Robust string stability and safety of CTH predictor-feedback CACCRobust string stability and safety of CTH predictor-feedback CACC Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2025-03-192023enWe establish robustness of string stability to delay uncertainty as well as positivity of spacing and speed states, for homogeneous vehicular platoons under predictor-feedback Cooperative Adaptive Cruise Control (CACC). Each individual vehicle’s dynamics are described by a second-order linear system with delayed desired acceleration, under acceleration information transmitted to the ego vehicle from a single, preceding vehicle. The nominal design (in the delay-free case) is a constant time-headway (CTH) policy and no restriction on the delay size, in relation with the desired time headway, is imposed. The proofs rely on combination of an input-output approach (on the frequency domain) and on deriving estimates on explicit, closed-loop solutions; under specific, sufficient conditions that are derived on initial conditions and parameters of the baseline, CTH controller. We illustrate in simulation and numerical examples, the guarantees of robust stability and string stability as well as of collisions avoidance, of CTH predictor-feedback CACC design. We also present extensions of our design and analysis approach to heterogeneous, third-order dynamic models of vehicles.This work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the 2nd Call for H.F.R.I. Research Projects to Support Faculty Members and Researchers under Project 3537/ORAMA.http://creativecommons.org/licenses/by/4.0/IEEE Transactions on Intelligent Transportation Systems2488209-8221 Bekiaris-Liberis Nikolaos Μπεκιαρης-Λυμπερης Νικολαος Institute of Electrical and Electronics Engineers Delay compensation String stability of vehicular platoons Cooperative adaptive cruise control (CACC) Predictor feedback Safety of vehicular platoons