A hierarchical control scheme to improve the travel performance of truck platoons in freeways

This paper deals with the control of truck platoons traveling in freeways. In order to improve their travel performance, in terms of travelling times and comfort and to guarantee safety, a hierarchical control scheme is proposed for each platoon. At the high level, the reference speed is computed according to a PI-based control rule with the main aim of reducing the time spent by the platoon in the congested area. This reference speed is communicated to the low control level which implements a Linear Quadratic Tracking policy and determines the optimal speed for each truck in the platoon. The application of these hierarchical controllers to a case study shows the effectiveness of the proposed scheme.