Abstract: A camshaft phasor control system for an engine includes a first camshaft position sensor that generates a first camshaft position signal based on a position of a first camshaft. A first summer generates a first error signal based on the first camshaft position signal and a first commanded position signal. A control module generates a raw duty cycle based on the first error signal. A second summer generates a modified duty cycle based on the raw duty cycle and a modifier. The control module generates the modifier based on the first error signal and speed of the first camshaft relative to a second camshaft.

Abstract: A method may include commanding operation of an engine in a first lift mode. The engine may include a valve lifter system that selectively operates a valve member in the first lift mode and a second lift mode through engagement with a camshaft. A first duty cycle of a cam phaser oil control valve (OCV) may be determined to maintain a first camshaft position corresponding to the first lift mode. The camshaft position may be maintained by a cam phaser that is coupled to the camshaft and in communication with the cam phaser OCV. Engine operation may be commanded to the second lift mode and a second duty cycle of the cam phaser OCV may be determined to maintain a second camshaft position corresponding to the second lift mode. A valve lifter system failure may be diagnosed based on a difference between the first and second duty cycles.

Abstract: A camshaft phasor control system for an engine includes a position control module. The position control module generates a position control signal based on a camshaft position command signal and a gain signal. A gain circuit generates the gain signal based on the position control signal and feeds the gain signal back to the position control module. The position control module positions a camshaft of the engine based on the gain signal.

Abstract: An engine control system includes a cam phaser that introduces a cam phase angle ? between a camshaft intake lobe and an associated crankshaft. An engine control module communicates with the cam phaser to introduce the cam phase angle ? while an engine is being started. The cam phase angle ? is selected such that the camshaft intake lobe opens an intake valve during at least a portion of a compression stroke of a cylinder that is associated with the camshaft intake lobe.

Abstract: A method of valve lift failure detection may include determining first and second intake air pressures in an engine having intake valve lifters that selectively operate intake valves in first and second lift modes. The first intake air pressure may correspond to an intake stroke of a first piston of the engine when the engine is commanded to operate in the first lift mode and the second intake air pressure may correspond to an intake stroke of a second piston of the engine when the engine is commanded to operate in the first lift mode. The method may further include determining a difference between the first and second intake air pressures and diagnosing an intake valve lifter failure when the difference exceeds a predetermined limit.

Abstract: A camshaft phasor control system for an engine includes a position control module. The position control module generates a position control signal based on a camshaft position command signal and a gain signal. A gain circuit generates the gain signal based on the position control signal and feeds the gain signal back to the position control module. The position control module positions a camshaft of the engine based on the gain signal.

Abstract: A control module may include a cam phaser control module, a cam phaser oil pressure determination module, and a system oil pressure prediction module. The cam phaser control module may control an oil control valve (OCV) to control an oil flow to a cam phaser. The cam phaser oil pressure determination module may be in communication with the cam phaser control module and may determine a first engine oil pressure at a location between the OCV and the cam phaser when the OCV is in a open position. The system oil pressure prediction module may determine a second engine oil pressure at a location between the OCV and an oil pump outlet based on the first engine oil pressure.

Abstract: A camshaft phasor control system for an engine includes a camshaft position sensor that generates a current camshaft position signal based on position of a camshaft. A first comparator generates a camshaft position signal based on the current camshaft position signal and a crankshaft position. The second comparator generates an error signal based on the relative camshaft position signal and a commanded camshaft position signal. A control module determines a current control hold duty cycle (CHDC) for a camshaft phasor based on an engine state parameter. The control module also generates a correction signal based on the error signal, adjusts the current CHDC based on the correction signal to generate a commanded CHDC signal, and generates another CHDC based on the commanded CHDC signal.

Abstract: A diagnostic system for an engine includes a pressure monitoring module that determines a plurality of first average pressure values and a plurality of second average pressure values of a fluid supply provided to a camshaft phaser. A diagnostic module identifies one of a plurality of cylinders associated with a failed variable valve lift mechanism based on the first and said second average pressure values. Each of the first and the second average pressure values respectively correspond to each of the plurality of cylinders.

Abstract: A system for controlling a variable valve lift system of an engine comprises a delay module that estimates a total delay based on at least one of a measured and an estimated delay of the variable valve lift system. A variable valve control module commands one of a first transition from a variable valve low-lift profile to a variable valve high-lift profile and a second transition from a variable valve high-lift profile to a variable valve low-lift profile based on the total delay.

