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 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.

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 microprocessor driven two dimensional search engine examines transmission operating points within a plurality of search range spaces and assists in determining properties associated with the driveline at various operating points within the space. The size of the space is reduced by rearrangement of data.

Abstract: A method for operating an engine includes defining a two-dimensional search region based upon an input power transmittable between the internal combustion engine and an electromechanical transmission. The method further includes iteratively dividing the two-dimensional search region into a plurality of subregions based upon one of the input power and the input speed, iteratively determining an engine operating point within each of the subregions, iteratively calculating an operating cost to operate the internal combustion engine and the electromechanical transmission to meet the operator torque request for each engine operating point within each of the subregions, and iteratively identifying the subregion having a minimum operating cost to meet the operator torque request. A preferred engine operating point is determined based upon the engine operating point within the identified subregion having the minimum operating cost to meet the operator torque request.

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 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 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 powertrain system including a transmission mechanically coupled to an engine and an electric machine to transfer power to an output member, the transmission selectively operative in one of a plurality of operating range states includes monitoring operator inputs to an accelerator pedal, determining a preferred operating point of the powertrain based upon the operator inputs, determining a preferred operating range state of the transmission based upon the preferred operating point, determining lead control signals for the engine and the transmission based upon the preferred operating point and the preferred operating range state of the transmission, determining immediate control signals for the electric machine and the transmission, wherein the immediate control signals are based upon a lead period calibrated to a difference in control signal reaction times of the engine and the electric machine in order to effect changes to an actual electric machine output substantially simultaneou

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 system includes an engine mechanically coupled to an electro-mechanical 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 transmission input speed trip 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: 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 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: 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. A method for controlling the powertrain includes commanding a shift from a first operating range state to a second operating range state, identifying an off-going clutch, controlling torque output from said electric machine to offload reactive torque transmitted through said off-going clutch, selectively applying an oncoming clutch to offload reactive torque transmitted through said off-going clutch, and reducing a clutch torque capacity of said off-going clutch when said reactive torque transmitted through said off-going clutch is substantially zero.

Abstract: A hybrid transmission is operative to transfer power between an input member and a torque machine and an output member. A method for controlling the powertrain system during a braking event includes evaluating candidate input torques. An output torque reactable through the transmission to the driveline and limited within the range of permissible output torques is determined for the candidate engine input torque. A preferred input torque is determined.

Abstract: A method for controlling a powertrain system includes monitoring an operator torque request, selecting a candidate powertrain system operating point, and determining a preferred engine torque range, a preferred torque machine torque range, and a preferred energy storage device output power range. The method further includes determining an engine torque, a torque machine torque, and an energy storage device output power based upon the operator torque request and the candidate powertrain system operating point. Power costs for operating the powertrain at the candidate powertrain system operating point are determined based on the determined engine torque, the determined torque machine torque, and the determined energy storage device output power range. Penalty costs are determined relative to the preferred engine torque range, the preferred torque machine torque range, and the preferred energy storage device output power range for operating the powertrain at the candidate powertrain system operating point.

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: An internal combustion engine is controlled to achieve a preferred temperature of the exhaust aftertreatment system and to minimize a total engine energy loss. A transmission is controlled to achieve a torque output based upon the preferred engine operation.

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.

Abstract: A vehicle includes a friction braking system and a powertrain system including a torque machine operative to react tractive torque input from a wheel of the vehicle. A method for controlling braking in a vehicle includes monitoring operation of the powertrain system, determining a driver intended total brake torque, determining a regenerative braking capacity based upon the operation of the powertrain system, determining a regenerative braking request based upon a time-rate change in the regenerative braking capacity, and determining a motor torque command for the torque machine based upon the regenerative braking request.