Abstract

Electromechanical valve actuators have been investigated in recent literature to implement variable valve timing (VVT) in spark ignition vehicle engines. Various types of electromechanical actuators are being investigated to control engine valves independently from crankshaft and ultimately get full benefits from variable valve timing. This thesis investigates a new type of electromechanical actuator - voice coil actuator (VCA). The thesis addresses the modeling of the voice coil actuated engine valve system and proposes a novel control strategy using pulse width modulation (PWM) that achieves fast transitions and low seating velocities. A Lyapunov-based stability analysis of a discrete-time model of the closed-loop PWM system as well as an experimental validation of the static force characteristics of the VCA are also presented in the thesis