One of the main hurdles facing diesel engineers is developing a real-time sensor to help the vehicle's on-board computer with fuel delivery timing. Through computer modeling and other research, engineers know there's a very small window in the combustion cycle that produces optimum power with hardly any harmful emissions. But this window of opportunity moves around depending on cylinder pressure.
Gas engines, of course, have been using oxygen sensors to help achieve the optimum air-fuel ratio. Before the O2 sensors, engine-management programmers could only estimate the best fuel-delivery options based on basic inputs, such as throttle position, air tempertature, rpm and other signals. With the addition of O2 sensors, engineers developed "closed-loop" fuel-injection systems that adjust fuel delivery based on real-time engine conditions.
A closed-loop system for diesel engines is just around the corner. BERU is a developer of cold-start technology for diesel engines and recently won a top award at the Automechanika Show in for its pressure-sensor glow plug. The plug can provide accurate and stable pressure signals from the combustion chamber, allowing for advanced closed-loop controls. A news release from Borg-Warner, which has a major stake in BERU, says the product will be launched in late 2007 by two major OEMs.
[Source: The Auto Channel]