Abstract: A control method adjusts fuel injection into an engine having a variable compression ratio. The method determines the cylinder air amount based on various sensors and the current compression ratio. The disclosed fuel injection method can perform both open loop and closed loop control. A method is also disclosed for putting the compression ratio to a base value during engine shutdown so that subsequent engine starts occur with a consistent compression ratio.

Abstract: A method for obtaining an accurate cylinder air-charge estimate is presented. First, a sensor-based powertrain torque estimate is obtained. Next, a torque converter-based powertrain torque estimate is obtained when the torque converter clutch is unlocked. The two estimates are compared, and if they differ by more than a predetermined amount, sensor drift is diagnosed, and corrected.

Abstract: A system (12) and method for determining a value for a control variable for an engine (10) are provided. The system (12) includes an electronic control unit (ECU) (62) configured to obtain a plurality of pairs of programmed timing values for the opening and closing, respectively, of an intake valve (30) and exhaust valve (32) in a cylinder (14) of the engine (10) responsive to different sets of engine operating conditions. The ECU (62) is further configured to obtain a corresponding plurality of conditional values for the control variable responsive to the speed of, and load on, the engine (10) and the plurality of pairs of programmed timing values. Finally, the ECU (62) is configured to determine through interpolation the value for the control variable responsive to the plurality of conditional values. The system and method enable accurate determination of engine control variables during transient conditions using existing engine data.

Abstract: A system and method for selecting one of first and second camshafts in an engine is provided. The first and second camshafts control air flow communicating with the first and second cylinders, respectively, of the engine. The engine includes a crankshaft being driven by first and second pistons with the first and second cylinders. The method includes determining which of the first and second camshafts is moving at a faster rate of movement toward a first scheduled phase angle with respect to the crankshaft. Finally, the method includes selecting one of the first and second camshafts having the faster rate of movement for reducing engine torque fluctuations.

Abstract: A system and method for controlling first and second phase shiftable camshafts in a variable cam timing engine is provided. The method includes determining when the first camshaft is moving toward a first scheduled phase angle with respect to the crankshaft at a faster rate than the second camshaft is moving toward the first scheduled phase angle. Finally, the method includes slowing down the first camshaft so that the rate of movement of the first camshaft approaches a rate or movement of the second camshaft toward the first scheduled phase angle.

Abstract: A method for obtaining an accurate cylinder air-charge estimate is presented. First, a sensor-based powertrain torque estimate is obtained. Next, a torque converter-based powertrain torque estimate is obtained when the torque converter clutch is unlocked. The two estimates are compared, and if they differ by more than a predetermined amount, sensor drift is diagnosed, and corrected.

Abstract: A method for obtaining an accurate cylinder air-charge estimate is presented. First, a sensor-based powertrain torque estimate is obtained. Next, a torque converter-based powertrain torque estimate is obtained when the torque converter clutch is unlocked. The two estimates are compared, and if they differ by more than a predetermined amount, sensor drift is diagnosed, and corrected.

Abstract: An internal combustion engine having variable camshaft timing that incorporates a method of determining the position of the variable cam timing phasing system for controlling the flow of intake and exhaust gases during the combustion process. The method includes the steps of creating a model for estimating a calculated cam position and a calculated rate-of-change of the cam position. The method also includes the step of measuring a measured cam position and a measured rate-of-change of the cam position. The calculated cam position is compared to the measured cam position and calculated rate-of-change of the cam position and measured rate-of-change of the cam position that are blended based upon a comparison of the two values. The engine controller is adjusted dependent upon the blended rate-of-change of the cam position.

Abstract: An internal combustion engine having variable camshaft timing that incorporates a method of determining the position of the variable cam timing phasing system for controlling the flow of intake and exhaust gases during the combustion process. The method includes the steps of creating a model for estimating a calculated cam position and a calculated rate-of-change of the cam position. The method also includes the step of measuring a measured cam position and a measured rate-of-change of the cam position. The calculated cam position is compared to the measured cam position and calculated rate-of-change of the cam position and measured rate-of-change of the cam position that are blended based upon a comparison of the two values. The engine controller is adjusted dependent upon the blended rate-of-change of the cam position.

Abstract: An improved method for estimating an input torque to the continuously variable transmission (CVT) is presented. The method includes calculating torque adaptation coefficients when the torque converter clutch is unlocked, and an accurate torque value can be obtained based on the torque converter characteristics. The adaptation coefficients are then used to correct the transmission torque estimate, which is then used to determine proper CVT clamping forces. This method improves fuel economy, transmission durability, and customer satisfaction.

