EP-4741252-A1 - DESIGNING AND/OR CONTROLLING A RAILWAY SIGNALLING SYSTEM

EP4741252A1EP 4741252 A1EP4741252 A1EP 4741252A1EP-4741252-A1

Abstract

The invention relates to a computer-implemented method of designing and/or controlling a railway signalling system (2) comprising the steps: - providing at least one finite state machine (FSM), for which ∘ a plurality of states (ST) are defined that can be assumed by the finite state machine (FSM), ∘ a plurality of transitions (31 to 35) are defined, each transition being a transition from one of the defined states (ST) to either the same defined state or to a different one of the defined states (ST), ∘ a plurality of conditions are defined, the conditions depending on input information, wherein fulfilment of any one of the conditions triggers an assigned one of the defined transitions (31 to 35), ∘ a plurality of attributes are defined as output information, wherein each attribute may assume, at a time, one of a plurality of pre-defined values, wherein each of the plurality of defined states (ST) is assigned to at least one of the defined attributes having a specific one of the pre-defined values, wherein the plurality of states (ST) of the finite state machine (FSM) are signalling states that can be realised in railway signalling systems in relation to a single component or an arrangement of components of a railway track or railway track system (1), - evaluating a functional behaviour of each of the at least one finite state machine (FSM), based on different sets of input information that result in the fulfillment of different ones of the plurality of defined conditions, by checking that respective ones of the plurality of defined states (ST), that are assumed in reaction to the different sets of input information, in each case correspond to an expected state and/or that the output information represented by the values of the plurality of defined attributes, that are assumed in reaction to the different sets of input information, in each case correspond to expected values, - receiving a design of a railway track or railway track system (1) that comprises a railway signalling system (2) and generating a computer model of the railway signalling system (2) by using at least one instance of at least one evaluated finite state machine (FSM), which has been evaluated according to the preceding step, - simulating a behaviour of the railway signalling system (2) by using the computer model and outputting results of the simulation for realizing the railway signalling system (2) in practice and/or using the computer model to control an operation of the railway signalling system (2).

Inventors

Nocente, Arianna
Spigarolo, Lorenza
Guerra, Alessandro

Assignees

ALSTOM Holdings
University of Pisa

Dates

Publication Date: 20260513
Application Date: 20241107

Claims (5)

A computer-implemented method of designing and/or controlling a railway signalling system (2) comprising the steps: - providing at least one finite state machine (FSM), for which ∘ a plurality of states (ST) are defined that can be assumed by the finite state machine (FSM), ∘ a plurality of transitions (31 to 35) are defined, each transition being a transition from one of the defined states (ST) to either the same defined state or to a different one of the defined states (ST), ∘ a plurality of conditions are defined, the conditions depending on input information, wherein fulfilment of any one of the conditions triggers an assigned one of the defined transitions (31 to 35), ∘ a plurality of attributes are defined as output information, wherein each attribute may assume, at a time, one of a plurality of pre-defined values, wherein each of the plurality of defined states (ST) is assigned to at least one of the defined attributes having a specific one of the predefined values, wherein the plurality of states (ST) of the finite state machine (FSM) are signalling states that can be realised in railway signalling systems in relation to a single component or an arrangement of components of a railway track or railway track system (1), - evaluating a functional behaviour of each of the at least one finite state machine (FSM), based on different sets of input information that result in the fulfillment of different ones of the plurality of defined conditions, by checking that respective ones of the plurality of defined states (ST), that are assumed in reaction to the different sets of input information, in each case correspond to an expected state and/or that the output information represented by the values of the plurality of defined attributes, that are assumed in reaction to the different sets of input information, in each case correspond to expected values, - receiving a design of a railway track or railway track system (1) that comprises a railway signalling system (2) and generating a computer model of the railway signalling system (2) by using at least one instance of at least one evaluated finite state machine (FSM), which has been evaluated according to the preceding step, - simulating a behaviour of the railway signalling system (2) by using the computer model and outputting results of the simulation for realizing the railway signalling system (2) in practice and/or using the computer model to control an operation of the railway signalling system (2).
The method of claim 1, wherein the step of evaluating a functional behaviour of each of the at least one finite state machine (FSM) is performed for a defined sequence of the different sets of input information, wherein each of the different sets of input information is provided in an evaluation step of evaluation that includes identifying at least one of the plurality of defined conditions which corresponds to the set of input information that is input in this evaluation step and includes performing a corresponding one of the plurality of defined transitions (31 to 35), wherein each following step of the evaluation starts with the state of the finite state machine (FSM) at the end of its previous step and uses the set of input information that is next in the defined sequence.
A computer program or an arrangement of computer programs comprising instructions that cause a computer or arrangement of computers to perform the steps of any one of the preceding method claims when the computer program or the arrangement of computer programs is executed.
Computer-readable storage medium comprising instructions that cause a computer or arrangement of computers to perform the steps of any one of the preceding method claims when the computer program or the arrangement of computer programs is executed.
Computer or computer arrangement comprising the computer program or the arrangement of computer programs of claim 3 and/or comprising the computer-readable storage medium of claim 4.

