Operational systems

KVB System

A major part of Clearsy’s activity is concentrated on the railway sector.

KVB, beacon speed control system


> CLIENT : Alstom
> DATE : June 2009/February 2010


KVB is a system being developped by Alstom since 1990, which ClearSy has contributed to. The KVB aims to record the speed of a train and communicate this to a system installed onboard, which interprets it and can act in the event of overspeed.

The KVB has been developed with the help of the formal B method, and works with the help of 2 devices:
> a “ground beacon” positioned on the track, which memorises the speed of a train
> an “onboard system”, (installed onboard the train), which receives the information communicated by the ground beacon.

These two elements contribute to controlling the speed of a train, and act on it according to the parametering of the onboard system… As such, in the event of overspeed, the system activates an emergency brake…

Our actions

Alstom has been using this system for their trains for over 20 years and called upon the services of ClearSy this year to assist in making developments to the KVB system.

> updates of the B Models
> proofing of the B models
> implementing of the tests on the host machine
> analysis of the code cover