Control of heterogeneous traffic flows in presence of pocket loss, time-varying communication delay and actuator lag

This paper deals with the control design and internal and string stability analysis of heterogeneous traffic flows with bi-directional communication topology under random data loss, time-varying communication delay, and actuator lag. A third-order linear model is employed to describe the longitudinal dynamics of each vehicle and the constant spacing policy is employed to adjust the inter-vehicle spacing. In the practical implementation of vehicular networks, due to the high amount of different exchanged information between vehicles and infrastructures, data loss and communication delay are unavoidable effects that may cause adverse effects on the closed-loop performance. Moreover, the actuator lag is an inherent characteristic of the engine which causes delay in implementing the control commands. Therefore, all these issues are considered in system modeling and stability analysis, simultaneously. A linear control protocol using the relative position and velocity measurements with respect to predecessor and subsequent vehicles is introduced for each following vehicle. The Lyapunov-Krassovskii theorem is employed to derive the necessary conditions on control parameters assuring internal stability. Afterward, by performing the error propagation analysis in the frequency domain, sufficient conditions on control parameters assuring string stability are obtained. Finally, several simulation results are provided to show the effectiveness of the presented algorithm.