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Technical Paper

Large Eddy Simulations and Tracer-LIF Diagnostics of Wall Film Dynamics in an Optically Accessible GDI Research Engine

2019-09-09
2019-24-0131
Large Eddy Simulations (LES) and tracer-based Laser-Induced Fluorescence (LIF) measurements were performed to study the dynamics of fuel wall-films on the piston top of an optically accessible, four-valve pent-roof GDI research engine for a total of eight operating conditions. Starting from a reference point, the systematic variations include changes in engine speed (600; 1,200 and 2,000 RPM) and load (1000 and 500 mbar intake pressure); concerning the fuel path the Start Of Injection (SOI=360°, 390° and 420° CA after gas exchange TDC) as well as the injection pressure (10, 20 and 35 MPa) were varied. For each condition, 40 experimental images were acquired phase-locked at 10° CA intervals after SOI, showing the wall-film dynamics in terms of spatial extent, thickness and temperature.
Technical Paper

Holistic Approach for Improved Safety Including a Proposal of New Virtual Test Conditions of Small Electric Vehicles

2015-04-14
2015-01-0571
In the next 20 years the share of small electric vehicles (SEVs) will increase especially in urban areas. SEVs show distinctive design differences compared to traditional vehicles. Thus the consequences of impacts of SEVs with vulnerable road users (VRUs) and other vehicles will be different from traditional collisions. No assessment concerning vehicle safety is defined for vehicles within European L7e category currently. Focus of the elaborated methodology is to define appropriate test scenarios for this vehicle category to be used within a virtual tool chain. A virtual tool chain has to be defined for the realization of a guideline of virtual certification. The derivation and development of new test conditions for SEVs are described and are the main focus of this work. As key methodology a prospective methodical analysis under consideration of future aspects like pre-crash safety systems is applied.
Technical Paper

Design of a Cryogenic Platform for New Communication Payload Technologies

1999-07-12
1999-01-2086
In this paper we present the design of a cryogenic platform for new space borne communication payloads. This platform is dedicated to service the operation of a communication payload in a cryogenic environment. In addition, an easy adaptation to any kind of available satellite buses must be reflected by the design of all interfaces. A first experimental demonstrator of this cryogenic platform with HTSC-components is foreseen to be operated on board the International Space Station (ISS) [1]. The paper will present such a new kind of cryogenic platform. The thermal requirements and boundary conditions for the platform development are summarized. A comparison of the typical thermal environment of a communication satellite with the environment of the ISS and is performed. Two different concepts for the design of a cryogenic platform will be presented. A redundancy concept for the provision of cooling power and the thermal control of the cryogenic platform is discussed.
Technical Paper

Simulation for the Development of the Bosch-VDC

1996-01-26
960486
A new automotive active safely system, the Vehicle Dynamics Control System (VDC) of BOSCH was introduced on the market in 1995. Besides improving the ABS/ASR functions, VDC will also actively support the driver in critical situations of lateral vehicle dynamics. This system includes new ABS/ASR-control algorithms and a superimposed control algorithm, the vehicle dynamics controller. Furthermore, an extension of the standard ABS/ASR-hydraulic system was necessary as well as the development of new automotive sensors. During all phases of the interdisciplinary system development, tests on experimental cars and extensive computer simulations were used in parallel. In order to provide adequate simulation models for different tasks, a modular concept for the simulation tool is important. Furthermore, a transparent and portable application of the control algorithm for both, experiment and simulation, is required.
Technical Paper

Generic X-Domain Hazard Analysis and Risk Assessment

2023-04-11
2023-01-0580
X-Domain describes the merging of different domains (i.e., braking, steering, propulsion, suspension) into single functionalities. One example in this context is torque-vectoring. Different goals can be pursued by applying X-Domain features. On the one hand, savings in fuel consumption and an improved vehicle driving performance can be potentially accomplished. On the other hand, safety can be improved by taking over a failed or degraded functionality of one domain by other domains. The safety-aspect from the viewpoint of requirements is highlighted within this contribution. Every automotive system being developed and influencing the vehicle safety must fulfill certain safety objectives. These are top-level safety requirements (ISO 26262-1) specifying functionalities to avoid unreasonable risk. Every safety objective is associated with an Automotive Safety Integrity Level (ASIL) derived from a Hazard Analysis and Risk Assessment (HARA).
Journal Article

Side View Assist - The World’s First Rider Assistance System for Two-Wheelers

2016-11-08
2016-32-0052
The Side View Assist is the World’s first rider assistance system for two-wheelers. This is a Blind Spot Warning system, which uses four ultrasonic sensors to monitor the surrounding of the rider. Whenever there is a vehicle (i.e. a car, truck, or another motorbike) in the rider’s blind spot, the technology warns the rider with an optical signal close to the mirror. This will allow the rider to avoid a collision when changing lanes. In the current vehicle application, Side View Assist is active at speeds ranging from 25 to 80 kilometers per hour and supports riders whenever the difference in relative speed to other road users is small. The system helps to improve safety especially in cities, where heavy traffic makes it necessary to change lanes more often. Originally such systems have been developed for cars and different system solutions for cars have been in serial production for several years. The challenge was to adapt these systems so they would work for two-wheelers as well.
Journal Article

Concept Design of a Parking Brake Module for Standstill Management and Wheel Individual Brake Torque Generation for EVs with Unconventional Service Brake Topology

2022-09-19
2022-01-1186
For electric vehicles the ability for regenerative braking reduces the use of friction brakes. Particularly on the rear axle of vehicles with reduced dynamic requirements such as urban vehicles, this can offer a potential for downsizing or, in extreme cases, even the elimination of the friction brakes on the rear axle. Due to the fact that the rear axle service brakes also represent the typical parking brake location in SoA (State-of-Art) vehicles, a rigorous rethinking of the parking brake concept is necessary to incorporate safe vehicle standstill management for such novel brake system topology. This research study introduces a novel parking brake design that covers SoA but also legal requirements while retaining potentials associated with the elimination of the rear service brakes such as cost and packaging.
Technical Paper

VDC, The Vehicle Dynamics Control System of Bosch

1995-02-01
950759
VDC is a new active safety system for road vehicles which controls the dynamic vehicle motion in emergency situations. From the steering angle, the accelerator pedal position and the brake pressure the desired motion is derived while the actual vehicle motion is derived from the yaw rate and the lateral acceleration. The system regulates the engine torque and the wheel brake pressures using traction control components to minimize the difference between the actual and the desired motion. Included is also a safety concept which supervises the proper operation of the components and the software.
Technical Paper

Optimization of Laminated Stack Solutions for Electric Motors in Electrified Vehicles

2024-04-09
2024-01-2214
The electrification of vehicles marks the introduction of new products to the automotive market and a continued effort to optimize their performance. The electric motor is an important component with which a further optimization of efficiency, power density and cost can be achieved. Additional benefits can be realized in the laminated core. This paper presents an innovative method to produce laminated stacks by a chain of processes different from conventional ways. The process chain presents a sequence of precision blanking, buffering, heat treatment and gluing. The effect of these processes is compared with existing solutions that typically contain some individual features but usually not the combination that enhances the overall effect. The heat treatment decreases residual stresses from previous process steps and reduces power losses in the laminated core. Depending on the design, benefits around 20% are found.
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