Abstract: A multi-speed drive unit is provided for an electrically variable transmission having a variable-range output gear ratio for a motor vehicle. The variable-range output electrically variable transmission has improved final drive gear ratios that allow the motor to be operated in its desired efficiency and/or performance range during both city and highway vehicle operation. Further, the variable-range output electrically variable transmission allows for increased vehicle speeds during electric vehicle operation and provides for the use of the vehicle engine during reverse gear operation.

Abstract: A method for managing a threshold increase in output torque capability in a vehicle includes detecting the threshold increase in output torque capability using a controller, and automatically limiting, via the controller, a rate of change of an actual output torque from a transmission of the vehicle in response to the threshold increase. The actual output torque is provided via a traction motor solely using battery power from an energy storage system. The method may include calculating a difference between the threshold increase and the actual output torque, and limiting the rate of change using a rate that is proportional to the difference. A vehicle includes the ESS, a transmission, and a controller. An output member of the transmission is powered using electrical energy from the ESS. The controller manages an increase in output torque capability as noted above.

Abstract: A method for controlling operating mode of a vehicle having the electrically variable transmission includes requesting a shift in the operating mode of the transmission and determining if the shift in operating mode is desirable given vehicle conditions. If a shift is desirable then the system compares a timer value with a predetermined time value. The system instructs a shift in the operating mode of the transmission when the timer value is greater than or equal to the predetermined time value and instructs no shift in operating mode of the transmission when the timer value is less than the predetermined time value.

Abstract: A powertrain system includes an engine coupled to an input member of a transmission operative to transmit power between the input member, a torque machine and an output member. The torque machine is connected to an energy storage device. The engine is selectively operative in engine states comprising an engine-on state and an engine-off state. A method for controlling a powertrain system includes determining a first power range for output power of the energy storage device, commanding the engine to transition from a first engine state to a second engine state, and expanding the first power range of the energy storage device and controlling the torque machine based upon the expanded power range of the energy storage device during the transition from the first engine state to the second engine state.

Abstract: A vehicle control system reduces vehicle rollback upon brake release. The control system includes a brake system, a vehicle grade measurement device and a controller that modulates applied brake pressure of the brake system based on a grade measurement of the grade measurement device. The controller actuates brake-hold device communicating with the brake system based on the grade measurement through pulse width modulation. The control system communicates with a motor generator and an engine to provide a start power to the engine upon brake release based on the grade measurement. Fuel injectors of the engine are enabled upon brake release based on the grade measurement. The control system further communicates with a transmission forward clutch to provide selective rotational communication between the transmission and the engine based on the grade measurement.

Abstract: A powertrain system is operative to transfer power between an input member and a plurality of power actuators and an output member to generate an output torque. The power actuators are connected to an energy storage device. A method for controlling the powertrain system includes monitoring operating conditions of the powertrain system, determining an electric power limit for output power of the energy storage device, selectively enabling electric power boost based upon the operating conditions of the powertrain system, and increasing the electric power limit when electric power boost is enabled.

Abstract: A method for operating a powertrain system includes monitoring a state of charge of an energy storage device and determining an effective state of charge based upon the monitored state of charge of the energy storage device and a range of available power from the energy storage device. A preferred output power to an output member is determined. A preferred charge state for operating the powertrain is concurrently selected with operating an engine in one of a cylinder deactivation state and an all-cylinder state based upon the effective state of charge and the preferred output power to the output member.

Abstract: A method is provided for controlling engine stop position in a vehicle having an engine with auto stop/auto start functionality. The method includes automatically ramping down engine speed upon initiation of an auto stop event, executing closed-loop speed control of the engine when the engine speed begins to ramp down, and for as long as the engine speed remains above a threshold engine speed while ramping down the engine speed; executing closed-loop position control of the engine while ramping down the engine speed once the engine speed is less than the threshold engine speed and greater than zero; and stopping the crankshaft to within a calibrated range of a targeted engine stop position. A controller is also provided that includes a hardware module and an algorithm adapted for executing the foregoing method, and a vehicle is provided having an engine with auto stop/start functionality and the controller noted above.

Abstract: A method of operating a hybrid powertrain includes commanding an engine start of an engine configured to operate at approximately zero engine speed. A spooling phase includes accelerating the first electric machine with the first machine torque, such that the first electric machine begins rotating. The first machine speed increases in magnitude from zero to non-zero, but engine speed is maintained at approximately zero. The mechanical energy of the rotating first electric machine is stored. A transfer phase includes commanding an increase in magnitude of the first machine torque and decelerating the first electric machine, such that the first machine speed decreases. The stored mechanical energy of the first electric machine is transferred to the engine to increase the engine speed to greater than zero, such that the engine starts.

Abstract: A method for controlling an inverter coupled to an electric motor for a vehicle includes generating a discontinuous PWM signal for the inverter when a torque of the electric motor and a speed of the electric motor are substantially zero, and when at least one predetermined vehicle condition is met.

