Experiences with Computer-Based Monitoring Systems in Polish Coal Mines

Copyright © IFAC Autom ation for Mineral Resource De velo pment Queensla nd . Australia. 1985

Experiences with Computer-Based Monitoring Systems in Polish Coal Mines S. CIERPISZ Technical University of Silesia. Gli'Nice. Research and Manufacturing Centre. EMAG. Katowice. Poland

Abstract. A modular computer-based monitoring system for mines is discussed. The system consists of the following modules : production monitoring system HADES, methane monitoring system

C~IC,

seismoacoustic and

seismometric systems SAK and SYLOK, communication systems. The system enables one to compose flexible, economic structures according to the specification of a mine. Application of microcomputer-based monitoring and control systems in coal preparation plants also is discussed. Keywords. Computer apptlcation; mining.

INTRODUCTION a minicomputer links with a set of senProduction of a mine as well as the safe-

sors and a transmission system and has

ty depend on a well designed centralized

typical and flexible software. These

monitoring system, the equipment used,

specialized "modules" allow one to build

and the methods of controlling the pro-

flexible monitoring and control systems

duction process.Initially, in the early

according to the specification of a mine.

sixties, the dis'patcher supervision was

A set of such "modules", covering a wide

limited to a communication system only.

range of the needs of mines, was deve-

Over the years, the control methods and

loped in the Research and Production

equipment have been systematically impro-

Centre El'1AU. All modules are built around

ved, and now in some mines there are

one type of minicomputer

management centers based on computer mo-

PR~-4

designed

and produced in IDIAG •

nitoring and control systems. Digital technique was introduced with

GBNERAL CONCEPT OF THl!;

:SYS ' L'E~l

caution in mining, and the obtained reThe general concept of the modular moni-

sults did not always meet the requirements. Negative results were mostly due

toring system is as follows

to poor reliability of the hardware and

The system should enable

conceptual errors.

emergency signalling, monitoring of

failure and

the production process and work safety

Since the very beginning, two trends in

parameters, current reporting, support-

application of computers emerged. First,

ing the dispatcher in case of rescue

was the use of one computer, sufficiently

operations, possible control of select-

large to cope with monitoring and data

ed installations or technological

processing concerning all mining processes. The second trend was to use small

links.

digital systems, each to solve one pro-

The system should be designed as a uni-

blem.

form construction based on a typical central unit, the structure of the

Because of easier implementation and

system should be modular in hardware

greater reliability of small systems, the

and software, enabling easy economical

second solution was adopted, whereby

75

76

S. Cierpisz configurations according to the current

regarding: longwall face shearer loaders

requirements of a mine.

and other winning machines, armoured face

The system has

be

to~designed

for stage-

conveyors, belt conveyors, loading bunkers,

wise construction and operation in a

shafts, main fans and booster fans, pwnps.

mine.

The system shown in Fig.2 covers the

In line with the adopted concept, the following sUb-systems

("modules It) were

designed and applied in mines: Monitoring of the production process-

following functions: Data acquisition from sensors installed on machines. Data processing, which includes:detect-

providing monitoring of the main win-

ion of state changes of the machines,

ning haulage process and production

keeping the timing card of the machine,

balance -

filtering out stppages longer than a

"HADES".

given time interval (e.g. 10 min), calMonitoring of methane concentration, providing also shut-down of power suply in the hazardous areas- liCMC".

culating the balance of the output by counting the cars and skips at loading points.

Bumps hazard evaluation by means of

Data presentation in the form of messag-

seismoacoustic methods -

es and reports automatically displayed

"SAK".

Localization of seismic events by means of microseismological methods -"SYLOK".

on VDU. For monitoring the operation 01' machines

Rock and gasses outbursts hazard evalu-

and underground equipment, the CP-l0 two-

ation, basing on the measurement of the

state current sensors are used, which are

volume of the emitted gasses and employ-

mounted on the power supplying cables.

ing seismoacoustic methods- "SAK-SG".

As the sensing element, the contacts of the switching circuitry may also be used.

