Self-diagnosing apparatus and method for fuel supply control system applicable to internal combustion engine
First Claim
1. A self diagnosing apparatus for a fuel supply control system in an internal combustion engine, comprising:
- a) first detecting means for detecting an air/fuel mixture ratio of an air/fuel mixture supplied to the engine and outputting a first signal indicative of the actual air/fuel mixture ratio;
b) second detecting means for detecting an engine driving condition and outputting a second signal indicative of the engine driving condition;
b) air/fuel mixture ratio feedback controlled variable setting means, responsive to the output first and second signals from the first and second detecting means, for comparing the actual air/fuel mixture ratio with a target air/fuel mixture ratio and for setting and determining an air/fuel mixture ratio feedback controlled variable on the basis of the first and second signals which serves to correct the air/fuel mixture ratio of the air/fuel mixture to be supplied to the engine according to a result of comparison so that the actual air/fuel mixture ratio is approached to a target air/fuel mixture ratio;
c) air/fuel mixture ratio decrement/increment correcting means for controlling the fuel supply quantity related to the air/fuel mixture ratio to be supplied to the engine so as to correct incrementally or decrementally the actual air/fuel mixture ratio on the basis of the air/fuel mixture feedback controlled variable set by the air/fuel mixture feedback controlled variable setting means; and
d) air/fuel mixture ratio increment/decrement control diagnosing means for diagnosing an air/fuel mixture ratio controlled state of the fuel supply control system on the basis of at least one of either each magnitude by which the air/fuel mixture ratio feedback controlled variable is changed to richen or lean the air/fuel mixture ratio so as to approach the actual air/fuel mixture ratio to the target air/fuel mixture ratio or a control duration of time during which the fuel supply control system executes the correction on the actual air/fuel mixture ratio by means of the air/fuel mixture ratio feedback controlled variable.
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Abstract
A self diagnosing apparatus and method for a fuel supply control system in an internal comustion engine are disclosed in which since an air/fuel mixture ratio feedback controlled variable is set so that an actual air/fuel mixture ratio is approached to a target (stoichiometric) air/fuel mixture ratio and movement (incremental or decremental change width) of the air/fuel mixture ratio feedback-controlled variable indicates a deviation of the actual air/fuel mixture ratio from the target air/fuel mixture ratio, a diagnosis of the air/fuel mixture ratio controlled state by means of the fuel supply control system is carried out on the basis of at least one of either a total sum of each magnitude by which the air/fuel mixture ratio feedback controlled variable is changed to enrich or enlean the air/fuel mixture ratio so as to approach it to the target air/fuel mixture ratio or a control duration of time during which the air/fuel mixture ratio feedback control variable is set to control the air/fuel mixture ratio.
19 Citations
20 Claims
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1. A self diagnosing apparatus for a fuel supply control system in an internal combustion engine, comprising:
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a) first detecting means for detecting an air/fuel mixture ratio of an air/fuel mixture supplied to the engine and outputting a first signal indicative of the actual air/fuel mixture ratio; b) second detecting means for detecting an engine driving condition and outputting a second signal indicative of the engine driving condition; b) air/fuel mixture ratio feedback controlled variable setting means, responsive to the output first and second signals from the first and second detecting means, for comparing the actual air/fuel mixture ratio with a target air/fuel mixture ratio and for setting and determining an air/fuel mixture ratio feedback controlled variable on the basis of the first and second signals which serves to correct the air/fuel mixture ratio of the air/fuel mixture to be supplied to the engine according to a result of comparison so that the actual air/fuel mixture ratio is approached to a target air/fuel mixture ratio; c) air/fuel mixture ratio decrement/increment correcting means for controlling the fuel supply quantity related to the air/fuel mixture ratio to be supplied to the engine so as to correct incrementally or decrementally the actual air/fuel mixture ratio on the basis of the air/fuel mixture feedback controlled variable set by the air/fuel mixture feedback controlled variable setting means; and d) air/fuel mixture ratio increment/decrement control diagnosing means for diagnosing an air/fuel mixture ratio controlled state of the fuel supply control system on the basis of at least one of either each magnitude by which the air/fuel mixture ratio feedback controlled variable is changed to richen or lean the air/fuel mixture ratio so as to approach the actual air/fuel mixture ratio to the target air/fuel mixture ratio or a control duration of time during which the fuel supply control system executes the correction on the actual air/fuel mixture ratio by means of the air/fuel mixture ratio feedback controlled variable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A self diagnosing apparatus for a system for controlling and learning an air/fuel mixture ratio applicable to an internal combustion engine installed in an automotive vehicle, comprising:
