II INTERNATIONAL CONFERENCE__________
TRANSPORT SYSTEMS TELEMATICS TST'02
ZESZY TY N A U K O W E P O LITEC H N IK I ŚLĄSKIEJ 2002
T R A N SP O R T z.45, nr kol. 1570
code current parameters control, rail circuit, device V ladim ir I. G A V R IL Y U K 1
Tatyana N. SER D Y U K 2
T E L E M E T R IC SY ST E M FO R T H E C O N TR O L O F SIG N A L PA R A M E T E R S O F R A IL C IR CU IT S
The characteristics of existing methods o f control of time and numerical parameters of codes transmitted in rail circuits are described. The device meant for this purpose is proposed. The principle of its work is considered.
T E L E M E T R Y C Z N E S Y ST E M Y K O N T R O L O W A N IA PA R A M E T R Ó W SY G N A Ł U O B W O D Ó W T O R O W Y C H
Referat dotyczy próby określenia kodu parametrów prądu obwodów torowych. Jest to potrzebne w celu polepszenia metod i środków utrzymania, związanych ze wzrostem niezawodności automatycznych urządzeń kolejowych. S ą to metody pomiaru prądu w przerwie pomiędzy jadącymi pociągami. Zaproponowane urządzenie jest zrealizowane na bazie nowoczesnego mikroprocesora i technik komputerowych.
1. IN TR O D U C TIO N
T he safety o f a railw ay transport depends on the different factors. O ne o f them is the reliable functioning o f the rail circuits.
It is know n that the refusals in rail circuits is 15%, and distortion o f signals transm itted on rail lines is 7 % from all refusals o f autom atic block system o f Ukrainian railway [1], Thus, It is necessary to increase the reliability o f rail circuits for the norm al functioning o f all railway autom atics devices.
Now the m easurem ent apparaturcs o f rail circuit param eters taking place have low exactitude and do not provide sufficient productivity o f the control. O ne o f m easures providing increase o f rail circuits reliability is the perfection o f m ethods and m eans o f diagnosing o f th eir capacity for work.
M odem developm ent level o f m icroprocessor and com puter techniques allow s us to decide a question about control o f param eters o f rail circuits and codes o f autom atic locomotive signaling devices effectively. In this article autom atic locom otive signalling code parameters control device on the base o f m icroprocessor have been described.
Automatics and Telecommunication Department, Dnepropetrovsk Technical State University of Railway Transport, Akad. Lazaryana 2, 49010 Dnepropetrovsk, Ukraine
Automatics and Telecommunication Department, Dnepropetrovsk Technical State University o f Railway Transport, Akad. Lazaryana 2, 49010 Dnepropetrovsk, Ukraine, serducheck_t@fromru.com
186 V ladim ir I. G A V R ILY U K , T atyana N. SER D YU K
2. C H A R A C T E R IST IC S O F EX ISTIN G C O N TR O L M ETH O D S OF CODES PA R AM ETER S
T he param eters o f electrical codes o f locom otive signaling system in rails have to correspond to the requirem ents, T he value o f this current in rails and duration o f pulses (intervals) o f electrical signals are controlled in the process o f exploitation.
V alue o f a code current on the rail circuit is se t norm s. A fter m easurem ents o f ballast resistance and w ith the help o f the regulation tables, the current in a rail circuit input has to be not less than 1,2 A at the diesel-locom otive traction, 1,4 A at the electrical traction o f an alternating current, 2A - d irect current and n o t m ore 25A in output in different weather conditions.
T h ere are follow ing m easurem ent m ethods o f current in rails in an interval between driving trains:
m easurem ent o f a continuous current transm itted in rail circuit at the check instead of pulse. T he contact o f transm itter-relay is shunted by the cross-w ire;
m easurem ent o f a current o f locom otive signal system in pulses. T he input o f rail circuit is shunted by the am voltm eter w ith the help o f the special w ire;
m easurem ent o f the locom otive signal system current in the additional w inding o f the dross-transform er. T he am m eter is connected in parallel to this w inding without interrupt in supply. In this case the am m eter shunts a rail circuit;
m easurem ent o f the autom atic locom otive signal system current w ith the help o f the shunting o f a rail circu it by the test shunt. T he given m ethod finds a use at the absence o f am m eter w ith low input resistance. T he voltage on the shunt is m easured and is divided on its resistance (0,06 O hm ). R eceived value is current o f autom atic locom otive signal system .
