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In an effort to improve the efficiency of internal combustion engines, much focus has been put into variable valve actuation technologies in recent years. Electromagnetic solenoid valves can provide the cycle-by-cycle flexible valve timing needed for throttleless engine control or high efficiency combustion modes such as Homogeneous Charge Compression Ignition. One challenge with electromagnetic solenoid intake and exhaust valves is the robust control of the motion to achieve smooth landing under a variety of operating conditions. Promising algorithms have been demonstrated under test-bench conditions, but no work to date has demonstrated a robust electromagnetic valve-train on a functional engine that also satisfies soft landing and transition timing criteria. In this work, two previously developed valve motion controllers are experimentally tested on a single cylinder test engine.

A physics-based control-oriented model is developed to dynamically predict cycle-to-cycle combustion timing in transient fueling conditions for Homogeneous Charge Compression Ignition (HCCI) engines. The model simulates the engine cycle from the intake stroke to the exhaust stroke and includes the thermal coupling dynamics caused by the residual gases from one cycle to the next cycle. A residual gas model, a modified knock integral model, a fuel burn rate model, and thermodynamic models for the gas state in combustion and exhaust strokes are incorporated to simulate the engine cycle. The gas exchange process, generated work and completeness of combustion are predicted using semi-empirical correlations. The resulting model is parameterized for the combustion of Primary Reference Fuel (PRF) blends using 5703 simulations from a detailed thermo-kinetic model. Semi-empirical correlations in the model are parameterized using the experimental data obtained from a single-cylinder engine.

Homogeneous Charge Compression Ignition (HCCI) is a promising combustion concept for internal combustion engines to reduce emissions and fuel consumption. Unlike spark ignition and diesel engines in which ignition is controlled by spark and spray injection timing respectively, HCCI combustion auto-ignites given the correct mixture conditions which makes HCCI ignition difficult to control. It is thus critical to understand the characteristics of HCCI ignition timing in order to find suitable strategies for ignition control. This paper presents a modified model of ignition timing which is based on the Knock-Integral Method. Since this model doesn't require instantaneous in-cylinder parameters, it is suitable for control application on HCCI combustion. The model is tested using both simulation results of a Thermo-Kinetic Model and experimental data.