The system is completed with Alarm communication system "AUD-80", Overall mine communication "UDG" ,

For data transmission, aIL intrinsically safe multiple fr.~uency transmission system CTT-J2 is used.

which are not based actually on the digital technique.

An exemplary installation 01' the "HADES"

The structure of the modular monitoring

system in mine

system is shown in Fig.l.

following configuration

During 1985-90, it is planned to redesign these systems using microprocessors and to widen the structure, including early

"~loszczenica"

has the

Transducers monitoring of shearers in 20 faces 20 CP-l0 sensors,

detection of fires and ventilation, which

monitoring 01' face conveyors and other

are under field tests.

face

equi~nent

- 80 CP-l0 sensors,

monitoring 01' shaft operation - 8 conUse of microcomputers as controllers on the first level of the system should provide the system with more functions of direct control. First experiences with

tacts, monitoring of face headings -

16 CP-l0,

monitoring 01' ventilation fans - 80 CP-l0 sensors.

the industrial application of microprocessors were gained in the coal preparation

Transmission

processes, which is presented in the last

Multiple frequency transmission system

part of the paper.

CTT-J2 with 12 units - each to transmit by a single pair 01' wires 22 binary data

PRODUCTION PROCESS MONITORING SYSTEM

at a distance of max. 10 km.

"HADES" Computing facilities The leading objective of our development efforts was to design a system for general supervision of a mine operation and the monitoring of all important data

PRS-4 mincomputer with 16k memory, Set 01' application programs including modules for:

Compute r-based Monitoring Systems in Po lish Coal Mines - Cace operation analysis,

77

of bumps hazards is designed Cor continu-

shaCt transport balance,

ous recording of the state of stresses in

- mine areas output balance,

strata. The system analyzes the monitored

.1I0ni toring o C ma in haulage,

parameters in order to determine seismo-

monitoring oC main and booster Cans.

acoustic activity related to the "conventional" energy of seismic events. It also

Ml!.'THANE

~10NITORING

SY::;TEH "L:HC"

analyzes the distribution of the energy with time and its deviations Crom the

This system, shown in Fig.J, is provided Cor continuous monitoring oC methane con-

mean value. The structure oC the system is shown in Fig.4.

centration in mines with a great nWllber oC controlled sensors. The system is built-

Output signals from max.16 geophones are

up oC

ampliCied and transmitted by the TSA-J2

underground, intrinsically saCe

transmission system to the inputs of an

equipment comprising:

analog memory, where the signal amplitu-

- Zener protection barriers,

des are recorded. Output signals from

- InterCace modules BOL, Two PRS-4 minicomputers working in pa-

analog memory are transmitted to compara-

rallel to increase the reliability oC

tors. When these signals exceed the thres-

the system, handling 1213 telemetry

hold value (O.sv), the comparators change

signals oC low and high concentration

their state and the interrupting signals

oC methane and air Clow and 12H power

are generated. The interrupt i on addresses

switching-oCC devices.

are then detected, the values of stored signal amplitudes are measured, and

InterCace BOL blocks perform the Collowing ma in Cunc tions:

ana log me mory is cleared. The measurements are made every 10 ms e c. Additionally, the

s upplying a ll l i nes with a charging current Cor the batteries in the coders, measurement of the noise in the selected telemetry line,

state of four signals from mining machines are monitored. During the operation of machines, the results of recording are stored in separate counters.

line break che cking, simplex audio communication for main-

The computer system performs the following functions:

tenance purposes.

acquisition of data such as: The PHs-4 minicomputer provides Cor: selection of sensors Cor measurement according to the given repetition time,

",it4.

comparing the measured value. the preset warning and alarm levels,

- exact moments o .f signals occurence in each channel, maximal signal amplitude in each channel, duration of the signal in each channel, the operation of mining machines (onoff),

activating the generator oC sl'litchingoCf pulses sent to selected lines

data processing

associated with the sensor where the

eva luation oC time differences oC the

alarm level was exceeded,

signals occuring in each channel,

periodical printouts of the processed

classification of signals by the value

data such as: alarms, mean value of

of their amplitude,

ClI concentration and its changes, 4 duration of alarm and fault states.

c al c ulation of the "conventional" energy

The "CHC" computer-based system is expected to replace most of the current CTT-6J/ 40up

and

CM~!-20

methanometric systems.

of seismic events. Another system, based on the PRS-4 minicomputer ("SYLOK") is designed Cor continuous monitoring of microseismic signals and for automatic localization of the

~IINING

SEISMOACOUSTIC AND SEISHOMETRIC

SYSTEMS

seismic events, determination of their occurence and their energy. The system is recommended as standard equipment in mine

The mining c omputer-based seismoacoustic system for the evaluation of the degree

stations Cor s eismic investigations.

