CN103644888A - Inertial reference measurement method for detecting bridge deformation - Google Patents

Abstract

The invention discloses an inertial reference measurement method for detecting bridge deformation, and the method is used for detecting bridge deformation and subsidence. The method comprises a step of planning a track path at the surface of a measured bridge, marking a plurality of reference points on the track path, establishing a reference by using high precision GPS information, and establishing an inertial reference by using an inertial system, a step of collecting the output of the inertial system and the output of an odometer, compensating the output of the odometer and identifying a bridge surface uneven influence test, then carrying out combined dead reckoning, completing the whole test of selected track, carrying out a closed correction process, and finally giving a tested accurate track and calculating the deformation and subsidence of the bridge. According to the method, based on the combination of an inertial navigation system, the odometer and a GPS, by using a three-dimensional inertial measurement mode, and the rapid and continuous measurement of bridge 3D small dynamic deformation is realized without the restrictions of the track and no track.

Description

A kind of inertial reference measuring method for detection of bridge deformation

Technical field

The invention belongs to inertial technology engineering application, concrete, relate to a kind of inertial reference measuring method for detection of bridge deformation.

Background technology

Along with the demand of scientific and technical progress and communications and transportation, many Longspan Bridges arise at the historic moment, and especially suspension bridge is large with its span, and beautiful design is saved material and enjoyed people's favor, becomes the first-selection of Longspan Bridge.But along with the increase of span, from hundreds of rice to km, owing to lacking necessary monitoring and corresponding maintenance, there are a large amount of bridge damage accidents all over the world, caused massive losses to national economy and lives and properties.Therefore, the bridge security use state for national economy service having put into effect being carried out to effective monitoring, guarantee people's life and national wealth safety, is a focus direction of current bridge circle application and research.

Along with people pay attention to increasingly to bridge security problem, be not only that Longspan Bridge is built supervisory system, when young span bridge has not been set up corresponding supervisory system yet.Sensing system is the core of supervisory system, and all subsystems of a complete supervisory system are all configured around sensing system.In recent years, Sensor Technology Development is very fast, and especially Fibre Optical Sensor and wireless senser progressively start to apply in engineering.The sensor kind of using from each bridge, is progressively to have increased, and what relate to is wider.The development of satellite remote sensing technology, is widely used in project security monitoring remote sensing technology, especially in distortion and settlement monitoring, is most widely used.

Instrument for bridge deformation monitoring mainly contains at present: transit, displacement transducer, acceleration transducer and laser testing method.Total powerstation is to utilize autoscan method, each measuring point is carried out to the continuous sweep of one week, obtains three-dimensional coordinate, and measuring accuracy is higher, but shortcoming to be each measuring point asynchronous and can not survey during large deformation; Displacement transducer is a kind of contact type sensor, and its shortcoming is cannot to measure and lateral displacement measurement be had any problem for being difficult to the points of proximity; Acceleration transducer, poor for low frequency static displacement identification result, precision is not high.The measuring accuracy of laser testing instrument is higher, but rocks when large and also cannot measure owing to cannot catching luminous point at bridge etc.The most emerging high-precision GPS can reach grade measuring accuracy, and shortcoming is that measurement for a long time and satellite navigation signals are unobstructed.

Aspect existing bridge deformation measurement, monitoring, adopt laser tracker, laser scanner, robot measurement, various high-precision GPS receiver, electronic total station, spirit-leveling instrument and various special measurement instrument, adopt one or more surveying instrument combinations, realize high-precision test.The stereo monitoring system being formed by various special-purpose monitoring instruments, surveying instrument and air to surface observation instrument, can realize automatic monitoring and Deformation Prediction that bridge is continued, the feature of this type of metering system is higher, the sustainable monitoring of measuring accuracy, but can only be to several point measurements, and artificial spanning equipment be very difficult.

