Range Policy of Adaptive Cruise Control Vehicles for Improved Flow Stability and String Stability

TLDR

The paper proposes a nonlinear range policy for adaptive cruise control vehicles to enhance traffic flow and string stability, comparing it with constant time headway, human driver, and Greenshields policies. The range policy is derived through an optimization procedure incorporating traffic flow and stability constraints, and a sliding‑mode complementary controller is designed to implement it. Microscopic simulations demonstrate that the proposed method maintains stable traffic flow at considerably higher densities than existing policies.

Abstract

A methodology to design the range policy of adaptive cruise control vehicles and its companion servoloop control algorithm is presented in this paper. A nonlinear range policy for improved traffic flow stability and string stability is proposed and its performance is compared against the constant time headway policy, the range policy employed by human drivers, and the Greenshields policy. The proposed range policy is obtained through an optimization procedure with traffic flow and stability constraints. A complementary controller is then designed based on the sliding mode technique. Microscopic simulation results show that stable traffic flow is achieved by the proposed method up to a significantly higher traffic density.