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Technical Paper

Developing Safe Software Solutions for X-By-Wire Applications

A promising technology for active safety is “X-by-Wire”, where mechanical and electromechanical components are replaced by electronic functions. One of the reasons for this is to have more than the driver input in the command chain, and also include some degree of intervention by the control system in case the driver behaviour is likely to put the car at risk. The adoption of a small number of computing nodes is a clear trend in vehicle design. A wide range of functions that are now distributed in the form of separate modules will instead be integrated. This approach will overcome the physical constraints of electrical and mechanical components and the costs of many separate electronic modules with their own power supplies.
Journal Article

Innovations In Experimental Techniques For The Development of Fuel Path Control In Diesel Engines

The recent development of diesel engine fuel injection systems has been dominated by how to manage the degrees of freedom that common rail multi-pulse systems now offer. A number of production engines already use four injection events while in research, work based on up to eight injection events has been reported. It is the degrees of freedom that lead to a novel experimental requirements. There is a potentially complex experimental program needed to simply understand how injection parameters influence the combustion process in steady state. Combustion behavior is not a continuum and as both injection and EGR rates are adjusted, distinct combustion modes emerge. Conventional calibration processes are severely challenged in the face of large number of degrees of freedom and as a consequence new development approaches are needed.
Technical Paper

Modeling for Diesel Engine Control: The CPower Environment

Diesel engine control has already become complex, and in order to meet future emissions standards (such as Euro 4) it is likely to be the control system that will provide the needed performance increment. Common rail fuel injection offers yet more degrees of freedom which will need to be exploited as new emissions standards emerge. Whatever the emissions standards, there is a need to reduce risk at the earliest stages in the development of the powertrain. This will involve early and extensive simulation of the powertrain including its control system, sensors and actuators. What is the best way to achieve this using current tools? The result lies in a combination of a phenomenological model of the engine and a flexible controls environment. To illustrate the principles of developing prototype control systems, we will use the example of the CPower environment, which is a combination of a detailed engine simulation code (GT-Power) and the Simulink simulation environment.
Technical Paper

Some More Diesel Engine Sensors

The information needs of engines have increased dramatically over recent years. In order to achieve the levels of performance and endurance that are now required in the marketplace, engine operation increasingly employs sophisticated control with closed-loop operation of various functions. This control trend will continue as performance expectations increase, calibration times reduce and systems become more complex and dependent on a variety of sensors. Available and emerging technologies offer a range of solutions for sensor systems but success in any particular application is often difficult to analyze. This makes the prediction of future trends more difficult. This paper looks back at some recent developments and forward to the next few years. In addition to the sensors required, some consideration is also given to control systems, which have increased dramatically in sophistication.
Technical Paper

The Demands of Cylinder Event Control

In the context of engine control the strategy is a statement of the control functions. Modern strategies are generally map based with a resolution corresponding to single cylinder events. However, future needs point to high speed control based on sensors which can observe cylinder events. Such sensors working with actuators such as gasoline and diesel fuel injection can act to minimise variations between cylinders and more closely control combustion conditions. A high speed strategy is a functional description of control which includes such high speed functions One strategy can be solved using different control structures and with different sensor types. A cascaded control scheme for example would allow high speed cylinder level controls to be fed by slower controllers able to take a longer term view. Such a cascaded scheme is a framework which allows high level diagnosis and control objectives to be realised within a common framework.