Visteon Global Technolgoies, Inc.

Cooper Automotive Products, Inc.

Chao Fu Daniels

Guoming Zhu

Kevin David Moran

Ibrahim Haskara

Michael T Nation

Bruce Wang

Kenneth L Gould

Mengyang Zhang

Mathew Ethan Breton

William Charles Mammen, Jr

Alcohol concentration level of flex fuel is estimated based upon in-cylinder ionization signals. The in-cylinder ionization signals are integrated and the rotational completion point of a chosen percentage of the integration total is identified as the integration location for the operating conditions under observation. The calculated integration location correlates with alcohol concentration level of flex fuel, and the integration calculations provide a basis for a virtual flex fuel sensor that provides calculated estimates of alcohol concentration rather than direct sensing using an expensive physical flex fuel sensor.

Virtual flex fuel sensor for spark ignition engines using ionization signal

A robust multi-criteria minimum timing for the best torque (MBT) timing estimation method and apparatus utilizes different ionization signal waveforms that are generated under different engine operating conditions. The MBT timing criteria is calculated based upon both ionization and analog derivative ionization. Multiple MBT timing criteria are determined and combined to increase the reliability and robustness of MBT timing estimation based upon spark plug ionization signal waveforms. In a preferred embodiment, a combination of the MBT timing estimation criteria comprises a maximum flame acceleration location, a 50% burn location, and a second peak location.

Method and system of estimating MBT timing using in-cylinder ionization signal

This feature of the present invention comprises a system and method of controlling exhaust gas recirculation (EGR) based on a measure combustion stability measure. The combustion stability measure is obtained by determining the integration duration of the engine ionization signal, i.e., the crank angle at which the integral of the ionization signal reaches a specified percentage of its total. The present invention uses the integration duration to control the maximum EGR rate of the engine in a closed loop while maintaining the combustion stability of an internal combustion engine.

System and method of controlling engine dilution rate using combustion stability measurer derived from the ionization signal

This feature of the present invention comprises a method and apparatus which uses an ionization signal to optimize the air to fuel ratio AFR of the combustion mixture when the engine is operated at wide open throttle (WOT). This feature of the present invention optimizes the air to fuel ratio AFR on-line using the relationship between an air to fuel ratio AFR index Cand the air to fuel ratio AFR. In a preferred embodiment, the real-time control strategy adjusts the engine air to fuel ratio AFR based upon an air to fuel ratio AFR gradient parameter.

Optimal wide open throttle air/fuel ratio control

This feature of the present invention comprises an ignition diagnostics and feedback control system based upon detected ionization current in an individual cylinder. The system is divided into two subsystems: an ignition diagnostics subsystem and an ignition feedback control system subsystem. The ignition diagnostics subsystem comprises an ignition system diagnostics, a misfire detector, a knock detector, and a robust multi-criteria minimum timing for best torque MBT timing estimator. The ionization feedback control subsystem comprises five main subsystems: a closed loop cold start retard spark control using ionization feedback, a closed loop MBT timing control using ionization feedback, a closed-loop individual cylinder air to fuel ratio balancing control system, an optimal wide open throttle air/fuel ratio control, and an exhaust gas control using a spark plug ionization signal.

Ignition diagnosis and combustion feedback control system using an ionization signal

This feature of the present invention comprises a method and apparatus to retard the spark time. As a result, the catalyst heats up quickly during the cold start. The retard spark control method of the present invention uses a closed loop to adjust the engine retard limit during an engine cold start to retard the engine spark as much as possible without engine misfire and with minimum partial burn. The increased exhaust temperature heats up the catalyst more quickly than conventional open loop approaches, which as a result, reduces hydrocarbon emissions. The closed loop retard spark control using ionization current feedback consists of four major components or functions, an error and gain generator, a proportional and integration control processing block, a default spark timing processor, and an adaptive learning apparatus.

Closed loop cold start retard spark control using ionization feedback

This feature of the present invention is a robust multi-criteria minimum timing for the best torque (MBT) timing estimation method and apparatus utilizing different ionization signal waveforms that are generated under different engine operating conditions. This feature of the present invention determines and combines multiple MBT timing criteria to increase the reliability and robustness of MBT timing estimation based upon spark plug ionization signal waveforms. In a preferred embodiment, the present invention combines MBT timing estimation criteria comprising a maximum flame acceleration location, a 50% burn location, and a second peak location.

