Design of cooperative vehicle safety systems based on tight coupling of communication, computing and physical vehicle dynamics

Abstract

One of the main characteristics of a Cyber Physical System (CPS) is the tight coupling of the computing and communications aspects of the system with its physical dynamics. In this paper, we examine this characteristic for a cooperative vehicle safety (CVS) system, and identify how the design and operation of such CPSs should consider this tight coupling. In CVS systems, vehicles broadcast their physical state information over a shared wireless network to allow their neighbors to track them and predict possible collisions. The physical dynamics of vehicle movement and the required accuracy from tracking process dictate certain load on the network. The network performance is directly affected by the amount of offered load, and in turn directly affects the tracking process and its required load. The tight mutual dependence of physical dynamics of vehicle (physical component), estimation/tracking process and communication process (cyber components) require a new look at how such systems are designed and operated. We consider these factors and propose methods to simplify the design procedure for such tightly coupled systems. The method includes modeling the subcomponent of the CPS and devising interaction and control algorithms to operate them. The proposed methods are compared with methods based on separate design of components that deal with physical and cyber aspects. Through simulation experiments we show significant gains in performance when CPS design considerations are respected.