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Abstract: Duplex steels are used for applications that require high strength and ductility combined with good corrosion resistance. An economical welding technology to handle these steels is achieved by combining the MIG and TIG arc processes. The aim is to improve welding speed and quality by utilizing a TIG-MIG hybrid welding process to join 1.4462 duplex steel with a thickness of 2 mm. The interaction between the two arcs, caused by the blowing effect, is an enormous challenge that can be counteracted with a defined torch position and current modulation. For this purpose, a variation of the MIG (pulsed and AC pulsed arc) and TIG process (AC and pulsed DC) took place. The influence of electrical parameters on process stability and material transfer was investigated. For analysis, an evaluation of high-speed recordings (5000 frames per second) and synchronized measured current/voltage curves (200 kHz) is carried out. Based on a number of selected specimens, a welding procedure test according to ISO 15614-1 is performed to determine the welding seam quality. The test includes the characterization by tensile and hardness testing and macroscopic and microscopic examination. Additionally, the specimens are examined according to ISO 5817.
Model predictive control (MPC) is a promising approach to the lateral and longitudinal control of autonomous vehicles. However, the parameterization of the MPC with respect to high-level requirements such as passenger comfort, as well as lateral and longitudinal tracking, is challenging. Numerous tuning parameters and conflicting requirements need to be considered. In this paper, we formulate the MPC tuning task as a multi-objective optimization problem. Its solution is demanding for two reasons: First, MPC-parameterizations are evaluated in a computationally expensive simulation environment. As a result, the optimization algorithm needs to be as sample-efficient as possible. Second, for some poor parameterizations, the simulation cannot be completed; therefore, useful objective function values are not available (for instance, learning with crash constraints). In this work, we compare the sample efficiency of multi-objective particle swarm optimization (MOPSO), a genetic algorithm (NSGA-II), and multiple versions of Bayesian optimization (BO). We extend BO by introducing an adaptive batch size to limit the computational overhead. In addition, we devise a method to deal with crash constraints. The results show that BO works best for a small budget, NSGA-II is best for medium budgets, and none of the evaluated optimizers are superior to random search for large budgets. Both proposed BO extensions are, therefore, shown to be beneficial.
Dynamically loaded structures made of thermoplastic polymers have been extensively exploited in several demanding industries. Due to the viscoelastic and thermal properties of thermoplastic polymers, self-heating is generally inevitable, especially during dynamic deformations at high frequencies. Therefore, the thermoplastic polyether ether ketone (PEEK), with its high temperature resistance and high specific strength, is a particularly ideal candidate for dynamically loaded applications. Using scanning laser Doppler vibrometry and infrared thermography, an experimental study of the vibration characteristics and the vibration-induced heating of flat-sheet PEEK specimens was carried out. The specimens were base-excited by means of a piezoelectric actuator at high frequencies in the range between 1 and 16 kHz. As a result, a maximum temperature rise of approximately 6.4 K was detected for the highest investigated excitation. A high correlation between the spatial distribution of the velocity along the beam’s axial direction and the resulting temperature increase was measured. To summarize, the occurring self-heating of PEEK due to the dissipation of vibrational energy has to be critically considered for dynamically loaded structural applications, especially areas with high displacement amplitudes, such as antinodes, which yield the highest temperature increase.
This master's thesis focuses on developing a robust framework for co-simulating microscopic traffic scenarios and vehicle dynamics, leveraging the capabilities of SUMO and CARLA. The essence of this research lies in its meticulous analysis of existing simulation tools, leading to identifying the most effective co-simulation strategies and intercommunication methods. A comparative study elucidates the strengths and limitations of these methodologies, guiding the selection of an optimal approach.
Central to the methodology is a thorough understanding and application of SUMO and CARLA, enhanced by the strategic implementation of intercommunication methods. The detailed integration of these tools and the introduction of test automation significantly boost simulation efficacy. The framework's reliability and accuracy are rigorously validated through well-defined procedures and metrics, ensuring fidelity in simulation results.
Key to this research is the design of experimental scenarios that reflect real-world traffic conditions underpinned by carefully chosen simulation parameters. These scenarios are pivotal in validating the co-simulation framework's performance, supplemented by a performance cost analysis focusing on processing efficiency. The thesis culminates with a critical discussion of the findings, addressing the research objectives and posing solutions to identified challenges. Potential areas for future enhancements are explored, highlighting the framework's limitations.
In conclusion, this thesis contributes significantly to the field of traffic simulation for autonomous driving technologies. It presents a comprehensive co-simulation framework, offering researchers and engineers a sophisticated tool for advanced testing and validation. The insights and recommendations provided are instrumental for ongoing research and development in this rapidly evolving domain.
