Electronic control of engine fuel injection based on engine duty cycle

A system for controlling operation of a fuel injector in an engine comprising:

• a first timing map for providing a first set of timing data;
• a second timing map for providing a second set of timing data;
• first timing value selecting means for selecting a first timing value from said first timing map based on current engine operating conditions;
• second timing value selecting means for selecting a second timing value from said second map based on current engine operating conditions;
• control variable determining means for determining a control variable as a function of engine operating conditions;
• and
• fuel injector timing determining means for variable determining fuel injector timing from said first and second timing values based on the value of said control variable.

A fuel injector system including an electronic control for controlling timing and fueling operations of a plurality of fuel injectors the electronic control comprising:

• first timing value means for providing first timing values for extreme transient engine operation;
• second timing value means for providing second timing values for steady state engine operation;
• and
• fuel injector timing determining means for determining fuel injector timing based on first and second timing values from said first and second timing value means, said fuel injector timing determining means including interpolating means for interpolating between respective first and second timing values of said first and second timing value means.

A fuel injector system having electronically controlled fuel injectors in which an electronic control unit receives signals which indicate operating conditions of the engine and said electronic control unit controls injection timing and fueling in response to the signals, the system comprising:

• speed indicator means for producing a signal indicative of engine speed;
• throttle position indicating means for producing a signal indicative of throttle position;
• and
• an electronic control unit comprising:
• (a) signal receiving means for receiving engine speed and throttle position signals;
• (b) signal transmitting means for transmitting timing signals for controlling fuel injector timing, and fueling signals for controlling fuel injector fueling;
• (c) fueling determining means for determining the fuel quantity to be injected and producing fueling signals for transmission by said signal transmitting means for commanding fuel injector fueling;
• (d) timing determining means for determining fuel injector timing and producing a timing signal for transmission by said transmitting means;
• said timing determining means including averaging means for determining an average engine speed over a predetermined period and speed difference means for determining a speed difference between current engine speed and the average engine speed, said timing determining means further including:
• (i) means for selecting an interpolating control variable based on the speed difference;
• (ii) first timing value means for producing a first timing value based on current commanded fueling produced by the fueling determining means, said first timing value further based on current engine speed as indicated by said speed indicating means;
• iii) second timing value means for producing a second timing value based on current commanded fueling produced by the fueling determining means, said second timing value further based on current engine speed as indicated by said speed indicating means;
• wherein said timing determining means utilizes said interpolating control variable for interpolating between said first and second timing values.

A method for controlling fuel injector operation in a fuel injector system of an engine comprising the steps of:

• selecting a first timing value based on engine operating conditions according to a first timing determining function;
• selecting a second timing value based on engine operating conditions according to a second timing determining function different from said first timing determining function;
• determining a control variable based on current engine operating conditions;
• and
• determining fuel injector timing based on a weighted summation of said first and second timing values, said values weighted variably in said summation according to the value of said control variable.