Method and apparatus for determining the position of an armature in an electromagnetic actuator
AssigneeCaterpillar Inc.
InventorsTony L. Marcott, Matthew G. Branch, Andrew H. Nippert, Kirk S. Shively
Life of this patent
Estimating the term…
Abstract
Electromagnetic actuators having a coil and an armature are used in a number of applications in which it is useful to have an indication of the position of the armature with respect to the coil without the use of external sensors. Accordingly, an actuator control system is provided for determining the position of the armature with respect to the coil in response to the magnitude and rate of change of current flowing in the coil.
Claims4
An apparatus for determining the position of an armature of an electromagnetic actuator having a coil, the armature being movable to and between first and second positions in response to a current flowing in the coil, comprising:
- means for measuring the magnitude of current in the coil and producing a magnitude signal;
- means for measuring the rate of change of current in the coil and producing a rate of change signal;
- means for receiving the rate of change signal, measuring the peak magnitude of the rate of change signal and producing a peak value signal;
- and
- means for determining the position of the armature with respect to the coil in response to the magnitude and peak value signals.
A method for determining the position of an armature of an electromagnetic actuator, the actuator having a coil with first and second terminals, the armature being movable to and between first and second positions in response to a current flowing in the coil, comprising the steps of:
- measuring the magnitude of current in the coil and producing a magnitude signal;
- measuring the rate of change of current in the coil and producing a rate of change signal;
- and
- receiving the rate of change signal, measuring the peak magnitude of the rate of change signal and producing a peak value signal;
- and
- determining the position of the armature with respect to the coil in response to the magnitude and peak value signals.
Dependencies are inferred from the claim text.