78

S. Cierpisz

The system "SYLOK" permitsoone to determine the absolute seismic activity in the mine and adjacent areas. It operates on low frequencies, which are little attenuated by the rock, and thus its range is several kilometers from the sensor 0eismometer) • The system performs the following functions: acquisition of data from 16 SPI seisme-

alarm telephones ATA - max.16, - ZeDer protective barriers SBO, AeA exchange , - AUR tape recorder block.

The dispatcher can communicate,choosing individual subscribers or transmiting evacuation signals to a maximum of 12 areas, using 4 programmable or 2 permanent warning communications. All rescue opera-

meters, determination of first entry

tions are recorded in the tape recorder

times in each channel, measurement of

block.

maximal amplitude of the cross wave in each channel, measurement of' time of

EXPERIENCES

signal termination in each channel, classification of pulses with respect

About 60 computer-based monitoring systems

to amplitudes,

t'modules"),as described above, have been

- calculation of "conventional" energy

designed and installed in Polish coal

during one shift,

mines and abroad. The number of installa-

determination of energy deviation from

tions is given in Table 1.

the mean energy, monitoring of operation of winning ma-

TABLE 1

Computer-based monitoring

chines that are the source of noise,

installations in Polish coal

collecting of parameters necessary for

mines

more accurate interpretation of data,

1984

System

Poland

e.g. face advance, value of sruall- dia-

Other countries

meter drillings, - determination of' differences of entry

Production monitor-

times in order to perform simplified

ing "HADES"

localization of the centres of shocks

J>lethane monitoring

within the face.

"CHC" Seismoacoustic sys-

Particularly useful is the look-back facility, whereby, in given time intervals (e.g. after shooting) and with storage up to 44 shifts, a display of the data permits one to trace the rate of changes.

6

4

3

22

5

4

5

35

6

tern "SAK" Seismometric system "SYLOK" Early detection of

:~r:s_l~xE::~m~n:a~) Alarm-broadcasting

COMMUNiCATION SYSTfl.1S

10

------

not com-

system "AUD"

puter

In Polish coal mines, besides technologi-

Overall mine tele-

based

cal loud-speaking and radio communication,

phone system "UUG"

48

two central communication systems are used, which usually complete the whole

During eight years of designing, implemen-

monitoring and control centre of a mine:

tation and operation of computerized

AUD -80 alarm-broadcasting system and

monitoring systems, the following conclu-

overall mine telephone UDG system.

sions can be withdrawn:

The AUU alarm-broadcasting system is used

- A modular monitoring system based on a

for central rescue operations in case of

relatively small central unit (mini or

fire, water, methane and other hazards.

microprocessor) appears to be a relia-

In such situations, withdrawal of the

ble, economic solution for the deversi-

miners is necessary. The system consists of: audible alarm signalling devices ASA max.64,

fied needs of mines. Such a system meets most of the functions demanded by the staff of a mine. However, the necessity of standardiza-

79

Computer-based Monitoring Syslellls in Polish Coal Min t's

tion (uniformity) of hardware and software, from the point of view of design,

COAL PHEPAnATION PROC ESSES NONITOHING AND CONTHOL

implementation,and maintenance of the system, is obvious. It is very

import~

In recent years, substantial progress has

ant to cooperate with experienced staff

been made in the automation of coal pre-

of the mine on the final form of reports

paration processes a s a r e sult of long -

to meet particular needs for processed

term research in lIIany cowltries. One can

information.

expect that future coal pre paration plants

- Information systems that are limited to

will use more microprocessors in various

a mine find almost full acceptance by

sections of the plant.

