Abstract: Temperature of an electric power device of a hybrid transmission is managed based upon device temperatures and power flow, ambient temperature, and a cooling circuit flow rate.

Abstract: A flow management valve is operative to enable a multi-range electro-mechanical transmission in first and second ranges. Fluid pressure in a hydraulic circuit is monitored to detect a fault in the flow management valve.

Abstract: Control of operation of a hybrid powertrain is provided, wherein mechanical power flow to an output is controlled through selective actuation of torque-transfer clutches. Electric machines are coupled to an energy storage system for electric power flow. The electro-mechanical transmission is operated in a continuously variable operating range state, and, operation of the transmission is monitored. Absence of a mismatch between the commanded continuously variable operating range state and an actual operating state of the transmission is determined. Presence of a mismatch between the commanded operating range state and the actual operating state of the transmission may be determined. Operation of the powertrain is modified when a mismatch between the commanded operating range state and the actual operating state of the transmission is detected.

Abstract: Temperature of an electric drive is regulated to prevent undesirable thermal effects. Temperature conditions of the electric drive system are monitored and torque of the electric drive system is limited based on the temperature conditions.

Abstract: A system for robust fault detection in an electrically variable, hydraulically controlled transmission includes independently monitoring hydraulic pressure within a hydraulic control circuit and electric machine rotation for detecting clutch state faults.

Abstract: There is provided a method to monitor a sensing system adapted to monitor an output of an electro-mechanical transmission. This includes monitoring rotational speed of a wheel operatively connected to a driveline operatively connected to the output of the electro-mechanical transmission. A first expected output of the transmission is determined based upon the output of the first sensor. A second expected output of the transmission is determined based upon a rotational speed of a torque-generative device operatively connected to the transmission. The first and second expected outputs and an output of the sensing system adapted to monitor the output of the electro-mechanical transmission are compared.

Abstract: Monitoring operation of an electromechanical transmission having a hydraulic circuit with flow management valves and pressure control solenoids to actuate clutches and pressure monitoring devices to monitor the hydraulic circuit is provided. The transmission operates in fixed gear and continuously variable operating range states. The method comprises controlling position of one of the flow management valves to control operation in one of the operating range states. A fault is detected in the one of the flow management valves based upon outputs of the pressure monitoring devices during steady state operation in one of the continuously variable operating range states. A fault is detected in the one of the flow management valves based upon the output of one of the pressure monitoring devices during a transition in the flow management valve.

Abstract: A method for operating the powertrain includes monitoring operator inputs, monitoring a transmission output, and terminating an engine operating mode when a time-rate change in the transmission output exceeds a threshold absent a change in the monitored operator inputs.

Abstract: A power distribution system for a hybrid vehicle having an engine is disclosed. The power distribution system includes an electric motor/generator, a vehicle accessory drive system comprising a first accessory, and a power distribution apparatus. The power distribution apparatus includes a first power transfer member comprising a first shaft, the first shaft being configured to transfer power to the engine and from the engine. The power distribution apparatus further includes a second power transfer member comprising a second shaft, the second shaft being configured to transfer power to the motor/generator and from the motor/generator. The power distribution apparatus further includes a third power transfer member comprising a third shaft, the third shaft being configured to transfer power to the accessory drive system to drive the first accessory. The power distribution apparatus further includes a first clutch and a second clutch.

Abstract: A method and an article of manufacture are provided to monitor a temperature sensing circuit and detect a fault therein. The method comprises monitoring sensor readings output from a plurality of temperature sensing circuits. An average sensor reading is determined, calculated from the sensor readings output from a subset of the temperature sensing circuits. Each of the sensor readings is compared to the average sensor reading. A fault is identified when one of the sensor readings deviates from the average sensor reading by an amount greater than a threshold, more particularly when one of the sensor readings deviates from the average sensor reading by an amount greater than the threshold at least a quantity of X times out of Y sensor readings.

Abstract: A method of regulating operation of a hybrid transmission in a vehicle includes determining a desired transmission state using a first module, generating transmission control signals based on the desired transmission state using a second module and receiving at least one transmission parameter signal at the second module. An actual transmission state is determined based on the at least one transmission parameter signal at the second module. Whether a fault is present within the hybrid transmission control system is determined based on the desired transmission state and the actual transmission state at the first control module.

Abstract: A method and an apparatus are provided to control operation of an electro-mechanical transmission device selectively operative in one of a plurality of fixed gear modes and two continuously variable modes. The method comprises controlling the flow control devices of the electro-hydraulic control circuit, and monitoring a plurality of pressure monitoring devices in the electro-hydraulic control circuit. A fault is identified in the electro-hydraulic control circuit when a signal output of one of the pressure monitoring devices does not correspond to an expected signal output for the pressure monitoring device after an elapsed time period.

