74
`
`Diesel locomotive reliability improvement by system
`monitoring
`
`KNFry BSc
`British Rail Research Railway Technical Centre Derby
`
`System monitoring for reliability SMR involves monitoring critical parts of
`and informing the owning business of an
`vehicle
`the largest opportunity for such systems and British Rail Research has developed
`locomotives offer
`impending fault Diesel
`system
`designed to improve Class 47 locomotive reliability
`The vehicle-mounted
`that continuously monitors the condition of the vehicle through sensors at key
`equipment comprises
`computer
`GPS satellite navigator The key elements in the success of
`points The computer
`radio telephone and modem and
`is connected
`to
`the system are the automated analysis of data on-board the vehicle and its ability to call for help ahead of the occurrence of service
`failures The business interface is through
`Windows based information display which runs on
`personal computer connected to the
`public telephone network This controls the display of messages from monitored vehicles and allows vehicles to be interrogated to check
`on current condition
`When fully implemented
`reduction in technical casualties of 40 per cent is anticipated There are additional financial benefits from
`efficiency improvements and vehicle maintenance
`cost savings
`
`Key words system monitoring for reliability diesel
`
`locomotives
`
`INTRODUCrION
`
`The Vehicle Systems Unit of British Rail Research has
`series of projects over many years con
`undertaken
`cerned with the development of condition monitoring
`for railway rolling stock and diesel
`locomotives in par
`on the
`ticular This work
`has recently
`concentrated
`development of systems
`to improve the reliability of
`vehicles System monitoring for reliability SMR is the
`name given to monitoring critical
`parts of
`vehicle in
`by informing the owing
`order to improve its reliability
`business of an impending fault
`This paper describes the development of
`system for
`monitoring Class 47 locomotives It begins with the
`for SMR It
`goes on to
`then
`guiding philosophy
`describe the component parts the on-board equipment
`and analysis of data the communication of information
`to and from the vehicle and thern information display
`review of the current position
`system Finally there is
`
`The MS was received on 25 November 1993 and was accepted for pubticatton on
`22 December 1994
`
`PHILOSOPHY OF SYSTEM MONITORING FOR
`RELIABILITY
`
`2.1 The economic background
`
`Studies into maintenance and maintenance-related costs
`types of rolling stock have been undertaken
`of typical
`to
`determine the most cost-effective areas for the applica
`tion of condition monitoring and diagnostic systems
`The four main vehicle types used by British Rail have
`been examined diesel
`locomotives electric locomotives
`diesel and electric multiple units
`The costs have been broken down by vehicle system
`and subsystem into five areas three directly associated
`and
`exams repairs and overhauls
`with maintenance
`and
`two indirectly
`related the cost of unreliability
`unavailability The results given in Fig
`show that the
`and the
`locomotives
`total cost
`is for diesel
`largest
`largest element of this total is the cost of unreliability
`Examination of the reasons for unreliability showed
`small number of causes
`is made up of
`that the total
`many of which are easily monitored and
`
`see Fig
`
`Elil Unavailability
`
`Reliability
`
`Overhauls
`
`Repairs
`
`Exams
`
`Icu2 707 --I
`
`Diesel
`
`locomotive
`
`Electric locomotive
`
`Diesel
`
`multiple unit
`
`Electric
`
`multiple unit
`
`Vehicle type
`Rolling stock maintenance and maintenanceaffected costs
`
`Fig
`
`F01693
`
`IMechE 1995
`
`Proc Instn Mech Engrs vol 209
`
`AVS EXHIBIT 2017
`Toyota Inc. v. American Vehicular Sciences LLC
`IPR2013-00417
`
`

