Vehicular networks supporting cooperative driving are among the most interesting and challenging ad-hoc networks. Platooning, or the act of coordinating a set of vehicles through an ad-hoc network, promises to improve traffic safety, and at the same time reduce congestion and pollution. The design of the control system for this application is challenging, especially because the coordination and cooperation between vehicles is obtained through a wireless network. So far, control and network issues of platooning have been investigated separately, but this is definitely a sub-optimal approach, as constraints of the networked control system impose bounds on the network performance, and network impairments translate into disturbances on the controlled system. In this work we design a cooperative driving system from a joint network and control perspective, determining upper bounds on the error subject to packet losses in the network, so that the actual inter-vehicle gap can be tuned depending on vehicle or network performance. Extensive simulations show that the system is very robust to packet losses and that the derived bounds are never violated. In addition, since the leader control law is part of the proposed control approach, we show that, besides taking into account external events and reacting within the given constraints to ensure the overall road safety, the system can be easily integrated into global traffic optimization tools that mandate the platoon behavior.
- Networked-control design