US 4,763,627 AGranted

Learning and control apparatus for electronically controlled internal combustion engine

AssigneeJapan Electronic Control Systems Co., Ltd.

InventorNaoki Tomisawa

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Abstract

A learning and control apparatus for an electronically controlled internal combustion engine having such an object to be controlled as a fuel injection valve for controlling the air-fuel ratio in an air-fuel mixture or an idle speed control valve for controlling the idle rotation number of the engine wherein a pulse duty signal corresponding to a basic control value is set according to engine driving states. The basic control value is corrected by adding an appropriate correction value to the basic control value. Feedback control is carried out so that the actual controlled value is made to follow the aimed control value, and a learning correction quantity is computed by learning said feedback control so that the feedback control amount is set as small as possible. Driving region judging means judges the driving region stored learning correction quantity in a memory map corresponding to the detected actual driving state with such a hysteresis that at least one of the driving region-defining lattice axes in the memory map is shifted by a predetermined value according to the direction of change of the parameter of the engine driving state, thereby when the engine is driven in the driving state near the boundary that is lattice axes, between adjacent driving regions having a large difference between respective learning correction quantities no hunting phenomenon of the control quantity in engine driving and stable control characteristics can be maintained.

Claims13

Dependent claims

A learning and control apparatus for an electronically controlled internal combustion engine, comprising:

means for detecting an actual value of a parameter of an object within the engine to provide a detected object parameter, said parameter to be controlled in accordance with a control value;
means for detecting an engine driving state;
basic control quantity setting means for setting a basic control quantity corresponding to a desired control value of the object;
memory means for storing lattice axes driving the engine driving state detected by said detecting means into a plurality of regions in accordance with a parameter of the engine driving state and storing correction quantities for correcting said basic control quantity for each respective region defined by said lattice axes;
learning correction quantity retrieving means for retrieving the stored correction quantity of each said corresponding region from said memory means based on the detected engine driving state of the engine;
feedback correction quantity setting means for comparing said desired control value with the detected actual value of the detected object parameter and setting a feedback correction value by increasing or decreasing a feedback correction quantity by a predetermined quantity so that the actual value is brought close to the desired control value;
control quantity computing means for computing a control quantity from (a) the basic control quantity set by said basic control quantity setting means, (b) the stored correction quantity retrieved by said learning correction quantity retrieving means and (c) the feedback correction quantity set by said feedback correction quantity setting means;
control means responsive to said control quantity for controlling the object to be controlled;
learning correction quantity correcting means for storing any deviation of the feedback correction quantity from a standard value and for correcting and rewriting the stored correction quantity corresponding to each region of the engine driving state in a direction to reduce the deviation;
driving state change direction judging means for judging a direction of change of the parameter of the engine driving state;
and
driving region judging means for determining a driving region in which the stored correction quantity retrieved from the memory means by said learning correction quantity retrieving means is stored with a quantity of hysteresis such that at least one of the lattice axes defining said driving region is shifted by a predetermined value according to the direction of change of the parameter of the engine driving state.

9 more elements

An apparatus for determining and electronically controlling air-fuel ratio in an internal combustion engine comprising:

means for detecting a driving state of the engine;
first detecting means for detecting a flow quantity Q of air sucked into the engine;
second detecting means for detecting an engine speed N;
third detecting means for detecting exhaust components of the engine and detecting an actual value of the air-fuel ratio in an air-fuel mixture sucked into the engine;
fuel injection means for injecting fuel according to a fuel injection quantity;
basic fuel injection quantity setting means for setting a basic fuel injection quantity corresponding to (a) a desired air-fuel ratio responsive to a flow quantity of air sucked into the engine detected by the first detecting means and (b) the engine speed N detected by the second detecting means;
memory means for storing lattice axes driving the engine state into a plurality of regions by parameters of the engine driving state N and Q and storing a correction coefficient Kl for correcting the basic fuel injection quantity for respective regions of the driving state of the engine defined by said lattice axes;
learning correction coefficient retrieving means for retrieving a stored correction coefficient Kl of a corresponding region from said memory means based on a detected driving state of the engine;
feedback correction coefficient setting means for comparing the detected air-fuel ratio detected by the third detecting means with the desired air-fuel ratio and setting a feedback correction coefficient .alpha. for correcting the basic fuel injection quantity by adjusting the feedback correction coefficient .alpha. by a predetermined quantity so that the actual air-fuel ratio is brought close to the desired air-fuel ration;
fuel injection quantity computing means for computing the fuel injection quantity based on (a) the basic fuel injection quantity computed by said basic fuel injection quantity computing means, (b) the stored correction coefficient Kl retrieved by the learning correction coefficient retrieving means and (c) the feedback correction coefficient .alpha. set by the feedback correction coefficient setting means;
control means operating according to said fuel injection quantity Tp to control said fuel injection means in an on-off manner by a driving pulse signal;
learning correction coefficient correcting means for determining a deviation .DELTA..alpha. of the feedback correction coefficient .alpha. of each region of the driving state of the engine from a standard value .alpha.1 and correcting and rewriting the learning correction coefficient Kl corresponding to each region of an existing driving state of the engine in a direction reducing said deviation;
driving state change direction judging means for judging the direction of change of parameters N and Tp of the engine driving state;
and
driving region judging means for judging the driving region in which the learning correction coefficient Kl retrieved from the memory means by said learning correction coefficient retrieving means is stored with an amount of hysteresis such that at least one of the driving region-defining lattice axes is shifted in a direction responsive to a direction of change of the parameters N and Tp of the engine driving state.

12 more elements

Dependencies are inferred from the claim text.