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Technical Paper

Time Resolved Spray Characterisation in a Common Rail Direct-Injection Production Type Diesel Engine Using Combined Mie/LIF Laser Diagnostics

2003-03-03
2003-01-1040
This study reports on laser-based diagnostics to temporally track the evolution of liquid and gaseous fuel in the cylinder of a direct injection production type Diesel engine. A two-dimensional Mie scattering technique is used to record the liquid phase and planar laser-induced fluorescence of Diesel is used to track both liquid and vaporised fuel. LIF-Signal is visible in liquid and gas phase, Mie scattering occurs only in zones where fuel droplets are present. Distinction between liquid and gaseous phase becomes therefore possible by comparing LIF- and Mie-Signals. Although the information is qualitative in nature, trends of spray evolution are accessible. Within this study a parametric variation of injection pressure, in-cylinder conditions such as gas temperature and pressure as well as piston geometry are discussed. Observations are used to identify the most sensitive parameters and to qualitatively describe the temporal evolution of the spray for real engine conditions.
Technical Paper

The Influence of Hydro Grinding at VCO Nozzles on the Mixture Preparation in a DI Diesel Engine

1996-02-01
960867
The hydro grinding process can be used for valve covered orifice (VCO) nozzle production. A comprehensive numerical and experimental investigation was performed to determine the influence of hydro grinding (HG) at VCO nozzles on the mixture preparation in pressure charged high speed direct injection diesel engines. Samples of five hole VCO nozzles with defined grades of HG and different sprayhole diameters were selected to ensure a constant mass flow at a fixed feeding pressure for comparable engine tests. The simulation of the internal flow shows a more symmetrical velocity profile indicating less shear flow and lower turbulence intensities at the orifice with increased HG grade. From these results an enhanced atomization at further penetration depth and reduced atomization close to the nozzle could be expected. This was confirmed by measuring the spray momentum distribution and spray tip speed by mechanical and optical probes in high pressure vessels.
Technical Paper

Advanced Engine Misfire Detection for SI-Engines

1997-02-24
970855
This paper presents a system concept for detecting combustion misfire. The relevant research grew out of the more stringent requirements for On-Board Diagnostic systems (OBDII) mandated by the California Air Resources Board (CARB), effective as of model year 1997 onward. The system concept is based on evaluation of variations in crankshaft speed. Processes using engine roughness are applied in non-critical operating areas and/or on engines with a small number of cylinders. The modulation process is used in more critical areas. Research was done using a 12-cylinder engine and indicated the potential to comply with the California Air Resources Board's regulations for the model year (MY) 1997 and later.
Technical Paper

Electroformed Multilayer Orifice Plate for Improved Fuel Injection Characteristics

1997-02-24
971070
A new orifice plate (OP) for advanced fuel injection characteristics is presented. The OP is designed to optimize the air-fuel mixture generation and transportation within individually shaped manifold geometries of spark-ignition engines. To generate the suitable spray characteristics, the basic OP design and its flow characteristics have some features originating from the well known turbulence nozzle principle: Turbulence generating flow deflections within the OP are achieved by superimposing layers containing flow cavities, which are displaced from one another. The flow deflections effect atomization and define the spatial spray beam orientation. A great variety and a high volume of precisely structured, low cost OPs can be produced daily by micromachining the layers in electroformed nickel. The flow cavities and outer dimensions of each layer are shaped by photo-resist structures.
Technical Paper

A New Combustion Pressure Sensor for Advanced Engine Management

1994-03-01
940379
A new combustion pressure sensor (CPS) for advanced engine management is presented, which is designed to carry out the functions: misfire detection, knock control, ignition control, camshaft phase detection and engine roughness control. For small size and high accuracy at a reasonable cost the piezoresistive effect, which is realized within an integrated circuit device and delivers low impedance output signals, has been chosen. Due to the optimized sensor housing, membrane and force transfer design, the sensor shows little offset drift when affected by flame front and environmental thermal stress. This paper describes the CPS and its performance in comparison with a well-known highly accurate reference sensor.
Technical Paper

Common Rail Injection System for Commercial Diesel Vehicles

1997-02-24
970345
Common Rail provides additional flexibility for the design and application of a diesel injection system. Contrary to conventional injection systems pressure generation and injection are decoupled in the common rail system. The injection pressure can be selected independent of engine speed and injected fuel quantity within certain limits. The fuel combustion and the corresponding noise can be improved by increasing the fuel pressure up to 1400 bar and introducing pilot injection or multiple injection. Furthermore the common rail system can replace conventional injection systems without requiring major engine modifications. BOSCH will provide this new injection system for the whole range of applications from light duty (30 kW per cylinder) to heavy duty vehicles (50 kW per cylinder).
Technical Paper

Yaw Rate Sensor for Vehicle Dynamics Control System

1995-02-01
950537
From the beginning of 1995 on, RB will start the production of the Vehicle Dynamics Control System. A key part of this system is the Yaw Rate Sensor described in this paper. The basic requirements for this sensor for automotive applications are: mass producibility, low cost, resistance against environmental influences (such as temperature, vibrations, EMI), stability of all characteristics over life time, high reliability and designed-in safety. Bosch developed a sensor on the basis of the “Vibrating Cylinder”. The sensor will be introduced into mass production in beginning of 1995.
Technical Paper

