CN112525111A - Method for detecting surface smoothness of straddle type monorail track - Google Patents

Method for detecting surface smoothness of straddle type monorail track Download PDF

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Publication number
CN112525111A
CN112525111A CN202011022985.XA CN202011022985A CN112525111A CN 112525111 A CN112525111 A CN 112525111A CN 202011022985 A CN202011022985 A CN 202011022985A CN 112525111 A CN112525111 A CN 112525111A
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track
smoothness
rail
trolley
mileage
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刘敏
汪慧云
李兴旺
常斌
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AVIC Shanghai Aeronautical Measurement Controlling Research Institute
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AVIC Shanghai Aeronautical Measurement Controlling Research Institute
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/30—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61D—BODY DETAILS OR KINDS OF RAILWAY VEHICLES
    • B61D15/00—Other railway vehicles, e.g. scaffold cars; Adaptations of vehicles for use on railways
    • B61D15/08—Railway inspection trolleys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61K—AUXILIARY EQUIPMENT SPECIALLY ADAPTED FOR RAILWAYS, NOT OTHERWISE PROVIDED FOR
    • B61K9/00—Railway vehicle profile gauges; Detecting or indicating overheating of components; Apparatus on locomotives or cars to indicate bad track sections; General design of track recording vehicles
    • B61K9/08—Measuring installations for surveying permanent way

Abstract

The invention discloses a method for detecting the smoothness of the surface of a straddle type monorail track, which comprises the following steps: step 1, installing an optical fiber gyroscope on a rail inspection trolley, and acquiring an inclination angle value of the rail inspection trolley by using the optical fiber gyroscope; mounting a rotary encoder at the wheel of the rail inspection trolley, and measuring the traveling mileage of the trolley; taking the measured dip angle and mileage as data samples to be calculated; step 2, carrying out digital signal processing on the data sample to be calculated to obtain an effective data sample; and 3, calculating the effective data sample by adopting an inertia track method and a curve interpolation fitting method to obtain the smoothness evaluation of the track surface. The method can effectively detect the surface smoothness of the longitudinal direction and the transverse direction of the track by utilizing an inertia track method and a curve interpolation fitting method, and has the characteristics of good measurement precision, high efficiency, excellent repeatability and the like.

