Remote Access to Vehicles and Condition Monitoring. Synopsis. Overview. Open standards PAPER

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1 PAPER g Remote Access to Vehicles and Condition Monitoring Synopsis In order to lower maintenance cost of rolling stock whilst raising the availability of the vehicles continuous knowledge about the state of the vehicles within a fleet is required. Within the research project da Vinci led by its Business Unit (BU) Service, Bombardier Transportation is developing the procedures and technical means for remote diagnosis, visualisation, vehicle dispatching and other wireless-based applications. This opens up a wide range of enhancements to maintenance services e.g. improved asset management through better product knowledge, better optimisation of maintenance and materials scheduling through enhanced knowledge of system condition, increased integration of business systems, time-efficient handling of preventive maintenance and repair, for team-based trouble shooting, and for an increased availability of the vehicles by reduction of down-times caused by planned (but unnecessary) and unplanned maintenance. The foundation for this work is the use of open standards for hardware, software and communication. Overview The core idea is to install Mobile Stations within railroad vehicles which serve as wireless access points for running a variety of wireless data services. They provide application-specific gateway functionality between one or more wireless networks and the on-board systems. Communication with Mobile Stations will be done via a Ground Station, the Ground Station acting as a secure single logical entry point for communications to and from land based networks to the Mobile stations and wireless data services. Users would interact with the wireless data services via Client Stations, PC with a standard web browser software. Open standards One of the founding principles of the da Vinci project is that it uses so called open standards for it s software framework and communication protocols. That is communication protocols and software frameworks whose implementation and design

2 are in the public domain. This is to promote the system as a standard and encourage the development of wireless services by third parties. Open standards used are: TCP/IP Open Service Gateway Initiative (OSGi) Hypertext Transfer Protocol (HTTP) Sun Microsystems JAVA Asset management Component serialisation Closer integration of existing maintenance management systems leading to more automation and better control of the maintenance process. For example the ability to associate on-board data (vehicle mileage, component condition, subsystem operation) with component serialisation and tracking through the maintenance refurbishment process. Parts ordering and spares logistics A lot of maintenance capital is tied up in spares holdings. Wireless services coupled with Bombardier Transportation spares and logistics e-commerce business address this problem by automating the ordering process. Refurbishment management and planning During the whole life of a normal rail vehicle it is expected that a series of modernisation and refurbishment programs will take place. This process can be enhanced by a greater understanding of asset condition and utilisation. Life cycle costs management Life cycle costs of railway vehicle assets is becoming increasingly important in an highly competitive market. For the first time it is possible to understand in great detail the usage of a rail vehicle over the duration of it s life. Optimisation of maintenance practises Maintenance planning/scheduling Within it s maintenance context the core benefit of the da Vinci project is seen as the ability to closely correlate vehicle system and subsystem condition data with accurate data on operational duration and circumstances, e.g. network quality and 2

3 line details. This information has always been available to the business but has traditionally been too costly to collect in sufficient detail to maximise business benefits. Wireless communication coupled with intelligent data collection and management means that this process can now be automated giving a real business benefit. The provision of condition data in a timely, concise and unambiguous manner leads to an increase in predictable and planned maintenance practices. Improved and guaranteed consistency of fault finding reduces the turn-round time following fault conditions. Reduced intervention during rectification repair procedures Condition monitoring leads to better diagnosis of the exact nature of fault conditions. This information means that a more targeted approach can be adopted to the fault rectification process reducing the amount of disturbance to other systems. Better utilisation of spares, tools facilities and manpower Timely information on vehicle condition on large fleets will lead to better utilisation of spares logistics and holdings with obvious benefits to the maintenance organisation. Reduction in non planned maintenance Non planned maintenance can be a significant burden to maintenance organisations as it is difficult to budget for. On the other hand the impact of events raising the necessity for unplanned maintenance on operational quality (delays) and network capacity (occupancy of lines by vehicles which are broken down) is of highest priority for operators. Reduction in no fault found defects A reduction in the number of no fault found conditions and random unforeseen failures leads to better planning and less manual intervention in on-board system while investigating problems. Environmental monitoring A more holistic view can be taken of the way in which a rail vehicle interacts with it s environment. For example this might be information from the Bogie Condition Monitoring project. System lay-out The overall lay-out of the network and its functional distribution between Ground Station, Mobile Stations and Client Stations is presented in fig.1. 3

