Comparing vehicle dynamics models of different complexity for comfortable and emergency steering in virtual assessment of active safety systems
Typ
Examensarbete för masterexamen
Program
Automotive engineering (MPAUT), MSc
Publicerad
2020
Författare
Kodgi, Aashish Udaykumar
Ramireddy Gangadhara Reddy, Raghavendra
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The World Health Organization (WHO) states that every year, 1.35 million people
die as a result of road traffic crashes [1]. According to the National Highway Traffic
Safety Administration (NHTSA), rear-end collisions are the type of crashes that
occur most frequently. Actually, 29 percent of all collisions are rear-end crashes
[2]. It is the responsibility of the automotive sector to make use of the technologies
available to the full extent, to reduce the number of fatalities caused every year due
to road traffic crashes. The development of Advanced Driver Assistance Systems
(ADAS) has led to the prevention or mitigation of many collisions. Therefore, testing
of active safety systems plays a vital role in improving these systems. Rigorous
analysis under different conditions can provide insight to further development of
these systems. Development of active safety and automated driving systems requires
safety evaluation during the development stage by using different tools for testing
and evaluation. One such tool for evaluation of active safety systems is performed
using computer simulations virtually, as evaluation of these systems in real traffic
scenarios is not only dangerous but also expensive. Since vehicle models take part
in simulations, it is important to study the impact of vehicle models of different
complexities for evaluating active safety systems. The main goal of the thesis is to
select different vehicle models of varying complexity levels and study what impact
the selection has on the last point of steering to avoid a stationary obstacle while
performing evasive manoeuvring. In the increasing order of their complexities, a
single-track model, a two-track model without load transfer, and a two-track model
with load transfer, were selected. These models were further subjected to changes
by considering different longitudinal speed, different cornering stiffness at the front
and rear axles of the vehicle, and different tire models. Analysis was performed
in terms of comparing the timing of the point of no return (last time to avoid the
obstacle) where no substantial difference was noticed among the different vehicle
models. Finally, based on considering the deviations in the last point of steering
in seconds and computational time required for 10,000 iterations, the conclusion is
made that the most complex model is not always necessarily the best model that
can be used in simulations.
Beskrivning
Ämne/nyckelord
Active safety , safety evaluation , virtual evaluations , vehicle models , evasive steering , lateral dynamics , the last point of no return