A well designed control strategy for platooning should perform better than human drivers without compromising safety. There are several potential performance gains when using automation for vehicle platoons, with increased throughputs being one of the most impactful ones. However, string instability -which hinders performance and safety- must be addressed when designing a control strategy. In this work, we study a unidirectional formation control scheme that achieves a tight formation in a linear time invariant 1D platoon. The scheme achieves constant inter-vehicle spacings (with no transient) for almost every vehicle pair whenever there are no disturbances. We build up from the basic leader following approach with a modification in the weight selection. In particular, each member tracks the movement of its immediate predecessor but also uses the leader state, which needs to be transmitted, in order to achieve a tight formation. The key design choice is the use of filters for the measurements that set the transfer functions from the leader trajectory to the inter-vehicle spacings to zero whenever possible. The main advantage of this strategy is that it can be used for heterogeneous strings in a straightforward manner. However, extra caution must be exercised in order to avoid string instability. We compare the proposed architecture to other strategies that achieve a similar behaviour.
11.10.2016