公开(公告)号：US10824050B2

公开(公告)日：2020-11-03

申请号：US14821395

申请日：2015-08-07

Applicant: ANALOG DEVICES GLOBAL UNLIMITED COMPANY

Inventor： Javier Calpe Maravilla ,  Eoin E. English ,  Rafael Mahiques ,  Jose Carlos Canada ,  Maria Jose Martinez

IPC: G03B3/10

Abstract: Actuators are used to move a variety of objects to desired positions. It is generally desirable that they can do this quickly without exhibiting overshoot or ringing. Some actuators are required to respond very quickly and examples of these are voice coil drivers used to move lenses in autofocus cameras provided in everyday devices such as smart phones and tablets. A rapid two step controller scheme had already been disclosed by Analog Devices Inc. While the scheme works well, it can only be used reliably if the resonant frequency of the actuator is known to within 2 or 3%. The inventors have discovered that the resonant frequency of an actuator unexpectedly changes as a function of position. This disclosure provides ways of modifying the control scheme to cope with changes in resonant frequency.