High-Authority Fuel Injection

Promising developments in diesel injection technology have given rise to an increasing acceptance of diesel engines in the passenger vehicle market, especially in Europe. As with heavy-duty vehicles, more stringent emission levels are achieved via control of the diesel combustion process through precise timing and metering of the injected fuel quantities. In particular, European manufacturers such as Siemens and Bosch are competing to bring the benefits of piezoelectric injection technology to the market (e.g., Pugeot in 2002). Their actuation mechanisms are state-of-the-art, but their techniques are typically "on-off" in nature, and although their engine control techniques work well, they rely on engine maps that enforce injection timing and quantity as a function of engine parameters, and they do not adequately handle transients and modifications due to age and wear. In contrast, Mid¿ Technology Corporation's proposed injection technique will provide proportional control over the injection process, and thus more degrees of freedom to control the problem. This new approach also closes an adaptation control loop in real time. Because of the associated injection and combustion modeling that govern controller operation, it is anticipated that this algorithm will converge faster than existing technologies, providing the ability to more effectively deal with transients. Phase I focused on generating a simplified combustion control model to predict and minimize the formation of NOx as a function of injection profile. These efforts were very successful in identifying an optimized shape and indicated that fine control of injection profile can have a marked effect on output emissions. The primary Phase II objective is to experimentally verify these analytical results. Working closely with an injector design sponsor, Mid¿ Technology Corporation will develop the actuation, control, and power components needed to realize the effect of injected trajectory on emissions. Additional Phase II objectives are to improve combustion modeling and predict an optimum injection shape for minimum NOx, hydrocarbons, and particulate matter. By succeeding in an experimental environment, Mid¿ Technology Corporation will be capable of commercializing this technology and marketing it to engine manufacturers as a critical method of satisfying environmental regulatory constraints. Furthermore, the development of breakthrough actuation and control technologies can be used to help realize innovative combustion control concepts, such as the Homogeneous Charge Compression Ignition technology. Finally, the introduction of NO suppressants through separate but precisely timed injection mechanisms can be achieved by the proposed valve technology. For example, a four-way proportional valve allows relative control of a diesel packet followed by a suppressant packet.