Assessing the benefits of coordination in automatically controlled vehicles

We present a methodology for assessing the benefits of coordination on the safety of a platoon during emergency braking. When every following vehicle brakes at its maximum possible deceleration in response to hard braking by the lead vehicle in the platoon, it is referred to as uncoordinated braking. A braking strategy B is referred to be more beneficial than a strategy A, if strategy B leads to a larger reduction in the probability of a collision, the expected number of collisions, and the expected relative velocity at impact as compared to strategy A. The sequence of maximum deceleration of vehicles in the platoon is assumed to be a sequence of independent and identically distributed random variables; this distribution is assumed to be discrete and known. Due to coordination, the "effective" deceleration of a following vehicle may not necessarily be its maximum value. The problem of assessing the benefits of coordination can be initiated by dealing with determining the probability distribution of the "effective" deceleration of following vehicles during emergency braking. It is intuitive that the smaller the variance of this distribution, the greater the safety benefits are. We present a coordination strategy, which offers distinct safety benefits in the asymptotic cases.