Robust high bandwidth oscillation-free digital feedforward compensator for micromachined actuators

Many micro-electro-mechanical systems applications suffer from large oscillations that come from high-quality factors. Designing feedback controllers is challenging because of the very limited phase margin. This work proposes a feedforward compensator approach to cancel the oscillation behaviours without the constraints of the stability margins. The essential element of this mechanism is to create a series of zeros to cancel the undesired oscillation poles. It is a practical solution because: (i) the selection of the parameters of the compensator is straight forward and robust to the model variations and (ii) the implementation uses a pipeline digital circuit architecture that enables MHz range bandwidth.