search vehicle FREDY (Function Carrier for Regen-
erative Electromobility and Vehicle Dynamics) with
four hierarchical levels based on (Scherler, 2019).
Figure 1: Mechatronic structuring of FREDY.
The lowest hierarchical level is made up of mech-
atronic function modules (MFM), which consist of
mechatronic systems that cannot be further subdi-
vided. They contain a mechanical structure, sensors,
actuators and information processing. Each encapsu-
lated MFM has a defined functionality and describes
the dynamics of the system. By coupling several
MFMs and adding an information processing, mech-
atronic function groups (MFG) are set up. MFGs en-
able the realization of higher-value functions by using
the subordinate MFMs. The combination of MFGs
leads to autonomous mechatronic systems (AMS),
e.g. the autonomous vehicle FREDY. By cross-link-
ing several AMS a cross-linked mechatronic system
(CMS), in this case a CPTS, is created.
After the hierarchical structuring, the mechatronic
composition takes place in a bottom-up procedure.
Starting with the lowest hierarchy level, each module
is designed, validated and successively integrated into
the overall system in a model-based, verification-ori-
ented process.
3 STATE OF THE ART
3.1 Automated Lateral Guidance
Modern ADAS for automated lateral guidance re-
quire vehicle sensors for determining the direction of
movement as well as environmental sensors, e.g. to
detect the course of the road or to calculate the devi-
ation from the centre of the lane (Bartels, 2015).
Self-localization is usually achieved by visual ori-
entation along the road markings. Currently used al-
gorithms are based either on lane color characteristics
or on manually programmed lane models. Such con-
ventional methods of image analysis achieve good re-
sults under suitable lighting conditions and clearly
visible road markings, e.g. on motorways. But they
are also very computationally intensive and reach
their limits in the case of disturbances such as poor
visibility as well as dirty, damaged or complex road
marking situations (Zang, 2018). If the position of the
vehicle in the lane cannot be clearly determined the
driver must take over the steering himself. Therefore,
depending on the manufacturer, modern lateral guid-
ance assistants are only enabled above 60 km·h
-1
(Bartels, 2015). As a result, these systems can only be
used on country roads and motorways. Their use in
complex inner-city scenarios is explicitly excluded.
The approach to lateral guidance presented in
(Koelbl, 2011) is based on the control of lateral accel-
eration. The actual value is determined using of vehi-
cle sensors and a behavior model. This implies that
the control performance depends on the complexity
of the underlying vehicle model, which is kept as low
as possible due to high real-time requirements. In
model-based design, the complexity and thus the time
and cost of controller synthesis increases with the
depth of modeling. This aspect is intensified if the in-
dividual perspective and acceptance of the passengers
are considered during function design. A real individ-
ualization of a driving function, i.e. the controller pa-
rameters, is hardly possible with conventional driver
models for reasons of effort (Semrau, 2017).
3.2 Artificial Neural Networks and
Reinforcement Learning
AI algorithms are characterized by a high fault toler-
ance as well as their ability to learn and are therefore
suitable for questions of automated vehicle guidance
(Eraqi, 2016). Particularly ANNs with machine learn-
ing have proven themselves in control engineering
with reliability despite incomplete data, the advanta-
geous design process and their performance (Duriez,
2017). ANNs try to imitate the structure of the human
brain and its function. Neurons are processing units
that accumulate input stimuli (signals) via weighted
connections and calculate an output using an activa-
tion function. The interconnection of several neurons
in at least two layers makes up the ANN.
ANNs have achieved very good results with su-
pervised learning in various fields. However, if the
ANN is to be used directly as a controller, there is
usually no sample data available for training. In this
case, reinforcement learning (RL) can be used. The
ANN learns the optimal strategy in terms of a reward
function given by the developer (Duriez, 2016). Q-
Learning and Policy Gradients are widely used gradi-
ent based RL algorithms. (Such, 2017) showed that
gradient based methods are in some cases not always