Multiobjective H∞ Control for String Stability of Cooperative Adaptive Cruise Control Systems

Autonomous vehicle following systems are playing a decisive role to increase vehicle density on roads by shortening intervehicle time gaps. However, disturbance attenuation along a platoon of vehicles, i.e., string stability, is being a challenging task while time gap is getting shorter. In order to guarantee the string stability of a vehicle platoon, a multiobjective H ∞ control formulation for adaptive cruise control and cooperative adaptive cruise control structures has been investigated in this paper. The proposed control method solves an optimization problem and achieves a controller that is able to provide not only the system stability, but also the string stability as distinct from the traditional H ∞ control.