2)m(k-(n+1)/2){m)}^2-{((s^{\′}-(n+1)/2)m-(s-(n+1)/2)m)}^2},$

Be D in the displacement of diode code-disc (2) _y

$D_y=\left|\stackrel{\→}{B_n^{\′\′}+B_{n+1}^{\′\′}}\right|=\sqrt{{(y_{n+1}^{\′\′}-y_n^{\′\′})}^2+{(z_{n+1}^{\′\′}-z_n^{\′\′})}^2},$

$=\sqrt{{((k^{\′}-(n+1)/2)m-(k-(n+1)/2)m)}^2-{((s^{\′}-(n+1)/2)m-(s-(n+1)/2)m)}^2}.$

Below in conjunction with accompanying drawing 4(a) and Fig. 4 (b) the present invention is conducted further description.

As shown in Fig. 4 (a) and Fig. 4 (b): the diode code-disc 1 that B point place's installation two is vertically placed under tested bridge floor and diode code-disc 22; Bridge due to the existence of natural reonant frequency, can produce the change of an amplitude when vibrating generation.If the maximal value changing value of measured point B amplitude is U, the damage that the vibration being in use subject to bridge floor for avoiding device brings, therefore at bridge pier distance bridge floor U place's installation support, two orthogonal laser beam emitting device Tx1 installed by support, Tx2, its beam emissions head rushes at diode code-disc 1 and diode code-disc 22 respectively.

The vibration effect produced by the risk factors such as load can be similar to compared to bridge floor to be ignored, therefore in measuring process, we do not consider self-vibration and the resonant conditions of support and bridge floor, assuming that their relative bridge floor absolute rest, both having put A is absolute reference point when measuring.

In conjunction with formula (7)-(14), we can draw the space displacement amount of B

$D=\sqrt{D_x^2+D_y^2},---\left(15\right)$

From above formula: if D _xwith D _yvalue larger, prove that displacement D is larger, just illustrate that to vibrate the impact brought larger, the potential safety hazard of measured object is larger.

The sampling interval of photodiode receiving screen associates with photoreceiver efficiency.We suppose that the wakeup time of apparatus of the present invention is zero and the receiving efficiency of photodiode code-disc is very high, will be acquired as long as the light beam that emitter sends slips over code-disc.Rapid due to what vibrate, on a time point, may can slip over one track on receiving screen by laser, and cause being described accurately.Therefore, the related data of the method for sampling to vibration is adopted to carry out Collection and analysis.Only record at a sample point position received at that time, utilize each component of these discrete points to bridge and various large scale structureization building to carry out real time health monitoring and critical early warning.Also critical early warning will be carried out while record data.Install originally at device, a security domain can be set, when the coordinate position of sample point is outside security domain, then report to the police.This security domain is changed along with the accumulation of time and the displacement of vibration generation accumulate.

The present invention is not limited to above-mentioned embodiment, any the present invention disclose technical scope in equivalent concepts or change, be all classified as protection scope of the present invention.

Claims (1)

