Method to adaptively control and derive the control voltage of solenoid operated valves based on the valve closure point

A computer implemented method for deriving a drive voltage waveform for a solenoid operated valve having a valve coil comprising the steps of:

• a) determining an initial estimate of electromagnetic parameters and a valve closure point, the electromagnetic parameters including a first L/R ratio corresponding to the pull-in time of the valve coil, a valve back emf, a second L/R ratio corresponding to the valve pull-hold time, and a hold resistance;
• b) deriving a drive voltage waveform based in part on the electromagnetic parameters and the valve closure point;
• c) obtaining a coil current feedback;
• d) determining the electromagnetic parameters and the valve closure point from the coil current feedback, thereby creating a revised estimate of the electromagnetic parameters and the closure point;
• e) updating the initial estimate with the revised estimate of the electromagnetic parameters and the valve closure point;
• and
• f) deriving a new voltage waveform based in part on the revised estimate of the electromagnetic parameters and the valve closure point.