`

`FRY
`
`Battery
`
`condition
`
`I-
`
`IL
`
`Traction control
`
`interlocks
`
`Loss of coolant
`
`and low oil
`
`pressure
`
`Brake condition
`
`Fig
`
`Causes of Class 47 failures in service
`
`amount of data requiring transmission which is partic
`ularly advantageous where communication is by radio
`Secondly it opens up the possibility of providing infor
`mation to the driver or
`train crew in those situations
`where it can be usefully acted upon
`The provision of
`continuous
`communications
`link
`between the owning business and an intelligent vehicle
`allows information on condition to be provided
`on
`demand Such vehicle interrogation may be useful as
`check on condition just prior to assignment or for mon
`itoring the development of
`fault already reported
`
`2.4 Information required
`
`allow warning to be given About 40 per cent are con
`through appropriate monitoring
`sidered preventable
`and notification of impending failure
`
`2.2 Reliability emphasis
`
`factors described
`
`The
`in Subsection
`led to the
`2.1
`reliability which is
`of system monitoring for
`concept
`aimed at
`in-service
`failure of
`reducing
`specifically
`than reducing maintenance costs or
`equipment
`rather
`increasing availability This very specific approach gives
`number of advantages
`
`the number of measurands is significantly reduced
`the maintenance philosophy of the vehicles does not
`is quicker and easier to implement
`change so it
`data analysis is generally easier since faults severe
`are more easily
`enough to cause
`vehicle to fail
`smaller changes
`identified than the comparatively
`need for maintenance
`associatcd with
`
`2.3 Importance of on-board analysis
`
`Most approaches
`to vehicle monitoring have involved
`and analysing the data
`fitting data logging equipment
`they have been downloaded This requires
`the
`after
`large amount of data the major
`routine download of
`ity of which will
`the vehicle is healthy It
`indicate that
`identification and will
`also introduces
`delay in fault
`miss the majority of faults likely to affect service reli
`ability on
`daily basis
`An emphasis on reliability improvement
`requires that
`in order to achieve
`response to developing faults
`fast
`the analysis of data must be automated and done on-
`board the vehicle the vehicle must also be able to call
`for
`for help It
`is this requirement
`high degree of
`com
`vehicle system intelligence in conjunction with
`munications system where the vehicle can call
`for help
`or be called at any time that
`is the key to successful
`SMR
`The move towards
`two
`an intelligent vehicle gives
`other major benefits Firstly it considerably reduces the
`
`the
`
`in the
`
`System monitoring is really only half the story In order
`to be improved not only must
`for the service reliability
`information about
`fault be provided but
`the informa
`tion must be suitably acted upon in order to remedy the
`situation If appropriate action is not carried out
`just as it would without monitoring In
`vehicle will
`fail
`the presentation of information to the end
`this respect
`user is of paramount importance
`An important part
`is the information content The
`majority of rolling stock
`is maintained by means of
`component
`replacement
`rapid return to
`to facilitate
`service and so the information provided should support
`this philosophy In other words faults in equipment
`need only be diagnosed down to the level of replaceable
`unit or the level of action required to allow the vehicle
`to continue running such as top up with coolant
`Diagnosis to this depth is particularly important
`case of
`vehicle reporting
`developing fault but
`long
`way from repair depot Should the vehicle be brought
`back to the depot repaired at an outstation repaired by
`mobile maintenance team or left
`while If
`for
`vehicle does need
`to return to depot
`diagnosis
`unit
`level allows an indication beforehand
`replaceable
`of what spares and depot
`resources are required for
`example under cover crane pit manpower etc This
`speeds up repair
`time considerably Similarly if
`mobile maintenance team needs to be sent
`to the vehicle
`they will know what equipment
`to take with them
`
`the
`
`to
`
`Journal of Rail and Rapid Transit
`
`IMecbE 1995
`
`

