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Users Manual for Program TRC_STRIX_TRACK2  

Table of Contents

Introduction

Program TRC_STRIX_TRACK2 transforms files recorded by the STRIX-recording car into files written in trax_wdesign-format. The format of the STRIX-recordings shall be of type SPL.

Calculation procedure

• Read the gauge column in the STRIX-SPL-file.
• Multiply with 0.01 in order get the signal in mm.
• Add the value 1435 to the signal
• Filter the errors in a N_SHORT_WAVES-order Butterworth low-pass filter with cut-off wave length of L_SHORT_WAVES [m]
• No filtering on long waves are made.

• Read the columns containing the long wave vertical errors for the left and right rail in the STRIX-SPL-file
• Calculate the average value of the two levels
• Multiply with 0.01 in order get the signal in mm.
• Change the sign of the signal
• Filter the errors in a N_SHORT_WAVES-order Butterworth low-pass filter with cut-off wave length of L_SHORT_WAVES [m]
• No filtering on long waves are made.

• Read the cant column in the STRIX-SPL-file.
• Multiply with 0.01 in order get the signal in mm.
• Change the sign of the signal
• Filter the errors in a N_SHORT_WAVES-order Butterworth low-pass filter with cut-off wave length of L_SHORT_WAVES [m]
• Filter the cant in a 8-order Butterworth high-pass filter with cut-off wave length of 100 [m]. Waves shorter than 100 [m] are considered to be track irregularities and written to column #5 in the TRAX_WDESIGN-file. Waves longer than 100 [m] are considered to be design track geometry and written to column #7 in the TRAX_WDESIGN-file.

• Read the columns containing the long wave lateral errors for the left and right rail in the STRIX-SPL-file
• Calculate the average value of the two levels
• Multiply with 0.01 in order get the signal in mm.
• Remove lateral track irregularities due to designed track geometry.
• Filter the errors in a N_SHORT_WAVES-order Butterworth low-pass filter with cut-off wave length of L_SHORT_WAVES [m]
• Filter the errors in a N_LATERAL_WAVES-order Butterworth high-pass filter with cut-off wave length of L_LATERAL_WAVES [m]

• Read the curvature column in the STRIX-SPL-file.
• Multiply the signal with SCALE_CURVE
• Filter the curvature in a N_CURVE_WAVES-order Butterworth low-pass filter with cut-off wave length of L_CURVE_WAVES [m]

• See cant irregularities above

• Divide designed cant by 2.
• Calculate the absolute value

Input data

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 points written to RESFIL.
Declared= Real*4    Default= Same step as read from file LATFIL

FILTER_SHORT_WAVES

Activate the filtering of short waves.
Computation time could be saved if filtering of short waves are skipped.
Declared= Character*3    Default= yes

INFIL

STRIX-file in SPL-format.
Declared= Character*132    Default= Blank

L_CURVE_WAVES

Low pass filter cut-off wave-length for curvature.
Declared= Real*4    Default= 50 [m]

N_CURVE_WAVES

Order of the curvature 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 waves. N_CURVE_WAVES must be an even number.
Declared= Integer*4    Default= 8

L_CANT_WAVES

Filter separating designed cant and cant errors.
Declared= Real*4    Default= 100 [m]

N_CANT_WAVES

Order of the cant separating 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_CANT_WAVES must be an even number.
Declared= Integer*4    Default= 4

L_LATERAL_WAVES

High pass filter cut-off frequency for lateral track irregularities.
Track irregularities of very low frequencies can be measured in the STRIX track measuring car. However too long waves in the lateral track irregularities are not of interest, if the track is going to be used for estimation of ride comfort and lateral track forces only.
Declared= Real*4    Default= 125 [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= 8

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= 2.5 [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= 2

UTFIL

Result file written in TRAX_WDESIGN-format.
Declared= Character*132    Default= trc_strix_track_UTFIL.trax_wdesign

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'

SCALE_CURVE

Scale factor which transforms column 20) in the SPL-file into curvature in meters. This input data is for historical reasons, when the curvature was expressed as filtered through the Mauzin measuring car.
Declared= Real*4    Default= 1.

XSTART_KM

Defines the first kilometer from where the translation shall begin.
Declared= Real*4    Default= 0

XSTART_M

Defines the meter within the first kilometer from where the translation shall begin.
Declared= Real*4    Default= 0

XSTOP_KM

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

XSTOP_M

Defines the meter within the last kilometer where the translation shall end.
Declared= Real*4    Default= 0

Example:

Following example: Master.trc_strix_track2f can be used as a master file:

                                                                                        
##                                                                                      
##      Input data for program TRC_STRIX_TRACK2                                         
##                                                                                      
                                                                                        
  INFIL= STRIX.SPL                                                                      
#                                                                                       
  SCALE_CURVE=  1.                                                                      
#                                                                                       
  REMOVE_UCAT_WORK= no                                                                  
#                                                                                       
  XSTART_KM= -1e6   XSTART_M=    0                                                      
  XSTOP_KM =  1e6   XSTOP_M = 1000                                                      
#                                                                                       
  DX= 0.5               # Equdistant steps in the track output data file UTFIL          
#                                                                                       
  L_LATERAL_WAVES= 125. # Filter the lateral track irregularities through a high pass   
  N_LATERAL_WAVES= 8    # filter, in order to remove very long waves                    
#                                                                                       
  FILTER_SHORT_WAVES= yes                                                               
  L_SHORT_WAVES=  2.5   # Filter the irregularities through a lowpass filter            
  N_SHORT_WAVES=  2     # in order to remove short waves                                
#                                                                                       
  CALC_QN    = yes                                                                      
  CREATE_PLOT= yes                                                                      
#                                                                                       
  UTFIL= transl_track.trax_wdesign