Abstract: A method of executing a downshift in a fixed-gear powertrain having an input node and an output node related by a starting speed ratio before the downshift and a finishing speed ratio after is provided. The downshift includes a torque phase and an inertia phase. A starting output torque is calculated as a function of a starting driver request. An electric machine applies a starting regenerative input torque which is calculated as substantially equal to the starting output torque divided by the starting speed ratio. A finishing output torque is calculated as a function of a finishing driver request. The electric machine applies a finishing regenerative input torque which is calculated as substantially equal to the finishing output torque divided by the finishing speed ratio.

Abstract: A vehicle includes an engine having autostart functionality, a source of fluid pressure when the engine is off, a flow control solenoid that outputs a variable clutch pressure, a transmission, an electric motor, and a controller. The transmission includes a clutch in fluid communication with the solenoid. The clutch applies via the clutch pressure to establish a first gear launch state. The motor is powered via a rechargeable energy storage system. The controller executes a method to transmit pulse width modulation (PWM) control signals to the solenoid upon detection of a set of conditions triggering the autostart event to lower clutch pressure to a first calibrated level. Restart of the engine is commanded, and the clutch pressure increases toward a second calibrated level while engine speed is increasing. The controller discontinues the PWM control signals and increases clutch pressure to line pressure when the input speed exceeds a calibrated threshold.

Abstract: A vehicle includes an engine having autostart functionality, a source of fluid pressure when the engine is off, a flow control solenoid that outputs a variable clutch pressure, a transmission, an electric motor, and a controller. The transmission includes a clutch in fluid communication with the solenoid. The clutch applies via the clutch pressure to establish a first gear launch state. The motor is powered via a rechargeable energy storage system. The controller executes a method to transmit pulse width modulation (PWM) control signals to the solenoid upon detection of a set of conditions triggering the autostart event to lower clutch pressure to a first calibrated level. Restart of the engine is commanded, and the clutch pressure increases toward a second calibrated level while engine speed is increasing. The controller discontinues the PWM control signals and increases clutch pressure to line pressure when the input speed exceeds a calibrated threshold.

Abstract: A powertrain system includes an electric motor/generator unit. Upon detecting an open high-voltage switch associated with a high-voltage DC electrical bus, low-voltage electrical power is employed to energize the high-voltage DC electrical bus, control parameters are adjusted to operate the electric motor/generator unit in a fault tolerant electric generation mode, an internal combustion engine is operated to spin the electric motor/generator unit, and the electric motor/generator unit is operated in the fault tolerant electric generation mode.

Abstract: A vehicle includes a high-voltage (HV) energy storage system (ESS), an HV device having HVIL source and return (SR) pins and an HV receptacle, an HV cable, and an HV terminal assembly. The assembly includes a tray portion and retainer for aligning the HV cables with the HV receptacle. An HVIL jumper device is connected to the tray portion and electrically connectable to the HVIL SR pins. The assembly includes a cover portion removably mountable to the tray portion to provide a suitable EMF shield and weather seal. The cover portion includes an HVIL shorting plug. HV electrical energy is supplied from said ESS to the HV device only when all three of the HVIL components, i.e., the HVIL SR pins, the HVIL jumper device, and the HVIL shorting plug, are electrically interconnected to form a closed HVIL circuit, while at the same time the HV cable is properly connected.

Abstract: A powertrain system includes an electric motor/generator unit. Upon detecting an open high-voltage switch associated with a high-voltage DC electrical bus, low-voltage electrical power is employed to energize the high-voltage DC electrical bus, control parameters are adjusted to operate the electric motor/generator unit in a fault tolerant electric generation mode, an internal combustion engine is operated to spin the electric motor/generator unit, and the electric motor/generator unit is operated in the fault tolerant electric generation mode.

Abstract: A hybrid powertrain system includes an electric motor/generator unit having a multiphase asynchronous AC machine electrically connected to a multiphase bridge inverter. A high-voltage capacitor is electrically connected between positive and negative sides of a high-voltage DC power bus. High-voltage DC bus pre-charge circuits are electrically connected between gate drive bias power supplies and the multiphase bridge inverter. A low-voltage battery electrically charges the high-voltage DC link capacitor via the gate drive bias power supplies and the high-voltage DC bus pre-charge circuits when the high-voltage energy storage system is disconnected from the high-voltage DC power bus.

Abstract: A method of executing a downshift in a fixed-gear powertrain having an input node and an output node related by a starting speed ratio before the downshift and a finishing speed ratio after is provided. The downshift includes a torque phase and an inertia phase. A starting output torque is calculated as a function of a starting driver request. An electric machine applies a starting regenerative input torque which is calculated as substantially equal to the starting output torque divided by the starting speed ratio. A finishing output torque is calculated as a function of a finishing driver request. The electric machine applies a finishing regenerative input torque which is calculated as substantially equal to the finishing output torque divided by the finishing speed ratio.

Abstract: A system includes an auxiliary pump that provides pressurized fluid to a transmission during an engine auto stop/start event. A mechanical pump provides pressurized fluid to a transmission during engine operation after the engine auto stop/start event. An auxiliary pump diagnostic system includes a slip determination module that determines slip of a torque converter based on an engine speed and a transmission input speed. A fault determination module diagnoses a fault in the auxiliary pump in response to an engine auto start and based on the slip of the torque converter.

Abstract: A method for determining the thermal efficiency of a heat sink for an electrical component includes determining an estimated temperature of the heat sink, determining an actual temperature of the heat sink, and determining a thermal efficiency of the heat sink based on a comparison of the estimated temperature of the heat sink to the actual temperature of the heat sink. A related diagnostic system is provided.

