Cooperative Adaptive Cruise Control with Unconnected Vehicle in the Loop

To improve the usability of cooperative adaptive cruise control (CACC) in the mixed traffic comprised of connected and unconnected vehicles, a CACC algorithm with unconnected vehicle in the loop (CACCu) is proposed. Unlike the traditional CACC that requires the feedforward signal from its nearest preceding vehicle or degrades to ACC otherwise, CACCu aims at utilizing the information from the out-of-sight preceding vehicle to maintain a short headway with guaranteed string stability. While similar work can be done for more scenarios, the design of CACCu in this paper focuses on the three-vehicle sandwich scenario (i.e., an unconnected vehicle is in between of two connected vehicles) which has the highest probability to occur among the mixed platooning scenarios. It proves that such design of CACCu can help the equipped vehicle stay string-stable at a headway shorter than half that of ACC when following an unconnected human-driven vehicle with uncertainty. The effects of control gains, communication delay, and vehicle dynamics on the string stability are discussed, which enables the user to choose proper control parameters of CACCu based on its operating condition. At last, the favorable properties of CACCu are validated by high-fidelity simulations using real vehicle trajectory data from Next Generation Simulation (NGSIM) program and a physics-based vehicle model from PreScan. The result shows that CACCu thoroughly over-performs ACC in string stability, ride comfort, and safety.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AHB30 Standing Committee on Vehicle-Highway Automation.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
    • Chen, Zheng
    • Park, B Brian
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 6p

Subject/Index Terms

Filing Info

  • Accession Number: 01697462
  • Record Type: Publication
  • Report/Paper Numbers: 19-04293
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:28AM