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An optimal idle speed control (ISC) system for an automotive engine is introduced in this paper. The system is based on a non-linear model including time delay. This model is linearized at the nominal operating point. The effect of the time delay on control is compensated by prediction. This methodology is applied to a Chrysler 2.0 liter 4-cylinder SOHC (Single Overhead Cam) engine. All of the unknown parameters of the model are identified by using the normal operating data from the test engine. Based on these identified parameters, an optimal controller was designed and implemented using a rapid prototyping system. Numerous experiments of the optimal controller were carried out at the Chrysler Technology Center in Auburn Hills, Michigan. The performance was compared to that of the existing controller. The results showed that the optimal controller has the capability to effectively control the engine idle speed under a variety of accessory loads and disturbances.

The purpose of this paper is to present a global description of an efficient, robust and clearly structured control design, based on different hierarchical predictive algorithms, applied to the automotive engine management. The main advantages of these structures are to be well adapted to engines with multiple combustion modes: homogeneous or stratified modes for gasoline direct injection engines, gasoline or compressed natural gas for hybrid fuels engines, etc… A global hierarchical structure is presented, with different levels of acting, from local regulations to global coordination. A model based predictive controller is recommended, to reduce the cross-influences in dynamics and provide a separation of each parameter adjustments. The global performances are thus not dependent on the numerical precision but on the structure quality of the controllers. The more complex the automotive systems become, the more structured the controllers must be designed.

This paper deals with estimating the lateral stability region of a nonlinear 2 DOF vehicle via Lyapunov Second Method and the non-Lyapunov methods of tangency points and trajectory reversal. The nonlinearity of the model is incorporated in an analytical expression for the lateral tire force. It is shown that the derived analytical expressions for equilibrium points defines the outer limits of the stability region.

This work presents an approach for developing a control algorithm for fuel delivery at cold start based on C.F.Aquino's fuel film dynamic model [1]. The control algorithm presented takes into account the fuel delivery both in the fuel film form and in the form of droplets and vapor, that allows setting the limits on the fuel supply calculation in order to achieve good startability (without spark plug wetting) and low CO and HC emission. An algorithm was developed as a computer program and tested in calculation experiments. Although the empirical parameters of mathematical fuel delivery model were determined on a carburetor engine, this control algorithm is also applicable to engines with fuel injection due to similarity of the physical nature of mixture preparation.

We developed the method to reduce the sliding friction of power steering rod seals by changing a lip configuration without lowering any interference and radial load. The data of various items and friction on several kinds of samples were analyzed in order to obtain how to reduce sliding friction. The sliding friction can be possibly analyzed in using the lubrication theory. The contact width and oil film thickness are important factors.

Modern passenger car engines are designed to operate at increasingly higher rated engine speeds with higher thermal loads. To reduce engine weight and length, the engines are usually siamesed without a cooling path between the cylinder liners. This leads to high temperatures in the siamesed area and to an increase in liner deformation. The distortion of the cylinder liners of internal combustion engines has a significant affect on engine operation. It can affect the oil consumption, the blow-by, the wear behavior and, due to friction, the fuel consumption. In order to achieve future requirements regarding exhaust emissions and fuel consumption, the development of low distortion engine blocks will play a significant role.

The somewhat dated FMVSS 208 regulation requires that crash dummies are belted with no slack. Reality shows that there is 120mm slack in the belt system for a 50 percentile occupant. Test results would yield more then 20% worse injury indexes when taking slack into account. This presentation will show how pretensioners can reduce injuries, giving a historical perspective from spring loaded systems to current pyrotechnic systems. Future developments using multi-cartridge and multi-piston systems and associated test results will be discussed.

Paper introduces cost effective design alternatives for “out of position” occupant safety, including: Extractable passenger side lids which move out of the way before airbag deploys. Multi-stage tether controlled airbag deployment dynamically senses “out of position” resistance and controls deployment of further stages. Airbag back pressure activated steering column forward and down movement. Two stage thorax bag with tether control to prevent catapulting “out of position” occupants. Two stage headrest that expands forward and sideways to protect occupant heads in rear end crashes. Second stage activates only if no “out of position” is detected.

Standard bonded transmission piston design specifies the use of low carbon steel for the piston carrier material. High strength low alloy (HSLA) steel is proposed for applications where load and packaging requirements dictate. The impact of carrier material selection on piston design and manufacturing needs to be comprehensively evaluated in these cases. This paper will discuss considerations for using HSLA steel and make recommendations for its application to bonded transmission pistons.

This study analyzes the vibration characteristics of the valve train of a 2.0L SOHC Chrysler Corp. Neon engine over a range of operating speeds to investigate and demonstrate the advantages and limitations of various dynamic measurements such as displacement, velocity, and acceleration in this application. The valve train was tested in a motoring fixture at speeds of 500 to 3500 camshaft rpm. The advantages of analyzing both time and frequency domain measurements are described. Both frequency and order analysis were done on the data. The theoretical order spectra of cam displacement and acceleration were computed and compared to the experimental data. Deconvolution was used to uncover characteristic frequencies of vibration in the system. The theoretical cam acceleration spectrum was deconvolved from measured acceleration spectra to reveal the frequency response function of the follower system.

The general trend in the IC engine design has been towards reduction in fuel consumption since the 1973 oil embargo. The improvement in combustion process has contributed greatly to a better fuel economy of today's engine and there are many challenges ahead on the GDI front towards the 3L/100km engine [1]. One of the biggest windows of opportunity in achieving higher engine fuel efficiency together with an acceptable emissions level is to reduce its friction. To achieve these an accurate method of assessing friction levels through the concept, design and development is paramount. Translation of friction torque to the total drive cycle's fuel consumption is carried out using Ford's in-house CAE analytical packages. A new method of directly measuring camshaft friction has been developed, which offers both exceptional accuracy and unprecedented convenience.

