Paper Info
Title
Modelling a car safety controller in road tunnels using hybrid petri nets
Abstract
In the last years, major accidents have occurred in road tunnels with human losses (e.g. Mont Blanc, March '99, St. Gotthard, Oct '01 and Frejus, June '05). The accidents have caused a large debate on how to increase road tunnel safety. One way to reduce risk is to minimize the undesired disturbances of the traffic flow by forcing vehicles to respect speed limits and safety distances. This paper investigates this specific issue and proposes a hybrid modeling approach based on fluid Petri nets (FPN). An FPN is used to represent a controller that keeps track of two consecutive vehicles, controls their speed and distance and issues alarms when the prescribed limits are violated. In the second part of the paper, it is shown that FPN is a valid paradigm to model the dynamics of a car in a detailed way. the disturbances of the traffic flow, and to avoid congestion and the presence of obstacles or obstructions. To achieve this goal, measures should be taken to prevent traffic speed to increase over a critical level, and to assure the preserva - tion of safety distances between vehicles. The safety requirements for road tunnels should take benefits from the current trend in the automotive industry to increase the power of programmable electronic systems (9). This trend will lead to the emergence of safety related onboard electronic equipment that will provide a number of safety related functions and will improve the overall safet y of the vehicle. This paper concentrates on an important as- pect of the tunnel safety: the control of the speed limits and the safety distances. The control system under study is a typical case of hybrid system where a discrete state con- troller operates on continuous quantities like distance, s peed and acceleration. The paper shows that a particular case of hybrid Petri nets, called fluid stochastic Petri net (FSPN) (4, 8, 7) constitutes a suitable formalism for modelling and analyzing this kind of hybrid systems. The main character- istics of FSPN is that its primitives (places, transitions a nd arcs) are partitioned in two groups: discrete and continu- ous (or fluid). Hence, in a single formalism, both discrete and continuous variables can be accommodated and their mutual interaction represented. A brief description of the FSPN paradigm is presented in Section 2. In Section 3, we model a controller that keeps track of two consecutive vehicles whose behaviour is simplified for the sake of proving the feasibility of the approach. The con- troller checks the speed and distance of the two vehicles and issues alarms when the prescribed limits are violated. Sec- tion 4 provides some results based on this model. In Section 5, in order to improve the model trustworthiness, we show that FSPN is a valuable framework to model the dynamics of a vehicle in a highly detailed manner.
Year
DOI
Venue
2006
10.1109/ITSC.2006.1707425
Toronto, Ont.
Keywords
Field
DocType
Petri nets,automobiles,road accidents,road safety,road traffic,tunnels,car safety controller,fluid Petri nets,hybrid Petri nets,road tunnel safety,traffic flow
Automotive engineering,Control theory,Petri net,Traffic flow,Road traffic,Engineering
Conference
ISBN
Citations 
PageRank 
1-4244-0094-5
2
0.47
References 
Authors
4
3
Name
Order
Citations
PageRank
Andrea Bobbio132736.53
M. Gribaudo220915.51
András Horváth3223.32