In HCCI mode with negative valve overlap, the understanding of the engine behavior in case of misfire and delayed combustion is important to provide a complete control strategy. A hybrid continuous zero dimensional model for gasoline HCCI, based on simplified chemical kinetics and a separate airflow model is introduced. CHEMKIN is used to simulate the chemical kinetics, whereas the airflow and the injection is simulated using MatLab. The model is compared to experimental data. The introduced model is used to analyze the effect of misfire and late combustions on the dynamics of the system. A state transition map is proposed to distinguish between misfire with and without recovery. Control strategies to improve the misfire recovery are suggested.

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Switching between 2-stroke and 4-stroke modes of Homogeneous Charge Compression Ignition (HCCI) operation is a promising method for extending load range of HCCI engine. Switching between the two modes introduces disturbances into the system resulting in significant tracking errors. We propose an architecture for control system and a method for calculation of control inputs which minimize the tracking errors during switching. Proposed method produces inputs for engine valve timings which insure smooth transitions between the two HCCI modes under a varying engine load. The method uses techniques from the theory of system identification and the theory of optimal control.

ElectroHydraulic Valve Systems (EHVS) have the ability to vary valve profiles of internal combustion engines on a per cycle basis, thus allowing one to optimize the combustion process and improve its efficiency and emissions characteristics. Such a capability makes an EHVS system a very suitable actuation mechanism for novel combustion strategies. However, designing a controller which ensures that the EHVS executes the desired valve profiles is challenging due to the required fast response time, the inherent non-linearity of the system, and the time delays associated with the servo valves, actuators and the interconnections. In this paper, we explore a systematic and semi-automatic way to design a controller for an EHVS. The controller has a feedforward and feedback structure. The feedforward controller is obtained by using an on-line system identification scheme, while the feedback controller is based on an off-line system identification model. This procedure is applied successfully to a laboratory EHVS engineered by Team Corporation covering the full range of engine operating speeds from 500 to 4000rpm.