T he check o f tim e param eters o f codes is involved the regulation o f transm itter-relay.
T he transm itter-relay o f a direct current regulates in follow ing way. T he tim e o f their sw itching on and o ff have to differ no m ore than on 0,03-0,05s. A lso It takes into account, that for d. c. transm itter-relay is characterised shorten pulses. F or the transm itter-relay of alternating current the tim e o f sw itching on and o ff have not to differ m ore than 0,01 s. It has the follow ing property: the tim es o f sw itching operations equal.
For the autom ated com plex evaluation o f capacity for w ork o f rail circuits the system
"C ontrol" is used widely.
T he m easuring system "C ontrol" is intended for m easurem ent o f a code current and definition o f tim e param eters o f a num erical code o f autom atic locom otive signaling. Also this system can supervise cross o f isolating jo in t, and thus to define length o f rail circuits.
D uring m easuring trip the duration o f the first pulse and first interval and value o f current in the input o f rail circu it are determ ined. T he m easurem ent o f a current is m ade w ith the help of receiving coils located under the car as coils o f autom atic locom otive signaling.
T he system “C on tro l” has such dem erits:
- detectors o f code current have low level o f protection from interference created tractive current;
it can not determ ine num erical and tim e param eters o f all codes signal;
it do not allow s us to determ ine phase o f current w ith the sufficient accuracy;
it do not define spectrum and values o f interference for the follow ing analysis and rem oval o f their action;
it has n o t function o f statistic processing given date;
Telem etric system fo r the control o f signal param eters o f rail circuits 187
- and it can n o t determ ine param eters o f rail circuits;
- the dislocation o f isolating jo in t is defined w ith the error o f 20-30 m. T he full resistance o f the circuit used for the definition o f cross o f isolating jo in t is depended on the stability o f w heel-rail contact and contact in the jo in t w heel-axis.
3. P R O PO SED SY STEM O F C O D E SIG N A L PA R A M ETER S C O N TR O L
T he ALS code param eters control device is realised on th e base o f personal com puter o f IBM P C type [2], Proposed devices is intended for the carrying out follow ing functions:
the input and digital transform ation o f electrical signals;
- saving recorded data in hard disk;
- the creation data base o f recorded and calculated data;
- converting o f given data to the W ord, Excel, M atlab, M athcad o r T ext files;
- the calculation o f am plitudc-frequency and phase-frequcncy characteristics o f the codes and interference w ith the help o f the Fast Fourier T ransform ation;
- the filtration o f tractive current w ith the help o f the special program ; - the definition o f asym m etry current value;
- the o u tp u t recorded signal and calculation data on the m onitor and print;
- the check o f the conform ity o f code param eters to the requirem ents and the reception o f recom m endations about probability causes their deviation and their rem oval;
- the probability and statistical processing o f m easurem ents result;
- the definition o f length and param eters o f rail circuit.
T he view o f w indow for the analysis and w ork with the recorded signal is given for example (F ig .l).
'■.'.’■'Signal processing window File V iew C alculation H elp
H U
O p e n ► i f \ \ Signal processing window
M - i P l * ! !
S a v e ► File V iew I C alculation Help
C o n v ertin g ►] Text S p ectru m analysis ...I
Print W o rd 1 l l l P r ' ' 1 S tatistics v v L : l . \
Exit E xsel C o d e p aram ete rs analysis ...
I
M atlab p aram ete rs of rail circuit
...
IM ath c ad
F ig.l. Window for the analysis and processing of recorded signal
This device consists o f such unit: the interface block, the analog-digital converter, the m ultiplexes, th e generator o f tact im pulse, the program m ed tim er, the data and operate registers and the personal com puter.
T he signal from the ALS receiving coils transm its to the com puter by the L PT parallel port. T he signal is accorded w ith the input diapason o f analog-digital converter (ADC) with
188 V ladim ir I. G A V R ILY U K , T atyana N. SER D Y U K the help o f the special block. T he ten-bit A D C is used in devices. T he application o f ADC, w hich has low er bit, d o n ’t give necessary exactness o f m easurem ents and in result high level o f errors in signal record. T he quantization frequency is 10 mV. T his device m eans to record signals by the value from -5 m V to +5m V . And It is possible to increase the input diapason to the ±100m V using the interface block.
