Delphi Technologies, Inc.

Jeffrey M Pfeiffer

Amanpal S Grewal

Daniel Lee McKay

Daniel George Gauthier

Jongmin Lee

Martin M&uuml;ller

Dennis C Reed

Peter James Maloney

James Patrick Waters

Martin Müller

Edward George Himes

Sebastien Stoltz-Douchet

Jon C Darrow

Timothy M Nieves

Joon-Ho Yoo

Gregg Stepien

A method is provided for sensing the position of a camshaft in an internal combustion engine having a camshaft phaser for controllably varying the phase relationship between a crankshaft of the internal combustion engine and the camshaft, the camshaft phaser being actuated by an electric motor and having a gear reduction mechanism with a predetermined gear reduction ratio and a sensor for determining the rotational position of the electric motor. The method includes generating a rotational position signal indicative of the rotational position of the electric motor by using the sensor to determine the rotational position of the electric motor and calculating the position of the camshaft based on the rotational position signal and the gear reduction ratio of the gear reduction mechanism.

Camshaft position sensing in engines with electric variable cam phasers

A method for determining an estimate of a response characteristic that depends on a number of input factors includes developing a mathematical model of the response as a function of the input factors based on a statistical fit of a plurality of measured data points. The method also includes mapping the value of the response characteristic and the input factors at a plurality of conditions. The method combines the mapped data with the mathematical model to produce an estimate of the response characteristic that is more accurate over a range of conditions than either the mapped data or the model taken individually.

Method for determining an engine response characteristic

An improved control and diagnostic algorithm for coordinating the operation and checking reliability of oil control valves for a vane-type camshaft phaser in an internal combustion engine. A first oil control valve governs the rotational position of the phaser rotor within the stator, and a second oil control valve controls the locking and unlocking of a locking pin operable between the rotor and the stator. The algorithm determines when a change is needed in the position of the locking pin, commands the rotor to a predetermined angular position to permit the position change to be carried out, determines whether the commanded change was carried out successfully, and reports instances wherein the commanded locking pin position change was unsuccessful.

Method for controlling and diagnosing a vane-type cam phaser having intermediate position pin locking

A standard cam phasing OCV may be employed as a virtual check valve to choke the backflow of oil during negative cam torque conditions, including execution of a duty cycle command in an event-based manner. Normally, OCV duty cycle commands are made on a time basis, but for VCV the duty cycle output change must be synchronized with engine events. A method is disclosed for calculating and delivering the VCV duty cycle so that both time-based and event-based controls are maintained and work together. Phase alignment of response time of the OCV solenoid is based upon cam target wheel edges and is event-based. An initial phase rate vs. phase angle is monitored by the Engine Control Module (ECM). Adjustment of the phase angle is provided to achieve maximum cam position phase rate.

Method for synchronizing an oil control valve as a virtual check valve

An internal combustion engine having valve deactivation capability for at least one cylinder, or for an entire bank of cylinders in a multiple-bank engine, is provided with a temperature probe in the exhaust stream of that cylinder or cylinder bank. The temperature probe is connected to an Engine Control Module programmed to determine the rate of temperature change during valve deactivation, to compare the determined value to an acceptable range of rates, and to signal, when the rate exceeds an acceptable range. When the valves of a cylinder are properly deactivated, the temperature in the exhaust pipe decreases slowly. However, when valve deactivation fails, the cylinders pump non-combusted air from the intake manifold into the exhaust manifold, resulting in a relatively rapid decrease in exhaust temperature. This abnormal rate of temperature decrease thus can be used as an indicator of failure of the VVA system.

Detection of valve deactivation failure by monitoring exhaust temperature

A camshaft phaser control system for reducing rotor positional instability. A phaser system includes a target wheel mounted on the phaser rotor such that during camshaft rotation wheel teeth chop a signal to generate first and second interruption signals indicative of amplitude of rotor instability. An instability monitor is used to monitor the level of instability against predetermined acceptable levels, depending upon engine operating conditions (RPM, temperature). An excessive level of instability is established by engine calibration. When measured instability exceeds a predetermined threshold level for a predetermined period, an instability diagnostic becomes alarmed. A default strategy is used to correct the excessive instability by applying a bias to the phaser control duty cycle. The system continues to monitor the level of instability, and when instability falls below the threshold limit, normal phasing operation is resumed.

Method for reducing phaser rotational instability in an internal combustion engine

A method of determining the position of a cam phaser determines and stores an adaptively updated base offset corresponding to the phase offset of a camshaft relative to a crankshaft for a reference or default position of a cam phaser. Thereafter, the phaser position is determined relative to the base offset. Individual base offsets are preferably determined for each tooth of a toothed cam wheel, and stored in a non-volatile memory device. During engine operation, the base offsets are subject to diagnostic testing and adaptive updating, and the updated base offsets are stored in the non-volatile memory at engine shut-down.

