in spark ignition (si) engines, the accurate control of air fuel ratio (afr) in the stoichiometric value is required to reduce emission and fuel consumption. the wide operating range, the inherent nonlinearities and the modeling uncertainties of the engine system are the main difficulties arising in the design of afr controller. in this paper, an optimization-based nonlinear control law is anal...

Two virtual sensors are proposed that use the spark-plug based ion current sensor for combustion engine control. The first sensor estimates combustion variability for the purpose of controlling exhaust gas recirculation (EGR) and the second sensor estimates the pressure peak position for control of ignition timing. Use of EGR in engines is important because the technique can reduce fuel consump...

This paper investigates optimal strategies for minimising the conflicting objectives of fuel consumption and warm up duration following an engine cold start. Using a reduced order model, parametric solutions for the optimal air-fuel ratio, valve timing, cam timing and idle speed setpoint are sought in the presence of input constraints. The results are then validated using a dynamic programming ...

The initial 1-2 minutes of operation of an automotive spark-ignition engine, commonly called as the ”coldstart” period, produces more than 75-80 % of the hydrocarbon (HC) emissions in a typical drive cycle. Model-based controller development requires accurate, yet simple, models that can run in realtime. Simple, intuitive models are developed to predict both tailpipe hydrocarbon (HC) emissions ...