Abstract: A system for controlling camshaft timing, air/fuel ratio and electronic throttle position in an automotive internal combustion engine uses a controller for operating a camshaft phaser, electronic throttle positioner and fuel injectors. The controller determines camshaft timing, steady-state electronic throttle position, steady-state fuel supply, and compensatory transient electronic throttle position, and transient fuel supply such that an engine operating with the present system has the torque output characteristics matching a conventional engine having fixed camshaft timing, but with lower fuel consumption and lower exhaust emissions than a conventional engine.

Abstract: A method and system for determining future cylinder air-charge of an internal combustion engine having a throttle plate and an intake manifold includes a throttle position sensor for sensing a current position of the throttle plate. Control logic determines a future position of the throttle plate based on the sensed current position. Based on a model governing a change in pressure of the intake manifold and the future position of the throttle plate, the control logic then determines the future cylinder air charge.

Abstract: EGR system for an internal combustion engine comprises a stepper motor driven EGR valve (150) to control the rate of exhaust gas recirculation in the engine and an electronic controller (EEC 100) for determining a desired EGR percent mass flow rate as a function comprising a rotational speed value and an aircharge value of the engine, converting the EGR percent mass flow rate to an EGR mass flow rate value, adjusting the EGR mass flow rate value as a function of an exhaust gas temperature value and an absolute exhaust gas backpressure value using MAP values, determining a pressure ratio value across an EGR orifice (155) cooperating with the EGR valve, and determining a required number of motor steps as a function of the adjusted EGR mass flow rate value and the pressure ratio value to achieve the desired EGR percent mass flow rate.

Abstract: A method of controlling the fueling rate of a compression ignition engine having an exhaust gas recirculation system (EGR) and a turbocharger. The method includes the steps of predicting the exhaust gas air/fuel ratio as a function engine operating characteristics and the operator-requested fueling rate. This value is compared to an air/fuel limit value stored in a table of values indexed by engine operating characteristics. The air/fuel limit is the value below which visible smoke occurs. The predicted air/fuel ratio is compared to the air/fuel ratio limit and either (1) the fuel is delivered at the requested rate, (2) the start of injection timing is modified and the fuel is delivered at the requested rate or (3) the fueling rate is limited as a function of the requested fueling rate and measured or determined engine operating parameters.

Abstract: A method of estimating the airflow into a compression ignition engine having an exhaust gas recirculation system (EGR) and a variable geometry turbocharger (VGT). The method includes the steps of generating an EGR flow value as a function of the intake manifold pressure (MAP), exhaust manifold pressure (EXMP), position of the exhaust gas recirculation valve, and temperature of the gas flowing through the EGR. From this calculation, the method generates an intake airflow value (MAF) as a function of the EGR flow value and the intake aircharge temperature. The intake airflow value is used, in turn, to control the position of the EGR valve. The disclosed method thereby eliminates the necessity for a MAF sensor.

Abstract: A method of controlling the airflow into a compression ignition engine having an EGR and a VGT. The control strategy includes the steps of generating desired EGR and VGT turbine mass flow rates as a function of the desired and measured compressor mass airflow values and exhaust manifold pressure values. The desired compressor mass airflow and exhaust manifold pressure values are generated as a function of the operator-requested fueling rate and engine speed. The EGR and VGT turbine mass flow rates are then inverted to corresponding EGR and VGT actuator positions to achieve the desired compressor mass airflow rate and exhaust manifold pressure. The control strategy also includes a method of estimating the intake manifold pressure used in generating the EGR valve and VGT turbine positions.

Abstract: A system for controlling camshaft timing, air/fuel ratio and electronic throttle position in an automotive internal combustion engine uses a controller for operating a camshaft phaser, electronic throttle positioner and fuel injectors. The controller determines camshaft timing, steady-state electronic throttle position, steady-state fuel supply, and compensatory transient electronic throttle position, and transient fuel supply such that an engine operating with the present system has the torque output characteristics matching a conventional engine having fixed camshaft timing, but with lower fuel consumption and lower exhaust emissions than a conventional engine.

Abstract: A method of compensating for torque variations resulting from camshaft motion in a variable camshaft timing system by adjusting the intake manifold mass air flow as a function of the camshaft schedule. The adjustment can be made using the air bypass valve, or by modifying the throttle command to an electronically controlled throttle if the vehicle is so equipped.