US 5,445,128 AGranted

Method for engine control

AssigneeDetroit Diesel Corporation

InventorsDennis M. Letang, Douglas J. Babcock, S. Miller Weisman, II

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Abstract

A method for comprehensive integrated control of a compression-ignition internal combustion engine having integral fuel pump-injectors utilizing an electronic control unit is disclosed. The control strategy integrates various functions of engine control including fuel delivery, cooling fan control, engine speed governing and overspeed protection, engine braking, torque control, and vehicle speed diagnostics and control. Cooling fan control is integrated with vehicle speed diagnostics and control as well as fuel delivery to provide an integrated cruise control function which incorporates engine braking. The method also includes improved control over the various engine speed governors while improving idle quality by balancing the power delivered by each of the engine cylinders when at idle. The integrated torque control employs functions to reduce NOx emissions and noise utilizing adaptive fuel delivery timing and a split injection strategy.

Claims9

Dependent claims

A method of controlling the output torque of a multi-cylinder compression-ignition internal combustion engine including an electronic control unit for controlling the engine, a plurality of cylinders each having an injector apparatus controlled by the electronic control unit for delivering fuel, the method comprising:

sensing at least one engine operating parameter to obtain at least one operating signal;
determining a desired output torque for each cylinder based on the at least one operating signal;
determining a base fuel pulse width for each cylinder to produce the desired output torque;
determining a pulse width adjustment factor for each cylinder for modifying the base fuel pulse width according to:
TMP=PWA.sub.old +G*(RPM.sub.bal -RPM.sub.avg)
PWA.sub.new =max(-ACBr.sub.LIM, min(ACB.sub.LIM, TMP))
wherein "max()" is a function which selects the largest of the parenthetical values, "min()" is a function which selects the smallest of the parenthetical values, ACB.sub.LIM is a limiting value for the adjustment, G represents a system gain factor, RPM.sub.bal is a balancing value of the engine rotational speed for the current cylinder, and RPM.sub.avg is an average of the balancing values of previously fired cylinders;
and
controlling the injector apparatus based on the modified base fuel pulse width.

6 more elements

sensing at least one engine operating parameter to obtain at least one operating signal;
determining a desired output torque for each cylinder based on the at least one operating signal;
determining a base fuel pulse width for each cylinder to produce the desired output torque;
determining a pulse width adjustment factor for each cylinder for modifying the base fuel pulse width based on the at least one operating signal, wherein the pulse width adjustment factor is normalized to have an average value of zero after every firing cycle in which each of the plurality of cylinders has fired once;
and controlling the injector apparatus based on the modified base fuel pulse width.

2 more elements

Dependencies are inferred from the claim text.