Description

Method for detecting surface smoothness of straddle type monorail track
Technical Field
The invention relates to the field of track detection, in particular to a method for detecting the surface smoothness of a straddle type monorail track.
Background
The straddle type rail transit is a form of urban rail transit, and has the advantages of environmental protection, low manufacturing cost, small occupied area and the like, so that a construction surge is raised in China. The track beam bridge system is used as an important component of a straddle type single track, the smoothness condition of the track beam bridge system directly influences the safety of the whole system, and the smoothness management problem is increasingly prominent as the track beam bridge system is gradually put into operation in China.
In order to ensure the driving safety and riding comfort of the train, strengthen the detection strength of the track smoothness and grasp the quality state of the track in time, the method has important significance for guiding maintenance and acceptance operation of the line. At present, straddle type single-track detection is mainly based on absolute measurement, and the method has the defects of low efficiency, high cost, complex operation and the like. The straddle type single-rail detection vehicle based on the inertial track method belongs to a relative measurement technology, emphasizes the relative smoothness of a line, adopts advanced detection and data processing equipment such as a high-precision fiber-optic gyroscope, a laser ranging sensor, a special portable computer and the like, can detect parameters such as height of a rail surface, horizontal fluctuation, rail direction irregularity and the like on line, effectively overcomes the defects of low absolute measurement efficiency and complex operation, and can play an important role in links such as line maintenance and whole-track, inspection and paving precision, acceptance check and acceptance operation and the like.
Disclosure of Invention
The invention aims to provide a method for detecting the surface smoothness of a straddle type monorail track, which effectively improves the measurement efficiency and can play an important role in links of line maintenance and finishing, pavement inspection precision, acceptance inspection and the like.
The invention aims to be realized by the following technical scheme:
a method for detecting the smoothness of the surface of a straddle type monorail track comprises the following steps:
step 1, installing an optical fiber gyroscope on a rail inspection trolley, and acquiring an inclination angle value of the rail inspection trolley by using the optical fiber gyroscope; mounting a rotary encoder at the wheel of the rail inspection trolley, and measuring the traveling mileage of the trolley; taking the measured inclination angle, distance and mileage as data samples to be calculated;
step 2, carrying out digital signal processing on the data sample to be calculated to obtain an effective data sample;
and 3, calculating the effective data sample by adopting an inertia track method and a curve interpolation fitting method to obtain the smoothness evaluation of the track surface.
Preferably, step 3 comprises the steps of:
first, a sagnac interferometer is configured based on the sagnac effect of a fiber optic gyroscope, and the steering angle Φ of the rail-inspecting carriage is calculated according to the following equation:
Figure BDA0002701271360000021
wherein λ is the wavelength of light; n is the total number of turns of the optical fiber; c is the speed of light; a is the area included by the optical path, and the phase difference of the two forward and backward beams in the closed optical path
Figure BDA0002701271360000023
Secondly, integrating the light path s and establishing the following formula, and calculating the inertia sequence { f) of the surface of the measured tracki；i＝0， 1，2，…n}：
Figure BDA0002701271360000022
Wherein x isi’，yi' is an inertial sequence f of different directions of the corresponding positioni(ii) a Delta s is the driving range of the trolley in each sampling interval; phi is aiThe steering angle corresponding to the mileage point;
finally, carrying out interpolation fitting by adopting a cubic spline curve function in Matlab, and respectively substituting a pitch angle, a driving mileage, a roll angle, a wheelbase of the trolley, a yaw angle and a mileage into an inertia sequence fiAnd obtaining the right rail actual measurement elevation, the level/superelevation and the rail direction by a calculation formula, and then calculating according to the right rail actual measurement elevation and the level/superelevation result to obtain the left rail actual measurement elevation.
Preferably, the digital signal processing comprises the steps of:
firstly, carrying out digital low-pass filtering on an inclination angle value output by the fiber optic gyroscope by using a second-order Butterworth low-pass filter;
then, taking the output signal of the fiber-optic gyroscope before each detection as a system zero point, and subtracting the system zero point from the filtered inclination angle value;
finally, linear interpolation is used for carrying out error compensation on the inclination angle value.
Preferably, the method for detecting the smoothness of the surface of the straddle-type monorail track further comprises the following steps:
and 4, evaluating different smoothness of left and right elevations and the track direction by adopting a midpoint chord computing method.
And 5, uniformly arranging a plurality of laser ranging sensors on the support near the wheels of the rail inspection trolley in the transverse direction, collecting the distance from the laser ranging sensors to the rail surface, carrying out interpolation fitting to realize the detection of the smoothness of the transverse surface of the rail, and evaluating the left and right running stability of the train.
The invention provides a measuring method for detecting and evaluating smoothness and smoothness of a track surface based on an inertial track method and a laser ranging curve interpolation fitting method of a fiber-optic gyroscope, a corresponding prototype is manufactured and a field test is carried out, and the following conclusion is reached:
the inertia track method is used for measuring the internal geometric dimension of the track, the measuring process is simple and efficient, and the measuring result is high in precision, good in stability and good in repeatability due to the high-precision optical fiber gyroscope.
Based on the laser ranging and the cubic spline curve interpolation fitting mode, the three-dimensional reappearance of the smoothness of the rail surface can be realized, and the method is effective for detecting and evaluating the smoothness of the rail surface.
The straddle type monorail detection method based on the inertial track method and the laser ranging discussed in the invention effectively improves the measurement efficiency compared with absolute measurement due to avoiding excessive dependence on an external reference point. Can play an important role in links such as line maintenance and road arrangement, pavement precision inspection, acceptance check and the like.
Drawings
FIG. 1 is a schematic flow chart of a method for detecting the smoothness of a surface of a straddle-type monorail track.
Fig. 2 unfiltered pitch angle waveform.
Fig. 3 pitch angle after digital processing.
Fig. 4 shows a local coordinate system of the rail detector.
FIG. 5 right rail measured elevation.
FIG. 6 left rail measured elevation.
Fig. 7 horizontal/super high calculation results.
Fig. 8 measured values in the track direction.