the managing staff. It is much more

In J::1>IAG Centre, microcomput er-based cont-

difficult to convince people of the

rol systems have been designed and appli-

value of hierarchical information sys-

ed to such processes as flotation,loading

tems for groups of mines (e.g. areas,

of coal into wagons, monitoring of calo-

concern, branch, etc.).

rific value of coal and of ash content

The Production Process Monitoring Sys-

in coal slurry. Control systems for sepa-

tem is used mainly by the staff of a

ration in heavy me di a and in jigs are

mine for evaluation of the advance of'

also under investig
winning works, finding weak points in

to design a modular distributed-control

the technological links, and for plan-

systelll for n typi cal

mi c ro c ~"put e r

cont

roller applied to sepa r ate sections of

ning of maintenance works.

tlle plant. The structure or the system The Central Digital Methanometry System

is shown in Fig.5.

has all the features of conventional systems and allows better control of the ventilation network of a mine.

control of the flotation process In this syst e m, a microprocessor control-

The benefits from seismoacoustic and seismometric systems for evaluation of

l e r for dosing th e r eagents into flotation cells is us ed . The value of control

the energy of btunps and their localiza-

signal

tion are not so evident, however,

ted by procedures or the application pro-

in

several cases it was possible to pre-

gram u s ing re la t i on:

dict bumps which occured. In these sys-

I

tems, which are based on imprecise knowledge of the relation between "acti-

Id for r e
whe re

d V

q uantity of flOl. or the

n

vity" of the strata and a generated

reed,

acoustic signal, other phenomena should be studied also. Ilo 'w ever, all monitoring systems that give some information, even if not very precise, on bwnps hazards are welcomed in mines. As regards the discussed modular moni-

C

density of the feed

n

The flo" of solids in th e feed to the flotation proces s , as "011 as th e total lIIass or the solids, are also calculated. Analogue input signals to t he controller are generated by the densitometer, elec-

toring system, minicomputers used in

tromagnetic flowmeter and the setting

"modules" will be replaced by micropro-

unit.

cessors. The use of microprocessors as controllers on the first level of the

Nonitoring of calorific v a lue of coal

system should provide more functions of

The L'irst microcomput e r-based monitoring

direct control. From the point of view

syst;ern was appli ed to continuous lIIeasure-

of required reliability irJLdirect cont-

me nt of coal quality, namely its calori-

rol, it seems desirable to separa te the

fic value.

functions of control from data proces-

Basic coal quality parameters,i.e. ash

sing and presenting results.

content and moistur e , are measured con-

Tile

sy s tem is shown in Fig.6.

tinuously on the belt c onveyor. The measurements are performed by the G-J

80

S. Cierpisz

radiometric ash monitor and WILHAG micro-

monitoring of the state of machines,

wave moisture meter.

start-up of drives in a sequence.

The calorific value of coal is calculated

Coal separation in jigs

by the equation: The reason for automation of jigs is to increase their separation efficiency, to coefficients determined

obtain high and uniform quality of a con-

experimentally,

centrate, better capacity of the machine,

ash and moisture content,

and lower losses of coal in refuse. This

calorific value of ashless

can be achieved by:

and free of moisture coal.

better stability of the feed to a jig,

The signals from monitors are processed

better loosenning of the bed in a jig,

in the microprocessor to determine,using

better accuracy of refuse removal from

regression analysiS, average values of ash

a jig,

and moisture content and calorific value

control of water flow in the machine.

of coal. The results are printed out and

Two microprocessor control systems have

projected on a monitor together with the

been proposed for th e separation process

nwnber of a loaded wagon.

in jigs.

Coal loading into wagons

The first one is assigned for the control

Automation of a coal loading station with buffer bunkers

was the other prob-

lem that was solved by application of the microprocessor controller. The control system perfonns the following functions:

of the cycle of air pulsations in a jig. The system allOWS one to choose easily the shape of a cycle, the moment of its beginning and the end according to !IIean c haracteristic of th e c oal being processed .

storage of load capacity of individual wagons, generation of steering signals for controlling the coal stream to batch bunkers,

monitoring of the load of wagons, Signalling the phases of the loading cycle, testing the correctness of the system operation.

