Abstract: A method for controlling an engine restart in a hybrid electric powertrain, including the steps of stopping the engine, using an electric power source and an electro-mechanical actuator connected to the source to engage a gear and stroke to zero torque capacity a dry clutch of a dual-clutch transmission, initiating an automatic engine restart, and increasing the torque capacity of the clutch to a desired torque capacity during the engine restart.

Abstract: The present invention provides a system and method for starting a vehicle in a cold temperature environment and minimizing the time spent by the vehicle within a resonance frequency zone during operation. The present invention includes a method of starting a vehicle engine comprising adjusting the speed of the engine during an engine start mode in accordance with a fixed value threshold. The method also includes determining whether the engine speed has reached the fixed value threshold or whether a time-based threshold has been reached. The method further includes transitioning out of the engine start mode into a normal operating mode when either the fixed value threshold or the time-based threshold has been reached.

Abstract: A system and method for controlling a vehicle powertrain having an internal combustion engine include determining a difference between a desired engine torque and a current engine torque, adjusting the difference based on a stored torque offset corresponding to a current engine speed, and controlling the engine to produce a torque corresponding to the adjusted torque difference. The stored torque offset is adjusted when the engine is operating in a predetermined engine speed range based on a steady-state difference between the desired and current engine torque to reduce the steady-state difference to zero. The adjusted torque difference may be limited by a maximum-engine-torque-available parameter and a minimum-engine-torque-available parameter, which is based on an operating temperature, such as the engine coolant temperature. The system and method may also include controlling spark to rapidly reduce current engine torque to the adjusted torque difference value.

Abstract: A method and system of engine start/stop control for a HEV that monitors the battery and requests a specific engine state based on condition of the battery. A battery parameter such as discharge power limit (DPL) or state of charge (SOC) is compared with a set of threshold levels including a MIN level, an ON level, and an OFF level and the result of the comparison provides inputs to a state machine. The state machine includes an ON state, an OFF state and a OPPORTUNISTIC state. The machine transitions between the various states as a function of DPL and SOC relative to the sets of threshold levels.

Abstract: A method and system of engine state determination includes a plurality of requestors each of which compares vehicle or environmental conditions to a requirement and outputs a request state variable. The requestors are grouped according to function or component and the request state variables are combined and simplified at the output of each group. A state machine receives the final combined and simplified request state, and evaluates it according to the active or inactive status of the requests. The state machine carries out the proper state transition and outputs the desired engine state to engine control algorithms that start or stop the engine as necessary.

Abstract: A controller and a control method for modifying battery discharge and charge power limits in a vehicle powertrain that includes an electric battery as a power source. The modification compensates for inaccurate estimates of battery discharge and charge power limits by using a closed loop feedback control based on error between a battery voltage set point and commanded battery voltage.

Abstract: A vehicle and method are provided that control engine start in the vehicle. The vehicle includes an electric machine operable to provide a starting torque to the engine. The vehicle also includes a battery capable of providing energy to operate the electric machine. A number of battery parameters are determined, including a discharge power limit, an output power, and an engine starting power level. The engine starting power level is related to the discharge power limit and an amount of output power for the battery necessary to operate the electric machine to provide the starting torque to the engine. When the output power of the battery is at or above the engine starting power level, the engine is automatically started.

Abstract: A method for operating a vehicle to reduce exhaust emissions is provided. The vehicle includes an engine, a motor, a battery for operating the motor, and a catalyst for reducing exhaust gas emissions. The vehicle is operated in a first mode when at least one predetermined condition is met. The first mode includes providing at least some of the desired vehicle output power with the motor. The engine is operated to quickly increase the temperature of the catalyst when the output power from the battery is within a first predetermined range. When the output power of the battery is outside the first predetermined range, the operation of the engine is adjusted to drive battery operation into the first predetermined range. When the at least one predetermined condition is not met, the vehicle is operated in a second mode based at least partly on driver demand and battery requirements.

Abstract: A vehicle and method are provided that determine a misfire torque limit for an engine in the vehicle. The vehicle includes an electric machine operable to provide torque to the engine. The method includes commanding the engine to operate at a predetermined torque and a predetermined speed, thereby putting the engine in an idle state. An output torque of the engine is then determined while the engine is in the idle state. A torque offset, defined as the difference between the torque command and the determined engine output torque, is also determined. The misfire torque limit for the engine is then determined based at least in part on the torque offset.