In this work, a new method for selecting suitable materials is presented. This method has a high potential for a variety of engineering applications, such as the design of sound-absorbing and vibration-loaded structures, where a large number of different requirements have to be met. The method is based on the derivation of functional dependencies of selected material parameters. These dependencies can be used in parameter studies to consider parameter combinations that lie in the range of real existing and targeted material groups. This allows the parameter space to be reduced, the calculation to be accelerated, and suitable materials to be (pre-)selected for the respective application, which contributes to a more target-oriented design. The method is applied to the example of a plate resonator. For this purpose, a semi-analytical model is implemented to calculate the transmission loss as well as the reflected and dissipated sound power of plate silencers, taking into account the influence of flow velocity and fluid temperature on the performance of plate silencers.
Analysis of a Film Forming Process through Coupled Image Correlation and Infrared Thermography
(2022)
The aim of the present investigation was to determine the dependence of the material and process parameters of the bending process of thermoplastic films. In this context, parameter combinations leading to high resulting forming ratios were identified. To measure the relevant parameters within the hot bending process, a coupled evaluation of infrared thermography (IRT) and deformation measurement using digital image correlation (DIC) was performed. The coupled measurement enables the identification of the actual mechanically stressed bending area of the film as a result of the bending process. This allows for the specification of the local forming temperatures required for the desired forming ratios. Furthermore, the mechanical and thermal strain along the defined measuring sections and their deviation in individual tests as well as the effect of thermal strain on process control on a larger scale were determined. Based on the results, a process window was defined for the film materials investigated, which will serve as a starting point for future efforts to develop a continuous manufacturing process.
The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and 4′,6-diamidino-phenylindole-(DAPI)-staining. Extracted human premolars were instrumented up to F2 (ProTaper Gold) under NaCl 0.9% irrigation and incubated with Enterococcus faecalis for 42 days. Subsequently, different ultrasonically agitated IP were applied to the roots: control (no irrigation), 1. NaOCl 3%, EDTA 20%, CHX 2%, 2. NaOCl 3%, EDTA 20%, 3. NaOCl 3%, EDTA 20%, SDF 3.8%, 4. SDF 3.8%, and 5. NaCl 0.9%. One half of the root was investigated fluorescent-microscopically with DAPI. The other half was grinded in a cryogenic mill and the bacterial DNA was quantified with qPCR. The qPCR results showed a statistically significant reduction of bacteria after the application of IP 1, 2, and 3 compared to the control group. While IP 4 lead to a bacterial reduction which was not significant, IP 5 showed no reduction. These data corresponded with DAPI staining. With qPCR a new molecular-biological method for the investigation of the complete root canal system was implemented. The novel IP 3 had an equally good cleansing effect as the already established IP.
The aim of this study was to investigate the antimicrobial efficacy of different disinfection protocols in a novel Enterococcus faecalis biofilm model based on a visualization method and to evaluate the potential alteration of dentinal surface. A total of 120 extracted human premolars were allocated to 6 groups with different irrigation protocols. The assessment of the effectiveness of each protocol and the alteration of dentinal surface were visualized by using SEM and fluorescence microscopy (DAPI). A dense E. faecalis biofilm with a penetration depth of 289 μm (medial part of the root canal) and 93 μm (apical part) validated that the biofilm model had been successfully implemented. A significant difference between the 3% NaOCl groups and all the other groups in both observed parts of the root canal (p < 0.05) was detected. However, the SEM analysis revealed that the dentinal surface in the 3% NaOCl groups was severely altered. The established biofilm model and the visualization method based on DAPI are appropriate for bacterial quantification and evaluation of the depth effect of different disinfection protocols in the root canal system. The combination of 3% NaOCl with 20% EDTA or MTAD with PUI allows the decontamination of deeper dentine zones within the root canal but simultaneously alters the dentinal surface.
Models of artificial root canals are used in several fields of endodontic investigations and pre-clinical endodontic training. They allow the physical testing of dental treatments, the operating of instruments used and the interaction between these instruments and the tissues. Currently, a large number of different artificial root canal models exist whose geometry is created either on the basis of selected natural root canal systems or to represent individual geometrical properties. Currently, only a few geometric properties such as the root canal curvature or the endodontic working width are taken into consideration when generating these models. To improve the representational capability of the artificial root canal models, the aim of the current study is therefore to generate an artificial root canal based on the statistical evaluation of selected natural root canals. Here, the approach introduced by Kucher for determining the geometry of a root canal model is used, which is based on the measurement and statistical evaluation of the root canal center line’s curvatures and their cross-sectional dimensions. Using the example of unbranched distal root canals of mandibular molars (n = 29), an artificial root canal model representing the mean length, curvature, torsion and cross-sectional dimensions of these teeth could be derived.
