11 research outputs found
Unambiguous and Reliable Positioning in the vehicle in terms of Functional Safety and Cyber Security
Functional security and agile software development are two modern areas in product development, which initially have very opposite approaches. For example, formal tests are required by the relevant standards for the former, which must be documented very extensively. The agile software development, on the other hand, tries to come to its conclusion with as few documentation and flexible tests as possible. Also, the proof that testing and development are independent of each other for safety-critical projects is difficult in the context of the use of agile methods. However, taking the constraints of functional safety as given and taking advantage of the enormous flexibility of agile software development, e.g. With the use of Scrum, the Daily Team Meetings create new opportunities in product development. In contrast to previous positioning methods for linearly movable axles, a new developed approach for rear axle steering has not been used as an absolute value encoder, but a novel positioning concept has been researched and developed. Functional Safety first! A new safety concept must therefore be developed. The absolute value encoder, usually realized as an optical or magnetic bar-coded sensor, is used reliably but cost-effectively in a large number of systems. In order to save costs as well as space, the development of the new approach to the sensor will be dispensed with and the positioning will be realized via a new concept. The conventional concepts for position determination of axes is an absolute value encoder. However, this is not highly reliable and has no redundancy. With the new safety concept, the exact position of an axis can be determined and output with high accuracy by means of the various safety devices directly after switching on the system. As a result, the sensor system is hardly susceptible to errors. Here, a detailed error analysis has been carried out. Even after system crashes, there are enough detection points, which are constantly detected during normal operation and thus the plausibility check can be restored. The new explored approach allows the steering to work normally even in safe modes. However, the algorithms for protection have to take effect immediately if, for example, an expected index signal does not occur
Unambiguous and Reliable Positioning in the vehicle in terms of Functional Safety and Cyber Security
Functional security and agile software development are two modern areas in product development, which initially have very opposite approaches. For example, formal tests are required by the relevant standards for the former, which must be documented very extensively. The agile software development, on the other hand, tries to come to its conclusion with as few documentation and flexible tests as possible. Also, the proof that testing and development are independent of each other for safety-critical projects is difficult in the context of the use of agile methods. However, taking the constraints of functional safety as given and taking advantage of the enormous flexibility of agile software development, e.g. With the use of Scrum, the Daily Team Meetings create new opportunities in product development. In contrast to previous positioning methods for linearly movable axles, a new developed approach for rear axle steering has not been used as an absolute value encoder, but a novel positioning concept has been researched and developed. Functional Safety first! A new safety concept must therefore be developed. The absolute value encoder, usually realized as an optical or magnetic bar-coded sensor, is used reliably but cost-effectively in a large number of systems. In order to save costs as well as space, the development of the new approach to the sensor will be dispensed with and the positioning will be realized via a new concept. The conventional concepts for position determination of axes is an absolute value encoder. However, this is not highly reliable and has no redundancy. With the new safety concept, the exact position of an axis can be determined and output with high accuracy by means of the various safety devices directly after switching on the system. As a result, the sensor system is hardly susceptible to errors. Here, a detailed error analysis has been carried out. Even after system crashes, there are enough detection points, which are constantly detected during normal operation and thus the plausibility check can be restored. The new explored approach allows the steering to work normally even in safe modes. However, the algorithms for protection have to take effect immediately if, for example, an expected index signal does not occur
Time Resolved Measurements of Soot Concentrations and Mean Particle Sizes during EUDC and ECE Cycles
In-line particle measurements of the undiluted exhaust of combustion engines by multi-wavelength extinction technique
On-Line / In-Line Measurements of Particle Emissions by a Combustion Aerosol Standard
A system for the on-line/in-line measurement of soot particle sizes and concentrations in the undiluted exhaust gas of diesel engines was developed and successfully tested. The unit uses the individual attenuations of three different laser wavelengths and is combined with an optical cell (white principle) with adjustable path lengths from 2.5 to 15 meters
Newly designed flow field-flow fractionation channel for macromolecules and particles in the submicrometer and micrometer range
The flow field-flow fractionation (FIFFF) technique is a promising method for separating and analysing particles and large size macromolecules from a few nanometers to approximately 50 μm. A new fractionation channel is described featuring well defined flow conditions even for low channel heights with convenient assembling and operations features. The application of the new flow field-flow fractionation channel is proved by the analysis of pigments and other small particles of technical interest in the submicrometer range. The experimental results including multimodal size distributions are presented and discussed
Langzeit-Aerosol-Überwachung mit einem kalibrierfreien, kompensierten Streulichtfotometer
Zur Messung geringer Massenkonzentrationen und der Partikelgrößenverteilung unter hohen Druck- und Temperaturbedingungen, wie sie z.B. bei Überwachung des Gasstromes in Druckwirbelschichtfeuerungen oder in Druckkohlestaubfeuerungen vorkommen, wird ein kompensiertes Streulichtfotometer vorgeschlagen. Streulicht- und Transmissionswerte des Partikelkollektivs werden erfasst und miteinander verknüpft. Als Vorteil dieses Mess- und Auswerteprinzips ergibt sich im Gegensatz zu konventionellen Fotometern eine weitgehende Unempfindlichkeit gegenüber Fenster-Verschmutzung und Alterung von Komponenten. Das neue Konzept ist bis etwa 900 ºC einsatzfähig.For monitoring of low mass concentrations and particle size distributions under high pressure and temperature conditions, e. g., in pressurized fluidized bed combustion or pressurized pulverized coal combustion processes, a self-compensating light-scattering photometer is presented. Light scattering signals measured for a particle collective are normalized with respect to light transmission data. The advantage of the new principle is the insensitivity against ageing and contamination of components which distinguishes it from conventional photometers. The system can be applied at temperatures of up to 900 ºC
Correlation of Measurements of a New Long Optical Path Length Particle Sensor against Gravimetric and Electrical Mobility based Particle Measurements in Diesel Exhaust
A prototype multiwavelength sensor able to characterise soot emissions in Diesel exhaust in terms of size and concentration has been tested against other methods for diesel particle measurements like electrical mobility sizing (SMPS) and raw exhaust gravimetric sampling (RES). Measurements carried out with the prototype sensor were correlated with the SMPS by assuming spherical and/or fractal aggregate morphology of the particles. Correlation of RES gravimetric data against the sensor and the SMPS led to the calculation of the solid density for soot particles to be 2.3 gr/cm3