Research Of Some Key Technology About Train Control System Based On Petri Nets

With the informatization of people’s daily life and industrial production, the quality ofsoftware development is paid more and more attention. Bring ambiguity, vagueness,incompleteness and abstract level of mixed problems, traditional software developmentmethod in the analysis and design process has more difficult to meet the needs of modernsoftware development, especially large-scale system safety requirements very high, any tinyerror may lead to life-threatening and severely economic consequences. Under thisbackground, formal software development method began to receive attention of softwaredevelopers. The benefits that formal software development method brings are self-evident, itcan in the design prototype stage of software engineering minimize error, shorten thedevelopment time, help software developers design more reliable system, and is convenient tocommunicate each other for developers. Formulation is a method that strictly based onmathematics, through the analysis and verification of the software development process ofvagueness and incompleteness, so as to approach the effective control over performanceindicators. Formulation is divided into two parts: formal specification instruction and formalverification. Petri nets is a kind of better formal description tool that currently meet the aboverequirements.The train control system linked the advanced control technology, communicationtechnology, computer technology and railway signal technology organically together, as animportant means to ensure the operation efficiency and safety, the number of the train controlsystem’s units is large, and physical system is complexity, scale large and the real-time andreliability requirements are very high, to make system run, need every subsystem coordinatework. As a formal description tool, Petri nets is based on strict mathematics, at the same timealso has a graphical concise, simple and intuitive, easy to understand and use. Although thecomplete formal of large software development will take time, the domestic and foreignrelated field staff have done a lot of work, some systemic software development platform hasbeen put into use, the combination of formal development and simulation technology in theapplication level, has become the future trend of software development technology. Therefore,using Petri nets build the model of the train control system, and then analyze and validate it,and evaluate and improve the train control system using the collected information. Developersand other persons get a powerful medium through Petri nets, the process of software isformalized.The main contents of this paper is to construct the train control system in train running indifferent stages using Petri nets theory, it contains two subsystems: station scheduling system and section running system, station scheduling system is divided into arrival stationscheduling and arrival and departure track scheduling, at the same time, some special casesduring train running, such as loss of signal and railway crossing are analyzed; some dynamicbehavior of model are analyzed and validated by S-invariant properties of Petri nets, to ensurethe safety and reliability of train control system plays a great role in.