FIG. 9 illustrates the dot chord calculation.
FIG. 10 calculation results for four meters of high and low short waves.
FIG. 11 lateral surface smoothness interpolation results.
Fig. 12 right rail elevation test repeatability comparison.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings.
The method for detecting the smoothness of the surface of the straddle type monorail track disclosed by the embodiment comprises the following steps of:
step 1, mounting a high-precision fiber-optic gyroscope on a rail inspection trolley, and collecting an inclination angle value of the rail inspection trolley by using the fiber-optic gyroscope, wherein the inclination angle value comprises a pitch angle, a yaw angle and a roll angle; uniformly arranging 3 point laser ranging sensors on a support near wheels of the rail inspection trolley in the transverse direction, and collecting the distance from the laser ranging sensors to a rail surface; mounting a rotary encoder at the wheel of the rail inspection trolley, and accurately measuring the traveling mileage of the trolley; and taking the measured inclination angle, distance and mileage parameters as data samples to be calculated. The tilt waveforms to be calculated are shown in figure 2.
And 2, sequentially carrying out digital low-pass filtering, automatic zero tracking and digital signal processing of a linear interpolation method on the data sample to be calculated to obtain an effective data sample. The effective tilt angle waveform is shown with reference to fig. 3.
In order to reduce the influence of high-frequency vibration of the road surface on the detection value of the vehicle-mounted optical fiber gyroscope, a formula shown below is adopted, and a second-order Butterworth low-pass filter is designed to perform digital low-pass filtering on the inclination angle value output by the optical fiber gyroscope.
Figure BDA0002701271360000051
In the formula: y (n) is a data filtering value of the fiber-optic gyroscope; x (n) the measured tilt angle value of the fiber optic gyroscope, and a (k), b (r) are the coefficients of the filter.
According to the walking characteristic of the rail inspection trolley, the cut-off frequency of low-pass filtering is 20Hz, and according to a Matlab signal processing tool kit, the coefficient of a second-order Butterworth low-pass filter is obtained as follows:
a(1)＝-1.373，a(2)＝0.4918
b(0)＝0.0461，b(1)＝0.0923，b(2)＝0.0461
substituting the parameters into a differential equation expression of a second-order Butterworth low-pass filter to obtain a specific expression as follows:
y(n)＝1.3073y(n-1)-0.4918y(n-2)+ 0.046x(n)+0.0923x(n-1)+0.0461x(n-2)
in order to inhibit the zero drift phenomenon of the optical fiber gyroscope, an automatic zero tracking method is adopted to weaken the influence of drift on the measurement precision of the optical fiber gyroscope, the output signal of the optical fiber gyroscope is collected before each detection, the collection result is used as a system zero point, and the result obtained by subtracting the system zero point from the filtered inclination angle value is used as the inclination angle value collected at the time.
In order to accurately calculate the change of parameters such as the height of an actual track and avoid the error accumulation of discrete numerical integration, a linear interpolation formula is used for carrying out error compensation on the inclination angle value, and the number of interpolation can be set according to the height of a sampling rate.
And 3, calculating the effective data sample by adopting an inertia track method and a curve interpolation fitting method to obtain the smoothness evaluation of the track surface.
The inertial trajectory method and the curve interpolation fitting method are mainly based on the measurement of a rail-inspecting trolley, and a local coordinate system of the inertial trajectory method and the curve interpolation fitting method is shown in figure 4.
Firstly, a Sagnac interferometer is formed according to the Sagnac effect of a fiber optic gyroscope, and the steering angle phi of the rail inspection trolley is calculated according to the following formula:
Figure BDA0002701271360000061
wherein λ is the wavelength of light; n is the total number of turns of the optical fiber; c is the speed of light; a is the area included by the light path, and the phase difference of the two forward and backward beams in the closed light path
Figure BDA0002701271360000063
Secondly, an inertia track method is adopted, the light path s is integrated according to the following formula, the following formula is established, and an inertia sequence { f of the surface of the measured track is calculatedi；i＝0，1，2，…n}：
Figure BDA0002701271360000062
Wherein x isi’，yi' is an inertial sequence f with different directions (up and down) corresponding to the positioni(ii) a Delta s is the car driving mileage of each sampling interval; phi is aiIs the steering angle corresponding to the mileage point.
And finally, considering the pouring and deformation characteristics of the track, the surface irregularity is mostly of gradual change characteristics, and a cubic spline curve function in Matlab is adopted for interpolation fitting to comprehensively reflect the change of the concave-convex characteristics of the road surface.
And (3) carrying out digital signal processing on the pitch angle, the yaw angle and the roll angle output by the fiber-optic gyroscope in the steps, and respectively carrying out three groups of parameters: inertia sequence f is brought into by pitch angle, driving mileage, roll angle, wheelbase of trolley, yaw angle and mileageiThe calculation formula obtains the right rail actual measurement elevation, the level/superelevation and the rail direction, and then the left rail actual measurement elevation is obtained through calculation according to the right rail actual measurement elevation and the level/superelevation result, and the calculation is shown in the figures 5 to 8.
And 4, evaluating different smoothness of left and right elevations and the track direction by adopting a midpoint chord computing method. As shown in fig. 9, the track values f of left and right elevations and the track directionsiSubstituting calculation to obtain irregularity sequences { v) of different wavelengthsiAnd i is 0, 1, 2, … n, and the specific calculation formula is as follows:
Figure BDA0002701271360000071
in the formula fi(i is 0, 1, 2 … n) is a track actual measurement plane trajectory value (deviation) in units of: mm; v. ofiTrack irregularity for the corresponding wavelength, unit: mm.
According to the mid-chord formula, the original measured height is calculated, taking the left rail as an example, to calculate the height-short wave of 4 meters, as shown in fig. 10.
And 5, considering the driving characteristics of the straddle type track, wherein the smoothness of the transverse surface of the straddle type track has important influence on the left and right stability of the running of the train, acquiring the measured data of the transversely arranged laser ranging sensors, performing interpolation fitting to realize the detection of the smoothness of the transverse surface of the track, and evaluating the left and right stability of the running of the train, wherein the measured result is shown in fig. 11.
And 6, in order to evaluate the repeated detection precision of the rail inspection trolley, taking the experimental section as an example, three times of tests are carried out, and the repeatability of the three times of tests is shown in figure 12. As can be seen from FIG. 12, the trends of the three tests are basically consistent, and the repeatability of the detection data of the surface rail inspection trolley is good.

