Abstract: A method for determining a preferred operating gradient for use in attaining a life objective for an electrical energy storage device is disclosed. A present state-of-life of the electrical energy storage device is provided and a life target for the electrical energy storage device is established as a predetermined limit in a predetermined metric at a predetermined state-of-life of the electrical energy storage device. A state-of-life gradient is then determined with respect to the predetermined metric which converges the state-of-life of the electrical energy storage device to the life target.

Abstract: A method and system for executing a shift from a first fixed gear to a second fixed gear in a powertrain system comprising a two-mode, compound-split, electro-mechanical transmission operative to receive a speed input from an engine is described. It includes deactivating an off-going clutch, and generating a time-based profile for rotational speed of an oncoming clutch. The input speed is controlled based upon the rotational speed of the oncoming clutch and an output of the transmission. The oncoming clutch is actuated, preferably when the input speed is synchronized with a rotational speed of an output shaft of the transmission multiplied by a gear ratio of the second fixed gear, preferably after a predetermined elapsed period of time in the range of 500 milliseconds.

Abstract: A hybrid powertrain includes a control unit that regulates electric power interchange an energy storage device and a motor/generator for causing selective torque generation by the motor/generator and for controlling engagement of torque-transmitting mechanisms. The control unit is configured to place the torque-transmitting mechanism in slipping engagement to launch the vehicle and thereby decouple a fixed relationship between engine torque and motor/generator torque or between engine torque and torque at the output member. A method of operating a hybrid vehicle powertrain is also provided.

Abstract: A module that calculates power loss for an internal combustion engine includes an air intake calculation module that determines a final air per cylinder (APC) value. A fuel mass rate calculation module that determines a fuel mass rate value based on the final APC value. A power loss calculation module that determines a power loss value for the internal combustion engine based on the fuel mass rate value.

Abstract: A vehicle propulsion system includes an internal combustion engine having an engine output, an electromechanical transmission and a control system. The engine output is coupled to the transmission output at a speed ratio which is established by one of a plurality of electrically variable or fixed operating modes. Selection and control among the various operating modes is managed by a control in accordance with preferred optimum operating costs.

Abstract: A hybrid powertrain includes an electrically variable transmission and an internal combustion engine. The transmission is operable to provide a continuously variable mode of operation. The engine is capable of variable displacement in that at least half of the cylinders contained therein are deactivatable. Additionally the internal combustion engine operates with a late intake valve closing strategy to increase the peak efficiency of the internal combustion engine.

Abstract: A powertrain control selects engine operating points in accordance with power loss minimization controls. Power loss contributions come from a variety of sources including engine power losses. Engine power losses are determined in accordance with engine operating metrics such as power production per unit fuel consumption and power production per unit emission production. Engine power losses are combined in accordance with assigned weighting into a single engine power loss term for use in the power loss minimization control and operating point selection.

Abstract: A preferred input torque for a hybrid powertrain is determined within a solution space of feasible input torques in accordance with a plurality of powertrain system constraints that results in a minimum overall powertrain system loss. System power losses and battery utilization costs are calculated at feasible input torques and a solution for the input torque corresponding to the minimum total powertrain system loss is converged upon to determine the preferred input torque.

Abstract: A method of operating a vehicle powertrain system comprising an electric motor and transmission where the electric motor is operably and selectively coupled to the transmission and adapted to provide an output torque contribution thereto, and the electric motor has a predetermined maximum motor output torque and a predetermined minimum motor output torque which are used to determine a range of permissible control points for at least one transmission control parameter.

Abstract: A method for determining output torque limits of a powertrain including an electrically variable transmission relies upon a model of the electrically variable transmission. Transmission operating space is defined by electric machine torque constraints, engine torque constraints and battery power constraints. Output torque limits are determined at the limits of the transmission operating space.

Abstract: A hybrid powertrain incorporates an engine, two motor/generator mechanisms, and a planetary gearset. The planetary gearset has at least one torque-transmitting mechanism, which may be selectively energized to provide a brake on one of the motor/generators thereby reducing the electrical power generation within the hybrid transmission.

Abstract: A powertrain control selects engine operating points in accordance with power loss minimization controls. Power loss contributions come from a variety of sources including engine power losses. Engine power losses are determined in accordance with engine operating metrics such as power production per unit fuel consumption and power production per unit emission production. Engine power losses are combined in accordance with assigned weighting into a single engine power loss term for use in the power loss minimization control and operating point selection.

Abstract: A hybrid vehicle includes a powertrain having a retarded diesel engine, an electric machine and energy storage system. The engine and motor are operatively coupled through one or more planetary gearsets and selective coupling paths in accordance with application and release of various torque transfer devices to a drivetrain via an output. Regenerative and retarded engine braking are coordinated to provide priority to energy return to an energy storage system in accordance with predetermined power flow limits. Power flow in excess of the limits are handled by increased engine retard braking contributions via engine speed increases.

Abstract: A method for determining output torque limits of a powertrain including an electrically variable transmission relies upon a model of the electrically variable transmission. Transmission operating space is defined by combined electric machine torque constraints and engine torque constraints. Output torque limits are determined at the limits of the transmission operating space.

Abstract: A hybrid vehicle includes a powertrain having a retarded diesel engine, an electric machine and energy storage system. The engine and motor are operatively coupled through one or more planetary gearsets and selective coupling paths in accordance with application and release of various torque transfer devices to a drivetrain via an output. Regenerative and retarded engine braking are coordinated to provide priority to energy return to an energy storage system in accordance with predetermined power flow limits.

Abstract: A method of operating a vehicle powertrain system comprising an electric motor and transmission where the electric motor is operably and selectively coupled to the transmission and adapted to provide an output torque contribution thereto, and the electric motor has a predetermined maximum motor output torque and a predetermined minimum motor output torque which are used to determine a range of permissible control points for at least one transmission control parameter.

Abstract: A condition of impaired speed and torque control of a parallel electrically variable transmission due to factors beyond nominal modeling and estimation errors is diagnosed under low speed operation. The transmission includes at least one electric machine and a motor torque controller for regulating the transmission input speed and output torque. The motor torque controller includes an open-loop control path based on predetermined torques and accelerations and a closed loop control path based on input speed error. The presence of a larger than expected closed-loop correction magnitude, combined with low output speed and one or more other conditions is used to diagnose a condition of potential torque error, in which case the transmission control is altered to prevent unwanted operation.

Abstract: An preferred input torque for a hybrid powertrain is determined within a solution space of feasible input torques in accordance with a plurality of powertrain system constraints that results in a minimum overall powertrain system loss. Aggregate powertrain system losses are calculated at feasible input torques and a solution for the input torque corresponding to the minimum aggregate powertrain system loss is converged upon to determine the preferred input torque.

Abstract: Preferred operating points for a vehicle powertrain including an engine and a transmission are determined in accordance with a comprehensive operational mapping of input and output conditions and corresponding aggregate system losses corresponding to engine and transmission losses. In a hybrid transmission application, additional losses from motors and batteries are aggregated into the system losses and battery constraints are considered in determining preferred operating points.

Abstract: A preferred input torque for a hybrid powertrain is determined within a solution space of feasible input torques in accordance with a plurality of powertrain system constraints that results in a minimum overall powertrain system loss. System power losses and battery utilization costs are calculated at feasible input torques and a solution for the input torque corresponding to the minimum total powertrain system loss is converged upon to determine the preferred input torque.