Structures made of the thermoplastic polymer polyether ether ketone (PEEK) are widely used in dynamically-loaded applications due to their high-temperature resistance and high mechanical properties. To design these dynamic applications, in addition to the well-known stiffness and strength properties the vibration-damping properties at the given frequencies are required. Depending on the application, frequencies from a few hertz to the ultrasonic range are of interest here. To characterize the frequency-dependent behavior, an experimental approach was chosen and applied to a sample polymer PEEK. The test setup consists of a piezoelectrically driven base excitation of the polymeric specimen and the non-contact measurement of the velocity as well as the surface temperature. The beam’s bending vibrations were analyzed by means of the Timoshenko theory to determine the polymer’s storage modulus. The mechanical loss factor was calculated using the half-power bandwidth method. For PEEK and a considered frequency range of 1 kHz to 16 kHz, a storage modulus between 3.9 GPa and 4.2 GPa and a loss factor between 9 × 10−3 and 17 × 10−3 were determined. For the used experimental parameters, the resulting mechanical properties were not essentially influenced by the amplitude of excitation, the duration of excitation, or thermal degrad.ation due to self-heating, but rather slightly by the clamping force within the fixation area.
This paper deals with systematic approaches for the analysis of stability properties and controller design for nonlinear dynamical systems. Numerical methods based on sum-of-squares decomposition or algebraic methods based on quantifier elimination are used. Starting from Lyapunov’s direct method, these methods can be used to derive conditions for the automatic verification of Lyapunov functions as well as for the structural determination of control laws. This contribution describes methods for the automatic verification of (control) Lyapunov functions as well as for the constructive determination of control laws.
This research investigates the Leipzigerstraße and Gießereistraße intersection in Rackwitz to enhance safety and sustainable transportation. The study analyzes existing designs that experience accidents and proposes a design plan of mini roundabout to improve safety while using the guideline Anlage von Kreisverkehren. In this project, the roundabout is planned according to the currently valid guidelines from phase 2 of the HOAI (Fee Structure for Architects and Engineers). Rainwater management strategies and traffic quality of the roundabout are considered. Additionally, cyclist-friendly paths connecting Rackwitz and Zschölkau are developed in line by using guideline ERA. The proposed roundabout design and elevated cycle paths are identified as effective solutions to enhance safety and support eco-friendly transportation. By adhering to established guidelines and prioritizing safety, this research contributes to creating a secure and sustainable urban transportation network.
Since Carbon emissions are soaring all over the atmosphere, the world suffers from significant problems daily. It has become apparent that reliance on single occupancy vehicle transportation is unsustainable, expensive, and primarily harmful to humankind. Rural areas are frequently abandoned while expanding
transportation infrastructure as urbanisation grows. In rural areas, a lack of adequate and inexpensive transportation options leads to seclusion and restricted access to products, facilities, and job opportunities.
This study explores the potential of alternative transportation methods to improve mobility in rural areas. The objectives of the research are to expand knowledge on sustainable alternative transportation in rural regions and to offer practical solutions for enhancing accessibility and mobility for rural residents.
The study employed a mixed-method approach, including a literature review, a survey, and interviews with participants in two rural regions, Mosel and Oberrothenbach. The findings suggest that the transportation challenges faced by rural inhabitants can be effectively and sustainably addressed through walking and by using alternative transportation modes, such as cycling and public transit. This thesis provides a range of ideas and strategies to improve regulations, programs, and infrastructure related to alternative transportation modes in rural areas. This study dives into the characteristics and requirements
of these places using a combination of quantitative and qualitative surveys done in representative two rural regions to recommend successful alternative transportation solutions of On-Demand Transport Services and Electric or Trolley bus Services for daily commutes. The findings underline the need for flexible, multimodal, and on-demand transit choices, as well as the need for community participation and technology integration.
Research and studies have indicated that rural highways globally exhibit a disproportionately high incidence of accidents and fatalities, which can be attributed to inadequate traffic safety measures. This paper primarily examines the causes of inadequate traffic safety, with a particular emphasis on factors associated with road conditions. These causes can be broadly categorized into human factors, road factors, and vehicle factors. Indeed, the movement of vehicles on these rural roads is characterized by unrestricted traffic flow, whereby the driving stability of a vehicle is primarily impacted by factors such as road alignments and surface conditions. Single-vehicle run-off-road crashes frequently exhibit a correlation with insufficient road conditions. Hence, enhancing the alignment design of roadways can prove to be efficacious in minimizing the occurrence of traffic accidents. However, constraints may arise in the context of rural roads, thereby imposing limitations on designers and engineers in their ability to modify road design. Therefore, it is imperative to explore alternative measures to enhance road safety as required. The objective of this study is to analyse driving behaviour on a two-lane rural road in Germany, taking into consideration the varying alignments of the road. The WHZ static simulator is an innovative technological tool utilized within the field of road design analysis, specifically for the purpose of evaluating driving behaviour. Speed, lateral positions, and are the primary parameters utilized in the evaluation of driving behaviours.
