PLATOONING UNDER COMMUNICATION UNCERTAINTY

Platooning in the presence of a speed drop

Platooning is expected to enhance the efficiency of operating autonomous vehicles. The positive impacts of platooning on travel time reliability, congestion, emissions, and energy consumption has been shown for homogenous roadway segments. However, unveiling the full potential of platooning requires stable platoons throughout the transportation system (end-to-end platooning). Speed limit changes frequently throughout the transportation network, due to either safety related considerations (e.g., change in geometry and workzone operations) or congestion management schemes (e.g., speed harmonization systems). These speed drops can result in shockwave formation and cause travel time unreliability. Therefore, in addition to enabling end-toend platooning, designing a platooning strategy for tracking a reference velocity profile can improve travel time reliability. Accordingly, this study introduces a generalized control model to track a desired velocity profile, while ensuring safety in the platoons of autonomous vehicles.

Speed profile over space

Simulation of vehicle going through the speed drop using our control logic.

Arefizadeh, S. and A., Talebpour. A Platooning Strategy for Automated Vehicles in the Presence of Speed Limit Fluctuations. Transportation Research Record: Journal of the Transportation Research Board of National Academies, DOI. 10.1177/0361198118784176.
Arefizadeh, S., A., Talebpour, and I., Zelenko. Platooning in the Presence of a Speed Drop: A Generalized Control Model. arXiv preprint arXiv:1709.10083, Under Review: IEEE Transactions on Automatic Control.
HasanzadeZonuzy, A., S., Arefizadeh, A., Talebpour, S., Shakkottai, and S., Darbha. Collaborative Platooning of Automated Vehicles Using Variable Time-Gaps. arXiv preprint arXiv:1710.02186.
Arefizadeh, S., A., HasanzadeZonuzy, A., Talebpour, and S., Shakkottai. Assessing Strong String Stability of Constant Spacing Policy under Speed Limit Fluctuations. Under Review: IEEE Transaction on Vehicular Technology.

platooning and communication uncertainty

Connectivity is expected to enhance safety and efficiency of platooning. Connectivity will provide information to drivers/autonomous vehicles to enhance decision-making reliability at the operational and tactical levels. Consequently, drivers are more likely to execute safe and efficient maneuvers and autonomous vehicles will have a more accurate perception of the traffic condition and an “error-free” execution of the driving maneuvers. Unfortunately, full connectivity does not always exist in vehicular ad-hoc networks (VANETs). To ensure connectivity in such a network, the correlation between communication range and connected vehicles density should be considered. To capture the effects of this correlation, this study uses the Continuum Percolation theory to determine the effects of the vehicular density and communication range on the connectivity level in telecommunications network and consequently, on the string stability of traffic flow.

Impact of communication network performance on vehicular maneuvers.

Talebpour, A., H. S., Mahmassani, and S. H., Hamdar. Effect of Information Availability on Stability of Traffic Flow: Percolation Theory Approach. Transportation Research Part B, In Press.
Talebpour, A., and H. S., Mahmassani, and F. E., Bustamante. Modeling Driver Behavior in a Connected Environment: Integrated Microscopic Simulation of Traffic and Mobile Wireless Telecommunication Systems. Transportation Research Record: Journal of the Transportation Research Board of National Academies, No. 2560, 2016, pp. 75-86.