This paper presents an integrated platoon control framework for heterogeneous vehicles on roads with varying slopes, aerodynamic drag, and wireless communication delays. First, a linear heterogeneous vehicle platoon model with decoupled longitudinal and lateral dynamics is built based on nonlinear feedback linearization and arc-length parametric transformation of an arbitrary curved road. The external disturbances are also considered, including the up-down road slopes, wind and equivalent time-delays caused by the wireless communication delay and discrete data in onboard sensors. Second, to achieve stable platoon control on a curved road, the platoon uses the state-feedback control method in the longitudinal direction while each vehicle tracks the centerline of the curved road to realize lateral control. Longitudinally, an H-infinity platoon controller is designed based on the Lyapunov-Krasovskii functional to ensure the inner-vehicle and string stability of the platoon, which suffers from parameter uncertainty, and external disturbances. Additionally, the L2 string stability is defined to guarantee that the perturbations do not grow unbounded as they propagate through the platoon. Simulation results indicate that the proposed robust controller achieves proper platoon intervehicle spacing in both the longitudinal and lateral directions.

In addition to the longitudinal dynamics, the lateral control of the platoon can significantly affect its performance on winding road. This paper presents a platoon control framework on winding road for electric vehicles subject to stochastic communication delay and interference. The intervehicle spacing errors (ISEs) in both longitudinal and lateral directions are transformed to an arc-length-based form first. Then, the relationship between single vehicle dynamics and the ISEs is created based on the feedback linearization of the nonlinear system and the arc-length parametric representation of the directed curve. In this way, the whole platoon can be represented by three decoupled linear single-input and single-output systems, i.e., the longitudinal, lateral, and yaw. To assure the steady-state stability of the platoon on a winding road, a robust controller based on the H∞ method is designed to suppress the affection of the communication delay and interference. Also, sufficient conditions that achieve the transient stability of the platoon are derived. Simulations are conducted to verify the effectiveness of the proposed method. Results show that the proposed platoon control can realize the stability of the platoon as well as the supernal road traceability.

Purpose: The purpose of this paper is to investigate problems in performing stable lane changes and to find a solution to reduce energy consumption of autonomous electric vehicles. Design/methodology/approach: An optimization algorithm, model predictive control (MPC) and Karush–Kuhn–Tucker (KKT) conditions are adopted to resolve the problems of obtaining optimal lane time, tracking dynamic reference and energy-efficient allocation. In this paper, the dynamic constraints of vehicles during lane change are first established based on the longitudinal and lateral force coupling characteristics and the nominal reference trajectory. Then, by optimizing the lane change time, the yaw rate and lateral acceleration that connect with the lane change time are limed. Furthermore, to assure the dynamic properties of autonomous vehicles, the real system inputs under the restraints are obtained by using the MPC method. Based on the gained inputs and the efficient map of brushless direct-current in-wheel motors (BLDC IWMs), the nonlinear cost function which combines vehicle dynamic and energy consumption is given and the KKT-based method is adopted. Findings: The effectiveness of the proposed control system is verified by numerical simulations. Consequently, the proposed control system can successfully achieve stable trajectory planning, which means that the yaw rate and longitudinal and lateral acceleration of vehicle are within stability boundaries, which accomplishes accurate tracking control and decreases obvious energy consumption. Originality/value: This paper proposes a solution to simultaneously satisfy stable lane change maneuvering and reduction of energy consumption for autonomous electric vehicles. Different from previous path planning researches in which only the geometric constraints are involved, this paper considers vehicle dynamics, and stability boundaries are established in path planning to ensure the feasibility of the generated reference path.

This paper investigates the impact of time delay factors on the lateral motion of electric vehicles with direct yaw moment control (DYC). The existence of internal time delay factors is inescapable in electric vehicle (EV) systems, which might affect the effectiveness of DYC. Computer simulation shows that DYC works well at small time delays, while significant oscillation or even loss of stability occurs when the delays are large enough. A frequency-domain method is used to determine the stability limit of the time-delayed system.