Abstract

In the last decades, vehicles have evolved from mechanical machines to sophisticated hardware and software (HW/SW) dominated systems. This digital paradigm shift can be explained with the rise of Advanced Driver Assistance Systems (ADAS), as well as applications of highly automated driving. However, such features require a nearly exponential amount of additional SW functionalities. To support the performance demands of such applications, powerful multi and many-processor HW platforms have been employed, exhibiting a trend toward more integrated architectures. Yet, as a consequence, the design and validation, as well as safety assessment of the digital in-vehicle infrastructure of modern cars has become immensely complex.Several techniques arose to bridge this gap, e.g., system engineering strategies, and model-based design and validation methods. In this thesis, it is proposed to augment such traditional approaches with purely simulation-driven techniques to improve and accelerate overall system design. Firstly, the utilization of driving simulators is suggested to conduct virtual road tests in an early application design stage. Furthermore, virtual prototyping is proposed to perform system exploration and extend the simulation scope of ADAS to the embedded HW/SW implementation.However, the main research contributions of the thesis are two techniques that enable efficient full-vehicle modeling. Firstly, multi-scale simulation, an approach to integrate submodels of a top-level simulation system on different design abstractions. Its main benefit is providing a tunable resolution for models, thus enabling a trade-off between the execution performance and the required simulation accuracy. Secondly, multi-domain co-simulation is proposed, a standardized method to interconnect and jointly utilize multiple vehicular simulation ecosystems. This approach addresses the multi-disciplinary nature of vehicles, requiring specialized simulators that are best suited to implement a formalism representing an individual domain.Putting all aforementioned concepts in practice, a comprehensive fully virtual ADAS prototyping ecosystem is presented in this thesis. The proposed framework assembly covers various phases of the ADAS development flow, such as model-based design, virtual system integration, virtual system testing and verification, as well as application refinement. To highlight its potentials, a multitude of ADAS applications are rapidly prototyped via the proposed system. Lastly, insights into application and system-level analyses are presented, while simulation performance evaluation is provided to highlight the acceleration potential of the virtual ecosystems.

Abstract

This paper examines the mechanical behavior of the short fiber reinforced plastic (SFRP) considering the microstructure using multi-scale simulation. The SFRP, which the microstructure consists of resin and fiver, has a rate, thermal, and fiber orientation dependency. The mechanical property is predicted by matrix and fiber properties. However, the properties by material testing are different from the prediction. Thus, this paper decides each microscopic material parameter on microstructure by the least-square method using the experimental data. Comparing the macro simulation results using homogenized values and the experimental results shows microstructure influences the macroscopic behavior. Moreover, the numerical examples compare the results under two types of tensile speed and three fiber orientation types. The present work completes the multi-scale simulation using a simple microstructure considering fiber orientation and strain rate.