Abstract: A method sustains auxiliary power generation aboard a mild hybrid electric vehicle (HEV) in response to a high-voltage (HV) electrical fault condition and executes one of a pair of default limp-home modes depending on the state of the engine at the time of the fault. Each limp-home mode sustains auxiliary power generation during the fault, and at least one mode charges capacitors in the HV bus circuit to provide magnetizing current to a motor generator unit (MGU). An HEV includes a controller and algorithm for sustaining auxiliary power generation during the above fault condition, with the algorithm adapted to control output of an auxiliary power module (APM) and execute one of a pair of default limp-home modes, including a mode in which the APM charges the capacitors to enable a power inverter module (PIM) to provide an initial excitation current to the MGU after the starter motor restarts the engine.

Abstract: A method sustains auxiliary power generation aboard a mild hybrid electric vehicle (HEV) in response to a high-voltage (HV) electrical fault condition and executes one of a pair of default limp-home modes depending on the state of the engine at the time of the fault. Each limp-home mode sustains auxiliary power generation during the fault, and at least one mode charges capacitors in the HV bus circuit to provide magnetizing current to a motor generator unit (MGU). An HEV includes a controller and algorithm for sustaining auxiliary power generation during the above fault condition, with the algorithm adapted to control output of an auxiliary power module (APM) and execute one of a pair of default limp-home modes, including a mode in which the APM charges the capacitors to enable a power inverter module (PIM) to provide an initial excitation current to the MGU after the starter motor restarts the engine.

Abstract: A hybrid powertrain system includes an electric motor/generator unit having a multiphase asynchronous AC machine electrically connected to a multiphase bridge inverter. A high-voltage capacitor is electrically connected between positive and negative sides of a high-voltage DC power bus. High-voltage DC bus pre-charge circuits are electrically connected between gate drive bias power supplies and the multiphase bridge inverter. A low-voltage battery electrically charges the high-voltage DC link capacitor via the gate drive bias power supplies and the high-voltage DC bus pre-charge circuits when the high-voltage energy storage system is disconnected from the high-voltage DC power bus.

Abstract: An auxiliary pump diagnostic system includes a slip determination module and a fault determination module. The slip determination module determines slip of a torque converter based on an engine speed and a transmission input speed. The fault determination module diagnoses a fault in an auxiliary pump based on the slip of the torque converter.

Abstract: A method for variable operation of a vehicle transmission using rough road sensing includes defining a first set of parameters to calibrate the vehicle transmission for a smooth road condition and a second set of parameters to calibrate the vehicle transmission for a rough road condition. The method includes sensing a road condition, generating a road condition signal corresponding to the road condition, and measuring a magnitude of the road condition signal. The method includes switching from the first set of parameters to the second set of parameters to operate the vehicle transmission when the magnitude of the road condition signal exceeds a first predetermined threshold. The method includes switching from the second set of parameters to the first set of parameters to operate the vehicle transmission when the magnitude of the road condition signal is less than a second predetermined threshold that is different than the first predetermined threshold.

Abstract: A vehicle includes a high-voltage (HV) energy storage system (ESS), an HV device having HVIL source and return (SR) pins and an HV receptacle, an HV cable, and an HV terminal assembly. The assembly includes a tray portion and retainer for aligning the HV cables with the HV receptacle. An HVIL jumper device is connected to the tray portion and electrically connectable to the HVIL SR pins. The assembly includes a cover portion removably mountable to the tray portion to provide a suitable EMF shield and weather seal. The cover portion includes an HVIL shorting plug. HV electrical energy is supplied from said ESS to the HV device only when all three of the HVIL components, i.e., the HVIL SR pins, the HVIL jumper device, and the HVIL shorting plug, are electrically interconnected to form a closed HVIL circuit, while at the same time the HV cable is properly connected.

Abstract: An accessory drive tensioning system for a belt coupled to an engine may include a first tensioner, a second tensioner, and a tensioner body. The first and second tensioners may be engaged with the belt. The tensioner body may have a first piston and a second piston that bias the first and second tensioners toward the belt.

Abstract: A method for determining the thermal efficiency of a heat sink for an electrical component includes determining an estimated temperature of the heat sink, determining an actual temperature of the heat sink, and determining a thermal efficiency of the heat sink based on a comparison of the estimated temperature of the heat sink to the actual temperature of the heat sink. A related diagnostic system is provided.

Abstract: A powertrain includes a rotary input member such as an engine crankshaft, a torque coupling such as a hydraulic torque converter, a drive plate, such as a flex plate or spider, connecting the input member to the coupling, and an annular generator rotor having an electrical power annulus, such as an annular induction member extending around the coupling, and a mounting ring fixed to the power annulus and including means extending inward for securing the mounting ring to the coupling and to the drive plate. Several embodiments of mounting rings and assemblies are disclosed which improve methods for assembly of the powertrain.

Abstract: A powertrain includes a rotary input member such as an engine crankshaft, a torque coupling such as a hydraulic torque converter, a drive plate, such as a flex plate or spider, connecting the input member to the coupling, and an annular generator rotor having an electrical power annulus, such as an annular induction member extending around the coupling, and a mounting ring fixed to the power annulus and including means extending inward for securing the mounting ring to the coupling and to the drive plate. Several embodiments of mounting rings and assemblies are disclosed which improve methods for assembly of the powertrain.