Centralized and Distributed Control Framework Under Homogeneous and Heterogeneous Platoon

Abstract

Platooning vehicles are beneficial in comfortable driving, safety, and enhanced transportation efficiency. Platooning vehicles with cooperative adaptive cruise control (CACC) mode can potentially result in a small distance between vehicles with assured string stability. This CACC-based platoon control can be realized by vehicle-to-vehicle (V2V) or vehicle-to-everything (V2X) communication between vehicles. In this regard, the distributed control framework is widely used. It claims robustness to communication uncertainties since each vehicle has its controller. With the rapid research on V2X, the centralized framework is another option for the platooning vehicle control framework. This paper investigates and analyzes the centralized and distributed control framework under platoon uncertainty. In most of the papers, the platoon uncertainty is considered as road slope and vehicle dynamics model. In this paper, the platoon uncertainty refers to the platoon types, namely homogeneous and heterogeneous platoon. The analytical platoon stability is studied for both frameworks under different platoon types. It gives the minimum time gap boundary to guarantee string stability for both frameworks. The numerical string stability is performed by the simulation to verify the analytical. The simulation is done using the integrated PreScan and Matlab/Simulink. Then, the robustness of both frameworks is evaluated under latency and packet loss. Finally, the performance of both frameworks is also evaluated.

Stability Analysis With LMI Based Distributed H ∞ Controller for Vehicle Platooning Under Random Multiple Packet Drops

“…Analysis of string stability and control performances of a platoon under packet drop and communication delay has been reported in [15], [37] and [38], [39], respectively. However, in contrast to the above mentioned research works, very few researchers have proposed control strategies for analysing internal stability, string stability and robust performance of the vehicle platoon systems under both networked packet drop or delay and parametric uncertainty or external disturbances [9], [14], [19], [25], [27], [40]. An LMI based distributed H ∞ controller has been designed for heterogeneous vehicle platoon systems under parametric uncertainties, external disturbances, and communication delays in [27].…”

“…In general, two different strategies such as constant spacing policy (CSP) and constant time headway policy (CTHP) are used for platoon stability and spacing control problem. CSP ensures that the distance between successive vehicles is kept constant, whereas, the inter-vehicle spacing is a function of velocity of vehicles under CTHP [6], [40], [45]. Although, CTHP is simpler to implement and provide more advantages for analysing string stability under simple IFT than CSP [40], [46], but CSP has higher traffic capacity over CTHP [6], [45] for vehicle platooning.…”

“…CSP ensures that the distance between successive vehicles is kept constant, whereas, the inter-vehicle spacing is a function of velocity of vehicles under CTHP [6], [40], [45]. Although, CTHP is simpler to implement and provide more advantages for analysing string stability under simple IFT than CSP [40], [46], but CSP has higher traffic capacity over CTHP [6], [45] for vehicle platooning. Here, we consider CSP as in [2], [6], [9], [10], [12], [14], [20], [24], [47], which means that vehicles are controlled to follow a leading vehicle in a rigid formation ensuring stability and robust performance under random consecutive packet drop and/or communication delay and external disturbances.…”

“…As shown in Theorem 2, the matrix L = (L + P) is symmetric, thus there also exist an orthogonal matrix ∈ R N×N with the satisfaction of T = −1 such that −1 L = D. Using this matrix property, the discrete time closed-loop transfer function (25) under random consecutive packet drop for the vehicle platoon system with undirected topology can be written as (40), shown at the top of the next page [9]. Eqn.…”

Adaptive Cruise Control With Gain Scheduling Technique Under Varying Vehicle Mass

“…Figure 3 show the architecture of LLC. The detail of the LLC and its performance can be seen in [54].…”