Data processing: measuring – calibrating – or testing – Measurement system – Performance or efficiency evaluation
Reexamination Certificate
2001-09-20
2004-03-02
Hoff, Marc S. (Department: 2857)
Data processing: measuring, calibrating, or testing
Measurement system
Performance or efficiency evaluation
C702S047000, C702S138000, C702S183000
Reexamination Certificate
active
06701282
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to diagnostic systems for internal combustion engines, and more particularly to diagnostic systems for identifying a fault in a throttle position sensor, a manifold absolute pressure sensor, and/or a mass airflow sensor of an onboard diagnostic system for an internal combustion engine.
BACKGROUND OF THE INVENTION
Vehicles with internal combustion engines generally employ intake system sensors including a throttle position sensor (TPS), a mass airflow (MAF) sensor, and a manifold absolute pressure (MAP) sensor. When one of these sensors is not operating properly, it is relatively difficult for a technician to readily identify which sensor is faulty. Part of the problem stems from the inability to identify the faulty sensor based upon available information such as fault codes, operating characteristics or other available diagnostic information. As a result, the diagnosis and repair times involving the failure of one of these sensors are relatively high, which increases the warranty cost of the vehicle.
SUMMARY OF THE INVENTION
A fault identification system for intake system sensors according to the invention includes a throttle position sensor (TPS), a manifold absolute pressure (MAP) sensor, and a mass airflow (MAF) sensor. A diagnostic controller is coupled to the TPS, the MAP sensor and the MAF sensor. The diagnostic controller implements a throttle model, a first intake model and a second intake model to identify faults in the TPS, the MAP sensor and the MAF sensor.
In other features of the invention, the throttle model generates a mass airflow estimate. The first intake model generates a first manifold absolute pressure estimate. The second intake model generates a second manifold absolute pressure estimate.
In still other features, the diagnostic controller performs residual calculations on outputs of the throttle model, the first intake model and the second intake model. The diagnostic controller performs a first order lag filter on the residual calculations and applies a truth table to identify faults in the TPS, MAP and MAF sensors.
In another aspect of the invention, a fault identification method for intake system sensors generates a mass airflow estimate using a throttle model. A first manifold absolute pressure (MAP) estimate is generated using a first intake model. A second MAP estimate is generated using a second intake model. Faults are identified in a throttle position sensor (TPS), a mass airflow (MAF) sensor and a MAP sensor using the mass airflow estimate, the first MAP estimate and the second MAP estimate.
In other features, residual calculations and a lag filter are performed on the mass airflow estimate, the first MAP estimate and the second MAP estimate. The first order lag filter calculations are used to access a truth table to identify faults in the TPS, the MAP sensor and the MAF sensor.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
REFERENCES:
patent: 5041976 (1991-08-01), Marko et al.
patent: 5431011 (1995-07-01), Casarella et al.
patent: 5509302 (1996-04-01), Drexel et al.
patent: 6145494 (2000-11-01), Klopp
patent: 6370935 (2002-04-01), He et al.
patent: 6484080 (2002-11-01), Breed
patent: 6497227 (2002-12-01), Wang et al.
SAE paper #970209; M. Nyberg/L. Nielsen, “Model Based Diagnosis for the Air Intake System of the SI-Engine”; Feb. 1997, p. 1-12.
Ting Thomas L.
Van Gilder John F.
General Motors Corporation
Hoff Marc S.
Juarez Felix
Simon Anthony Luke
LandOfFree
Fault identification diagnostic for intake system sensors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fault identification diagnostic for intake system sensors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fault identification diagnostic for intake system sensors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3223636