# Truck Platoon Control Considering Heterogeneous Vehicles
## 1 Introduction
Reference [13] developed an autonomous intelligent cruise control (AICC) system for automatic vehicle following, examined its effect on traffic flow, and compared its performance with that of the human driver models. Reference [14] presented a two-layered hierarchical framework for truck platoon speed control: a speed planning layer for en route speed profile calculation and a control layer for vehicle speed tracking. Considering longitudinal control, many papers discussed the string stability of platoons as follows. The authors of [15] analyzed the string stability of platoons of Adaptive Cruise Control (ACC) trucks. Reference [16] provided a means to evaluate the ACC systems applying the sliding-mode controller, and designed the ACC controller from the perspective of the practical string stability. Reference [17] proposed a spacing policy to maximize the traffic throughput, and reduced the inter-vehicle distances while ensuring the string stability. Many papers handled longitudinal control under external disturbance, network-induced disturbance, delay, or packet losses as follows. In [18], the problem of longitudinal control of networked intelligent vehicles with external disturbance and network-induced disturbance was studied. Reference [19] considered both communication and parasitic delays in the design of longitudinal control of truck platoon. Reference [20] synthesized performance-aware safe cruise control policies for longitudinal motion of platoons of autonomous vehicles. Using set-invariance theories, reference [20] guaranteed infinite-time collision avoidance in the presence of bounded additive disturbances, while ensuring that the length and the cruise speed of the platoon are bounded within specified ranges. Reference [21] investigated the effect of packet losses on string stability while varying the control gains, and determined the minimum achievable time gap below which stability cannot be achieved. This paper handles a truck platoon with heterogeneous vehicles. Heterogeneous trucks imply that the hardware information (e.g., truck length, break, accelerator, or engine) of a truck may be distinct from that of another truck. This is a feasible scenario, since the functionality of a truck's hardware system (e.g., break, accelerator, or engine) gets worse as time goes on. Thus, we argue that no two trucks are identical in practice. In addition, there may be a practical scenario where we need to use various trucks with distinct size. Many papers on a truck platoon considered heterogeneous vehicles. Reference [22] handled the adaptive longitudinal control of 1-D platoon of non-identical (heterogeneous) vehicles. Reference [23] studied a heterogeneous vehicle platoon equipped with CACC systems. The influence of controller parameters and headway time on string stability was studied in [23]. Reference [24] proposed nonlinear consensus-based control strategies for a truck platoon under different communication topologies. In [25], a switched control strategy of heterogeneous vehicle platoon for multiple objectives with state constraints was proposed. Reference [26] considered analysis and synthesis problems of the cooperative control of a platoon of heterogeneous connected vehicles with directed acyclic interactions. As far as the author knows, all papers on the longitudinal control of truck platoon considered the case where the trucks move along a straight lane. In practice, the trucks may need to maintain a designated distance with its predecessor truck while they move along a curved lane. Platoon dissolution in winding roads is a critical problem to solve in a platoon of vehicles [27]. This paper is novel in presenting the longitudinal control of truck platoon, as the trucks move along a curved lane as well as a straight lane. This paper handles both lateral maneuver and speed control considering heterogeneous trucks. Extensive simulations, which consider noise in the system, are used to present the stability of the control system. This paper is organized as follows.