Ford Global Technolgoies, LLC

Fca US LLC

Arthur Joseph Varady

John Michael Kacewicz

Robert Joseph Dalbo

Thomas Joseph Hermann

Sheran Anthony Alles

Lynn Edward Davison

Davor Hrovat

Timothy Mark Feldkamp

Richard K Moote

Moses Alexander Fridman

Jahan Asgari

Mitch McConnell

Cheryl Jeanette Stark

Jae Doo Chung

Satyadeo Narain Sinha

Marsha Wendel

Craig Stephens

Ilias Anagnostopoulos-Politis

Jaeyeong Chang

Zhe Wang

Patrick J Kohler

Richard John Gilbert

Yan Zhang

Johnathan M Swanson

A misfire detection system and method for a vehicle utilize a controller to obtain a crankshaft speed signal indicative of a rotational speed of an engine crankshaft connected to a device that mitigates vibrational disturbances at the crankshaft caused by misfires of the engine, detect that a first firing event of the engine is a first misfire based on the crankshaft speed signal, monitor a vibrational response of the crankshaft, detect that a consecutive second firing event of the engine is a second misfire based on a first modified crankshaft speed signal and the first set of thresholds, and in response to detecting the second misfire, reset the monitoring of the vibrational response of the crankshaft including modifying the amplitude of the crankshaft speed signal to obtain a second modified crankshaft speed signal and comparing the second modified crankshaft speed signal to a set of thresholds.

Crank velocity driveline filtering for consecutive misfire detection

Computer-implemented techniques include determining, at a controller of a vehicle, a wheel speed for each of two front wheels of the vehicle and two rear wheels of the vehicle. The techniques include calculating, at the controller, a difference between (i) an average of the wheel speeds for the two front wheels of the vehicle and (ii) an average of the wheel speeds for the two rear wheels of the vehicle to obtain an error. The techniques include setting, at the controller, a rough road detection bit when the error is greater than or equal to a threshold indicative of an error corresponding to rough road. The techniques include monitoring, at the controller, the rough road detection bit for a period to obtain a hysteresis band. The techniques also include determining, at the controller, whether the vehicle is traveling on rough road based on the hysteresis band.

Rough road detection and misfire control

An on-board diagnostic system of a vehicle comprises disabling diagnostic operation, such as a misfire monitor, based on road roughness. In one example, the disabling of the diagnostic operation is based on brake actuation and degradation of an anti-lock braking system.

Rough road detection system used in an on-board diagnostic system

A method is provided for controlling an engine in a vehicle to facilitate determination of engine position sensor correction factors. The vehicle includes a motor, which is operatively connected to the engine, a sensor configured to detect engine position, and a controller, which is in communication with the engine, the sensor and the motor. It is determined when an engine shutdown is requested, for example, when the controller commands the vehicle to be powered by the motor. It is next determined whether engine position sensor correction factors are known. If they are, the engine control routine is stopped. If the correction factors are not known, fuel to the engine is discontinued, and the motor is employed to spin the engine at an approximately constant speed. The engine position sensor correction factors can then be determined while the engine is rotating in a defueled state.

System and method for improved engine position sensing

The invention is a strategy to detect spark plug misfires in a multiple spark plug per cylinder internal combustion engine (ICE). The present invention monitors spark plug misfires for each plug within each cylinder and initiates diagnostic fault code setting and failure mode actions such as modifying spark timing and the air/fuel ratio for the cylinder with the misfiring plug to optimize emissions and performance. The strategy modifies spark timing (such as spark retard) of a spark plug not under test but within the same cylinder of the tested spark plug and tests the tested spark plug for misfire (such as changes in crankshaft velocity or acceleration). The amount of spark retard invoked can be a calibrated value such as 30 or 50 degrees off Maximum Brake Torque (MBT) timing. The invention provides improvement over the prior art in that the strategy does not require the complete disabling of a spark plug within the same cylinder as the tested spark plug.

Method and system to detect spark loss in a multiple spark plug per cylinder internal combustion engine

An engine misfire detection circuit and method for operation includes a reference window generator that generates a misfire window reference signal having a misfire sampling window. A misfire window calculator is coupled to a condition variable input and the reference window generator. The condition varying input may be a filter input or an input from various engine sensors. The misfire window calculator calculates an offset for adjusting the sampling window in response to the condition variable input.

Engine misfire detection using adjustable windowing

Methods of utilizing engine crankshaft acceleration to monitor cold start spark retard are presented. A first method utilizes a variance in a crankshaft acceleration based deviation signal and looks for changes in the variance to confirm if cold spark retard has occurred by the ignition system. In a second method, a threshold level of a group of cylinder crankshaft acceleration deviation signals &Dgr;, can be detected and compared to a level of crankshaft deviant acceleration when normal spark is commanded to determine if commanded spark retard has been realized.

Method to verify cold start spark retard

A rotational sensing assembly including a ferromagnetic sensor wheel rotationally fixed to a shaft having a tooth pattern including a missing tooth. An inductive sensor is mounted adjacent the periphery of the sensor wheel and in communication with a processor. The sensor produces a generally sinusoidal signal in response to the wheel rotation, with voltage zero crossings that are time stamped by the processor. The geometry of the sensor wheel around the missing tooth location is altered to equalize the induced voltage in the sensor for fixed time intervals in order to maintain proper timing of the zero crossings in the sensor signal.

Magnetic rotary position sensing

A method for more accurately sensing the rotational position of a shaft having a toothed sensor wheel with a missing tooth is disclosed. The method includes employing an inductive sensor to produce a signal in response to the passing of the teeth on the sensor wheel. The sensor signal is altered by the geometry of the wheel about a gap formed by the missing tooth in order to correct for residual stored energy in the sensor at this location, and thus correct the signal for the timing measured by a processor in communication with the sensor.

Method of sensing rotational information of shaft with toothed wheel

An improved misfired detection system and method for high data rate engine control systems. A method of detecting misfires of individual cylinder events in an internal combustion engine is disclosed which includes the step of generating a high data rate velocity signal indicative of the torque behavior of the engine. The velocity signal is then filtered and separated into a plurality of non-interlaced homogeneous data sets wherein each of the data sets represents like portions of the internal combustion engine cycle. A median filter is then applied to each of the plurality of non-interlaced homogeneous data sets. In this manner, the data sets are normalized according to the applied recursive median filter and centered about a relative zero. This centering effect allows the signals to be recombined after filtering, thereby monitoring the nature of any deviations present in the signal. A threshold comparison of the resulting signal is then made to determine whether a misfire has occurred.

Misfire detection system and method using recursive median filtering for

A misfire correction factor is included in the calculation of the fuel pulse width so that upon detection of a misfire, the excess fuel that would normally have entered the engine is offset or canceled, thus reducing or desensitizing the effects of the reaction of the lean biased exhaust gas oxygen sensor signal. This compensation allows for normally firing cylinders to operate closer to stoichiometric air/fuel ratio when other cylinders are operating in a misfire condition. The fuel adjustment due to engine misfire not only protects against catalyst degradation, but also decreases unwanted emissions.

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Chelsea, MI, United States of America

Arthur Joseph Varady