HIGH PRESSURE FUEL SYSTEM CONTROLS, DIAGNOSTICS, AND PROGNOSTICS USING FUEL MASS CHANGE ESTIMATES
A method includes operating a pump to pump fuel to a rail and concurrently operating one or more injectors to inject fuel from the rail into one or more cylinders of an engine. The method further includes filtering measurements of fuel pressure of the rail to determine filtered pressures for at least a first pressure measurement zone preceding a target event and a second pressure measurement zone succeeding a target fuel mass change event, determining a pressure change in response to the filtered pressures, and determining a fuel mass change of the target event in response to the pressure change.
1 . A method comprising:
operating a fuel system including operating a pump to pump fuel to a rail and concurrently operating one or more injectors to inject fuel from the rail into one or more cylinders of an engine;
filtering measurements of fuel pressure of the rail taken during the operating to determine filtered pressures for a first pressure measurement zone preceding a target fuel mass change event of the fuel system and a second pressure measurement zone succeeding the target fuel mass change event;
determining a pressure change in response to the filtered pressures of the first pressure measurement zone and the second pressure measurement zone if the filtered pressures of the first pressure measurement zone and the second pressure measurement zone satisfy a pressure change requirement;
determining a fuel mass change corresponding to the target fuel mass change event in response to the pressure change; and
at least one of controlling and diagnosing one of the one or more injectors and the pump in response to the fuel mass change.
2 . The method of claim 1 , comprising: prior to the filtering, identifying a specific engine cycle as one of a plurality of precessing engine cycles, each of the plurality of precessing engine cycles having different phasing of the pump relative to the engine.
3 . The method of claim 2 , wherein the identifying comprises comparing a plurality of measured characteristics of the specific engine cycle with corresponding pluralities of previously determined characteristics each of the plurality of precessing engine cycles.
4 . The method of claim 3 , wherein the plurality of measured characteristics comprise one or more of: an injection duration of one or more injection events, a pumping duration of one or more pumping events, and a pressure measurement zone duration of one or more pressure measurement zones satisfying the pressure change requirement.
5 . The method of claim 1 , wherein the determining the pressure change of the target fuel mass change event comprises determining a net pressure change between the first pressure measurement zone and the second pressure measurement zone, and removing remove an effect of a confounding fuel mass change event from the net pressure change.
6 . The method of claim 1 , wherein the filtering is effective to mitigate ringing/oscillation in the measurements.
7 . The method of claim 1 , comprising: prior to the filtering, predicting the first pressure measurement zone and the second pressure measurement zone.
8 . The method of claim 7 , wherein the pressure change requirement comprises a maximum pressure change limit and the predicting the first pressure measurement zone and the second pressure measurement zone is based at least in part upon the maximum pressure change limit.
9 . The method of claim 8 , wherein the maximum pressure change limit is defined relative to a steady state pressure decay rate.
10 . The method of claim 1 , wherein the target fuel mass change event is settable as either an injection by a particular one of the one or more injectors or a pumping by the pump.
11 . A system comprising:
a fuel system including a pump configured to pump fuel to a rail and one or more injectors to inject fuel from the rail into one or more cylinders of an engine; and
an electronic control system configured to perform the acts of:
filtering measurements of fuel pressure of the rail taken during operation of the pump and the one or more injectors to determine filtered pressures for a first pressure measurement zone preceding a target fuel mass change event of the fuel system and a second pressure measurement zone succeeding the target fuel mass change event,
determining a pressure change in response to the filtered pressures of the first pressure measurement zone and the second pressure measurement zone if the filtered pressures of the first pressure measurement zone and the second pressure measurement zone satisfy a pressure change requirement,
determining a fuel mass change corresponding to the target fuel mass change event in response to the pressure change, and
at least one of controlling and diagnosing a selected one of the particular one of the one or more injectors and the pump in response to the fuel mass change.
12 . The system of claim 11 , wherein the electronic control system configured to perform the act of identifying a specific engine cycle as one of a plurality of precessing engine cycles, each of the plurality of precessing engine cycles having different phasing of the pump relative to the engine.