The at present domestic deformation that has proposition to adopt inertial technology mode testing engineering, comprises the deformation of the heavy constructions such as dam, bridge.Existing inertia test mode mainly adopts some parameters of bidimensional gyro or independent three-dimensional gyro to measure track (in order to measure engineering deformation, when engineering construction, can bury in advance some fixing tracks underground, can facilitate the monitoring in follow-up operation process), started the beginning of inertia measurement.But the metering system of bidimensional, is the requirement that can meet plane surveying from demand, but exist to measure defect, measurement requirement that cannot capable of meeting requirements on three-dimensional solid.

Summary of the invention

Above defect or Improvement requirement for prior art, the invention provides a kind of inertial reference measuring method for detection of bridge deformation, its object is not to be subject to the restriction of rail and trackless, realize the measurement to the deformation of the three-dimensional petty action state of bridge rapidly, continuously, solve thus existing bridge deformation measure in equipment set up difficulty, be subject to deformation among a small circle, the technical matters of bridge rail-free restriction.

An inertial reference measuring method for detection of bridge deformation, comprises the following steps:

Measurement environment is built step:

Prepare to measure dolly, on measurement dolly, inertial navigation system is installed, on four wheels measuring dolly, lay respectively a mileage gauge;

Reference data establishment step:

At the two ends of bridge to be measured, selected two reference points, locate latitude, longitude and the height above sea level of determining two reference points by GPS; Using one of them reference point as initial point foundation measurement coordinate system, and another reference point is positioned in the coordinate axis of coordinate system; At the surperficial planned trajectory route of bridge to be measured, make planning path must be through two reference points; Utilize latitude, longitude and the altitude information of reference point to set up inertia system test benchmark, and using the world, northeast reason coordinate system as inertial navigation coordinate system;

Mileage measuring process:

Start measurement dolly and move along path planning, at current sampling period t _i-t _i-1, obtain the mileage increment information of four mileage gauge outputs, mileage increment information is carried out to wheel deformation error compensation, then consider that wheel hanging merges four mileage increment informations after compensating, and obtains current sampling period t _i-t _i-1measure the true mileage increment Delta L of dolly _i;

Inertial navigation step:

Enable inertial navigation system, at current sampling instant t _iobtain and measure the attitude angle of dolly in navigation coordinate system

Integrated navigation step:

Note odometer coordinate is m system, and inertial navigation coordinate is b system, and the conversion cosine battle array that b is tied to m system is

Note mileage increment Delta L _ibeing projected as of m system ${\mathrm{\ΔL}}_i^m={\left[\begin{array}{ccc}0& \mathrm{\Δ}{L}_i& 0\end{array}\right]}^T,$ Subscript T represents transposition; By coordinate system, be converted to mileage increment

being projected as of b system

and then obtain mileage increment Delta L _ithe projection of fastening at navigation coordinate

t _iconstantly measure the attitude angle of dolly;

Calculate current sampling instant t _imeasure the position coordinates of dolly under navigation coordinate system

p _i-1for last sampling instant t _i-1measure the position coordinates of dolly under navigation coordinate system;

Position coordinates to measurement dolly under navigation coordinate system carries out integration and obtains the bridge floor track under navigation coordinate system, and then by coordinate system, is converted to the bridge floor track of measuring under coordinate system;

Deformation determination step:

Bridge floor track and the benchmark bridge floor track measured under coordinate system are compared, determine the bridge deformation situation that detects.

The specific implementation of further, in described mileage measuring process, mileage increment information being carried out to wheel deformation error compensation is: make current sampling period t _i-t _i-1the mileage increment of mileage gauge output is L _i, it is carried out to wheel error compensation and obtains effective mileage increment

wherein, δ K _dfor mileage gauge calibration factor error, W ₀the stochastic error of jolting and causing for measuring dolly.