Integrated Silicon Pressure Sensor for Automotive Application with Electronic Trimming

1995-02-01
950533
An integrated manifold pressure sensor using bulk silicon micromachining techniques is presented. The sensor incorporates the entire signal amplification, temperature compensation, and circuitry for electronic trimming of the sensor chip. The chip circuitry and the manufacturing and assembly process will be discussed. Trimming of the sensitivity and offset production tolerances as well as the temperature coefficients of sensitivity and offset is performed using an electrical trim method. A binary coded digital compensation information is serially fed into an on-chip control unit. The individual bits are decoded and sent to the gates of a bank of trimming thyristors. Once the correct binary code has been selected so that the sensor characteristic is centered in the specified range, the programming voltage is increased and the data is irreversibely stored similarly to the zener zapping method.
Technical Paper

Variable Orifice Geometry Verified on the Two-Phase Nozzle (VRD)

1995-02-01
950081
Innovative solutions for reducing particulate emissions will be necessary in order to comply with the even more stringent exhaust-gas standards of the future. The potential of a diesel nozzle with variable orifice geometry has long been common knowledge in the area of engine construction. But up to now, a fully functional solution of such a nozzle has not appeared which operates with a reduced orifice at low engine speeds and/or low loads. Here with regard to target costing, the requirements implicit in function and manufacture must also be taken into account. Using calculations on nozzle interior flow and injection-spray investigations, it will be shown which nozzle geometries best fulfill the various requirements. In order to achieve low levels of particulate emission in an engine with a combustion chamber designed for optimum use of a hole-type nozzle, the injection-spray direction and its geometry must to a large extent correspond to those of a hole-type nozzle.
Technical Paper

GDI: Interaction Between Mixture Preparation, Combustion System and Injector Performance

1998-02-23
980498
The development of future engine generations for Gasoline Direct Injection requires sophisticated combustion systems to reach reduced fuel consumption and future emission standards. The design process of these combustion systems has to be based on a fundamental knowledge of the interacting mixture preparation mechanisms. Beside the air motion inside the cylinder mixture preparation is mainly feeded by the fuel spray quality, injector performance respectively. The article therefore presents a fundamental analysis of the GDI mixture preparation and affords an insight into the injector development. Comprehensive experimental studies were performed in high pressure/temperature vessels using Phase Doppler Anemometry, Laser Induced Fluorescence and video techniques to define the significant fuel spray features for GDI. CFD-calculations were additionally applied to study the temporal behavior of the mixture preparation under injection parameter variation.
Technical Paper

Cartronic-An Ordering Concept for Future Vehicle Control Systems

1998-10-19
98C011
The continuously increasing performance of modern automotive microelectronics is leading to ever more complex open and closed-loop control functions. Rigid mechanical connections a broken down and electronics applied to make them controllable. Among the examples are camshaft control, or future systems for variable valve-lift control. In addition, the individual systems in the vehicle, such as engine management, transmission-shift control, and ABSR will be networked with one another. The result is a system alliance which communicates through a car-wide web. The major challenge posed by this development in the future, lies in still being able to reliably control the complexity of the system alliance from the point of view of reliability and safety. This means that the suitable sensor and actuator basis, together with an architecture having fixed configuration rulings and matching development methods, are indispensable.
Technical Paper

New Approaches to Electronic Throttle Control

1991-02-01
910085
An electronic control of throttle angle is required for safety systems like traction control (ASR) and for advanced engine management systems with regard to further improvements of driving comfort and fuel economy. For applications, in which only ASR is required, two versions of a new traction control actuator (TCA) have been developed. Their function is based on controlling the effective length of the bowden cable between the accelerator pedal and the throttle. Besides retaining the mechanical linkage to the throttle, the concept has no need for a pedal position sensor, which is necessary for a drive-by-wire system. Design and performance of both actuators are described and their individual advantages are compared. Moreover, the communication of the system with ASR and its behaviour with regard to vehicle dynamics are illustrated.
Technical Paper

ASR-Traction Control, State of the Art and Some Prospects

1990-02-01
900204
Closed loop vehicle control comprising of the driver, the vehicle and the environment is now achieved by the automatic wheel slip control combination of ABS and ASR. To improve directional control during acceleration, the Robert Bosch Corporation has introduced five ASR-Systems into series production. In one system, the electronic control unit works exclusively with the engine management system to assure directional control. In two other systems, brake intervention works in concert with throttle intervention. For this task, it was necessary to develop different highly sophisticated hydraulic units. The other systems improve traction by controlling limited slip differentials. The safety concept for all five systems includes two redundant micro controllers which crosscheck and compare input and output signals. A Traction Control System can be achieved through a number of torque intervention methods.
Technical Paper

