On busy lanes, where public transport buses are frequent, bus bunching is a common phenomenon:
Bunching leads to non-homogeneous utilization of buses and therefore degradation of service quality.
The objective is to (i) adhere buses to a timetable and (ii) guarantee equal headways.
The proposed control methodology is a shrinking horizon model predictive velocity control.
Different control strategies are considered:
(i) timetable tracking: buses prioritize the timetable over the headway reference.
(ii) headway tracking: buses try to keep equal headways.
(iii) balanced: both objectives are equally important.
The controllers are simulated in VISSIM in a realistic traffic setting (Göteborg):
The system was evaluated in the event of severe perturbation
(Xdes: desired position, Xref: reference position, ETD: estimated time of departure):
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