Method of controlling fuel supply to internal combustion engine

Claim 1

A method of controlling fuel supply to a multicylinder internal combustion engine having a fuel injection valve and a plurality of sensors for measuring engine operating conditions, comprising the steps of: (a) measuring engine crankshaft rotation; (b) producing a crank angle pulse signal on the basis of said crank rotation measurement, the pulses of which signal occur each time the crankshaft rotates through a predetermined angle; (c) measuring a plurality of other engine operating conditions; (d) producing information signals indicative of the plurality of the other engine operating conditions; (e) beginning a calculation of a fuel injection duration adjustment and calculating the adjustment as a function of at least one information signal indicative of engine operating conditions in response to a first pulse of said crank angle signal; (f) starting a calculation of a basic fuel injection duration and calculating the duration as a function of information signals indicative of engine operating conditions, including crankshaft rotation, after the fuel injection duration adjustment calculation, ending the basic fuel injection duration calculation before the crank angle signal pulse immediately following said first pulse; (g) starting a calculation of an output value and calculating the value as a function of said basic fuel injection duration and said fuel injection duration adjustment after said basic fuel injection duration calculation, ending the output value calculation before the crank angle signal pulse immediately following said first pulse; (h) opening the fuel injection valve in response to the crank angle signal pulse immediately following said first pulse; and (i) closing the fuel injection valve after a time interval corresponding to said output value.

Claim 2

A method of controlling fuel supply to a multicylinder internal combustion engine having a fuel injection valve and a plurality of sensors for measuring engine operating conditions, comprising the steps of: (a) measuring engine crankshaft rotation; (b) producing a crank angle pulse signal on the basis of said crank rotation measurement, the pulses of which signal occur each time the crankshaft rotates through a predetermined angle; (c) measuring a plurality of other engine operating conditions; (d) producing information signals indicative of the plurality of the other engine operating conditions; (e) beginning a calculation of a fuel injection duration adjustment and calculating the adjustment as a function of at least one information signal indicative of engine operating conditions in response to a first pulse of said crank angle signal; (f) starting a calculation of a basic fuel injection duration and calculating the duration as a function of information signals indicative of engine operating conditions, including crankshaft rotation, after the fuel injection duration adjustment calculation, ending the basic fuel injection duration calculation before the crank angle signal pulse immediately following said first pulse; (g) starting a calculation of an output value and calculating the value as a function of said basic fuel injection duration and said fuel injection duration adjustment after said basic fuel injection duration calculation, ending the output value calculation before the crank angle signal pulse immediately following said first pulse; (h) opening the fuel injection valve in response to the crank angle signal pulse immediately following said first pulse; and (i) closing the fuel injection valve after a time interval corresponding to said output value.

Claim 3

A method of controlling fuel supply to an internal combustion engine having a fuel injection valve and a plurality of sensors for measuring engine operating conditions, comprising the steps of: (a) measuring engine crankshaft rotation; (b) producing a crank angle pulse signal on the basis of said crank rotation measurement, the pulses of which signal occur for each crank rotation of 720°/P, where P is the number of engine cylinders; (c) measuring a plurality of other engine operating conditions; (d) producing information signals indicative of the plurality of other engine operating conditions; (e) beginning a calculation of a fuel injection duration adjustment and calculating the adjustment as a function of at least one information signal indicative of engine operating conditions in response to a first pulse of said crank angle signal; (f) starting a calculation of a basic fuel injection duration and calculating the duration as a function of information signals indicative of engine operating conditions, including crankshaft rotation, in response to the crank angle signal pulse immediately following said first pulse; (g) starting a calculation of an output value and calculating the value as a function of said basic fuel injection duration and said fuel injection duration adjustment immediately after said basic fuel injection duration calculation; (h) opening the fuel injection valve immediately after said output value calculation; and (i) providing a control signal representative of said output value, and displacing said control signal in time from the time of opening the fuel injection valve by a time interval corresponding to said output value; and (j) closing the fuel injection valve responsively to said displaced control signal.

Claim 4

A method of controlling fuel supply to an internal combustion engine having a fuel injection valve and a plurality of sensors for measuring engine operating conditions, comprising the steps of: (a) measuring engine crankshaft rotation; (b) producing a crank angle pulse signal on the basis of said crank rotation measurement, the pulses of which signal occur for each crank rotation of 720°/P, where P is the number of engine cylinders; (c) measuring a plurality of other engine operating conditions; (d) producing information signals indicative of the plurality of other engine operating conditions; (e) beginning a calculation of a fuel injection duration adjustment and calculating the adjustment as a function of at least one information signal indicative of engine operating conditions in response to a first pulse of said crank angle signal; (f) starting a calculation of a basic fuel injection duration and calculating the duration as a function of information signals indicative of engine operating conditions, including crankshaft rotation, in response to the crank angle signal pulse immediately following said first pulse; (g) starting a calculation of an output value and calculating the value as a function of said basic fuel injection duration and said fuel injection duration adjustment immediately after said basic fuel injection duration calculation; (h) opening the fuel injection valve immediately after said output value calculation; and (i) providing a control signal representative of said output value, and displacing said control signal in time from the time of opening the fuel injection valve by a time interval corresponding to said output value; and (j) closing the fuel injection valve responsively to said displaced control signal.

Claim 7

The method of any one of claims 1-4, further comprising the step of measuring intake air flow into the engine, wherein the basic fuel injection duration is calculated on the basis of engine rotation speed as measured via the engine crankshaft, and intake air flow.

Claim 8

The method of any one of claims 1-4, wherein said step of measuring a plurality of other engine operating conditions further comprises the steps of: measuring engine coolant temperature, and measuring exhaust gas oxygen concentration, wherein said step of calculating a fuel injection duration adjustment is based on said measured engine temperature, exhaust gas oxygen concentration, and engine load.