Sensorless Movement Control of Solenoid Fuel Injectors

Precise fuel metering and high linear flow ranges (LFR) are the key issues for advanced injection systems for diesel and gasoline engines. They ensure lower emission, lower noise and higher fuel efficiency. Fast-switching solenoid injectors show high valve needle impact velocities and thus bouncing at injector closing. This causes multiple parasitic injections which reduce injection precision and deteriorates emission and efficiency. Mechanical and hydraulic anti-bounce concepts reduce the injection dynamic range while electronic open-loop controlled concepts are instable. For this reason a new sensorless electronic closed-loop anti-bounce solution able to reduce bouncing effectively and providing robust soft landing under all operating conditions was developed.