The second system is assigned for refuse removal from a jig and is based on a conventional float as a sensor of the thickness of the b e d. The use of a microprocessor allows one to measure the thickness of the bed in a chosen time interval in each cycle of air/water pulsation. This procedure is expected to increase the accuracy of the control system in comparison with the apparatus being used

The system consists of EWZ-10 hopper

now.

scales, PSP-2 controller, operator's desk, and interface equipment. Heavy medium separation process Designed and installed in 1983, the cont-

REFEHENCES Firganek,Il.,and Zymelka,K. (1984). System for monitoring of production and safe-

rol system for the heavy medium separation

ty in the Polish coal industry.Procee

process is an example of the application

dings of ICAHC-84,Budapest.

of the microprocessor controller, in which its advantage over conventional control system can be demonstrated. The process control actually includes:

Cierpisz,S. ,and ~lironowicz,W. (1984).Trends of automation in mining in ceedings of

Poland.~

ICA~1C-84,Budapest.

Cierpisz,S. ,et al. (1981+). Hicrocomputer-

stabilization of the density of heavy

based control systems for coal prepa-

media,

ration processes. Proceedings of ICAMC-

control of the levels of slurries in

84, Budapest.

tanks. Experiments are being made with control of the preparation of fresh heavy medium,

81

Computer-based Monitoring Systems in Polish Coal Mines

Overall m lr. e telephone comm untc ltlon Alarm broadcas:lng .---.., commufllcahon

--y--

Local mine network

~GlobaT

i

I dolo 'memo'}'

I I

7nax~Hb-'

I

current geophones transducers

bTI

L ~

smoke, CO, air flow temperature detectors

sei smome/ers me fhane and air flow defecfors

Fig.1. Hodular computer-based monitoring system for mines

SignaltransmlSSiOI PertpherJI Minicomputer system CTT-32 equipment C77-32

"

22 signals module

"

"

--

C7T-32

"

..

PRS-i. Software face operation analysls,sl'alt transport balanee,mme areas output b, monitoring -main haulage -mal" fJns auxlll/ary Ions

0

HADES

@

I

counters :; / CJr,

5";;

Fig.2. Production process monitoring system HADES

82

S. Cierpisz

Peripher al equipme nt

Hinicom puters in parallel Sol/war e ' - selectian of sensors -signal/n oise measurements -genera tion of swifch off signals -display of alarms on VDU -periodic al printouts on methane situation

I

I I

PRS-I.: PRS-1. I I

I

I/O UNITS I

BOL

I I I

BOL

(Z)

CHC System

@

I r,iifrinsiciiTTy ~ rsafe barflers 1

.L

61.sigools 61.signals

,-

-----

I I

I

I I L __ _ __ _

I I ...J

Hethane detector s C.....[ ..: -.] Anemome1r!rS OptIon S .:. -;;' - CO a,1alyse r -dlfferen c al pre s> . :e meter s CR .-

Fig. J. ~le thane moni toring sys tem CHC

Energy graoh ,-. -

Teleprinter

. -- " l

G32 1 I

I

$8

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[1

-_ . .. - -

Time G2 r1230 xx 32 xxxx I 31. x , 36 Xxxxx I 38 xxxx I 1.0 xxx

'-UU dISplay

I t.2 x , 1.1. xx L_

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'---- -1 I I

.(1)

ontfor

,,,

,

1.:j:.--- 'iJ=J Honifore d ar ea o Geophones DF7C} .. G32

-15--"" ,

I I first I enlry of ;'he SIgnals

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,

,

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signal flow analysis

Fig.4. Mining seismo acoust ic system SAK

I

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Computer-based Monitoring Systems in Polish Coal Mines

in/ outputs Two - stale

,tJcomputer controller

83

recor ding and

signa lling

i n/ outputs

Heavy media process

-measuremen t s , -alar ms

1- con t rols

Fig. 5

Distribution-control system for coal preparation plants.

,-_- .. ,.. I

' ~' "' .... . .

Fig. 5

Radiometric ashmo nitor G-3.