A New MOTRONIC System with 16 Bit Micro Controller

1989-08-01
891648
The functionality of engine management systems has grown rapidly over the last few years. The paper presents a new Motronic concept, the engine management control M3. The Motronic family M3 is a modular design destined to control engines with up to eight cylinders individually. The main features of this system and the ECU's concept are discussed.
Technical Paper

Pressure Modulation in Separate and Integrated Antiskid Systems with Regard to Safety

1984-02-01
840467
The antiskid systems which have been on the market for some time are characterized by the fact that they are separate from the brake power-assist unit and are positioned between the master cylinder and the wheel brakes (separate configuration). At present, integrated antiskid systems are also being prepared for launching on the market. In these systems the hydraulic brake power-assist unit performs the functions of brake boosting and partly also of ABS pressure modulation. The principles of ABS pressure modulation in separate and integrated antiskid systems are compared and questions concerning safety are discussed. With the separate ABS (plunger system, return system) the brake circuits are closed, i.e. when braking and also during ABS operation the volume of brake fluid between the master cylinders and the wheel brake cylinders is closed and separated from the energy supply of the hydraulic brake power-assist unit.
Technical Paper

Bosch System Solutions for Reduction of CO2 and Emissions

2008-01-09
2008-28-0005
For about 20 years now, legislation for emission standards has become more and more strict. Main current standards are LEVII legislation for US- and EU4 for the European Market. Many emerging markets like e.g. China, India, Russia adopt EU regulations (directly or modified. Mid of 90's discussions began on restrictions and legislation for CO2 emissions. The European commission recently proposed concrete legislation standards for 2012 and 2020. These will have strong influence on the strategies of the Car Manufacturers. Single measures like start stop will be of general interest. But for reaching the fleet average combinations of measures in a single engine configuration will be necessary. Bosch system solutions for engine- and power-train management are available for the whole span of world car segments, ranging from value concepts optimized for emerging markets up to high feature solutions for most stringent requirements world wide.
Technical Paper

A New Datadriven Approach to Modeling the Combustion of a Diesel Engine in HCCI Mode

2009-04-20
2009-01-0128
The contribution presents a new data driven modeling approach for diesel HCCI combustion. Input parameters of the combustion model are external actuating variables as for example the start of injection. The model incorporates experimental data of the engine in HCCI mode, in the standard diesel mode and in the transition region between both modes. New disclosed dependencies between characteristic values of the cylinder pressure and the fuel burn rate are used to linearize the combustion model for a given operating point. In this paper the validation of the combustion model is discussed based on dynamic measuring data of the urban part of the NEDC. Finally, the combustion model is integrated in a zero-dimensional diesel engine model.
Technical Paper

Investigation into the Formation and Prevention of Internal Diesel Injector Deposits

2008-04-14
2008-01-0926
1 High precision high pressure diesel common rail fuel injection systems play a key role in emission control, fuel consumption and driving performance. Deposits have been observed on internal injector components, for example in the armature assembly, in the slots of the piston and on the nozzle needle. The brownish to colourless deposits can adversely impact driveability and result in non-compliance with the Euro 4 or Euro 5 emission limits. The deposits have been extensively studied to understand their composition and their formation mechanism. Due to the location of these deposits, the influence of combustion gas can be completely ruled out. In fact, their formation can be explained by interactions of certain diesel fuel additives, including di- and mono-fatty acids. This paper describes the methodology used and the data generated that support the proposed mechanisms. Moreover, approaches to avoid such interactions are discussed.
Technical Paper

Design of a Boosted 2-Cylinder SI-Engine with Gasoline Direct Injection to Define the Needs of Future Powertrains

2012-04-16
2012-01-0832
To meet future CO₂ emissions limits and satisfy the bounds set by exhaust gas legislation reducing the engine displacement while maintaining the power output ("Downsizing") becomes of more and more importance to the SI-engine development process. The total number of cylinders per engine has to be reduced to keep the thermodynamic disadvantages of a small combustion chamber layout as small as possible. Doing so leads to new challenges concerning the mechanical design, the design of the combustion system concept as well as strategies maintaining a satisfying transient torque behavior. To address these challenges a turbocharged 2-cylinder SI engine with gasoline direct injection was designed for research purposes by Weber Motor and Bosch. This paper wants to offer an insight in the design process. The mechanical design as well as the combustion system concept process will be discussed.
Technical Paper

AUTOSAR Gets on the Road - More and More

2012-04-16
2012-01-0014
AUTOSAR (AUTomotive Open System ARchitecture) is a worldwide standard for automotive basic software in line with an architecture that eases exchange and transfer of application software components between platforms or companies. AUTOSAR provides the standardized architecture together with the specifications of the basics software along with the methodology for developing embedded control units for automotive applications. AUTOSAR matured over the last several years through intensive development, implementation and maintenance. Two main releases (R3.2 and R4.0) represent its current degree of maturity. AUTOSAR is driven by so called core partners: leading car manufacturers (BMW, Daimler, Ford, GM, PSA, Toyota, Volkswagen) together with the tier 1 suppliers Continental and Bosch. AUTOSAR in total has more than 150 companies (OEM, Tier X suppliers, SW and tool suppliers, and silicon suppliers) as members from all over the world.
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