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a) first means for detecting an engine driving condition including a driving parameter related to an intake air quantity sucked into the engine; b) second means for setting a basic fuel supply quantity Tp on the basis of the engine driving condition; c) third means for detecting an air/fuel mixture ratio of the supplied air/fuel mixture of the engine; d) fourth means for comparing the detected air/fuel mixture ratio with a target air/fuel mixture ratio and for setting an air/fuel mixture ratio feedback correction coefficient LMD used to correct the basic fuel injection quantity so as to approach the actual air/fuel mixture ratio to the target air/fuel mixture ratio; e0 fifth means for rewritably storing an air/fuel mixture ratio learning correction coefficient KBLRC for each driving region, a whole driving region on the engine driving condition being divided into a plurality of subdivided driving regions and the learning correction coefficient being used to correct the basic fuel supply quantity; f) sixth means for learning a deviation of a value of the air/fuel mixture ratio feedback correction coefficient to a target convergence value and for modifying and rewriting the air/fuel mixture ratio learning correction coefficient stored so as to correspond to one of the dubdivided driving regions in the fifth means so that the deviation thereof is reduced; g) seventh means for determining the present corresponding driving region in the fifth means as a learned region when the value of the air/fuel mixture ratio feedback correction coefficient substantially coincides wih the target convergence value and for storing a result of determination on the learned region according to each driving region; h) eighth means for driving a final fuel supply quantity on the basis of the basic fuel injection quantity Tp, air/fuel mixture ratio feedback correction coefficient LMD, and the learned air/fuel mixture ratio learning correction coefficient KBLRC stored so as to correspond to the present driving region, the fuel quantity being a quantity of fuel to be supplied to the engine; and i) ninth means for diagnosing an air/fuel mixture ratio controlled state of the fuel supply control system on the basis of at least one of either a sum of a magnitude by which the air/fuel mixture ratio feedback correction coefficient LMD is decrementally or incrementally changed to richen or lean the air/fuel mixture ratio so as to approach the actual air/fuel mixture ratio to the target air/fuel mixture ratio or a control duration of time during which the fuel supply control system executes the correction of the basic fuel supply quantity to calculate the final fuel supply quantity on the actual air/fuel mixture ratio by means of the air/fuel mixture ratio feedback correction coefficient LMD. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A self diagnosing method for a system for controlling and learning an air/fuel mixture ratio applicable to an internal combustion engine installed in an automotive vehicle, comprising the steps of:
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a) detecting an engine driving condition including a driving parameter related to an intake air quantity sucked into the engine; b) setting a basic fuel supply quantity Tp on the basis of the engine driving condition; c) detecting an air/fuel mixture ratio of the supplied air/fuel mixture of the engine; d) comparing the detected air/fuel mixture ratio with a target air/fuel mixture ratio and setting an air/fuel mixture ratio feedback correction coefficient LMD used to correct the basic fuel injection quantity so as to approach the actual air/fuel mixture ratio to the target air/fuel mixture ratio; e) rewritably storing an air/fuel mixture ratio learning correction coefficient KBLRC for each driving region, a whole driving region on the engine driving condition being divided into a plurality of subdivided driving regions and the learning correction coefficient being used to correct the basic fuel supply quantity; f) learning a deviation of a value of the air/fuel mixture ratio feedback correction coefficient to a target convergence value and modifying and rewriting the air/fuel mixture ratio learning correction coefficient stored so as to correspond to one of the dubdivided driving regions so that the deviation thereof is reduced; g) determining the present corresponding driving region in the fifth means as a learned region when the value of the air/fuel mixture ratio feedback correction coefficient substantially coincides wih the target convergence value and storing a result of determination on the learned region according to each driving region; h) deriving a final fuel supply quantity on the basis of the basic fuel injection quantity Tp, air/fuel mixture ratio feedback correction coefficient LMD, and teh learned air/fuel mixture ratio learning correction coefficient KBLRC stored so as to correspond to the present driving region, the fuel quantity being a quantity of fuel to be supplied to the engine; and i) self diagnosing an air/fuel mixture ratio controlled state of the fuel supply control system on the basis of at least one of either a sum of a magnitude by which the air/fuel mixture ratio feedback correction coefficient LMD is decrementally or incrementally changed to richen or lean the air/fuel mixture ratio so as to approach the actual air/fuel mixture ratio to the target air/fuel mixture ratio or a control duration of time during which the fuel supply control system executes the correction of the basic fuel supply quantity to calculate the final fuel supply quantity on the actual air/fuel mixture ratio by means of the air/fuel mixture ratio feedback correction coefficient LMD.
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Specification