公开(公告)号：US20200072113A1

公开(公告)日：2020-03-05

申请号：US16500824

申请日：2018-04-06

Applicant: DELPHI TECHNOLOGIES IP LIMITED

Inventor： MARTIN A. SYKES

IPC: F01N11/00 ,  F01N3/20

Abstract: A method of detecting a valve opening or closing event in a solenoid operated reductant injector valve includes applying a voltage to the solenoid to actuate the valve, the voltage having a chopped waveform. A resultant current through the solenoid is sampled at local maxima and minima. Values of a difference between the local maxima and subsequent local minima or between local minima and subsequent local maxima are determined. A rate of change of the difference values are determined and a valve opening or closing event based on the rate of change is determined.