Kil Young Lee

The advent of virtual reality (VR) enables immersive visualization, evaluation, and interaction with 3D models. Efforts have been made to integrate parametric solid modeling into VR, but efficient 3D solid model processing and intuitive user interface (UI) design remain challenging. This work proposes an architecture, which, unlike existing approaches, integrates the geometric modeling kernel Open CASCADE directly into the game engine Unreal Engine allowing standalone operation on a VR device without external hardware or software. Our prototype supports creating and editing primitives, and applying topological algorithms. 3D models in STEP format can be imported, edited, and exported ensuring compatibility with conventional computer-aided design (CAD) applications. A foundation for CAD in VR is established, focusing on a customizable UI design to enhance interaction in future developments.

Electric road systems (ERSs) are a promising solution for electrifying heavy-duty freight transport by providing traction and charging power from the power lines installed along the road. Development of ERSs has been accelerated in the last decade, and several pilot projects have been successfully implemented, proving the high level of maturity that the technology has achieved. One crucial step that could be initiated before a rollout is the standardization and certification of ERS infrastructure and system components. For instance, pantographs for overhead ERSs face unique challenges, in that the power transfer should be safe and reliable in the presence of dynamic longitudinal and lateral movements of the vehicle. To tackle this problem, we outline the requirements for overhead ERSs and ERS pantograph testing. Among the key requirements are the rising and lowering times, response to lateral maneuvers, such as lane changes, and high electrical current during stillstand. We introduce our developed test stands capable of testing various aspects of an ERS pantograph. The lateral test stand was developed to test basic functionalities and simulate lateral movements. A second test stand was implemented, to test high currents and the subsequent temperature development. Furthermore, a digital test stand used for planning, design, and modeling is introduced.

Light electric vehicles (LEV) are seen as an effective solution for reducing the carbon emissions in the transportation sector thanks to their light weight and low energy requirement. Integrated photovoltaic (PV) panels on LEVs have great potential because a higher portion of the energy demands can be covered by PV panels compared to heavier vehicles. Integrated PV panels on LEVs are constrained by the surface shape and available area, which results in panels facing different angles. In this work, we assess the effectiveness of such integrated PV panels based on simulations with meteorological data and measurements from a real prototype on an electric scooter. It is shown that the measured PV power correlates well with the simulated data. A number of design options such as the number of PV panels and the angle of the panels are evaluated through simulations and we compare seasonal and regional differences. Based on the assessment, we make design suggestions for cost-effective and energy-efficient integrated PV panels on LEVs. Results indicate that with the right design and favorable circumstances, the integrated PV panels can generate more energy over a day than is consumed by the LEV in a day.

Decarbonizing heavy-duty vehicles through electrification is a demanding task due to their large energy and power requirements. One promising solution to address this problem are electric road systems (ERS), which provide dynamic charging and traction power for electric vehicles. While their technological feasibility has been proven in numerous pilot projects, its reliability under realistic traffic scenarios is yet to be thoroughly investigated. In this paper, we define the reliability criteria for ERS and investigate how they are influenced by various realistic traffic scenarios. Then, the relationship between the ERS reliability criteria and the key system parameters such as the DC link voltage, distance between substations and feeding arrangement is analyzed. We find that the continuous current limit is the most critical criterion under heavy traffic conditions. Furthermore, we look into a number of run-time techniques to cope with electrical stress on the system and propose a technique based on successive approximation of the total current demand. We compare and evaluate the effectiveness of the run-time techniques and show that our proposed technique is able to improve ERS utilization while ensuring reliable operation.