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Technical Paper

Active Pedestrian Protection - System Development

2004-03-08
2004-01-1604
Pedestrian protection is an upcoming field for research and development. Active pedestrian protection is described from a system perspective. In this view, the development of an active pedestrian protection system is shown. First an overview on statistics and legal requirements is given and the system requirements are discussed. Sensor concepts and realizations are shown, also different test methods and results are explained. FE-simulations to complete and later replace additional tests are developed, after cross check with the experimental results. In combination with the shown actuator concept this leads to a full functioning active pedestrian protection system.
Technical Paper

Automated Model-Based GDI Engine Calibration Adaptive Online DoE Approach

2002-03-04
2002-01-0708
Due to its high number of free parameters, the new generation of gasoline engines with direct injection require an efficient calibration process to handle the system complexity and to avoid a dramatic increase in calibration costs. This paper presents a concept of specific toolboxes within a standardized and automated calibration environment, supporting the complexity of GDI engines and establishing standard procedures for distributed development. The basic idea is the combination of a new and more efficient online DoE approach with the automatic and adaptive identification of the region of interest in the high dimensional parameter space. This guarantees efficient experimental designs even for highly non-linear systems with often irregularly shaped valid regions. As the main advantage for the calibration engineer, the new approach requires almost no pre-investigations and no specific statistical knowledge.
Technical Paper

CARTRONIC® Based Safety Analysis: Introducing Safety Aspects In Early Development Phases

2002-03-04
2002-01-0269
This article gives an overview of the CARTRONIC® based safety analysis (CSA) including an approach for the automatic determination of failure dependencies in automotive systems. CSA is a safety analysis in an early stage of product development. The goals are to identify safety critical components as soon as practicable in the product development process and to automate the analysis as far as possible. This implies that the system view is abstract, i.e. independent of a certain realization just regarding system functionality. In the CSA so called global failure effects will be systematically identified and assessed regarding severity of potential injuries. Global failure effects are especially important because they reveal failures within the system to the outside world (see also definition 3.1). Additionally the CSA keeps track of failure dependencies and supports the integration of safety measures in the system structure.
Technical Paper

A New Approach to Assess the Accuracy of Service Timing Devices for Injection Pumps of Diesel Engines

1999-03-01
1999-01-0823
The correct timing of the diesel injection pump on engine is of major importance for all functions of the engine and for its exhaust emissions, during production pass off as well as in the field. Within the diesel service workshops a variety of devices exist to test the timing of the injection pump on engine. Most of them operate by clamp-on transducer being fitted to the injection pipe. A large uncertainty exists concerning the accuracy of such timing systems. Most diesel engine manufacturers do not have confidence in the timing devices capability and, therefore, do not recommend their usage. A working group within the International Organization for Standardization (ISO) adopted a method for the validation of these measurement systems, which usually is used to judge the capability of measurement gauges for industrial production processes.
Technical Paper

Simulation, Performance and Quality Evaluation of ABS and ASR

1988-02-01
880323
The article describes the methods, which are employed in order to ensure high performance, safety and quality of ABS and ASR. System behaviour is evaluated and optimized by computer simulation. Moreover, a real-time simulator has been developed by which the consequences of hardware defects can be investigated systematically, Despite the increasing use of simulation the testing of vehicles remains the most important tool for system evaluation. For that purpose, a digital data acquisition system has been developed and objective evaluation criteria have been established. In order to achieve high product quality the Failure Mode and Effect Analysis (FMEA) is carried out at an early phase of development. Another prerequisite for high product quality is thorough durability and endurance testing before release of production.
Technical Paper

Progress in Electronic Diesel Control

1984-02-01
840442
The usage of Electronic Diesel Control is increasing with todays stringent emissions regulations. This requirement also necessitates that such systems be versatile to meet the needs of the engine/vehicle manufacturer. EGR, start of injection, and fuel delivery can be electronically controlled. Depending on the design goals of the manufacturer any one or two of these can be controlled for partial and all of them for full Electronic Diesel Control. The development and application process has several critical areas. These include, development of the sensors, application of the different subsystems, failure warning and failure mode operation. All of these must be combined if design goals are to be met. As the capabilities of electronics increase it follows that electronic vehicle systems will also improve. Today impressive results have been achieved with systems that are in full or pilot production.
Technical Paper

