Position-Sensorless Control and End-Position Monitoring of a Two-Point Switching Actuator

This publication addresses a non-model-based position-sensorless control approach for a single-coil rotating linear two-point switching actuator without permanent magnets. A shift current controller was combined with a position-sensorless signal-injection method, which enables reliable shift operations and continuous rest-position monitoring. A sinusoidal test signal is therefore superimposed on the voltage output of the shift current controller and the current response of the voltage test signal is obtained using a Gortzel-filter to evaluate the sensorless mover position. The position lookup-table(s) required for this can be configured automatically with initial measurements at the end positions of the switching actuator. The outstanding advantage of the proposed data-based control approach is that no system parameters need to be known a priori. The variable coil resistance can be identified with a dc current measurement. Moreover, a simple temperature and resistance change compensation method using the complex ac calculus is presented and verified in simulation. The performance of self-sensing end-position detection and monitoring was successfully evaluated on a dynamic test bench.