Keywords: Driving Simulators, Driving Behaviour, Traffic Safety, Trajectory Classification
This thesis presents a case study conducted at the Potsdamer Platz intersection in Berlin, focusing on the effects of transitioning from fixed phase control to Vehicle Actuated Signal Control (VA). The objective is to optimize the signal control system to improve traffic flow and reduce waiting times for motorists. Traffic data from the Berlin authority is analyzed, and various stage sequences are developed using the signal planning tool LISA+ and simulated using VISSIM microsimulation. The impact of the proposed vehicle-actuated signal control system on overall traffic performance is evaluated by comparing the Level of Service (LOS) with the existing fixed-time plan. The analysis reveals the limitations of the proposed approach and identifies areas for further improvement in control systems. Results indicate that the VA system shows comparable effectiveness to the current scenario only at lower volume, with room for enhancement. By considering two variations of the signal group from the current sequence, valuable insights are gained into the effects of the proposed changes. The results contribute to the development of optimized signal control strategies, aiming to create safer and more efficient traffic environments at urban intersections.
WHO estimates that 1.25 million people worldwide pass away in traffic accidents each year. Accidental damage to the economy costs USD 520 per year. Road traffic accidents account for 2.1% of all fatalities worldwide. In total, 50,000 people die in Europe each year. One of the most significant economic and social issues, traffic accidents result in thousands of fatalities and serious injuries each year in Germany and around the world. Whenever there is an accident involving vehicles, trucks, motorized two-wheelers, bicycles, or pedestrians that results in casualties or property damage, the questions of what caused the accident and how it could have been prevented naturally arises: whether it was due to human factors (e.g., carelessness, speeding, or drinking), vehicular flaw (e.g., faulty brakes, a faulty chassis, or old tires), road surface, poor visibility, and so on. The list of possible explanations is really long. The problem is to implement effective steps to prevent accidents from happening in the first place, regardless of what caused the mishap.
The German federal states of Sachsen, Sachsen-Anhalt, Brandenburg, Hessen, and cities of Hamburg, and Bremen are examined in this study's analysis of accidents. This study aims to (i) identify the human factors, environmental factors, and road/infrastructural factors that lead to human failures which cause road accidents, and (ii) explore ways of mitigating these accidents.
Automotive transportation plays an important role in everyday urban life. The motorization is increasing along with rising population every year. The constant increase of cars causes various problems in big cities. One of the major problems is parking. Parking search traffic contributes to about 30% of the traffic volume in city centers. This leads to problems like congestion, road accidents, increase of fuel emission due to the circling of cars inside the city looking for parking facilities, environmental pollution etc. Most of the cities face this problem not because of the unavailability of parking spots in parking facilities but rather because drivers don't have the right information on where to park. This can be solved by providing proper guidance about the parking facilities to the drivers. For this, efficient parking space management including the design of a suitable parking guidance system is required. The Entsorgungs and Vekehrsbetrieb (EVB) Wismar has been responsible for the parking space management in the city since 2012 and is implementing the parking space concept in Wismar that was approved by the town council. So far, there is a static parking guidance system in Wismar, which consists of 20 locations with signs pointing to six parking facilities. The Entsorgungs und Vekehrsbetrieb (EVB) intends to replace the static parking guidance system of the Hanseatic City of Wismar with a dynamic parking guidance system (DPGS). The aim of my master thesis is to create a concept for the development of a dynamic parking guidance system in the Hanseatic city of Wismar, including the technical operation and possible implementation, taking autonomous driving into account.
Despite lacking sufficient evidence, the shift to automated mobility has often been regarded as progress towards a safer road transport system. Following the introduction of the first production car that has been officially certified as Level 3 earlier in 2022, the driver can shift their role to only as a fallback when the automated driving system reaches its limit of the Operational Design Domain. In the event of an accident, though, the matter will only get even more complicated, especially in the process of unravelling the party that was performing the Dynamic Driving Task at the time of the collision. An accident investigation is done to provide insight into how it occurred and uncover the liable parties. This thesis reviews various methods reconstructing an accident scene, such as photogrammetry and laser scanning, as well as elaborating the relevant data that has already available in the vehicle and from the infrastructure. Recommendations are also presented on for the future data collection, specifically in the scenario of automated driving, to improve such practice.
The objective of the study is to improve the functionality of the Virtual Reality Laboratory (VR Labs) of the Faculty of Automotive Engineering and enhance its applicability in Road Traffic Engineering education and training at the University of Applied Sciences Zwickau (WHZ). In this study, a comprehensive description of Virtual Reality (VR) and Augmented Reality (AR) as well as their wide application in education has been given.
An insight into the VR Labs of the Faculty of Automotive Engineering at WHZ is provided. The study built and proposed eight use cases of VR Labs in road traffic engineering training and education at WHZ. The limitations and barriers in deploying application cases are analyzed and suitable solutions are given. The adoption of virtual reality can be an easy transition based on BIM modeling software development, and 3D and 360 degrees scanning.
