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Diss. (sammanfattning) Helsingfors : Aalto-universitetet, 2023

This thesis focuses on the analysis of internal stability and string stability of vehicle platoons under the multiple-predecessor following (MPF) topology, a configuration intended to lower the minimum employable time headway and increase road throughput. Within the scope of this thesis, stability is investigated for three important scenarios: in the presence of homogeneous delays, heterogeneous delays, and an observer-based controller. In the first scenario, it is assumed that vehicle-to-vehicle (V2V) communications cause the platoon to experience a constant homogenous time delay. The internal stability and string stability are then analyzed for two cases: when all data comes from the delayed network, and when onboard sensors are also employed, providing delay-free but limited information. A lower bound for the time headway is also proposed for both aforementioned cases. The second scenario focuses on the investigation of string stability for a very general case of heterogeneous vehicle platoons with the MPF topology. More specifically, we look at the following forms of heterogeneity: different parasitic lags, different time headways, different controller parameters, and most importantly, different communication time delays. Finding a lower bound for the time headway is also studied for this scenario. Finally, we propose a distributed observer-based controller as an alternative to the conventional proportional integral derivative (PID) controllers. This new controller can guarantee the internal and string stability of the platoon system and achieve a high platooning control performance. Furthermore, an algorithm is presented to find the minimum available value of the time headway.