Researches of common-rail diesel engine emission control based on cylinder pressure feedback

For improving power output, fuel economy, and emissions of diesel engines, pressure feedback technology is introduced to electronic control high pressure common rail system. In this paper, the geometry characteristic index in the pressure difference curve is presented after analyzing pressure difference curve; the relations of the pressure characteristic indexes with injection parameter, output torque and NO_x emission are researched by using simulation and testing method; the effect of simulation and testing shows that the characteristic index can reflect the input and output variable of diesel engine. By selecting radial basis function (RBF) neural net, feedback variable module using the pressure characteristic index is structured; conversion to feedback variable from pressure characteristic index is performed. The test of electronic controlled injection using cylinder pressure feedback is conducted on the diesel engine equipped with high pressure common rail system, testing data shows that introducing pressure feedback to electronic controlled system can perform closed-loop control for NO_x ; the engine emission control of common-rail diesel engine based on cylinder pressure feedback is feasible and effectively.