13 . The system of claim 12 , wherein the identifying comprises comparing a plurality of measured characteristics of the specific engine cycle measurements with corresponding pluralities of previously determined characteristics each of the plurality of precessing engine cycles.
14 . The system of claim 13 , wherein the plurality of measured characteristics comprise one or more of: an injection duration of one or more injection events, a pumping duration of one or more pumping events, and a pressure measurement zone duration of one or more pressure measurement zones satisfying the pressure change requirement.
15 . The system of claim 11 , wherein the determining the pressure change of the target fuel mass change event comprises determining a net pressure change between the first pressure measurement zone and the second pressure measurement zone, and removing remove an effect of a confounding fuel mass change event from the net pressure change.
16 . The system of claim 11 , wherein the filtering is effective to mitigate ringing/oscillation in the measurements.
17 . The system of claim 11 , wherein the electronic control system is configured to perform the act of predicting the first pressure measurement zone and the second pressure measurement zone.
18 . The system of claim 17 , wherein the pressure change requirement comprises a maximum pressure change limit and the predicting the first pressure measurement zone and the second pressure measurement zone is based at least in part upon the maximum pressure change limit.
19 . The system of claim 18 , wherein the maximum pressure change limit is defined relative to a steady state pressure decay rate.
20 . The system of claim 11 , wherein the target fuel mass change event is settable as either an injection by a particular one of the one or more injectors or a pumping by the pump.
21 . An apparatus for controlling operation of a fuel system including a pump configured to pump fuel to a rail and one or more injectors to inject fuel from the rail into one or more cylinders of an engine, the apparatus comprising:
one or more non-transitory memory media configured with instructions executable by one or more processors of an electronic control system to perform acts of:
filtering measurements of fuel pressure of the rail taken during operation of the pump and the one or more injectors to determine filtered pressures for a first pressure measurement zone preceding a target fuel mass change event of the fuel system and a second pressure measurement zone succeeding the target fuel mass change event,
determining a pressure change in response to the filtered pressures of the first pressure measurement zone and the second pressure measurement zone if the filtered pressures of the first pressure measurement zone and the second pressure measurement zone satisfy a pressure change criterion,
determining a fuel mass change corresponding to the target fuel mass change event in response to the pressure change, and
at least one of controlling and diagnosing a selected one of the particular one of the one or more injectors and the pump in response to the fuel mass change.
22 . The apparatus of claim 21 , wherein the instructions are executable by the electronic control system configured to perform the act of identifying a particular engine cycle as one of a plurality of repeating engine cycles, each of the plurality of repeating engine cycles having different phasing of the pump relative to the engine.
23 . The apparatus of claim 22 , wherein the identifying comprises comparing a plurality of measured characteristics of the particular engine cycle measurements with corresponding pluralities of previously determined characteristics each of the plurality of repeating engine cycles.
24 . The apparatus of claim 23 , wherein the plurality of measured characteristics comprise one or more of: an injection duration of one or more injection events, a pumping duration of one or more pumping events, and a pressure measurement zone duration of one or more pressure measurement zones satisfying the pressure change criterion.
25 . The apparatus of claim 21 wherein the determining the pressure change of the target fuel mass change event comprises determining a net pressure change between the first pressure measurement zone and the second pressure measurement zone, and removing remove an effect of a confounding fuel mass change event from the net pressure change.
26 . The apparatus of claim 21 , wherein the filtering is effective to mitigate ringing/oscillation in the measurements.
27 . The apparatus of claim 21 , wherein the instructions are executable by the electronic control system configured to perform the act of predicting the first pressure measurement zone and the second pressure measurement zone.
28 . The apparatus of claim 27 , wherein the predicting the first pressure measurement zone and the second pressure measurement zone is based at least in part upon a maximum pressure change criterion.
29 . The apparatus of claim 28 , wherein the maximum pressure change criterion is defined relative to a steady state pressure decay rate.
30 . The apparatus of claim 21 , wherein the target fuel mass change event is settable as either an injection by a particular one of the one or more injectors or a pumping by the pump.