An extension of the VR Labs application for other areas of education at WHZ has been identified. In addition, technologies, areas of application, and future research directions are mentioned. Innovations such as 3D modeling and BIM-based workflows that are being encouraged through the development of content-created engines will provide students with opportunities for using VR/AR on road traffic and infrastructure projects in the future.
The traffic calming measures aim to slow down traffic speed, accident frequency, and reduction of through traffic caused mainly by motorized vehicles in residential areas. These measures are primarily addressed to the specific streets and lead the necessary or remaining traffic to drive in a restrained or considerate manner. While these measures are designed to prevent conflicts between pedestrians and motorists, they impose unstable traffic patterns and are sometimes unable to accommodate the increasing motor vehicle flows, as they are concentrated only on certain streets.
This paper investigates area-wide urban traffic calming techniques from existing projects. It explains how traffic regulatory and structural measures link together or separately to restrict the movement of motor vehicles traveling through neighborhood streets and divert them to main roads. The implemented sample measures were illustrated and described with photos of their current locations.
In this thesis, the district Äußere Neustadt was defined as a model area in Dresden to analyze and redesign the existing mobility plan in order to reduce the MIV flows with the main objectives of giving space for pedestrians, cyclists, and public transport. The district's street infrastructure is heavily impacted by the presence of parked vehicles, raising challenges to the safe movement of both bicyclists and oncoming motor vehicles. In the frame of the model project initiative - "Woche des guten Lebens", the volunteer team has designed a traffic experiment and carried out an online survey to assess citizens' opinions of the Äußere Neustadt. The analyses demonstrate and emphasize the necessity of political support and interactive communication with citizens regarding the area-wide radical sustainable mobility plan. Considering the positive feedback of the citizens, the new mobility plan was realized in this paper.
Area-specific traffic calming techniques such as diagonal or cross barriers, zone speed limits, offsets, one-way streets, etc. were analyzed from the implemented projects to determine the appropriate solutions for the specified streets. The district's existing traffic network and the new solutions offered were visualized using QGIS software.
The implemented new traffic plan will lead to more space for pedestrians and bicycle traffic and a reduction in traffic noise.
Over the last few decades, the motorization rate has steadily increased because of an increase in private car ownership each year. According to the survey, the vehicle-to-person ratio is at an all-time high. An increase in accidents and parking space issues are some of the consequences of having more vehicles on the road.
Autonomous vehicles can be a solution to these problems. To allow autonomous vehicles to drive on the road, their efficiency and functionality to perform various tasks such as object detection, path planning, and path following must be tested.
Autonomous parking can be extremely beneficial for both autonomous vehicles and conventional vehicles. This thesis aims to develop a methodology to find if Reinforcement Learning can be used as an alternative approach to motion planning for autonomous parking. Three Reinforcement Learning algorithms, namely Soft Actor Critic, Truncated Quantile Critics and Twin Delay Deep Deterministic Policy, were used to accomplish the motion planning task.
The reinforcement Learning agents were trained on three scenarios with different levels of complexity. The agent learned the behaviour to follow, which led to a higher success rate and reward maximization at the end of the training phase. In the testing phase, agents were tested on various scenarios, including unknown scenarios. Additionally,
a comparison between the three agent’s training and testing results has been made with possible reasons behind the behaviour of all three agents. The potential benefit from autonomous parking by Reinforcement Learning includes an effective solution for various parking scenarios and a generalized model which can be used without repetition of the training process.
Traffic signal priority for Public Transit vehicle is considered as an effective strategy to reduce the delay times and increase service reliability. This strategy is implemented to stop the vicious cycle of traffic congestion due to excess utilization of private vehicle. Though this is an attractive alternative for a private vehicle, this strategy can be implemented without opting for any new transportation infrastructure. On doing so the concern towards sustainable mobility solutions is also addressed. Therefore, prioritizing public transport is the best possible way to adapt to the increasing mobility demands in urban areas. Along with the technological advancements, these priority strategies are also being developed.
With these advancements in priority strategies, more research towards Estimated Time of Arrival of transit vehicles a key parameter in Transit signal priority has been observed. One such new traffic signal priority is with C-ITS message profiles CAM and SREM. Though this advanced priority method is considered to outperform the existing traffic signal priority strategies, how much better they can perform is not yet determined. This thesis focuses on this aspect by comparing the existing Transit signal priority method with the advanced CAM and SREM Transit signal priority, in four different scenarios. Signal Control tool LISA and Simulation tool VISSIM are used for the whole design and evaluation process. Delay time, waiting time,and average speed evaluation parameters are considered for comparing and determining the performance of two Transit Signal priority methods.
