Robust Model Predictive Control Framework for Energy-Optimal Adaptive Cruise Control of Battery Electric Vehicles

The autonomous vehicle following problem has been extensively studied for at least two decades with the rapid development of intelligent transport systems. In this context, this paper proposes a robust model predictive control (RMPC) method that aims to find the energy-efficient following velocity of an ego battery electric vehicle and to guarantee a safe rear-end distance in the presence of disturbances and modelling errors. The optimisation problem is formulated in the space domain so that the overall problem can be convexified in the form of a semi-definite program, which ensures a rapid solving speed and a unique solution. Simulations are carried out to provide numerical comparisons with a nominal model predictive control (MPC) scheme. It is shown that the RMPC guarantees robust constraint satisfaction for the closed-loop system whereas constraints may be violated when the nominal MPC is in use. Moreover, the impact of the prediction horizon length on optimality is investigated, showing that a finely tuned horizon could produce significant energy savings.