Direct Field-Feedback Eddy-Current Pattern Control Based on System Order Reduction

This paper presents a direct field-feedback eddy-current (EC) pattern control method based on order reduced model with multiple cylindrical electromagnets (EMs). Instead of using unmeasurable EC fields, the measurable magnetic fields generated by the EC field are provided as the system feedback. A state-space representation for EC modeling is provided by discretizing the conductor into multiple elements. The system order is reduced based on the EC character that the mutual EC effect is relatively small and exponentially decreases with the distance increase. After checking the controllability and observability conditions of the order-reduced system, a feedback controller and Luenberger observer are designed using a pole-placement method for the multiple-input multiple-output (MIMO) distributed parameter system. The feasibility and efficiency of this direct field-feedback method are numerically illustrated and demonstrated by generating an EC pattern with an elliptical contour.