Microscopic Traffic Simulations for Exploring the Interaction Dynamics of Connected & Autonomous Vehicles in Merging Scenarios
Typ
Examensarbete för masterexamen
Program
Publicerad
2020
Författare
Maleki, Mehdi
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
As the number of Autonomous Vehicles (AVs) in today’s traffic increases, it is important
to incorporate their existence in traffic simulations to consider their possible
negative effects on traffic and predict their advantages and disadvantages to propose
feasible solutions concerning their deployment and operation. In this regard, having
a realistic traffic simulation increases the accuracy of such prediction results.
Therefore, the main aim of this master thesis is to design realistic traffic simulation
environment for mixed traffic including AVs, to analyze the interaction of AVs and
Human Operated Vehicles (HOVs). At the same time, analyze the AVs effects on
traffic flow in terms of efficiency and safety. To achieve this goal, the thesis studies
the background theory and terms behind traffic simulation and safety indicators,
it also studies the traditional car-following and lane-change models which are the
fundamentals of the traffic simulation.
Then, in order to simulate the interaction patterns of AVs with HOVs and eventually
examine their effect on traffic safety and flow parameters, this thesis uses Simulation
of Urban Mobility (SUMO) as the microscopic traffic simulation tool. Also, in second
half of thesis, SUMO is integrated to Unity 3D game engine to create 3D model
of the original 2D scenario in SUMO and control the ego vehicle with human driver
as live agent which can make our simulation more realistic. Besides, it allows the
interactive agent behavior to be represented in contrast to ’reactive’ agent structure
of SUMO. This also gives us the opportunity to go beyond the ’omniscient’ and
centralized structure of SUMO. For this reason, TCP/IP connection have been used
to generate a communication between SUMO and Unity, and SUMO-TraCI library
have been used to transmit vehicles and other simulation information between these
two platforms.
As a case study for human-in-the-loop co-simulations, we focused on on-ramp merging
scenario. The aim of this case-study is to understand what kind of effects AVs
will have on the number of safety critical events (SCE) and traffic flow in a merging
scenario. For this reason we consider three possible main scenarios, (1) normal connection
of on-ramp road to main road, (2) merging in presence of acceleration lane
in merge zone, (3) connected AVs in merging areas. Additionally, each scenario is
divided to several sub-scenarios which considers different combinations of numbers
for AV and HOV during merging at on-ramp.
Finally, few ADAS (Advanced Driving Assistance System) features have been added
to simulation environment to analyze the impact of multi-cue interfaces on drivers.
For this purpose, two types of cues have been designed in Unity 3D environment,
visual and auditory interfaces. During designing these interfaces the Time to Collision
(TTC) and distance to lead vehicle have been considered as safety indicators.
(1) visual interface: the driver being warned by visual interface with appearance of different colors during driving, like red represents dangerous, yellow represents the
situations needing attention from driver. (2) auditory feedback: by setting different
sounds to represent the different situations of driving into the simulation environment,
the driver has been warned.
Beskrivning
Ämne/nyckelord
Traffic simulations , heterogeneous vehicle fleet , autonomous and connected vehicles , merging scenario , safety analysis