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.

Abstract: A method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an engine and an electric machine adapted to selectively transmit mechanical power to an output member through selective application of a plurality of torque-transfer clutches includes monitoring a clutch slip speed, synchronizing an oncoming clutch, and constraining reactive clutch torque limits for the oncoming clutch to achieve a reactive clutch torque that is less than an estimated clutch torque capacity.

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 hydraulic flow within a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an engine adapted to selectively transmit power to an output, wherein the transmission utilizes a hydraulic control system serving a number of hydraulic oil consuming functions includes monitoring minimum hydraulic pressure requirements for each of the functions, determining a requested hydraulic pressure based upon the monitoring minimum hydraulic pressure requirements and physical limits of the hydraulic control system including a maximum pressure, determining a desired flow utilizing a hydraulic control system flow model based upon the requested hydraulic pressure, and utilizing the desired flow to control an auxiliary hydraulic pump.

Abstract: A method to monitor integrity of a signal in a distributed control system for a powertrain system includes communications link transmitting signals between control modules. Integrity of each of the control modules is monitored. The signal is generated and verified in an originating control module and transmitted to a receiving control module whereat it is subsequently verified.

Abstract: A method to monitor integrity of a signal generated and communicated in a distributed control module system for a hybrid powertrain system includes generating and verifying signal within an originating control module. A message is generated based upon the signal. The message is transmitted and received at a receiving control module. The signal is extracted from the message and its integrity is verified.

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 control a powertrain including a transmission, an engine, and an electric machine includes applying through a series of clutch fill events a series of incrementally changing command pressures in a pressure control solenoid controllably connected to a clutch within the transmission, monitoring a pressure switch fluidly connected to the pressure control solenoid and configured to indicate when the pressure switch is in a full feed state, determining changes in cycle times of the pressure switch corresponding to sequential applications of the series of incrementally changing command pressures, selecting a preferred command pressure to achieve a transient state in the clutch based upon the changes in pressure switch cycle times, and controlling the clutch based upon the preferred command pressure.

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 operating a powertrain, including an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine, includes monitoring slip across a selectively applied clutch within the transmission to indicate a clutch slip event, and if the monitoring indicates the clutch slip event decreasing a load across the selectively applied clutch by reducing torque of at least one of the engine and the electric machine, in order to reduce the slip, thereby ending the clutch slip event.

Abstract: A method for estimating an operating life for an electrical energy storage system electrically connected to transmit power to a hybrid powertrain system includes monitoring temperature state-of-charge and electric current of the electrical energy storage system, calculating a battery life metric for a time interval based upon the temperature, the state-of-charge, and the electric current discharge, determining a total battery life metric therefrom and determining the remaining operating life of the electrical energy storage system.

Abstract: A method for controlling a powertrain comprising a transmission coupled to an engine and an electric machine adapted to selectively transmit mechanical power to an output member via selective application of a plurality of hydraulically actuated torque transfer clutches includes filling one of the hydraulic clutches to a reference fill volume expected to create a touching state in the clutch, wherein the filling is accomplished through control of a pressure control solenoid, monitoring an actual fill time of the hydraulic clutch, monitoring a flow utilized in the filling, determining a measured fill volume based upon the actual fill time and the flow, calculating a fill volume error based upon the measured fill volume and the reference fill volume, and adjusting the reference fill volume based upon the fill volume error.

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 method for controlling an electro-mechanical transmission through an unlocking state of a clutch, the transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member includes decreasing a reactive torque acting upon the clutch, including overriding torque commands to the engine and to the electric machine, and simultaneously decreasing a clutch torque capacity, including, during a lead period selected according to an engine command reaction time, commanding an intermediate clutch torque command maintaining sufficient clutch torque capacity to exceed an initial reactive torque calculated at an initiation of the unlocking state, and following the lead period, decreasing through a ramp down the clutch torque capacity, maintaining sufficient clutch torque capacity to exceed the decreasing reactive torque.

Abstract: A method for monitoring a main control module operative to command first and second motor control processors of a hybrid powertrain system includes signally connecting a programmable logic device to the main control module and the first and second motor control processors, communicating a first seed signal from the programmable logic device to the main control module, and determining an invalid key signal in the main control module in response to the first seed signal. The invalid key signal is communicated to the programmable logic device.

Abstract: A method for controlling hydraulic line pressure of a hydraulic control system in 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 via selective application of a plurality of hydraulically-applied torque transfer clutches includes monitoring requirements for transmission of clutch reactive torque in one of the clutches, monitoring a hydraulic line pressure within the hydraulic control system, determining a minimum clutch torque capacity required to keep the clutch from slipping, determining a hydraulic line pressure required to create the minimum clutch torque capacity, and modulating hydraulic line pressure applied to the clutch by modulating operation of the hydraulic control system based upon the hydraulic line pressure required to create the minimum clutch torque capacity.

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 operating a powertrain system includes monitoring a state of charge of an energy storage device and determining an effective state of charge based upon the monitored state of charge of the energy storage device and a range of available power from the energy storage device. A preferred output power to an output member is determined. A preferred charge state for operating the powertrain is concurrently selected with operating an engine in one of a cylinder deactivation state and an all-cylinder state based upon the effective state of charge and the preferred output power to the output member.

Abstract: A hybrid powertrain system includes torque generative devices to transfer power to an output member. An operator torque request, a rotational direction and speed of the output member, and a signal output from a transmission range selector are monitored. When a change in a direction of intended motion is determined, the powertrain system can change rotational direction of the output member when the speed of the output member is less than a threshold. The powertrain can inhibit a change in the rotational direction of the output member.