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: 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 for controlling a powertrain includes monitoring a desired synchronous transmission shift during deceleration of an output member including a desired operating range state, monitoring an output speed, predicting output deceleration through the desired synchronous transmission shift, determining a penalty cost associated with the desired synchronous transmission shift based upon an input speed profile resulting from the predicted output deceleration and from the desired synchronous transmission shift, and executing the synchronous transmission shift based upon the penalty cost.

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 hybrid powertrain system includes a transmission device operative to transfer power between an input member, a torque machine and an output member, the output member coupled to a driveline coupled to a wheel to transfer tractive torque therebetween. A method for controlling the hybrid powertrain system includes monitoring an operator torque request, determining an operating range state of the transmission device, determining a net output torque to the output member based upon the operator torque request, determining a lash state of the driveline, and determining a command for transferring output torque to the output member based upon the operating range state of the transmission device, the net output torque, and the lash state of the driveline.

Abstract: A powertrain system includes an engine coupled to an input member of a transmission operative to transmit power between the input member, a torque machine and an output member. The torque machine is connected to an energy storage device. The engine is selectively operative in engine states comprising an engine-on state and an engine-off state. A method for controlling a powertrain system includes determining a first power range for output power of the energy storage device, commanding the engine to transition from a first engine state to a second engine state, and expanding the first power range of the energy storage device and controlling the torque machine based upon the expanded power range of the energy storage device during the transition from the first engine state to the second engine state.

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 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 an engine coupled to an input member of a transmission device operative to transmit torque between the input member and a torque machine and an output member. The torque machine is connected to an energy storage device. A method for controlling the powertrain system include monitoring a temperature of the torque machine, selecting a candidate powertrain system operating point, determining an electrical power input and a motor power output of the torque machine for the candidate powertrain system operating point, determining a power loss for the torque machine associated with the motor power output of the torque machine and the electrical power input, and determining operating costs for operating the powertrain system at the candidate powertrain system operating point associated with the power loss from the torque machine and based upon the temperature of the torque machine.

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 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 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 improving drivability of the powertrain system having an accelerator control includes determining a first transmission input speed having an associated first power loss and operating said transmission using said first transmission input speed. An operational parameter relating to said accelerator control is determined and a second transmission input speed responsive to said operational parameter and having an associated second power loss is determined. The value of at least one of said first and second power loss is biased based on said operational parameter. The first power loss is compared to said second power loss subsequent to the biasing. A third transmission input speed is determined and the transmission is operated using the third transmission input speed.

Abstract: A method to monitor integrity of a signal output from an operator-manipulable transmission range selector for a powertrain system includes equipping the transmission range selector with a range encoder and a direction encoder, determining a range state and a direction state based upon signals from the range encoder and the direction encoder, determining a discrete position of the transmission range selector based upon the range state and the direction state, and performing back rationality to verify the discrete position of the transmission range selector.

Abstract: A hybrid powertrain system includes a transmission operative in a plurality of operating range states. An operating range state can be secured, including assigning each operating range state to a group that can be verified, monitoring a transition path from a first to a second operating range state, and monitoring a torque equation for the present operating range state.

Abstract: A method for controlling a powertrain including an electro-mechanical transmission coupled to an engine and an electric machine includes monitoring a desired input speed; signal processing the desired input speed to create a lead control signal to control the engine, wherein the signal processing includes low pass filtering the desired input speed and applying system constraint limits upon the desired input speed; signal processing the desired input speed to create an immediate control signal to control the electric machine, wherein the signal processing includes delaying the desired input speed by a lead period, low pass filtering the desired input speed, and applying system constraint limits upon the desired input speed; and controlling the powertrain through a powertrain transition based upon the lead control signal and said immediate control signal.

Abstract: A method for controlling a powertrain system includes monitoring operating conditions of an engine, a transmission device, and an energy storage device. The method further includes determining a first power constraint, filtering the first power constraint utilizing a first filter response time when the first power constraint changes in a first direction, and filtering the first power constraint utilizing a second filter response time when the first power constraint changes in a second direction.

Abstract: A method to determine excessive clutch slippage in a transmission coupled to an engine and an electric machine adapted to selectively transmit power to an output member through selective application of torque-transfer clutches includes monitoring rotational velocities of the electric machine, engine and output member, monitoring a transmission operating range state, determining a clutch slip based upon monitored rotational velocities for one of the torque-transfer clutches intended to be synchronized based upon the transmission operating range state, and indicating a runaway slip event if the clutch slip is in excess of a threshold slip level through a threshold slip duration.

Abstract: A method for controlling hydraulic line pressure of a hydraulic control system in transmission includes determining an available flow from a plurality of hydraulic pumps, determining a flow consumption of functions served by the hydraulic control system, determining an estimated hydraulic line pressure based upon the flow from the pumps and the flow consumption, determining a desired hydraulic line pressure, and controlling the hydraulic pumps based upon the desired hydraulic line pressure and the estimated hydraulic line pressure.

Abstract: A method for controlling an electromechanical transmission includes monitoring a current hydraulic circuit oil temperature, monitoring a current state of flow management valves, monitoring a command for cooling of electric machines, monitoring a desired transmission operating range state, utilizing a state machine to determine a sequence for controlling positions of the flow management valves to achieve the desired transmission operating range state based upon the monitored properties.