Multi-objective optimization of a model predictive vehicle dynamics control system using NSGA-II
(2022)
The development of the Automated Driving System (ADS) had a substantial significant impression on scientists. Throughout ADS, different units and controllers are installed, monitored, and analysed. The research is based on the theory of the Model Predictive Controller (MPC) system. which tackles the Multi-Objective Optimization (MOO) problem by calling out the cost function on the path-following problem using the MPC (i:e Model Predictive Path Following Control (MPFC)) with the defined constraints for the lateral control of the vehicle. The cost function helps to minimize the errors and compute the data. But the computation through the cost function is a bit complex. To overcome the complexity, an Non-Dominated Sorting Genetic Algorithm II (NSGA-II) algorithm is proposed, which helps to minimize the errors of set parameters and provides an optimal solution. The notion of NSGA-II is to find a wide variety of solutions and obtain better convergence in the form of the Pareto Optimal Front. Moreover, the detail of the Non-Dominated Genetic Algorithm II is theoretically enlightened to understand the Evolutionary Algorithm (EA) concept and the workability of the genetic algorithm. And the whole function is scripted in the MATLAB program.
Furthermore, we analyse the generated data in the Pareto Optimal Front and compare it with the Hyper-volume indicator, the most popular set-quality metric for rating stochastic multi-objective optimizer performance. Its theoretical characteristics, particularly the strict monotonicity concerning set dominance, which is still exclusive
to hyper-volume based indicators, justify its widespread acceptance. Hyper-volume indicator scrutinizes the optimal solution of multiple results. The analysis and
evaluation are completed between two other data sets generated and received through the RandomDATA and Multiple Objective Particle Swarm Optimization (MOPSO)
algorithm, which describe the quality of the best optimal solution between the results generated by the three algorithms.
Keywords: Non-Dominated Genetic Algorithm II, Model Predictive Path following Control, MATLAB, Algorithm, Pareto Optimal Front, Multi-Object optimization, Cost
Function
This study aimed to investigate the component structural behaviour and response under overturned truck crash that subsequently collides with road-side pole or tree. The safety of the truck occupants in an accident is very important and should be considered in the process of cabin design. Specific focus will be on the structural integrity of the truck cabin in response to a collision with a cylindrical pendulum. In the past, dynamic analysis was done by real world testing. Nowadays crash simulation is proven to be much more efficient by being a virtual representation of destructive crash impact and providing opportunities to reduce the number of physical prototypes consumed for design verification, thus reducing development time. According to cab strength tests (ECE R29), the cabin body of the truck shall be attached to the chassis in such a way that in the event of impact it ensures a sufficient survival space and eliminates the risk of injury. This paper investigates the FE (finite element) simulation of a frontal impact on the cabin structure to validate the cabin according to the ECE regulation 29 tests. The study also includes the assessment of the energy absorption capabilities of the cabin during the pendulum impact. The pendulum impact was carried out using Ansys LS-Dyna explicit solver to evaluate the cabin strength under the loads.
Experimental tests on the type-approval of motor vehicles with regard to safety belt anchorages, ISOFIX anchorages and ISOFIX top anchorages have been carried out in accordance with Regulation No. 14 UNECE. From the design stage, the safety belt anchorages must comply with the requirements for the installation of a safety belt and reduce slipping and damage to the belt while wearing it. These can be components of the seat structure or of the body's resistance structure, which have the role of fastening the seat belts. The position of the anchor points is determined by the R point. The R point is defined as the seat reference point on the seat. This point is set by the vehicle manufacturer for each seat in the vehicle. In this paper, two models of chairs were tested. Both seat models are equipped with seat belts anchored at three anchor points. Seat belt anchorages were tested simultaneously using parallel force devices. These traction devices are placed on the seat cushion and are pressed into the seat back. The pulling device has a vertical pulling arm, which has the role of anchoring the steel wire cables. Two test forces are applied simultaneously to the anchor points during the test.
Level crossings represent high risk for both rail and road users due to the severe consequences of any possible accident. Between 2011-2020, a total of 1602 accidents occurred at level crossings in Germany and resulted in 344 fatalities. Therefore, elimination of accident risk through consolidation of level crossings becomes a priority. However, due to the scarcity of financial resources in comparison to the high costs that level crossings consolidation or safety upgrade projects require, there is a need for the creation of tools that prioritize the level crossings for consolidation projects based on several criteria that is not related to safety only but to social, economic and environmental aspects as well. Such tool would be particularly useful for authorities and decision-makers in Germany to improve the resource allocation process and increase overall safety at German level crossings. In this project, the level crossing prioritization and consolidation models that are applied all over the world are reviewed and analyzed to benefit from the international experiences in this field. Additionally, a literature review to determine the most influencing factors on level crossing safety was performed. After that, a points-based priority score for German level crossings was developed based on analytic hierarchy process (AHP) methodology after a pairwise comparison survey was conducted to a selected level crossing group of experts. The developed model assigns a priority score from 1000 points to each level crossing. Crossings could be ranked according to their priority for consolidation and safety upgrade based on the points received as crossings with the highest priority score have a higher priority for elimination.
