New design of electromagnetic valve actuator

Hummel, Thomas
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University of Guelph

Electromagnetic Valvetrains are a developing automotive technology, which promises to increase the efficiency of internal combustion engines. This system allows an internal combustion engine to adjust induction and exhaust behavior during operation, allowing optimization of thermodynamic efficiency for the engine's operating state during engine operation. The electromagnetic valvetrain approach allows opening and closing of exhaust/intake valves using electromagnetic actuators in a real time fashion. Existing approaches to real time control of valve operation rely on complex mechanical components to achieve operation, while existing electromagnetic valve train approaches lack a truly robust control system and are quite complex mechanically. This work, will introduce a new design for an electromagnetic valve actuator which aims to simplify the existing approach and use a more robust control system in order to maintain a low valve closing velcoity in the required time window. Existing theory of operation is maintained, however simplification is achieved by incorporating a single torsion bar spring instead of current double spring systems, as well as a fuzzy controller coupled with an optical position sensor improving noise rejection. Separating the design into its respective mechanical, electromagnetic, and control components, each component is designed and tested utilizing a low cost test bed. It was found that all components operated as expected, save for issues with saturation remanance in the electromagnets and dynamic range of the position sensor. This issue necessitated modification of the control system experimental method, since initial state conditions (armature velocity) could not be satisfied. Results can thus be used to improved the concepts described in this work, leading to a fully operational prototype on a running engine.

design, electromagnetic valve actuator, control system, low valve closing velcoity, internal combustion engine| induction behaviour, exhaust behaviour