Robust multi-criteria MBT timing estimation using ionization signal

The present feature of the invention comprises a method and apparatus for determining cylinder ID. When a cylinder is compressed, the resistance increases across the spark plug gap. Thus, if a spark coil is only partially charged before activation of the spark, the air gap is not broken down and no ignition occurs in the cylinder in compression. The failure of a spark plug to spark is reflected in the ionization signal. In a preferred embodiment, the dwell time is selected so that the spark plug located in a cylinder that is not in compression will spark, while a spark plug in a cylinder that is in compression will not. The cylinder in compression will output an ionization signal with a shorter duration than a cylinder not in compression. In a preferred embodiment, two methods are used to calculate the duration of the spark, edge detection and integration.

Method of detecting cylinder ID using in-cylinder ionization for spark detection following partial coil charging

The individual cylinder air to fuel ratio of an internal combustion engine varies due to the fact that the intake manifold cannot distribute airflow into the individual cylinders evenly. This feature of the present invention utilizes minimum timing for best torque MBT timing criterion provided by the ionization signals or by the in-cylinder pressure signals to balance the air to fuel ratios of the individual cylinders. The control method of the present invention comprises: calculating a mean timing coefficient, calculating a timing coefficient error, integrating the minimum timing for best torque timing coefficient error, calculating a raw fuel trim coefficient, resealing the raw fuel trim coefficient, updating a feedforward look-up table based upon the current engine operating conditions, and calculating a final fueling command.

Closed-loop individual cylinder A/F ratio balancing

This feature of the present invention comprises a closed loop which uses estimated MBT timing criteria and ignition diagnostics (knock, partial-burn, and misfire) to control engine ignition. When the engine is not knock limited, it operates at its MBT timing. When the engine is knock limited, the engine runs at its inaudible knock limit. When the engine is misfire/partial-burn limited, the engine is maintained at its misfire/partial-burn limit. Three different embodiments of the closed loop MBT timing control architecture are disclosed: a cylinder-by-cylinder control, an average control and a mixed control.

Closed loop MBT timing control using ionization feedback

The present feature of the invention is generally directed to a subsystem of an ignition diagnostics and feedback control system using ionization current feedback. It utilizes the ionization signal from an ionization detection circuit to monitor ignition parameters, such as primary charge timing, primary charge duration, ignition/spark timing, and ignition/spark duration for future 'smart' ignition system control. In addition, the ionization signal is also used to detect spark plug carbon fouling, as well as plug insulator overheating. These parameters can be monitored for every cylinder of the engine for each engine cycle.

Ignition diagnosis using ionization signal

This feature of the present invention comprises a method and apparatus to reduce NOx emissions in an internal combustion engine. This feature of the present invention uses a closed loop control of the exhaust gas re-circulation to provide the engine with the either EGR MBT timing or a knock limited timing to yield the minimum NOx emission with maximum fuel economy benefits associated with exhaust gas re-circulation. When the exhaust gas re-circulation rate is not knock limited, the engine sets its exhaust gas re-circulation rate to an optimal rate at which the engine runs at the exhaust gas re-circulation minimum best time for best torque spark timing limit. When the exhaust gas re-circulation rate is knock limited, the engine sets its exhaust gas re-circulation rate to a knock limited rate at which the engine runs at a retarded MBT spark timing limit. The engine uses calibratable MBT timing criteria to determine the retarded MBT spark timing limit.

Exhaust gas control using a spark plug ionization signal

The present invention includes an engine diagnostic method and routine, wherein a method of using an ionization signal to perform an engine diagnostic routine includes the steps of detecting the ionization signal; integrating the ionization signal over a first sampling window to generate a first integration ionization value; detecting a peak of the ionization signal over said first sampling window to generate a first peak ionization value; integrating the ionization over a second sampling window to generate a second integration ionization value; detecting a peak of the ionization signal over a second sampling window to generate a second peak ionization value; and diagnosing the engine using said ionization signal.

IC engine diagnostic system using the peak and integration ionization current signals

Maximum braking torque timing in an internal combustion engine can be determined by calculating the net pressure change in an engine cylinder during combustion. The second derivative of the net pressure change is then calculated. The spark timing of the engine is then varied until the maximum acceleration point of the net pressure change is aligned with top dead center.

Method for determining MBT timing in an internal combustion engine

Mass fraction burned in a cylinder of an internal combustion engine is determined by measuring an ion signal across a gap of a spark plug and identifying an inflection point of the ion signal. The mass fraction burned is determined using an expression that includes a constant. A value for the constant is determined using the inflection point of the ion signal, and the mass fraction burned is determined using the expression and the constant.

Growing community of inventors

Ypsilanti, MI, United States of America

Chao Fu Daniels