US 11,948,739 B2
Minimizing transient artifact of position estimate in inductively-sensed electromagnetic actuator system with shared inductive sensor
Emmanuel A. Marchais, Dripping Springs, TX (US); Tejasvi Das, Austin, TX (US); and Siddharth Maru, Austin, TX (US)
Assigned to Cirrus Logic Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on Jan. 4, 2022, as Appl. No. 17/568,248.
Claims priority of provisional application 63/186,169, filed on May 9, 2021.
Prior Publication US 2022/0359113 A1, Nov. 10, 2022
Int. Cl. H01F 7/18 (2006.01)
CPC H01F 7/1844 (2013.01) [H01F 2007/185 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A system comprising:
an electromagnetic actuator;
a first coil configured to drive mechanical displacement of the electromagnetic actuator;
a second coil configured to drive mechanical displacement of the electromagnetic actuator; and
an impedance sensing subsystem having an impedance sensing path coupled to the first coil and the second coil and configured to:
select one of the first coil and the second coil for driving mechanical displacement of the electromagnetic actuator;
select the other of the first coil and the second coil as a sensing coil for sensing displacement of the electromagnetic actuator;
determine a displacement of the electromagnetic actuator based on a measurement of estimated impedance of the sensing coil; and
when switching selection of the sensing coil from the first coil to the second coil:
determine the displacement of the first coil based on a measured impedance of the first coil at approximately the time of switching selection;
estimate state variables of the impedance sensing path to be used with the second coil based on the displacement; and
apply the state variables to the impedance sensing path after switching selection of the sensing coil from the first coil to the second coil.