  This paper proposes an event-triggered add-on safety mechanism to adjust the
control parameters for timely braking in a networked vehicular system while
maintaining maneuverability. Passenger vehicle maneuverability is significantly
affected by the combined-slip friction effect, in which larger longitudinal
tire slips result in considerable drop in lateral tire forces. This is of
higher importance when unexpected dangerous situations occur on the road and
immediate actions, such as braking, need to be taken to avoid collision. Harsh
braking can lead to high-slip and loss of maneuverability, hence, timely
braking is essential to reduce high-slip scenarios. In addition to the vehicles
own active safety systems, the proposed event-triggered add-on safety is
activated upon being informed about dangers by the road-side infrastructure.
The aim is to incorporate the add-on safety feature to adjust the automatic
control parameters for smooth and timely braking such that a collision is
avoided while vehicle's maneuverability is maintained. We study two different
wireless technologies for communication between the infrastructure and the
vehicles, the Long-Term Evolution (LTE) and the fifth generation (5G) schemes.
The framework is validated through high-fidelity software simulations and the
advantages of including the add-on feature to augment the safety margins for
each communication technology is evaluated.