Abstract: A method for controlling a low-voltage circuit of a vehicle having a generator includes monitoring operating conditions of the vehicle and determining whether surplus generator load is available. Available surplus generator load is captured and used to power the low-voltage circuit. The low-voltage circuit may include a low-voltage battery, which may be charged with the surplus generator load. The surplus generator load may be utilized for anti-sulfation of the low-voltage battery. The method is usable with both a hybrid vehicle and a conventional vehicle. The method may further include powering the low-voltage circuit with energy stored in the low-voltage battery as a result of charging the low-voltage battery with the surplus generator load.

Abstract: A method minimizes driveline disturbances in a vehicle having a motor generator unit (MGU) and a controller, which may be a motor control processor or a hybrid control processor. The method includes determining a set of motor values of the MGU, including a change in motor speed, a derivative of the change in motor speed, and a motor jerk value; calculating a corrective final torque value for the MGU as a function of the set of motor values; and commanding the corrective final torque value from the MGU during a predetermined event, e.g., engine restart. Calculations and commanding the corrective final torque value are conducted by the controller within a calibrated minimum processing loop time. A vehicle includes first and second MGUs, and a controller electrically connected to the second MGU. The controller has the algorithm for minimizing driveline disturbances as noted above.

Abstract: A method of output torque smoothing for a hybrid powertrain having an electric machine and a spark ignition engine with a first cylinder and a second cylinder includes commanding a fuel-cut transition, including consecutively initiating and completing deactivation of the first cylinder and initiating and completing deactivation of the second cylinder. The fuel-cut transition is characterized by an absence of retarding spark to the first cylinder and second cylinder. Fuel is supplied to the first cylinder until the first cylinder completes deactivation and to the second cylinder until the second cylinder completes deactivation. The electric machine captures a first torque from the first cylinder by generating electricity until the first cylinder completes deactivation and captures a second torque from the second cylinder by generating electricity until the second cylinder completes deactivation.

Abstract: A control system for a hybrid vehicle that includes an internal combustion engine and an electric motor includes an engine speed control module, an air pressure control module, and an engine torque control module. The engine speed control module increases engine speed during a first calibration period based on a driver torque request and a predetermined torque threshold. The air pressure control module decreases intake manifold pressure (MAP) of the engine during a second calibration period based on the driver torque request and the predetermined torque threshold. The engine torque control module starts the engine during a period after the first and second calibration periods by activating N of M cylinders of the engine, wherein N is based on the driver torque request and the predetermined torque threshold.

Abstract: Vehicle creep control includes executing a first control scheme to determine a preferred output torque as a first function of the operator input to the brake pedal when the actual direction of vehicle travel is a first direction and the operator-selected direction of vehicle travel is also the first direction, and executing a second control scheme to determine the preferred output torque as a second function of the operator input to the brake pedal when the actual direction of vehicle travel is a second direction and the operator-selected direction of vehicle travel is the first direction.

Abstract: Methods and apparatus are provided for providing a torque boost in an electric motor system at low speeds. The electric motor system comprises an alternating current (AC) synchronous electric motor, an inverter and a controller. The inverter is coupled to the AC synchronous electric motor and provides electric control therefore. The controller is coupled to the inverter and provides operational control signals thereto for operation of the electric motor. The controller includes a torque command gain block which modifies a torque command to generate a boosted torque signal in response to a detected speed of the electric motor, the torque command modified to define the boosted torque signal defined in accordance with a torque dependent scaling factor calculated in response to the torque command.

Abstract: A method for operating a hybrid powertrain system includes monitoring operation of the torque machine, and limiting the motor torque output from the torque machine to a maximum allowable motor torque that is associated with an acceptable audible noise level when the motor speed of the torque machine is within a motor speed range associated with objectionable audible noise.

Abstract: A control system for controlling an electric machine (EM) of a hybrid electric vehicle is provided. The system includes: an enable module that selectively enables a motoring mode of the EM based on ambient air temperature; and an EM control module that commands the EM to provide motoring torque as a function of engine speed during the motoring mode.

Abstract: A method for controlling regeneration of a battery includes determining a scaled value for a state of charge of the battery, a scaled value for a battery temperature and a scaled value for a maximum charging power of the battery. An actual battery temperature is then compared with a predetermined operating temperature. When the actual battery temperature is less than the predetermined operating temperature, an actual regeneration amount is calculated based upon the scaled value for the state of charge of the battery and the scaled value for the battery temperature. When the actual battery temperature is greater than the predetermined operating temperature, the actual regeneration amount is based upon the scaled value for the state of charge of the battery, the scaled value for the battery temperature, and the scaled value for the maximum charging power of the battery.

Abstract: A method of operating an auxiliary pump for an electrically variable transmission includes purging the auxiliary pump when an auxiliary pump temperature is below a minimum operating temperature and above a minimum purge temperature. The auxiliary pump fluid temperature and the minimum purge temperature are determined based upon the transmission fluid temperature and the ambient temperature.