Development of the DLR Next Generation Train running gear research facility (NGT-FuN)

A full-scale prototype of the Next Generation Train (NGT) running gear with a roller rig installation bench will be built as proof of concept of the running gear and its suitability for high-speed traffic. It will be available as the research platform “Forschungsinfrastruktur NGT-Fahrwerk” (FuN) for the German Aerospace Center (DLR) internal and external research activities. This work presents an innovative method and tool chain to develop application software for the automation of a mechatronic running gear (prototype). The methodology, development, and simulation tools that offer a consistent tool chain from model creation to real-time software and measurement data processing are presented. The model and software structures that are necessary for the software environment are described. The software-in-the-loop environment couples the existing multi-body simulations for the development process with signal-based simulation software using a co-simulation interface. The resulting software-in-theloop simulation environment contains a novel interface layer that translates the mechanical states of the multi-body simulation to pseudo-electrical signals that are read or written by the application software. This makes it possible to develop real-time applications and software structures in software-in-the-loop architectures. The real-time software contains a dedicated model structure of input, processing and output submodels, which is based on signal flow and distinct assignment of tasks. On the rapid-control-prototyping hardware, the real-time software is investigated with a virtual installation bench simulation

Non-invasive dynamic condition assessment techniques for railway pantographs

The railway industry desires to improve the dependability and longevity of railway pantographs by providing more effective maintenance. The problem addressed in this thesis is the development of an effective condition-based fault detection and diagnosis procedure capable of supporting improved on–condition maintenance actions. A laboratory-based pantograph test rig established during the course of the project at the University of Birmingham has been enhanced with additional sensors and used to develop and carry out dynamic tests that provide indicators that support practical pantograph fault detection and diagnosis. A 3D multibody simulation of a Pendolino pantograph has also been developed. Three distinct dynamic tests have been identified as useful for fault detection and diagnosis: (i) a hysteresis test; (ii) a frequency-response test; and (iii) a novel changing-gradient test. These tests were carried out on a new Pendolino pantograph, a used pantograph about to go for an overhaul, the new pantograph with individual parts replaced by old components, and on the new pantograph with various changes made to, for example, the greasing or chain tightness. Through a comparison of absolute measurements and features acquired from the three dynamic tests, it was possible to extract features associated with different failure modes. Finally, with a focus on the practical constraints of depot operations, a condition-based pantograph fault detection and diagnosis routine is proposed that draws on decision tree analysis. This novel testing procedure integrates the three dynamic tests and is able to identify and locate common failure modes on pantographs. The approach is considered to be appropriate for an application using an adapted version of the test rig in a depot setting

System and Thermal Modeling of Hydraulic Hybrids: Thermal Characteristics Analysis

Hybrid vehicles have become a popular alternative to conventional powertrain architectures by offering improved fuel efficiency along with various other environmental benefits. Among them, hydraulic hybrid vehicles (HHVs) have several benefits, which make it the superior technology for certain applications over other types of hybrid vehicles, such as lower component costs, more environmentally friendly construction materials, higher power densities, and more regenerative energy available from braking. There have been various studies on HHVs, such as energy management optimization, control strategies for various system configurations, the effect of system parameters on the hybrid system, and proposals for novel hybrid architectures. One area not been thoroughly covered in the past is a detailed modeling and examination of the thermal characteristics for HHVs due to a difficulty of describing the rapid thermal transients in the unsteady state systems. In this dissertation, a comprehensive system and thermal modeling has been studied for hydraulic hybrid transmissions (HHTs). The main motivation behind developing a thermal model of HHTs is to gain a deeper understanding of the system’s thermal performance, and key influencing factors, without relying on experimental data. This will enable HHVs to be designed more efficiently by identifying and addressing potential issues with transmission’s thermal performance prior to hardware testing. Since there exists no thermal study on HHVs in the past, a thermal modeling method has been introduced, which can be applicable to hydraulic hybrid architectures. A thermal modeling methodology based on a novel numerical scheme and accurate theoretical description has been developed in order to capture the rapid thermal transient in the hydraulic system under unsteady state conditions. The model has been applied to a series HHT and validated with measured data from the hardware-in-the-loop (HIL) test rig with a standard driving cycle, FTP-72. In addition, the proposed thermal modeling methodology has been used to analyze and optimize the cooling system of a novel HHV architecture, which is implemented in a sport utility vehicle (SUV) in Maha Fluid Power Research Center. The modeling results have been compared with the measured data while driving the vehicle. In both studies, the simulation results have shown a good correlation with the experimental data in terms of the overall trends and variation ranges. The goal of the developed model is the application to the system and thermal issues in HHVs, such as thermal stability analysis, management of the cooling system, packaging and hydraulic component optimization, and evaluation of thermal characteristics of different architectures. As an advanced topic of this research, thermal management of an open and a closed circuit hydraulic hybrid systems has been studied by simulation. The comparison results show a potential to a better thermal management for the open circuit systems with smaller heat exchangers, as well as less power consumption with incorporation of smaller charge pumps compared to the closed circuit systems. In the future, the developed comprehensive system and thermal modeling method can be applied to different advanced topics, such as analysis of performance and thermal characteristics, systems and components optimization, and systems evaluation with different external conditions, for different hydraulic hybrid systems

