Method for detecting an abnormal disturbance of an internal combustion engine torque
AssigneeRENAULT s.a.s.
InventorGuillaume Dony
Life of this patent
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Abstract
A method for detecting an abnormal disturbance of an internal combustion engine torque and for suspending the functioning of a system in which combustion misfiring has been diagnosed. The method operates by analysis of values of a quantity representing the quality of combustion by observing engine crank shaft rotation. A stability criterion is defined of the quantity for each of the engine cylinders. Then, after each combustion the stability criterion is compared with a predetermined threshold, and an abnormal torque disturbance is detected when the stability criterion is greater than the threshold for a given number of consecutive times for at least one cylinder.
Claims10
A process for detecting an abnormal perturbation of a torque of an internal combustion engine and suspending an operation of a system for diagnosis of misfires, which system operates by analysis of values of a variable representative of firing quality by observation of rotation of an engine crankshaft, said process comprising the steps of:
- defining a criterion of stability of said variable for each cylinder of the engine and for each firing;
- comparing, after each firing, the stability criterion with a predetermined threshold;
- and
- detecting an abnormal torque perturbation when said stability criterion exceeds, for at least one cylinder, the threshold for a given number of consecutive times,
- wherein said stability criterion quantifies, for a given cylinder and given firing, an absolute deviation between the value of said variable and the value of a statistical variable representative of a mean of different values of said variable.
A process for detecting an abnormal perturbation of a torque of an internal combustion engine and suspending an operation of a system for diagnosis of misfires, which system operates by analysis of values of a variable representative of firing quality by observation of rotation of an engine crankshaft, said process comprising the steps of:
- defining a criterion of stability of said variable for each cylinder of the engine and for each firing;
- comparing, after each firing, the stability criterion with a predetermined threshold;
- and
- detecting an abnormal torque perturbation when said stability criterion exceeds, for at least one cylinder, the threshold for a given number of consecutive times,
- wherein said predetermined threshold is deduced from variations of a statistical variable observed during normal engine operation, and therefore depends on an engine operating point.
A process for detecting an abnormal perturbation of a torque of an internal combustion engine and suspending an operation of a system for diagnosis of misfires, which system operates by analysis of values of a variable representative of firing quality by observation of rotation of an engine crankshaft, said process comprising the steps of:
- defining a criterion of stability of said variable for each cylinder of the engine and for each firing;
- comparing, after each firing, the stability criterion with a predetermined threshold;
- and
- detecting an abnormal torque perturbation when said stability criterion exceeds, for at least one cylinder, the threshold for a given number of consecutive times,
- wherein the firings being diagnosed as misfires initiate a particular treatment in the calculation of said stability criterion.
A process for detecting an abnormal perturbation of a torque of an internal combustion engine and suspending an operation of a system for diagnosis of misfires, which system operates by analysis of values of a variable representative of firing quality by observation of rotation of an engine crankshaft, said process comprising the steps of:
- defining a criterion of stability of said variable for each cylinder of the engine and for each firing;
- comparing, after each firing, the stability criterion with a predetermined threshold;
- and
- detecting an abnormal torque perturbation when said stability criterion exceeds, for at least one cylinder, the threshold for a given number of consecutive times,
- wherein the firings being diagnosed as misfires initiate a particular treatment in the step of comparing the stability criterion with said predetermined threshold.
Dependencies are inferred from the claim text.