`

`DIESEL LOCOMOTIVE RELIABILITY
`
`IMPROVEMENT BY SYSTEM MONITORING
`
`from the system must be sent
`Information
`to the
`business maintenance
`controllers They respond to calls
`from outstations reporting problems with vehicles and
`replacement vehicle
`arrange repair or
`For fault diagnosis messages should be sent from the
`vehicle immediately but this is not necessarily
`the case
`when prognosis is involved There are situations where
`if the existing set of circumstances were to continue the
`vehicle would fail but
`the fault may be naturally reme-
`died before it occurs For example
`battery draining
`stopped may be just about
`with the engine
`to be
`charged following an engine start or
`vehicle with
`leak may be just running on to
`to have
`coolant
`depot
`topped up In these
`its coolant
`circumstances
`the
`failure limit and make
`has been to define
`approach
`the remaining time to failure Messages
`predictions of
`can then be generated
`time before failure is esti
`set
`mated The maintenance controller can then decide on
`whether
`the fault will
`require action based upon the
`
`duty of the vehicle
`
`ON-BOARD SYSTEM
`
`3.1 Equipment fitted
`
`The vehicle-mounted equipment
`computer
`comprises
`that continuously monitors the condition of the vehicle
`is con-
`through sensors at key points The computer
`radio telephone and modem allowing the
`nected
`to
`system to ring out with fault messages or be inter-
`rogated by the owning business at any time The com-
`
`puter knows the vehicles position through connection
`to OPS satellite navigator
`The equipment
`is housed in three rugged steel enclo
`sures sealed to 1P66 and protected against the electro
`magnetic environment of the locomotive Also fitted are
`number of transducers mounted directly on to existing
`some small enclosures
`components
`containing trans
`ducers and appropriate interconnection via high specifi
`cation cable sealed into flexible conduit Two aerials are
`short whip aerial mounted on the end of the
`also used
`vehicle and
`flat antenna mounted on the roof
`small
`for the GPS navigator
`This equipment
`is designed to
`into the vehicle without
`interfering with its
`retrofit
`and maintenance
`normal operation
`general sche
`matic is shown in Fig
`
`3.1.1 Computer
`
`Hardware The on-board computer
`is an industry stan-
`dard VME bus-based system made up of single height
`eurocards The use of the VME bus standard allows
`system to be made up in
`very modular and flexible
`from one or
`number of sup
`way using equipment
`pliers The system can be easily expanded
`to include
`additional processing power memory communications
`or monitoring channels
`Software Most computers use an operating system as
`the master supervisor of their resources memory pro
`devices such as sensors
`cessing time and input/output
`modems and disk drives The operating system also
`between
`the computer and the
`provides an interface
`
`Fuel
`
`level
`
`PRS
`
`aerial
`
`Computer
`
`PC logic
`
`Ambient temperature internal
`
`Navigator aerial
`roofcL
`
`Lr
`
`Navigator
`
`Cubicle end
`Terminal box
`
`5looj
`
`Thbe to bis
`
`TC
`
`Cubicle end
`
`Batteryl
`BatteryV
`
`Thrbine temperature
`Boost pressure
`Ambient pressure
`inside box
`
`Main alternator
`
`Main alternator
`
`15
`
`1207
`
`J412/208J
`
`From governor end
`
`M/Croomend
`
`Hydraulic oil
`
`level 6W PLY FXD SKT
`Oil temperature 6W PLY FXD SKT
`level 6W PLY FXD SKT
`Water
`Oil pressure in manifold
`Oil pressure out manifold
`Governor air manifold
`
`6W PLY
`IFXDSKT
`
`Engine speed
`
`__________
`
`Crankcase pressure
`
`tMcchE 1995
`
`Fig
`
`Monitoring equipment general arrangement
`
`Proc tnatn Mccli Engra Vol 209
`
`

