Method and apparatus for controlling an internal combustion engine
AssigneeRobert Bosch GmbH
InventorsReinhard Latsch, Valerio Bianchi
Life of this patent
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Abstract
A control apparatus for an internal combustion engine performs cyclic modulations of an operational parameter of the engine, for example by periodic leaning out of the fuel-air mixture to some of the engine's cylinders. The resulting changes in angular acceleration of the crankshaft are sensed by an electro-inductive transducer and the elapsed time between successive pulses so generated is measured. Depending on whether the change in acceleration is positive or negative, the circuit generates an appropriate control signal which may be used to steer a final control element which moves the center of modulation, i.e., the operational point of the engine, toward an optimum value of, for example, the fuel-air ratio.
Claims19
A method for controlling an internal combustion engine comprising the steps of
- modulating the magnitude of an engine control variable at a frequency locked to the engine speed;
- measuring the resultant variation in crankshaft acceleration;
- comparing the phase of the modulation with the phase of the resultant crankshaft acceleration;
- adjusting the magnitude of an engine control variable according to said comparison of phase.
An apparatus for controlling an internal combustion engine comprising:
- modulator means for periodic alteration of an engine variable;
- detector means for detecting the resulting alteration in engine performance;
- means for comparing the engine performance with set-point data, including
- a logical circuit for producing phase-shifted signal trains,
- a subsequent processor circuit for processing and comparing signals, and a subsequent controller for adjusting and regulating said engine variable, and
- control means for changing an engine variable according to the results of comparisons performed by said means for comparing engine performance.
An apparatus for controlling an internal combustion engine comprising:
- modulator means for periodic alteration of an engine variable;
- detector means for detecting the resulting alteration in engine performance;
- means for comparing the engine performance with set-point data, including
- a logical circuit for producing phase-shifted signal trains,
- a subsequent processor circuit for processing and comparing signals, and a subsequent controller for adjusting and regulating said engine variable, said processor circuit including a saw-tooth generator in which a capacitor is charged in proportion to the period of crankshaft revolution and two differentiating circuits connected in series;
- and
- control means for changing an engine variable according to the results of comparisons performed by said means for comparing engine performance.
An apparatus for controlling an internal combustion engine comprising:
- modulator means for periodic alteration of an engine variable;
- detector means for detecting the resulting alteration in engine performance;
- means for comparing the engine performance with set-point data, including
- a logical circuit for producing phase-shifted signal trains,
- a subsequent processor circuit for processing and comparing signals, and a subsequent controller for adjusting and regulating said engine variable,
- a multiplier circuit fed by said processor circuit and by said modulator means;
- an integrating circuit connected to the multiplier circuit;
- control means for changing an engine variable according to the results of comparisons performed by said means for comparing engine performance;
- and
- a final control element actuated by said integrating circuit, whereby said final control element alters engine variables to obtain optimum engine operation.
An apparatus for controlling an internal combustion engine comprising;
- modulator means for periodic alteration of an engine variable;
- detector means for detecting the resulting alteration in engine performance;
- means for comparing the engine performance with set-point data, including
- a logical circuit for producing phase-shifted signal trains,
- a subsequent processor circuit for processing and comparing signals, and a subsequent controller for adjusting and regulating said engine variable;
- two bi-stable flip-flops connected to said detector means, with a signal from the first of said be-stable flip-flaps being fed to said logical circuit;
- an integrator connected to said multiplier circuit, said integrator receiving the output signal from said second bi-stable flip-flop, whereby the output of the integrator is an immediate measure of the modulation signal and any correction signal;
- and
- control means for changing an engine variable according to the results of comparisons performed by said means for comparing engine performance.
Dependencies are inferred from the claim text.