Further, in described mileage measuring process, consider that the specific implementation that wheel hanging merges four mileage increment informations after compensating is:

By test car off-front wheel, the near front wheel, left rear wheel, off hind wheel odometer at current sampling period t _i-t _i-1output mileage increment be designated as respectively Δ L _a, Δ L _b, Δ L _c, Δ L _d, Δ L _ifor the true mileage increment after merging;

As Δ L _c≤ Δ L _d, show that car body turns left, now Δ L _y=Δ L _a;

As Δ L _a< Δ L _b, show that off-front wheel occurs unsettled, now Δ L _y=Δ L _b* Δ L _d/ Δ L _c, Δ L _c≠ 0;

Work as L _c> L _dtime, car body is turned right, now:

1. work as L _a≤ L _btime,

If L _b-L _a> L _c-L _d, off-front wheel is unsettled, now Δ L _y=Δ L _b* Δ L _d/ Δ L _c, Δ L _c≠ 0;

If Δ L _b-Δ L _a≤ Δ L _c-Δ L _d, without wheel hanging, Δ L now _y=Δ L _a;

2. work as L _a> L _btime, the near front wheel is unsettled, now Δ L _y=Δ L _a.

Further, the measurement dolly mileage increment also gathering in conjunction with the history samples period carries out linear interpolation smoothing processing, the vibration interference causing to eliminate bridge pavement out-of-flatness to the true mileage increment of measurement dolly of current sampling period.

Further, also the bridge floor track of measuring under coordinate system is carried out to error correction, specific implementation is:

In described measurement coordinate system, making the three-dimensional coordinate of planned trajectory route starting point is (0,0,0), and the three-dimensional coordinate of terminal is (Xf, 0,0); The starting point three-dimensional coordinate that bridge floor track under navigation coordinate system is transformed under reference frame is (Xa, Ya, Za), and terminal three-dimensional coordinate is (Xb, Yb, Zb); The bridge floor track three-dimensional coordinate of revising under pre-test coordinate system is expressed as (Sx, Sy, Sz);

Determine the Ratio for error modification Kx=Xf/(Xb-Xa of X-direction), Ratio for error modification Ky=(the Yb-Ya)/Xf of Y-direction is, Ratio for error modification Kz=(the Zb-Za)/Xf of Z-direction;

The bridge floor track that adopts three correction factor corrections to measure under coordinate system obtains revised bridge floor track $(\tilde{S}x,\tilde{S}y,\tilde{S}z),\tilde{S}x=\mathrm{Kx}\&CenterDot;\mathrm{Sx},\tilde{S}y=\mathrm{Ky}\&CenterDot;\mathrm{Sy},\tilde{S}z=\mathrm{Kz}\&CenterDot;\mathrm{Sz}.$

Compared with prior art, useful technique effect of the present invention is embodied in:

(1) the present invention adopts high-precision GPS information to set up reference data and utilize inertia system to set up inertial reference, combines inertia combined navigation technology and closed measuring technique, and measuring accuracy is effectively promoted.

(2) mileage increment information is carried out to wheel deformation error compensation, and consider that wheel hanging carries out effective integration to four mileage increment informations after compensating, and has improved measuring accuracy.

(3) the measurement dolly mileage increment gathering in conjunction with the history samples period carries out linear interpolation smoothing processing, the vibration interference causing to eliminate bridge pavement out-of-flatness to the true mileage increment of measurement dolly of current sampling period.

(4) adopt closed modification method, the bridge floor track of measuring under coordinate system is carried out to error correction, further improved precision.

In sum, owing to the present invention is based on inertial navigation system and mileage gauge, GPS combination, the measurement to bridge three-dimensional deformation rapidly, continuously, and be not subject to path planning, not affected by pavement behavior, can meet bridge miniature deformation and measure requirement.

Accompanying drawing explanation

Fig. 1 is that inertial reference is measured bridge settlement method flow diagram;

Fig. 2 is reference data and path planning schematic diagram;

Fig. 3 sets up inertial reference schematic flow sheet;

Fig. 4 is mileage gauge information fault tolerance processing flow chart;

Fig. 5 is the program flow diagram of software change rate filtering part;

Fig. 6 is inertia system and mileage dead reckoning and integrated navigation computing method process flow diagram.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.In addition,, in each embodiment of described the present invention, involved technical characterictic just can not combine mutually as long as do not form each other conflict.

