Decentralized overlapping control of a platoon of vehicles

A methodology is proposed for longitudinal control design of platoons of automotive vehicles within intelligent vehicle/highway systems (IVHSs). The proposed decentralized overlapping control law is obtained by using the inclusion principle, i.e., by decomposing the original system model by an appropriate input/state expansion, and by applying the linear quadratic (LQ) optimization to the locally extracted subsystems. The local quadratic criteria directly reflect the desired system performance. Optimization is carried out by using a sequential algorithm adapted to the lower block triangular (LBT) structure of the closed-loop system model. Contraction to the original space provides a decentralized platoon controller which preserves the asymptotic stability and the steady-state behavior of the controller obtained in the expanded space. Conditions for eliminating the "slinky effect" and obtaining the strict string stability are defined; it is shown that the corresponding constraints on the controller parameters are not too restrictive. A new dynamic platoon controller structure, consisting of a reduced order observer and a static feedback map, is obtained by applying the inclusion principle to the decentralized overlapping platoon control design in the case when the information from the preceding vehicle is missing. Numerous simulation results show that the proposed methodology provides a reliable tool for a systematic and efficient design of platoon controllers within IVHS.