Abstract: A method for diagnosing malfunctions of switching valve lifters includes sensing variations in pressure of trapped oil in a drive chamber of a hydraulic camshaft drive, such as a cam phaser, comparing peak oil pressure readings in the drive chamber resulting from the increased torque of opening the valves of various cylinders of an engine and identifying cylinders having lower than normal valve opening pressure readings, indicating failure of an associated valve lifter to properly actuate a valve of the cylinder. Apparatus for indicating such malfunctions could include a cam phaser with pressure chamber, a pressure sensor connected to indicate pressure variations in the chamber; and a pressure indicator connected to the sensor and adapted to indicate actual pressure variations for comparison with normal variations to identify low pressure peaks indicating malfunction of a switching lifter. A computer could be used to receive and act upon the malfunction indications.

Abstract: An electronic enhanced mobility control interface of a mobility enhancement system implemented in a motor vehicle having a conventional electronic throttle control system. The electronic enhanced mobility throttle interface includes an auxiliary electronic throttle sensor in duplication of the conventional throttle pedal electronic throttle sensor, wherein the driver's selection of either the auxiliary or throttle pedal position throttle sensor is interfaced transparently to an engine electronic controller, as for example an engine control module (ECM/PCM) for processing to the electronic throttle control (ETC) subsystem. The electronic mobility enhancement throttle interface further includes an auxiliary throttle control by which the driver executes throttle commands to the auxiliary electronic throttle sensor, a data switch for connecting one or the other of the throttle pedal position and auxiliary electronic throttle sensors processing electronics to the ECM/PCM.

Abstract: A control decreases dilution (EGR) in an internal combustion engine from a schedule if surge is detected and allows it to return to the schedule in the absence of surge. Surge is detected by timing a predetermined crank angle of 70-10 degrees BTDC, an angle including only crank deceleration, for consecutive engine firings, updating an average time therewith and computing the difference between the new time and the average. The successive differences are examined for zero crossings and compared to a stored maximum difference. If difference exceeds the maximum it becomes the new maximum difference. If a zero crossing is detected, the time since the last zero crossing is calculated to determine if the difference variations have a frequency of 2-10 Hz. If so, and the maximum difference exceeds a reference, a surge signal is generated.

Abstract: A dilution control adjusts an EGR valve, variable valve lift mechanism or similar dilution control device in an internal combustion engine in response to the relationship between ignition timing and the timing of peak combustion pressure (LPP) in the vicinity of a desired timing of peak combustion pressure (DLPP). The relationship is derived in the process of controlling ignition timing in response to LPP, wherein LPP is controlled to DLPP or as close to it as possible. In this process, LPP varies slightly back and forth through DLPP or through a maximum retard value, if LPP is not attainable. The apparatus detects whether LPP is retarded with respect to DLPP as it reverses from retard to advance, increases dilution if it is so retarded and decreases dilution if it is not. The engine thus operates with maximum EGR consistent with LPP being equal to the desired value DLPP.

Abstract: An internal combustion engine with a throttle valve, fuel supply and dilution (EGR) control includes apparatus effective to detect a throttle tipout condition comprising a rate of throttle closing exceeding a predetermined reference rate and decrease the dilution from the scheduled value to its minimum value during the existence of the throttle tipout condition and further apparatus effective to detect the end of the throttle tipout condition and return the dilution to its scheduled value at a controlled rate. Thus, a sudden unscheduled increase in dilution caused by a throttle tipout associated increase in intake manifold vacuum is reduced and driveability improved.

Abstract: An LLP ignition timing control for an internal combustion engine periodically senses LPP in an engine combustion chamber and generates an average LPP value. A DLPP value indicating a desired LPP is generated; and ignition timing is periodically adjusted. The apparatus advances ignition timing if the average LPP value is retarded with respect to the DLPP value. The ignition timing is maintained in the same direction as the previous adjustment if the average LPP is advanced and becoming less advanced with respect to the DLPP value, but is reversed to the opposite direction from that of the previous adjustment if the average LPP is advanced and becoming more advanced with respect to the DLPP value. The amount of adjustment is proportional to the product of the difference between the average LPP value and DLPP value and the rate of change in the average LPP value. Thus, MBT is maintained in spite of the foldover effect in the LPP vs.