Abstract: A system and method for controlling an engine in a hybrid vehicle based on the use of a calculated combustion stability value to modify a pulsewidth signal to fuel injectors of the engine to reduce hydrocarbon emissions, especially following an engine start. The calculated combustion stability value is determined as a function of a torque signal obtained from an electric motor of the hybrid vehicle.

Abstract: A system and method for controlling an engine in a hybrid vehicle based on the use of a calculated combustion stability value to modify a pulsewidth signal to fuel injectors of the engine to reduce hydrocarbon emissions, especially following an engine start. The calculated combustion stability value is determined as a function of a torque signal obtained from an electric motor of the hybrid vehicle.

Abstract: A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

Abstract: A method for preparing an internal combustion (IC) engine component of a hybrid automotive powertrain for shutdown so as to enable clean restart is disclosed herein. The method includes determining if the IC engine is about to enter a shutdown mode. The method includes determining a number of engine run cycles to fill an intake manifold of the IC engine with clean air, if it is determined the IC engine is about to enter the shutdown mode. The method includes running the IC engine for the determined number of cycles to fill the intake manifold of the IC engine with clean air before shutting the IC engine down.

Abstract: A secondary air system comprising a variable speed air pump and a gated check valve connected between the variable speed air pump and an IC engine. The gated check valve has two ports, and generally, a first of the two ports is connected to a first bank of engine cylinders, and a second of the two ports is connected to a second bank of engine cylinders. The system further comprises a controller for controlling the speed of the variable speed air pump, and the positioning of the gated check valve. The gated check valve is operable to fully close air flow to both ports, fully open air flow to one of the two ports, or variably split air flow between the two ports.

Abstract: A method and powertrain apparatus for controlling a hybrid electric vehicle powertrain to maintain a catalyst within a catalytic converter at an efficient operating temperature while also maximizing the use of electric vehicle operating mode. The method and apparatus determine, during an electric vehicle operating mode, whether a catalyst efficiency is below a predetermined threshold and, if it is determined that the catalyst efficiency is below the predetermined threshold, suspend the electric vehicle operating mode and turn on the vehicle's engine to bring the catalyst efficiency to or above the predetermined threshold.

Abstract: A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

Abstract: A method for preparing an internal combustion (IC) engine component of a hybrid automotive powertrain for shutdown so as to enable clean restart is disclosed herein. The method includes determining if the IC engine is about to enter a shutdown mode. The method includes determining a number of engine run cycles to fill an intake manifold of the IC engine with clean air, if it is determined the IC engine is about to enter the shutdown mode. The method includes running the IC engine for the determined number of cycles to fill the intake manifold of the IC engine with clean air before shutting the IC engine down.

Abstract: A secondary air system comprising a variable speed air pump and a gated check valve connected between the variable speed air pump and an IC engine. The gated check valve has two ports, and generally, a first of the two ports is connected to a first bank of engine cylinders, and a second of the two ports is connected to a second bank of engine cylinders. The system further comprises a controller for controlling the speed of the variable speed air pump, and the positioning of the gated check valve. The gated check valve is operable to fully close air flow to both ports, fully open air flow to one of the two ports, or variably split air flow between the two ports.

Abstract: Ignition timing for a combustion engine may be controlled by determining the roughness of current engine operation, comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness, and changing the ignition timing in a subsequent fuel delivery event as a function of the difference between the determined roughness and the control roughness. Preferably, the ignition timing is changed at least when the determined roughness is not within the threshold limit, although other factors may be taken into account when changing the ignition timing.

Abstract: Ignition timing for a combustion engine may be controlled by determining the roughness of current engine operation, comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness, and changing the ignition timing in a subsequent fuel delivery event as a function of the difference between the determined roughness and the control roughness. Preferably, the ignition timing is changed at least when the determined roughness is not within the threshold limit, although other factors may be taken into account when changing the ignition timing.

Abstract: Fuel delivery to a combustion engine may be controlled by determining the roughness of current engine operation, comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness, and changing the fuel delivery to the engine in a subsequent fuel delivery event as a function of the difference between the determined roughness and the control roughness. Preferably, the fuel delivery is changed at least when the determined roughness is not within the threshold limit, although other factors may be taken into account when changing the fuel delivery to the engine.

Abstract: A circuit for improving the resolution of an oxygen sensor in a vehicle exhaust system. The circuit expands a limited output voltage range of an oxygen sensor to full voltage range of an analog-to-digital (A/D) converter, prior to input of the expanded signal into the A/D converter. Utilization of the full range of converter provides improved resolution for analyzing the analog signal.

