Method, system and apparatus for detecting injector closing time

A non-transitory machine-readable medium that provides instructions, which when executed by a control unit for a vehicle having an injector valve, cause the control unit to perform operations comprising:

• receiving a valve current profile of the injector valve;
• processing the valve current profile using at least a slope discriminator;
• determining a stuck status of the injector valve based on an output of the slope discriminator;
• and
• if the injector valve is not stuck, determining the closing time of the injector valve based on the output of the slope discriminator,
• wherein processing the valve current profile includes determining an output of the slope discriminator based on the valve current profile, and determining the stuck status and the closing time of the injector valve includes comparing the output to a predetermined closing time detection threshold, wherein
• processing the valve current profile comprises determining median values within a median window and mean values within a mean window,
• processing the valve current profile comprises calculating a series of mean output data points and a series of median output data points,
• each median output data point in the median window is a median value of data points within the median window at a corresponding time,
• the data points within the median window are sorted in increasing value,
• each mean output data point in the mean window is a mean value of data points within the mean window at a corresponding time,
• the mean window encompasses fewer data points than the median window, and
• the mean window begins at a predefined offset from the median window start point.

An apparatus for a vehicle system, the vehicle system having at least one injector and a least one sensor therefor, comprising:

• a controller connected to the at least one sensor, the controller being operable to receive a profile of the current draw of the injector, the controller being operable to process the profile using a slope discriminator and to determine a stuck status and a closing time of the injector based on an output of the slope discriminator,
• wherein the controller is further operable to determine the output of the slope discriminator based on the valve current profile, and wherein the controller is further operable to compare the output to a predetermined closing time detection threshold,
• the controller being further operable to determine median values within a median window and mean values within a mean window, and to calculate a series of mean output data points and a series of median output data points,
• wherein each median output data point in the median window is a median value of data points within the median window at a corresponding time;
• wherein the data points within the median window are sorted in increasing value;
• wherein each mean output data point in the mean window is a mean value of data points within the mean window at a corresponding time;
• wherein the mean window encompasses fewer data points than the median window;
• and
• wherein the mean window begins at a predefined offset from the median window start point.

A non-transitory machine-readable medium that provides instructions, which when executed by a control unit for a vehicle having an injector valve, cause the control unit to perform operations comprising:

• receiving a valve current profile of the injector valve;
• processing the valve current profile using at least a slope discriminator;
• determining a stuck status of the injector valve based on an output of the slope discriminator;
• if the injector valve is not stuck, determining the closing time of the injector valve based on the output of the slope discriminator,
• wherein processing the valve current profile includes determining an output of the slope discriminator based on the valve current profile, and determining the stuck status and the closing time of the injector valve includes comparing the output to a predetermined closing time detection threshold,
• determining whether a maximum output value of the slope discriminator is below the predetermined closing detection time detection threshold;
• and if the maximum output value is below the predetermined closing time detection threshold, the controller is operable to determine that the stuck status is stuck;
• and if the maximum output value is above the predetermined closing time detection threshold, the controller is operable to determine that the stuck status is not stuck, and
• determining the closing time of the injector valve based on a location of the maximum output value, if the stuck status is that the injector valve is not stuck.