4 Figure 1 Overview of Remote Diagnosis and Access Mobile station The Mobile Stations are to be installed within the railroad vehicles of the fleet under consideration. They serve as wireless access points for running a variety of wireless data services like transmission of operational (speed, distance run, load) and condition data (subsystem performance, status information, monitored component condition). They provide applicationspecific gateway functionality between one or more wireless networks and the on-board systems. The on-board systems comprise of standard equipment like drive/brake control unit, Passenger Information Systems, Heating & Ventilation Systems also a number of new services like load monitoring, operation control of electric equipment like doors, and bogie condition monitoring. Ground station This central installation runs data-based applications for the overall logging and control of the fleet s operation, e.g. variant / equipment management of the single vehicles, time / distance run since the last repair / exchange of equipment, load / capacity utilisation, condition history of components and subsystems, The ground station is in continuous wireless contact with the mobile stations of the running vehicles of the fleet for fetching current information to update its multipurpose database. On the other hand the ground station can be accessed by client stations to supply them with a required subset or condensation of the database s contents. 4

5 Client station These are PCs installed at distributed locations running a standard web browser software and task-specific applications like maintenance scheduling and spare parts management, condition logging of the parts on board of the specific vehicles, load and vehicle dispatch, fleet capacity management, The client stations communicate with the ground station via Internet-based dial-in services. Condition monitoring projects Bombardier Transportation has a number of trial projects exploring wireless communications in the maintenance context. The objective of these projects is to better understand the integration of condition data into the maintenance organisation on a practical day to day basis. Trials on railway vehicles in passenger service Two trial projects started at the end of 2000 on different Bombardier Transportation maintenance sites in the South East of England. Two high speed passenger trains, one DMU and EMU, were equipment with advanced condition monitoring equipment giving maintenance staff the following wireless services: Door condition monitoring Numbers of door operation cycles per door station, door opening and closing times statistics and safety related door health checking. Wheel adhesion system monitoring Poor wheel rail adhesion is recorded on a per axle basis. Compressor Oil Level Monitors the oil lubricant level in the air compressor system. GPS location The trains locations can be traced and are automatically logged during passenger service. Battery condition monitoring Monitors the number of deep discharge cycles, cell temperatures and charge discharge characteristics. 5

6 Propulsion system monitoring System monitors the state of the three phase AC propulsion system and drive control circuits. Figure 2 Overview of monitoring systems on EMU trial Bogie Condition Monitoring The project Bogie Condition Monitoring or shortly BCM is an advanced technology approach to develop on-board equipment for gaining information about the white area of mechanical components of rolling stock in real-time. Present Situation Bogies are utmost safety-related subsystems of rolling stock for vehicles. Hence keeping them in good state is an issue of paramount importance for railway operation. On the other hand due to the specifics of the high loads which they have to carry on tiny contact areas between wheel and rail bogies are exposed to severe excitations by the wheel-rail dynamics causing wear and being the source for vibrations transmitted up to the passenger. Hence the ability to keep a high comfort level for the passengers of a railway vehicle heavily depends on comprehensive maintenance of the various bogie components. Since the major structural components are designed for durability, and the progress of wear or deterioration of other components suffering a decrease in performance is well known, the standard procedure is to define fixed intervals (in terms of distance run and/or elapsed period of time) for inspection and/or prescribed exchange of components. This not only causes much labour cost for most often unnecessary activities in this preventive maintenance regime but also reduces the availability of the vehicles due to the down-times in depots. On the other hand it cannot 6

