Introducing the ATO on suburban line Paris

Transcription

1 Introducing the ATO on suburban line Paris SNCF Engineering All rights reserved Tous droits réservés - SNCF 28/10/2014

2 Overview Context ATO : answer and benefits Introducing CBTC, ATO Handle the system complexity Global system approach Lessons learnt SNCF DOCUMENT CONFIDENTIEL 28/10/2014 page 2

3 Mass transportation in dense railway network Facts Large cities as Paris, London are facing a significant increase of the transport capacity demand. Suburban lines are crossing the city. In the core area, the passenger flow is tremendous. Challenge Without extending the existing infrastructure, our challenge is to offer to passengers a significant improvement of the service quality by : Increasing the transport capacity offer, Increasing the service regularity, Increasing the overall availability. Challenges to improve the service quality in dense area of the existing railway network 28/10/2014 page 3

4 Mass transportation in dense railway network Passenger s expectations Constraints Journey Time Regularity Safety Existing system Transport capacity Rules & regulati ons Challenges : How to provide the best answer? How to answer? 28/10/2014 page 4

5 Shortening headway Increasing the number of train per direction reduces the headway Headway The headway theory Speed 1 Block 2 Blocks 3 Blocks Moving blocks To sustain 30 tpd or over while keeping a high commercial speed Train speed profile has to be very close to the safety speed profile Driver has less time to react Any variation of driver s behaviour as an impact on the headway, the throughput Block signalling system with manual driving mode provides no operational margin That situation makes the system instable Resulting of a wide variability of train speed profile, Having potentially human factor risks by increasing the driver s stress. ATO, allows to run train at the maximum speed permitted by the safety speed profile 28/10/2014 page 5

6 ATO, which benefits? Thanks to ATO, the system becomes deterministic Train behaviours are the same Train speed profile can follow the emergency brake intervention curve within a margin of 1 m/s The throughput is optimised and based on technical parameters. Driver s behaviour is not anymore part of the overall performance. Perturbation point ATO s regular running curve ATO s target point (non safety) Safety kinematic envelope ATP s control curve ATP s target point (safety) Introducing the ATO allows to benefit of additional features Automatic train regulation : makes the system more reactive to disturbance Energy saving : controlling train speed profile, using coasting mode makes the system globally more efficient Main issues ATP system with performances in accordance with the ATO objectives is mandatory Signalling system and rolling stock share interfaces MMI and new human factor risks have to be addressed Introducing the ATO requests to be under the control of an ATP system 28/10/2014 page 6

7 Introducing CBTC, ATO on suburban line Rolling stock Interlocking Railway system CBTC ATO Operation and Maintenance Trackside CBTC and ATO technologies but in an open railway environment? Handle the complexity without forgetting the final users expectations 28/10/2014 page 7

8 CBTC, ATO in a railway system Rolling out CBTC, ATO technologies in a railway system is not just upgrading the signalling sub-system. The Railway System is an entire complex system consisting of Trackside Technical Systems Train sets Technical interfaces between sub-systems, components Environment in which the system is operated Operation rules Maintenance policies Human resources The overall performances of the railway system is achieved by a system wide vision approach. Introducing CBTC, ATO technologies in a railway system requires to visit all its components and to govern signalling revamping project through an holistic approach 28/10/2014 page 8

9 Handle complexity : Facts Functional and safety requirements are not anymore confined in a single piece of equipment or subsystem. They are spread off between rolling stock, trackside systems, Context: A tight management of the interfaces is required, The functional allocation makes the interfaces more fuzzy, Digital systems and distributed architecture require to manage time effects, Operation and maintenance constraints have to be addressed, Diversity between rolling stock and trackside principles, Diversity of signalling systems, Diversity of geographic configurations, Diversity of suppliers, Difficulties to communicate between suppliers and railway experts. Text-based specification not efficient enough for handling such a complexity. 28/10/2014 page 9

10 Handle complexity System performances Global safety The signalling system has to be considered in the overall system with all its intricacies The overall performances of the railway system is achieved by determining the right allocation of performance of each subsystem: Rolling stock, Signalling, Headway, Dwell time in station, Global safety : Safe braking model, track conditions, A global system vision approach has to be developed. System performances are achieved through a global system vision 28/10/2014 page 10

11 Holistic approach from the definition phase up to the construction phase Main goals have to be addressed Requirements Performance allocations Definition phase What we are expecting System performances Construction phase What we get During the earliest stage of the project Define performance requirements of main system parameters Coordinate expert with skills in a wide range of disciplines Get a clear cut picture of what requires modification Define functional and technical requirements During the project execution Check continuously the system consistency. Check the cutover program and its performance Detect at the soonest non compliance Holistic approach for reducing project risks 28/10/2014 page 11

12 Holistic approach and system requirements Refine Specify Check & proof Our approach is to develop a model-based system design methodology starting from the earliest stage of the project Determine performance allocation Build up models of existing signalling system Build up kinematic model for rolling stock Build up models of functional requirements Follow a continuous refinement and improvement of models Use of models to validate interface specifications Use of models to proof safety requirements Connect all models Connect model based design and Hardware in the Loop Setup a versatile system integration platform Key to success : Model-based system approach as a collaborative tool with suppliers and partners 28/10/2014 page 12

13 Holistic approach and system requirements Three examples of model based system approach System performance allocation Signalling model System integration platform Key-success : Model-based system approach as a collaborative tool with suppliers 28/10/2014 page 13

14 Performance allocation Performance allocation thanks to simulation tool allows assessment of : Sensitivity of the various parameters Safe braking model parameters Braking capability Propulsion capability Degraded modes Response times of the different systems Traffic regulation margins Energy consumption optimisation Modes of operation Final choice to be governed by the best balance between CAPEX OPEX Performance achievement Performance allocation is a key project driver 28/10/2014 page 14

15 Signalling Interface management PRCI Interlocking is a relay based technology Using such interlocking in the CBTC environment requires some adaptation. The main goal is to switch from a functional specification to a dynamic model in order to Make available an interlocking with a real behaviour Define and check the modification at the interlocking level Introduce the model in CBTC and system integration platform Define and check all migration phases of the interlocking Assess performances of each migration phase Model of Interlocking provides system assurance 28/10/2014 page 15

16 System integration platform Tender specifications Models during system design HIL system integration Environment models Refinement Reuse of environment models The integration of the system follows the system development cycle 28/10/2014 page 16

17 Global system vision through modelling Our first lessons Model-based approach launched in the early phase of the project provides means : To define more accurately the system and its interfaces To define rolling stock parameters To clarify the behaviour of the system To locate and to correct non conformance along the design and construction phases and not at the end of the project To communicate and to share with external partners and to create more efficient supplier relationships. To get a better vision at project management level Model-based system approach as a collaborative tool with partners and suppliers 28/10/2014 page 17

18 Global system vision through modelling Our first lessons Model-based approach increases the efficiency of the project by : Reducing on site and dynamic testing costs : dynamic testing is focused on the verification of real time constraints, Giving a clear guide of the project s testing plan, Providing a clear vision of the status of the project : the validation of functional requirements in advance of the design phase clears specification s uncertainties, Reducing project s risks and providing a better assurance in project s risk assessment Securing the overall project schedule: clearance of technical risks in the early stages of the project procures margins for optimizing the overall schedule. Model-based system approach increases the efficiency of the project 28/10/2014 page 18

19 Thanks for your attention SNCF DOCUMENT CONFIDENTIEL 28/10/2014 page 19