`

`the system
`user managing the basic operations of
`input
`programs managing
`loading and executing
`files and allocating
`directory of
`output managing
`memory Application
`data
`programs
`performing
`analysis data storage and communications
`sit on
`all
`top of the operating system and call on it
`to perform
`low-level
`tasks
`The operating system used in the on-board computer
`is OS-9 This is multi-tasking operating system similar
`to UNIX but specifically developed
`for use in real time
`embedded systems
`Multi-tasking means that several programs may run
`from
`simultaneously by rapidly switching
`apparently
`one program to the next many times per second This
`capability is used extensively for the on-board software
`It considerably simplifies the task of managing
`data
`analysis allowing for example communications
`over
`the radio telephone to occur while analysing data from
`the oil system while reading the position from the navi
`gator while storing vehicle operating data to file etc
`Each task can be written as
`separate program sim
`and testing and removing any risk
`plifying development
`of programs interfering with each other
`
`3.1.2 Cellular radio telephone and modem
`The computer
`is connected
`Racal Vodafone cellular
`to
`radio telephone and modem Modems for cellular radio
`special error correction protocol cellular data
`require
`link control CDLC which gives 100 per cent error-free
`data transmission at speeds up to 2400 bits per second
`The modem is configured for auto-dial and auto-answer
`allowing the vehicle to call out or be called at any time
`Development of additional hardware and
`consider-
`
`ADC
`
`Logger
`
`Data logging
`
`Data analysis
`
`FRY
`
`able amount of software has been necessary
`to ensure
`reliable phone management across the two-way lint
`
`3.1.3 GPS satellite navigator
`
`Navstar XRS OPS
`The
`vehicle is equipped with
`receiver which gives satellite.based positioning Position
`information from the receiver accurate to mean error
`of 28 metres is available
`to the on-board
`computer
`serial data link The latitude and longitude is
`through
`converted to eastings and northings by the computer
`
`3.2 Data analysis
`
`The general structure of the data analysis performed is
`shown in Fig
`This structure separates
`the data
`analysis from the hardware allowing more generalized
`program modules to be produced
`The program logger reads all
`the sensors and the
`vehicle location from the satellite navigator
`and writes
`the mea
`the data to
`global buffer The buffer holds all
`surements made over the last minute
`The program validate takes information from the
`measurement buffer and places it
`second similar
`buffer after
`
`in
`
`converting it
`
`to engineering units
`for the value of supply voltage existing
`
`adjusting it
`at the time
`checking it against limits to ensure validity
`
`Validate also sets flags to identify engine operating
`status and transducer and power supply faults
`The analysis programs for
`individual
`systems then
`simply extract data from this buffer when their own cii
`teria for analysis are met for example the engine
`has
`
`Data stored at
`
`Hz as %its
`
`values to continuously
`updated
`60 second ring buffer
`
`Validate
`
`Data converted to engineering
`units supply voltage
`compensated and checked
`sensor faults
`
`for
`
`pNsYs
`
`NBAf No9
`
`Current status information
`
`EMONO1L ct
`
`Data analysis
`
`Cominunitj5
`
`Statu7
`Callei
`
`CDLC modem
`
`Fault message files
`
`Part
`
`Jouma of Rail and Rapid Transit
`
`Fig
`
`Structure of DEMON SMR47 software
`
`lMetb 1995
`
`

