Soft-landing control of low-energy solenoid valve actuators

An automotive, fluid-control solenoid valve is composed of an electromagnetic reluctance actuator and a near-constant-force spring. Its motion profile is characterized by short closed-to-open transition times which demand fast switching, while valve lifetime improves by minimizing the impact velocity, i.e. a soft landing. In this paper, a cascaded position- and current-feedback control is designed and implemented on nonlinear, axisymmetric magnetostatic finite element simulations of a low-energy solenoid valve actuator. By applying the cascaded control, actuator performance is improved considerably, as a soft landing, a timely actuation, and an increased energy-efficient device have been obtained.