Modelling and control for the oscillating water column

xxii, 219 p.Renewable energies are definitely part of the equation to limit our dependence to fossil fuels. Within this sector, ocean energies, and especially wave energy, represent a huge potential but is still a growing area. And like any new field, it is synonym to a high cost of energy production. Increasing the energy production, while keeping the costs controlled, has the leverage to drop down the cost of energy produced by wave energy converters (WECs). The main objective of this thesis is to make progress on the understanding of the effect of advanced control algorithms in the improvement of the power produced by wave energy devices. For that purpose, several control strategies are designed, compared, and assessed. To support this analysis, numerical models representing the overall energy conversion chain of WECs are developed. The Basque Country in Spain is fortunate enough to host the development and operation of two devices based on the Oscillating Water Column (OWC) principle. One is the Mutriku OWC plant, and the second is the floating buoy Marmok-A from Oceantec/IDOM, both devices were made available for sea trials. Several control algorithms were then implemented to be tested in real environments. Among them was a non-linear predictive control algorithm. Its test in real conditions represent a world first in the area of control for OWC systems, and maybe for the whole WEC sector if comparing with publicly available information. An outstanding results of the thesis is undoubtedly to move forward the predictive control algorithm from TRL3 to TRL6 after successful implementation and operation in both devices under real environmental conditions

Development of automated and connected testing processes for electric vehicles

Electric vehicles provide a practical transportation solution to overcome emission and energy deficiencies posed by combustion vehicles. However, high product costs driven by the price of components and immaturity of the processes to create them reduce the product’s financial competitiveness. Manufacturers need to adapt their processes to develop cars more economically while adhering to emission requirements by legislative bodies. This EngD determined the estimated R&D cost saving made through innovating automated and connected technologies into the development process to reduce the development costs of vehicles holistically. The research targeted physical testing costs due to the potential increase in demand for testing to improve the characterisation of virtual models while the automotive industry transitions to vehicle electrification. The research established objectives to target human, capital and facility costs as significant cost drivers for physical testing. Three applications of automation and connected systems were ideated and investigated to evaluate the saving potential of each cost driver. Firstly, an automated dynamometer was designed and experimentally tested to demonstrate its capability in reducing man-hours for powertrain component testing. Secondly, a distributed test network was virtually modelled to understand the opportunities to supplement physical prototype vehicles by utilising connected component test facilities. Finally, an automated test management system with test case generation capability was proposed and evaluated to determine its capability to improve testing productivity. Using the results from each technology innovation and Jaguar Land Rover’s historical strategy, a numerical model identified an estimated saving of £225m across 12 vehicle models representing a net change of 1.71%. Changes in human resources demand were the most significant contributor toward total development cost savings. DTS and automated dynamometer innovations provided 90% and 9% of human resource cost-saving, respectively. The results suggested that these technological innovations would make only a marginal impact on saving for customers. Ultimately, a combination of further developing of these technologies to maximise application and saving made on other portions of the vehicle development process is necessary to bridge the gap between combustion and electric vehicle. However, the savings proposed would benefit manufacturers financially and allow them to also gain additional revenue by providing opportunities to release vehicle models marginally earlier