Patent ID: 8055460
Filing Date: 2011-11-08
Classification: G01R

Abstract:
1. A method for monitoring the state of health (SOH) of a solenoid powered by a battery, the method comprising: measuring a voltage and a current supplied to the solenoid by the battery; using a controller to determine each of an equivalent resistance and an equivalent inductance of the solenoid using the voltage and the current; comparing each of the equivalent resistance and the equivalent inductance to a corresponding calibrated threshold; recording deviations of each of the equivalent resistance and the equivalent inductance from the corresponding calibrated threshold on a computer-readable medium as a pair of SOH values; continuously monitoring, via the controller, a trend of each of the pair of SOH values with respect to a corresponding calibrated lower limit; and automatically executing a first control action providing a first prognosis of the solenoid when either of the pair of SOH values drops below the corresponding calibrated lower limit.