Adaptive Bidirectional Platoon Control Using a Coupled Sliding Mode Control Method

This paper proposes an adaptive bidirectional platoon-control method for an interconnected vehicular system using a coupled sliding mode control (CSMC) to improve the performance and stability of the bidirectional platoon control and to guarantee string stability. The previous work in the field of platoon control is based on two strategies, i.e., the leader-predecessor and bidirectional strategies. In the case of the leader-predecessor strategy, all vehicles should use the information of all the leading and preceding vehicles. On the other hand, the bidirectional strategy uses the information of its neighboring preceding and following vehicles. Due to the drawbacks of the bidirectional strategy, most previous work has preferred to employ the leader-predecessor strategy, which can guarantee stability and improved performance. The bidirectional strategy is, however, advantageous in that its implementation of the actual system becomes much more feasible than that of the leader-predecessor strategy. Thus, to employ the platoon-control law to an actual system, we propose the platoon-control law using a CSMC method for an interconnected vehicular system based on the bidirectional strategy such that the problems arising from communication devices in the previous work can be overcome. In particular, unlike the previous work using the bidirectional strategy, the proposed adaptive platoon-control law can lead to improved control performance of the whole system and can guarantee string stability. The stability analysis and simulation results of the proposed method in the presence of uncertainties and disturbances are included to demonstrate the practical application of the proposed algorithm.

I. Introduction

PLATOON control is an interconnected vehicle control maintaining the desired space between adjacent vehicles. This interconnected vehicular system with a platoon control has become a popular research area since there has been much interest in the intelligent transportation system (ITS), the adaptive cruise control (ACC), and the intelligent highway system due to increased traffic congestion and collisions [1]– [17]. In these applications, each vehicle in the interconnected system should be controlled to maintain the desired space between the vehicles and to guarantee the stability of the whole system, which is called string stability [3]– [5]. Due to the slinky-type effect [6], the string of the vehicles can be destabilized [6], [7]. Accordingly, the string stability of the interconnected system cannot be guaranteed even when the desired space can be maintained between the neighboring vehicles (i.e., even when the platoon is stable, it may not be string stable) since the stability of the whole system cannot be considered the individual platoon-control algorithm, which does not consider string stability [1], [2].