`

`DIESEL LOCOMOTIVE RELIABILITY
`
`IMPROVEMENT BY SYSTEM MONITORING
`
`set time or is idling or has just
`
`tifies
`
`been at full power for
`been turned off
`the results of the analysis require message to be
`If
`sent from the vehicle this is instigated by creating
`file
`the message This file
`forms the interface
`containing
`between the analysis program and the software control
`separate program iden
`ling the communications link
`has
`been created establishes
`that
`fault
`file
`communications via cellular telephone with the infor
`mation display system and passes over
`the information
`The complexity of on-board analysis varies with the
`system in question There are
`parameter or vehicle
`lead to the task being more
`number of
`factors
`that
`complex than is initially apparent such as the effects of
`varying duty the need to normalize for ambient condi
`to provide prognostic infor
`tions and the requirement
`mation
`too sim
`The use of out-of-limit alarms is in general
`plistic for many parameters and will not provide the
`needed
`level of decision
`the system is
`support
`to
`to know that
`is far more useful
`failure is
`time as this then allows the con
`particular
`likely at
`to make
`decision based upon
`the remaining
`troller
`duty requirement and the best point of repair In other
`words
`is not one of simple
`the primary requirement
`diagnostics but of prognos tics
`level of
`have
`Prognostic estimates will
`always
`uncertainty The approach that has been taken through
`time to failure estimates on 95
`out has been to base all
`per cent confidence limits The statistics are obviously
`to the information receiver who just sees an
`transparent
`upper and lower
`time to failure The information is
`given in absolute time so that
`is not affected by any
`communication delays it does not require the receiver
`to make mental calculations of likely failure time and it
`compares easily with operating schedules
`
`succeed It
`
`if
`
`it
`
`3.2.1 System development and testing
`The first stage in the development of data analysis pro
`grams was the collection of data to see how the.oper
`is easy to be
`ation of the vehicle affected
`the results It
`swamped in data by condition monitoring systems so
`to avoid this it was decided that data collection would
`be targeted specifically for each of the systems of inter
`est Using past experience of condition monitoring data
`data collection pro
`collection and analysis
`specific
`grams were written for each monitored system These
`stored at the appropriate time or engine condition and
`at an appropriate sampling and averaging rate only the
`measurements
`considered relevant
`This resulted in completely different data collection
`each monitored system all
`running
`programs for
`together at the same time The data collected was auto
`from the vehicle each night
`matically downloaded
`to
`microVAX computer network where it was archived
`The data collected were stored in files compatible
`with standard spreadsheet programs This meant
`that
`downloaded
`could
`be
`data
`into
`placed
`straight
`spreadsheet where they could be plotted and manipu
`functions and macros were
`lated with ease Spreadsheet
`used to experiment with analysis possibilities before
`suitable method
`they were finally programmed When
`of analysing the data was decided upon
`program was
`written for inclusion on the vehicle
`
`IMechE 1995
`
`was
`comprehensive software
`environment
`test
`created The physical
`from the sensors on the
`outputs
`vehicle were replaced by program that wrote data from
`The data
`file into either of the data buffers in Fig
`file format used to seed the buffer was the same as that
`used for data storage This gave an easily controlled
`and repeatable means of
`the
`testing the response of
`programs to either previously
`analysis
`collected real
`data or simulated fault data designed
`analysis under
`particular set of circumstances
`
`to test
`
`the
`
`3.2.2 Coolant monitoring
`
`tank is measured by
`The level of water in the header
`pivoted float arm During
`potentiometer attached to
`periods when the engine is off or idling the level stays
`is no leak However
`constant
`there
`provided
`fairly
`when the engine is running under power the level fluc
`tuates due to vehicle movement The level also changes
`the water with
`due to expansion and contraction of
`is mea
`temperature As the temperature of
`the water
`sured and the capacity of the system is known the level
`can be corrected for temperature Prognostic analysis
`the time at which the tank will be empty and
`predicts
`sends out
`message when this time is less than two
`hours away
`Refills need to be detected in order that predictions
`can be reset Data have shown that sudden increases in
`level can occur normally when the engine is running
`and the engine is not always stopped in order to refill
`the tank so the refill detection method used depends
`on
`the engine is running at the time
`whether
`
`3.2.3 Fuel monitoring
`
`locomotive
`
`occurrence
`
`so
`
`fuel
`
`is
`
`very
`
`rare
`
`running out of
`simply involves
`sending
`analysis
`the level in the tank drops below ten
`warning message if
`per cent
`calculated The
`Fuel efficiency information is also
`power output of the main generator is integrated to give
`and this is divided by the
`the total energy provided
`the fuel used over
`calomific value of
`reasonable time
`
`period
`Measurement errors occur while the vehicle is
`in
`or deceleration Addi
`motion due
`to acceleration
`tionally because of the arrangement of the fuel supply
`system track gradients or cant can cause the engine to
`draw fuel
`from only one tank while the vehicle is sta
`these effects
`are not significant
`tionary Fortunately
`when measuring engine efficiency over
`tank of fuel
`since the amount of fuel burnt is quite large in compari
`son with the errors
`One problem with efficiencies calculated in this way is
`from the vehicle
`the measured power
`output
`that
`by the main generator
`includes only that provided
`for auxiliary equipment
`Therefore power
`produced
`battery charging electric train heating etc is ignored
`
`3.2.4 Battery monitoring
`
`There are two problems that occur with the battery
`system
`
`flat batteries due to poor battery health
`
`Proc Instn Mech Engrs vol 209
`
`