Description

The invention relates to a computer-implemented method of designing and/or controlling a railway signalling system. Furthermore, the invention relates to a computer program or an arrangement of computer programs for executing the computer-implemented method. Also, the invention relates to a computer-readable storage medium comprising instructions that cause a computer or an arrangement of computers to execute the method. A computer or computer arrangement comprising the computer program or arrangement of computer programs and/or comprising the computer-readable storage medium is also related to the invention. Operating rail vehicles on railways requires control of the movement of the rail vehicles, which control is performed using railway signalling systems. If a new railway signalling system is to be implemented, or if an existing railway signalling system shall be updated or adapted to new requirements, it is common practice to design the railway signalling system first and then to realize it in practice. In particular with respect to a specific railway track system, designing the railway signalling system first allows for implementing and testing of the correct function. However, this requires substantial time and effort. It is an object of the present invention to provide a method of designing a railway signalling system, a computer program or an arrangement of computer programs for performing the method and/or a computer-readable storage medium comprising instructions that cause a computer or a computer arrangement to perform the method that reduces the effort of designing. It is proposed to use at least one finite state machine in order to represent signalling states of a railway signalling system and to evaluate a functional behaviour of the finite state machine(s) before an implementation of the finite state machine(s) is used to model a specific realization of a railway signalling system. A finite-state machine (FSM) is also known as finite-state automaton (FSA), or (in short) a state machine. It is a mathematical description of computation and/or modelling and the state machine can be in exactly one of a finite number of defined states at any given time. The FSM can change from one state to another in response to and therefore depending on input information. The change from one state to another is known as a transition. An FSM can be defined by a set of its states, its initial and/or default state and the input information that triggers each transition. Advantages of the proposal are that components of a computer model, namely implementations of the at least one finite state machine, of a specific railway signalling system can be tested in an early stage of its design and that the tested finite state machines can be used in multiple implementations of specific railway signalling systems. In particular, different implementations of the same tested finite state machine can be used in a computer model of the same railway signalling system and can be used in several computer models, each modelling a different one of railway signalling systems. According to the proposal, the states of the finite state machine are signalling states that can be realized in railway signalling systems. Preferably, there are different types of the finite state machines. Although some of the signalling states defined for the different types might be the same signalling states, the complete set of defined states differs for the various types. For example, one type of finite state machine may be related to control of entry of railway vehicles into a railway station (or alternatively to control of railway vehicles leaving a railway station),control of track section occupation,transition of different levels of control of vehicle departure,control of a shunting area for shunting rail vehicles,control, evaluation and/or management of track-side mounted sensors for monitoring traffic or monitoring states of rail vehicles, such as states of axles, wheels and brakes, wherein certain sensor signals result in changes of traffic control, such as reduced vehicle speed in track sections,control of entry/occupation of a track section with a crossing (e.g. a road crossing the track section). For all these controls and other subjects with respect to in each case one part of a railway track system, the complete sets of defined states differ. In more general terms, types of finite state machines may be defined for in each case one set of signalling states in relation to control of rail traffic in a corresponding part of a railway or of a railway track system. Examples of signalling states are "locked" (i.e. entry/passage is not allowed), "unlocked" (i.e. entry/passage is allowed), "unlocked on sight" (i.e. entry/passage is allowed, but the driver of the rail vehicle must take into account that the entered track section may be occupied by another vehicle), "emergency locking" (i.e. travelling/entry is not allowed based on emergency and/or safet