Abstract: A vehicular powertrain system includes an engine, an electro-mechanical transmission and an electric machine arranged in an input-split hybrid configuration. A control system for the powertrain system includes a control module signally connected to a plurality of input devices and configured to execute program code stored on a computer readable medium to control the powertrain. The program code monitors operator inputs, determines an intent to service the vehicle based upon the operator inputs, commands the electric machine to generate a net torque output of zero, and controls the engine speed correlative to an operator depression of an accelerator pedal.

Abstract: A powertrain includes an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member. An apparatus for controlling the powertrain includes the first and second electric machines, a first electric machine cooling circuit directing a cooling hydraulic flow to the first electric machine, a second electric machine cooling circuit directing a cooling hydraulic flow to the second electric machine, a hydraulic control system receiving a hydraulic flow and selectively channeling the hydraulic flow to the first and second electric machine cooling circuits, and an active electric machine cooling control system monitoring temperatures of the first and second electric machines, monitoring operation of the hydraulic control system, and selectively controlling the hydraulic control system.

Abstract: A method for controlling a powertrain includes determining an operator torque request, determining a time-based derivative of the operator torque request, determining a first future time, and predicting a change in the operator torque request based upon the operator torque request, the time-based derivative of the operator torque request, and the first future time.

Abstract: A method for controlling hydraulic line pressure of a hydraulic control system in an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member via selective application of a plurality of hydraulically-applied torque transfer clutches includes monitoring requirements for transmission of clutch reactive torque in one of the clutches, monitoring a hydraulic line pressure within the hydraulic control system, determining a minimum clutch torque capacity required to keep the clutch from slipping, determining a hydraulic line pressure required to create the minimum clutch torque capacity, and modulating hydraulic line pressure applied to the clutch by modulating operation of the hydraulic control system based upon the hydraulic line pressure required to create the minimum clutch torque capacity.

Abstract: A rotatable shaft is equipped with a measurement device that generates output signals corresponding to discrete angular positions of the shaft. Rotational angles of the shaft are measured for a complete rotational period. A true angular velocity of the shaft is determined. Angular velocity is calculated between contiguous pairs of the discrete angular positions. A velocity correction is determined, and a rotational angle error term is determined based upon the velocity correction.

Abstract: A method for controlling a hydraulic flow within a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an engine adapted to selectively transmit power to an output, wherein the transmission utilizes a hydraulic control system serving a number of hydraulic oil consuming functions includes monitoring minimum hydraulic pressure requirements for each of the functions, determining a requested hydraulic pressure based upon the monitoring minimum hydraulic pressure requirements and physical limits of the hydraulic control system including a maximum pressure, determining a desired flow utilizing a hydraulic control system flow model based upon the requested hydraulic pressure, and utilizing the desired flow to control an auxiliary hydraulic pump.

Abstract: A method for controlling a powertrain including an transmission coupled to an engine and an electric machine and a hydraulic control system providing hydraulic flow to a cooling circuit of the electric machine, wherein the transmission is adapted to selectively transmit mechanical power to an output member, includes monitoring a temperature of the electric machine, determining a cooling flow requirement for the cooling circuit based upon the temperature of the electric machine, comparing the cooling flow requirement to a threshold cooling flow, and requesting active electric machine cooling of the electric machine based upon the comparing.

Abstract: A method to control a powertrain including a transmission, an engine, and an electric machine includes monitoring an input speed, monitoring an output speed, upon initiation of a transmission shift, determining a plurality of input acceleration profiles for controlling the engine and electric machine during the shift, identifying an input acceleration constraint affecting one of the input acceleration profiles, reprofiling the input acceleration profiles based upon the identified input acceleration constraint, and controlling operation of the engine and electric machine based upon the reprofiled input acceleration profiles.

Abstract: A powertrain system includes an engine coupled to an input member of a hybrid transmission. The hybrid transmission is operative to transmit torque between the input member and a torque generating machine and an output member. A method for controlling the powertrain system includes monitoring an operator torque request, determining an output torque command and an output speed of the output member, iteratively selecting candidate input speeds to the input member, determining mechanical power loss in the hybrid transmission for each of the candidate input speeds and the output speed, and selecting a preferred input speed comprising the candidate input speed that achieves a minimum mechanical power loss in the hybrid transmission at the output speed.

