Bidirectionality in Disturbance Decoupled Longitudinal Vehicles Platoon

Disturbance decoupling, a control framework aiming to make a controlled output independent from external disturbances, has shown to be effective in cooperative platooning. The reason is that this control framework can make the inter-vehicle spacing error independent from an exogenous acceleration disturbance, while also guaranteeing desirable properties like string stability. However, the study of disturbance decoupling has traditionally relied on unidirectional (look-ahead) information exchange, where each vehicle only interacts with its predecessor, and the exogenous acceleration disturbance only comes from the predecessor. In this work, we investigate the potential of integrating disturbance decoupling in bidirectional (look-ahead-and-behind) interaction. We show that disturbance decoupling and string stability can be achieved even when each vehicle interacts with its predecessor and its follower. Simulation results, performed in both string and ring paths, demonstrate that bidirectionality significantly improves smoothness of the platoon as compared to the conventional unidirectional approach.