Comparison of Shadowgraph Imaging, Laser-Doppler Anemometry and X-Ray Imaging for the Analysis of Near Nozzle Velocities of GDI Fuel Injectors

2017-10-08
2017-01-2302
The fuel spray behavior in the near nozzle region of a gasoline injector is challenging to predict due to existing pressure gradients and turbulences of the internal flow and in-nozzle cavitation. Therefore, statistical parameters for spray characterization through experiments must be considered. The characterization of spray velocity fields in the near-nozzle region is of particular importance as the velocity information is crucial in understanding the hydrodynamic processes which take place further downstream during fuel atomization and mixture formation. This knowledge is needed in order to optimize injector nozzles for future requirements. In this study, the results of three experimental approaches for determination of spray velocity in the near-nozzle region are presented. Two different injector nozzle types were measured through high-speed shadowgraph imaging, Laser Doppler Anemometry (LDA) and X-ray imaging.
Technical Paper

Analysis of Non-Police Reported Accidents on Indian Highways

2017-01-10
2017-26-0005
The official Indian accident statistics show that the number of road accidents and fatalities are one of the highest worldwide. These official statistics provide important facts about the current accident situation. It is suspected that for various reasons not all accidents are reported to the official statistic. This study estimates the degree of underreporting of traffic accidents with casualties in India. In order to get a national overview of the traffic accident situation it is necessary to improve the knowledge about underreported accidents. Therefore, the in-depth accident database of “Road Accident Sampling System India” (RASSI) was analyzed [1]. This project is organized by a consortium that has collected traffic accidents scientifically in four different regions since 2011 on the spot which have been reported either by police or by local hospitals and own patrol by RASSI engineers.
Technical Paper

Analyze This! Sound Static Analysis for Integration Verification of Large-Scale Automotive Software

2019-04-02
2019-01-1246
Safety-critical embedded software has to satisfy stringent quality requirements. One such requirement, imposed by all contemporary safety standards, is that no critical run-time errors must occur. Runtime errors can be caused by undefined or unspecified behavior of the programming language; examples are buffer overflows or data races. They may cause erroneous or erratic behavior, induce system failures, and constitute security vulnerabilities. A sound static analyzer reports all such defects in the code, or proves their absence. Sound static program analysis is a verification technique recommended by ISO/FDIS 26262 for software unit verification and for the verification of software integration. In this article we propose an analysis methodology that has been implemented with the static analyzer Astrée. It supports quick turn-around times and gives highly precise whole-program results.
Technical Paper

Numerical Analysis of the Influences of Wear on the Vibrations of Power Units

2020-09-30
2020-01-1506
Numerical Analysis of the Influences of Wear on the Vibrations of Power Units Yashwant Kolluru, Rolando Doelling eBike Department Robert Bosch GmbH Kusterdingen, Germany yashwant.kolluru@de.bosch.com rolando.doelling@de.bosch.com Lars Hedrich Institute of Informatics Goethe University Frankfurt Frankfurt, Germany hedrich@em.informatik.uni-frankfurt.de The prime factor, which influences vibrations of electro-mechanical drives, is wear at the components. This paper discusses the numerical methods developed for abrasion, vibration calculations and the coupling between wear and NVH models of drive unit. Wear is a complex process and understanding it is essential for vibro-acoustics. The paper initially depicts finite element static model used for wear calculations. The special subroutines developed, aids in coupling the wear equations, various contact and friction formulations to the numerical model.
Technical Paper

Multi Domain Modeling of NVH for Electro-Mechanical Drives

2020-09-30
2020-01-1584
Acoustics and vibrations are amongst the foremost indicators in perceiving the quality of drive units. Analyzing these factors is vital for improve the performances of electro-mechanical systems. This paper deals with the study of vibro-acoustic behavior concerning the drivetrain components using system modeling and Finite Element calculations. A generic simulation methodology within system modeling is proposed enabling the vibro-acoustic simulation of electro-mechanical drivetrains. Excitations for these systems mostly arise from the electric motor and mechanical gears. The paper initially depicts the system model for gear whining considering the associated nonlinearities of the mesh. The results obtained from the gear mesh submodel, together with the excitations resulting from the motor, aid in the comprehension of the forces at the bearings and of the vibrations at the housings.
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