Based on inertial reference, measuring detection bridge deformation mode is to rely on inertia system hardware platform, with inertial navigation system, mileage, count fundamental measurement unit, gps signal is for auxiliary, wherein inertial navigation system, mileage gauge are arranged on and measure on dolly, and the system software of testing as main of take is arranged in inertial navigation system and acquisition system.The present invention includes utilize high-precision GPS information set up reference data, utilize inertia system set up inertial reference, with the dead reckoning of the auxiliary mileage gauge of inertial navigation system, on the distortion of car body wheel and idle running cause error fault-tolerant processing, for bridge floor out-of-flatness impact test identify, dead reckoning data are closed several parts such as revises and form.Its inertial reference measurement bridge settlement method flow and block diagram are as shown in Figure 1.

Below in conjunction with accompanying drawing, describe in detail.

The first step, measurement environment are built step.

Prepare to measure dolly, on measurement dolly, inertial navigation system is installed, on four wheels measuring dolly, lay respectively a mileage gauge; The first step: set up reference data.

Second step, reference data establishment step.

At the two ends of measured bridge, selected two fixing benchmark, utilize high-precision GPS to determine latitude, longitude and the height above sea level of these 2 reference points, and positioning precision is 2cm.Utilize afterwards these 2 reference points to set up measurement coordinate system.One of them reference point is positioned at the initial point of coordinate system, and another reference point is positioned in the X-axis of coordinate system, and coordinate axis Y points to X-axis left side along local level, and Z axis and X, Y-axis form left-handed coordinate system.

Selected test trails on measured bridge floor, its track can be arbitrarily, but selected track must can pre-establish some monumented points by reference data 2 points of above-mentioned foundation simultaneously in selected test trails, and these monumented points can be arbitrarily.Set up benchmark and path planning as shown in Figure 2.

By GPS, provide the initial high information of longitude and latitude, some parameters that inertial navigation system realizes bookbinding complete autoregistration.On fixed position, car body stops 5min, the static output that gathers inertia system, and carry out autoregistration according to the initial parameter of bookbinding, set up the benchmark of inertia system test.Initial parameter is carried out parameter by host computer and is uploaded.First carry out the coarse alignment of 60s, proceed to fine alignment process after 60s, utilize KALMAN filtering and parameter identification, 5min fine alignment completes, and output identified parameters, aims at and finish, and system proceeds to flow of navigation.Set up inertial reference flow process and see Fig. 3.

The 3rd step: mileage measuring process.

At current sampling period t _i-t _i-1, obtain the mileage increment information of four mileage gauge outputs, mileage increment information is carried out to wheel deformation error compensation, then consider that wheel hanging merges four mileage increment informations after compensating, and obtains current sampling period t _i-t _i-1measure the true mileage increment Delta L of dolly _i.

In this step, in utilizing inertial technology measurement bridge floor sedimentation and deformation process, be subject to aeration quantity due to deck conditions, wheel, tire size is changed in tire heating and the factors such as wear condition of tire cause that mileage gauge calibration factor becomes slowly, be difficult to determine the real stroke (being mileage gauge calibration factor) of each pulse representative, become the principal element of restriction mileage gauge rate accuracy.In order to improve precision, mileage gauge calibration factor is proofreaied and correct, improve measuring accuracy.

The mathematical model of mileage gauge can be written as:

L _i＝N _pulse.K _d （1）

In formula: L _ifor mileage gauge is at each the Δ t time interval (Δ t=t _i+1-t _i) interior measured mileage value; N _pulsefor the umber of pulse producing in each Δ t time interval; K _dcalibration factor for mileage gauge.

