Abstract: A hybrid transmission is operative to transfer torque between an input member and torque machines and an output member in one of a plurality of fixed gear and continuously variable operating range states through selective application of torque transfer clutches. The torque machines are operative to transfer power from an energy storage device. A method for controlling the hybrid transmission includes operating the hybrid transmission in one of the operating range states, determining a first set of internal system constraints on output torque transferred to the output member, determining a second set of internal system constraints on the output torque transferred to the output member, and determining an allowable output torque range that is achievable within the first set of internal system constraints and the second set of internal system constraints on the output torque transferred to the output member.

Abstract: A powertrain system includes an engine coupled to an electro-mechanical transmission to transfer power between the engine and a plurality of torque generating machines and an output member. The transmission is operative in one of a plurality of operating range states through selective application of torque transfer clutches and the engine is operatively coupled to a main hydraulic pump to supply pressurized fluid to a hydraulic circuit operative to apply the torque transfer clutches. A method for controlling the powertrain system includes determining an output torque request to the output member, determining a pressure output of the main hydraulic pump based upon an engine input speed, calculating a clutch reactive torque capacity for each applied torque transfer clutch based upon the pressure output of the main hydraulic pump, and determining a preferred engine input speed to achieve the clutch reactive torque capacity to meet the output torque request to the output member.

Abstract: A powertrain includes an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member through selective application of a plurality of clutches. A method for controlling the powertrain includes commanding a shift from a fixed gear operating range state to a second operating range state, commanding decreased reactive torque through an off-going clutch during a torque phase of said commanded shift, and decreasing said reactive torque through said off-going clutch through control of engine input torque.

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 method to determine a limit torque associated with an electro-mechanical transmission includes determining electric motor torque constraints and battery power constraints. A limit torque function and a standard form of the limit torque function are determined. The limit torque function and the motor torque constraints and the battery power constraints are transposed to the standard form to determine a limit torque.

Abstract: A method for controlling a transmission operative to transfer power between an input member and torque machines and an output member includes determining available power, motor torque constraints, and other constraints on torque transfer. Equations are provided, transformed to a second coordinate system and simultaneously solved. An achievable torque operating region is determined.

Abstract: A method for controlling a powertrain system includes monitoring voltage of an energy storage device. The method further includes modifying a preferred voltage limit when the voltage of the energy storage device transgresses a trigger voltage limit, and determining the power constraint of a first power actuator based on the estimated output power of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

Abstract: A method for controlling an electromechanical transmission mechanically coupled to first and second electric machines to transmit power to an output member includes determining motor torque constraints and battery power constraints. A preferred output torque to an output member is determined that is achievable within the motor torque constraints, within a range for an additional torque input and based upon the battery power constraints.

Abstract: A hybrid transmission includes torque machines and an energy storage device connected thereto. Thee hybrid transmission is operative to transfer power between an input member and an output member and the torque machines. A method for controlling the hybrid transmission includes monitoring operating parameters of the hybrid transmission, monitoring an operator demand for power, determining an output torque range to the output member based upon states of the operating parameters of the hybrid transmission, constraining the output torque range to the output member based upon the operator demand for power, and determining input torque constraints to the input member based upon the constrained output torque range to the output member.

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: An engine is coupled to an input member of a hybrid transmission and 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. A method for controlling the engine includes determining a preferred input torque from the engine to the hybrid transmission based upon operator inputs to an accelerator pedal and a brake pedal, determining maximum and minimum allowable input torques from the engine to the hybrid transmission, controlling the engine at the preferred input torque when the preferred input torque is within the maximum and minimum allowable input torques, and controlling the engine based upon the maximum and minimum allowable input torques when the preferred input torque is outside one of the maximum and minimum allowable input torques.

Abstract: A method for controlling an input torque provided to a transmission includes executing a first iterative search within a first range of permissible torque values to determine a first torque value based on a first cost value. The first cost value is based on a first set of powertrain measurements measured at a first time. A second cost value based on a second torque value and the first set of powertrain measurements measured at the first time is calculated. The second torque value is determined using a second set of powertrain measurements measured at a second time prior to the first time. One of the first torque value and the second torque value is then selected based on the first cost value and the second cost value.

Abstract: An engine is coupled to an input member of a hybrid transmission, the hybrid transmission operative to transfer power between the engine and a second torque machine and an output member. A method for controlling the engine includes monitoring an operator torque request, commanding operation of the hybrid transmission in a continuously variable operating range state, determining engine commands comprising a first engine torque request and a second engine torque request based upon the operator torque request and the operation of the hybrid transmission, determining an engine torque constraint comprising a maximum engine torque based upon a capacity of the hybrid transmission to react the engine torque, and controlling engine operation based upon the first engine torque request only when the second engine torque request exceeds the engine torque constraint.

Abstract: A powertrain system includes an engine mechanically coupled to an electromechanical transmission selectively operative in one of a plurality of transmission operating range states and one of a plurality of engine states. A method for controlling the powertrain system includes determining a current transmission operating range state and engine state, determining at least one potential transmission operating range state and engine state, determining preferability factors associated with the current and potential transmission operating range state and the engine state wherein the preferability factors associated with potential transmission operating range states include load-stabilizing preferability factors, preferentially weighting the preferability factors for the current transmission operating range state and engine state, and selectively commanding changing the present transmission operating range state and engine state based upon the preferability factors.

Abstract: A method for controlling a hybrid powertrain system based upon determined inertial effects for a continuously variable operating range state includes monitoring an operator torque request and a rotational speed of the output member, determining an inertial effect on an input speed of the input member for a continuously variable operating range state, and controlling motor torque outputs from the electric machines to meet the operator torque request based upon the inertial effect on the input speed of the input member.

Abstract: An internal combustion engine is fluidly connected to an exhaust aftertreatment system and operatively connected to an electro-mechanical transmission to transmit tractive power to a driveline. The engine is controlled during an engine operating cycle by determining a temperature of the exhaust aftertreatment system and adjusting power output of the engine based upon the temperature of the exhaust aftertreatment system and a preferred temperature range of the exhaust aftertreatment system. The electro-mechanical transmission is controlled to transmit tractive power to the driveline to meet an operator torque request based upon the adjusted power output of the engine.

Abstract: A powertrain includes an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine to selectively transmit mechanical power to an output member. Powertrain operation includes monitoring operator inputs, and determining input speeds and changes in input speeds for the internal combustion engine and the electric machine. The input speeds are compared to threshold input speeds, and the changes in input speeds are compared to threshold changes in input speeds. Input torques of the internal combustion engine and the electric machine are reduced when any one of the input speeds and changes in input speeds exceeds the corresponding threshold.

Abstract: A method for controlling a hybrid powertrain system including an engine selectively operative in one of an all-cylinder state and a cylinder deactivation state based upon power costs includes determining engine power costs for each operating range state of the transmission, determining a system power cost, selecting a preferred cost and corresponding engine operating points, selecting a preferred operating range state, selecting the engine state, and controlling the engine based upon the selected operating range state, the selected engine state, and the engine operating points.

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 to determine a preferred operating point for an internal combustion engine includes determining a current set of candidate operating points for a current search iteration. The method further includes iteratively determining an operating cost for operating the internal combustion engine at each candidate operating point of the current search iteration, and determining the preferred operating point for operating the internal combustion engine after a predetermined number of search iterations.