Ibrahim Haskara

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Spark timing of an Internal Combustion (IC) engine is often limited by engine knock in the advanced direction. The ability to operate the engine at its advanced (borderline knock) spark limit is the key for improving output power and fuel economy. Due to combustion cycle-to-cycle variations, IC engine combustion behaves similar to a random process and so(More)
Internal combustion engines are designed to maximize power subject to meeting exhaust emission requirements and minimizing fuel consumption. However, the usable range of ignition timing is often limited by knock in the advance direction and by combustion instability (partial burn and misfire) in the retard direction. This paper details a retard limit(More)
This paper presents an optimal control method of tracking the desired air-to-fuel ratio (AFR) based upon the adaptively estimated biofuel content for internal combustion engines equipped with the lean NOx trap (LNT) aftertreatment system. This biofuel content (or percentage of biofuel) is adaptively estimated based upon the exhaust oxygen AFR sensor signal(More)
Minimal advance for best torque (MBT) timing for an internal combustion (IC) spark ignition (SI) engine is the minimum advance of spark timing for the best torque or, in other words, for the best fuel economy. But MBT timing is often limited by engine knock in the advanced direction and spark timing is also constrained by partial burn and misfire in the(More)
This paper proposes a closed loop multivariable VGT/EGR control system for a turbocharged diesel engine. The control system is synthesized based on quantitative feedback theory to maintain robust stability and performance in the presence of model variations via sequential MIMO loop-shaping. Simulation results from a turbocharged diesel engine are included(More)
This paper presents a combustion stability index derived from an in-cylinder ionization signal to control the engine maximum EGR limit. Different from the existing approaches that use the ionization signal values to gauge how much EGR was added during the combustion, the proposed method concentrates on using the ionization signal duration and its stochastic(More)
This paper presents a method of controlling the air-to-fuel ratio (AFR) based upon an adaptively estimated biodiesel fuel content for a diesel engine equipped with the lean NOx trap (LNT) aftertreatment system. The fuel content (or percentage of biodiesel fuel) is estimated by an adaptive estimation scheme based upon the exhaust oxygen sensor signal during(More)