Dalay Almeida

ClearSy System Engineering

In previous work, we have presented a methodology for the specification and verification of relay-based Railway Interlocking Systems (RIS) based on their transient states. By using CSP as formal support, it is possible to use a model checker in order to analyse the safety of such critical systems as a way to improve their safety. However, this type...

In France, the railway lines are divided into the national and international lines. While the former has a proper implementation of the railway signalling systems as relay-based or computer-based systems, the latter follows the guidelines defined by the ERTMS standards, focusing on the interoperability throughout Europe. In a previous work we prese...

The system of a train line crossing a border must consider the operating rules of each country. Furthermore, a safe transient mode must be implemented, allowing the system to switch from a set of rules to another. This chapter presents how safety operating rules may be designed by a model-based approach. UML and B-method are used in order to allow...

Relay-based Railway Interlocking Systems (RIS) are critical systems and must be specified and safety proved in order to guarantee the absence of hazards during their execution. However, this is a challenging task, since Relay-based RIS are generally only structurally modelled in a way that their behavioural analysis are made manually based on the e...

Relay-based Railway Interlocking Systems (RIS) are developed with the objective of controlling the movement of trains in a safe manner. However, these systems are generally specified by informal languages whose analyses are made by human inspection, which are error prone. A previous work presented an approach for specifying these systems in a forma...

A railway interlocking system is one example of a critical system, and, therefore, it must have a high level of reliability in order to avoid problems that may result on the loss of people's lives. However, many railway systems are still specified using historical relay-based diagrams, whose analysis are made by human inspection, which is error pro...

A railway interlocking system is one example of a critical system, and therefore it must have a high level of reliability in order to avoid problems that may result on the loss of people’s lives. However, many railway systems are still specified using historical relay-based diagrams, whose analysis are made by human inspection, which is error prone...

In previous work we have presented a CSP based approach for developing component-based asynchronous systems, \(\mathcal {B}\mathcal {R}\mathcal {I}\mathcal {C}\), which guarantees deadlock freedom by construction. It uses CSP to specify the constraints and interactions between the components to allow a formal verification of the composition’s behav...

Using the component-based development approach, the system complexity is reduced and its maintenance is facilitated, bringing more reliability and reuse of components. However, the composition of components (and their interactions) is still a significant source of problems and requires a more detailed analysis. This problem is even more relevant wh...