Ma, Guoqi (Texas A&M University), Pagilla, Prabhakar Reddy (Texas A&M University), Darbha, Swaroop (Texas A&M University, College Station)

Effect of Parasitic Actuation Lag on the Lower Bound of Time Headway in Adaptive and Cooperative Adaptive Cruise Control Systems

Scheduled for presentation during the Regular Session "Driver Assistance Systems I" (FrAT11), Friday, September 27, 2024, 11:50−12:10, Salon 19

2024 IEEE 27th International Conference on Intelligent Transportation Systems (ITSC), September 24- 27, 2024, Edmonton, Canada

This information is tentative and subject to change. Compiled on October 7, 2024

Abstract

Adaptive and cooperative adaptive cruise control systems (ACC/CACC) are essential components of advanced driver assistance systems (ADAS). They both employ a constant time headway policy (CTHP) to design an appropriate controller to maintain a desired inter-vehicular spacing that is velocity dependent. In the case of ACC, the ego vehicle uses onboard sensors to measure the position and velocity of the predecessor vehicle to control the spacing with the predecessor vehicle. In CACC, in addition to the onboard sensors, acceleration information of the predecessor vehicle, communicated via vehicle-to-vehicle (V2V) communication, is utilized in the ego vehicle controller design; this has been shown to result in improved spacing performance, throughput, and safety of the platoon over ACC. To address the issue of parasitic actuation lag, a first-order inertial vehicle acceleration dynamics model is often employed to evaluate robust string stability of CTHP based controllers for a given upper bound on the parasitic actuation lag ($tau_0$). For ACC, the minimum lower bound on the time headway that one can choose is $2tau_0$, whereas it is $2tau_0/(1+k_a)$ for CACC where $k_a in [0,1)$ is the acceleration feedback gain. In this paper, we show that for the general parasitic actuation lag, without the first-order approximation, the minimum time headway bounds for ACC and CACC are valid. We also show numerical simulation results to corroborate the result.