Abstract: A method for controlling a powertrain system including an internal combustion engine coupled to a multi-mode transmission in response to a command to execute a shift from a first EVT Mode range to a second EVT Mode range includes executing a first shift from the first EVT Mode range to an intermediate transmission range. The multi-mode transmission operates in the intermediate transmission range and the engine is controlled at an engine torque command that corresponds to an output torque request. A second shift is executed from the intermediate transmission range to the second transmission range. The powertrain system operates in the second transmission range to transfer torque to an output member of the transmission.

Abstract: A multi-mode vehicular powertrain system includes an internal combustion engine fluidly coupled to an exhaust aftertreatment system including a catalytic device and an electric machine electrically coupled to a battery. A method for effecting light-off of the catalytic device includes monitoring an output torque request for the powertrain system and determining a preferred engine operating point having a minimum engine operating cost within a predetermined engine operating region for catalyst light-off. When a state-of-charge of the battery is not approaching a predetermined state-of-charge limit, operation of the engine is controlled to the preferred engine operating point and operation of the electric machine is controlled to a machine operating point wherein the combination of engine torque at the preferred engine operating point and electric machine torque at the machine operating point satisfies the output torque request.

Abstract: A method for operating a powertrain system including a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline, includes executing a first search to determine a first engine operating point within an all-cylinder state and a corresponding operating cost for operating the powertrain system in response to an output torque request. A second search is executed to determine a second engine operating point within a cylinder deactivation state and a corresponding operating cost for operating the powertrain system in response to the output torque request. One of the first and second engine operating points is selected as a preferred engine operating point based upon the operating costs and the engine is controlled at the preferred engine operating point in the corresponding one of the all-cylinder state and the cylinder deactivation state.

Abstract: A method for operating a powertrain system to transfer torque among an engine, torque machines, and a driveline includes executing a search to determine a preferred engine operating point for operating the powertrain system in a transmission range in response to an output torque request. The search includes employing a candidate torque normalization ratio to determine a candidate engine torque from a normalized torque search space, and determining a candidate power cost associated with operating the powertrain system at the candidate engine torque for each of a plurality of candidate engine speeds within an input speed range and a plurality of candidate torque normalization ratios. A preferred engine speed is determined, and includes the candidate engine speed corresponding to the one of the candidate engine torques associated with a minimum of the candidate power costs. Engine operation is controlled responsive to the preferred engine speed.

Abstract: A powertrain system includes an internal combustion engine, a multi-mode transmission having a plurality of torque machines, and a driveline. A method for deactivating a torque transfer clutch of the multi-mode transmission includes imposing prioritized clutch torque constraints to an off-going clutch. The constraints include minimum and maximum long-term desired clutch torque constraints that are superseded by minimum and maximum soft clutch torque constraints that are superseded by minimum and maximum short-term desired clutch torque constraints that are superseded by minimum and maximum hard clutch torque constraints. The off-going clutch is controlled in response to the prioritized clutch torque constraints.

Abstract: A method for operating a powertrain system includes selecting a plurality of candidate transmission ranges associated with a present powertrain operating point and deselecting candidate transmission ranges not associated with the present powertrain operating point. A high resolution engine speed/torque search is executed for each of the selected candidate transmission ranges. A low resolution engine speed/torque search is executed for each of the deselected candidate transmission ranges. Each search is executed to determine a respective minimum power cost for operating the powertrain system in one of the candidate transmission ranges in response to an output torque request and output speed. A preferred transmission range is determined from the candidate transmission ranges. A preferred engine operating point is determined corresponding to the minimum power cost for the preferred transmission range.

Abstract: A method for operating a powertrain system to transfer torque among an engine, torque machines, and a driveline includes identifying a speed/torque search window responsive to a parameter affecting engine power output and the output torque request. A search is executed to determine a preferred engine operating point for operating the powertrain system in response to an output torque request. The search includes determining a candidate power cost associated with operating the powertrain system at the candidate engine torque and candidate engine speed for each of a plurality of candidate engine speeds and candidate engine torques within the speed/torque search window. A preferred engine operating point is determined as the candidate engine speed and the candidate engine torque associated with a minimum of the candidate power costs. Engine operation is controlled responsive to the preferred engine speed.

Abstract: A multi-mode powertrain system employing a power-split configuration to transfer torque to a driveline includes an internal combustion engine fluidly coupled to an exhaust aftertreatment system having a catalytic device. A method for controlling the multi-mode powertrain system includes identifying permitted transition paths between a plurality of engine states. The plurality of engine states includes a default state, a pre-light-off state, a light-off state, and a post-light-off state. A preferred one of the plurality of engine states is selected in response to an output torque request and an operating temperature of the catalytic device. Engine operation is transitioned to the preferred one of the plurality of engine states via the permitted transition paths, and the engine is operated in the preferred one of the plurality of engine states.

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 system includes an internal combustion engine, a multi-mode transmission having a plurality of torque machines, and a driveline. A method to determine extrema for an objective function employed to control operation of the powertrain system includes establishing an objective component equation related to an objective function and corresponding to an object component of interest. A plurality of linear constraints and a non-linear constraint are imposed on the objective component equation. The objective component equation is solved in relation to the plurality of linear constraints and the non-linear constraint to determine the extrema for the objective function. The extrema for the objective function are employed to control operation of the powertrain system.