Public transport not only plays an essential role in helping people with diverse economic backgrounds to access employment and services but also the everyday life and mobility of people. Public transport is one of the most essential segments of public infrastructure in any country and a key pointer towards the economic development of that country. This study will examine the current public transport system in the United Kingdom and Germany. The focus will be bus and rail services. The study will review the present transport policy in both countries, and the system of governance – stakeholders, infrastructure, planning, and the role of public transport in everyday life of the citizens. Based on these key aspects, the paper will analyze the better developed and the lagging areas of public transport by way of comparison between both countries. After analyzation, the paper will comment on and highlight areas with room for better policy and planning in future in the United Kingdom and Germany.
Keywords – public transport, analyze, governance, policy, infrastructure, comparison, future policy.
Autonomous Vehicles (AVs) as a means of public transportation is set to revolutionize the mobility behavior of elderly people in the coming future. Though the vehicle manufacturers and corporates emphasize on potential benefits of AVs to elderly citizens, very little has been researched and studied about this large cohort (age 65+) in society. This study aims to measure the experience of the elderlies in this Highly Automat Shuttle (HAS) in Berlin and find out the potential pros and cons affecting the design, trust and security, and perception to adopt this technology in the future. Among the elderly respondents surveyed, 93% found the HAS convenient, with minor design issues addressed. Respondents (90%) were willing to use it for their first and last-mile journey and considered that the HAS would help improve the social participation of elderlies with mobility restrictions. However, elderlies still have trust issues integrating a fully driverless vehicle in the domain of public transportation. The significant findings on the difference in the experience of HAS between the elderlies, adults, and younger adults could be adopted to develop the design further, making it more comfortable and trustworthy towards the elderly population.
Active Traffic Management Systems – Developing a Package of Measurements for the City of Füssen
(2021)
Intelligent Transportation Systems (ITS) and Active Transportation and Demand Management (ATDM) are new commanders in the world of transportation engineering. The combination of ATDM and ITS has created a concept called “Active Traffic Management (ATM)”. The world’s ATM is getting a higher point for major technological changes that have been bringing new ways in public and private transport managing, decision making, smart cities, traffic control, safety and environment.
The management, control, influence of travel demand and traffic flow in transportation facilities is referred to as ATM. Actions are taken in real time to improve system performance, such as preventing or delaying breakdown conditions, enhancing safety, encouraging sustainable travel modes or cutting emissions, using archived data and or/predictive methods.
In this Master's thesis, it has been exanimated the prominent different areas of Active Traffic Management in traffic engineering with a special focus on the sections of traffic management, signal control, and simulations with the program VISSIM. To discuss this issue, this paper begins with a brief introduction of the names and concepts of the current technologies in ATM, followed by an example. Important data and challenges for the study case of the city of Füssen in Germany will be presented in the text, subsequent to some results, conclusions and recommendations. In addition, the current and alternative scenarios with their respective level of service are researched according to German regulations. A simulation of different nodes has been modeled to observe the respective delays, level of services and emissions of the intersections selected in the city.
Keywords
Traffic Engineering, Intelligent Transportation Systems (ITS), Active Traffic Management (ATM), Level of Service (LOS) and Traffic Simulation.
The accident data analysis uses data mining and machine learning techniques, focusing on the factors that are involved in the accident occurrence. This data is collected by the police who is a first investigator and is afterwards used by the accident researcher to examine possible accident causes and influences. The main purpose of this thesis is to get an in-depth understanding by creating new data for accident researchers which helps to understand certain accident scenarios in more detail.
The additional data is based on information derived from the decodation of Vehicle Identification Number (VIN) or in the German Language it is also known as Fahrzeugidentifikationsnummer (FIN). The FIN was decoded into its various sections in order to get the detail on its company, model and model year so that the analysis based on this factor can be added to the accident information and accident participant information. This system is automized for a fast integration of new FIN-data into the accident database and can further be used in the future in-depth study of accident occurrence. It is expected that the research and findings mentioned in this thesis report will help the researcher to analyze the influence of these vehicle characteristics in accident occurrence.
The thesis analysis the car parks’ elements and the factors that influence the drivers’ behaviour on them. Then makes an approach to the definition of the strategy of how the car drivers search for free parking spaces. The reason for it is that there is a need to assess car parks’ design parameters in the terms of their performance. One of the decisive factors is also the drivers’ behaviour. A car park simulation based on the environment of matrices is designed and implemented in MATLAB. The algorithm for searching for the parking spaces is designed and implemented within that as well. The results of the simulation are presented.