`

`flat batteries due to excessive discharge over
`period
`
`Battery health Battery health and state of charge can
`be determined by measuring the voltage drop under
`load The load needs to be of reasonable magnitude and
`should last for some time For the Class 47 locomotive
`are met when the electrically
`the necessary conditions
`powered fuel oil and water
`triple pump runs with the
`engine turned off This situation occurs before engine
`short time
`start-up and also after shutdown for
`is anticipated that battery health will deteriorate
`It
`slowly so that occasions when insufficient
`running to
`fully charge the battery happen
`thus prohibiting the
`determination of condition should not severely affect
`the prediction of battery maintenance need
`The fact
`that battery health and state of charge cause
`the same effect on the voltage drop under load means
`the effect of battery deterioration on voltage drop
`that
`tests Tests have
`be determined from laboratory
`can
`to determine the voltage drop under an
`been conducted
`triple pump load for
`good battery at
`equivalent
`known states of charge
`voltage drop equivalent
`to
`value of health below 70 per cent generates
`message
`The
`Discharge monitoring and ability to start engine
`system predicts the time when the available energy will
`just meet
`the engine and
`the energy required to start
`then sends out warning one hour before The battery
`capacity available depends upon the amount of charg
`ing before engine shutdown the amount of discharge
`and the
`shutdown
`the discharge
`since
`the rate of
`battery state of health The amount of energy required
`upon the engine tem
`to start
`the engine
`depends
`perature and condition
`As mentioned the initial
`capacity of the battery can
`be determined when the engine is turned off by measur
`ing the voltage drop due to the triple pump load From
`the known initial
`is possible to calculate the
`charge it
`theoretical charge at any point in time by counting out
`the ampere-hours discharged By assuming that
`the
`remain unchanged
`rate will
`the
`discharge
`present
`at any time in the future can be pre
`
`fault
`
`battery capacity
`dicted
`The battery capacity required to start
`the engine at
`value
`temperatures is well defined as it
`different
`is
`used in the vehicle design for battery sizing These data
`loco
`design case where
`relate only to the severest
`motive is to be started Trom cold after an overnight
`the case where
`stand They do not cover
`vehicle has
`short time and is then required to start In
`stood for
`the engine will be
`this case the energy required to start
`much less and using the data above will be very conser
`vative resulting in unnecessary warning messages To
`allow for warm start cases the temperaturestart capac
`ity relationship has been extrapolated to higher tem
`temperature is used
`peratures and the engine oil
`
`3.2.5 Oil monitoring
`
`Experience has shown that idling is the best condition
`under which
`to analyse oil system data because
`this
`condition is the most critical with respect
`to possible
`engine shutdowns Oil pressure is affected by the oil
`temperature and engine speed complicating the detec
`
`FRY
`
`reduction in pressure
`
`Or
`
`black box
`
`related to
`
`tion of low-pressure faults since
`can be caused by
`reduction in engine
`speed or
`reduction in oil viscosity due to either fuel dilution
`an increase in oil
`temperature
`Neural networks can be envisaged as
`that can be trained to provide an output
`inputs Work
`conducted
`by British Rail
`certain
`Research has shown that neural networks can be sue
`cessfully used to normalize oil pressure data for oil
`ten
`perature and the engine speed The neural network is
`inlet and outlet pressures and two new
`used to predict
`are then produced the difference
`parameters
`between
`inlet and outlet pressure
`the measured and predicted
`Using these new parameters
`considerable increase
`diagnostic
`sensitivity to genuine low-pressure faults can
`be obtained These parameters are used
`to identify
`low oil
`pressure while the engine is still
`potential
`warming up and correct
`for the filter
`variation with temperature
`and easily
`neural network was quickly
`using data from the system in good condition The
`was
`network
`code
`then generated
`as computer
`and
`embedded within the on-board analysis program for the
`oil system
`
`in
`
`pressure drop
`
`trained
`
`3.2.6 Engine monitoring
`
`two tasks
`
`power
`
`is
`
`the
`
`The engine monitoring program carries out
`Firstly it monitors the engine to provide
`record of its
`duty Secondly it
`identifies the cause of engine
`loss due to isolation of the engine power controL
`Engine monitoring When the engine is running the gov
`measure of engine power
`ernor air pressure effectively
`demand is monitored and divided up into ten bands
`The total amount of time spent
`in each band is calcu
`lated and stored
`Control relay monitoring Power from the engine is con
`relay coil Only when 110
`trolled by the power control
`is supplied to this coil can power be provided by the
`main generator When the engine is started the coil
`After this when the engine
`directly supplied with 110
`number
`is running normally the 110
`is supplied via
`of other contacts These contacts are controlled by the
`correct operation of the power control relay the power
`the auto air gover
`earth fault relay the load regulator
`nor the equipment governor and the control governor
`When
`faults on these devices occur
`intermittent
`supply to the power relay coil
`is broken and the trac
`tion power
`is cut off If this happens while the engine is
`running under power power
`is cut off to the traction
`motors and cannot be reapplied for at least 30 seconds
`This type of occurrence
`is obviously very inconvenient
`for the driver
`When any of these devices has an intermittent
`to detect which
`one of
`is very difficult
`because once power has been
`react by opening their contacts
`as well By
`systems will
`the time the driver is able to examine the contacts it will
`not be possible to determine which contact opened first
`It may also be difficult
`for the maintenance staff to iden
`tify the causes of such faults
`The analysis program monitors the voltage at each of
`the contacts which control
`the supply to the power
`control relay to see which contact opens first When the
`the new condition is
`state of any of the contacts changes
`
`fault it
`
`them it
`
`lost all of
`
`the healthy
`
`Journal of Rail and Rapid Transit
`
`oiMecbEiiSS
`
`