Method of determining the position of a cam phaser

The present invention provides a method and apparatus to control the rate of change of the variable cam phasing system during transient engine operating conditions. It does this primarily to maintain combustion stability. The invention controls the rate of change of the variable cam phasing system based upon the operating point of the engine, the desired operating point of the engine, and the rate of change of the variable cam phasing system necessary to maintain combustion stability.

Method and apparatus for controlling a variable valve system for an internal combustion engine

The present invention provides an improvement over conventional engine controls by providing a method and system that operates a variable valve system immediately subsequent to engine start, and disengages the variable valve system when engine performance is unacceptable. If the variable valve system is disengaged after engine start due to poor engine performance, a time delay occurs to allow the engine to create a sufficient amount of oil pressure to operate the variable valve system.

Method and apparatus to control a variable valve system

A cam phase control method for an internal combustion engine schedules cam phase to optimize emissions and fuel economy, but bounds the scheduled cam phase for continuous achievement of the desired inlet airflow. The volumetric efficiency required to achieve the desired inlet airflow at a specified intake manifold vacuum is compared to the maximum achievable volumetric efficiency at the specified vacuum. When the required volumetric efficiency is less than the maximum value, the cam phase is controlled according to the lesser of the scheduled cam phase and the highest cam phase for achieving the required volumetric efficiency; when the required volumetric efficiency is equal to or greater than the maximum value, the cam phase is controlled to a setting that maximizes the volumetric efficiency.

Method of bounding cam phase adjustment in an internal combustion engine

A camshaft phaser control system including a camshaft target wheel, the target wheel having first and second teeth for measuring camshaft oscillatory instability. The trailing edge of the first tooth coincides with the negative camshaft oscillation peak, and the trailing edge of the second tooth coincides with the positive camshaft oscillation peak. During each camshaft rotation, each tooth initiates an input signal to generate first and second input signals in known fashion. During crankshaft rotation, a third input signal is generated corresponding to the rotational position of the crankshaft. From these signals, operational camshaft oscillatory instability is computed by an engine monitoring system (EMS). Any deviation from the operational instability while the engine is operating is a direct measurement of oscillatory instability of the camshaft about its nominal holding position. A change in oscillatory instability is inferred as system malfunction, permitting defensive action to be taken by the EMS.

Engine phaser control system using phaser instability measurement

The present invention is a method and apparatus to clean an oil control valve for use by an internal combustion engine. The invention causes the oil control valve to execute a cleaning routine when specific entrance criteria are met. This ensures cleaning of the valve to remove contaminants that are wedged, pinched or otherwise trapped on the valve, without interference in the operation of the engine.

Method and apparatus for cleaning an oil control valve for an internal combustion engine

An improved method of estimating the oil temperature of an internal combustion engine models the net heat flow through the oil during operation of the engine based on known engine operating parameters and integrates the net heat flow to update the oil temperature estimate. The net heat flow components include heat added to the oil due to fuel combustion and heat rejected from the oil to the engine coolant and atmospheric air, and are based on heat transfer coefficients that are adjusted to take into account variations in engine speed, vehicle speed and cooling fan operation.

Model-based method of estimating crankcase oil temperature in an internal combustion engine

An improved method of estimating the oil pressure of an internal combustion engine utilizes a physical model that takes into account both engine speed and engine oil temperature. The oil pressure is estimated as the sum of static and dynamic components, where the dynamic component includes a first portion that primarily models flow-related effects, and a second portion that primarily models temperature-related effects. The constants and temperature-related variables of the physical model are combined to form one constant calibration value, and two temperature-dependent calibration values. The parameters of the physical model provide a starting point for the calibration values, and the calibration values are then tuned during a calibration procedure so that the estimated oil pressure tracks an accurate measure of the oil pressure during both steady-state and transient engine operating conditions.

Model-based method of estimating crankcase oil pressure in an internal combustion engine

A method of estimating the concentration of residual exhaust gas in an internal combustion engine having variable cam phase control is based on engine dynamometer and engine simulator data. Since both the volumetric efficiency and the residual exhaust gas concentration of an engine vary monotonically in response to changes in cam phase, the simulated residual concentration data is deemed to be reliable if the simulated volumetric efficiency data matches volumetric efficiency data determined by engine dynamometer testing. Volumetric efficiency test data is compared to simulated volumetric efficiency data, and the simulation software is tuned until the simulated data matches the test data. At such point, the simulated residual concentration data is deemed to be reliable, and is used to calibrate a model relating residual concentration to cam phase angle, and such model is then used by an engine controller to estimate residual exhaust gas concentration during operation of the engine.

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Walled Lake, MI, United States of America

Jeffrey M Pfeiffer