Suboptimal decentralized controller design for chain structures: Applications to vehicle formations

We consider suboptimal decentralized controller design for subsystems with interconnected dynamics and cost functions. A systematic design methodology is presented over the class of linear quadratic regulators (LQR) for chain graphs. The methodology is evaluated on heavy duty vehicle platooning with physical constraints. A simulation and frequency analysis is performed. The results show that the decentralized controller gives good tracking performance and a robust system. We also show that the design methodology produces a string stable system for an arbitrary number of vehicles in the platoon, if the vehicle configurations and the LQR weighting parameters are identical for the considered subsystems.