T w o m ultiplexers arc used to connect A CD w ith the LPT port because A CD has ten-bit data bus and L PT port has eight-bit data bus. So W e have six lines in reserve and T hey can be used at the sixteen-bit ACD.
T he program m ed tim er is used to control w ork o f A DC. It determ ines the discretization frequency o f input signal. It is possible to set dicretization frequency to 40kH z. W e can change this value determ ining dicretization coefficient at the clipboard input.
T he registers o f operate and o f data are used to set dicretization frequency and control o f tim er. T he operation o f given devices is carried out w ith the help o f the program s written on language o f a high level Delphi.
T he control o f A D C readiness is realized through a special input o f L PT port causing hardw are interrupt. T he subprogram o f processing o f interrupt reads the A D C data bus in the R A M o f com puter through m ultiplexers. T hen It is done the com puter p rocessing o f results.
T he w indow o f digital transform ing o f signal is show n in the Fig.2.
\ N Digital transforming of signal (“ O p era tio n
1 S tart
-'eus* ,
l o p .
E X IT
O p eratio n of signal re c o rd "
R e c o rd from th e ALS coils“
(• 1 coil C 2 coils
Input ty p e — —~ “ (• O p e n input C C lo sed input
"L o co m o tiv e filter --- C R e c o r d of sig n al from coils o u tp u ts (• R e c o rd signal from o u tp u ts of filter
P ro g ram filtration of tra ctiv e c u r r e n t"
C U s e filter
<• D o n 't u s e filter
S a v e of signal f “ a u t o s a v e of signal
S i z e o f file : |0 0 0 0 0 0 k B yte
r O sc ilo s c o p e
S h o w H ide
Fig.2. Window for the operation of digital signal transforming
T his device allow s to record a signal from an output o f a filter, as it is required w ith the Instruction to the m aintenance o f devices o f signaling, centralization and block, and from outputs o f ALS coils. T he m easurem ent has to carry out tw o tim es in year. T he signal recording from the A LS coils represents a sum o f code ALS signals and tractive current with all harm onic com ponents and im pulse hindrances arising during w ork locom otive and electrosupply system . T h at is w hy given device allow s us to analyse not only tim e and num erical param eters o f A LS codes, but also to evaluate a degree o f influence o f hindrances on w ork o f autom atics system s and to define analytically reasons o f their appearance.
Telem etric system for the control o f signal param eters o f rail circuits 189
T he results o f m easurem ent can be shown on the separate w indow - osciloscope (Fig.3).
There is real signal recorded from the receiving coils o f autom atic locom otive signaling system.
Osciloscope i â Ë l D l
■ Signal — --- 1 - --- ' „ •' ' r --- '
Axis Y: ¡0.5 V/point Axis X: |0-02 sec/point
Fig.3. The Osciloscogram and spectr of signal recorded from automatic locomotive signaling coils
190 V ladim ir I. G A V R ILY U K , T atyana N. SER D YU K
4. CO N C LU SIO N
T he follow ing conclusion are done:
- ALS code param eters control device build on the base o f m icroprocessor techniques and personal com puter is proposed;
this device is allow ed to analyse value o f interference arising in the rail circuits in the result o f influence o f tractive current and other sources and to determ ine their causes in further;
- so proposed device is m ultifunction and It can use to take inform ation as in m easuring jou rn ey as in w ork regim e o f locom otive. A lso this device can be applied in the car- laboratory w hich used on the railw ay o f U kraine for the definition o f autom atic locom otive signaling codes param eters.
B IB LIO G R A PH Y
[1] BOYNIK A.B., KOVALENKO G.V., MAKARENKO R.V., History o f development of way Railway Automatics System, Railway Transport o f Ukraine, ff“4, 2001- 40-43p.
[2] SERDYUK T.N., Device for The Definition o f Code Parameters o f Automatic Locomotive Signaling and Evaluation o f Electromagnetic Influence o f Tractive Systems on It, EMC 2002, Sixteenth International Wroclaw Symposium and Exhibition on Electromagnetic Compatibility, 2002.
[3] SHILO V.L., Popular Digital Microschemes, Reference Book, Moscow, Radio and Communication, 1987.
[4] UDOVIKOV A.A., Automation o f Rail Circuit Capacity for Work Control on The Base of Technical Means of Car-Laboratories, Thesis o f the dissertation on a competition o f scientific degree o f the candidate of engineering science, Charkov 1995.
R eview er: Ph. D. A ndrzej Białoń
