ENHANCED INDIRECT-DRIVEN SELF-SENSING ACTUATION FOR PIEZOELECTRIC STRUCTURES

Enhanced Indirect-Driven Self-Sensing Actuation (EIDSSA) is proposed to eliminate the coupling issue between sensing and actuation by improving the topology in [1]. With EIDSSA, actuation efforts can be fully delivered to PZT elements without compromising sensing performance. In addition, EIDSSA can be seamless switched on and off without servo loop retuning. A theoretical framework is established to quantitatively analyse the performance of self-sensing actuation in terms of sensing, actuation, decoupling and amplification. An implementation of EIDSSA on a commercial dual-stage Hard Disk Drive (HDD) shows that sensing can be designed independently from actuation and Total-Runout (TRO) is slightly improved with EIDSSA compared to baseline set-up when same servo control loop is used.