The principal objective of this thesis is to execute a priority system for public transport buses at a signalized intersection. Based on the actual demand for buses, a dedicated bus lane is proposed to provide spatio-temporal priority. The optimal location was examined with the help of microscopic simulation software before bus lanes were introduced in the network. Bus priority lanes interrupted the existing traffic flow pattern and compelled straight-ahead vehicles to shift into adjacent lanes. Therefore, median turning lanes were added to improve the capacity of mainstreams. A fixed-time signal program with an additional transit priority phase was designed to accommodate peak-hour traffic flow. In order to achieve variabilities in the cycle length, a vehicle-actuated signal controller was implemented to operate the modeled intersection, which responds to the real-time traffic demand.
A simulation test was performed in VISSIM on both the actual and modeled intersection. Comprehensive result analysis in terms of travel time, vehicle delays, and queue lengths was made to determine the performance and saturation level of the selected intersection.
ABSTRACT
Traffic congestion is a worldwide issue seen in various metropolitan cities. The reason for the existence of traffic congestion is overpopulation and high volumes of private cars that the roads are not able to sustain. The causes of traffic congestion are accidents, pollution, rush hours, bus bunching, and delays. Data and statistics are provided for traffic congestion related to rush hours. The benefits of public transportation such as buses are discussed. In this paper various forms of transit signal priority (TSP) strategies are assessed. TSP is a strategy that improves public transportation. The goal is to lessen congestion, lessen wait times, lessen travel times, and improve the service. Various forms of transit signal priority are researched and analyzed such as green wave, red truncation, dedicated bus lanes, queue jumps, etc.
The principal objective and aim of this thesis are improving traffic flow at the intersections of 2nd avenue @ 97th street, 2nd avenue @ 98th street and 2nd avenue @ 99th street in Manhattan. VISSIM will be utilized in implementing and setting up a high-quality microscopic simulation model of the signalized intersection in Manhattan. Providing prioritization for public transportation (specifically buses). Analyzing deficiencies in the traffic flow at the intersection 2nd avenue @ 97th, 98 and 99th street. The real time aspects will be considered on the selected intersections such as traffic signal coordination, speeds, pedestrians, various types of vehicles, public transportation, and bus stops.
There will be two models simulated: one that simulates the real time conditions. The second model in VISSIM implement changes to traffic flow on signalized intersection through V-A controller logic system. Improved signalization utilizes tsp and shows changes to congestion by giving buses priority with the help of detectors on signalized intersections. The aim of this model is to provide priority to buses and allows them special treatment; ultimately improves the bus service and traffic congestion.
KEYWORDS:
Bus priority, transit signal priority, detectors, public transportation, green extension, V-A Signal controller.
Vehicular emission is often the main source of air pollution. The chief pollutants react with air and secondary pollutants resulting in adverse effects to the environment. European commission has legislated laws in order to reduce the air pollution from vehicular emissions.
Traffic modelling has been used for many decades and particularly in the last decade, flow of traffic based on vehicle type has been used to estimate emission of polluting gases and particles. Passenger car and Heavy duty Emission Model (PHEM) is used along with microscopic traffic flow simulation software VISSIM (In German: Verkehr In Städten – SIMulationsmodell meaning "Traffic in cities - simulation model") for estimation of major two major pollutants of greenhouse gases (carbon dioxide, nitrogen oxides) and particulate matter emitted from passenger cars and heavy-duty vehicles, based on their technical performance characteristics in a traffic flow at a typical German motorway segment. With a country’s fixed fleet composition for a particular year, PHEM gives fuel consumption and emission as outputs using fuel types used (diesel or petrol) and based on the trajectories of the vehicles.
This study is planned to exploit the developments and investigate the validation of this software with HBEFA. Different 25 scenarios are created for a German motorway segment with varying traffic behaviours; and the emission results between two emission modelling software tools are compared.
Railways is one of the most important ways of transporting people and goods from place to another in the whole world. In Germany, it comes as the second most used way of transport. The German railways network is so big and covers the whole maps of Germany. That is why it is so important to develop and improve the performance of it. At this thesis work, the performance of every route at the German railways is calculated using a digital model which is created in PTV Visum software using the programming language python. Furthermore, the workload of every node (junction) at the German Railways is calculated, and according to that, recommendations to build an overpass structure at the overloaded Junctions is suggested to improve the capacity of this Junctions.
Due to the current emission standards and the even more environmentally friendly vehicle developing. The ethanol level in the fuel has been increased more and more over the past few years. This is the reason why the manufactures must look out for while developing the engine management software.
To get a subjective point of view of what happens with this increase, a universal test procedure was established. A fully instrumented gasoline vehicle was tested with four test fuels. During testing the procedure had to be modified from the first seen data. That is why two Drive cycles had been generated.
After the evaluation of the collected data, the influence of ethanol on the cold start and warm up phase was shown. As a result, higher ethanol content in the fuel increased hesitation and negative effect of that component. Also, it became even more clear, that this test procedure should be used for more than just one vehicle. This would help with clarifying if this effect was caused by the ethanol alone or if the software or design of the engine had an influence on it.