Abstract: A method for controlling a hybrid powertrain system based upon a predicted speed of an output member, a predicted operator torque request, and a predicted accelerator pedal position is disclosed. The method comprises predicting the accelerator pedal position based upon a monitored accelerator pedal position and a filtered accelerator pedal position, predicting the speed of an output member based upon a monitored speed of the output member, and predicting the operator torque request based upon the predicted speed of the output member and the predicted accelerator position.

Abstract: A vehicle includes a powertrain system and a friction braking system, the powertrain system including a hybrid transmission operative in one of a fixed gear operating range state and a continuously variable operating range state to transmit torque between an input member and a torque machine and an output member coupled to a driveline.

Abstract: A method to monitor integrity of a motor torque command for a transmission in a hybrid powertrain system includes calculating motor torque commands for the torque generating machines. Torque corrections for the motor torque commands are determined. The motor torque commands are adjusted based upon the torque corrections. The adjusted motor torque commands are verified based upon an estimated output torque.

Abstract: A powertrain including an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines to transmit power to an output member is disclosed. A method for controlling the electro-mechanical transmission includes determining minimum and maximum motor torque constraints for the first and second electric machines, and determining available battery power in terms of battery power constraints. One of a first, a second and a third case is determined based upon the motor torque constraints and the battery power constraints. A preferred output torque is determined for transmitting to the output member of the electro-mechanical transmission.

Abstract: A hybrid powertrain system includes a transmission operative to transfer power between an input member and a torque machine and an output member coupled to a driveline coupled to a wheel including an actuable friction brake. The torque machine is operative to react torque transferred from the wheel through the driveline to the output member of the transmission. The torque machine is connected to an energy storage device.

Abstract: A powertrain system includes a transmission operative to transfer power between an engine coupled to an input member and a plurality of torque machines and an output member, A method for controlling the powertrain system includes monitoring system operation and determining an output torque request, determining a closed loop speed error, determining motor torque offsets to the torque machines based upon the closed loop speed error, determining output torque constraints based upon the motor torque offsets and the system operation, determining an output torque command based upon the output torque request and the output torque constraints, determining preferred motor torque commands for the torque machines based upon the output torque command, reducing the preferred motor torque commands for the torque machines using the motor torque offsets to the torque machines, and adjusting the reduced preferred motor torque commands for the torque machines based upon the closed loop speed error.

Abstract: A vehicle includes a powertrain system and a friction braking system communicating tractive torque with a driveline, the powertrain system including a torque machine, and an energy storage device connected to the torque machine, said torque machine communicating tractive torque with the driveline. A method for controlling regenerative braking and friction braking includes monitoring a vehicle operating point, determining a braking torque request, determining a regenerative braking motor torque ratio based upon the vehicle operating point wherein the regenerative braking motor torque ratio is non-linearly dependent on the vehicle operating point, and actuating the friction brake based upon the regenerative braking motor torque ratio and the braking torque request.

Abstract: Operation of an electro-mechanical transmission includes determining motor torque constraints and battery power constraints. An additional constraint on the electro-mechanical transmission is determined. A preferred output torque is determined that is achievable within the motor torque constraints and based upon the additional constraint and the battery power constraints.

Abstract: A hybrid transmission includes a torque machine and an energy storage device connected thereto. The hybrid transmission is operative to transfer power between an input member and an output member and the torque machines in a fixed gear operating range state.

Abstract: A method for controlling a powertrain system includes monitoring a state-of-charge of the energy storage device and determining a first set of electric power limits and a second set of electric power limits based on the state-of-charge of the energy storage device. The method further includes providing a power range for opportunity charging and discharging of the energy storage device based on the first set of electric power limits. The method further includes providing a power range for controlling output power of the energy storage device based on the second set of electric power limits.

Abstract: A powertrain system includes a multi-cylinder engine coupled to a hybrid transmission. The engine is selectively operative in one of a plurality of main engine states to transfer engine torque to the hybrid transmission. A method for operating a powertrain system includes monitoring an operator torque request, determining a preferred main engine state and a preferred engine torque associated with the preferred engine state, determining an engine state transition path from a present main engine state to the preferred main engine state including an engine transition state, and executing the engine state transition path between the present main engine state and the preferred main engine state and adjusting engine torque to the preferred engine torque.