Abstract: A method for controlling power to wheels in a vehicle, the vehicle having an electric storage device for providing power to an electric machine. The method includes determining a first power demand for the vehicle based at least in part on a driver input, determining a second power demand based at least in part on the magnitude of the first power demand, determining a power adjustment based on at least one condition of the battery, and applying the power adjustment to the second power demand, thereby generating a wheel power request.

Abstract: A method for controlling starting of an internal combustion engine in a hybrid electric vehicle powertrain having multiple power flow paths to vehicle traction wheels from the engine and from an electric motor. A smoothness factor is calculated to determine how smooth an engine start should be. Engine operating variables regulate engine smoothness during engine start events as determined by the calculated smoothness factor appropriate for selected vehicle operating conditions.

Abstract: A method for controlling starting of an internal combustion engine in a hybrid electric vehicle powertrain having multiple power flow paths to vehicle traction wheels from the engine and from an electric motor. A smoothness factor is calculated to determine how smooth an engine start should be. Engine operating variables regulate engine smoothness during engine start events as determined by the calculated smoothness factor appropriate for selected vehicle operating conditions.

Abstract: An indicator to indicate an amount of power available from an energy storage device. The indicator normalizes raw power values to values which are understood by the driver. The indicator indicates the normalized values to facilitate making a driving decision.

Abstract: A method for controlling starting of an internal combustion engine in a hybrid electric vehicle powertrain having multiple power flow paths to vehicle traction wheels from the engine and from an electric motor. A smoothness factor is calculated to determine how smooth an engine start should be. Engine operating variables regulate engine smoothness during engine start events as determined by the calculated smoothness factor appropriate for selected vehicle operating conditions.

Abstract: A method for operating a vehicle to reduce exhaust emissions is provided. The vehicle includes an engine, a motor, a battery for operating the motor, and a catalyst for reducing exhaust gas emissions. The vehicle is operated in a first mode when at least one predetermined condition is met. The first mode includes providing at least some of the desired vehicle output power with the motor. The engine is operated to quickly increase the temperature of the catalyst when the output power from the battery is within a first predetermined range. When the output power of the battery is outside the first predetermined range, the operation of the engine is adjusted to drive battery operation into the first predetermined range. When the at least one predetermined condition is not met, the vehicle is operated in a second mode based at least partly on driver demand and battery requirements.

Abstract: A vehicle and method are provided that determine a misfire torque limit for an engine in the vehicle. The vehicle includes an electric machine operable to provide torque to the engine. The method includes commanding the engine to operate at a predetermined torque and a predetermined speed, thereby putting the engine in an idle state. An output torque of the engine is then determined while the engine is in the idle state. A torque offset, defined as the difference between the torque command and the determined engine output torque, is also determined. The misfire torque limit for the engine is then determined based at least in part on the torque offset.

Abstract: A controller and a control method for modifying battery discharge and charge power limits in a vehicle powertrain that includes an electric battery as a power source. The modification compensates for inaccurate estimates of battery discharge and charge power limits by using a closed loop feedback control based on error between a battery voltage set point and commanded battery voltage.

Abstract: A vehicle and method are provided that control engine start in the vehicle. The vehicle includes an electric machine operable to provide a starting torque to the engine. The vehicle also includes a battery capable of providing energy to operate the electric machine. A number of battery parameters are determined, including a discharge power limit, an output power, and an engine starting power level. The engine starting power level is related to the discharge power limit and an amount of output power for the battery necessary to operate the electric machine to provide the starting torque to the engine. When the output power of the battery is at or above the engine starting power level, the engine is automatically started.

Abstract: The present invention provides a system and method for starting a vehicle in a cold temperature environment and minimizing the time spent by the vehicle within a resonance frequency zone during operation. The present invention includes a method of starting a vehicle engine comprising adjusting the speed of the engine during an engine start mode in accordance with a fixed value threshold. The method also includes determining whether the engine speed has reached the fixed value threshold or whether a time-based threshold has been reached. The method further includes transitioning out of the engine start mode into a normal operating mode when either the fixed value threshold or the time-based threshold has been reached.

Abstract: A method for controlling starting of an internal combustion engine in a hybrid electric vehicle powertrain having multiple power flow paths to vehicle traction wheels from the engine and from an electric motor. A smoothness factor is calculated to determine how smooth an engine start should be. Engine operating variables regulate engine smoothness during engine start events as determined by the calculated smoothness factor appropriate for selected vehicle operating conditions.