A switching observer for sensorless control of an electromagnetic valve actuator for camless internal combustion engines

In this paper, the design and operation of a special electromagnetic motor as a variable engine valve actuator are presented. Further, this paper presents feasible approximated velocity switching estimator based on measurements of current and input voltage to achieve sensorless control. This approach avoids a more complex structure for the observer and yields an particular control strategy with an acceptable performance. In general, this approach can represent a viable strategy to build reduced-order observer to estimate not only velocity but also position of a such as type of systems through the measurement of input current and input voltage. This control strategy is presented and discussed as well. Computer simulations of the sensorless control structure are presented in which results are visible in the closed-loop control.