Design Of A Flagging Protocol For A Cooperative Adaptive Cruise Control Lane Change

Cooperative adaptive cruise control (CACC) has come to be a favorite among researchers inthe field of automobile automation. A relatively new concept only dating back a few decades, thisnew field of research has become very popular not only as a result of automobile manufacturersneed for innovation but more importantly the strong need to automate cars and highways due to anincrease in vehicular transportation across the globe and the increase in traffic congestion andaccidents that comes with it. CACC an offshoot of traditional cruise control is the form of vehicularcontrol in which the vehicles involved exchange information about their locations and travelvelocities via radio signals rather than a separate estimation done by each vehicle (Adaptive CruiseControl). This hence makes control less complex.This research presents a robust mode of control: sliding mode control to deal with theuncertain nature of traffic situations, choosing a trapezoidal acceleration profile trajectory forlateral motion while considering riding comfort of the driver by carefully choosing lateral jerk andacceleration. Various scenarios are presented at the time of lane change and for each scenario asafety inequality needs to be satisfied before lane change is commenced.A flagging system is also discussed further smoothening maneuvering between lanes andenhancing safety of the maneuver and traffic in general. Unlike traditional flagging systems, weconsider a continuous scanning system in which the vehicles involved continue scanning andtransmitting their surrounding situations and based on that raise a red flag or green flag signaling“Safe to maneuver” and “Unsafe to maneuver” to vehicles which intend to maneuver into theirtravelling lanes.Using Matlab, we further discuss the advantages of our method in terms of saving time andadding safety in the process of lane change and also the possibilities that present themselves as aresult of this method such as a leader follower reversal as a result of an all green flag scenario fromthe surrounding vehicles.