Abstract: A piston and cylinder assembly according to the invention includes a cylinder block having a cylinder defined by a cylinder bore wall, a cylinder head connected to the cylinder block, and a piston for reciprocating in the cylinder relative the cylinder head. A combustion chamber for an air/fuel mixture has a volume formed by the cylinder bore wall, cylinder head, and the piston, and is divided into an intake side and an exhaust side by a longitudinal center axis of the piston. A spark plug is mounted in the cylinder head and extends into the combustion chamber to ignite the air/fuel mixture therein. A crown of the piston has a raised peak offset from the longitudinal center axis for providing a homogeneous air/fuel mixture in the combustion chamber near the spark plug.

Abstract: A method of determining a goal voltage for a fuel/air sensor of an engine electronic fuel injection system includes the steps of determining a goal fuel/air sensor voltage, superimposing a wave form forcing function to the fuel/air sensor voltage for providing a goal fuel/air sensor voltage having a wave form pattern and controlling the engine to operate according to the goal fuel/air sensor voltage. The wave form forcing function provides the required fuel/air perturbations that are required to retain proper oxygen storage of the catalyst to maintain high three-way conversion efficiency.

Abstract: A method for reducing hydrocarbon emissions in an engine of a vehicle. The methodology is triggered following the switching off of the ignition by the operator. First, fuel delivery to the engine is terminated. Second, spark ignition is continued based on a predetermined parameter such as time or engine cycles following the termination of the fuel delivery. Last, spark ignition is stopped. Since combustion continues until no fuel exists in the cylinder, there is no over abundance of fuel in the catalyst at a subsequent start up. As such, the catalyst operates effectively at start up and hydrocarbon emissions are lowered.

Abstract: An exhaust system is provided including two catalysts and three oxygen sensors. The second catalyst is disposed downstream of the first catalyst. The first oxygen sensor is disposed upstream of the first catalyst, the second oxygen sensor is disposed downstream of the first catalyst and upstream of the second catalyst, and the third oxygen sensor is disposed downstream of the second catalyst. A goal voltage corresponding to a desired level of oxygen within the exhaust is provided for the third oxygen sensor based on engine RPM and MAP. The engine controller compares the goal voltage to an actual voltage generated by the third oxygen sensor and an error value is obtained and converted into a goal voltage for the second oxygen sensor. The engine controller compares the goal voltage to an actual voltage generated by the second oxygen sensor and an error value is obtained and converted into a goal voltage for the first oxygen sensor.

Abstract: An exhaust system is provided including two catalysts and three oxygen sensors. The second catalyst is disposed downstream of the first catalyst. The first oxygen sensor is disposed upstream of the first catalyst, the second oxygen sensor is disposed downstream of the first catalyst and upstream of the second catalyst, and the third oxygen sensor is disposed downstream of the second catalyst. A goal voltage corresponding to a desired level of nitrous oxide and hydrocarbon within the exhaust is provided for the third oxygen sensor. This goal voltage is based on engine RPM and MAP. The engine controller compares the goal voltage to an actual voltage generated by sensing the level of oxygen downstream of the second catalyst. Based on this comparison, an error value between the goal voltage and the actual voltage is obtained. This error value is converted into a goal voltage for the first oxygen sensor.

Abstract: A fuel control system is provided for enhancing the fueling strategy of a vehicle at start up when fueling is being supplemented with purge vapors from the fuel tank. The system includes monitoring the purge vapor flow rate from the purge vapor control system to the engine at start-up. A dynamic crankshaft fuel control fuel multiplier is then calculated based on engine roughness. If the engine is operating rough during purge vapor fueling, the amount of injected fuel is adjusted according to the fuel multiplier. Once oxygen sensor feedback is available, the dynamic crankshaft fuel control fuel multiplier is recalculated based on the oxygen sensor goal voltage. If necessary, the amount of injected fuel may be readjusted with the updated fuel multiplier. Once the engine is warm, the purge vapor fueling stops and the present methodology ends.

Abstract: The analog input of a sensor is connected to a 10-bit analog-to-digital converter. The converted is powered using a 5V supply. The A/D is interfaced with a microprocessor; however, only the least significant eight bits of the A/D output are connected to the microprocessor input. The microprocessor is used to adjust the fuel-air mixture used in engine combustion based on the output of the sensor. The use of the 10-bit A/D interfaced with only eight bits allows increased precision and increased computational speed. The increased precision allows more accurate adjustment of the fuel-air mixture to enable the engine to run closer to its stoichiometric point.