String Stability Under Actuator Saturation on Straight Level Roads: Sufficient Conditions and Optimal Trajectory Generation

Bingol H., Schmidt K. W.

IEEE Transactions on Intelligent Transportation Systems, vol.23, no.12, pp.24588-24598, 2022 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 23 Issue: 12
  • Publication Date: 2022
  • Doi Number: 10.1109/tits.2022.3213554
  • Journal Name: IEEE Transactions on Intelligent Transportation Systems
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.24588-24598
  • Keywords: actuator saturation, Cooperative adaptive cruise control (CACC), force bound, minimum-time optimal control, string stability
  • Middle East Technical University Affiliated: Yes


IEEEThe heterogeneity of vehicles is an important factor when realizing cooperative adaptive cruise control (CACC) in practice. Specifically, it has to be considered that platoons generally consist of vehicles with both different dynamic properties and actuator limits on the engine and braking force, which is expected to have a negative impact on important properties such as string stability. Accordingly, the subject of this paper is the preservation of string stability for CACC in heterogeneous vehicle strings with potential actuator saturation. To this end, the paper formulates a velocity-dependent force bound that enables the derivation of sufficient conditions for preserving string stability during velocity changes of heterogeneous platoons. These conditions are then used for the analytical computation of trajectories for time-optimal velocity changes. The formal results of the paper are supported by an illustrative simulation study.