7 completely be excluded that the condition of some components in most cases not safety critical but having considerable effect on ride comfort or running performance falls below a tolerable level between two scheduled inspections leading to impacts on the operational schedule reducing as well the vehicle s availability as the capacity of the line section concerned. Goal and Basic Idea In order to keep the required condition of the bogies while on the one-hand side lowering cost to the amount for actions which are really necessary and on the other-hand side being capable of detecting unexpected deterioration vehicle-based condition monitoring is a useful measure. It allows for determining the remaining time or running distance some component still can be kept in use before it has to be repaired or exchanged forming the basis for an effective availability-centred scheduling and management of corrective maintenance activities. Since the main goal of introducing such a functionality is to raise the availability of the vehicles the condition monitoring system itself must not introduce a counter-productive effect by additional failure probabilities of its own components. On the other hand the inferior operation of some bogie components affects e.g. the vibrational behaviour at locations which are rather distant from the malfunctioning element. Finally the deterioration of some components may not simply lead to the transgression of some predefined characteristic threshold value but its detection may anyhow require sophisticated analysis of some physical phenomenon. Hence our approach is not a one symptom one sensor approach which would lead to a multitude of sensors and wired connections. Instead we are working on a model-based system which by analysing continuously fetched signals measured by a few sensors which are mounted at carefully selected positions in the bogie predicts the behaviour of the bogie for the immediate future and compares it with the real movements, accelerations a.s.o. By intelligent combination and correlation of the incoming measurement values and their stored time history this detailed model allows for the identification of the respective component causing some divergence from the normal state. In bogies which will be equipped with active components e.g. to increase ride comfort or to reduce the impact on the infrastructure some aspects of this CM model will form an integral part of the controllers for the different actuators, which naturally have to feature some self-diagnosis functionality too. Additional Benefit: Infrastructure Monitoring A large amount of variability in the running dynamics of bogies is introduced by changing conditions of the track, the presence of points or rail joints a.s.o. In order to discriminate those external effects from those concerning the condition of the bogie elements themselves a correlation of the findings made by the condition monitoring systems of the different bogies has 7

8 to take place. This leads to an additional benefit provided by such vehicle-based equipment: The monitoring of the track condition! In an environment like the presented wireless remote access network developed within da Vinci, which will comprise means like GPS for determining the vehicle s position in the network, the records of each single train allow to locate defects or peculiar phenomena of the tracks without the need for specific measuring runs. Even if the single records are only of limited accuracy, the correlation between the data sets supplied by the whole fleet will yield an appropriate level of precision. Summing-up model-based condition monitoring of the bogies of running rail vehicles by onboard equipment forms a valuable module of a remote access network for fleets of rolling stock. It permanently presents an overview about the state of the different vehicles, and delivers predictive data concerning the remaining operational time or distance till some maintenance activity is required, thus supplying information required for operation scheduling and availability-centred maintenance planning and scheduling of the fleet. Additionally information about the state of the infrastructure is generated en-route and can be delivered to the operator of the track network. Figure 3 Pictorial Overview of the BCM project 8

9 Conclusion The introduction of a wireless network linking the vehicles of a railway fleet with the ground station will bring a completely new quality into life: On-line information about operational conditions and equipment status. Remote client stations will have available condition data in a timely, concise and unambiguous manner whenever needed. Thus maintenance on demand will be possible instead of pre-scheduled activities (with no regard on the actual necessity), and the correlation of (the history of) load conditions with the actual status allows for prognosis and early adaptive planning of service and dispatch actions. Availability-centred maintenance and vehicle operation planning will be possible instead of a rather static when scheduled, and the overall understanding of the behaviour of the vehicles during operation with respect to the specific conditions they are exposed to will dramatically increase. Registered trademarks of Bombardier Inc. 9