Method for detecting valve leakage in a combustion engine
AssigneeVolvo Car Corporation
InventorsAndreas Storm, Niklas Särnberger, Fredrik Fridmar
Life of this patent
Estimating the term…
Abstract
A method for detecting valve leakage of a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the method comprising: acquiring a set of pressure data points indicative of the pressure in the cylinder intake manifold or exhaust manifold for crankshaft angular positions covering crankshaft angular rotation degrees such that each of the at least one valve has opened at least one time; and determining at least one test value based on the set of pressure data points, wherein a valve leakage is detected based on a comparison of the at least one test value to a threshold value.
Claims17
A method for detecting a valve leakage in a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the method comprising:
- acquiring, while operating the vehicle engine at steady state operating conditions such that the engine speed and load are within normal operating ranges that cause the engine to be warmed up, a set of pressure data points indicative of the pressure in the cylinder intake manifold or exhaust manifold for crankshaft angular positions covering crankshaft angular rotation degrees such that each of the at least one valve has opened at least one time, wherein the set of pressure data points is sampled as a function of crankshaft angular positions covering 720 degrees;
- correlating the pressure data points with crankshaft angular positions in a range of 0-720 degrees;
- and
- determining at least one test value based on the set of pressure data points correlated with the crankshaft angular positions, the at least one test value reflecting a deviation of the set of pressure data points sampled as a function of crankshaft angular positions from a steady periodic pattern indicative of a manifold without leakage, wherein a valve leakage is detected based on a comparison of the at least one test value to a threshold value associated with the steady periodic pattern indicative of the manifold without leakage.
A control unit for detecting a valve leakage in a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the control unit being configured to:
- acquire, while the vehicle engine is operated at steady state operating conditions such that the engine speed and load are within normal operating ranges that cause the engine to be warmed up, a set of pressure data points indicative of the pressure in the cylinder intake manifold or exhaust manifold at crankshaft angular positions covering crankshaft angular rotation degrees such that each of the at least one valve has opened at least one time, wherein the set of pressure data points is sampled as a function of crankshaft angular positions covering 720 degrees;
- correlating the pressure data points with crankshaft angular positions in a range of 0-720 degrees;
- and
- determine at least one test value based on the set of pressure data points correlated with the crankshaft angular positions, the at least one test value reflecting a deviation of the set of pressure data points sampled as a function of crankshaft angular positions from a steady periodic pattern indicative of a manifold without leakage, wherein a valve leakage is detected based on a comparison of the at least one test value to a threshold value associated with the steady periodic pattern indicative of the manifold without leakage.
A non-transitory computer readable medium comprising instructions stored in a memory and executed by a processor to carry out steps for detecting a valve leakage of a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the steps comprising:
- determining at least one test value based on an acquired set of pressure data points correlated with crankshaft angular positions in a range of 0-720 degrees and acquired while operating the vehicle engine at steady state operating conditions such that the engine speed and load are within normal operating ranges that cause the engine to be warmed up, wherein the set of pressure data points are indicative of the pressure in the cylinder intake manifold or exhaust manifold at known crankshaft angle positions covering at least 720 degrees, the at least one test value reflecting a deviation of the set of pressure data points as a function of crankshaft angular positions from a steady periodic pattern indicative of a manifold without leakage;
- and
- detecting a valve leakage is based on relation between the at least one test value and a threshold value associated with the steady periodic pattern indicative of the manifold without leakage.
Dependencies are inferred from the claim text.