A particulate trap with additive supported regeneration is a very effective way of reducing soot emissions of diesel exhaust gas. Particulate traps presently available on the market clearly show that the regeneration process is the most important detail in particulate trap technology. In this specific case of particulate traps, active rare earth oxides are added into the fuel to produce an initial and almost continuous regeneration without external burners, resistance heating, etc., as is well known from other systems. It should not be forgotten that an externally initiated regeneration will always produce a temperature peak inside the soot collecting filter media which may destroy them. Such damage can be avoided by catalytically supported regeneration of particulate traps. In the presence of an active catalyst, an inorganic cerium compound, regeneration temperature will decrease from 550 to 600 deg. C normally to about 350 to 400 deg. C.

A light duty truck Renault Trafic with a naturally aspirated 2.5 l diesel engine was equipped with metal particulate filters of different sizes, installed at different positions along the exhaust pipe of the vehicle. The filters were operated on diesel fuel doped with a cerium based additive at concentration of 100 ppm in the fuel. Tests were carried out on chassis dynamometer using continuous repetition of the urban part of the European Driving Cycle as a « worst case » approach. Comparisons are made between the different sizes and positioning as regards both back-pressure build up and catalytic regeneration behavior. The results show that filter regeneration was always possible at continuous low speed driving, at relatively high filter back-pressure levels (i.e. high particulate accumulation in the filter), with an effect on fuel consumption.

Previous research in our laboratory has shown that NOx emissions can be sharply reduced by PREDIC (PRE-mixed lean DIesel Combustion), in which fuel is injected very early in the compression process. However some problems still remain, such as higher fuel consumption, a lack of ignition timing control, and a large increase in THC and CO, compared to conventional diesel combustion. Appropriate mixture formation is necessary to solve these problems. In this paper, the influence of mixture formation on PREDIC was investigated. It was found that the pintle type injection nozzle was shown to be suitable for PREDIC, because it produced a comparatively uniform mixture in the combustion chamber and avoided collision of the fuel spray with the cylinder liner. Modeling by the KIVA-II software package was carried out to improve our understanding of the mixture formation process.

Airbag systems have undergone an unbelievable success story during the past years. The story really began in 1969 when the US Federal Government first proposed that all cars be equipped with inflatable restraints. It took nearly 20 years to get the market break-through and in the year 2000 one expects a market volume of round about 70 million airbag units worldwide. Challenges have not only been set to the developers and engineers but also to policy makers, marketing experts, biomedical scientists and the consumer associations before the real success story could happen. Today the smart car occupant protection system is again one step before another quantum jump. Cost, efficiency and performance drive nearly all car manufacturers and their system supplier towards new frontiers of airbag technology. Implications of the current systems like the risk of fatal injuries, danger to children and the ‘out-of-position’ problem challenge again engineers and scientists.

Diesel fuel was injected into the inlet air port of a Perkins 4-236 NADI diesel engine using a Stanadyne 5 micron fuel injector directed onto the back of the inlet valve so as to give the best port fuel injection vaporisation. The fuel was timed to be injected when the inlet valve was open and the exhaust valve closed. Up to 20% of the maximum power fuel flow was injected into the inlet port and the effect is to reduce the diffusion burning phase of diesel combustion at maximum power and hence to reduce soot emissions. The results show that an older relatively high emitting diesel engine can be retrofitted with this technology to produce large soot emission reductions with soot reduced to the level of modern low emission engines. Fumigation also decreases the ignition delay, which at constant fuel injection timing reduces the NOx emissions.

This paper presents the conceptual model and the fundamental mechanisms for software development in the context of the Brite-EuRam project Safety Related Fault Tolerant Systems in Vehicles (nick-named X-By-Wire). The objective of the X-By-Wire project is to achieve a framework for the introduction of safety related fault tolerant electronic systems without mechanical backup in vehicles. To achieve the required level of fault-tolerance, an X-By-Wire system must be designed as a distributed system comprising a number of fault-tolerant units connected by a reliable real-time communication system. For the communication system, the time-triggered TTP/C real-time communication protocol was selected. TTP/C provides fault-tolerance message transfer, state synchronization, reliable detection of node failures, a global time base, and a distributed membership service. Redundancy is used for masking failures of individual processor nodes and hardware peripherals.

The effect of a ceramic diesel particle trap on the size and number of particles emitted from an IDI diesel engine was investigated. Transient effects on the distribution were revealed by utilizing an Electrical Low Pressure Impactor for real time measurement of the particle distribution. A conventional and a low sulfur - low aromatics fuel were used with and without Cerium based additive. Both parameters considerably affect the number of emitted particles, while the median size, expressed as the aerodynamic diameter equivalent, is found in the range of 60 to 110nm. Furthermore, a major influence of the trap load on the total particle number was detected during the accelerations of an urban driving cycle.

Fault diagnosis for automotive systems is driven by government regulations, vehicle repairability, and customer satisfaction. Several methods have been developed to detect and isolate faults in automotive systems, subsystems and components with special emphasis on those faults that affect the exhaust gas emission levels. Limit checks, model-based, and knowledge-based methods are applied for diagnosing malfunctions in emission control systems. Incipient and partial faults may be hard to detect when using a detection scheme that implements any of the previously mentioned methods individually; the integration of model-based and knowledge-based diagnostic methods may provide a more robust approach. In the present paper, use is made of fuzzy residual evaluation and of a fuzzy expert system to improve the performance of a fault detection method based on a mathematical model of the engine.