Method and apparatus for determining the position of an armature in an electromagnetic actuator by measuring the driving voltage frequency
AssigneeCaterpillar Inc.
InventorAndrew H. Nippert
Life of this patent
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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 current magnitude and frequency of current flowing in the coil.
Claims6
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 current flowing through the coil, comprising:
- means for applying a voltage to said coil to cause current to flow through said coil at a desired current magnitude;
- means for measuring the frequency of said applied voltage;
- and
- means for determining the position of the armature with respect to the coil in response to the applied voltage frequency and desired current magnitude.
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 current flowing through the coil, comprising:
- means for applying a driving signal to said coil;
- means for measuring the frequency of said driving signal and producing a voltage signal;
- means for measuring the magnitude of current in the coil and producing a magnitude signal;
- and
- means for receiving said magnitude and voltage signals, and responsively determining the position of the armature with respect to the coil.
A method 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 current flowing in the coil, comprising the steps of:
- applying a voltage to said coil to cause current to flow through said coil at a desired current magnitude;
- measuring the frequency of said applied voltage;
- and
- determining the position of the armature with respect to the coil in response to applied voltage frequency and desired current magnitude.
Dependencies are inferred from the claim text.