Practical delay modeling of externally recirculated burned gas fraction for Spark-Ignited Engines

Practical Delay Modeling of Externally Recirculated Burned Gas Fraction for Spark-Ignited Engines

This paper studies the low-pressure burned gas recirculation in spark-ignited engines and shows, at the light of supportive experimental results, that a linear delay system permits to capture the dominant effects of the system dynamics. The modeled transport delay is defined by implicit equations stemming from first principles. This model is shown to be sufficiently accurate to replace a sensor...

Cylinder Pressure and Ionization Current Modeling for Spark Ignited Engines

Engine management systems (EMS) need feedback on combustion performance to optimally control internal combustion engines. Ion sensing is one of the cheapest and most simple methods for monitoring the combustion event in a spark ignited engine, but still the physical processes behind the formation of the ionization current are not fully understood. The goal here is to investigate models for ioni...

Detecting Knock in Spark Ignited Engines

In this paper we consider signal processing algorithms for detecting knock, i.e. auto-ignition of unburned fuel, in spark-ignited engines. To operate an engine with optimal efficiency, there is a need to operate close to the knock limit. This motivates the need for efficient knock detection algorithms that not only indicates knock, but also gives estimates on knock timing and size. The proposed...

Sensor Selection for Observer Feedback in Turbocharged Spark Ignited Engines

Precise air/fuel control is necessary for low emissions in turbocharged (TC) SI-engines. Observers are often proposed for accurate cylinder air charge estimation in air/fuel controllers. First it is shown using a structural method that the system is locally structurally observable using observer-feedback from any measured state. A systematic method to select observer feedback signals is importa...

Catalytic Converters for Small Spark-Ignited Nonhandheld Utility Engines