`

`DIESEL LOCOMOTIVE RELIABILITY IMPROVEMENT BY SYSTEM MONITORING
`
`latched in hardware just after the change The computer
`then reads the status of the contacts and the analysis
`the change was due to
`program decides whether
`normal set of circumstances such as the driver shutting
`fault on one of the interlocking
`down the engine or
`
`systems
`
`3.2.7 System self-monitoring
`
`is important
`In order to provide reliable information it
`the monitoring system is able to identify faults with
`that
`itself and ensure that such faults do not
`result
`in mis-
`has
`shown
`the automatic
`that
`diagnosis Experience
`identification of monitoring system faults is vitally
`to be produced and
`false messages are not
`important
`in the majority of cases this can be handled fairly
`
`that
`
`if
`
`are
`
`easily
`set of self-monitoring procedures
`comprehensive
`set up that cover
`the detection
`of
`transducer/
`channel
`faults the detection of power supply faults the
`detection of clock faults and the detection of computer
`faults
`
`DATA COMMUNICATIONS
`
`continuous
`There is an advantage
`link
`to having
`fault messages from and
`available in order to receive
`interrogate both moving and stationary vehicles
`in
`
`this means radio is the only option for cost-
`practice
`effective communications
`the vehicle and the
`Data communications between
`maintenance controller are provided through the Voda
`fone mobile data service Communications are generally
`radio-based communications
`good though
`like any
`to certain limitations Contact
`system they are subject
`may not be possible if
`the land line to cellular conver
`is busy or
`sion service
`range which can happen if
`is located in
`tunnel or
`is surrounded by high buildings
`deep cutting also if
`remote area not covered by the cellular
`or situated in
`network
`For
`
`if
`
`the vehicle
`
`is not
`
`in radio
`
`it
`
`it
`
`better
`
`if
`
`communications
`these
`reasons
`areS generally
`lies in an
`the vehicle is stationary provided it
`area of good radio reception Communication with
`moving vehicles works with
`dependent
`reliability
`upon the geography of the surrounding area In practice
`this limits call duration the line being lost as the vehicle
`moves into areas of poor reception
`The required contact
`duration
`the
`upon
`depends
`amount of
`information to be transferred For system
`development large quantities of logged data were down
`loaded this being done at night when the vehicle was
`most likely to be stationary and the Vodafone network
`was not busy The contact duration for fault message
`transfer and vehicle interrogation is quite short
`less
`minute so loss of
`line does not affect per
`than
`formance too frequently
`
`111
`
`Actions
`
`DEMON Inform ation Di splay System
`view Qptlons
`
`Vkv Mcs
`
`IF
`
`Interrogate vehicle
`
`Messages from Vehicles
`
`..
`
`Vehicle Time Message
`mn rruirrcn nm çj Is
`
`Viewed
`
`at
`
`________
`
`Message
`
`tAY tx
`
`...
`
`$1n4
`
`047971
`
`47971
`
`09 Mar 1993
`10 Date
`_________________
`1128
`Piie
`_____
`The engine may shutdown due to low coolant
`tank has dropped below 5%
`The header
`The tank is currently 0.4% full
`
`Inc tioi
`
`Selection at previous responses
`
`Bristol depot informed of fault
`
`Refill arranged at Leeds on arrival
`
`Enter Response Below
`
`Crewe depot
`
`to retil4
`
`Close
`
`1I___9ff
`
`flis
`
`11.5
`
`ItklilI
`
`41
`
`IMechE 1995
`
`Proc Insto Mech Engrs Vol 209
`
`Fig
`
`Display system message screen
`
`