Can release again:

$L_i=N_{\mathrm{pulse}}.K_d={\tilde{L}}_i(1+\mathrm{\&delta;}{K}_d)+W_0---\left(2\right)$

In formula:

actual distance for Vehicle Driving Cycle in each time interval; δ K _dfor calibration factor error; W ₀stochastic error for jolting of vehicle causes, may be defined as white noise.

According to formula (2) is known, carry out effective mileage increment that wheel error compensation obtains

In measuring process, because the structure of car body causes in test process, there is not coplanar phenomenon in four wheels, can cause measuring wheel unsettled, causes this mileage gauge no-output, need to carry out fault-tolerant processing to this row.Mileage gauge information fault tolerance processing flow chart is shown in Fig. 4.

By test car off-front wheel, the near front wheel, left rear wheel, off hind wheel odometer at current sampling period t _i-t _i-1output mileage increment be designated as respectively Δ L _a, Δ L _b, Δ L _c, Δ L _d, Δ L _ifor the true mileage increment after merging;

As Δ L _c≤ Δ L _d, show that car body turns left, now Δ L _y=Δ L _a;

As Δ L _a< Δ L _b, show that off-front wheel occurs unsettled, now Δ L _y=Δ L _b* Δ L _d/ Δ L _c, Δ L _c≠ 0;

Work as L _c> L _dtime, car body is turned right, now:

1. work as L _a≤ L _btime,

If L _b-L _a> L _c-L _d, off-front wheel is unsettled, now Δ L _y=Δ L _b* Δ L _d/ Δ L _c, Δ L _c≠ 0;

If Δ L _b-Δ L _a≤ Δ L _c-Δ L _d, without wheel hanging, Δ L now _y=Δ L _a.

L _a> L _btime, the near front wheel is unsettled, now Δ L _y=Δ L _a.

Within the same sampling period, computing machine gathers respectively the pulse number of four mileage gauge outputs, through type (2) calculates each mileage gauge output mileage in each sampling period, then according to above-mentioned mileage gauge information fusion flow process, in each computation period T, judge the rolling of carrier, the vacant state of judgement four road mileages, and filter the undesired signal in mileage output, by the calculating of Dui Si road odometer, merge the final output real mileage information Δ L that can display carriers moves _y.

In measuring process, because bridge floor exists uneven, cause testing apparatus vibration, and produce error.In software flow, adopt rate of change ripple filtering algorithm, can overcome the interference that the irregular vibration of bridge pavement brings, the data error that the vibration that road pavement out-of-flatness produces causes is processed, and adopts the mode of digit rate ripple to propose error.

First to determine error band by the identification of bridge floor hollow, then error be put to assignment again.The method of assignment is setting to 0 a recovery original value.The nearly step of method by linear interpolation between the starting point of error band and end point is level and smooth.The program flow diagram of software change rate filtering part is shown in Fig. 5.

When equipment process hollow bridge floor, two secondary travelling wheels and a secondary relocatable measuring wheel are by the potted road surface of falling in various degree.Produce larger vibration, make the horizontal data distortion recording.Known, in the information of each road level parameter, not single.But form one group by a plurality of, according to these features.Rate of change filtering adopts following methods to carry out rail gap identification: twice adjacent sampled point subtracted each other.Obtain its increment (with absolute value representation), the maximum difference DY then allowing with double sampling, compares, if be less than DY, this point is set to 0; If be greater than DY, think error point, at this point, put y0 (y0 value rule of thumb or experiment draw).That is:

As y (n)-y (n-1)≤DY, time, y (n)=0 got;

As y (n)-y (n-1) >DY, time, y (n)=y0 got

Then, to 0 and these group data of y0 carry out 5 average.Its objective is and can select need by changing the size of y0 value, using the starting point of y (n-1) as error band; Find y (n+i) >0, the point of y (n+i+1)=0, usings the end point of y (n+i+1) as error band again.

