On Structural and Safety Properties of Head-to-Tail String Stability in Mixed Platoons

Di Liu, Bart Besselink, Simone Baldi*, Wenwu Yu*, Harry L. Trentelman

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Scopus)
34 Downloads (Pure)


The interaction between automated and human-driven vehicles in mixed (human/automated) platoons is far from understood. To study this interaction, the notion of head-to-tail string stability was proposed in the literature. Head-to-tail string stability is an extension of the standard string stability concept where, instead of asking every vehicle to achieve string stability, a lack of string stability is allowed due to human drivers, provided it can be suitably compensated by automated vehicles sparsely inserted in the platoon. This work introduces a theoretical framework for the problem of head-to-tail string stability of mixed platoons: it discusses a suitable vehicle-following human driver model to study mixed platoons, and it gives a reduced-order design strategy for head-to-tail string stability only depending on three gains. The work further discusses the safety limitations of the head-to-tail string stability notion, and it shows that safety improvements can be attained by an appropriate reduced-order design strategy only depending on two additional gains. To validate the effectiveness of the design, linear and nonlinear simulations show that the string stability/safety trade-offs of the proposed reduced-order design are comparable with those resulting from full-order designs.

Original languageEnglish
Pages (from-to)6614 - 6626
Number of pages13
JournalIEEE Transactions on Intelligent Transportation Systems
Issue number6
Early online date23-Feb-2022
Publication statusPublished - Jun-2023


  • automated vehicles
  • head-to-tail string stability
  • human driving model.
  • Mixed platoons
  • string stability

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