1. a photodiode code-disc, comprise laser pick-off plate and send out laser aid, it is characterized in that: laser pick-off plate is made up of diode code-disc one (1) and diode code-disc two (2), one end of diode code-disc one (1) and diode code-disc two (2) is vertically fixed mutually, the size structure function of diode code-disc one (1) and diode code-disc two (2) is consistent, and the photodiode array that diode code-disc one (1) is arranged by the capable n of n forms; Often row arranges n photodiode, often row n photodiode is set, n be greater than 1 positive odd number; Often row and often the photodiode that arranges all to be on same straight line and each row and column are parallel to each other, often row and the straight line of photodiode composition that often arranges mutually vertical, often row and often arrange be spaced apart m millimeter, m is greater than 0; Send out laser aid to be made up of two laser heads, one end of two laser heads is vertically arranged mutually; Laser pick-off plate and a laser aid are arranged on different stiff ends; Diode code-disc one (1) and diode code-disc two (2) external power supply; The position of laser pick-off plate and a laser aid is arranged on different positions; Laser pick-off plate is arranged on the object of the position change wanting tested; Send out laser aid and be arranged on static position, the laser beam vertical irradiation that original state two laser heads send is on diode code-disc one (1) and (n+1)/2 row of diode code-disc two (2) and the photodiode of (n+1)/2 row; Laser pick-off plate connects computing module; The intersection point arranged (n+1)/2 row (n+1)/2 of n capable n row diode code-disc one (1) is set to initial point and sets up two-dimensional coordinate system, (n+1)/2 row is set to coordinate system x-axis, and (n+1)/2 row are set to coordinate system y-axis; Position setting is carried out to the photodiode of the capable n row of the n of diode code-disc one (1), from first photodiode in the lower left corner, number consecutively is that 1 to n represents line number from top to bottom, from left to right number consecutively 1 to n represent row number, n be greater than 1 positive odd number; The photodiode positions of (n+1)/2 row (n+1)/2 row is setting coordinate (0,0), the photodiode positions that (n+1)/2 row ((n+1)/2)+1 arranges is (m, 0), the photodiode positions that (n+1)/2 row ((n+1)/2)-1 arranges is (-m, 0); With the diode location of each photoelectricity of this rule settings, namely the diode location of the photoelectricity of s capable k row be ((k-(n+1)/2) m, (s-(n+1)/2) m), s, k are less than or equal to n; The change in location of laser pick-off plate can be driven when laser pick-off plate stationary device position changes, the position of the initial reception laser beam of such diode code-disc one (1) can change thereupon, receives the change that laser beam position change can be embodied in the diode of the photoelectricity receiving laser; With should laser pick-off plate stationary device position change time, the position of the initial reception laser beam of diode code-disc two (2) can change thereupon, and diode code-disc two (2) receives the change that laser beam position change can be embodied in the diode of the photoelectricity receiving laser; The relative position that can be obtained measured object by the algorithm of computing module is changed; The algorithm realization of described computing module is as follows:

Suppose that diode code-disc one (1) in use procedure at n reception to the photodiode coordinate of laser spots is

B′ _n＝(x′ _n,y′ _n)，(1)

(x ' _n, y ' _n) represent the photodiode of photodiode at the capable kth row of the position coordinates i.e. s of diode code-disc one (1), (x ' _s, y ' _k)=((k-(n+1)/2) m, (s-(n+1)/2) m);

N+1 reception to the photodiode coordinate of the point of laser is

B′ _n+1＝(x′ _n+1,y′ _n+1)，(2)

(x ' _n+1, y ' _n+1) represent the position coordinates i.e. photodiode positions of the s ' row kth ' row of photodiode at diode code-disc one (1),

(x′ _s,y′ _k)＝((k′－(n+1)/2)m,(s′－(n+1)/2)m)，

Diode code-disc one (1) plane receives the vector of the point of laser

With formula (1) (2) (3) in like manner, diode code-disc two (2) at n reception to the photodiode coordinate of laser spots is

B″ _n＝(y″ _n,z″ _n)，

(y " _n, z " _n) represent the photodiode positions of photodiode at the capable kth row of the position coordinates i.e. s of diode code-disc two (2),

(y″ _n,z″ _n)＝((k－(n+1)/2)m,(s－(n+1)/2)m)，

N+1 reception to the photodiode coordinate of laser spots is

B″ _n+1＝(y″ _n+1,z″ _n+1)，

(y " _n+1, z " _n+1) represent photodiode and at the position coordinates i.e. photodiode coordinate of the s ' row kth ' row of diode code-disc two (2) be,

(y″ _n+1,z″ _n+1)＝((k′－(n+1)/2)m,(s′－(n+1)/2)m)，

Diode code-disc two (2) plane receives the vector of the point of laser

The displacement be located in diode code-disc one (1) is D _x,

Be D in the displacement of diode code-disc two (2) _y