For example, in history continuously in a plurality of (5) sampling periods, calculate successively mileage signal output, level and smooth to the nearly step of data according to the method by linear interpolation between starting point and end point, eliminate the interference that the irregular vibration of bridge pavement brings, improve measurement accuracy.

The 4th step, inertial navigation step:

Enable inertial navigation system, at current sampling instant ti, obtain and measure the attitude angle of dolly in navigation coordinate system

The 5th step, integrated navigation step

In Integrated Navigation Algorithm, dead reckoning algorithm is directly used the attitude matrix of strapdown algorithm, therefore dead reckoning algorithm has identical attitude, course angle error with strapdown algorithm, along with the attitude of strapdown inertial navitation system (SINS), the increase of course angle error, will inevitably affect the positioning precision of dead reckoning.In Integrated Navigation Algorithm, estimate attitude, the course angle error of system and compensate, improve the measuring precision.

Choosing sky, northeast (ENU) geographic coordinate is inertial navigation coordinate system, is designated as n system, when inertial navigation is installed on year car by certain orientation, thinks that year car coordinate system and inertial navigation demarcation coordinate system overlap, and are designated as b system.Odometer coordinate system is designated as m system, and odometer is at a bit of time Δ t=t _i+1-t _ithe mileage increment Delta L of interior measurement _iin the projection of m system, being write as vector form is:

${\mathrm{\&Delta;L}}_i^m={\left[\begin{array}{ccc}0& \mathrm{\&Delta;}{L}_i& 0\end{array}\right]}^T---3$

Supposing has installation deviation angle between m system and b system, is respectively installation deviation angle, course

pitching installation deviation angle α _θwith roll installation deviation angle α _γ, the conversion cosine battle array that can be tied to m system from b is:

Thereby mileage increment at b, fastening projective representation is:

By the visible b of above formula, fastened mileage increment and the α of expression _γirrelevant, further can obtain the projection that mileage increment is fastened at navigation coordinate:

$\mathrm{\&Delta;}{L}_i^n=C_b^n\left(i\right)\mathrm{\&Delta;}{L}_i^b---\left(6\right)$

In formula

t _iattitude matrix constantly.

Calculate current sampling instant t _imeasure the position coordinates of dolly under navigation coordinate system

p _i-1for last sampling instant t _i-1measure the position coordinates of dolly under navigation coordinate system.Position coordinates is expressed as three-dimensional coordinate as the formula (7)

$\begin{array}{c}{X}_i=X_{i-1}+\mathrm{\&Delta;}{L}_{\mathrm{iN}}^n\\ Y_i=Y_{i-1}+\mathrm{\&Delta;}{L}_{\mathrm{iE}}^n\\ Z_i=Z_{i-1}+\mathrm{\&Delta;}{L}_{\mathrm{iU}}^n\end{array}---\left(7\right)$

In formula: X _i, Y _iand Z _irepresent respectively t _iconstantly measure the position coordinates of dolly under navigation coordinate system at the component of X, Y and Z-direction,

with

represent respectively

component in X, Y and Z-direction.

Position coordinates to measurement dolly under navigation coordinate system carries out integration and obtains bridge floor track to be measured, and obtains measuring the bridge floor track under coordinate system by coordinate conversion.

Inertia system and mileage dead reckoning and integrated navigation computational algorithm process flow diagram are shown in Fig. 6.

The 6th step: adopt Closed-cycle correction.

In described measurement coordinate system, making the three-dimensional coordinate of planned trajectory route starting point is (0,0,0), and the three-dimensional coordinate of terminal is (Xf, 0,0); The starting point three-dimensional coordinate that bridge floor track under navigation coordinate system is transformed under reference frame is (Xa, Ya, Za), and terminal three-dimensional coordinate is (Xb, Yb, Zb); The bridge floor track three-dimensional coordinate of revising under pre-test coordinate system is expressed as (Sx, Sy, Sz)

Determine the Ratio for error modification Kx=Xf/(Xb-Xa of X-direction), Ratio for error modification Ky=(the Yb-Ya)/Xf of Y-direction is, Ratio for error modification Kz=(the Zb-Za)/Xf of Z-direction;

