Abstract
The over-damped string stability criterion is a very strong stability condition that not only addresses the stability in a stricter sense but also adequately captures the safety performance of a platoon. However, the mathematical representation of this criterion is incomplete in the literature. Here, this representation is completely described. Moreover, this article presents the mathematical test method to evaluate this stability condition for linear or linearized systems from the transfer function. The classical sting stability condition does not address the transient undesired convergent dynamics of a platoon, such as over-shooting, under-shooting or damped oscillating dynamics. This paper demonstrates that the over-damped string stability characteristic significantly attenuates these undesired convergent dynamics in the upstream direction. Thus, the advantage of this condition over the classical criterion for linear system is clarified theoretically and by simulation. Later, the numerical method to analyze the over-damped string stability criterion for nonlinear systems is discussed. Additionally, numerical simulations of an over-damped string stable adaptive cruise control (ACC) vehicle model are compared with that of some experimental test results on platoons of commercially implemented ACC equipped vehicles.
Reference28 articles.
1. R. Rajamani, Vehicle dynamics and control, 2nd ed. New York, NY, USA: Springer Science & Business Media, 2012, pp. 141-200.
2. P. Khound, P. Will, and F. Gronwald, "Local and string stability conditions of a generalized adaptive cruise control system," in AmE 2020 - Automotive meets Electronics
3. 11th GMM-Symp., Dortmund, Germany, Mar. 2020, pp. 29-36.
4. J. Zhou and H. Peng, “String stability conditions of adaptive cruise control algorithms,” in IFAC Symp. Advances in Automotive Control, Salerno, Italy, Apr. 2004, pp. 649–654.
5. J. Zhou and H. Peng, “Range policy of adaptive cruise control vehicles for improved flow stability and string stability,” IEEE Trans. Intell. Transp. Syst., vol. 6, no. 2, pp. 229-237, Jun. 2005.