2 research outputs found
Diesel Engine Emission Model Transient Cycle Validation
A control intended data driven B-spline model for NOx and soot emitted was developed and validated for the 5-cylinder, 2.4-litre Volvo passenger car diesel engine in earlier work. This work extends on the same methodology with some improvements on the model structure for more intuitive calibration and is also developed for the new generation 4-cylinder, 2- litre Volvo passenger car diesel engine. The earlier model was validated using steady state engine measurements and proposed that the model would hold good for transient engine operation.
The hypothesis formulated is that a transient engine emission model can be envisioned as a sequence of multi-step steady state engine operation points with minor deviations from the nominal engine operating conditions. The theory is supported by the literature that provides
more insight into the transient operation. This idea is carried out in the current work using engine test cell measurements validated for a NEDC as well as a normal road drive cycle that depicts a more transient driving behaviour in comparison to the standard emission driving
cycles. Nearly 4600 engine operating points with steady state measurement including nominal and deviant conditions have been used in the development of the model. The ability of the data driven approach to mimic the engine emission generation characteristics during the engine transient operation is analysed and its superior performance in comparison to the Nominal model and the Regression model is demonstrated
Testing the Effectiveness of the Misfire Detection System
A methodology to analyse and predict the behaviour of the current misfire detection
system & algorithm is presented with special focus on the effects and contribution of
the noise contributed mainly by the variation in driveline configuration.
The existing line up of CNG engines are used to compare the performance of the
simulating model with the real time functioning of the system. Two distinct diesel
vehicle models with known and reported significantly varying driveline disturbances
are investigated along with the developed model of the system.
Sufficient tolerance band coupled with accurate algorithms in the existing misfire
detection system have been a key advantage providing the opportunity to extend the
same system across future possible vehicle variants in spite of noise contributions.
A misfire generating system designed and built with the possibilities to induce and
generate misfires at controlled rate in order to assist real time evaluation of the
detection system and diagnostics performance is also presented.
A comprehensive study from available literatures in the automotive research industry
carried out to determine possibilities to improve the existing misfire detection system
and algorithm resulted in identification of usage of a viable alternate detection system
as an assisting contribution to the current algorithm