The bridge floor track that adopts three correction factor corrections to measure under coordinate system obtains revised bridge floor track $(\tilde{S}x,\tilde{S}y,\tilde{S}z),\tilde{S}x=\mathrm{Kx}\&CenterDot;\mathrm{Sx},\tilde{S}y=\mathrm{Ky}\&CenterDot;\mathrm{Sy},\tilde{S}z=\mathrm{Kz}\&CenterDot;\mathrm{Sz}.$

Through the closed data of revising, its precision can improve an order of magnitude on the basis of original dead reckoning, than the result of inertial navigation, can improve two orders of magnitude, and these data can characterize the deformed state of bridge pavement.According to above-mentioned aspect, carry out repeatedly repeated test, or compare with reference point, can access the deformation of bridge.

The 7th step, deformation determination step.

Bridge floor track and the benchmark bridge floor track measured under coordinate system are compared, determine the bridge deformation situation that detects.

In system work process, the output of system acquisition mileage gauge, fault-tolerant, filtering, the mileage of output under m system, can obtain mileage output three-dimensional data by formula 3.Simultaneous computer gathers the output of three optical fibre gyros and three quartz flexible accelerometers, and through instrumental error compensation and revision, hypercomplex number is resolved, and exports one group of attitude matrix parameter, and export attitude angle within 4 employing cycles.The attitude information and the mileage information that by formula 5,6, are calculated merge, and utilize the mode of dead reckoning, are engraved in the displacement information under navigation coordinate while exporting each, by formula (7), carry out integration, can extrapolate the track on whole measured road surface.Computing machine is exported the three-dimensional track information after resolving in real time, saves as a data file simultaneously, after being completed, providing and carries out Closed-cycle correction, and output accuracy is provided.

Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.

Claims (5)

1. for detection of an inertial reference measuring method for bridge deformation, it is characterized in that, comprise the following steps:

Measurement environment is built step:

Prepare to measure dolly, on measurement dolly, inertial navigation system is installed, on four wheels measuring dolly, lay respectively a mileage gauge;

Reference data establishment step:

At the two ends of bridge to be measured, selected two reference points, locate latitude, longitude and the height above sea level of determining two reference points by GPS; Using one of them reference point as initial point foundation measurement coordinate system, and another reference point is positioned in the coordinate axis of coordinate system; At the surperficial planned trajectory route of bridge to be measured, make planning path must be through two reference points; Utilize latitude, longitude and the altitude information of reference point to set up inertia system test benchmark, and using the world, northeast reason coordinate system as inertial navigation coordinate system;

Mileage measuring process:

Start measurement dolly and move along path planning, at current sampling period t _i-t _i-1, obtain the mileage increment information of four mileage gauge outputs, mileage increment information is carried out to wheel deformation error compensation, then consider that wheel hanging merges four mileage increment informations after compensating, and obtains current sampling period t _i-t _i-1measure the true mileage increment Delta L of dolly _i;

Inertial navigation step:

Enable inertial navigation system, at current sampling instant t _iobtain and measure the attitude angle of dolly in navigation coordinate system

Integrated navigation step:

Note odometer coordinate is m system, and inertial navigation coordinate is b system, and the conversion cosine battle array that b is tied to m system is

Note mileage increment Delta L _ibeing projected as of m system ${\mathrm{\&Delta;L}}_i^m={\left[\begin{array}{ccc}0& \mathrm{\&Delta;}{L}_i& 0\end{array}\right]}^T,$ Subscript T represents transposition; By coordinate system, be converted to mileage increment

being projected as of b system

and then obtain mileage increment Delta L _ithe projection of fastening at navigation coordinate

t _iconstantly measure the attitude angle of dolly;

Calculate current sampling instant t _imeasure the position coordinates of dolly under navigation coordinate system

p _i-1for last sampling instant t _i-1measure the position coordinates of dolly under navigation coordinate system;

Position coordinates to measurement dolly under navigation coordinate system carries out integration and obtains the bridge floor track under navigation coordinate system, and then by coordinate system, is converted to the bridge floor track of measuring under coordinate system;

Deformation determination step:

Bridge floor track and the benchmark bridge floor track measured under coordinate system are compared, determine the bridge deformation situation that detects.