Abstract: A method for controlling a powertrain system includes determining minimum and maximum states for an object component of interest based upon a plurality of linear constraints that are associated with operating parameters for the torque machines and the multi-mode transmission. Minimum and maximum objective battery powers are determined based upon the minimum and maximum states for the object component of interest. When the minimum and maximum objective battery powers are outside the minimum and maximum battery power limits, a problem recomposition process is executed to recompose the minimum and maximum battery power limits and the linear constraints. Recomposed minimum and maximum states for the object component of interest are determined based upon the recomposed minimum and maximum battery power limits and the recomposed linear constraints. The recomposed minimum and maximum states for the object component of interest are employed to control the powertrain system.

Abstract: An engine is coupled to an input member of a hybrid transmission. The hybrid transmission is operative to transfer torque between the input member and a torque machine and an output member to generate an output torque in response to an operator torque request. The torque machine is connected to an energy storage device.

Abstract: A method for activating an oncoming clutch in a transmission includes monitoring rotational speeds of clutch elements of the oncoming clutch wherein the clutch elements are coupled to first and second rotationally independent torque actuators. A control speed profile for the first rotationally independent torque actuator is commanded. A speed profile of the oncoming clutch approaching zero speed is generated as is a control speed profile for the second rotationally independent torque actuator corresponding to a speed of the first rotationally independent torque actuator, the speed profile of the oncoming clutch, and an output speed of the transmission. A speed of the second rotationally independent torque actuator is controlled using the control speed profile for the second rotationally independent torque actuator. A speed of the oncoming clutch is monitored and the oncoming clutch is activated when the speed of the oncoming clutch is zero.

Abstract: A method of operating a hybrid powertrain including an engine, an electric motor and a high voltage battery includes preventing fuel flow to the engine when the high voltage battery includes a state of charge at or above a pre-defined upper limit, and when the hybrid powertrain is operating in a second fueling condition in which fuel flow to the engine is preferably maintained. The engine is rotated with torque supplied by the electric motor to maintain rotation of the engine without producing any engine torque.

Abstract: A multi-mode transmission for a powertrain system includes a high-voltage electrical system with a high-voltage battery and high-voltage electrical bus coupled to a power inverter electrically coupled to torque machines configured to transform electric power to torque. A method for controlling the multi-mode transmission includes monitoring voltage and current on the high-voltage electrical bus, and estimating electric power limits for the high-voltage electric bus including a constrained battery power command based upon a total motor torque electrical power for the torque machines. Torque commands for the torque machines are constrained in response to the estimated electric power limits for the high-voltage electric bus. Operation of the torque machines of the multi-mode transmission is controlled in response to the torque commands for the torque machines.

Abstract: A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.

Abstract: A powertrain system including a multi-mode transmission is configured to transfer torque among an input member, torque machines and an output member. A method for controlling the multi-mode transmission includes employing a closed-loop speed control system to determine torque commands for physical torque actuators including the torque machines. The closed-loop speed control system includes employing a virtual torque actuator control scheme to generate torque commands for the physical torque actuators responsive to output commands for a plurality of virtual torque actuators.

Abstract: A hybrid diesel-electric powertrain includes an electric motor in electrical communication with a traction battery, a diesel engine in power-flow communication with the electric motor and with an automatic transmission, and a controller. The diesel engine and electric motor are configured to provide a combined torque to the automatic transmission. The powertrain further includes an exhaust aftertreatment device in fluid communication with the diesel engine. The controller is configured to: receive a regeneration request from the exhaust aftertreatment device; determine if a state-of-charge of the fraction battery is within a predetermined range of a target value; initiate a regeneration event if the state-of-charge of the traction battery is within the predetermined range of the target value; receive an immediate torque request from the automatic transmission; and provide a torque command to the electric motor in response to the immediate torque request.

Abstract: A controller architecture for a vehicle including a multi-mode powertrain system includes an engine controller having a control routine for determining and executing engine torque commands responsive to a hybrid engine torque command, and a control routine for determining a propulsion axle torque command responsive to an output torque request. The controller architecture further includes transmission controller having a control routine for selecting and effecting operation of the passive transmission in a preferred gear responsive to the output torque request. The controller architecture further includes a hybrid controller having control routines for determining and executing torque commands for each of the non-combustion torque machines and for determining the hybrid engine torque command to achieve a desired axle torque in response to the propulsion axle torque command with the passive transmission operating in the preferred gear.

Abstract: A hybrid diesel-electric powertrain includes a diesel engine in power flow communication with an electric motor and a controller. The diesel engine and electric motor are each configured to generate a respective torque in response to a provided torque command. The controller is in communication with the electric motor, the diesel engine, and an accelerator pedal, and configured to receive a driver torque request from the accelerator pedal. In response to the driver torque request, the controller is further configured to command the diesel engine to generate an output torque that is less than a smoke limit torque, and command the electric motor to generate an output torque equal to the difference between the driver torque request and the output torque of the diesel engine.