Robust Control of Cooperative Adaptive Cruise Control in the Absence of Information About Preceding Vehicle Acceleration

Cooperative adaptive cruise control (CACC) has a potential to improve traffic throughput, fuel efficiency and vehicle safety. The CACC utilizes onboard sensors and a wireless communication to achieve vehicle stability and string stability of a platoon. The performance of CACC is degraded due to unreliable wireless communication and uncertain dynamics of the vehicle. In this paper, a disturbance observer based sliding mode control is proposed for the control of cooperative adaptive cruise control system. This scheme estimates the uncertainty present in the actuator dynamics and the acceleration of preceding vehicle as a lumped disturbance. The proposed strategy addresses practical issues such as unavailability of preceding vehicle acceleration and range of uncertainty in the vehicle dynamics. The stability of individual vehicles and the string stability of a platoon are derived. The performance of the proposed scheme is verified by considering various traffic scenarios, and it is compared with an existing method.