FUEL INJECTOR CALIBRATION AND CONTROL
A method includes operating a fuel injector to perform a fuel injection, determining an estimate of the actual injected quantity of the fuel injection, determining a change in a commanded on time to achieve an injected quantity relative to the commanded on time required to initiate injection of the injector in response to the estimate of the actual injected quantity and a commanded injection quantity, and determining an injector opening rate shape slope estimate for the injector in response to the commanded on time required to initiate injection. The method may further include one or more of outputting a diagnostic or prognostic of the fuel injector, adjusting an injection control parameter, or adjusting an injector monitoring operation in response to the injector opening rate shape slope estimate.
1 . A method comprising:
operating an individual injector of a fuel injection system to perform a fuel injection;
determining an estimate of the actual injected quantity of the fuel injection;
determining an on time control parameter of the individual injector in response to the estimate of the actual injected quantity and a commanded injection quantity;
determining an injector opening rate shape slope estimate for the individual injector in response to the on time control parameter of the individual injector; and
performing a fuel injection system control operation in response to the injector opening rate shape slope estimate for the individual injector.
2 . The method of claim 1 , wherein the on time control parameter of the individual injector comprises a change in a commanded on time to achieve an injected quantity relative to the commanded on time required to initiate injection of the individual injector.
3 . The method of claim 1 , wherein the performing the fuel injection system control operation comprises outputting a diagnostic or prognostic of the system in response to the injector opening rate shape slope estimate for the individual injector.
4 . The method of claim 3 , wherein the diagnostic or prognostic is determined based on a difference between the injector opening rate shape slope estimate for the individual injector and a reference value.
5 . The method of claim 4 , wherein the reference value comprises one of an injector opening rate shape slope estimate for a nominal injector and a previously determined value of the injector opening rate shape slope estimate for the individual injector.
6 . The method of claim 1 , wherein the performing the fuel injection system control operation comprises adjusting one or more injection control parameters in response to the injector opening rate shape slope estimate for the individual injector.
7 . The method of claim 6 , wherein the one or more injection control parameters comprise one or more response surfaces configured to provide one or more values of the one or more injector control parameters in response to a fueling command.
8 . The method of claim 6 , wherein the one or more injector control parameters comprise one or more of an injector on time, a rail pressure, and a start of injection timing.
9 . The method of claim 1 , wherein the performing the fuel injection system control operation comprises adjusting an injector monitoring operation in response to the injector opening rate shape slope estimate for the individual injector.
10 . The method of claim 9 , wherein the adjusting the injector monitoring operation comprises increasing a rate or frequency of monitoring.
11 . A system comprising:
a fuel injection system; and
an electronic control system in operative communication with the fuel injection system and configured to:
operate an individual injector of a fuel injection system to perform a fuel injection;
determine an estimate of the actual injected quantity of the fuel injection;
determine an on time control parameter of the individual injector in response to the estimate of the actual injected quantity and a commanded injection quantity;
determine an injector opening rate shape slope estimate for the individual injector in response to the on time control parameter of the individual injector; and
perform a fuel injection system control operation in response to the injector opening rate shape slope estimate for the individual injector.
12 . The system of claim 11 , wherein the on time control parameter of the individual injector comprises a change in a commanded on time to achieve an injected quantity relative to the commanded on time required to initiate injection of the individual injector.
13 . The system of claim 11 , wherein the fuel injection system control operation comprises a diagnostic or prognostic of the system performed in response to the injector opening rate shape slope estimate for the individual injector.
14 . The system of claim 13 , wherein the diagnostic or prognostic is determined based on a difference between the injector opening rate shape slope estimate for the individual injector and a reference value.
15 . The system of claim 14 , wherein the reference value comprises one of an injector opening rate shape slope estimate for a nominal injector and a previously determined value of the injector opening rate shape slope estimate for the individual injector.
16 . The system of claim 11 , wherein the fuel injection system control operation comprises an adjustment of one or more injection control parameters in response to the injector opening rate shape slope estimate for the individual injector.
17 . The system of claim 16 , wherein the one or more injection control parameters comprise one or more response surfaces configured to provide one or more values of the one or more injector control parameters in response to a fueling command.
18 . The system of claim 16 , wherein the one or more injector control parameters comprise one or more of an injector on time, a rail pressure, and a start of injection timing.
19 . The system of claim 11 , wherein the fuel injection system control operation comprises an adjustment of an injector monitoring operation in response to the injector opening rate shape slope estimate for the individual injector.
20 . The system of claim 19 , wherein the adjustment of the injector monitoring operation comprises increasing a rate or frequency of monitoring.
21 . A method comprising:
operating a fuel injector to perform a fuel injection;
determining an estimated actual injected quantity of the fuel injection; and
determining an injector opening rate shape slope estimate for an individual injector based on the actual injected quantity of the fuel injection.
22 . The method of claim 21 comprising:
controlling operation of the fuel injector to perform a subsequent fuel injection in response to the injector opening rate shape slope estimate.
23 . The method of claim 21 comprising:
diagnosing operation of the fuel injector in response to the injector opening rate shape slope estimate.
24 . An apparatus comprising:
one or more non-transitory memory media configured to store instructions executable by a controller to perform the acts of:
operating a fuel injector to perform a fuel injection;
determining an estimated actual injected quantity of the fuel injection; and
determining an injector opening rate shape slope estimate for an individual injector based on the actual injected quantity of the fuel injection.
25 . The apparatus of claim 24 , wherein the instructions are further executable by a controller to perform the act of controlling operation of the fuel injector to perform a subsequent fuel injection in response to the injector opening rate shape slope estimate.
26 . The apparatus of claim 24 , wherein the instructions are further executable by a controller to perform the act of diagnosing operation of the fuel injector in response to the injector opening rate shape slope estimate.