2. the inertial reference measuring method for detection of bridge deformation according to claim 1, is characterized in that, the specific implementation of in described mileage measuring process, mileage increment information being carried out to wheel deformation error compensation is: make current sampling period t _i-t _i-1the mileage increment of mileage gauge output is L _i, it is carried out to wheel error compensation and obtains effective mileage increment

wherein, δ K _dfor mileage gauge calibration factor error, W ₀the stochastic error of jolting and causing for measuring dolly.

3. the inertial reference measuring method for detection of bridge deformation according to claim 2, is characterized in that, considers that the specific implementation that four mileage increment informations after wheel hanging is to compensation merge is in described mileage measuring process:

By test car off-front wheel, the near front wheel, left rear wheel, off hind wheel odometer at current sampling period t _i-t _i-1output mileage increment be designated as respectively Δ L _a, Δ L _b, Δ L _c, Δ L _d, Δ L _ifor the true mileage increment after merging;

As Δ L _c≤ Δ L _d, show that car body turns left, now Δ L _y=Δ L _a;

As Δ L _a< Δ L _b, show that off-front wheel occurs unsettled, now Δ L _y=Δ L _b* Δ L _d/ Δ L _c, Δ L _c≠ 0;

Work as L _c> L _dtime, car body is turned right, now:

1. work as L _a≤ L _btime,

If L _b-L _a> L _c-L _d, off-front wheel is unsettled, now Δ L _y=Δ L _b* Δ L _d/ Δ L _c, Δ L _c≠ 0;

If Δ L _b-Δ L _a≤ Δ L _c-Δ L _d, without wheel hanging, Δ L now _y=Δ L _a;

2. work as L _a> L _btime, the near front wheel is unsettled, now Δ L _y=Δ L _a.

4. according to the inertial reference measuring method for detection of bridge deformation described in claim 1 or 2 or 3, it is characterized in that, the measurement dolly mileage increment also gathering in conjunction with the history samples period carries out linear interpolation smoothing processing, the vibration interference causing to eliminate bridge pavement out-of-flatness to the true mileage increment of measurement dolly of current sampling period.

5. according to the inertial reference measuring method for detection of bridge deformation described in claim 1 or 2 or 3, it is characterized in that, also the bridge floor track of measuring under coordinate system is carried out to error correction, specific implementation is:

In described measurement coordinate system, making the three-dimensional coordinate of planned trajectory route starting point is (0,0,0), and the three-dimensional coordinate of terminal is (Xf, 0,0); The starting point three-dimensional coordinate that bridge floor track under navigation coordinate system is transformed under reference frame is (Xa, Ya, Za), and terminal three-dimensional coordinate is (Xb, Yb, Zb); The bridge floor track three-dimensional coordinate of revising under pre-test coordinate system is expressed as (Sx, Sy, Sz);

Determine the Ratio for error modification Kx=Xf/(Xb-Xa of X-direction), Ratio for error modification Ky=(the Yb-Ya)/Xf of Y-direction is, Ratio for error modification Kz=(the Zb-Za)/Xf of Z-direction;

The bridge floor track that adopts three correction factor corrections to measure under coordinate system obtains revised bridge floor track $(\tilde{S}x,\tilde{S}y,\tilde{S}z),\tilde{S}x=\mathrm{Kx}\&CenterDot;\mathrm{Sx},\tilde{S}y=\mathrm{Ky}\&CenterDot;\mathrm{Sy},\tilde{S}z=\mathrm{Kz}\&CenterDot;\mathrm{Sz}.$

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