17 research outputs found
String Stability towards Leader thanks to Asymmetric Bidirectional Controller
This paper deals with the problem of string stability of interconnected
systems with double-integrator open loop dynamics (e.g.~acceleration-controlled
vehicles). We analyze an asymmetric bidirectional linear controller, where each
vehicle is coupled solely to its immediate predecessor and to its immediate
follower with different gains in these two directions. We show that in this
setting, unlike with unidirectional or symmetric bidirectional controllers,
string stability can be recovered when disturbances act only on a small
(-independent) set of leading vehicles. This improves existing results from
the literature with this assumption. We also indicate that string stability
with respect to arbitrarily distributed disturbances cannot be achieved with
this controller.Comment: Version 2 corrects a typo in the proof, and adds the proof of
stability before string stability. Slightly longer than published versio
Transients of platoons with asymmetric and different Laplacians
We consider an asymmetric control of platoons of identical vehicles with
nearest-neighbor interaction. Recent results show that if the vehicle uses
different asymmetries for position and velocity errors, the platoon has a short
transient and low overshoots. In this paper we investigate the properties of
vehicles with friction. To achieve consensus, an integral part is added to the
controller, making the vehicle a third-order system. We show that the
parameters can be chosen so that the platoon behaves as a wave equation with
different wave velocities. Simulations suggest that our system has a better
performance than other nearest-neighbor scenarios. Moreover, an
optimization-based procedure is used to find the controller properties