Abstract: A method and system to control engine shutdown in a hybrid electric vehicle (HEV) are provided. Tailpipe emissions are reduced during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle, and evaporative emissions are reduced during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.

Abstract: A hybrid electric vehicle 10 and a method for operating the hybrid electric vehicle 10 is provided. Combustion is made to occur within the internal combustion engine 24 only after the crankshaft 25 of the engine 24 has been rotated by an electric motor or generator 30 to a certain speed and according to a certain ramped or partially ramped profile 114, 112, thereby reducing the amount of emissions from the engine 24, allowing for a more efficient torque transfer to wheels 42, and allowing for a smoother operation of the vehicle 10. The fuel injectors 13, throttle plate 11, and spark plugs 15 are also controlled in order to allow emissions to be reduced during activation of the engine and to allow the catalytic converter 7 to be heated in order to allow these emissions to be further reduced as the engine 24 is operating.

Abstract: A method and system to control engine shutdown for a hybrid electric vehicle (HEV) is provided. Tailpipe emissions are reduced during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle, and evaporative emissions are reduced during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.

Abstract: A hybrid electric vehicle 10 and a method for operating the hybrid electric vehicle 10 is provided. Combustion is made to occur within the internal combustion engine 24 only after the crankshaft 25 of the engine 24 has been rotated by an electric motor or generator 30 to a certain speed and according to a certain ramped or partially ramped profile 114, 112, thereby reducing the amount of emissions from the engine 24, allowing for a more efficient torque transfer to wheels 42, and allowing for a smoother operation of the vehicle 10. The fuel injectors 13, throttle plate 11, and spark plugs 15 are also controlled in order to allow emissions to be reduced during activation of the engine and to allow the catalytic converter 7 to be heated in order to allow these emissions to be further reduced as the engine 24 is operating.

Abstract: A hybrid electric vehicle 10 and a method for operating the hybrid electric vehicle 10 in which combustion is made to occur within the internal combustion engine 24 only after the crankshaft 25 of the engine 24 has been rotated by an electric motor or generator 30 to a certain speed and according to a certain ramped or partially ramped profile 114, 112, thereby reducing the amount of emissions from the engine 24, allowing for a more efficient torque transfer to wheels 42, and allowing for a more smoother operation of the vehicle 10. The fuel injectors 13, throttle plate 11, and spark plugs 15 are also controlled in order to allow emissions to be reduced during activation of the engine and to allow the catalytic converter 7 to be heated in order to allow these emissions to be further reduced as the engine 24 is operating.

Abstract: This invention is a method and system for determining whether the engine should be running in a Hybrid Electric Vehicle during vehicle idle conditions. Specifically, a controller determines if the vehicle is in idle and if engine operation is necessary. To determine whether engine operation is necessary, the controller determines whether the battery needs charging, whether vacuum needs to be replaced in the climate control system or brake system reservoir, whether the vapor canister requires purging, whether the adaptive fuel tables require fast adapting, whether the engine or catalyst temperatures are unacceptable, or whether the air conditioning has been requested. Once the controller determines that the engine must be running, the controller determines in which control mode to run the engine, either speed control mode (using powertrain controllers) or torque control mode (using a generator and generator controller).

Abstract: This invention relates to a hybrid electric vehicle component coolant control system and method. The coolant system has an electric pump to move coolant through a closed system including engine and motor components. Such components to be cooled can include any electric motors, power electronics, engine, and transmission. The preferred embodiment controls coolant flow to the vehicle engine and motor in a single closed loop. Vehicle components have temperature sensors that send temperature signals to an electric coolant pump duty cycle control strategy. The control strategy makes a determination of a duty cycle of the electric coolant pump as a function of the temperatures of vehicle components and orders the duty cycle of the electric pump. In the preferred configuration, engine temperature sensors can acquire either engine coolant temperature or engine cylinder head temperature.

Abstract: A method of controlling an engine 12 during engine shutdown to reduce evaporative emissions is provided. The method includes a step 50 of shutting off a fuel pump 28 of the engine 12. The method also includes a step 52 of burning off the fuel from a fuel rail 24 in a cylinder 18 of the engine 12 after the fuel pump 28 is shut off. During the burning off of the fuel, a duty cycle of each fuel injector 22of engine 12 is controlled to allow the engine 12 to operate generally cyclically about a predetermined air/fuel ratio. The predetermined air/fuel ratio is preferably stoichiometric. By burning off the fuel in the fuel rail 24 after the fuel pump 28 is shut off, the fuel pressure in the fuel rail 24 is reduced. The reduced fuel pressure in the fuel rail 24results in reduced evaporative emissions from the engine 12.

Abstract: A hybrid electric vehicle 10 and a method for operating the hybrid electric vehicle 10 in which combustion is made to occur within the internal combustion engine 24 only after the crankshaft 25 of the engine 24 has been rotated by an electric motor or generator 30 to a certain speed and according to a certain ramped or partially ramped profile 114, 112, thereby reducing the amount of emissions from the engine 24, allowing for a more efficient torque transfer to wheels 42, and allowing for a more smoother operation of the vehicle 10. The fuel injectors 13, throttle plate 11, and spark plugs 15 are also controlled in order to allow emissions to be reduced during activation of the engine and to allow the catalytic converter 7 to be heated in order to allow these emissions to be further reduced as the engine 24 is operating.

