Output Feedback Regulation of Electromagnetic Valves for Camless Engines

Conventional internal combustion engines use mechanical camshafts to command the opening and closing phases of the intake and exhaust valves. The lift valve profile is designed to reach a good compromise among various requirements of the engine operating conditions. In principle, optimality in every engine condition can be attained by camless valvetrains. In this context, electromagnetic valves offer an interesting solution, although there are still some relevant open problems to be solved before they can be introduced in production. One of the main problem is due to the fact that valve position and velocity sensors should not be used, due to the constraint in terms of actuator cost and space limitations. In this work an observer-based controller is proposed, ensuring the so called "soft-landing". This controller, based on a state controller derived making use of the regulation theory, exploits an observer of the the state variables not measured and of the disturbance acting on the system.