Implications of as-built highway horizontal curves on vehicle dynamics/kinematics characteristics under adaptive cruise control

Abstract

Due to road curvature and sensors’ limited field of view, as-built highway curves would pose an operational challenge to the adaptive cruise control (ACC) system and its shared control. However, very few studies explored the adaptability of ACC system-dedicated vehicles (V-ACC) considering the vehicle-road geometry interaction. Therefore, the objectives of this study are twofold: (i) investigating the implications of horizontal curves on V-ACC dynamics and kinematics characteristics; and (ii) evaluating V-ACC's adaptability from the safety, comfort, and speed consistency (S-C-S) aspects. To this end, a PreScan/CarSim/MATLAB/Simulink co-simulation platform is established and it is validated by OpenACC database followed by designing many tests featuring circular curve radius (R_C), desired speed (V_de), and clearance. The impact mechanism of geometric features was analysed by interpreting dynamics and kinematics characteristics along curves and critical features were further extracted by reference to S-C-S thresholds. The results show that: (i) either smaller R_C or higher V_de causes those characteristics toward their S-C-S margins; (ii) neither sideslip nor rollover occurs, and speed consistency is good in most R_C conditions; and (iii) drivers can follow the leading car comfortably with V_de = 40, 80–100 km/h but feel uncomfortable when V_de = 50–70 km/h and R_C approaches its lower bounds.