  As the development of autonomous vehicles rapidly advances, the use of
convoying/platooning becomes a more widely explored technology option for
saving fuel and increasing the efficiency of traffic. In cooperative adaptive
cruise control (CACC), the vehicles in a convoy follow each other under
adaptive cruise control (ACC) that is augmented by the sharing of preceding
vehicle acceleration through the vehicle to vehicle communication in a
feedforward control path. In general, the desired velocity optimization for
vehicles in the convoy is based on fuel economy optimization, rather than
driveability. This paper is a preliminary study on the impact of the desired
velocity profile on the driveability characteristics of a convoy of vehicles
and the controller gain impact on the driveability. A simple low-level
longitudinal model of the vehicle has been used along with a PD type cruise
controller and a generic spacing policy for ACC/CACC. The acceleration of the
previous vehicle is available to the next vehicle as input, and the simulations
are performed as Cooperative Adaptive Cruise Control of a convoy of vehicles.
Individual vehicle acceleration profiles have been analyzed for driveability
for two different velocity profiles that are followed in a stretch of 720 m
between stop signs. The controller gains have been re-tuned based on the
parameter space robust control PID approach for driveability and compared with
the original gains. The US06 SFTP drive cycle has also been used for the
comparison of the two different controller gain sets.