Claims (5)

1. A method for detecting the smoothness of the surface of a straddle type monorail track comprises the following steps:
step 1, installing an optical fiber gyroscope on a rail inspection trolley, and acquiring an inclination angle value of the rail inspection trolley by using the optical fiber gyroscope; mounting a rotary encoder at the wheel of the rail inspection trolley, and measuring the traveling mileage of the trolley; taking the measured dip angle and mileage as data samples to be calculated;
step 2, carrying out digital signal processing on the data sample to be calculated to obtain an effective data sample;
and 3, calculating the effective data sample by adopting an inertia track method and a curve interpolation fitting method to obtain the smoothness evaluation of the track surface.
2. The method for detecting the smoothness of the surface of the straddle-type monorail track according to claim 1, wherein the step 3 comprises the following steps:
firstly, a Sagnac interferometer is formed according to the Sagnac effect of a fiber optic gyroscope, and the steering angle phi of the rail inspection trolley is calculated according to the following formula:
Figure FDA0002701271350000011
wherein λ is the wavelength of light; n is the total number of turns of the optical fiber; c is the speed of light; a is the area included by the light path, and the phase difference of the two forward and backward beams in the closed light path
Figure FDA0002701271350000012
Secondly, integrating the light path s and establishing the following formula, and calculating the inertia sequence { f) of the surface of the measured tracki；i＝0，1，2，…n}：
Figure FDA0002701271350000013
Wherein x isi’，yi' is an inertial sequence f of different directions of the corresponding positioni(ii) a Delta s is the driving mileage of the trolley in each sampling interval; phi is aiThe steering angle corresponding to the mileage point;
finally, carrying out interpolation fitting by adopting a cubic spline curve function in Matlab, and respectively substituting a pitch angle, a driving mileage, a roll angle, a wheelbase of the trolley, a yaw angle and a mileage into an inertia sequence fiAnd obtaining the right rail actual measurement elevation, the level/superelevation and the rail direction by a calculation formula, and then calculating according to the right rail actual measurement elevation and the level/superelevation result to obtain the left rail actual measurement elevation.
3. The method according to claim 1, wherein said digital signal processing comprises the steps of:
firstly, carrying out digital low-pass filtering on an inclination angle value output by the fiber optic gyroscope by using a second-order Butterworth low-pass filter;
then, taking the output signal of the fiber-optic gyroscope before each detection as a system zero point, and subtracting the system zero point from the filtered inclination value;
finally, linear interpolation is used for carrying out error compensation on the inclination angle value.
4. The method for detecting the smoothness of the surface of a straddle-type monorail track according to claim 1, further comprising:
and 4, evaluating different smoothness of left and right elevations and the track direction by adopting a midpoint chord computing method.
5. The method for detecting the smoothness of the surface of a straddle-type monorail track according to claim 1, further comprising:
and 5, uniformly arranging a plurality of laser ranging sensors on the support near the wheels of the rail inspection trolley in the transverse direction, collecting the distance from the laser ranging sensors to the rail surface, carrying out interpolation fitting to realize the detection of the smoothness of the transverse surface of the rail, and evaluating the left and right running stability of the train.
CN202011022985.XA 2020-09-25 2020-09-25 Method for detecting surface smoothness of straddle type monorail track Pending CN112525111A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113548068A (en) * 2021-07-23 2021-10-26 中车长春轨道客车股份有限公司 Rail surface irregularity detection device and detection method
CN114407968A (en) * 2022-01-18 2022-04-29 中南大学 Track irregularity detection device and method for straddle type monorail travel traffic system

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113548068A (en) * 2021-07-23 2021-10-26 中车长春轨道客车股份有限公司 Rail surface irregularity detection device and detection method
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CN114407968A (en) * 2022-01-18 2022-04-29 中南大学 Track irregularity detection device and method for straddle type monorail travel traffic system

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