Abstract: The present invention provides a method and system for purging a vapor canister in a Hybrid Electric Vehicle during vehicle idle conditions. The present invention first determines whether purging is necessary by measuring fuel tank pressure and the time since the last purge. If either of these elements exceeds a calibratable threshold, the controller determines that the engine needs to be on and that purging must occur. An electronic throttle controller can also be used to command the throttle plate to low positions to increase intake manifold vacuum while purging. This allows for very rapid ingestion of the fuel vapor without risk of engine stalls, if used in an HEV where the engine speed is controlled by an electric motor. Upon completion of the purging process, the engine is shut “off” and the vehicle is returned to its normal idle conditions.

Abstract: The present invention provides a method and system for determining “engine on” status in a Hybrid Electric Vehicle. A controller determines that the engine is necessary and then checks the current “engine on” status. If the engine is not currently running, the controller proceeds to start the engine by commanding the generator to spin or “motor” the engine. The controller then starts fuel and spark within the engine to create combustion. Measuring devices are then used to determine the ion current/breakdown voltage across a spark gap in the engine. The controller receives this measurement and determines whether the measured ion current/breakdown voltage exceeds a calibratable threshold. If the calibratable threshold is exceeded, combustion is occurring and the engine is on. The controller then turns on the “engine on” status flag.

Abstract: The present invention provides a method and system for determining “engine on” status in a Hybrid Electric Vehicle. A controller determines the engine is necessary and then checks the current “engine on” status. If the engine is not currently running, the controller proceeds to start the engine by commanding the generator to spin or “motor” the engine. The controller then starts fuel flow and spark within the engine to create combustion. A measuring device is then used to determine the crankshaft speed. The controller receives this measurement and determines whether the measured variations in crankshaft speed exceed a calibratable threshold. If the calibratable threshold is exceeded, combustion is determined to be occurring and the engine is on. The controller then turns on the “engine on” status flag.

Abstract: A method of determining an operating state of an internal combustion engine in a hybrid electric vehicle drive system comprising an internal combustion engine having an output shaft which is coupled to a generator. The engine includes a fuel injector responsive to a fuel command. The method comprises the steps of determining an ON/OFF status of the fuel command and determining the generator torque. The generator torque provides an indication of the actual engine torque. An engine running flag is set ON when the fuel command is ON and the generator torque value is greater than a predetermined value. Otherwise, the engine running flag is set OFF.

Abstract: A method and apparatus for controlling the idle speed of a hybrid electric vehicle drive system or transaxle (10) including an internal combustion engine (12), a generator/motor (14) which is coupled to engine (12) by use of a planetary gear set (20), and an electric motor (16). Drive system (10) includes a brake or clutch assembly (34) which is operatively and selectively coupled to a generator/motor (14) and is effective to supplement the generator-produced reaction torque, thereby cooperating with the generator/motor (14) to control the idle speed of engine (12) in a wide variety of engine operating conditions.

Abstract: This invention is a method and system to control engine shutdown in a hybrid electric vehicle (HEV). The invention allows for reduced tailpipe emissions during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle and reduced evaporative emissions during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.

Abstract: This invention is a method and system to control engine shutdown for a hybrid electric vehicle (HEV). The invention allows for reduced tailpipe emissions during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle and reduced evaporative emissions during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.

Abstract: This invention is a method and system for cooling Hybrid Electric Vehicle (“HEV”) components. The present invention cools HEV components, including an A/C system, an Internal Combustion Engine and its associated parts, an electric drive system and its associated parts, including an inverter, a DC/DC Converter, a generator motor, and a traction motor. Cooling these components, is accomplished by implementing a cooling system that is comprised of fluid filled cooling loops, radiators, fans, pumps, an air conditioning condenser and a controller. The pumps move the fluid through the cooling loops, allowing the fluid to absorb heat from the components and vent through the radiators with help from the fan's airflow. The controller monitors component temperature data by measuring actual component temperature or corresponding coolant temperature and compares the component temperature data to a calibratable threshold to determine whether the fan should operate.

Abstract: This invention is a method and system for a hybrid electric vehicle adaptive fuel strategy to quickly mature an adaptive fuel table. The strategy adaptively alters the amount of fuel delivered to an internal combustion engine to optimize engine efficiency and emissions using engine sensors. Before the adaptive fuel strategy is permitted, an engine “on” idle arbitration logic requires the HEV to be in idle conditions, with normal battery state of charge, normal vacuum in the climate control and brake system reservoir; and, the vapor canister not needing purging. The strategy orders the engine throttle to sweep different airflow regions of the engine to adapt cells within the adaptive fuel table. In the preferred configuration, a generator attached to the vehicle drive train, adds and subtracts torque to maintain constant engine speed during the throttle sweeps.

Abstract: Periodic shutdown of the internal combustion engine (12) during operation of a hybrid electric vehicle (HEV) is achieved by shutdown of a vapor management valve (VMV) of the engine evaporative emission control system and an EGR valve (150) of the tailpipe emission control system at the time an engine shutdown command is provided to a controlled engine shutdown routine that, after closing of the VMV and EGR valves, then commands disabling of the engine fuel injectors (160) in a manner to stop engine operation.

Abstract: The present invention provides a method and system for purging a vapor canister in a Hybrid Electric Vehicle during vehicle idle conditions. The present invention first determines whether purging is necessary by measuring fuel tank pressure and the time since the last purge. If either of these elements exceeds a calibratable threshold, the controller determines that the engine needs to be on and that purging must occur. An electronic throttle controller can also be used to command the throttle plate to low positions to increase intake manifold vacuum while purging. This allows for very rapid ingestion of the fuel vapor without risk of engine stalls, if used in an HEV where the engine speed is controlled by an electric motor. Upon completion of the purging process, the engine is shut “off” and the vehicle is returned to its normal idle conditions.