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Users Manual for Program TRC_IPLAS2





Table of Contents

   Introduction
   Input data commands
   Input data Example
   Output data Example




Introduction

Program TRC_IPLAS2 is designed for translating track measurements made by a Plasser&Theurer EM80 track measuring vehicle.

The EM80-car have 3 measuring axles for lateral measurements and 3 other axles for vertical measurements. The three axles measuring vertical irregularities are not equally spaced. The advantage of not having the axles equally spaced, is that it is possible to reduce the number of zeros in the measuring vehicle transfer function.
The input data file is read in free format, but the columns in the file shall have the same contents as in a SPL-file. The output data file is written in trax_wdesign-format. Since the transfer function of the track measuring car is low for some waves lengths, the transfer function back to Cartesian coordinates cannot be ideal, it must be delimited. The filtering takes place in program FTRANS, filter IMAUZ and IPLASSER.

See also:

TRC_PLAS Calculates versines of the columns in a track irregularity file


Input data commands

Input data is read in free format, valid separators between the input values are <space>, <comma>, <tab>, <equal sign> or <carriage return>. The commands can be written both in lower and upper case letters. The operation of the program is controlled by the commands described below; some of the commands also need arguments.


CALC_QN
Activate the calculation of QN-numbers according to UIC 518.
Computation time could be saved if calculation of QN-numbers are skipped.
Declared= Character*3    Default= yes

CREATE_PLOT
Activate the generation of plots.
Computation time could be saved if generation of plots are skipped.
Declared= Character*3    Default= yes

DX
Equidistant step between the interpolated points in the X-axis.
The FFT-algorithm in the backward transformation requires that the points in input data have equidistant distances in their X-axles. Therefore the curves read from INFIL always will be interpolated before any calculations takes place.
Declared= Real*4    Default= 0.5

INFIL
File containing the track measurements written in *.spl-format. However only the columns for short waves irregularities are used.
Declared= Character*132    Default= Blank

REMOVE_UCAT_WORK
Command which controls if the working directory "ucat_work" should be removed or not after the calculation.
Declared= Character*4    Default= 'NO'

QNUMB_SPEED
Speed to be used when evaluating track quality.
Valid values are: 80, 120, 160, 200 and 300 [km/h].
Declared= Real*4    Default= 120 [km/h]

VEHICLE_DIRECTION
'A' If the A-end of the measuring-trolley is facing towards increasing kilometers of the track.
'B' If the B-end of the measuring-trolley is facing towards increasing kilometers of the track.
Declared= Character*1    Default= Blank

L_LATERAL_WAVES
High pass filter cut-off frequency for lateral track irregularities.
Declared= Real*4    Default= 55.55 [m]

N_LATERAL_WAVES
Order of the lateral high pass filter.
The filter is of type Butterworth in two stages. First forward filtering then backward filtering. This type of filtering avoids different delays for different waves. N_LATERAL_WAVES must be an even number.
Declared= Integer*4    Default= 6

L_SHORT_WAVES
Low pass filter cut-off frequency.
Track irregularities of very high frequencies can be measured in the STRIX track measuring car. However too short waves in the track are not of interest, if the track is going to be used for estimation of ride comfort and lateral track forces only. The short waves makes simulation times longer, because the integrate needs to make smaller time-steps.
Declared= Real*4    Default= 1.2 [m]

N_SHORT_WAVES
Order of the low pass filter.
The filter is of type Butterworth in two stages. First forward filtering then backward filtering. This type of filtering avoids different delays for different wave lengths. N_SHORT_WAVES must be an even number.
Declared= Integer*4    Default= 16

UTFIL
File containing the output data, written in *.trax-format.
Declared= Character*132    Default= Blank

XSTART_KM
Defines the first kilometer from where the translation shall begin.
Declared= Real*4    Default= -1000000

XSTART_M
Defines the meter within the first kilometer from where the translation shall begin.
Declared= Real*4    Default= -1000

XSTOP_KM
Defines the last kilometer where the translation shall end.
Declared= Real*4    Default= 1000000

XSTOP_M
Defines the meter within the last kilometer where the translation shall end.
Declared= Real*4    Default= 1000


Input data Example

Following example: Master.trc_iplas2f can be used as a master file:

##
##      Input data for program TRC_IPLAS2
##

  VEHICLE_DIRECTION= A
  QNUMB_SPEED      = 120             # Valid speeds are 80, 120, 160, 200 and 300
  REMOVE_UCAT_WORK = yes

  L_SHORT_WAVES= 1.5
  N_SHORT_WAVES= 4

  CALC_QN    = yes
  CREATE_PLOT= yes

  XSTART_KM= -1000000  XSTART_M= -1000
  XSTOP_KM =  1000000  XSTOP_M =  1000

  INFIL= SPL-file.txt
  UTFIL= output.trax_wdesign


Output data example:

Y_mid-, z_mid-, gauge- and cant- errors:

trc_iplas21.png


Derivative of the y_mid-, z_mid-, gauge- and cant- errors:

trc_iplas22.png


Designed track geometry:

trc_iplas23.png


Fourier spectra of the y_mid- and z_mid- errors:

trc_iplas24.png


Fourier spectra of the gauge- and cant- errors:

trc_iplas25.png