Abstract: A method and apparatus are provided to control operation of an electro-mechanical torque transmission device selectively operative in one of a plurality of fixed gear modes and two continuously variable modes, and operative to transmit torque input from a plurality of torque-generative devices. The transmission device includes a hydraulic circuit and is operative in one of a plurality of operating modes by selective actuation of a plurality of hydraulically-actuated torque-transfer clutches. The method comprises monitoring pressures in the hydraulic circuit, and restricting operation of the transmission when any one of the monitored hydraulic pressures does not correspond to an expected pressure thereat. Presence of a fault is verified during the restricted operation.

Abstract: A method and apparatus to control an electro-mechanical transmission during a shift event, including identifying a fault in an off-going clutch, is provided. The method includes deactivating an off-going torque-transfer clutch, monitoring slippage of the off-going torque-transfer clutch, and limiting a change in operation of an electrical machine operatively connected to the transmission until the slippage of the off-going torque-transfer clutch exceeds a threshold. Limiting a change in operation of the electrical machine comprises limiting an output torque of the electrical machine, comprising limiting a time-rate change in the output torque and limiting a magnitude of the output torque. The limit of the change Is discontinued when the slippage of the off-going torque-transfer clutch exceeds the threshold.

Abstract: The invention comprises a method and apparatus to monitor operation of an electrically-actuated hydraulic pump selectively operative to supply pressurized fluid to a hydraulic circuit for a transmission device operably connected to an internal combustion engine of a vehicle. It includes monitoring vehicle operation and passively and intrusively monitoring hydraulic circuit pressure. The hydraulic pump is functioning properly when the monitored pressure in the hydraulic circuit exceeds a threshold. A fault related to the hydraulic circuit is identified when the monitored pressure in the hydraulic circuit does not exceed the threshold.

Abstract: A fault-tolerant gear selector lever position apparatus is described. Included is a first sensor operable to detect each position, and a second sensor operable to detect subsets of the positions. A first controller monitors the second sensor, and a second controller monitors the first sensor. The second controller identifies and communicates one of the positions to the first controller, and the first controller validates the position and communicates the position to a control system. The lever is applicable to a power transmission device. Each sensor preferably comprises digital encoding sensor; the first sensor generates a unique signal for each position, and the second sensor generates a unique signal for each subset of the positions, preferably a unique signal for each of Park, Reverse, Neutral, and Forward Drive. The controllers identify faults in the sensors, and communicate and act accordingly.

Abstract: A distributed on-board diagnostic (OBD) architecture for a control system of a vehicle includes a plurality of control modules that are in communication with one another and a designated master OBD control module that is one of the plurality of control modules. The master OBD control module performs functions that a remainder of the plurality of control modules are incapable of performing including at least one of arbitrating a malfunction indicator lamp (MIL) state, arbitrating and storing OBD freeze frame data and determining OBD status flags of the remainder of the plurality of control modules.

Abstract: A vehicle transmission system and method of controlling a vehicle transmission are provided that control clutch temperatures to extend clutch life. The system is comprised of an input drive shaft configured to be driven by an engine, an output drive shaft configured to drive a drive mechanism and a plurality of torque-transmitting devices connecting the input drive shaft to the output drive shaft and configured to engage and disengage to provide a transition between a plurality of operating ratios. The system is also comprised of a control module configured to calculate a temperature of the plurality of transmitting devices based at least in part upon a shifting status of the plurality of transmitting devices. The control module is further configured to conduct at least a first modification if the temperature is greater than a first predetermined temperature and a second modification if the temperature is greater than a second predetermined temperature.

Abstract: A vehicle transmission system and method of controlling a vehicle transmission are provided that control clutch temperatures to extend clutch life. The system is comprised of an input drive shaft configured to be driven by an engine, an output drive shaft configured to drive a drive mechanism and a plurality of torque-transmitting devices connecting the input drive shaft to the output drive shaft and configured to engage and disengage to provide a transition between a plurality of operating ratios. The system is also comprised of a control module configured to calculate a temperature of the plurality of transmitting devices based at least in part upon a shifting status of the plurality of transmitting devices. The control module is further configured to conduct at least a first modification if the temperature is greater than a first predetermined temperature and a second modification if the temperature is greater than a second predetermined temperature.

Abstract: Slip across a torque converter of an automotive powertrain is estimated using powertrain operating parameters throughout a powertrain operating cycle for use in powertrain control and diagnostic operations. Slip across the torque converter is estimated and is periodically updated in accordance with an adaptive control procedure to maintain model accuracy over time. The slip is estimated for both torque converter coupling and torque multiplication scenarios, with the greater of the estimates identified as indicating current slip. Current slip is applied to generate actual transmission gear ratio which is compared to commanded gear ratio when a transmission shift maneuver is not in process to identify transmission solenoid fault conditions, and which is applied for precise transmission shift enhancement control during a transmission shift maneuver.