`

`FRY
`
`Table
`
`Possible messages from vehicle
`
`Trigger condition
`
`Message
`
`Generated when an empty header
`tank is
`hours away
`predicted to be less than
`
`Generated when the battery capacity will be
`less than that needed to start the engine
`within the next hour Based on the current
`battery drain and the battery charge
`the present engine temperature
`required at
`The charge needed to start the engine
`increases as the temperature drops
`Fuel level below 81 gallons no auxiliary
`tanks fitted
`
`Generated when the difference between the
`measured and neural network predicted oil
`pressure is less than
`
`p.s.i
`
`The engine may soon shut down due to
`low coolant
`is estimated that
`the
`It
`coolant tank will he empty between
`timemjn and time1
`The present battery capacity will be too
`low to start
`the engine in approximately
`hours It
`is recommended that the
`engine be started now to charge the
`battery up
`
`The engine may run out of fuel The
`fuel tank is less than 10% full There
`
`are
`
`gallons left
`
`The engine may shut down if
`the oil
`pressure at idle falls below 16 p.s.i The
`oil pressure may be too low when the
`engine is up to full
`temperature
`
`show that
`Communications
`performance
`statistics
`two thirds of messages are received by the information
`display system within three minutes of detection by the
`on-board system and over 80 per cent are received
`take very much
`within ten minutes
`small percentage
`to get through probably because the vehicle was
`longer
`stationary in an area of poor radio reception
`
`INFORMATION DISPLAY SYSTEM
`
`The business interface to the vehicle
`
`information is
`
`through an information display system which runs on
`PC connected
`network
`The
`to the public telephone
`information display system provides
`means of dis
`from monitored vehicles and inter-
`playing messages
`
`________
`
`Actions
`
`LE
`r-Velucl
`
`47815
`
`rw 47815Sn47015
`
`17015
`47815
`
`Actions
`
`ii
`
`DEMON Information Display System
`View Qptions
`
`ft
`
`%flew Mpc.snp.e
`Coolant Condition
`
`It
`
`._._ .. I_
`
`Level
`
`Full
`
`90% Empty
`
`talus Display
`
`Loss rate
`
`0.0 %/hr
`
`Last tilled
`
`1203 09 Mar 1993
`DUDDESTON
`
`Lse
`
`line System
`
`Battery System
`
`LU JIr ij
`
`system
`
`OIl System
`
`Part
`
`Journal of Rail and Rapid Transit
`
`Fig
`
`Display system interrogation screen
`
`tMcchElS
`
`cios
`
`

`

`DIESEL LOCOMOTIVE RELIABILITY
`
`IMPROVEMENT BY SYSTEM MONITORING
`
`their current condition The
`rogating them to check
`system is designed to be very easy to use and is based
`upon the popular Windows graphical
`interface
`Messages from vehicles The receipt of
`message pro
`